1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 above the level of expressions, using subroutines in exp*.c and emit-rtl.c.
24 It also creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 The functions whose names start with `expand_' are called by the
28 parser to generate RTL instructions for various kinds of constructs.
30 Some control and binding constructs require calling several such
31 functions at different times. For example, a simple if-then
32 is expanded by calling `expand_start_cond' (with the condition-expression
33 as argument) before parsing the then-clause and calling `expand_end_cond'
34 after parsing the then-clause. */
44 #include "insn-flags.h"
45 #include "insn-config.h"
46 #include "insn-codes.h"
48 #include "hard-reg-set.h"
56 #define obstack_chunk_alloc xmalloc
57 #define obstack_chunk_free free
58 struct obstack stmt_obstack
;
60 /* Assume that case vectors are not pc-relative. */
61 #ifndef CASE_VECTOR_PC_RELATIVE
62 #define CASE_VECTOR_PC_RELATIVE 0
65 /* Filename and line number of last line-number note,
66 whether we actually emitted it or not. */
70 /* Nonzero if within a ({...}) grouping, in which case we must
71 always compute a value for each expr-stmt in case it is the last one. */
73 int expr_stmts_for_value
;
75 /* Each time we expand an expression-statement,
76 record the expr's type and its RTL value here. */
78 static tree last_expr_type
;
79 static rtx last_expr_value
;
81 /* Each time we expand the end of a binding contour (in `expand_end_bindings')
82 and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here.
83 This is used by the `remember_end_note' function to record the endpoint
84 of each generated block in its associated BLOCK node. */
86 static rtx last_block_end_note
;
88 /* Number of binding contours started so far in this function. */
90 int block_start_count
;
92 /* Nonzero if function being compiled needs to
93 return the address of where it has put a structure value. */
95 extern int current_function_returns_pcc_struct
;
97 /* Label that will go on parm cleanup code, if any.
98 Jumping to this label runs cleanup code for parameters, if
99 such code must be run. Following this code is the logical return label. */
101 extern rtx cleanup_label
;
103 /* Label that will go on function epilogue.
104 Jumping to this label serves as a "return" instruction
105 on machines which require execution of the epilogue on all returns. */
107 extern rtx return_label
;
109 /* Offset to end of allocated area of stack frame.
110 If stack grows down, this is the address of the last stack slot allocated.
111 If stack grows up, this is the address for the next slot. */
112 extern int frame_offset
;
114 /* Label to jump back to for tail recursion, or 0 if we have
115 not yet needed one for this function. */
116 extern rtx tail_recursion_label
;
118 /* Place after which to insert the tail_recursion_label if we need one. */
119 extern rtx tail_recursion_reentry
;
121 /* Location at which to save the argument pointer if it will need to be
122 referenced. There are two cases where this is done: if nonlocal gotos
123 exist, or if vars whose is an offset from the argument pointer will be
124 needed by inner routines. */
126 extern rtx arg_pointer_save_area
;
128 /* Chain of all RTL_EXPRs that have insns in them. */
129 extern tree rtl_expr_chain
;
131 /* Functions and data structures for expanding case statements. */
133 /* Case label structure, used to hold info on labels within case
134 statements. We handle "range" labels; for a single-value label
135 as in C, the high and low limits are the same.
137 An AVL tree of case nodes is initially created, and later transformed
138 to a list linked via the RIGHT fields in the nodes. Nodes with
139 higher case values are later in the list.
141 Switch statements can be output in one of two forms. A branch table
142 is used if there are more than a few labels and the labels are dense
143 within the range between the smallest and largest case value. If a
144 branch table is used, no further manipulations are done with the case
147 The alternative to the use of a branch table is to generate a series
148 of compare and jump insns. When that is done, we use the LEFT, RIGHT,
149 and PARENT fields to hold a binary tree. Initially the tree is
150 totally unbalanced, with everything on the right. We balance the tree
151 with nodes on the left having lower case values than the parent
152 and nodes on the right having higher values. We then output the tree
157 struct case_node
*left
; /* Left son in binary tree */
158 struct case_node
*right
; /* Right son in binary tree; also node chain */
159 struct case_node
*parent
; /* Parent of node in binary tree */
160 tree low
; /* Lowest index value for this label */
161 tree high
; /* Highest index value for this label */
162 tree code_label
; /* Label to jump to when node matches */
166 typedef struct case_node case_node
;
167 typedef struct case_node
*case_node_ptr
;
169 /* These are used by estimate_case_costs and balance_case_nodes. */
171 /* This must be a signed type, and non-ANSI compilers lack signed char. */
172 static short *cost_table
;
173 static int use_cost_table
;
175 /* Stack of control and binding constructs we are currently inside.
177 These constructs begin when you call `expand_start_WHATEVER'
178 and end when you call `expand_end_WHATEVER'. This stack records
179 info about how the construct began that tells the end-function
180 what to do. It also may provide information about the construct
181 to alter the behavior of other constructs within the body.
182 For example, they may affect the behavior of C `break' and `continue'.
184 Each construct gets one `struct nesting' object.
185 All of these objects are chained through the `all' field.
186 `nesting_stack' points to the first object (innermost construct).
187 The position of an entry on `nesting_stack' is in its `depth' field.
189 Each type of construct has its own individual stack.
190 For example, loops have `loop_stack'. Each object points to the
191 next object of the same type through the `next' field.
193 Some constructs are visible to `break' exit-statements and others
194 are not. Which constructs are visible depends on the language.
195 Therefore, the data structure allows each construct to be visible
196 or not, according to the args given when the construct is started.
197 The construct is visible if the `exit_label' field is non-null.
198 In that case, the value should be a CODE_LABEL rtx. */
203 struct nesting
*next
;
208 /* For conds (if-then and if-then-else statements). */
211 /* Label for the end of the if construct.
212 There is none if EXITFLAG was not set
213 and no `else' has been seen yet. */
215 /* Label for the end of this alternative.
216 This may be the end of the if or the next else/elseif. */
222 /* Label at the top of the loop; place to loop back to. */
224 /* Label at the end of the whole construct. */
226 /* Label before a jump that branches to the end of the whole
227 construct. This is where destructors go if any. */
229 /* Label for `continue' statement to jump to;
230 this is in front of the stepper of the loop. */
233 /* For variable binding contours. */
236 /* Sequence number of this binding contour within the function,
237 in order of entry. */
238 int block_start_count
;
239 /* Nonzero => value to restore stack to on exit. */
241 /* The NOTE that starts this contour.
242 Used by expand_goto to check whether the destination
243 is within each contour or not. */
245 /* Innermost containing binding contour that has a stack level. */
246 struct nesting
*innermost_stack_block
;
247 /* List of cleanups to be run on exit from this contour.
248 This is a list of expressions to be evaluated.
249 The TREE_PURPOSE of each link is the ..._DECL node
250 which the cleanup pertains to. */
252 /* List of cleanup-lists of blocks containing this block,
253 as they were at the locus where this block appears.
254 There is an element for each containing block,
255 ordered innermost containing block first.
256 The tail of this list can be 0,
257 if all remaining elements would be empty lists.
258 The element's TREE_VALUE is the cleanup-list of that block,
259 which may be null. */
261 /* Chain of labels defined inside this binding contour.
262 For contours that have stack levels or cleanups. */
263 struct label_chain
*label_chain
;
264 /* Number of function calls seen, as of start of this block. */
265 int function_call_count
;
266 /* Nonzero if this is associated with a EH region. */
267 int exception_region
;
268 /* The saved target_temp_slot_level from our outer block.
269 We may reset target_temp_slot_level to be the level of
270 this block, if that is done, target_temp_slot_level
271 reverts to the saved target_temp_slot_level at the very
273 int target_temp_slot_level
;
274 /* True if we are currently emitting insns in an area of
275 output code that is controlled by a conditional
276 expression. This is used by the cleanup handling code to
277 generate conditional cleanup actions. */
278 int conditional_code
;
279 /* A place to move the start of the exception region for any
280 of the conditional cleanups, must be at the end or after
281 the start of the last unconditional cleanup, and before any
282 conditional branch points. */
283 rtx last_unconditional_cleanup
;
284 /* When in a conditional context, this is the specific
285 cleanup list associated with last_unconditional_cleanup,
286 where we place the conditionalized cleanups. */
289 /* For switch (C) or case (Pascal) statements,
290 and also for dummies (see `expand_start_case_dummy'). */
293 /* The insn after which the case dispatch should finally
294 be emitted. Zero for a dummy. */
296 /* A list of case labels; it is first built as an AVL tree.
297 During expand_end_case, this is converted to a list, and may be
298 rearranged into a nearly balanced binary tree. */
299 struct case_node
*case_list
;
300 /* Label to jump to if no case matches. */
302 /* The expression to be dispatched on. */
304 /* Type that INDEX_EXPR should be converted to. */
306 /* Number of range exprs in case statement. */
308 /* Name of this kind of statement, for warnings. */
310 /* Used to save no_line_numbers till we see the first case label.
311 We set this to -1 when we see the first case label in this
313 int line_number_status
;
318 /* Chain of all pending binding contours. */
319 struct nesting
*block_stack
;
321 /* If any new stacks are added here, add them to POPSTACKS too. */
323 /* Chain of all pending binding contours that restore stack levels
325 struct nesting
*stack_block_stack
;
327 /* Chain of all pending conditional statements. */
328 struct nesting
*cond_stack
;
330 /* Chain of all pending loops. */
331 struct nesting
*loop_stack
;
333 /* Chain of all pending case or switch statements. */
334 struct nesting
*case_stack
;
336 /* Separate chain including all of the above,
337 chained through the `all' field. */
338 struct nesting
*nesting_stack
;
340 /* Number of entries on nesting_stack now. */
343 /* Allocate and return a new `struct nesting'. */
345 #define ALLOC_NESTING() \
346 (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting))
348 /* Pop the nesting stack element by element until we pop off
349 the element which is at the top of STACK.
350 Update all the other stacks, popping off elements from them
351 as we pop them from nesting_stack. */
353 #define POPSTACK(STACK) \
354 do { struct nesting *target = STACK; \
355 struct nesting *this; \
356 do { this = nesting_stack; \
357 if (loop_stack == this) \
358 loop_stack = loop_stack->next; \
359 if (cond_stack == this) \
360 cond_stack = cond_stack->next; \
361 if (block_stack == this) \
362 block_stack = block_stack->next; \
363 if (stack_block_stack == this) \
364 stack_block_stack = stack_block_stack->next; \
365 if (case_stack == this) \
366 case_stack = case_stack->next; \
367 nesting_depth = nesting_stack->depth - 1; \
368 nesting_stack = this->all; \
369 obstack_free (&stmt_obstack, this); } \
370 while (this != target); } while (0)
372 /* In some cases it is impossible to generate code for a forward goto
373 until the label definition is seen. This happens when it may be necessary
374 for the goto to reset the stack pointer: we don't yet know how to do that.
375 So expand_goto puts an entry on this fixup list.
376 Each time a binding contour that resets the stack is exited,
378 If the target label has now been defined, we can insert the proper code. */
382 /* Points to following fixup. */
383 struct goto_fixup
*next
;
384 /* Points to the insn before the jump insn.
385 If more code must be inserted, it goes after this insn. */
387 /* The LABEL_DECL that this jump is jumping to, or 0
388 for break, continue or return. */
390 /* The BLOCK for the place where this goto was found. */
392 /* The CODE_LABEL rtx that this is jumping to. */
394 /* Number of binding contours started in current function
395 before the label reference. */
396 int block_start_count
;
397 /* The outermost stack level that should be restored for this jump.
398 Each time a binding contour that resets the stack is exited,
399 if the target label is *not* yet defined, this slot is updated. */
401 /* List of lists of cleanup expressions to be run by this goto.
402 There is one element for each block that this goto is within.
403 The tail of this list can be 0,
404 if all remaining elements would be empty.
405 The TREE_VALUE contains the cleanup list of that block as of the
406 time this goto was seen.
407 The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */
408 tree cleanup_list_list
;
411 static struct goto_fixup
*goto_fixup_chain
;
413 /* Within any binding contour that must restore a stack level,
414 all labels are recorded with a chain of these structures. */
418 /* Points to following fixup. */
419 struct label_chain
*next
;
424 /* Non-zero if we are using EH to handle cleanus. */
425 static int using_eh_for_cleanups_p
= 0;
428 static int n_occurrences
PROTO((int, char *));
429 static void expand_goto_internal
PROTO((tree
, rtx
, rtx
));
430 static int expand_fixup
PROTO((tree
, rtx
, rtx
));
431 static void expand_nl_handler_label
PROTO((rtx
, rtx
));
432 static void expand_nl_goto_receiver
PROTO((void));
433 static void expand_nl_goto_receivers
PROTO((struct nesting
*));
434 static void fixup_gotos
PROTO((struct nesting
*, rtx
, tree
,
436 static void expand_null_return_1
PROTO((rtx
, int));
437 static void expand_value_return
PROTO((rtx
));
438 static int tail_recursion_args
PROTO((tree
, tree
));
439 static void expand_cleanups
PROTO((tree
, tree
, int, int));
440 static void check_seenlabel
PROTO((void));
441 static void do_jump_if_equal
PROTO((rtx
, rtx
, rtx
, int));
442 static int estimate_case_costs
PROTO((case_node_ptr
));
443 static void group_case_nodes
PROTO((case_node_ptr
));
444 static void balance_case_nodes
PROTO((case_node_ptr
*,
446 static int node_has_low_bound
PROTO((case_node_ptr
, tree
));
447 static int node_has_high_bound
PROTO((case_node_ptr
, tree
));
448 static int node_is_bounded
PROTO((case_node_ptr
, tree
));
449 static void emit_jump_if_reachable
PROTO((rtx
));
450 static void emit_case_nodes
PROTO((rtx
, case_node_ptr
, rtx
, tree
));
451 static int add_case_node
PROTO((tree
, tree
, tree
, tree
*));
452 static struct case_node
*case_tree2list
PROTO((case_node
*, case_node
*));
455 using_eh_for_cleanups ()
457 using_eh_for_cleanups_p
= 1;
463 gcc_obstack_init (&stmt_obstack
);
468 init_stmt_for_function ()
470 /* We are not currently within any block, conditional, loop or case. */
472 stack_block_stack
= 0;
479 block_start_count
= 0;
481 /* No gotos have been expanded yet. */
482 goto_fixup_chain
= 0;
484 /* We are not processing a ({...}) grouping. */
485 expr_stmts_for_value
= 0;
488 init_eh_for_function ();
495 p
->block_stack
= block_stack
;
496 p
->stack_block_stack
= stack_block_stack
;
497 p
->cond_stack
= cond_stack
;
498 p
->loop_stack
= loop_stack
;
499 p
->case_stack
= case_stack
;
500 p
->nesting_stack
= nesting_stack
;
501 p
->nesting_depth
= nesting_depth
;
502 p
->block_start_count
= block_start_count
;
503 p
->last_expr_type
= last_expr_type
;
504 p
->last_expr_value
= last_expr_value
;
505 p
->expr_stmts_for_value
= expr_stmts_for_value
;
506 p
->emit_filename
= emit_filename
;
507 p
->emit_lineno
= emit_lineno
;
508 p
->goto_fixup_chain
= goto_fixup_chain
;
513 restore_stmt_status (p
)
516 block_stack
= p
->block_stack
;
517 stack_block_stack
= p
->stack_block_stack
;
518 cond_stack
= p
->cond_stack
;
519 loop_stack
= p
->loop_stack
;
520 case_stack
= p
->case_stack
;
521 nesting_stack
= p
->nesting_stack
;
522 nesting_depth
= p
->nesting_depth
;
523 block_start_count
= p
->block_start_count
;
524 last_expr_type
= p
->last_expr_type
;
525 last_expr_value
= p
->last_expr_value
;
526 expr_stmts_for_value
= p
->expr_stmts_for_value
;
527 emit_filename
= p
->emit_filename
;
528 emit_lineno
= p
->emit_lineno
;
529 goto_fixup_chain
= p
->goto_fixup_chain
;
530 restore_eh_status (p
);
533 /* Emit a no-op instruction. */
540 last_insn
= get_last_insn ();
542 && (GET_CODE (last_insn
) == CODE_LABEL
543 || (GET_CODE (last_insn
) == NOTE
544 && prev_real_insn (last_insn
) == 0)))
545 emit_insn (gen_nop ());
548 /* Return the rtx-label that corresponds to a LABEL_DECL,
549 creating it if necessary. */
555 if (TREE_CODE (label
) != LABEL_DECL
)
558 if (DECL_RTL (label
))
559 return DECL_RTL (label
);
561 return DECL_RTL (label
) = gen_label_rtx ();
564 /* Add an unconditional jump to LABEL as the next sequential instruction. */
570 do_pending_stack_adjust ();
571 emit_jump_insn (gen_jump (label
));
575 /* Emit code to jump to the address
576 specified by the pointer expression EXP. */
579 expand_computed_goto (exp
)
582 rtx x
= expand_expr (exp
, NULL_RTX
, VOIDmode
, 0);
584 #ifdef POINTERS_EXTEND_UNSIGNED
585 x
= convert_memory_address (Pmode
, x
);
589 /* Be sure the function is executable. */
590 if (current_function_check_memory_usage
)
591 emit_library_call (chkr_check_exec_libfunc
, 1,
592 VOIDmode
, 1, x
, ptr_mode
);
594 do_pending_stack_adjust ();
595 emit_indirect_jump (x
);
598 /* Handle goto statements and the labels that they can go to. */
600 /* Specify the location in the RTL code of a label LABEL,
601 which is a LABEL_DECL tree node.
603 This is used for the kind of label that the user can jump to with a
604 goto statement, and for alternatives of a switch or case statement.
605 RTL labels generated for loops and conditionals don't go through here;
606 they are generated directly at the RTL level, by other functions below.
608 Note that this has nothing to do with defining label *names*.
609 Languages vary in how they do that and what that even means. */
615 struct label_chain
*p
;
617 do_pending_stack_adjust ();
618 emit_label (label_rtx (label
));
619 if (DECL_NAME (label
))
620 LABEL_NAME (DECL_RTL (label
)) = IDENTIFIER_POINTER (DECL_NAME (label
));
622 if (stack_block_stack
!= 0)
624 p
= (struct label_chain
*) oballoc (sizeof (struct label_chain
));
625 p
->next
= stack_block_stack
->data
.block
.label_chain
;
626 stack_block_stack
->data
.block
.label_chain
= p
;
631 /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos
632 from nested functions. */
635 declare_nonlocal_label (label
)
638 rtx slot
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
640 nonlocal_labels
= tree_cons (NULL_TREE
, label
, nonlocal_labels
);
641 LABEL_PRESERVE_P (label_rtx (label
)) = 1;
642 if (nonlocal_goto_handler_slots
== 0)
644 emit_stack_save (SAVE_NONLOCAL
,
645 &nonlocal_goto_stack_level
,
646 PREV_INSN (tail_recursion_reentry
));
648 nonlocal_goto_handler_slots
649 = gen_rtx_EXPR_LIST (VOIDmode
, slot
, nonlocal_goto_handler_slots
);
652 /* Generate RTL code for a `goto' statement with target label LABEL.
653 LABEL should be a LABEL_DECL tree node that was or will later be
654 defined with `expand_label'. */
662 /* Check for a nonlocal goto to a containing function. */
663 context
= decl_function_context (label
);
664 if (context
!= 0 && context
!= current_function_decl
)
666 struct function
*p
= find_function_data (context
);
667 rtx label_ref
= gen_rtx_LABEL_REF (Pmode
, label_rtx (label
));
668 rtx temp
, handler_slot
;
671 /* Find the corresponding handler slot for this label. */
672 handler_slot
= p
->nonlocal_goto_handler_slots
;
673 for (link
= p
->nonlocal_labels
; TREE_VALUE (link
) != label
;
674 link
= TREE_CHAIN (link
))
675 handler_slot
= XEXP (handler_slot
, 1);
676 handler_slot
= XEXP (handler_slot
, 0);
678 p
->has_nonlocal_label
= 1;
679 current_function_has_nonlocal_goto
= 1;
680 LABEL_REF_NONLOCAL_P (label_ref
) = 1;
682 /* Copy the rtl for the slots so that they won't be shared in
683 case the virtual stack vars register gets instantiated differently
684 in the parent than in the child. */
686 #if HAVE_nonlocal_goto
687 if (HAVE_nonlocal_goto
)
688 emit_insn (gen_nonlocal_goto (lookup_static_chain (label
),
689 copy_rtx (handler_slot
),
690 copy_rtx (p
->nonlocal_goto_stack_level
),
697 /* Restore frame pointer for containing function.
698 This sets the actual hard register used for the frame pointer
699 to the location of the function's incoming static chain info.
700 The non-local goto handler will then adjust it to contain the
701 proper value and reload the argument pointer, if needed. */
702 emit_move_insn (hard_frame_pointer_rtx
, lookup_static_chain (label
));
704 /* We have now loaded the frame pointer hardware register with
705 the address of that corresponds to the start of the virtual
706 stack vars. So replace virtual_stack_vars_rtx in all
707 addresses we use with stack_pointer_rtx. */
709 /* Get addr of containing function's current nonlocal goto handler,
710 which will do any cleanups and then jump to the label. */
711 addr
= copy_rtx (handler_slot
);
712 temp
= copy_to_reg (replace_rtx (addr
, virtual_stack_vars_rtx
,
713 hard_frame_pointer_rtx
));
715 /* Restore the stack pointer. Note this uses fp just restored. */
716 addr
= p
->nonlocal_goto_stack_level
;
718 addr
= replace_rtx (copy_rtx (addr
),
719 virtual_stack_vars_rtx
,
720 hard_frame_pointer_rtx
);
722 emit_stack_restore (SAVE_NONLOCAL
, addr
, NULL_RTX
);
724 /* USE of hard_frame_pointer_rtx added for consistency; not clear if
726 emit_insn (gen_rtx_USE (VOIDmode
, hard_frame_pointer_rtx
));
727 emit_insn (gen_rtx_USE (VOIDmode
, stack_pointer_rtx
));
728 emit_indirect_jump (temp
);
732 expand_goto_internal (label
, label_rtx (label
), NULL_RTX
);
735 /* Generate RTL code for a `goto' statement with target label BODY.
736 LABEL should be a LABEL_REF.
737 LAST_INSN, if non-0, is the rtx we should consider as the last
738 insn emitted (for the purposes of cleaning up a return). */
741 expand_goto_internal (body
, label
, last_insn
)
746 struct nesting
*block
;
749 if (GET_CODE (label
) != CODE_LABEL
)
752 /* If label has already been defined, we can tell now
753 whether and how we must alter the stack level. */
755 if (PREV_INSN (label
) != 0)
757 /* Find the innermost pending block that contains the label.
758 (Check containment by comparing insn-uids.)
759 Then restore the outermost stack level within that block,
760 and do cleanups of all blocks contained in it. */
761 for (block
= block_stack
; block
; block
= block
->next
)
763 if (INSN_UID (block
->data
.block
.first_insn
) < INSN_UID (label
))
765 if (block
->data
.block
.stack_level
!= 0)
766 stack_level
= block
->data
.block
.stack_level
;
767 /* Execute the cleanups for blocks we are exiting. */
768 if (block
->data
.block
.cleanups
!= 0)
770 expand_cleanups (block
->data
.block
.cleanups
, NULL_TREE
, 1, 1);
771 do_pending_stack_adjust ();
777 /* Ensure stack adjust isn't done by emit_jump, as this
778 would clobber the stack pointer. This one should be
779 deleted as dead by flow. */
780 clear_pending_stack_adjust ();
781 do_pending_stack_adjust ();
782 emit_stack_restore (SAVE_BLOCK
, stack_level
, NULL_RTX
);
785 if (body
!= 0 && DECL_TOO_LATE (body
))
786 error ("jump to `%s' invalidly jumps into binding contour",
787 IDENTIFIER_POINTER (DECL_NAME (body
)));
789 /* Label not yet defined: may need to put this goto
790 on the fixup list. */
791 else if (! expand_fixup (body
, label
, last_insn
))
793 /* No fixup needed. Record that the label is the target
794 of at least one goto that has no fixup. */
796 TREE_ADDRESSABLE (body
) = 1;
802 /* Generate if necessary a fixup for a goto
803 whose target label in tree structure (if any) is TREE_LABEL
804 and whose target in rtl is RTL_LABEL.
806 If LAST_INSN is nonzero, we pretend that the jump appears
807 after insn LAST_INSN instead of at the current point in the insn stream.
809 The fixup will be used later to insert insns just before the goto.
810 Those insns will restore the stack level as appropriate for the
811 target label, and will (in the case of C++) also invoke any object
812 destructors which have to be invoked when we exit the scopes which
813 are exited by the goto.
815 Value is nonzero if a fixup is made. */
818 expand_fixup (tree_label
, rtl_label
, last_insn
)
823 struct nesting
*block
, *end_block
;
825 /* See if we can recognize which block the label will be output in.
826 This is possible in some very common cases.
827 If we succeed, set END_BLOCK to that block.
828 Otherwise, set it to 0. */
831 && (rtl_label
== cond_stack
->data
.cond
.endif_label
832 || rtl_label
== cond_stack
->data
.cond
.next_label
))
833 end_block
= cond_stack
;
834 /* If we are in a loop, recognize certain labels which
835 are likely targets. This reduces the number of fixups
836 we need to create. */
838 && (rtl_label
== loop_stack
->data
.loop
.start_label
839 || rtl_label
== loop_stack
->data
.loop
.end_label
840 || rtl_label
== loop_stack
->data
.loop
.continue_label
))
841 end_block
= loop_stack
;
845 /* Now set END_BLOCK to the binding level to which we will return. */
849 struct nesting
*next_block
= end_block
->all
;
852 /* First see if the END_BLOCK is inside the innermost binding level.
853 If so, then no cleanups or stack levels are relevant. */
854 while (next_block
&& next_block
!= block
)
855 next_block
= next_block
->all
;
860 /* Otherwise, set END_BLOCK to the innermost binding level
861 which is outside the relevant control-structure nesting. */
862 next_block
= block_stack
->next
;
863 for (block
= block_stack
; block
!= end_block
; block
= block
->all
)
864 if (block
== next_block
)
865 next_block
= next_block
->next
;
866 end_block
= next_block
;
869 /* Does any containing block have a stack level or cleanups?
870 If not, no fixup is needed, and that is the normal case
871 (the only case, for standard C). */
872 for (block
= block_stack
; block
!= end_block
; block
= block
->next
)
873 if (block
->data
.block
.stack_level
!= 0
874 || block
->data
.block
.cleanups
!= 0)
877 if (block
!= end_block
)
879 /* Ok, a fixup is needed. Add a fixup to the list of such. */
880 struct goto_fixup
*fixup
881 = (struct goto_fixup
*) oballoc (sizeof (struct goto_fixup
));
882 /* In case an old stack level is restored, make sure that comes
883 after any pending stack adjust. */
884 /* ?? If the fixup isn't to come at the present position,
885 doing the stack adjust here isn't useful. Doing it with our
886 settings at that location isn't useful either. Let's hope
889 do_pending_stack_adjust ();
890 fixup
->target
= tree_label
;
891 fixup
->target_rtl
= rtl_label
;
893 /* Create a BLOCK node and a corresponding matched set of
894 NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at
895 this point. The notes will encapsulate any and all fixup
896 code which we might later insert at this point in the insn
897 stream. Also, the BLOCK node will be the parent (i.e. the
898 `SUPERBLOCK') of any other BLOCK nodes which we might create
899 later on when we are expanding the fixup code.
901 Note that optimization passes (including expand_end_loop)
902 might move the *_BLOCK notes away, so we use a NOTE_INSN_DELETED
906 register rtx original_before_jump
907 = last_insn
? last_insn
: get_last_insn ();
912 start
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_BEG
);
913 fixup
->before_jump
= emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
914 last_block_end_note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_END
);
915 fixup
->context
= poplevel (1, 0, 0); /* Create the BLOCK node now! */
917 emit_insns_after (start
, original_before_jump
);
920 fixup
->block_start_count
= block_start_count
;
921 fixup
->stack_level
= 0;
922 fixup
->cleanup_list_list
923 = ((block
->data
.block
.outer_cleanups
924 || block
->data
.block
.cleanups
)
925 ? tree_cons (NULL_TREE
, block
->data
.block
.cleanups
,
926 block
->data
.block
.outer_cleanups
)
928 fixup
->next
= goto_fixup_chain
;
929 goto_fixup_chain
= fixup
;
937 /* Expand any needed fixups in the outputmost binding level of the
938 function. FIRST_INSN is the first insn in the function. */
941 expand_fixups (first_insn
)
944 fixup_gotos (NULL_PTR
, NULL_RTX
, NULL_TREE
, first_insn
, 0);
947 /* When exiting a binding contour, process all pending gotos requiring fixups.
948 THISBLOCK is the structure that describes the block being exited.
949 STACK_LEVEL is the rtx for the stack level to restore exiting this contour.
950 CLEANUP_LIST is a list of expressions to evaluate on exiting this contour.
951 FIRST_INSN is the insn that began this contour.
953 Gotos that jump out of this contour must restore the
954 stack level and do the cleanups before actually jumping.
956 DONT_JUMP_IN nonzero means report error there is a jump into this
957 contour from before the beginning of the contour.
958 This is also done if STACK_LEVEL is nonzero. */
961 fixup_gotos (thisblock
, stack_level
, cleanup_list
, first_insn
, dont_jump_in
)
962 struct nesting
*thisblock
;
968 register struct goto_fixup
*f
, *prev
;
970 /* F is the fixup we are considering; PREV is the previous one. */
971 /* We run this loop in two passes so that cleanups of exited blocks
972 are run first, and blocks that are exited are marked so
975 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
977 /* Test for a fixup that is inactive because it is already handled. */
978 if (f
->before_jump
== 0)
980 /* Delete inactive fixup from the chain, if that is easy to do. */
982 prev
->next
= f
->next
;
984 /* Has this fixup's target label been defined?
985 If so, we can finalize it. */
986 else if (PREV_INSN (f
->target_rtl
) != 0)
988 register rtx cleanup_insns
;
990 /* Get the first non-label after the label
991 this goto jumps to. If that's before this scope begins,
992 we don't have a jump into the scope. */
993 rtx after_label
= f
->target_rtl
;
994 while (after_label
!= 0 && GET_CODE (after_label
) == CODE_LABEL
)
995 after_label
= NEXT_INSN (after_label
);
997 /* If this fixup jumped into this contour from before the beginning
998 of this contour, report an error. */
999 /* ??? Bug: this does not detect jumping in through intermediate
1000 blocks that have stack levels or cleanups.
1001 It detects only a problem with the innermost block
1002 around the label. */
1004 && (dont_jump_in
|| stack_level
|| cleanup_list
)
1005 /* If AFTER_LABEL is 0, it means the jump goes to the end
1006 of the rtl, which means it jumps into this scope. */
1007 && (after_label
== 0
1008 || INSN_UID (first_insn
) < INSN_UID (after_label
))
1009 && INSN_UID (first_insn
) > INSN_UID (f
->before_jump
)
1010 && ! DECL_ERROR_ISSUED (f
->target
))
1012 error_with_decl (f
->target
,
1013 "label `%s' used before containing binding contour");
1014 /* Prevent multiple errors for one label. */
1015 DECL_ERROR_ISSUED (f
->target
) = 1;
1018 /* We will expand the cleanups into a sequence of their own and
1019 then later on we will attach this new sequence to the insn
1020 stream just ahead of the actual jump insn. */
1024 /* Temporarily restore the lexical context where we will
1025 logically be inserting the fixup code. We do this for the
1026 sake of getting the debugging information right. */
1029 set_block (f
->context
);
1031 /* Expand the cleanups for blocks this jump exits. */
1032 if (f
->cleanup_list_list
)
1035 for (lists
= f
->cleanup_list_list
; lists
; lists
= TREE_CHAIN (lists
))
1036 /* Marked elements correspond to blocks that have been closed.
1037 Do their cleanups. */
1038 if (TREE_ADDRESSABLE (lists
)
1039 && TREE_VALUE (lists
) != 0)
1041 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1042 /* Pop any pushes done in the cleanups,
1043 in case function is about to return. */
1044 do_pending_stack_adjust ();
1048 /* Restore stack level for the biggest contour that this
1049 jump jumps out of. */
1051 emit_stack_restore (SAVE_BLOCK
, f
->stack_level
, f
->before_jump
);
1053 /* Finish up the sequence containing the insns which implement the
1054 necessary cleanups, and then attach that whole sequence to the
1055 insn stream just ahead of the actual jump insn. Attaching it
1056 at that point insures that any cleanups which are in fact
1057 implicit C++ object destructions (which must be executed upon
1058 leaving the block) appear (to the debugger) to be taking place
1059 in an area of the generated code where the object(s) being
1060 destructed are still "in scope". */
1062 cleanup_insns
= get_insns ();
1066 emit_insns_after (cleanup_insns
, f
->before_jump
);
1073 /* For any still-undefined labels, do the cleanups for this block now.
1074 We must do this now since items in the cleanup list may go out
1075 of scope when the block ends. */
1076 for (prev
= 0, f
= goto_fixup_chain
; f
; prev
= f
, f
= f
->next
)
1077 if (f
->before_jump
!= 0
1078 && PREV_INSN (f
->target_rtl
) == 0
1079 /* Label has still not appeared. If we are exiting a block with
1080 a stack level to restore, that started before the fixup,
1081 mark this stack level as needing restoration
1082 when the fixup is later finalized. */
1084 /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it
1085 means the label is undefined. That's erroneous, but possible. */
1086 && (thisblock
->data
.block
.block_start_count
1087 <= f
->block_start_count
))
1089 tree lists
= f
->cleanup_list_list
;
1092 for (; lists
; lists
= TREE_CHAIN (lists
))
1093 /* If the following elt. corresponds to our containing block
1094 then the elt. must be for this block. */
1095 if (TREE_CHAIN (lists
) == thisblock
->data
.block
.outer_cleanups
)
1099 set_block (f
->context
);
1100 expand_cleanups (TREE_VALUE (lists
), NULL_TREE
, 1, 1);
1101 do_pending_stack_adjust ();
1102 cleanup_insns
= get_insns ();
1105 if (cleanup_insns
!= 0)
1107 = emit_insns_after (cleanup_insns
, f
->before_jump
);
1109 f
->cleanup_list_list
= TREE_CHAIN (lists
);
1113 f
->stack_level
= stack_level
;
1117 /* Return the number of times character C occurs in string S. */
1119 n_occurrences (c
, s
)
1129 /* Generate RTL for an asm statement (explicit assembler code).
1130 BODY is a STRING_CST node containing the assembler code text,
1131 or an ADDR_EXPR containing a STRING_CST. */
1137 if (current_function_check_memory_usage
)
1139 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1143 if (TREE_CODE (body
) == ADDR_EXPR
)
1144 body
= TREE_OPERAND (body
, 0);
1146 emit_insn (gen_rtx_ASM_INPUT (VOIDmode
,
1147 TREE_STRING_POINTER (body
)));
1151 /* Generate RTL for an asm statement with arguments.
1152 STRING is the instruction template.
1153 OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs.
1154 Each output or input has an expression in the TREE_VALUE and
1155 a constraint-string in the TREE_PURPOSE.
1156 CLOBBERS is a list of STRING_CST nodes each naming a hard register
1157 that is clobbered by this insn.
1159 Not all kinds of lvalue that may appear in OUTPUTS can be stored directly.
1160 Some elements of OUTPUTS may be replaced with trees representing temporary
1161 values. The caller should copy those temporary values to the originally
1164 VOL nonzero means the insn is volatile; don't optimize it. */
1167 expand_asm_operands (string
, outputs
, inputs
, clobbers
, vol
, filename
, line
)
1168 tree string
, outputs
, inputs
, clobbers
;
1173 rtvec argvec
, constraints
;
1175 int ninputs
= list_length (inputs
);
1176 int noutputs
= list_length (outputs
);
1181 /* Vector of RTX's of evaluated output operands. */
1182 rtx
*output_rtx
= (rtx
*) alloca (noutputs
* sizeof (rtx
));
1183 int *inout_opnum
= (int *) alloca (noutputs
* sizeof (int));
1184 enum machine_mode
*inout_mode
1185 = (enum machine_mode
*) alloca (noutputs
* sizeof (enum machine_mode
));
1186 /* The insn we have emitted. */
1189 /* An ASM with no outputs needs to be treated as volatile, for now. */
1193 if (current_function_check_memory_usage
)
1195 error ("`asm' cannot be used with `-fcheck-memory-usage'");
1199 /* Count the number of meaningful clobbered registers, ignoring what
1200 we would ignore later. */
1202 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1204 char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1205 i
= decode_reg_name (regname
);
1206 if (i
>= 0 || i
== -4)
1209 error ("unknown register name `%s' in `asm'", regname
);
1214 /* Check that the number of alternatives is constant across all
1216 if (outputs
|| inputs
)
1218 tree tmp
= TREE_PURPOSE (outputs
? outputs
: inputs
);
1219 int nalternatives
= n_occurrences (',', TREE_STRING_POINTER (tmp
));
1222 if (nalternatives
+ 1 > MAX_RECOG_ALTERNATIVES
)
1224 error ("too many alternatives in `asm'");
1231 char *constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tmp
));
1232 if (n_occurrences (',', constraint
) != nalternatives
)
1234 error ("operand constraints for `asm' differ in number of alternatives");
1237 if (TREE_CHAIN (tmp
))
1238 tmp
= TREE_CHAIN (tmp
);
1240 tmp
= next
, next
= 0;
1244 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1246 tree val
= TREE_VALUE (tail
);
1247 tree type
= TREE_TYPE (val
);
1255 /* If there's an erroneous arg, emit no insn. */
1256 if (TREE_TYPE (val
) == error_mark_node
)
1259 /* Make sure constraint has `=' and does not have `+'. Also, see
1260 if it allows any register. Be liberal on the latter test, since
1261 the worst that happens if we get it wrong is we issue an error
1264 c_len
= TREE_STRING_LENGTH (TREE_PURPOSE (tail
)) - 1;
1265 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1267 /* Allow the `=' or `+' to not be at the beginning of the string,
1268 since it wasn't explicitly documented that way, and there is a
1269 large body of code that puts it last. Swap the character to
1270 the front, so as not to uglify any place else. */
1274 if ((p
= strchr (constraint
, '=')) != NULL
)
1276 if ((p
= strchr (constraint
, '+')) != NULL
)
1279 error ("output operand constraint lacks `='");
1283 if (p
!= constraint
)
1286 bcopy (constraint
, constraint
+1, p
-constraint
);
1289 warning ("output constraint `%c' for operand %d is not at the beginning", j
, i
);
1292 is_inout
= constraint
[0] == '+';
1293 /* Replace '+' with '='. */
1294 constraint
[0] = '=';
1295 /* Make sure we can specify the matching operand. */
1296 if (is_inout
&& i
> 9)
1298 error ("output operand constraint %d contains `+'", i
);
1302 for (j
= 1; j
< c_len
; j
++)
1303 switch (constraint
[j
])
1307 error ("operand constraint contains '+' or '=' at illegal position.");
1311 if (i
+ 1 == ninputs
+ noutputs
)
1313 error ("`%%' constraint used with last operand");
1318 case '?': case '!': case '*': case '&':
1319 case 'V': case 'm': case 'o': case '<': case '>':
1320 case 'E': case 'F': case 'G': case 'H': case 'X':
1321 case 's': case 'i': case 'n':
1322 case 'I': case 'J': case 'K': case 'L': case 'M':
1323 case 'N': case 'O': case 'P': case ',':
1324 #ifdef EXTRA_CONSTRAINT
1325 case 'Q': case 'R': case 'S': case 'T': case 'U':
1329 case '0': case '1': case '2': case '3': case '4':
1330 case '5': case '6': case '7': case '8': case '9':
1331 error ("matching constraint not valid in output operand");
1334 case 'p': case 'g': case 'r':
1340 /* If an output operand is not a decl or indirect ref and our constraint
1341 allows a register, make a temporary to act as an intermediate.
1342 Make the asm insn write into that, then our caller will copy it to
1343 the real output operand. Likewise for promoted variables. */
1345 if (TREE_CODE (val
) == INDIRECT_REF
1346 || (TREE_CODE_CLASS (TREE_CODE (val
)) == 'd'
1347 && ! (GET_CODE (DECL_RTL (val
)) == REG
1348 && GET_MODE (DECL_RTL (val
)) != TYPE_MODE (type
)))
1353 mark_addressable (TREE_VALUE (tail
));
1356 = expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
,
1357 EXPAND_MEMORY_USE_WO
);
1359 if (! allows_reg
&& GET_CODE (output_rtx
[i
]) != MEM
)
1360 error ("output number %d not directly addressable", i
);
1364 output_rtx
[i
] = assign_temp (type
, 0, 0, 0);
1365 TREE_VALUE (tail
) = make_tree (type
, output_rtx
[i
]);
1370 inout_mode
[ninout
] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
)));
1371 inout_opnum
[ninout
++] = i
;
1376 if (ninputs
+ noutputs
> MAX_RECOG_OPERANDS
)
1378 error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS
);
1382 /* Make vectors for the expression-rtx and constraint strings. */
1384 argvec
= rtvec_alloc (ninputs
);
1385 constraints
= rtvec_alloc (ninputs
);
1387 body
= gen_rtx_ASM_OPERANDS (VOIDmode
,
1388 TREE_STRING_POINTER (string
), "", 0, argvec
,
1389 constraints
, filename
, line
);
1391 MEM_VOLATILE_P (body
) = vol
;
1393 /* Eval the inputs and put them into ARGVEC.
1394 Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */
1397 for (tail
= inputs
; tail
; tail
= TREE_CHAIN (tail
))
1400 int allows_reg
= 0, allows_mem
= 0;
1401 char *constraint
, *orig_constraint
;
1405 /* If there's an erroneous arg, emit no insn,
1406 because the ASM_INPUT would get VOIDmode
1407 and that could cause a crash in reload. */
1408 if (TREE_TYPE (TREE_VALUE (tail
)) == error_mark_node
)
1411 /* ??? Can this happen, and does the error message make any sense? */
1412 if (TREE_PURPOSE (tail
) == NULL_TREE
)
1414 error ("hard register `%s' listed as input operand to `asm'",
1415 TREE_STRING_POINTER (TREE_VALUE (tail
)) );
1419 c_len
= TREE_STRING_LENGTH (TREE_PURPOSE (tail
)) - 1;
1420 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (tail
));
1421 orig_constraint
= constraint
;
1423 /* Make sure constraint has neither `=', `+', nor '&'. */
1425 for (j
= 0; j
< c_len
; j
++)
1426 switch (constraint
[j
])
1428 case '+': case '=': case '&':
1429 if (constraint
== orig_constraint
)
1431 error ("input operand constraint contains `%c'", constraint
[j
]);
1437 if (constraint
== orig_constraint
1438 && i
+ 1 == ninputs
- ninout
)
1440 error ("`%%' constraint used with last operand");
1445 case 'V': case 'm': case 'o':
1450 case '?': case '!': case '*':
1451 case 'E': case 'F': case 'G': case 'H': case 'X':
1452 case 's': case 'i': case 'n':
1453 case 'I': case 'J': case 'K': case 'L': case 'M':
1454 case 'N': case 'O': case 'P': case ',':
1455 #ifdef EXTRA_CONSTRAINT
1456 case 'Q': case 'R': case 'S': case 'T': case 'U':
1460 /* Whether or not a numeric constraint allows a register is
1461 decided by the matching constraint, and so there is no need
1462 to do anything special with them. We must handle them in
1463 the default case, so that we don't unnecessarily force
1464 operands to memory. */
1465 case '0': case '1': case '2': case '3': case '4':
1466 case '5': case '6': case '7': case '8': case '9':
1467 if (constraint
[j
] >= '0' + noutputs
)
1470 ("matching constraint references invalid operand number");
1474 /* Try and find the real constraint for this dup. */
1475 if (j
== 0 && c_len
== 1)
1478 for (j
= constraint
[j
] - '0'; j
> 0; --j
)
1481 c_len
= TREE_STRING_LENGTH (TREE_PURPOSE (o
)) - 1;
1482 constraint
= TREE_STRING_POINTER (TREE_PURPOSE (o
));
1487 /* ... fall through ... */
1500 if (! allows_reg
&& allows_mem
)
1501 mark_addressable (TREE_VALUE (tail
));
1503 op
= expand_expr (TREE_VALUE (tail
), NULL_RTX
, VOIDmode
, 0);
1505 if (! asm_operand_ok (op
, constraint
))
1508 op
= force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))), op
);
1509 else if (!allows_mem
)
1510 warning ("asm operand %d probably doesn't match constraints", i
);
1511 else if (CONSTANT_P (op
))
1512 op
= force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1514 else if (GET_CODE (op
) == REG
1515 || GET_CODE (op
) == SUBREG
1516 || GET_CODE (op
) == CONCAT
)
1518 tree type
= TREE_TYPE (TREE_VALUE (tail
));
1519 rtx memloc
= assign_temp (type
, 1, 1, 1);
1521 emit_move_insn (memloc
, op
);
1524 else if (GET_CODE (op
) == MEM
&& MEM_VOLATILE_P (op
))
1525 /* We won't recognize volatile memory as available a
1526 memory_operand at this point. Ignore it. */
1528 else if (queued_subexp_p (op
))
1531 /* ??? Leave this only until we have experience with what
1532 happens in combine and elsewhere when constraints are
1534 warning ("asm operand %d probably doesn't match constraints", i
);
1536 XVECEXP (body
, 3, i
) = op
;
1538 XVECEXP (body
, 4, i
) /* constraints */
1539 = gen_rtx_ASM_INPUT (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail
))),
1544 /* Protect all the operands from the queue,
1545 now that they have all been evaluated. */
1547 for (i
= 0; i
< ninputs
- ninout
; i
++)
1548 XVECEXP (body
, 3, i
) = protect_from_queue (XVECEXP (body
, 3, i
), 0);
1550 for (i
= 0; i
< noutputs
; i
++)
1551 output_rtx
[i
] = protect_from_queue (output_rtx
[i
], 1);
1553 /* For in-out operands, copy output rtx to input rtx. */
1554 for (i
= 0; i
< ninout
; i
++)
1556 static char match
[9+1][2]
1557 = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
1558 int j
= inout_opnum
[i
];
1560 XVECEXP (body
, 3, ninputs
- ninout
+ i
) /* argvec */
1562 XVECEXP (body
, 4, ninputs
- ninout
+ i
) /* constraints */
1563 = gen_rtx_ASM_INPUT (inout_mode
[j
], match
[j
]);
1566 /* Now, for each output, construct an rtx
1567 (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT
1568 ARGVEC CONSTRAINTS))
1569 If there is more than one, put them inside a PARALLEL. */
1571 if (noutputs
== 1 && nclobbers
== 0)
1573 XSTR (body
, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs
));
1574 insn
= emit_insn (gen_rtx_SET (VOIDmode
, output_rtx
[0], body
));
1576 else if (noutputs
== 0 && nclobbers
== 0)
1578 /* No output operands: put in a raw ASM_OPERANDS rtx. */
1579 insn
= emit_insn (body
);
1585 if (num
== 0) num
= 1;
1586 body
= gen_rtx_PARALLEL (VOIDmode
, rtvec_alloc (num
+ nclobbers
));
1588 /* For each output operand, store a SET. */
1590 for (i
= 0, tail
= outputs
; tail
; tail
= TREE_CHAIN (tail
), i
++)
1592 XVECEXP (body
, 0, i
)
1593 = gen_rtx_SET (VOIDmode
,
1595 gen_rtx_ASM_OPERANDS (VOIDmode
,
1596 TREE_STRING_POINTER (string
),
1597 TREE_STRING_POINTER (TREE_PURPOSE (tail
)),
1598 i
, argvec
, constraints
,
1600 MEM_VOLATILE_P (SET_SRC (XVECEXP (body
, 0, i
))) = vol
;
1603 /* If there are no outputs (but there are some clobbers)
1604 store the bare ASM_OPERANDS into the PARALLEL. */
1607 XVECEXP (body
, 0, i
++) = obody
;
1609 /* Store (clobber REG) for each clobbered register specified. */
1611 for (tail
= clobbers
; tail
; tail
= TREE_CHAIN (tail
))
1613 char *regname
= TREE_STRING_POINTER (TREE_VALUE (tail
));
1614 int j
= decode_reg_name (regname
);
1618 if (j
== -3) /* `cc', which is not a register */
1621 if (j
== -4) /* `memory', don't cache memory across asm */
1623 XVECEXP (body
, 0, i
++)
1624 = gen_rtx_CLOBBER (VOIDmode
,
1625 gen_rtx_MEM (BLKmode
,
1626 gen_rtx_SCRATCH (VOIDmode
)));
1630 /* Ignore unknown register, error already signaled. */
1634 /* Use QImode since that's guaranteed to clobber just one reg. */
1635 XVECEXP (body
, 0, i
++)
1636 = gen_rtx_CLOBBER (VOIDmode
, gen_rtx_REG (QImode
, j
));
1639 insn
= emit_insn (body
);
1645 /* Generate RTL to evaluate the expression EXP
1646 and remember it in case this is the VALUE in a ({... VALUE; }) constr. */
1649 expand_expr_stmt (exp
)
1652 /* If -W, warn about statements with no side effects,
1653 except for an explicit cast to void (e.g. for assert()), and
1654 except inside a ({...}) where they may be useful. */
1655 if (expr_stmts_for_value
== 0 && exp
!= error_mark_node
)
1657 if (! TREE_SIDE_EFFECTS (exp
) && (extra_warnings
|| warn_unused
)
1658 && !(TREE_CODE (exp
) == CONVERT_EXPR
1659 && TREE_TYPE (exp
) == void_type_node
))
1660 warning_with_file_and_line (emit_filename
, emit_lineno
,
1661 "statement with no effect");
1662 else if (warn_unused
)
1663 warn_if_unused_value (exp
);
1666 /* If EXP is of function type and we are expanding statements for
1667 value, convert it to pointer-to-function. */
1668 if (expr_stmts_for_value
&& TREE_CODE (TREE_TYPE (exp
)) == FUNCTION_TYPE
)
1669 exp
= build1 (ADDR_EXPR
, build_pointer_type (TREE_TYPE (exp
)), exp
);
1671 last_expr_type
= TREE_TYPE (exp
);
1672 if (flag_syntax_only
&& ! expr_stmts_for_value
)
1673 last_expr_value
= 0;
1675 last_expr_value
= expand_expr (exp
,
1676 (expr_stmts_for_value
1677 ? NULL_RTX
: const0_rtx
),
1680 /* If all we do is reference a volatile value in memory,
1681 copy it to a register to be sure it is actually touched. */
1682 if (last_expr_value
!= 0 && GET_CODE (last_expr_value
) == MEM
1683 && TREE_THIS_VOLATILE (exp
))
1685 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
)
1687 else if (TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
)
1688 copy_to_reg (last_expr_value
);
1691 rtx lab
= gen_label_rtx ();
1693 /* Compare the value with itself to reference it. */
1694 emit_cmp_insn (last_expr_value
, last_expr_value
, EQ
,
1695 expand_expr (TYPE_SIZE (last_expr_type
),
1696 NULL_RTX
, VOIDmode
, 0),
1698 TYPE_ALIGN (last_expr_type
) / BITS_PER_UNIT
);
1699 emit_jump_insn ((*bcc_gen_fctn
[(int) EQ
]) (lab
));
1704 /* If this expression is part of a ({...}) and is in memory, we may have
1705 to preserve temporaries. */
1706 preserve_temp_slots (last_expr_value
);
1708 /* Free any temporaries used to evaluate this expression. Any temporary
1709 used as a result of this expression will already have been preserved
1716 /* Warn if EXP contains any computations whose results are not used.
1717 Return 1 if a warning is printed; 0 otherwise. */
1720 warn_if_unused_value (exp
)
1723 if (TREE_USED (exp
))
1726 switch (TREE_CODE (exp
))
1728 case PREINCREMENT_EXPR
:
1729 case POSTINCREMENT_EXPR
:
1730 case PREDECREMENT_EXPR
:
1731 case POSTDECREMENT_EXPR
:
1736 case METHOD_CALL_EXPR
:
1738 case TRY_CATCH_EXPR
:
1739 case WITH_CLEANUP_EXPR
:
1741 /* We don't warn about COND_EXPR because it may be a useful
1742 construct if either arm contains a side effect. */
1747 /* For a binding, warn if no side effect within it. */
1748 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1751 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1753 case TRUTH_ORIF_EXPR
:
1754 case TRUTH_ANDIF_EXPR
:
1755 /* In && or ||, warn if 2nd operand has no side effect. */
1756 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1759 if (TREE_NO_UNUSED_WARNING (exp
))
1761 if (warn_if_unused_value (TREE_OPERAND (exp
, 0)))
1763 /* Let people do `(foo (), 0)' without a warning. */
1764 if (TREE_CONSTANT (TREE_OPERAND (exp
, 1)))
1766 return warn_if_unused_value (TREE_OPERAND (exp
, 1));
1770 case NON_LVALUE_EXPR
:
1771 /* Don't warn about values cast to void. */
1772 if (TREE_TYPE (exp
) == void_type_node
)
1774 /* Don't warn about conversions not explicit in the user's program. */
1775 if (TREE_NO_UNUSED_WARNING (exp
))
1777 /* Assignment to a cast usually results in a cast of a modify.
1778 Don't complain about that. There can be an arbitrary number of
1779 casts before the modify, so we must loop until we find the first
1780 non-cast expression and then test to see if that is a modify. */
1782 tree tem
= TREE_OPERAND (exp
, 0);
1784 while (TREE_CODE (tem
) == CONVERT_EXPR
|| TREE_CODE (tem
) == NOP_EXPR
)
1785 tem
= TREE_OPERAND (tem
, 0);
1787 if (TREE_CODE (tem
) == MODIFY_EXPR
|| TREE_CODE (tem
) == INIT_EXPR
1788 || TREE_CODE (tem
) == CALL_EXPR
)
1794 /* Don't warn about automatic dereferencing of references, since
1795 the user cannot control it. */
1796 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == REFERENCE_TYPE
)
1797 return warn_if_unused_value (TREE_OPERAND (exp
, 0));
1798 /* ... fall through ... */
1801 /* Referencing a volatile value is a side effect, so don't warn. */
1802 if ((TREE_CODE_CLASS (TREE_CODE (exp
)) == 'd'
1803 || TREE_CODE_CLASS (TREE_CODE (exp
)) == 'r')
1804 && TREE_THIS_VOLATILE (exp
))
1807 warning_with_file_and_line (emit_filename
, emit_lineno
,
1808 "value computed is not used");
1813 /* Clear out the memory of the last expression evaluated. */
1821 /* Begin a statement which will return a value.
1822 Return the RTL_EXPR for this statement expr.
1823 The caller must save that value and pass it to expand_end_stmt_expr. */
1826 expand_start_stmt_expr ()
1831 /* Make the RTL_EXPR node temporary, not momentary,
1832 so that rtl_expr_chain doesn't become garbage. */
1833 momentary
= suspend_momentary ();
1834 t
= make_node (RTL_EXPR
);
1835 resume_momentary (momentary
);
1836 do_pending_stack_adjust ();
1837 start_sequence_for_rtl_expr (t
);
1839 expr_stmts_for_value
++;
1843 /* Restore the previous state at the end of a statement that returns a value.
1844 Returns a tree node representing the statement's value and the
1845 insns to compute the value.
1847 The nodes of that expression have been freed by now, so we cannot use them.
1848 But we don't want to do that anyway; the expression has already been
1849 evaluated and now we just want to use the value. So generate a RTL_EXPR
1850 with the proper type and RTL value.
1852 If the last substatement was not an expression,
1853 return something with type `void'. */
1856 expand_end_stmt_expr (t
)
1861 if (last_expr_type
== 0)
1863 last_expr_type
= void_type_node
;
1864 last_expr_value
= const0_rtx
;
1866 else if (last_expr_value
== 0)
1867 /* There are some cases where this can happen, such as when the
1868 statement is void type. */
1869 last_expr_value
= const0_rtx
;
1870 else if (GET_CODE (last_expr_value
) != REG
&& ! CONSTANT_P (last_expr_value
))
1871 /* Remove any possible QUEUED. */
1872 last_expr_value
= protect_from_queue (last_expr_value
, 0);
1876 TREE_TYPE (t
) = last_expr_type
;
1877 RTL_EXPR_RTL (t
) = last_expr_value
;
1878 RTL_EXPR_SEQUENCE (t
) = get_insns ();
1880 rtl_expr_chain
= tree_cons (NULL_TREE
, t
, rtl_expr_chain
);
1884 /* Don't consider deleting this expr or containing exprs at tree level. */
1885 TREE_SIDE_EFFECTS (t
) = 1;
1886 /* Propagate volatility of the actual RTL expr. */
1887 TREE_THIS_VOLATILE (t
) = volatile_refs_p (last_expr_value
);
1890 expr_stmts_for_value
--;
1895 /* Generate RTL for the start of an if-then. COND is the expression
1896 whose truth should be tested.
1898 If EXITFLAG is nonzero, this conditional is visible to
1899 `exit_something'. */
1902 expand_start_cond (cond
, exitflag
)
1906 struct nesting
*thiscond
= ALLOC_NESTING ();
1908 /* Make an entry on cond_stack for the cond we are entering. */
1910 thiscond
->next
= cond_stack
;
1911 thiscond
->all
= nesting_stack
;
1912 thiscond
->depth
= ++nesting_depth
;
1913 thiscond
->data
.cond
.next_label
= gen_label_rtx ();
1914 /* Before we encounter an `else', we don't need a separate exit label
1915 unless there are supposed to be exit statements
1916 to exit this conditional. */
1917 thiscond
->exit_label
= exitflag
? gen_label_rtx () : 0;
1918 thiscond
->data
.cond
.endif_label
= thiscond
->exit_label
;
1919 cond_stack
= thiscond
;
1920 nesting_stack
= thiscond
;
1922 do_jump (cond
, thiscond
->data
.cond
.next_label
, NULL_RTX
);
1925 /* Generate RTL between then-clause and the elseif-clause
1926 of an if-then-elseif-.... */
1929 expand_start_elseif (cond
)
1932 if (cond_stack
->data
.cond
.endif_label
== 0)
1933 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
1934 emit_jump (cond_stack
->data
.cond
.endif_label
);
1935 emit_label (cond_stack
->data
.cond
.next_label
);
1936 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
1937 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
1940 /* Generate RTL between the then-clause and the else-clause
1941 of an if-then-else. */
1944 expand_start_else ()
1946 if (cond_stack
->data
.cond
.endif_label
== 0)
1947 cond_stack
->data
.cond
.endif_label
= gen_label_rtx ();
1949 emit_jump (cond_stack
->data
.cond
.endif_label
);
1950 emit_label (cond_stack
->data
.cond
.next_label
);
1951 cond_stack
->data
.cond
.next_label
= 0; /* No more _else or _elseif calls. */
1954 /* After calling expand_start_else, turn this "else" into an "else if"
1955 by providing another condition. */
1958 expand_elseif (cond
)
1961 cond_stack
->data
.cond
.next_label
= gen_label_rtx ();
1962 do_jump (cond
, cond_stack
->data
.cond
.next_label
, NULL_RTX
);
1965 /* Generate RTL for the end of an if-then.
1966 Pop the record for it off of cond_stack. */
1971 struct nesting
*thiscond
= cond_stack
;
1973 do_pending_stack_adjust ();
1974 if (thiscond
->data
.cond
.next_label
)
1975 emit_label (thiscond
->data
.cond
.next_label
);
1976 if (thiscond
->data
.cond
.endif_label
)
1977 emit_label (thiscond
->data
.cond
.endif_label
);
1979 POPSTACK (cond_stack
);
1985 /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this
1986 loop should be exited by `exit_something'. This is a loop for which
1987 `expand_continue' will jump to the top of the loop.
1989 Make an entry on loop_stack to record the labels associated with
1993 expand_start_loop (exit_flag
)
1996 register struct nesting
*thisloop
= ALLOC_NESTING ();
1998 /* Make an entry on loop_stack for the loop we are entering. */
2000 thisloop
->next
= loop_stack
;
2001 thisloop
->all
= nesting_stack
;
2002 thisloop
->depth
= ++nesting_depth
;
2003 thisloop
->data
.loop
.start_label
= gen_label_rtx ();
2004 thisloop
->data
.loop
.end_label
= gen_label_rtx ();
2005 thisloop
->data
.loop
.alt_end_label
= 0;
2006 thisloop
->data
.loop
.continue_label
= thisloop
->data
.loop
.start_label
;
2007 thisloop
->exit_label
= exit_flag
? thisloop
->data
.loop
.end_label
: 0;
2008 loop_stack
= thisloop
;
2009 nesting_stack
= thisloop
;
2011 do_pending_stack_adjust ();
2013 emit_note (NULL_PTR
, NOTE_INSN_LOOP_BEG
);
2014 emit_label (thisloop
->data
.loop
.start_label
);
2019 /* Like expand_start_loop but for a loop where the continuation point
2020 (for expand_continue_loop) will be specified explicitly. */
2023 expand_start_loop_continue_elsewhere (exit_flag
)
2026 struct nesting
*thisloop
= expand_start_loop (exit_flag
);
2027 loop_stack
->data
.loop
.continue_label
= gen_label_rtx ();
2031 /* Specify the continuation point for a loop started with
2032 expand_start_loop_continue_elsewhere.
2033 Use this at the point in the code to which a continue statement
2037 expand_loop_continue_here ()
2039 do_pending_stack_adjust ();
2040 emit_note (NULL_PTR
, NOTE_INSN_LOOP_CONT
);
2041 emit_label (loop_stack
->data
.loop
.continue_label
);
2044 /* Finish a loop. Generate a jump back to the top and the loop-exit label.
2045 Pop the block off of loop_stack. */
2050 rtx start_label
= loop_stack
->data
.loop
.start_label
;
2051 rtx insn
= get_last_insn ();
2053 /* Mark the continue-point at the top of the loop if none elsewhere. */
2054 if (start_label
== loop_stack
->data
.loop
.continue_label
)
2055 emit_note_before (NOTE_INSN_LOOP_CONT
, start_label
);
2057 do_pending_stack_adjust ();
2059 /* If optimizing, perhaps reorder the loop. If the loop starts with
2060 a loop exit, roll that to the end where it will optimize together
2063 We look for the conditional branch to the exit, except that once
2064 we find such a branch, we don't look past 30 instructions.
2066 In more detail, if the loop presently looks like this (in pseudo-C):
2069 if (test) goto end_label;
2074 transform it to look like:
2080 if (test) goto end_label;
2081 goto newstart_label;
2084 Here, the `test' may actually consist of some reasonably complex
2085 code, terminating in a test. */
2089 ! (GET_CODE (insn
) == JUMP_INSN
2090 && GET_CODE (PATTERN (insn
)) == SET
2091 && SET_DEST (PATTERN (insn
)) == pc_rtx
2092 && GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
))
2096 rtx last_test_insn
= NULL_RTX
;
2098 /* Scan insns from the top of the loop looking for a qualified
2099 conditional exit. */
2100 for (insn
= NEXT_INSN (loop_stack
->data
.loop
.start_label
); insn
;
2101 insn
= NEXT_INSN (insn
))
2103 if (GET_CODE (insn
) == NOTE
)
2106 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2107 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2108 /* The code that actually moves the exit test will
2109 carefully leave BLOCK notes in their original
2110 location. That means, however, that we can't debug
2111 the exit test itself. So, we refuse to move code
2112 containing BLOCK notes at low optimization levels. */
2115 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_BEG
)
2117 else if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EH_REGION_END
)
2121 /* We've come to the end of an EH region, but
2122 never saw the beginning of that region. That
2123 means that an EH region begins before the top
2124 of the loop, and ends in the middle of it. The
2125 existence of such a situation violates a basic
2126 assumption in this code, since that would imply
2127 that even when EH_REGIONS is zero, we might
2128 move code out of an exception region. */
2132 /* We already know this INSN is a NOTE, so there's no
2133 point in looking at it to see if it's a JUMP. */
2137 if (GET_CODE (insn
) == JUMP_INSN
|| GET_CODE (insn
) == INSN
)
2140 if (last_test_insn
&& num_insns
> 30)
2144 /* We don't want to move a partial EH region. Consider:
2158 This isn't legal C++, but here's what it's supposed to
2159 mean: if cond() is true, stop looping. Otherwise,
2160 call bar, and keep looping. In addition, if cond
2161 throws an exception, catch it and keep looping. Such
2162 constructs are certainy legal in LISP.
2164 We should not move the `if (cond()) 0' test since then
2165 the EH-region for the try-block would be broken up.
2166 (In this case we would the EH_BEG note for the `try'
2167 and `if cond()' but not the call to bar() or the
2170 So we don't look for tests within an EH region. */
2173 if (GET_CODE (insn
) == JUMP_INSN
2174 && GET_CODE (PATTERN (insn
)) == SET
2175 && SET_DEST (PATTERN (insn
)) == pc_rtx
)
2177 /* This is indeed a jump. */
2178 rtx dest1
= NULL_RTX
;
2179 rtx dest2
= NULL_RTX
;
2180 rtx potential_last_test
;
2181 if (GET_CODE (SET_SRC (PATTERN (insn
))) == IF_THEN_ELSE
)
2183 /* A conditional jump. */
2184 dest1
= XEXP (SET_SRC (PATTERN (insn
)), 1);
2185 dest2
= XEXP (SET_SRC (PATTERN (insn
)), 2);
2186 potential_last_test
= insn
;
2190 /* An unconditional jump. */
2191 dest1
= SET_SRC (PATTERN (insn
));
2192 /* Include the BARRIER after the JUMP. */
2193 potential_last_test
= NEXT_INSN (insn
);
2197 if (dest1
&& GET_CODE (dest1
) == LABEL_REF
2198 && ((XEXP (dest1
, 0)
2199 == loop_stack
->data
.loop
.alt_end_label
)
2201 == loop_stack
->data
.loop
.end_label
)))
2203 last_test_insn
= potential_last_test
;
2207 /* If this was a conditional jump, there may be
2208 another label at which we should look. */
2215 if (last_test_insn
!= 0 && last_test_insn
!= get_last_insn ())
2217 /* We found one. Move everything from there up
2218 to the end of the loop, and add a jump into the loop
2219 to jump to there. */
2220 register rtx newstart_label
= gen_label_rtx ();
2221 register rtx start_move
= start_label
;
2224 /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note,
2225 then we want to move this note also. */
2226 if (GET_CODE (PREV_INSN (start_move
)) == NOTE
2227 && (NOTE_LINE_NUMBER (PREV_INSN (start_move
))
2228 == NOTE_INSN_LOOP_CONT
))
2229 start_move
= PREV_INSN (start_move
);
2231 emit_label_after (newstart_label
, PREV_INSN (start_move
));
2233 /* Actually move the insns. Start at the beginning, and
2234 keep copying insns until we've copied the
2236 for (insn
= start_move
; insn
; insn
= next_insn
)
2238 /* Figure out which insn comes after this one. We have
2239 to do this before we move INSN. */
2240 if (insn
== last_test_insn
)
2241 /* We've moved all the insns. */
2242 next_insn
= NULL_RTX
;
2244 next_insn
= NEXT_INSN (insn
);
2246 if (GET_CODE (insn
) == NOTE
2247 && (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
2248 || NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
))
2249 /* We don't want to move NOTE_INSN_BLOCK_BEGs or
2250 NOTE_INSN_BLOCK_ENDs because the correct generation
2251 of debugging information depends on these appearing
2252 in the same order in the RTL and in the tree
2253 structure, where they are represented as BLOCKs.
2254 So, we don't move block notes. Of course, moving
2255 the code inside the block is likely to make it
2256 impossible to debug the instructions in the exit
2257 test, but such is the price of optimization. */
2260 /* Move the INSN. */
2261 reorder_insns (insn
, insn
, get_last_insn ());
2264 emit_jump_insn_after (gen_jump (start_label
),
2265 PREV_INSN (newstart_label
));
2266 emit_barrier_after (PREV_INSN (newstart_label
));
2267 start_label
= newstart_label
;
2271 emit_jump (start_label
);
2272 emit_note (NULL_PTR
, NOTE_INSN_LOOP_END
);
2273 emit_label (loop_stack
->data
.loop
.end_label
);
2275 POPSTACK (loop_stack
);
2280 /* Generate a jump to the current loop's continue-point.
2281 This is usually the top of the loop, but may be specified
2282 explicitly elsewhere. If not currently inside a loop,
2283 return 0 and do nothing; caller will print an error message. */
2286 expand_continue_loop (whichloop
)
2287 struct nesting
*whichloop
;
2291 whichloop
= loop_stack
;
2294 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.continue_label
,
2299 /* Generate a jump to exit the current loop. If not currently inside a loop,
2300 return 0 and do nothing; caller will print an error message. */
2303 expand_exit_loop (whichloop
)
2304 struct nesting
*whichloop
;
2308 whichloop
= loop_stack
;
2311 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
, NULL_RTX
);
2315 /* Generate a conditional jump to exit the current loop if COND
2316 evaluates to zero. If not currently inside a loop,
2317 return 0 and do nothing; caller will print an error message. */
2320 expand_exit_loop_if_false (whichloop
, cond
)
2321 struct nesting
*whichloop
;
2324 rtx label
= gen_label_rtx ();
2329 whichloop
= loop_stack
;
2332 /* In order to handle fixups, we actually create a conditional jump
2333 around a unconditional branch to exit the loop. If fixups are
2334 necessary, they go before the unconditional branch. */
2337 do_jump (cond
, NULL_RTX
, label
);
2338 last_insn
= get_last_insn ();
2339 if (GET_CODE (last_insn
) == CODE_LABEL
)
2340 whichloop
->data
.loop
.alt_end_label
= last_insn
;
2341 expand_goto_internal (NULL_TREE
, whichloop
->data
.loop
.end_label
,
2348 /* Return non-zero if we should preserve sub-expressions as separate
2349 pseudos. We never do so if we aren't optimizing. We always do so
2350 if -fexpensive-optimizations.
2352 Otherwise, we only do so if we are in the "early" part of a loop. I.e.,
2353 the loop may still be a small one. */
2356 preserve_subexpressions_p ()
2360 if (flag_expensive_optimizations
)
2363 if (optimize
== 0 || loop_stack
== 0)
2366 insn
= get_last_insn_anywhere ();
2369 && (INSN_UID (insn
) - INSN_UID (loop_stack
->data
.loop
.start_label
)
2370 < n_non_fixed_regs
* 3));
2374 /* Generate a jump to exit the current loop, conditional, binding contour
2375 or case statement. Not all such constructs are visible to this function,
2376 only those started with EXIT_FLAG nonzero. Individual languages use
2377 the EXIT_FLAG parameter to control which kinds of constructs you can
2380 If not currently inside anything that can be exited,
2381 return 0 and do nothing; caller will print an error message. */
2384 expand_exit_something ()
2388 for (n
= nesting_stack
; n
; n
= n
->all
)
2389 if (n
->exit_label
!= 0)
2391 expand_goto_internal (NULL_TREE
, n
->exit_label
, NULL_RTX
);
2398 /* Generate RTL to return from the current function, with no value.
2399 (That is, we do not do anything about returning any value.) */
2402 expand_null_return ()
2404 struct nesting
*block
= block_stack
;
2407 /* Does any pending block have cleanups? */
2409 while (block
&& block
->data
.block
.cleanups
== 0)
2410 block
= block
->next
;
2412 /* If yes, use a goto to return, since that runs cleanups. */
2414 expand_null_return_1 (last_insn
, block
!= 0);
2417 /* Generate RTL to return from the current function, with value VAL. */
2420 expand_value_return (val
)
2423 struct nesting
*block
= block_stack
;
2424 rtx last_insn
= get_last_insn ();
2425 rtx return_reg
= DECL_RTL (DECL_RESULT (current_function_decl
));
2427 /* Copy the value to the return location
2428 unless it's already there. */
2430 if (return_reg
!= val
)
2432 #ifdef PROMOTE_FUNCTION_RETURN
2433 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
2434 int unsignedp
= TREE_UNSIGNED (type
);
2435 enum machine_mode mode
2436 = promote_mode (type
, DECL_MODE (DECL_RESULT (current_function_decl
)),
2439 if (GET_MODE (val
) != VOIDmode
&& GET_MODE (val
) != mode
)
2440 convert_move (return_reg
, val
, unsignedp
);
2443 emit_move_insn (return_reg
, val
);
2445 if (GET_CODE (return_reg
) == REG
2446 && REGNO (return_reg
) < FIRST_PSEUDO_REGISTER
)
2447 emit_insn (gen_rtx_USE (VOIDmode
, return_reg
));
2448 /* Handle calls that return values in multiple non-contiguous locations.
2449 The Irix 6 ABI has examples of this. */
2450 else if (GET_CODE (return_reg
) == PARALLEL
)
2454 for (i
= 0; i
< XVECLEN (return_reg
, 0); i
++)
2456 rtx x
= XEXP (XVECEXP (return_reg
, 0, i
), 0);
2458 if (GET_CODE (x
) == REG
2459 && REGNO (x
) < FIRST_PSEUDO_REGISTER
)
2460 emit_insn (gen_rtx_USE (VOIDmode
, x
));
2464 /* Does any pending block have cleanups? */
2466 while (block
&& block
->data
.block
.cleanups
== 0)
2467 block
= block
->next
;
2469 /* If yes, use a goto to return, since that runs cleanups.
2470 Use LAST_INSN to put cleanups *before* the move insn emitted above. */
2472 expand_null_return_1 (last_insn
, block
!= 0);
2475 /* Output a return with no value. If LAST_INSN is nonzero,
2476 pretend that the return takes place after LAST_INSN.
2477 If USE_GOTO is nonzero then don't use a return instruction;
2478 go to the return label instead. This causes any cleanups
2479 of pending blocks to be executed normally. */
2482 expand_null_return_1 (last_insn
, use_goto
)
2486 rtx end_label
= cleanup_label
? cleanup_label
: return_label
;
2488 clear_pending_stack_adjust ();
2489 do_pending_stack_adjust ();
2492 /* PCC-struct return always uses an epilogue. */
2493 if (current_function_returns_pcc_struct
|| use_goto
)
2496 end_label
= return_label
= gen_label_rtx ();
2497 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2501 /* Otherwise output a simple return-insn if one is available,
2502 unless it won't do the job. */
2504 if (HAVE_return
&& use_goto
== 0 && cleanup_label
== 0)
2506 emit_jump_insn (gen_return ());
2512 /* Otherwise jump to the epilogue. */
2513 expand_goto_internal (NULL_TREE
, end_label
, last_insn
);
2516 /* Generate RTL to evaluate the expression RETVAL and return it
2517 from the current function. */
2520 expand_return (retval
)
2523 /* If there are any cleanups to be performed, then they will
2524 be inserted following LAST_INSN. It is desirable
2525 that the last_insn, for such purposes, should be the
2526 last insn before computing the return value. Otherwise, cleanups
2527 which call functions can clobber the return value. */
2528 /* ??? rms: I think that is erroneous, because in C++ it would
2529 run destructors on variables that might be used in the subsequent
2530 computation of the return value. */
2532 register rtx val
= 0;
2537 /* If function wants no value, give it none. */
2538 if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl
))) == VOID_TYPE
)
2540 expand_expr (retval
, NULL_RTX
, VOIDmode
, 0);
2542 expand_null_return ();
2546 /* Are any cleanups needed? E.g. C++ destructors to be run? */
2547 /* This is not sufficient. We also need to watch for cleanups of the
2548 expression we are about to expand. Unfortunately, we cannot know
2549 if it has cleanups until we expand it, and we want to change how we
2550 expand it depending upon if we need cleanups. We can't win. */
2552 cleanups
= any_pending_cleanups (1);
2557 if (TREE_CODE (retval
) == RESULT_DECL
)
2558 retval_rhs
= retval
;
2559 else if ((TREE_CODE (retval
) == MODIFY_EXPR
|| TREE_CODE (retval
) == INIT_EXPR
)
2560 && TREE_CODE (TREE_OPERAND (retval
, 0)) == RESULT_DECL
)
2561 retval_rhs
= TREE_OPERAND (retval
, 1);
2562 else if (TREE_TYPE (retval
) == void_type_node
)
2563 /* Recognize tail-recursive call to void function. */
2564 retval_rhs
= retval
;
2566 retval_rhs
= NULL_TREE
;
2568 /* Only use `last_insn' if there are cleanups which must be run. */
2569 if (cleanups
|| cleanup_label
!= 0)
2570 last_insn
= get_last_insn ();
2572 /* Distribute return down conditional expr if either of the sides
2573 may involve tail recursion (see test below). This enhances the number
2574 of tail recursions we see. Don't do this always since it can produce
2575 sub-optimal code in some cases and we distribute assignments into
2576 conditional expressions when it would help. */
2578 if (optimize
&& retval_rhs
!= 0
2579 && frame_offset
== 0
2580 && TREE_CODE (retval_rhs
) == COND_EXPR
2581 && (TREE_CODE (TREE_OPERAND (retval_rhs
, 1)) == CALL_EXPR
2582 || TREE_CODE (TREE_OPERAND (retval_rhs
, 2)) == CALL_EXPR
))
2584 rtx label
= gen_label_rtx ();
2587 do_jump (TREE_OPERAND (retval_rhs
, 0), label
, NULL_RTX
);
2588 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
2589 DECL_RESULT (current_function_decl
),
2590 TREE_OPERAND (retval_rhs
, 1));
2591 TREE_SIDE_EFFECTS (expr
) = 1;
2592 expand_return (expr
);
2595 expr
= build (MODIFY_EXPR
, TREE_TYPE (TREE_TYPE (current_function_decl
)),
2596 DECL_RESULT (current_function_decl
),
2597 TREE_OPERAND (retval_rhs
, 2));
2598 TREE_SIDE_EFFECTS (expr
) = 1;
2599 expand_return (expr
);
2603 /* Attempt to optimize the call if it is tail recursive. */
2604 optimize_tail_recursion (retval_rhs
, last_insn
);
2607 /* This optimization is safe if there are local cleanups
2608 because expand_null_return takes care of them.
2609 ??? I think it should also be safe when there is a cleanup label,
2610 because expand_null_return takes care of them, too.
2611 Any reason why not? */
2612 if (HAVE_return
&& cleanup_label
== 0
2613 && ! current_function_returns_pcc_struct
2614 && BRANCH_COST
<= 1)
2616 /* If this is return x == y; then generate
2617 if (x == y) return 1; else return 0;
2618 if we can do it with explicit return insns and branches are cheap,
2619 but not if we have the corresponding scc insn. */
2622 switch (TREE_CODE (retval_rhs
))
2648 case TRUTH_ANDIF_EXPR
:
2649 case TRUTH_ORIF_EXPR
:
2650 case TRUTH_AND_EXPR
:
2652 case TRUTH_NOT_EXPR
:
2653 case TRUTH_XOR_EXPR
:
2656 op0
= gen_label_rtx ();
2657 jumpifnot (retval_rhs
, op0
);
2658 expand_value_return (const1_rtx
);
2660 expand_value_return (const0_rtx
);
2669 #endif /* HAVE_return */
2671 /* If the result is an aggregate that is being returned in one (or more)
2672 registers, load the registers here. The compiler currently can't handle
2673 copying a BLKmode value into registers. We could put this code in a
2674 more general area (for use by everyone instead of just function
2675 call/return), but until this feature is generally usable it is kept here
2676 (and in expand_call). The value must go into a pseudo in case there
2677 are cleanups that will clobber the real return register. */
2680 && TYPE_MODE (TREE_TYPE (retval_rhs
)) == BLKmode
2681 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
)
2683 int i
, bitpos
, xbitpos
;
2684 int big_endian_correction
= 0;
2685 int bytes
= int_size_in_bytes (TREE_TYPE (retval_rhs
));
2686 int n_regs
= (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
2687 int bitsize
= MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs
)),
2688 (unsigned int)BITS_PER_WORD
);
2689 rtx
*result_pseudos
= (rtx
*) alloca (sizeof (rtx
) * n_regs
);
2690 rtx result_reg
, src
= NULL_RTX
, dst
= NULL_RTX
;
2691 rtx result_val
= expand_expr (retval_rhs
, NULL_RTX
, VOIDmode
, 0);
2692 enum machine_mode tmpmode
, result_reg_mode
;
2694 /* Structures whose size is not a multiple of a word are aligned
2695 to the least significant byte (to the right). On a BYTES_BIG_ENDIAN
2696 machine, this means we must skip the empty high order bytes when
2697 calculating the bit offset. */
2698 if (BYTES_BIG_ENDIAN
&& bytes
% UNITS_PER_WORD
)
2699 big_endian_correction
= (BITS_PER_WORD
- ((bytes
% UNITS_PER_WORD
)
2702 /* Copy the structure BITSIZE bits at a time. */
2703 for (bitpos
= 0, xbitpos
= big_endian_correction
;
2704 bitpos
< bytes
* BITS_PER_UNIT
;
2705 bitpos
+= bitsize
, xbitpos
+= bitsize
)
2707 /* We need a new destination pseudo each time xbitpos is
2708 on a word boundary and when xbitpos == big_endian_correction
2709 (the first time through). */
2710 if (xbitpos
% BITS_PER_WORD
== 0
2711 || xbitpos
== big_endian_correction
)
2713 /* Generate an appropriate register. */
2714 dst
= gen_reg_rtx (word_mode
);
2715 result_pseudos
[xbitpos
/ BITS_PER_WORD
] = dst
;
2717 /* Clobber the destination before we move anything into it. */
2718 emit_insn (gen_rtx_CLOBBER (VOIDmode
, dst
));
2721 /* We need a new source operand each time bitpos is on a word
2723 if (bitpos
% BITS_PER_WORD
== 0)
2724 src
= operand_subword_force (result_val
,
2725 bitpos
/ BITS_PER_WORD
,
2728 /* Use bitpos for the source extraction (left justified) and
2729 xbitpos for the destination store (right justified). */
2730 store_bit_field (dst
, bitsize
, xbitpos
% BITS_PER_WORD
, word_mode
,
2731 extract_bit_field (src
, bitsize
,
2732 bitpos
% BITS_PER_WORD
, 1,
2733 NULL_RTX
, word_mode
,
2735 bitsize
/ BITS_PER_UNIT
,
2737 bitsize
/ BITS_PER_UNIT
, BITS_PER_WORD
);
2740 /* Find the smallest integer mode large enough to hold the
2741 entire structure and use that mode instead of BLKmode
2742 on the USE insn for the return register. */
2743 bytes
= int_size_in_bytes (TREE_TYPE (retval_rhs
));
2744 for (tmpmode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
2745 tmpmode
!= MAX_MACHINE_MODE
;
2746 tmpmode
= GET_MODE_WIDER_MODE (tmpmode
))
2748 /* Have we found a large enough mode? */
2749 if (GET_MODE_SIZE (tmpmode
) >= bytes
)
2753 /* No suitable mode found. */
2754 if (tmpmode
== MAX_MACHINE_MODE
)
2757 PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl
)), tmpmode
);
2759 if (GET_MODE_SIZE (tmpmode
) < GET_MODE_SIZE (word_mode
))
2760 result_reg_mode
= word_mode
;
2762 result_reg_mode
= tmpmode
;
2763 result_reg
= gen_reg_rtx (result_reg_mode
);
2766 for (i
= 0; i
< n_regs
; i
++)
2767 emit_move_insn (operand_subword (result_reg
, i
, 0, result_reg_mode
),
2770 if (tmpmode
!= result_reg_mode
)
2771 result_reg
= gen_lowpart (tmpmode
, result_reg
);
2773 expand_value_return (result_reg
);
2777 && TREE_TYPE (retval_rhs
) != void_type_node
2778 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
)
2780 /* Calculate the return value into a pseudo reg. */
2781 val
= gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl
)));
2782 val
= expand_expr (retval_rhs
, val
, GET_MODE (val
), 0);
2783 val
= force_not_mem (val
);
2785 /* Return the calculated value, doing cleanups first. */
2786 expand_value_return (val
);
2790 /* No cleanups or no hard reg used;
2791 calculate value into hard return reg. */
2792 expand_expr (retval
, const0_rtx
, VOIDmode
, 0);
2794 expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl
)));
2798 /* Return 1 if the end of the generated RTX is not a barrier.
2799 This means code already compiled can drop through. */
2802 drop_through_at_end_p ()
2804 rtx insn
= get_last_insn ();
2805 while (insn
&& GET_CODE (insn
) == NOTE
)
2806 insn
= PREV_INSN (insn
);
2807 return insn
&& GET_CODE (insn
) != BARRIER
;
2810 /* Test CALL_EXPR to determine if it is a potential tail recursion call
2811 and emit code to optimize the tail recursion. LAST_INSN indicates where
2812 to place the jump to the tail recursion label.
2814 This is only used by expand_return, but expand_call is expected to
2818 optimize_tail_recursion (call_expr
, last_insn
)
2822 /* For tail-recursive call to current function,
2823 just jump back to the beginning.
2824 It's unsafe if any auto variable in this function
2825 has its address taken; for simplicity,
2826 require stack frame to be empty. */
2827 if (optimize
&& call_expr
!= 0
2828 && frame_offset
== 0
2829 && TREE_CODE (call_expr
) == CALL_EXPR
2830 && TREE_CODE (TREE_OPERAND (call_expr
, 0)) == ADDR_EXPR
2831 && TREE_OPERAND (TREE_OPERAND (call_expr
, 0), 0) == current_function_decl
2832 /* Finish checking validity, and if valid emit code
2833 to set the argument variables for the new call. */
2834 && tail_recursion_args (TREE_OPERAND (call_expr
, 1),
2835 DECL_ARGUMENTS (current_function_decl
)))
2837 if (tail_recursion_label
== 0)
2839 tail_recursion_label
= gen_label_rtx ();
2840 emit_label_after (tail_recursion_label
,
2841 tail_recursion_reentry
);
2844 expand_goto_internal (NULL_TREE
, tail_recursion_label
, last_insn
);
2849 /* Emit code to alter this function's formal parms for a tail-recursive call.
2850 ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs).
2851 FORMALS is the chain of decls of formals.
2852 Return 1 if this can be done;
2853 otherwise return 0 and do not emit any code. */
2856 tail_recursion_args (actuals
, formals
)
2857 tree actuals
, formals
;
2859 register tree a
= actuals
, f
= formals
;
2861 register rtx
*argvec
;
2863 /* Check that number and types of actuals are compatible
2864 with the formals. This is not always true in valid C code.
2865 Also check that no formal needs to be addressable
2866 and that all formals are scalars. */
2868 /* Also count the args. */
2870 for (a
= actuals
, f
= formals
, i
= 0; a
&& f
; a
= TREE_CHAIN (a
), f
= TREE_CHAIN (f
), i
++)
2872 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a
)))
2873 != TYPE_MAIN_VARIANT (TREE_TYPE (f
)))
2875 if (GET_CODE (DECL_RTL (f
)) != REG
|| DECL_MODE (f
) == BLKmode
)
2878 if (a
!= 0 || f
!= 0)
2881 /* Compute all the actuals. */
2883 argvec
= (rtx
*) alloca (i
* sizeof (rtx
));
2885 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
2886 argvec
[i
] = expand_expr (TREE_VALUE (a
), NULL_RTX
, VOIDmode
, 0);
2888 /* Find which actual values refer to current values of previous formals.
2889 Copy each of them now, before any formal is changed. */
2891 for (a
= actuals
, i
= 0; a
; a
= TREE_CHAIN (a
), i
++)
2895 for (f
= formals
, j
= 0; j
< i
; f
= TREE_CHAIN (f
), j
++)
2896 if (reg_mentioned_p (DECL_RTL (f
), argvec
[i
]))
2897 { copy
= 1; break; }
2899 argvec
[i
] = copy_to_reg (argvec
[i
]);
2902 /* Store the values of the actuals into the formals. */
2904 for (f
= formals
, a
= actuals
, i
= 0; f
;
2905 f
= TREE_CHAIN (f
), a
= TREE_CHAIN (a
), i
++)
2907 if (GET_MODE (DECL_RTL (f
)) == GET_MODE (argvec
[i
]))
2908 emit_move_insn (DECL_RTL (f
), argvec
[i
]);
2910 convert_move (DECL_RTL (f
), argvec
[i
],
2911 TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a
))));
2918 /* Generate the RTL code for entering a binding contour.
2919 The variables are declared one by one, by calls to `expand_decl'.
2921 EXIT_FLAG is nonzero if this construct should be visible to
2922 `exit_something'. */
2925 expand_start_bindings (exit_flag
)
2928 struct nesting
*thisblock
= ALLOC_NESTING ();
2929 rtx note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_BEG
);
2931 /* Make an entry on block_stack for the block we are entering. */
2933 thisblock
->next
= block_stack
;
2934 thisblock
->all
= nesting_stack
;
2935 thisblock
->depth
= ++nesting_depth
;
2936 thisblock
->data
.block
.stack_level
= 0;
2937 thisblock
->data
.block
.cleanups
= 0;
2938 thisblock
->data
.block
.function_call_count
= 0;
2939 thisblock
->data
.block
.exception_region
= 0;
2940 thisblock
->data
.block
.target_temp_slot_level
= target_temp_slot_level
;
2942 thisblock
->data
.block
.conditional_code
= 0;
2943 thisblock
->data
.block
.last_unconditional_cleanup
= note
;
2944 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
2947 && !(block_stack
->data
.block
.cleanups
== NULL_TREE
2948 && block_stack
->data
.block
.outer_cleanups
== NULL_TREE
))
2949 thisblock
->data
.block
.outer_cleanups
2950 = tree_cons (NULL_TREE
, block_stack
->data
.block
.cleanups
,
2951 block_stack
->data
.block
.outer_cleanups
);
2953 thisblock
->data
.block
.outer_cleanups
= 0;
2954 thisblock
->data
.block
.label_chain
= 0;
2955 thisblock
->data
.block
.innermost_stack_block
= stack_block_stack
;
2956 thisblock
->data
.block
.first_insn
= note
;
2957 thisblock
->data
.block
.block_start_count
= ++block_start_count
;
2958 thisblock
->exit_label
= exit_flag
? gen_label_rtx () : 0;
2959 block_stack
= thisblock
;
2960 nesting_stack
= thisblock
;
2962 /* Make a new level for allocating stack slots. */
2966 /* Specify the scope of temporaries created by TARGET_EXPRs. Similar
2967 to CLEANUP_POINT_EXPR, but handles cases when a series of calls to
2968 expand_expr are made. After we end the region, we know that all
2969 space for all temporaries that were created by TARGET_EXPRs will be
2970 destroyed and their space freed for reuse. */
2973 expand_start_target_temps ()
2975 /* This is so that even if the result is preserved, the space
2976 allocated will be freed, as we know that it is no longer in use. */
2979 /* Start a new binding layer that will keep track of all cleanup
2980 actions to be performed. */
2981 expand_start_bindings (0);
2983 target_temp_slot_level
= temp_slot_level
;
2987 expand_end_target_temps ()
2989 expand_end_bindings (NULL_TREE
, 0, 0);
2991 /* This is so that even if the result is preserved, the space
2992 allocated will be freed, as we know that it is no longer in use. */
2996 /* Mark top block of block_stack as an implicit binding for an
2997 exception region. This is used to prevent infinite recursion when
2998 ending a binding with expand_end_bindings. It is only ever called
2999 by expand_eh_region_start, as that it the only way to create a
3000 block stack for a exception region. */
3003 mark_block_as_eh_region ()
3005 block_stack
->data
.block
.exception_region
= 1;
3006 if (block_stack
->next
3007 && block_stack
->next
->data
.block
.conditional_code
)
3009 block_stack
->data
.block
.conditional_code
3010 = block_stack
->next
->data
.block
.conditional_code
;
3011 block_stack
->data
.block
.last_unconditional_cleanup
3012 = block_stack
->next
->data
.block
.last_unconditional_cleanup
;
3013 block_stack
->data
.block
.cleanup_ptr
3014 = block_stack
->next
->data
.block
.cleanup_ptr
;
3018 /* True if we are currently emitting insns in an area of output code
3019 that is controlled by a conditional expression. This is used by
3020 the cleanup handling code to generate conditional cleanup actions. */
3023 conditional_context ()
3025 return block_stack
&& block_stack
->data
.block
.conditional_code
;
3028 /* Mark top block of block_stack as not for an implicit binding for an
3029 exception region. This is only ever done by expand_eh_region_end
3030 to let expand_end_bindings know that it is being called explicitly
3031 to end the binding layer for just the binding layer associated with
3032 the exception region, otherwise expand_end_bindings would try and
3033 end all implicit binding layers for exceptions regions, and then
3034 one normal binding layer. */
3037 mark_block_as_not_eh_region ()
3039 block_stack
->data
.block
.exception_region
= 0;
3042 /* True if the top block of block_stack was marked as for an exception
3043 region by mark_block_as_eh_region. */
3048 return block_stack
&& block_stack
->data
.block
.exception_region
;
3051 /* Given a pointer to a BLOCK node, save a pointer to the most recently
3052 generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given
3056 remember_end_note (block
)
3057 register tree block
;
3059 BLOCK_END_NOTE (block
) = last_block_end_note
;
3060 last_block_end_note
= NULL_RTX
;
3063 /* Emit a handler label for a nonlocal goto handler.
3064 Also emit code to store the handler label in SLOT before BEFORE_INSN. */
3067 expand_nl_handler_label (slot
, before_insn
)
3068 rtx slot
, before_insn
;
3071 rtx handler_label
= gen_label_rtx ();
3073 /* Don't let jump_optimize delete the handler. */
3074 LABEL_PRESERVE_P (handler_label
) = 1;
3077 emit_move_insn (slot
, gen_rtx_LABEL_REF (Pmode
, handler_label
));
3078 insns
= get_insns ();
3080 emit_insns_before (insns
, before_insn
);
3082 emit_label (handler_label
);
3085 /* Emit code to restore vital registers at the beginning of a nonlocal goto
3088 expand_nl_goto_receiver ()
3090 #ifdef HAVE_nonlocal_goto
3091 if (! HAVE_nonlocal_goto
)
3093 /* First adjust our frame pointer to its actual value. It was
3094 previously set to the start of the virtual area corresponding to
3095 the stacked variables when we branched here and now needs to be
3096 adjusted to the actual hardware fp value.
3098 Assignments are to virtual registers are converted by
3099 instantiate_virtual_regs into the corresponding assignment
3100 to the underlying register (fp in this case) that makes
3101 the original assignment true.
3102 So the following insn will actually be
3103 decrementing fp by STARTING_FRAME_OFFSET. */
3104 emit_move_insn (virtual_stack_vars_rtx
, hard_frame_pointer_rtx
);
3106 #if ARG_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
3107 if (fixed_regs
[ARG_POINTER_REGNUM
])
3109 #ifdef ELIMINABLE_REGS
3110 /* If the argument pointer can be eliminated in favor of the
3111 frame pointer, we don't need to restore it. We assume here
3112 that if such an elimination is present, it can always be used.
3113 This is the case on all known machines; if we don't make this
3114 assumption, we do unnecessary saving on many machines. */
3115 static struct elims
{int from
, to
;} elim_regs
[] = ELIMINABLE_REGS
;
3118 for (i
= 0; i
< sizeof elim_regs
/ sizeof elim_regs
[0]; i
++)
3119 if (elim_regs
[i
].from
== ARG_POINTER_REGNUM
3120 && elim_regs
[i
].to
== HARD_FRAME_POINTER_REGNUM
)
3123 if (i
== sizeof elim_regs
/ sizeof elim_regs
[0])
3126 /* Now restore our arg pointer from the address at which it
3127 was saved in our stack frame.
3128 If there hasn't be space allocated for it yet, make
3130 if (arg_pointer_save_area
== 0)
3131 arg_pointer_save_area
3132 = assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
3133 emit_move_insn (virtual_incoming_args_rtx
,
3134 /* We need a pseudo here, or else
3135 instantiate_virtual_regs_1 complains. */
3136 copy_to_reg (arg_pointer_save_area
));
3141 #ifdef HAVE_nonlocal_goto_receiver
3142 if (HAVE_nonlocal_goto_receiver
)
3143 emit_insn (gen_nonlocal_goto_receiver ());
3147 /* Make handlers for nonlocal gotos taking place in the function calls in
3151 expand_nl_goto_receivers (thisblock
)
3152 struct nesting
*thisblock
;
3155 rtx afterward
= gen_label_rtx ();
3159 /* Record the handler address in the stack slot for that purpose,
3160 during this block, saving and restoring the outer value. */
3161 if (thisblock
->next
!= 0)
3162 for (slot
= nonlocal_goto_handler_slots
; slot
; slot
= XEXP (slot
, 1))
3164 rtx save_receiver
= gen_reg_rtx (Pmode
);
3165 emit_move_insn (XEXP (slot
, 0), save_receiver
);
3168 emit_move_insn (save_receiver
, XEXP (slot
, 0));
3169 insns
= get_insns ();
3171 emit_insns_before (insns
, thisblock
->data
.block
.first_insn
);
3174 /* Jump around the handlers; they run only when specially invoked. */
3175 emit_jump (afterward
);
3177 /* Make a separate handler for each label. */
3178 link
= nonlocal_labels
;
3179 slot
= nonlocal_goto_handler_slots
;
3180 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3181 /* Skip any labels we shouldn't be able to jump to from here,
3182 we generate one special handler for all of them below which just calls
3184 if (! DECL_TOO_LATE (TREE_VALUE (link
)))
3186 expand_nl_handler_label (XEXP (slot
, 0),
3187 thisblock
->data
.block
.first_insn
);
3188 expand_nl_goto_receiver ();
3190 /* Jump to the "real" nonlocal label. */
3191 expand_goto (TREE_VALUE (link
));
3194 /* A second pass over all nonlocal labels; this time we handle those
3195 we should not be able to jump to at this point. */
3196 link
= nonlocal_labels
;
3197 slot
= nonlocal_goto_handler_slots
;
3199 for (; link
; link
= TREE_CHAIN (link
), slot
= XEXP (slot
, 1))
3200 if (DECL_TOO_LATE (TREE_VALUE (link
)))
3202 expand_nl_handler_label (XEXP (slot
, 0),
3203 thisblock
->data
.block
.first_insn
);
3209 expand_nl_goto_receiver ();
3210 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "abort"), 0,
3215 emit_label (afterward
);
3218 /* Generate RTL code to terminate a binding contour.
3219 VARS is the chain of VAR_DECL nodes
3220 for the variables bound in this contour.
3221 MARK_ENDS is nonzero if we should put a note at the beginning
3222 and end of this binding contour.
3224 DONT_JUMP_IN is nonzero if it is not valid to jump into this contour.
3225 (That is true automatically if the contour has a saved stack level.) */
3228 expand_end_bindings (vars
, mark_ends
, dont_jump_in
)
3233 register struct nesting
*thisblock
;
3236 while (block_stack
->data
.block
.exception_region
)
3238 /* Because we don't need or want a new temporary level and
3239 because we didn't create one in expand_eh_region_start,
3240 create a fake one now to avoid removing one in
3241 expand_end_bindings. */
3244 block_stack
->data
.block
.exception_region
= 0;
3246 expand_end_bindings (NULL_TREE
, 0, 0);
3249 /* Since expand_eh_region_start does an expand_start_bindings, we
3250 have to first end all the bindings that were created by
3251 expand_eh_region_start. */
3253 thisblock
= block_stack
;
3256 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3257 if (! TREE_USED (decl
) && TREE_CODE (decl
) == VAR_DECL
3258 && ! DECL_IN_SYSTEM_HEADER (decl
)
3259 && DECL_NAME (decl
) && ! DECL_ARTIFICIAL (decl
))
3260 warning_with_decl (decl
, "unused variable `%s'");
3262 if (thisblock
->exit_label
)
3264 do_pending_stack_adjust ();
3265 emit_label (thisblock
->exit_label
);
3268 /* If necessary, make handlers for nonlocal gotos taking
3269 place in the function calls in this block. */
3270 if (function_call_count
!= thisblock
->data
.block
.function_call_count
3272 /* Make handler for outermost block
3273 if there were any nonlocal gotos to this function. */
3274 && (thisblock
->next
== 0 ? current_function_has_nonlocal_label
3275 /* Make handler for inner block if it has something
3276 special to do when you jump out of it. */
3277 : (thisblock
->data
.block
.cleanups
!= 0
3278 || thisblock
->data
.block
.stack_level
!= 0)))
3279 expand_nl_goto_receivers (thisblock
);
3281 /* Don't allow jumping into a block that has a stack level.
3282 Cleanups are allowed, though. */
3284 || thisblock
->data
.block
.stack_level
!= 0)
3286 struct label_chain
*chain
;
3288 /* Any labels in this block are no longer valid to go to.
3289 Mark them to cause an error message. */
3290 for (chain
= thisblock
->data
.block
.label_chain
; chain
; chain
= chain
->next
)
3292 DECL_TOO_LATE (chain
->label
) = 1;
3293 /* If any goto without a fixup came to this label,
3294 that must be an error, because gotos without fixups
3295 come from outside all saved stack-levels. */
3296 if (TREE_ADDRESSABLE (chain
->label
))
3297 error_with_decl (chain
->label
,
3298 "label `%s' used before containing binding contour");
3302 /* Restore stack level in effect before the block
3303 (only if variable-size objects allocated). */
3304 /* Perform any cleanups associated with the block. */
3306 if (thisblock
->data
.block
.stack_level
!= 0
3307 || thisblock
->data
.block
.cleanups
!= 0)
3309 /* Only clean up here if this point can actually be reached. */
3310 int reachable
= GET_CODE (get_last_insn ()) != BARRIER
;
3312 /* Don't let cleanups affect ({...}) constructs. */
3313 int old_expr_stmts_for_value
= expr_stmts_for_value
;
3314 rtx old_last_expr_value
= last_expr_value
;
3315 tree old_last_expr_type
= last_expr_type
;
3316 expr_stmts_for_value
= 0;
3318 /* Do the cleanups. */
3319 expand_cleanups (thisblock
->data
.block
.cleanups
, NULL_TREE
, 0, reachable
);
3321 do_pending_stack_adjust ();
3323 expr_stmts_for_value
= old_expr_stmts_for_value
;
3324 last_expr_value
= old_last_expr_value
;
3325 last_expr_type
= old_last_expr_type
;
3327 /* Restore the stack level. */
3329 if (reachable
&& thisblock
->data
.block
.stack_level
!= 0)
3331 emit_stack_restore (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3332 thisblock
->data
.block
.stack_level
, NULL_RTX
);
3333 if (nonlocal_goto_handler_slots
!= 0)
3334 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
,
3338 /* Any gotos out of this block must also do these things.
3339 Also report any gotos with fixups that came to labels in this
3341 fixup_gotos (thisblock
,
3342 thisblock
->data
.block
.stack_level
,
3343 thisblock
->data
.block
.cleanups
,
3344 thisblock
->data
.block
.first_insn
,
3348 /* Mark the beginning and end of the scope if requested.
3349 We do this now, after running cleanups on the variables
3350 just going out of scope, so they are in scope for their cleanups. */
3353 last_block_end_note
= emit_note (NULL_PTR
, NOTE_INSN_BLOCK_END
);
3355 /* Get rid of the beginning-mark if we don't make an end-mark. */
3356 NOTE_LINE_NUMBER (thisblock
->data
.block
.first_insn
) = NOTE_INSN_DELETED
;
3358 /* If doing stupid register allocation, make sure lives of all
3359 register variables declared here extend thru end of scope. */
3362 for (decl
= vars
; decl
; decl
= TREE_CHAIN (decl
))
3364 rtx rtl
= DECL_RTL (decl
);
3365 if (TREE_CODE (decl
) == VAR_DECL
&& rtl
!= 0)
3369 /* Restore the temporary level of TARGET_EXPRs. */
3370 target_temp_slot_level
= thisblock
->data
.block
.target_temp_slot_level
;
3372 /* Restore block_stack level for containing block. */
3374 stack_block_stack
= thisblock
->data
.block
.innermost_stack_block
;
3375 POPSTACK (block_stack
);
3377 /* Pop the stack slot nesting and free any slots at this level. */
3381 /* Generate RTL for the automatic variable declaration DECL.
3382 (Other kinds of declarations are simply ignored if seen here.) */
3388 struct nesting
*thisblock
= block_stack
;
3391 type
= TREE_TYPE (decl
);
3393 /* Only automatic variables need any expansion done.
3394 Static and external variables, and external functions,
3395 will be handled by `assemble_variable' (called from finish_decl).
3396 TYPE_DECL and CONST_DECL require nothing.
3397 PARM_DECLs are handled in `assign_parms'. */
3399 if (TREE_CODE (decl
) != VAR_DECL
)
3401 if (TREE_STATIC (decl
) || DECL_EXTERNAL (decl
))
3404 /* Create the RTL representation for the variable. */
3406 if (type
== error_mark_node
)
3407 DECL_RTL (decl
) = gen_rtx_MEM (BLKmode
, const0_rtx
);
3408 else if (DECL_SIZE (decl
) == 0)
3409 /* Variable with incomplete type. */
3411 if (DECL_INITIAL (decl
) == 0)
3412 /* Error message was already done; now avoid a crash. */
3413 DECL_RTL (decl
) = assign_stack_temp (DECL_MODE (decl
), 0, 1);
3415 /* An initializer is going to decide the size of this array.
3416 Until we know the size, represent its address with a reg. */
3417 DECL_RTL (decl
) = gen_rtx_MEM (BLKmode
, gen_reg_rtx (Pmode
));
3418 MEM_IN_STRUCT_P (DECL_RTL (decl
)) = AGGREGATE_TYPE_P (type
);
3420 else if (DECL_MODE (decl
) != BLKmode
3421 /* If -ffloat-store, don't put explicit float vars
3423 && !(flag_float_store
3424 && TREE_CODE (type
) == REAL_TYPE
)
3425 && ! TREE_THIS_VOLATILE (decl
)
3426 && ! TREE_ADDRESSABLE (decl
)
3427 && (DECL_REGISTER (decl
) || ! obey_regdecls
)
3428 /* if -fcheck-memory-usage, check all variables. */
3429 && ! current_function_check_memory_usage
)
3431 /* Automatic variable that can go in a register. */
3432 int unsignedp
= TREE_UNSIGNED (type
);
3433 enum machine_mode reg_mode
3434 = promote_mode (type
, DECL_MODE (decl
), &unsignedp
, 0);
3436 DECL_RTL (decl
) = gen_reg_rtx (reg_mode
);
3437 mark_user_reg (DECL_RTL (decl
));
3439 if (POINTER_TYPE_P (type
))
3440 mark_reg_pointer (DECL_RTL (decl
),
3441 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (decl
)))
3445 else if (TREE_CODE (DECL_SIZE (decl
)) == INTEGER_CST
3446 && ! (flag_stack_check
&& ! STACK_CHECK_BUILTIN
3447 && (TREE_INT_CST_HIGH (DECL_SIZE (decl
)) != 0
3448 || (TREE_INT_CST_LOW (DECL_SIZE (decl
))
3449 > STACK_CHECK_MAX_VAR_SIZE
* BITS_PER_UNIT
))))
3451 /* Variable of fixed size that goes on the stack. */
3455 /* If we previously made RTL for this decl, it must be an array
3456 whose size was determined by the initializer.
3457 The old address was a register; set that register now
3458 to the proper address. */
3459 if (DECL_RTL (decl
) != 0)
3461 if (GET_CODE (DECL_RTL (decl
)) != MEM
3462 || GET_CODE (XEXP (DECL_RTL (decl
), 0)) != REG
)
3464 oldaddr
= XEXP (DECL_RTL (decl
), 0);
3468 = assign_stack_temp (DECL_MODE (decl
),
3469 ((TREE_INT_CST_LOW (DECL_SIZE (decl
))
3470 + BITS_PER_UNIT
- 1)
3473 MEM_IN_STRUCT_P (DECL_RTL (decl
)) = AGGREGATE_TYPE_P (TREE_TYPE (decl
));
3475 /* Set alignment we actually gave this decl. */
3476 DECL_ALIGN (decl
) = (DECL_MODE (decl
) == BLKmode
? BIGGEST_ALIGNMENT
3477 : GET_MODE_BITSIZE (DECL_MODE (decl
)));
3481 addr
= force_operand (XEXP (DECL_RTL (decl
), 0), oldaddr
);
3482 if (addr
!= oldaddr
)
3483 emit_move_insn (oldaddr
, addr
);
3486 /* If this is a memory ref that contains aggregate components,
3487 mark it as such for cse and loop optimize. */
3488 MEM_IN_STRUCT_P (DECL_RTL (decl
)) = AGGREGATE_TYPE_P (TREE_TYPE (decl
));
3490 /* If this is in memory because of -ffloat-store,
3491 set the volatile bit, to prevent optimizations from
3492 undoing the effects. */
3493 if (flag_float_store
&& TREE_CODE (type
) == REAL_TYPE
)
3494 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
3497 MEM_ALIAS_SET (DECL_RTL (decl
)) = get_alias_set (decl
);
3500 /* Dynamic-size object: must push space on the stack. */
3504 /* Record the stack pointer on entry to block, if have
3505 not already done so. */
3506 if (thisblock
->data
.block
.stack_level
== 0)
3508 do_pending_stack_adjust ();
3509 emit_stack_save (thisblock
->next
? SAVE_BLOCK
: SAVE_FUNCTION
,
3510 &thisblock
->data
.block
.stack_level
,
3511 thisblock
->data
.block
.first_insn
);
3512 stack_block_stack
= thisblock
;
3515 /* Compute the variable's size, in bytes. */
3516 size
= expand_expr (size_binop (CEIL_DIV_EXPR
,
3518 size_int (BITS_PER_UNIT
)),
3519 NULL_RTX
, VOIDmode
, 0);
3522 /* Allocate space on the stack for the variable. Note that
3523 DECL_ALIGN says how the variable is to be aligned and we
3524 cannot use it to conclude anything about the alignment of
3526 address
= allocate_dynamic_stack_space (size
, NULL_RTX
,
3527 TYPE_ALIGN (TREE_TYPE (decl
)));
3529 /* Reference the variable indirect through that rtx. */
3530 DECL_RTL (decl
) = gen_rtx_MEM (DECL_MODE (decl
), address
);
3532 /* If this is a memory ref that contains aggregate components,
3533 mark it as such for cse and loop optimize. */
3534 MEM_IN_STRUCT_P (DECL_RTL (decl
)) = AGGREGATE_TYPE_P (TREE_TYPE (decl
));
3536 /* Indicate the alignment we actually gave this variable. */
3537 #ifdef STACK_BOUNDARY
3538 DECL_ALIGN (decl
) = STACK_BOUNDARY
;
3540 DECL_ALIGN (decl
) = BIGGEST_ALIGNMENT
;
3544 if (TREE_THIS_VOLATILE (decl
))
3545 MEM_VOLATILE_P (DECL_RTL (decl
)) = 1;
3546 #if 0 /* A variable is not necessarily unchanging
3547 just because it is const. RTX_UNCHANGING_P
3548 means no change in the function,
3549 not merely no change in the variable's scope.
3550 It is correct to set RTX_UNCHANGING_P if the variable's scope
3551 is the whole function. There's no convenient way to test that. */
3552 if (TREE_READONLY (decl
))
3553 RTX_UNCHANGING_P (DECL_RTL (decl
)) = 1;
3556 /* If doing stupid register allocation, make sure life of any
3557 register variable starts here, at the start of its scope. */
3560 use_variable (DECL_RTL (decl
));
3565 /* Emit code to perform the initialization of a declaration DECL. */
3568 expand_decl_init (decl
)
3571 int was_used
= TREE_USED (decl
);
3573 /* If this is a CONST_DECL, we don't have to generate any code, but
3574 if DECL_INITIAL is a constant, call expand_expr to force TREE_CST_RTL
3575 to be set while in the obstack containing the constant. If we don't
3576 do this, we can lose if we have functions nested three deep and the middle
3577 function makes a CONST_DECL whose DECL_INITIAL is a STRING_CST while
3578 the innermost function is the first to expand that STRING_CST. */
3579 if (TREE_CODE (decl
) == CONST_DECL
)
3581 if (DECL_INITIAL (decl
) && TREE_CONSTANT (DECL_INITIAL (decl
)))
3582 expand_expr (DECL_INITIAL (decl
), NULL_RTX
, VOIDmode
,
3583 EXPAND_INITIALIZER
);
3587 if (TREE_STATIC (decl
))
3590 /* Compute and store the initial value now. */
3592 if (DECL_INITIAL (decl
) == error_mark_node
)
3594 enum tree_code code
= TREE_CODE (TREE_TYPE (decl
));
3596 if (code
== INTEGER_TYPE
|| code
== REAL_TYPE
|| code
== ENUMERAL_TYPE
3597 || code
== POINTER_TYPE
|| code
== REFERENCE_TYPE
)
3598 expand_assignment (decl
, convert (TREE_TYPE (decl
), integer_zero_node
),
3602 else if (DECL_INITIAL (decl
) && TREE_CODE (DECL_INITIAL (decl
)) != TREE_LIST
)
3604 emit_line_note (DECL_SOURCE_FILE (decl
), DECL_SOURCE_LINE (decl
));
3605 expand_assignment (decl
, DECL_INITIAL (decl
), 0, 0);
3609 /* Don't let the initialization count as "using" the variable. */
3610 TREE_USED (decl
) = was_used
;
3612 /* Free any temporaries we made while initializing the decl. */
3613 preserve_temp_slots (NULL_RTX
);
3617 /* CLEANUP is an expression to be executed at exit from this binding contour;
3618 for example, in C++, it might call the destructor for this variable.
3620 We wrap CLEANUP in an UNSAVE_EXPR node, so that we can expand the
3621 CLEANUP multiple times, and have the correct semantics. This
3622 happens in exception handling, for gotos, returns, breaks that
3623 leave the current scope.
3625 If CLEANUP is nonzero and DECL is zero, we record a cleanup
3626 that is not associated with any particular variable. */
3629 expand_decl_cleanup (decl
, cleanup
)
3632 struct nesting
*thisblock
= block_stack
;
3634 /* Error if we are not in any block. */
3638 /* Record the cleanup if there is one. */
3644 tree
*cleanups
= &thisblock
->data
.block
.cleanups
;
3645 int cond_context
= conditional_context ();
3649 rtx flag
= gen_reg_rtx (word_mode
);
3654 emit_move_insn (flag
, const0_rtx
);
3655 set_flag_0
= get_insns ();
3658 thisblock
->data
.block
.last_unconditional_cleanup
3659 = emit_insns_after (set_flag_0
,
3660 thisblock
->data
.block
.last_unconditional_cleanup
);
3662 emit_move_insn (flag
, const1_rtx
);
3664 /* All cleanups must be on the function_obstack. */
3665 push_obstacks_nochange ();
3666 resume_temporary_allocation ();
3668 cond
= build_decl (VAR_DECL
, NULL_TREE
, type_for_mode (word_mode
, 1));
3669 DECL_RTL (cond
) = flag
;
3671 /* Conditionalize the cleanup. */
3672 cleanup
= build (COND_EXPR
, void_type_node
,
3673 truthvalue_conversion (cond
),
3674 cleanup
, integer_zero_node
);
3675 cleanup
= fold (cleanup
);
3679 cleanups
= thisblock
->data
.block
.cleanup_ptr
;
3682 /* All cleanups must be on the function_obstack. */
3683 push_obstacks_nochange ();
3684 resume_temporary_allocation ();
3685 cleanup
= unsave_expr (cleanup
);
3688 t
= *cleanups
= temp_tree_cons (decl
, cleanup
, *cleanups
);
3691 /* If this block has a cleanup, it belongs in stack_block_stack. */
3692 stack_block_stack
= thisblock
;
3699 /* If this was optimized so that there is no exception region for the
3700 cleanup, then mark the TREE_LIST node, so that we can later tell
3701 if we need to call expand_eh_region_end. */
3702 if (! using_eh_for_cleanups_p
3703 || expand_eh_region_start_tree (decl
, cleanup
))
3704 TREE_ADDRESSABLE (t
) = 1;
3705 /* If that started a new EH region, we're in a new block. */
3706 thisblock
= block_stack
;
3713 thisblock
->data
.block
.last_unconditional_cleanup
3714 = emit_insns_after (seq
,
3715 thisblock
->data
.block
.last_unconditional_cleanup
);
3719 thisblock
->data
.block
.last_unconditional_cleanup
3721 thisblock
->data
.block
.cleanup_ptr
= &thisblock
->data
.block
.cleanups
;
3727 /* Like expand_decl_cleanup, but suppress generating an exception handler
3728 to perform the cleanup. */
3731 expand_decl_cleanup_no_eh (decl
, cleanup
)
3734 int save_eh
= using_eh_for_cleanups_p
;
3737 using_eh_for_cleanups_p
= 0;
3738 result
= expand_decl_cleanup (decl
, cleanup
);
3739 using_eh_for_cleanups_p
= save_eh
;
3744 /* Arrange for the top element of the dynamic cleanup chain to be
3745 popped if we exit the current binding contour. DECL is the
3746 associated declaration, if any, otherwise NULL_TREE. If the
3747 current contour is left via an exception, then __sjthrow will pop
3748 the top element off the dynamic cleanup chain. The code that
3749 avoids doing the action we push into the cleanup chain in the
3750 exceptional case is contained in expand_cleanups.
3752 This routine is only used by expand_eh_region_start, and that is
3753 the only way in which an exception region should be started. This
3754 routine is only used when using the setjmp/longjmp codegen method
3755 for exception handling. */
3758 expand_dcc_cleanup (decl
)
3761 struct nesting
*thisblock
= block_stack
;
3764 /* Error if we are not in any block. */
3768 /* Record the cleanup for the dynamic handler chain. */
3770 /* All cleanups must be on the function_obstack. */
3771 push_obstacks_nochange ();
3772 resume_temporary_allocation ();
3773 cleanup
= make_node (POPDCC_EXPR
);
3776 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
3777 thisblock
->data
.block
.cleanups
3778 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
3780 /* If this block has a cleanup, it belongs in stack_block_stack. */
3781 stack_block_stack
= thisblock
;
3785 /* Arrange for the top element of the dynamic handler chain to be
3786 popped if we exit the current binding contour. DECL is the
3787 associated declaration, if any, otherwise NULL_TREE. If the current
3788 contour is left via an exception, then __sjthrow will pop the top
3789 element off the dynamic handler chain. The code that avoids doing
3790 the action we push into the handler chain in the exceptional case
3791 is contained in expand_cleanups.
3793 This routine is only used by expand_eh_region_start, and that is
3794 the only way in which an exception region should be started. This
3795 routine is only used when using the setjmp/longjmp codegen method
3796 for exception handling. */
3799 expand_dhc_cleanup (decl
)
3802 struct nesting
*thisblock
= block_stack
;
3805 /* Error if we are not in any block. */
3809 /* Record the cleanup for the dynamic handler chain. */
3811 /* All cleanups must be on the function_obstack. */
3812 push_obstacks_nochange ();
3813 resume_temporary_allocation ();
3814 cleanup
= make_node (POPDHC_EXPR
);
3817 /* Add the cleanup in a manner similar to expand_decl_cleanup. */
3818 thisblock
->data
.block
.cleanups
3819 = temp_tree_cons (decl
, cleanup
, thisblock
->data
.block
.cleanups
);
3821 /* If this block has a cleanup, it belongs in stack_block_stack. */
3822 stack_block_stack
= thisblock
;
3826 /* DECL is an anonymous union. CLEANUP is a cleanup for DECL.
3827 DECL_ELTS is the list of elements that belong to DECL's type.
3828 In each, the TREE_VALUE is a VAR_DECL, and the TREE_PURPOSE a cleanup. */
3831 expand_anon_union_decl (decl
, cleanup
, decl_elts
)
3832 tree decl
, cleanup
, decl_elts
;
3834 struct nesting
*thisblock
= block_stack
;
3838 expand_decl_cleanup (decl
, cleanup
);
3839 x
= DECL_RTL (decl
);
3843 tree decl_elt
= TREE_VALUE (decl_elts
);
3844 tree cleanup_elt
= TREE_PURPOSE (decl_elts
);
3845 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (decl_elt
));
3847 /* Propagate the union's alignment to the elements. */
3848 DECL_ALIGN (decl_elt
) = DECL_ALIGN (decl
);
3850 /* If the element has BLKmode and the union doesn't, the union is
3851 aligned such that the element doesn't need to have BLKmode, so
3852 change the element's mode to the appropriate one for its size. */
3853 if (mode
== BLKmode
&& DECL_MODE (decl
) != BLKmode
)
3854 DECL_MODE (decl_elt
) = mode
3855 = mode_for_size (TREE_INT_CST_LOW (DECL_SIZE (decl_elt
)),
3858 /* (SUBREG (MEM ...)) at RTL generation time is invalid, so we
3859 instead create a new MEM rtx with the proper mode. */
3860 if (GET_CODE (x
) == MEM
)
3862 if (mode
== GET_MODE (x
))
3863 DECL_RTL (decl_elt
) = x
;
3866 DECL_RTL (decl_elt
) = gen_rtx_MEM (mode
, copy_rtx (XEXP (x
, 0)));
3867 MEM_IN_STRUCT_P (DECL_RTL (decl_elt
)) = MEM_IN_STRUCT_P (x
);
3868 RTX_UNCHANGING_P (DECL_RTL (decl_elt
)) = RTX_UNCHANGING_P (x
);
3871 else if (GET_CODE (x
) == REG
)
3873 if (mode
== GET_MODE (x
))
3874 DECL_RTL (decl_elt
) = x
;
3876 DECL_RTL (decl_elt
) = gen_rtx_SUBREG (mode
, x
, 0);
3881 /* Record the cleanup if there is one. */
3884 thisblock
->data
.block
.cleanups
3885 = temp_tree_cons (decl_elt
, cleanup_elt
,
3886 thisblock
->data
.block
.cleanups
);
3888 decl_elts
= TREE_CHAIN (decl_elts
);
3892 /* Expand a list of cleanups LIST.
3893 Elements may be expressions or may be nested lists.
3895 If DONT_DO is nonnull, then any list-element
3896 whose TREE_PURPOSE matches DONT_DO is omitted.
3897 This is sometimes used to avoid a cleanup associated with
3898 a value that is being returned out of the scope.
3900 If IN_FIXUP is non-zero, we are generating this cleanup for a fixup
3901 goto and handle protection regions specially in that case.
3903 If REACHABLE, we emit code, otherwise just inform the exception handling
3904 code about this finalization. */
3907 expand_cleanups (list
, dont_do
, in_fixup
, reachable
)
3914 for (tail
= list
; tail
; tail
= TREE_CHAIN (tail
))
3915 if (dont_do
== 0 || TREE_PURPOSE (tail
) != dont_do
)
3917 if (TREE_CODE (TREE_VALUE (tail
)) == TREE_LIST
)
3918 expand_cleanups (TREE_VALUE (tail
), dont_do
, in_fixup
, reachable
);
3923 tree cleanup
= TREE_VALUE (tail
);
3925 /* See expand_d{h,c}c_cleanup for why we avoid this. */
3926 if (TREE_CODE (cleanup
) != POPDHC_EXPR
3927 && TREE_CODE (cleanup
) != POPDCC_EXPR
3928 /* See expand_eh_region_start_tree for this case. */
3929 && ! TREE_ADDRESSABLE (tail
))
3931 cleanup
= protect_with_terminate (cleanup
);
3932 expand_eh_region_end (cleanup
);
3938 /* Cleanups may be run multiple times. For example,
3939 when exiting a binding contour, we expand the
3940 cleanups associated with that contour. When a goto
3941 within that binding contour has a target outside that
3942 contour, it will expand all cleanups from its scope to
3943 the target. Though the cleanups are expanded multiple
3944 times, the control paths are non-overlapping so the
3945 cleanups will not be executed twice. */
3947 /* We may need to protect fixups with rethrow regions. */
3948 int protect
= (in_fixup
&& ! TREE_ADDRESSABLE (tail
));
3951 expand_fixup_region_start ();
3953 expand_expr (TREE_VALUE (tail
), const0_rtx
, VOIDmode
, 0);
3955 expand_fixup_region_end (TREE_VALUE (tail
));
3962 /* Mark when the context we are emitting RTL for as a conditional
3963 context, so that any cleanup actions we register with
3964 expand_decl_init will be properly conditionalized when those
3965 cleanup actions are later performed. Must be called before any
3966 expression (tree) is expanded that is within a conditional context. */
3969 start_cleanup_deferral ()
3971 /* block_stack can be NULL if we are inside the parameter list. It is
3972 OK to do nothing, because cleanups aren't possible here. */
3974 ++block_stack
->data
.block
.conditional_code
;
3977 /* Mark the end of a conditional region of code. Because cleanup
3978 deferrals may be nested, we may still be in a conditional region
3979 after we end the currently deferred cleanups, only after we end all
3980 deferred cleanups, are we back in unconditional code. */
3983 end_cleanup_deferral ()
3985 /* block_stack can be NULL if we are inside the parameter list. It is
3986 OK to do nothing, because cleanups aren't possible here. */
3988 --block_stack
->data
.block
.conditional_code
;
3991 /* Move all cleanups from the current block_stack
3992 to the containing block_stack, where they are assumed to
3993 have been created. If anything can cause a temporary to
3994 be created, but not expanded for more than one level of
3995 block_stacks, then this code will have to change. */
4000 struct nesting
*block
= block_stack
;
4001 struct nesting
*outer
= block
->next
;
4003 outer
->data
.block
.cleanups
4004 = chainon (block
->data
.block
.cleanups
,
4005 outer
->data
.block
.cleanups
);
4006 block
->data
.block
.cleanups
= 0;
4010 last_cleanup_this_contour ()
4012 if (block_stack
== 0)
4015 return block_stack
->data
.block
.cleanups
;
4018 /* Return 1 if there are any pending cleanups at this point.
4019 If THIS_CONTOUR is nonzero, check the current contour as well.
4020 Otherwise, look only at the contours that enclose this one. */
4023 any_pending_cleanups (this_contour
)
4026 struct nesting
*block
;
4028 if (block_stack
== 0)
4031 if (this_contour
&& block_stack
->data
.block
.cleanups
!= NULL
)
4033 if (block_stack
->data
.block
.cleanups
== 0
4034 && block_stack
->data
.block
.outer_cleanups
== 0)
4037 for (block
= block_stack
->next
; block
; block
= block
->next
)
4038 if (block
->data
.block
.cleanups
!= 0)
4044 /* Enter a case (Pascal) or switch (C) statement.
4045 Push a block onto case_stack and nesting_stack
4046 to accumulate the case-labels that are seen
4047 and to record the labels generated for the statement.
4049 EXIT_FLAG is nonzero if `exit_something' should exit this case stmt.
4050 Otherwise, this construct is transparent for `exit_something'.
4052 EXPR is the index-expression to be dispatched on.
4053 TYPE is its nominal type. We could simply convert EXPR to this type,
4054 but instead we take short cuts. */
4057 expand_start_case (exit_flag
, expr
, type
, printname
)
4063 register struct nesting
*thiscase
= ALLOC_NESTING ();
4065 /* Make an entry on case_stack for the case we are entering. */
4067 thiscase
->next
= case_stack
;
4068 thiscase
->all
= nesting_stack
;
4069 thiscase
->depth
= ++nesting_depth
;
4070 thiscase
->exit_label
= exit_flag
? gen_label_rtx () : 0;
4071 thiscase
->data
.case_stmt
.case_list
= 0;
4072 thiscase
->data
.case_stmt
.index_expr
= expr
;
4073 thiscase
->data
.case_stmt
.nominal_type
= type
;
4074 thiscase
->data
.case_stmt
.default_label
= 0;
4075 thiscase
->data
.case_stmt
.num_ranges
= 0;
4076 thiscase
->data
.case_stmt
.printname
= printname
;
4077 thiscase
->data
.case_stmt
.line_number_status
= force_line_numbers ();
4078 case_stack
= thiscase
;
4079 nesting_stack
= thiscase
;
4081 do_pending_stack_adjust ();
4083 /* Make sure case_stmt.start points to something that won't
4084 need any transformation before expand_end_case. */
4085 if (GET_CODE (get_last_insn ()) != NOTE
)
4086 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4088 thiscase
->data
.case_stmt
.start
= get_last_insn ();
4090 start_cleanup_deferral ();
4094 /* Start a "dummy case statement" within which case labels are invalid
4095 and are not connected to any larger real case statement.
4096 This can be used if you don't want to let a case statement jump
4097 into the middle of certain kinds of constructs. */
4100 expand_start_case_dummy ()
4102 register struct nesting
*thiscase
= ALLOC_NESTING ();
4104 /* Make an entry on case_stack for the dummy. */
4106 thiscase
->next
= case_stack
;
4107 thiscase
->all
= nesting_stack
;
4108 thiscase
->depth
= ++nesting_depth
;
4109 thiscase
->exit_label
= 0;
4110 thiscase
->data
.case_stmt
.case_list
= 0;
4111 thiscase
->data
.case_stmt
.start
= 0;
4112 thiscase
->data
.case_stmt
.nominal_type
= 0;
4113 thiscase
->data
.case_stmt
.default_label
= 0;
4114 thiscase
->data
.case_stmt
.num_ranges
= 0;
4115 case_stack
= thiscase
;
4116 nesting_stack
= thiscase
;
4117 start_cleanup_deferral ();
4120 /* End a dummy case statement. */
4123 expand_end_case_dummy ()
4125 end_cleanup_deferral ();
4126 POPSTACK (case_stack
);
4129 /* Return the data type of the index-expression
4130 of the innermost case statement, or null if none. */
4133 case_index_expr_type ()
4136 return TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4143 /* If this is the first label, warn if any insns have been emitted. */
4144 if (case_stack
->data
.case_stmt
.line_number_status
>= 0)
4148 restore_line_number_status
4149 (case_stack
->data
.case_stmt
.line_number_status
);
4150 case_stack
->data
.case_stmt
.line_number_status
= -1;
4152 for (insn
= case_stack
->data
.case_stmt
.start
;
4154 insn
= NEXT_INSN (insn
))
4156 if (GET_CODE (insn
) == CODE_LABEL
)
4158 if (GET_CODE (insn
) != NOTE
4159 && (GET_CODE (insn
) != INSN
|| GET_CODE (PATTERN (insn
)) != USE
))
4162 insn
= PREV_INSN (insn
);
4163 while (insn
&& (GET_CODE (insn
) != NOTE
|| NOTE_LINE_NUMBER (insn
) < 0));
4165 /* If insn is zero, then there must have been a syntax error. */
4167 warning_with_file_and_line (NOTE_SOURCE_FILE(insn
),
4168 NOTE_LINE_NUMBER(insn
),
4169 "unreachable code at beginning of %s",
4170 case_stack
->data
.case_stmt
.printname
);
4177 /* Accumulate one case or default label inside a case or switch statement.
4178 VALUE is the value of the case (a null pointer, for a default label).
4179 The function CONVERTER, when applied to arguments T and V,
4180 converts the value V to the type T.
4182 If not currently inside a case or switch statement, return 1 and do
4183 nothing. The caller will print a language-specific error message.
4184 If VALUE is a duplicate or overlaps, return 2 and do nothing
4185 except store the (first) duplicate node in *DUPLICATE.
4186 If VALUE is out of range, return 3 and do nothing.
4187 If we are jumping into the scope of a cleanup or var-sized array, return 5.
4188 Return 0 on success.
4190 Extended to handle range statements. */
4193 pushcase (value
, converter
, label
, duplicate
)
4194 register tree value
;
4195 tree (*converter
) PROTO((tree
, tree
));
4196 register tree label
;
4202 /* Fail if not inside a real case statement. */
4203 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4206 if (stack_block_stack
4207 && stack_block_stack
->depth
> case_stack
->depth
)
4210 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4211 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4213 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4214 if (index_type
== error_mark_node
)
4217 /* Convert VALUE to the type in which the comparisons are nominally done. */
4219 value
= (*converter
) (nominal_type
, value
);
4223 /* Fail if this value is out of range for the actual type of the index
4224 (which may be narrower than NOMINAL_TYPE). */
4225 if (value
!= 0 && ! int_fits_type_p (value
, index_type
))
4228 /* Fail if this is a duplicate or overlaps another entry. */
4231 if (case_stack
->data
.case_stmt
.default_label
!= 0)
4233 *duplicate
= case_stack
->data
.case_stmt
.default_label
;
4236 case_stack
->data
.case_stmt
.default_label
= label
;
4239 return add_case_node (value
, value
, label
, duplicate
);
4241 expand_label (label
);
4245 /* Like pushcase but this case applies to all values between VALUE1 and
4246 VALUE2 (inclusive). If VALUE1 is NULL, the range starts at the lowest
4247 value of the index type and ends at VALUE2. If VALUE2 is NULL, the range
4248 starts at VALUE1 and ends at the highest value of the index type.
4249 If both are NULL, this case applies to all values.
4251 The return value is the same as that of pushcase but there is one
4252 additional error code: 4 means the specified range was empty. */
4255 pushcase_range (value1
, value2
, converter
, label
, duplicate
)
4256 register tree value1
, value2
;
4257 tree (*converter
) PROTO((tree
, tree
));
4258 register tree label
;
4264 /* Fail if not inside a real case statement. */
4265 if (! (case_stack
&& case_stack
->data
.case_stmt
.start
))
4268 if (stack_block_stack
4269 && stack_block_stack
->depth
> case_stack
->depth
)
4272 index_type
= TREE_TYPE (case_stack
->data
.case_stmt
.index_expr
);
4273 nominal_type
= case_stack
->data
.case_stmt
.nominal_type
;
4275 /* If the index is erroneous, avoid more problems: pretend to succeed. */
4276 if (index_type
== error_mark_node
)
4281 /* Convert VALUEs to type in which the comparisons are nominally done
4282 and replace any unspecified value with the corresponding bound. */
4284 value1
= TYPE_MIN_VALUE (index_type
);
4286 value2
= TYPE_MAX_VALUE (index_type
);
4288 /* Fail if the range is empty. Do this before any conversion since
4289 we want to allow out-of-range empty ranges. */
4290 if (value2
&& tree_int_cst_lt (value2
, value1
))
4293 value1
= (*converter
) (nominal_type
, value1
);
4295 /* If the max was unbounded, use the max of the nominal_type we are
4296 converting to. Do this after the < check above to suppress false
4299 value2
= TYPE_MAX_VALUE (nominal_type
);
4300 value2
= (*converter
) (nominal_type
, value2
);
4302 /* Fail if these values are out of range. */
4303 if (TREE_CONSTANT_OVERFLOW (value1
)
4304 || ! int_fits_type_p (value1
, index_type
))
4307 if (TREE_CONSTANT_OVERFLOW (value2
)
4308 || ! int_fits_type_p (value2
, index_type
))
4311 return add_case_node (value1
, value2
, label
, duplicate
);
4314 /* Do the actual insertion of a case label for pushcase and pushcase_range
4315 into case_stack->data.case_stmt.case_list. Use an AVL tree to avoid
4316 slowdown for large switch statements. */
4319 add_case_node (low
, high
, label
, duplicate
)
4324 struct case_node
*p
, **q
, *r
;
4326 q
= &case_stack
->data
.case_stmt
.case_list
;
4333 /* Keep going past elements distinctly greater than HIGH. */
4334 if (tree_int_cst_lt (high
, p
->low
))
4337 /* or distinctly less than LOW. */
4338 else if (tree_int_cst_lt (p
->high
, low
))
4343 /* We have an overlap; this is an error. */
4344 *duplicate
= p
->code_label
;
4349 /* Add this label to the chain, and succeed.
4350 Copy LOW, HIGH so they are on temporary rather than momentary
4351 obstack and will thus survive till the end of the case statement. */
4353 r
= (struct case_node
*) oballoc (sizeof (struct case_node
));
4354 r
->low
= copy_node (low
);
4356 /* If the bounds are equal, turn this into the one-value case. */
4358 if (tree_int_cst_equal (low
, high
))
4362 r
->high
= copy_node (high
);
4363 case_stack
->data
.case_stmt
.num_ranges
++;
4366 r
->code_label
= label
;
4367 expand_label (label
);
4377 struct case_node
*s
;
4383 if (! (b
= p
->balance
))
4384 /* Growth propagation from left side. */
4391 if ((p
->left
= s
= r
->right
))
4400 if ((r
->parent
= s
))
4408 case_stack
->data
.case_stmt
.case_list
= r
;
4411 /* r->balance == +1 */
4416 struct case_node
*t
= r
->right
;
4418 if ((p
->left
= s
= t
->right
))
4422 if ((r
->right
= s
= t
->left
))
4436 if ((t
->parent
= s
))
4444 case_stack
->data
.case_stmt
.case_list
= t
;
4451 /* p->balance == +1; growth of left side balances the node. */
4461 if (! (b
= p
->balance
))
4462 /* Growth propagation from right side. */
4470 if ((p
->right
= s
= r
->left
))
4478 if ((r
->parent
= s
))
4487 case_stack
->data
.case_stmt
.case_list
= r
;
4491 /* r->balance == -1 */
4495 struct case_node
*t
= r
->left
;
4497 if ((p
->right
= s
= t
->left
))
4502 if ((r
->left
= s
= t
->right
))
4516 if ((t
->parent
= s
))
4525 case_stack
->data
.case_stmt
.case_list
= t
;
4531 /* p->balance == -1; growth of right side balances the node. */
4545 /* Returns the number of possible values of TYPE.
4546 Returns -1 if the number is unknown or variable.
4547 Returns -2 if the number does not fit in a HOST_WIDE_INT.
4548 Sets *SPARENESS to 2 if TYPE is an ENUMERAL_TYPE whose values
4549 do not increase monotonically (there may be duplicates);
4550 to 1 if the values increase monotonically, but not always by 1;
4551 otherwise sets it to 0. */
4554 all_cases_count (type
, spareness
)
4558 HOST_WIDE_INT count
;
4561 switch (TREE_CODE (type
))
4568 count
= 1 << BITS_PER_UNIT
;
4572 if (TREE_CODE (TYPE_MIN_VALUE (type
)) != INTEGER_CST
4573 || TYPE_MAX_VALUE (type
) == NULL
4574 || TREE_CODE (TYPE_MAX_VALUE (type
)) != INTEGER_CST
)
4579 = TREE_INT_CST_LOW (TYPE_MAX_VALUE (type))
4580 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (type)) + 1
4581 but with overflow checking. */
4582 tree mint
= TYPE_MIN_VALUE (type
);
4583 tree maxt
= TYPE_MAX_VALUE (type
);
4584 HOST_WIDE_INT lo
, hi
;
4585 neg_double(TREE_INT_CST_LOW (mint
), TREE_INT_CST_HIGH (mint
),
4587 add_double(TREE_INT_CST_LOW (maxt
), TREE_INT_CST_HIGH (maxt
),
4589 add_double (lo
, hi
, 1, 0, &lo
, &hi
);
4590 if (hi
!= 0 || lo
< 0)
4597 for (t
= TYPE_VALUES (type
); t
!= NULL_TREE
; t
= TREE_CHAIN (t
))
4599 if (TREE_CODE (TYPE_MIN_VALUE (type
)) != INTEGER_CST
4600 || TREE_CODE (TREE_VALUE (t
)) != INTEGER_CST
4601 || TREE_INT_CST_LOW (TYPE_MIN_VALUE (type
)) + count
4602 != TREE_INT_CST_LOW (TREE_VALUE (t
)))
4606 if (*spareness
== 1)
4608 tree prev
= TREE_VALUE (TYPE_VALUES (type
));
4609 for (t
= TYPE_VALUES (type
); t
= TREE_CHAIN (t
), t
!= NULL_TREE
; )
4611 if (! tree_int_cst_lt (prev
, TREE_VALUE (t
)))
4616 prev
= TREE_VALUE (t
);
4625 #define BITARRAY_TEST(ARRAY, INDEX) \
4626 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4627 & (1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR)))
4628 #define BITARRAY_SET(ARRAY, INDEX) \
4629 ((ARRAY)[(unsigned) (INDEX) / HOST_BITS_PER_CHAR]\
4630 |= 1 << ((unsigned) (INDEX) % HOST_BITS_PER_CHAR))
4632 /* Set the elements of the bitstring CASES_SEEN (which has length COUNT),
4633 with the case values we have seen, assuming the case expression
4635 SPARSENESS is as determined by all_cases_count.
4637 The time needed is proportional to COUNT, unless
4638 SPARSENESS is 2, in which case quadratic time is needed. */
4641 mark_seen_cases (type
, cases_seen
, count
, sparseness
)
4643 unsigned char *cases_seen
;
4647 tree next_node_to_try
= NULL_TREE
;
4648 long next_node_offset
= 0;
4650 register struct case_node
*n
, *root
= case_stack
->data
.case_stmt
.case_list
;
4651 tree val
= make_node (INTEGER_CST
);
4652 TREE_TYPE (val
) = type
;
4655 else if (sparseness
== 2)
4660 /* This less efficient loop is only needed to handle
4661 duplicate case values (multiple enum constants
4662 with the same value). */
4663 TREE_TYPE (val
) = TREE_TYPE (root
->low
);
4664 for (t
= TYPE_VALUES (type
), xlo
= 0; t
!= NULL_TREE
;
4665 t
= TREE_CHAIN (t
), xlo
++)
4667 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (TREE_VALUE (t
));
4668 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (TREE_VALUE (t
));
4672 /* Keep going past elements distinctly greater than VAL. */
4673 if (tree_int_cst_lt (val
, n
->low
))
4676 /* or distinctly less than VAL. */
4677 else if (tree_int_cst_lt (n
->high
, val
))
4682 /* We have found a matching range. */
4683 BITARRAY_SET (cases_seen
, xlo
);
4693 case_stack
->data
.case_stmt
.case_list
= root
= case_tree2list (root
, 0);
4694 for (n
= root
; n
; n
= n
->right
)
4696 TREE_INT_CST_LOW (val
) = TREE_INT_CST_LOW (n
->low
);
4697 TREE_INT_CST_HIGH (val
) = TREE_INT_CST_HIGH (n
->low
);
4698 while ( ! tree_int_cst_lt (n
->high
, val
))
4700 /* Calculate (into xlo) the "offset" of the integer (val).
4701 The element with lowest value has offset 0, the next smallest
4702 element has offset 1, etc. */
4704 HOST_WIDE_INT xlo
, xhi
;
4706 if (sparseness
&& TYPE_VALUES (type
) != NULL_TREE
)
4708 /* The TYPE_VALUES will be in increasing order, so
4709 starting searching where we last ended. */
4710 t
= next_node_to_try
;
4711 xlo
= next_node_offset
;
4717 t
= TYPE_VALUES (type
);
4720 if (tree_int_cst_equal (val
, TREE_VALUE (t
)))
4722 next_node_to_try
= TREE_CHAIN (t
);
4723 next_node_offset
= xlo
+ 1;
4728 if (t
== next_node_to_try
)
4737 t
= TYPE_MIN_VALUE (type
);
4739 neg_double (TREE_INT_CST_LOW (t
), TREE_INT_CST_HIGH (t
),
4743 add_double (xlo
, xhi
,
4744 TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
4748 if (xhi
== 0 && xlo
>= 0 && xlo
< count
)
4749 BITARRAY_SET (cases_seen
, xlo
);
4750 add_double (TREE_INT_CST_LOW (val
), TREE_INT_CST_HIGH (val
),
4752 &TREE_INT_CST_LOW (val
), &TREE_INT_CST_HIGH (val
));
4758 /* Called when the index of a switch statement is an enumerated type
4759 and there is no default label.
4761 Checks that all enumeration literals are covered by the case
4762 expressions of a switch. Also, warn if there are any extra
4763 switch cases that are *not* elements of the enumerated type.
4765 If all enumeration literals were covered by the case expressions,
4766 turn one of the expressions into the default expression since it should
4767 not be possible to fall through such a switch. */
4770 check_for_full_enumeration_handling (type
)
4773 register struct case_node
*n
;
4774 register tree chain
;
4775 #if 0 /* variable used by 'if 0'ed code below. */
4776 register struct case_node
**l
;
4780 /* True iff the selector type is a numbered set mode. */
4783 /* The number of possible selector values. */
4786 /* For each possible selector value. a one iff it has been matched
4787 by a case value alternative. */
4788 unsigned char *cases_seen
;
4790 /* The allocated size of cases_seen, in chars. */
4796 size
= all_cases_count (type
, &sparseness
);
4797 bytes_needed
= (size
+ HOST_BITS_PER_CHAR
) / HOST_BITS_PER_CHAR
;
4799 if (size
> 0 && size
< 600000
4800 /* We deliberately use malloc here - not xmalloc. */
4801 && (cases_seen
= (unsigned char *) malloc (bytes_needed
)) != NULL
)
4804 tree v
= TYPE_VALUES (type
);
4805 bzero (cases_seen
, bytes_needed
);
4807 /* The time complexity of this code is normally O(N), where
4808 N being the number of members in the enumerated type.
4809 However, if type is a ENUMERAL_TYPE whose values do not
4810 increase monotonically, O(N*log(N)) time may be needed. */
4812 mark_seen_cases (type
, cases_seen
, size
, sparseness
);
4814 for (i
= 0; v
!= NULL_TREE
&& i
< size
; i
++, v
= TREE_CHAIN (v
))
4816 if (BITARRAY_TEST(cases_seen
, i
) == 0)
4817 warning ("enumeration value `%s' not handled in switch",
4818 IDENTIFIER_POINTER (TREE_PURPOSE (v
)));
4824 /* Now we go the other way around; we warn if there are case
4825 expressions that don't correspond to enumerators. This can
4826 occur since C and C++ don't enforce type-checking of
4827 assignments to enumeration variables. */
4829 if (case_stack
->data
.case_stmt
.case_list
4830 && case_stack
->data
.case_stmt
.case_list
->left
)
4831 case_stack
->data
.case_stmt
.case_list
4832 = case_tree2list (case_stack
->data
.case_stmt
.case_list
, 0);
4834 for (n
= case_stack
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
4836 for (chain
= TYPE_VALUES (type
);
4837 chain
&& !tree_int_cst_equal (n
->low
, TREE_VALUE (chain
));
4838 chain
= TREE_CHAIN (chain
))
4843 if (TYPE_NAME (type
) == 0)
4844 warning ("case value `%ld' not in enumerated type",
4845 (long) TREE_INT_CST_LOW (n
->low
));
4847 warning ("case value `%ld' not in enumerated type `%s'",
4848 (long) TREE_INT_CST_LOW (n
->low
),
4849 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
4852 : DECL_NAME (TYPE_NAME (type
))));
4854 if (!tree_int_cst_equal (n
->low
, n
->high
))
4856 for (chain
= TYPE_VALUES (type
);
4857 chain
&& !tree_int_cst_equal (n
->high
, TREE_VALUE (chain
));
4858 chain
= TREE_CHAIN (chain
))
4863 if (TYPE_NAME (type
) == 0)
4864 warning ("case value `%ld' not in enumerated type",
4865 (long) TREE_INT_CST_LOW (n
->high
));
4867 warning ("case value `%ld' not in enumerated type `%s'",
4868 (long) TREE_INT_CST_LOW (n
->high
),
4869 IDENTIFIER_POINTER ((TREE_CODE (TYPE_NAME (type
))
4872 : DECL_NAME (TYPE_NAME (type
))));
4878 /* ??? This optimization is disabled because it causes valid programs to
4879 fail. ANSI C does not guarantee that an expression with enum type
4880 will have a value that is the same as one of the enumeration literals. */
4882 /* If all values were found as case labels, make one of them the default
4883 label. Thus, this switch will never fall through. We arbitrarily pick
4884 the last one to make the default since this is likely the most
4885 efficient choice. */
4889 for (l
= &case_stack
->data
.case_stmt
.case_list
;
4894 case_stack
->data
.case_stmt
.default_label
= (*l
)->code_label
;
4901 /* Terminate a case (Pascal) or switch (C) statement
4902 in which ORIG_INDEX is the expression to be tested.
4903 Generate the code to test it and jump to the right place. */
4906 expand_end_case (orig_index
)
4909 tree minval
, maxval
, range
, orig_minval
;
4910 rtx default_label
= 0;
4911 register struct case_node
*n
;
4919 register struct nesting
*thiscase
= case_stack
;
4920 tree index_expr
, index_type
;
4923 table_label
= gen_label_rtx ();
4924 index_expr
= thiscase
->data
.case_stmt
.index_expr
;
4925 index_type
= TREE_TYPE (index_expr
);
4926 unsignedp
= TREE_UNSIGNED (index_type
);
4928 do_pending_stack_adjust ();
4930 /* This might get an spurious warning in the presence of a syntax error;
4931 it could be fixed by moving the call to check_seenlabel after the
4932 check for error_mark_node, and copying the code of check_seenlabel that
4933 deals with case_stack->data.case_stmt.line_number_status /
4934 restore_line_number_status in front of the call to end_cleanup_deferral;
4935 However, this might miss some useful warnings in the presence of
4936 non-syntax errors. */
4939 /* An ERROR_MARK occurs for various reasons including invalid data type. */
4940 if (index_type
!= error_mark_node
)
4942 /* If switch expression was an enumerated type, check that all
4943 enumeration literals are covered by the cases.
4944 No sense trying this if there's a default case, however. */
4946 if (!thiscase
->data
.case_stmt
.default_label
4947 && TREE_CODE (TREE_TYPE (orig_index
)) == ENUMERAL_TYPE
4948 && TREE_CODE (index_expr
) != INTEGER_CST
)
4949 check_for_full_enumeration_handling (TREE_TYPE (orig_index
));
4951 /* If we don't have a default-label, create one here,
4952 after the body of the switch. */
4953 if (thiscase
->data
.case_stmt
.default_label
== 0)
4955 thiscase
->data
.case_stmt
.default_label
4956 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
4957 expand_label (thiscase
->data
.case_stmt
.default_label
);
4959 default_label
= label_rtx (thiscase
->data
.case_stmt
.default_label
);
4961 before_case
= get_last_insn ();
4963 if (thiscase
->data
.case_stmt
.case_list
4964 && thiscase
->data
.case_stmt
.case_list
->left
)
4965 thiscase
->data
.case_stmt
.case_list
4966 = case_tree2list(thiscase
->data
.case_stmt
.case_list
, 0);
4968 /* Simplify the case-list before we count it. */
4969 group_case_nodes (thiscase
->data
.case_stmt
.case_list
);
4971 /* Get upper and lower bounds of case values.
4972 Also convert all the case values to the index expr's data type. */
4975 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
4977 /* Check low and high label values are integers. */
4978 if (TREE_CODE (n
->low
) != INTEGER_CST
)
4980 if (TREE_CODE (n
->high
) != INTEGER_CST
)
4983 n
->low
= convert (index_type
, n
->low
);
4984 n
->high
= convert (index_type
, n
->high
);
4986 /* Count the elements and track the largest and smallest
4987 of them (treating them as signed even if they are not). */
4995 if (INT_CST_LT (n
->low
, minval
))
4997 if (INT_CST_LT (maxval
, n
->high
))
5000 /* A range counts double, since it requires two compares. */
5001 if (! tree_int_cst_equal (n
->low
, n
->high
))
5005 orig_minval
= minval
;
5007 /* Compute span of values. */
5009 range
= fold (build (MINUS_EXPR
, index_type
, maxval
, minval
));
5011 end_cleanup_deferral ();
5015 expand_expr (index_expr
, const0_rtx
, VOIDmode
, 0);
5017 emit_jump (default_label
);
5020 /* If range of values is much bigger than number of values,
5021 make a sequence of conditional branches instead of a dispatch.
5022 If the switch-index is a constant, do it this way
5023 because we can optimize it. */
5025 #ifndef CASE_VALUES_THRESHOLD
5027 #define CASE_VALUES_THRESHOLD (HAVE_casesi ? 4 : 5)
5029 /* If machine does not have a case insn that compares the
5030 bounds, this means extra overhead for dispatch tables
5031 which raises the threshold for using them. */
5032 #define CASE_VALUES_THRESHOLD 5
5033 #endif /* HAVE_casesi */
5034 #endif /* CASE_VALUES_THRESHOLD */
5036 else if (TREE_INT_CST_HIGH (range
) != 0
5037 || count
< (unsigned int) CASE_VALUES_THRESHOLD
5038 || ((unsigned HOST_WIDE_INT
) (TREE_INT_CST_LOW (range
))
5040 #ifndef ASM_OUTPUT_ADDR_DIFF_ELT
5043 || TREE_CODE (index_expr
) == INTEGER_CST
5044 /* These will reduce to a constant. */
5045 || (TREE_CODE (index_expr
) == CALL_EXPR
5046 && TREE_CODE (TREE_OPERAND (index_expr
, 0)) == ADDR_EXPR
5047 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == FUNCTION_DECL
5048 && DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (index_expr
, 0), 0)) == BUILT_IN_CLASSIFY_TYPE
)
5049 || (TREE_CODE (index_expr
) == COMPOUND_EXPR
5050 && TREE_CODE (TREE_OPERAND (index_expr
, 1)) == INTEGER_CST
))
5052 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5054 /* If the index is a short or char that we do not have
5055 an insn to handle comparisons directly, convert it to
5056 a full integer now, rather than letting each comparison
5057 generate the conversion. */
5059 if (GET_MODE_CLASS (GET_MODE (index
)) == MODE_INT
5060 && (cmp_optab
->handlers
[(int) GET_MODE(index
)].insn_code
5061 == CODE_FOR_nothing
))
5063 enum machine_mode wider_mode
;
5064 for (wider_mode
= GET_MODE (index
); wider_mode
!= VOIDmode
;
5065 wider_mode
= GET_MODE_WIDER_MODE (wider_mode
))
5066 if (cmp_optab
->handlers
[(int) wider_mode
].insn_code
5067 != CODE_FOR_nothing
)
5069 index
= convert_to_mode (wider_mode
, index
, unsignedp
);
5075 do_pending_stack_adjust ();
5077 index
= protect_from_queue (index
, 0);
5078 if (GET_CODE (index
) == MEM
)
5079 index
= copy_to_reg (index
);
5080 if (GET_CODE (index
) == CONST_INT
5081 || TREE_CODE (index_expr
) == INTEGER_CST
)
5083 /* Make a tree node with the proper constant value
5084 if we don't already have one. */
5085 if (TREE_CODE (index_expr
) != INTEGER_CST
)
5088 = build_int_2 (INTVAL (index
),
5089 unsignedp
|| INTVAL (index
) >= 0 ? 0 : -1);
5090 index_expr
= convert (index_type
, index_expr
);
5093 /* For constant index expressions we need only
5094 issue a unconditional branch to the appropriate
5095 target code. The job of removing any unreachable
5096 code is left to the optimisation phase if the
5097 "-O" option is specified. */
5098 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5099 if (! tree_int_cst_lt (index_expr
, n
->low
)
5100 && ! tree_int_cst_lt (n
->high
, index_expr
))
5104 emit_jump (label_rtx (n
->code_label
));
5106 emit_jump (default_label
);
5110 /* If the index expression is not constant we generate
5111 a binary decision tree to select the appropriate
5112 target code. This is done as follows:
5114 The list of cases is rearranged into a binary tree,
5115 nearly optimal assuming equal probability for each case.
5117 The tree is transformed into RTL, eliminating
5118 redundant test conditions at the same time.
5120 If program flow could reach the end of the
5121 decision tree an unconditional jump to the
5122 default code is emitted. */
5125 = (TREE_CODE (TREE_TYPE (orig_index
)) != ENUMERAL_TYPE
5126 && estimate_case_costs (thiscase
->data
.case_stmt
.case_list
));
5127 balance_case_nodes (&thiscase
->data
.case_stmt
.case_list
,
5129 emit_case_nodes (index
, thiscase
->data
.case_stmt
.case_list
,
5130 default_label
, index_type
);
5131 emit_jump_if_reachable (default_label
);
5140 enum machine_mode index_mode
= SImode
;
5141 int index_bits
= GET_MODE_BITSIZE (index_mode
);
5143 enum machine_mode op_mode
;
5145 /* Convert the index to SImode. */
5146 if (GET_MODE_BITSIZE (TYPE_MODE (index_type
))
5147 > GET_MODE_BITSIZE (index_mode
))
5149 enum machine_mode omode
= TYPE_MODE (index_type
);
5150 rtx rangertx
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5152 /* We must handle the endpoints in the original mode. */
5153 index_expr
= build (MINUS_EXPR
, index_type
,
5154 index_expr
, minval
);
5155 minval
= integer_zero_node
;
5156 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5157 emit_cmp_insn (rangertx
, index
, LTU
, NULL_RTX
, omode
, 1, 0);
5158 emit_jump_insn (gen_bltu (default_label
));
5159 /* Now we can safely truncate. */
5160 index
= convert_to_mode (index_mode
, index
, 0);
5164 if (TYPE_MODE (index_type
) != index_mode
)
5166 index_expr
= convert (type_for_size (index_bits
, 0),
5168 index_type
= TREE_TYPE (index_expr
);
5171 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5174 index
= protect_from_queue (index
, 0);
5175 do_pending_stack_adjust ();
5177 op_mode
= insn_operand_mode
[(int)CODE_FOR_casesi
][0];
5178 if (! (*insn_operand_predicate
[(int)CODE_FOR_casesi
][0])
5180 index
= copy_to_mode_reg (op_mode
, index
);
5182 op1
= expand_expr (minval
, NULL_RTX
, VOIDmode
, 0);
5184 op_mode
= insn_operand_mode
[(int)CODE_FOR_casesi
][1];
5185 if (! (*insn_operand_predicate
[(int)CODE_FOR_casesi
][1])
5187 op1
= copy_to_mode_reg (op_mode
, op1
);
5189 op2
= expand_expr (range
, NULL_RTX
, VOIDmode
, 0);
5191 op_mode
= insn_operand_mode
[(int)CODE_FOR_casesi
][2];
5192 if (! (*insn_operand_predicate
[(int)CODE_FOR_casesi
][2])
5194 op2
= copy_to_mode_reg (op_mode
, op2
);
5196 emit_jump_insn (gen_casesi (index
, op1
, op2
,
5197 table_label
, default_label
));
5201 #ifdef HAVE_tablejump
5202 if (! win
&& HAVE_tablejump
)
5204 index_expr
= convert (thiscase
->data
.case_stmt
.nominal_type
,
5205 fold (build (MINUS_EXPR
, index_type
,
5206 index_expr
, minval
)));
5207 index_type
= TREE_TYPE (index_expr
);
5208 index
= expand_expr (index_expr
, NULL_RTX
, VOIDmode
, 0);
5210 index
= protect_from_queue (index
, 0);
5211 do_pending_stack_adjust ();
5213 do_tablejump (index
, TYPE_MODE (index_type
),
5214 expand_expr (range
, NULL_RTX
, VOIDmode
, 0),
5215 table_label
, default_label
);
5222 /* Get table of labels to jump to, in order of case index. */
5224 ncases
= TREE_INT_CST_LOW (range
) + 1;
5225 labelvec
= (rtx
*) alloca (ncases
* sizeof (rtx
));
5226 bzero ((char *) labelvec
, ncases
* sizeof (rtx
));
5228 for (n
= thiscase
->data
.case_stmt
.case_list
; n
; n
= n
->right
)
5230 register HOST_WIDE_INT i
5231 = TREE_INT_CST_LOW (n
->low
) - TREE_INT_CST_LOW (orig_minval
);
5236 = gen_rtx_LABEL_REF (Pmode
, label_rtx (n
->code_label
));
5237 if (i
+ TREE_INT_CST_LOW (orig_minval
)
5238 == TREE_INT_CST_LOW (n
->high
))
5244 /* Fill in the gaps with the default. */
5245 for (i
= 0; i
< ncases
; i
++)
5246 if (labelvec
[i
] == 0)
5247 labelvec
[i
] = gen_rtx_LABEL_REF (Pmode
, default_label
);
5249 /* Output the table */
5250 emit_label (table_label
);
5252 if (CASE_VECTOR_PC_RELATIVE
|| flag_pic
)
5253 emit_jump_insn (gen_rtx_ADDR_DIFF_VEC (CASE_VECTOR_MODE
,
5254 gen_rtx_LABEL_REF (Pmode
, table_label
),
5255 gen_rtvec_v (ncases
, labelvec
),
5256 const0_rtx
, const0_rtx
, 0));
5258 emit_jump_insn (gen_rtx_ADDR_VEC (CASE_VECTOR_MODE
,
5259 gen_rtvec_v (ncases
, labelvec
)));
5261 /* If the case insn drops through the table,
5262 after the table we must jump to the default-label.
5263 Otherwise record no drop-through after the table. */
5264 #ifdef CASE_DROPS_THROUGH
5265 emit_jump (default_label
);
5271 before_case
= squeeze_notes (NEXT_INSN (before_case
), get_last_insn ());
5272 reorder_insns (before_case
, get_last_insn (),
5273 thiscase
->data
.case_stmt
.start
);
5276 end_cleanup_deferral ();
5278 if (thiscase
->exit_label
)
5279 emit_label (thiscase
->exit_label
);
5281 POPSTACK (case_stack
);
5286 /* Convert the tree NODE into a list linked by the right field, with the left
5287 field zeroed. RIGHT is used for recursion; it is a list to be placed
5288 rightmost in the resulting list. */
5290 static struct case_node
*
5291 case_tree2list (node
, right
)
5292 struct case_node
*node
, *right
;
5294 struct case_node
*left
;
5297 right
= case_tree2list (node
->right
, right
);
5299 node
->right
= right
;
5300 if ((left
= node
->left
))
5303 return case_tree2list (left
, node
);
5309 /* Generate code to jump to LABEL if OP1 and OP2 are equal. */
5312 do_jump_if_equal (op1
, op2
, label
, unsignedp
)
5313 rtx op1
, op2
, label
;
5316 if (GET_CODE (op1
) == CONST_INT
5317 && GET_CODE (op2
) == CONST_INT
)
5319 if (INTVAL (op1
) == INTVAL (op2
))
5324 enum machine_mode mode
= GET_MODE (op1
);
5325 if (mode
== VOIDmode
)
5326 mode
= GET_MODE (op2
);
5327 emit_cmp_insn (op1
, op2
, EQ
, NULL_RTX
, mode
, unsignedp
, 0);
5328 emit_jump_insn (gen_beq (label
));
5332 /* Not all case values are encountered equally. This function
5333 uses a heuristic to weight case labels, in cases where that
5334 looks like a reasonable thing to do.
5336 Right now, all we try to guess is text, and we establish the
5339 chars above space: 16
5348 If we find any cases in the switch that are not either -1 or in the range
5349 of valid ASCII characters, or are control characters other than those
5350 commonly used with "\", don't treat this switch scanning text.
5352 Return 1 if these nodes are suitable for cost estimation, otherwise
5356 estimate_case_costs (node
)
5359 tree min_ascii
= build_int_2 (-1, -1);
5360 tree max_ascii
= convert (TREE_TYPE (node
->high
), build_int_2 (127, 0));
5364 /* If we haven't already made the cost table, make it now. Note that the
5365 lower bound of the table is -1, not zero. */
5367 if (cost_table
== NULL
)
5369 cost_table
= ((short *) xmalloc (129 * sizeof (short))) + 1;
5370 bzero ((char *) (cost_table
- 1), 129 * sizeof (short));
5372 for (i
= 0; i
< 128; i
++)
5376 else if (ISPUNCT (i
))
5378 else if (ISCNTRL (i
))
5382 cost_table
[' '] = 8;
5383 cost_table
['\t'] = 4;
5384 cost_table
['\0'] = 4;
5385 cost_table
['\n'] = 2;
5386 cost_table
['\f'] = 1;
5387 cost_table
['\v'] = 1;
5388 cost_table
['\b'] = 1;
5391 /* See if all the case expressions look like text. It is text if the
5392 constant is >= -1 and the highest constant is <= 127. Do all comparisons
5393 as signed arithmetic since we don't want to ever access cost_table with a
5394 value less than -1. Also check that none of the constants in a range
5395 are strange control characters. */
5397 for (n
= node
; n
; n
= n
->right
)
5399 if ((INT_CST_LT (n
->low
, min_ascii
)) || INT_CST_LT (max_ascii
, n
->high
))
5402 for (i
= TREE_INT_CST_LOW (n
->low
); i
<= TREE_INT_CST_LOW (n
->high
); i
++)
5403 if (cost_table
[i
] < 0)
5407 /* All interesting values are within the range of interesting
5408 ASCII characters. */
5412 /* Scan an ordered list of case nodes
5413 combining those with consecutive values or ranges.
5415 Eg. three separate entries 1: 2: 3: become one entry 1..3: */
5418 group_case_nodes (head
)
5421 case_node_ptr node
= head
;
5425 rtx lb
= next_real_insn (label_rtx (node
->code_label
));
5427 case_node_ptr np
= node
;
5429 /* Try to group the successors of NODE with NODE. */
5430 while (((np
= np
->right
) != 0)
5431 /* Do they jump to the same place? */
5432 && ((lb2
= next_real_insn (label_rtx (np
->code_label
))) == lb
5433 || (lb
!= 0 && lb2
!= 0
5434 && simplejump_p (lb
)
5435 && simplejump_p (lb2
)
5436 && rtx_equal_p (SET_SRC (PATTERN (lb
)),
5437 SET_SRC (PATTERN (lb2
)))))
5438 /* Are their ranges consecutive? */
5439 && tree_int_cst_equal (np
->low
,
5440 fold (build (PLUS_EXPR
,
5441 TREE_TYPE (node
->high
),
5444 /* An overflow is not consecutive. */
5445 && tree_int_cst_lt (node
->high
,
5446 fold (build (PLUS_EXPR
,
5447 TREE_TYPE (node
->high
),
5449 integer_one_node
))))
5451 node
->high
= np
->high
;
5453 /* NP is the first node after NODE which can't be grouped with it.
5454 Delete the nodes in between, and move on to that node. */
5460 /* Take an ordered list of case nodes
5461 and transform them into a near optimal binary tree,
5462 on the assumption that any target code selection value is as
5463 likely as any other.
5465 The transformation is performed by splitting the ordered
5466 list into two equal sections plus a pivot. The parts are
5467 then attached to the pivot as left and right branches. Each
5468 branch is then transformed recursively. */
5471 balance_case_nodes (head
, parent
)
5472 case_node_ptr
*head
;
5473 case_node_ptr parent
;
5475 register case_node_ptr np
;
5483 register case_node_ptr
*npp
;
5486 /* Count the number of entries on branch. Also count the ranges. */
5490 if (!tree_int_cst_equal (np
->low
, np
->high
))
5494 cost
+= cost_table
[TREE_INT_CST_LOW (np
->high
)];
5498 cost
+= cost_table
[TREE_INT_CST_LOW (np
->low
)];
5506 /* Split this list if it is long enough for that to help. */
5511 /* Find the place in the list that bisects the list's total cost,
5512 Here I gets half the total cost. */
5517 /* Skip nodes while their cost does not reach that amount. */
5518 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5519 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->high
)];
5520 i
-= cost_table
[TREE_INT_CST_LOW ((*npp
)->low
)];
5523 npp
= &(*npp
)->right
;
5528 /* Leave this branch lopsided, but optimize left-hand
5529 side and fill in `parent' fields for right-hand side. */
5531 np
->parent
= parent
;
5532 balance_case_nodes (&np
->left
, np
);
5533 for (; np
->right
; np
= np
->right
)
5534 np
->right
->parent
= np
;
5538 /* If there are just three nodes, split at the middle one. */
5540 npp
= &(*npp
)->right
;
5543 /* Find the place in the list that bisects the list's total cost,
5544 where ranges count as 2.
5545 Here I gets half the total cost. */
5546 i
= (i
+ ranges
+ 1) / 2;
5549 /* Skip nodes while their cost does not reach that amount. */
5550 if (!tree_int_cst_equal ((*npp
)->low
, (*npp
)->high
))
5555 npp
= &(*npp
)->right
;
5560 np
->parent
= parent
;
5563 /* Optimize each of the two split parts. */
5564 balance_case_nodes (&np
->left
, np
);
5565 balance_case_nodes (&np
->right
, np
);
5569 /* Else leave this branch as one level,
5570 but fill in `parent' fields. */
5572 np
->parent
= parent
;
5573 for (; np
->right
; np
= np
->right
)
5574 np
->right
->parent
= np
;
5579 /* Search the parent sections of the case node tree
5580 to see if a test for the lower bound of NODE would be redundant.
5581 INDEX_TYPE is the type of the index expression.
5583 The instructions to generate the case decision tree are
5584 output in the same order as nodes are processed so it is
5585 known that if a parent node checks the range of the current
5586 node minus one that the current node is bounded at its lower
5587 span. Thus the test would be redundant. */
5590 node_has_low_bound (node
, index_type
)
5595 case_node_ptr pnode
;
5597 /* If the lower bound of this node is the lowest value in the index type,
5598 we need not test it. */
5600 if (tree_int_cst_equal (node
->low
, TYPE_MIN_VALUE (index_type
)))
5603 /* If this node has a left branch, the value at the left must be less
5604 than that at this node, so it cannot be bounded at the bottom and
5605 we need not bother testing any further. */
5610 low_minus_one
= fold (build (MINUS_EXPR
, TREE_TYPE (node
->low
),
5611 node
->low
, integer_one_node
));
5613 /* If the subtraction above overflowed, we can't verify anything.
5614 Otherwise, look for a parent that tests our value - 1. */
5616 if (! tree_int_cst_lt (low_minus_one
, node
->low
))
5619 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5620 if (tree_int_cst_equal (low_minus_one
, pnode
->high
))
5626 /* Search the parent sections of the case node tree
5627 to see if a test for the upper bound of NODE would be redundant.
5628 INDEX_TYPE is the type of the index expression.
5630 The instructions to generate the case decision tree are
5631 output in the same order as nodes are processed so it is
5632 known that if a parent node checks the range of the current
5633 node plus one that the current node is bounded at its upper
5634 span. Thus the test would be redundant. */
5637 node_has_high_bound (node
, index_type
)
5642 case_node_ptr pnode
;
5644 /* If there is no upper bound, obviously no test is needed. */
5646 if (TYPE_MAX_VALUE (index_type
) == NULL
)
5649 /* If the upper bound of this node is the highest value in the type
5650 of the index expression, we need not test against it. */
5652 if (tree_int_cst_equal (node
->high
, TYPE_MAX_VALUE (index_type
)))
5655 /* If this node has a right branch, the value at the right must be greater
5656 than that at this node, so it cannot be bounded at the top and
5657 we need not bother testing any further. */
5662 high_plus_one
= fold (build (PLUS_EXPR
, TREE_TYPE (node
->high
),
5663 node
->high
, integer_one_node
));
5665 /* If the addition above overflowed, we can't verify anything.
5666 Otherwise, look for a parent that tests our value + 1. */
5668 if (! tree_int_cst_lt (node
->high
, high_plus_one
))
5671 for (pnode
= node
->parent
; pnode
; pnode
= pnode
->parent
)
5672 if (tree_int_cst_equal (high_plus_one
, pnode
->low
))
5678 /* Search the parent sections of the
5679 case node tree to see if both tests for the upper and lower
5680 bounds of NODE would be redundant. */
5683 node_is_bounded (node
, index_type
)
5687 return (node_has_low_bound (node
, index_type
)
5688 && node_has_high_bound (node
, index_type
));
5691 /* Emit an unconditional jump to LABEL unless it would be dead code. */
5694 emit_jump_if_reachable (label
)
5697 if (GET_CODE (get_last_insn ()) != BARRIER
)
5701 /* Emit step-by-step code to select a case for the value of INDEX.
5702 The thus generated decision tree follows the form of the
5703 case-node binary tree NODE, whose nodes represent test conditions.
5704 INDEX_TYPE is the type of the index of the switch.
5706 Care is taken to prune redundant tests from the decision tree
5707 by detecting any boundary conditions already checked by
5708 emitted rtx. (See node_has_high_bound, node_has_low_bound
5709 and node_is_bounded, above.)
5711 Where the test conditions can be shown to be redundant we emit
5712 an unconditional jump to the target code. As a further
5713 optimization, the subordinates of a tree node are examined to
5714 check for bounded nodes. In this case conditional and/or
5715 unconditional jumps as a result of the boundary check for the
5716 current node are arranged to target the subordinates associated
5717 code for out of bound conditions on the current node.
5719 We can assume that when control reaches the code generated here,
5720 the index value has already been compared with the parents
5721 of this node, and determined to be on the same side of each parent
5722 as this node is. Thus, if this node tests for the value 51,
5723 and a parent tested for 52, we don't need to consider
5724 the possibility of a value greater than 51. If another parent
5725 tests for the value 50, then this node need not test anything. */
5728 emit_case_nodes (index
, node
, default_label
, index_type
)
5734 /* If INDEX has an unsigned type, we must make unsigned branches. */
5735 int unsignedp
= TREE_UNSIGNED (index_type
);
5736 typedef rtx
rtx_fn ();
5737 rtx_fn
*gen_bgt_pat
= unsignedp
? gen_bgtu
: gen_bgt
;
5738 rtx_fn
*gen_bge_pat
= unsignedp
? gen_bgeu
: gen_bge
;
5739 rtx_fn
*gen_blt_pat
= unsignedp
? gen_bltu
: gen_blt
;
5740 rtx_fn
*gen_ble_pat
= unsignedp
? gen_bleu
: gen_ble
;
5741 enum machine_mode mode
= GET_MODE (index
);
5743 /* See if our parents have already tested everything for us.
5744 If they have, emit an unconditional jump for this node. */
5745 if (node_is_bounded (node
, index_type
))
5746 emit_jump (label_rtx (node
->code_label
));
5748 else if (tree_int_cst_equal (node
->low
, node
->high
))
5750 /* Node is single valued. First see if the index expression matches
5751 this node and then check our children, if any. */
5753 do_jump_if_equal (index
, expand_expr (node
->low
, NULL_RTX
, VOIDmode
, 0),
5754 label_rtx (node
->code_label
), unsignedp
);
5756 if (node
->right
!= 0 && node
->left
!= 0)
5758 /* This node has children on both sides.
5759 Dispatch to one side or the other
5760 by comparing the index value with this node's value.
5761 If one subtree is bounded, check that one first,
5762 so we can avoid real branches in the tree. */
5764 if (node_is_bounded (node
->right
, index_type
))
5766 emit_cmp_insn (index
, expand_expr (node
->high
, NULL_RTX
,
5768 GT
, NULL_RTX
, mode
, unsignedp
, 0);
5770 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (node
->right
->code_label
)));
5771 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5774 else if (node_is_bounded (node
->left
, index_type
))
5776 emit_cmp_insn (index
, expand_expr (node
->high
, NULL_RTX
,
5778 LT
, NULL_RTX
, mode
, unsignedp
, 0);
5779 emit_jump_insn ((*gen_blt_pat
) (label_rtx (node
->left
->code_label
)));
5780 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5785 /* Neither node is bounded. First distinguish the two sides;
5786 then emit the code for one side at a time. */
5789 = build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5791 /* See if the value is on the right. */
5792 emit_cmp_insn (index
, expand_expr (node
->high
, NULL_RTX
,
5794 GT
, NULL_RTX
, mode
, unsignedp
, 0);
5795 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (test_label
)));
5797 /* Value must be on the left.
5798 Handle the left-hand subtree. */
5799 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5800 /* If left-hand subtree does nothing,
5802 emit_jump_if_reachable (default_label
);
5804 /* Code branches here for the right-hand subtree. */
5805 expand_label (test_label
);
5806 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5810 else if (node
->right
!= 0 && node
->left
== 0)
5812 /* Here we have a right child but no left so we issue conditional
5813 branch to default and process the right child.
5815 Omit the conditional branch to default if we it avoid only one
5816 right child; it costs too much space to save so little time. */
5818 if (node
->right
->right
|| node
->right
->left
5819 || !tree_int_cst_equal (node
->right
->low
, node
->right
->high
))
5821 if (!node_has_low_bound (node
, index_type
))
5823 emit_cmp_insn (index
, expand_expr (node
->high
, NULL_RTX
,
5825 LT
, NULL_RTX
, mode
, unsignedp
, 0);
5826 emit_jump_insn ((*gen_blt_pat
) (default_label
));
5829 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5832 /* We cannot process node->right normally
5833 since we haven't ruled out the numbers less than
5834 this node's value. So handle node->right explicitly. */
5835 do_jump_if_equal (index
,
5836 expand_expr (node
->right
->low
, NULL_RTX
,
5838 label_rtx (node
->right
->code_label
), unsignedp
);
5841 else if (node
->right
== 0 && node
->left
!= 0)
5843 /* Just one subtree, on the left. */
5845 #if 0 /* The following code and comment were formerly part
5846 of the condition here, but they didn't work
5847 and I don't understand what the idea was. -- rms. */
5848 /* If our "most probable entry" is less probable
5849 than the default label, emit a jump to
5850 the default label using condition codes
5851 already lying around. With no right branch,
5852 a branch-greater-than will get us to the default
5855 && cost_table
[TREE_INT_CST_LOW (node
->high
)] < 12)
5858 if (node
->left
->left
|| node
->left
->right
5859 || !tree_int_cst_equal (node
->left
->low
, node
->left
->high
))
5861 if (!node_has_high_bound (node
, index_type
))
5863 emit_cmp_insn (index
, expand_expr (node
->high
, NULL_RTX
,
5865 GT
, NULL_RTX
, mode
, unsignedp
, 0);
5866 emit_jump_insn ((*gen_bgt_pat
) (default_label
));
5869 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5872 /* We cannot process node->left normally
5873 since we haven't ruled out the numbers less than
5874 this node's value. So handle node->left explicitly. */
5875 do_jump_if_equal (index
,
5876 expand_expr (node
->left
->low
, NULL_RTX
,
5878 label_rtx (node
->left
->code_label
), unsignedp
);
5883 /* Node is a range. These cases are very similar to those for a single
5884 value, except that we do not start by testing whether this node
5885 is the one to branch to. */
5887 if (node
->right
!= 0 && node
->left
!= 0)
5889 /* Node has subtrees on both sides.
5890 If the right-hand subtree is bounded,
5891 test for it first, since we can go straight there.
5892 Otherwise, we need to make a branch in the control structure,
5893 then handle the two subtrees. */
5894 tree test_label
= 0;
5896 emit_cmp_insn (index
, expand_expr (node
->high
, NULL_RTX
,
5898 GT
, NULL_RTX
, mode
, unsignedp
, 0);
5900 if (node_is_bounded (node
->right
, index_type
))
5901 /* Right hand node is fully bounded so we can eliminate any
5902 testing and branch directly to the target code. */
5903 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (node
->right
->code_label
)));
5906 /* Right hand node requires testing.
5907 Branch to a label where we will handle it later. */
5909 test_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
5910 emit_jump_insn ((*gen_bgt_pat
) (label_rtx (test_label
)));
5913 /* Value belongs to this node or to the left-hand subtree. */
5915 emit_cmp_insn (index
, expand_expr (node
->low
, NULL_RTX
, VOIDmode
, 0),
5916 GE
, NULL_RTX
, mode
, unsignedp
, 0);
5917 emit_jump_insn ((*gen_bge_pat
) (label_rtx (node
->code_label
)));
5919 /* Handle the left-hand subtree. */
5920 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5922 /* If right node had to be handled later, do that now. */
5926 /* If the left-hand subtree fell through,
5927 don't let it fall into the right-hand subtree. */
5928 emit_jump_if_reachable (default_label
);
5930 expand_label (test_label
);
5931 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5935 else if (node
->right
!= 0 && node
->left
== 0)
5937 /* Deal with values to the left of this node,
5938 if they are possible. */
5939 if (!node_has_low_bound (node
, index_type
))
5941 emit_cmp_insn (index
, expand_expr (node
->low
, NULL_RTX
,
5943 LT
, NULL_RTX
, mode
, unsignedp
, 0);
5944 emit_jump_insn ((*gen_blt_pat
) (default_label
));
5947 /* Value belongs to this node or to the right-hand subtree. */
5949 emit_cmp_insn (index
, expand_expr (node
->high
, NULL_RTX
,
5951 LE
, NULL_RTX
, mode
, unsignedp
, 0);
5952 emit_jump_insn ((*gen_ble_pat
) (label_rtx (node
->code_label
)));
5954 emit_case_nodes (index
, node
->right
, default_label
, index_type
);
5957 else if (node
->right
== 0 && node
->left
!= 0)
5959 /* Deal with values to the right of this node,
5960 if they are possible. */
5961 if (!node_has_high_bound (node
, index_type
))
5963 emit_cmp_insn (index
, expand_expr (node
->high
, NULL_RTX
,
5965 GT
, NULL_RTX
, mode
, unsignedp
, 0);
5966 emit_jump_insn ((*gen_bgt_pat
) (default_label
));
5969 /* Value belongs to this node or to the left-hand subtree. */
5971 emit_cmp_insn (index
, expand_expr (node
->low
, NULL_RTX
, VOIDmode
, 0),
5972 GE
, NULL_RTX
, mode
, unsignedp
, 0);
5973 emit_jump_insn ((*gen_bge_pat
) (label_rtx (node
->code_label
)));
5975 emit_case_nodes (index
, node
->left
, default_label
, index_type
);
5980 /* Node has no children so we check low and high bounds to remove
5981 redundant tests. Only one of the bounds can exist,
5982 since otherwise this node is bounded--a case tested already. */
5984 if (!node_has_high_bound (node
, index_type
))
5986 emit_cmp_insn (index
, expand_expr (node
->high
, NULL_RTX
,
5988 GT
, NULL_RTX
, mode
, unsignedp
, 0);
5989 emit_jump_insn ((*gen_bgt_pat
) (default_label
));
5992 if (!node_has_low_bound (node
, index_type
))
5994 emit_cmp_insn (index
, expand_expr (node
->low
, NULL_RTX
,
5996 LT
, NULL_RTX
, mode
, unsignedp
, 0);
5997 emit_jump_insn ((*gen_blt_pat
) (default_label
));
6000 emit_jump (label_rtx (node
->code_label
));
6005 /* These routines are used by the loop unrolling code. They copy BLOCK trees
6006 so that the debugging info will be correct for the unrolled loop. */
6008 /* Indexed by block number, contains a pointer to the N'th block node.
6010 Allocated by the call to identify_blocks, then released after the call
6011 to reorder_blocks in the function unroll_block_trees. */
6013 static tree
*block_vector
;
6016 find_loop_tree_blocks ()
6018 tree block
= DECL_INITIAL (current_function_decl
);
6020 block_vector
= identify_blocks (block
, get_insns ());
6024 unroll_block_trees ()
6026 tree block
= DECL_INITIAL (current_function_decl
);
6028 reorder_blocks (block_vector
, block
, get_insns ());
6030 /* Release any memory allocated by identify_blocks. */
6032 free (block_vector
);