1 /* Structure for saving state for a nested function.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 #ifndef GCC_FUNCTION_H
22 #define GCC_FUNCTION_H
27 /* Stack of pending (incomplete) sequences saved by `start_sequence'.
28 Each element describes one pending sequence.
29 The main insn-chain is saved in the last element of the chain,
30 unless the chain is empty. */
32 struct sequence_stack
GTY(())
34 /* First and last insns in the chain of the saved sequence. */
37 struct sequence_stack
*next
;
40 struct emit_status
GTY(())
42 /* This is reset to LAST_VIRTUAL_REGISTER + 1 at the start of each function.
43 After rtl generation, it is 1 plus the largest register number used. */
46 /* Lowest label number in current function. */
47 int x_first_label_num
;
49 /* The ends of the doubly-linked chain of rtl for the current function.
50 Both are reset to null at the start of rtl generation for the function.
52 start_sequence saves both of these on `sequence_stack' and then starts
53 a new, nested sequence of insns. */
57 /* Stack of pending (incomplete) sequences saved by `start_sequence'.
58 Each element describes one pending sequence.
59 The main insn-chain is saved in the last element of the chain,
60 unless the chain is empty. */
61 struct sequence_stack
*sequence_stack
;
63 /* INSN_UID for next insn emitted.
64 Reset to 1 for each function compiled. */
67 /* Location the last line-number NOTE emitted.
68 This is used to avoid generating duplicates. */
69 location_t x_last_location
;
71 /* The length of the regno_pointer_align, regno_decl, and x_regno_reg_rtx
72 vectors. Since these vectors are needed during the expansion phase when
73 the total number of registers in the function is not yet known, the
74 vectors are copied and made bigger when necessary. */
75 int regno_pointer_align_length
;
77 /* Indexed by pseudo register number, if nonzero gives the known alignment
78 for that pseudo (if REG_POINTER is set in x_regno_reg_rtx).
79 Allocated in parallel with x_regno_reg_rtx. */
80 unsigned char * GTY ((length ("%h.x_reg_rtx_no")))
83 /* Indexed by pseudo register number, gives the rtx for that pseudo.
84 Allocated in parallel with regno_pointer_align. */
85 rtx
* GTY ((length ("%h.x_reg_rtx_no"))) x_regno_reg_rtx
;
88 /* For backward compatibility... eventually these should all go away. */
89 #define reg_rtx_no (cfun->emit->x_reg_rtx_no)
90 #define regno_reg_rtx (cfun->emit->x_regno_reg_rtx)
91 #define seq_stack (cfun->emit->sequence_stack)
93 #define REGNO_POINTER_ALIGN(REGNO) (cfun->emit->regno_pointer_align[REGNO])
95 struct expr_status
GTY(())
97 /* Number of units that we should eventually pop off the stack.
98 These are the arguments to function calls that have already returned. */
99 int x_pending_stack_adjust
;
101 /* Under some ABIs, it is the caller's responsibility to pop arguments
102 pushed for function calls. A naive implementation would simply pop
103 the arguments immediately after each call. However, if several
104 function calls are made in a row, it is typically cheaper to pop
105 all the arguments after all of the calls are complete since a
106 single pop instruction can be used. Therefore, GCC attempts to
107 defer popping the arguments until absolutely necessary. (For
108 example, at the end of a conditional, the arguments must be popped,
109 since code outside the conditional won't know whether or not the
110 arguments need to be popped.)
112 When INHIBIT_DEFER_POP is nonzero, however, the compiler does not
113 attempt to defer pops. Instead, the stack is popped immediately
114 after each call. Rather then setting this variable directly, use
115 NO_DEFER_POP and OK_DEFER_POP. */
116 int x_inhibit_defer_pop
;
118 /* If PREFERRED_STACK_BOUNDARY and PUSH_ROUNDING are defined, the stack
119 boundary can be momentarily unaligned while pushing the arguments.
120 Record the delta since last aligned boundary here in order to get
121 stack alignment in the nested function calls working right. */
122 int x_stack_pointer_delta
;
124 /* Nonzero means __builtin_saveregs has already been done in this function.
125 The value is the pseudoreg containing the value __builtin_saveregs
127 rtx x_saveregs_value
;
129 /* Similarly for __builtin_apply_args. */
130 rtx x_apply_args_value
;
132 /* List of labels that must never be deleted. */
136 #define pending_stack_adjust (cfun->expr->x_pending_stack_adjust)
137 #define inhibit_defer_pop (cfun->expr->x_inhibit_defer_pop)
138 #define saveregs_value (cfun->expr->x_saveregs_value)
139 #define apply_args_value (cfun->expr->x_apply_args_value)
140 #define forced_labels (cfun->expr->x_forced_labels)
141 #define stack_pointer_delta (cfun->expr->x_stack_pointer_delta)
145 typedef struct temp_slot
*temp_slot_p
;
147 DEF_VEC_P(temp_slot_p
);
148 DEF_VEC_ALLOC_P(temp_slot_p
,gc
);
150 enum function_frequency
{
151 /* This function most likely won't be executed at all.
152 (set only when profile feedback is available or via function attribute). */
153 FUNCTION_FREQUENCY_UNLIKELY_EXECUTED
,
154 /* The default value. */
155 FUNCTION_FREQUENCY_NORMAL
,
156 /* Optimize this function hard
157 (set only when profile feedback is available or via function attribute). */
158 FUNCTION_FREQUENCY_HOT
161 /* This structure can save all the important global and static variables
162 describing the status of the current function. */
164 struct function
GTY(())
166 struct eh_status
*eh
;
167 struct expr_status
*expr
;
168 struct emit_status
*emit
;
169 struct varasm_status
*varasm
;
171 /* The control flow graph for this function. */
172 struct control_flow_graph
*cfg
;
173 /* SSA and dataflow information. */
174 struct gimple_df
*gimple_df
;
176 /* The loops in this function. */
177 struct loops
*x_current_loops
;
179 /* Value histograms attached to particular statements. */
180 htab_t
GTY((skip
)) value_histograms
;
182 /* For function.c. */
184 /* Points to the FUNCTION_DECL of this function. */
187 /* Function containing this function, if any. */
188 struct function
*outer
;
190 /* Number of bytes of args popped by function being compiled on its return.
191 Zero if no bytes are to be popped.
192 May affect compilation of return insn or of function epilogue. */
195 /* If function's args have a fixed size, this is that size, in bytes.
197 May affect compilation of return insn or of function epilogue. */
200 /* # bytes the prologue should push and pretend that the caller pushed them.
201 The prologue must do this, but only if parms can be passed in
203 int pretend_args_size
;
205 /* # of bytes of outgoing arguments. If ACCUMULATE_OUTGOING_ARGS is
206 defined, the needed space is pushed by the prologue. */
207 int outgoing_args_size
;
209 /* This is the offset from the arg pointer to the place where the first
210 anonymous arg can be found, if there is one. */
213 /* Quantities of various kinds of registers
214 used for the current function's args. */
215 CUMULATIVE_ARGS args_info
;
217 /* If nonzero, an RTL expression for the location at which the current
218 function returns its result. If the current function returns its
219 result in a register, current_function_return_rtx will always be
220 the hard register containing the result. */
223 /* The arg pointer hard register, or the pseudo into which it was copied. */
224 rtx internal_arg_pointer
;
226 /* Opaque pointer used by get_hard_reg_initial_val and
227 has_hard_reg_initial_val (see integrate.[hc]). */
228 struct initial_value_struct
*hard_reg_initial_vals
;
230 /* List (chain of EXPR_LIST) of labels heading the current handlers for
232 rtx x_nonlocal_goto_handler_labels
;
234 /* Label that will go on function epilogue.
235 Jumping to this label serves as a "return" instruction
236 on machines which require execution of the epilogue on all returns. */
239 /* Label that will go on the end of function epilogue.
240 Jumping to this label serves as a "naked return" instruction
241 on machines which require execution of the epilogue on all returns. */
242 rtx x_naked_return_label
;
244 /* List (chain of EXPR_LISTs) of all stack slots in this function.
245 Made for the sake of unshare_all_rtl. */
246 rtx x_stack_slot_list
;
248 /* Place after which to insert the tail_recursion_label if we need one. */
249 rtx x_stack_check_probe_note
;
251 /* Location at which to save the argument pointer if it will need to be
252 referenced. There are two cases where this is done: if nonlocal gotos
253 exist, or if vars stored at an offset from the argument pointer will be
254 needed by inner routines. */
255 rtx x_arg_pointer_save_area
;
257 /* Offset to end of allocated area of stack frame.
258 If stack grows down, this is the address of the last stack slot allocated.
259 If stack grows up, this is the address for the next slot. */
260 HOST_WIDE_INT x_frame_offset
;
262 /* A PARM_DECL that should contain the static chain for this function.
263 It will be initialized at the beginning of the function. */
264 tree static_chain_decl
;
266 /* An expression that contains the non-local goto save area. The first
267 word is the saved frame pointer and the second is the saved stack
269 tree nonlocal_goto_save_area
;
271 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
272 rtx x_parm_birth_insn
;
274 /* List of all used temporaries allocated, by level. */
275 VEC(temp_slot_p
,gc
) *x_used_temp_slots
;
277 /* List of available temp slots. */
278 struct temp_slot
*x_avail_temp_slots
;
280 /* Current nesting level for temporaries. */
281 int x_temp_slot_level
;
283 /* Highest label number in current function. */
284 int inl_max_label_num
;
286 /* Function sequence number for profiling, debugging, etc. */
291 /* tm.h can use this to store whatever it likes. */
292 struct machine_function
* GTY ((maybe_undef
)) machine
;
294 /* The largest alignment of slot allocated on the stack. */
295 unsigned int stack_alignment_needed
;
297 /* Preferred alignment of the end of stack frame. */
298 unsigned int preferred_stack_boundary
;
300 /* Language-specific code can use this to store whatever it likes. */
301 struct language_function
* language
;
303 /* Used types hash table. */
304 htab_t
GTY ((param_is (union tree_node
))) used_types_hash
;
308 /* If some insns can be deferred to the delay slots of the epilogue, the
309 delay list for them is recorded here. */
310 rtx epilogue_delay_list
;
312 /* Maximal number of entities in the single jumptable. Used to estimate
313 final flowgraph size. */
314 int max_jumptable_ents
;
316 /* UIDs for LABEL_DECLs. */
319 /* Line number of the end of the function. */
320 location_t function_end_locus
;
322 /* The variables unexpanded so far. */
323 tree unexpanded_var_list
;
325 /* Assembly labels for the hot and cold text sections, to
326 be used by debugger functions for determining the size of text
329 const char *hot_section_label
;
330 const char *cold_section_label
;
331 const char *hot_section_end_label
;
332 const char *cold_section_end_label
;
334 /* String to be used for name of cold text sections, via
335 targetm.asm_out.named_section. */
337 const char *unlikely_text_section_name
;
339 /* A variable living at the top of the frame that holds a known value.
340 Used for detecting stack clobbers. */
341 tree stack_protect_guard
;
343 /* Properties used by the pass manager. */
344 unsigned int curr_properties
;
345 unsigned int last_verified
;
347 /* Collected bit flags. */
349 /* Number of units of general registers that need saving in stdarg
350 function. What unit is depends on the backend, either it is number
351 of bytes, or it can be number of registers. */
352 unsigned int va_list_gpr_size
: 8;
354 /* Number of units of floating point registers that need saving in stdarg
356 unsigned int va_list_fpr_size
: 8;
359 /* How commonly executed the function is. Initialized during branch
360 probabilities pass. */
361 ENUM_BITFIELD (function_frequency
) function_frequency
: 2;
363 /* Nonzero if function being compiled can call setjmp. */
364 unsigned int calls_setjmp
: 1;
366 /* Nonzero if function being compiled can call alloca,
367 either as a subroutine or builtin. */
368 unsigned int calls_alloca
: 1;
370 /* Nonzero if function being compiled called builtin_return_addr or
371 builtin_frame_address with nonzero count. */
372 unsigned int accesses_prior_frames
: 1;
374 /* Nonzero if the function calls __builtin_eh_return. */
375 unsigned int calls_eh_return
: 1;
378 /* Nonzero if function being compiled receives nonlocal gotos
379 from nested functions. */
380 unsigned int has_nonlocal_label
: 1;
382 /* Nonzero if function saves all registers, e.g. if it has a nonlocal
383 label that can reach the exit block via non-exceptional paths. */
384 unsigned int saves_all_registers
: 1;
386 /* Nonzero if function being compiled has nonlocal gotos to parent
388 unsigned int has_nonlocal_goto
: 1;
390 /* Nonzero if function being compiled has an asm statement. */
391 unsigned int has_asm_statement
: 1;
393 /* Nonzero if the current function is a thunk, i.e., a lightweight
394 function implemented by the output_mi_thunk hook) that just
395 adjusts one of its arguments and forwards to another
397 unsigned int is_thunk
: 1;
399 /* This bit is used by the exception handling logic. It is set if all
400 calls (if any) are sibling calls. Such functions do not have to
401 have EH tables generated, as they cannot throw. A call to such a
402 function, however, should be treated as throwing if any of its callees
404 unsigned int all_throwers_are_sibcalls
: 1;
406 /* Nonzero if profiling code should be generated. */
407 unsigned int profile
: 1;
409 /* Nonzero if stack limit checking should be enabled in the current
411 unsigned int limit_stack
: 1;
414 /* Nonzero if current function uses stdarg.h or equivalent. */
415 unsigned int stdarg
: 1;
417 /* Nonzero if the back-end should not keep track of expressions that
418 determine the size of variable-sized objects. Normally, such
419 expressions are saved away, and then expanded when the next
420 function is started. For example, if a parameter has a
421 variable-sized type, then the size of the parameter is computed
422 when the function body is entered. However, some front-ends do
423 not desire this behavior. */
424 unsigned int x_dont_save_pending_sizes_p
: 1;
426 /* Nonzero if the current function uses the constant pool. */
427 unsigned int uses_const_pool
: 1;
429 /* Nonzero if the current function uses pic_offset_table_rtx. */
430 unsigned int uses_pic_offset_table
: 1;
432 /* Nonzero if the current function needs an lsda for exception handling. */
433 unsigned int uses_eh_lsda
: 1;
435 /* Nonzero if code to initialize arg_pointer_save_area has been emitted. */
436 unsigned int arg_pointer_save_area_init
: 1;
438 unsigned int after_inlining
: 1;
440 /* Set when the call to function itself has been emit. */
441 unsigned int recursive_call_emit
: 1;
444 /* Set when the tail call has been produced. */
445 unsigned int tail_call_emit
: 1;
447 /* FIXME tuples: This bit is temporarily here to mark when a
448 function has been gimplified, so we can make sure we're not
449 creating non GIMPLE tuples after gimplification. */
450 unsigned int gimplified
: 1;
452 /* Fields below this point are not set for abstract functions; see
453 allocate_struct_function. */
455 /* Nonzero if function being compiled needs to be given an address
456 where the value should be stored. */
457 unsigned int returns_struct
: 1;
459 /* Nonzero if function being compiled needs to
460 return the address of where it has put a structure value. */
461 unsigned int returns_pcc_struct
: 1;
464 /* If va_list_[gf]pr_size is set to this, it means we don't know how
465 many units need to be saved. */
466 #define VA_LIST_MAX_GPR_SIZE 255
467 #define VA_LIST_MAX_FPR_SIZE 255
469 /* The function currently being compiled. */
470 extern GTY(()) struct function
*cfun
;
472 /* In order to ensure that cfun is not set directly, we redefine it so
473 that it is not an lvalue. Rather than assign to cfun, use
474 push_cfun or set_cfun. */
475 #define cfun (cfun + 0)
477 /* Pointer to chain of `struct function' for containing functions. */
478 extern GTY(()) struct function
*outer_function_chain
;
480 /* Nonzero if we've already converted virtual regs to hard regs. */
481 extern int virtuals_instantiated
;
483 /* Nonzero if at least one trampoline has been created. */
484 extern int trampolines_created
;
486 /* cfun shouldn't be set directly; use one of these functions instead. */
487 extern void set_cfun (struct function
*new_cfun
);
488 extern void push_cfun (struct function
*new_cfun
);
489 extern void pop_cfun (void);
491 /* For backward compatibility... eventually these should all go away. */
492 #define current_function_pops_args (cfun->pops_args)
493 #define current_function_returns_struct (cfun->returns_struct)
494 #define current_function_returns_pcc_struct (cfun->returns_pcc_struct)
495 #define current_function_calls_setjmp (cfun->calls_setjmp)
496 #define current_function_calls_alloca (cfun->calls_alloca)
497 #define current_function_accesses_prior_frames (cfun->accesses_prior_frames)
498 #define current_function_calls_eh_return (cfun->calls_eh_return)
499 #define current_function_is_thunk (cfun->is_thunk)
500 #define current_function_args_info (cfun->args_info)
501 #define current_function_args_size (cfun->args_size)
502 #define current_function_pretend_args_size (cfun->pretend_args_size)
503 #define current_function_outgoing_args_size (cfun->outgoing_args_size)
504 #define current_function_arg_offset_rtx (cfun->arg_offset_rtx)
505 #define current_function_stdarg (cfun->stdarg)
506 #define current_function_internal_arg_pointer (cfun->internal_arg_pointer)
507 #define current_function_return_rtx (cfun->return_rtx)
508 #define current_function_profile (cfun->profile)
509 #define current_function_funcdef_no (cfun->funcdef_no)
510 #define current_function_limit_stack (cfun->limit_stack)
511 #define current_function_uses_pic_offset_table (cfun->uses_pic_offset_table)
512 #define current_function_uses_const_pool (cfun->uses_const_pool)
513 #define current_function_epilogue_delay_list (cfun->epilogue_delay_list)
514 #define current_function_has_nonlocal_label (cfun->has_nonlocal_label)
515 #define current_function_saves_all_registers (cfun->saves_all_registers)
516 #define current_function_has_nonlocal_goto (cfun->has_nonlocal_goto)
517 #define current_function_has_asm_statement (cfun->has_asm_statement)
519 #define return_label (cfun->x_return_label)
520 #define naked_return_label (cfun->x_naked_return_label)
521 #define stack_slot_list (cfun->x_stack_slot_list)
522 #define parm_birth_insn (cfun->x_parm_birth_insn)
523 #define frame_offset (cfun->x_frame_offset)
524 #define stack_check_probe_note (cfun->x_stack_check_probe_note)
525 #define arg_pointer_save_area (cfun->x_arg_pointer_save_area)
526 #define used_temp_slots (cfun->x_used_temp_slots)
527 #define avail_temp_slots (cfun->x_avail_temp_slots)
528 #define temp_slot_level (cfun->x_temp_slot_level)
529 #define nonlocal_goto_handler_labels (cfun->x_nonlocal_goto_handler_labels)
530 #define rtl_df (cfun->df)
531 #define current_loops (cfun->x_current_loops)
532 #define dom_computed (cfun->cfg->x_dom_computed)
533 #define n_bbs_in_dom_tree (cfun->cfg->x_n_bbs_in_dom_tree)
534 #define VALUE_HISTOGRAMS(fun) (fun)->value_histograms
536 /* Given a function decl for a containing function,
537 return the `struct function' for it. */
538 struct function
*find_function_data (tree
);
540 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
541 and create duplicate blocks. */
542 extern void reorder_blocks (void);
544 /* Set BLOCK_NUMBER for all the blocks in FN. */
545 extern void number_blocks (tree
);
547 extern void clear_block_marks (tree
);
548 extern tree
blocks_nreverse (tree
);
550 /* Return size needed for stack frame based on slots so far allocated.
551 This size counts from zero. It is not rounded to STACK_BOUNDARY;
552 the caller may have to do that. */
553 extern HOST_WIDE_INT
get_frame_size (void);
555 /* Issue an error message and return TRUE if frame OFFSET overflows in
556 the signed target pointer arithmetics for function FUNC. Otherwise
558 extern bool frame_offset_overflow (HOST_WIDE_INT
, tree
);
560 /* A pointer to a function to create target specific, per-function
562 extern struct machine_function
* (*init_machine_status
) (void);
564 /* Save and restore status information for a nested function. */
565 extern void free_after_parsing (struct function
*);
566 extern void free_after_compilation (struct function
*);
568 extern void init_varasm_status (struct function
*);
571 extern void diddle_return_value (void (*)(rtx
, void*), void*);
572 extern void clobber_return_register (void);
575 extern rtx
get_arg_pointer_save_area (struct function
*);
577 /* Returns the name of the current function. */
578 extern const char *current_function_name (void);
579 /* Returns the assembler name (raw, mangled) of the current function. */
580 extern const char *current_function_assembler_name (void);
582 extern void do_warn_unused_parameter (tree
);
584 extern bool pass_by_reference (CUMULATIVE_ARGS
*, enum machine_mode
,
586 extern bool reference_callee_copied (CUMULATIVE_ARGS
*, enum machine_mode
,
589 extern void used_types_insert (tree
);
591 extern int get_next_funcdef_no (void);
592 #endif /* GCC_FUNCTION_H */