1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1991, 1992 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, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file handles the generation of rtl code from tree structure
22 at the level of the function as a whole.
23 It creates the rtl expressions for parameters and auto variables
24 and has full responsibility for allocating stack slots.
26 `expand_function_start' is called at the beginning of a function,
27 before the function body is parsed, and `expand_function_end' is
28 called after parsing the body.
30 Call `assign_stack_local' to allocate a stack slot for a local variable.
31 This is usually done during the RTL generation for the function body,
32 but it can also be done in the reload pass when a pseudo-register does
33 not get a hard register.
35 Call `put_var_into_stack' when you learn, belatedly, that a variable
36 previously given a pseudo-register must in fact go in the stack.
37 This function changes the DECL_RTL to be a stack slot instead of a reg
38 then scans all the RTL instructions so far generated to correct them. */
48 #include "insn-flags.h"
50 #include "insn-codes.h"
52 #include "hard-reg-set.h"
53 #include "insn-config.h"
56 #include "basic-block.h"
58 /* Round a value to the lowest integer less than it that is a multiple of
59 the required alignment. Avoid using division in case the value is
60 negative. Assume the alignment is a power of two. */
61 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
63 /* Similar, but round to the next highest integer that meets the
65 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
67 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
68 during rtl generation. If they are different register numbers, this is
69 always true. It may also be true if
70 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
71 generation. See fix_lexical_addr for details. */
73 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
74 #define NEED_SEPARATE_AP
77 /* Number of bytes of args popped by function being compiled on its return.
78 Zero if no bytes are to be popped.
79 May affect compilation of return insn or of function epilogue. */
81 int current_function_pops_args
;
83 /* Nonzero if function being compiled needs to be given an address
84 where the value should be stored. */
86 int current_function_returns_struct
;
88 /* Nonzero if function being compiled needs to
89 return the address of where it has put a structure value. */
91 int current_function_returns_pcc_struct
;
93 /* Nonzero if function being compiled needs to be passed a static chain. */
95 int current_function_needs_context
;
97 /* Nonzero if function being compiled can call setjmp. */
99 int current_function_calls_setjmp
;
101 /* Nonzero if function being compiled can call longjmp. */
103 int current_function_calls_longjmp
;
105 /* Nonzero if function being compiled receives nonlocal gotos
106 from nested functions. */
108 int current_function_has_nonlocal_label
;
110 /* Nonzero if function being compiled contains nested functions. */
112 int current_function_contains_functions
;
114 /* Nonzero if function being compiled can call alloca,
115 either as a subroutine or builtin. */
117 int current_function_calls_alloca
;
119 /* Nonzero if the current function returns a pointer type */
121 int current_function_returns_pointer
;
123 /* If some insns can be deferred to the delay slots of the epilogue, the
124 delay list for them is recorded here. */
126 rtx current_function_epilogue_delay_list
;
128 /* If function's args have a fixed size, this is that size, in bytes.
130 May affect compilation of return insn or of function epilogue. */
132 int current_function_args_size
;
134 /* # bytes the prologue should push and pretend that the caller pushed them.
135 The prologue must do this, but only if parms can be passed in registers. */
137 int current_function_pretend_args_size
;
139 /* # of bytes of outgoing arguments required to be pushed by the prologue.
140 If this is non-zero, it means that ACCUMULATE_OUTGOING_ARGS was defined
141 and no stack adjusts will be done on function calls. */
143 int current_function_outgoing_args_size
;
145 /* This is the offset from the arg pointer to the place where the first
146 anonymous arg can be found, if there is one. */
148 rtx current_function_arg_offset_rtx
;
150 /* Nonzero if current function uses varargs.h or equivalent.
151 Zero for functions that use stdarg.h. */
153 int current_function_varargs
;
155 /* Quantities of various kinds of registers
156 used for the current function's args. */
158 CUMULATIVE_ARGS current_function_args_info
;
160 /* Name of function now being compiled. */
162 char *current_function_name
;
164 /* If non-zero, an RTL expression for that location at which the current
165 function returns its result. Always equal to
166 DECL_RTL (DECL_RESULT (current_function_decl)), but provided
167 independently of the tree structures. */
169 rtx current_function_return_rtx
;
171 /* Nonzero if the current function uses the constant pool. */
173 int current_function_uses_const_pool
;
175 /* Nonzero if the current function uses pic_offset_table_rtx. */
176 int current_function_uses_pic_offset_table
;
178 /* The arg pointer hard register, or the pseudo into which it was copied. */
179 rtx current_function_internal_arg_pointer
;
181 /* The FUNCTION_DECL for an inline function currently being expanded. */
182 tree inline_function_decl
;
184 /* Number of function calls seen so far in current function. */
186 int function_call_count
;
188 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
189 (labels to which there can be nonlocal gotos from nested functions)
192 tree nonlocal_labels
;
194 /* RTX for stack slot that holds the current handler for nonlocal gotos.
195 Zero when function does not have nonlocal labels. */
197 rtx nonlocal_goto_handler_slot
;
199 /* RTX for stack slot that holds the stack pointer value to restore
201 Zero when function does not have nonlocal labels. */
203 rtx nonlocal_goto_stack_level
;
205 /* Label that will go on parm cleanup code, if any.
206 Jumping to this label runs cleanup code for parameters, if
207 such code must be run. Following this code is the logical return label. */
211 /* Label that will go on function epilogue.
212 Jumping to this label serves as a "return" instruction
213 on machines which require execution of the epilogue on all returns. */
217 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
218 So we can mark them all live at the end of the function, if nonopt. */
221 /* List (chain of EXPR_LISTs) of all stack slots in this function.
222 Made for the sake of unshare_all_rtl. */
225 /* Chain of all RTL_EXPRs that have insns in them. */
228 /* Label to jump back to for tail recursion, or 0 if we have
229 not yet needed one for this function. */
230 rtx tail_recursion_label
;
232 /* Place after which to insert the tail_recursion_label if we need one. */
233 rtx tail_recursion_reentry
;
235 /* Location at which to save the argument pointer if it will need to be
236 referenced. There are two cases where this is done: if nonlocal gotos
237 exist, or if vars stored at an offset from the argument pointer will be
238 needed by inner routines. */
240 rtx arg_pointer_save_area
;
242 /* Offset to end of allocated area of stack frame.
243 If stack grows down, this is the address of the last stack slot allocated.
244 If stack grows up, this is the address for the next slot. */
247 /* List (chain of TREE_LISTs) of static chains for containing functions.
248 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
249 in an RTL_EXPR in the TREE_VALUE. */
250 static tree context_display
;
252 /* List (chain of TREE_LISTs) of trampolines for nested functions.
253 The trampoline sets up the static chain and jumps to the function.
254 We supply the trampoline's address when the function's address is requested.
256 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
257 in an RTL_EXPR in the TREE_VALUE. */
258 static tree trampoline_list
;
260 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
261 static rtx parm_birth_insn
;
264 /* Nonzero if a stack slot has been generated whose address is not
265 actually valid. It means that the generated rtl must all be scanned
266 to detect and correct the invalid addresses where they occur. */
267 static int invalid_stack_slot
;
270 /* Last insn of those whose job was to put parms into their nominal homes. */
271 static rtx last_parm_insn
;
273 /* 1 + last pseudo register number used for loading a copy
274 of a parameter of this function. */
275 static int max_parm_reg
;
277 /* Vector indexed by REGNO, containing location on stack in which
278 to put the parm which is nominally in pseudo register REGNO,
279 if we discover that that parm must go in the stack. */
280 static rtx
*parm_reg_stack_loc
;
282 #if 0 /* Turned off because 0 seems to work just as well. */
283 /* Cleanup lists are required for binding levels regardless of whether
284 that binding level has cleanups or not. This node serves as the
285 cleanup list whenever an empty list is required. */
286 static tree empty_cleanup_list
;
289 /* Nonzero once virtual register instantiation has been done.
290 assign_stack_local uses frame_pointer_rtx when this is nonzero. */
291 static int virtuals_instantiated
;
293 /* Nonzero if we need to distinguish between the return value of this function
294 and the return value of a function called by this function. This helps
297 extern int rtx_equal_function_value_matters
;
301 static tree
round_down ();
302 static rtx
round_trampoline_addr ();
303 static rtx
fixup_stack_1 ();
304 static void fixup_var_refs ();
305 static void fixup_var_refs_insns ();
306 static void fixup_var_refs_1 ();
307 static void optimize_bit_field ();
308 static void instantiate_decls ();
309 static void instantiate_decls_1 ();
310 static void instantiate_decl ();
311 static int instantiate_virtual_regs_1 ();
312 static rtx
fixup_memory_subreg ();
313 static rtx
walk_fixup_memory_subreg ();
315 /* In order to evaluate some expressions, such as function calls returning
316 structures in memory, we need to temporarily allocate stack locations.
317 We record each allocated temporary in the following structure.
319 Associated with each temporary slot is a nesting level. When we pop up
320 one level, all temporaries associated with the previous level are freed.
321 Normally, all temporaries are freed after the execution of the statement
322 in which they were created. However, if we are inside a ({...}) grouping,
323 the result may be in a temporary and hence must be preserved. If the
324 result could be in a temporary, we preserve it if we can determine which
325 one it is in. If we cannot determine which temporary may contain the
326 result, all temporaries are preserved. A temporary is preserved by
327 pretending it was allocated at the previous nesting level.
329 Automatic variables are also assigned temporary slots, at the nesting
330 level where they are defined. They are marked a "kept" so that
331 free_temp_slots will not free them. */
335 /* Points to next temporary slot. */
336 struct temp_slot
*next
;
337 /* The rtx to used to reference the slot. */
339 /* The size, in units, of the slot. */
341 /* Non-zero if this temporary is currently in use. */
343 /* Nesting level at which this slot is being used. */
345 /* Non-zero if this should survive a call to free_temp_slots. */
349 /* List of all temporaries allocated, both available and in use. */
351 struct temp_slot
*temp_slots
;
353 /* Current nesting level for temporaries. */
357 /* Pointer to chain of `struct function' for containing functions. */
358 struct function
*outer_function_chain
;
360 /* Given a function decl for a containing function,
361 return the `struct function' for it. */
364 find_function_data (decl
)
368 for (p
= outer_function_chain
; p
; p
= p
->next
)
374 /* Save the current context for compilation of a nested function.
375 This is called from language-specific code.
376 The caller is responsible for saving any language-specific status,
377 since this function knows only about language-independent variables. */
380 push_function_context ()
382 struct function
*p
= (struct function
*) xmalloc (sizeof (struct function
));
384 p
->next
= outer_function_chain
;
385 outer_function_chain
= p
;
387 p
->name
= current_function_name
;
388 p
->decl
= current_function_decl
;
389 p
->pops_args
= current_function_pops_args
;
390 p
->returns_struct
= current_function_returns_struct
;
391 p
->returns_pcc_struct
= current_function_returns_pcc_struct
;
392 p
->needs_context
= current_function_needs_context
;
393 p
->calls_setjmp
= current_function_calls_setjmp
;
394 p
->calls_longjmp
= current_function_calls_longjmp
;
395 p
->calls_alloca
= current_function_calls_alloca
;
396 p
->has_nonlocal_label
= current_function_has_nonlocal_label
;
397 p
->args_size
= current_function_args_size
;
398 p
->pretend_args_size
= current_function_pretend_args_size
;
399 p
->arg_offset_rtx
= current_function_arg_offset_rtx
;
400 p
->uses_const_pool
= current_function_uses_const_pool
;
401 p
->uses_pic_offset_table
= current_function_uses_pic_offset_table
;
402 p
->internal_arg_pointer
= current_function_internal_arg_pointer
;
403 p
->max_parm_reg
= max_parm_reg
;
404 p
->parm_reg_stack_loc
= parm_reg_stack_loc
;
405 p
->outgoing_args_size
= current_function_outgoing_args_size
;
406 p
->return_rtx
= current_function_return_rtx
;
407 p
->nonlocal_goto_handler_slot
= nonlocal_goto_handler_slot
;
408 p
->nonlocal_goto_stack_level
= nonlocal_goto_stack_level
;
409 p
->nonlocal_labels
= nonlocal_labels
;
410 p
->cleanup_label
= cleanup_label
;
411 p
->return_label
= return_label
;
412 p
->save_expr_regs
= save_expr_regs
;
413 p
->stack_slot_list
= stack_slot_list
;
414 p
->parm_birth_insn
= parm_birth_insn
;
415 p
->frame_offset
= frame_offset
;
416 p
->tail_recursion_label
= tail_recursion_label
;
417 p
->tail_recursion_reentry
= tail_recursion_reentry
;
418 p
->arg_pointer_save_area
= arg_pointer_save_area
;
419 p
->rtl_expr_chain
= rtl_expr_chain
;
420 p
->last_parm_insn
= last_parm_insn
;
421 p
->context_display
= context_display
;
422 p
->trampoline_list
= trampoline_list
;
423 p
->function_call_count
= function_call_count
;
424 p
->temp_slots
= temp_slots
;
425 p
->temp_slot_level
= temp_slot_level
;
426 p
->fixup_var_refs_queue
= 0;
427 p
->epilogue_delay_list
= current_function_epilogue_delay_list
;
429 save_tree_status (p
);
430 save_storage_status (p
);
431 save_emit_status (p
);
433 save_expr_status (p
);
434 save_stmt_status (p
);
435 save_varasm_status (p
);
438 /* Restore the last saved context, at the end of a nested function.
439 This function is called from language-specific code. */
442 pop_function_context ()
444 struct function
*p
= outer_function_chain
;
446 outer_function_chain
= p
->next
;
448 current_function_name
= p
->name
;
449 current_function_decl
= p
->decl
;
450 current_function_pops_args
= p
->pops_args
;
451 current_function_returns_struct
= p
->returns_struct
;
452 current_function_returns_pcc_struct
= p
->returns_pcc_struct
;
453 current_function_needs_context
= p
->needs_context
;
454 current_function_calls_setjmp
= p
->calls_setjmp
;
455 current_function_calls_longjmp
= p
->calls_longjmp
;
456 current_function_calls_alloca
= p
->calls_alloca
;
457 current_function_has_nonlocal_label
= p
->has_nonlocal_label
;
458 current_function_contains_functions
= 1;
459 current_function_args_size
= p
->args_size
;
460 current_function_pretend_args_size
= p
->pretend_args_size
;
461 current_function_arg_offset_rtx
= p
->arg_offset_rtx
;
462 current_function_uses_const_pool
= p
->uses_const_pool
;
463 current_function_uses_pic_offset_table
= p
->uses_pic_offset_table
;
464 current_function_internal_arg_pointer
= p
->internal_arg_pointer
;
465 max_parm_reg
= p
->max_parm_reg
;
466 parm_reg_stack_loc
= p
->parm_reg_stack_loc
;
467 current_function_outgoing_args_size
= p
->outgoing_args_size
;
468 current_function_return_rtx
= p
->return_rtx
;
469 nonlocal_goto_handler_slot
= p
->nonlocal_goto_handler_slot
;
470 nonlocal_goto_stack_level
= p
->nonlocal_goto_stack_level
;
471 nonlocal_labels
= p
->nonlocal_labels
;
472 cleanup_label
= p
->cleanup_label
;
473 return_label
= p
->return_label
;
474 save_expr_regs
= p
->save_expr_regs
;
475 stack_slot_list
= p
->stack_slot_list
;
476 parm_birth_insn
= p
->parm_birth_insn
;
477 frame_offset
= p
->frame_offset
;
478 tail_recursion_label
= p
->tail_recursion_label
;
479 tail_recursion_reentry
= p
->tail_recursion_reentry
;
480 arg_pointer_save_area
= p
->arg_pointer_save_area
;
481 rtl_expr_chain
= p
->rtl_expr_chain
;
482 last_parm_insn
= p
->last_parm_insn
;
483 context_display
= p
->context_display
;
484 trampoline_list
= p
->trampoline_list
;
485 function_call_count
= p
->function_call_count
;
486 temp_slots
= p
->temp_slots
;
487 temp_slot_level
= p
->temp_slot_level
;
488 current_function_epilogue_delay_list
= p
->epilogue_delay_list
;
490 restore_tree_status (p
);
491 restore_storage_status (p
);
492 restore_expr_status (p
);
493 restore_emit_status (p
);
494 restore_stmt_status (p
);
495 restore_varasm_status (p
);
497 /* Finish doing put_var_into_stack for any of our variables
498 which became addressable during the nested function. */
500 struct var_refs_queue
*queue
= p
->fixup_var_refs_queue
;
501 for (; queue
; queue
= queue
->next
)
502 fixup_var_refs (queue
->modified
, queue
->promoted_mode
, queue
->unsignedp
);
507 /* Reset variables that have known state during rtx generation. */
508 rtx_equal_function_value_matters
= 1;
509 virtuals_instantiated
= 0;
512 /* Allocate fixed slots in the stack frame of the current function. */
514 /* Return size needed for stack frame based on slots so far allocated.
515 This size counts from zero. It is not rounded to STACK_BOUNDARY;
516 the caller may have to do that. */
521 #ifdef FRAME_GROWS_DOWNWARD
522 return -frame_offset
;
528 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
529 with machine mode MODE.
531 ALIGN controls the amount of alignment for the address of the slot:
532 0 means according to MODE,
533 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
534 positive specifies alignment boundary in bits.
536 We do not round to stack_boundary here. */
539 assign_stack_local (mode
, size
, align
)
540 enum machine_mode mode
;
544 register rtx x
, addr
;
545 int bigend_correction
= 0;
550 alignment
= GET_MODE_ALIGNMENT (mode
) / BITS_PER_UNIT
;
552 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
554 else if (align
== -1)
556 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
557 size
= CEIL_ROUND (size
, alignment
);
560 alignment
= align
/ BITS_PER_UNIT
;
562 /* Round frame offset to that alignment.
563 We must be careful here, since FRAME_OFFSET might be negative and
564 division with a negative dividend isn't as well defined as we might
565 like. So we instead assume that ALIGNMENT is a power of two and
566 use logical operations which are unambiguous. */
567 #ifdef FRAME_GROWS_DOWNWARD
568 frame_offset
= FLOOR_ROUND (frame_offset
, alignment
);
570 frame_offset
= CEIL_ROUND (frame_offset
, alignment
);
573 /* On a big-endian machine, if we are allocating more space than we will use,
574 use the least significant bytes of those that are allocated. */
577 bigend_correction
= size
- GET_MODE_SIZE (mode
);
580 #ifdef FRAME_GROWS_DOWNWARD
581 frame_offset
-= size
;
584 /* If we have already instantiated virtual registers, return the actual
585 address relative to the frame pointer. */
586 if (virtuals_instantiated
)
587 addr
= plus_constant (frame_pointer_rtx
,
588 (frame_offset
+ bigend_correction
589 + STARTING_FRAME_OFFSET
));
591 addr
= plus_constant (virtual_stack_vars_rtx
,
592 frame_offset
+ bigend_correction
);
594 #ifndef FRAME_GROWS_DOWNWARD
595 frame_offset
+= size
;
598 x
= gen_rtx (MEM
, mode
, addr
);
600 stack_slot_list
= gen_rtx (EXPR_LIST
, VOIDmode
, x
, stack_slot_list
);
605 /* Assign a stack slot in a containing function.
606 First three arguments are same as in preceding function.
607 The last argument specifies the function to allocate in. */
610 assign_outer_stack_local (mode
, size
, align
, function
)
611 enum machine_mode mode
;
614 struct function
*function
;
616 register rtx x
, addr
;
617 int bigend_correction
= 0;
620 /* Allocate in the memory associated with the function in whose frame
622 push_obstacks (function
->function_obstack
,
623 function
->function_maybepermanent_obstack
);
627 alignment
= GET_MODE_ALIGNMENT (mode
) / BITS_PER_UNIT
;
629 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
631 else if (align
== -1)
633 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
634 size
= CEIL_ROUND (size
, alignment
);
637 alignment
= align
/ BITS_PER_UNIT
;
639 /* Round frame offset to that alignment. */
640 #ifdef FRAME_GROWS_DOWNWARD
641 frame_offset
= FLOOR_ROUND (frame_offset
, alignment
);
643 frame_offset
= CEIL_ROUND (frame_offset
, alignment
);
646 /* On a big-endian machine, if we are allocating more space than we will use,
647 use the least significant bytes of those that are allocated. */
650 bigend_correction
= size
- GET_MODE_SIZE (mode
);
653 #ifdef FRAME_GROWS_DOWNWARD
654 function
->frame_offset
-= size
;
656 addr
= plus_constant (virtual_stack_vars_rtx
,
657 function
->frame_offset
+ bigend_correction
);
658 #ifndef FRAME_GROWS_DOWNWARD
659 function
->frame_offset
+= size
;
662 x
= gen_rtx (MEM
, mode
, addr
);
664 function
->stack_slot_list
665 = gen_rtx (EXPR_LIST
, VOIDmode
, x
, function
->stack_slot_list
);
672 /* Allocate a temporary stack slot and record it for possible later
675 MODE is the machine mode to be given to the returned rtx.
677 SIZE is the size in units of the space required. We do no rounding here
678 since assign_stack_local will do any required rounding.
680 KEEP is non-zero if this slot is to be retained after a call to
681 free_temp_slots. Automatic variables for a block are allocated with this
685 assign_stack_temp (mode
, size
, keep
)
686 enum machine_mode mode
;
690 struct temp_slot
*p
, *best_p
= 0;
692 /* First try to find an available, already-allocated temporary that is the
693 exact size we require. */
694 for (p
= temp_slots
; p
; p
= p
->next
)
695 if (p
->size
== size
&& GET_MODE (p
->slot
) == mode
&& ! p
->in_use
)
698 /* If we didn't find, one, try one that is larger than what we want. We
699 find the smallest such. */
701 for (p
= temp_slots
; p
; p
= p
->next
)
702 if (p
->size
> size
&& GET_MODE (p
->slot
) == mode
&& ! p
->in_use
703 && (best_p
== 0 || best_p
->size
> p
->size
))
706 /* Make our best, if any, the one to use. */
710 /* If we still didn't find one, make a new temporary. */
713 p
= (struct temp_slot
*) oballoc (sizeof (struct temp_slot
));
715 /* If the temp slot mode doesn't indicate the alignment,
716 use the largest possible, so no one will be disappointed. */
717 p
->slot
= assign_stack_local (mode
, size
, mode
== BLKmode
? -1 : 0);
718 p
->next
= temp_slots
;
723 p
->level
= temp_slot_level
;
728 /* If X could be a reference to a temporary slot, mark that slot as belonging
729 to the to one level higher. If X matched one of our slots, just mark that
730 one. Otherwise, we can't easily predict which it is, so upgrade all of
731 them. Kept slots need not be touched.
733 This is called when an ({...}) construct occurs and a statement
734 returns a value in memory. */
737 preserve_temp_slots (x
)
742 /* If X is not in memory or is at a constant address, it cannot be in
744 if (x
== 0 || GET_CODE (x
) != MEM
|| CONSTANT_P (XEXP (x
, 0)))
747 /* First see if we can find a match. */
748 for (p
= temp_slots
; p
; p
= p
->next
)
749 if (p
->in_use
&& x
== p
->slot
)
755 /* Otherwise, preserve all non-kept slots at this level. */
756 for (p
= temp_slots
; p
; p
= p
->next
)
757 if (p
->in_use
&& p
->level
== temp_slot_level
&& ! p
->keep
)
761 /* Free all temporaries used so far. This is normally called at the end
762 of generating code for a statement. */
769 for (p
= temp_slots
; p
; p
= p
->next
)
770 if (p
->in_use
&& p
->level
== temp_slot_level
&& ! p
->keep
)
774 /* Push deeper into the nesting level for stack temporaries. */
779 /* For GNU C++, we must allow a sequence to be emitted anywhere in
780 the level where the sequence was started. By not changing levels
781 when the compiler is inside a sequence, the temporaries for the
782 sequence and the temporaries will not unwittingly conflict with
783 the temporaries for other sequences and/or code at that level. */
784 if (in_sequence_p ())
790 /* Pop a temporary nesting level. All slots in use in the current level
798 /* See comment in push_temp_slots about why we don't change levels
800 if (in_sequence_p ())
803 for (p
= temp_slots
; p
; p
= p
->next
)
804 if (p
->in_use
&& p
->level
== temp_slot_level
)
810 /* Retroactively move an auto variable from a register to a stack slot.
811 This is done when an address-reference to the variable is seen. */
814 put_var_into_stack (decl
)
818 register rtx
new = 0;
819 enum machine_mode promoted_mode
, decl_mode
;
820 struct function
*function
= 0;
821 tree context
= decl_function_context (decl
);
823 /* Get the current rtl used for this object and it's original mode. */
824 reg
= TREE_CODE (decl
) == SAVE_EXPR
? SAVE_EXPR_RTL (decl
) : DECL_RTL (decl
);
826 /* No need to do anything if decl has no rtx yet
827 since in that case caller is setting TREE_ADDRESSABLE
828 and a stack slot will be assigned when the rtl is made. */
832 /* Get the declared mode for this object. */
833 decl_mode
= (TREE_CODE (decl
) == SAVE_EXPR
? TYPE_MODE (TREE_TYPE (decl
))
835 /* Get the mode it's actually stored in. */
836 promoted_mode
= GET_MODE (reg
);
838 /* If this variable comes from an outer function,
839 find that function's saved context. */
840 if (context
!= current_function_decl
)
841 for (function
= outer_function_chain
; function
; function
= function
->next
)
842 if (function
->decl
== context
)
845 /* If this is a variable-size object with a pseudo to address it,
846 put that pseudo into the stack, if the var is nonlocal. */
847 if (DECL_NONLOCAL (decl
)
848 && GET_CODE (reg
) == MEM
849 && GET_CODE (XEXP (reg
, 0)) == REG
850 && REGNO (XEXP (reg
, 0)) > LAST_VIRTUAL_REGISTER
)
852 if (GET_CODE (reg
) != REG
)
857 if (REGNO (reg
) < function
->max_parm_reg
)
858 new = function
->parm_reg_stack_loc
[REGNO (reg
)];
860 new = assign_outer_stack_local (GET_MODE (reg
),
861 GET_MODE_SIZE (decl_mode
),
866 if (REGNO (reg
) < max_parm_reg
)
867 new = parm_reg_stack_loc
[REGNO (reg
)];
869 new = assign_stack_local (GET_MODE (reg
),
870 GET_MODE_SIZE (decl_mode
), 0);
873 XEXP (reg
, 0) = XEXP (new, 0);
874 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
875 REG_USERVAR_P (reg
) = 0;
877 PUT_MODE (reg
, decl_mode
);
879 /* If this is a memory ref that contains aggregate components,
880 mark it as such for cse and loop optimize. */
881 MEM_IN_STRUCT_P (reg
)
882 = (TREE_CODE (TREE_TYPE (decl
)) == ARRAY_TYPE
883 || TREE_CODE (TREE_TYPE (decl
)) == RECORD_TYPE
884 || TREE_CODE (TREE_TYPE (decl
)) == UNION_TYPE
);
886 /* Now make sure that all refs to the variable, previously made
887 when it was a register, are fixed up to be valid again. */
890 struct var_refs_queue
*temp
;
892 /* Variable is inherited; fix it up when we get back to its function. */
893 push_obstacks (function
->function_obstack
,
894 function
->function_maybepermanent_obstack
);
896 = (struct var_refs_queue
*) oballoc (sizeof (struct var_refs_queue
));
897 temp
->modified
= reg
;
898 temp
->promoted_mode
= promoted_mode
;
899 temp
->unsignedp
= TREE_UNSIGNED (TREE_TYPE (decl
));
900 temp
->next
= function
->fixup_var_refs_queue
;
901 function
->fixup_var_refs_queue
= temp
;
905 /* Variable is local; fix it up now. */
906 fixup_var_refs (reg
, promoted_mode
, TREE_UNSIGNED (TREE_TYPE (decl
)));
910 fixup_var_refs (var
, promoted_mode
, unsignedp
)
912 enum machine_mode promoted_mode
;
916 rtx first_insn
= get_insns ();
917 struct sequence_stack
*stack
= sequence_stack
;
918 tree rtl_exps
= rtl_expr_chain
;
920 /* Must scan all insns for stack-refs that exceed the limit. */
921 fixup_var_refs_insns (var
, promoted_mode
, unsignedp
, first_insn
, stack
== 0);
923 /* Scan all pending sequences too. */
924 for (; stack
; stack
= stack
->next
)
926 push_to_sequence (stack
->first
);
927 fixup_var_refs_insns (var
, promoted_mode
, unsignedp
,
928 stack
->first
, stack
->next
!= 0);
929 /* Update remembered end of sequence
930 in case we added an insn at the end. */
931 stack
->last
= get_last_insn ();
935 /* Scan all waiting RTL_EXPRs too. */
936 for (pending
= rtl_exps
; pending
; pending
= TREE_CHAIN (pending
))
938 rtx seq
= RTL_EXPR_SEQUENCE (TREE_VALUE (pending
));
939 if (seq
!= const0_rtx
&& seq
!= 0)
941 push_to_sequence (seq
);
942 fixup_var_refs_insns (var
, promoted_mode
, unsignedp
, seq
, 0);
948 /* This structure is used by the following two functions to record MEMs or
949 pseudos used to replace VAR, any SUBREGs of VAR, and any MEMs containing
950 VAR as an address. We need to maintain this list in case two operands of
951 an insn were required to match; in that case we must ensure we use the
954 struct fixup_replacement
958 struct fixup_replacement
*next
;
961 /* REPLACEMENTS is a pointer to a list of the above structures and X is
962 some part of an insn. Return a struct fixup_replacement whose OLD
963 value is equal to X. Allocate a new structure if no such entry exists. */
965 static struct fixup_replacement
*
966 find_replacement (replacements
, x
)
967 struct fixup_replacement
**replacements
;
970 struct fixup_replacement
*p
;
972 /* See if we have already replaced this. */
973 for (p
= *replacements
; p
&& p
->old
!= x
; p
= p
->next
)
978 p
= (struct fixup_replacement
*) oballoc (sizeof (struct fixup_replacement
));
981 p
->next
= *replacements
;
988 /* Scan the insn-chain starting with INSN for refs to VAR
989 and fix them up. TOPLEVEL is nonzero if this chain is the
990 main chain of insns for the current function. */
993 fixup_var_refs_insns (var
, promoted_mode
, unsignedp
, insn
, toplevel
)
995 enum machine_mode promoted_mode
;
1002 rtx next
= NEXT_INSN (insn
);
1004 if (GET_CODE (insn
) == INSN
|| GET_CODE (insn
) == CALL_INSN
1005 || GET_CODE (insn
) == JUMP_INSN
)
1007 /* The insn to load VAR from a home in the arglist
1008 is now a no-op. When we see it, just delete it. */
1010 && GET_CODE (PATTERN (insn
)) == SET
1011 && SET_DEST (PATTERN (insn
)) == var
1012 && rtx_equal_p (SET_SRC (PATTERN (insn
)), var
))
1014 next
= delete_insn (insn
);
1015 if (insn
== last_parm_insn
)
1016 last_parm_insn
= PREV_INSN (next
);
1020 /* See if we have to do anything to INSN now that VAR is in
1021 memory. If it needs to be loaded into a pseudo, use a single
1022 pseudo for the entire insn in case there is a MATCH_DUP
1023 between two operands. We pass a pointer to the head of
1024 a list of struct fixup_replacements. If fixup_var_refs_1
1025 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1026 it will record them in this list.
1028 If it allocated a pseudo for any replacement, we copy into
1031 struct fixup_replacement
*replacements
= 0;
1033 fixup_var_refs_1 (var
, promoted_mode
, &PATTERN (insn
), insn
,
1036 while (replacements
)
1038 if (GET_CODE (replacements
->new) == REG
)
1043 /* OLD might be a (subreg (mem)). */
1044 if (GET_CODE (replacements
->old
) == SUBREG
)
1046 = fixup_memory_subreg (replacements
->old
, insn
, 0);
1049 = fixup_stack_1 (replacements
->old
, insn
);
1051 /* We can not separate USE insns from the CALL_INSN
1052 that they belong to. If this is a CALL_INSN, insert
1053 the move insn before the USE insns preceding it
1054 instead of immediately before the insn. */
1055 if (GET_CODE (insn
) == CALL_INSN
)
1057 insert_before
= insn
;
1058 while (GET_CODE (PREV_INSN (insert_before
)) == INSN
1059 && GET_CODE (PATTERN (PREV_INSN (insert_before
))) == USE
)
1060 insert_before
= PREV_INSN (insert_before
);
1063 insert_before
= insn
;
1065 /* If we are changing the mode, do a conversion.
1066 This might be wasteful, but combine.c will
1067 eliminate much of the waste. */
1069 if (GET_MODE (replacements
->new)
1070 != GET_MODE (replacements
->old
))
1073 convert_move (replacements
->new,
1074 replacements
->old
, unsignedp
);
1075 seq
= gen_sequence ();
1079 seq
= gen_move_insn (replacements
->new,
1082 emit_insn_before (seq
, insert_before
);
1085 replacements
= replacements
->next
;
1089 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1090 But don't touch other insns referred to by reg-notes;
1091 we will get them elsewhere. */
1092 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
1093 if (GET_CODE (note
) != INSN_LIST
)
1094 XEXP (note
, 0) = walk_fixup_memory_subreg (XEXP (note
, 0), insn
);
1100 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1101 See if the rtx expression at *LOC in INSN needs to be changed.
1103 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1104 contain a list of original rtx's and replacements. If we find that we need
1105 to modify this insn by replacing a memory reference with a pseudo or by
1106 making a new MEM to implement a SUBREG, we consult that list to see if
1107 we have already chosen a replacement. If none has already been allocated,
1108 we allocate it and update the list. fixup_var_refs_insns will copy VAR
1109 or the SUBREG, as appropriate, to the pseudo. */
1112 fixup_var_refs_1 (var
, promoted_mode
, loc
, insn
, replacements
)
1114 enum machine_mode promoted_mode
;
1117 struct fixup_replacement
**replacements
;
1120 register rtx x
= *loc
;
1121 RTX_CODE code
= GET_CODE (x
);
1123 register rtx tem
, tem1
;
1124 struct fixup_replacement
*replacement
;
1131 /* If we already have a replacement, use it. Otherwise,
1132 try to fix up this address in case it is invalid. */
1134 replacement
= find_replacement (replacements
, var
);
1135 if (replacement
->new)
1137 *loc
= replacement
->new;
1141 *loc
= replacement
->new = x
= fixup_stack_1 (x
, insn
);
1143 /* Unless we are forcing memory to register or we changed the mode,
1144 we can leave things the way they are if the insn is valid. */
1146 INSN_CODE (insn
) = -1;
1147 if (! flag_force_mem
&& GET_MODE (x
) == promoted_mode
1148 && recog_memoized (insn
) >= 0)
1151 *loc
= replacement
->new = gen_reg_rtx (promoted_mode
);
1155 /* If X contains VAR, we need to unshare it here so that we update
1156 each occurrence separately. But all identical MEMs in one insn
1157 must be replaced with the same rtx because of the possibility of
1160 if (reg_mentioned_p (var
, x
))
1162 replacement
= find_replacement (replacements
, x
);
1163 if (replacement
->new == 0)
1164 replacement
->new = copy_most_rtx (x
, var
);
1166 *loc
= x
= replacement
->new;
1182 /* Note that in some cases those types of expressions are altered
1183 by optimize_bit_field, and do not survive to get here. */
1184 if (XEXP (x
, 0) == var
1185 || (GET_CODE (XEXP (x
, 0)) == SUBREG
1186 && SUBREG_REG (XEXP (x
, 0)) == var
))
1188 /* Get TEM as a valid MEM in the mode presently in the insn.
1190 We don't worry about the possibility of MATCH_DUP here; it
1191 is highly unlikely and would be tricky to handle. */
1194 if (GET_CODE (tem
) == SUBREG
)
1195 tem
= fixup_memory_subreg (tem
, insn
, 1);
1196 tem
= fixup_stack_1 (tem
, insn
);
1198 /* Unless we want to load from memory, get TEM into the proper mode
1199 for an extract from memory. This can only be done if the
1200 extract is at a constant position and length. */
1202 if (! flag_force_mem
&& GET_CODE (XEXP (x
, 1)) == CONST_INT
1203 && GET_CODE (XEXP (x
, 2)) == CONST_INT
1204 && ! mode_dependent_address_p (XEXP (tem
, 0))
1205 && ! MEM_VOLATILE_P (tem
))
1207 enum machine_mode wanted_mode
= VOIDmode
;
1208 enum machine_mode is_mode
= GET_MODE (tem
);
1209 int width
= INTVAL (XEXP (x
, 1));
1210 int pos
= INTVAL (XEXP (x
, 2));
1213 if (GET_CODE (x
) == ZERO_EXTRACT
)
1214 wanted_mode
= insn_operand_mode
[(int) CODE_FOR_extzv
][1];
1217 if (GET_CODE (x
) == SIGN_EXTRACT
)
1218 wanted_mode
= insn_operand_mode
[(int) CODE_FOR_extv
][1];
1220 /* If we have a narrower mode, we can do something. */
1221 if (wanted_mode
!= VOIDmode
1222 && GET_MODE_SIZE (wanted_mode
) < GET_MODE_SIZE (is_mode
))
1224 int offset
= pos
/ BITS_PER_UNIT
;
1225 rtx old_pos
= XEXP (x
, 2);
1228 /* If the bytes and bits are counted differently, we
1229 must adjust the offset. */
1230 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1231 offset
= (GET_MODE_SIZE (is_mode
)
1232 - GET_MODE_SIZE (wanted_mode
) - offset
);
1235 pos
%= GET_MODE_BITSIZE (wanted_mode
);
1237 newmem
= gen_rtx (MEM
, wanted_mode
,
1238 plus_constant (XEXP (tem
, 0), offset
));
1239 RTX_UNCHANGING_P (newmem
) = RTX_UNCHANGING_P (tem
);
1240 MEM_VOLATILE_P (newmem
) = MEM_VOLATILE_P (tem
);
1241 MEM_IN_STRUCT_P (newmem
) = MEM_IN_STRUCT_P (tem
);
1243 /* Make the change and see if the insn remains valid. */
1244 INSN_CODE (insn
) = -1;
1245 XEXP (x
, 0) = newmem
;
1246 XEXP (x
, 2) = GEN_INT (pos
);
1248 if (recog_memoized (insn
) >= 0)
1251 /* Otherwise, restore old position. XEXP (x, 0) will be
1253 XEXP (x
, 2) = old_pos
;
1257 /* If we get here, the bitfield extract insn can't accept a memory
1258 reference. Copy the input into a register. */
1260 tem1
= gen_reg_rtx (GET_MODE (tem
));
1261 emit_insn_before (gen_move_insn (tem1
, tem
), insn
);
1268 if (SUBREG_REG (x
) == var
)
1270 /* If this is a special SUBREG made because VAR was promoted
1271 from a wider mode, replace it with VAR and call ourself
1272 recursively, this time saying that the object previously
1273 had its current mode (by virtue of the SUBREG). */
1275 if (SUBREG_PROMOTED_VAR_P (x
))
1278 fixup_var_refs_1 (var
, GET_MODE (var
), loc
, insn
, replacements
);
1282 /* If this SUBREG makes VAR wider, it has become a paradoxical
1283 SUBREG with VAR in memory, but these aren't allowed at this
1284 stage of the compilation. So load VAR into a pseudo and take
1285 a SUBREG of that pseudo. */
1286 if (GET_MODE_SIZE (GET_MODE (x
)) > GET_MODE_SIZE (GET_MODE (var
)))
1288 replacement
= find_replacement (replacements
, var
);
1289 if (replacement
->new == 0)
1290 replacement
->new = gen_reg_rtx (GET_MODE (var
));
1291 SUBREG_REG (x
) = replacement
->new;
1295 /* See if we have already found a replacement for this SUBREG.
1296 If so, use it. Otherwise, make a MEM and see if the insn
1297 is recognized. If not, or if we should force MEM into a register,
1298 make a pseudo for this SUBREG. */
1299 replacement
= find_replacement (replacements
, x
);
1300 if (replacement
->new)
1302 *loc
= replacement
->new;
1306 replacement
->new = *loc
= fixup_memory_subreg (x
, insn
, 0);
1308 if (! flag_force_mem
&& recog_memoized (insn
) >= 0)
1311 *loc
= replacement
->new = gen_reg_rtx (GET_MODE (x
));
1317 /* First do special simplification of bit-field references. */
1318 if (GET_CODE (SET_DEST (x
)) == SIGN_EXTRACT
1319 || GET_CODE (SET_DEST (x
)) == ZERO_EXTRACT
)
1320 optimize_bit_field (x
, insn
, 0);
1321 if (GET_CODE (SET_SRC (x
)) == SIGN_EXTRACT
1322 || GET_CODE (SET_SRC (x
)) == ZERO_EXTRACT
)
1323 optimize_bit_field (x
, insn
, NULL_PTR
);
1325 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
1326 insn into a pseudo and store the low part of the pseudo into VAR. */
1327 if (GET_CODE (SET_DEST (x
)) == SUBREG
1328 && SUBREG_REG (SET_DEST (x
)) == var
1329 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x
)))
1330 > GET_MODE_SIZE (GET_MODE (var
))))
1332 SET_DEST (x
) = tem
= gen_reg_rtx (GET_MODE (SET_DEST (x
)));
1333 emit_insn_after (gen_move_insn (var
, gen_lowpart (GET_MODE (var
),
1340 rtx dest
= SET_DEST (x
);
1341 rtx src
= SET_SRC (x
);
1342 rtx outerdest
= dest
;
1344 while (GET_CODE (dest
) == SUBREG
|| GET_CODE (dest
) == STRICT_LOW_PART
1345 || GET_CODE (dest
) == SIGN_EXTRACT
1346 || GET_CODE (dest
) == ZERO_EXTRACT
)
1347 dest
= XEXP (dest
, 0);
1349 if (GET_CODE (src
) == SUBREG
)
1350 src
= XEXP (src
, 0);
1352 /* If VAR does not appear at the top level of the SET
1353 just scan the lower levels of the tree. */
1355 if (src
!= var
&& dest
!= var
)
1358 /* We will need to rerecognize this insn. */
1359 INSN_CODE (insn
) = -1;
1362 if (GET_CODE (outerdest
) == ZERO_EXTRACT
&& dest
== var
)
1364 /* Since this case will return, ensure we fixup all the
1366 fixup_var_refs_1 (var
, promoted_mode
, &XEXP (outerdest
, 1),
1367 insn
, replacements
);
1368 fixup_var_refs_1 (var
, promoted_mode
, &XEXP (outerdest
, 2),
1369 insn
, replacements
);
1370 fixup_var_refs_1 (var
, promoted_mode
, &SET_SRC (x
),
1371 insn
, replacements
);
1373 tem
= XEXP (outerdest
, 0);
1375 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
1376 that may appear inside a ZERO_EXTRACT.
1377 This was legitimate when the MEM was a REG. */
1378 if (GET_CODE (tem
) == SUBREG
1379 && SUBREG_REG (tem
) == var
)
1380 tem
= fixup_memory_subreg (tem
, insn
, 1);
1382 tem
= fixup_stack_1 (tem
, insn
);
1384 if (GET_CODE (XEXP (outerdest
, 1)) == CONST_INT
1385 && GET_CODE (XEXP (outerdest
, 2)) == CONST_INT
1386 && ! mode_dependent_address_p (XEXP (tem
, 0))
1387 && ! MEM_VOLATILE_P (tem
))
1389 enum machine_mode wanted_mode
1390 = insn_operand_mode
[(int) CODE_FOR_insv
][0];
1391 enum machine_mode is_mode
= GET_MODE (tem
);
1392 int width
= INTVAL (XEXP (outerdest
, 1));
1393 int pos
= INTVAL (XEXP (outerdest
, 2));
1395 /* If we have a narrower mode, we can do something. */
1396 if (GET_MODE_SIZE (wanted_mode
) < GET_MODE_SIZE (is_mode
))
1398 int offset
= pos
/ BITS_PER_UNIT
;
1399 rtx old_pos
= XEXP (outerdest
, 2);
1402 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1403 offset
= (GET_MODE_SIZE (is_mode
)
1404 - GET_MODE_SIZE (wanted_mode
) - offset
);
1407 pos
%= GET_MODE_BITSIZE (wanted_mode
);
1409 newmem
= gen_rtx (MEM
, wanted_mode
,
1410 plus_constant (XEXP (tem
, 0), offset
));
1411 RTX_UNCHANGING_P (newmem
) = RTX_UNCHANGING_P (tem
);
1412 MEM_VOLATILE_P (newmem
) = MEM_VOLATILE_P (tem
);
1413 MEM_IN_STRUCT_P (newmem
) = MEM_IN_STRUCT_P (tem
);
1415 /* Make the change and see if the insn remains valid. */
1416 INSN_CODE (insn
) = -1;
1417 XEXP (outerdest
, 0) = newmem
;
1418 XEXP (outerdest
, 2) = GEN_INT (pos
);
1420 if (recog_memoized (insn
) >= 0)
1423 /* Otherwise, restore old position. XEXP (x, 0) will be
1425 XEXP (outerdest
, 2) = old_pos
;
1429 /* If we get here, the bit-field store doesn't allow memory
1430 or isn't located at a constant position. Load the value into
1431 a register, do the store, and put it back into memory. */
1433 tem1
= gen_reg_rtx (GET_MODE (tem
));
1434 emit_insn_before (gen_move_insn (tem1
, tem
), insn
);
1435 emit_insn_after (gen_move_insn (tem
, tem1
), insn
);
1436 XEXP (outerdest
, 0) = tem1
;
1441 /* STRICT_LOW_PART is a no-op on memory references
1442 and it can cause combinations to be unrecognizable,
1445 if (dest
== var
&& GET_CODE (SET_DEST (x
)) == STRICT_LOW_PART
)
1446 SET_DEST (x
) = XEXP (SET_DEST (x
), 0);
1448 /* A valid insn to copy VAR into or out of a register
1449 must be left alone, to avoid an infinite loop here.
1450 If the reference to VAR is by a subreg, fix that up,
1451 since SUBREG is not valid for a memref.
1452 Also fix up the address of the stack slot. */
1454 if ((SET_SRC (x
) == var
1455 || (GET_CODE (SET_SRC (x
)) == SUBREG
1456 && SUBREG_REG (SET_SRC (x
)) == var
))
1457 && (GET_CODE (SET_DEST (x
)) == REG
1458 || (GET_CODE (SET_DEST (x
)) == SUBREG
1459 && GET_CODE (SUBREG_REG (SET_DEST (x
))) == REG
))
1460 && recog_memoized (insn
) >= 0)
1462 replacement
= find_replacement (replacements
, SET_SRC (x
));
1463 if (replacement
->new)
1465 SET_SRC (x
) = replacement
->new;
1468 else if (GET_CODE (SET_SRC (x
)) == SUBREG
)
1469 SET_SRC (x
) = replacement
->new
1470 = fixup_memory_subreg (SET_SRC (x
), insn
, 0);
1472 SET_SRC (x
) = replacement
->new
1473 = fixup_stack_1 (SET_SRC (x
), insn
);
1477 if ((SET_DEST (x
) == var
1478 || (GET_CODE (SET_DEST (x
)) == SUBREG
1479 && SUBREG_REG (SET_DEST (x
)) == var
))
1480 && (GET_CODE (SET_SRC (x
)) == REG
1481 || (GET_CODE (SET_SRC (x
)) == SUBREG
1482 && GET_CODE (SUBREG_REG (SET_SRC (x
))) == REG
))
1483 && recog_memoized (insn
) >= 0)
1485 if (GET_CODE (SET_DEST (x
)) == SUBREG
)
1486 SET_DEST (x
) = fixup_memory_subreg (SET_DEST (x
), insn
, 0);
1488 SET_DEST (x
) = fixup_stack_1 (SET_DEST (x
), insn
);
1492 /* Otherwise, storing into VAR must be handled specially
1493 by storing into a temporary and copying that into VAR
1494 with a new insn after this one. Note that this case
1495 will be used when storing into a promoted scalar since
1496 the insn will now have different modes on the input
1497 and output and hence will be invalid (except for the case
1498 of setting it to a constant, which does not need any
1499 change if it is valid). We generate extra code in that case,
1500 but combine.c will eliminate it. */
1505 rtx fixeddest
= SET_DEST (x
);
1507 /* STRICT_LOW_PART can be discarded, around a MEM. */
1508 if (GET_CODE (fixeddest
) == STRICT_LOW_PART
)
1509 fixeddest
= XEXP (fixeddest
, 0);
1510 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
1511 if (GET_CODE (fixeddest
) == SUBREG
)
1512 fixeddest
= fixup_memory_subreg (fixeddest
, insn
, 0);
1514 fixeddest
= fixup_stack_1 (fixeddest
, insn
);
1516 temp
= gen_reg_rtx (GET_MODE (SET_SRC (x
)) == VOIDmode
1517 ? GET_MODE (fixeddest
)
1518 : GET_MODE (SET_SRC (x
)));
1520 emit_insn_after (gen_move_insn (fixeddest
,
1521 gen_lowpart (GET_MODE (fixeddest
),
1525 SET_DEST (x
) = temp
;
1530 /* Nothing special about this RTX; fix its operands. */
1532 fmt
= GET_RTX_FORMAT (code
);
1533 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1536 fixup_var_refs_1 (var
, promoted_mode
, &XEXP (x
, i
), insn
, replacements
);
1540 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1541 fixup_var_refs_1 (var
, promoted_mode
, &XVECEXP (x
, i
, j
),
1542 insn
, replacements
);
1547 /* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
1548 return an rtx (MEM:m1 newaddr) which is equivalent.
1549 If any insns must be emitted to compute NEWADDR, put them before INSN.
1551 UNCRITICAL nonzero means accept paradoxical subregs.
1552 This is used for subregs found inside of ZERO_EXTRACTs. */
1555 fixup_memory_subreg (x
, insn
, uncritical
)
1560 int offset
= SUBREG_WORD (x
) * UNITS_PER_WORD
;
1561 rtx addr
= XEXP (SUBREG_REG (x
), 0);
1562 enum machine_mode mode
= GET_MODE (x
);
1565 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
1566 if (GET_MODE_SIZE (mode
) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x
)))
1570 #if BYTES_BIG_ENDIAN
1571 offset
+= (MIN (UNITS_PER_WORD
, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x
))))
1572 - MIN (UNITS_PER_WORD
, GET_MODE_SIZE (mode
)));
1574 addr
= plus_constant (addr
, offset
);
1575 if (!flag_force_addr
&& memory_address_p (mode
, addr
))
1576 /* Shortcut if no insns need be emitted. */
1577 return change_address (SUBREG_REG (x
), mode
, addr
);
1579 result
= change_address (SUBREG_REG (x
), mode
, addr
);
1580 emit_insn_before (gen_sequence (), insn
);
1585 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
1586 Replace subexpressions of X in place.
1587 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
1588 Otherwise return X, with its contents possibly altered.
1590 If any insns must be emitted to compute NEWADDR, put them before INSN. */
1593 walk_fixup_memory_subreg (x
, insn
)
1597 register enum rtx_code code
;
1604 code
= GET_CODE (x
);
1606 if (code
== SUBREG
&& GET_CODE (SUBREG_REG (x
)) == MEM
)
1607 return fixup_memory_subreg (x
, insn
, 0);
1609 /* Nothing special about this RTX; fix its operands. */
1611 fmt
= GET_RTX_FORMAT (code
);
1612 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1615 XEXP (x
, i
) = walk_fixup_memory_subreg (XEXP (x
, i
), insn
);
1619 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1621 = walk_fixup_memory_subreg (XVECEXP (x
, i
, j
), insn
);
1628 /* Fix up any references to stack slots that are invalid memory addresses
1629 because they exceed the maximum range of a displacement. */
1632 fixup_stack_slots ()
1636 /* Did we generate a stack slot that is out of range
1637 or otherwise has an invalid address? */
1638 if (invalid_stack_slot
)
1640 /* Yes. Must scan all insns for stack-refs that exceed the limit. */
1641 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
1642 if (GET_CODE (insn
) == INSN
|| GET_CODE (insn
) == CALL_INSN
1643 || GET_CODE (insn
) == JUMP_INSN
)
1644 fixup_stack_1 (PATTERN (insn
), insn
);
1649 /* For each memory ref within X, if it refers to a stack slot
1650 with an out of range displacement, put the address in a temp register
1651 (emitting new insns before INSN to load these registers)
1652 and alter the memory ref to use that register.
1653 Replace each such MEM rtx with a copy, to avoid clobberage. */
1656 fixup_stack_1 (x
, insn
)
1661 register RTX_CODE code
= GET_CODE (x
);
1666 register rtx ad
= XEXP (x
, 0);
1667 /* If we have address of a stack slot but it's not valid
1668 (displacement is too large), compute the sum in a register. */
1669 if (GET_CODE (ad
) == PLUS
1670 && GET_CODE (XEXP (ad
, 0)) == REG
1671 && REGNO (XEXP (ad
, 0)) >= FIRST_VIRTUAL_REGISTER
1672 && REGNO (XEXP (ad
, 0)) <= LAST_VIRTUAL_REGISTER
1673 && GET_CODE (XEXP (ad
, 1)) == CONST_INT
)
1676 if (memory_address_p (GET_MODE (x
), ad
))
1680 temp
= copy_to_reg (ad
);
1681 seq
= gen_sequence ();
1683 emit_insn_before (seq
, insn
);
1684 return change_address (x
, VOIDmode
, temp
);
1689 fmt
= GET_RTX_FORMAT (code
);
1690 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1693 XEXP (x
, i
) = fixup_stack_1 (XEXP (x
, i
), insn
);
1697 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1698 XVECEXP (x
, i
, j
) = fixup_stack_1 (XVECEXP (x
, i
, j
), insn
);
1704 /* Optimization: a bit-field instruction whose field
1705 happens to be a byte or halfword in memory
1706 can be changed to a move instruction.
1708 We call here when INSN is an insn to examine or store into a bit-field.
1709 BODY is the SET-rtx to be altered.
1711 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
1712 (Currently this is called only from function.c, and EQUIV_MEM
1716 optimize_bit_field (body
, insn
, equiv_mem
)
1721 register rtx bitfield
;
1724 enum machine_mode mode
;
1726 if (GET_CODE (SET_DEST (body
)) == SIGN_EXTRACT
1727 || GET_CODE (SET_DEST (body
)) == ZERO_EXTRACT
)
1728 bitfield
= SET_DEST (body
), destflag
= 1;
1730 bitfield
= SET_SRC (body
), destflag
= 0;
1732 /* First check that the field being stored has constant size and position
1733 and is in fact a byte or halfword suitably aligned. */
1735 if (GET_CODE (XEXP (bitfield
, 1)) == CONST_INT
1736 && GET_CODE (XEXP (bitfield
, 2)) == CONST_INT
1737 && ((mode
= mode_for_size (INTVAL (XEXP (bitfield
, 1)), MODE_INT
, 1))
1739 && INTVAL (XEXP (bitfield
, 2)) % INTVAL (XEXP (bitfield
, 1)) == 0)
1741 register rtx memref
= 0;
1743 /* Now check that the containing word is memory, not a register,
1744 and that it is safe to change the machine mode. */
1746 if (GET_CODE (XEXP (bitfield
, 0)) == MEM
)
1747 memref
= XEXP (bitfield
, 0);
1748 else if (GET_CODE (XEXP (bitfield
, 0)) == REG
1750 memref
= equiv_mem
[REGNO (XEXP (bitfield
, 0))];
1751 else if (GET_CODE (XEXP (bitfield
, 0)) == SUBREG
1752 && GET_CODE (SUBREG_REG (XEXP (bitfield
, 0))) == MEM
)
1753 memref
= SUBREG_REG (XEXP (bitfield
, 0));
1754 else if (GET_CODE (XEXP (bitfield
, 0)) == SUBREG
1756 && GET_CODE (SUBREG_REG (XEXP (bitfield
, 0))) == REG
)
1757 memref
= equiv_mem
[REGNO (SUBREG_REG (XEXP (bitfield
, 0)))];
1760 && ! mode_dependent_address_p (XEXP (memref
, 0))
1761 && ! MEM_VOLATILE_P (memref
))
1763 /* Now adjust the address, first for any subreg'ing
1764 that we are now getting rid of,
1765 and then for which byte of the word is wanted. */
1767 register int offset
= INTVAL (XEXP (bitfield
, 2));
1768 /* Adjust OFFSET to count bits from low-address byte. */
1769 #if BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN
1770 offset
= (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield
, 0)))
1771 - offset
- INTVAL (XEXP (bitfield
, 1)));
1773 /* Adjust OFFSET to count bytes from low-address byte. */
1774 offset
/= BITS_PER_UNIT
;
1775 if (GET_CODE (XEXP (bitfield
, 0)) == SUBREG
)
1777 offset
+= SUBREG_WORD (XEXP (bitfield
, 0)) * UNITS_PER_WORD
;
1778 #if BYTES_BIG_ENDIAN
1779 offset
-= (MIN (UNITS_PER_WORD
,
1780 GET_MODE_SIZE (GET_MODE (XEXP (bitfield
, 0))))
1781 - MIN (UNITS_PER_WORD
,
1782 GET_MODE_SIZE (GET_MODE (memref
))));
1786 memref
= change_address (memref
, mode
,
1787 plus_constant (XEXP (memref
, 0), offset
));
1789 /* Store this memory reference where
1790 we found the bit field reference. */
1794 validate_change (insn
, &SET_DEST (body
), memref
, 1);
1795 if (! CONSTANT_ADDRESS_P (SET_SRC (body
)))
1797 rtx src
= SET_SRC (body
);
1798 while (GET_CODE (src
) == SUBREG
1799 && SUBREG_WORD (src
) == 0)
1800 src
= SUBREG_REG (src
);
1801 if (GET_MODE (src
) != GET_MODE (memref
))
1802 src
= gen_lowpart (GET_MODE (memref
), SET_SRC (body
));
1803 validate_change (insn
, &SET_SRC (body
), src
, 1);
1805 else if (GET_MODE (SET_SRC (body
)) != VOIDmode
1806 && GET_MODE (SET_SRC (body
)) != GET_MODE (memref
))
1807 /* This shouldn't happen because anything that didn't have
1808 one of these modes should have got converted explicitly
1809 and then referenced through a subreg.
1810 This is so because the original bit-field was
1811 handled by agg_mode and so its tree structure had
1812 the same mode that memref now has. */
1817 rtx dest
= SET_DEST (body
);
1819 while (GET_CODE (dest
) == SUBREG
1820 && SUBREG_WORD (dest
) == 0)
1821 dest
= SUBREG_REG (dest
);
1823 validate_change (insn
, &SET_DEST (body
), dest
, 1);
1825 if (GET_MODE (dest
) == GET_MODE (memref
))
1826 validate_change (insn
, &SET_SRC (body
), memref
, 1);
1829 /* Convert the mem ref to the destination mode. */
1830 rtx newreg
= gen_reg_rtx (GET_MODE (dest
));
1833 convert_move (newreg
, memref
,
1834 GET_CODE (SET_SRC (body
)) == ZERO_EXTRACT
);
1838 validate_change (insn
, &SET_SRC (body
), newreg
, 1);
1842 /* See if we can convert this extraction or insertion into
1843 a simple move insn. We might not be able to do so if this
1844 was, for example, part of a PARALLEL.
1846 If we succeed, write out any needed conversions. If we fail,
1847 it is hard to guess why we failed, so don't do anything
1848 special; just let the optimization be suppressed. */
1850 if (apply_change_group () && seq
)
1851 emit_insns_before (seq
, insn
);
1856 /* These routines are responsible for converting virtual register references
1857 to the actual hard register references once RTL generation is complete.
1859 The following four variables are used for communication between the
1860 routines. They contain the offsets of the virtual registers from their
1861 respective hard registers. */
1863 static int in_arg_offset
;
1864 static int var_offset
;
1865 static int dynamic_offset
;
1866 static int out_arg_offset
;
1868 /* In most machines, the stack pointer register is equivalent to the bottom
1871 #ifndef STACK_POINTER_OFFSET
1872 #define STACK_POINTER_OFFSET 0
1875 /* If not defined, pick an appropriate default for the offset of dynamically
1876 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1877 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1879 #ifndef STACK_DYNAMIC_OFFSET
1881 #ifdef ACCUMULATE_OUTGOING_ARGS
1882 /* The bottom of the stack points to the actual arguments. If
1883 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1884 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1885 stack space for register parameters is not pushed by the caller, but
1886 rather part of the fixed stack areas and hence not included in
1887 `current_function_outgoing_args_size'. Nevertheless, we must allow
1888 for it when allocating stack dynamic objects. */
1890 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1891 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1892 (current_function_outgoing_args_size \
1893 + REG_PARM_STACK_SPACE (FNDECL) + (STACK_POINTER_OFFSET))
1896 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1897 (current_function_outgoing_args_size + (STACK_POINTER_OFFSET))
1901 #define STACK_DYNAMIC_OFFSET(FNDECL) STACK_POINTER_OFFSET
1905 /* Pass through the INSNS of function FNDECL and convert virtual register
1906 references to hard register references. */
1909 instantiate_virtual_regs (fndecl
, insns
)
1915 /* Compute the offsets to use for this function. */
1916 in_arg_offset
= FIRST_PARM_OFFSET (fndecl
);
1917 var_offset
= STARTING_FRAME_OFFSET
;
1918 dynamic_offset
= STACK_DYNAMIC_OFFSET (fndecl
);
1919 out_arg_offset
= STACK_POINTER_OFFSET
;
1921 /* Scan all variables and parameters of this function. For each that is
1922 in memory, instantiate all virtual registers if the result is a valid
1923 address. If not, we do it later. That will handle most uses of virtual
1924 regs on many machines. */
1925 instantiate_decls (fndecl
, 1);
1927 /* Initialize recognition, indicating that volatile is OK. */
1930 /* Scan through all the insns, instantiating every virtual register still
1932 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
1933 if (GET_CODE (insn
) == INSN
|| GET_CODE (insn
) == JUMP_INSN
1934 || GET_CODE (insn
) == CALL_INSN
)
1936 instantiate_virtual_regs_1 (&PATTERN (insn
), insn
, 1);
1937 instantiate_virtual_regs_1 (®_NOTES (insn
), NULL_RTX
, 0);
1940 /* Now instantiate the remaining register equivalences for debugging info.
1941 These will not be valid addresses. */
1942 instantiate_decls (fndecl
, 0);
1944 /* Indicate that, from now on, assign_stack_local should use
1945 frame_pointer_rtx. */
1946 virtuals_instantiated
= 1;
1949 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1950 all virtual registers in their DECL_RTL's.
1952 If VALID_ONLY, do this only if the resulting address is still valid.
1953 Otherwise, always do it. */
1956 instantiate_decls (fndecl
, valid_only
)
1962 if (DECL_INLINE (fndecl
))
1963 /* When compiling an inline function, the obstack used for
1964 rtl allocation is the maybepermanent_obstack. Calling
1965 `resume_temporary_allocation' switches us back to that
1966 obstack while we process this function's parameters. */
1967 resume_temporary_allocation ();
1969 /* Process all parameters of the function. */
1970 for (decl
= DECL_ARGUMENTS (fndecl
); decl
; decl
= TREE_CHAIN (decl
))
1972 instantiate_decl (DECL_RTL (decl
), int_size_in_bytes (TREE_TYPE (decl
)),
1974 instantiate_decl (DECL_INCOMING_RTL (decl
),
1975 int_size_in_bytes (TREE_TYPE (decl
)), valid_only
);
1978 /* Now process all variables defined in the function or its subblocks. */
1979 instantiate_decls_1 (DECL_INITIAL (fndecl
), valid_only
);
1981 if (DECL_INLINE (fndecl
))
1983 /* Save all rtl allocated for this function by raising the
1984 high-water mark on the maybepermanent_obstack. */
1986 /* All further rtl allocation is now done in the current_obstack. */
1987 rtl_in_current_obstack ();
1991 /* Subroutine of instantiate_decls: Process all decls in the given
1992 BLOCK node and all its subblocks. */
1995 instantiate_decls_1 (let
, valid_only
)
2001 for (t
= BLOCK_VARS (let
); t
; t
= TREE_CHAIN (t
))
2002 instantiate_decl (DECL_RTL (t
), int_size_in_bytes (TREE_TYPE (t
)),
2005 /* Process all subblocks. */
2006 for (t
= BLOCK_SUBBLOCKS (let
); t
; t
= TREE_CHAIN (t
))
2007 instantiate_decls_1 (t
, valid_only
);
2010 /* Subroutine of the preceeding procedures: Given RTL representing a
2011 decl and the size of the object, do any instantiation required.
2013 If VALID_ONLY is non-zero, it means that the RTL should only be
2014 changed if the new address is valid. */
2017 instantiate_decl (x
, size
, valid_only
)
2022 enum machine_mode mode
;
2025 /* If this is not a MEM, no need to do anything. Similarly if the
2026 address is a constant or a register that is not a virtual register. */
2028 if (x
== 0 || GET_CODE (x
) != MEM
)
2032 if (CONSTANT_P (addr
)
2033 || (GET_CODE (addr
) == REG
2034 && (REGNO (addr
) < FIRST_VIRTUAL_REGISTER
2035 || REGNO (addr
) > LAST_VIRTUAL_REGISTER
)))
2038 /* If we should only do this if the address is valid, copy the address.
2039 We need to do this so we can undo any changes that might make the
2040 address invalid. This copy is unfortunate, but probably can't be
2044 addr
= copy_rtx (addr
);
2046 instantiate_virtual_regs_1 (&addr
, NULL_RTX
, 0);
2051 /* Now verify that the resulting address is valid for every integer or
2052 floating-point mode up to and including SIZE bytes long. We do this
2053 since the object might be accessed in any mode and frame addresses
2056 for (mode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
2057 mode
!= VOIDmode
&& GET_MODE_SIZE (mode
) <= size
;
2058 mode
= GET_MODE_WIDER_MODE (mode
))
2059 if (! memory_address_p (mode
, addr
))
2062 for (mode
= GET_CLASS_NARROWEST_MODE (MODE_FLOAT
);
2063 mode
!= VOIDmode
&& GET_MODE_SIZE (mode
) <= size
;
2064 mode
= GET_MODE_WIDER_MODE (mode
))
2065 if (! memory_address_p (mode
, addr
))
2068 /* Otherwise, put back the address, now that we have updated it and we
2069 know it is valid. */
2074 /* Given a pointer to a piece of rtx and an optional pointer to the
2075 containing object, instantiate any virtual registers present in it.
2077 If EXTRA_INSNS, we always do the replacement and generate
2078 any extra insns before OBJECT. If it zero, we do nothing if replacement
2081 Return 1 if we either had nothing to do or if we were able to do the
2082 needed replacement. Return 0 otherwise; we only return zero if
2083 EXTRA_INSNS is zero.
2085 We first try some simple transformations to avoid the creation of extra
2089 instantiate_virtual_regs_1 (loc
, object
, extra_insns
)
2103 /* Re-start here to avoid recursion in common cases. */
2110 code
= GET_CODE (x
);
2112 /* Check for some special cases. */
2129 /* We are allowed to set the virtual registers. This means that
2130 that the actual register should receive the source minus the
2131 appropriate offset. This is used, for example, in the handling
2132 of non-local gotos. */
2133 if (SET_DEST (x
) == virtual_incoming_args_rtx
)
2134 new = arg_pointer_rtx
, offset
= - in_arg_offset
;
2135 else if (SET_DEST (x
) == virtual_stack_vars_rtx
)
2136 new = frame_pointer_rtx
, offset
= - var_offset
;
2137 else if (SET_DEST (x
) == virtual_stack_dynamic_rtx
)
2138 new = stack_pointer_rtx
, offset
= - dynamic_offset
;
2139 else if (SET_DEST (x
) == virtual_outgoing_args_rtx
)
2140 new = stack_pointer_rtx
, offset
= - out_arg_offset
;
2144 /* The only valid sources here are PLUS or REG. Just do
2145 the simplest possible thing to handle them. */
2146 if (GET_CODE (SET_SRC (x
)) != REG
2147 && GET_CODE (SET_SRC (x
)) != PLUS
)
2151 if (GET_CODE (SET_SRC (x
)) != REG
)
2152 temp
= force_operand (SET_SRC (x
), NULL_RTX
);
2155 temp
= force_operand (plus_constant (temp
, offset
), NULL_RTX
);
2159 emit_insns_before (seq
, object
);
2162 if (!validate_change (object
, &SET_SRC (x
), temp
, 0)
2169 instantiate_virtual_regs_1 (&SET_DEST (x
), object
, extra_insns
);
2174 /* Handle special case of virtual register plus constant. */
2175 if (CONSTANT_P (XEXP (x
, 1)))
2179 /* Check for (plus (plus VIRT foo) (const_int)) first. */
2180 if (GET_CODE (XEXP (x
, 0)) == PLUS
)
2182 rtx inner
= XEXP (XEXP (x
, 0), 0);
2184 if (inner
== virtual_incoming_args_rtx
)
2185 new = arg_pointer_rtx
, offset
= in_arg_offset
;
2186 else if (inner
== virtual_stack_vars_rtx
)
2187 new = frame_pointer_rtx
, offset
= var_offset
;
2188 else if (inner
== virtual_stack_dynamic_rtx
)
2189 new = stack_pointer_rtx
, offset
= dynamic_offset
;
2190 else if (inner
== virtual_outgoing_args_rtx
)
2191 new = stack_pointer_rtx
, offset
= out_arg_offset
;
2198 instantiate_virtual_regs_1 (&XEXP (XEXP (x
, 0), 1), object
,
2200 new = gen_rtx (PLUS
, Pmode
, new, XEXP (XEXP (x
, 0), 1));
2203 else if (XEXP (x
, 0) == virtual_incoming_args_rtx
)
2204 new = arg_pointer_rtx
, offset
= in_arg_offset
;
2205 else if (XEXP (x
, 0) == virtual_stack_vars_rtx
)
2206 new = frame_pointer_rtx
, offset
= var_offset
;
2207 else if (XEXP (x
, 0) == virtual_stack_dynamic_rtx
)
2208 new = stack_pointer_rtx
, offset
= dynamic_offset
;
2209 else if (XEXP (x
, 0) == virtual_outgoing_args_rtx
)
2210 new = stack_pointer_rtx
, offset
= out_arg_offset
;
2213 /* We know the second operand is a constant. Unless the
2214 first operand is a REG (which has been already checked),
2215 it needs to be checked. */
2216 if (GET_CODE (XEXP (x
, 0)) != REG
)
2226 new = plus_constant (XEXP (x
, 1), offset
);
2228 /* If the new constant is zero, try to replace the sum with its
2230 if (new == const0_rtx
2231 && validate_change (object
, loc
, XEXP (x
, 0), 0))
2234 /* Next try to replace constant with new one. */
2235 if (!validate_change (object
, &XEXP (x
, 1), new, 0))
2243 /* Otherwise copy the new constant into a register and replace
2244 constant with that register. */
2245 temp
= gen_reg_rtx (Pmode
);
2246 if (validate_change (object
, &XEXP (x
, 1), temp
, 0))
2247 emit_insn_before (gen_move_insn (temp
, new), object
);
2250 /* If that didn't work, replace this expression with a
2251 register containing the sum. */
2253 new = gen_rtx (PLUS
, Pmode
, XEXP (x
, 0), new);
2257 temp
= force_operand (new, NULL_RTX
);
2261 emit_insns_before (seq
, object
);
2262 if (! validate_change (object
, loc
, temp
, 0)
2263 && ! validate_replace_rtx (x
, temp
, object
))
2271 /* Fall through to generic two-operand expression case. */
2277 case DIV
: case UDIV
:
2278 case MOD
: case UMOD
:
2279 case AND
: case IOR
: case XOR
:
2280 case LSHIFT
: case ASHIFT
: case ROTATE
:
2281 case ASHIFTRT
: case LSHIFTRT
: case ROTATERT
:
2283 case GE
: case GT
: case GEU
: case GTU
:
2284 case LE
: case LT
: case LEU
: case LTU
:
2285 if (XEXP (x
, 1) && ! CONSTANT_P (XEXP (x
, 1)))
2286 instantiate_virtual_regs_1 (&XEXP (x
, 1), object
, extra_insns
);
2291 /* Most cases of MEM that convert to valid addresses have already been
2292 handled by our scan of regno_reg_rtx. The only special handling we
2293 need here is to make a copy of the rtx to ensure it isn't being
2294 shared if we have to change it to a pseudo.
2296 If the rtx is a simple reference to an address via a virtual register,
2297 it can potentially be shared. In such cases, first try to make it
2298 a valid address, which can also be shared. Otherwise, copy it and
2301 First check for common cases that need no processing. These are
2302 usually due to instantiation already being done on a previous instance
2306 if (CONSTANT_ADDRESS_P (temp
)
2307 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2308 || temp
== arg_pointer_rtx
2310 || temp
== frame_pointer_rtx
)
2313 if (GET_CODE (temp
) == PLUS
2314 && CONSTANT_ADDRESS_P (XEXP (temp
, 1))
2315 && (XEXP (temp
, 0) == frame_pointer_rtx
2316 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2317 || XEXP (temp
, 0) == arg_pointer_rtx
2322 if (temp
== virtual_stack_vars_rtx
2323 || temp
== virtual_incoming_args_rtx
2324 || (GET_CODE (temp
) == PLUS
2325 && CONSTANT_ADDRESS_P (XEXP (temp
, 1))
2326 && (XEXP (temp
, 0) == virtual_stack_vars_rtx
2327 || XEXP (temp
, 0) == virtual_incoming_args_rtx
)))
2329 /* This MEM may be shared. If the substitution can be done without
2330 the need to generate new pseudos, we want to do it in place
2331 so all copies of the shared rtx benefit. The call below will
2332 only make substitutions if the resulting address is still
2335 Note that we cannot pass X as the object in the recursive call
2336 since the insn being processed may not allow all valid
2337 addresses. However, if we were not passed on object, we can
2338 only modify X without copying it if X will have a valid
2341 ??? Also note that this can still lose if OBJECT is an insn that
2342 has less restrictions on an address that some other insn.
2343 In that case, we will modify the shared address. This case
2344 doesn't seem very likely, though. */
2346 if (instantiate_virtual_regs_1 (&XEXP (x
, 0),
2347 object
? object
: x
, 0))
2350 /* Otherwise make a copy and process that copy. We copy the entire
2351 RTL expression since it might be a PLUS which could also be
2353 *loc
= x
= copy_rtx (x
);
2356 /* Fall through to generic unary operation case. */
2360 case STRICT_LOW_PART
:
2362 case PRE_DEC
: case PRE_INC
: case POST_DEC
: case POST_INC
:
2363 case SIGN_EXTEND
: case ZERO_EXTEND
:
2364 case TRUNCATE
: case FLOAT_EXTEND
: case FLOAT_TRUNCATE
:
2365 case FLOAT
: case FIX
:
2366 case UNSIGNED_FIX
: case UNSIGNED_FLOAT
:
2370 /* These case either have just one operand or we know that we need not
2371 check the rest of the operands. */
2376 /* Try to replace with a PLUS. If that doesn't work, compute the sum
2377 in front of this insn and substitute the temporary. */
2378 if (x
== virtual_incoming_args_rtx
)
2379 new = arg_pointer_rtx
, offset
= in_arg_offset
;
2380 else if (x
== virtual_stack_vars_rtx
)
2381 new = frame_pointer_rtx
, offset
= var_offset
;
2382 else if (x
== virtual_stack_dynamic_rtx
)
2383 new = stack_pointer_rtx
, offset
= dynamic_offset
;
2384 else if (x
== virtual_outgoing_args_rtx
)
2385 new = stack_pointer_rtx
, offset
= out_arg_offset
;
2389 temp
= plus_constant (new, offset
);
2390 if (!validate_change (object
, loc
, temp
, 0))
2396 temp
= force_operand (temp
, NULL_RTX
);
2400 emit_insns_before (seq
, object
);
2401 if (! validate_change (object
, loc
, temp
, 0)
2402 && ! validate_replace_rtx (x
, temp
, object
))
2410 /* Scan all subexpressions. */
2411 fmt
= GET_RTX_FORMAT (code
);
2412 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++, fmt
++)
2415 if (!instantiate_virtual_regs_1 (&XEXP (x
, i
), object
, extra_insns
))
2418 else if (*fmt
== 'E')
2419 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
2420 if (! instantiate_virtual_regs_1 (&XVECEXP (x
, i
, j
), object
,
2427 /* Optimization: assuming this function does not receive nonlocal gotos,
2428 delete the handlers for such, as well as the insns to establish
2429 and disestablish them. */
2435 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
2437 /* Delete the handler by turning off the flag that would
2438 prevent jump_optimize from deleting it.
2439 Also permit deletion of the nonlocal labels themselves
2440 if nothing local refers to them. */
2441 if (GET_CODE (insn
) == CODE_LABEL
)
2442 LABEL_PRESERVE_P (insn
) = 0;
2443 if (GET_CODE (insn
) == INSN
2444 && ((nonlocal_goto_handler_slot
!= 0
2445 && reg_mentioned_p (nonlocal_goto_handler_slot
, PATTERN (insn
)))
2446 || (nonlocal_goto_stack_level
!= 0
2447 && reg_mentioned_p (nonlocal_goto_stack_level
,
2453 /* Return a list (chain of EXPR_LIST nodes) for the nonlocal labels
2454 of the current function. */
2457 nonlocal_label_rtx_list ()
2462 for (t
= nonlocal_labels
; t
; t
= TREE_CHAIN (t
))
2463 x
= gen_rtx (EXPR_LIST
, VOIDmode
, label_rtx (TREE_VALUE (t
)), x
);
2468 /* Output a USE for any register use in RTL.
2469 This is used with -noreg to mark the extent of lifespan
2470 of any registers used in a user-visible variable's DECL_RTL. */
2476 if (GET_CODE (rtl
) == REG
)
2477 /* This is a register variable. */
2478 emit_insn (gen_rtx (USE
, VOIDmode
, rtl
));
2479 else if (GET_CODE (rtl
) == MEM
2480 && GET_CODE (XEXP (rtl
, 0)) == REG
2481 && (REGNO (XEXP (rtl
, 0)) < FIRST_VIRTUAL_REGISTER
2482 || REGNO (XEXP (rtl
, 0)) > LAST_VIRTUAL_REGISTER
)
2483 && XEXP (rtl
, 0) != current_function_internal_arg_pointer
)
2484 /* This is a variable-sized structure. */
2485 emit_insn (gen_rtx (USE
, VOIDmode
, XEXP (rtl
, 0)));
2488 /* Like use_variable except that it outputs the USEs after INSN
2489 instead of at the end of the insn-chain. */
2492 use_variable_after (rtl
, insn
)
2495 if (GET_CODE (rtl
) == REG
)
2496 /* This is a register variable. */
2497 emit_insn_after (gen_rtx (USE
, VOIDmode
, rtl
), insn
);
2498 else if (GET_CODE (rtl
) == MEM
2499 && GET_CODE (XEXP (rtl
, 0)) == REG
2500 && (REGNO (XEXP (rtl
, 0)) < FIRST_VIRTUAL_REGISTER
2501 || REGNO (XEXP (rtl
, 0)) > LAST_VIRTUAL_REGISTER
)
2502 && XEXP (rtl
, 0) != current_function_internal_arg_pointer
)
2503 /* This is a variable-sized structure. */
2504 emit_insn_after (gen_rtx (USE
, VOIDmode
, XEXP (rtl
, 0)), insn
);
2510 return max_parm_reg
;
2513 /* Return the first insn following those generated by `assign_parms'. */
2516 get_first_nonparm_insn ()
2519 return NEXT_INSN (last_parm_insn
);
2520 return get_insns ();
2523 /* Return the first NOTE_INSN_BLOCK_BEG note in the function.
2524 Crash if there is none. */
2527 get_first_block_beg ()
2529 register rtx searcher
;
2530 register rtx insn
= get_first_nonparm_insn ();
2532 for (searcher
= insn
; searcher
; searcher
= NEXT_INSN (searcher
))
2533 if (GET_CODE (searcher
) == NOTE
2534 && NOTE_LINE_NUMBER (searcher
) == NOTE_INSN_BLOCK_BEG
)
2537 abort (); /* Invalid call to this function. (See comments above.) */
2541 /* Return 1 if EXP returns an aggregate value, for which an address
2542 must be passed to the function or returned by the function. */
2545 aggregate_value_p (exp
)
2548 int i
, regno
, nregs
;
2550 if (TYPE_MODE (TREE_TYPE (exp
)) == BLKmode
)
2552 if (RETURN_IN_MEMORY (TREE_TYPE (exp
)))
2554 if (flag_pcc_struct_return
2555 && (TREE_CODE (TREE_TYPE (exp
)) == RECORD_TYPE
2556 || TREE_CODE (TREE_TYPE (exp
)) == UNION_TYPE
))
2558 /* Make sure we have suitable call-clobbered regs to return
2559 the value in; if not, we must return it in memory. */
2560 reg
= hard_function_value (TREE_TYPE (exp
), 0);
2561 regno
= REGNO (reg
);
2562 nregs
= HARD_REGNO_NREGS (regno
, TYPE_MODE (TREE_TYPE (exp
)));
2563 for (i
= 0; i
< nregs
; i
++)
2564 if (! call_used_regs
[regno
+ i
])
2569 /* Assign RTL expressions to the function's parameters.
2570 This may involve copying them into registers and using
2571 those registers as the RTL for them.
2573 If SECOND_TIME is non-zero it means that this function is being
2574 called a second time. This is done by integrate.c when a function's
2575 compilation is deferred. We need to come back here in case the
2576 FUNCTION_ARG macro computes items needed for the rest of the compilation
2577 (such as changing which registers are fixed or caller-saved). But suppress
2578 writing any insns or setting DECL_RTL of anything in this case. */
2581 assign_parms (fndecl
, second_time
)
2586 register rtx entry_parm
= 0;
2587 register rtx stack_parm
= 0;
2588 CUMULATIVE_ARGS args_so_far
;
2589 enum machine_mode promoted_mode
, passed_mode
, nominal_mode
;
2591 /* Total space needed so far for args on the stack,
2592 given as a constant and a tree-expression. */
2593 struct args_size stack_args_size
;
2594 tree fntype
= TREE_TYPE (fndecl
);
2595 tree fnargs
= DECL_ARGUMENTS (fndecl
);
2596 /* This is used for the arg pointer when referring to stack args. */
2597 rtx internal_arg_pointer
;
2598 /* This is a dummy PARM_DECL that we used for the function result if
2599 the function returns a structure. */
2600 tree function_result_decl
= 0;
2601 int nparmregs
= list_length (fnargs
) + LAST_VIRTUAL_REGISTER
+ 1;
2602 int varargs_setup
= 0;
2604 /* Nonzero if the last arg is named `__builtin_va_alist',
2605 which is used on some machines for old-fashioned non-ANSI varargs.h;
2606 this should be stuck onto the stack as if it had arrived there. */
2609 && (parm
= tree_last (fnargs
)) != 0
2611 && (! strcmp (IDENTIFIER_POINTER (DECL_NAME (parm
)),
2612 "__builtin_va_alist")));
2614 /* Nonzero if function takes extra anonymous args.
2615 This means the last named arg must be on the stack
2616 right before the anonymous ones. */
2618 = (TYPE_ARG_TYPES (fntype
) != 0
2619 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype
)))
2620 != void_type_node
));
2622 /* If the reg that the virtual arg pointer will be translated into is
2623 not a fixed reg or is the stack pointer, make a copy of the virtual
2624 arg pointer, and address parms via the copy. The frame pointer is
2625 considered fixed even though it is not marked as such.
2627 The second time through, simply use ap to avoid generating rtx. */
2629 if ((ARG_POINTER_REGNUM
== STACK_POINTER_REGNUM
2630 || ! (fixed_regs
[ARG_POINTER_REGNUM
]
2631 || ARG_POINTER_REGNUM
== FRAME_POINTER_REGNUM
))
2633 internal_arg_pointer
= copy_to_reg (virtual_incoming_args_rtx
);
2635 internal_arg_pointer
= virtual_incoming_args_rtx
;
2636 current_function_internal_arg_pointer
= internal_arg_pointer
;
2638 stack_args_size
.constant
= 0;
2639 stack_args_size
.var
= 0;
2641 /* If struct value address is treated as the first argument, make it so. */
2642 if (aggregate_value_p (DECL_RESULT (fndecl
))
2643 && ! current_function_returns_pcc_struct
2644 && struct_value_incoming_rtx
== 0)
2646 tree type
= build_pointer_type (fntype
);
2648 function_result_decl
= build_decl (PARM_DECL
, NULL_TREE
, type
);
2650 DECL_ARG_TYPE (function_result_decl
) = type
;
2651 TREE_CHAIN (function_result_decl
) = fnargs
;
2652 fnargs
= function_result_decl
;
2655 parm_reg_stack_loc
= (rtx
*) oballoc (nparmregs
* sizeof (rtx
));
2656 bzero (parm_reg_stack_loc
, nparmregs
* sizeof (rtx
));
2658 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2659 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far
, fntype
, NULL_PTR
);
2661 INIT_CUMULATIVE_ARGS (args_so_far
, fntype
, NULL_PTR
);
2664 /* We haven't yet found an argument that we must push and pretend the
2666 current_function_pretend_args_size
= 0;
2668 for (parm
= fnargs
; parm
; parm
= TREE_CHAIN (parm
))
2671 = (TREE_CODE (TREE_TYPE (parm
)) == ARRAY_TYPE
2672 || TREE_CODE (TREE_TYPE (parm
)) == RECORD_TYPE
2673 || TREE_CODE (TREE_TYPE (parm
)) == UNION_TYPE
);
2674 struct args_size stack_offset
;
2675 struct args_size arg_size
;
2676 int passed_pointer
= 0;
2677 tree passed_type
= DECL_ARG_TYPE (parm
);
2679 /* Set LAST_NAMED if this is last named arg before some
2680 anonymous args. We treat it as if it were anonymous too. */
2681 int last_named
= ((TREE_CHAIN (parm
) == 0
2682 || DECL_NAME (TREE_CHAIN (parm
)) == 0)
2683 && (vararg
|| stdarg
));
2685 if (TREE_TYPE (parm
) == error_mark_node
2686 /* This can happen after weird syntax errors
2687 or if an enum type is defined among the parms. */
2688 || TREE_CODE (parm
) != PARM_DECL
2689 || passed_type
== NULL
)
2691 DECL_INCOMING_RTL (parm
) = DECL_RTL (parm
) = gen_rtx (MEM
, BLKmode
,
2693 TREE_USED (parm
) = 1;
2697 /* For varargs.h function, save info about regs and stack space
2698 used by the individual args, not including the va_alist arg. */
2699 if (vararg
&& last_named
)
2700 current_function_args_info
= args_so_far
;
2702 /* Find mode of arg as it is passed, and mode of arg
2703 as it should be during execution of this function. */
2704 passed_mode
= TYPE_MODE (passed_type
);
2705 nominal_mode
= TYPE_MODE (TREE_TYPE (parm
));
2707 /* If the parm's mode is VOID, its value doesn't matter,
2708 and avoid the usual things like emit_move_insn that could crash. */
2709 if (nominal_mode
== VOIDmode
)
2711 DECL_INCOMING_RTL (parm
) = DECL_RTL (parm
) = const0_rtx
;
2715 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
2716 /* See if this arg was passed by invisible reference. */
2717 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far
, passed_mode
,
2718 passed_type
, ! last_named
))
2720 passed_type
= build_pointer_type (passed_type
);
2722 passed_mode
= nominal_mode
= Pmode
;
2726 promoted_mode
= passed_mode
;
2728 #ifdef PROMOTE_FUNCTION_ARGS
2729 /* Compute the mode in which the arg is actually extended to. */
2730 if (TREE_CODE (passed_type
) == INTEGER_TYPE
2731 || TREE_CODE (passed_type
) == ENUMERAL_TYPE
2732 || TREE_CODE (passed_type
) == BOOLEAN_TYPE
2733 || TREE_CODE (passed_type
) == CHAR_TYPE
2734 || TREE_CODE (passed_type
) == REAL_TYPE
2735 || TREE_CODE (passed_type
) == POINTER_TYPE
2736 || TREE_CODE (passed_type
) == OFFSET_TYPE
)
2738 unsignedp
= TREE_UNSIGNED (passed_type
);
2739 PROMOTE_MODE (promoted_mode
, unsignedp
, passed_type
);
2743 /* Let machine desc say which reg (if any) the parm arrives in.
2744 0 means it arrives on the stack. */
2745 #ifdef FUNCTION_INCOMING_ARG
2746 entry_parm
= FUNCTION_INCOMING_ARG (args_so_far
, promoted_mode
,
2747 passed_type
, ! last_named
);
2749 entry_parm
= FUNCTION_ARG (args_so_far
, promoted_mode
,
2750 passed_type
, ! last_named
);
2754 passed_mode
= promoted_mode
;
2756 #ifdef SETUP_INCOMING_VARARGS
2757 /* If this is the last named parameter, do any required setup for
2758 varargs or stdargs. We need to know about the case of this being an
2759 addressable type, in which case we skip the registers it
2760 would have arrived in.
2762 For stdargs, LAST_NAMED will be set for two parameters, the one that
2763 is actually the last named, and the dummy parameter. We only
2764 want to do this action once.
2766 Also, indicate when RTL generation is to be suppressed. */
2767 if (last_named
&& !varargs_setup
)
2769 SETUP_INCOMING_VARARGS (args_so_far
, passed_mode
, passed_type
,
2770 current_function_pretend_args_size
,
2776 /* Determine parm's home in the stack,
2777 in case it arrives in the stack or we should pretend it did.
2779 Compute the stack position and rtx where the argument arrives
2782 There is one complexity here: If this was a parameter that would
2783 have been passed in registers, but wasn't only because it is
2784 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2785 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2786 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
2787 0 as it was the previous time. */
2789 locate_and_pad_parm (passed_mode
, passed_type
,
2790 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2793 #ifdef FUNCTION_INCOMING_ARG
2794 FUNCTION_INCOMING_ARG (args_so_far
, passed_mode
,
2797 || varargs_setup
)) != 0,
2799 FUNCTION_ARG (args_so_far
, passed_mode
,
2801 ! last_named
|| varargs_setup
) != 0,
2804 fndecl
, &stack_args_size
, &stack_offset
, &arg_size
);
2808 rtx offset_rtx
= ARGS_SIZE_RTX (stack_offset
);
2810 if (offset_rtx
== const0_rtx
)
2811 stack_parm
= gen_rtx (MEM
, passed_mode
, internal_arg_pointer
);
2813 stack_parm
= gen_rtx (MEM
, passed_mode
,
2814 gen_rtx (PLUS
, Pmode
,
2815 internal_arg_pointer
, offset_rtx
));
2817 /* If this is a memory ref that contains aggregate components,
2818 mark it as such for cse and loop optimize. */
2819 MEM_IN_STRUCT_P (stack_parm
) = aggregate
;
2822 /* If this parameter was passed both in registers and in the stack,
2823 use the copy on the stack. */
2824 if (MUST_PASS_IN_STACK (passed_mode
, passed_type
))
2827 /* If this parm was passed part in regs and part in memory,
2828 pretend it arrived entirely in memory
2829 by pushing the register-part onto the stack.
2831 In the special case of a DImode or DFmode that is split,
2832 we could put it together in a pseudoreg directly,
2833 but for now that's not worth bothering with. */
2838 #ifdef FUNCTION_ARG_PARTIAL_NREGS
2839 nregs
= FUNCTION_ARG_PARTIAL_NREGS (args_so_far
, passed_mode
,
2840 passed_type
, ! last_named
);
2845 current_function_pretend_args_size
2846 = (((nregs
* UNITS_PER_WORD
) + (PARM_BOUNDARY
/ BITS_PER_UNIT
) - 1)
2847 / (PARM_BOUNDARY
/ BITS_PER_UNIT
)
2848 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
2851 move_block_from_reg (REGNO (entry_parm
),
2852 validize_mem (stack_parm
), nregs
);
2853 entry_parm
= stack_parm
;
2857 /* If we didn't decide this parm came in a register,
2858 by default it came on the stack. */
2859 if (entry_parm
== 0)
2860 entry_parm
= stack_parm
;
2862 /* Record permanently how this parm was passed. */
2864 DECL_INCOMING_RTL (parm
) = entry_parm
;
2866 /* If there is actually space on the stack for this parm,
2867 count it in stack_args_size; otherwise set stack_parm to 0
2868 to indicate there is no preallocated stack slot for the parm. */
2870 if (entry_parm
== stack_parm
2871 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
2872 /* On some machines, even if a parm value arrives in a register
2873 there is still an (uninitialized) stack slot allocated for it.
2875 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
2876 whether this parameter already has a stack slot allocated,
2877 because an arg block exists only if current_function_args_size
2878 is larger than some threshhold, and we haven't calculated that
2879 yet. So, for now, we just assume that stack slots never exist
2881 || REG_PARM_STACK_SPACE (fndecl
) > 0
2885 stack_args_size
.constant
+= arg_size
.constant
;
2887 ADD_PARM_SIZE (stack_args_size
, arg_size
.var
);
2890 /* No stack slot was pushed for this parm. */
2893 /* Update info on where next arg arrives in registers. */
2895 FUNCTION_ARG_ADVANCE (args_so_far
, passed_mode
,
2896 passed_type
, ! last_named
);
2898 /* If this is our second time through, we are done with this parm. */
2902 /* If we can't trust the parm stack slot to be aligned enough
2903 for its ultimate type, don't use that slot after entry.
2904 We'll make another stack slot, if we need one. */
2906 #ifdef FUNCTION_ARG_BOUNDARY
2907 int thisparm_boundary
2908 = FUNCTION_ARG_BOUNDARY (passed_mode
, passed_type
);
2910 int thisparm_boundary
= PARM_BOUNDARY
;
2913 if (GET_MODE_ALIGNMENT (nominal_mode
) > thisparm_boundary
)
2917 /* Now adjust STACK_PARM to the mode and precise location
2918 where this parameter should live during execution,
2919 if we discover that it must live in the stack during execution.
2920 To make debuggers happier on big-endian machines, we store
2921 the value in the last bytes of the space available. */
2923 if (nominal_mode
!= BLKmode
&& nominal_mode
!= passed_mode
2928 #if BYTES_BIG_ENDIAN
2929 if (GET_MODE_SIZE (nominal_mode
) < UNITS_PER_WORD
)
2930 stack_offset
.constant
+= (GET_MODE_SIZE (passed_mode
)
2931 - GET_MODE_SIZE (nominal_mode
));
2934 offset_rtx
= ARGS_SIZE_RTX (stack_offset
);
2935 if (offset_rtx
== const0_rtx
)
2936 stack_parm
= gen_rtx (MEM
, nominal_mode
, internal_arg_pointer
);
2938 stack_parm
= gen_rtx (MEM
, nominal_mode
,
2939 gen_rtx (PLUS
, Pmode
,
2940 internal_arg_pointer
, offset_rtx
));
2942 /* If this is a memory ref that contains aggregate components,
2943 mark it as such for cse and loop optimize. */
2944 MEM_IN_STRUCT_P (stack_parm
) = aggregate
;
2947 /* ENTRY_PARM is an RTX for the parameter as it arrives,
2948 in the mode in which it arrives.
2949 STACK_PARM is an RTX for a stack slot where the parameter can live
2950 during the function (in case we want to put it there).
2951 STACK_PARM is 0 if no stack slot was pushed for it.
2953 Now output code if necessary to convert ENTRY_PARM to
2954 the type in which this function declares it,
2955 and store that result in an appropriate place,
2956 which may be a pseudo reg, may be STACK_PARM,
2957 or may be a local stack slot if STACK_PARM is 0.
2959 Set DECL_RTL to that place. */
2961 if (nominal_mode
== BLKmode
)
2963 /* If a BLKmode arrives in registers, copy it to a stack slot. */
2964 if (GET_CODE (entry_parm
) == REG
)
2966 int size_stored
= CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm
)),
2969 /* Note that we will be storing an integral number of words.
2970 So we have to be careful to ensure that we allocate an
2971 integral number of words. We do this below in the
2972 assign_stack_local if space was not allocated in the argument
2973 list. If it was, this will not work if PARM_BOUNDARY is not
2974 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2975 if it becomes a problem. */
2977 if (stack_parm
== 0)
2980 = assign_stack_local (GET_MODE (entry_parm
), size_stored
, 0);
2981 /* If this is a memory ref that contains aggregate components,
2982 mark it as such for cse and loop optimize. */
2983 MEM_IN_STRUCT_P (stack_parm
) = aggregate
;
2986 else if (PARM_BOUNDARY
% BITS_PER_WORD
!= 0)
2989 move_block_from_reg (REGNO (entry_parm
),
2990 validize_mem (stack_parm
),
2991 size_stored
/ UNITS_PER_WORD
);
2993 DECL_RTL (parm
) = stack_parm
;
2995 else if (! ((obey_regdecls
&& ! DECL_REGISTER (parm
)
2996 && ! DECL_INLINE (fndecl
))
2997 /* layout_decl may set this. */
2998 || TREE_ADDRESSABLE (parm
)
2999 || TREE_SIDE_EFFECTS (parm
)
3000 /* If -ffloat-store specified, don't put explicit
3001 float variables into registers. */
3002 || (flag_float_store
3003 && TREE_CODE (TREE_TYPE (parm
)) == REAL_TYPE
))
3004 /* Always assign pseudo to structure return or item passed
3005 by invisible reference. */
3006 || passed_pointer
|| parm
== function_result_decl
)
3008 /* Store the parm in a pseudoregister during the function, but we
3009 may need to do it in a wider mode. */
3011 register rtx parmreg
;
3013 unsignedp
= TREE_UNSIGNED (TREE_TYPE (parm
));
3014 if (TREE_CODE (TREE_TYPE (parm
)) == INTEGER_TYPE
3015 || TREE_CODE (TREE_TYPE (parm
)) == ENUMERAL_TYPE
3016 || TREE_CODE (TREE_TYPE (parm
)) == BOOLEAN_TYPE
3017 || TREE_CODE (TREE_TYPE (parm
)) == CHAR_TYPE
3018 || TREE_CODE (TREE_TYPE (parm
)) == REAL_TYPE
3019 || TREE_CODE (TREE_TYPE (parm
)) == POINTER_TYPE
3020 || TREE_CODE (TREE_TYPE (parm
)) == OFFSET_TYPE
)
3022 PROMOTE_MODE (nominal_mode
, unsignedp
, TREE_TYPE (parm
));
3025 parmreg
= gen_reg_rtx (nominal_mode
);
3026 REG_USERVAR_P (parmreg
) = 1;
3028 /* If this was an item that we received a pointer to, set DECL_RTL
3032 DECL_RTL (parm
) = gen_rtx (MEM
, TYPE_MODE (TREE_TYPE (passed_type
)), parmreg
);
3033 MEM_IN_STRUCT_P (DECL_RTL (parm
)) = aggregate
;
3036 DECL_RTL (parm
) = parmreg
;
3038 /* Copy the value into the register. */
3039 if (GET_MODE (parmreg
) != GET_MODE (entry_parm
))
3041 /* If ENTRY_PARM is a hard register, it might be in a register
3042 not valid for operating in its mode (e.g., an odd-numbered
3043 register for a DFmode). In that case, moves are the only
3044 thing valid, so we can't do a convert from there. This
3045 occurs when the calling sequence allow such misaligned
3047 if (GET_CODE (entry_parm
) == REG
3048 && REGNO (entry_parm
) < FIRST_PSEUDO_REGISTER
3049 && ! HARD_REGNO_MODE_OK (REGNO (entry_parm
),
3050 GET_MODE (entry_parm
)))
3051 convert_move (parmreg
, copy_to_reg (entry_parm
), unsignedp
);
3053 convert_move (parmreg
, validize_mem (entry_parm
), unsignedp
);
3056 emit_move_insn (parmreg
, validize_mem (entry_parm
));
3058 /* If we were passed a pointer but the actual value
3059 can safely live in a register, put it in one. */
3060 if (passed_pointer
&& TYPE_MODE (TREE_TYPE (parm
)) != BLKmode
3061 && ! ((obey_regdecls
&& ! DECL_REGISTER (parm
)
3062 && ! DECL_INLINE (fndecl
))
3063 /* layout_decl may set this. */
3064 || TREE_ADDRESSABLE (parm
)
3065 || TREE_SIDE_EFFECTS (parm
)
3066 /* If -ffloat-store specified, don't put explicit
3067 float variables into registers. */
3068 || (flag_float_store
3069 && TREE_CODE (TREE_TYPE (parm
)) == REAL_TYPE
)))
3071 /* We can't use nominal_mode, because it will have been set to
3072 Pmode above. We must use the actual mode of the parm. */
3073 parmreg
= gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm
)));
3074 emit_move_insn (parmreg
, DECL_RTL (parm
));
3075 DECL_RTL (parm
) = parmreg
;
3078 /* In any case, record the parm's desired stack location
3079 in case we later discover it must live in the stack. */
3080 if (REGNO (parmreg
) >= nparmregs
)
3083 nparmregs
= REGNO (parmreg
) + 5;
3084 new = (rtx
*) oballoc (nparmregs
* sizeof (rtx
));
3085 bcopy (parm_reg_stack_loc
, new, nparmregs
* sizeof (rtx
));
3086 parm_reg_stack_loc
= new;
3088 parm_reg_stack_loc
[REGNO (parmreg
)] = stack_parm
;
3090 /* Mark the register as eliminable if we did no conversion
3091 and it was copied from memory at a fixed offset,
3092 and the arg pointer was not copied to a pseudo-reg.
3093 If the arg pointer is a pseudo reg or the offset formed
3094 an invalid address, such memory-equivalences
3095 as we make here would screw up life analysis for it. */
3096 if (nominal_mode
== passed_mode
3097 && GET_CODE (entry_parm
) == MEM
3098 && entry_parm
== stack_parm
3099 && stack_offset
.var
== 0
3100 && reg_mentioned_p (virtual_incoming_args_rtx
,
3101 XEXP (entry_parm
, 0)))
3102 REG_NOTES (get_last_insn ())
3103 = gen_rtx (EXPR_LIST
, REG_EQUIV
,
3104 entry_parm
, REG_NOTES (get_last_insn ()));
3106 /* For pointer data type, suggest pointer register. */
3107 if (TREE_CODE (TREE_TYPE (parm
)) == POINTER_TYPE
)
3108 mark_reg_pointer (parmreg
);
3112 /* Value must be stored in the stack slot STACK_PARM
3113 during function execution. */
3115 if (passed_mode
!= nominal_mode
)
3117 /* Conversion is required. */
3118 if (GET_CODE (entry_parm
) == REG
3119 && REGNO (entry_parm
) < FIRST_PSEUDO_REGISTER
3120 && ! HARD_REGNO_MODE_OK (REGNO (entry_parm
), passed_mode
))
3121 entry_parm
= copy_to_reg (entry_parm
);
3123 entry_parm
= convert_to_mode (nominal_mode
, entry_parm
,
3124 TREE_UNSIGNED (TREE_TYPE (parm
)));
3127 if (entry_parm
!= stack_parm
)
3129 if (stack_parm
== 0)
3132 = assign_stack_local (GET_MODE (entry_parm
),
3133 GET_MODE_SIZE (GET_MODE (entry_parm
)), 0);
3134 /* If this is a memory ref that contains aggregate components,
3135 mark it as such for cse and loop optimize. */
3136 MEM_IN_STRUCT_P (stack_parm
) = aggregate
;
3139 emit_move_insn (validize_mem (stack_parm
),
3140 validize_mem (entry_parm
));
3143 DECL_RTL (parm
) = stack_parm
;
3146 /* If this "parameter" was the place where we are receiving the
3147 function's incoming structure pointer, set up the result. */
3148 if (parm
== function_result_decl
)
3149 DECL_RTL (DECL_RESULT (fndecl
))
3150 = gen_rtx (MEM
, DECL_MODE (DECL_RESULT (fndecl
)), DECL_RTL (parm
));
3152 if (TREE_THIS_VOLATILE (parm
))
3153 MEM_VOLATILE_P (DECL_RTL (parm
)) = 1;
3154 if (TREE_READONLY (parm
))
3155 RTX_UNCHANGING_P (DECL_RTL (parm
)) = 1;
3158 max_parm_reg
= max_reg_num ();
3159 last_parm_insn
= get_last_insn ();
3161 current_function_args_size
= stack_args_size
.constant
;
3163 /* Adjust function incoming argument size for alignment and
3166 #ifdef REG_PARM_STACK_SPACE
3167 #ifndef MAYBE_REG_PARM_STACK_SPACE
3168 current_function_args_size
= MAX (current_function_args_size
,
3169 REG_PARM_STACK_SPACE (fndecl
));
3173 #ifdef STACK_BOUNDARY
3174 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
3176 current_function_args_size
3177 = ((current_function_args_size
+ STACK_BYTES
- 1)
3178 / STACK_BYTES
) * STACK_BYTES
;
3181 #ifdef ARGS_GROW_DOWNWARD
3182 current_function_arg_offset_rtx
3183 = (stack_args_size
.var
== 0 ? GEN_INT (-stack_args_size
.constant
)
3184 : expand_expr (size_binop (MINUS_EXPR
, stack_args_size
.var
,
3185 size_int (-stack_args_size
.constant
)),
3186 NULL_RTX
, VOIDmode
, 0));
3188 current_function_arg_offset_rtx
= ARGS_SIZE_RTX (stack_args_size
);
3191 /* See how many bytes, if any, of its args a function should try to pop
3194 current_function_pops_args
= RETURN_POPS_ARGS (TREE_TYPE (fndecl
),
3195 current_function_args_size
);
3197 /* For stdarg.h function, save info about regs and stack space
3198 used by the named args. */
3201 current_function_args_info
= args_so_far
;
3203 /* Set the rtx used for the function return value. Put this in its
3204 own variable so any optimizers that need this information don't have
3205 to include tree.h. Do this here so it gets done when an inlined
3206 function gets output. */
3208 current_function_return_rtx
= DECL_RTL (DECL_RESULT (fndecl
));
3211 /* Compute the size and offset from the start of the stacked arguments for a
3212 parm passed in mode PASSED_MODE and with type TYPE.
3214 INITIAL_OFFSET_PTR points to the current offset into the stacked
3217 The starting offset and size for this parm are returned in *OFFSET_PTR
3218 and *ARG_SIZE_PTR, respectively.
3220 IN_REGS is non-zero if the argument will be passed in registers. It will
3221 never be set if REG_PARM_STACK_SPACE is not defined.
3223 FNDECL is the function in which the argument was defined.
3225 There are two types of rounding that are done. The first, controlled by
3226 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3227 list to be aligned to the specific boundary (in bits). This rounding
3228 affects the initial and starting offsets, but not the argument size.
3230 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3231 optionally rounds the size of the parm to PARM_BOUNDARY. The
3232 initial offset is not affected by this rounding, while the size always
3233 is and the starting offset may be. */
3235 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
3236 initial_offset_ptr is positive because locate_and_pad_parm's
3237 callers pass in the total size of args so far as
3238 initial_offset_ptr. arg_size_ptr is always positive.*/
3240 static void pad_to_arg_alignment (), pad_below ();
3243 locate_and_pad_parm (passed_mode
, type
, in_regs
, fndecl
,
3244 initial_offset_ptr
, offset_ptr
, arg_size_ptr
)
3245 enum machine_mode passed_mode
;
3249 struct args_size
*initial_offset_ptr
;
3250 struct args_size
*offset_ptr
;
3251 struct args_size
*arg_size_ptr
;
3254 = type
? size_in_bytes (type
) : size_int (GET_MODE_SIZE (passed_mode
));
3255 enum direction where_pad
= FUNCTION_ARG_PADDING (passed_mode
, type
);
3256 int boundary
= FUNCTION_ARG_BOUNDARY (passed_mode
, type
);
3257 int boundary_in_bytes
= boundary
/ BITS_PER_UNIT
;
3258 int reg_parm_stack_space
= 0;
3260 #ifdef REG_PARM_STACK_SPACE
3261 /* If we have found a stack parm before we reach the end of the
3262 area reserved for registers, skip that area. */
3265 #ifdef MAYBE_REG_PARM_STACK_SPACE
3266 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
3268 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
3270 if (reg_parm_stack_space
> 0)
3272 if (initial_offset_ptr
->var
)
3274 initial_offset_ptr
->var
3275 = size_binop (MAX_EXPR
, ARGS_SIZE_TREE (*initial_offset_ptr
),
3276 size_int (reg_parm_stack_space
));
3277 initial_offset_ptr
->constant
= 0;
3279 else if (initial_offset_ptr
->constant
< reg_parm_stack_space
)
3280 initial_offset_ptr
->constant
= reg_parm_stack_space
;
3283 #endif /* REG_PARM_STACK_SPACE */
3285 arg_size_ptr
->var
= 0;
3286 arg_size_ptr
->constant
= 0;
3288 #ifdef ARGS_GROW_DOWNWARD
3289 if (initial_offset_ptr
->var
)
3291 offset_ptr
->constant
= 0;
3292 offset_ptr
->var
= size_binop (MINUS_EXPR
, integer_zero_node
,
3293 initial_offset_ptr
->var
);
3297 offset_ptr
->constant
= - initial_offset_ptr
->constant
;
3298 offset_ptr
->var
= 0;
3300 if (where_pad
== upward
3301 && (TREE_CODE (sizetree
) != INTEGER_CST
3302 || ((TREE_INT_CST_LOW (sizetree
) * BITS_PER_UNIT
) % PARM_BOUNDARY
)))
3303 sizetree
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3304 SUB_PARM_SIZE (*offset_ptr
, sizetree
);
3305 pad_to_arg_alignment (offset_ptr
, boundary
);
3306 if (initial_offset_ptr
->var
)
3308 arg_size_ptr
->var
= size_binop (MINUS_EXPR
,
3309 size_binop (MINUS_EXPR
,
3311 initial_offset_ptr
->var
),
3316 arg_size_ptr
->constant
= (- initial_offset_ptr
->constant
-
3317 offset_ptr
->constant
);
3319 /* ADD_PARM_SIZE (*arg_size_ptr, sizetree); */
3320 if (where_pad
== downward
)
3321 pad_below (arg_size_ptr
, passed_mode
, sizetree
);
3322 #else /* !ARGS_GROW_DOWNWARD */
3323 pad_to_arg_alignment (initial_offset_ptr
, boundary
);
3324 *offset_ptr
= *initial_offset_ptr
;
3325 if (where_pad
== downward
)
3326 pad_below (offset_ptr
, passed_mode
, sizetree
);
3328 #ifdef PUSH_ROUNDING
3329 if (passed_mode
!= BLKmode
)
3330 sizetree
= size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree
)));
3333 if (where_pad
!= none
3334 && (TREE_CODE (sizetree
) != INTEGER_CST
3335 || ((TREE_INT_CST_LOW (sizetree
) * BITS_PER_UNIT
) % PARM_BOUNDARY
)))
3336 sizetree
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3338 ADD_PARM_SIZE (*arg_size_ptr
, sizetree
);
3339 #endif /* ARGS_GROW_DOWNWARD */
3342 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3343 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3346 pad_to_arg_alignment (offset_ptr
, boundary
)
3347 struct args_size
*offset_ptr
;
3350 int boundary_in_bytes
= boundary
/ BITS_PER_UNIT
;
3352 if (boundary
> BITS_PER_UNIT
)
3354 if (offset_ptr
->var
)
3357 #ifdef ARGS_GROW_DOWNWARD
3362 (ARGS_SIZE_TREE (*offset_ptr
),
3363 boundary
/ BITS_PER_UNIT
);
3364 offset_ptr
->constant
= 0; /*?*/
3367 offset_ptr
->constant
=
3368 #ifdef ARGS_GROW_DOWNWARD
3369 FLOOR_ROUND (offset_ptr
->constant
, boundary_in_bytes
);
3371 CEIL_ROUND (offset_ptr
->constant
, boundary_in_bytes
);
3377 pad_below (offset_ptr
, passed_mode
, sizetree
)
3378 struct args_size
*offset_ptr
;
3379 enum machine_mode passed_mode
;
3382 if (passed_mode
!= BLKmode
)
3384 if (GET_MODE_BITSIZE (passed_mode
) % PARM_BOUNDARY
)
3385 offset_ptr
->constant
3386 += (((GET_MODE_BITSIZE (passed_mode
) + PARM_BOUNDARY
- 1)
3387 / PARM_BOUNDARY
* PARM_BOUNDARY
/ BITS_PER_UNIT
)
3388 - GET_MODE_SIZE (passed_mode
));
3392 if (TREE_CODE (sizetree
) != INTEGER_CST
3393 || (TREE_INT_CST_LOW (sizetree
) * BITS_PER_UNIT
) % PARM_BOUNDARY
)
3395 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3396 tree s2
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3398 ADD_PARM_SIZE (*offset_ptr
, s2
);
3399 SUB_PARM_SIZE (*offset_ptr
, sizetree
);
3405 round_down (value
, divisor
)
3409 return size_binop (MULT_EXPR
,
3410 size_binop (FLOOR_DIV_EXPR
, value
, size_int (divisor
)),
3411 size_int (divisor
));
3414 /* Walk the tree of blocks describing the binding levels within a function
3415 and warn about uninitialized variables.
3416 This is done after calling flow_analysis and before global_alloc
3417 clobbers the pseudo-regs to hard regs. */
3420 uninitialized_vars_warning (block
)
3423 register tree decl
, sub
;
3424 for (decl
= BLOCK_VARS (block
); decl
; decl
= TREE_CHAIN (decl
))
3426 if (TREE_CODE (decl
) == VAR_DECL
3427 /* These warnings are unreliable for and aggregates
3428 because assigning the fields one by one can fail to convince
3429 flow.c that the entire aggregate was initialized.
3430 Unions are troublesome because members may be shorter. */
3431 && TREE_CODE (TREE_TYPE (decl
)) != RECORD_TYPE
3432 && TREE_CODE (TREE_TYPE (decl
)) != UNION_TYPE
3433 && TREE_CODE (TREE_TYPE (decl
)) != ARRAY_TYPE
3434 && DECL_RTL (decl
) != 0
3435 && GET_CODE (DECL_RTL (decl
)) == REG
3436 && regno_uninitialized (REGNO (DECL_RTL (decl
))))
3437 warning_with_decl (decl
,
3438 "`%s' may be used uninitialized in this function");
3439 if (TREE_CODE (decl
) == VAR_DECL
3440 && DECL_RTL (decl
) != 0
3441 && GET_CODE (DECL_RTL (decl
)) == REG
3442 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl
))))
3443 warning_with_decl (decl
,
3444 "variable `%s' may be clobbered by `longjmp'");
3446 for (sub
= BLOCK_SUBBLOCKS (block
); sub
; sub
= TREE_CHAIN (sub
))
3447 uninitialized_vars_warning (sub
);
3450 /* Do the appropriate part of uninitialized_vars_warning
3451 but for arguments instead of local variables. */
3454 setjmp_args_warning (block
)
3458 for (decl
= DECL_ARGUMENTS (current_function_decl
);
3459 decl
; decl
= TREE_CHAIN (decl
))
3460 if (DECL_RTL (decl
) != 0
3461 && GET_CODE (DECL_RTL (decl
)) == REG
3462 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl
))))
3463 warning_with_decl (decl
, "argument `%s' may be clobbered by `longjmp'");
3466 /* If this function call setjmp, put all vars into the stack
3467 unless they were declared `register'. */
3470 setjmp_protect (block
)
3473 register tree decl
, sub
;
3474 for (decl
= BLOCK_VARS (block
); decl
; decl
= TREE_CHAIN (decl
))
3475 if ((TREE_CODE (decl
) == VAR_DECL
3476 || TREE_CODE (decl
) == PARM_DECL
)
3477 && DECL_RTL (decl
) != 0
3478 && GET_CODE (DECL_RTL (decl
)) == REG
3479 /* If this variable came from an inline function, it must be
3480 that it's life doesn't overlap the setjmp. If there was a
3481 setjmp in the function, it would already be in memory. We
3482 must exclude such variable because their DECL_RTL might be
3483 set to strange things such as virtual_stack_vars_rtx. */
3484 && ! DECL_FROM_INLINE (decl
)
3486 #ifdef NON_SAVING_SETJMP
3487 /* If longjmp doesn't restore the registers,
3488 don't put anything in them. */
3492 ! DECL_REGISTER (decl
)))
3493 put_var_into_stack (decl
);
3494 for (sub
= BLOCK_SUBBLOCKS (block
); sub
; sub
= TREE_CHAIN (sub
))
3495 setjmp_protect (sub
);
3498 /* Like the previous function, but for args instead of local variables. */
3501 setjmp_protect_args ()
3503 register tree decl
, sub
;
3504 for (decl
= DECL_ARGUMENTS (current_function_decl
);
3505 decl
; decl
= TREE_CHAIN (decl
))
3506 if ((TREE_CODE (decl
) == VAR_DECL
3507 || TREE_CODE (decl
) == PARM_DECL
)
3508 && DECL_RTL (decl
) != 0
3509 && GET_CODE (DECL_RTL (decl
)) == REG
3511 /* If longjmp doesn't restore the registers,
3512 don't put anything in them. */
3513 #ifdef NON_SAVING_SETJMP
3517 ! DECL_REGISTER (decl
)))
3518 put_var_into_stack (decl
);
3521 /* Return the context-pointer register corresponding to DECL,
3522 or 0 if it does not need one. */
3525 lookup_static_chain (decl
)
3528 tree context
= decl_function_context (decl
);
3534 /* We treat inline_function_decl as an alias for the current function
3535 because that is the inline function whose vars, types, etc.
3536 are being merged into the current function.
3537 See expand_inline_function. */
3538 if (context
== current_function_decl
|| context
== inline_function_decl
)
3539 return virtual_stack_vars_rtx
;
3541 for (link
= context_display
; link
; link
= TREE_CHAIN (link
))
3542 if (TREE_PURPOSE (link
) == context
)
3543 return RTL_EXPR_RTL (TREE_VALUE (link
));
3548 /* Convert a stack slot address ADDR for variable VAR
3549 (from a containing function)
3550 into an address valid in this function (using a static chain). */
3553 fix_lexical_addr (addr
, var
)
3559 tree context
= decl_function_context (var
);
3560 struct function
*fp
;
3563 /* If this is the present function, we need not do anything. */
3564 if (context
== current_function_decl
|| context
== inline_function_decl
)
3567 for (fp
= outer_function_chain
; fp
; fp
= fp
->next
)
3568 if (fp
->decl
== context
)
3574 /* Decode given address as base reg plus displacement. */
3575 if (GET_CODE (addr
) == REG
)
3576 basereg
= addr
, displacement
= 0;
3577 else if (GET_CODE (addr
) == PLUS
&& GET_CODE (XEXP (addr
, 1)) == CONST_INT
)
3578 basereg
= XEXP (addr
, 0), displacement
= INTVAL (XEXP (addr
, 1));
3582 /* We accept vars reached via the containing function's
3583 incoming arg pointer and via its stack variables pointer. */
3584 if (basereg
== fp
->internal_arg_pointer
)
3586 /* If reached via arg pointer, get the arg pointer value
3587 out of that function's stack frame.
3589 There are two cases: If a separate ap is needed, allocate a
3590 slot in the outer function for it and dereference it that way.
3591 This is correct even if the real ap is actually a pseudo.
3592 Otherwise, just adjust the offset from the frame pointer to
3595 #ifdef NEED_SEPARATE_AP
3598 if (fp
->arg_pointer_save_area
== 0)
3599 fp
->arg_pointer_save_area
3600 = assign_outer_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0, fp
);
3602 addr
= fix_lexical_addr (XEXP (fp
->arg_pointer_save_area
, 0), var
);
3603 addr
= memory_address (Pmode
, addr
);
3605 base
= copy_to_reg (gen_rtx (MEM
, Pmode
, addr
));
3607 displacement
+= (FIRST_PARM_OFFSET (context
) - STARTING_FRAME_OFFSET
);
3608 base
= lookup_static_chain (var
);
3612 else if (basereg
== virtual_stack_vars_rtx
)
3614 /* This is the same code as lookup_static_chain, duplicated here to
3615 avoid an extra call to decl_function_context. */
3618 for (link
= context_display
; link
; link
= TREE_CHAIN (link
))
3619 if (TREE_PURPOSE (link
) == context
)
3621 base
= RTL_EXPR_RTL (TREE_VALUE (link
));
3629 /* Use same offset, relative to appropriate static chain or argument
3631 return plus_constant (base
, displacement
);
3634 /* Return the address of the trampoline for entering nested fn FUNCTION.
3635 If necessary, allocate a trampoline (in the stack frame)
3636 and emit rtl to initialize its contents (at entry to this function). */
3639 trampoline_address (function
)
3645 struct function
*fp
;
3648 /* Find an existing trampoline and return it. */
3649 for (link
= trampoline_list
; link
; link
= TREE_CHAIN (link
))
3650 if (TREE_PURPOSE (link
) == function
)
3651 return XEXP (RTL_EXPR_RTL (TREE_VALUE (link
)), 0);
3652 for (fp
= outer_function_chain
; fp
; fp
= fp
->next
)
3653 for (link
= fp
->trampoline_list
; link
; link
= TREE_CHAIN (link
))
3654 if (TREE_PURPOSE (link
) == function
)
3656 tramp
= fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link
)), 0),
3658 return round_trampoline_addr (tramp
);
3661 /* None exists; we must make one. */
3663 /* Find the `struct function' for the function containing FUNCTION. */
3665 fn_context
= decl_function_context (function
);
3666 if (fn_context
!= current_function_decl
)
3667 for (fp
= outer_function_chain
; fp
; fp
= fp
->next
)
3668 if (fp
->decl
== fn_context
)
3671 /* Allocate run-time space for this trampoline
3672 (usually in the defining function's stack frame). */
3673 #ifdef ALLOCATE_TRAMPOLINE
3674 tramp
= ALLOCATE_TRAMPOLINE (fp
);
3676 /* If rounding needed, allocate extra space
3677 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
3678 #ifdef TRAMPOLINE_ALIGNMENT
3679 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE + TRAMPOLINE_ALIGNMENT - 1)
3681 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE)
3684 tramp
= assign_outer_stack_local (BLKmode
, TRAMPOLINE_REAL_SIZE
, 0, fp
);
3686 tramp
= assign_stack_local (BLKmode
, TRAMPOLINE_REAL_SIZE
, 0);
3689 /* Record the trampoline for reuse and note it for later initialization
3690 by expand_function_end. */
3693 push_obstacks (fp
->current_obstack
, fp
->function_maybepermanent_obstack
);
3694 rtlexp
= make_node (RTL_EXPR
);
3695 RTL_EXPR_RTL (rtlexp
) = tramp
;
3696 fp
->trampoline_list
= tree_cons (function
, rtlexp
, fp
->trampoline_list
);
3701 /* Make the RTL_EXPR node temporary, not momentary, so that the
3702 trampoline_list doesn't become garbage. */
3703 int momentary
= suspend_momentary ();
3704 rtlexp
= make_node (RTL_EXPR
);
3705 resume_momentary (momentary
);
3707 RTL_EXPR_RTL (rtlexp
) = tramp
;
3708 trampoline_list
= tree_cons (function
, rtlexp
, trampoline_list
);
3711 tramp
= fix_lexical_addr (XEXP (tramp
, 0), function
);
3712 return round_trampoline_addr (tramp
);
3715 /* Given a trampoline address,
3716 round it to multiple of TRAMPOLINE_ALIGNMENT. */
3719 round_trampoline_addr (tramp
)
3722 #ifdef TRAMPOLINE_ALIGNMENT
3723 /* Round address up to desired boundary. */
3724 rtx temp
= gen_reg_rtx (Pmode
);
3725 temp
= expand_binop (Pmode
, add_optab
, tramp
,
3726 GEN_INT (TRAMPOLINE_ALIGNMENT
- 1),
3727 temp
, 0, OPTAB_LIB_WIDEN
);
3728 tramp
= expand_binop (Pmode
, and_optab
, temp
,
3729 GEN_INT (- TRAMPOLINE_ALIGNMENT
),
3730 temp
, 0, OPTAB_LIB_WIDEN
);
3735 /* The functions identify_blocks and reorder_blocks provide a way to
3736 reorder the tree of BLOCK nodes, for optimizers that reshuffle or
3737 duplicate portions of the RTL code. Call identify_blocks before
3738 changing the RTL, and call reorder_blocks after. */
3740 static int all_blocks ();
3741 static tree
blocks_nreverse ();
3743 /* Put all this function's BLOCK nodes into a vector, and return it.
3744 Also store in each NOTE for the beginning or end of a block
3745 the index of that block in the vector.
3746 The arguments are TOP_BLOCK, the top-level block of the function,
3747 and INSNS, the insn chain of the function. */
3750 identify_blocks (top_block
, insns
)
3758 int next_block_number
= 0;
3759 int current_block_number
= 0;
3765 n_blocks
= all_blocks (top_block
, 0);
3766 block_vector
= (tree
*) xmalloc (n_blocks
* sizeof (tree
));
3767 block_stack
= (int *) alloca (n_blocks
* sizeof (int));
3769 all_blocks (top_block
, block_vector
);
3771 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
3772 if (GET_CODE (insn
) == NOTE
)
3774 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
)
3776 block_stack
[depth
++] = current_block_number
;
3777 current_block_number
= next_block_number
;
3778 NOTE_BLOCK_NUMBER (insn
) = next_block_number
++;
3780 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
)
3782 current_block_number
= block_stack
[--depth
];
3783 NOTE_BLOCK_NUMBER (insn
) = current_block_number
;
3787 return block_vector
;
3790 /* Given BLOCK_VECTOR which was returned by identify_blocks,
3791 and a revised instruction chain, rebuild the tree structure
3792 of BLOCK nodes to correspond to the new order of RTL.
3793 The new block tree is inserted below TOP_BLOCK.
3794 Returns the current top-level block. */
3797 reorder_blocks (block_vector
, top_block
, insns
)
3802 tree current_block
= top_block
;
3805 if (block_vector
== 0)
3808 /* Prune the old tree away, so that it doesn't get in the way. */
3809 BLOCK_SUBBLOCKS (current_block
) = 0;
3811 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
3812 if (GET_CODE (insn
) == NOTE
)
3814 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
)
3816 tree block
= block_vector
[NOTE_BLOCK_NUMBER (insn
)];
3817 /* If we have seen this block before, copy it. */
3818 if (TREE_ASM_WRITTEN (block
))
3819 block
= copy_node (block
);
3820 BLOCK_SUBBLOCKS (block
) = 0;
3821 TREE_ASM_WRITTEN (block
) = 1;
3822 BLOCK_SUPERCONTEXT (block
) = current_block
;
3823 BLOCK_CHAIN (block
) = BLOCK_SUBBLOCKS (current_block
);
3824 BLOCK_SUBBLOCKS (current_block
) = block
;
3825 current_block
= block
;
3826 NOTE_SOURCE_FILE (insn
) = 0;
3828 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
)
3830 BLOCK_SUBBLOCKS (current_block
)
3831 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block
));
3832 current_block
= BLOCK_SUPERCONTEXT (current_block
);
3833 NOTE_SOURCE_FILE (insn
) = 0;
3837 return current_block
;
3840 /* Reverse the order of elements in the chain T of blocks,
3841 and return the new head of the chain (old last element). */
3847 register tree prev
= 0, decl
, next
;
3848 for (decl
= t
; decl
; decl
= next
)
3850 next
= BLOCK_CHAIN (decl
);
3851 BLOCK_CHAIN (decl
) = prev
;
3857 /* Count the subblocks of BLOCK, and list them all into the vector VECTOR.
3858 Also clear TREE_ASM_WRITTEN in all blocks. */
3861 all_blocks (block
, vector
)
3868 TREE_ASM_WRITTEN (block
) = 0;
3869 /* Record this block. */
3873 /* Record the subblocks, and their subblocks. */
3874 for (subblocks
= BLOCK_SUBBLOCKS (block
);
3875 subblocks
; subblocks
= BLOCK_CHAIN (subblocks
))
3876 n_blocks
+= all_blocks (subblocks
, vector
? vector
+ n_blocks
: 0);
3881 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
3882 and initialize static variables for generating RTL for the statements
3886 init_function_start (subr
, filename
, line
)
3893 init_stmt_for_function ();
3895 cse_not_expected
= ! optimize
;
3897 /* Caller save not needed yet. */
3898 caller_save_needed
= 0;
3900 /* No stack slots have been made yet. */
3901 stack_slot_list
= 0;
3903 /* There is no stack slot for handling nonlocal gotos. */
3904 nonlocal_goto_handler_slot
= 0;
3905 nonlocal_goto_stack_level
= 0;
3907 /* No labels have been declared for nonlocal use. */
3908 nonlocal_labels
= 0;
3910 /* No function calls so far in this function. */
3911 function_call_count
= 0;
3913 /* No parm regs have been allocated.
3914 (This is important for output_inline_function.) */
3915 max_parm_reg
= LAST_VIRTUAL_REGISTER
+ 1;
3917 /* Initialize the RTL mechanism. */
3920 /* Initialize the queue of pending postincrement and postdecrements,
3921 and some other info in expr.c. */
3924 /* We haven't done register allocation yet. */
3927 init_const_rtx_hash_table ();
3929 current_function_name
= (*decl_printable_name
) (subr
, &junk
);
3931 /* Nonzero if this is a nested function that uses a static chain. */
3933 current_function_needs_context
3934 = (decl_function_context (current_function_decl
) != 0);
3936 /* Set if a call to setjmp is seen. */
3937 current_function_calls_setjmp
= 0;
3939 /* Set if a call to longjmp is seen. */
3940 current_function_calls_longjmp
= 0;
3942 current_function_calls_alloca
= 0;
3943 current_function_has_nonlocal_label
= 0;
3944 current_function_contains_functions
= 0;
3946 current_function_returns_pcc_struct
= 0;
3947 current_function_returns_struct
= 0;
3948 current_function_epilogue_delay_list
= 0;
3949 current_function_uses_const_pool
= 0;
3950 current_function_uses_pic_offset_table
= 0;
3952 /* We have not yet needed to make a label to jump to for tail-recursion. */
3953 tail_recursion_label
= 0;
3955 /* We haven't had a need to make a save area for ap yet. */
3957 arg_pointer_save_area
= 0;
3959 /* No stack slots allocated yet. */
3962 /* No SAVE_EXPRs in this function yet. */
3965 /* No RTL_EXPRs in this function yet. */
3968 /* We have not allocated any temporaries yet. */
3970 temp_slot_level
= 0;
3972 /* Within function body, compute a type's size as soon it is laid out. */
3973 immediate_size_expand
++;
3975 init_pending_stack_adjust ();
3976 inhibit_defer_pop
= 0;
3978 current_function_outgoing_args_size
= 0;
3980 /* Initialize the insn lengths. */
3981 init_insn_lengths ();
3983 /* Prevent ever trying to delete the first instruction of a function.
3984 Also tell final how to output a linenum before the function prologue. */
3985 emit_line_note (filename
, line
);
3987 /* Make sure first insn is a note even if we don't want linenums.
3988 This makes sure the first insn will never be deleted.
3989 Also, final expects a note to appear there. */
3990 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
3992 /* Set flags used by final.c. */
3993 if (aggregate_value_p (DECL_RESULT (subr
)))
3995 #ifdef PCC_STATIC_STRUCT_RETURN
3996 if (flag_pcc_struct_return
)
3997 current_function_returns_pcc_struct
= 1;
4000 current_function_returns_struct
= 1;
4003 /* Warn if this value is an aggregate type,
4004 regardless of which calling convention we are using for it. */
4005 if (warn_aggregate_return
4006 && (TREE_CODE (TREE_TYPE (DECL_RESULT (subr
))) == RECORD_TYPE
4007 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr
))) == UNION_TYPE
4008 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr
))) == ARRAY_TYPE
))
4009 warning ("function returns an aggregate");
4011 current_function_returns_pointer
4012 = (TREE_CODE (TREE_TYPE (DECL_RESULT (subr
))) == POINTER_TYPE
);
4014 /* Indicate that we need to distinguish between the return value of the
4015 present function and the return value of a function being called. */
4016 rtx_equal_function_value_matters
= 1;
4018 /* Indicate that we have not instantiated virtual registers yet. */
4019 virtuals_instantiated
= 0;
4021 /* Indicate we have no need of a frame pointer yet. */
4022 frame_pointer_needed
= 0;
4024 /* By default assume not varargs. */
4025 current_function_varargs
= 0;
4028 /* Indicate that the current function uses extra args
4029 not explicitly mentioned in the argument list in any fashion. */
4034 current_function_varargs
= 1;
4037 /* Expand a call to __main at the beginning of a possible main function. */
4040 expand_main_function ()
4042 #if !defined (INIT_SECTION_ASM_OP) || defined (INVOKE__main)
4043 emit_library_call (gen_rtx (SYMBOL_REF
, Pmode
, "__main"), 0,
4045 #endif /* not INIT_SECTION_ASM_OP or INVOKE__main */
4048 /* Start the RTL for a new function, and set variables used for
4050 SUBR is the FUNCTION_DECL node.
4051 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4052 the function's parameters, which must be run at any return statement. */
4055 expand_function_start (subr
, parms_have_cleanups
)
4057 int parms_have_cleanups
;
4063 /* Make sure volatile mem refs aren't considered
4064 valid operands of arithmetic insns. */
4065 init_recog_no_volatile ();
4067 /* If function gets a static chain arg, store it in the stack frame.
4068 Do this first, so it gets the first stack slot offset. */
4069 if (current_function_needs_context
)
4071 last_ptr
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
4072 emit_move_insn (last_ptr
, static_chain_incoming_rtx
);
4075 /* If the parameters of this function need cleaning up, get a label
4076 for the beginning of the code which executes those cleanups. This must
4077 be done before doing anything with return_label. */
4078 if (parms_have_cleanups
)
4079 cleanup_label
= gen_label_rtx ();
4083 /* Make the label for return statements to jump to, if this machine
4084 does not have a one-instruction return and uses an epilogue,
4085 or if it returns a structure, or if it has parm cleanups. */
4087 if (cleanup_label
== 0 && HAVE_return
4088 && ! current_function_returns_pcc_struct
4089 && ! (current_function_returns_struct
&& ! optimize
))
4092 return_label
= gen_label_rtx ();
4094 return_label
= gen_label_rtx ();
4097 /* Initialize rtx used to return the value. */
4098 /* Do this before assign_parms so that we copy the struct value address
4099 before any library calls that assign parms might generate. */
4101 /* Decide whether to return the value in memory or in a register. */
4102 if (aggregate_value_p (DECL_RESULT (subr
)))
4104 /* Returning something that won't go in a register. */
4105 register rtx value_address
;
4107 #ifdef PCC_STATIC_STRUCT_RETURN
4108 if (current_function_returns_pcc_struct
)
4110 int size
= int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr
)));
4111 value_address
= assemble_static_space (size
);
4116 /* Expect to be passed the address of a place to store the value.
4117 If it is passed as an argument, assign_parms will take care of
4119 if (struct_value_incoming_rtx
)
4121 value_address
= gen_reg_rtx (Pmode
);
4122 emit_move_insn (value_address
, struct_value_incoming_rtx
);
4126 DECL_RTL (DECL_RESULT (subr
))
4127 = gen_rtx (MEM
, DECL_MODE (DECL_RESULT (subr
)),
4130 else if (DECL_MODE (DECL_RESULT (subr
)) == VOIDmode
)
4131 /* If return mode is void, this decl rtl should not be used. */
4132 DECL_RTL (DECL_RESULT (subr
)) = 0;
4133 else if (parms_have_cleanups
)
4135 /* If function will end with cleanup code for parms,
4136 compute the return values into a pseudo reg,
4137 which we will copy into the true return register
4138 after the cleanups are done. */
4140 enum machine_mode mode
= DECL_MODE (DECL_RESULT (subr
));
4141 #ifdef PROMOTE_FUNCTION_RETURN
4142 tree type
= TREE_TYPE (DECL_RESULT (subr
));
4143 int unsignedp
= TREE_UNSIGNED (type
);
4145 if (TREE_CODE (type
) == INTEGER_TYPE
|| TREE_CODE (type
) == ENUMERAL_TYPE
4146 || TREE_CODE (type
) == BOOLEAN_TYPE
|| TREE_CODE (type
) == CHAR_TYPE
4147 || TREE_CODE (type
) == REAL_TYPE
|| TREE_CODE (type
) == POINTER_TYPE
4148 || TREE_CODE (type
) == OFFSET_TYPE
)
4150 PROMOTE_MODE (mode
, unsignedp
, type
);
4154 DECL_RTL (DECL_RESULT (subr
)) = gen_reg_rtx (mode
);
4157 /* Scalar, returned in a register. */
4159 #ifdef FUNCTION_OUTGOING_VALUE
4160 DECL_RTL (DECL_RESULT (subr
))
4161 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (subr
)), subr
);
4163 DECL_RTL (DECL_RESULT (subr
))
4164 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (subr
)), subr
);
4167 /* Mark this reg as the function's return value. */
4168 if (GET_CODE (DECL_RTL (DECL_RESULT (subr
))) == REG
)
4170 REG_FUNCTION_VALUE_P (DECL_RTL (DECL_RESULT (subr
))) = 1;
4171 /* Needed because we may need to move this to memory
4172 in case it's a named return value whose address is taken. */
4173 DECL_REGISTER (DECL_RESULT (subr
)) = 1;
4177 /* Initialize rtx for parameters and local variables.
4178 In some cases this requires emitting insns. */
4180 assign_parms (subr
, 0);
4182 /* The following was moved from init_function_start.
4183 The move is supposed to make sdb output more accurate. */
4184 /* Indicate the beginning of the function body,
4185 as opposed to parm setup. */
4186 emit_note (NULL_PTR
, NOTE_INSN_FUNCTION_BEG
);
4188 /* If doing stupid allocation, mark parms as born here. */
4190 if (GET_CODE (get_last_insn ()) != NOTE
)
4191 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4192 parm_birth_insn
= get_last_insn ();
4196 for (i
= LAST_VIRTUAL_REGISTER
+ 1; i
< max_parm_reg
; i
++)
4197 use_variable (regno_reg_rtx
[i
]);
4199 if (current_function_internal_arg_pointer
!= virtual_incoming_args_rtx
)
4200 use_variable (current_function_internal_arg_pointer
);
4203 /* Fetch static chain values for containing functions. */
4204 tem
= decl_function_context (current_function_decl
);
4205 /* If not doing stupid register allocation, then start off with the static
4206 chain pointer in a pseudo register. Otherwise, we use the stack
4207 address that was generated above. */
4208 if (tem
&& ! obey_regdecls
)
4209 last_ptr
= copy_to_reg (static_chain_incoming_rtx
);
4210 context_display
= 0;
4213 tree rtlexp
= make_node (RTL_EXPR
);
4215 RTL_EXPR_RTL (rtlexp
) = last_ptr
;
4216 context_display
= tree_cons (tem
, rtlexp
, context_display
);
4217 tem
= decl_function_context (tem
);
4220 /* Chain thru stack frames, assuming pointer to next lexical frame
4221 is found at the place we always store it. */
4222 #ifdef FRAME_GROWS_DOWNWARD
4223 last_ptr
= plus_constant (last_ptr
, - GET_MODE_SIZE (Pmode
));
4225 last_ptr
= copy_to_reg (gen_rtx (MEM
, Pmode
,
4226 memory_address (Pmode
, last_ptr
)));
4229 /* After the display initializations is where the tail-recursion label
4230 should go, if we end up needing one. Ensure we have a NOTE here
4231 since some things (like trampolines) get placed before this. */
4232 tail_recursion_reentry
= emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4234 /* Evaluate now the sizes of any types declared among the arguments. */
4235 for (tem
= nreverse (get_pending_sizes ()); tem
; tem
= TREE_CHAIN (tem
))
4236 expand_expr (TREE_VALUE (tem
), NULL_RTX
, VOIDmode
, 0);
4238 /* Make sure there is a line number after the function entry setup code. */
4239 force_next_line_note ();
4242 /* Generate RTL for the end of the current function.
4243 FILENAME and LINE are the current position in the source file. */
4245 /* It is up to language-specific callers to do cleanups for parameters. */
4248 expand_function_end (filename
, line
)
4255 static rtx initial_trampoline
;
4257 #ifdef NON_SAVING_SETJMP
4258 /* Don't put any variables in registers if we call setjmp
4259 on a machine that fails to restore the registers. */
4260 if (NON_SAVING_SETJMP
&& current_function_calls_setjmp
)
4262 setjmp_protect (DECL_INITIAL (current_function_decl
));
4263 setjmp_protect_args ();
4267 /* Save the argument pointer if a save area was made for it. */
4268 if (arg_pointer_save_area
)
4270 rtx x
= gen_move_insn (arg_pointer_save_area
, virtual_incoming_args_rtx
);
4271 emit_insn_before (x
, tail_recursion_reentry
);
4274 /* Initialize any trampolines required by this function. */
4275 for (link
= trampoline_list
; link
; link
= TREE_CHAIN (link
))
4277 tree function
= TREE_PURPOSE (link
);
4278 rtx context
= lookup_static_chain (function
);
4279 rtx tramp
= RTL_EXPR_RTL (TREE_VALUE (link
));
4282 /* First make sure this compilation has a template for
4283 initializing trampolines. */
4284 if (initial_trampoline
== 0)
4286 end_temporary_allocation ();
4288 = gen_rtx (MEM
, BLKmode
, assemble_trampoline_template ());
4289 resume_temporary_allocation ();
4292 /* Generate insns to initialize the trampoline. */
4294 tramp
= change_address (initial_trampoline
, BLKmode
,
4295 round_trampoline_addr (XEXP (tramp
, 0)));
4296 emit_block_move (tramp
, initial_trampoline
, GEN_INT (TRAMPOLINE_SIZE
),
4297 FUNCTION_BOUNDARY
/ BITS_PER_UNIT
);
4298 INITIALIZE_TRAMPOLINE (XEXP (tramp
, 0),
4299 XEXP (DECL_RTL (function
), 0), context
);
4303 /* Put those insns at entry to the containing function (this one). */
4304 emit_insns_before (seq
, tail_recursion_reentry
);
4306 /* Clear the trampoline_list for the next function. */
4307 trampoline_list
= 0;
4309 #if 0 /* I think unused parms are legitimate enough. */
4310 /* Warn about unused parms. */
4315 for (decl
= DECL_ARGUMENTS (current_function_decl
);
4316 decl
; decl
= TREE_CHAIN (decl
))
4317 if (! TREE_USED (decl
) && TREE_CODE (decl
) == VAR_DECL
)
4318 warning_with_decl (decl
, "unused parameter `%s'");
4322 /* Delete handlers for nonlocal gotos if nothing uses them. */
4323 if (nonlocal_goto_handler_slot
!= 0 && !current_function_has_nonlocal_label
)
4326 /* End any sequences that failed to be closed due to syntax errors. */
4327 while (in_sequence_p ())
4330 /* Outside function body, can't compute type's actual size
4331 until next function's body starts. */
4332 immediate_size_expand
--;
4334 /* If doing stupid register allocation,
4335 mark register parms as dying here. */
4340 for (i
= LAST_VIRTUAL_REGISTER
+ 1; i
< max_parm_reg
; i
++)
4341 use_variable (regno_reg_rtx
[i
]);
4343 /* Likewise for the regs of all the SAVE_EXPRs in the function. */
4345 for (tem
= save_expr_regs
; tem
; tem
= XEXP (tem
, 1))
4347 use_variable (XEXP (tem
, 0));
4348 use_variable_after (XEXP (tem
, 0), parm_birth_insn
);
4351 if (current_function_internal_arg_pointer
!= virtual_incoming_args_rtx
)
4352 use_variable (current_function_internal_arg_pointer
);
4355 clear_pending_stack_adjust ();
4356 do_pending_stack_adjust ();
4358 /* Mark the end of the function body.
4359 If control reaches this insn, the function can drop through
4360 without returning a value. */
4361 emit_note (NULL_PTR
, NOTE_INSN_FUNCTION_END
);
4363 /* Output a linenumber for the end of the function.
4364 SDB depends on this. */
4365 emit_line_note_force (filename
, line
);
4367 /* Output the label for the actual return from the function,
4368 if one is expected. This happens either because a function epilogue
4369 is used instead of a return instruction, or because a return was done
4370 with a goto in order to run local cleanups, or because of pcc-style
4371 structure returning. */
4374 emit_label (return_label
);
4376 /* If we had calls to alloca, and this machine needs
4377 an accurate stack pointer to exit the function,
4378 insert some code to save and restore the stack pointer. */
4379 #ifdef EXIT_IGNORE_STACK
4380 if (! EXIT_IGNORE_STACK
)
4382 if (current_function_calls_alloca
)
4386 emit_stack_save (SAVE_FUNCTION
, &tem
, parm_birth_insn
);
4387 emit_stack_restore (SAVE_FUNCTION
, tem
, NULL_RTX
);
4390 /* If scalar return value was computed in a pseudo-reg,
4391 copy that to the hard return register. */
4392 if (DECL_RTL (DECL_RESULT (current_function_decl
)) != 0
4393 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
4394 && (REGNO (DECL_RTL (DECL_RESULT (current_function_decl
)))
4395 >= FIRST_PSEUDO_REGISTER
))
4397 rtx real_decl_result
;
4399 #ifdef FUNCTION_OUTGOING_VALUE
4401 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl
)),
4402 current_function_decl
);
4405 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl
)),
4406 current_function_decl
);
4408 REG_FUNCTION_VALUE_P (real_decl_result
) = 1;
4409 emit_move_insn (real_decl_result
,
4410 DECL_RTL (DECL_RESULT (current_function_decl
)));
4411 emit_insn (gen_rtx (USE
, VOIDmode
, real_decl_result
));
4414 /* If returning a structure, arrange to return the address of the value
4415 in a place where debuggers expect to find it.
4417 If returning a structure PCC style,
4418 the caller also depends on this value.
4419 And current_function_returns_pcc_struct is not necessarily set. */
4420 if (current_function_returns_struct
4421 || current_function_returns_pcc_struct
)
4423 rtx value_address
= XEXP (DECL_RTL (DECL_RESULT (current_function_decl
)), 0);
4424 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
4425 #ifdef FUNCTION_OUTGOING_VALUE
4427 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type
),
4428 current_function_decl
);
4431 = FUNCTION_VALUE (build_pointer_type (type
),
4432 current_function_decl
);
4435 /* Mark this as a function return value so integrate will delete the
4436 assignment and USE below when inlining this function. */
4437 REG_FUNCTION_VALUE_P (outgoing
) = 1;
4439 emit_move_insn (outgoing
, value_address
);
4440 use_variable (outgoing
);
4443 /* Output a return insn if we are using one.
4444 Otherwise, let the rtl chain end here, to drop through
4445 into the epilogue. */
4450 emit_jump_insn (gen_return ());
4455 /* Fix up any gotos that jumped out to the outermost
4456 binding level of the function.
4457 Must follow emitting RETURN_LABEL. */
4459 /* If you have any cleanups to do at this point,
4460 and they need to create temporary variables,
4461 then you will lose. */
4462 fixup_gotos (NULL_PTR
, NULL_RTX
, NULL_TREE
, get_insns (), 0);
4465 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
4467 static int *prologue
;
4468 static int *epilogue
;
4470 /* Create an array that records the INSN_UIDs of INSNS (either a sequence
4471 or a single insn). */
4474 record_insns (insns
)
4479 if (GET_CODE (insns
) == SEQUENCE
)
4481 int len
= XVECLEN (insns
, 0);
4482 vec
= (int *) oballoc ((len
+ 1) * sizeof (int));
4485 vec
[len
] = INSN_UID (XVECEXP (insns
, 0, len
));
4489 vec
= (int *) oballoc (2 * sizeof (int));
4490 vec
[0] = INSN_UID (insns
);
4496 /* Determine how many INSN_UIDs in VEC are part of INSN. */
4499 contains (insn
, vec
)
4505 if (GET_CODE (insn
) == INSN
4506 && GET_CODE (PATTERN (insn
)) == SEQUENCE
)
4509 for (i
= XVECLEN (PATTERN (insn
), 0) - 1; i
>= 0; i
--)
4510 for (j
= 0; vec
[j
]; j
++)
4511 if (INSN_UID (XVECEXP (PATTERN (insn
), 0, i
)) == vec
[j
])
4517 for (j
= 0; vec
[j
]; j
++)
4518 if (INSN_UID (insn
) == vec
[j
])
4524 /* Generate the prologe and epilogue RTL if the machine supports it. Thread
4525 this into place with notes indicating where the prologue ends and where
4526 the epilogue begins. Update the basic block information when possible. */
4529 thread_prologue_and_epilogue_insns (f
)
4532 #ifdef HAVE_prologue
4535 rtx head
, seq
, insn
;
4537 /* The first insn (a NOTE_INSN_DELETED) is followed by zero or more
4538 prologue insns and a NOTE_INSN_PROLOGUE_END. */
4539 emit_note_after (NOTE_INSN_PROLOGUE_END
, f
);
4540 seq
= gen_prologue ();
4541 head
= emit_insn_after (seq
, f
);
4543 /* Include the new prologue insns in the first block. Ignore them
4544 if they form a basic block unto themselves. */
4545 if (basic_block_head
&& n_basic_blocks
4546 && GET_CODE (basic_block_head
[0]) != CODE_LABEL
)
4547 basic_block_head
[0] = NEXT_INSN (f
);
4549 /* Retain a map of the prologue insns. */
4550 prologue
= record_insns (GET_CODE (seq
) == SEQUENCE
? seq
: head
);
4556 #ifdef HAVE_epilogue
4559 rtx insn
= get_last_insn ();
4560 rtx prev
= prev_nonnote_insn (insn
);
4562 /* If we end with a BARRIER, we don't need an epilogue. */
4563 if (! (prev
&& GET_CODE (prev
) == BARRIER
))
4567 /* The last basic block ends with a NOTE_INSN_EPILOGUE_BEG,
4568 the epilogue insns (this must include the jump insn that
4569 returns), USE insns ad the end of a function, and a BARRIER. */
4571 emit_barrier_after (insn
);
4573 /* Place the epilogue before the USE insns at the end of a
4576 && GET_CODE (prev
) == INSN
4577 && GET_CODE (PATTERN (prev
)) == USE
)
4579 insn
= PREV_INSN (prev
);
4580 prev
= prev_nonnote_insn (prev
);
4583 seq
= gen_epilogue ();
4584 tail
= emit_jump_insn_after (seq
, insn
);
4585 emit_note_after (NOTE_INSN_EPILOGUE_BEG
, insn
);
4587 /* Include the new epilogue insns in the last block. Ignore
4588 them if they form a basic block unto themselves. */
4589 if (basic_block_end
&& n_basic_blocks
4590 && GET_CODE (basic_block_end
[n_basic_blocks
- 1]) != JUMP_INSN
)
4591 basic_block_end
[n_basic_blocks
- 1] = tail
;
4593 /* Retain a map of the epilogue insns. */
4594 epilogue
= record_insns (GET_CODE (seq
) == SEQUENCE
? seq
: tail
);
4602 /* Reposition the prologue-end and epilogue-begin notes after instruction
4603 scheduling and delayed branch scheduling. */
4606 reposition_prologue_and_epilogue_notes (f
)
4609 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
4610 /* Reposition the prologue and epilogue notes. */
4618 register rtx insn
, note
= 0;
4620 /* Scan from the beginning until we reach the last prologue insn.
4621 We apparently can't depend on basic_block_{head,end} after
4623 for (len
= 0; prologue
[len
]; len
++)
4625 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
4626 if (GET_CODE (insn
) == NOTE
)
4628 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_PROLOGUE_END
)
4631 else if ((len
-= contains (insn
, prologue
)) == 0)
4633 /* Find the prologue-end note if we haven't already, and
4634 move it to just after the last prologue insn. */
4636 for (note
= insn
; note
= NEXT_INSN (note
);)
4637 if (GET_CODE (note
) == NOTE
4638 && NOTE_LINE_NUMBER (note
) == NOTE_INSN_PROLOGUE_END
)
4640 next
= NEXT_INSN (note
);
4641 prev
= PREV_INSN (note
);
4643 NEXT_INSN (prev
) = next
;
4645 PREV_INSN (next
) = prev
;
4646 add_insn_after (note
, insn
);
4653 register rtx insn
, note
= 0;
4655 /* Scan from the end until we reach the first epilogue insn.
4656 We apparently can't depend on basic_block_{head,end} after
4658 for (len
= 0; epilogue
[len
]; len
++)
4660 for (insn
= get_last_insn (); insn
; insn
= PREV_INSN (insn
))
4661 if (GET_CODE (insn
) == NOTE
)
4663 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EPILOGUE_BEG
)
4666 else if ((len
-= contains (insn
, epilogue
)) == 0)
4668 /* Find the epilogue-begin note if we haven't already, and
4669 move it to just before the first epilogue insn. */
4671 for (note
= insn
; note
= PREV_INSN (note
);)
4672 if (GET_CODE (note
) == NOTE
4673 && NOTE_LINE_NUMBER (note
) == NOTE_INSN_EPILOGUE_BEG
)
4675 next
= NEXT_INSN (note
);
4676 prev
= PREV_INSN (note
);
4678 NEXT_INSN (prev
) = next
;
4680 PREV_INSN (next
) = prev
;
4681 add_insn_after (note
, PREV_INSN (insn
));
4686 #endif /* HAVE_prologue or HAVE_epilogue */