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);
437 /* Restore the last saved context, at the end of a nested function.
438 This function is called from language-specific code. */
441 pop_function_context ()
443 struct function *p = outer_function_chain;
445 outer_function_chain = p->next;
447 current_function_name = p->name;
448 current_function_decl = p->decl;
449 current_function_pops_args = p->pops_args;
450 current_function_returns_struct = p->returns_struct;
451 current_function_returns_pcc_struct = p->returns_pcc_struct;
452 current_function_needs_context = p->needs_context;
453 current_function_calls_setjmp = p->calls_setjmp;
454 current_function_calls_longjmp = p->calls_longjmp;
455 current_function_calls_alloca = p->calls_alloca;
456 current_function_has_nonlocal_label = p->has_nonlocal_label;
457 current_function_contains_functions = 1;
458 current_function_args_size = p->args_size;
459 current_function_pretend_args_size = p->pretend_args_size;
460 current_function_arg_offset_rtx = p->arg_offset_rtx;
461 current_function_uses_const_pool = p->uses_const_pool;
462 current_function_uses_pic_offset_table = p->uses_pic_offset_table;
463 current_function_internal_arg_pointer = p->internal_arg_pointer;
464 max_parm_reg = p->max_parm_reg;
465 parm_reg_stack_loc = p->parm_reg_stack_loc;
466 current_function_outgoing_args_size = p->outgoing_args_size;
467 current_function_return_rtx = p->return_rtx;
468 nonlocal_goto_handler_slot = p->nonlocal_goto_handler_slot;
469 nonlocal_goto_stack_level = p->nonlocal_goto_stack_level;
470 nonlocal_labels = p->nonlocal_labels;
471 cleanup_label = p->cleanup_label;
472 return_label = p->return_label;
473 save_expr_regs = p->save_expr_regs;
474 stack_slot_list = p->stack_slot_list;
475 parm_birth_insn = p->parm_birth_insn;
476 frame_offset = p->frame_offset;
477 tail_recursion_label = p->tail_recursion_label;
478 tail_recursion_reentry = p->tail_recursion_reentry;
479 arg_pointer_save_area = p->arg_pointer_save_area;
480 rtl_expr_chain = p->rtl_expr_chain;
481 last_parm_insn = p->last_parm_insn;
482 context_display = p->context_display;
483 trampoline_list = p->trampoline_list;
484 function_call_count = p->function_call_count;
485 temp_slots = p->temp_slots;
486 temp_slot_level = p->temp_slot_level;
487 current_function_epilogue_delay_list = p->epilogue_delay_list;
489 restore_tree_status (p);
490 restore_storage_status (p);
491 restore_expr_status (p);
492 restore_emit_status (p);
493 restore_stmt_status (p);
495 /* Finish doing put_var_into_stack for any of our variables
496 which became addressable during the nested function. */
498 struct var_refs_queue *queue = p->fixup_var_refs_queue;
499 for (; queue; queue = queue->next)
500 fixup_var_refs (queue->modified, queue->promoted_mode, queue->unsignedp);
505 /* Reset variables that have known state during rtx generation. */
506 rtx_equal_function_value_matters = 1;
507 virtuals_instantiated = 0;
510 /* Allocate fixed slots in the stack frame of the current function. */
512 /* Return size needed for stack frame based on slots so far allocated.
513 This size counts from zero. It is not rounded to STACK_BOUNDARY;
514 the caller may have to do that. */
519 #ifdef FRAME_GROWS_DOWNWARD
520 return -frame_offset;
526 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
527 with machine mode MODE.
529 ALIGN controls the amount of alignment for the address of the slot:
530 0 means according to MODE,
531 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
532 positive specifies alignment boundary in bits.
534 We do not round to stack_boundary here. */
537 assign_stack_local (mode, size, align)
538 enum machine_mode mode;
542 register rtx x, addr;
543 int bigend_correction = 0;
548 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
550 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
552 else if (align == -1)
554 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
555 size = CEIL_ROUND (size, alignment);
558 alignment = align / BITS_PER_UNIT;
560 /* Round frame offset to that alignment.
561 We must be careful here, since FRAME_OFFSET might be negative and
562 division with a negative dividend isn't as well defined as we might
563 like. So we instead assume that ALIGNMENT is a power of two and
564 use logical operations which are unambiguous. */
565 #ifdef FRAME_GROWS_DOWNWARD
566 frame_offset = FLOOR_ROUND (frame_offset, alignment);
568 frame_offset = CEIL_ROUND (frame_offset, alignment);
571 /* On a big-endian machine, if we are allocating more space than we will use,
572 use the least significant bytes of those that are allocated. */
575 bigend_correction = size - GET_MODE_SIZE (mode);
578 #ifdef FRAME_GROWS_DOWNWARD
579 frame_offset -= size;
582 /* If we have already instantiated virtual registers, return the actual
583 address relative to the frame pointer. */
584 if (virtuals_instantiated)
585 addr = plus_constant (frame_pointer_rtx,
586 (frame_offset + bigend_correction
587 + STARTING_FRAME_OFFSET));
589 addr = plus_constant (virtual_stack_vars_rtx,
590 frame_offset + bigend_correction);
592 #ifndef FRAME_GROWS_DOWNWARD
593 frame_offset += size;
596 x = gen_rtx (MEM, mode, addr);
598 stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, x, stack_slot_list);
603 /* Assign a stack slot in a containing function.
604 First three arguments are same as in preceding function.
605 The last argument specifies the function to allocate in. */
608 assign_outer_stack_local (mode, size, align, function)
609 enum machine_mode mode;
612 struct function *function;
614 register rtx x, addr;
615 int bigend_correction = 0;
618 /* Allocate in the memory associated with the function in whose frame
620 push_obstacks (function->function_obstack,
621 function->function_maybepermanent_obstack);
625 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
627 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
629 else if (align == -1)
631 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
632 size = CEIL_ROUND (size, alignment);
635 alignment = align / BITS_PER_UNIT;
637 /* Round frame offset to that alignment. */
638 #ifdef FRAME_GROWS_DOWNWARD
639 frame_offset = FLOOR_ROUND (frame_offset, alignment);
641 frame_offset = CEIL_ROUND (frame_offset, alignment);
644 /* On a big-endian machine, if we are allocating more space than we will use,
645 use the least significant bytes of those that are allocated. */
648 bigend_correction = size - GET_MODE_SIZE (mode);
651 #ifdef FRAME_GROWS_DOWNWARD
652 function->frame_offset -= size;
654 addr = plus_constant (virtual_stack_vars_rtx,
655 function->frame_offset + bigend_correction);
656 #ifndef FRAME_GROWS_DOWNWARD
657 function->frame_offset += size;
660 x = gen_rtx (MEM, mode, addr);
662 function->stack_slot_list
663 = gen_rtx (EXPR_LIST, VOIDmode, x, function->stack_slot_list);
670 /* Allocate a temporary stack slot and record it for possible later
673 MODE is the machine mode to be given to the returned rtx.
675 SIZE is the size in units of the space required. We do no rounding here
676 since assign_stack_local will do any required rounding.
678 KEEP is non-zero if this slot is to be retained after a call to
679 free_temp_slots. Automatic variables for a block are allocated with this
683 assign_stack_temp (mode, size, keep)
684 enum machine_mode mode;
688 struct temp_slot *p, *best_p = 0;
690 /* First try to find an available, already-allocated temporary that is the
691 exact size we require. */
692 for (p = temp_slots; p; p = p->next)
693 if (p->size == size && GET_MODE (p->slot) == mode && ! p->in_use)
696 /* If we didn't find, one, try one that is larger than what we want. We
697 find the smallest such. */
699 for (p = temp_slots; p; p = p->next)
700 if (p->size > size && GET_MODE (p->slot) == mode && ! p->in_use
701 && (best_p == 0 || best_p->size > p->size))
704 /* Make our best, if any, the one to use. */
708 /* If we still didn't find one, make a new temporary. */
711 p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
713 /* If the temp slot mode doesn't indicate the alignment,
714 use the largest possible, so no one will be disappointed. */
715 p->slot = assign_stack_local (mode, size, mode == BLKmode ? -1 : 0);
716 p->next = temp_slots;
721 p->level = temp_slot_level;
726 /* If X could be a reference to a temporary slot, mark that slot as belonging
727 to the to one level higher. If X matched one of our slots, just mark that
728 one. Otherwise, we can't easily predict which it is, so upgrade all of
729 them. Kept slots need not be touched.
731 This is called when an ({...}) construct occurs and a statement
732 returns a value in memory. */
735 preserve_temp_slots (x)
740 /* If X is not in memory or is at a constant address, it cannot be in
742 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
745 /* First see if we can find a match. */
746 for (p = temp_slots; p; p = p->next)
747 if (p->in_use && x == p->slot)
753 /* Otherwise, preserve all non-kept slots at this level. */
754 for (p = temp_slots; p; p = p->next)
755 if (p->in_use && p->level == temp_slot_level && ! p->keep)
759 /* Free all temporaries used so far. This is normally called at the end
760 of generating code for a statement. */
767 for (p = temp_slots; p; p = p->next)
768 if (p->in_use && p->level == temp_slot_level && ! p->keep)
772 /* Push deeper into the nesting level for stack temporaries. */
777 /* For GNU C++, we must allow a sequence to be emitted anywhere in
778 the level where the sequence was started. By not changing levels
779 when the compiler is inside a sequence, the temporaries for the
780 sequence and the temporaries will not unwittingly conflict with
781 the temporaries for other sequences and/or code at that level. */
782 if (in_sequence_p ())
788 /* Pop a temporary nesting level. All slots in use in the current level
796 /* See comment in push_temp_slots about why we don't change levels
798 if (in_sequence_p ())
801 for (p = temp_slots; p; p = p->next)
802 if (p->in_use && p->level == temp_slot_level)
808 /* Retroactively move an auto variable from a register to a stack slot.
809 This is done when an address-reference to the variable is seen. */
812 put_var_into_stack (decl)
816 register rtx new = 0;
817 enum machine_mode promoted_mode, decl_mode;
818 struct function *function = 0;
819 tree context = decl_function_context (decl);
821 /* Get the current rtl used for this object and it's original mode. */
822 reg = TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl) : DECL_RTL (decl);
824 /* No need to do anything if decl has no rtx yet
825 since in that case caller is setting TREE_ADDRESSABLE
826 and a stack slot will be assigned when the rtl is made. */
830 /* Get the declared mode for this object. */
831 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
833 /* Get the mode it's actually stored in. */
834 promoted_mode = GET_MODE (reg);
836 /* If this variable comes from an outer function,
837 find that function's saved context. */
838 if (context != current_function_decl)
839 for (function = outer_function_chain; function; function = function->next)
840 if (function->decl == context)
843 /* If this is a variable-size object with a pseudo to address it,
844 put that pseudo into the stack, if the var is nonlocal. */
845 if (DECL_NONLOCAL (decl)
846 && GET_CODE (reg) == MEM
847 && GET_CODE (XEXP (reg, 0)) == REG
848 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
850 if (GET_CODE (reg) != REG)
855 if (REGNO (reg) < function->max_parm_reg)
856 new = function->parm_reg_stack_loc[REGNO (reg)];
858 new = assign_outer_stack_local (GET_MODE (reg),
859 GET_MODE_SIZE (decl_mode),
864 if (REGNO (reg) < max_parm_reg)
865 new = parm_reg_stack_loc[REGNO (reg)];
867 new = assign_stack_local (GET_MODE (reg),
868 GET_MODE_SIZE (decl_mode), 0);
871 XEXP (reg, 0) = XEXP (new, 0);
872 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
873 REG_USERVAR_P (reg) = 0;
875 PUT_MODE (reg, decl_mode);
877 /* If this is a memory ref that contains aggregate components,
878 mark it as such for cse and loop optimize. */
879 MEM_IN_STRUCT_P (reg)
880 = (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
881 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
882 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE);
884 /* Now make sure that all refs to the variable, previously made
885 when it was a register, are fixed up to be valid again. */
888 struct var_refs_queue *temp;
890 /* Variable is inherited; fix it up when we get back to its function. */
891 push_obstacks (function->function_obstack,
892 function->function_maybepermanent_obstack);
894 = (struct var_refs_queue *) oballoc (sizeof (struct var_refs_queue));
895 temp->modified = reg;
896 temp->promoted_mode = promoted_mode;
897 temp->unsignedp = TREE_UNSIGNED (TREE_TYPE (decl));
898 temp->next = function->fixup_var_refs_queue;
899 function->fixup_var_refs_queue = temp;
903 /* Variable is local; fix it up now. */
904 fixup_var_refs (reg, promoted_mode, TREE_UNSIGNED (TREE_TYPE (decl)));
908 fixup_var_refs (var, promoted_mode, unsignedp)
910 enum machine_mode promoted_mode;
914 rtx first_insn = get_insns ();
915 struct sequence_stack *stack = sequence_stack;
916 tree rtl_exps = rtl_expr_chain;
918 /* Must scan all insns for stack-refs that exceed the limit. */
919 fixup_var_refs_insns (var, promoted_mode, unsignedp, first_insn, stack == 0);
921 /* Scan all pending sequences too. */
922 for (; stack; stack = stack->next)
924 push_to_sequence (stack->first);
925 fixup_var_refs_insns (var, promoted_mode, unsignedp,
926 stack->first, stack->next != 0);
927 /* Update remembered end of sequence
928 in case we added an insn at the end. */
929 stack->last = get_last_insn ();
933 /* Scan all waiting RTL_EXPRs too. */
934 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
936 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
937 if (seq != const0_rtx && seq != 0)
939 push_to_sequence (seq);
940 fixup_var_refs_insns (var, promoted_mode, unsignedp, seq, 0);
946 /* This structure is used by the following two functions to record MEMs or
947 pseudos used to replace VAR, any SUBREGs of VAR, and any MEMs containing
948 VAR as an address. We need to maintain this list in case two operands of
949 an insn were required to match; in that case we must ensure we use the
952 struct fixup_replacement
956 struct fixup_replacement *next;
959 /* REPLACEMENTS is a pointer to a list of the above structures and X is
960 some part of an insn. Return a struct fixup_replacement whose OLD
961 value is equal to X. Allocate a new structure if no such entry exists. */
963 static struct fixup_replacement *
964 find_replacement (replacements, x)
965 struct fixup_replacement **replacements;
968 struct fixup_replacement *p;
970 /* See if we have already replaced this. */
971 for (p = *replacements; p && p->old != x; p = p->next)
976 p = (struct fixup_replacement *) oballoc (sizeof (struct fixup_replacement));
979 p->next = *replacements;
986 /* Scan the insn-chain starting with INSN for refs to VAR
987 and fix them up. TOPLEVEL is nonzero if this chain is the
988 main chain of insns for the current function. */
991 fixup_var_refs_insns (var, promoted_mode, unsignedp, insn, toplevel)
993 enum machine_mode promoted_mode;
1000 rtx next = NEXT_INSN (insn);
1002 if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN
1003 || GET_CODE (insn) == JUMP_INSN)
1005 /* The insn to load VAR from a home in the arglist
1006 is now a no-op. When we see it, just delete it. */
1008 && GET_CODE (PATTERN (insn)) == SET
1009 && SET_DEST (PATTERN (insn)) == var
1010 && rtx_equal_p (SET_SRC (PATTERN (insn)), var))
1012 next = delete_insn (insn);
1013 if (insn == last_parm_insn)
1014 last_parm_insn = PREV_INSN (next);
1018 /* See if we have to do anything to INSN now that VAR is in
1019 memory. If it needs to be loaded into a pseudo, use a single
1020 pseudo for the entire insn in case there is a MATCH_DUP
1021 between two operands. We pass a pointer to the head of
1022 a list of struct fixup_replacements. If fixup_var_refs_1
1023 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1024 it will record them in this list.
1026 If it allocated a pseudo for any replacement, we copy into
1029 struct fixup_replacement *replacements = 0;
1031 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1034 while (replacements)
1036 if (GET_CODE (replacements->new) == REG)
1041 /* OLD might be a (subreg (mem)). */
1042 if (GET_CODE (replacements->old) == SUBREG)
1044 = fixup_memory_subreg (replacements->old, insn, 0);
1047 = fixup_stack_1 (replacements->old, insn);
1049 /* We can not separate USE insns from the CALL_INSN
1050 that they belong to. If this is a CALL_INSN, insert
1051 the move insn before the USE insns preceding it
1052 instead of immediately before the insn. */
1053 if (GET_CODE (insn) == CALL_INSN)
1055 insert_before = insn;
1056 while (GET_CODE (PREV_INSN (insert_before)) == INSN
1057 && GET_CODE (PATTERN (PREV_INSN (insert_before))) == USE)
1058 insert_before = PREV_INSN (insert_before);
1061 insert_before = insn;
1063 /* If we are changing the mode, do a conversion.
1064 This might be wasteful, but combine.c will
1065 eliminate much of the waste. */
1067 if (GET_MODE (replacements->new)
1068 != GET_MODE (replacements->old))
1071 convert_move (replacements->new,
1072 replacements->old, unsignedp);
1073 seq = gen_sequence ();
1077 seq = gen_move_insn (replacements->new,
1080 emit_insn_before (seq, insert_before);
1083 replacements = replacements->next;
1087 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1088 But don't touch other insns referred to by reg-notes;
1089 we will get them elsewhere. */
1090 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1091 if (GET_CODE (note) != INSN_LIST)
1092 XEXP (note, 0) = walk_fixup_memory_subreg (XEXP (note, 0), insn);
1098 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1099 See if the rtx expression at *LOC in INSN needs to be changed.
1101 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1102 contain a list of original rtx's and replacements. If we find that we need
1103 to modify this insn by replacing a memory reference with a pseudo or by
1104 making a new MEM to implement a SUBREG, we consult that list to see if
1105 we have already chosen a replacement. If none has already been allocated,
1106 we allocate it and update the list. fixup_var_refs_insns will copy VAR
1107 or the SUBREG, as appropriate, to the pseudo. */
1110 fixup_var_refs_1 (var, promoted_mode, loc, insn, replacements)
1112 enum machine_mode promoted_mode;
1115 struct fixup_replacement **replacements;
1118 register rtx x = *loc;
1119 RTX_CODE code = GET_CODE (x);
1121 register rtx tem, tem1;
1122 struct fixup_replacement *replacement;
1129 /* If we already have a replacement, use it. Otherwise,
1130 try to fix up this address in case it is invalid. */
1132 replacement = find_replacement (replacements, var);
1133 if (replacement->new)
1135 *loc = replacement->new;
1139 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1141 /* Unless we are forcing memory to register or we changed the mode,
1142 we can leave things the way they are if the insn is valid. */
1144 INSN_CODE (insn) = -1;
1145 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1146 && recog_memoized (insn) >= 0)
1149 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1153 /* If X contains VAR, we need to unshare it here so that we update
1154 each occurrence separately. But all identical MEMs in one insn
1155 must be replaced with the same rtx because of the possibility of
1158 if (reg_mentioned_p (var, x))
1160 replacement = find_replacement (replacements, x);
1161 if (replacement->new == 0)
1162 replacement->new = copy_most_rtx (x, var);
1164 *loc = x = replacement->new;
1180 /* Note that in some cases those types of expressions are altered
1181 by optimize_bit_field, and do not survive to get here. */
1182 if (XEXP (x, 0) == var
1183 || (GET_CODE (XEXP (x, 0)) == SUBREG
1184 && SUBREG_REG (XEXP (x, 0)) == var))
1186 /* Get TEM as a valid MEM in the mode presently in the insn.
1188 We don't worry about the possibility of MATCH_DUP here; it
1189 is highly unlikely and would be tricky to handle. */
1192 if (GET_CODE (tem) == SUBREG)
1193 tem = fixup_memory_subreg (tem, insn, 1);
1194 tem = fixup_stack_1 (tem, insn);
1196 /* Unless we want to load from memory, get TEM into the proper mode
1197 for an extract from memory. This can only be done if the
1198 extract is at a constant position and length. */
1200 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
1201 && GET_CODE (XEXP (x, 2)) == CONST_INT
1202 && ! mode_dependent_address_p (XEXP (tem, 0))
1203 && ! MEM_VOLATILE_P (tem))
1205 enum machine_mode wanted_mode = VOIDmode;
1206 enum machine_mode is_mode = GET_MODE (tem);
1207 int width = INTVAL (XEXP (x, 1));
1208 int pos = INTVAL (XEXP (x, 2));
1211 if (GET_CODE (x) == ZERO_EXTRACT)
1212 wanted_mode = insn_operand_mode[(int) CODE_FOR_extzv][1];
1215 if (GET_CODE (x) == SIGN_EXTRACT)
1216 wanted_mode = insn_operand_mode[(int) CODE_FOR_extv][1];
1218 /* If we have a narrower mode, we can do something. */
1219 if (wanted_mode != VOIDmode
1220 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
1222 int offset = pos / BITS_PER_UNIT;
1223 rtx old_pos = XEXP (x, 2);
1226 /* If the bytes and bits are counted differently, we
1227 must adjust the offset. */
1228 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1229 offset = (GET_MODE_SIZE (is_mode)
1230 - GET_MODE_SIZE (wanted_mode) - offset);
1233 pos %= GET_MODE_BITSIZE (wanted_mode);
1235 newmem = gen_rtx (MEM, wanted_mode,
1236 plus_constant (XEXP (tem, 0), offset));
1237 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
1238 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
1239 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
1241 /* Make the change and see if the insn remains valid. */
1242 INSN_CODE (insn) = -1;
1243 XEXP (x, 0) = newmem;
1244 XEXP (x, 2) = GEN_INT (pos);
1246 if (recog_memoized (insn) >= 0)
1249 /* Otherwise, restore old position. XEXP (x, 0) will be
1251 XEXP (x, 2) = old_pos;
1255 /* If we get here, the bitfield extract insn can't accept a memory
1256 reference. Copy the input into a register. */
1258 tem1 = gen_reg_rtx (GET_MODE (tem));
1259 emit_insn_before (gen_move_insn (tem1, tem), insn);
1266 if (SUBREG_REG (x) == var)
1268 /* If this is a special SUBREG made because VAR was promoted
1269 from a wider mode, replace it with VAR and call ourself
1270 recursively, this time saying that the object previously
1271 had its current mode (by virtue of the SUBREG). */
1273 if (SUBREG_PROMOTED_VAR_P (x))
1276 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements);
1280 /* If this SUBREG makes VAR wider, it has become a paradoxical
1281 SUBREG with VAR in memory, but these aren't allowed at this
1282 stage of the compilation. So load VAR into a pseudo and take
1283 a SUBREG of that pseudo. */
1284 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
1286 replacement = find_replacement (replacements, var);
1287 if (replacement->new == 0)
1288 replacement->new = gen_reg_rtx (GET_MODE (var));
1289 SUBREG_REG (x) = replacement->new;
1293 /* See if we have already found a replacement for this SUBREG.
1294 If so, use it. Otherwise, make a MEM and see if the insn
1295 is recognized. If not, or if we should force MEM into a register,
1296 make a pseudo for this SUBREG. */
1297 replacement = find_replacement (replacements, x);
1298 if (replacement->new)
1300 *loc = replacement->new;
1304 replacement->new = *loc = fixup_memory_subreg (x, insn, 0);
1306 if (! flag_force_mem && recog_memoized (insn) >= 0)
1309 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
1315 /* First do special simplification of bit-field references. */
1316 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
1317 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
1318 optimize_bit_field (x, insn, 0);
1319 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
1320 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
1321 optimize_bit_field (x, insn, NULL_PTR);
1323 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
1324 insn into a pseudo and store the low part of the pseudo into VAR. */
1325 if (GET_CODE (SET_DEST (x)) == SUBREG
1326 && SUBREG_REG (SET_DEST (x)) == var
1327 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
1328 > GET_MODE_SIZE (GET_MODE (var))))
1330 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
1331 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
1338 rtx dest = SET_DEST (x);
1339 rtx src = SET_SRC (x);
1340 rtx outerdest = dest;
1342 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
1343 || GET_CODE (dest) == SIGN_EXTRACT
1344 || GET_CODE (dest) == ZERO_EXTRACT)
1345 dest = XEXP (dest, 0);
1347 if (GET_CODE (src) == SUBREG)
1348 src = XEXP (src, 0);
1350 /* If VAR does not appear at the top level of the SET
1351 just scan the lower levels of the tree. */
1353 if (src != var && dest != var)
1356 /* We will need to rerecognize this insn. */
1357 INSN_CODE (insn) = -1;
1360 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var)
1362 /* Since this case will return, ensure we fixup all the
1364 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
1365 insn, replacements);
1366 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
1367 insn, replacements);
1368 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
1369 insn, replacements);
1371 tem = XEXP (outerdest, 0);
1373 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
1374 that may appear inside a ZERO_EXTRACT.
1375 This was legitimate when the MEM was a REG. */
1376 if (GET_CODE (tem) == SUBREG
1377 && SUBREG_REG (tem) == var)
1378 tem = fixup_memory_subreg (tem, insn, 1);
1380 tem = fixup_stack_1 (tem, insn);
1382 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
1383 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
1384 && ! mode_dependent_address_p (XEXP (tem, 0))
1385 && ! MEM_VOLATILE_P (tem))
1387 enum machine_mode wanted_mode
1388 = insn_operand_mode[(int) CODE_FOR_insv][0];
1389 enum machine_mode is_mode = GET_MODE (tem);
1390 int width = INTVAL (XEXP (outerdest, 1));
1391 int pos = INTVAL (XEXP (outerdest, 2));
1393 /* If we have a narrower mode, we can do something. */
1394 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
1396 int offset = pos / BITS_PER_UNIT;
1397 rtx old_pos = XEXP (outerdest, 2);
1400 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1401 offset = (GET_MODE_SIZE (is_mode)
1402 - GET_MODE_SIZE (wanted_mode) - offset);
1405 pos %= GET_MODE_BITSIZE (wanted_mode);
1407 newmem = gen_rtx (MEM, wanted_mode,
1408 plus_constant (XEXP (tem, 0), offset));
1409 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
1410 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
1411 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
1413 /* Make the change and see if the insn remains valid. */
1414 INSN_CODE (insn) = -1;
1415 XEXP (outerdest, 0) = newmem;
1416 XEXP (outerdest, 2) = GEN_INT (pos);
1418 if (recog_memoized (insn) >= 0)
1421 /* Otherwise, restore old position. XEXP (x, 0) will be
1423 XEXP (outerdest, 2) = old_pos;
1427 /* If we get here, the bit-field store doesn't allow memory
1428 or isn't located at a constant position. Load the value into
1429 a register, do the store, and put it back into memory. */
1431 tem1 = gen_reg_rtx (GET_MODE (tem));
1432 emit_insn_before (gen_move_insn (tem1, tem), insn);
1433 emit_insn_after (gen_move_insn (tem, tem1), insn);
1434 XEXP (outerdest, 0) = tem1;
1439 /* STRICT_LOW_PART is a no-op on memory references
1440 and it can cause combinations to be unrecognizable,
1443 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
1444 SET_DEST (x) = XEXP (SET_DEST (x), 0);
1446 /* A valid insn to copy VAR into or out of a register
1447 must be left alone, to avoid an infinite loop here.
1448 If the reference to VAR is by a subreg, fix that up,
1449 since SUBREG is not valid for a memref.
1450 Also fix up the address of the stack slot. */
1452 if ((SET_SRC (x) == var
1453 || (GET_CODE (SET_SRC (x)) == SUBREG
1454 && SUBREG_REG (SET_SRC (x)) == var))
1455 && (GET_CODE (SET_DEST (x)) == REG
1456 || (GET_CODE (SET_DEST (x)) == SUBREG
1457 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
1458 && recog_memoized (insn) >= 0)
1460 replacement = find_replacement (replacements, SET_SRC (x));
1461 if (replacement->new)
1463 SET_SRC (x) = replacement->new;
1466 else if (GET_CODE (SET_SRC (x)) == SUBREG)
1467 SET_SRC (x) = replacement->new
1468 = fixup_memory_subreg (SET_SRC (x), insn, 0);
1470 SET_SRC (x) = replacement->new
1471 = fixup_stack_1 (SET_SRC (x), insn);
1475 if ((SET_DEST (x) == var
1476 || (GET_CODE (SET_DEST (x)) == SUBREG
1477 && SUBREG_REG (SET_DEST (x)) == var))
1478 && (GET_CODE (SET_SRC (x)) == REG
1479 || (GET_CODE (SET_SRC (x)) == SUBREG
1480 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
1481 && recog_memoized (insn) >= 0)
1483 if (GET_CODE (SET_DEST (x)) == SUBREG)
1484 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn, 0);
1486 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
1490 /* Otherwise, storing into VAR must be handled specially
1491 by storing into a temporary and copying that into VAR
1492 with a new insn after this one. Note that this case
1493 will be used when storing into a promoted scalar since
1494 the insn will now have different modes on the input
1495 and output and hence will be invalid (except for the case
1496 of setting it to a constant, which does not need any
1497 change if it is valid). We generate extra code in that case,
1498 but combine.c will eliminate it. */
1503 rtx fixeddest = SET_DEST (x);
1505 /* STRICT_LOW_PART can be discarded, around a MEM. */
1506 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
1507 fixeddest = XEXP (fixeddest, 0);
1508 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
1509 if (GET_CODE (fixeddest) == SUBREG)
1510 fixeddest = fixup_memory_subreg (fixeddest, insn, 0);
1512 fixeddest = fixup_stack_1 (fixeddest, insn);
1514 temp = gen_reg_rtx (GET_MODE (SET_SRC (x)) == VOIDmode
1515 ? GET_MODE (fixeddest)
1516 : GET_MODE (SET_SRC (x)));
1518 emit_insn_after (gen_move_insn (fixeddest,
1519 gen_lowpart (GET_MODE (fixeddest),
1523 SET_DEST (x) = temp;
1528 /* Nothing special about this RTX; fix its operands. */
1530 fmt = GET_RTX_FORMAT (code);
1531 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1534 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements);
1538 for (j = 0; j < XVECLEN (x, i); j++)
1539 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
1540 insn, replacements);
1545 /* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
1546 return an rtx (MEM:m1 newaddr) which is equivalent.
1547 If any insns must be emitted to compute NEWADDR, put them before INSN.
1549 UNCRITICAL nonzero means accept paradoxical subregs.
1550 This is used for subregs found inside of ZERO_EXTRACTs. */
1553 fixup_memory_subreg (x, insn, uncritical)
1558 int offset = SUBREG_WORD (x) * UNITS_PER_WORD;
1559 rtx addr = XEXP (SUBREG_REG (x), 0);
1560 enum machine_mode mode = GET_MODE (x);
1563 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
1564 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
1568 #if BYTES_BIG_ENDIAN
1569 offset += (MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
1570 - MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)));
1572 addr = plus_constant (addr, offset);
1573 if (!flag_force_addr && memory_address_p (mode, addr))
1574 /* Shortcut if no insns need be emitted. */
1575 return change_address (SUBREG_REG (x), mode, addr);
1577 result = change_address (SUBREG_REG (x), mode, addr);
1578 emit_insn_before (gen_sequence (), insn);
1583 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
1584 Replace subexpressions of X in place.
1585 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
1586 Otherwise return X, with its contents possibly altered.
1588 If any insns must be emitted to compute NEWADDR, put them before INSN. */
1591 walk_fixup_memory_subreg (x, insn)
1595 register enum rtx_code code;
1602 code = GET_CODE (x);
1604 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
1605 return fixup_memory_subreg (x, insn, 0);
1607 /* Nothing special about this RTX; fix its operands. */
1609 fmt = GET_RTX_FORMAT (code);
1610 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1613 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn);
1617 for (j = 0; j < XVECLEN (x, i); j++)
1619 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn);
1626 /* Fix up any references to stack slots that are invalid memory addresses
1627 because they exceed the maximum range of a displacement. */
1630 fixup_stack_slots ()
1634 /* Did we generate a stack slot that is out of range
1635 or otherwise has an invalid address? */
1636 if (invalid_stack_slot)
1638 /* Yes. Must scan all insns for stack-refs that exceed the limit. */
1639 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1640 if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN
1641 || GET_CODE (insn) == JUMP_INSN)
1642 fixup_stack_1 (PATTERN (insn), insn);
1647 /* For each memory ref within X, if it refers to a stack slot
1648 with an out of range displacement, put the address in a temp register
1649 (emitting new insns before INSN to load these registers)
1650 and alter the memory ref to use that register.
1651 Replace each such MEM rtx with a copy, to avoid clobberage. */
1654 fixup_stack_1 (x, insn)
1659 register RTX_CODE code = GET_CODE (x);
1664 register rtx ad = XEXP (x, 0);
1665 /* If we have address of a stack slot but it's not valid
1666 (displacement is too large), compute the sum in a register. */
1667 if (GET_CODE (ad) == PLUS
1668 && GET_CODE (XEXP (ad, 0)) == REG
1669 && REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
1670 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER
1671 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
1674 if (memory_address_p (GET_MODE (x), ad))
1678 temp = copy_to_reg (ad);
1679 seq = gen_sequence ();
1681 emit_insn_before (seq, insn);
1682 return change_address (x, VOIDmode, temp);
1687 fmt = GET_RTX_FORMAT (code);
1688 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1691 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
1695 for (j = 0; j < XVECLEN (x, i); j++)
1696 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
1702 /* Optimization: a bit-field instruction whose field
1703 happens to be a byte or halfword in memory
1704 can be changed to a move instruction.
1706 We call here when INSN is an insn to examine or store into a bit-field.
1707 BODY is the SET-rtx to be altered.
1709 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
1710 (Currently this is called only from function.c, and EQUIV_MEM
1714 optimize_bit_field (body, insn, equiv_mem)
1719 register rtx bitfield;
1722 enum machine_mode mode;
1724 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
1725 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
1726 bitfield = SET_DEST (body), destflag = 1;
1728 bitfield = SET_SRC (body), destflag = 0;
1730 /* First check that the field being stored has constant size and position
1731 and is in fact a byte or halfword suitably aligned. */
1733 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
1734 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
1735 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
1737 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
1739 register rtx memref = 0;
1741 /* Now check that the containing word is memory, not a register,
1742 and that it is safe to change the machine mode. */
1744 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
1745 memref = XEXP (bitfield, 0);
1746 else if (GET_CODE (XEXP (bitfield, 0)) == REG
1748 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
1749 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
1750 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
1751 memref = SUBREG_REG (XEXP (bitfield, 0));
1752 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
1754 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
1755 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
1758 && ! mode_dependent_address_p (XEXP (memref, 0))
1759 && ! MEM_VOLATILE_P (memref))
1761 /* Now adjust the address, first for any subreg'ing
1762 that we are now getting rid of,
1763 and then for which byte of the word is wanted. */
1765 register int offset = INTVAL (XEXP (bitfield, 2));
1766 /* Adjust OFFSET to count bits from low-address byte. */
1767 #if BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN
1768 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
1769 - offset - INTVAL (XEXP (bitfield, 1)));
1771 /* Adjust OFFSET to count bytes from low-address byte. */
1772 offset /= BITS_PER_UNIT;
1773 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
1775 offset += SUBREG_WORD (XEXP (bitfield, 0)) * UNITS_PER_WORD;
1776 #if BYTES_BIG_ENDIAN
1777 offset -= (MIN (UNITS_PER_WORD,
1778 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
1779 - MIN (UNITS_PER_WORD,
1780 GET_MODE_SIZE (GET_MODE (memref))));
1784 memref = change_address (memref, mode,
1785 plus_constant (XEXP (memref, 0), offset));
1787 /* Store this memory reference where
1788 we found the bit field reference. */
1792 validate_change (insn, &SET_DEST (body), memref, 1);
1793 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
1795 rtx src = SET_SRC (body);
1796 while (GET_CODE (src) == SUBREG
1797 && SUBREG_WORD (src) == 0)
1798 src = SUBREG_REG (src);
1799 if (GET_MODE (src) != GET_MODE (memref))
1800 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
1801 validate_change (insn, &SET_SRC (body), src, 1);
1803 else if (GET_MODE (SET_SRC (body)) != VOIDmode
1804 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
1805 /* This shouldn't happen because anything that didn't have
1806 one of these modes should have got converted explicitly
1807 and then referenced through a subreg.
1808 This is so because the original bit-field was
1809 handled by agg_mode and so its tree structure had
1810 the same mode that memref now has. */
1815 rtx dest = SET_DEST (body);
1817 while (GET_CODE (dest) == SUBREG
1818 && SUBREG_WORD (dest) == 0)
1819 dest = SUBREG_REG (dest);
1821 validate_change (insn, &SET_DEST (body), dest, 1);
1823 if (GET_MODE (dest) == GET_MODE (memref))
1824 validate_change (insn, &SET_SRC (body), memref, 1);
1827 /* Convert the mem ref to the destination mode. */
1828 rtx newreg = gen_reg_rtx (GET_MODE (dest));
1831 convert_move (newreg, memref,
1832 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
1836 validate_change (insn, &SET_SRC (body), newreg, 1);
1840 /* See if we can convert this extraction or insertion into
1841 a simple move insn. We might not be able to do so if this
1842 was, for example, part of a PARALLEL.
1844 If we succeed, write out any needed conversions. If we fail,
1845 it is hard to guess why we failed, so don't do anything
1846 special; just let the optimization be suppressed. */
1848 if (apply_change_group () && seq)
1849 emit_insns_before (seq, insn);
1854 /* These routines are responsible for converting virtual register references
1855 to the actual hard register references once RTL generation is complete.
1857 The following four variables are used for communication between the
1858 routines. They contain the offsets of the virtual registers from their
1859 respective hard registers. */
1861 static int in_arg_offset;
1862 static int var_offset;
1863 static int dynamic_offset;
1864 static int out_arg_offset;
1866 /* In most machines, the stack pointer register is equivalent to the bottom
1869 #ifndef STACK_POINTER_OFFSET
1870 #define STACK_POINTER_OFFSET 0
1873 /* If not defined, pick an appropriate default for the offset of dynamically
1874 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1875 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1877 #ifndef STACK_DYNAMIC_OFFSET
1879 #ifdef ACCUMULATE_OUTGOING_ARGS
1880 /* The bottom of the stack points to the actual arguments. If
1881 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1882 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1883 stack space for register parameters is not pushed by the caller, but
1884 rather part of the fixed stack areas and hence not included in
1885 `current_function_outgoing_args_size'. Nevertheless, we must allow
1886 for it when allocating stack dynamic objects. */
1888 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1889 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1890 (current_function_outgoing_args_size \
1891 + REG_PARM_STACK_SPACE (FNDECL) + (STACK_POINTER_OFFSET))
1894 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1895 (current_function_outgoing_args_size + (STACK_POINTER_OFFSET))
1899 #define STACK_DYNAMIC_OFFSET(FNDECL) STACK_POINTER_OFFSET
1903 /* Pass through the INSNS of function FNDECL and convert virtual register
1904 references to hard register references. */
1907 instantiate_virtual_regs (fndecl, insns)
1913 /* Compute the offsets to use for this function. */
1914 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
1915 var_offset = STARTING_FRAME_OFFSET;
1916 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
1917 out_arg_offset = STACK_POINTER_OFFSET;
1919 /* Scan all variables and parameters of this function. For each that is
1920 in memory, instantiate all virtual registers if the result is a valid
1921 address. If not, we do it later. That will handle most uses of virtual
1922 regs on many machines. */
1923 instantiate_decls (fndecl, 1);
1925 /* Initialize recognition, indicating that volatile is OK. */
1928 /* Scan through all the insns, instantiating every virtual register still
1930 for (insn = insns; insn; insn = NEXT_INSN (insn))
1931 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
1932 || GET_CODE (insn) == CALL_INSN)
1934 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
1935 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
1938 /* Now instantiate the remaining register equivalences for debugging info.
1939 These will not be valid addresses. */
1940 instantiate_decls (fndecl, 0);
1942 /* Indicate that, from now on, assign_stack_local should use
1943 frame_pointer_rtx. */
1944 virtuals_instantiated = 1;
1947 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1948 all virtual registers in their DECL_RTL's.
1950 If VALID_ONLY, do this only if the resulting address is still valid.
1951 Otherwise, always do it. */
1954 instantiate_decls (fndecl, valid_only)
1960 if (DECL_INLINE (fndecl))
1961 /* When compiling an inline function, the obstack used for
1962 rtl allocation is the maybepermanent_obstack. Calling
1963 `resume_temporary_allocation' switches us back to that
1964 obstack while we process this function's parameters. */
1965 resume_temporary_allocation ();
1967 /* Process all parameters of the function. */
1968 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1970 instantiate_decl (DECL_RTL (decl), int_size_in_bytes (TREE_TYPE (decl)),
1972 instantiate_decl (DECL_INCOMING_RTL (decl),
1973 int_size_in_bytes (TREE_TYPE (decl)), valid_only);
1976 /* Now process all variables defined in the function or its subblocks. */
1977 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
1979 if (DECL_INLINE (fndecl))
1981 /* Save all rtl allocated for this function by raising the
1982 high-water mark on the maybepermanent_obstack. */
1984 /* All further rtl allocation is now done in the current_obstack. */
1985 rtl_in_current_obstack ();
1989 /* Subroutine of instantiate_decls: Process all decls in the given
1990 BLOCK node and all its subblocks. */
1993 instantiate_decls_1 (let, valid_only)
1999 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
2000 instantiate_decl (DECL_RTL (t), int_size_in_bytes (TREE_TYPE (t)),
2003 /* Process all subblocks. */
2004 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
2005 instantiate_decls_1 (t, valid_only);
2008 /* Subroutine of the preceeding procedures: Given RTL representing a
2009 decl and the size of the object, do any instantiation required.
2011 If VALID_ONLY is non-zero, it means that the RTL should only be
2012 changed if the new address is valid. */
2015 instantiate_decl (x, size, valid_only)
2020 enum machine_mode mode;
2023 /* If this is not a MEM, no need to do anything. Similarly if the
2024 address is a constant or a register that is not a virtual register. */
2026 if (x == 0 || GET_CODE (x) != MEM)
2030 if (CONSTANT_P (addr)
2031 || (GET_CODE (addr) == REG
2032 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
2033 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
2036 /* If we should only do this if the address is valid, copy the address.
2037 We need to do this so we can undo any changes that might make the
2038 address invalid. This copy is unfortunate, but probably can't be
2042 addr = copy_rtx (addr);
2044 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
2049 /* Now verify that the resulting address is valid for every integer or
2050 floating-point mode up to and including SIZE bytes long. We do this
2051 since the object might be accessed in any mode and frame addresses
2054 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2055 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2056 mode = GET_MODE_WIDER_MODE (mode))
2057 if (! memory_address_p (mode, addr))
2060 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
2061 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2062 mode = GET_MODE_WIDER_MODE (mode))
2063 if (! memory_address_p (mode, addr))
2066 /* Otherwise, put back the address, now that we have updated it and we
2067 know it is valid. */
2072 /* Given a pointer to a piece of rtx and an optional pointer to the
2073 containing object, instantiate any virtual registers present in it.
2075 If EXTRA_INSNS, we always do the replacement and generate
2076 any extra insns before OBJECT. If it zero, we do nothing if replacement
2079 Return 1 if we either had nothing to do or if we were able to do the
2080 needed replacement. Return 0 otherwise; we only return zero if
2081 EXTRA_INSNS is zero.
2083 We first try some simple transformations to avoid the creation of extra
2087 instantiate_virtual_regs_1 (loc, object, extra_insns)
2101 /* Re-start here to avoid recursion in common cases. */
2108 code = GET_CODE (x);
2110 /* Check for some special cases. */
2127 /* We are allowed to set the virtual registers. This means that
2128 that the actual register should receive the source minus the
2129 appropriate offset. This is used, for example, in the handling
2130 of non-local gotos. */
2131 if (SET_DEST (x) == virtual_incoming_args_rtx)
2132 new = arg_pointer_rtx, offset = - in_arg_offset;
2133 else if (SET_DEST (x) == virtual_stack_vars_rtx)
2134 new = frame_pointer_rtx, offset = - var_offset;
2135 else if (SET_DEST (x) == virtual_stack_dynamic_rtx)
2136 new = stack_pointer_rtx, offset = - dynamic_offset;
2137 else if (SET_DEST (x) == virtual_outgoing_args_rtx)
2138 new = stack_pointer_rtx, offset = - out_arg_offset;
2142 /* The only valid sources here are PLUS or REG. Just do
2143 the simplest possible thing to handle them. */
2144 if (GET_CODE (SET_SRC (x)) != REG
2145 && GET_CODE (SET_SRC (x)) != PLUS)
2149 if (GET_CODE (SET_SRC (x)) != REG)
2150 temp = force_operand (SET_SRC (x), NULL_RTX);
2153 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
2157 emit_insns_before (seq, object);
2160 if (!validate_change (object, &SET_SRC (x), temp, 0)
2167 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
2172 /* Handle special case of virtual register plus constant. */
2173 if (CONSTANT_P (XEXP (x, 1)))
2177 /* Check for (plus (plus VIRT foo) (const_int)) first. */
2178 if (GET_CODE (XEXP (x, 0)) == PLUS)
2180 rtx inner = XEXP (XEXP (x, 0), 0);
2182 if (inner == virtual_incoming_args_rtx)
2183 new = arg_pointer_rtx, offset = in_arg_offset;
2184 else if (inner == virtual_stack_vars_rtx)
2185 new = frame_pointer_rtx, offset = var_offset;
2186 else if (inner == virtual_stack_dynamic_rtx)
2187 new = stack_pointer_rtx, offset = dynamic_offset;
2188 else if (inner == virtual_outgoing_args_rtx)
2189 new = stack_pointer_rtx, offset = out_arg_offset;
2196 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
2198 new = gen_rtx (PLUS, Pmode, new, XEXP (XEXP (x, 0), 1));
2201 else if (XEXP (x, 0) == virtual_incoming_args_rtx)
2202 new = arg_pointer_rtx, offset = in_arg_offset;
2203 else if (XEXP (x, 0) == virtual_stack_vars_rtx)
2204 new = frame_pointer_rtx, offset = var_offset;
2205 else if (XEXP (x, 0) == virtual_stack_dynamic_rtx)
2206 new = stack_pointer_rtx, offset = dynamic_offset;
2207 else if (XEXP (x, 0) == virtual_outgoing_args_rtx)
2208 new = stack_pointer_rtx, offset = out_arg_offset;
2211 /* We know the second operand is a constant. Unless the
2212 first operand is a REG (which has been already checked),
2213 it needs to be checked. */
2214 if (GET_CODE (XEXP (x, 0)) != REG)
2224 new = plus_constant (XEXP (x, 1), offset);
2226 /* If the new constant is zero, try to replace the sum with its
2228 if (new == const0_rtx
2229 && validate_change (object, loc, XEXP (x, 0), 0))
2232 /* Next try to replace constant with new one. */
2233 if (!validate_change (object, &XEXP (x, 1), new, 0))
2241 /* Otherwise copy the new constant into a register and replace
2242 constant with that register. */
2243 temp = gen_reg_rtx (Pmode);
2244 if (validate_change (object, &XEXP (x, 1), temp, 0))
2245 emit_insn_before (gen_move_insn (temp, new), object);
2248 /* If that didn't work, replace this expression with a
2249 register containing the sum. */
2251 new = gen_rtx (PLUS, Pmode, XEXP (x, 0), new);
2255 temp = force_operand (new, NULL_RTX);
2259 emit_insns_before (seq, object);
2260 if (! validate_change (object, loc, temp, 0)
2261 && ! validate_replace_rtx (x, temp, object))
2269 /* Fall through to generic two-operand expression case. */
2275 case DIV: case UDIV:
2276 case MOD: case UMOD:
2277 case AND: case IOR: case XOR:
2278 case LSHIFT: case ASHIFT: case ROTATE:
2279 case ASHIFTRT: case LSHIFTRT: case ROTATERT:
2281 case GE: case GT: case GEU: case GTU:
2282 case LE: case LT: case LEU: case LTU:
2283 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
2284 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
2289 /* Most cases of MEM that convert to valid addresses have already been
2290 handled by our scan of regno_reg_rtx. The only special handling we
2291 need here is to make a copy of the rtx to ensure it isn't being
2292 shared if we have to change it to a pseudo.
2294 If the rtx is a simple reference to an address via a virtual register,
2295 it can potentially be shared. In such cases, first try to make it
2296 a valid address, which can also be shared. Otherwise, copy it and
2299 First check for common cases that need no processing. These are
2300 usually due to instantiation already being done on a previous instance
2304 if (CONSTANT_ADDRESS_P (temp)
2305 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2306 || temp == arg_pointer_rtx
2308 || temp == frame_pointer_rtx)
2311 if (GET_CODE (temp) == PLUS
2312 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2313 && (XEXP (temp, 0) == frame_pointer_rtx
2314 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2315 || XEXP (temp, 0) == arg_pointer_rtx
2320 if (temp == virtual_stack_vars_rtx
2321 || temp == virtual_incoming_args_rtx
2322 || (GET_CODE (temp) == PLUS
2323 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2324 && (XEXP (temp, 0) == virtual_stack_vars_rtx
2325 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
2327 /* This MEM may be shared. If the substitution can be done without
2328 the need to generate new pseudos, we want to do it in place
2329 so all copies of the shared rtx benefit. The call below will
2330 only make substitutions if the resulting address is still
2333 Note that we cannot pass X as the object in the recursive call
2334 since the insn being processed may not allow all valid
2335 addresses. However, if we were not passed on object, we can
2336 only modify X without copying it if X will have a valid
2339 ??? Also note that this can still lose if OBJECT is an insn that
2340 has less restrictions on an address that some other insn.
2341 In that case, we will modify the shared address. This case
2342 doesn't seem very likely, though. */
2344 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
2345 object ? object : x, 0))
2348 /* Otherwise make a copy and process that copy. We copy the entire
2349 RTL expression since it might be a PLUS which could also be
2351 *loc = x = copy_rtx (x);
2354 /* Fall through to generic unary operation case. */
2358 case STRICT_LOW_PART:
2360 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
2361 case SIGN_EXTEND: case ZERO_EXTEND:
2362 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2363 case FLOAT: case FIX:
2364 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2368 /* These case either have just one operand or we know that we need not
2369 check the rest of the operands. */
2374 /* Try to replace with a PLUS. If that doesn't work, compute the sum
2375 in front of this insn and substitute the temporary. */
2376 if (x == virtual_incoming_args_rtx)
2377 new = arg_pointer_rtx, offset = in_arg_offset;
2378 else if (x == virtual_stack_vars_rtx)
2379 new = frame_pointer_rtx, offset = var_offset;
2380 else if (x == virtual_stack_dynamic_rtx)
2381 new = stack_pointer_rtx, offset = dynamic_offset;
2382 else if (x == virtual_outgoing_args_rtx)
2383 new = stack_pointer_rtx, offset = out_arg_offset;
2387 temp = plus_constant (new, offset);
2388 if (!validate_change (object, loc, temp, 0))
2394 temp = force_operand (temp, NULL_RTX);
2398 emit_insns_before (seq, object);
2399 if (! validate_change (object, loc, temp, 0)
2400 && ! validate_replace_rtx (x, temp, object))
2408 /* Scan all subexpressions. */
2409 fmt = GET_RTX_FORMAT (code);
2410 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2413 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
2416 else if (*fmt == 'E')
2417 for (j = 0; j < XVECLEN (x, i); j++)
2418 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
2425 /* Optimization: assuming this function does not receive nonlocal gotos,
2426 delete the handlers for such, as well as the insns to establish
2427 and disestablish them. */
2433 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
2435 /* Delete the handler by turning off the flag that would
2436 prevent jump_optimize from deleting it.
2437 Also permit deletion of the nonlocal labels themselves
2438 if nothing local refers to them. */
2439 if (GET_CODE (insn) == CODE_LABEL)
2440 LABEL_PRESERVE_P (insn) = 0;
2441 if (GET_CODE (insn) == INSN
2442 && ((nonlocal_goto_handler_slot != 0
2443 && reg_mentioned_p (nonlocal_goto_handler_slot, PATTERN (insn)))
2444 || (nonlocal_goto_stack_level != 0
2445 && reg_mentioned_p (nonlocal_goto_stack_level,
2451 /* Return a list (chain of EXPR_LIST nodes) for the nonlocal labels
2452 of the current function. */
2455 nonlocal_label_rtx_list ()
2460 for (t = nonlocal_labels; t; t = TREE_CHAIN (t))
2461 x = gen_rtx (EXPR_LIST, VOIDmode, label_rtx (TREE_VALUE (t)), x);
2466 /* Output a USE for any register use in RTL.
2467 This is used with -noreg to mark the extent of lifespan
2468 of any registers used in a user-visible variable's DECL_RTL. */
2474 if (GET_CODE (rtl) == REG)
2475 /* This is a register variable. */
2476 emit_insn (gen_rtx (USE, VOIDmode, rtl));
2477 else if (GET_CODE (rtl) == MEM
2478 && GET_CODE (XEXP (rtl, 0)) == REG
2479 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
2480 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
2481 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
2482 /* This is a variable-sized structure. */
2483 emit_insn (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)));
2486 /* Like use_variable except that it outputs the USEs after INSN
2487 instead of at the end of the insn-chain. */
2490 use_variable_after (rtl, insn)
2493 if (GET_CODE (rtl) == REG)
2494 /* This is a register variable. */
2495 emit_insn_after (gen_rtx (USE, VOIDmode, rtl), insn);
2496 else if (GET_CODE (rtl) == MEM
2497 && GET_CODE (XEXP (rtl, 0)) == REG
2498 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
2499 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
2500 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
2501 /* This is a variable-sized structure. */
2502 emit_insn_after (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)), insn);
2508 return max_parm_reg;
2511 /* Return the first insn following those generated by `assign_parms'. */
2514 get_first_nonparm_insn ()
2517 return NEXT_INSN (last_parm_insn);
2518 return get_insns ();
2521 /* Return the first NOTE_INSN_BLOCK_BEG note in the function.
2522 Crash if there is none. */
2525 get_first_block_beg ()
2527 register rtx searcher;
2528 register rtx insn = get_first_nonparm_insn ();
2530 for (searcher = insn; searcher; searcher = NEXT_INSN (searcher))
2531 if (GET_CODE (searcher) == NOTE
2532 && NOTE_LINE_NUMBER (searcher) == NOTE_INSN_BLOCK_BEG)
2535 abort (); /* Invalid call to this function. (See comments above.) */
2539 /* Return 1 if EXP returns an aggregate value, for which an address
2540 must be passed to the function or returned by the function. */
2543 aggregate_value_p (exp)
2546 if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2548 if (RETURN_IN_MEMORY (TREE_TYPE (exp)))
2550 if (flag_pcc_struct_return
2551 && (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
2552 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE))
2557 /* Assign RTL expressions to the function's parameters.
2558 This may involve copying them into registers and using
2559 those registers as the RTL for them.
2561 If SECOND_TIME is non-zero it means that this function is being
2562 called a second time. This is done by integrate.c when a function's
2563 compilation is deferred. We need to come back here in case the
2564 FUNCTION_ARG macro computes items needed for the rest of the compilation
2565 (such as changing which registers are fixed or caller-saved). But suppress
2566 writing any insns or setting DECL_RTL of anything in this case. */
2569 assign_parms (fndecl, second_time)
2574 register rtx entry_parm = 0;
2575 register rtx stack_parm = 0;
2576 CUMULATIVE_ARGS args_so_far;
2577 enum machine_mode promoted_mode, passed_mode, nominal_mode;
2579 /* Total space needed so far for args on the stack,
2580 given as a constant and a tree-expression. */
2581 struct args_size stack_args_size;
2582 tree fntype = TREE_TYPE (fndecl);
2583 tree fnargs = DECL_ARGUMENTS (fndecl);
2584 /* This is used for the arg pointer when referring to stack args. */
2585 rtx internal_arg_pointer;
2586 /* This is a dummy PARM_DECL that we used for the function result if
2587 the function returns a structure. */
2588 tree function_result_decl = 0;
2589 int nparmregs = list_length (fnargs) + LAST_VIRTUAL_REGISTER + 1;
2590 int varargs_setup = 0;
2592 /* Nonzero if the last arg is named `__builtin_va_alist',
2593 which is used on some machines for old-fashioned non-ANSI varargs.h;
2594 this should be stuck onto the stack as if it had arrived there. */
2597 && (parm = tree_last (fnargs)) != 0
2599 && (! strcmp (IDENTIFIER_POINTER (DECL_NAME (parm)),
2600 "__builtin_va_alist")));
2602 /* Nonzero if function takes extra anonymous args.
2603 This means the last named arg must be on the stack
2604 right before the anonymous ones. */
2606 = (TYPE_ARG_TYPES (fntype) != 0
2607 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
2608 != void_type_node));
2610 /* If the reg that the virtual arg pointer will be translated into is
2611 not a fixed reg or is the stack pointer, make a copy of the virtual
2612 arg pointer, and address parms via the copy. The frame pointer is
2613 considered fixed even though it is not marked as such.
2615 The second time through, simply use ap to avoid generating rtx. */
2617 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
2618 || ! (fixed_regs[ARG_POINTER_REGNUM]
2619 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM))
2621 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
2623 internal_arg_pointer = virtual_incoming_args_rtx;
2624 current_function_internal_arg_pointer = internal_arg_pointer;
2626 stack_args_size.constant = 0;
2627 stack_args_size.var = 0;
2629 /* If struct value address is treated as the first argument, make it so. */
2630 if (aggregate_value_p (DECL_RESULT (fndecl))
2631 && ! current_function_returns_pcc_struct
2632 && struct_value_incoming_rtx == 0)
2634 tree type = build_pointer_type (fntype);
2636 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
2638 DECL_ARG_TYPE (function_result_decl) = type;
2639 TREE_CHAIN (function_result_decl) = fnargs;
2640 fnargs = function_result_decl;
2643 parm_reg_stack_loc = (rtx *) oballoc (nparmregs * sizeof (rtx));
2644 bzero (parm_reg_stack_loc, nparmregs * sizeof (rtx));
2646 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2647 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_PTR);
2649 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_PTR);
2652 /* We haven't yet found an argument that we must push and pretend the
2654 current_function_pretend_args_size = 0;
2656 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
2659 = (TREE_CODE (TREE_TYPE (parm)) == ARRAY_TYPE
2660 || TREE_CODE (TREE_TYPE (parm)) == RECORD_TYPE
2661 || TREE_CODE (TREE_TYPE (parm)) == UNION_TYPE);
2662 struct args_size stack_offset;
2663 struct args_size arg_size;
2664 int passed_pointer = 0;
2665 tree passed_type = DECL_ARG_TYPE (parm);
2667 /* Set LAST_NAMED if this is last named arg before some
2668 anonymous args. We treat it as if it were anonymous too. */
2669 int last_named = ((TREE_CHAIN (parm) == 0
2670 || DECL_NAME (TREE_CHAIN (parm)) == 0)
2671 && (vararg || stdarg));
2673 if (TREE_TYPE (parm) == error_mark_node
2674 /* This can happen after weird syntax errors
2675 or if an enum type is defined among the parms. */
2676 || TREE_CODE (parm) != PARM_DECL
2677 || passed_type == NULL)
2679 DECL_RTL (parm) = gen_rtx (MEM, BLKmode, const0_rtx);
2680 TREE_USED (parm) = 1;
2684 /* For varargs.h function, save info about regs and stack space
2685 used by the individual args, not including the va_alist arg. */
2686 if (vararg && last_named)
2687 current_function_args_info = args_so_far;
2689 /* Find mode of arg as it is passed, and mode of arg
2690 as it should be during execution of this function. */
2691 passed_mode = TYPE_MODE (passed_type);
2692 nominal_mode = TYPE_MODE (TREE_TYPE (parm));
2694 /* If the parm's mode is VOID, its value doesn't matter,
2695 and avoid the usual things like emit_move_insn that could crash. */
2696 if (nominal_mode == VOIDmode)
2698 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = const0_rtx;
2702 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
2703 /* See if this arg was passed by invisible reference. */
2704 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
2705 passed_type, ! last_named))
2707 passed_type = build_pointer_type (passed_type);
2709 passed_mode = nominal_mode = Pmode;
2713 promoted_mode = passed_mode;
2715 #ifdef PROMOTE_FUNCTION_ARGS
2716 /* Compute the mode in which the arg is actually extended to. */
2717 if (TREE_CODE (passed_type) == INTEGER_TYPE
2718 || TREE_CODE (passed_type) == ENUMERAL_TYPE
2719 || TREE_CODE (passed_type) == BOOLEAN_TYPE
2720 || TREE_CODE (passed_type) == CHAR_TYPE
2721 || TREE_CODE (passed_type) == REAL_TYPE
2722 || TREE_CODE (passed_type) == POINTER_TYPE
2723 || TREE_CODE (passed_type) == OFFSET_TYPE)
2725 unsignedp = TREE_UNSIGNED (passed_type);
2726 PROMOTE_MODE (promoted_mode, unsignedp, passed_type);
2730 /* Let machine desc say which reg (if any) the parm arrives in.
2731 0 means it arrives on the stack. */
2732 #ifdef FUNCTION_INCOMING_ARG
2733 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
2734 passed_type, ! last_named);
2736 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
2737 passed_type, ! last_named);
2741 passed_mode = promoted_mode;
2743 #ifdef SETUP_INCOMING_VARARGS
2744 /* If this is the last named parameter, do any required setup for
2745 varargs or stdargs. We need to know about the case of this being an
2746 addressable type, in which case we skip the registers it
2747 would have arrived in.
2749 For stdargs, LAST_NAMED will be set for two parameters, the one that
2750 is actually the last named, and the dummy parameter. We only
2751 want to do this action once.
2753 Also, indicate when RTL generation is to be suppressed. */
2754 if (last_named && !varargs_setup)
2756 SETUP_INCOMING_VARARGS (args_so_far, passed_mode, passed_type,
2757 current_function_pretend_args_size,
2763 /* Determine parm's home in the stack,
2764 in case it arrives in the stack or we should pretend it did.
2766 Compute the stack position and rtx where the argument arrives
2769 There is one complexity here: If this was a parameter that would
2770 have been passed in registers, but wasn't only because it is
2771 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2772 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2773 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
2774 0 as it was the previous time. */
2776 locate_and_pad_parm (passed_mode, passed_type,
2777 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2780 #ifdef FUNCTION_INCOMING_ARG
2781 FUNCTION_INCOMING_ARG (args_so_far, passed_mode,
2784 || varargs_setup)) != 0,
2786 FUNCTION_ARG (args_so_far, passed_mode,
2788 ! last_named || varargs_setup) != 0,
2791 fndecl, &stack_args_size, &stack_offset, &arg_size);
2795 rtx offset_rtx = ARGS_SIZE_RTX (stack_offset);
2797 if (offset_rtx == const0_rtx)
2798 stack_parm = gen_rtx (MEM, passed_mode, internal_arg_pointer);
2800 stack_parm = gen_rtx (MEM, passed_mode,
2801 gen_rtx (PLUS, Pmode,
2802 internal_arg_pointer, offset_rtx));
2804 /* If this is a memory ref that contains aggregate components,
2805 mark it as such for cse and loop optimize. */
2806 MEM_IN_STRUCT_P (stack_parm) = aggregate;
2809 /* If this parameter was passed both in registers and in the stack,
2810 use the copy on the stack. */
2811 if (MUST_PASS_IN_STACK (passed_mode, passed_type))
2814 /* If this parm was passed part in regs and part in memory,
2815 pretend it arrived entirely in memory
2816 by pushing the register-part onto the stack.
2818 In the special case of a DImode or DFmode that is split,
2819 we could put it together in a pseudoreg directly,
2820 but for now that's not worth bothering with. */
2825 #ifdef FUNCTION_ARG_PARTIAL_NREGS
2826 nregs = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, passed_mode,
2827 passed_type, ! last_named);
2832 current_function_pretend_args_size
2833 = (((nregs * UNITS_PER_WORD) + (PARM_BOUNDARY / BITS_PER_UNIT) - 1)
2834 / (PARM_BOUNDARY / BITS_PER_UNIT)
2835 * (PARM_BOUNDARY / BITS_PER_UNIT));
2838 move_block_from_reg (REGNO (entry_parm),
2839 validize_mem (stack_parm), nregs);
2840 entry_parm = stack_parm;
2844 /* If we didn't decide this parm came in a register,
2845 by default it came on the stack. */
2846 if (entry_parm == 0)
2847 entry_parm = stack_parm;
2849 /* Record permanently how this parm was passed. */
2851 DECL_INCOMING_RTL (parm) = entry_parm;
2853 /* If there is actually space on the stack for this parm,
2854 count it in stack_args_size; otherwise set stack_parm to 0
2855 to indicate there is no preallocated stack slot for the parm. */
2857 if (entry_parm == stack_parm
2858 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
2859 /* On some machines, even if a parm value arrives in a register
2860 there is still an (uninitialized) stack slot allocated for it.
2862 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
2863 whether this parameter already has a stack slot allocated,
2864 because an arg block exists only if current_function_args_size
2865 is larger than some threshhold, and we haven't calculated that
2866 yet. So, for now, we just assume that stack slots never exist
2868 || REG_PARM_STACK_SPACE (fndecl) > 0
2872 stack_args_size.constant += arg_size.constant;
2874 ADD_PARM_SIZE (stack_args_size, arg_size.var);
2877 /* No stack slot was pushed for this parm. */
2880 /* Update info on where next arg arrives in registers. */
2882 FUNCTION_ARG_ADVANCE (args_so_far, passed_mode,
2883 passed_type, ! last_named);
2885 /* If this is our second time through, we are done with this parm. */
2889 /* If we can't trust the parm stack slot to be aligned enough
2890 for its ultimate type, don't use that slot after entry.
2891 We'll make another stack slot, if we need one. */
2893 #ifdef FUNCTION_ARG_BOUNDARY
2894 int thisparm_boundary
2895 = FUNCTION_ARG_BOUNDARY (passed_mode, passed_type);
2897 int thisparm_boundary = PARM_BOUNDARY;
2900 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
2904 /* Now adjust STACK_PARM to the mode and precise location
2905 where this parameter should live during execution,
2906 if we discover that it must live in the stack during execution.
2907 To make debuggers happier on big-endian machines, we store
2908 the value in the last bytes of the space available. */
2910 if (nominal_mode != BLKmode && nominal_mode != passed_mode
2915 #if BYTES_BIG_ENDIAN
2916 if (GET_MODE_SIZE (nominal_mode) < UNITS_PER_WORD)
2917 stack_offset.constant += (GET_MODE_SIZE (passed_mode)
2918 - GET_MODE_SIZE (nominal_mode));
2921 offset_rtx = ARGS_SIZE_RTX (stack_offset);
2922 if (offset_rtx == const0_rtx)
2923 stack_parm = gen_rtx (MEM, nominal_mode, internal_arg_pointer);
2925 stack_parm = gen_rtx (MEM, nominal_mode,
2926 gen_rtx (PLUS, Pmode,
2927 internal_arg_pointer, offset_rtx));
2929 /* If this is a memory ref that contains aggregate components,
2930 mark it as such for cse and loop optimize. */
2931 MEM_IN_STRUCT_P (stack_parm) = aggregate;
2934 /* ENTRY_PARM is an RTX for the parameter as it arrives,
2935 in the mode in which it arrives.
2936 STACK_PARM is an RTX for a stack slot where the parameter can live
2937 during the function (in case we want to put it there).
2938 STACK_PARM is 0 if no stack slot was pushed for it.
2940 Now output code if necessary to convert ENTRY_PARM to
2941 the type in which this function declares it,
2942 and store that result in an appropriate place,
2943 which may be a pseudo reg, may be STACK_PARM,
2944 or may be a local stack slot if STACK_PARM is 0.
2946 Set DECL_RTL to that place. */
2948 if (nominal_mode == BLKmode)
2950 /* If a BLKmode arrives in registers, copy it to a stack slot. */
2951 if (GET_CODE (entry_parm) == REG)
2953 int size_stored = CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm)),
2956 /* Note that we will be storing an integral number of words.
2957 So we have to be careful to ensure that we allocate an
2958 integral number of words. We do this below in the
2959 assign_stack_local if space was not allocated in the argument
2960 list. If it was, this will not work if PARM_BOUNDARY is not
2961 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2962 if it becomes a problem. */
2964 if (stack_parm == 0)
2967 = assign_stack_local (GET_MODE (entry_parm), size_stored, 0);
2968 /* If this is a memory ref that contains aggregate components,
2969 mark it as such for cse and loop optimize. */
2970 MEM_IN_STRUCT_P (stack_parm) = aggregate;
2973 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
2976 move_block_from_reg (REGNO (entry_parm),
2977 validize_mem (stack_parm),
2978 size_stored / UNITS_PER_WORD);
2980 DECL_RTL (parm) = stack_parm;
2982 else if (! ((obey_regdecls && ! DECL_REGISTER (parm)
2983 && ! DECL_INLINE (fndecl))
2984 /* layout_decl may set this. */
2985 || TREE_ADDRESSABLE (parm)
2986 || TREE_SIDE_EFFECTS (parm)
2987 /* If -ffloat-store specified, don't put explicit
2988 float variables into registers. */
2989 || (flag_float_store
2990 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
2991 /* Always assign pseudo to structure return or item passed
2992 by invisible reference. */
2993 || passed_pointer || parm == function_result_decl)
2995 /* Store the parm in a pseudoregister during the function, but we
2996 may need to do it in a wider mode. */
2998 register rtx parmreg;
3000 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
3001 if (TREE_CODE (TREE_TYPE (parm)) == INTEGER_TYPE
3002 || TREE_CODE (TREE_TYPE (parm)) == ENUMERAL_TYPE
3003 || TREE_CODE (TREE_TYPE (parm)) == BOOLEAN_TYPE
3004 || TREE_CODE (TREE_TYPE (parm)) == CHAR_TYPE
3005 || TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE
3006 || TREE_CODE (TREE_TYPE (parm)) == POINTER_TYPE
3007 || TREE_CODE (TREE_TYPE (parm)) == OFFSET_TYPE)
3009 PROMOTE_MODE (nominal_mode, unsignedp, TREE_TYPE (parm));
3012 parmreg = gen_reg_rtx (nominal_mode);
3013 REG_USERVAR_P (parmreg) = 1;
3015 /* If this was an item that we received a pointer to, set DECL_RTL
3019 DECL_RTL (parm) = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (passed_type)), parmreg);
3020 MEM_IN_STRUCT_P (DECL_RTL (parm)) = aggregate;
3023 DECL_RTL (parm) = parmreg;
3025 /* Copy the value into the register. */
3026 if (GET_MODE (parmreg) != GET_MODE (entry_parm))
3028 /* If ENTRY_PARM is a hard register, it might be in a register
3029 not valid for operating in its mode (e.g., an odd-numbered
3030 register for a DFmode). In that case, moves are the only
3031 thing valid, so we can't do a convert from there. This
3032 occurs when the calling sequence allow such misaligned
3034 if (GET_CODE (entry_parm) == REG
3035 && REGNO (entry_parm) < FIRST_PSEUDO_REGISTER
3036 && ! HARD_REGNO_MODE_OK (REGNO (entry_parm),
3037 GET_MODE (entry_parm)))
3038 convert_move (parmreg, copy_to_reg (entry_parm), unsignedp);
3040 convert_move (parmreg, validize_mem (entry_parm), unsignedp);
3043 emit_move_insn (parmreg, validize_mem (entry_parm));
3045 /* If we were passed a pointer but the actual value
3046 can safely live in a register, put it in one. */
3047 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
3048 && ! ((obey_regdecls && ! DECL_REGISTER (parm)
3049 && ! DECL_INLINE (fndecl))
3050 /* layout_decl may set this. */
3051 || TREE_ADDRESSABLE (parm)
3052 || TREE_SIDE_EFFECTS (parm)
3053 /* If -ffloat-store specified, don't put explicit
3054 float variables into registers. */
3055 || (flag_float_store
3056 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE)))
3058 /* We can't use nominal_mode, because it will have been set to
3059 Pmode above. We must use the actual mode of the parm. */
3060 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3061 emit_move_insn (parmreg, DECL_RTL (parm));
3062 DECL_RTL (parm) = parmreg;
3065 /* In any case, record the parm's desired stack location
3066 in case we later discover it must live in the stack. */
3067 if (REGNO (parmreg) >= nparmregs)
3070 nparmregs = REGNO (parmreg) + 5;
3071 new = (rtx *) oballoc (nparmregs * sizeof (rtx));
3072 bcopy (parm_reg_stack_loc, new, nparmregs * sizeof (rtx));
3073 parm_reg_stack_loc = new;
3075 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
3077 /* Mark the register as eliminable if we did no conversion
3078 and it was copied from memory at a fixed offset,
3079 and the arg pointer was not copied to a pseudo-reg.
3080 If the arg pointer is a pseudo reg or the offset formed
3081 an invalid address, such memory-equivalences
3082 as we make here would screw up life analysis for it. */
3083 if (nominal_mode == passed_mode
3084 && GET_CODE (entry_parm) == MEM
3085 && entry_parm == stack_parm
3086 && stack_offset.var == 0
3087 && reg_mentioned_p (virtual_incoming_args_rtx,
3088 XEXP (entry_parm, 0)))
3089 REG_NOTES (get_last_insn ())
3090 = gen_rtx (EXPR_LIST, REG_EQUIV,
3091 entry_parm, REG_NOTES (get_last_insn ()));
3093 /* For pointer data type, suggest pointer register. */
3094 if (TREE_CODE (TREE_TYPE (parm)) == POINTER_TYPE)
3095 mark_reg_pointer (parmreg);
3099 /* Value must be stored in the stack slot STACK_PARM
3100 during function execution. */
3102 if (passed_mode != nominal_mode)
3104 /* Conversion is required. */
3105 if (GET_CODE (entry_parm) == REG
3106 && REGNO (entry_parm) < FIRST_PSEUDO_REGISTER
3107 && ! HARD_REGNO_MODE_OK (REGNO (entry_parm), passed_mode))
3108 entry_parm = copy_to_reg (entry_parm);
3110 entry_parm = convert_to_mode (nominal_mode, entry_parm,
3111 TREE_UNSIGNED (TREE_TYPE (parm)));
3114 if (entry_parm != stack_parm)
3116 if (stack_parm == 0)
3119 = assign_stack_local (GET_MODE (entry_parm),
3120 GET_MODE_SIZE (GET_MODE (entry_parm)), 0);
3121 /* If this is a memory ref that contains aggregate components,
3122 mark it as such for cse and loop optimize. */
3123 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3126 emit_move_insn (validize_mem (stack_parm),
3127 validize_mem (entry_parm));
3130 DECL_RTL (parm) = stack_parm;
3133 /* If this "parameter" was the place where we are receiving the
3134 function's incoming structure pointer, set up the result. */
3135 if (parm == function_result_decl)
3136 DECL_RTL (DECL_RESULT (fndecl))
3137 = gen_rtx (MEM, DECL_MODE (DECL_RESULT (fndecl)), DECL_RTL (parm));
3139 if (TREE_THIS_VOLATILE (parm))
3140 MEM_VOLATILE_P (DECL_RTL (parm)) = 1;
3141 if (TREE_READONLY (parm))
3142 RTX_UNCHANGING_P (DECL_RTL (parm)) = 1;
3145 max_parm_reg = max_reg_num ();
3146 last_parm_insn = get_last_insn ();
3148 current_function_args_size = stack_args_size.constant;
3150 /* Adjust function incoming argument size for alignment and
3153 #ifdef REG_PARM_STACK_SPACE
3154 #ifndef MAYBE_REG_PARM_STACK_SPACE
3155 current_function_args_size = MAX (current_function_args_size,
3156 REG_PARM_STACK_SPACE (fndecl));
3160 #ifdef STACK_BOUNDARY
3161 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
3163 current_function_args_size
3164 = ((current_function_args_size + STACK_BYTES - 1)
3165 / STACK_BYTES) * STACK_BYTES;
3168 #ifdef ARGS_GROW_DOWNWARD
3169 current_function_arg_offset_rtx
3170 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
3171 : expand_expr (size_binop (MINUS_EXPR, stack_args_size.var,
3172 size_int (-stack_args_size.constant)),
3173 NULL_RTX, VOIDmode, 0));
3175 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
3178 /* See how many bytes, if any, of its args a function should try to pop
3181 current_function_pops_args = RETURN_POPS_ARGS (TREE_TYPE (fndecl),
3182 current_function_args_size);
3184 /* For stdarg.h function, save info about regs and stack space
3185 used by the named args. */
3188 current_function_args_info = args_so_far;
3190 /* Set the rtx used for the function return value. Put this in its
3191 own variable so any optimizers that need this information don't have
3192 to include tree.h. Do this here so it gets done when an inlined
3193 function gets output. */
3195 current_function_return_rtx = DECL_RTL (DECL_RESULT (fndecl));
3198 /* Compute the size and offset from the start of the stacked arguments for a
3199 parm passed in mode PASSED_MODE and with type TYPE.
3201 INITIAL_OFFSET_PTR points to the current offset into the stacked
3204 The starting offset and size for this parm are returned in *OFFSET_PTR
3205 and *ARG_SIZE_PTR, respectively.
3207 IN_REGS is non-zero if the argument will be passed in registers. It will
3208 never be set if REG_PARM_STACK_SPACE is not defined.
3210 FNDECL is the function in which the argument was defined.
3212 There are two types of rounding that are done. The first, controlled by
3213 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3214 list to be aligned to the specific boundary (in bits). This rounding
3215 affects the initial and starting offsets, but not the argument size.
3217 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3218 optionally rounds the size of the parm to PARM_BOUNDARY. The
3219 initial offset is not affected by this rounding, while the size always
3220 is and the starting offset may be. */
3222 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
3223 initial_offset_ptr is positive because locate_and_pad_parm's
3224 callers pass in the total size of args so far as
3225 initial_offset_ptr. arg_size_ptr is always positive.*/
3227 static void pad_to_arg_alignment (), pad_below ();
3230 locate_and_pad_parm (passed_mode, type, in_regs, fndecl,
3231 initial_offset_ptr, offset_ptr, arg_size_ptr)
3232 enum machine_mode passed_mode;
3236 struct args_size *initial_offset_ptr;
3237 struct args_size *offset_ptr;
3238 struct args_size *arg_size_ptr;
3241 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3242 enum direction where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3243 int boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3244 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3245 int reg_parm_stack_space = 0;
3247 #ifdef REG_PARM_STACK_SPACE
3248 /* If we have found a stack parm before we reach the end of the
3249 area reserved for registers, skip that area. */
3252 #ifdef MAYBE_REG_PARM_STACK_SPACE
3253 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3255 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3257 if (reg_parm_stack_space > 0)
3259 if (initial_offset_ptr->var)
3261 initial_offset_ptr->var
3262 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3263 size_int (reg_parm_stack_space));
3264 initial_offset_ptr->constant = 0;
3266 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3267 initial_offset_ptr->constant = reg_parm_stack_space;
3270 #endif /* REG_PARM_STACK_SPACE */
3272 arg_size_ptr->var = 0;
3273 arg_size_ptr->constant = 0;
3275 #ifdef ARGS_GROW_DOWNWARD
3276 if (initial_offset_ptr->var)
3278 offset_ptr->constant = 0;
3279 offset_ptr->var = size_binop (MINUS_EXPR, integer_zero_node,
3280 initial_offset_ptr->var);
3284 offset_ptr->constant = - initial_offset_ptr->constant;
3285 offset_ptr->var = 0;
3287 if (where_pad == upward
3288 && (TREE_CODE (sizetree) != INTEGER_CST
3289 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
3290 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3291 SUB_PARM_SIZE (*offset_ptr, sizetree);
3292 pad_to_arg_alignment (offset_ptr, boundary);
3293 if (initial_offset_ptr->var)
3295 arg_size_ptr->var = size_binop (MINUS_EXPR,
3296 size_binop (MINUS_EXPR,
3298 initial_offset_ptr->var),
3303 arg_size_ptr->constant = (- initial_offset_ptr->constant -
3304 offset_ptr->constant);
3306 /* ADD_PARM_SIZE (*arg_size_ptr, sizetree); */
3307 if (where_pad == downward)
3308 pad_below (arg_size_ptr, passed_mode, sizetree);
3309 #else /* !ARGS_GROW_DOWNWARD */
3310 pad_to_arg_alignment (initial_offset_ptr, boundary);
3311 *offset_ptr = *initial_offset_ptr;
3312 if (where_pad == downward)
3313 pad_below (offset_ptr, passed_mode, sizetree);
3315 #ifdef PUSH_ROUNDING
3316 if (passed_mode != BLKmode)
3317 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3320 if (where_pad != none
3321 && (TREE_CODE (sizetree) != INTEGER_CST
3322 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
3323 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3325 ADD_PARM_SIZE (*arg_size_ptr, sizetree);
3326 #endif /* ARGS_GROW_DOWNWARD */
3329 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3330 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3333 pad_to_arg_alignment (offset_ptr, boundary)
3334 struct args_size *offset_ptr;
3337 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3339 if (boundary > BITS_PER_UNIT)
3341 if (offset_ptr->var)
3344 #ifdef ARGS_GROW_DOWNWARD
3349 (ARGS_SIZE_TREE (*offset_ptr),
3350 boundary / BITS_PER_UNIT);
3351 offset_ptr->constant = 0; /*?*/
3354 offset_ptr->constant =
3355 #ifdef ARGS_GROW_DOWNWARD
3356 FLOOR_ROUND (offset_ptr->constant, boundary_in_bytes);
3358 CEIL_ROUND (offset_ptr->constant, boundary_in_bytes);
3364 pad_below (offset_ptr, passed_mode, sizetree)
3365 struct args_size *offset_ptr;
3366 enum machine_mode passed_mode;
3369 if (passed_mode != BLKmode)
3371 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3372 offset_ptr->constant
3373 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3374 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3375 - GET_MODE_SIZE (passed_mode));
3379 if (TREE_CODE (sizetree) != INTEGER_CST
3380 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3382 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3383 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3385 ADD_PARM_SIZE (*offset_ptr, s2);
3386 SUB_PARM_SIZE (*offset_ptr, sizetree);
3392 round_down (value, divisor)
3396 return size_binop (MULT_EXPR,
3397 size_binop (FLOOR_DIV_EXPR, value, size_int (divisor)),
3398 size_int (divisor));
3401 /* Walk the tree of blocks describing the binding levels within a function
3402 and warn about uninitialized variables.
3403 This is done after calling flow_analysis and before global_alloc
3404 clobbers the pseudo-regs to hard regs. */
3407 uninitialized_vars_warning (block)
3410 register tree decl, sub;
3411 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3413 if (TREE_CODE (decl) == VAR_DECL
3414 /* These warnings are unreliable for and aggregates
3415 because assigning the fields one by one can fail to convince
3416 flow.c that the entire aggregate was initialized.
3417 Unions are troublesome because members may be shorter. */
3418 && TREE_CODE (TREE_TYPE (decl)) != RECORD_TYPE
3419 && TREE_CODE (TREE_TYPE (decl)) != UNION_TYPE
3420 && TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE
3421 && DECL_RTL (decl) != 0
3422 && GET_CODE (DECL_RTL (decl)) == REG
3423 && regno_uninitialized (REGNO (DECL_RTL (decl))))
3424 warning_with_decl (decl,
3425 "`%s' may be used uninitialized in this function");
3426 if (TREE_CODE (decl) == VAR_DECL
3427 && DECL_RTL (decl) != 0
3428 && GET_CODE (DECL_RTL (decl)) == REG
3429 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
3430 warning_with_decl (decl,
3431 "variable `%s' may be clobbered by `longjmp'");
3433 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
3434 uninitialized_vars_warning (sub);
3437 /* Do the appropriate part of uninitialized_vars_warning
3438 but for arguments instead of local variables. */
3441 setjmp_args_warning (block)
3445 for (decl = DECL_ARGUMENTS (current_function_decl);
3446 decl; decl = TREE_CHAIN (decl))
3447 if (DECL_RTL (decl) != 0
3448 && GET_CODE (DECL_RTL (decl)) == REG
3449 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
3450 warning_with_decl (decl, "argument `%s' may be clobbered by `longjmp'");
3453 /* If this function call setjmp, put all vars into the stack
3454 unless they were declared `register'. */
3457 setjmp_protect (block)
3460 register tree decl, sub;
3461 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3462 if ((TREE_CODE (decl) == VAR_DECL
3463 || TREE_CODE (decl) == PARM_DECL)
3464 && DECL_RTL (decl) != 0
3465 && GET_CODE (DECL_RTL (decl)) == REG
3466 /* If this variable came from an inline function, it must be
3467 that it's life doesn't overlap the setjmp. If there was a
3468 setjmp in the function, it would already be in memory. We
3469 must exclude such variable because their DECL_RTL might be
3470 set to strange things such as virtual_stack_vars_rtx. */
3471 && ! DECL_FROM_INLINE (decl)
3473 #ifdef NON_SAVING_SETJMP
3474 /* If longjmp doesn't restore the registers,
3475 don't put anything in them. */
3479 ! DECL_REGISTER (decl)))
3480 put_var_into_stack (decl);
3481 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
3482 setjmp_protect (sub);
3485 /* Like the previous function, but for args instead of local variables. */
3488 setjmp_protect_args ()
3490 register tree decl, sub;
3491 for (decl = DECL_ARGUMENTS (current_function_decl);
3492 decl; decl = TREE_CHAIN (decl))
3493 if ((TREE_CODE (decl) == VAR_DECL
3494 || TREE_CODE (decl) == PARM_DECL)
3495 && DECL_RTL (decl) != 0
3496 && GET_CODE (DECL_RTL (decl)) == REG
3498 /* If longjmp doesn't restore the registers,
3499 don't put anything in them. */
3500 #ifdef NON_SAVING_SETJMP
3504 ! DECL_REGISTER (decl)))
3505 put_var_into_stack (decl);
3508 /* Return the context-pointer register corresponding to DECL,
3509 or 0 if it does not need one. */
3512 lookup_static_chain (decl)
3515 tree context = decl_function_context (decl);
3521 /* We treat inline_function_decl as an alias for the current function
3522 because that is the inline function whose vars, types, etc.
3523 are being merged into the current function.
3524 See expand_inline_function. */
3525 if (context == current_function_decl || context == inline_function_decl)
3526 return virtual_stack_vars_rtx;
3528 for (link = context_display; link; link = TREE_CHAIN (link))
3529 if (TREE_PURPOSE (link) == context)
3530 return RTL_EXPR_RTL (TREE_VALUE (link));
3535 /* Convert a stack slot address ADDR for variable VAR
3536 (from a containing function)
3537 into an address valid in this function (using a static chain). */
3540 fix_lexical_addr (addr, var)
3546 tree context = decl_function_context (var);
3547 struct function *fp;
3550 /* If this is the present function, we need not do anything. */
3551 if (context == current_function_decl || context == inline_function_decl)
3554 for (fp = outer_function_chain; fp; fp = fp->next)
3555 if (fp->decl == context)
3561 /* Decode given address as base reg plus displacement. */
3562 if (GET_CODE (addr) == REG)
3563 basereg = addr, displacement = 0;
3564 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
3565 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
3569 /* We accept vars reached via the containing function's
3570 incoming arg pointer and via its stack variables pointer. */
3571 if (basereg == fp->internal_arg_pointer)
3573 /* If reached via arg pointer, get the arg pointer value
3574 out of that function's stack frame.
3576 There are two cases: If a separate ap is needed, allocate a
3577 slot in the outer function for it and dereference it that way.
3578 This is correct even if the real ap is actually a pseudo.
3579 Otherwise, just adjust the offset from the frame pointer to
3582 #ifdef NEED_SEPARATE_AP
3585 if (fp->arg_pointer_save_area == 0)
3586 fp->arg_pointer_save_area
3587 = assign_outer_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0, fp);
3589 addr = fix_lexical_addr (XEXP (fp->arg_pointer_save_area, 0), var);
3590 addr = memory_address (Pmode, addr);
3592 base = copy_to_reg (gen_rtx (MEM, Pmode, addr));
3594 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
3595 base = lookup_static_chain (var);
3599 else if (basereg == virtual_stack_vars_rtx)
3601 /* This is the same code as lookup_static_chain, duplicated here to
3602 avoid an extra call to decl_function_context. */
3605 for (link = context_display; link; link = TREE_CHAIN (link))
3606 if (TREE_PURPOSE (link) == context)
3608 base = RTL_EXPR_RTL (TREE_VALUE (link));
3616 /* Use same offset, relative to appropriate static chain or argument
3618 return plus_constant (base, displacement);
3621 /* Return the address of the trampoline for entering nested fn FUNCTION.
3622 If necessary, allocate a trampoline (in the stack frame)
3623 and emit rtl to initialize its contents (at entry to this function). */
3626 trampoline_address (function)
3632 struct function *fp;
3635 /* Find an existing trampoline and return it. */
3636 for (link = trampoline_list; link; link = TREE_CHAIN (link))
3637 if (TREE_PURPOSE (link) == function)
3638 return XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0);
3639 for (fp = outer_function_chain; fp; fp = fp->next)
3640 for (link = fp->trampoline_list; link; link = TREE_CHAIN (link))
3641 if (TREE_PURPOSE (link) == function)
3643 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
3645 return round_trampoline_addr (tramp);
3648 /* None exists; we must make one. */
3650 /* Find the `struct function' for the function containing FUNCTION. */
3652 fn_context = decl_function_context (function);
3653 if (fn_context != current_function_decl)
3654 for (fp = outer_function_chain; fp; fp = fp->next)
3655 if (fp->decl == fn_context)
3658 /* Allocate run-time space for this trampoline
3659 (usually in the defining function's stack frame). */
3660 #ifdef ALLOCATE_TRAMPOLINE
3661 tramp = ALLOCATE_TRAMPOLINE (fp);
3663 /* If rounding needed, allocate extra space
3664 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
3665 #ifdef TRAMPOLINE_ALIGNMENT
3666 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE + TRAMPOLINE_ALIGNMENT - 1)
3668 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE)
3671 tramp = assign_outer_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0, fp);
3673 tramp = assign_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0);
3676 /* Record the trampoline for reuse and note it for later initialization
3677 by expand_function_end. */
3680 push_obstacks (fp->current_obstack, fp->function_maybepermanent_obstack);
3681 rtlexp = make_node (RTL_EXPR);
3682 RTL_EXPR_RTL (rtlexp) = tramp;
3683 fp->trampoline_list = tree_cons (function, rtlexp, fp->trampoline_list);
3688 /* Make the RTL_EXPR node temporary, not momentary, so that the
3689 trampoline_list doesn't become garbage. */
3690 int momentary = suspend_momentary ();
3691 rtlexp = make_node (RTL_EXPR);
3692 resume_momentary (momentary);
3694 RTL_EXPR_RTL (rtlexp) = tramp;
3695 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
3698 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
3699 return round_trampoline_addr (tramp);
3702 /* Given a trampoline address,
3703 round it to multiple of TRAMPOLINE_ALIGNMENT. */
3706 round_trampoline_addr (tramp)
3709 #ifdef TRAMPOLINE_ALIGNMENT
3710 /* Round address up to desired boundary. */
3711 rtx temp = gen_reg_rtx (Pmode);
3712 temp = expand_binop (Pmode, add_optab, tramp,
3713 GEN_INT (TRAMPOLINE_ALIGNMENT - 1),
3714 temp, 0, OPTAB_LIB_WIDEN);
3715 tramp = expand_binop (Pmode, and_optab, temp,
3716 GEN_INT (- TRAMPOLINE_ALIGNMENT),
3717 temp, 0, OPTAB_LIB_WIDEN);
3722 /* The functions identify_blocks and reorder_blocks provide a way to
3723 reorder the tree of BLOCK nodes, for optimizers that reshuffle or
3724 duplicate portions of the RTL code. Call identify_blocks before
3725 changing the RTL, and call reorder_blocks after. */
3727 static int all_blocks ();
3728 static tree blocks_nreverse ();
3730 /* Put all this function's BLOCK nodes into a vector, and return it.
3731 Also store in each NOTE for the beginning or end of a block
3732 the index of that block in the vector.
3733 The arguments are TOP_BLOCK, the top-level block of the function,
3734 and INSNS, the insn chain of the function. */
3737 identify_blocks (top_block, insns)
3745 int next_block_number = 0;
3746 int current_block_number = 0;
3752 n_blocks = all_blocks (top_block, 0);
3753 block_vector = (tree *) xmalloc (n_blocks * sizeof (tree));
3754 block_stack = (int *) alloca (n_blocks * sizeof (int));
3756 all_blocks (top_block, block_vector);
3758 for (insn = insns; insn; insn = NEXT_INSN (insn))
3759 if (GET_CODE (insn) == NOTE)
3761 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
3763 block_stack[depth++] = current_block_number;
3764 current_block_number = next_block_number;
3765 NOTE_BLOCK_NUMBER (insn) = next_block_number++;
3767 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
3769 current_block_number = block_stack[--depth];
3770 NOTE_BLOCK_NUMBER (insn) = current_block_number;
3774 return block_vector;
3777 /* Given BLOCK_VECTOR which was returned by identify_blocks,
3778 and a revised instruction chain, rebuild the tree structure
3779 of BLOCK nodes to correspond to the new order of RTL.
3780 The new block tree is inserted below TOP_BLOCK.
3781 Returns the current top-level block. */
3784 reorder_blocks (block_vector, top_block, insns)
3789 tree current_block = top_block;
3792 if (block_vector == 0)
3795 /* Prune the old tree away, so that it doesn't get in the way. */
3796 BLOCK_SUBBLOCKS (current_block) = 0;
3798 for (insn = insns; insn; insn = NEXT_INSN (insn))
3799 if (GET_CODE (insn) == NOTE)
3801 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
3803 tree block = block_vector[NOTE_BLOCK_NUMBER (insn)];
3804 /* If we have seen this block before, copy it. */
3805 if (TREE_ASM_WRITTEN (block))
3806 block = copy_node (block);
3807 BLOCK_SUBBLOCKS (block) = 0;
3808 TREE_ASM_WRITTEN (block) = 1;
3809 BLOCK_SUPERCONTEXT (block) = current_block;
3810 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3811 BLOCK_SUBBLOCKS (current_block) = block;
3812 current_block = block;
3813 NOTE_SOURCE_FILE (insn) = 0;
3815 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
3817 BLOCK_SUBBLOCKS (current_block)
3818 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3819 current_block = BLOCK_SUPERCONTEXT (current_block);
3820 NOTE_SOURCE_FILE (insn) = 0;
3824 return current_block;
3827 /* Reverse the order of elements in the chain T of blocks,
3828 and return the new head of the chain (old last element). */
3834 register tree prev = 0, decl, next;
3835 for (decl = t; decl; decl = next)
3837 next = BLOCK_CHAIN (decl);
3838 BLOCK_CHAIN (decl) = prev;
3844 /* Count the subblocks of BLOCK, and list them all into the vector VECTOR.
3845 Also clear TREE_ASM_WRITTEN in all blocks. */
3848 all_blocks (block, vector)
3855 TREE_ASM_WRITTEN (block) = 0;
3856 /* Record this block. */
3860 /* Record the subblocks, and their subblocks. */
3861 for (subblocks = BLOCK_SUBBLOCKS (block);
3862 subblocks; subblocks = BLOCK_CHAIN (subblocks))
3863 n_blocks += all_blocks (subblocks, vector ? vector + n_blocks : 0);
3868 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
3869 and initialize static variables for generating RTL for the statements
3873 init_function_start (subr, filename, line)
3880 init_stmt_for_function ();
3882 cse_not_expected = ! optimize;
3884 /* Caller save not needed yet. */
3885 caller_save_needed = 0;
3887 /* No stack slots have been made yet. */
3888 stack_slot_list = 0;
3890 /* There is no stack slot for handling nonlocal gotos. */
3891 nonlocal_goto_handler_slot = 0;
3892 nonlocal_goto_stack_level = 0;
3894 /* No labels have been declared for nonlocal use. */
3895 nonlocal_labels = 0;
3897 /* No function calls so far in this function. */
3898 function_call_count = 0;
3900 /* No parm regs have been allocated.
3901 (This is important for output_inline_function.) */
3902 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
3904 /* Initialize the RTL mechanism. */
3907 /* Initialize the queue of pending postincrement and postdecrements,
3908 and some other info in expr.c. */
3911 /* We haven't done register allocation yet. */
3914 init_const_rtx_hash_table ();
3916 current_function_name = (*decl_printable_name) (subr, &junk);
3918 /* Nonzero if this is a nested function that uses a static chain. */
3920 current_function_needs_context
3921 = (decl_function_context (current_function_decl) != 0);
3923 /* Set if a call to setjmp is seen. */
3924 current_function_calls_setjmp = 0;
3926 /* Set if a call to longjmp is seen. */
3927 current_function_calls_longjmp = 0;
3929 current_function_calls_alloca = 0;
3930 current_function_has_nonlocal_label = 0;
3931 current_function_contains_functions = 0;
3933 current_function_returns_pcc_struct = 0;
3934 current_function_returns_struct = 0;
3935 current_function_epilogue_delay_list = 0;
3936 current_function_uses_const_pool = 0;
3937 current_function_uses_pic_offset_table = 0;
3939 /* We have not yet needed to make a label to jump to for tail-recursion. */
3940 tail_recursion_label = 0;
3942 /* We haven't had a need to make a save area for ap yet. */
3944 arg_pointer_save_area = 0;
3946 /* No stack slots allocated yet. */
3949 /* No SAVE_EXPRs in this function yet. */
3952 /* No RTL_EXPRs in this function yet. */
3955 /* We have not allocated any temporaries yet. */
3957 temp_slot_level = 0;
3959 /* Within function body, compute a type's size as soon it is laid out. */
3960 immediate_size_expand++;
3962 init_pending_stack_adjust ();
3963 inhibit_defer_pop = 0;
3965 current_function_outgoing_args_size = 0;
3967 /* Initialize the insn lengths. */
3968 init_insn_lengths ();
3970 /* Prevent ever trying to delete the first instruction of a function.
3971 Also tell final how to output a linenum before the function prologue. */
3972 emit_line_note (filename, line);
3974 /* Make sure first insn is a note even if we don't want linenums.
3975 This makes sure the first insn will never be deleted.
3976 Also, final expects a note to appear there. */
3977 emit_note (NULL_PTR, NOTE_INSN_DELETED);
3979 /* Set flags used by final.c. */
3980 if (aggregate_value_p (DECL_RESULT (subr)))
3982 #ifdef PCC_STATIC_STRUCT_RETURN
3983 if (flag_pcc_struct_return)
3984 current_function_returns_pcc_struct = 1;
3987 current_function_returns_struct = 1;
3990 /* Warn if this value is an aggregate type,
3991 regardless of which calling convention we are using for it. */
3992 if (warn_aggregate_return
3993 && (TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == RECORD_TYPE
3994 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == UNION_TYPE
3995 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == ARRAY_TYPE))
3996 warning ("function returns an aggregate");
3998 current_function_returns_pointer
3999 = (TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == POINTER_TYPE);
4001 /* Indicate that we need to distinguish between the return value of the
4002 present function and the return value of a function being called. */
4003 rtx_equal_function_value_matters = 1;
4005 /* Indicate that we have not instantiated virtual registers yet. */
4006 virtuals_instantiated = 0;
4008 /* Indicate we have no need of a frame pointer yet. */
4009 frame_pointer_needed = 0;
4011 /* By default assume not varargs. */
4012 current_function_varargs = 0;
4015 /* Indicate that the current function uses extra args
4016 not explicitly mentioned in the argument list in any fashion. */
4021 current_function_varargs = 1;
4024 /* Expand a call to __main at the beginning of a possible main function. */
4027 expand_main_function ()
4029 #if !defined (INIT_SECTION_ASM_OP) || defined (INVOKE__main)
4030 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__main"), 0,
4032 #endif /* not INIT_SECTION_ASM_OP or INVOKE__main */
4035 /* Start the RTL for a new function, and set variables used for
4037 SUBR is the FUNCTION_DECL node.
4038 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4039 the function's parameters, which must be run at any return statement. */
4042 expand_function_start (subr, parms_have_cleanups)
4044 int parms_have_cleanups;
4050 /* Make sure volatile mem refs aren't considered
4051 valid operands of arithmetic insns. */
4052 init_recog_no_volatile ();
4054 /* If function gets a static chain arg, store it in the stack frame.
4055 Do this first, so it gets the first stack slot offset. */
4056 if (current_function_needs_context)
4058 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4059 emit_move_insn (last_ptr, static_chain_incoming_rtx);
4062 /* If the parameters of this function need cleaning up, get a label
4063 for the beginning of the code which executes those cleanups. This must
4064 be done before doing anything with return_label. */
4065 if (parms_have_cleanups)
4066 cleanup_label = gen_label_rtx ();
4070 /* Make the label for return statements to jump to, if this machine
4071 does not have a one-instruction return and uses an epilogue,
4072 or if it returns a structure, or if it has parm cleanups. */
4074 if (cleanup_label == 0 && HAVE_return
4075 && ! current_function_returns_pcc_struct
4076 && ! (current_function_returns_struct && ! optimize))
4079 return_label = gen_label_rtx ();
4081 return_label = gen_label_rtx ();
4084 /* Initialize rtx used to return the value. */
4085 /* Do this before assign_parms so that we copy the struct value address
4086 before any library calls that assign parms might generate. */
4088 /* Decide whether to return the value in memory or in a register. */
4089 if (aggregate_value_p (DECL_RESULT (subr)))
4091 /* Returning something that won't go in a register. */
4092 register rtx value_address;
4094 #ifdef PCC_STATIC_STRUCT_RETURN
4095 if (current_function_returns_pcc_struct)
4097 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4098 value_address = assemble_static_space (size);
4103 /* Expect to be passed the address of a place to store the value.
4104 If it is passed as an argument, assign_parms will take care of
4106 if (struct_value_incoming_rtx)
4108 value_address = gen_reg_rtx (Pmode);
4109 emit_move_insn (value_address, struct_value_incoming_rtx);
4113 DECL_RTL (DECL_RESULT (subr))
4114 = gen_rtx (MEM, DECL_MODE (DECL_RESULT (subr)),
4117 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4118 /* If return mode is void, this decl rtl should not be used. */
4119 DECL_RTL (DECL_RESULT (subr)) = 0;
4120 else if (parms_have_cleanups)
4122 /* If function will end with cleanup code for parms,
4123 compute the return values into a pseudo reg,
4124 which we will copy into the true return register
4125 after the cleanups are done. */
4127 enum machine_mode mode = DECL_MODE (DECL_RESULT (subr));
4128 #ifdef PROMOTE_FUNCTION_RETURN
4129 tree type = TREE_TYPE (DECL_RESULT (subr));
4130 int unsignedp = TREE_UNSIGNED (type);
4132 if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE
4133 || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE
4134 || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE
4135 || TREE_CODE (type) == OFFSET_TYPE)
4137 PROMOTE_MODE (mode, unsignedp, type);
4141 DECL_RTL (DECL_RESULT (subr)) = gen_reg_rtx (mode);
4144 /* Scalar, returned in a register. */
4146 #ifdef FUNCTION_OUTGOING_VALUE
4147 DECL_RTL (DECL_RESULT (subr))
4148 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
4150 DECL_RTL (DECL_RESULT (subr))
4151 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
4154 /* Mark this reg as the function's return value. */
4155 if (GET_CODE (DECL_RTL (DECL_RESULT (subr))) == REG)
4157 REG_FUNCTION_VALUE_P (DECL_RTL (DECL_RESULT (subr))) = 1;
4158 /* Needed because we may need to move this to memory
4159 in case it's a named return value whose address is taken. */
4160 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4164 /* Initialize rtx for parameters and local variables.
4165 In some cases this requires emitting insns. */
4167 assign_parms (subr, 0);
4169 /* The following was moved from init_function_start.
4170 The move is supposed to make sdb output more accurate. */
4171 /* Indicate the beginning of the function body,
4172 as opposed to parm setup. */
4173 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_BEG);
4175 /* If doing stupid allocation, mark parms as born here. */
4177 if (GET_CODE (get_last_insn ()) != NOTE)
4178 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4179 parm_birth_insn = get_last_insn ();
4183 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
4184 use_variable (regno_reg_rtx[i]);
4186 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
4187 use_variable (current_function_internal_arg_pointer);
4190 /* Fetch static chain values for containing functions. */
4191 tem = decl_function_context (current_function_decl);
4192 /* If not doing stupid register allocation, then start off with the static
4193 chain pointer in a pseudo register. Otherwise, we use the stack
4194 address that was generated above. */
4195 if (tem && ! obey_regdecls)
4196 last_ptr = copy_to_reg (static_chain_incoming_rtx);
4197 context_display = 0;
4200 tree rtlexp = make_node (RTL_EXPR);
4202 RTL_EXPR_RTL (rtlexp) = last_ptr;
4203 context_display = tree_cons (tem, rtlexp, context_display);
4204 tem = decl_function_context (tem);
4207 /* Chain thru stack frames, assuming pointer to next lexical frame
4208 is found at the place we always store it. */
4209 #ifdef FRAME_GROWS_DOWNWARD
4210 last_ptr = plus_constant (last_ptr, - GET_MODE_SIZE (Pmode));
4212 last_ptr = copy_to_reg (gen_rtx (MEM, Pmode,
4213 memory_address (Pmode, last_ptr)));
4216 /* After the display initializations is where the tail-recursion label
4217 should go, if we end up needing one. Ensure we have a NOTE here
4218 since some things (like trampolines) get placed before this. */
4219 tail_recursion_reentry = emit_note (NULL_PTR, NOTE_INSN_DELETED);
4221 /* Evaluate now the sizes of any types declared among the arguments. */
4222 for (tem = nreverse (get_pending_sizes ()); tem; tem = TREE_CHAIN (tem))
4223 expand_expr (TREE_VALUE (tem), NULL_RTX, VOIDmode, 0);
4225 /* Make sure there is a line number after the function entry setup code. */
4226 force_next_line_note ();
4229 /* Generate RTL for the end of the current function.
4230 FILENAME and LINE are the current position in the source file. */
4232 /* It is up to language-specific callers to do cleanups for parameters. */
4235 expand_function_end (filename, line)
4242 static rtx initial_trampoline;
4244 #ifdef NON_SAVING_SETJMP
4245 /* Don't put any variables in registers if we call setjmp
4246 on a machine that fails to restore the registers. */
4247 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
4249 setjmp_protect (DECL_INITIAL (current_function_decl));
4250 setjmp_protect_args ();
4254 /* Save the argument pointer if a save area was made for it. */
4255 if (arg_pointer_save_area)
4257 rtx x = gen_move_insn (arg_pointer_save_area, virtual_incoming_args_rtx);
4258 emit_insn_before (x, tail_recursion_reentry);
4261 /* Initialize any trampolines required by this function. */
4262 for (link = trampoline_list; link; link = TREE_CHAIN (link))
4264 tree function = TREE_PURPOSE (link);
4265 rtx context = lookup_static_chain (function);
4266 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
4269 /* First make sure this compilation has a template for
4270 initializing trampolines. */
4271 if (initial_trampoline == 0)
4273 end_temporary_allocation ();
4275 = gen_rtx (MEM, BLKmode, assemble_trampoline_template ());
4276 resume_temporary_allocation ();
4279 /* Generate insns to initialize the trampoline. */
4281 tramp = change_address (initial_trampoline, BLKmode,
4282 round_trampoline_addr (XEXP (tramp, 0)));
4283 emit_block_move (tramp, initial_trampoline, GEN_INT (TRAMPOLINE_SIZE),
4284 FUNCTION_BOUNDARY / BITS_PER_UNIT);
4285 INITIALIZE_TRAMPOLINE (XEXP (tramp, 0),
4286 XEXP (DECL_RTL (function), 0), context);
4290 /* Put those insns at entry to the containing function (this one). */
4291 emit_insns_before (seq, tail_recursion_reentry);
4293 /* Clear the trampoline_list for the next function. */
4294 trampoline_list = 0;
4296 #if 0 /* I think unused parms are legitimate enough. */
4297 /* Warn about unused parms. */
4302 for (decl = DECL_ARGUMENTS (current_function_decl);
4303 decl; decl = TREE_CHAIN (decl))
4304 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL)
4305 warning_with_decl (decl, "unused parameter `%s'");
4309 /* Delete handlers for nonlocal gotos if nothing uses them. */
4310 if (nonlocal_goto_handler_slot != 0 && !current_function_has_nonlocal_label)
4313 /* End any sequences that failed to be closed due to syntax errors. */
4314 while (in_sequence_p ())
4317 /* Outside function body, can't compute type's actual size
4318 until next function's body starts. */
4319 immediate_size_expand--;
4321 /* If doing stupid register allocation,
4322 mark register parms as dying here. */
4327 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
4328 use_variable (regno_reg_rtx[i]);
4330 /* Likewise for the regs of all the SAVE_EXPRs in the function. */
4332 for (tem = save_expr_regs; tem; tem = XEXP (tem, 1))
4334 use_variable (XEXP (tem, 0));
4335 use_variable_after (XEXP (tem, 0), parm_birth_insn);
4338 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
4339 use_variable (current_function_internal_arg_pointer);
4342 clear_pending_stack_adjust ();
4343 do_pending_stack_adjust ();
4345 /* Mark the end of the function body.
4346 If control reaches this insn, the function can drop through
4347 without returning a value. */
4348 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_END);
4350 /* Output a linenumber for the end of the function.
4351 SDB depends on this. */
4352 emit_line_note_force (filename, line);
4354 /* Output the label for the actual return from the function,
4355 if one is expected. This happens either because a function epilogue
4356 is used instead of a return instruction, or because a return was done
4357 with a goto in order to run local cleanups, or because of pcc-style
4358 structure returning. */
4361 emit_label (return_label);
4363 /* If we had calls to alloca, and this machine needs
4364 an accurate stack pointer to exit the function,
4365 insert some code to save and restore the stack pointer. */
4366 #ifdef EXIT_IGNORE_STACK
4367 if (! EXIT_IGNORE_STACK)
4369 if (current_function_calls_alloca)
4373 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4374 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4377 /* If scalar return value was computed in a pseudo-reg,
4378 copy that to the hard return register. */
4379 if (DECL_RTL (DECL_RESULT (current_function_decl)) != 0
4380 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG
4381 && (REGNO (DECL_RTL (DECL_RESULT (current_function_decl)))
4382 >= FIRST_PSEUDO_REGISTER))
4384 rtx real_decl_result;
4386 #ifdef FUNCTION_OUTGOING_VALUE
4388 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
4389 current_function_decl);
4392 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
4393 current_function_decl);
4395 REG_FUNCTION_VALUE_P (real_decl_result) = 1;
4396 emit_move_insn (real_decl_result,
4397 DECL_RTL (DECL_RESULT (current_function_decl)));
4398 emit_insn (gen_rtx (USE, VOIDmode, real_decl_result));
4401 /* If returning a structure, arrange to return the address of the value
4402 in a place where debuggers expect to find it.
4404 If returning a structure PCC style,
4405 the caller also depends on this value.
4406 And current_function_returns_pcc_struct is not necessarily set. */
4407 if (current_function_returns_struct
4408 || current_function_returns_pcc_struct)
4410 rtx value_address = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
4411 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4412 #ifdef FUNCTION_OUTGOING_VALUE
4414 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
4415 current_function_decl);
4418 = FUNCTION_VALUE (build_pointer_type (type),
4419 current_function_decl);
4422 /* Mark this as a function return value so integrate will delete the
4423 assignment and USE below when inlining this function. */
4424 REG_FUNCTION_VALUE_P (outgoing) = 1;
4426 emit_move_insn (outgoing, value_address);
4427 use_variable (outgoing);
4430 /* Output a return insn if we are using one.
4431 Otherwise, let the rtl chain end here, to drop through
4432 into the epilogue. */
4437 emit_jump_insn (gen_return ());
4442 /* Fix up any gotos that jumped out to the outermost
4443 binding level of the function.
4444 Must follow emitting RETURN_LABEL. */
4446 /* If you have any cleanups to do at this point,
4447 and they need to create temporary variables,
4448 then you will lose. */
4449 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, get_insns (), 0);
4452 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
4454 static int *prologue;
4455 static int *epilogue;
4457 /* Create an array that records the INSN_UIDs of INSNS (either a sequence
4458 or a single insn). */
4461 record_insns (insns)
4466 if (GET_CODE (insns) == SEQUENCE)
4468 int len = XVECLEN (insns, 0);
4469 vec = (int *) oballoc ((len + 1) * sizeof (int));
4472 vec[len] = INSN_UID (XVECEXP (insns, 0, len));
4476 vec = (int *) oballoc (2 * sizeof (int));
4477 vec[0] = INSN_UID (insns);
4483 /* Determine how many INSN_UIDs in VEC are part of INSN. */
4486 contains (insn, vec)
4492 if (GET_CODE (insn) == INSN
4493 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4496 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4497 for (j = 0; vec[j]; j++)
4498 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == vec[j])
4504 for (j = 0; vec[j]; j++)
4505 if (INSN_UID (insn) == vec[j])
4511 /* Generate the prologe and epilogue RTL if the machine supports it. Thread
4512 this into place with notes indicating where the prologue ends and where
4513 the epilogue begins. Update the basic block information when possible. */
4516 thread_prologue_and_epilogue_insns (f)
4519 #ifdef HAVE_prologue
4522 rtx head, seq, insn;
4524 /* The first insn (a NOTE_INSN_DELETED) is followed by zero or more
4525 prologue insns and a NOTE_INSN_PROLOGUE_END. */
4526 emit_note_after (NOTE_INSN_PROLOGUE_END, f);
4527 seq = gen_prologue ();
4528 head = emit_insn_after (seq, f);
4530 /* Include the new prologue insns in the first block. Ignore them
4531 if they form a basic block unto themselves. */
4532 if (basic_block_head && n_basic_blocks
4533 && GET_CODE (basic_block_head[0]) != CODE_LABEL)
4534 basic_block_head[0] = NEXT_INSN (f);
4536 /* Retain a map of the prologue insns. */
4537 prologue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : head);
4543 #ifdef HAVE_epilogue
4546 rtx insn = get_last_insn ();
4547 rtx prev = prev_nonnote_insn (insn);
4549 /* If we end with a BARRIER, we don't need an epilogue. */
4550 if (! (prev && GET_CODE (prev) == BARRIER))
4554 /* The last basic block ends with a NOTE_INSN_EPILOGUE_BEG,
4555 the epilogue insns (this must include the jump insn that
4556 returns), USE insns ad the end of a function, and a BARRIER. */
4558 emit_barrier_after (insn);
4560 /* Place the epilogue before the USE insns at the end of a
4563 && GET_CODE (prev) == INSN
4564 && GET_CODE (PATTERN (prev)) == USE)
4566 insn = PREV_INSN (prev);
4567 prev = prev_nonnote_insn (prev);
4570 seq = gen_epilogue ();
4571 tail = emit_jump_insn_after (seq, insn);
4572 emit_note_after (NOTE_INSN_EPILOGUE_BEG, insn);
4574 /* Include the new epilogue insns in the last block. Ignore
4575 them if they form a basic block unto themselves. */
4576 if (basic_block_end && n_basic_blocks
4577 && GET_CODE (basic_block_end[n_basic_blocks - 1]) != JUMP_INSN)
4578 basic_block_end[n_basic_blocks - 1] = tail;
4580 /* Retain a map of the epilogue insns. */
4581 epilogue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : tail);
4589 /* Reposition the prologue-end and epilogue-begin notes after instruction
4590 scheduling and delayed branch scheduling. */
4593 reposition_prologue_and_epilogue_notes (f)
4596 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
4597 /* Reposition the prologue and epilogue notes. */
4605 register rtx insn, note = 0;
4607 /* Scan from the beginning until we reach the last prologue insn.
4608 We apparently can't depend on basic_block_{head,end} after
4610 for (len = 0; prologue[len]; len++)
4612 for (insn = f; insn; insn = NEXT_INSN (insn))
4613 if (GET_CODE (insn) == NOTE)
4615 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
4618 else if ((len -= contains (insn, prologue)) == 0)
4620 /* Find the prologue-end note if we haven't already, and
4621 move it to just after the last prologue insn. */
4623 for (note = insn; note = NEXT_INSN (note);)
4624 if (GET_CODE (note) == NOTE
4625 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
4627 next = NEXT_INSN (note);
4628 prev = PREV_INSN (note);
4630 NEXT_INSN (prev) = next;
4632 PREV_INSN (next) = prev;
4633 add_insn_after (note, insn);
4640 register rtx insn, note = 0;
4642 /* Scan from the end until we reach the first epilogue insn.
4643 We apparently can't depend on basic_block_{head,end} after
4645 for (len = 0; epilogue[len]; len++)
4647 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
4648 if (GET_CODE (insn) == NOTE)
4650 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
4653 else if ((len -= contains (insn, epilogue)) == 0)
4655 /* Find the epilogue-begin note if we haven't already, and
4656 move it to just before the first epilogue insn. */
4658 for (note = insn; note = PREV_INSN (note);)
4659 if (GET_CODE (note) == NOTE
4660 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
4662 next = NEXT_INSN (note);
4663 prev = PREV_INSN (note);
4665 NEXT_INSN (prev) = next;
4667 PREV_INSN (next) = prev;
4668 add_insn_after (note, PREV_INSN (insn));
4673 #endif /* HAVE_prologue or HAVE_epilogue */