arm.c (ARM_ADDRESS_COST, [...]): Convert macros to inline functions...
[gcc.git] / gcc / function.c
1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
21
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
26
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
30
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register.
35
36 Call `put_var_into_stack' when you learn, belatedly, that a variable
37 previously given a pseudo-register must in fact go in the stack.
38 This function changes the DECL_RTL to be a stack slot instead of a reg
39 then scans all the RTL instructions so far generated to correct them. */
40
41 #include "config.h"
42 #include "system.h"
43 #include "coretypes.h"
44 #include "tm.h"
45 #include "rtl.h"
46 #include "tree.h"
47 #include "flags.h"
48 #include "except.h"
49 #include "function.h"
50 #include "expr.h"
51 #include "optabs.h"
52 #include "libfuncs.h"
53 #include "regs.h"
54 #include "hard-reg-set.h"
55 #include "insn-config.h"
56 #include "recog.h"
57 #include "output.h"
58 #include "basic-block.h"
59 #include "toplev.h"
60 #include "hashtab.h"
61 #include "ggc.h"
62 #include "tm_p.h"
63 #include "integrate.h"
64 #include "langhooks.h"
65 #include "target.h"
66
67 #ifndef TRAMPOLINE_ALIGNMENT
68 #define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
69 #endif
70
71 #ifndef LOCAL_ALIGNMENT
72 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
73 #endif
74
75 #ifndef STACK_ALIGNMENT_NEEDED
76 #define STACK_ALIGNMENT_NEEDED 1
77 #endif
78
79 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
80
81 /* Some systems use __main in a way incompatible with its use in gcc, in these
82 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
83 give the same symbol without quotes for an alternative entry point. You
84 must define both, or neither. */
85 #ifndef NAME__MAIN
86 #define NAME__MAIN "__main"
87 #endif
88
89 /* Round a value to the lowest integer less than it that is a multiple of
90 the required alignment. Avoid using division in case the value is
91 negative. Assume the alignment is a power of two. */
92 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
93
94 /* Similar, but round to the next highest integer that meets the
95 alignment. */
96 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
97
98 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
99 during rtl generation. If they are different register numbers, this is
100 always true. It may also be true if
101 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
102 generation. See fix_lexical_addr for details. */
103
104 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
105 #define NEED_SEPARATE_AP
106 #endif
107
108 /* Nonzero if function being compiled doesn't contain any calls
109 (ignoring the prologue and epilogue). This is set prior to
110 local register allocation and is valid for the remaining
111 compiler passes. */
112 int current_function_is_leaf;
113
114 /* Nonzero if function being compiled doesn't contain any instructions
115 that can throw an exception. This is set prior to final. */
116
117 int current_function_nothrow;
118
119 /* Nonzero if function being compiled doesn't modify the stack pointer
120 (ignoring the prologue and epilogue). This is only valid after
121 life_analysis has run. */
122 int current_function_sp_is_unchanging;
123
124 /* Nonzero if the function being compiled is a leaf function which only
125 uses leaf registers. This is valid after reload (specifically after
126 sched2) and is useful only if the port defines LEAF_REGISTERS. */
127 int current_function_uses_only_leaf_regs;
128
129 /* Nonzero once virtual register instantiation has been done.
130 assign_stack_local uses frame_pointer_rtx when this is nonzero.
131 calls.c:emit_library_call_value_1 uses it to set up
132 post-instantiation libcalls. */
133 int virtuals_instantiated;
134
135 /* Nonzero if at least one trampoline has been created. */
136 int trampolines_created;
137
138 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
139 static GTY(()) int funcdef_no;
140
141 /* These variables hold pointers to functions to create and destroy
142 target specific, per-function data structures. */
143 struct machine_function * (*init_machine_status) (void);
144
145 /* The FUNCTION_DECL for an inline function currently being expanded. */
146 tree inline_function_decl;
147
148 /* The currently compiled function. */
149 struct function *cfun = 0;
150
151 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
152 static GTY(()) varray_type prologue;
153 static GTY(()) varray_type epilogue;
154
155 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
156 in this function. */
157 static GTY(()) varray_type sibcall_epilogue;
158 \f
159 /* In order to evaluate some expressions, such as function calls returning
160 structures in memory, we need to temporarily allocate stack locations.
161 We record each allocated temporary in the following structure.
162
163 Associated with each temporary slot is a nesting level. When we pop up
164 one level, all temporaries associated with the previous level are freed.
165 Normally, all temporaries are freed after the execution of the statement
166 in which they were created. However, if we are inside a ({...}) grouping,
167 the result may be in a temporary and hence must be preserved. If the
168 result could be in a temporary, we preserve it if we can determine which
169 one it is in. If we cannot determine which temporary may contain the
170 result, all temporaries are preserved. A temporary is preserved by
171 pretending it was allocated at the previous nesting level.
172
173 Automatic variables are also assigned temporary slots, at the nesting
174 level where they are defined. They are marked a "kept" so that
175 free_temp_slots will not free them. */
176
177 struct temp_slot GTY(())
178 {
179 /* Points to next temporary slot. */
180 struct temp_slot *next;
181 /* The rtx to used to reference the slot. */
182 rtx slot;
183 /* The rtx used to represent the address if not the address of the
184 slot above. May be an EXPR_LIST if multiple addresses exist. */
185 rtx address;
186 /* The alignment (in bits) of the slot. */
187 unsigned int align;
188 /* The size, in units, of the slot. */
189 HOST_WIDE_INT size;
190 /* The type of the object in the slot, or zero if it doesn't correspond
191 to a type. We use this to determine whether a slot can be reused.
192 It can be reused if objects of the type of the new slot will always
193 conflict with objects of the type of the old slot. */
194 tree type;
195 /* The value of `sequence_rtl_expr' when this temporary is allocated. */
196 tree rtl_expr;
197 /* Nonzero if this temporary is currently in use. */
198 char in_use;
199 /* Nonzero if this temporary has its address taken. */
200 char addr_taken;
201 /* Nesting level at which this slot is being used. */
202 int level;
203 /* Nonzero if this should survive a call to free_temp_slots. */
204 int keep;
205 /* The offset of the slot from the frame_pointer, including extra space
206 for alignment. This info is for combine_temp_slots. */
207 HOST_WIDE_INT base_offset;
208 /* The size of the slot, including extra space for alignment. This
209 info is for combine_temp_slots. */
210 HOST_WIDE_INT full_size;
211 };
212 \f
213 /* This structure is used to record MEMs or pseudos used to replace VAR, any
214 SUBREGs of VAR, and any MEMs containing VAR as an address. We need to
215 maintain this list in case two operands of an insn were required to match;
216 in that case we must ensure we use the same replacement. */
217
218 struct fixup_replacement GTY(())
219 {
220 rtx old;
221 rtx new;
222 struct fixup_replacement *next;
223 };
224
225 struct insns_for_mem_entry
226 {
227 /* A MEM. */
228 rtx key;
229 /* These are the INSNs which reference the MEM. */
230 rtx insns;
231 };
232
233 /* Forward declarations. */
234
235 static rtx assign_stack_local_1 (enum machine_mode, HOST_WIDE_INT, int,
236 struct function *);
237 static struct temp_slot *find_temp_slot_from_address (rtx);
238 static void put_reg_into_stack (struct function *, rtx, tree, enum machine_mode,
239 enum machine_mode, int, unsigned int, int, htab_t);
240 static void schedule_fixup_var_refs (struct function *, rtx, tree, enum machine_mode,
241 htab_t);
242 static void fixup_var_refs (rtx, enum machine_mode, int, rtx, htab_t);
243 static struct fixup_replacement
244 *find_fixup_replacement (struct fixup_replacement **, rtx);
245 static void fixup_var_refs_insns (rtx, rtx, enum machine_mode, int, int, rtx);
246 static void fixup_var_refs_insns_with_hash (htab_t, rtx, enum machine_mode, int, rtx);
247 static void fixup_var_refs_insn (rtx, rtx, enum machine_mode, int, int, rtx);
248 static void fixup_var_refs_1 (rtx, enum machine_mode, rtx *, rtx,
249 struct fixup_replacement **, rtx);
250 static rtx fixup_memory_subreg (rtx, rtx, enum machine_mode, int);
251 static rtx walk_fixup_memory_subreg (rtx, rtx, enum machine_mode, int);
252 static rtx fixup_stack_1 (rtx, rtx);
253 static void optimize_bit_field (rtx, rtx, rtx *);
254 static void instantiate_decls (tree, int);
255 static void instantiate_decls_1 (tree, int);
256 static void instantiate_decl (rtx, HOST_WIDE_INT, int);
257 static rtx instantiate_new_reg (rtx, HOST_WIDE_INT *);
258 static int instantiate_virtual_regs_1 (rtx *, rtx, int);
259 static void delete_handlers (void);
260 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
261 static void pad_below (struct args_size *, enum machine_mode, tree);
262 static rtx round_trampoline_addr (rtx);
263 static rtx adjust_trampoline_addr (rtx);
264 static tree *identify_blocks_1 (rtx, tree *, tree *, tree *);
265 static void reorder_blocks_0 (tree);
266 static void reorder_blocks_1 (rtx, tree, varray_type *);
267 static void reorder_fix_fragments (tree);
268 static tree blocks_nreverse (tree);
269 static int all_blocks (tree, tree *);
270 static tree *get_block_vector (tree, int *);
271 extern tree debug_find_var_in_block_tree (tree, tree);
272 /* We always define `record_insns' even if its not used so that we
273 can always export `prologue_epilogue_contains'. */
274 static void record_insns (rtx, varray_type *) ATTRIBUTE_UNUSED;
275 static int contains (rtx, varray_type);
276 #ifdef HAVE_return
277 static void emit_return_into_block (basic_block, rtx);
278 #endif
279 static void put_addressof_into_stack (rtx, htab_t);
280 static bool purge_addressof_1 (rtx *, rtx, int, int, int, htab_t);
281 static void purge_single_hard_subreg_set (rtx);
282 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
283 static rtx keep_stack_depressed (rtx);
284 #endif
285 static int is_addressof (rtx *, void *);
286 static hashval_t insns_for_mem_hash (const void *);
287 static int insns_for_mem_comp (const void *, const void *);
288 static int insns_for_mem_walk (rtx *, void *);
289 static void compute_insns_for_mem (rtx, rtx, htab_t);
290 static void prepare_function_start (tree);
291 static void do_clobber_return_reg (rtx, void *);
292 static void do_use_return_reg (rtx, void *);
293 static void instantiate_virtual_regs_lossage (rtx);
294 static tree split_complex_args (tree);
295 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
296 \f
297 /* Pointer to chain of `struct function' for containing functions. */
298 struct function *outer_function_chain;
299
300 /* List of insns that were postponed by purge_addressof_1. */
301 static rtx postponed_insns;
302
303 /* Given a function decl for a containing function,
304 return the `struct function' for it. */
305
306 struct function *
307 find_function_data (tree decl)
308 {
309 struct function *p;
310
311 for (p = outer_function_chain; p; p = p->outer)
312 if (p->decl == decl)
313 return p;
314
315 abort ();
316 }
317
318 /* Save the current context for compilation of a nested function.
319 This is called from language-specific code. The caller should use
320 the enter_nested langhook to save any language-specific state,
321 since this function knows only about language-independent
322 variables. */
323
324 void
325 push_function_context_to (tree context)
326 {
327 struct function *p;
328
329 if (context)
330 {
331 if (context == current_function_decl)
332 cfun->contains_functions = 1;
333 else
334 {
335 struct function *containing = find_function_data (context);
336 containing->contains_functions = 1;
337 }
338 }
339
340 if (cfun == 0)
341 init_dummy_function_start ();
342 p = cfun;
343
344 p->outer = outer_function_chain;
345 outer_function_chain = p;
346 p->fixup_var_refs_queue = 0;
347
348 (*lang_hooks.function.enter_nested) (p);
349
350 cfun = 0;
351 }
352
353 void
354 push_function_context (void)
355 {
356 push_function_context_to (current_function_decl);
357 }
358
359 /* Restore the last saved context, at the end of a nested function.
360 This function is called from language-specific code. */
361
362 void
363 pop_function_context_from (tree context ATTRIBUTE_UNUSED)
364 {
365 struct function *p = outer_function_chain;
366 struct var_refs_queue *queue;
367
368 cfun = p;
369 outer_function_chain = p->outer;
370
371 current_function_decl = p->decl;
372 reg_renumber = 0;
373
374 restore_emit_status (p);
375
376 (*lang_hooks.function.leave_nested) (p);
377
378 /* Finish doing put_var_into_stack for any of our variables which became
379 addressable during the nested function. If only one entry has to be
380 fixed up, just do that one. Otherwise, first make a list of MEMs that
381 are not to be unshared. */
382 if (p->fixup_var_refs_queue == 0)
383 ;
384 else if (p->fixup_var_refs_queue->next == 0)
385 fixup_var_refs (p->fixup_var_refs_queue->modified,
386 p->fixup_var_refs_queue->promoted_mode,
387 p->fixup_var_refs_queue->unsignedp,
388 p->fixup_var_refs_queue->modified, 0);
389 else
390 {
391 rtx list = 0;
392
393 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
394 list = gen_rtx_EXPR_LIST (VOIDmode, queue->modified, list);
395
396 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
397 fixup_var_refs (queue->modified, queue->promoted_mode,
398 queue->unsignedp, list, 0);
399
400 }
401
402 p->fixup_var_refs_queue = 0;
403
404 /* Reset variables that have known state during rtx generation. */
405 rtx_equal_function_value_matters = 1;
406 virtuals_instantiated = 0;
407 generating_concat_p = 1;
408 }
409
410 void
411 pop_function_context (void)
412 {
413 pop_function_context_from (current_function_decl);
414 }
415
416 /* Clear out all parts of the state in F that can safely be discarded
417 after the function has been parsed, but not compiled, to let
418 garbage collection reclaim the memory. */
419
420 void
421 free_after_parsing (struct function *f)
422 {
423 /* f->expr->forced_labels is used by code generation. */
424 /* f->emit->regno_reg_rtx is used by code generation. */
425 /* f->varasm is used by code generation. */
426 /* f->eh->eh_return_stub_label is used by code generation. */
427
428 (*lang_hooks.function.final) (f);
429 f->stmt = NULL;
430 }
431
432 /* Clear out all parts of the state in F that can safely be discarded
433 after the function has been compiled, to let garbage collection
434 reclaim the memory. */
435
436 void
437 free_after_compilation (struct function *f)
438 {
439 f->eh = NULL;
440 f->expr = NULL;
441 f->emit = NULL;
442 f->varasm = NULL;
443 f->machine = NULL;
444
445 f->x_temp_slots = NULL;
446 f->arg_offset_rtx = NULL;
447 f->return_rtx = NULL;
448 f->internal_arg_pointer = NULL;
449 f->x_nonlocal_labels = NULL;
450 f->x_nonlocal_goto_handler_slots = NULL;
451 f->x_nonlocal_goto_handler_labels = NULL;
452 f->x_nonlocal_goto_stack_level = NULL;
453 f->x_cleanup_label = NULL;
454 f->x_return_label = NULL;
455 f->x_naked_return_label = NULL;
456 f->computed_goto_common_label = NULL;
457 f->computed_goto_common_reg = NULL;
458 f->x_save_expr_regs = NULL;
459 f->x_stack_slot_list = NULL;
460 f->x_rtl_expr_chain = NULL;
461 f->x_tail_recursion_label = NULL;
462 f->x_tail_recursion_reentry = NULL;
463 f->x_arg_pointer_save_area = NULL;
464 f->x_clobber_return_insn = NULL;
465 f->x_context_display = NULL;
466 f->x_trampoline_list = NULL;
467 f->x_parm_birth_insn = NULL;
468 f->x_last_parm_insn = NULL;
469 f->x_parm_reg_stack_loc = NULL;
470 f->fixup_var_refs_queue = NULL;
471 f->original_arg_vector = NULL;
472 f->original_decl_initial = NULL;
473 f->inl_last_parm_insn = NULL;
474 f->epilogue_delay_list = NULL;
475 }
476 \f
477 /* Allocate fixed slots in the stack frame of the current function. */
478
479 /* Return size needed for stack frame based on slots so far allocated in
480 function F.
481 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
482 the caller may have to do that. */
483
484 HOST_WIDE_INT
485 get_func_frame_size (struct function *f)
486 {
487 #ifdef FRAME_GROWS_DOWNWARD
488 return -f->x_frame_offset;
489 #else
490 return f->x_frame_offset;
491 #endif
492 }
493
494 /* Return size needed for stack frame based on slots so far allocated.
495 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
496 the caller may have to do that. */
497 HOST_WIDE_INT
498 get_frame_size (void)
499 {
500 return get_func_frame_size (cfun);
501 }
502
503 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
504 with machine mode MODE.
505
506 ALIGN controls the amount of alignment for the address of the slot:
507 0 means according to MODE,
508 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
509 positive specifies alignment boundary in bits.
510
511 We do not round to stack_boundary here.
512
513 FUNCTION specifies the function to allocate in. */
514
515 static rtx
516 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size, int align,
517 struct function *function)
518 {
519 rtx x, addr;
520 int bigend_correction = 0;
521 int alignment;
522 int frame_off, frame_alignment, frame_phase;
523
524 if (align == 0)
525 {
526 tree type;
527
528 if (mode == BLKmode)
529 alignment = BIGGEST_ALIGNMENT;
530 else
531 alignment = GET_MODE_ALIGNMENT (mode);
532
533 /* Allow the target to (possibly) increase the alignment of this
534 stack slot. */
535 type = (*lang_hooks.types.type_for_mode) (mode, 0);
536 if (type)
537 alignment = LOCAL_ALIGNMENT (type, alignment);
538
539 alignment /= BITS_PER_UNIT;
540 }
541 else if (align == -1)
542 {
543 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
544 size = CEIL_ROUND (size, alignment);
545 }
546 else
547 alignment = align / BITS_PER_UNIT;
548
549 #ifdef FRAME_GROWS_DOWNWARD
550 function->x_frame_offset -= size;
551 #endif
552
553 /* Ignore alignment we can't do with expected alignment of the boundary. */
554 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
555 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
556
557 if (function->stack_alignment_needed < alignment * BITS_PER_UNIT)
558 function->stack_alignment_needed = alignment * BITS_PER_UNIT;
559
560 /* Calculate how many bytes the start of local variables is off from
561 stack alignment. */
562 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
563 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
564 frame_phase = frame_off ? frame_alignment - frame_off : 0;
565
566 /* Round the frame offset to the specified alignment. The default is
567 to always honor requests to align the stack but a port may choose to
568 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
569 if (STACK_ALIGNMENT_NEEDED
570 || mode != BLKmode
571 || size != 0)
572 {
573 /* We must be careful here, since FRAME_OFFSET might be negative and
574 division with a negative dividend isn't as well defined as we might
575 like. So we instead assume that ALIGNMENT is a power of two and
576 use logical operations which are unambiguous. */
577 #ifdef FRAME_GROWS_DOWNWARD
578 function->x_frame_offset
579 = (FLOOR_ROUND (function->x_frame_offset - frame_phase, alignment)
580 + frame_phase);
581 #else
582 function->x_frame_offset
583 = (CEIL_ROUND (function->x_frame_offset - frame_phase, alignment)
584 + frame_phase);
585 #endif
586 }
587
588 /* On a big-endian machine, if we are allocating more space than we will use,
589 use the least significant bytes of those that are allocated. */
590 if (BYTES_BIG_ENDIAN && mode != BLKmode)
591 bigend_correction = size - GET_MODE_SIZE (mode);
592
593 /* If we have already instantiated virtual registers, return the actual
594 address relative to the frame pointer. */
595 if (function == cfun && virtuals_instantiated)
596 addr = plus_constant (frame_pointer_rtx,
597 trunc_int_for_mode
598 (frame_offset + bigend_correction
599 + STARTING_FRAME_OFFSET, Pmode));
600 else
601 addr = plus_constant (virtual_stack_vars_rtx,
602 trunc_int_for_mode
603 (function->x_frame_offset + bigend_correction,
604 Pmode));
605
606 #ifndef FRAME_GROWS_DOWNWARD
607 function->x_frame_offset += size;
608 #endif
609
610 x = gen_rtx_MEM (mode, addr);
611
612 function->x_stack_slot_list
613 = gen_rtx_EXPR_LIST (VOIDmode, x, function->x_stack_slot_list);
614
615 return x;
616 }
617
618 /* Wrapper around assign_stack_local_1; assign a local stack slot for the
619 current function. */
620
621 rtx
622 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
623 {
624 return assign_stack_local_1 (mode, size, align, cfun);
625 }
626 \f
627 /* Allocate a temporary stack slot and record it for possible later
628 reuse.
629
630 MODE is the machine mode to be given to the returned rtx.
631
632 SIZE is the size in units of the space required. We do no rounding here
633 since assign_stack_local will do any required rounding.
634
635 KEEP is 1 if this slot is to be retained after a call to
636 free_temp_slots. Automatic variables for a block are allocated
637 with this flag. KEEP is 2 if we allocate a longer term temporary,
638 whose lifetime is controlled by CLEANUP_POINT_EXPRs. KEEP is 3
639 if we are to allocate something at an inner level to be treated as
640 a variable in the block (e.g., a SAVE_EXPR).
641
642 TYPE is the type that will be used for the stack slot. */
643
644 rtx
645 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size, int keep,
646 tree type)
647 {
648 unsigned int align;
649 struct temp_slot *p, *best_p = 0;
650 rtx slot;
651
652 /* If SIZE is -1 it means that somebody tried to allocate a temporary
653 of a variable size. */
654 if (size == -1)
655 abort ();
656
657 if (mode == BLKmode)
658 align = BIGGEST_ALIGNMENT;
659 else
660 align = GET_MODE_ALIGNMENT (mode);
661
662 if (! type)
663 type = (*lang_hooks.types.type_for_mode) (mode, 0);
664
665 if (type)
666 align = LOCAL_ALIGNMENT (type, align);
667
668 /* Try to find an available, already-allocated temporary of the proper
669 mode which meets the size and alignment requirements. Choose the
670 smallest one with the closest alignment. */
671 for (p = temp_slots; p; p = p->next)
672 if (p->align >= align && p->size >= size && GET_MODE (p->slot) == mode
673 && ! p->in_use
674 && objects_must_conflict_p (p->type, type)
675 && (best_p == 0 || best_p->size > p->size
676 || (best_p->size == p->size && best_p->align > p->align)))
677 {
678 if (p->align == align && p->size == size)
679 {
680 best_p = 0;
681 break;
682 }
683 best_p = p;
684 }
685
686 /* Make our best, if any, the one to use. */
687 if (best_p)
688 {
689 /* If there are enough aligned bytes left over, make them into a new
690 temp_slot so that the extra bytes don't get wasted. Do this only
691 for BLKmode slots, so that we can be sure of the alignment. */
692 if (GET_MODE (best_p->slot) == BLKmode)
693 {
694 int alignment = best_p->align / BITS_PER_UNIT;
695 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
696
697 if (best_p->size - rounded_size >= alignment)
698 {
699 p = ggc_alloc (sizeof (struct temp_slot));
700 p->in_use = p->addr_taken = 0;
701 p->size = best_p->size - rounded_size;
702 p->base_offset = best_p->base_offset + rounded_size;
703 p->full_size = best_p->full_size - rounded_size;
704 p->slot = gen_rtx_MEM (BLKmode,
705 plus_constant (XEXP (best_p->slot, 0),
706 rounded_size));
707 p->align = best_p->align;
708 p->address = 0;
709 p->rtl_expr = 0;
710 p->type = best_p->type;
711 p->next = temp_slots;
712 temp_slots = p;
713
714 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
715 stack_slot_list);
716
717 best_p->size = rounded_size;
718 best_p->full_size = rounded_size;
719 }
720 }
721
722 p = best_p;
723 }
724
725 /* If we still didn't find one, make a new temporary. */
726 if (p == 0)
727 {
728 HOST_WIDE_INT frame_offset_old = frame_offset;
729
730 p = ggc_alloc (sizeof (struct temp_slot));
731
732 /* We are passing an explicit alignment request to assign_stack_local.
733 One side effect of that is assign_stack_local will not round SIZE
734 to ensure the frame offset remains suitably aligned.
735
736 So for requests which depended on the rounding of SIZE, we go ahead
737 and round it now. We also make sure ALIGNMENT is at least
738 BIGGEST_ALIGNMENT. */
739 if (mode == BLKmode && align < BIGGEST_ALIGNMENT)
740 abort ();
741 p->slot = assign_stack_local (mode,
742 (mode == BLKmode
743 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
744 : size),
745 align);
746
747 p->align = align;
748
749 /* The following slot size computation is necessary because we don't
750 know the actual size of the temporary slot until assign_stack_local
751 has performed all the frame alignment and size rounding for the
752 requested temporary. Note that extra space added for alignment
753 can be either above or below this stack slot depending on which
754 way the frame grows. We include the extra space if and only if it
755 is above this slot. */
756 #ifdef FRAME_GROWS_DOWNWARD
757 p->size = frame_offset_old - frame_offset;
758 #else
759 p->size = size;
760 #endif
761
762 /* Now define the fields used by combine_temp_slots. */
763 #ifdef FRAME_GROWS_DOWNWARD
764 p->base_offset = frame_offset;
765 p->full_size = frame_offset_old - frame_offset;
766 #else
767 p->base_offset = frame_offset_old;
768 p->full_size = frame_offset - frame_offset_old;
769 #endif
770 p->address = 0;
771 p->next = temp_slots;
772 temp_slots = p;
773 }
774
775 p->in_use = 1;
776 p->addr_taken = 0;
777 p->rtl_expr = seq_rtl_expr;
778 p->type = type;
779
780 if (keep == 2)
781 {
782 p->level = target_temp_slot_level;
783 p->keep = 0;
784 }
785 else if (keep == 3)
786 {
787 p->level = var_temp_slot_level;
788 p->keep = 0;
789 }
790 else
791 {
792 p->level = temp_slot_level;
793 p->keep = keep;
794 }
795
796
797 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
798 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
799 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
800
801 /* If we know the alias set for the memory that will be used, use
802 it. If there's no TYPE, then we don't know anything about the
803 alias set for the memory. */
804 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
805 set_mem_align (slot, align);
806
807 /* If a type is specified, set the relevant flags. */
808 if (type != 0)
809 {
810 RTX_UNCHANGING_P (slot) = (lang_hooks.honor_readonly
811 && TYPE_READONLY (type));
812 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
813 MEM_SET_IN_STRUCT_P (slot, AGGREGATE_TYPE_P (type));
814 }
815
816 return slot;
817 }
818
819 /* Allocate a temporary stack slot and record it for possible later
820 reuse. First three arguments are same as in preceding function. */
821
822 rtx
823 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
824 {
825 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
826 }
827 \f
828 /* Assign a temporary.
829 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
830 and so that should be used in error messages. In either case, we
831 allocate of the given type.
832 KEEP is as for assign_stack_temp.
833 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
834 it is 0 if a register is OK.
835 DONT_PROMOTE is 1 if we should not promote values in register
836 to wider modes. */
837
838 rtx
839 assign_temp (tree type_or_decl, int keep, int memory_required,
840 int dont_promote ATTRIBUTE_UNUSED)
841 {
842 tree type, decl;
843 enum machine_mode mode;
844 #ifndef PROMOTE_FOR_CALL_ONLY
845 int unsignedp;
846 #endif
847
848 if (DECL_P (type_or_decl))
849 decl = type_or_decl, type = TREE_TYPE (decl);
850 else
851 decl = NULL, type = type_or_decl;
852
853 mode = TYPE_MODE (type);
854 #ifndef PROMOTE_FOR_CALL_ONLY
855 unsignedp = TREE_UNSIGNED (type);
856 #endif
857
858 if (mode == BLKmode || memory_required)
859 {
860 HOST_WIDE_INT size = int_size_in_bytes (type);
861 rtx tmp;
862
863 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
864 problems with allocating the stack space. */
865 if (size == 0)
866 size = 1;
867
868 /* Unfortunately, we don't yet know how to allocate variable-sized
869 temporaries. However, sometimes we have a fixed upper limit on
870 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
871 instead. This is the case for Chill variable-sized strings. */
872 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
873 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
874 && host_integerp (TYPE_ARRAY_MAX_SIZE (type), 1))
875 size = tree_low_cst (TYPE_ARRAY_MAX_SIZE (type), 1);
876
877 /* The size of the temporary may be too large to fit into an integer. */
878 /* ??? Not sure this should happen except for user silliness, so limit
879 this to things that aren't compiler-generated temporaries. The
880 rest of the time we'll abort in assign_stack_temp_for_type. */
881 if (decl && size == -1
882 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
883 {
884 error ("%Jsize of variable '%D' is too large", decl, decl);
885 size = 1;
886 }
887
888 tmp = assign_stack_temp_for_type (mode, size, keep, type);
889 return tmp;
890 }
891
892 #ifndef PROMOTE_FOR_CALL_ONLY
893 if (! dont_promote)
894 mode = promote_mode (type, mode, &unsignedp, 0);
895 #endif
896
897 return gen_reg_rtx (mode);
898 }
899 \f
900 /* Combine temporary stack slots which are adjacent on the stack.
901
902 This allows for better use of already allocated stack space. This is only
903 done for BLKmode slots because we can be sure that we won't have alignment
904 problems in this case. */
905
906 void
907 combine_temp_slots (void)
908 {
909 struct temp_slot *p, *q;
910 struct temp_slot *prev_p, *prev_q;
911 int num_slots;
912
913 /* We can't combine slots, because the information about which slot
914 is in which alias set will be lost. */
915 if (flag_strict_aliasing)
916 return;
917
918 /* If there are a lot of temp slots, don't do anything unless
919 high levels of optimization. */
920 if (! flag_expensive_optimizations)
921 for (p = temp_slots, num_slots = 0; p; p = p->next, num_slots++)
922 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
923 return;
924
925 for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
926 {
927 int delete_p = 0;
928
929 if (! p->in_use && GET_MODE (p->slot) == BLKmode)
930 for (q = p->next, prev_q = p; q; q = prev_q->next)
931 {
932 int delete_q = 0;
933 if (! q->in_use && GET_MODE (q->slot) == BLKmode)
934 {
935 if (p->base_offset + p->full_size == q->base_offset)
936 {
937 /* Q comes after P; combine Q into P. */
938 p->size += q->size;
939 p->full_size += q->full_size;
940 delete_q = 1;
941 }
942 else if (q->base_offset + q->full_size == p->base_offset)
943 {
944 /* P comes after Q; combine P into Q. */
945 q->size += p->size;
946 q->full_size += p->full_size;
947 delete_p = 1;
948 break;
949 }
950 }
951 /* Either delete Q or advance past it. */
952 if (delete_q)
953 prev_q->next = q->next;
954 else
955 prev_q = q;
956 }
957 /* Either delete P or advance past it. */
958 if (delete_p)
959 {
960 if (prev_p)
961 prev_p->next = p->next;
962 else
963 temp_slots = p->next;
964 }
965 else
966 prev_p = p;
967 }
968 }
969 \f
970 /* Find the temp slot corresponding to the object at address X. */
971
972 static struct temp_slot *
973 find_temp_slot_from_address (rtx x)
974 {
975 struct temp_slot *p;
976 rtx next;
977
978 for (p = temp_slots; p; p = p->next)
979 {
980 if (! p->in_use)
981 continue;
982
983 else if (XEXP (p->slot, 0) == x
984 || p->address == x
985 || (GET_CODE (x) == PLUS
986 && XEXP (x, 0) == virtual_stack_vars_rtx
987 && GET_CODE (XEXP (x, 1)) == CONST_INT
988 && INTVAL (XEXP (x, 1)) >= p->base_offset
989 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
990 return p;
991
992 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
993 for (next = p->address; next; next = XEXP (next, 1))
994 if (XEXP (next, 0) == x)
995 return p;
996 }
997
998 /* If we have a sum involving a register, see if it points to a temp
999 slot. */
1000 if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == REG
1001 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
1002 return p;
1003 else if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == REG
1004 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
1005 return p;
1006
1007 return 0;
1008 }
1009
1010 /* Indicate that NEW is an alternate way of referring to the temp slot
1011 that previously was known by OLD. */
1012
1013 void
1014 update_temp_slot_address (rtx old, rtx new)
1015 {
1016 struct temp_slot *p;
1017
1018 if (rtx_equal_p (old, new))
1019 return;
1020
1021 p = find_temp_slot_from_address (old);
1022
1023 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
1024 is a register, see if one operand of the PLUS is a temporary
1025 location. If so, NEW points into it. Otherwise, if both OLD and
1026 NEW are a PLUS and if there is a register in common between them.
1027 If so, try a recursive call on those values. */
1028 if (p == 0)
1029 {
1030 if (GET_CODE (old) != PLUS)
1031 return;
1032
1033 if (GET_CODE (new) == REG)
1034 {
1035 update_temp_slot_address (XEXP (old, 0), new);
1036 update_temp_slot_address (XEXP (old, 1), new);
1037 return;
1038 }
1039 else if (GET_CODE (new) != PLUS)
1040 return;
1041
1042 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
1043 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
1044 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
1045 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
1046 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
1047 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
1048 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
1049 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
1050
1051 return;
1052 }
1053
1054 /* Otherwise add an alias for the temp's address. */
1055 else if (p->address == 0)
1056 p->address = new;
1057 else
1058 {
1059 if (GET_CODE (p->address) != EXPR_LIST)
1060 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
1061
1062 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
1063 }
1064 }
1065
1066 /* If X could be a reference to a temporary slot, mark the fact that its
1067 address was taken. */
1068
1069 void
1070 mark_temp_addr_taken (rtx x)
1071 {
1072 struct temp_slot *p;
1073
1074 if (x == 0)
1075 return;
1076
1077 /* If X is not in memory or is at a constant address, it cannot be in
1078 a temporary slot. */
1079 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1080 return;
1081
1082 p = find_temp_slot_from_address (XEXP (x, 0));
1083 if (p != 0)
1084 p->addr_taken = 1;
1085 }
1086
1087 /* If X could be a reference to a temporary slot, mark that slot as
1088 belonging to the to one level higher than the current level. If X
1089 matched one of our slots, just mark that one. Otherwise, we can't
1090 easily predict which it is, so upgrade all of them. Kept slots
1091 need not be touched.
1092
1093 This is called when an ({...}) construct occurs and a statement
1094 returns a value in memory. */
1095
1096 void
1097 preserve_temp_slots (rtx x)
1098 {
1099 struct temp_slot *p = 0;
1100
1101 /* If there is no result, we still might have some objects whose address
1102 were taken, so we need to make sure they stay around. */
1103 if (x == 0)
1104 {
1105 for (p = temp_slots; p; p = p->next)
1106 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1107 p->level--;
1108
1109 return;
1110 }
1111
1112 /* If X is a register that is being used as a pointer, see if we have
1113 a temporary slot we know it points to. To be consistent with
1114 the code below, we really should preserve all non-kept slots
1115 if we can't find a match, but that seems to be much too costly. */
1116 if (GET_CODE (x) == REG && REG_POINTER (x))
1117 p = find_temp_slot_from_address (x);
1118
1119 /* If X is not in memory or is at a constant address, it cannot be in
1120 a temporary slot, but it can contain something whose address was
1121 taken. */
1122 if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
1123 {
1124 for (p = temp_slots; p; p = p->next)
1125 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1126 p->level--;
1127
1128 return;
1129 }
1130
1131 /* First see if we can find a match. */
1132 if (p == 0)
1133 p = find_temp_slot_from_address (XEXP (x, 0));
1134
1135 if (p != 0)
1136 {
1137 /* Move everything at our level whose address was taken to our new
1138 level in case we used its address. */
1139 struct temp_slot *q;
1140
1141 if (p->level == temp_slot_level)
1142 {
1143 for (q = temp_slots; q; q = q->next)
1144 if (q != p && q->addr_taken && q->level == p->level)
1145 q->level--;
1146
1147 p->level--;
1148 p->addr_taken = 0;
1149 }
1150 return;
1151 }
1152
1153 /* Otherwise, preserve all non-kept slots at this level. */
1154 for (p = temp_slots; p; p = p->next)
1155 if (p->in_use && p->level == temp_slot_level && ! p->keep)
1156 p->level--;
1157 }
1158
1159 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
1160 with that RTL_EXPR, promote it into a temporary slot at the present
1161 level so it will not be freed when we free slots made in the
1162 RTL_EXPR. */
1163
1164 void
1165 preserve_rtl_expr_result (rtx x)
1166 {
1167 struct temp_slot *p;
1168
1169 /* If X is not in memory or is at a constant address, it cannot be in
1170 a temporary slot. */
1171 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1172 return;
1173
1174 /* If we can find a match, move it to our level unless it is already at
1175 an upper level. */
1176 p = find_temp_slot_from_address (XEXP (x, 0));
1177 if (p != 0)
1178 {
1179 p->level = MIN (p->level, temp_slot_level);
1180 p->rtl_expr = 0;
1181 }
1182
1183 return;
1184 }
1185
1186 /* Free all temporaries used so far. This is normally called at the end
1187 of generating code for a statement. Don't free any temporaries
1188 currently in use for an RTL_EXPR that hasn't yet been emitted.
1189 We could eventually do better than this since it can be reused while
1190 generating the same RTL_EXPR, but this is complex and probably not
1191 worthwhile. */
1192
1193 void
1194 free_temp_slots (void)
1195 {
1196 struct temp_slot *p;
1197
1198 for (p = temp_slots; p; p = p->next)
1199 if (p->in_use && p->level == temp_slot_level && ! p->keep
1200 && p->rtl_expr == 0)
1201 p->in_use = 0;
1202
1203 combine_temp_slots ();
1204 }
1205
1206 /* Free all temporary slots used in T, an RTL_EXPR node. */
1207
1208 void
1209 free_temps_for_rtl_expr (tree t)
1210 {
1211 struct temp_slot *p;
1212
1213 for (p = temp_slots; p; p = p->next)
1214 if (p->rtl_expr == t)
1215 {
1216 /* If this slot is below the current TEMP_SLOT_LEVEL, then it
1217 needs to be preserved. This can happen if a temporary in
1218 the RTL_EXPR was addressed; preserve_temp_slots will move
1219 the temporary into a higher level. */
1220 if (temp_slot_level <= p->level)
1221 p->in_use = 0;
1222 else
1223 p->rtl_expr = NULL_TREE;
1224 }
1225
1226 combine_temp_slots ();
1227 }
1228
1229 /* Mark all temporaries ever allocated in this function as not suitable
1230 for reuse until the current level is exited. */
1231
1232 void
1233 mark_all_temps_used (void)
1234 {
1235 struct temp_slot *p;
1236
1237 for (p = temp_slots; p; p = p->next)
1238 {
1239 p->in_use = p->keep = 1;
1240 p->level = MIN (p->level, temp_slot_level);
1241 }
1242 }
1243
1244 /* Push deeper into the nesting level for stack temporaries. */
1245
1246 void
1247 push_temp_slots (void)
1248 {
1249 temp_slot_level++;
1250 }
1251
1252 /* Pop a temporary nesting level. All slots in use in the current level
1253 are freed. */
1254
1255 void
1256 pop_temp_slots (void)
1257 {
1258 struct temp_slot *p;
1259
1260 for (p = temp_slots; p; p = p->next)
1261 if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
1262 p->in_use = 0;
1263
1264 combine_temp_slots ();
1265
1266 temp_slot_level--;
1267 }
1268
1269 /* Initialize temporary slots. */
1270
1271 void
1272 init_temp_slots (void)
1273 {
1274 /* We have not allocated any temporaries yet. */
1275 temp_slots = 0;
1276 temp_slot_level = 0;
1277 var_temp_slot_level = 0;
1278 target_temp_slot_level = 0;
1279 }
1280 \f
1281 /* Retroactively move an auto variable from a register to a stack
1282 slot. This is done when an address-reference to the variable is
1283 seen. If RESCAN is true, all previously emitted instructions are
1284 examined and modified to handle the fact that DECL is now
1285 addressable. */
1286
1287 void
1288 put_var_into_stack (tree decl, int rescan)
1289 {
1290 rtx reg;
1291 enum machine_mode promoted_mode, decl_mode;
1292 struct function *function = 0;
1293 tree context;
1294 int can_use_addressof;
1295 int volatilep = TREE_CODE (decl) != SAVE_EXPR && TREE_THIS_VOLATILE (decl);
1296 int usedp = (TREE_USED (decl)
1297 || (TREE_CODE (decl) != SAVE_EXPR && DECL_INITIAL (decl) != 0));
1298
1299 context = decl_function_context (decl);
1300
1301 /* Get the current rtl used for this object and its original mode. */
1302 reg = (TREE_CODE (decl) == SAVE_EXPR
1303 ? SAVE_EXPR_RTL (decl)
1304 : DECL_RTL_IF_SET (decl));
1305
1306 /* No need to do anything if decl has no rtx yet
1307 since in that case caller is setting TREE_ADDRESSABLE
1308 and a stack slot will be assigned when the rtl is made. */
1309 if (reg == 0)
1310 return;
1311
1312 /* Get the declared mode for this object. */
1313 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1314 : DECL_MODE (decl));
1315 /* Get the mode it's actually stored in. */
1316 promoted_mode = GET_MODE (reg);
1317
1318 /* If this variable comes from an outer function, find that
1319 function's saved context. Don't use find_function_data here,
1320 because it might not be in any active function.
1321 FIXME: Is that really supposed to happen?
1322 It does in ObjC at least. */
1323 if (context != current_function_decl && context != inline_function_decl)
1324 for (function = outer_function_chain; function; function = function->outer)
1325 if (function->decl == context)
1326 break;
1327
1328 /* If this is a variable-sized object or a structure passed by invisible
1329 reference, with a pseudo to address it, put that pseudo into the stack
1330 if the var is non-local. */
1331 if (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl)
1332 && GET_CODE (reg) == MEM
1333 && GET_CODE (XEXP (reg, 0)) == REG
1334 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1335 {
1336 reg = XEXP (reg, 0);
1337 decl_mode = promoted_mode = GET_MODE (reg);
1338 }
1339
1340 /* If this variable lives in the current function and we don't need to put it
1341 in the stack for the sake of setjmp or the non-locality, try to keep it in
1342 a register until we know we actually need the address. */
1343 can_use_addressof
1344 = (function == 0
1345 && ! (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl))
1346 && optimize > 0
1347 /* FIXME make it work for promoted modes too */
1348 && decl_mode == promoted_mode
1349 #ifdef NON_SAVING_SETJMP
1350 && ! (NON_SAVING_SETJMP && current_function_calls_setjmp)
1351 #endif
1352 );
1353
1354 /* If we can't use ADDRESSOF, make sure we see through one we already
1355 generated. */
1356 if (! can_use_addressof && GET_CODE (reg) == MEM
1357 && GET_CODE (XEXP (reg, 0)) == ADDRESSOF)
1358 reg = XEXP (XEXP (reg, 0), 0);
1359
1360 /* Now we should have a value that resides in one or more pseudo regs. */
1361
1362 if (GET_CODE (reg) == REG)
1363 {
1364 if (can_use_addressof)
1365 gen_mem_addressof (reg, decl, rescan);
1366 else
1367 put_reg_into_stack (function, reg, TREE_TYPE (decl), promoted_mode,
1368 decl_mode, volatilep, 0, usedp, 0);
1369 }
1370 else if (GET_CODE (reg) == CONCAT)
1371 {
1372 /* A CONCAT contains two pseudos; put them both in the stack.
1373 We do it so they end up consecutive.
1374 We fixup references to the parts only after we fixup references
1375 to the whole CONCAT, lest we do double fixups for the latter
1376 references. */
1377 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1378 tree part_type = (*lang_hooks.types.type_for_mode) (part_mode, 0);
1379 rtx lopart = XEXP (reg, 0);
1380 rtx hipart = XEXP (reg, 1);
1381 #ifdef FRAME_GROWS_DOWNWARD
1382 /* Since part 0 should have a lower address, do it second. */
1383 put_reg_into_stack (function, hipart, part_type, part_mode,
1384 part_mode, volatilep, 0, 0, 0);
1385 put_reg_into_stack (function, lopart, part_type, part_mode,
1386 part_mode, volatilep, 0, 0, 0);
1387 #else
1388 put_reg_into_stack (function, lopart, part_type, part_mode,
1389 part_mode, volatilep, 0, 0, 0);
1390 put_reg_into_stack (function, hipart, part_type, part_mode,
1391 part_mode, volatilep, 0, 0, 0);
1392 #endif
1393
1394 /* Change the CONCAT into a combined MEM for both parts. */
1395 PUT_CODE (reg, MEM);
1396 MEM_ATTRS (reg) = 0;
1397
1398 /* set_mem_attributes uses DECL_RTL to avoid re-generating of
1399 already computed alias sets. Here we want to re-generate. */
1400 if (DECL_P (decl))
1401 SET_DECL_RTL (decl, NULL);
1402 set_mem_attributes (reg, decl, 1);
1403 if (DECL_P (decl))
1404 SET_DECL_RTL (decl, reg);
1405
1406 /* The two parts are in memory order already.
1407 Use the lower parts address as ours. */
1408 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1409 /* Prevent sharing of rtl that might lose. */
1410 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1411 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1412 if (usedp && rescan)
1413 {
1414 schedule_fixup_var_refs (function, reg, TREE_TYPE (decl),
1415 promoted_mode, 0);
1416 schedule_fixup_var_refs (function, lopart, part_type, part_mode, 0);
1417 schedule_fixup_var_refs (function, hipart, part_type, part_mode, 0);
1418 }
1419 }
1420 else
1421 return;
1422 }
1423
1424 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1425 into the stack frame of FUNCTION (0 means the current function).
1426 DECL_MODE is the machine mode of the user-level data type.
1427 PROMOTED_MODE is the machine mode of the register.
1428 VOLATILE_P is nonzero if this is for a "volatile" decl.
1429 USED_P is nonzero if this reg might have already been used in an insn. */
1430
1431 static void
1432 put_reg_into_stack (struct function *function, rtx reg, tree type,
1433 enum machine_mode promoted_mode, enum machine_mode decl_mode,
1434 int volatile_p, unsigned int original_regno, int used_p, htab_t ht)
1435 {
1436 struct function *func = function ? function : cfun;
1437 rtx new = 0;
1438 unsigned int regno = original_regno;
1439
1440 if (regno == 0)
1441 regno = REGNO (reg);
1442
1443 if (regno < func->x_max_parm_reg)
1444 new = func->x_parm_reg_stack_loc[regno];
1445
1446 if (new == 0)
1447 new = assign_stack_local_1 (decl_mode, GET_MODE_SIZE (decl_mode), 0, func);
1448
1449 PUT_CODE (reg, MEM);
1450 PUT_MODE (reg, decl_mode);
1451 XEXP (reg, 0) = XEXP (new, 0);
1452 MEM_ATTRS (reg) = 0;
1453 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1454 MEM_VOLATILE_P (reg) = volatile_p;
1455
1456 /* If this is a memory ref that contains aggregate components,
1457 mark it as such for cse and loop optimize. If we are reusing a
1458 previously generated stack slot, then we need to copy the bit in
1459 case it was set for other reasons. For instance, it is set for
1460 __builtin_va_alist. */
1461 if (type)
1462 {
1463 MEM_SET_IN_STRUCT_P (reg,
1464 AGGREGATE_TYPE_P (type) || MEM_IN_STRUCT_P (new));
1465 set_mem_alias_set (reg, get_alias_set (type));
1466 }
1467
1468 if (used_p)
1469 schedule_fixup_var_refs (function, reg, type, promoted_mode, ht);
1470 }
1471
1472 /* Make sure that all refs to the variable, previously made
1473 when it was a register, are fixed up to be valid again.
1474 See function above for meaning of arguments. */
1475
1476 static void
1477 schedule_fixup_var_refs (struct function *function, rtx reg, tree type,
1478 enum machine_mode promoted_mode, htab_t ht)
1479 {
1480 int unsigned_p = type ? TREE_UNSIGNED (type) : 0;
1481
1482 if (function != 0)
1483 {
1484 struct var_refs_queue *temp;
1485
1486 temp = ggc_alloc (sizeof (struct var_refs_queue));
1487 temp->modified = reg;
1488 temp->promoted_mode = promoted_mode;
1489 temp->unsignedp = unsigned_p;
1490 temp->next = function->fixup_var_refs_queue;
1491 function->fixup_var_refs_queue = temp;
1492 }
1493 else
1494 /* Variable is local; fix it up now. */
1495 fixup_var_refs (reg, promoted_mode, unsigned_p, reg, ht);
1496 }
1497 \f
1498 static void
1499 fixup_var_refs (rtx var, enum machine_mode promoted_mode, int unsignedp,
1500 rtx may_share, htab_t ht)
1501 {
1502 tree pending;
1503 rtx first_insn = get_insns ();
1504 struct sequence_stack *stack = seq_stack;
1505 tree rtl_exps = rtl_expr_chain;
1506
1507 /* If there's a hash table, it must record all uses of VAR. */
1508 if (ht)
1509 {
1510 if (stack != 0)
1511 abort ();
1512 fixup_var_refs_insns_with_hash (ht, var, promoted_mode, unsignedp,
1513 may_share);
1514 return;
1515 }
1516
1517 fixup_var_refs_insns (first_insn, var, promoted_mode, unsignedp,
1518 stack == 0, may_share);
1519
1520 /* Scan all pending sequences too. */
1521 for (; stack; stack = stack->next)
1522 {
1523 push_to_full_sequence (stack->first, stack->last);
1524 fixup_var_refs_insns (stack->first, var, promoted_mode, unsignedp,
1525 stack->next != 0, may_share);
1526 /* Update remembered end of sequence
1527 in case we added an insn at the end. */
1528 stack->last = get_last_insn ();
1529 end_sequence ();
1530 }
1531
1532 /* Scan all waiting RTL_EXPRs too. */
1533 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1534 {
1535 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1536 if (seq != const0_rtx && seq != 0)
1537 {
1538 push_to_sequence (seq);
1539 fixup_var_refs_insns (seq, var, promoted_mode, unsignedp, 0,
1540 may_share);
1541 end_sequence ();
1542 }
1543 }
1544 }
1545 \f
1546 /* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
1547 some part of an insn. Return a struct fixup_replacement whose OLD
1548 value is equal to X. Allocate a new structure if no such entry exists. */
1549
1550 static struct fixup_replacement *
1551 find_fixup_replacement (struct fixup_replacement **replacements, rtx x)
1552 {
1553 struct fixup_replacement *p;
1554
1555 /* See if we have already replaced this. */
1556 for (p = *replacements; p != 0 && ! rtx_equal_p (p->old, x); p = p->next)
1557 ;
1558
1559 if (p == 0)
1560 {
1561 p = xmalloc (sizeof (struct fixup_replacement));
1562 p->old = x;
1563 p->new = 0;
1564 p->next = *replacements;
1565 *replacements = p;
1566 }
1567
1568 return p;
1569 }
1570
1571 /* Scan the insn-chain starting with INSN for refs to VAR and fix them
1572 up. TOPLEVEL is nonzero if this chain is the main chain of insns
1573 for the current function. MAY_SHARE is either a MEM that is not
1574 to be unshared or a list of them. */
1575
1576 static void
1577 fixup_var_refs_insns (rtx insn, rtx var, enum machine_mode promoted_mode,
1578 int unsignedp, int toplevel, rtx may_share)
1579 {
1580 while (insn)
1581 {
1582 /* fixup_var_refs_insn might modify insn, so save its next
1583 pointer now. */
1584 rtx next = NEXT_INSN (insn);
1585
1586 /* CALL_PLACEHOLDERs are special; we have to switch into each of
1587 the three sequences they (potentially) contain, and process
1588 them recursively. The CALL_INSN itself is not interesting. */
1589
1590 if (GET_CODE (insn) == CALL_INSN
1591 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
1592 {
1593 int i;
1594
1595 /* Look at the Normal call, sibling call and tail recursion
1596 sequences attached to the CALL_PLACEHOLDER. */
1597 for (i = 0; i < 3; i++)
1598 {
1599 rtx seq = XEXP (PATTERN (insn), i);
1600 if (seq)
1601 {
1602 push_to_sequence (seq);
1603 fixup_var_refs_insns (seq, var, promoted_mode, unsignedp, 0,
1604 may_share);
1605 XEXP (PATTERN (insn), i) = get_insns ();
1606 end_sequence ();
1607 }
1608 }
1609 }
1610
1611 else if (INSN_P (insn))
1612 fixup_var_refs_insn (insn, var, promoted_mode, unsignedp, toplevel,
1613 may_share);
1614
1615 insn = next;
1616 }
1617 }
1618
1619 /* Look up the insns which reference VAR in HT and fix them up. Other
1620 arguments are the same as fixup_var_refs_insns.
1621
1622 N.B. No need for special processing of CALL_PLACEHOLDERs here,
1623 because the hash table will point straight to the interesting insn
1624 (inside the CALL_PLACEHOLDER). */
1625
1626 static void
1627 fixup_var_refs_insns_with_hash (htab_t ht, rtx var, enum machine_mode promoted_mode,
1628 int unsignedp, rtx may_share)
1629 {
1630 struct insns_for_mem_entry tmp;
1631 struct insns_for_mem_entry *ime;
1632 rtx insn_list;
1633
1634 tmp.key = var;
1635 ime = htab_find (ht, &tmp);
1636 for (insn_list = ime->insns; insn_list != 0; insn_list = XEXP (insn_list, 1))
1637 if (INSN_P (XEXP (insn_list, 0)))
1638 fixup_var_refs_insn (XEXP (insn_list, 0), var, promoted_mode,
1639 unsignedp, 1, may_share);
1640 }
1641
1642
1643 /* Per-insn processing by fixup_var_refs_insns(_with_hash). INSN is
1644 the insn under examination, VAR is the variable to fix up
1645 references to, PROMOTED_MODE and UNSIGNEDP describe VAR, and
1646 TOPLEVEL is nonzero if this is the main insn chain for this
1647 function. */
1648
1649 static void
1650 fixup_var_refs_insn (rtx insn, rtx var, enum machine_mode promoted_mode,
1651 int unsignedp, int toplevel, rtx no_share)
1652 {
1653 rtx call_dest = 0;
1654 rtx set, prev, prev_set;
1655 rtx note;
1656
1657 /* Remember the notes in case we delete the insn. */
1658 note = REG_NOTES (insn);
1659
1660 /* If this is a CLOBBER of VAR, delete it.
1661
1662 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1663 and REG_RETVAL notes too. */
1664 if (GET_CODE (PATTERN (insn)) == CLOBBER
1665 && (XEXP (PATTERN (insn), 0) == var
1666 || (GET_CODE (XEXP (PATTERN (insn), 0)) == CONCAT
1667 && (XEXP (XEXP (PATTERN (insn), 0), 0) == var
1668 || XEXP (XEXP (PATTERN (insn), 0), 1) == var))))
1669 {
1670 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1671 /* The REG_LIBCALL note will go away since we are going to
1672 turn INSN into a NOTE, so just delete the
1673 corresponding REG_RETVAL note. */
1674 remove_note (XEXP (note, 0),
1675 find_reg_note (XEXP (note, 0), REG_RETVAL,
1676 NULL_RTX));
1677
1678 delete_insn (insn);
1679 }
1680
1681 /* The insn to load VAR from a home in the arglist
1682 is now a no-op. When we see it, just delete it.
1683 Similarly if this is storing VAR from a register from which
1684 it was loaded in the previous insn. This will occur
1685 when an ADDRESSOF was made for an arglist slot. */
1686 else if (toplevel
1687 && (set = single_set (insn)) != 0
1688 && SET_DEST (set) == var
1689 /* If this represents the result of an insn group,
1690 don't delete the insn. */
1691 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1692 && (rtx_equal_p (SET_SRC (set), var)
1693 || (GET_CODE (SET_SRC (set)) == REG
1694 && (prev = prev_nonnote_insn (insn)) != 0
1695 && (prev_set = single_set (prev)) != 0
1696 && SET_DEST (prev_set) == SET_SRC (set)
1697 && rtx_equal_p (SET_SRC (prev_set), var))))
1698 {
1699 delete_insn (insn);
1700 }
1701 else
1702 {
1703 struct fixup_replacement *replacements = 0;
1704 rtx next_insn = NEXT_INSN (insn);
1705
1706 if (SMALL_REGISTER_CLASSES)
1707 {
1708 /* If the insn that copies the results of a CALL_INSN
1709 into a pseudo now references VAR, we have to use an
1710 intermediate pseudo since we want the life of the
1711 return value register to be only a single insn.
1712
1713 If we don't use an intermediate pseudo, such things as
1714 address computations to make the address of VAR valid
1715 if it is not can be placed between the CALL_INSN and INSN.
1716
1717 To make sure this doesn't happen, we record the destination
1718 of the CALL_INSN and see if the next insn uses both that
1719 and VAR. */
1720
1721 if (call_dest != 0 && GET_CODE (insn) == INSN
1722 && reg_mentioned_p (var, PATTERN (insn))
1723 && reg_mentioned_p (call_dest, PATTERN (insn)))
1724 {
1725 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1726
1727 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1728
1729 PATTERN (insn) = replace_rtx (PATTERN (insn),
1730 call_dest, temp);
1731 }
1732
1733 if (GET_CODE (insn) == CALL_INSN
1734 && GET_CODE (PATTERN (insn)) == SET)
1735 call_dest = SET_DEST (PATTERN (insn));
1736 else if (GET_CODE (insn) == CALL_INSN
1737 && GET_CODE (PATTERN (insn)) == PARALLEL
1738 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1739 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1740 else
1741 call_dest = 0;
1742 }
1743
1744 /* See if we have to do anything to INSN now that VAR is in
1745 memory. If it needs to be loaded into a pseudo, use a single
1746 pseudo for the entire insn in case there is a MATCH_DUP
1747 between two operands. We pass a pointer to the head of
1748 a list of struct fixup_replacements. If fixup_var_refs_1
1749 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1750 it will record them in this list.
1751
1752 If it allocated a pseudo for any replacement, we copy into
1753 it here. */
1754
1755 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1756 &replacements, no_share);
1757
1758 /* If this is last_parm_insn, and any instructions were output
1759 after it to fix it up, then we must set last_parm_insn to
1760 the last such instruction emitted. */
1761 if (insn == last_parm_insn)
1762 last_parm_insn = PREV_INSN (next_insn);
1763
1764 while (replacements)
1765 {
1766 struct fixup_replacement *next;
1767
1768 if (GET_CODE (replacements->new) == REG)
1769 {
1770 rtx insert_before;
1771 rtx seq;
1772
1773 /* OLD might be a (subreg (mem)). */
1774 if (GET_CODE (replacements->old) == SUBREG)
1775 replacements->old
1776 = fixup_memory_subreg (replacements->old, insn,
1777 promoted_mode, 0);
1778 else
1779 replacements->old
1780 = fixup_stack_1 (replacements->old, insn);
1781
1782 insert_before = insn;
1783
1784 /* If we are changing the mode, do a conversion.
1785 This might be wasteful, but combine.c will
1786 eliminate much of the waste. */
1787
1788 if (GET_MODE (replacements->new)
1789 != GET_MODE (replacements->old))
1790 {
1791 start_sequence ();
1792 convert_move (replacements->new,
1793 replacements->old, unsignedp);
1794 seq = get_insns ();
1795 end_sequence ();
1796 }
1797 else
1798 seq = gen_move_insn (replacements->new,
1799 replacements->old);
1800
1801 emit_insn_before (seq, insert_before);
1802 }
1803
1804 next = replacements->next;
1805 free (replacements);
1806 replacements = next;
1807 }
1808 }
1809
1810 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1811 But don't touch other insns referred to by reg-notes;
1812 we will get them elsewhere. */
1813 while (note)
1814 {
1815 if (GET_CODE (note) != INSN_LIST)
1816 XEXP (note, 0)
1817 = walk_fixup_memory_subreg (XEXP (note, 0), insn,
1818 promoted_mode, 1);
1819 note = XEXP (note, 1);
1820 }
1821 }
1822 \f
1823 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1824 See if the rtx expression at *LOC in INSN needs to be changed.
1825
1826 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1827 contain a list of original rtx's and replacements. If we find that we need
1828 to modify this insn by replacing a memory reference with a pseudo or by
1829 making a new MEM to implement a SUBREG, we consult that list to see if
1830 we have already chosen a replacement. If none has already been allocated,
1831 we allocate it and update the list. fixup_var_refs_insn will copy VAR
1832 or the SUBREG, as appropriate, to the pseudo. */
1833
1834 static void
1835 fixup_var_refs_1 (rtx var, enum machine_mode promoted_mode, rtx *loc, rtx insn,
1836 struct fixup_replacement **replacements, rtx no_share)
1837 {
1838 int i;
1839 rtx x = *loc;
1840 RTX_CODE code = GET_CODE (x);
1841 const char *fmt;
1842 rtx tem, tem1;
1843 struct fixup_replacement *replacement;
1844
1845 switch (code)
1846 {
1847 case ADDRESSOF:
1848 if (XEXP (x, 0) == var)
1849 {
1850 /* Prevent sharing of rtl that might lose. */
1851 rtx sub = copy_rtx (XEXP (var, 0));
1852
1853 if (! validate_change (insn, loc, sub, 0))
1854 {
1855 rtx y = gen_reg_rtx (GET_MODE (sub));
1856 rtx seq, new_insn;
1857
1858 /* We should be able to replace with a register or all is lost.
1859 Note that we can't use validate_change to verify this, since
1860 we're not caring for replacing all dups simultaneously. */
1861 if (! validate_replace_rtx (*loc, y, insn))
1862 abort ();
1863
1864 /* Careful! First try to recognize a direct move of the
1865 value, mimicking how things are done in gen_reload wrt
1866 PLUS. Consider what happens when insn is a conditional
1867 move instruction and addsi3 clobbers flags. */
1868
1869 start_sequence ();
1870 new_insn = emit_insn (gen_rtx_SET (VOIDmode, y, sub));
1871 seq = get_insns ();
1872 end_sequence ();
1873
1874 if (recog_memoized (new_insn) < 0)
1875 {
1876 /* That failed. Fall back on force_operand and hope. */
1877
1878 start_sequence ();
1879 sub = force_operand (sub, y);
1880 if (sub != y)
1881 emit_insn (gen_move_insn (y, sub));
1882 seq = get_insns ();
1883 end_sequence ();
1884 }
1885
1886 #ifdef HAVE_cc0
1887 /* Don't separate setter from user. */
1888 if (PREV_INSN (insn) && sets_cc0_p (PREV_INSN (insn)))
1889 insn = PREV_INSN (insn);
1890 #endif
1891
1892 emit_insn_before (seq, insn);
1893 }
1894 }
1895 return;
1896
1897 case MEM:
1898 if (var == x)
1899 {
1900 /* If we already have a replacement, use it. Otherwise,
1901 try to fix up this address in case it is invalid. */
1902
1903 replacement = find_fixup_replacement (replacements, var);
1904 if (replacement->new)
1905 {
1906 *loc = replacement->new;
1907 return;
1908 }
1909
1910 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1911
1912 /* Unless we are forcing memory to register or we changed the mode,
1913 we can leave things the way they are if the insn is valid. */
1914
1915 INSN_CODE (insn) = -1;
1916 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1917 && recog_memoized (insn) >= 0)
1918 return;
1919
1920 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1921 return;
1922 }
1923
1924 /* If X contains VAR, we need to unshare it here so that we update
1925 each occurrence separately. But all identical MEMs in one insn
1926 must be replaced with the same rtx because of the possibility of
1927 MATCH_DUPs. */
1928
1929 if (reg_mentioned_p (var, x))
1930 {
1931 replacement = find_fixup_replacement (replacements, x);
1932 if (replacement->new == 0)
1933 replacement->new = copy_most_rtx (x, no_share);
1934
1935 *loc = x = replacement->new;
1936 code = GET_CODE (x);
1937 }
1938 break;
1939
1940 case REG:
1941 case CC0:
1942 case PC:
1943 case CONST_INT:
1944 case CONST:
1945 case SYMBOL_REF:
1946 case LABEL_REF:
1947 case CONST_DOUBLE:
1948 case CONST_VECTOR:
1949 return;
1950
1951 case SIGN_EXTRACT:
1952 case ZERO_EXTRACT:
1953 /* Note that in some cases those types of expressions are altered
1954 by optimize_bit_field, and do not survive to get here. */
1955 if (XEXP (x, 0) == var
1956 || (GET_CODE (XEXP (x, 0)) == SUBREG
1957 && SUBREG_REG (XEXP (x, 0)) == var))
1958 {
1959 /* Get TEM as a valid MEM in the mode presently in the insn.
1960
1961 We don't worry about the possibility of MATCH_DUP here; it
1962 is highly unlikely and would be tricky to handle. */
1963
1964 tem = XEXP (x, 0);
1965 if (GET_CODE (tem) == SUBREG)
1966 {
1967 if (GET_MODE_BITSIZE (GET_MODE (tem))
1968 > GET_MODE_BITSIZE (GET_MODE (var)))
1969 {
1970 replacement = find_fixup_replacement (replacements, var);
1971 if (replacement->new == 0)
1972 replacement->new = gen_reg_rtx (GET_MODE (var));
1973 SUBREG_REG (tem) = replacement->new;
1974
1975 /* The following code works only if we have a MEM, so we
1976 need to handle the subreg here. We directly substitute
1977 it assuming that a subreg must be OK here. We already
1978 scheduled a replacement to copy the mem into the
1979 subreg. */
1980 XEXP (x, 0) = tem;
1981 return;
1982 }
1983 else
1984 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
1985 }
1986 else
1987 tem = fixup_stack_1 (tem, insn);
1988
1989 /* Unless we want to load from memory, get TEM into the proper mode
1990 for an extract from memory. This can only be done if the
1991 extract is at a constant position and length. */
1992
1993 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
1994 && GET_CODE (XEXP (x, 2)) == CONST_INT
1995 && ! mode_dependent_address_p (XEXP (tem, 0))
1996 && ! MEM_VOLATILE_P (tem))
1997 {
1998 enum machine_mode wanted_mode = VOIDmode;
1999 enum machine_mode is_mode = GET_MODE (tem);
2000 HOST_WIDE_INT pos = INTVAL (XEXP (x, 2));
2001
2002 if (GET_CODE (x) == ZERO_EXTRACT)
2003 {
2004 enum machine_mode new_mode
2005 = mode_for_extraction (EP_extzv, 1);
2006 if (new_mode != MAX_MACHINE_MODE)
2007 wanted_mode = new_mode;
2008 }
2009 else if (GET_CODE (x) == SIGN_EXTRACT)
2010 {
2011 enum machine_mode new_mode
2012 = mode_for_extraction (EP_extv, 1);
2013 if (new_mode != MAX_MACHINE_MODE)
2014 wanted_mode = new_mode;
2015 }
2016
2017 /* If we have a narrower mode, we can do something. */
2018 if (wanted_mode != VOIDmode
2019 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2020 {
2021 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2022 rtx old_pos = XEXP (x, 2);
2023 rtx newmem;
2024
2025 /* If the bytes and bits are counted differently, we
2026 must adjust the offset. */
2027 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2028 offset = (GET_MODE_SIZE (is_mode)
2029 - GET_MODE_SIZE (wanted_mode) - offset);
2030
2031 pos %= GET_MODE_BITSIZE (wanted_mode);
2032
2033 newmem = adjust_address_nv (tem, wanted_mode, offset);
2034
2035 /* Make the change and see if the insn remains valid. */
2036 INSN_CODE (insn) = -1;
2037 XEXP (x, 0) = newmem;
2038 XEXP (x, 2) = GEN_INT (pos);
2039
2040 if (recog_memoized (insn) >= 0)
2041 return;
2042
2043 /* Otherwise, restore old position. XEXP (x, 0) will be
2044 restored later. */
2045 XEXP (x, 2) = old_pos;
2046 }
2047 }
2048
2049 /* If we get here, the bitfield extract insn can't accept a memory
2050 reference. Copy the input into a register. */
2051
2052 tem1 = gen_reg_rtx (GET_MODE (tem));
2053 emit_insn_before (gen_move_insn (tem1, tem), insn);
2054 XEXP (x, 0) = tem1;
2055 return;
2056 }
2057 break;
2058
2059 case SUBREG:
2060 if (SUBREG_REG (x) == var)
2061 {
2062 /* If this is a special SUBREG made because VAR was promoted
2063 from a wider mode, replace it with VAR and call ourself
2064 recursively, this time saying that the object previously
2065 had its current mode (by virtue of the SUBREG). */
2066
2067 if (SUBREG_PROMOTED_VAR_P (x))
2068 {
2069 *loc = var;
2070 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements,
2071 no_share);
2072 return;
2073 }
2074
2075 /* If this SUBREG makes VAR wider, it has become a paradoxical
2076 SUBREG with VAR in memory, but these aren't allowed at this
2077 stage of the compilation. So load VAR into a pseudo and take
2078 a SUBREG of that pseudo. */
2079 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
2080 {
2081 replacement = find_fixup_replacement (replacements, var);
2082 if (replacement->new == 0)
2083 replacement->new = gen_reg_rtx (promoted_mode);
2084 SUBREG_REG (x) = replacement->new;
2085 return;
2086 }
2087
2088 /* See if we have already found a replacement for this SUBREG.
2089 If so, use it. Otherwise, make a MEM and see if the insn
2090 is recognized. If not, or if we should force MEM into a register,
2091 make a pseudo for this SUBREG. */
2092 replacement = find_fixup_replacement (replacements, x);
2093 if (replacement->new)
2094 {
2095 enum machine_mode mode = GET_MODE (x);
2096 *loc = replacement->new;
2097
2098 /* Careful! We may have just replaced a SUBREG by a MEM, which
2099 means that the insn may have become invalid again. We can't
2100 in this case make a new replacement since we already have one
2101 and we must deal with MATCH_DUPs. */
2102 if (GET_CODE (replacement->new) == MEM)
2103 {
2104 INSN_CODE (insn) = -1;
2105 if (recog_memoized (insn) >= 0)
2106 return;
2107
2108 fixup_var_refs_1 (replacement->new, mode, &PATTERN (insn),
2109 insn, replacements, no_share);
2110 }
2111
2112 return;
2113 }
2114
2115 replacement->new = *loc = fixup_memory_subreg (x, insn,
2116 promoted_mode, 0);
2117
2118 INSN_CODE (insn) = -1;
2119 if (! flag_force_mem && recog_memoized (insn) >= 0)
2120 return;
2121
2122 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
2123 return;
2124 }
2125 break;
2126
2127 case SET:
2128 /* First do special simplification of bit-field references. */
2129 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
2130 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
2131 optimize_bit_field (x, insn, 0);
2132 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
2133 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
2134 optimize_bit_field (x, insn, 0);
2135
2136 /* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
2137 into a register and then store it back out. */
2138 if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
2139 && GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
2140 && SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
2141 && (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
2142 > GET_MODE_SIZE (GET_MODE (var))))
2143 {
2144 replacement = find_fixup_replacement (replacements, var);
2145 if (replacement->new == 0)
2146 replacement->new = gen_reg_rtx (GET_MODE (var));
2147
2148 SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
2149 emit_insn_after (gen_move_insn (var, replacement->new), insn);
2150 }
2151
2152 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
2153 insn into a pseudo and store the low part of the pseudo into VAR. */
2154 if (GET_CODE (SET_DEST (x)) == SUBREG
2155 && SUBREG_REG (SET_DEST (x)) == var
2156 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
2157 > GET_MODE_SIZE (GET_MODE (var))))
2158 {
2159 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
2160 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
2161 tem)),
2162 insn);
2163 break;
2164 }
2165
2166 {
2167 rtx dest = SET_DEST (x);
2168 rtx src = SET_SRC (x);
2169 rtx outerdest = dest;
2170
2171 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
2172 || GET_CODE (dest) == SIGN_EXTRACT
2173 || GET_CODE (dest) == ZERO_EXTRACT)
2174 dest = XEXP (dest, 0);
2175
2176 if (GET_CODE (src) == SUBREG)
2177 src = SUBREG_REG (src);
2178
2179 /* If VAR does not appear at the top level of the SET
2180 just scan the lower levels of the tree. */
2181
2182 if (src != var && dest != var)
2183 break;
2184
2185 /* We will need to rerecognize this insn. */
2186 INSN_CODE (insn) = -1;
2187
2188 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var
2189 && mode_for_extraction (EP_insv, -1) != MAX_MACHINE_MODE)
2190 {
2191 /* Since this case will return, ensure we fixup all the
2192 operands here. */
2193 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
2194 insn, replacements, no_share);
2195 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
2196 insn, replacements, no_share);
2197 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
2198 insn, replacements, no_share);
2199
2200 tem = XEXP (outerdest, 0);
2201
2202 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
2203 that may appear inside a ZERO_EXTRACT.
2204 This was legitimate when the MEM was a REG. */
2205 if (GET_CODE (tem) == SUBREG
2206 && SUBREG_REG (tem) == var)
2207 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2208 else
2209 tem = fixup_stack_1 (tem, insn);
2210
2211 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
2212 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
2213 && ! mode_dependent_address_p (XEXP (tem, 0))
2214 && ! MEM_VOLATILE_P (tem))
2215 {
2216 enum machine_mode wanted_mode;
2217 enum machine_mode is_mode = GET_MODE (tem);
2218 HOST_WIDE_INT pos = INTVAL (XEXP (outerdest, 2));
2219
2220 wanted_mode = mode_for_extraction (EP_insv, 0);
2221
2222 /* If we have a narrower mode, we can do something. */
2223 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2224 {
2225 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2226 rtx old_pos = XEXP (outerdest, 2);
2227 rtx newmem;
2228
2229 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2230 offset = (GET_MODE_SIZE (is_mode)
2231 - GET_MODE_SIZE (wanted_mode) - offset);
2232
2233 pos %= GET_MODE_BITSIZE (wanted_mode);
2234
2235 newmem = adjust_address_nv (tem, wanted_mode, offset);
2236
2237 /* Make the change and see if the insn remains valid. */
2238 INSN_CODE (insn) = -1;
2239 XEXP (outerdest, 0) = newmem;
2240 XEXP (outerdest, 2) = GEN_INT (pos);
2241
2242 if (recog_memoized (insn) >= 0)
2243 return;
2244
2245 /* Otherwise, restore old position. XEXP (x, 0) will be
2246 restored later. */
2247 XEXP (outerdest, 2) = old_pos;
2248 }
2249 }
2250
2251 /* If we get here, the bit-field store doesn't allow memory
2252 or isn't located at a constant position. Load the value into
2253 a register, do the store, and put it back into memory. */
2254
2255 tem1 = gen_reg_rtx (GET_MODE (tem));
2256 emit_insn_before (gen_move_insn (tem1, tem), insn);
2257 emit_insn_after (gen_move_insn (tem, tem1), insn);
2258 XEXP (outerdest, 0) = tem1;
2259 return;
2260 }
2261
2262 /* STRICT_LOW_PART is a no-op on memory references
2263 and it can cause combinations to be unrecognizable,
2264 so eliminate it. */
2265
2266 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2267 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2268
2269 /* A valid insn to copy VAR into or out of a register
2270 must be left alone, to avoid an infinite loop here.
2271 If the reference to VAR is by a subreg, fix that up,
2272 since SUBREG is not valid for a memref.
2273 Also fix up the address of the stack slot.
2274
2275 Note that we must not try to recognize the insn until
2276 after we know that we have valid addresses and no
2277 (subreg (mem ...) ...) constructs, since these interfere
2278 with determining the validity of the insn. */
2279
2280 if ((SET_SRC (x) == var
2281 || (GET_CODE (SET_SRC (x)) == SUBREG
2282 && SUBREG_REG (SET_SRC (x)) == var))
2283 && (GET_CODE (SET_DEST (x)) == REG
2284 || (GET_CODE (SET_DEST (x)) == SUBREG
2285 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
2286 && GET_MODE (var) == promoted_mode
2287 && x == single_set (insn))
2288 {
2289 rtx pat, last;
2290
2291 if (GET_CODE (SET_SRC (x)) == SUBREG
2292 && (GET_MODE_SIZE (GET_MODE (SET_SRC (x)))
2293 > GET_MODE_SIZE (GET_MODE (var))))
2294 {
2295 /* This (subreg VAR) is now a paradoxical subreg. We need
2296 to replace VAR instead of the subreg. */
2297 replacement = find_fixup_replacement (replacements, var);
2298 if (replacement->new == NULL_RTX)
2299 replacement->new = gen_reg_rtx (GET_MODE (var));
2300 SUBREG_REG (SET_SRC (x)) = replacement->new;
2301 }
2302 else
2303 {
2304 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2305 if (replacement->new)
2306 SET_SRC (x) = replacement->new;
2307 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2308 SET_SRC (x) = replacement->new
2309 = fixup_memory_subreg (SET_SRC (x), insn, promoted_mode,
2310 0);
2311 else
2312 SET_SRC (x) = replacement->new
2313 = fixup_stack_1 (SET_SRC (x), insn);
2314 }
2315
2316 if (recog_memoized (insn) >= 0)
2317 return;
2318
2319 /* INSN is not valid, but we know that we want to
2320 copy SET_SRC (x) to SET_DEST (x) in some way. So
2321 we generate the move and see whether it requires more
2322 than one insn. If it does, we emit those insns and
2323 delete INSN. Otherwise, we can just replace the pattern
2324 of INSN; we have already verified above that INSN has
2325 no other function that to do X. */
2326
2327 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2328 if (NEXT_INSN (pat) != NULL_RTX)
2329 {
2330 last = emit_insn_before (pat, insn);
2331
2332 /* INSN might have REG_RETVAL or other important notes, so
2333 we need to store the pattern of the last insn in the
2334 sequence into INSN similarly to the normal case. LAST
2335 should not have REG_NOTES, but we allow them if INSN has
2336 no REG_NOTES. */
2337 if (REG_NOTES (last) && REG_NOTES (insn))
2338 abort ();
2339 if (REG_NOTES (last))
2340 REG_NOTES (insn) = REG_NOTES (last);
2341 PATTERN (insn) = PATTERN (last);
2342
2343 delete_insn (last);
2344 }
2345 else
2346 PATTERN (insn) = PATTERN (pat);
2347
2348 return;
2349 }
2350
2351 if ((SET_DEST (x) == var
2352 || (GET_CODE (SET_DEST (x)) == SUBREG
2353 && SUBREG_REG (SET_DEST (x)) == var))
2354 && (GET_CODE (SET_SRC (x)) == REG
2355 || (GET_CODE (SET_SRC (x)) == SUBREG
2356 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
2357 && GET_MODE (var) == promoted_mode
2358 && x == single_set (insn))
2359 {
2360 rtx pat, last;
2361
2362 if (GET_CODE (SET_DEST (x)) == SUBREG)
2363 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn,
2364 promoted_mode, 0);
2365 else
2366 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2367
2368 if (recog_memoized (insn) >= 0)
2369 return;
2370
2371 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2372 if (NEXT_INSN (pat) != NULL_RTX)
2373 {
2374 last = emit_insn_before (pat, insn);
2375
2376 /* INSN might have REG_RETVAL or other important notes, so
2377 we need to store the pattern of the last insn in the
2378 sequence into INSN similarly to the normal case. LAST
2379 should not have REG_NOTES, but we allow them if INSN has
2380 no REG_NOTES. */
2381 if (REG_NOTES (last) && REG_NOTES (insn))
2382 abort ();
2383 if (REG_NOTES (last))
2384 REG_NOTES (insn) = REG_NOTES (last);
2385 PATTERN (insn) = PATTERN (last);
2386
2387 delete_insn (last);
2388 }
2389 else
2390 PATTERN (insn) = PATTERN (pat);
2391
2392 return;
2393 }
2394
2395 /* Otherwise, storing into VAR must be handled specially
2396 by storing into a temporary and copying that into VAR
2397 with a new insn after this one. Note that this case
2398 will be used when storing into a promoted scalar since
2399 the insn will now have different modes on the input
2400 and output and hence will be invalid (except for the case
2401 of setting it to a constant, which does not need any
2402 change if it is valid). We generate extra code in that case,
2403 but combine.c will eliminate it. */
2404
2405 if (dest == var)
2406 {
2407 rtx temp;
2408 rtx fixeddest = SET_DEST (x);
2409 enum machine_mode temp_mode;
2410
2411 /* STRICT_LOW_PART can be discarded, around a MEM. */
2412 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2413 fixeddest = XEXP (fixeddest, 0);
2414 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2415 if (GET_CODE (fixeddest) == SUBREG)
2416 {
2417 fixeddest = fixup_memory_subreg (fixeddest, insn,
2418 promoted_mode, 0);
2419 temp_mode = GET_MODE (fixeddest);
2420 }
2421 else
2422 {
2423 fixeddest = fixup_stack_1 (fixeddest, insn);
2424 temp_mode = promoted_mode;
2425 }
2426
2427 temp = gen_reg_rtx (temp_mode);
2428
2429 emit_insn_after (gen_move_insn (fixeddest,
2430 gen_lowpart (GET_MODE (fixeddest),
2431 temp)),
2432 insn);
2433
2434 SET_DEST (x) = temp;
2435 }
2436 }
2437
2438 default:
2439 break;
2440 }
2441
2442 /* Nothing special about this RTX; fix its operands. */
2443
2444 fmt = GET_RTX_FORMAT (code);
2445 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2446 {
2447 if (fmt[i] == 'e')
2448 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements,
2449 no_share);
2450 else if (fmt[i] == 'E')
2451 {
2452 int j;
2453 for (j = 0; j < XVECLEN (x, i); j++)
2454 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2455 insn, replacements, no_share);
2456 }
2457 }
2458 }
2459 \f
2460 /* Previously, X had the form (SUBREG:m1 (REG:PROMOTED_MODE ...)).
2461 The REG was placed on the stack, so X now has the form (SUBREG:m1
2462 (MEM:m2 ...)).
2463
2464 Return an rtx (MEM:m1 newaddr) which is equivalent. If any insns
2465 must be emitted to compute NEWADDR, put them before INSN.
2466
2467 UNCRITICAL nonzero means accept paradoxical subregs.
2468 This is used for subregs found inside REG_NOTES. */
2469
2470 static rtx
2471 fixup_memory_subreg (rtx x, rtx insn, enum machine_mode promoted_mode, int uncritical)
2472 {
2473 int offset;
2474 rtx mem = SUBREG_REG (x);
2475 rtx addr = XEXP (mem, 0);
2476 enum machine_mode mode = GET_MODE (x);
2477 rtx result, seq;
2478
2479 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2480 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (mem)) && ! uncritical)
2481 abort ();
2482
2483 offset = SUBREG_BYTE (x);
2484 if (BYTES_BIG_ENDIAN)
2485 /* If the PROMOTED_MODE is wider than the mode of the MEM, adjust
2486 the offset so that it points to the right location within the
2487 MEM. */
2488 offset -= (GET_MODE_SIZE (promoted_mode) - GET_MODE_SIZE (GET_MODE (mem)));
2489
2490 if (!flag_force_addr
2491 && memory_address_p (mode, plus_constant (addr, offset)))
2492 /* Shortcut if no insns need be emitted. */
2493 return adjust_address (mem, mode, offset);
2494
2495 start_sequence ();
2496 result = adjust_address (mem, mode, offset);
2497 seq = get_insns ();
2498 end_sequence ();
2499
2500 emit_insn_before (seq, insn);
2501 return result;
2502 }
2503
2504 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
2505 Replace subexpressions of X in place.
2506 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
2507 Otherwise return X, with its contents possibly altered.
2508
2509 INSN, PROMOTED_MODE and UNCRITICAL are as for
2510 fixup_memory_subreg. */
2511
2512 static rtx
2513 walk_fixup_memory_subreg (rtx x, rtx insn, enum machine_mode promoted_mode,
2514 int uncritical)
2515 {
2516 enum rtx_code code;
2517 const char *fmt;
2518 int i;
2519
2520 if (x == 0)
2521 return 0;
2522
2523 code = GET_CODE (x);
2524
2525 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
2526 return fixup_memory_subreg (x, insn, promoted_mode, uncritical);
2527
2528 /* Nothing special about this RTX; fix its operands. */
2529
2530 fmt = GET_RTX_FORMAT (code);
2531 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2532 {
2533 if (fmt[i] == 'e')
2534 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn,
2535 promoted_mode, uncritical);
2536 else if (fmt[i] == 'E')
2537 {
2538 int j;
2539 for (j = 0; j < XVECLEN (x, i); j++)
2540 XVECEXP (x, i, j)
2541 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn,
2542 promoted_mode, uncritical);
2543 }
2544 }
2545 return x;
2546 }
2547 \f
2548 /* For each memory ref within X, if it refers to a stack slot
2549 with an out of range displacement, put the address in a temp register
2550 (emitting new insns before INSN to load these registers)
2551 and alter the memory ref to use that register.
2552 Replace each such MEM rtx with a copy, to avoid clobberage. */
2553
2554 static rtx
2555 fixup_stack_1 (rtx x, rtx insn)
2556 {
2557 int i;
2558 RTX_CODE code = GET_CODE (x);
2559 const char *fmt;
2560
2561 if (code == MEM)
2562 {
2563 rtx ad = XEXP (x, 0);
2564 /* If we have address of a stack slot but it's not valid
2565 (displacement is too large), compute the sum in a register. */
2566 if (GET_CODE (ad) == PLUS
2567 && GET_CODE (XEXP (ad, 0)) == REG
2568 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2569 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2570 || REGNO (XEXP (ad, 0)) == FRAME_POINTER_REGNUM
2571 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2572 || REGNO (XEXP (ad, 0)) == HARD_FRAME_POINTER_REGNUM
2573 #endif
2574 || REGNO (XEXP (ad, 0)) == STACK_POINTER_REGNUM
2575 || REGNO (XEXP (ad, 0)) == ARG_POINTER_REGNUM
2576 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2577 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2578 {
2579 rtx temp, seq;
2580 if (memory_address_p (GET_MODE (x), ad))
2581 return x;
2582
2583 start_sequence ();
2584 temp = copy_to_reg (ad);
2585 seq = get_insns ();
2586 end_sequence ();
2587 emit_insn_before (seq, insn);
2588 return replace_equiv_address (x, temp);
2589 }
2590 return x;
2591 }
2592
2593 fmt = GET_RTX_FORMAT (code);
2594 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2595 {
2596 if (fmt[i] == 'e')
2597 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2598 else if (fmt[i] == 'E')
2599 {
2600 int j;
2601 for (j = 0; j < XVECLEN (x, i); j++)
2602 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2603 }
2604 }
2605 return x;
2606 }
2607 \f
2608 /* Optimization: a bit-field instruction whose field
2609 happens to be a byte or halfword in memory
2610 can be changed to a move instruction.
2611
2612 We call here when INSN is an insn to examine or store into a bit-field.
2613 BODY is the SET-rtx to be altered.
2614
2615 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2616 (Currently this is called only from function.c, and EQUIV_MEM
2617 is always 0.) */
2618
2619 static void
2620 optimize_bit_field (rtx body, rtx insn, rtx *equiv_mem)
2621 {
2622 rtx bitfield;
2623 int destflag;
2624 rtx seq = 0;
2625 enum machine_mode mode;
2626
2627 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2628 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2629 bitfield = SET_DEST (body), destflag = 1;
2630 else
2631 bitfield = SET_SRC (body), destflag = 0;
2632
2633 /* First check that the field being stored has constant size and position
2634 and is in fact a byte or halfword suitably aligned. */
2635
2636 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2637 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2638 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2639 != BLKmode)
2640 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2641 {
2642 rtx memref = 0;
2643
2644 /* Now check that the containing word is memory, not a register,
2645 and that it is safe to change the machine mode. */
2646
2647 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2648 memref = XEXP (bitfield, 0);
2649 else if (GET_CODE (XEXP (bitfield, 0)) == REG
2650 && equiv_mem != 0)
2651 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2652 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2653 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2654 memref = SUBREG_REG (XEXP (bitfield, 0));
2655 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2656 && equiv_mem != 0
2657 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
2658 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2659
2660 if (memref
2661 && ! mode_dependent_address_p (XEXP (memref, 0))
2662 && ! MEM_VOLATILE_P (memref))
2663 {
2664 /* Now adjust the address, first for any subreg'ing
2665 that we are now getting rid of,
2666 and then for which byte of the word is wanted. */
2667
2668 HOST_WIDE_INT offset = INTVAL (XEXP (bitfield, 2));
2669 rtx insns;
2670
2671 /* Adjust OFFSET to count bits from low-address byte. */
2672 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2673 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2674 - offset - INTVAL (XEXP (bitfield, 1)));
2675
2676 /* Adjust OFFSET to count bytes from low-address byte. */
2677 offset /= BITS_PER_UNIT;
2678 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2679 {
2680 offset += (SUBREG_BYTE (XEXP (bitfield, 0))
2681 / UNITS_PER_WORD) * UNITS_PER_WORD;
2682 if (BYTES_BIG_ENDIAN)
2683 offset -= (MIN (UNITS_PER_WORD,
2684 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2685 - MIN (UNITS_PER_WORD,
2686 GET_MODE_SIZE (GET_MODE (memref))));
2687 }
2688
2689 start_sequence ();
2690 memref = adjust_address (memref, mode, offset);
2691 insns = get_insns ();
2692 end_sequence ();
2693 emit_insn_before (insns, insn);
2694
2695 /* Store this memory reference where
2696 we found the bit field reference. */
2697
2698 if (destflag)
2699 {
2700 validate_change (insn, &SET_DEST (body), memref, 1);
2701 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2702 {
2703 rtx src = SET_SRC (body);
2704 while (GET_CODE (src) == SUBREG
2705 && SUBREG_BYTE (src) == 0)
2706 src = SUBREG_REG (src);
2707 if (GET_MODE (src) != GET_MODE (memref))
2708 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2709 validate_change (insn, &SET_SRC (body), src, 1);
2710 }
2711 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2712 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2713 /* This shouldn't happen because anything that didn't have
2714 one of these modes should have got converted explicitly
2715 and then referenced through a subreg.
2716 This is so because the original bit-field was
2717 handled by agg_mode and so its tree structure had
2718 the same mode that memref now has. */
2719 abort ();
2720 }
2721 else
2722 {
2723 rtx dest = SET_DEST (body);
2724
2725 while (GET_CODE (dest) == SUBREG
2726 && SUBREG_BYTE (dest) == 0
2727 && (GET_MODE_CLASS (GET_MODE (dest))
2728 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest))))
2729 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
2730 <= UNITS_PER_WORD))
2731 dest = SUBREG_REG (dest);
2732
2733 validate_change (insn, &SET_DEST (body), dest, 1);
2734
2735 if (GET_MODE (dest) == GET_MODE (memref))
2736 validate_change (insn, &SET_SRC (body), memref, 1);
2737 else
2738 {
2739 /* Convert the mem ref to the destination mode. */
2740 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2741
2742 start_sequence ();
2743 convert_move (newreg, memref,
2744 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2745 seq = get_insns ();
2746 end_sequence ();
2747
2748 validate_change (insn, &SET_SRC (body), newreg, 1);
2749 }
2750 }
2751
2752 /* See if we can convert this extraction or insertion into
2753 a simple move insn. We might not be able to do so if this
2754 was, for example, part of a PARALLEL.
2755
2756 If we succeed, write out any needed conversions. If we fail,
2757 it is hard to guess why we failed, so don't do anything
2758 special; just let the optimization be suppressed. */
2759
2760 if (apply_change_group () && seq)
2761 emit_insn_before (seq, insn);
2762 }
2763 }
2764 }
2765 \f
2766 /* These routines are responsible for converting virtual register references
2767 to the actual hard register references once RTL generation is complete.
2768
2769 The following four variables are used for communication between the
2770 routines. They contain the offsets of the virtual registers from their
2771 respective hard registers. */
2772
2773 static int in_arg_offset;
2774 static int var_offset;
2775 static int dynamic_offset;
2776 static int out_arg_offset;
2777 static int cfa_offset;
2778
2779 /* In most machines, the stack pointer register is equivalent to the bottom
2780 of the stack. */
2781
2782 #ifndef STACK_POINTER_OFFSET
2783 #define STACK_POINTER_OFFSET 0
2784 #endif
2785
2786 /* If not defined, pick an appropriate default for the offset of dynamically
2787 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2788 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2789
2790 #ifndef STACK_DYNAMIC_OFFSET
2791
2792 /* The bottom of the stack points to the actual arguments. If
2793 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2794 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2795 stack space for register parameters is not pushed by the caller, but
2796 rather part of the fixed stack areas and hence not included in
2797 `current_function_outgoing_args_size'. Nevertheless, we must allow
2798 for it when allocating stack dynamic objects. */
2799
2800 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2801 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2802 ((ACCUMULATE_OUTGOING_ARGS \
2803 ? (current_function_outgoing_args_size + REG_PARM_STACK_SPACE (FNDECL)) : 0)\
2804 + (STACK_POINTER_OFFSET)) \
2805
2806 #else
2807 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2808 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
2809 + (STACK_POINTER_OFFSET))
2810 #endif
2811 #endif
2812
2813 /* On most machines, the CFA coincides with the first incoming parm. */
2814
2815 #ifndef ARG_POINTER_CFA_OFFSET
2816 #define ARG_POINTER_CFA_OFFSET(FNDECL) FIRST_PARM_OFFSET (FNDECL)
2817 #endif
2818
2819 /* Build up a (MEM (ADDRESSOF (REG))) rtx for a register REG that just
2820 had its address taken. DECL is the decl or SAVE_EXPR for the
2821 object stored in the register, for later use if we do need to force
2822 REG into the stack. REG is overwritten by the MEM like in
2823 put_reg_into_stack. RESCAN is true if previously emitted
2824 instructions must be rescanned and modified now that the REG has
2825 been transformed. */
2826
2827 rtx
2828 gen_mem_addressof (rtx reg, tree decl, int rescan)
2829 {
2830 rtx r = gen_rtx_ADDRESSOF (Pmode, gen_reg_rtx (GET_MODE (reg)),
2831 REGNO (reg), decl);
2832
2833 /* Calculate this before we start messing with decl's RTL. */
2834 HOST_WIDE_INT set = decl ? get_alias_set (decl) : 0;
2835
2836 /* If the original REG was a user-variable, then so is the REG whose
2837 address is being taken. Likewise for unchanging. */
2838 REG_USERVAR_P (XEXP (r, 0)) = REG_USERVAR_P (reg);
2839 RTX_UNCHANGING_P (XEXP (r, 0)) = RTX_UNCHANGING_P (reg);
2840
2841 PUT_CODE (reg, MEM);
2842 MEM_ATTRS (reg) = 0;
2843 XEXP (reg, 0) = r;
2844
2845 if (decl)
2846 {
2847 tree type = TREE_TYPE (decl);
2848 enum machine_mode decl_mode
2849 = (DECL_P (decl) ? DECL_MODE (decl) : TYPE_MODE (TREE_TYPE (decl)));
2850 rtx decl_rtl = (TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl)
2851 : DECL_RTL_IF_SET (decl));
2852
2853 PUT_MODE (reg, decl_mode);
2854
2855 /* Clear DECL_RTL momentarily so functions below will work
2856 properly, then set it again. */
2857 if (DECL_P (decl) && decl_rtl == reg)
2858 SET_DECL_RTL (decl, 0);
2859
2860 set_mem_attributes (reg, decl, 1);
2861 set_mem_alias_set (reg, set);
2862
2863 if (DECL_P (decl) && decl_rtl == reg)
2864 SET_DECL_RTL (decl, reg);
2865
2866 if (rescan
2867 && (TREE_USED (decl) || (DECL_P (decl) && DECL_INITIAL (decl) != 0)))
2868 fixup_var_refs (reg, GET_MODE (reg), TREE_UNSIGNED (type), reg, 0);
2869 }
2870 else if (rescan)
2871 {
2872 /* This can only happen during reload. Clear the same flag bits as
2873 reload. */
2874 MEM_VOLATILE_P (reg) = 0;
2875 RTX_UNCHANGING_P (reg) = 0;
2876 MEM_IN_STRUCT_P (reg) = 0;
2877 MEM_SCALAR_P (reg) = 0;
2878 MEM_ATTRS (reg) = 0;
2879
2880 fixup_var_refs (reg, GET_MODE (reg), 0, reg, 0);
2881 }
2882
2883 return reg;
2884 }
2885
2886 /* If DECL has an RTL that is an ADDRESSOF rtx, put it into the stack. */
2887
2888 void
2889 flush_addressof (tree decl)
2890 {
2891 if ((TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL)
2892 && DECL_RTL (decl) != 0
2893 && GET_CODE (DECL_RTL (decl)) == MEM
2894 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF
2895 && GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == REG)
2896 put_addressof_into_stack (XEXP (DECL_RTL (decl), 0), 0);
2897 }
2898
2899 /* Force the register pointed to by R, an ADDRESSOF rtx, into the stack. */
2900
2901 static void
2902 put_addressof_into_stack (rtx r, htab_t ht)
2903 {
2904 tree decl, type;
2905 int volatile_p, used_p;
2906
2907 rtx reg = XEXP (r, 0);
2908
2909 if (GET_CODE (reg) != REG)
2910 abort ();
2911
2912 decl = ADDRESSOF_DECL (r);
2913 if (decl)
2914 {
2915 type = TREE_TYPE (decl);
2916 volatile_p = (TREE_CODE (decl) != SAVE_EXPR
2917 && TREE_THIS_VOLATILE (decl));
2918 used_p = (TREE_USED (decl)
2919 || (DECL_P (decl) && DECL_INITIAL (decl) != 0));
2920 }
2921 else
2922 {
2923 type = NULL_TREE;
2924 volatile_p = 0;
2925 used_p = 1;
2926 }
2927
2928 put_reg_into_stack (0, reg, type, GET_MODE (reg), GET_MODE (reg),
2929 volatile_p, ADDRESSOF_REGNO (r), used_p, ht);
2930 }
2931
2932 /* List of replacements made below in purge_addressof_1 when creating
2933 bitfield insertions. */
2934 static rtx purge_bitfield_addressof_replacements;
2935
2936 /* List of replacements made below in purge_addressof_1 for patterns
2937 (MEM (ADDRESSOF (REG ...))). The key of the list entry is the
2938 corresponding (ADDRESSOF (REG ...)) and value is a substitution for
2939 the all pattern. List PURGE_BITFIELD_ADDRESSOF_REPLACEMENTS is not
2940 enough in complex cases, e.g. when some field values can be
2941 extracted by usage MEM with narrower mode. */
2942 static rtx purge_addressof_replacements;
2943
2944 /* Helper function for purge_addressof. See if the rtx expression at *LOC
2945 in INSN needs to be changed. If FORCE, always put any ADDRESSOFs into
2946 the stack. If the function returns FALSE then the replacement could not
2947 be made. If MAY_POSTPONE is true and we would not put the addressof
2948 to stack, postpone processing of the insn. */
2949
2950 static bool
2951 purge_addressof_1 (rtx *loc, rtx insn, int force, int store, int may_postpone,
2952 htab_t ht)
2953 {
2954 rtx x;
2955 RTX_CODE code;
2956 int i, j;
2957 const char *fmt;
2958 bool result = true;
2959 bool libcall = false;
2960
2961 /* Re-start here to avoid recursion in common cases. */
2962 restart:
2963
2964 x = *loc;
2965 if (x == 0)
2966 return true;
2967
2968 /* Is this a libcall? */
2969 if (!insn)
2970 libcall = REG_NOTE_KIND (*loc) == REG_RETVAL;
2971
2972 code = GET_CODE (x);
2973
2974 /* If we don't return in any of the cases below, we will recurse inside
2975 the RTX, which will normally result in any ADDRESSOF being forced into
2976 memory. */
2977 if (code == SET)
2978 {
2979 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1,
2980 may_postpone, ht);
2981 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0,
2982 may_postpone, ht);
2983 return result;
2984 }
2985 else if (code == ADDRESSOF)
2986 {
2987 rtx sub, insns;
2988
2989 if (GET_CODE (XEXP (x, 0)) != MEM)
2990 put_addressof_into_stack (x, ht);
2991
2992 /* We must create a copy of the rtx because it was created by
2993 overwriting a REG rtx which is always shared. */
2994 sub = copy_rtx (XEXP (XEXP (x, 0), 0));
2995 if (validate_change (insn, loc, sub, 0)
2996 || validate_replace_rtx (x, sub, insn))
2997 return true;
2998
2999 start_sequence ();
3000
3001 /* If SUB is a hard or virtual register, try it as a pseudo-register.
3002 Otherwise, perhaps SUB is an expression, so generate code to compute
3003 it. */
3004 if (GET_CODE (sub) == REG && REGNO (sub) <= LAST_VIRTUAL_REGISTER)
3005 sub = copy_to_reg (sub);
3006 else
3007 sub = force_operand (sub, NULL_RTX);
3008
3009 if (! validate_change (insn, loc, sub, 0)
3010 && ! validate_replace_rtx (x, sub, insn))
3011 abort ();
3012
3013 insns = get_insns ();
3014 end_sequence ();
3015 emit_insn_before (insns, insn);
3016 return true;
3017 }
3018
3019 else if (code == MEM && GET_CODE (XEXP (x, 0)) == ADDRESSOF && ! force)
3020 {
3021 rtx sub = XEXP (XEXP (x, 0), 0);
3022
3023 if (GET_CODE (sub) == MEM)
3024 sub = adjust_address_nv (sub, GET_MODE (x), 0);
3025 else if (GET_CODE (sub) == REG
3026 && (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode))
3027 ;
3028 else if (GET_CODE (sub) == REG && GET_MODE (x) != GET_MODE (sub))
3029 {
3030 int size_x, size_sub;
3031
3032 if (may_postpone)
3033 {
3034 /* Postpone for now, so that we do not emit bitfield arithmetics
3035 unless there is some benefit from it. */
3036 if (!postponed_insns || XEXP (postponed_insns, 0) != insn)
3037 postponed_insns = alloc_INSN_LIST (insn, postponed_insns);
3038 return true;
3039 }
3040
3041 if (!insn)
3042 {
3043 /* When processing REG_NOTES look at the list of
3044 replacements done on the insn to find the register that X
3045 was replaced by. */
3046 rtx tem;
3047
3048 for (tem = purge_bitfield_addressof_replacements;
3049 tem != NULL_RTX;
3050 tem = XEXP (XEXP (tem, 1), 1))
3051 if (rtx_equal_p (x, XEXP (tem, 0)))
3052 {
3053 *loc = XEXP (XEXP (tem, 1), 0);
3054 return true;
3055 }
3056
3057 /* See comment for purge_addressof_replacements. */
3058 for (tem = purge_addressof_replacements;
3059 tem != NULL_RTX;
3060 tem = XEXP (XEXP (tem, 1), 1))
3061 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3062 {
3063 rtx z = XEXP (XEXP (tem, 1), 0);
3064
3065 if (GET_MODE (x) == GET_MODE (z)
3066 || (GET_CODE (XEXP (XEXP (tem, 1), 0)) != REG
3067 && GET_CODE (XEXP (XEXP (tem, 1), 0)) != SUBREG))
3068 abort ();
3069
3070 /* It can happen that the note may speak of things
3071 in a wider (or just different) mode than the
3072 code did. This is especially true of
3073 REG_RETVAL. */
3074
3075 if (GET_CODE (z) == SUBREG && SUBREG_BYTE (z) == 0)
3076 z = SUBREG_REG (z);
3077
3078 if (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3079 && (GET_MODE_SIZE (GET_MODE (x))
3080 > GET_MODE_SIZE (GET_MODE (z))))
3081 {
3082 /* This can occur as a result in invalid
3083 pointer casts, e.g. float f; ...
3084 *(long long int *)&f.
3085 ??? We could emit a warning here, but
3086 without a line number that wouldn't be
3087 very helpful. */
3088 z = gen_rtx_SUBREG (GET_MODE (x), z, 0);
3089 }
3090 else
3091 z = gen_lowpart (GET_MODE (x), z);
3092
3093 *loc = z;
3094 return true;
3095 }
3096
3097 /* When we are processing the REG_NOTES of the last instruction
3098 of a libcall, there will be typically no replacements
3099 for that insn; the replacements happened before, piecemeal
3100 fashion. OTOH we are not interested in the details of
3101 this for the REG_EQUAL note, we want to know the big picture,
3102 which can be succinctly described with a simple SUBREG.
3103 Note that removing the REG_EQUAL note is not an option
3104 on the last insn of a libcall, so we must do a replacement. */
3105
3106 /* In compile/990107-1.c:7 compiled at -O1 -m1 for sh-elf,
3107 we got
3108 (mem:DI (addressof:SI (reg/v:DF 160) 159 0x401c8510)
3109 [0 S8 A32]), which can be expressed with a simple
3110 same-size subreg */
3111 if ((GET_MODE_SIZE (GET_MODE (x))
3112 <= GET_MODE_SIZE (GET_MODE (sub)))
3113 /* Again, invalid pointer casts (as in
3114 compile/990203-1.c) can require paradoxical
3115 subregs. */
3116 || (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3117 && (GET_MODE_SIZE (GET_MODE (x))
3118 > GET_MODE_SIZE (GET_MODE (sub)))
3119 && libcall))
3120 {
3121 *loc = gen_rtx_SUBREG (GET_MODE (x), sub, 0);
3122 return true;
3123 }
3124 /* ??? Are there other cases we should handle? */
3125
3126 /* Sometimes we may not be able to find the replacement. For
3127 example when the original insn was a MEM in a wider mode,
3128 and the note is part of a sign extension of a narrowed
3129 version of that MEM. Gcc testcase compile/990829-1.c can
3130 generate an example of this situation. Rather than complain
3131 we return false, which will prompt our caller to remove the
3132 offending note. */
3133 return false;
3134 }
3135
3136 size_x = GET_MODE_BITSIZE (GET_MODE (x));
3137 size_sub = GET_MODE_BITSIZE (GET_MODE (sub));
3138
3139 /* Do not frob unchanging MEMs. If a later reference forces the
3140 pseudo to the stack, we can wind up with multiple writes to
3141 an unchanging memory, which is invalid. */
3142 if (RTX_UNCHANGING_P (x) && size_x != size_sub)
3143 ;
3144
3145 /* Don't even consider working with paradoxical subregs,
3146 or the moral equivalent seen here. */
3147 else if (size_x <= size_sub
3148 && int_mode_for_mode (GET_MODE (sub)) != BLKmode)
3149 {
3150 /* Do a bitfield insertion to mirror what would happen
3151 in memory. */
3152
3153 rtx val, seq;
3154
3155 if (store)
3156 {
3157 rtx p = PREV_INSN (insn);
3158
3159 start_sequence ();
3160 val = gen_reg_rtx (GET_MODE (x));
3161 if (! validate_change (insn, loc, val, 0))
3162 {
3163 /* Discard the current sequence and put the
3164 ADDRESSOF on stack. */
3165 end_sequence ();
3166 goto give_up;
3167 }
3168 seq = get_insns ();
3169 end_sequence ();
3170 emit_insn_before (seq, insn);
3171 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3172 insn, ht);
3173
3174 start_sequence ();
3175 store_bit_field (sub, size_x, 0, GET_MODE (x),
3176 val, GET_MODE_SIZE (GET_MODE (sub)));
3177
3178 /* Make sure to unshare any shared rtl that store_bit_field
3179 might have created. */
3180 unshare_all_rtl_again (get_insns ());
3181
3182 seq = get_insns ();
3183 end_sequence ();
3184 p = emit_insn_after (seq, insn);
3185 if (NEXT_INSN (insn))
3186 compute_insns_for_mem (NEXT_INSN (insn),
3187 p ? NEXT_INSN (p) : NULL_RTX,
3188 ht);
3189 }
3190 else
3191 {
3192 rtx p = PREV_INSN (insn);
3193
3194 start_sequence ();
3195 val = extract_bit_field (sub, size_x, 0, 1, NULL_RTX,
3196 GET_MODE (x), GET_MODE (x),
3197 GET_MODE_SIZE (GET_MODE (sub)));
3198
3199 if (! validate_change (insn, loc, val, 0))
3200 {
3201 /* Discard the current sequence and put the
3202 ADDRESSOF on stack. */
3203 end_sequence ();
3204 goto give_up;
3205 }
3206
3207 seq = get_insns ();
3208 end_sequence ();
3209 emit_insn_before (seq, insn);
3210 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3211 insn, ht);
3212 }
3213
3214 /* Remember the replacement so that the same one can be done
3215 on the REG_NOTES. */
3216 purge_bitfield_addressof_replacements
3217 = gen_rtx_EXPR_LIST (VOIDmode, x,
3218 gen_rtx_EXPR_LIST
3219 (VOIDmode, val,
3220 purge_bitfield_addressof_replacements));
3221
3222 /* We replaced with a reg -- all done. */
3223 return true;
3224 }
3225 }
3226
3227 else if (validate_change (insn, loc, sub, 0))
3228 {
3229 /* Remember the replacement so that the same one can be done
3230 on the REG_NOTES. */
3231 if (GET_CODE (sub) == REG || GET_CODE (sub) == SUBREG)
3232 {
3233 rtx tem;
3234
3235 for (tem = purge_addressof_replacements;
3236 tem != NULL_RTX;
3237 tem = XEXP (XEXP (tem, 1), 1))
3238 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3239 {
3240 XEXP (XEXP (tem, 1), 0) = sub;
3241 return true;
3242 }
3243 purge_addressof_replacements
3244 = gen_rtx (EXPR_LIST, VOIDmode, XEXP (x, 0),
3245 gen_rtx_EXPR_LIST (VOIDmode, sub,
3246 purge_addressof_replacements));
3247 return true;
3248 }
3249 goto restart;
3250 }
3251 }
3252
3253 give_up:
3254 /* Scan all subexpressions. */
3255 fmt = GET_RTX_FORMAT (code);
3256 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3257 {
3258 if (*fmt == 'e')
3259 result &= purge_addressof_1 (&XEXP (x, i), insn, force, 0,
3260 may_postpone, ht);
3261 else if (*fmt == 'E')
3262 for (j = 0; j < XVECLEN (x, i); j++)
3263 result &= purge_addressof_1 (&XVECEXP (x, i, j), insn, force, 0,
3264 may_postpone, ht);
3265 }
3266
3267 return result;
3268 }
3269
3270 /* Return a hash value for K, a REG. */
3271
3272 static hashval_t
3273 insns_for_mem_hash (const void *k)
3274 {
3275 /* Use the address of the key for the hash value. */
3276 struct insns_for_mem_entry *m = (struct insns_for_mem_entry *) k;
3277 return htab_hash_pointer (m->key);
3278 }
3279
3280 /* Return nonzero if K1 and K2 (two REGs) are the same. */
3281
3282 static int
3283 insns_for_mem_comp (const void *k1, const void *k2)
3284 {
3285 struct insns_for_mem_entry *m1 = (struct insns_for_mem_entry *) k1;
3286 struct insns_for_mem_entry *m2 = (struct insns_for_mem_entry *) k2;
3287 return m1->key == m2->key;
3288 }
3289
3290 struct insns_for_mem_walk_info
3291 {
3292 /* The hash table that we are using to record which INSNs use which
3293 MEMs. */
3294 htab_t ht;
3295
3296 /* The INSN we are currently processing. */
3297 rtx insn;
3298
3299 /* Zero if we are walking to find ADDRESSOFs, one if we are walking
3300 to find the insns that use the REGs in the ADDRESSOFs. */
3301 int pass;
3302 };
3303
3304 /* Called from compute_insns_for_mem via for_each_rtx. If R is a REG
3305 that might be used in an ADDRESSOF expression, record this INSN in
3306 the hash table given by DATA (which is really a pointer to an
3307 insns_for_mem_walk_info structure). */
3308
3309 static int
3310 insns_for_mem_walk (rtx *r, void *data)
3311 {
3312 struct insns_for_mem_walk_info *ifmwi
3313 = (struct insns_for_mem_walk_info *) data;
3314 struct insns_for_mem_entry tmp;
3315 tmp.insns = NULL_RTX;
3316
3317 if (ifmwi->pass == 0 && *r && GET_CODE (*r) == ADDRESSOF
3318 && GET_CODE (XEXP (*r, 0)) == REG)
3319 {
3320 void **e;
3321 tmp.key = XEXP (*r, 0);
3322 e = htab_find_slot (ifmwi->ht, &tmp, INSERT);
3323 if (*e == NULL)
3324 {
3325 *e = ggc_alloc (sizeof (tmp));
3326 memcpy (*e, &tmp, sizeof (tmp));
3327 }
3328 }
3329 else if (ifmwi->pass == 1 && *r && GET_CODE (*r) == REG)
3330 {
3331 struct insns_for_mem_entry *ifme;
3332 tmp.key = *r;
3333 ifme = htab_find (ifmwi->ht, &tmp);
3334
3335 /* If we have not already recorded this INSN, do so now. Since
3336 we process the INSNs in order, we know that if we have
3337 recorded it it must be at the front of the list. */
3338 if (ifme && (!ifme->insns || XEXP (ifme->insns, 0) != ifmwi->insn))
3339 ifme->insns = gen_rtx_EXPR_LIST (VOIDmode, ifmwi->insn,
3340 ifme->insns);
3341 }
3342
3343 return 0;
3344 }
3345
3346 /* Walk the INSNS, until we reach LAST_INSN, recording which INSNs use
3347 which REGs in HT. */
3348
3349 static void
3350 compute_insns_for_mem (rtx insns, rtx last_insn, htab_t ht)
3351 {
3352 rtx insn;
3353 struct insns_for_mem_walk_info ifmwi;
3354 ifmwi.ht = ht;
3355
3356 for (ifmwi.pass = 0; ifmwi.pass < 2; ++ifmwi.pass)
3357 for (insn = insns; insn != last_insn; insn = NEXT_INSN (insn))
3358 if (INSN_P (insn))
3359 {
3360 ifmwi.insn = insn;
3361 for_each_rtx (&insn, insns_for_mem_walk, &ifmwi);
3362 }
3363 }
3364
3365 /* Helper function for purge_addressof called through for_each_rtx.
3366 Returns true iff the rtl is an ADDRESSOF. */
3367
3368 static int
3369 is_addressof (rtx *rtl, void *data ATTRIBUTE_UNUSED)
3370 {
3371 return GET_CODE (*rtl) == ADDRESSOF;
3372 }
3373
3374 /* Eliminate all occurrences of ADDRESSOF from INSNS. Elide any remaining
3375 (MEM (ADDRESSOF)) patterns, and force any needed registers into the
3376 stack. */
3377
3378 void
3379 purge_addressof (rtx insns)
3380 {
3381 rtx insn, tmp;
3382 htab_t ht;
3383
3384 /* When we actually purge ADDRESSOFs, we turn REGs into MEMs. That
3385 requires a fixup pass over the instruction stream to correct
3386 INSNs that depended on the REG being a REG, and not a MEM. But,
3387 these fixup passes are slow. Furthermore, most MEMs are not
3388 mentioned in very many instructions. So, we speed up the process
3389 by pre-calculating which REGs occur in which INSNs; that allows
3390 us to perform the fixup passes much more quickly. */
3391 ht = htab_create_ggc (1000, insns_for_mem_hash, insns_for_mem_comp, NULL);
3392 compute_insns_for_mem (insns, NULL_RTX, ht);
3393
3394 postponed_insns = NULL;
3395
3396 for (insn = insns; insn; insn = NEXT_INSN (insn))
3397 if (INSN_P (insn))
3398 {
3399 if (! purge_addressof_1 (&PATTERN (insn), insn,
3400 asm_noperands (PATTERN (insn)) > 0, 0, 1, ht))
3401 /* If we could not replace the ADDRESSOFs in the insn,
3402 something is wrong. */
3403 abort ();
3404
3405 if (! purge_addressof_1 (&REG_NOTES (insn), NULL_RTX, 0, 0, 0, ht))
3406 {
3407 /* If we could not replace the ADDRESSOFs in the insn's notes,
3408 we can just remove the offending notes instead. */
3409 rtx note;
3410
3411 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
3412 {
3413 /* If we find a REG_RETVAL note then the insn is a libcall.
3414 Such insns must have REG_EQUAL notes as well, in order
3415 for later passes of the compiler to work. So it is not
3416 safe to delete the notes here, and instead we abort. */
3417 if (REG_NOTE_KIND (note) == REG_RETVAL)
3418 abort ();
3419 if (for_each_rtx (&note, is_addressof, NULL))
3420 remove_note (insn, note);
3421 }
3422 }
3423 }
3424
3425 /* Process the postponed insns. */
3426 while (postponed_insns)
3427 {
3428 insn = XEXP (postponed_insns, 0);
3429 tmp = postponed_insns;
3430 postponed_insns = XEXP (postponed_insns, 1);
3431 free_INSN_LIST_node (tmp);
3432
3433 if (! purge_addressof_1 (&PATTERN (insn), insn,
3434 asm_noperands (PATTERN (insn)) > 0, 0, 0, ht))
3435 abort ();
3436 }
3437
3438 /* Clean up. */
3439 purge_bitfield_addressof_replacements = 0;
3440 purge_addressof_replacements = 0;
3441
3442 /* REGs are shared. purge_addressof will destructively replace a REG
3443 with a MEM, which creates shared MEMs.
3444
3445 Unfortunately, the children of put_reg_into_stack assume that MEMs
3446 referring to the same stack slot are shared (fixup_var_refs and
3447 the associated hash table code).
3448
3449 So, we have to do another unsharing pass after we have flushed any
3450 REGs that had their address taken into the stack.
3451
3452 It may be worth tracking whether or not we converted any REGs into
3453 MEMs to avoid this overhead when it is not needed. */
3454 unshare_all_rtl_again (get_insns ());
3455 }
3456 \f
3457 /* Convert a SET of a hard subreg to a set of the appropriate hard
3458 register. A subroutine of purge_hard_subreg_sets. */
3459
3460 static void
3461 purge_single_hard_subreg_set (rtx pattern)
3462 {
3463 rtx reg = SET_DEST (pattern);
3464 enum machine_mode mode = GET_MODE (SET_DEST (pattern));
3465 int offset = 0;
3466
3467 if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG
3468 && REGNO (SUBREG_REG (reg)) < FIRST_PSEUDO_REGISTER)
3469 {
3470 offset = subreg_regno_offset (REGNO (SUBREG_REG (reg)),
3471 GET_MODE (SUBREG_REG (reg)),
3472 SUBREG_BYTE (reg),
3473 GET_MODE (reg));
3474 reg = SUBREG_REG (reg);
3475 }
3476
3477
3478 if (GET_CODE (reg) == REG && REGNO (reg) < FIRST_PSEUDO_REGISTER)
3479 {
3480 reg = gen_rtx_REG (mode, REGNO (reg) + offset);
3481 SET_DEST (pattern) = reg;
3482 }
3483 }
3484
3485 /* Eliminate all occurrences of SETs of hard subregs from INSNS. The
3486 only such SETs that we expect to see are those left in because
3487 integrate can't handle sets of parts of a return value register.
3488
3489 We don't use alter_subreg because we only want to eliminate subregs
3490 of hard registers. */
3491
3492 void
3493 purge_hard_subreg_sets (rtx insn)
3494 {
3495 for (; insn; insn = NEXT_INSN (insn))
3496 {
3497 if (INSN_P (insn))
3498 {
3499 rtx pattern = PATTERN (insn);
3500 switch (GET_CODE (pattern))
3501 {
3502 case SET:
3503 if (GET_CODE (SET_DEST (pattern)) == SUBREG)
3504 purge_single_hard_subreg_set (pattern);
3505 break;
3506 case PARALLEL:
3507 {
3508 int j;
3509 for (j = XVECLEN (pattern, 0) - 1; j >= 0; j--)
3510 {
3511 rtx inner_pattern = XVECEXP (pattern, 0, j);
3512 if (GET_CODE (inner_pattern) == SET
3513 && GET_CODE (SET_DEST (inner_pattern)) == SUBREG)
3514 purge_single_hard_subreg_set (inner_pattern);
3515 }
3516 }
3517 break;
3518 default:
3519 break;
3520 }
3521 }
3522 }
3523 }
3524 \f
3525 /* Pass through the INSNS of function FNDECL and convert virtual register
3526 references to hard register references. */
3527
3528 void
3529 instantiate_virtual_regs (tree fndecl, rtx insns)
3530 {
3531 rtx insn;
3532 unsigned int i;
3533
3534 /* Compute the offsets to use for this function. */
3535 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
3536 var_offset = STARTING_FRAME_OFFSET;
3537 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
3538 out_arg_offset = STACK_POINTER_OFFSET;
3539 cfa_offset = ARG_POINTER_CFA_OFFSET (fndecl);
3540
3541 /* Scan all variables and parameters of this function. For each that is
3542 in memory, instantiate all virtual registers if the result is a valid
3543 address. If not, we do it later. That will handle most uses of virtual
3544 regs on many machines. */
3545 instantiate_decls (fndecl, 1);
3546
3547 /* Initialize recognition, indicating that volatile is OK. */
3548 init_recog ();
3549
3550 /* Scan through all the insns, instantiating every virtual register still
3551 present. */
3552 for (insn = insns; insn; insn = NEXT_INSN (insn))
3553 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3554 || GET_CODE (insn) == CALL_INSN)
3555 {
3556 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
3557 if (INSN_DELETED_P (insn))
3558 continue;
3559 instantiate_virtual_regs_1 (&REG_NOTES (insn), NULL_RTX, 0);
3560 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
3561 if (GET_CODE (insn) == CALL_INSN)
3562 instantiate_virtual_regs_1 (&CALL_INSN_FUNCTION_USAGE (insn),
3563 NULL_RTX, 0);
3564
3565 /* Past this point all ASM statements should match. Verify that
3566 to avoid failures later in the compilation process. */
3567 if (asm_noperands (PATTERN (insn)) >= 0
3568 && ! check_asm_operands (PATTERN (insn)))
3569 instantiate_virtual_regs_lossage (insn);
3570 }
3571
3572 /* Instantiate the stack slots for the parm registers, for later use in
3573 addressof elimination. */
3574 for (i = 0; i < max_parm_reg; ++i)
3575 if (parm_reg_stack_loc[i])
3576 instantiate_virtual_regs_1 (&parm_reg_stack_loc[i], NULL_RTX, 0);
3577
3578 /* Now instantiate the remaining register equivalences for debugging info.
3579 These will not be valid addresses. */
3580 instantiate_decls (fndecl, 0);
3581
3582 /* Indicate that, from now on, assign_stack_local should use
3583 frame_pointer_rtx. */
3584 virtuals_instantiated = 1;
3585 }
3586
3587 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
3588 all virtual registers in their DECL_RTL's.
3589
3590 If VALID_ONLY, do this only if the resulting address is still valid.
3591 Otherwise, always do it. */
3592
3593 static void
3594 instantiate_decls (tree fndecl, int valid_only)
3595 {
3596 tree decl;
3597
3598 /* Process all parameters of the function. */
3599 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
3600 {
3601 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));
3602 HOST_WIDE_INT size_rtl;
3603
3604 instantiate_decl (DECL_RTL (decl), size, valid_only);
3605
3606 /* If the parameter was promoted, then the incoming RTL mode may be
3607 larger than the declared type size. We must use the larger of
3608 the two sizes. */
3609 size_rtl = GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl)));
3610 size = MAX (size_rtl, size);
3611 instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
3612 }
3613
3614 /* Now process all variables defined in the function or its subblocks. */
3615 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
3616 }
3617
3618 /* Subroutine of instantiate_decls: Process all decls in the given
3619 BLOCK node and all its subblocks. */
3620
3621 static void
3622 instantiate_decls_1 (tree let, int valid_only)
3623 {
3624 tree t;
3625
3626 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
3627 if (DECL_RTL_SET_P (t))
3628 instantiate_decl (DECL_RTL (t),
3629 int_size_in_bytes (TREE_TYPE (t)),
3630 valid_only);
3631
3632 /* Process all subblocks. */
3633 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
3634 instantiate_decls_1 (t, valid_only);
3635 }
3636
3637 /* Subroutine of the preceding procedures: Given RTL representing a
3638 decl and the size of the object, do any instantiation required.
3639
3640 If VALID_ONLY is nonzero, it means that the RTL should only be
3641 changed if the new address is valid. */
3642
3643 static void
3644 instantiate_decl (rtx x, HOST_WIDE_INT size, int valid_only)
3645 {
3646 enum machine_mode mode;
3647 rtx addr;
3648
3649 /* If this is not a MEM, no need to do anything. Similarly if the
3650 address is a constant or a register that is not a virtual register. */
3651
3652 if (x == 0 || GET_CODE (x) != MEM)
3653 return;
3654
3655 addr = XEXP (x, 0);
3656 if (CONSTANT_P (addr)
3657 || (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == REG)
3658 || (GET_CODE (addr) == REG
3659 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
3660 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
3661 return;
3662
3663 /* If we should only do this if the address is valid, copy the address.
3664 We need to do this so we can undo any changes that might make the
3665 address invalid. This copy is unfortunate, but probably can't be
3666 avoided. */
3667
3668 if (valid_only)
3669 addr = copy_rtx (addr);
3670
3671 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
3672
3673 if (valid_only && size >= 0)
3674 {
3675 unsigned HOST_WIDE_INT decl_size = size;
3676
3677 /* Now verify that the resulting address is valid for every integer or
3678 floating-point mode up to and including SIZE bytes long. We do this
3679 since the object might be accessed in any mode and frame addresses
3680 are shared. */
3681
3682 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3683 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3684 mode = GET_MODE_WIDER_MODE (mode))
3685 if (! memory_address_p (mode, addr))
3686 return;
3687
3688 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
3689 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3690 mode = GET_MODE_WIDER_MODE (mode))
3691 if (! memory_address_p (mode, addr))
3692 return;
3693 }
3694
3695 /* Put back the address now that we have updated it and we either know
3696 it is valid or we don't care whether it is valid. */
3697
3698 XEXP (x, 0) = addr;
3699 }
3700 \f
3701 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
3702 is a virtual register, return the equivalent hard register and set the
3703 offset indirectly through the pointer. Otherwise, return 0. */
3704
3705 static rtx
3706 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
3707 {
3708 rtx new;
3709 HOST_WIDE_INT offset;
3710
3711 if (x == virtual_incoming_args_rtx)
3712 new = arg_pointer_rtx, offset = in_arg_offset;
3713 else if (x == virtual_stack_vars_rtx)
3714 new = frame_pointer_rtx, offset = var_offset;
3715 else if (x == virtual_stack_dynamic_rtx)
3716 new = stack_pointer_rtx, offset = dynamic_offset;
3717 else if (x == virtual_outgoing_args_rtx)
3718 new = stack_pointer_rtx, offset = out_arg_offset;
3719 else if (x == virtual_cfa_rtx)
3720 new = arg_pointer_rtx, offset = cfa_offset;
3721 else
3722 return 0;
3723
3724 *poffset = offset;
3725 return new;
3726 }
3727 \f
3728
3729 /* Called when instantiate_virtual_regs has failed to update the instruction.
3730 Usually this means that non-matching instruction has been emit, however for
3731 asm statements it may be the problem in the constraints. */
3732 static void
3733 instantiate_virtual_regs_lossage (rtx insn)
3734 {
3735 if (asm_noperands (PATTERN (insn)) >= 0)
3736 {
3737 error_for_asm (insn, "impossible constraint in `asm'");
3738 delete_insn (insn);
3739 }
3740 else
3741 abort ();
3742 }
3743 /* Given a pointer to a piece of rtx and an optional pointer to the
3744 containing object, instantiate any virtual registers present in it.
3745
3746 If EXTRA_INSNS, we always do the replacement and generate
3747 any extra insns before OBJECT. If it zero, we do nothing if replacement
3748 is not valid.
3749
3750 Return 1 if we either had nothing to do or if we were able to do the
3751 needed replacement. Return 0 otherwise; we only return zero if
3752 EXTRA_INSNS is zero.
3753
3754 We first try some simple transformations to avoid the creation of extra
3755 pseudos. */
3756
3757 static int
3758 instantiate_virtual_regs_1 (rtx *loc, rtx object, int extra_insns)
3759 {
3760 rtx x;
3761 RTX_CODE code;
3762 rtx new = 0;
3763 HOST_WIDE_INT offset = 0;
3764 rtx temp;
3765 rtx seq;
3766 int i, j;
3767 const char *fmt;
3768
3769 /* Re-start here to avoid recursion in common cases. */
3770 restart:
3771
3772 x = *loc;
3773 if (x == 0)
3774 return 1;
3775
3776 /* We may have detected and deleted invalid asm statements. */
3777 if (object && INSN_P (object) && INSN_DELETED_P (object))
3778 return 1;
3779
3780 code = GET_CODE (x);
3781
3782 /* Check for some special cases. */
3783 switch (code)
3784 {
3785 case CONST_INT:
3786 case CONST_DOUBLE:
3787 case CONST_VECTOR:
3788 case CONST:
3789 case SYMBOL_REF:
3790 case CODE_LABEL:
3791 case PC:
3792 case CC0:
3793 case ASM_INPUT:
3794 case ADDR_VEC:
3795 case ADDR_DIFF_VEC:
3796 case RETURN:
3797 return 1;
3798
3799 case SET:
3800 /* We are allowed to set the virtual registers. This means that
3801 the actual register should receive the source minus the
3802 appropriate offset. This is used, for example, in the handling
3803 of non-local gotos. */
3804 if ((new = instantiate_new_reg (SET_DEST (x), &offset)) != 0)
3805 {
3806 rtx src = SET_SRC (x);
3807
3808 /* We are setting the register, not using it, so the relevant
3809 offset is the negative of the offset to use were we using
3810 the register. */
3811 offset = - offset;
3812 instantiate_virtual_regs_1 (&src, NULL_RTX, 0);
3813
3814 /* The only valid sources here are PLUS or REG. Just do
3815 the simplest possible thing to handle them. */
3816 if (GET_CODE (src) != REG && GET_CODE (src) != PLUS)
3817 {
3818 instantiate_virtual_regs_lossage (object);
3819 return 1;
3820 }
3821
3822 start_sequence ();
3823 if (GET_CODE (src) != REG)
3824 temp = force_operand (src, NULL_RTX);
3825 else
3826 temp = src;
3827 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
3828 seq = get_insns ();
3829 end_sequence ();
3830
3831 emit_insn_before (seq, object);
3832 SET_DEST (x) = new;
3833
3834 if (! validate_change (object, &SET_SRC (x), temp, 0)
3835 || ! extra_insns)
3836 instantiate_virtual_regs_lossage (object);
3837
3838 return 1;
3839 }
3840
3841 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
3842 loc = &SET_SRC (x);
3843 goto restart;
3844
3845 case PLUS:
3846 /* Handle special case of virtual register plus constant. */
3847 if (CONSTANT_P (XEXP (x, 1)))
3848 {
3849 rtx old, new_offset;
3850
3851 /* Check for (plus (plus VIRT foo) (const_int)) first. */
3852 if (GET_CODE (XEXP (x, 0)) == PLUS)
3853 {
3854 if ((new = instantiate_new_reg (XEXP (XEXP (x, 0), 0), &offset)))
3855 {
3856 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
3857 extra_insns);
3858 new = gen_rtx_PLUS (Pmode, new, XEXP (XEXP (x, 0), 1));
3859 }
3860 else
3861 {
3862 loc = &XEXP (x, 0);
3863 goto restart;
3864 }
3865 }
3866
3867 #ifdef POINTERS_EXTEND_UNSIGNED
3868 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
3869 we can commute the PLUS and SUBREG because pointers into the
3870 frame are well-behaved. */
3871 else if (GET_CODE (XEXP (x, 0)) == SUBREG && GET_MODE (x) == ptr_mode
3872 && GET_CODE (XEXP (x, 1)) == CONST_INT
3873 && 0 != (new
3874 = instantiate_new_reg (SUBREG_REG (XEXP (x, 0)),
3875 &offset))
3876 && validate_change (object, loc,
3877 plus_constant (gen_lowpart (ptr_mode,
3878 new),
3879 offset
3880 + INTVAL (XEXP (x, 1))),
3881 0))
3882 return 1;
3883 #endif
3884 else if ((new = instantiate_new_reg (XEXP (x, 0), &offset)) == 0)
3885 {
3886 /* We know the second operand is a constant. Unless the
3887 first operand is a REG (which has been already checked),
3888 it needs to be checked. */
3889 if (GET_CODE (XEXP (x, 0)) != REG)
3890 {
3891 loc = &XEXP (x, 0);
3892 goto restart;
3893 }
3894 return 1;
3895 }
3896
3897 new_offset = plus_constant (XEXP (x, 1), offset);
3898
3899 /* If the new constant is zero, try to replace the sum with just
3900 the register. */
3901 if (new_offset == const0_rtx
3902 && validate_change (object, loc, new, 0))
3903 return 1;
3904
3905 /* Next try to replace the register and new offset.
3906 There are two changes to validate here and we can't assume that
3907 in the case of old offset equals new just changing the register
3908 will yield a valid insn. In the interests of a little efficiency,
3909 however, we only call validate change once (we don't queue up the
3910 changes and then call apply_change_group). */
3911
3912 old = XEXP (x, 0);
3913 if (offset == 0
3914 ? ! validate_change (object, &XEXP (x, 0), new, 0)
3915 : (XEXP (x, 0) = new,
3916 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
3917 {
3918 if (! extra_insns)
3919 {
3920 XEXP (x, 0) = old;
3921 return 0;
3922 }
3923
3924 /* Otherwise copy the new constant into a register and replace
3925 constant with that register. */
3926 temp = gen_reg_rtx (Pmode);
3927 XEXP (x, 0) = new;
3928 if (validate_change (object, &XEXP (x, 1), temp, 0))
3929 emit_insn_before (gen_move_insn (temp, new_offset), object);
3930 else
3931 {
3932 /* If that didn't work, replace this expression with a
3933 register containing the sum. */
3934
3935 XEXP (x, 0) = old;
3936 new = gen_rtx_PLUS (Pmode, new, new_offset);
3937
3938 start_sequence ();
3939 temp = force_operand (new, NULL_RTX);
3940 seq = get_insns ();
3941 end_sequence ();
3942
3943 emit_insn_before (seq, object);
3944 if (! validate_change (object, loc, temp, 0)
3945 && ! validate_replace_rtx (x, temp, object))
3946 {
3947 instantiate_virtual_regs_lossage (object);
3948 return 1;
3949 }
3950 }
3951 }
3952
3953 return 1;
3954 }
3955
3956 /* Fall through to generic two-operand expression case. */
3957 case EXPR_LIST:
3958 case CALL:
3959 case COMPARE:
3960 case MINUS:
3961 case MULT:
3962 case DIV: case UDIV:
3963 case MOD: case UMOD:
3964 case AND: case IOR: case XOR:
3965 case ROTATERT: case ROTATE:
3966 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
3967 case NE: case EQ:
3968 case GE: case GT: case GEU: case GTU:
3969 case LE: case LT: case LEU: case LTU:
3970 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
3971 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
3972 loc = &XEXP (x, 0);
3973 goto restart;
3974
3975 case MEM:
3976 /* Most cases of MEM that convert to valid addresses have already been
3977 handled by our scan of decls. The only special handling we
3978 need here is to make a copy of the rtx to ensure it isn't being
3979 shared if we have to change it to a pseudo.
3980
3981 If the rtx is a simple reference to an address via a virtual register,
3982 it can potentially be shared. In such cases, first try to make it
3983 a valid address, which can also be shared. Otherwise, copy it and
3984 proceed normally.
3985
3986 First check for common cases that need no processing. These are
3987 usually due to instantiation already being done on a previous instance
3988 of a shared rtx. */
3989
3990 temp = XEXP (x, 0);
3991 if (CONSTANT_ADDRESS_P (temp)
3992 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3993 || temp == arg_pointer_rtx
3994 #endif
3995 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
3996 || temp == hard_frame_pointer_rtx
3997 #endif
3998 || temp == frame_pointer_rtx)
3999 return 1;
4000
4001 if (GET_CODE (temp) == PLUS
4002 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4003 && (XEXP (temp, 0) == frame_pointer_rtx
4004 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4005 || XEXP (temp, 0) == hard_frame_pointer_rtx
4006 #endif
4007 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4008 || XEXP (temp, 0) == arg_pointer_rtx
4009 #endif
4010 ))
4011 return 1;
4012
4013 if (temp == virtual_stack_vars_rtx
4014 || temp == virtual_incoming_args_rtx
4015 || (GET_CODE (temp) == PLUS
4016 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4017 && (XEXP (temp, 0) == virtual_stack_vars_rtx
4018 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
4019 {
4020 /* This MEM may be shared. If the substitution can be done without
4021 the need to generate new pseudos, we want to do it in place
4022 so all copies of the shared rtx benefit. The call below will
4023 only make substitutions if the resulting address is still
4024 valid.
4025
4026 Note that we cannot pass X as the object in the recursive call
4027 since the insn being processed may not allow all valid
4028 addresses. However, if we were not passed on object, we can
4029 only modify X without copying it if X will have a valid
4030 address.
4031
4032 ??? Also note that this can still lose if OBJECT is an insn that
4033 has less restrictions on an address that some other insn.
4034 In that case, we will modify the shared address. This case
4035 doesn't seem very likely, though. One case where this could
4036 happen is in the case of a USE or CLOBBER reference, but we
4037 take care of that below. */
4038
4039 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
4040 object ? object : x, 0))
4041 return 1;
4042
4043 /* Otherwise make a copy and process that copy. We copy the entire
4044 RTL expression since it might be a PLUS which could also be
4045 shared. */
4046 *loc = x = copy_rtx (x);
4047 }
4048
4049 /* Fall through to generic unary operation case. */
4050 case PREFETCH:
4051 case SUBREG:
4052 case STRICT_LOW_PART:
4053 case NEG: case NOT:
4054 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
4055 case SIGN_EXTEND: case ZERO_EXTEND:
4056 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
4057 case FLOAT: case FIX:
4058 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
4059 case ABS:
4060 case SQRT:
4061 case FFS:
4062 case CLZ: case CTZ:
4063 case POPCOUNT: case PARITY:
4064 /* These case either have just one operand or we know that we need not
4065 check the rest of the operands. */
4066 loc = &XEXP (x, 0);
4067 goto restart;
4068
4069 case USE:
4070 case CLOBBER:
4071 /* If the operand is a MEM, see if the change is a valid MEM. If not,
4072 go ahead and make the invalid one, but do it to a copy. For a REG,
4073 just make the recursive call, since there's no chance of a problem. */
4074
4075 if ((GET_CODE (XEXP (x, 0)) == MEM
4076 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
4077 0))
4078 || (GET_CODE (XEXP (x, 0)) == REG
4079 && instantiate_virtual_regs_1 (&XEXP (x, 0), object, 0)))
4080 return 1;
4081
4082 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
4083 loc = &XEXP (x, 0);
4084 goto restart;
4085
4086 case REG:
4087 /* Try to replace with a PLUS. If that doesn't work, compute the sum
4088 in front of this insn and substitute the temporary. */
4089 if ((new = instantiate_new_reg (x, &offset)) != 0)
4090 {
4091 temp = plus_constant (new, offset);
4092 if (!validate_change (object, loc, temp, 0))
4093 {
4094 if (! extra_insns)
4095 return 0;
4096
4097 start_sequence ();
4098 temp = force_operand (temp, NULL_RTX);
4099 seq = get_insns ();
4100 end_sequence ();
4101
4102 emit_insn_before (seq, object);
4103 if (! validate_change (object, loc, temp, 0)
4104 && ! validate_replace_rtx (x, temp, object))
4105 instantiate_virtual_regs_lossage (object);
4106 }
4107 }
4108
4109 return 1;
4110
4111 case ADDRESSOF:
4112 if (GET_CODE (XEXP (x, 0)) == REG)
4113 return 1;
4114
4115 else if (GET_CODE (XEXP (x, 0)) == MEM)
4116 {
4117 /* If we have a (addressof (mem ..)), do any instantiation inside
4118 since we know we'll be making the inside valid when we finally
4119 remove the ADDRESSOF. */
4120 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), NULL_RTX, 0);
4121 return 1;
4122 }
4123 break;
4124
4125 default:
4126 break;
4127 }
4128
4129 /* Scan all subexpressions. */
4130 fmt = GET_RTX_FORMAT (code);
4131 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
4132 if (*fmt == 'e')
4133 {
4134 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
4135 return 0;
4136 }
4137 else if (*fmt == 'E')
4138 for (j = 0; j < XVECLEN (x, i); j++)
4139 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
4140 extra_insns))
4141 return 0;
4142
4143 return 1;
4144 }
4145 \f
4146 /* Optimization: assuming this function does not receive nonlocal gotos,
4147 delete the handlers for such, as well as the insns to establish
4148 and disestablish them. */
4149
4150 static void
4151 delete_handlers (void)
4152 {
4153 rtx insn;
4154 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4155 {
4156 /* Delete the handler by turning off the flag that would
4157 prevent jump_optimize from deleting it.
4158 Also permit deletion of the nonlocal labels themselves
4159 if nothing local refers to them. */
4160 if (GET_CODE (insn) == CODE_LABEL)
4161 {
4162 tree t, last_t;
4163
4164 LABEL_PRESERVE_P (insn) = 0;
4165
4166 /* Remove it from the nonlocal_label list, to avoid confusing
4167 flow. */
4168 for (t = nonlocal_labels, last_t = 0; t;
4169 last_t = t, t = TREE_CHAIN (t))
4170 if (DECL_RTL (TREE_VALUE (t)) == insn)
4171 break;
4172 if (t)
4173 {
4174 if (! last_t)
4175 nonlocal_labels = TREE_CHAIN (nonlocal_labels);
4176 else
4177 TREE_CHAIN (last_t) = TREE_CHAIN (t);
4178 }
4179 }
4180 if (GET_CODE (insn) == INSN)
4181 {
4182 int can_delete = 0;
4183 rtx t;
4184 for (t = nonlocal_goto_handler_slots; t != 0; t = XEXP (t, 1))
4185 if (reg_mentioned_p (t, PATTERN (insn)))
4186 {
4187 can_delete = 1;
4188 break;
4189 }
4190 if (can_delete
4191 || (nonlocal_goto_stack_level != 0
4192 && reg_mentioned_p (nonlocal_goto_stack_level,
4193 PATTERN (insn))))
4194 delete_related_insns (insn);
4195 }
4196 }
4197 }
4198 \f
4199 /* Return the first insn following those generated by `assign_parms'. */
4200
4201 rtx
4202 get_first_nonparm_insn (void)
4203 {
4204 if (last_parm_insn)
4205 return NEXT_INSN (last_parm_insn);
4206 return get_insns ();
4207 }
4208
4209 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
4210 This means a type for which function calls must pass an address to the
4211 function or get an address back from the function.
4212 EXP may be a type node or an expression (whose type is tested). */
4213
4214 int
4215 aggregate_value_p (tree exp, tree fntype)
4216 {
4217 int i, regno, nregs;
4218 rtx reg;
4219
4220 tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
4221
4222 if (fntype)
4223 switch (TREE_CODE (fntype))
4224 {
4225 case CALL_EXPR:
4226 fntype = get_callee_fndecl (fntype);
4227 fntype = fntype ? TREE_TYPE (fntype) : 0;
4228 break;
4229 case FUNCTION_DECL:
4230 fntype = TREE_TYPE (fntype);
4231 break;
4232 case FUNCTION_TYPE:
4233 case METHOD_TYPE:
4234 break;
4235 case IDENTIFIER_NODE:
4236 fntype = 0;
4237 break;
4238 default:
4239 /* We don't expect other rtl types here. */
4240 abort();
4241 }
4242
4243 if (TREE_CODE (type) == VOID_TYPE)
4244 return 0;
4245 if (targetm.calls.return_in_memory (type, fntype))
4246 return 1;
4247 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
4248 and thus can't be returned in registers. */
4249 if (TREE_ADDRESSABLE (type))
4250 return 1;
4251 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
4252 return 1;
4253 /* Make sure we have suitable call-clobbered regs to return
4254 the value in; if not, we must return it in memory. */
4255 reg = hard_function_value (type, 0, 0);
4256
4257 /* If we have something other than a REG (e.g. a PARALLEL), then assume
4258 it is OK. */
4259 if (GET_CODE (reg) != REG)
4260 return 0;
4261
4262 regno = REGNO (reg);
4263 nregs = HARD_REGNO_NREGS (regno, TYPE_MODE (type));
4264 for (i = 0; i < nregs; i++)
4265 if (! call_used_regs[regno + i])
4266 return 1;
4267 return 0;
4268 }
4269 \f
4270 /* Assign RTL expressions to the function's parameters.
4271 This may involve copying them into registers and using
4272 those registers as the RTL for them. */
4273
4274 void
4275 assign_parms (tree fndecl)
4276 {
4277 tree parm;
4278 CUMULATIVE_ARGS args_so_far;
4279 /* Total space needed so far for args on the stack,
4280 given as a constant and a tree-expression. */
4281 struct args_size stack_args_size;
4282 tree fntype = TREE_TYPE (fndecl);
4283 tree fnargs = DECL_ARGUMENTS (fndecl), orig_fnargs;
4284 /* This is used for the arg pointer when referring to stack args. */
4285 rtx internal_arg_pointer;
4286 /* This is a dummy PARM_DECL that we used for the function result if
4287 the function returns a structure. */
4288 tree function_result_decl = 0;
4289 int varargs_setup = 0;
4290 int reg_parm_stack_space ATTRIBUTE_UNUSED = 0;
4291 rtx conversion_insns = 0;
4292
4293 /* Nonzero if function takes extra anonymous args.
4294 This means the last named arg must be on the stack
4295 right before the anonymous ones. */
4296 int stdarg
4297 = (TYPE_ARG_TYPES (fntype) != 0
4298 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
4299 != void_type_node));
4300
4301 current_function_stdarg = stdarg;
4302
4303 /* If the reg that the virtual arg pointer will be translated into is
4304 not a fixed reg or is the stack pointer, make a copy of the virtual
4305 arg pointer, and address parms via the copy. The frame pointer is
4306 considered fixed even though it is not marked as such.
4307
4308 The second time through, simply use ap to avoid generating rtx. */
4309
4310 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
4311 || ! (fixed_regs[ARG_POINTER_REGNUM]
4312 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
4313 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
4314 else
4315 internal_arg_pointer = virtual_incoming_args_rtx;
4316 current_function_internal_arg_pointer = internal_arg_pointer;
4317
4318 stack_args_size.constant = 0;
4319 stack_args_size.var = 0;
4320
4321 /* If struct value address is treated as the first argument, make it so. */
4322 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
4323 && ! current_function_returns_pcc_struct
4324 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
4325 {
4326 tree type = build_pointer_type (TREE_TYPE (fntype));
4327
4328 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
4329
4330 DECL_ARG_TYPE (function_result_decl) = type;
4331 TREE_CHAIN (function_result_decl) = fnargs;
4332 fnargs = function_result_decl;
4333 }
4334
4335 orig_fnargs = fnargs;
4336
4337 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4338 parm_reg_stack_loc = ggc_alloc_cleared (max_parm_reg * sizeof (rtx));
4339
4340 if (SPLIT_COMPLEX_ARGS)
4341 fnargs = split_complex_args (fnargs);
4342
4343 #ifdef REG_PARM_STACK_SPACE
4344 #ifdef MAYBE_REG_PARM_STACK_SPACE
4345 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
4346 #else
4347 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
4348 #endif
4349 #endif
4350
4351 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
4352 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
4353 #else
4354 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, fndecl);
4355 #endif
4356
4357 /* We haven't yet found an argument that we must push and pretend the
4358 caller did. */
4359 current_function_pretend_args_size = 0;
4360
4361 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
4362 {
4363 rtx entry_parm;
4364 rtx stack_parm;
4365 enum machine_mode promoted_mode, passed_mode;
4366 enum machine_mode nominal_mode, promoted_nominal_mode;
4367 int unsignedp;
4368 struct locate_and_pad_arg_data locate;
4369 int passed_pointer = 0;
4370 int did_conversion = 0;
4371 tree passed_type = DECL_ARG_TYPE (parm);
4372 tree nominal_type = TREE_TYPE (parm);
4373 int last_named = 0, named_arg;
4374 int in_regs;
4375 int partial = 0;
4376 int pretend_bytes = 0;
4377
4378 /* Set LAST_NAMED if this is last named arg before last
4379 anonymous args. */
4380 if (stdarg)
4381 {
4382 tree tem;
4383
4384 for (tem = TREE_CHAIN (parm); tem; tem = TREE_CHAIN (tem))
4385 if (DECL_NAME (tem))
4386 break;
4387
4388 if (tem == 0)
4389 last_named = 1;
4390 }
4391 /* Set NAMED_ARG if this arg should be treated as a named arg. For
4392 most machines, if this is a varargs/stdarg function, then we treat
4393 the last named arg as if it were anonymous too. */
4394 named_arg = targetm.calls.strict_argument_naming (&args_so_far) ? 1 : ! last_named;
4395
4396 if (TREE_TYPE (parm) == error_mark_node
4397 /* This can happen after weird syntax errors
4398 or if an enum type is defined among the parms. */
4399 || TREE_CODE (parm) != PARM_DECL
4400 || passed_type == NULL)
4401 {
4402 SET_DECL_RTL (parm, gen_rtx_MEM (BLKmode, const0_rtx));
4403 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4404 TREE_USED (parm) = 1;
4405 continue;
4406 }
4407
4408 /* Find mode of arg as it is passed, and mode of arg
4409 as it should be during execution of this function. */
4410 passed_mode = TYPE_MODE (passed_type);
4411 nominal_mode = TYPE_MODE (nominal_type);
4412
4413 /* If the parm's mode is VOID, its value doesn't matter,
4414 and avoid the usual things like emit_move_insn that could crash. */
4415 if (nominal_mode == VOIDmode)
4416 {
4417 SET_DECL_RTL (parm, const0_rtx);
4418 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4419 continue;
4420 }
4421
4422 /* If the parm is to be passed as a transparent union, use the
4423 type of the first field for the tests below. We have already
4424 verified that the modes are the same. */
4425 if (DECL_TRANSPARENT_UNION (parm)
4426 || (TREE_CODE (passed_type) == UNION_TYPE
4427 && TYPE_TRANSPARENT_UNION (passed_type)))
4428 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
4429
4430 /* See if this arg was passed by invisible reference. It is if
4431 it is an object whose size depends on the contents of the
4432 object itself or if the machine requires these objects be passed
4433 that way. */
4434
4435 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (passed_type))
4436 || TREE_ADDRESSABLE (passed_type)
4437 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
4438 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
4439 passed_type, named_arg)
4440 #endif
4441 )
4442 {
4443 passed_type = nominal_type = build_pointer_type (passed_type);
4444 passed_pointer = 1;
4445 passed_mode = nominal_mode = Pmode;
4446 }
4447 /* See if the frontend wants to pass this by invisible reference. */
4448 else if (passed_type != nominal_type
4449 && POINTER_TYPE_P (passed_type)
4450 && TREE_TYPE (passed_type) == nominal_type)
4451 {
4452 nominal_type = passed_type;
4453 passed_pointer = 1;
4454 passed_mode = nominal_mode = Pmode;
4455 }
4456
4457 promoted_mode = passed_mode;
4458
4459 if (targetm.calls.promote_function_args (TREE_TYPE (fndecl)))
4460 {
4461 /* Compute the mode in which the arg is actually extended to. */
4462 unsignedp = TREE_UNSIGNED (passed_type);
4463 promoted_mode = promote_mode (passed_type, promoted_mode, &unsignedp, 1);
4464 }
4465
4466 /* Let machine desc say which reg (if any) the parm arrives in.
4467 0 means it arrives on the stack. */
4468 #ifdef FUNCTION_INCOMING_ARG
4469 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4470 passed_type, named_arg);
4471 #else
4472 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
4473 passed_type, named_arg);
4474 #endif
4475
4476 if (entry_parm == 0)
4477 promoted_mode = passed_mode;
4478
4479 /* If this is the last named parameter, do any required setup for
4480 varargs or stdargs. We need to know about the case of this being an
4481 addressable type, in which case we skip the registers it
4482 would have arrived in.
4483
4484 For stdargs, LAST_NAMED will be set for two parameters, the one that
4485 is actually the last named, and the dummy parameter. We only
4486 want to do this action once.
4487
4488 Also, indicate when RTL generation is to be suppressed. */
4489 if (last_named && !varargs_setup)
4490 {
4491 int varargs_pretend_bytes = 0;
4492 targetm.calls.setup_incoming_varargs (&args_so_far, promoted_mode,
4493 passed_type,
4494 &varargs_pretend_bytes, 0);
4495 varargs_setup = 1;
4496
4497 /* If the back-end has requested extra stack space, record how
4498 much is needed. Do not change pretend_args_size otherwise
4499 since it may be nonzero from an earlier partial argument. */
4500 if (varargs_pretend_bytes > 0)
4501 current_function_pretend_args_size = varargs_pretend_bytes;
4502 }
4503
4504 /* Determine parm's home in the stack,
4505 in case it arrives in the stack or we should pretend it did.
4506
4507 Compute the stack position and rtx where the argument arrives
4508 and its size.
4509
4510 There is one complexity here: If this was a parameter that would
4511 have been passed in registers, but wasn't only because it is
4512 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
4513 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
4514 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
4515 0 as it was the previous time. */
4516 in_regs = entry_parm != 0;
4517 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4518 in_regs = 1;
4519 #endif
4520 if (!in_regs && !named_arg)
4521 {
4522 int pretend_named =
4523 targetm.calls.pretend_outgoing_varargs_named (&args_so_far);
4524 if (pretend_named)
4525 {
4526 #ifdef FUNCTION_INCOMING_ARG
4527 in_regs = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4528 passed_type,
4529 pretend_named) != 0;
4530 #else
4531 in_regs = FUNCTION_ARG (args_so_far, promoted_mode,
4532 passed_type,
4533 pretend_named) != 0;
4534 #endif
4535 }
4536 }
4537
4538 /* If this parameter was passed both in registers and in the stack,
4539 use the copy on the stack. */
4540 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
4541 entry_parm = 0;
4542
4543 #ifdef FUNCTION_ARG_PARTIAL_NREGS
4544 if (entry_parm)
4545 {
4546 partial = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
4547 passed_type, named_arg);
4548 if (partial
4549 #ifndef MAYBE_REG_PARM_STACK_SPACE
4550 /* The caller might already have allocated stack space
4551 for the register parameters. */
4552 && reg_parm_stack_space == 0
4553 #endif
4554 )
4555 {
4556 /* Part of this argument is passed in registers and part
4557 is passed on the stack. Ask the prologue code to extend
4558 the stack part so that we can recreate the full value.
4559
4560 PRETEND_BYTES is the size of the registers we need to store.
4561 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
4562 stack space that the prologue should allocate.
4563
4564 Internally, gcc assumes that the argument pointer is
4565 aligned to STACK_BOUNDARY bits. This is used both for
4566 alignment optimizations (see init_emit) and to locate
4567 arguments that are aligned to more than PARM_BOUNDARY
4568 bits. We must preserve this invariant by rounding
4569 CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to a stack
4570 boundary. */
4571 pretend_bytes = partial * UNITS_PER_WORD;
4572 current_function_pretend_args_size
4573 = CEIL_ROUND (pretend_bytes, STACK_BYTES);
4574
4575 /* If PRETEND_BYTES != CURRENT_FUNCTION_PRETEND_ARGS_SIZE,
4576 insert the padding before the start of the first pretend
4577 argument. */
4578 stack_args_size.constant
4579 = (current_function_pretend_args_size - pretend_bytes);
4580 }
4581 }
4582 #endif
4583
4584 memset (&locate, 0, sizeof (locate));
4585 locate_and_pad_parm (promoted_mode, passed_type, in_regs,
4586 entry_parm ? partial : 0, fndecl,
4587 &stack_args_size, &locate);
4588
4589 {
4590 rtx offset_rtx;
4591
4592 /* If we're passing this arg using a reg, make its stack home
4593 the aligned stack slot. */
4594 if (entry_parm)
4595 offset_rtx = ARGS_SIZE_RTX (locate.slot_offset);
4596 else
4597 offset_rtx = ARGS_SIZE_RTX (locate.offset);
4598
4599 if (offset_rtx == const0_rtx)
4600 stack_parm = gen_rtx_MEM (promoted_mode, internal_arg_pointer);
4601 else
4602 stack_parm = gen_rtx_MEM (promoted_mode,
4603 gen_rtx_PLUS (Pmode,
4604 internal_arg_pointer,
4605 offset_rtx));
4606
4607 set_mem_attributes (stack_parm, parm, 1);
4608 if (entry_parm && MEM_ATTRS (stack_parm)->align < PARM_BOUNDARY)
4609 set_mem_align (stack_parm, PARM_BOUNDARY);
4610
4611 /* Set also REG_ATTRS if parameter was passed in a register. */
4612 if (entry_parm)
4613 set_reg_attrs_for_parm (entry_parm, stack_parm);
4614 }
4615
4616 /* If this parm was passed part in regs and part in memory,
4617 pretend it arrived entirely in memory
4618 by pushing the register-part onto the stack.
4619
4620 In the special case of a DImode or DFmode that is split,
4621 we could put it together in a pseudoreg directly,
4622 but for now that's not worth bothering with. */
4623
4624 if (partial)
4625 {
4626 /* Handle calls that pass values in multiple non-contiguous
4627 locations. The Irix 6 ABI has examples of this. */
4628 if (GET_CODE (entry_parm) == PARALLEL)
4629 emit_group_store (validize_mem (stack_parm), entry_parm,
4630 TREE_TYPE (parm),
4631 int_size_in_bytes (TREE_TYPE (parm)));
4632
4633 else
4634 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
4635 partial);
4636
4637 entry_parm = stack_parm;
4638 }
4639
4640 /* If we didn't decide this parm came in a register,
4641 by default it came on the stack. */
4642 if (entry_parm == 0)
4643 entry_parm = stack_parm;
4644
4645 /* Record permanently how this parm was passed. */
4646 DECL_INCOMING_RTL (parm) = entry_parm;
4647
4648 /* If there is actually space on the stack for this parm,
4649 count it in stack_args_size; otherwise set stack_parm to 0
4650 to indicate there is no preallocated stack slot for the parm. */
4651
4652 if (entry_parm == stack_parm
4653 || (GET_CODE (entry_parm) == PARALLEL
4654 && XEXP (XVECEXP (entry_parm, 0, 0), 0) == NULL_RTX)
4655 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
4656 /* On some machines, even if a parm value arrives in a register
4657 there is still an (uninitialized) stack slot allocated for it.
4658
4659 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
4660 whether this parameter already has a stack slot allocated,
4661 because an arg block exists only if current_function_args_size
4662 is larger than some threshold, and we haven't calculated that
4663 yet. So, for now, we just assume that stack slots never exist
4664 in this case. */
4665 || REG_PARM_STACK_SPACE (fndecl) > 0
4666 #endif
4667 )
4668 {
4669 stack_args_size.constant += pretend_bytes + locate.size.constant;
4670 if (locate.size.var)
4671 ADD_PARM_SIZE (stack_args_size, locate.size.var);
4672 }
4673 else
4674 /* No stack slot was pushed for this parm. */
4675 stack_parm = 0;
4676
4677 /* Update info on where next arg arrives in registers. */
4678
4679 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
4680 passed_type, named_arg);
4681
4682 /* If we can't trust the parm stack slot to be aligned enough
4683 for its ultimate type, don't use that slot after entry.
4684 We'll make another stack slot, if we need one. */
4685 {
4686 unsigned int thisparm_boundary
4687 = FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type);
4688
4689 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
4690 stack_parm = 0;
4691 }
4692
4693 /* If parm was passed in memory, and we need to convert it on entry,
4694 don't store it back in that same slot. */
4695 if (entry_parm == stack_parm
4696 && nominal_mode != BLKmode && nominal_mode != passed_mode)
4697 stack_parm = 0;
4698
4699 /* When an argument is passed in multiple locations, we can't
4700 make use of this information, but we can save some copying if
4701 the whole argument is passed in a single register. */
4702 if (GET_CODE (entry_parm) == PARALLEL
4703 && nominal_mode != BLKmode && passed_mode != BLKmode)
4704 {
4705 int i, len = XVECLEN (entry_parm, 0);
4706
4707 for (i = 0; i < len; i++)
4708 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
4709 && GET_CODE (XEXP (XVECEXP (entry_parm, 0, i), 0)) == REG
4710 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
4711 == passed_mode)
4712 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
4713 {
4714 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
4715 DECL_INCOMING_RTL (parm) = entry_parm;
4716 break;
4717 }
4718 }
4719
4720 /* ENTRY_PARM is an RTX for the parameter as it arrives,
4721 in the mode in which it arrives.
4722 STACK_PARM is an RTX for a stack slot where the parameter can live
4723 during the function (in case we want to put it there).
4724 STACK_PARM is 0 if no stack slot was pushed for it.
4725
4726 Now output code if necessary to convert ENTRY_PARM to
4727 the type in which this function declares it,
4728 and store that result in an appropriate place,
4729 which may be a pseudo reg, may be STACK_PARM,
4730 or may be a local stack slot if STACK_PARM is 0.
4731
4732 Set DECL_RTL to that place. */
4733
4734 if (GET_CODE (entry_parm) == PARALLEL && nominal_mode != BLKmode
4735 && XVECLEN (entry_parm, 0) > 1)
4736 {
4737 /* Reconstitute objects the size of a register or larger using
4738 register operations instead of the stack. */
4739 rtx parmreg = gen_reg_rtx (nominal_mode);
4740
4741 if (REG_P (parmreg))
4742 {
4743 emit_group_store (parmreg, entry_parm, TREE_TYPE (parm),
4744 int_size_in_bytes (TREE_TYPE (parm)));
4745 SET_DECL_RTL (parm, parmreg);
4746 }
4747 }
4748
4749 if (nominal_mode == BLKmode
4750 #ifdef BLOCK_REG_PADDING
4751 || (locate.where_pad == (BYTES_BIG_ENDIAN ? upward : downward)
4752 && GET_MODE_SIZE (promoted_mode) < UNITS_PER_WORD)
4753 #endif
4754 || GET_CODE (entry_parm) == PARALLEL)
4755 {
4756 /* If a BLKmode arrives in registers, copy it to a stack slot.
4757 Handle calls that pass values in multiple non-contiguous
4758 locations. The Irix 6 ABI has examples of this. */
4759 if (GET_CODE (entry_parm) == REG
4760 || GET_CODE (entry_parm) == PARALLEL)
4761 {
4762 int size = int_size_in_bytes (TREE_TYPE (parm));
4763 int size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
4764 rtx mem;
4765
4766 /* Note that we will be storing an integral number of words.
4767 So we have to be careful to ensure that we allocate an
4768 integral number of words. We do this below in the
4769 assign_stack_local if space was not allocated in the argument
4770 list. If it was, this will not work if PARM_BOUNDARY is not
4771 a multiple of BITS_PER_WORD. It isn't clear how to fix this
4772 if it becomes a problem. Exception is when BLKmode arrives
4773 with arguments not conforming to word_mode. */
4774
4775 if (stack_parm == 0)
4776 {
4777 stack_parm = assign_stack_local (BLKmode, size_stored, 0);
4778 PUT_MODE (stack_parm, GET_MODE (entry_parm));
4779 set_mem_attributes (stack_parm, parm, 1);
4780 }
4781 else if (GET_CODE (entry_parm) == PARALLEL
4782 && GET_MODE(entry_parm) == BLKmode)
4783 ;
4784 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
4785 abort ();
4786
4787 mem = validize_mem (stack_parm);
4788
4789 /* Handle calls that pass values in multiple non-contiguous
4790 locations. The Irix 6 ABI has examples of this. */
4791 if (GET_CODE (entry_parm) == PARALLEL)
4792 emit_group_store (mem, entry_parm, TREE_TYPE (parm), size);
4793
4794 else if (size == 0)
4795 ;
4796
4797 /* If SIZE is that of a mode no bigger than a word, just use
4798 that mode's store operation. */
4799 else if (size <= UNITS_PER_WORD)
4800 {
4801 enum machine_mode mode
4802 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
4803
4804 if (mode != BLKmode
4805 #ifdef BLOCK_REG_PADDING
4806 && (size == UNITS_PER_WORD
4807 || (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4808 != (BYTES_BIG_ENDIAN ? upward : downward)))
4809 #endif
4810 )
4811 {
4812 rtx reg = gen_rtx_REG (mode, REGNO (entry_parm));
4813 emit_move_insn (change_address (mem, mode, 0), reg);
4814 }
4815
4816 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
4817 machine must be aligned to the left before storing
4818 to memory. Note that the previous test doesn't
4819 handle all cases (e.g. SIZE == 3). */
4820 else if (size != UNITS_PER_WORD
4821 #ifdef BLOCK_REG_PADDING
4822 && (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4823 == downward)
4824 #else
4825 && BYTES_BIG_ENDIAN
4826 #endif
4827 )
4828 {
4829 rtx tem, x;
4830 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
4831 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
4832
4833 x = expand_binop (word_mode, ashl_optab, reg,
4834 GEN_INT (by), 0, 1, OPTAB_WIDEN);
4835 tem = change_address (mem, word_mode, 0);
4836 emit_move_insn (tem, x);
4837 }
4838 else
4839 move_block_from_reg (REGNO (entry_parm), mem,
4840 size_stored / UNITS_PER_WORD);
4841 }
4842 else
4843 move_block_from_reg (REGNO (entry_parm), mem,
4844 size_stored / UNITS_PER_WORD);
4845 }
4846 /* If parm is already bound to register pair, don't change
4847 this binding. */
4848 if (! DECL_RTL_SET_P (parm))
4849 SET_DECL_RTL (parm, stack_parm);
4850 }
4851 else if (! ((! optimize
4852 && ! DECL_REGISTER (parm))
4853 || TREE_SIDE_EFFECTS (parm)
4854 /* If -ffloat-store specified, don't put explicit
4855 float variables into registers. */
4856 || (flag_float_store
4857 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
4858 /* Always assign pseudo to structure return or item passed
4859 by invisible reference. */
4860 || passed_pointer || parm == function_result_decl)
4861 {
4862 /* Store the parm in a pseudoregister during the function, but we
4863 may need to do it in a wider mode. */
4864
4865 rtx parmreg;
4866 unsigned int regno, regnoi = 0, regnor = 0;
4867
4868 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
4869
4870 promoted_nominal_mode
4871 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
4872
4873 parmreg = gen_reg_rtx (promoted_nominal_mode);
4874 mark_user_reg (parmreg);
4875
4876 /* If this was an item that we received a pointer to, set DECL_RTL
4877 appropriately. */
4878 if (passed_pointer)
4879 {
4880 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (passed_type)),
4881 parmreg);
4882 set_mem_attributes (x, parm, 1);
4883 SET_DECL_RTL (parm, x);
4884 }
4885 else
4886 {
4887 SET_DECL_RTL (parm, parmreg);
4888 maybe_set_unchanging (DECL_RTL (parm), parm);
4889 }
4890
4891 /* Copy the value into the register. */
4892 if (nominal_mode != passed_mode
4893 || promoted_nominal_mode != promoted_mode)
4894 {
4895 int save_tree_used;
4896 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
4897 mode, by the caller. We now have to convert it to
4898 NOMINAL_MODE, if different. However, PARMREG may be in
4899 a different mode than NOMINAL_MODE if it is being stored
4900 promoted.
4901
4902 If ENTRY_PARM is a hard register, it might be in a register
4903 not valid for operating in its mode (e.g., an odd-numbered
4904 register for a DFmode). In that case, moves are the only
4905 thing valid, so we can't do a convert from there. This
4906 occurs when the calling sequence allow such misaligned
4907 usages.
4908
4909 In addition, the conversion may involve a call, which could
4910 clobber parameters which haven't been copied to pseudo
4911 registers yet. Therefore, we must first copy the parm to
4912 a pseudo reg here, and save the conversion until after all
4913 parameters have been moved. */
4914
4915 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4916
4917 emit_move_insn (tempreg, validize_mem (entry_parm));
4918
4919 push_to_sequence (conversion_insns);
4920 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
4921
4922 if (GET_CODE (tempreg) == SUBREG
4923 && GET_MODE (tempreg) == nominal_mode
4924 && GET_CODE (SUBREG_REG (tempreg)) == REG
4925 && nominal_mode == passed_mode
4926 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (entry_parm)
4927 && GET_MODE_SIZE (GET_MODE (tempreg))
4928 < GET_MODE_SIZE (GET_MODE (entry_parm)))
4929 {
4930 /* The argument is already sign/zero extended, so note it
4931 into the subreg. */
4932 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
4933 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
4934 }
4935
4936 /* TREE_USED gets set erroneously during expand_assignment. */
4937 save_tree_used = TREE_USED (parm);
4938 expand_assignment (parm,
4939 make_tree (nominal_type, tempreg), 0);
4940 TREE_USED (parm) = save_tree_used;
4941 conversion_insns = get_insns ();
4942 did_conversion = 1;
4943 end_sequence ();
4944 }
4945 else
4946 emit_move_insn (parmreg, validize_mem (entry_parm));
4947
4948 /* If we were passed a pointer but the actual value
4949 can safely live in a register, put it in one. */
4950 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
4951 /* If by-reference argument was promoted, demote it. */
4952 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
4953 || ! ((! optimize
4954 && ! DECL_REGISTER (parm))
4955 || TREE_SIDE_EFFECTS (parm)
4956 /* If -ffloat-store specified, don't put explicit
4957 float variables into registers. */
4958 || (flag_float_store
4959 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))))
4960 {
4961 /* We can't use nominal_mode, because it will have been set to
4962 Pmode above. We must use the actual mode of the parm. */
4963 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
4964 mark_user_reg (parmreg);
4965 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
4966 {
4967 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
4968 int unsigned_p = TREE_UNSIGNED (TREE_TYPE (parm));
4969 push_to_sequence (conversion_insns);
4970 emit_move_insn (tempreg, DECL_RTL (parm));
4971 SET_DECL_RTL (parm,
4972 convert_to_mode (GET_MODE (parmreg),
4973 tempreg,
4974 unsigned_p));
4975 emit_move_insn (parmreg, DECL_RTL (parm));
4976 conversion_insns = get_insns();
4977 did_conversion = 1;
4978 end_sequence ();
4979 }
4980 else
4981 emit_move_insn (parmreg, DECL_RTL (parm));
4982 SET_DECL_RTL (parm, parmreg);
4983 /* STACK_PARM is the pointer, not the parm, and PARMREG is
4984 now the parm. */
4985 stack_parm = 0;
4986 }
4987 #ifdef FUNCTION_ARG_CALLEE_COPIES
4988 /* If we are passed an arg by reference and it is our responsibility
4989 to make a copy, do it now.
4990 PASSED_TYPE and PASSED mode now refer to the pointer, not the
4991 original argument, so we must recreate them in the call to
4992 FUNCTION_ARG_CALLEE_COPIES. */
4993 /* ??? Later add code to handle the case that if the argument isn't
4994 modified, don't do the copy. */
4995
4996 else if (passed_pointer
4997 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
4998 TYPE_MODE (TREE_TYPE (passed_type)),
4999 TREE_TYPE (passed_type),
5000 named_arg)
5001 && ! TREE_ADDRESSABLE (TREE_TYPE (passed_type)))
5002 {
5003 rtx copy;
5004 tree type = TREE_TYPE (passed_type);
5005
5006 /* This sequence may involve a library call perhaps clobbering
5007 registers that haven't been copied to pseudos yet. */
5008
5009 push_to_sequence (conversion_insns);
5010
5011 if (!COMPLETE_TYPE_P (type)
5012 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5013 /* This is a variable sized object. */
5014 copy = gen_rtx_MEM (BLKmode,
5015 allocate_dynamic_stack_space
5016 (expr_size (parm), NULL_RTX,
5017 TYPE_ALIGN (type)));
5018 else
5019 copy = assign_stack_temp (TYPE_MODE (type),
5020 int_size_in_bytes (type), 1);
5021 set_mem_attributes (copy, parm, 1);
5022
5023 store_expr (parm, copy, 0);
5024 emit_move_insn (parmreg, XEXP (copy, 0));
5025 conversion_insns = get_insns ();
5026 did_conversion = 1;
5027 end_sequence ();
5028 }
5029 #endif /* FUNCTION_ARG_CALLEE_COPIES */
5030
5031 /* In any case, record the parm's desired stack location
5032 in case we later discover it must live in the stack.
5033
5034 If it is a COMPLEX value, store the stack location for both
5035 halves. */
5036
5037 if (GET_CODE (parmreg) == CONCAT)
5038 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
5039 else
5040 regno = REGNO (parmreg);
5041
5042 if (regno >= max_parm_reg)
5043 {
5044 rtx *new;
5045 int old_max_parm_reg = max_parm_reg;
5046
5047 /* It's slow to expand this one register at a time,
5048 but it's also rare and we need max_parm_reg to be
5049 precisely correct. */
5050 max_parm_reg = regno + 1;
5051 new = ggc_realloc (parm_reg_stack_loc,
5052 max_parm_reg * sizeof (rtx));
5053 memset (new + old_max_parm_reg, 0,
5054 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
5055 parm_reg_stack_loc = new;
5056 }
5057
5058 if (GET_CODE (parmreg) == CONCAT)
5059 {
5060 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
5061
5062 regnor = REGNO (gen_realpart (submode, parmreg));
5063 regnoi = REGNO (gen_imagpart (submode, parmreg));
5064
5065 if (stack_parm != 0)
5066 {
5067 parm_reg_stack_loc[regnor]
5068 = gen_realpart (submode, stack_parm);
5069 parm_reg_stack_loc[regnoi]
5070 = gen_imagpart (submode, stack_parm);
5071 }
5072 else
5073 {
5074 parm_reg_stack_loc[regnor] = 0;
5075 parm_reg_stack_loc[regnoi] = 0;
5076 }
5077 }
5078 else
5079 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
5080
5081 /* Mark the register as eliminable if we did no conversion
5082 and it was copied from memory at a fixed offset,
5083 and the arg pointer was not copied to a pseudo-reg.
5084 If the arg pointer is a pseudo reg or the offset formed
5085 an invalid address, such memory-equivalences
5086 as we make here would screw up life analysis for it. */
5087 if (nominal_mode == passed_mode
5088 && ! did_conversion
5089 && stack_parm != 0
5090 && GET_CODE (stack_parm) == MEM
5091 && locate.offset.var == 0
5092 && reg_mentioned_p (virtual_incoming_args_rtx,
5093 XEXP (stack_parm, 0)))
5094 {
5095 rtx linsn = get_last_insn ();
5096 rtx sinsn, set;
5097
5098 /* Mark complex types separately. */
5099 if (GET_CODE (parmreg) == CONCAT)
5100 /* Scan backwards for the set of the real and
5101 imaginary parts. */
5102 for (sinsn = linsn; sinsn != 0;
5103 sinsn = prev_nonnote_insn (sinsn))
5104 {
5105 set = single_set (sinsn);
5106 if (set != 0
5107 && SET_DEST (set) == regno_reg_rtx [regnoi])
5108 REG_NOTES (sinsn)
5109 = gen_rtx_EXPR_LIST (REG_EQUIV,
5110 parm_reg_stack_loc[regnoi],
5111 REG_NOTES (sinsn));
5112 else if (set != 0
5113 && SET_DEST (set) == regno_reg_rtx [regnor])
5114 REG_NOTES (sinsn)
5115 = gen_rtx_EXPR_LIST (REG_EQUIV,
5116 parm_reg_stack_loc[regnor],
5117 REG_NOTES (sinsn));
5118 }
5119 else if ((set = single_set (linsn)) != 0
5120 && SET_DEST (set) == parmreg)
5121 REG_NOTES (linsn)
5122 = gen_rtx_EXPR_LIST (REG_EQUIV,
5123 stack_parm, REG_NOTES (linsn));
5124 }
5125
5126 /* For pointer data type, suggest pointer register. */
5127 if (POINTER_TYPE_P (TREE_TYPE (parm)))
5128 mark_reg_pointer (parmreg,
5129 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5130
5131 /* If something wants our address, try to use ADDRESSOF. */
5132 if (TREE_ADDRESSABLE (parm))
5133 {
5134 /* If we end up putting something into the stack,
5135 fixup_var_refs_insns will need to make a pass over
5136 all the instructions. It looks through the pending
5137 sequences -- but it can't see the ones in the
5138 CONVERSION_INSNS, if they're not on the sequence
5139 stack. So, we go back to that sequence, just so that
5140 the fixups will happen. */
5141 push_to_sequence (conversion_insns);
5142 put_var_into_stack (parm, /*rescan=*/true);
5143 conversion_insns = get_insns ();
5144 end_sequence ();
5145 }
5146 }
5147 else
5148 {
5149 /* Value must be stored in the stack slot STACK_PARM
5150 during function execution. */
5151
5152 if (promoted_mode != nominal_mode)
5153 {
5154 /* Conversion is required. */
5155 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
5156
5157 emit_move_insn (tempreg, validize_mem (entry_parm));
5158
5159 push_to_sequence (conversion_insns);
5160 entry_parm = convert_to_mode (nominal_mode, tempreg,
5161 TREE_UNSIGNED (TREE_TYPE (parm)));
5162 if (stack_parm)
5163 /* ??? This may need a big-endian conversion on sparc64. */
5164 stack_parm = adjust_address (stack_parm, nominal_mode, 0);
5165
5166 conversion_insns = get_insns ();
5167 did_conversion = 1;
5168 end_sequence ();
5169 }
5170
5171 if (entry_parm != stack_parm)
5172 {
5173 if (stack_parm == 0)
5174 {
5175 stack_parm
5176 = assign_stack_local (GET_MODE (entry_parm),
5177 GET_MODE_SIZE (GET_MODE (entry_parm)),
5178 0);
5179 set_mem_attributes (stack_parm, parm, 1);
5180 }
5181
5182 if (promoted_mode != nominal_mode)
5183 {
5184 push_to_sequence (conversion_insns);
5185 emit_move_insn (validize_mem (stack_parm),
5186 validize_mem (entry_parm));
5187 conversion_insns = get_insns ();
5188 end_sequence ();
5189 }
5190 else
5191 emit_move_insn (validize_mem (stack_parm),
5192 validize_mem (entry_parm));
5193 }
5194
5195 SET_DECL_RTL (parm, stack_parm);
5196 }
5197 }
5198
5199 if (SPLIT_COMPLEX_ARGS && fnargs != orig_fnargs)
5200 {
5201 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
5202 {
5203 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE)
5204 {
5205 SET_DECL_RTL (parm,
5206 gen_rtx_CONCAT (DECL_MODE (parm),
5207 DECL_RTL (fnargs),
5208 DECL_RTL (TREE_CHAIN (fnargs))));
5209 DECL_INCOMING_RTL (parm)
5210 = gen_rtx_CONCAT (DECL_MODE (parm),
5211 DECL_INCOMING_RTL (fnargs),
5212 DECL_INCOMING_RTL (TREE_CHAIN (fnargs)));
5213 fnargs = TREE_CHAIN (fnargs);
5214 }
5215 else
5216 {
5217 SET_DECL_RTL (parm, DECL_RTL (fnargs));
5218 DECL_INCOMING_RTL (parm) = DECL_INCOMING_RTL (fnargs);
5219 }
5220 fnargs = TREE_CHAIN (fnargs);
5221 }
5222 }
5223
5224 /* Output all parameter conversion instructions (possibly including calls)
5225 now that all parameters have been copied out of hard registers. */
5226 emit_insn (conversion_insns);
5227
5228 /* If we are receiving a struct value address as the first argument, set up
5229 the RTL for the function result. As this might require code to convert
5230 the transmitted address to Pmode, we do this here to ensure that possible
5231 preliminary conversions of the address have been emitted already. */
5232 if (function_result_decl)
5233 {
5234 tree result = DECL_RESULT (fndecl);
5235 rtx addr = DECL_RTL (function_result_decl);
5236 rtx x;
5237
5238 addr = convert_memory_address (Pmode, addr);
5239 x = gen_rtx_MEM (DECL_MODE (result), addr);
5240 set_mem_attributes (x, result, 1);
5241 SET_DECL_RTL (result, x);
5242 }
5243
5244 last_parm_insn = get_last_insn ();
5245
5246 current_function_args_size = stack_args_size.constant;
5247
5248 /* Adjust function incoming argument size for alignment and
5249 minimum length. */
5250
5251 #ifdef REG_PARM_STACK_SPACE
5252 #ifndef MAYBE_REG_PARM_STACK_SPACE
5253 current_function_args_size = MAX (current_function_args_size,
5254 REG_PARM_STACK_SPACE (fndecl));
5255 #endif
5256 #endif
5257
5258 current_function_args_size
5259 = ((current_function_args_size + STACK_BYTES - 1)
5260 / STACK_BYTES) * STACK_BYTES;
5261
5262 #ifdef ARGS_GROW_DOWNWARD
5263 current_function_arg_offset_rtx
5264 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
5265 : expand_expr (size_diffop (stack_args_size.var,
5266 size_int (-stack_args_size.constant)),
5267 NULL_RTX, VOIDmode, 0));
5268 #else
5269 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
5270 #endif
5271
5272 /* See how many bytes, if any, of its args a function should try to pop
5273 on return. */
5274
5275 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
5276 current_function_args_size);
5277
5278 /* For stdarg.h function, save info about
5279 regs and stack space used by the named args. */
5280
5281 current_function_args_info = args_so_far;
5282
5283 /* Set the rtx used for the function return value. Put this in its
5284 own variable so any optimizers that need this information don't have
5285 to include tree.h. Do this here so it gets done when an inlined
5286 function gets output. */
5287
5288 current_function_return_rtx
5289 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
5290 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
5291
5292 /* If scalar return value was computed in a pseudo-reg, or was a named
5293 return value that got dumped to the stack, copy that to the hard
5294 return register. */
5295 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
5296 {
5297 tree decl_result = DECL_RESULT (fndecl);
5298 rtx decl_rtl = DECL_RTL (decl_result);
5299
5300 if (REG_P (decl_rtl)
5301 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5302 : DECL_REGISTER (decl_result))
5303 {
5304 rtx real_decl_rtl;
5305
5306 #ifdef FUNCTION_OUTGOING_VALUE
5307 real_decl_rtl = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl_result),
5308 fndecl);
5309 #else
5310 real_decl_rtl = FUNCTION_VALUE (TREE_TYPE (decl_result),
5311 fndecl);
5312 #endif
5313 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
5314 /* The delay slot scheduler assumes that current_function_return_rtx
5315 holds the hard register containing the return value, not a
5316 temporary pseudo. */
5317 current_function_return_rtx = real_decl_rtl;
5318 }
5319 }
5320 }
5321
5322 /* If ARGS contains entries with complex types, split the entry into two
5323 entries of the component type. Return a new list of substitutions are
5324 needed, else the old list. */
5325
5326 static tree
5327 split_complex_args (tree args)
5328 {
5329 tree p;
5330
5331 /* Before allocating memory, check for the common case of no complex. */
5332 for (p = args; p; p = TREE_CHAIN (p))
5333 if (TREE_CODE (TREE_TYPE (p)) == COMPLEX_TYPE)
5334 goto found;
5335 return args;
5336
5337 found:
5338 args = copy_list (args);
5339
5340 for (p = args; p; p = TREE_CHAIN (p))
5341 {
5342 tree type = TREE_TYPE (p);
5343 if (TREE_CODE (type) == COMPLEX_TYPE)
5344 {
5345 tree decl;
5346 tree subtype = TREE_TYPE (type);
5347
5348 /* Rewrite the PARM_DECL's type with its component. */
5349 TREE_TYPE (p) = subtype;
5350 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
5351 DECL_MODE (p) = VOIDmode;
5352 DECL_SIZE (p) = NULL;
5353 DECL_SIZE_UNIT (p) = NULL;
5354 layout_decl (p, 0);
5355
5356 /* Build a second synthetic decl. */
5357 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
5358 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
5359 layout_decl (decl, 0);
5360
5361 /* Splice it in; skip the new decl. */
5362 TREE_CHAIN (decl) = TREE_CHAIN (p);
5363 TREE_CHAIN (p) = decl;
5364 p = decl;
5365 }
5366 }
5367
5368 return args;
5369 }
5370 \f
5371 /* Indicate whether REGNO is an incoming argument to the current function
5372 that was promoted to a wider mode. If so, return the RTX for the
5373 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
5374 that REGNO is promoted from and whether the promotion was signed or
5375 unsigned. */
5376
5377 rtx
5378 promoted_input_arg (unsigned int regno, enum machine_mode *pmode, int *punsignedp)
5379 {
5380 tree arg;
5381
5382 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
5383 arg = TREE_CHAIN (arg))
5384 if (GET_CODE (DECL_INCOMING_RTL (arg)) == REG
5385 && REGNO (DECL_INCOMING_RTL (arg)) == regno
5386 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
5387 {
5388 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
5389 int unsignedp = TREE_UNSIGNED (TREE_TYPE (arg));
5390
5391 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
5392 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
5393 && mode != DECL_MODE (arg))
5394 {
5395 *pmode = DECL_MODE (arg);
5396 *punsignedp = unsignedp;
5397 return DECL_INCOMING_RTL (arg);
5398 }
5399 }
5400
5401 return 0;
5402 }
5403
5404 \f
5405 /* Compute the size and offset from the start of the stacked arguments for a
5406 parm passed in mode PASSED_MODE and with type TYPE.
5407
5408 INITIAL_OFFSET_PTR points to the current offset into the stacked
5409 arguments.
5410
5411 The starting offset and size for this parm are returned in
5412 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
5413 nonzero, the offset is that of stack slot, which is returned in
5414 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
5415 padding required from the initial offset ptr to the stack slot.
5416
5417 IN_REGS is nonzero if the argument will be passed in registers. It will
5418 never be set if REG_PARM_STACK_SPACE is not defined.
5419
5420 FNDECL is the function in which the argument was defined.
5421
5422 There are two types of rounding that are done. The first, controlled by
5423 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
5424 list to be aligned to the specific boundary (in bits). This rounding
5425 affects the initial and starting offsets, but not the argument size.
5426
5427 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
5428 optionally rounds the size of the parm to PARM_BOUNDARY. The
5429 initial offset is not affected by this rounding, while the size always
5430 is and the starting offset may be. */
5431
5432 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
5433 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
5434 callers pass in the total size of args so far as
5435 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
5436
5437 void
5438 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
5439 int partial, tree fndecl ATTRIBUTE_UNUSED,
5440 struct args_size *initial_offset_ptr,
5441 struct locate_and_pad_arg_data *locate)
5442 {
5443 tree sizetree;
5444 enum direction where_pad;
5445 int boundary;
5446 int reg_parm_stack_space = 0;
5447 int part_size_in_regs;
5448
5449 #ifdef REG_PARM_STACK_SPACE
5450 #ifdef MAYBE_REG_PARM_STACK_SPACE
5451 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
5452 #else
5453 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
5454 #endif
5455
5456 /* If we have found a stack parm before we reach the end of the
5457 area reserved for registers, skip that area. */
5458 if (! in_regs)
5459 {
5460 if (reg_parm_stack_space > 0)
5461 {
5462 if (initial_offset_ptr->var)
5463 {
5464 initial_offset_ptr->var
5465 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
5466 ssize_int (reg_parm_stack_space));
5467 initial_offset_ptr->constant = 0;
5468 }
5469 else if (initial_offset_ptr->constant < reg_parm_stack_space)
5470 initial_offset_ptr->constant = reg_parm_stack_space;
5471 }
5472 }
5473 #endif /* REG_PARM_STACK_SPACE */
5474
5475 part_size_in_regs = 0;
5476 if (reg_parm_stack_space == 0)
5477 part_size_in_regs = ((partial * UNITS_PER_WORD)
5478 / (PARM_BOUNDARY / BITS_PER_UNIT)
5479 * (PARM_BOUNDARY / BITS_PER_UNIT));
5480
5481 sizetree
5482 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
5483 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
5484 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
5485 locate->where_pad = where_pad;
5486
5487 #ifdef ARGS_GROW_DOWNWARD
5488 locate->slot_offset.constant = -initial_offset_ptr->constant;
5489 if (initial_offset_ptr->var)
5490 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
5491 initial_offset_ptr->var);
5492
5493 {
5494 tree s2 = sizetree;
5495 if (where_pad != none
5496 && (!host_integerp (sizetree, 1)
5497 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5498 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
5499 SUB_PARM_SIZE (locate->slot_offset, s2);
5500 }
5501
5502 locate->slot_offset.constant += part_size_in_regs;
5503
5504 if (!in_regs
5505 #ifdef REG_PARM_STACK_SPACE
5506 || REG_PARM_STACK_SPACE (fndecl) > 0
5507 #endif
5508 )
5509 pad_to_arg_alignment (&locate->slot_offset, boundary,
5510 &locate->alignment_pad);
5511
5512 locate->size.constant = (-initial_offset_ptr->constant
5513 - locate->slot_offset.constant);
5514 if (initial_offset_ptr->var)
5515 locate->size.var = size_binop (MINUS_EXPR,
5516 size_binop (MINUS_EXPR,
5517 ssize_int (0),
5518 initial_offset_ptr->var),
5519 locate->slot_offset.var);
5520
5521 /* Pad_below needs the pre-rounded size to know how much to pad
5522 below. */
5523 locate->offset = locate->slot_offset;
5524 if (where_pad == downward)
5525 pad_below (&locate->offset, passed_mode, sizetree);
5526
5527 #else /* !ARGS_GROW_DOWNWARD */
5528 if (!in_regs
5529 #ifdef REG_PARM_STACK_SPACE
5530 || REG_PARM_STACK_SPACE (fndecl) > 0
5531 #endif
5532 )
5533 pad_to_arg_alignment (initial_offset_ptr, boundary,
5534 &locate->alignment_pad);
5535 locate->slot_offset = *initial_offset_ptr;
5536
5537 #ifdef PUSH_ROUNDING
5538 if (passed_mode != BLKmode)
5539 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
5540 #endif
5541
5542 /* Pad_below needs the pre-rounded size to know how much to pad below
5543 so this must be done before rounding up. */
5544 locate->offset = locate->slot_offset;
5545 if (where_pad == downward)
5546 pad_below (&locate->offset, passed_mode, sizetree);
5547
5548 if (where_pad != none
5549 && (!host_integerp (sizetree, 1)
5550 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5551 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5552
5553 ADD_PARM_SIZE (locate->size, sizetree);
5554
5555 locate->size.constant -= part_size_in_regs;
5556 #endif /* ARGS_GROW_DOWNWARD */
5557 }
5558
5559 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
5560 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
5561
5562 static void
5563 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
5564 struct args_size *alignment_pad)
5565 {
5566 tree save_var = NULL_TREE;
5567 HOST_WIDE_INT save_constant = 0;
5568 int boundary_in_bytes = boundary / BITS_PER_UNIT;
5569 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
5570
5571 #ifdef SPARC_STACK_BOUNDARY_HACK
5572 /* The sparc port has a bug. It sometimes claims a STACK_BOUNDARY
5573 higher than the real alignment of %sp. However, when it does this,
5574 the alignment of %sp+STACK_POINTER_OFFSET will be STACK_BOUNDARY.
5575 This is a temporary hack while the sparc port is fixed. */
5576 if (SPARC_STACK_BOUNDARY_HACK)
5577 sp_offset = 0;
5578 #endif
5579
5580 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5581 {
5582 save_var = offset_ptr->var;
5583 save_constant = offset_ptr->constant;
5584 }
5585
5586 alignment_pad->var = NULL_TREE;
5587 alignment_pad->constant = 0;
5588
5589 if (boundary > BITS_PER_UNIT)
5590 {
5591 if (offset_ptr->var)
5592 {
5593 tree sp_offset_tree = ssize_int (sp_offset);
5594 tree offset = size_binop (PLUS_EXPR,
5595 ARGS_SIZE_TREE (*offset_ptr),
5596 sp_offset_tree);
5597 #ifdef ARGS_GROW_DOWNWARD
5598 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
5599 #else
5600 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
5601 #endif
5602
5603 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
5604 /* ARGS_SIZE_TREE includes constant term. */
5605 offset_ptr->constant = 0;
5606 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5607 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
5608 save_var);
5609 }
5610 else
5611 {
5612 offset_ptr->constant = -sp_offset +
5613 #ifdef ARGS_GROW_DOWNWARD
5614 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5615 #else
5616 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5617 #endif
5618 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5619 alignment_pad->constant = offset_ptr->constant - save_constant;
5620 }
5621 }
5622 }
5623
5624 static void
5625 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
5626 {
5627 if (passed_mode != BLKmode)
5628 {
5629 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
5630 offset_ptr->constant
5631 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
5632 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
5633 - GET_MODE_SIZE (passed_mode));
5634 }
5635 else
5636 {
5637 if (TREE_CODE (sizetree) != INTEGER_CST
5638 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
5639 {
5640 /* Round the size up to multiple of PARM_BOUNDARY bits. */
5641 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5642 /* Add it in. */
5643 ADD_PARM_SIZE (*offset_ptr, s2);
5644 SUB_PARM_SIZE (*offset_ptr, sizetree);
5645 }
5646 }
5647 }
5648 \f
5649 /* Walk the tree of blocks describing the binding levels within a function
5650 and warn about uninitialized variables.
5651 This is done after calling flow_analysis and before global_alloc
5652 clobbers the pseudo-regs to hard regs. */
5653
5654 void
5655 uninitialized_vars_warning (tree block)
5656 {
5657 tree decl, sub;
5658 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5659 {
5660 if (warn_uninitialized
5661 && TREE_CODE (decl) == VAR_DECL
5662 /* These warnings are unreliable for and aggregates
5663 because assigning the fields one by one can fail to convince
5664 flow.c that the entire aggregate was initialized.
5665 Unions are troublesome because members may be shorter. */
5666 && ! AGGREGATE_TYPE_P (TREE_TYPE (decl))
5667 && DECL_RTL (decl) != 0
5668 && GET_CODE (DECL_RTL (decl)) == REG
5669 /* Global optimizations can make it difficult to determine if a
5670 particular variable has been initialized. However, a VAR_DECL
5671 with a nonzero DECL_INITIAL had an initializer, so do not
5672 claim it is potentially uninitialized.
5673
5674 When the DECL_INITIAL is NULL call the language hook to tell us
5675 if we want to warn. */
5676 && (DECL_INITIAL (decl) == NULL_TREE || lang_hooks.decl_uninit (decl))
5677 && regno_uninitialized (REGNO (DECL_RTL (decl))))
5678 warning ("%J'%D' might be used uninitialized in this function",
5679 decl, decl);
5680 if (extra_warnings
5681 && TREE_CODE (decl) == VAR_DECL
5682 && DECL_RTL (decl) != 0
5683 && GET_CODE (DECL_RTL (decl)) == REG
5684 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5685 warning ("%Jvariable '%D' might be clobbered by `longjmp' or `vfork'",
5686 decl, decl);
5687 }
5688 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5689 uninitialized_vars_warning (sub);
5690 }
5691
5692 /* Do the appropriate part of uninitialized_vars_warning
5693 but for arguments instead of local variables. */
5694
5695 void
5696 setjmp_args_warning (void)
5697 {
5698 tree decl;
5699 for (decl = DECL_ARGUMENTS (current_function_decl);
5700 decl; decl = TREE_CHAIN (decl))
5701 if (DECL_RTL (decl) != 0
5702 && GET_CODE (DECL_RTL (decl)) == REG
5703 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5704 warning ("%Jargument '%D' might be clobbered by `longjmp' or `vfork'",
5705 decl, decl);
5706 }
5707
5708 /* If this function call setjmp, put all vars into the stack
5709 unless they were declared `register'. */
5710
5711 void
5712 setjmp_protect (tree block)
5713 {
5714 tree decl, sub;
5715 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5716 if ((TREE_CODE (decl) == VAR_DECL
5717 || TREE_CODE (decl) == PARM_DECL)
5718 && DECL_RTL (decl) != 0
5719 && (GET_CODE (DECL_RTL (decl)) == REG
5720 || (GET_CODE (DECL_RTL (decl)) == MEM
5721 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5722 /* If this variable came from an inline function, it must be
5723 that its life doesn't overlap the setjmp. If there was a
5724 setjmp in the function, it would already be in memory. We
5725 must exclude such variable because their DECL_RTL might be
5726 set to strange things such as virtual_stack_vars_rtx. */
5727 && ! DECL_FROM_INLINE (decl)
5728 && (
5729 #ifdef NON_SAVING_SETJMP
5730 /* If longjmp doesn't restore the registers,
5731 don't put anything in them. */
5732 NON_SAVING_SETJMP
5733 ||
5734 #endif
5735 ! DECL_REGISTER (decl)))
5736 put_var_into_stack (decl, /*rescan=*/true);
5737 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5738 setjmp_protect (sub);
5739 }
5740 \f
5741 /* Like the previous function, but for args instead of local variables. */
5742
5743 void
5744 setjmp_protect_args (void)
5745 {
5746 tree decl;
5747 for (decl = DECL_ARGUMENTS (current_function_decl);
5748 decl; decl = TREE_CHAIN (decl))
5749 if ((TREE_CODE (decl) == VAR_DECL
5750 || TREE_CODE (decl) == PARM_DECL)
5751 && DECL_RTL (decl) != 0
5752 && (GET_CODE (DECL_RTL (decl)) == REG
5753 || (GET_CODE (DECL_RTL (decl)) == MEM
5754 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5755 && (
5756 /* If longjmp doesn't restore the registers,
5757 don't put anything in them. */
5758 #ifdef NON_SAVING_SETJMP
5759 NON_SAVING_SETJMP
5760 ||
5761 #endif
5762 ! DECL_REGISTER (decl)))
5763 put_var_into_stack (decl, /*rescan=*/true);
5764 }
5765 \f
5766 /* Return the context-pointer register corresponding to DECL,
5767 or 0 if it does not need one. */
5768
5769 rtx
5770 lookup_static_chain (tree decl)
5771 {
5772 tree context = decl_function_context (decl);
5773 tree link;
5774
5775 if (context == 0
5776 || (TREE_CODE (decl) == FUNCTION_DECL && DECL_NO_STATIC_CHAIN (decl)))
5777 return 0;
5778
5779 /* We treat inline_function_decl as an alias for the current function
5780 because that is the inline function whose vars, types, etc.
5781 are being merged into the current function.
5782 See expand_inline_function. */
5783 if (context == current_function_decl || context == inline_function_decl)
5784 return virtual_stack_vars_rtx;
5785
5786 for (link = context_display; link; link = TREE_CHAIN (link))
5787 if (TREE_PURPOSE (link) == context)
5788 return RTL_EXPR_RTL (TREE_VALUE (link));
5789
5790 abort ();
5791 }
5792 \f
5793 /* Convert a stack slot address ADDR for variable VAR
5794 (from a containing function)
5795 into an address valid in this function (using a static chain). */
5796
5797 rtx
5798 fix_lexical_addr (rtx addr, tree var)
5799 {
5800 rtx basereg;
5801 HOST_WIDE_INT displacement;
5802 tree context = decl_function_context (var);
5803 struct function *fp;
5804 rtx base = 0;
5805
5806 /* If this is the present function, we need not do anything. */
5807 if (context == current_function_decl || context == inline_function_decl)
5808 return addr;
5809
5810 fp = find_function_data (context);
5811
5812 if (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == MEM)
5813 addr = XEXP (XEXP (addr, 0), 0);
5814
5815 /* Decode given address as base reg plus displacement. */
5816 if (GET_CODE (addr) == REG)
5817 basereg = addr, displacement = 0;
5818 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
5819 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
5820 else
5821 abort ();
5822
5823 /* We accept vars reached via the containing function's
5824 incoming arg pointer and via its stack variables pointer. */
5825 if (basereg == fp->internal_arg_pointer)
5826 {
5827 /* If reached via arg pointer, get the arg pointer value
5828 out of that function's stack frame.
5829
5830 There are two cases: If a separate ap is needed, allocate a
5831 slot in the outer function for it and dereference it that way.
5832 This is correct even if the real ap is actually a pseudo.
5833 Otherwise, just adjust the offset from the frame pointer to
5834 compensate. */
5835
5836 #ifdef NEED_SEPARATE_AP
5837 rtx addr;
5838
5839 addr = get_arg_pointer_save_area (fp);
5840 addr = fix_lexical_addr (XEXP (addr, 0), var);
5841 addr = memory_address (Pmode, addr);
5842
5843 base = gen_rtx_MEM (Pmode, addr);
5844 set_mem_alias_set (base, get_frame_alias_set ());
5845 base = copy_to_reg (base);
5846 #else
5847 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
5848 base = lookup_static_chain (var);
5849 #endif
5850 }
5851
5852 else if (basereg == virtual_stack_vars_rtx)
5853 {
5854 /* This is the same code as lookup_static_chain, duplicated here to
5855 avoid an extra call to decl_function_context. */
5856 tree link;
5857
5858 for (link = context_display; link; link = TREE_CHAIN (link))
5859 if (TREE_PURPOSE (link) == context)
5860 {
5861 base = RTL_EXPR_RTL (TREE_VALUE (link));
5862 break;
5863 }
5864 }
5865
5866 if (base == 0)
5867 abort ();
5868
5869 /* Use same offset, relative to appropriate static chain or argument
5870 pointer. */
5871 return plus_constant (base, displacement);
5872 }
5873 \f
5874 /* Return the address of the trampoline for entering nested fn FUNCTION.
5875 If necessary, allocate a trampoline (in the stack frame)
5876 and emit rtl to initialize its contents (at entry to this function). */
5877
5878 rtx
5879 trampoline_address (tree function)
5880 {
5881 tree link;
5882 tree rtlexp;
5883 rtx tramp;
5884 struct function *fp;
5885 tree fn_context;
5886
5887 /* Find an existing trampoline and return it. */
5888 for (link = trampoline_list; link; link = TREE_CHAIN (link))
5889 if (TREE_PURPOSE (link) == function)
5890 return
5891 adjust_trampoline_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0));
5892
5893 for (fp = outer_function_chain; fp; fp = fp->outer)
5894 for (link = fp->x_trampoline_list; link; link = TREE_CHAIN (link))
5895 if (TREE_PURPOSE (link) == function)
5896 {
5897 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
5898 function);
5899 return adjust_trampoline_addr (tramp);
5900 }
5901
5902 /* None exists; we must make one. */
5903
5904 /* Find the `struct function' for the function containing FUNCTION. */
5905 fp = 0;
5906 fn_context = decl_function_context (function);
5907 if (fn_context != current_function_decl
5908 && fn_context != inline_function_decl)
5909 fp = find_function_data (fn_context);
5910
5911 /* Allocate run-time space for this trampoline. */
5912 /* If rounding needed, allocate extra space
5913 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
5914 #define TRAMPOLINE_REAL_SIZE \
5915 (TRAMPOLINE_SIZE + (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT) - 1)
5916 tramp = assign_stack_local_1 (BLKmode, TRAMPOLINE_REAL_SIZE, 0,
5917 fp ? fp : cfun);
5918 /* Record the trampoline for reuse and note it for later initialization
5919 by expand_function_end. */
5920 if (fp != 0)
5921 {
5922 rtlexp = make_node (RTL_EXPR);
5923 RTL_EXPR_RTL (rtlexp) = tramp;
5924 fp->x_trampoline_list = tree_cons (function, rtlexp,
5925 fp->x_trampoline_list);
5926 }
5927 else
5928 {
5929 /* Make the RTL_EXPR node temporary, not momentary, so that the
5930 trampoline_list doesn't become garbage. */
5931 rtlexp = make_node (RTL_EXPR);
5932
5933 RTL_EXPR_RTL (rtlexp) = tramp;
5934 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
5935 }
5936
5937 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
5938 return adjust_trampoline_addr (tramp);
5939 }
5940
5941 /* Given a trampoline address,
5942 round it to multiple of TRAMPOLINE_ALIGNMENT. */
5943
5944 static rtx
5945 round_trampoline_addr (rtx tramp)
5946 {
5947 /* Round address up to desired boundary. */
5948 rtx temp = gen_reg_rtx (Pmode);
5949 rtx addend = GEN_INT (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT - 1);
5950 rtx mask = GEN_INT (-TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
5951
5952 temp = expand_simple_binop (Pmode, PLUS, tramp, addend,
5953 temp, 0, OPTAB_LIB_WIDEN);
5954 tramp = expand_simple_binop (Pmode, AND, temp, mask,
5955 temp, 0, OPTAB_LIB_WIDEN);
5956
5957 return tramp;
5958 }
5959
5960 /* Given a trampoline address, round it then apply any
5961 platform-specific adjustments so that the result can be used for a
5962 function call . */
5963
5964 static rtx
5965 adjust_trampoline_addr (rtx tramp)
5966 {
5967 tramp = round_trampoline_addr (tramp);
5968 #ifdef TRAMPOLINE_ADJUST_ADDRESS
5969 TRAMPOLINE_ADJUST_ADDRESS (tramp);
5970 #endif
5971 return tramp;
5972 }
5973 \f
5974 /* Put all this function's BLOCK nodes including those that are chained
5975 onto the first block into a vector, and return it.
5976 Also store in each NOTE for the beginning or end of a block
5977 the index of that block in the vector.
5978 The arguments are BLOCK, the chain of top-level blocks of the function,
5979 and INSNS, the insn chain of the function. */
5980
5981 void
5982 identify_blocks (void)
5983 {
5984 int n_blocks;
5985 tree *block_vector, *last_block_vector;
5986 tree *block_stack;
5987 tree block = DECL_INITIAL (current_function_decl);
5988
5989 if (block == 0)
5990 return;
5991
5992 /* Fill the BLOCK_VECTOR with all of the BLOCKs in this function, in
5993 depth-first order. */
5994 block_vector = get_block_vector (block, &n_blocks);
5995 block_stack = xmalloc (n_blocks * sizeof (tree));
5996
5997 last_block_vector = identify_blocks_1 (get_insns (),
5998 block_vector + 1,
5999 block_vector + n_blocks,
6000 block_stack);
6001
6002 /* If we didn't use all of the subblocks, we've misplaced block notes. */
6003 /* ??? This appears to happen all the time. Latent bugs elsewhere? */
6004 if (0 && last_block_vector != block_vector + n_blocks)
6005 abort ();
6006
6007 free (block_vector);
6008 free (block_stack);
6009 }
6010
6011 /* Subroutine of identify_blocks. Do the block substitution on the
6012 insn chain beginning with INSNS. Recurse for CALL_PLACEHOLDER chains.
6013
6014 BLOCK_STACK is pushed and popped for each BLOCK_BEGIN/BLOCK_END pair.
6015 BLOCK_VECTOR is incremented for each block seen. */
6016
6017 static tree *
6018 identify_blocks_1 (rtx insns, tree *block_vector, tree *end_block_vector,
6019 tree *orig_block_stack)
6020 {
6021 rtx insn;
6022 tree *block_stack = orig_block_stack;
6023
6024 for (insn = insns; insn; insn = NEXT_INSN (insn))
6025 {
6026 if (GET_CODE (insn) == NOTE)
6027 {
6028 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
6029 {
6030 tree b;
6031
6032 /* If there are more block notes than BLOCKs, something
6033 is badly wrong. */
6034 if (block_vector == end_block_vector)
6035 abort ();
6036
6037 b = *block_vector++;
6038 NOTE_BLOCK (insn) = b;
6039 *block_stack++ = b;
6040 }
6041 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
6042 {
6043 /* If there are more NOTE_INSN_BLOCK_ENDs than
6044 NOTE_INSN_BLOCK_BEGs, something is badly wrong. */
6045 if (block_stack == orig_block_stack)
6046 abort ();
6047
6048 NOTE_BLOCK (insn) = *--block_stack;
6049 }
6050 }
6051 else if (GET_CODE (insn) == CALL_INSN
6052 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
6053 {
6054 rtx cp = PATTERN (insn);
6055
6056 block_vector = identify_blocks_1 (XEXP (cp, 0), block_vector,
6057 end_block_vector, block_stack);
6058 if (XEXP (cp, 1))
6059 block_vector = identify_blocks_1 (XEXP (cp, 1), block_vector,
6060 end_block_vector, block_stack);
6061 if (XEXP (cp, 2))
6062 block_vector = identify_blocks_1 (XEXP (cp, 2), block_vector,
6063 end_block_vector, block_stack);
6064 }
6065 }
6066
6067 /* If there are more NOTE_INSN_BLOCK_BEGINs than NOTE_INSN_BLOCK_ENDs,
6068 something is badly wrong. */
6069 if (block_stack != orig_block_stack)
6070 abort ();
6071
6072 return block_vector;
6073 }
6074
6075 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
6076 and create duplicate blocks. */
6077 /* ??? Need an option to either create block fragments or to create
6078 abstract origin duplicates of a source block. It really depends
6079 on what optimization has been performed. */
6080
6081 void
6082 reorder_blocks (void)
6083 {
6084 tree block = DECL_INITIAL (current_function_decl);
6085 varray_type block_stack;
6086
6087 if (block == NULL_TREE)
6088 return;
6089
6090 VARRAY_TREE_INIT (block_stack, 10, "block_stack");
6091
6092 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
6093 reorder_blocks_0 (block);
6094
6095 /* Prune the old trees away, so that they don't get in the way. */
6096 BLOCK_SUBBLOCKS (block) = NULL_TREE;
6097 BLOCK_CHAIN (block) = NULL_TREE;
6098
6099 /* Recreate the block tree from the note nesting. */
6100 reorder_blocks_1 (get_insns (), block, &block_stack);
6101 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
6102
6103 /* Remove deleted blocks from the block fragment chains. */
6104 reorder_fix_fragments (block);
6105 }
6106
6107 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
6108
6109 static void
6110 reorder_blocks_0 (tree block)
6111 {
6112 while (block)
6113 {
6114 TREE_ASM_WRITTEN (block) = 0;
6115 reorder_blocks_0 (BLOCK_SUBBLOCKS (block));
6116 block = BLOCK_CHAIN (block);
6117 }
6118 }
6119
6120 static void
6121 reorder_blocks_1 (rtx insns, tree current_block, varray_type *p_block_stack)
6122 {
6123 rtx insn;
6124
6125 for (insn = insns; insn; insn = NEXT_INSN (insn))
6126 {
6127 if (GET_CODE (insn) == NOTE)
6128 {
6129 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
6130 {
6131 tree block = NOTE_BLOCK (insn);
6132
6133 /* If we have seen this block before, that means it now
6134 spans multiple address regions. Create a new fragment. */
6135 if (TREE_ASM_WRITTEN (block))
6136 {
6137 tree new_block = copy_node (block);
6138 tree origin;
6139
6140 origin = (BLOCK_FRAGMENT_ORIGIN (block)
6141 ? BLOCK_FRAGMENT_ORIGIN (block)
6142 : block);
6143 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
6144 BLOCK_FRAGMENT_CHAIN (new_block)
6145 = BLOCK_FRAGMENT_CHAIN (origin);
6146 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
6147
6148 NOTE_BLOCK (insn) = new_block;
6149 block = new_block;
6150 }
6151
6152 BLOCK_SUBBLOCKS (block) = 0;
6153 TREE_ASM_WRITTEN (block) = 1;
6154 /* When there's only one block for the entire function,
6155 current_block == block and we mustn't do this, it
6156 will cause infinite recursion. */
6157 if (block != current_block)
6158 {
6159 BLOCK_SUPERCONTEXT (block) = current_block;
6160 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
6161 BLOCK_SUBBLOCKS (current_block) = block;
6162 current_block = block;
6163 }
6164 VARRAY_PUSH_TREE (*p_block_stack, block);
6165 }
6166 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
6167 {
6168 NOTE_BLOCK (insn) = VARRAY_TOP_TREE (*p_block_stack);
6169 VARRAY_POP (*p_block_stack);
6170 BLOCK_SUBBLOCKS (current_block)
6171 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
6172 current_block = BLOCK_SUPERCONTEXT (current_block);
6173 }
6174 }
6175 else if (GET_CODE (insn) == CALL_INSN
6176 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
6177 {
6178 rtx cp = PATTERN (insn);
6179 reorder_blocks_1 (XEXP (cp, 0), current_block, p_block_stack);
6180 if (XEXP (cp, 1))
6181 reorder_blocks_1 (XEXP (cp, 1), current_block, p_block_stack);
6182 if (XEXP (cp, 2))
6183 reorder_blocks_1 (XEXP (cp, 2), current_block, p_block_stack);
6184 }
6185 }
6186 }
6187
6188 /* Rationalize BLOCK_FRAGMENT_ORIGIN. If an origin block no longer
6189 appears in the block tree, select one of the fragments to become
6190 the new origin block. */
6191
6192 static void
6193 reorder_fix_fragments (tree block)
6194 {
6195 while (block)
6196 {
6197 tree dup_origin = BLOCK_FRAGMENT_ORIGIN (block);
6198 tree new_origin = NULL_TREE;
6199
6200 if (dup_origin)
6201 {
6202 if (! TREE_ASM_WRITTEN (dup_origin))
6203 {
6204 new_origin = BLOCK_FRAGMENT_CHAIN (dup_origin);
6205
6206 /* Find the first of the remaining fragments. There must
6207 be at least one -- the current block. */
6208 while (! TREE_ASM_WRITTEN (new_origin))
6209 new_origin = BLOCK_FRAGMENT_CHAIN (new_origin);
6210 BLOCK_FRAGMENT_ORIGIN (new_origin) = NULL_TREE;
6211 }
6212 }
6213 else if (! dup_origin)
6214 new_origin = block;
6215
6216 /* Re-root the rest of the fragments to the new origin. In the
6217 case that DUP_ORIGIN was null, that means BLOCK was the origin
6218 of a chain of fragments and we want to remove those fragments
6219 that didn't make it to the output. */
6220 if (new_origin)
6221 {
6222 tree *pp = &BLOCK_FRAGMENT_CHAIN (new_origin);
6223 tree chain = *pp;
6224
6225 while (chain)
6226 {
6227 if (TREE_ASM_WRITTEN (chain))
6228 {
6229 BLOCK_FRAGMENT_ORIGIN (chain) = new_origin;
6230 *pp = chain;
6231 pp = &BLOCK_FRAGMENT_CHAIN (chain);
6232 }
6233 chain = BLOCK_FRAGMENT_CHAIN (chain);
6234 }
6235 *pp = NULL_TREE;
6236 }
6237
6238 reorder_fix_fragments (BLOCK_SUBBLOCKS (block));
6239 block = BLOCK_CHAIN (block);
6240 }
6241 }
6242
6243 /* Reverse the order of elements in the chain T of blocks,
6244 and return the new head of the chain (old last element). */
6245
6246 static tree
6247 blocks_nreverse (tree t)
6248 {
6249 tree prev = 0, decl, next;
6250 for (decl = t; decl; decl = next)
6251 {
6252 next = BLOCK_CHAIN (decl);
6253 BLOCK_CHAIN (decl) = prev;
6254 prev = decl;
6255 }
6256 return prev;
6257 }
6258
6259 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
6260 non-NULL, list them all into VECTOR, in a depth-first preorder
6261 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
6262 blocks. */
6263
6264 static int
6265 all_blocks (tree block, tree *vector)
6266 {
6267 int n_blocks = 0;
6268
6269 while (block)
6270 {
6271 TREE_ASM_WRITTEN (block) = 0;
6272
6273 /* Record this block. */
6274 if (vector)
6275 vector[n_blocks] = block;
6276
6277 ++n_blocks;
6278
6279 /* Record the subblocks, and their subblocks... */
6280 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
6281 vector ? vector + n_blocks : 0);
6282 block = BLOCK_CHAIN (block);
6283 }
6284
6285 return n_blocks;
6286 }
6287
6288 /* Return a vector containing all the blocks rooted at BLOCK. The
6289 number of elements in the vector is stored in N_BLOCKS_P. The
6290 vector is dynamically allocated; it is the caller's responsibility
6291 to call `free' on the pointer returned. */
6292
6293 static tree *
6294 get_block_vector (tree block, int *n_blocks_p)
6295 {
6296 tree *block_vector;
6297
6298 *n_blocks_p = all_blocks (block, NULL);
6299 block_vector = xmalloc (*n_blocks_p * sizeof (tree));
6300 all_blocks (block, block_vector);
6301
6302 return block_vector;
6303 }
6304
6305 static GTY(()) int next_block_index = 2;
6306
6307 /* Set BLOCK_NUMBER for all the blocks in FN. */
6308
6309 void
6310 number_blocks (tree fn)
6311 {
6312 int i;
6313 int n_blocks;
6314 tree *block_vector;
6315
6316 /* For SDB and XCOFF debugging output, we start numbering the blocks
6317 from 1 within each function, rather than keeping a running
6318 count. */
6319 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
6320 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
6321 next_block_index = 1;
6322 #endif
6323
6324 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
6325
6326 /* The top-level BLOCK isn't numbered at all. */
6327 for (i = 1; i < n_blocks; ++i)
6328 /* We number the blocks from two. */
6329 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
6330
6331 free (block_vector);
6332
6333 return;
6334 }
6335
6336 /* If VAR is present in a subblock of BLOCK, return the subblock. */
6337
6338 tree
6339 debug_find_var_in_block_tree (tree var, tree block)
6340 {
6341 tree t;
6342
6343 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
6344 if (t == var)
6345 return block;
6346
6347 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
6348 {
6349 tree ret = debug_find_var_in_block_tree (var, t);
6350 if (ret)
6351 return ret;
6352 }
6353
6354 return NULL_TREE;
6355 }
6356 \f
6357 /* Allocate a function structure for FNDECL and set its contents
6358 to the defaults. */
6359
6360 void
6361 allocate_struct_function (tree fndecl)
6362 {
6363 tree result;
6364
6365 cfun = ggc_alloc_cleared (sizeof (struct function));
6366
6367 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
6368
6369 cfun->stack_alignment_needed = STACK_BOUNDARY;
6370 cfun->preferred_stack_boundary = STACK_BOUNDARY;
6371
6372 current_function_funcdef_no = funcdef_no++;
6373
6374 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
6375
6376 init_stmt_for_function ();
6377 init_eh_for_function ();
6378 init_emit ();
6379 init_expr ();
6380 init_varasm_status (cfun);
6381
6382 (*lang_hooks.function.init) (cfun);
6383 if (init_machine_status)
6384 cfun->machine = (*init_machine_status) ();
6385
6386 if (fndecl == NULL)
6387 return;
6388
6389 DECL_SAVED_INSNS (fndecl) = cfun;
6390 cfun->decl = fndecl;
6391
6392 current_function_name = (*lang_hooks.decl_printable_name) (fndecl, 2);
6393
6394 result = DECL_RESULT (fndecl);
6395 if (aggregate_value_p (result, fndecl))
6396 {
6397 #ifdef PCC_STATIC_STRUCT_RETURN
6398 current_function_returns_pcc_struct = 1;
6399 #endif
6400 current_function_returns_struct = 1;
6401 }
6402
6403 current_function_returns_pointer = POINTER_TYPE_P (TREE_TYPE (result));
6404
6405 current_function_needs_context
6406 = (decl_function_context (current_function_decl) != 0
6407 && ! DECL_NO_STATIC_CHAIN (current_function_decl));
6408 }
6409
6410 /* Reset cfun, and other non-struct-function variables to defaults as
6411 appropriate for emitting rtl at the start of a function. */
6412
6413 static void
6414 prepare_function_start (tree fndecl)
6415 {
6416 if (fndecl && DECL_SAVED_INSNS (fndecl))
6417 cfun = DECL_SAVED_INSNS (fndecl);
6418 else
6419 allocate_struct_function (fndecl);
6420
6421 cse_not_expected = ! optimize;
6422
6423 /* Caller save not needed yet. */
6424 caller_save_needed = 0;
6425
6426 /* We haven't done register allocation yet. */
6427 reg_renumber = 0;
6428
6429 /* Indicate that we need to distinguish between the return value of the
6430 present function and the return value of a function being called. */
6431 rtx_equal_function_value_matters = 1;
6432
6433 /* Indicate that we have not instantiated virtual registers yet. */
6434 virtuals_instantiated = 0;
6435
6436 /* Indicate that we want CONCATs now. */
6437 generating_concat_p = 1;
6438
6439 /* Indicate we have no need of a frame pointer yet. */
6440 frame_pointer_needed = 0;
6441 }
6442
6443 /* Initialize the rtl expansion mechanism so that we can do simple things
6444 like generate sequences. This is used to provide a context during global
6445 initialization of some passes. */
6446 void
6447 init_dummy_function_start (void)
6448 {
6449 prepare_function_start (NULL);
6450 }
6451
6452 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
6453 and initialize static variables for generating RTL for the statements
6454 of the function. */
6455
6456 void
6457 init_function_start (tree subr)
6458 {
6459 prepare_function_start (subr);
6460
6461 /* Within function body, compute a type's size as soon it is laid out. */
6462 immediate_size_expand++;
6463
6464 /* Prevent ever trying to delete the first instruction of a
6465 function. Also tell final how to output a linenum before the
6466 function prologue. Note linenums could be missing, e.g. when
6467 compiling a Java .class file. */
6468 if (DECL_SOURCE_LINE (subr))
6469 emit_line_note (DECL_SOURCE_LOCATION (subr));
6470
6471 /* Make sure first insn is a note even if we don't want linenums.
6472 This makes sure the first insn will never be deleted.
6473 Also, final expects a note to appear there. */
6474 emit_note (NOTE_INSN_DELETED);
6475
6476 /* Warn if this value is an aggregate type,
6477 regardless of which calling convention we are using for it. */
6478 if (warn_aggregate_return
6479 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
6480 warning ("function returns an aggregate");
6481 }
6482
6483 /* Make sure all values used by the optimization passes have sane
6484 defaults. */
6485 void
6486 init_function_for_compilation (void)
6487 {
6488 reg_renumber = 0;
6489
6490 /* No prologue/epilogue insns yet. */
6491 VARRAY_GROW (prologue, 0);
6492 VARRAY_GROW (epilogue, 0);
6493 VARRAY_GROW (sibcall_epilogue, 0);
6494 }
6495
6496 /* Expand a call to __main at the beginning of a possible main function. */
6497
6498 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
6499 #undef HAS_INIT_SECTION
6500 #define HAS_INIT_SECTION
6501 #endif
6502
6503 void
6504 expand_main_function (void)
6505 {
6506 #ifdef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN
6507 if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN)
6508 {
6509 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
6510 rtx tmp, seq;
6511
6512 start_sequence ();
6513 /* Forcibly align the stack. */
6514 #ifdef STACK_GROWS_DOWNWARD
6515 tmp = expand_simple_binop (Pmode, AND, stack_pointer_rtx, GEN_INT(-align),
6516 stack_pointer_rtx, 1, OPTAB_WIDEN);
6517 #else
6518 tmp = expand_simple_binop (Pmode, PLUS, stack_pointer_rtx,
6519 GEN_INT (align - 1), NULL_RTX, 1, OPTAB_WIDEN);
6520 tmp = expand_simple_binop (Pmode, AND, tmp, GEN_INT (-align),
6521 stack_pointer_rtx, 1, OPTAB_WIDEN);
6522 #endif
6523 if (tmp != stack_pointer_rtx)
6524 emit_move_insn (stack_pointer_rtx, tmp);
6525
6526 /* Enlist allocate_dynamic_stack_space to pick up the pieces. */
6527 tmp = force_reg (Pmode, const0_rtx);
6528 allocate_dynamic_stack_space (tmp, NULL_RTX, BIGGEST_ALIGNMENT);
6529 seq = get_insns ();
6530 end_sequence ();
6531
6532 for (tmp = get_last_insn (); tmp; tmp = PREV_INSN (tmp))
6533 if (NOTE_P (tmp) && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_FUNCTION_BEG)
6534 break;
6535 if (tmp)
6536 emit_insn_before (seq, tmp);
6537 else
6538 emit_insn (seq);
6539 }
6540 #endif
6541
6542 #ifndef HAS_INIT_SECTION
6543 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
6544 #endif
6545 }
6546 \f
6547 /* The PENDING_SIZES represent the sizes of variable-sized types.
6548 Create RTL for the various sizes now (using temporary variables),
6549 so that we can refer to the sizes from the RTL we are generating
6550 for the current function. The PENDING_SIZES are a TREE_LIST. The
6551 TREE_VALUE of each node is a SAVE_EXPR. */
6552
6553 void
6554 expand_pending_sizes (tree pending_sizes)
6555 {
6556 tree tem;
6557
6558 /* Evaluate now the sizes of any types declared among the arguments. */
6559 for (tem = pending_sizes; tem; tem = TREE_CHAIN (tem))
6560 {
6561 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
6562 /* Flush the queue in case this parameter declaration has
6563 side-effects. */
6564 emit_queue ();
6565 }
6566 }
6567
6568 /* Start the RTL for a new function, and set variables used for
6569 emitting RTL.
6570 SUBR is the FUNCTION_DECL node.
6571 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
6572 the function's parameters, which must be run at any return statement. */
6573
6574 void
6575 expand_function_start (tree subr, int parms_have_cleanups)
6576 {
6577 tree tem;
6578 rtx last_ptr = NULL_RTX;
6579
6580 /* Make sure volatile mem refs aren't considered
6581 valid operands of arithmetic insns. */
6582 init_recog_no_volatile ();
6583
6584 current_function_instrument_entry_exit
6585 = (flag_instrument_function_entry_exit
6586 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6587
6588 current_function_profile
6589 = (profile_flag
6590 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6591
6592 current_function_limit_stack
6593 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
6594
6595 /* If function gets a static chain arg, store it in the stack frame.
6596 Do this first, so it gets the first stack slot offset. */
6597 if (current_function_needs_context)
6598 {
6599 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
6600
6601 /* Delay copying static chain if it is not a register to avoid
6602 conflicts with regs used for parameters. */
6603 if (! SMALL_REGISTER_CLASSES
6604 || GET_CODE (static_chain_incoming_rtx) == REG)
6605 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6606 }
6607
6608 /* If the parameters of this function need cleaning up, get a label
6609 for the beginning of the code which executes those cleanups. This must
6610 be done before doing anything with return_label. */
6611 if (parms_have_cleanups)
6612 cleanup_label = gen_label_rtx ();
6613 else
6614 cleanup_label = 0;
6615
6616 /* Make the label for return statements to jump to. Do not special
6617 case machines with special return instructions -- they will be
6618 handled later during jump, ifcvt, or epilogue creation. */
6619 return_label = gen_label_rtx ();
6620
6621 /* Initialize rtx used to return the value. */
6622 /* Do this before assign_parms so that we copy the struct value address
6623 before any library calls that assign parms might generate. */
6624
6625 /* Decide whether to return the value in memory or in a register. */
6626 if (aggregate_value_p (DECL_RESULT (subr), subr))
6627 {
6628 /* Returning something that won't go in a register. */
6629 rtx value_address = 0;
6630
6631 #ifdef PCC_STATIC_STRUCT_RETURN
6632 if (current_function_returns_pcc_struct)
6633 {
6634 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
6635 value_address = assemble_static_space (size);
6636 }
6637 else
6638 #endif
6639 {
6640 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 1);
6641 /* Expect to be passed the address of a place to store the value.
6642 If it is passed as an argument, assign_parms will take care of
6643 it. */
6644 if (sv)
6645 {
6646 value_address = gen_reg_rtx (Pmode);
6647 emit_move_insn (value_address, sv);
6648 }
6649 }
6650 if (value_address)
6651 {
6652 rtx x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), value_address);
6653 set_mem_attributes (x, DECL_RESULT (subr), 1);
6654 SET_DECL_RTL (DECL_RESULT (subr), x);
6655 }
6656 }
6657 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
6658 /* If return mode is void, this decl rtl should not be used. */
6659 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
6660 else
6661 {
6662 /* Compute the return values into a pseudo reg, which we will copy
6663 into the true return register after the cleanups are done. */
6664
6665 /* In order to figure out what mode to use for the pseudo, we
6666 figure out what the mode of the eventual return register will
6667 actually be, and use that. */
6668 rtx hard_reg
6669 = hard_function_value (TREE_TYPE (DECL_RESULT (subr)),
6670 subr, 1);
6671
6672 /* Structures that are returned in registers are not aggregate_value_p,
6673 so we may see a PARALLEL or a REG. */
6674 if (REG_P (hard_reg))
6675 SET_DECL_RTL (DECL_RESULT (subr), gen_reg_rtx (GET_MODE (hard_reg)));
6676 else if (GET_CODE (hard_reg) == PARALLEL)
6677 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
6678 else
6679 abort ();
6680
6681 /* Set DECL_REGISTER flag so that expand_function_end will copy the
6682 result to the real return register(s). */
6683 DECL_REGISTER (DECL_RESULT (subr)) = 1;
6684 }
6685
6686 /* Initialize rtx for parameters and local variables.
6687 In some cases this requires emitting insns. */
6688
6689 assign_parms (subr);
6690
6691 /* Copy the static chain now if it wasn't a register. The delay is to
6692 avoid conflicts with the parameter passing registers. */
6693
6694 if (SMALL_REGISTER_CLASSES && current_function_needs_context)
6695 if (GET_CODE (static_chain_incoming_rtx) != REG)
6696 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6697
6698 /* The following was moved from init_function_start.
6699 The move is supposed to make sdb output more accurate. */
6700 /* Indicate the beginning of the function body,
6701 as opposed to parm setup. */
6702 emit_note (NOTE_INSN_FUNCTION_BEG);
6703
6704 if (GET_CODE (get_last_insn ()) != NOTE)
6705 emit_note (NOTE_INSN_DELETED);
6706 parm_birth_insn = get_last_insn ();
6707
6708 context_display = 0;
6709 if (current_function_needs_context)
6710 {
6711 /* Fetch static chain values for containing functions. */
6712 tem = decl_function_context (current_function_decl);
6713 /* Copy the static chain pointer into a pseudo. If we have
6714 small register classes, copy the value from memory if
6715 static_chain_incoming_rtx is a REG. */
6716 if (tem)
6717 {
6718 /* If the static chain originally came in a register, put it back
6719 there, then move it out in the next insn. The reason for
6720 this peculiar code is to satisfy function integration. */
6721 if (SMALL_REGISTER_CLASSES
6722 && GET_CODE (static_chain_incoming_rtx) == REG)
6723 emit_move_insn (static_chain_incoming_rtx, last_ptr);
6724 last_ptr = copy_to_reg (static_chain_incoming_rtx);
6725 }
6726
6727 while (tem)
6728 {
6729 tree rtlexp = make_node (RTL_EXPR);
6730
6731 RTL_EXPR_RTL (rtlexp) = last_ptr;
6732 context_display = tree_cons (tem, rtlexp, context_display);
6733 tem = decl_function_context (tem);
6734 if (tem == 0)
6735 break;
6736 /* Chain thru stack frames, assuming pointer to next lexical frame
6737 is found at the place we always store it. */
6738 #ifdef FRAME_GROWS_DOWNWARD
6739 last_ptr = plus_constant (last_ptr,
6740 -(HOST_WIDE_INT) GET_MODE_SIZE (Pmode));
6741 #endif
6742 last_ptr = gen_rtx_MEM (Pmode, memory_address (Pmode, last_ptr));
6743 set_mem_alias_set (last_ptr, get_frame_alias_set ());
6744 last_ptr = copy_to_reg (last_ptr);
6745
6746 /* If we are not optimizing, ensure that we know that this
6747 piece of context is live over the entire function. */
6748 if (! optimize)
6749 save_expr_regs = gen_rtx_EXPR_LIST (VOIDmode, last_ptr,
6750 save_expr_regs);
6751 }
6752 }
6753
6754 if (current_function_instrument_entry_exit)
6755 {
6756 rtx fun = DECL_RTL (current_function_decl);
6757 if (GET_CODE (fun) == MEM)
6758 fun = XEXP (fun, 0);
6759 else
6760 abort ();
6761 emit_library_call (profile_function_entry_libfunc, LCT_NORMAL, VOIDmode,
6762 2, fun, Pmode,
6763 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
6764 0,
6765 hard_frame_pointer_rtx),
6766 Pmode);
6767 }
6768
6769 if (current_function_profile)
6770 {
6771 #ifdef PROFILE_HOOK
6772 PROFILE_HOOK (current_function_funcdef_no);
6773 #endif
6774 }
6775
6776 /* After the display initializations is where the tail-recursion label
6777 should go, if we end up needing one. Ensure we have a NOTE here
6778 since some things (like trampolines) get placed before this. */
6779 tail_recursion_reentry = emit_note (NOTE_INSN_DELETED);
6780
6781 /* Evaluate now the sizes of any types declared among the arguments. */
6782 expand_pending_sizes (nreverse (get_pending_sizes ()));
6783
6784 /* Make sure there is a line number after the function entry setup code. */
6785 force_next_line_note ();
6786 }
6787 \f
6788 /* Undo the effects of init_dummy_function_start. */
6789 void
6790 expand_dummy_function_end (void)
6791 {
6792 /* End any sequences that failed to be closed due to syntax errors. */
6793 while (in_sequence_p ())
6794 end_sequence ();
6795
6796 /* Outside function body, can't compute type's actual size
6797 until next function's body starts. */
6798
6799 free_after_parsing (cfun);
6800 free_after_compilation (cfun);
6801 cfun = 0;
6802 }
6803
6804 /* Call DOIT for each hard register used as a return value from
6805 the current function. */
6806
6807 void
6808 diddle_return_value (void (*doit) (rtx, void *), void *arg)
6809 {
6810 rtx outgoing = current_function_return_rtx;
6811
6812 if (! outgoing)
6813 return;
6814
6815 if (GET_CODE (outgoing) == REG)
6816 (*doit) (outgoing, arg);
6817 else if (GET_CODE (outgoing) == PARALLEL)
6818 {
6819 int i;
6820
6821 for (i = 0; i < XVECLEN (outgoing, 0); i++)
6822 {
6823 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
6824
6825 if (GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
6826 (*doit) (x, arg);
6827 }
6828 }
6829 }
6830
6831 static void
6832 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6833 {
6834 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
6835 }
6836
6837 void
6838 clobber_return_register (void)
6839 {
6840 diddle_return_value (do_clobber_return_reg, NULL);
6841
6842 /* In case we do use pseudo to return value, clobber it too. */
6843 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
6844 {
6845 tree decl_result = DECL_RESULT (current_function_decl);
6846 rtx decl_rtl = DECL_RTL (decl_result);
6847 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
6848 {
6849 do_clobber_return_reg (decl_rtl, NULL);
6850 }
6851 }
6852 }
6853
6854 static void
6855 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6856 {
6857 emit_insn (gen_rtx_USE (VOIDmode, reg));
6858 }
6859
6860 void
6861 use_return_register (void)
6862 {
6863 diddle_return_value (do_use_return_reg, NULL);
6864 }
6865
6866 static GTY(()) rtx initial_trampoline;
6867
6868 /* Generate RTL for the end of the current function. */
6869
6870 void
6871 expand_function_end (void)
6872 {
6873 tree link;
6874 rtx clobber_after;
6875
6876 finish_expr_for_function ();
6877
6878 /* If arg_pointer_save_area was referenced only from a nested
6879 function, we will not have initialized it yet. Do that now. */
6880 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
6881 get_arg_pointer_save_area (cfun);
6882
6883 #ifdef NON_SAVING_SETJMP
6884 /* Don't put any variables in registers if we call setjmp
6885 on a machine that fails to restore the registers. */
6886 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
6887 {
6888 if (DECL_INITIAL (current_function_decl) != error_mark_node)
6889 setjmp_protect (DECL_INITIAL (current_function_decl));
6890
6891 setjmp_protect_args ();
6892 }
6893 #endif
6894
6895 /* Initialize any trampolines required by this function. */
6896 for (link = trampoline_list; link; link = TREE_CHAIN (link))
6897 {
6898 tree function = TREE_PURPOSE (link);
6899 rtx context ATTRIBUTE_UNUSED = lookup_static_chain (function);
6900 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
6901 #ifdef TRAMPOLINE_TEMPLATE
6902 rtx blktramp;
6903 #endif
6904 rtx seq;
6905
6906 #ifdef TRAMPOLINE_TEMPLATE
6907 /* First make sure this compilation has a template for
6908 initializing trampolines. */
6909 if (initial_trampoline == 0)
6910 {
6911 initial_trampoline
6912 = gen_rtx_MEM (BLKmode, assemble_trampoline_template ());
6913 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
6914 }
6915 #endif
6916
6917 /* Generate insns to initialize the trampoline. */
6918 start_sequence ();
6919 tramp = round_trampoline_addr (XEXP (tramp, 0));
6920 #ifdef TRAMPOLINE_TEMPLATE
6921 blktramp = replace_equiv_address (initial_trampoline, tramp);
6922 emit_block_move (blktramp, initial_trampoline,
6923 GEN_INT (TRAMPOLINE_SIZE), BLOCK_OP_NORMAL);
6924 #endif
6925 trampolines_created = 1;
6926 INITIALIZE_TRAMPOLINE (tramp, XEXP (DECL_RTL (function), 0), context);
6927 seq = get_insns ();
6928 end_sequence ();
6929
6930 /* Put those insns at entry to the containing function (this one). */
6931 emit_insn_before (seq, tail_recursion_reentry);
6932 }
6933
6934 /* If we are doing stack checking and this function makes calls,
6935 do a stack probe at the start of the function to ensure we have enough
6936 space for another stack frame. */
6937 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
6938 {
6939 rtx insn, seq;
6940
6941 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6942 if (GET_CODE (insn) == CALL_INSN)
6943 {
6944 start_sequence ();
6945 probe_stack_range (STACK_CHECK_PROTECT,
6946 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
6947 seq = get_insns ();
6948 end_sequence ();
6949 emit_insn_before (seq, tail_recursion_reentry);
6950 break;
6951 }
6952 }
6953
6954 /* Possibly warn about unused parameters. */
6955 if (warn_unused_parameter)
6956 {
6957 tree decl;
6958
6959 for (decl = DECL_ARGUMENTS (current_function_decl);
6960 decl; decl = TREE_CHAIN (decl))
6961 if (! TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
6962 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
6963 warning ("%Junused parameter '%D'", decl, decl);
6964 }
6965
6966 /* Delete handlers for nonlocal gotos if nothing uses them. */
6967 if (nonlocal_goto_handler_slots != 0
6968 && ! current_function_has_nonlocal_label)
6969 delete_handlers ();
6970
6971 /* End any sequences that failed to be closed due to syntax errors. */
6972 while (in_sequence_p ())
6973 end_sequence ();
6974
6975 /* Outside function body, can't compute type's actual size
6976 until next function's body starts. */
6977 immediate_size_expand--;
6978
6979 clear_pending_stack_adjust ();
6980 do_pending_stack_adjust ();
6981
6982 /* Mark the end of the function body.
6983 If control reaches this insn, the function can drop through
6984 without returning a value. */
6985 emit_note (NOTE_INSN_FUNCTION_END);
6986
6987 /* Must mark the last line number note in the function, so that the test
6988 coverage code can avoid counting the last line twice. This just tells
6989 the code to ignore the immediately following line note, since there
6990 already exists a copy of this note somewhere above. This line number
6991 note is still needed for debugging though, so we can't delete it. */
6992 if (flag_test_coverage)
6993 emit_note (NOTE_INSN_REPEATED_LINE_NUMBER);
6994
6995 /* Output a linenumber for the end of the function.
6996 SDB depends on this. */
6997 force_next_line_note ();
6998 emit_line_note (input_location);
6999
7000 /* Before the return label (if any), clobber the return
7001 registers so that they are not propagated live to the rest of
7002 the function. This can only happen with functions that drop
7003 through; if there had been a return statement, there would
7004 have either been a return rtx, or a jump to the return label.
7005
7006 We delay actual code generation after the current_function_value_rtx
7007 is computed. */
7008 clobber_after = get_last_insn ();
7009
7010 /* Output the label for the actual return from the function,
7011 if one is expected. This happens either because a function epilogue
7012 is used instead of a return instruction, or because a return was done
7013 with a goto in order to run local cleanups, or because of pcc-style
7014 structure returning. */
7015 if (return_label)
7016 emit_label (return_label);
7017
7018 if (current_function_instrument_entry_exit)
7019 {
7020 rtx fun = DECL_RTL (current_function_decl);
7021 if (GET_CODE (fun) == MEM)
7022 fun = XEXP (fun, 0);
7023 else
7024 abort ();
7025 emit_library_call (profile_function_exit_libfunc, LCT_NORMAL, VOIDmode,
7026 2, fun, Pmode,
7027 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
7028 0,
7029 hard_frame_pointer_rtx),
7030 Pmode);
7031 }
7032
7033 /* Let except.c know where it should emit the call to unregister
7034 the function context for sjlj exceptions. */
7035 if (flag_exceptions && USING_SJLJ_EXCEPTIONS)
7036 sjlj_emit_function_exit_after (get_last_insn ());
7037
7038 /* If we had calls to alloca, and this machine needs
7039 an accurate stack pointer to exit the function,
7040 insert some code to save and restore the stack pointer. */
7041 #ifdef EXIT_IGNORE_STACK
7042 if (! EXIT_IGNORE_STACK)
7043 #endif
7044 if (current_function_calls_alloca)
7045 {
7046 rtx tem = 0;
7047
7048 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
7049 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
7050 }
7051
7052 /* If scalar return value was computed in a pseudo-reg, or was a named
7053 return value that got dumped to the stack, copy that to the hard
7054 return register. */
7055 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
7056 {
7057 tree decl_result = DECL_RESULT (current_function_decl);
7058 rtx decl_rtl = DECL_RTL (decl_result);
7059
7060 if (REG_P (decl_rtl)
7061 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
7062 : DECL_REGISTER (decl_result))
7063 {
7064 rtx real_decl_rtl = current_function_return_rtx;
7065
7066 /* This should be set in assign_parms. */
7067 if (! REG_FUNCTION_VALUE_P (real_decl_rtl))
7068 abort ();
7069
7070 /* If this is a BLKmode structure being returned in registers,
7071 then use the mode computed in expand_return. Note that if
7072 decl_rtl is memory, then its mode may have been changed,
7073 but that current_function_return_rtx has not. */
7074 if (GET_MODE (real_decl_rtl) == BLKmode)
7075 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
7076
7077 /* If a named return value dumped decl_return to memory, then
7078 we may need to re-do the PROMOTE_MODE signed/unsigned
7079 extension. */
7080 if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
7081 {
7082 int unsignedp = TREE_UNSIGNED (TREE_TYPE (decl_result));
7083
7084 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
7085 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
7086 &unsignedp, 1);
7087
7088 convert_move (real_decl_rtl, decl_rtl, unsignedp);
7089 }
7090 else if (GET_CODE (real_decl_rtl) == PARALLEL)
7091 {
7092 /* If expand_function_start has created a PARALLEL for decl_rtl,
7093 move the result to the real return registers. Otherwise, do
7094 a group load from decl_rtl for a named return. */
7095 if (GET_CODE (decl_rtl) == PARALLEL)
7096 emit_group_move (real_decl_rtl, decl_rtl);
7097 else
7098 emit_group_load (real_decl_rtl, decl_rtl,
7099 TREE_TYPE (decl_result),
7100 int_size_in_bytes (TREE_TYPE (decl_result)));
7101 }
7102 else
7103 emit_move_insn (real_decl_rtl, decl_rtl);
7104 }
7105 }
7106
7107 /* If returning a structure, arrange to return the address of the value
7108 in a place where debuggers expect to find it.
7109
7110 If returning a structure PCC style,
7111 the caller also depends on this value.
7112 And current_function_returns_pcc_struct is not necessarily set. */
7113 if (current_function_returns_struct
7114 || current_function_returns_pcc_struct)
7115 {
7116 rtx value_address
7117 = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
7118 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
7119 #ifdef FUNCTION_OUTGOING_VALUE
7120 rtx outgoing
7121 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
7122 current_function_decl);
7123 #else
7124 rtx outgoing
7125 = FUNCTION_VALUE (build_pointer_type (type), current_function_decl);
7126 #endif
7127
7128 /* Mark this as a function return value so integrate will delete the
7129 assignment and USE below when inlining this function. */
7130 REG_FUNCTION_VALUE_P (outgoing) = 1;
7131
7132 /* The address may be ptr_mode and OUTGOING may be Pmode. */
7133 value_address = convert_memory_address (GET_MODE (outgoing),
7134 value_address);
7135
7136 emit_move_insn (outgoing, value_address);
7137
7138 /* Show return register used to hold result (in this case the address
7139 of the result. */
7140 current_function_return_rtx = outgoing;
7141 }
7142
7143 /* If this is an implementation of throw, do what's necessary to
7144 communicate between __builtin_eh_return and the epilogue. */
7145 expand_eh_return ();
7146
7147 /* Emit the actual code to clobber return register. */
7148 {
7149 rtx seq, after;
7150
7151 start_sequence ();
7152 clobber_return_register ();
7153 seq = get_insns ();
7154 end_sequence ();
7155
7156 after = emit_insn_after (seq, clobber_after);
7157
7158 if (clobber_after != after)
7159 cfun->x_clobber_return_insn = after;
7160 }
7161
7162 /* Output the label for the naked return from the function, if one is
7163 expected. This is currently used only by __builtin_return. */
7164 if (naked_return_label)
7165 emit_label (naked_return_label);
7166
7167 /* ??? This should no longer be necessary since stupid is no longer with
7168 us, but there are some parts of the compiler (eg reload_combine, and
7169 sh mach_dep_reorg) that still try and compute their own lifetime info
7170 instead of using the general framework. */
7171 use_return_register ();
7172
7173 /* Fix up any gotos that jumped out to the outermost
7174 binding level of the function.
7175 Must follow emitting RETURN_LABEL. */
7176
7177 /* If you have any cleanups to do at this point,
7178 and they need to create temporary variables,
7179 then you will lose. */
7180 expand_fixups (get_insns ());
7181 }
7182
7183 rtx
7184 get_arg_pointer_save_area (struct function *f)
7185 {
7186 rtx ret = f->x_arg_pointer_save_area;
7187
7188 if (! ret)
7189 {
7190 ret = assign_stack_local_1 (Pmode, GET_MODE_SIZE (Pmode), 0, f);
7191 f->x_arg_pointer_save_area = ret;
7192 }
7193
7194 if (f == cfun && ! f->arg_pointer_save_area_init)
7195 {
7196 rtx seq;
7197
7198 /* Save the arg pointer at the beginning of the function. The
7199 generated stack slot may not be a valid memory address, so we
7200 have to check it and fix it if necessary. */
7201 start_sequence ();
7202 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
7203 seq = get_insns ();
7204 end_sequence ();
7205
7206 push_topmost_sequence ();
7207 emit_insn_after (seq, get_insns ());
7208 pop_topmost_sequence ();
7209 }
7210
7211 return ret;
7212 }
7213 \f
7214 /* Extend a vector that records the INSN_UIDs of INSNS
7215 (a list of one or more insns). */
7216
7217 static void
7218 record_insns (rtx insns, varray_type *vecp)
7219 {
7220 int i, len;
7221 rtx tmp;
7222
7223 tmp = insns;
7224 len = 0;
7225 while (tmp != NULL_RTX)
7226 {
7227 len++;
7228 tmp = NEXT_INSN (tmp);
7229 }
7230
7231 i = VARRAY_SIZE (*vecp);
7232 VARRAY_GROW (*vecp, i + len);
7233 tmp = insns;
7234 while (tmp != NULL_RTX)
7235 {
7236 VARRAY_INT (*vecp, i) = INSN_UID (tmp);
7237 i++;
7238 tmp = NEXT_INSN (tmp);
7239 }
7240 }
7241
7242 /* Set the specified locator to the insn chain. */
7243 static void
7244 set_insn_locators (rtx insn, int loc)
7245 {
7246 while (insn != NULL_RTX)
7247 {
7248 if (INSN_P (insn))
7249 INSN_LOCATOR (insn) = loc;
7250 insn = NEXT_INSN (insn);
7251 }
7252 }
7253
7254 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
7255 be running after reorg, SEQUENCE rtl is possible. */
7256
7257 static int
7258 contains (rtx insn, varray_type vec)
7259 {
7260 int i, j;
7261
7262 if (GET_CODE (insn) == INSN
7263 && GET_CODE (PATTERN (insn)) == SEQUENCE)
7264 {
7265 int count = 0;
7266 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
7267 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
7268 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == VARRAY_INT (vec, j))
7269 count++;
7270 return count;
7271 }
7272 else
7273 {
7274 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
7275 if (INSN_UID (insn) == VARRAY_INT (vec, j))
7276 return 1;
7277 }
7278 return 0;
7279 }
7280
7281 int
7282 prologue_epilogue_contains (rtx insn)
7283 {
7284 if (contains (insn, prologue))
7285 return 1;
7286 if (contains (insn, epilogue))
7287 return 1;
7288 return 0;
7289 }
7290
7291 int
7292 sibcall_epilogue_contains (rtx insn)
7293 {
7294 if (sibcall_epilogue)
7295 return contains (insn, sibcall_epilogue);
7296 return 0;
7297 }
7298
7299 #ifdef HAVE_return
7300 /* Insert gen_return at the end of block BB. This also means updating
7301 block_for_insn appropriately. */
7302
7303 static void
7304 emit_return_into_block (basic_block bb, rtx line_note)
7305 {
7306 emit_jump_insn_after (gen_return (), BB_END (bb));
7307 if (line_note)
7308 emit_note_copy_after (line_note, PREV_INSN (BB_END (bb)));
7309 }
7310 #endif /* HAVE_return */
7311
7312 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
7313
7314 /* These functions convert the epilogue into a variant that does not modify the
7315 stack pointer. This is used in cases where a function returns an object
7316 whose size is not known until it is computed. The called function leaves the
7317 object on the stack, leaves the stack depressed, and returns a pointer to
7318 the object.
7319
7320 What we need to do is track all modifications and references to the stack
7321 pointer, deleting the modifications and changing the references to point to
7322 the location the stack pointer would have pointed to had the modifications
7323 taken place.
7324
7325 These functions need to be portable so we need to make as few assumptions
7326 about the epilogue as we can. However, the epilogue basically contains
7327 three things: instructions to reset the stack pointer, instructions to
7328 reload registers, possibly including the frame pointer, and an
7329 instruction to return to the caller.
7330
7331 If we can't be sure of what a relevant epilogue insn is doing, we abort.
7332 We also make no attempt to validate the insns we make since if they are
7333 invalid, we probably can't do anything valid. The intent is that these
7334 routines get "smarter" as more and more machines start to use them and
7335 they try operating on different epilogues.
7336
7337 We use the following structure to track what the part of the epilogue that
7338 we've already processed has done. We keep two copies of the SP equivalence,
7339 one for use during the insn we are processing and one for use in the next
7340 insn. The difference is because one part of a PARALLEL may adjust SP
7341 and the other may use it. */
7342
7343 struct epi_info
7344 {
7345 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
7346 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
7347 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
7348 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
7349 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
7350 should be set to once we no longer need
7351 its value. */
7352 rtx const_equiv[FIRST_PSEUDO_REGISTER]; /* Any known constant equivalences
7353 for registers. */
7354 };
7355
7356 static void handle_epilogue_set (rtx, struct epi_info *);
7357 static void update_epilogue_consts (rtx, rtx, void *);
7358 static void emit_equiv_load (struct epi_info *);
7359
7360 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
7361 no modifications to the stack pointer. Return the new list of insns. */
7362
7363 static rtx
7364 keep_stack_depressed (rtx insns)
7365 {
7366 int j;
7367 struct epi_info info;
7368 rtx insn, next;
7369
7370 /* If the epilogue is just a single instruction, it must be OK as is. */
7371 if (NEXT_INSN (insns) == NULL_RTX)
7372 return insns;
7373
7374 /* Otherwise, start a sequence, initialize the information we have, and
7375 process all the insns we were given. */
7376 start_sequence ();
7377
7378 info.sp_equiv_reg = stack_pointer_rtx;
7379 info.sp_offset = 0;
7380 info.equiv_reg_src = 0;
7381
7382 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
7383 info.const_equiv[j] = 0;
7384
7385 insn = insns;
7386 next = NULL_RTX;
7387 while (insn != NULL_RTX)
7388 {
7389 next = NEXT_INSN (insn);
7390
7391 if (!INSN_P (insn))
7392 {
7393 add_insn (insn);
7394 insn = next;
7395 continue;
7396 }
7397
7398 /* If this insn references the register that SP is equivalent to and
7399 we have a pending load to that register, we must force out the load
7400 first and then indicate we no longer know what SP's equivalent is. */
7401 if (info.equiv_reg_src != 0
7402 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
7403 {
7404 emit_equiv_load (&info);
7405 info.sp_equiv_reg = 0;
7406 }
7407
7408 info.new_sp_equiv_reg = info.sp_equiv_reg;
7409 info.new_sp_offset = info.sp_offset;
7410
7411 /* If this is a (RETURN) and the return address is on the stack,
7412 update the address and change to an indirect jump. */
7413 if (GET_CODE (PATTERN (insn)) == RETURN
7414 || (GET_CODE (PATTERN (insn)) == PARALLEL
7415 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
7416 {
7417 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
7418 rtx base = 0;
7419 HOST_WIDE_INT offset = 0;
7420 rtx jump_insn, jump_set;
7421
7422 /* If the return address is in a register, we can emit the insn
7423 unchanged. Otherwise, it must be a MEM and we see what the
7424 base register and offset are. In any case, we have to emit any
7425 pending load to the equivalent reg of SP, if any. */
7426 if (GET_CODE (retaddr) == REG)
7427 {
7428 emit_equiv_load (&info);
7429 add_insn (insn);
7430 insn = next;
7431 continue;
7432 }
7433 else if (GET_CODE (retaddr) == MEM
7434 && GET_CODE (XEXP (retaddr, 0)) == REG)
7435 base = gen_rtx_REG (Pmode, REGNO (XEXP (retaddr, 0))), offset = 0;
7436 else if (GET_CODE (retaddr) == MEM
7437 && GET_CODE (XEXP (retaddr, 0)) == PLUS
7438 && GET_CODE (XEXP (XEXP (retaddr, 0), 0)) == REG
7439 && GET_CODE (XEXP (XEXP (retaddr, 0), 1)) == CONST_INT)
7440 {
7441 base = gen_rtx_REG (Pmode, REGNO (XEXP (XEXP (retaddr, 0), 0)));
7442 offset = INTVAL (XEXP (XEXP (retaddr, 0), 1));
7443 }
7444 else
7445 abort ();
7446
7447 /* If the base of the location containing the return pointer
7448 is SP, we must update it with the replacement address. Otherwise,
7449 just build the necessary MEM. */
7450 retaddr = plus_constant (base, offset);
7451 if (base == stack_pointer_rtx)
7452 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
7453 plus_constant (info.sp_equiv_reg,
7454 info.sp_offset));
7455
7456 retaddr = gen_rtx_MEM (Pmode, retaddr);
7457
7458 /* If there is a pending load to the equivalent register for SP
7459 and we reference that register, we must load our address into
7460 a scratch register and then do that load. */
7461 if (info.equiv_reg_src
7462 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
7463 {
7464 unsigned int regno;
7465 rtx reg;
7466
7467 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
7468 if (HARD_REGNO_MODE_OK (regno, Pmode)
7469 && !fixed_regs[regno]
7470 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
7471 && !REGNO_REG_SET_P (EXIT_BLOCK_PTR->global_live_at_start,
7472 regno)
7473 && !refers_to_regno_p (regno,
7474 regno + HARD_REGNO_NREGS (regno,
7475 Pmode),
7476 info.equiv_reg_src, NULL)
7477 && info.const_equiv[regno] == 0)
7478 break;
7479
7480 if (regno == FIRST_PSEUDO_REGISTER)
7481 abort ();
7482
7483 reg = gen_rtx_REG (Pmode, regno);
7484 emit_move_insn (reg, retaddr);
7485 retaddr = reg;
7486 }
7487
7488 emit_equiv_load (&info);
7489 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
7490
7491 /* Show the SET in the above insn is a RETURN. */
7492 jump_set = single_set (jump_insn);
7493 if (jump_set == 0)
7494 abort ();
7495 else
7496 SET_IS_RETURN_P (jump_set) = 1;
7497 }
7498
7499 /* If SP is not mentioned in the pattern and its equivalent register, if
7500 any, is not modified, just emit it. Otherwise, if neither is set,
7501 replace the reference to SP and emit the insn. If none of those are
7502 true, handle each SET individually. */
7503 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
7504 && (info.sp_equiv_reg == stack_pointer_rtx
7505 || !reg_set_p (info.sp_equiv_reg, insn)))
7506 add_insn (insn);
7507 else if (! reg_set_p (stack_pointer_rtx, insn)
7508 && (info.sp_equiv_reg == stack_pointer_rtx
7509 || !reg_set_p (info.sp_equiv_reg, insn)))
7510 {
7511 if (! validate_replace_rtx (stack_pointer_rtx,
7512 plus_constant (info.sp_equiv_reg,
7513 info.sp_offset),
7514 insn))
7515 abort ();
7516
7517 add_insn (insn);
7518 }
7519 else if (GET_CODE (PATTERN (insn)) == SET)
7520 handle_epilogue_set (PATTERN (insn), &info);
7521 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
7522 {
7523 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
7524 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
7525 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
7526 }
7527 else
7528 add_insn (insn);
7529
7530 info.sp_equiv_reg = info.new_sp_equiv_reg;
7531 info.sp_offset = info.new_sp_offset;
7532
7533 /* Now update any constants this insn sets. */
7534 note_stores (PATTERN (insn), update_epilogue_consts, &info);
7535 insn = next;
7536 }
7537
7538 insns = get_insns ();
7539 end_sequence ();
7540 return insns;
7541 }
7542
7543 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
7544 structure that contains information about what we've seen so far. We
7545 process this SET by either updating that data or by emitting one or
7546 more insns. */
7547
7548 static void
7549 handle_epilogue_set (rtx set, struct epi_info *p)
7550 {
7551 /* First handle the case where we are setting SP. Record what it is being
7552 set from. If unknown, abort. */
7553 if (reg_set_p (stack_pointer_rtx, set))
7554 {
7555 if (SET_DEST (set) != stack_pointer_rtx)
7556 abort ();
7557
7558 if (GET_CODE (SET_SRC (set)) == PLUS)
7559 {
7560 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
7561 if (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
7562 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
7563 else if (GET_CODE (XEXP (SET_SRC (set), 1)) == REG
7564 && REGNO (XEXP (SET_SRC (set), 1)) < FIRST_PSEUDO_REGISTER
7565 && p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))] != 0)
7566 p->new_sp_offset
7567 = INTVAL (p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
7568 else
7569 abort ();
7570 }
7571 else
7572 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
7573
7574 /* If we are adjusting SP, we adjust from the old data. */
7575 if (p->new_sp_equiv_reg == stack_pointer_rtx)
7576 {
7577 p->new_sp_equiv_reg = p->sp_equiv_reg;
7578 p->new_sp_offset += p->sp_offset;
7579 }
7580
7581 if (p->new_sp_equiv_reg == 0 || GET_CODE (p->new_sp_equiv_reg) != REG)
7582 abort ();
7583
7584 return;
7585 }
7586
7587 /* Next handle the case where we are setting SP's equivalent register.
7588 If we already have a value to set it to, abort. We could update, but
7589 there seems little point in handling that case. Note that we have
7590 to allow for the case where we are setting the register set in
7591 the previous part of a PARALLEL inside a single insn. But use the
7592 old offset for any updates within this insn. We must allow for the case
7593 where the register is being set in a different (usually wider) mode than
7594 Pmode). */
7595 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
7596 {
7597 if (p->equiv_reg_src != 0
7598 || GET_CODE (p->new_sp_equiv_reg) != REG
7599 || GET_CODE (SET_DEST (set)) != REG
7600 || GET_MODE_BITSIZE (GET_MODE (SET_DEST (set))) > BITS_PER_WORD
7601 || REGNO (p->new_sp_equiv_reg) != REGNO (SET_DEST (set)))
7602 abort ();
7603 else
7604 p->equiv_reg_src
7605 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7606 plus_constant (p->sp_equiv_reg,
7607 p->sp_offset));
7608 }
7609
7610 /* Otherwise, replace any references to SP in the insn to its new value
7611 and emit the insn. */
7612 else
7613 {
7614 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7615 plus_constant (p->sp_equiv_reg,
7616 p->sp_offset));
7617 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
7618 plus_constant (p->sp_equiv_reg,
7619 p->sp_offset));
7620 emit_insn (set);
7621 }
7622 }
7623
7624 /* Update the tracking information for registers set to constants. */
7625
7626 static void
7627 update_epilogue_consts (rtx dest, rtx x, void *data)
7628 {
7629 struct epi_info *p = (struct epi_info *) data;
7630
7631 if (GET_CODE (dest) != REG || REGNO (dest) >= FIRST_PSEUDO_REGISTER)
7632 return;
7633 else if (GET_CODE (x) == CLOBBER || ! rtx_equal_p (dest, SET_DEST (x))
7634 || GET_CODE (SET_SRC (x)) != CONST_INT)
7635 p->const_equiv[REGNO (dest)] = 0;
7636 else
7637 p->const_equiv[REGNO (dest)] = SET_SRC (x);
7638 }
7639
7640 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
7641
7642 static void
7643 emit_equiv_load (struct epi_info *p)
7644 {
7645 if (p->equiv_reg_src != 0)
7646 {
7647 rtx dest = p->sp_equiv_reg;
7648
7649 if (GET_MODE (p->equiv_reg_src) != GET_MODE (dest))
7650 dest = gen_rtx_REG (GET_MODE (p->equiv_reg_src),
7651 REGNO (p->sp_equiv_reg));
7652
7653 emit_move_insn (dest, p->equiv_reg_src);
7654 p->equiv_reg_src = 0;
7655 }
7656 }
7657 #endif
7658
7659 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
7660 this into place with notes indicating where the prologue ends and where
7661 the epilogue begins. Update the basic block information when possible. */
7662
7663 void
7664 thread_prologue_and_epilogue_insns (rtx f ATTRIBUTE_UNUSED)
7665 {
7666 int inserted = 0;
7667 edge e;
7668 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
7669 rtx seq;
7670 #endif
7671 #ifdef HAVE_prologue
7672 rtx prologue_end = NULL_RTX;
7673 #endif
7674 #if defined (HAVE_epilogue) || defined(HAVE_return)
7675 rtx epilogue_end = NULL_RTX;
7676 #endif
7677
7678 #ifdef HAVE_prologue
7679 if (HAVE_prologue)
7680 {
7681 start_sequence ();
7682 seq = gen_prologue ();
7683 emit_insn (seq);
7684
7685 /* Retain a map of the prologue insns. */
7686 record_insns (seq, &prologue);
7687 prologue_end = emit_note (NOTE_INSN_PROLOGUE_END);
7688
7689 seq = get_insns ();
7690 end_sequence ();
7691 set_insn_locators (seq, prologue_locator);
7692
7693 /* Can't deal with multiple successors of the entry block
7694 at the moment. Function should always have at least one
7695 entry point. */
7696 if (!ENTRY_BLOCK_PTR->succ || ENTRY_BLOCK_PTR->succ->succ_next)
7697 abort ();
7698
7699 insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
7700 inserted = 1;
7701 }
7702 #endif
7703
7704 /* If the exit block has no non-fake predecessors, we don't need
7705 an epilogue. */
7706 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7707 if ((e->flags & EDGE_FAKE) == 0)
7708 break;
7709 if (e == NULL)
7710 goto epilogue_done;
7711
7712 #ifdef HAVE_return
7713 if (optimize && HAVE_return)
7714 {
7715 /* If we're allowed to generate a simple return instruction,
7716 then by definition we don't need a full epilogue. Examine
7717 the block that falls through to EXIT. If it does not
7718 contain any code, examine its predecessors and try to
7719 emit (conditional) return instructions. */
7720
7721 basic_block last;
7722 edge e_next;
7723 rtx label;
7724
7725 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7726 if (e->flags & EDGE_FALLTHRU)
7727 break;
7728 if (e == NULL)
7729 goto epilogue_done;
7730 last = e->src;
7731
7732 /* Verify that there are no active instructions in the last block. */
7733 label = BB_END (last);
7734 while (label && GET_CODE (label) != CODE_LABEL)
7735 {
7736 if (active_insn_p (label))
7737 break;
7738 label = PREV_INSN (label);
7739 }
7740
7741 if (BB_HEAD (last) == label && GET_CODE (label) == CODE_LABEL)
7742 {
7743 rtx epilogue_line_note = NULL_RTX;
7744
7745 /* Locate the line number associated with the closing brace,
7746 if we can find one. */
7747 for (seq = get_last_insn ();
7748 seq && ! active_insn_p (seq);
7749 seq = PREV_INSN (seq))
7750 if (GET_CODE (seq) == NOTE && NOTE_LINE_NUMBER (seq) > 0)
7751 {
7752 epilogue_line_note = seq;
7753 break;
7754 }
7755
7756 for (e = last->pred; e; e = e_next)
7757 {
7758 basic_block bb = e->src;
7759 rtx jump;
7760
7761 e_next = e->pred_next;
7762 if (bb == ENTRY_BLOCK_PTR)
7763 continue;
7764
7765 jump = BB_END (bb);
7766 if ((GET_CODE (jump) != JUMP_INSN) || JUMP_LABEL (jump) != label)
7767 continue;
7768
7769 /* If we have an unconditional jump, we can replace that
7770 with a simple return instruction. */
7771 if (simplejump_p (jump))
7772 {
7773 emit_return_into_block (bb, epilogue_line_note);
7774 delete_insn (jump);
7775 }
7776
7777 /* If we have a conditional jump, we can try to replace
7778 that with a conditional return instruction. */
7779 else if (condjump_p (jump))
7780 {
7781 if (! redirect_jump (jump, 0, 0))
7782 continue;
7783
7784 /* If this block has only one successor, it both jumps
7785 and falls through to the fallthru block, so we can't
7786 delete the edge. */
7787 if (bb->succ->succ_next == NULL)
7788 continue;
7789 }
7790 else
7791 continue;
7792
7793 /* Fix up the CFG for the successful change we just made. */
7794 redirect_edge_succ (e, EXIT_BLOCK_PTR);
7795 }
7796
7797 /* Emit a return insn for the exit fallthru block. Whether
7798 this is still reachable will be determined later. */
7799
7800 emit_barrier_after (BB_END (last));
7801 emit_return_into_block (last, epilogue_line_note);
7802 epilogue_end = BB_END (last);
7803 last->succ->flags &= ~EDGE_FALLTHRU;
7804 goto epilogue_done;
7805 }
7806 }
7807 #endif
7808 #ifdef HAVE_epilogue
7809 if (HAVE_epilogue)
7810 {
7811 /* Find the edge that falls through to EXIT. Other edges may exist
7812 due to RETURN instructions, but those don't need epilogues.
7813 There really shouldn't be a mixture -- either all should have
7814 been converted or none, however... */
7815
7816 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7817 if (e->flags & EDGE_FALLTHRU)
7818 break;
7819 if (e == NULL)
7820 goto epilogue_done;
7821
7822 start_sequence ();
7823 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
7824
7825 seq = gen_epilogue ();
7826
7827 #ifdef INCOMING_RETURN_ADDR_RTX
7828 /* If this function returns with the stack depressed and we can support
7829 it, massage the epilogue to actually do that. */
7830 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
7831 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
7832 seq = keep_stack_depressed (seq);
7833 #endif
7834
7835 emit_jump_insn (seq);
7836
7837 /* Retain a map of the epilogue insns. */
7838 record_insns (seq, &epilogue);
7839 set_insn_locators (seq, epilogue_locator);
7840
7841 seq = get_insns ();
7842 end_sequence ();
7843
7844 insert_insn_on_edge (seq, e);
7845 inserted = 1;
7846 }
7847 #endif
7848 epilogue_done:
7849
7850 if (inserted)
7851 commit_edge_insertions ();
7852
7853 #ifdef HAVE_sibcall_epilogue
7854 /* Emit sibling epilogues before any sibling call sites. */
7855 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7856 {
7857 basic_block bb = e->src;
7858 rtx insn = BB_END (bb);
7859 rtx i;
7860 rtx newinsn;
7861
7862 if (GET_CODE (insn) != CALL_INSN
7863 || ! SIBLING_CALL_P (insn))
7864 continue;
7865
7866 start_sequence ();
7867 emit_insn (gen_sibcall_epilogue ());
7868 seq = get_insns ();
7869 end_sequence ();
7870
7871 /* Retain a map of the epilogue insns. Used in life analysis to
7872 avoid getting rid of sibcall epilogue insns. Do this before we
7873 actually emit the sequence. */
7874 record_insns (seq, &sibcall_epilogue);
7875 set_insn_locators (seq, epilogue_locator);
7876
7877 i = PREV_INSN (insn);
7878 newinsn = emit_insn_before (seq, insn);
7879 }
7880 #endif
7881
7882 #ifdef HAVE_prologue
7883 if (prologue_end)
7884 {
7885 rtx insn, prev;
7886
7887 /* GDB handles `break f' by setting a breakpoint on the first
7888 line note after the prologue. Which means (1) that if
7889 there are line number notes before where we inserted the
7890 prologue we should move them, and (2) we should generate a
7891 note before the end of the first basic block, if there isn't
7892 one already there.
7893
7894 ??? This behavior is completely broken when dealing with
7895 multiple entry functions. We simply place the note always
7896 into first basic block and let alternate entry points
7897 to be missed.
7898 */
7899
7900 for (insn = prologue_end; insn; insn = prev)
7901 {
7902 prev = PREV_INSN (insn);
7903 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7904 {
7905 /* Note that we cannot reorder the first insn in the
7906 chain, since rest_of_compilation relies on that
7907 remaining constant. */
7908 if (prev == NULL)
7909 break;
7910 reorder_insns (insn, insn, prologue_end);
7911 }
7912 }
7913
7914 /* Find the last line number note in the first block. */
7915 for (insn = BB_END (ENTRY_BLOCK_PTR->next_bb);
7916 insn != prologue_end && insn;
7917 insn = PREV_INSN (insn))
7918 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7919 break;
7920
7921 /* If we didn't find one, make a copy of the first line number
7922 we run across. */
7923 if (! insn)
7924 {
7925 for (insn = next_active_insn (prologue_end);
7926 insn;
7927 insn = PREV_INSN (insn))
7928 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7929 {
7930 emit_note_copy_after (insn, prologue_end);
7931 break;
7932 }
7933 }
7934 }
7935 #endif
7936 #ifdef HAVE_epilogue
7937 if (epilogue_end)
7938 {
7939 rtx insn, next;
7940
7941 /* Similarly, move any line notes that appear after the epilogue.
7942 There is no need, however, to be quite so anal about the existence
7943 of such a note. */
7944 for (insn = epilogue_end; insn; insn = next)
7945 {
7946 next = NEXT_INSN (insn);
7947 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7948 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
7949 }
7950 }
7951 #endif
7952 }
7953
7954 /* Reposition the prologue-end and epilogue-begin notes after instruction
7955 scheduling and delayed branch scheduling. */
7956
7957 void
7958 reposition_prologue_and_epilogue_notes (rtx f ATTRIBUTE_UNUSED)
7959 {
7960 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
7961 rtx insn, last, note;
7962 int len;
7963
7964 if ((len = VARRAY_SIZE (prologue)) > 0)
7965 {
7966 last = 0, note = 0;
7967
7968 /* Scan from the beginning until we reach the last prologue insn.
7969 We apparently can't depend on basic_block_{head,end} after
7970 reorg has run. */
7971 for (insn = f; insn; insn = NEXT_INSN (insn))
7972 {
7973 if (GET_CODE (insn) == NOTE)
7974 {
7975 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
7976 note = insn;
7977 }
7978 else if (contains (insn, prologue))
7979 {
7980 last = insn;
7981 if (--len == 0)
7982 break;
7983 }
7984 }
7985
7986 if (last)
7987 {
7988 /* Find the prologue-end note if we haven't already, and
7989 move it to just after the last prologue insn. */
7990 if (note == 0)
7991 {
7992 for (note = last; (note = NEXT_INSN (note));)
7993 if (GET_CODE (note) == NOTE
7994 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
7995 break;
7996 }
7997
7998 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
7999 if (GET_CODE (last) == CODE_LABEL)
8000 last = NEXT_INSN (last);
8001 reorder_insns (note, note, last);
8002 }
8003 }
8004
8005 if ((len = VARRAY_SIZE (epilogue)) > 0)
8006 {
8007 last = 0, note = 0;
8008
8009 /* Scan from the end until we reach the first epilogue insn.
8010 We apparently can't depend on basic_block_{head,end} after
8011 reorg has run. */
8012 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
8013 {
8014 if (GET_CODE (insn) == NOTE)
8015 {
8016 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
8017 note = insn;
8018 }
8019 else if (contains (insn, epilogue))
8020 {
8021 last = insn;
8022 if (--len == 0)
8023 break;
8024 }
8025 }
8026
8027 if (last)
8028 {
8029 /* Find the epilogue-begin note if we haven't already, and
8030 move it to just before the first epilogue insn. */
8031 if (note == 0)
8032 {
8033 for (note = insn; (note = PREV_INSN (note));)
8034 if (GET_CODE (note) == NOTE
8035 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
8036 break;
8037 }
8038
8039 if (PREV_INSN (last) != note)
8040 reorder_insns (note, note, PREV_INSN (last));
8041 }
8042 }
8043 #endif /* HAVE_prologue or HAVE_epilogue */
8044 }
8045
8046 /* Called once, at initialization, to initialize function.c. */
8047
8048 void
8049 init_function_once (void)
8050 {
8051 VARRAY_INT_INIT (prologue, 0, "prologue");
8052 VARRAY_INT_INIT (epilogue, 0, "epilogue");
8053 VARRAY_INT_INIT (sibcall_epilogue, 0, "sibcall_epilogue");
8054 }
8055
8056 #include "gt-function.h"