1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register.
36 Call `put_var_into_stack' when you learn, belatedly, that a variable
37 previously given a pseudo-register must in fact go in the stack.
38 This function changes the DECL_RTL to be a stack slot instead of a reg
39 then scans all the RTL instructions so far generated to correct them. */
43 #include "coretypes.h"
54 #include "hard-reg-set.h"
55 #include "insn-config.h"
58 #include "basic-block.h"
63 #include "integrate.h"
64 #include "langhooks.h"
67 #ifndef TRAMPOLINE_ALIGNMENT
68 #define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
71 #ifndef LOCAL_ALIGNMENT
72 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
75 #ifndef STACK_ALIGNMENT_NEEDED
76 #define STACK_ALIGNMENT_NEEDED 1
79 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
81 /* Some systems use __main in a way incompatible with its use in gcc, in these
82 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
83 give the same symbol without quotes for an alternative entry point. You
84 must define both, or neither. */
86 #define NAME__MAIN "__main"
89 /* Round a value to the lowest integer less than it that is a multiple of
90 the required alignment. Avoid using division in case the value is
91 negative. Assume the alignment is a power of two. */
92 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
94 /* Similar, but round to the next highest integer that meets the
96 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
98 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
99 during rtl generation. If they are different register numbers, this is
100 always true. It may also be true if
101 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
102 generation. See fix_lexical_addr for details. */
104 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
105 #define NEED_SEPARATE_AP
108 /* Nonzero if function being compiled doesn't contain any calls
109 (ignoring the prologue and epilogue). This is set prior to
110 local register allocation and is valid for the remaining
112 int current_function_is_leaf;
114 /* Nonzero if function being compiled doesn't contain any instructions
115 that can throw an exception. This is set prior to final. */
117 int current_function_nothrow;
119 /* Nonzero if function being compiled doesn't modify the stack pointer
120 (ignoring the prologue and epilogue). This is only valid after
121 life_analysis has run. */
122 int current_function_sp_is_unchanging;
124 /* Nonzero if the function being compiled is a leaf function which only
125 uses leaf registers. This is valid after reload (specifically after
126 sched2) and is useful only if the port defines LEAF_REGISTERS. */
127 int current_function_uses_only_leaf_regs;
129 /* Nonzero once virtual register instantiation has been done.
130 assign_stack_local uses frame_pointer_rtx when this is nonzero.
131 calls.c:emit_library_call_value_1 uses it to set up
132 post-instantiation libcalls. */
133 int virtuals_instantiated;
135 /* Nonzero if at least one trampoline has been created. */
136 int trampolines_created;
138 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
139 static GTY(()) int funcdef_no;
141 /* These variables hold pointers to functions to create and destroy
142 target specific, per-function data structures. */
143 struct machine_function * (*init_machine_status) (void);
145 /* The FUNCTION_DECL for an inline function currently being expanded. */
146 tree inline_function_decl;
148 /* The currently compiled function. */
149 struct function *cfun = 0;
151 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
152 static GTY(()) varray_type prologue;
153 static GTY(()) varray_type epilogue;
155 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
157 static GTY(()) varray_type sibcall_epilogue;
159 /* In order to evaluate some expressions, such as function calls returning
160 structures in memory, we need to temporarily allocate stack locations.
161 We record each allocated temporary in the following structure.
163 Associated with each temporary slot is a nesting level. When we pop up
164 one level, all temporaries associated with the previous level are freed.
165 Normally, all temporaries are freed after the execution of the statement
166 in which they were created. However, if we are inside a ({...}) grouping,
167 the result may be in a temporary and hence must be preserved. If the
168 result could be in a temporary, we preserve it if we can determine which
169 one it is in. If we cannot determine which temporary may contain the
170 result, all temporaries are preserved. A temporary is preserved by
171 pretending it was allocated at the previous nesting level.
173 Automatic variables are also assigned temporary slots, at the nesting
174 level where they are defined. They are marked a "kept" so that
175 free_temp_slots will not free them. */
177 struct temp_slot GTY(())
179 /* Points to next temporary slot. */
180 struct temp_slot *next;
181 /* The rtx to used to reference the slot. */
183 /* The rtx used to represent the address if not the address of the
184 slot above. May be an EXPR_LIST if multiple addresses exist. */
186 /* The alignment (in bits) of the slot. */
188 /* The size, in units, of the slot. */
190 /* The type of the object in the slot, or zero if it doesn't correspond
191 to a type. We use this to determine whether a slot can be reused.
192 It can be reused if objects of the type of the new slot will always
193 conflict with objects of the type of the old slot. */
195 /* The value of `sequence_rtl_expr' when this temporary is allocated. */
197 /* Nonzero if this temporary is currently in use. */
199 /* Nonzero if this temporary has its address taken. */
201 /* Nesting level at which this slot is being used. */
203 /* Nonzero if this should survive a call to free_temp_slots. */
205 /* The offset of the slot from the frame_pointer, including extra space
206 for alignment. This info is for combine_temp_slots. */
207 HOST_WIDE_INT base_offset;
208 /* The size of the slot, including extra space for alignment. This
209 info is for combine_temp_slots. */
210 HOST_WIDE_INT full_size;
213 /* This structure is used to record MEMs or pseudos used to replace VAR, any
214 SUBREGs of VAR, and any MEMs containing VAR as an address. We need to
215 maintain this list in case two operands of an insn were required to match;
216 in that case we must ensure we use the same replacement. */
218 struct fixup_replacement GTY(())
222 struct fixup_replacement *next;
225 struct insns_for_mem_entry
229 /* These are the INSNs which reference the MEM. */
233 /* Forward declarations. */
235 static rtx assign_stack_local_1 (enum machine_mode, HOST_WIDE_INT, int,
237 static struct temp_slot *find_temp_slot_from_address (rtx);
238 static void put_reg_into_stack (struct function *, rtx, tree, enum machine_mode,
239 enum machine_mode, int, unsigned int, int, htab_t);
240 static void schedule_fixup_var_refs (struct function *, rtx, tree, enum machine_mode,
242 static void fixup_var_refs (rtx, enum machine_mode, int, rtx, htab_t);
243 static struct fixup_replacement
244 *find_fixup_replacement (struct fixup_replacement **, rtx);
245 static void fixup_var_refs_insns (rtx, rtx, enum machine_mode, int, int, rtx);
246 static void fixup_var_refs_insns_with_hash (htab_t, rtx, enum machine_mode, int, rtx);
247 static void fixup_var_refs_insn (rtx, rtx, enum machine_mode, int, int, rtx);
248 static void fixup_var_refs_1 (rtx, enum machine_mode, rtx *, rtx,
249 struct fixup_replacement **, rtx);
250 static rtx fixup_memory_subreg (rtx, rtx, enum machine_mode, int);
251 static rtx walk_fixup_memory_subreg (rtx, rtx, enum machine_mode, int);
252 static rtx fixup_stack_1 (rtx, rtx);
253 static void optimize_bit_field (rtx, rtx, rtx *);
254 static void instantiate_decls (tree, int);
255 static void instantiate_decls_1 (tree, int);
256 static void instantiate_decl (rtx, HOST_WIDE_INT, int);
257 static rtx instantiate_new_reg (rtx, HOST_WIDE_INT *);
258 static int instantiate_virtual_regs_1 (rtx *, rtx, int);
259 static void delete_handlers (void);
260 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
261 static void pad_below (struct args_size *, enum machine_mode, tree);
262 static rtx round_trampoline_addr (rtx);
263 static rtx adjust_trampoline_addr (rtx);
264 static tree *identify_blocks_1 (rtx, tree *, tree *, tree *);
265 static void reorder_blocks_0 (tree);
266 static void reorder_blocks_1 (rtx, tree, varray_type *);
267 static void reorder_fix_fragments (tree);
268 static tree blocks_nreverse (tree);
269 static int all_blocks (tree, tree *);
270 static tree *get_block_vector (tree, int *);
271 extern tree debug_find_var_in_block_tree (tree, tree);
272 /* We always define `record_insns' even if it's not used so that we
273 can always export `prologue_epilogue_contains'. */
274 static void record_insns (rtx, varray_type *) ATTRIBUTE_UNUSED;
275 static int contains (rtx, varray_type);
277 static void emit_return_into_block (basic_block, rtx);
279 static void put_addressof_into_stack (rtx, htab_t);
280 static bool purge_addressof_1 (rtx *, rtx, int, int, int, htab_t);
281 static void purge_single_hard_subreg_set (rtx);
282 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
283 static rtx keep_stack_depressed (rtx);
285 static int is_addressof (rtx *, void *);
286 static hashval_t insns_for_mem_hash (const void *);
287 static int insns_for_mem_comp (const void *, const void *);
288 static int insns_for_mem_walk (rtx *, void *);
289 static void compute_insns_for_mem (rtx, rtx, htab_t);
290 static void prepare_function_start (tree);
291 static void do_clobber_return_reg (rtx, void *);
292 static void do_use_return_reg (rtx, void *);
293 static void instantiate_virtual_regs_lossage (rtx);
294 static tree split_complex_args (tree);
295 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
297 /* Pointer to chain of `struct function' for containing functions. */
298 struct function *outer_function_chain;
300 /* List of insns that were postponed by purge_addressof_1. */
301 static rtx postponed_insns;
303 /* Given a function decl for a containing function,
304 return the `struct function' for it. */
307 find_function_data (tree decl)
311 for (p = outer_function_chain; p; p = p->outer)
318 /* Save the current context for compilation of a nested function.
319 This is called from language-specific code. The caller should use
320 the enter_nested langhook to save any language-specific state,
321 since this function knows only about language-independent
325 push_function_context_to (tree context)
331 if (context == current_function_decl)
332 cfun->contains_functions = 1;
335 struct function *containing = find_function_data (context);
336 containing->contains_functions = 1;
341 init_dummy_function_start ();
344 p->outer = outer_function_chain;
345 outer_function_chain = p;
346 p->fixup_var_refs_queue = 0;
348 lang_hooks.function.enter_nested (p);
354 push_function_context (void)
356 push_function_context_to (current_function_decl);
359 /* Restore the last saved context, at the end of a nested function.
360 This function is called from language-specific code. */
363 pop_function_context_from (tree context ATTRIBUTE_UNUSED)
365 struct function *p = outer_function_chain;
366 struct var_refs_queue *queue;
369 outer_function_chain = p->outer;
371 current_function_decl = p->decl;
374 restore_emit_status (p);
376 lang_hooks.function.leave_nested (p);
378 /* Finish doing put_var_into_stack for any of our variables which became
379 addressable during the nested function. If only one entry has to be
380 fixed up, just do that one. Otherwise, first make a list of MEMs that
381 are not to be unshared. */
382 if (p->fixup_var_refs_queue == 0)
384 else if (p->fixup_var_refs_queue->next == 0)
385 fixup_var_refs (p->fixup_var_refs_queue->modified,
386 p->fixup_var_refs_queue->promoted_mode,
387 p->fixup_var_refs_queue->unsignedp,
388 p->fixup_var_refs_queue->modified, 0);
393 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
394 list = gen_rtx_EXPR_LIST (VOIDmode, queue->modified, list);
396 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
397 fixup_var_refs (queue->modified, queue->promoted_mode,
398 queue->unsignedp, list, 0);
402 p->fixup_var_refs_queue = 0;
404 /* Reset variables that have known state during rtx generation. */
405 rtx_equal_function_value_matters = 1;
406 virtuals_instantiated = 0;
407 generating_concat_p = 1;
411 pop_function_context (void)
413 pop_function_context_from (current_function_decl);
416 /* Clear out all parts of the state in F that can safely be discarded
417 after the function has been parsed, but not compiled, to let
418 garbage collection reclaim the memory. */
421 free_after_parsing (struct function *f)
423 /* f->expr->forced_labels is used by code generation. */
424 /* f->emit->regno_reg_rtx is used by code generation. */
425 /* f->varasm is used by code generation. */
426 /* f->eh->eh_return_stub_label is used by code generation. */
428 lang_hooks.function.final (f);
432 /* Clear out all parts of the state in F that can safely be discarded
433 after the function has been compiled, to let garbage collection
434 reclaim the memory. */
437 free_after_compilation (struct function *f)
445 f->x_temp_slots = NULL;
446 f->arg_offset_rtx = NULL;
447 f->return_rtx = NULL;
448 f->internal_arg_pointer = NULL;
449 f->x_nonlocal_labels = NULL;
450 f->x_nonlocal_goto_handler_slots = NULL;
451 f->x_nonlocal_goto_handler_labels = NULL;
452 f->x_nonlocal_goto_stack_level = NULL;
453 f->x_cleanup_label = NULL;
454 f->x_return_label = NULL;
455 f->x_naked_return_label = NULL;
456 f->computed_goto_common_label = NULL;
457 f->computed_goto_common_reg = NULL;
458 f->x_save_expr_regs = NULL;
459 f->x_stack_slot_list = NULL;
460 f->x_rtl_expr_chain = NULL;
461 f->x_tail_recursion_label = NULL;
462 f->x_tail_recursion_reentry = NULL;
463 f->x_arg_pointer_save_area = NULL;
464 f->x_clobber_return_insn = NULL;
465 f->x_context_display = NULL;
466 f->x_trampoline_list = NULL;
467 f->x_parm_birth_insn = NULL;
468 f->x_last_parm_insn = NULL;
469 f->x_parm_reg_stack_loc = NULL;
470 f->fixup_var_refs_queue = NULL;
471 f->original_arg_vector = NULL;
472 f->original_decl_initial = NULL;
473 f->inl_last_parm_insn = NULL;
474 f->epilogue_delay_list = NULL;
477 /* Allocate fixed slots in the stack frame of the current function. */
479 /* Return size needed for stack frame based on slots so far allocated in
481 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
482 the caller may have to do that. */
485 get_func_frame_size (struct function *f)
487 #ifdef FRAME_GROWS_DOWNWARD
488 return -f->x_frame_offset;
490 return f->x_frame_offset;
494 /* Return size needed for stack frame based on slots so far allocated.
495 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
496 the caller may have to do that. */
498 get_frame_size (void)
500 return get_func_frame_size (cfun);
503 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
504 with machine mode MODE.
506 ALIGN controls the amount of alignment for the address of the slot:
507 0 means according to MODE,
508 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
509 positive specifies alignment boundary in bits.
511 We do not round to stack_boundary here.
513 FUNCTION specifies the function to allocate in. */
516 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size, int align,
517 struct function *function)
520 int bigend_correction = 0;
522 int frame_off, frame_alignment, frame_phase;
529 alignment = BIGGEST_ALIGNMENT;
531 alignment = GET_MODE_ALIGNMENT (mode);
533 /* Allow the target to (possibly) increase the alignment of this
535 type = lang_hooks.types.type_for_mode (mode, 0);
537 alignment = LOCAL_ALIGNMENT (type, alignment);
539 alignment /= BITS_PER_UNIT;
541 else if (align == -1)
543 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
544 size = CEIL_ROUND (size, alignment);
547 alignment = align / BITS_PER_UNIT;
549 #ifdef FRAME_GROWS_DOWNWARD
550 function->x_frame_offset -= size;
553 /* Ignore alignment we can't do with expected alignment of the boundary. */
554 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
555 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
557 if (function->stack_alignment_needed < alignment * BITS_PER_UNIT)
558 function->stack_alignment_needed = alignment * BITS_PER_UNIT;
560 /* Calculate how many bytes the start of local variables is off from
562 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
563 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
564 frame_phase = frame_off ? frame_alignment - frame_off : 0;
566 /* Round the frame offset to the specified alignment. The default is
567 to always honor requests to align the stack but a port may choose to
568 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
569 if (STACK_ALIGNMENT_NEEDED
573 /* We must be careful here, since FRAME_OFFSET might be negative and
574 division with a negative dividend isn't as well defined as we might
575 like. So we instead assume that ALIGNMENT is a power of two and
576 use logical operations which are unambiguous. */
577 #ifdef FRAME_GROWS_DOWNWARD
578 function->x_frame_offset
579 = (FLOOR_ROUND (function->x_frame_offset - frame_phase, alignment)
582 function->x_frame_offset
583 = (CEIL_ROUND (function->x_frame_offset - frame_phase, alignment)
588 /* On a big-endian machine, if we are allocating more space than we will use,
589 use the least significant bytes of those that are allocated. */
590 if (BYTES_BIG_ENDIAN && mode != BLKmode)
591 bigend_correction = size - GET_MODE_SIZE (mode);
593 /* If we have already instantiated virtual registers, return the actual
594 address relative to the frame pointer. */
595 if (function == cfun && virtuals_instantiated)
596 addr = plus_constant (frame_pointer_rtx,
598 (frame_offset + bigend_correction
599 + STARTING_FRAME_OFFSET, Pmode));
601 addr = plus_constant (virtual_stack_vars_rtx,
603 (function->x_frame_offset + bigend_correction,
606 #ifndef FRAME_GROWS_DOWNWARD
607 function->x_frame_offset += size;
610 x = gen_rtx_MEM (mode, addr);
612 function->x_stack_slot_list
613 = gen_rtx_EXPR_LIST (VOIDmode, x, function->x_stack_slot_list);
618 /* Wrapper around assign_stack_local_1; assign a local stack slot for the
622 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
624 return assign_stack_local_1 (mode, size, align, cfun);
627 /* Allocate a temporary stack slot and record it for possible later
630 MODE is the machine mode to be given to the returned rtx.
632 SIZE is the size in units of the space required. We do no rounding here
633 since assign_stack_local will do any required rounding.
635 KEEP is 1 if this slot is to be retained after a call to
636 free_temp_slots. Automatic variables for a block are allocated
637 with this flag. KEEP is 2 if we allocate a longer term temporary,
638 whose lifetime is controlled by CLEANUP_POINT_EXPRs. KEEP is 3
639 if we are to allocate something at an inner level to be treated as
640 a variable in the block (e.g., a SAVE_EXPR).
642 TYPE is the type that will be used for the stack slot. */
645 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size, int keep,
649 struct temp_slot *p, *best_p = 0;
652 /* If SIZE is -1 it means that somebody tried to allocate a temporary
653 of a variable size. */
658 align = BIGGEST_ALIGNMENT;
660 align = GET_MODE_ALIGNMENT (mode);
663 type = lang_hooks.types.type_for_mode (mode, 0);
666 align = LOCAL_ALIGNMENT (type, align);
668 /* Try to find an available, already-allocated temporary of the proper
669 mode which meets the size and alignment requirements. Choose the
670 smallest one with the closest alignment. */
671 for (p = temp_slots; p; p = p->next)
672 if (p->align >= align && p->size >= size && GET_MODE (p->slot) == mode
674 && objects_must_conflict_p (p->type, type)
675 && (best_p == 0 || best_p->size > p->size
676 || (best_p->size == p->size && best_p->align > p->align)))
678 if (p->align == align && p->size == size)
686 /* Make our best, if any, the one to use. */
689 /* If there are enough aligned bytes left over, make them into a new
690 temp_slot so that the extra bytes don't get wasted. Do this only
691 for BLKmode slots, so that we can be sure of the alignment. */
692 if (GET_MODE (best_p->slot) == BLKmode)
694 int alignment = best_p->align / BITS_PER_UNIT;
695 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
697 if (best_p->size - rounded_size >= alignment)
699 p = ggc_alloc (sizeof (struct temp_slot));
700 p->in_use = p->addr_taken = 0;
701 p->size = best_p->size - rounded_size;
702 p->base_offset = best_p->base_offset + rounded_size;
703 p->full_size = best_p->full_size - rounded_size;
704 p->slot = gen_rtx_MEM (BLKmode,
705 plus_constant (XEXP (best_p->slot, 0),
707 p->align = best_p->align;
710 p->type = best_p->type;
711 p->next = temp_slots;
714 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
717 best_p->size = rounded_size;
718 best_p->full_size = rounded_size;
725 /* If we still didn't find one, make a new temporary. */
728 HOST_WIDE_INT frame_offset_old = frame_offset;
730 p = ggc_alloc (sizeof (struct temp_slot));
732 /* We are passing an explicit alignment request to assign_stack_local.
733 One side effect of that is assign_stack_local will not round SIZE
734 to ensure the frame offset remains suitably aligned.
736 So for requests which depended on the rounding of SIZE, we go ahead
737 and round it now. We also make sure ALIGNMENT is at least
738 BIGGEST_ALIGNMENT. */
739 if (mode == BLKmode && align < BIGGEST_ALIGNMENT)
741 p->slot = assign_stack_local (mode,
743 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
749 /* The following slot size computation is necessary because we don't
750 know the actual size of the temporary slot until assign_stack_local
751 has performed all the frame alignment and size rounding for the
752 requested temporary. Note that extra space added for alignment
753 can be either above or below this stack slot depending on which
754 way the frame grows. We include the extra space if and only if it
755 is above this slot. */
756 #ifdef FRAME_GROWS_DOWNWARD
757 p->size = frame_offset_old - frame_offset;
762 /* Now define the fields used by combine_temp_slots. */
763 #ifdef FRAME_GROWS_DOWNWARD
764 p->base_offset = frame_offset;
765 p->full_size = frame_offset_old - frame_offset;
767 p->base_offset = frame_offset_old;
768 p->full_size = frame_offset - frame_offset_old;
771 p->next = temp_slots;
777 p->rtl_expr = seq_rtl_expr;
782 p->level = target_temp_slot_level;
787 p->level = var_temp_slot_level;
792 p->level = temp_slot_level;
797 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
798 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
799 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
801 /* If we know the alias set for the memory that will be used, use
802 it. If there's no TYPE, then we don't know anything about the
803 alias set for the memory. */
804 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
805 set_mem_align (slot, align);
807 /* If a type is specified, set the relevant flags. */
810 RTX_UNCHANGING_P (slot) = (lang_hooks.honor_readonly
811 && TYPE_READONLY (type));
812 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
813 MEM_SET_IN_STRUCT_P (slot, AGGREGATE_TYPE_P (type));
819 /* Allocate a temporary stack slot and record it for possible later
820 reuse. First three arguments are same as in preceding function. */
823 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
825 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
828 /* Assign a temporary.
829 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
830 and so that should be used in error messages. In either case, we
831 allocate of the given type.
832 KEEP is as for assign_stack_temp.
833 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
834 it is 0 if a register is OK.
835 DONT_PROMOTE is 1 if we should not promote values in register
839 assign_temp (tree type_or_decl, int keep, int memory_required,
840 int dont_promote ATTRIBUTE_UNUSED)
843 enum machine_mode mode;
848 if (DECL_P (type_or_decl))
849 decl = type_or_decl, type = TREE_TYPE (decl);
851 decl = NULL, type = type_or_decl;
853 mode = TYPE_MODE (type);
855 unsignedp = TYPE_UNSIGNED (type);
858 if (mode == BLKmode || memory_required)
860 HOST_WIDE_INT size = int_size_in_bytes (type);
863 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
864 problems with allocating the stack space. */
868 /* Unfortunately, we don't yet know how to allocate variable-sized
869 temporaries. However, sometimes we have a fixed upper limit on
870 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
871 instead. This is the case for Chill variable-sized strings. */
872 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
873 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
874 && host_integerp (TYPE_ARRAY_MAX_SIZE (type), 1))
875 size = tree_low_cst (TYPE_ARRAY_MAX_SIZE (type), 1);
877 /* The size of the temporary may be too large to fit into an integer. */
878 /* ??? Not sure this should happen except for user silliness, so limit
879 this to things that aren't compiler-generated temporaries. The
880 rest of the time we'll abort in assign_stack_temp_for_type. */
881 if (decl && size == -1
882 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
884 error ("%Jsize of variable '%D' is too large", decl, decl);
888 tmp = assign_stack_temp_for_type (mode, size, keep, type);
894 mode = promote_mode (type, mode, &unsignedp, 0);
897 return gen_reg_rtx (mode);
900 /* Combine temporary stack slots which are adjacent on the stack.
902 This allows for better use of already allocated stack space. This is only
903 done for BLKmode slots because we can be sure that we won't have alignment
904 problems in this case. */
907 combine_temp_slots (void)
909 struct temp_slot *p, *q;
910 struct temp_slot *prev_p, *prev_q;
913 /* We can't combine slots, because the information about which slot
914 is in which alias set will be lost. */
915 if (flag_strict_aliasing)
918 /* If there are a lot of temp slots, don't do anything unless
919 high levels of optimization. */
920 if (! flag_expensive_optimizations)
921 for (p = temp_slots, num_slots = 0; p; p = p->next, num_slots++)
922 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
925 for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
929 if (! p->in_use && GET_MODE (p->slot) == BLKmode)
930 for (q = p->next, prev_q = p; q; q = prev_q->next)
933 if (! q->in_use && GET_MODE (q->slot) == BLKmode)
935 if (p->base_offset + p->full_size == q->base_offset)
937 /* Q comes after P; combine Q into P. */
939 p->full_size += q->full_size;
942 else if (q->base_offset + q->full_size == p->base_offset)
944 /* P comes after Q; combine P into Q. */
946 q->full_size += p->full_size;
951 /* Either delete Q or advance past it. */
953 prev_q->next = q->next;
957 /* Either delete P or advance past it. */
961 prev_p->next = p->next;
963 temp_slots = p->next;
970 /* Find the temp slot corresponding to the object at address X. */
972 static struct temp_slot *
973 find_temp_slot_from_address (rtx x)
978 for (p = temp_slots; p; p = p->next)
983 else if (XEXP (p->slot, 0) == x
985 || (GET_CODE (x) == PLUS
986 && XEXP (x, 0) == virtual_stack_vars_rtx
987 && GET_CODE (XEXP (x, 1)) == CONST_INT
988 && INTVAL (XEXP (x, 1)) >= p->base_offset
989 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
992 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
993 for (next = p->address; next; next = XEXP (next, 1))
994 if (XEXP (next, 0) == x)
998 /* If we have a sum involving a register, see if it points to a temp
1000 if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == REG
1001 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
1003 else if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == REG
1004 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
1010 /* Indicate that NEW is an alternate way of referring to the temp slot
1011 that previously was known by OLD. */
1014 update_temp_slot_address (rtx old, rtx new)
1016 struct temp_slot *p;
1018 if (rtx_equal_p (old, new))
1021 p = find_temp_slot_from_address (old);
1023 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
1024 is a register, see if one operand of the PLUS is a temporary
1025 location. If so, NEW points into it. Otherwise, if both OLD and
1026 NEW are a PLUS and if there is a register in common between them.
1027 If so, try a recursive call on those values. */
1030 if (GET_CODE (old) != PLUS)
1033 if (GET_CODE (new) == REG)
1035 update_temp_slot_address (XEXP (old, 0), new);
1036 update_temp_slot_address (XEXP (old, 1), new);
1039 else if (GET_CODE (new) != PLUS)
1042 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
1043 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
1044 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
1045 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
1046 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
1047 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
1048 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
1049 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
1054 /* Otherwise add an alias for the temp's address. */
1055 else if (p->address == 0)
1059 if (GET_CODE (p->address) != EXPR_LIST)
1060 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
1062 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
1066 /* If X could be a reference to a temporary slot, mark the fact that its
1067 address was taken. */
1070 mark_temp_addr_taken (rtx x)
1072 struct temp_slot *p;
1077 /* If X is not in memory or is at a constant address, it cannot be in
1078 a temporary slot. */
1079 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1082 p = find_temp_slot_from_address (XEXP (x, 0));
1087 /* If X could be a reference to a temporary slot, mark that slot as
1088 belonging to the to one level higher than the current level. If X
1089 matched one of our slots, just mark that one. Otherwise, we can't
1090 easily predict which it is, so upgrade all of them. Kept slots
1091 need not be touched.
1093 This is called when an ({...}) construct occurs and a statement
1094 returns a value in memory. */
1097 preserve_temp_slots (rtx x)
1099 struct temp_slot *p = 0;
1101 /* If there is no result, we still might have some objects whose address
1102 were taken, so we need to make sure they stay around. */
1105 for (p = temp_slots; p; p = p->next)
1106 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1112 /* If X is a register that is being used as a pointer, see if we have
1113 a temporary slot we know it points to. To be consistent with
1114 the code below, we really should preserve all non-kept slots
1115 if we can't find a match, but that seems to be much too costly. */
1116 if (GET_CODE (x) == REG && REG_POINTER (x))
1117 p = find_temp_slot_from_address (x);
1119 /* If X is not in memory or is at a constant address, it cannot be in
1120 a temporary slot, but it can contain something whose address was
1122 if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
1124 for (p = temp_slots; p; p = p->next)
1125 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1131 /* First see if we can find a match. */
1133 p = find_temp_slot_from_address (XEXP (x, 0));
1137 /* Move everything at our level whose address was taken to our new
1138 level in case we used its address. */
1139 struct temp_slot *q;
1141 if (p->level == temp_slot_level)
1143 for (q = temp_slots; q; q = q->next)
1144 if (q != p && q->addr_taken && q->level == p->level)
1153 /* Otherwise, preserve all non-kept slots at this level. */
1154 for (p = temp_slots; p; p = p->next)
1155 if (p->in_use && p->level == temp_slot_level && ! p->keep)
1159 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
1160 with that RTL_EXPR, promote it into a temporary slot at the present
1161 level so it will not be freed when we free slots made in the
1165 preserve_rtl_expr_result (rtx x)
1167 struct temp_slot *p;
1169 /* If X is not in memory or is at a constant address, it cannot be in
1170 a temporary slot. */
1171 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1174 /* If we can find a match, move it to our level unless it is already at
1176 p = find_temp_slot_from_address (XEXP (x, 0));
1179 p->level = MIN (p->level, temp_slot_level);
1186 /* Free all temporaries used so far. This is normally called at the end
1187 of generating code for a statement. Don't free any temporaries
1188 currently in use for an RTL_EXPR that hasn't yet been emitted.
1189 We could eventually do better than this since it can be reused while
1190 generating the same RTL_EXPR, but this is complex and probably not
1194 free_temp_slots (void)
1196 struct temp_slot *p;
1198 for (p = temp_slots; p; p = p->next)
1199 if (p->in_use && p->level == temp_slot_level && ! p->keep
1200 && p->rtl_expr == 0)
1203 combine_temp_slots ();
1206 /* Free all temporary slots used in T, an RTL_EXPR node. */
1209 free_temps_for_rtl_expr (tree t)
1211 struct temp_slot *p;
1213 for (p = temp_slots; p; p = p->next)
1214 if (p->rtl_expr == t)
1216 /* If this slot is below the current TEMP_SLOT_LEVEL, then it
1217 needs to be preserved. This can happen if a temporary in
1218 the RTL_EXPR was addressed; preserve_temp_slots will move
1219 the temporary into a higher level. */
1220 if (temp_slot_level <= p->level)
1223 p->rtl_expr = NULL_TREE;
1226 combine_temp_slots ();
1229 /* Mark all temporaries ever allocated in this function as not suitable
1230 for reuse until the current level is exited. */
1233 mark_all_temps_used (void)
1235 struct temp_slot *p;
1237 for (p = temp_slots; p; p = p->next)
1239 p->in_use = p->keep = 1;
1240 p->level = MIN (p->level, temp_slot_level);
1244 /* Push deeper into the nesting level for stack temporaries. */
1247 push_temp_slots (void)
1252 /* Pop a temporary nesting level. All slots in use in the current level
1256 pop_temp_slots (void)
1258 struct temp_slot *p;
1260 for (p = temp_slots; p; p = p->next)
1261 if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
1264 combine_temp_slots ();
1269 /* Initialize temporary slots. */
1272 init_temp_slots (void)
1274 /* We have not allocated any temporaries yet. */
1276 temp_slot_level = 0;
1277 var_temp_slot_level = 0;
1278 target_temp_slot_level = 0;
1281 /* Retroactively move an auto variable from a register to a stack
1282 slot. This is done when an address-reference to the variable is
1283 seen. If RESCAN is true, all previously emitted instructions are
1284 examined and modified to handle the fact that DECL is now
1288 put_var_into_stack (tree decl, int rescan)
1291 enum machine_mode promoted_mode, decl_mode;
1292 struct function *function = 0;
1294 int can_use_addressof;
1295 int volatilep = TREE_CODE (decl) != SAVE_EXPR && TREE_THIS_VOLATILE (decl);
1296 int usedp = (TREE_USED (decl)
1297 || (TREE_CODE (decl) != SAVE_EXPR && DECL_INITIAL (decl) != 0));
1299 context = decl_function_context (decl);
1301 /* Get the current rtl used for this object and its original mode. */
1302 orig_reg = reg = (TREE_CODE (decl) == SAVE_EXPR
1303 ? SAVE_EXPR_RTL (decl)
1304 : DECL_RTL_IF_SET (decl));
1306 /* No need to do anything if decl has no rtx yet
1307 since in that case caller is setting TREE_ADDRESSABLE
1308 and a stack slot will be assigned when the rtl is made. */
1312 /* Get the declared mode for this object. */
1313 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1314 : DECL_MODE (decl));
1315 /* Get the mode it's actually stored in. */
1316 promoted_mode = GET_MODE (reg);
1318 /* If this variable comes from an outer function, find that
1319 function's saved context. Don't use find_function_data here,
1320 because it might not be in any active function.
1321 FIXME: Is that really supposed to happen?
1322 It does in ObjC at least. */
1323 if (context != current_function_decl && context != inline_function_decl)
1324 for (function = outer_function_chain; function; function = function->outer)
1325 if (function->decl == context)
1328 /* If this is a variable-sized object or a structure passed by invisible
1329 reference, with a pseudo to address it, put that pseudo into the stack
1330 if the var is non-local. */
1331 if (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl)
1332 && GET_CODE (reg) == MEM
1333 && GET_CODE (XEXP (reg, 0)) == REG
1334 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1336 orig_reg = reg = XEXP (reg, 0);
1337 decl_mode = promoted_mode = GET_MODE (reg);
1340 /* If this variable lives in the current function and we don't need to put it
1341 in the stack for the sake of setjmp or the non-locality, try to keep it in
1342 a register until we know we actually need the address. */
1345 && ! (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl))
1347 /* FIXME make it work for promoted modes too */
1348 && decl_mode == promoted_mode
1349 #ifdef NON_SAVING_SETJMP
1350 && ! (NON_SAVING_SETJMP && current_function_calls_setjmp)
1354 /* If we can't use ADDRESSOF, make sure we see through one we already
1356 if (! can_use_addressof && GET_CODE (reg) == MEM
1357 && GET_CODE (XEXP (reg, 0)) == ADDRESSOF)
1358 reg = XEXP (XEXP (reg, 0), 0);
1360 /* Now we should have a value that resides in one or more pseudo regs. */
1362 if (GET_CODE (reg) == REG)
1364 if (can_use_addressof)
1365 gen_mem_addressof (reg, decl, rescan);
1367 put_reg_into_stack (function, reg, TREE_TYPE (decl), promoted_mode,
1368 decl_mode, volatilep, 0, usedp, 0);
1370 /* If this was previously a MEM but we've removed the ADDRESSOF,
1371 set this address into that MEM so we always use the same
1372 rtx for this variable. */
1373 if (orig_reg != reg && GET_CODE (orig_reg) == MEM)
1374 XEXP (orig_reg, 0) = XEXP (reg, 0);
1376 else if (GET_CODE (reg) == CONCAT)
1378 /* A CONCAT contains two pseudos; put them both in the stack.
1379 We do it so they end up consecutive.
1380 We fixup references to the parts only after we fixup references
1381 to the whole CONCAT, lest we do double fixups for the latter
1383 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1384 tree part_type = lang_hooks.types.type_for_mode (part_mode, 0);
1385 rtx lopart = XEXP (reg, 0);
1386 rtx hipart = XEXP (reg, 1);
1387 #ifdef FRAME_GROWS_DOWNWARD
1388 /* Since part 0 should have a lower address, do it second. */
1389 put_reg_into_stack (function, hipart, part_type, part_mode,
1390 part_mode, volatilep, 0, 0, 0);
1391 put_reg_into_stack (function, lopart, part_type, part_mode,
1392 part_mode, volatilep, 0, 0, 0);
1394 put_reg_into_stack (function, lopart, part_type, part_mode,
1395 part_mode, volatilep, 0, 0, 0);
1396 put_reg_into_stack (function, hipart, part_type, part_mode,
1397 part_mode, volatilep, 0, 0, 0);
1400 /* Change the CONCAT into a combined MEM for both parts. */
1401 PUT_CODE (reg, MEM);
1402 MEM_ATTRS (reg) = 0;
1404 /* set_mem_attributes uses DECL_RTL to avoid re-generating of
1405 already computed alias sets. Here we want to re-generate. */
1407 SET_DECL_RTL (decl, NULL);
1408 set_mem_attributes (reg, decl, 1);
1410 SET_DECL_RTL (decl, reg);
1412 /* The two parts are in memory order already.
1413 Use the lower parts address as ours. */
1414 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1415 /* Prevent sharing of rtl that might lose. */
1416 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1417 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1418 if (usedp && rescan)
1420 schedule_fixup_var_refs (function, reg, TREE_TYPE (decl),
1422 schedule_fixup_var_refs (function, lopart, part_type, part_mode, 0);
1423 schedule_fixup_var_refs (function, hipart, part_type, part_mode, 0);
1430 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1431 into the stack frame of FUNCTION (0 means the current function).
1432 DECL_MODE is the machine mode of the user-level data type.
1433 PROMOTED_MODE is the machine mode of the register.
1434 VOLATILE_P is nonzero if this is for a "volatile" decl.
1435 USED_P is nonzero if this reg might have already been used in an insn. */
1438 put_reg_into_stack (struct function *function, rtx reg, tree type,
1439 enum machine_mode promoted_mode,
1440 enum machine_mode decl_mode, int volatile_p,
1441 unsigned int original_regno, int used_p, htab_t ht)
1443 struct function *func = function ? function : cfun;
1445 unsigned int regno = original_regno;
1448 regno = REGNO (reg);
1450 if (regno < func->x_max_parm_reg)
1452 if (!func->x_parm_reg_stack_loc)
1454 new = func->x_parm_reg_stack_loc[regno];
1458 new = assign_stack_local_1 (decl_mode, GET_MODE_SIZE (decl_mode), 0, func);
1460 PUT_CODE (reg, MEM);
1461 PUT_MODE (reg, decl_mode);
1462 XEXP (reg, 0) = XEXP (new, 0);
1463 MEM_ATTRS (reg) = 0;
1464 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1465 MEM_VOLATILE_P (reg) = volatile_p;
1467 /* If this is a memory ref that contains aggregate components,
1468 mark it as such for cse and loop optimize. If we are reusing a
1469 previously generated stack slot, then we need to copy the bit in
1470 case it was set for other reasons. For instance, it is set for
1471 __builtin_va_alist. */
1474 MEM_SET_IN_STRUCT_P (reg,
1475 AGGREGATE_TYPE_P (type) || MEM_IN_STRUCT_P (new));
1476 set_mem_alias_set (reg, get_alias_set (type));
1480 schedule_fixup_var_refs (function, reg, type, promoted_mode, ht);
1483 /* Make sure that all refs to the variable, previously made
1484 when it was a register, are fixed up to be valid again.
1485 See function above for meaning of arguments. */
1488 schedule_fixup_var_refs (struct function *function, rtx reg, tree type,
1489 enum machine_mode promoted_mode, htab_t ht)
1491 int unsigned_p = type ? TYPE_UNSIGNED (type) : 0;
1495 struct var_refs_queue *temp;
1497 temp = ggc_alloc (sizeof (struct var_refs_queue));
1498 temp->modified = reg;
1499 temp->promoted_mode = promoted_mode;
1500 temp->unsignedp = unsigned_p;
1501 temp->next = function->fixup_var_refs_queue;
1502 function->fixup_var_refs_queue = temp;
1505 /* Variable is local; fix it up now. */
1506 fixup_var_refs (reg, promoted_mode, unsigned_p, reg, ht);
1510 fixup_var_refs (rtx var, enum machine_mode promoted_mode, int unsignedp,
1511 rtx may_share, htab_t ht)
1514 rtx first_insn = get_insns ();
1515 struct sequence_stack *stack = seq_stack;
1516 tree rtl_exps = rtl_expr_chain;
1517 int save_volatile_ok = volatile_ok;
1519 /* If there's a hash table, it must record all uses of VAR. */
1524 fixup_var_refs_insns_with_hash (ht, var, promoted_mode, unsignedp,
1529 /* Volatile is valid in MEMs because all we're doing in changing the
1532 fixup_var_refs_insns (first_insn, var, promoted_mode, unsignedp,
1533 stack == 0, may_share);
1535 /* Scan all pending sequences too. */
1536 for (; stack; stack = stack->next)
1538 push_to_full_sequence (stack->first, stack->last);
1539 fixup_var_refs_insns (stack->first, var, promoted_mode, unsignedp,
1540 stack->next != 0, may_share);
1541 /* Update remembered end of sequence
1542 in case we added an insn at the end. */
1543 stack->last = get_last_insn ();
1547 /* Scan all waiting RTL_EXPRs too. */
1548 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1550 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1551 if (seq != const0_rtx && seq != 0)
1553 push_to_sequence (seq);
1554 fixup_var_refs_insns (seq, var, promoted_mode, unsignedp, 0,
1560 volatile_ok = save_volatile_ok;
1563 /* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
1564 some part of an insn. Return a struct fixup_replacement whose OLD
1565 value is equal to X. Allocate a new structure if no such entry exists. */
1567 static struct fixup_replacement *
1568 find_fixup_replacement (struct fixup_replacement **replacements, rtx x)
1570 struct fixup_replacement *p;
1572 /* See if we have already replaced this. */
1573 for (p = *replacements; p != 0 && ! rtx_equal_p (p->old, x); p = p->next)
1578 p = xmalloc (sizeof (struct fixup_replacement));
1581 p->next = *replacements;
1588 /* Scan the insn-chain starting with INSN for refs to VAR and fix them
1589 up. TOPLEVEL is nonzero if this chain is the main chain of insns
1590 for the current function. MAY_SHARE is either a MEM that is not
1591 to be unshared or a list of them. */
1594 fixup_var_refs_insns (rtx insn, rtx var, enum machine_mode promoted_mode,
1595 int unsignedp, int toplevel, rtx may_share)
1599 /* fixup_var_refs_insn might modify insn, so save its next
1601 rtx next = NEXT_INSN (insn);
1603 /* CALL_PLACEHOLDERs are special; we have to switch into each of
1604 the three sequences they (potentially) contain, and process
1605 them recursively. The CALL_INSN itself is not interesting. */
1607 if (GET_CODE (insn) == CALL_INSN
1608 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
1612 /* Look at the Normal call, sibling call and tail recursion
1613 sequences attached to the CALL_PLACEHOLDER. */
1614 for (i = 0; i < 3; i++)
1616 rtx seq = XEXP (PATTERN (insn), i);
1619 push_to_sequence (seq);
1620 fixup_var_refs_insns (seq, var, promoted_mode, unsignedp, 0,
1622 XEXP (PATTERN (insn), i) = get_insns ();
1628 else if (INSN_P (insn))
1629 fixup_var_refs_insn (insn, var, promoted_mode, unsignedp, toplevel,
1636 /* Look up the insns which reference VAR in HT and fix them up. Other
1637 arguments are the same as fixup_var_refs_insns.
1639 N.B. No need for special processing of CALL_PLACEHOLDERs here,
1640 because the hash table will point straight to the interesting insn
1641 (inside the CALL_PLACEHOLDER). */
1644 fixup_var_refs_insns_with_hash (htab_t ht, rtx var, enum machine_mode promoted_mode,
1645 int unsignedp, rtx may_share)
1647 struct insns_for_mem_entry tmp;
1648 struct insns_for_mem_entry *ime;
1652 ime = htab_find (ht, &tmp);
1653 for (insn_list = ime->insns; insn_list != 0; insn_list = XEXP (insn_list, 1))
1654 if (INSN_P (XEXP (insn_list, 0)))
1655 fixup_var_refs_insn (XEXP (insn_list, 0), var, promoted_mode,
1656 unsignedp, 1, may_share);
1660 /* Per-insn processing by fixup_var_refs_insns(_with_hash). INSN is
1661 the insn under examination, VAR is the variable to fix up
1662 references to, PROMOTED_MODE and UNSIGNEDP describe VAR, and
1663 TOPLEVEL is nonzero if this is the main insn chain for this
1667 fixup_var_refs_insn (rtx insn, rtx var, enum machine_mode promoted_mode,
1668 int unsignedp, int toplevel, rtx no_share)
1671 rtx set, prev, prev_set;
1674 /* Remember the notes in case we delete the insn. */
1675 note = REG_NOTES (insn);
1677 /* If this is a CLOBBER of VAR, delete it.
1679 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1680 and REG_RETVAL notes too. */
1681 if (GET_CODE (PATTERN (insn)) == CLOBBER
1682 && (XEXP (PATTERN (insn), 0) == var
1683 || (GET_CODE (XEXP (PATTERN (insn), 0)) == CONCAT
1684 && (XEXP (XEXP (PATTERN (insn), 0), 0) == var
1685 || XEXP (XEXP (PATTERN (insn), 0), 1) == var))))
1687 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1688 /* The REG_LIBCALL note will go away since we are going to
1689 turn INSN into a NOTE, so just delete the
1690 corresponding REG_RETVAL note. */
1691 remove_note (XEXP (note, 0),
1692 find_reg_note (XEXP (note, 0), REG_RETVAL,
1698 /* The insn to load VAR from a home in the arglist
1699 is now a no-op. When we see it, just delete it.
1700 Similarly if this is storing VAR from a register from which
1701 it was loaded in the previous insn. This will occur
1702 when an ADDRESSOF was made for an arglist slot. */
1704 && (set = single_set (insn)) != 0
1705 && SET_DEST (set) == var
1706 /* If this represents the result of an insn group,
1707 don't delete the insn. */
1708 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1709 && (rtx_equal_p (SET_SRC (set), var)
1710 || (GET_CODE (SET_SRC (set)) == REG
1711 && (prev = prev_nonnote_insn (insn)) != 0
1712 && (prev_set = single_set (prev)) != 0
1713 && SET_DEST (prev_set) == SET_SRC (set)
1714 && rtx_equal_p (SET_SRC (prev_set), var))))
1720 struct fixup_replacement *replacements = 0;
1721 rtx next_insn = NEXT_INSN (insn);
1723 if (SMALL_REGISTER_CLASSES)
1725 /* If the insn that copies the results of a CALL_INSN
1726 into a pseudo now references VAR, we have to use an
1727 intermediate pseudo since we want the life of the
1728 return value register to be only a single insn.
1730 If we don't use an intermediate pseudo, such things as
1731 address computations to make the address of VAR valid
1732 if it is not can be placed between the CALL_INSN and INSN.
1734 To make sure this doesn't happen, we record the destination
1735 of the CALL_INSN and see if the next insn uses both that
1738 if (call_dest != 0 && GET_CODE (insn) == INSN
1739 && reg_mentioned_p (var, PATTERN (insn))
1740 && reg_mentioned_p (call_dest, PATTERN (insn)))
1742 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1744 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1746 PATTERN (insn) = replace_rtx (PATTERN (insn),
1750 if (GET_CODE (insn) == CALL_INSN
1751 && GET_CODE (PATTERN (insn)) == SET)
1752 call_dest = SET_DEST (PATTERN (insn));
1753 else if (GET_CODE (insn) == CALL_INSN
1754 && GET_CODE (PATTERN (insn)) == PARALLEL
1755 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1756 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1761 /* See if we have to do anything to INSN now that VAR is in
1762 memory. If it needs to be loaded into a pseudo, use a single
1763 pseudo for the entire insn in case there is a MATCH_DUP
1764 between two operands. We pass a pointer to the head of
1765 a list of struct fixup_replacements. If fixup_var_refs_1
1766 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1767 it will record them in this list.
1769 If it allocated a pseudo for any replacement, we copy into
1772 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1773 &replacements, no_share);
1775 /* If this is last_parm_insn, and any instructions were output
1776 after it to fix it up, then we must set last_parm_insn to
1777 the last such instruction emitted. */
1778 if (insn == last_parm_insn)
1779 last_parm_insn = PREV_INSN (next_insn);
1781 while (replacements)
1783 struct fixup_replacement *next;
1785 if (GET_CODE (replacements->new) == REG)
1790 /* OLD might be a (subreg (mem)). */
1791 if (GET_CODE (replacements->old) == SUBREG)
1793 = fixup_memory_subreg (replacements->old, insn,
1797 = fixup_stack_1 (replacements->old, insn);
1799 insert_before = insn;
1801 /* If we are changing the mode, do a conversion.
1802 This might be wasteful, but combine.c will
1803 eliminate much of the waste. */
1805 if (GET_MODE (replacements->new)
1806 != GET_MODE (replacements->old))
1809 convert_move (replacements->new,
1810 replacements->old, unsignedp);
1815 seq = gen_move_insn (replacements->new,
1818 emit_insn_before (seq, insert_before);
1821 next = replacements->next;
1822 free (replacements);
1823 replacements = next;
1827 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1828 But don't touch other insns referred to by reg-notes;
1829 we will get them elsewhere. */
1832 if (GET_CODE (note) != INSN_LIST)
1834 = walk_fixup_memory_subreg (XEXP (note, 0), insn,
1836 note = XEXP (note, 1);
1840 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1841 See if the rtx expression at *LOC in INSN needs to be changed.
1843 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1844 contain a list of original rtx's and replacements. If we find that we need
1845 to modify this insn by replacing a memory reference with a pseudo or by
1846 making a new MEM to implement a SUBREG, we consult that list to see if
1847 we have already chosen a replacement. If none has already been allocated,
1848 we allocate it and update the list. fixup_var_refs_insn will copy VAR
1849 or the SUBREG, as appropriate, to the pseudo. */
1852 fixup_var_refs_1 (rtx var, enum machine_mode promoted_mode, rtx *loc, rtx insn,
1853 struct fixup_replacement **replacements, rtx no_share)
1857 RTX_CODE code = GET_CODE (x);
1860 struct fixup_replacement *replacement;
1865 if (XEXP (x, 0) == var)
1867 /* Prevent sharing of rtl that might lose. */
1868 rtx sub = copy_rtx (XEXP (var, 0));
1870 if (! validate_change (insn, loc, sub, 0))
1872 rtx y = gen_reg_rtx (GET_MODE (sub));
1875 /* We should be able to replace with a register or all is lost.
1876 Note that we can't use validate_change to verify this, since
1877 we're not caring for replacing all dups simultaneously. */
1878 if (! validate_replace_rtx (*loc, y, insn))
1881 /* Careful! First try to recognize a direct move of the
1882 value, mimicking how things are done in gen_reload wrt
1883 PLUS. Consider what happens when insn is a conditional
1884 move instruction and addsi3 clobbers flags. */
1887 new_insn = emit_insn (gen_rtx_SET (VOIDmode, y, sub));
1891 if (recog_memoized (new_insn) < 0)
1893 /* That failed. Fall back on force_operand and hope. */
1896 sub = force_operand (sub, y);
1898 emit_insn (gen_move_insn (y, sub));
1904 /* Don't separate setter from user. */
1905 if (PREV_INSN (insn) && sets_cc0_p (PREV_INSN (insn)))
1906 insn = PREV_INSN (insn);
1909 emit_insn_before (seq, insn);
1917 /* If we already have a replacement, use it. Otherwise,
1918 try to fix up this address in case it is invalid. */
1920 replacement = find_fixup_replacement (replacements, var);
1921 if (replacement->new)
1923 *loc = replacement->new;
1927 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1929 /* Unless we are forcing memory to register or we changed the mode,
1930 we can leave things the way they are if the insn is valid. */
1932 INSN_CODE (insn) = -1;
1933 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1934 && recog_memoized (insn) >= 0)
1937 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1941 /* If X contains VAR, we need to unshare it here so that we update
1942 each occurrence separately. But all identical MEMs in one insn
1943 must be replaced with the same rtx because of the possibility of
1946 if (reg_mentioned_p (var, x))
1948 replacement = find_fixup_replacement (replacements, x);
1949 if (replacement->new == 0)
1950 replacement->new = copy_most_rtx (x, no_share);
1952 *loc = x = replacement->new;
1953 code = GET_CODE (x);
1970 /* Note that in some cases those types of expressions are altered
1971 by optimize_bit_field, and do not survive to get here. */
1972 if (XEXP (x, 0) == var
1973 || (GET_CODE (XEXP (x, 0)) == SUBREG
1974 && SUBREG_REG (XEXP (x, 0)) == var))
1976 /* Get TEM as a valid MEM in the mode presently in the insn.
1978 We don't worry about the possibility of MATCH_DUP here; it
1979 is highly unlikely and would be tricky to handle. */
1982 if (GET_CODE (tem) == SUBREG)
1984 if (GET_MODE_BITSIZE (GET_MODE (tem))
1985 > GET_MODE_BITSIZE (GET_MODE (var)))
1987 replacement = find_fixup_replacement (replacements, var);
1988 if (replacement->new == 0)
1989 replacement->new = gen_reg_rtx (GET_MODE (var));
1990 SUBREG_REG (tem) = replacement->new;
1992 /* The following code works only if we have a MEM, so we
1993 need to handle the subreg here. We directly substitute
1994 it assuming that a subreg must be OK here. We already
1995 scheduled a replacement to copy the mem into the
2001 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2004 tem = fixup_stack_1 (tem, insn);
2006 /* Unless we want to load from memory, get TEM into the proper mode
2007 for an extract from memory. This can only be done if the
2008 extract is at a constant position and length. */
2010 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
2011 && GET_CODE (XEXP (x, 2)) == CONST_INT
2012 && ! mode_dependent_address_p (XEXP (tem, 0))
2013 && ! MEM_VOLATILE_P (tem))
2015 enum machine_mode wanted_mode = VOIDmode;
2016 enum machine_mode is_mode = GET_MODE (tem);
2017 HOST_WIDE_INT pos = INTVAL (XEXP (x, 2));
2019 if (GET_CODE (x) == ZERO_EXTRACT)
2021 enum machine_mode new_mode
2022 = mode_for_extraction (EP_extzv, 1);
2023 if (new_mode != MAX_MACHINE_MODE)
2024 wanted_mode = new_mode;
2026 else if (GET_CODE (x) == SIGN_EXTRACT)
2028 enum machine_mode new_mode
2029 = mode_for_extraction (EP_extv, 1);
2030 if (new_mode != MAX_MACHINE_MODE)
2031 wanted_mode = new_mode;
2034 /* If we have a narrower mode, we can do something. */
2035 if (wanted_mode != VOIDmode
2036 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2038 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2039 rtx old_pos = XEXP (x, 2);
2042 /* If the bytes and bits are counted differently, we
2043 must adjust the offset. */
2044 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2045 offset = (GET_MODE_SIZE (is_mode)
2046 - GET_MODE_SIZE (wanted_mode) - offset);
2048 pos %= GET_MODE_BITSIZE (wanted_mode);
2050 newmem = adjust_address_nv (tem, wanted_mode, offset);
2052 /* Make the change and see if the insn remains valid. */
2053 INSN_CODE (insn) = -1;
2054 XEXP (x, 0) = newmem;
2055 XEXP (x, 2) = GEN_INT (pos);
2057 if (recog_memoized (insn) >= 0)
2060 /* Otherwise, restore old position. XEXP (x, 0) will be
2062 XEXP (x, 2) = old_pos;
2066 /* If we get here, the bitfield extract insn can't accept a memory
2067 reference. Copy the input into a register. */
2069 tem1 = gen_reg_rtx (GET_MODE (tem));
2070 emit_insn_before (gen_move_insn (tem1, tem), insn);
2077 if (SUBREG_REG (x) == var)
2079 /* If this is a special SUBREG made because VAR was promoted
2080 from a wider mode, replace it with VAR and call ourself
2081 recursively, this time saying that the object previously
2082 had its current mode (by virtue of the SUBREG). */
2084 if (SUBREG_PROMOTED_VAR_P (x))
2087 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements,
2092 /* If this SUBREG makes VAR wider, it has become a paradoxical
2093 SUBREG with VAR in memory, but these aren't allowed at this
2094 stage of the compilation. So load VAR into a pseudo and take
2095 a SUBREG of that pseudo. */
2096 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
2098 replacement = find_fixup_replacement (replacements, var);
2099 if (replacement->new == 0)
2100 replacement->new = gen_reg_rtx (promoted_mode);
2101 SUBREG_REG (x) = replacement->new;
2105 /* See if we have already found a replacement for this SUBREG.
2106 If so, use it. Otherwise, make a MEM and see if the insn
2107 is recognized. If not, or if we should force MEM into a register,
2108 make a pseudo for this SUBREG. */
2109 replacement = find_fixup_replacement (replacements, x);
2110 if (replacement->new)
2112 enum machine_mode mode = GET_MODE (x);
2113 *loc = replacement->new;
2115 /* Careful! We may have just replaced a SUBREG by a MEM, which
2116 means that the insn may have become invalid again. We can't
2117 in this case make a new replacement since we already have one
2118 and we must deal with MATCH_DUPs. */
2119 if (GET_CODE (replacement->new) == MEM)
2121 INSN_CODE (insn) = -1;
2122 if (recog_memoized (insn) >= 0)
2125 fixup_var_refs_1 (replacement->new, mode, &PATTERN (insn),
2126 insn, replacements, no_share);
2132 replacement->new = *loc = fixup_memory_subreg (x, insn,
2135 INSN_CODE (insn) = -1;
2136 if (! flag_force_mem && recog_memoized (insn) >= 0)
2139 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
2145 /* First do special simplification of bit-field references. */
2146 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
2147 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
2148 optimize_bit_field (x, insn, 0);
2149 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
2150 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
2151 optimize_bit_field (x, insn, 0);
2153 /* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
2154 into a register and then store it back out. */
2155 if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
2156 && GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
2157 && SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
2158 && (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
2159 > GET_MODE_SIZE (GET_MODE (var))))
2161 replacement = find_fixup_replacement (replacements, var);
2162 if (replacement->new == 0)
2163 replacement->new = gen_reg_rtx (GET_MODE (var));
2165 SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
2166 emit_insn_after (gen_move_insn (var, replacement->new), insn);
2169 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
2170 insn into a pseudo and store the low part of the pseudo into VAR. */
2171 if (GET_CODE (SET_DEST (x)) == SUBREG
2172 && SUBREG_REG (SET_DEST (x)) == var
2173 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
2174 > GET_MODE_SIZE (GET_MODE (var))))
2176 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
2177 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
2184 rtx dest = SET_DEST (x);
2185 rtx src = SET_SRC (x);
2186 rtx outerdest = dest;
2188 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
2189 || GET_CODE (dest) == SIGN_EXTRACT
2190 || GET_CODE (dest) == ZERO_EXTRACT)
2191 dest = XEXP (dest, 0);
2193 if (GET_CODE (src) == SUBREG)
2194 src = SUBREG_REG (src);
2196 /* If VAR does not appear at the top level of the SET
2197 just scan the lower levels of the tree. */
2199 if (src != var && dest != var)
2202 /* We will need to rerecognize this insn. */
2203 INSN_CODE (insn) = -1;
2205 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var
2206 && mode_for_extraction (EP_insv, -1) != MAX_MACHINE_MODE)
2208 /* Since this case will return, ensure we fixup all the
2210 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
2211 insn, replacements, no_share);
2212 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
2213 insn, replacements, no_share);
2214 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
2215 insn, replacements, no_share);
2217 tem = XEXP (outerdest, 0);
2219 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
2220 that may appear inside a ZERO_EXTRACT.
2221 This was legitimate when the MEM was a REG. */
2222 if (GET_CODE (tem) == SUBREG
2223 && SUBREG_REG (tem) == var)
2224 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2226 tem = fixup_stack_1 (tem, insn);
2228 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
2229 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
2230 && ! mode_dependent_address_p (XEXP (tem, 0))
2231 && ! MEM_VOLATILE_P (tem))
2233 enum machine_mode wanted_mode;
2234 enum machine_mode is_mode = GET_MODE (tem);
2235 HOST_WIDE_INT pos = INTVAL (XEXP (outerdest, 2));
2237 wanted_mode = mode_for_extraction (EP_insv, 0);
2239 /* If we have a narrower mode, we can do something. */
2240 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2242 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2243 rtx old_pos = XEXP (outerdest, 2);
2246 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2247 offset = (GET_MODE_SIZE (is_mode)
2248 - GET_MODE_SIZE (wanted_mode) - offset);
2250 pos %= GET_MODE_BITSIZE (wanted_mode);
2252 newmem = adjust_address_nv (tem, wanted_mode, offset);
2254 /* Make the change and see if the insn remains valid. */
2255 INSN_CODE (insn) = -1;
2256 XEXP (outerdest, 0) = newmem;
2257 XEXP (outerdest, 2) = GEN_INT (pos);
2259 if (recog_memoized (insn) >= 0)
2262 /* Otherwise, restore old position. XEXP (x, 0) will be
2264 XEXP (outerdest, 2) = old_pos;
2268 /* If we get here, the bit-field store doesn't allow memory
2269 or isn't located at a constant position. Load the value into
2270 a register, do the store, and put it back into memory. */
2272 tem1 = gen_reg_rtx (GET_MODE (tem));
2273 emit_insn_before (gen_move_insn (tem1, tem), insn);
2274 emit_insn_after (gen_move_insn (tem, tem1), insn);
2275 XEXP (outerdest, 0) = tem1;
2279 /* STRICT_LOW_PART is a no-op on memory references
2280 and it can cause combinations to be unrecognizable,
2283 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2284 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2286 /* A valid insn to copy VAR into or out of a register
2287 must be left alone, to avoid an infinite loop here.
2288 If the reference to VAR is by a subreg, fix that up,
2289 since SUBREG is not valid for a memref.
2290 Also fix up the address of the stack slot.
2292 Note that we must not try to recognize the insn until
2293 after we know that we have valid addresses and no
2294 (subreg (mem ...) ...) constructs, since these interfere
2295 with determining the validity of the insn. */
2297 if ((SET_SRC (x) == var
2298 || (GET_CODE (SET_SRC (x)) == SUBREG
2299 && SUBREG_REG (SET_SRC (x)) == var))
2300 && (GET_CODE (SET_DEST (x)) == REG
2301 || (GET_CODE (SET_DEST (x)) == SUBREG
2302 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
2303 && GET_MODE (var) == promoted_mode
2304 && x == single_set (insn))
2308 if (GET_CODE (SET_SRC (x)) == SUBREG
2309 && (GET_MODE_SIZE (GET_MODE (SET_SRC (x)))
2310 > GET_MODE_SIZE (GET_MODE (var))))
2312 /* This (subreg VAR) is now a paradoxical subreg. We need
2313 to replace VAR instead of the subreg. */
2314 replacement = find_fixup_replacement (replacements, var);
2315 if (replacement->new == NULL_RTX)
2316 replacement->new = gen_reg_rtx (GET_MODE (var));
2317 SUBREG_REG (SET_SRC (x)) = replacement->new;
2321 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2322 if (replacement->new)
2323 SET_SRC (x) = replacement->new;
2324 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2325 SET_SRC (x) = replacement->new
2326 = fixup_memory_subreg (SET_SRC (x), insn, promoted_mode,
2329 SET_SRC (x) = replacement->new
2330 = fixup_stack_1 (SET_SRC (x), insn);
2333 if (recog_memoized (insn) >= 0)
2336 /* INSN is not valid, but we know that we want to
2337 copy SET_SRC (x) to SET_DEST (x) in some way. So
2338 we generate the move and see whether it requires more
2339 than one insn. If it does, we emit those insns and
2340 delete INSN. Otherwise, we can just replace the pattern
2341 of INSN; we have already verified above that INSN has
2342 no other function that to do X. */
2344 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2345 if (NEXT_INSN (pat) != NULL_RTX)
2347 last = emit_insn_before (pat, insn);
2349 /* INSN might have REG_RETVAL or other important notes, so
2350 we need to store the pattern of the last insn in the
2351 sequence into INSN similarly to the normal case. LAST
2352 should not have REG_NOTES, but we allow them if INSN has
2354 if (REG_NOTES (last) && REG_NOTES (insn))
2356 if (REG_NOTES (last))
2357 REG_NOTES (insn) = REG_NOTES (last);
2358 PATTERN (insn) = PATTERN (last);
2363 PATTERN (insn) = PATTERN (pat);
2368 if ((SET_DEST (x) == var
2369 || (GET_CODE (SET_DEST (x)) == SUBREG
2370 && SUBREG_REG (SET_DEST (x)) == var))
2371 && (GET_CODE (SET_SRC (x)) == REG
2372 || (GET_CODE (SET_SRC (x)) == SUBREG
2373 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
2374 && GET_MODE (var) == promoted_mode
2375 && x == single_set (insn))
2379 if (GET_CODE (SET_DEST (x)) == SUBREG)
2380 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn,
2383 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2385 if (recog_memoized (insn) >= 0)
2388 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2389 if (NEXT_INSN (pat) != NULL_RTX)
2391 last = emit_insn_before (pat, insn);
2393 /* INSN might have REG_RETVAL or other important notes, so
2394 we need to store the pattern of the last insn in the
2395 sequence into INSN similarly to the normal case. LAST
2396 should not have REG_NOTES, but we allow them if INSN has
2398 if (REG_NOTES (last) && REG_NOTES (insn))
2400 if (REG_NOTES (last))
2401 REG_NOTES (insn) = REG_NOTES (last);
2402 PATTERN (insn) = PATTERN (last);
2407 PATTERN (insn) = PATTERN (pat);
2412 /* Otherwise, storing into VAR must be handled specially
2413 by storing into a temporary and copying that into VAR
2414 with a new insn after this one. Note that this case
2415 will be used when storing into a promoted scalar since
2416 the insn will now have different modes on the input
2417 and output and hence will be invalid (except for the case
2418 of setting it to a constant, which does not need any
2419 change if it is valid). We generate extra code in that case,
2420 but combine.c will eliminate it. */
2425 rtx fixeddest = SET_DEST (x);
2426 enum machine_mode temp_mode;
2428 /* STRICT_LOW_PART can be discarded, around a MEM. */
2429 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2430 fixeddest = XEXP (fixeddest, 0);
2431 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2432 if (GET_CODE (fixeddest) == SUBREG)
2434 fixeddest = fixup_memory_subreg (fixeddest, insn,
2436 temp_mode = GET_MODE (fixeddest);
2440 fixeddest = fixup_stack_1 (fixeddest, insn);
2441 temp_mode = promoted_mode;
2444 temp = gen_reg_rtx (temp_mode);
2446 emit_insn_after (gen_move_insn (fixeddest,
2447 gen_lowpart (GET_MODE (fixeddest),
2451 SET_DEST (x) = temp;
2459 /* Nothing special about this RTX; fix its operands. */
2461 fmt = GET_RTX_FORMAT (code);
2462 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2465 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements,
2467 else if (fmt[i] == 'E')
2470 for (j = 0; j < XVECLEN (x, i); j++)
2471 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2472 insn, replacements, no_share);
2477 /* Previously, X had the form (SUBREG:m1 (REG:PROMOTED_MODE ...)).
2478 The REG was placed on the stack, so X now has the form (SUBREG:m1
2481 Return an rtx (MEM:m1 newaddr) which is equivalent. If any insns
2482 must be emitted to compute NEWADDR, put them before INSN.
2484 UNCRITICAL nonzero means accept paradoxical subregs.
2485 This is used for subregs found inside REG_NOTES. */
2488 fixup_memory_subreg (rtx x, rtx insn, enum machine_mode promoted_mode, int uncritical)
2491 rtx mem = SUBREG_REG (x);
2492 rtx addr = XEXP (mem, 0);
2493 enum machine_mode mode = GET_MODE (x);
2496 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2497 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (mem)) && ! uncritical)
2500 offset = SUBREG_BYTE (x);
2501 if (BYTES_BIG_ENDIAN)
2502 /* If the PROMOTED_MODE is wider than the mode of the MEM, adjust
2503 the offset so that it points to the right location within the
2505 offset -= (GET_MODE_SIZE (promoted_mode) - GET_MODE_SIZE (GET_MODE (mem)));
2507 if (!flag_force_addr
2508 && memory_address_p (mode, plus_constant (addr, offset)))
2509 /* Shortcut if no insns need be emitted. */
2510 return adjust_address (mem, mode, offset);
2513 result = adjust_address (mem, mode, offset);
2517 emit_insn_before (seq, insn);
2521 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
2522 Replace subexpressions of X in place.
2523 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
2524 Otherwise return X, with its contents possibly altered.
2526 INSN, PROMOTED_MODE and UNCRITICAL are as for
2527 fixup_memory_subreg. */
2530 walk_fixup_memory_subreg (rtx x, rtx insn, enum machine_mode promoted_mode,
2540 code = GET_CODE (x);
2542 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
2543 return fixup_memory_subreg (x, insn, promoted_mode, uncritical);
2545 /* Nothing special about this RTX; fix its operands. */
2547 fmt = GET_RTX_FORMAT (code);
2548 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2551 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn,
2552 promoted_mode, uncritical);
2553 else if (fmt[i] == 'E')
2556 for (j = 0; j < XVECLEN (x, i); j++)
2558 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn,
2559 promoted_mode, uncritical);
2565 /* For each memory ref within X, if it refers to a stack slot
2566 with an out of range displacement, put the address in a temp register
2567 (emitting new insns before INSN to load these registers)
2568 and alter the memory ref to use that register.
2569 Replace each such MEM rtx with a copy, to avoid clobberage. */
2572 fixup_stack_1 (rtx x, rtx insn)
2575 RTX_CODE code = GET_CODE (x);
2580 rtx ad = XEXP (x, 0);
2581 /* If we have address of a stack slot but it's not valid
2582 (displacement is too large), compute the sum in a register. */
2583 if (GET_CODE (ad) == PLUS
2584 && GET_CODE (XEXP (ad, 0)) == REG
2585 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2586 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2587 || REGNO (XEXP (ad, 0)) == FRAME_POINTER_REGNUM
2588 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2589 || REGNO (XEXP (ad, 0)) == HARD_FRAME_POINTER_REGNUM
2591 || REGNO (XEXP (ad, 0)) == STACK_POINTER_REGNUM
2592 || REGNO (XEXP (ad, 0)) == ARG_POINTER_REGNUM
2593 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2594 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2597 if (memory_address_p (GET_MODE (x), ad))
2601 temp = copy_to_reg (ad);
2604 emit_insn_before (seq, insn);
2605 return replace_equiv_address (x, temp);
2610 fmt = GET_RTX_FORMAT (code);
2611 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2614 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2615 else if (fmt[i] == 'E')
2618 for (j = 0; j < XVECLEN (x, i); j++)
2619 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2625 /* Optimization: a bit-field instruction whose field
2626 happens to be a byte or halfword in memory
2627 can be changed to a move instruction.
2629 We call here when INSN is an insn to examine or store into a bit-field.
2630 BODY is the SET-rtx to be altered.
2632 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2633 (Currently this is called only from function.c, and EQUIV_MEM
2637 optimize_bit_field (rtx body, rtx insn, rtx *equiv_mem)
2642 enum machine_mode mode;
2644 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2645 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2646 bitfield = SET_DEST (body), destflag = 1;
2648 bitfield = SET_SRC (body), destflag = 0;
2650 /* First check that the field being stored has constant size and position
2651 and is in fact a byte or halfword suitably aligned. */
2653 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2654 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2655 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2657 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2661 /* Now check that the containing word is memory, not a register,
2662 and that it is safe to change the machine mode. */
2664 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2665 memref = XEXP (bitfield, 0);
2666 else if (GET_CODE (XEXP (bitfield, 0)) == REG
2668 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2669 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2670 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2671 memref = SUBREG_REG (XEXP (bitfield, 0));
2672 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2674 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
2675 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2678 && ! mode_dependent_address_p (XEXP (memref, 0))
2679 && ! MEM_VOLATILE_P (memref))
2681 /* Now adjust the address, first for any subreg'ing
2682 that we are now getting rid of,
2683 and then for which byte of the word is wanted. */
2685 HOST_WIDE_INT offset = INTVAL (XEXP (bitfield, 2));
2688 /* Adjust OFFSET to count bits from low-address byte. */
2689 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2690 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2691 - offset - INTVAL (XEXP (bitfield, 1)));
2693 /* Adjust OFFSET to count bytes from low-address byte. */
2694 offset /= BITS_PER_UNIT;
2695 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2697 offset += (SUBREG_BYTE (XEXP (bitfield, 0))
2698 / UNITS_PER_WORD) * UNITS_PER_WORD;
2699 if (BYTES_BIG_ENDIAN)
2700 offset -= (MIN (UNITS_PER_WORD,
2701 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2702 - MIN (UNITS_PER_WORD,
2703 GET_MODE_SIZE (GET_MODE (memref))));
2707 memref = adjust_address (memref, mode, offset);
2708 insns = get_insns ();
2710 emit_insn_before (insns, insn);
2712 /* Store this memory reference where
2713 we found the bit field reference. */
2717 validate_change (insn, &SET_DEST (body), memref, 1);
2718 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2720 rtx src = SET_SRC (body);
2721 while (GET_CODE (src) == SUBREG
2722 && SUBREG_BYTE (src) == 0)
2723 src = SUBREG_REG (src);
2724 if (GET_MODE (src) != GET_MODE (memref))
2725 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2726 validate_change (insn, &SET_SRC (body), src, 1);
2728 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2729 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2730 /* This shouldn't happen because anything that didn't have
2731 one of these modes should have got converted explicitly
2732 and then referenced through a subreg.
2733 This is so because the original bit-field was
2734 handled by agg_mode and so its tree structure had
2735 the same mode that memref now has. */
2740 rtx dest = SET_DEST (body);
2742 while (GET_CODE (dest) == SUBREG
2743 && SUBREG_BYTE (dest) == 0
2744 && (GET_MODE_CLASS (GET_MODE (dest))
2745 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest))))
2746 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
2748 dest = SUBREG_REG (dest);
2750 validate_change (insn, &SET_DEST (body), dest, 1);
2752 if (GET_MODE (dest) == GET_MODE (memref))
2753 validate_change (insn, &SET_SRC (body), memref, 1);
2756 /* Convert the mem ref to the destination mode. */
2757 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2760 convert_move (newreg, memref,
2761 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2765 validate_change (insn, &SET_SRC (body), newreg, 1);
2769 /* See if we can convert this extraction or insertion into
2770 a simple move insn. We might not be able to do so if this
2771 was, for example, part of a PARALLEL.
2773 If we succeed, write out any needed conversions. If we fail,
2774 it is hard to guess why we failed, so don't do anything
2775 special; just let the optimization be suppressed. */
2777 if (apply_change_group () && seq)
2778 emit_insn_before (seq, insn);
2783 /* These routines are responsible for converting virtual register references
2784 to the actual hard register references once RTL generation is complete.
2786 The following four variables are used for communication between the
2787 routines. They contain the offsets of the virtual registers from their
2788 respective hard registers. */
2790 static int in_arg_offset;
2791 static int var_offset;
2792 static int dynamic_offset;
2793 static int out_arg_offset;
2794 static int cfa_offset;
2796 /* In most machines, the stack pointer register is equivalent to the bottom
2799 #ifndef STACK_POINTER_OFFSET
2800 #define STACK_POINTER_OFFSET 0
2803 /* If not defined, pick an appropriate default for the offset of dynamically
2804 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2805 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2807 #ifndef STACK_DYNAMIC_OFFSET
2809 /* The bottom of the stack points to the actual arguments. If
2810 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2811 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2812 stack space for register parameters is not pushed by the caller, but
2813 rather part of the fixed stack areas and hence not included in
2814 `current_function_outgoing_args_size'. Nevertheless, we must allow
2815 for it when allocating stack dynamic objects. */
2817 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2818 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2819 ((ACCUMULATE_OUTGOING_ARGS \
2820 ? (current_function_outgoing_args_size + REG_PARM_STACK_SPACE (FNDECL)) : 0)\
2821 + (STACK_POINTER_OFFSET)) \
2824 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2825 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
2826 + (STACK_POINTER_OFFSET))
2830 /* On most machines, the CFA coincides with the first incoming parm. */
2832 #ifndef ARG_POINTER_CFA_OFFSET
2833 #define ARG_POINTER_CFA_OFFSET(FNDECL) FIRST_PARM_OFFSET (FNDECL)
2836 /* Build up a (MEM (ADDRESSOF (REG))) rtx for a register REG that just
2837 had its address taken. DECL is the decl or SAVE_EXPR for the
2838 object stored in the register, for later use if we do need to force
2839 REG into the stack. REG is overwritten by the MEM like in
2840 put_reg_into_stack. RESCAN is true if previously emitted
2841 instructions must be rescanned and modified now that the REG has
2842 been transformed. */
2845 gen_mem_addressof (rtx reg, tree decl, int rescan)
2847 rtx r = gen_rtx_ADDRESSOF (Pmode, gen_reg_rtx (GET_MODE (reg)),
2850 /* Calculate this before we start messing with decl's RTL. */
2851 HOST_WIDE_INT set = decl ? get_alias_set (decl) : 0;
2853 /* If the original REG was a user-variable, then so is the REG whose
2854 address is being taken. Likewise for unchanging. */
2855 REG_USERVAR_P (XEXP (r, 0)) = REG_USERVAR_P (reg);
2856 RTX_UNCHANGING_P (XEXP (r, 0)) = RTX_UNCHANGING_P (reg);
2858 PUT_CODE (reg, MEM);
2859 MEM_VOLATILE_P (reg) = 0;
2860 MEM_ATTRS (reg) = 0;
2865 tree type = TREE_TYPE (decl);
2866 enum machine_mode decl_mode
2867 = (DECL_P (decl) ? DECL_MODE (decl) : TYPE_MODE (TREE_TYPE (decl)));
2868 rtx decl_rtl = (TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl)
2869 : DECL_RTL_IF_SET (decl));
2871 PUT_MODE (reg, decl_mode);
2873 /* Clear DECL_RTL momentarily so functions below will work
2874 properly, then set it again. */
2875 if (DECL_P (decl) && decl_rtl == reg)
2876 SET_DECL_RTL (decl, 0);
2878 set_mem_attributes (reg, decl, 1);
2879 set_mem_alias_set (reg, set);
2881 if (DECL_P (decl) && decl_rtl == reg)
2882 SET_DECL_RTL (decl, reg);
2885 && (TREE_USED (decl) || (DECL_P (decl) && DECL_INITIAL (decl) != 0)))
2886 fixup_var_refs (reg, GET_MODE (reg), TYPE_UNSIGNED (type), reg, 0);
2890 /* This can only happen during reload. Clear the same flag bits as
2892 RTX_UNCHANGING_P (reg) = 0;
2893 MEM_IN_STRUCT_P (reg) = 0;
2894 MEM_SCALAR_P (reg) = 0;
2896 fixup_var_refs (reg, GET_MODE (reg), 0, reg, 0);
2902 /* If DECL has an RTL that is an ADDRESSOF rtx, put it into the stack. */
2905 flush_addressof (tree decl)
2907 if ((TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL)
2908 && DECL_RTL (decl) != 0
2909 && GET_CODE (DECL_RTL (decl)) == MEM
2910 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF
2911 && GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == REG)
2912 put_addressof_into_stack (XEXP (DECL_RTL (decl), 0), 0);
2915 /* Force the register pointed to by R, an ADDRESSOF rtx, into the stack. */
2918 put_addressof_into_stack (rtx r, htab_t ht)
2921 int volatile_p, used_p;
2923 rtx reg = XEXP (r, 0);
2925 if (GET_CODE (reg) != REG)
2928 decl = ADDRESSOF_DECL (r);
2931 type = TREE_TYPE (decl);
2932 volatile_p = (TREE_CODE (decl) != SAVE_EXPR
2933 && TREE_THIS_VOLATILE (decl));
2934 used_p = (TREE_USED (decl)
2935 || (DECL_P (decl) && DECL_INITIAL (decl) != 0));
2944 put_reg_into_stack (0, reg, type, GET_MODE (reg), GET_MODE (reg),
2945 volatile_p, ADDRESSOF_REGNO (r), used_p, ht);
2948 /* List of replacements made below in purge_addressof_1 when creating
2949 bitfield insertions. */
2950 static rtx purge_bitfield_addressof_replacements;
2952 /* List of replacements made below in purge_addressof_1 for patterns
2953 (MEM (ADDRESSOF (REG ...))). The key of the list entry is the
2954 corresponding (ADDRESSOF (REG ...)) and value is a substitution for
2955 the all pattern. List PURGE_BITFIELD_ADDRESSOF_REPLACEMENTS is not
2956 enough in complex cases, e.g. when some field values can be
2957 extracted by usage MEM with narrower mode. */
2958 static rtx purge_addressof_replacements;
2960 /* Helper function for purge_addressof. See if the rtx expression at *LOC
2961 in INSN needs to be changed. If FORCE, always put any ADDRESSOFs into
2962 the stack. If the function returns FALSE then the replacement could not
2963 be made. If MAY_POSTPONE is true and we would not put the addressof
2964 to stack, postpone processing of the insn. */
2967 purge_addressof_1 (rtx *loc, rtx insn, int force, int store, int may_postpone,
2975 bool libcall = false;
2977 /* Re-start here to avoid recursion in common cases. */
2984 /* Is this a libcall? */
2986 libcall = REG_NOTE_KIND (*loc) == REG_RETVAL;
2988 code = GET_CODE (x);
2990 /* If we don't return in any of the cases below, we will recurse inside
2991 the RTX, which will normally result in any ADDRESSOF being forced into
2995 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1,
2997 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0,
3001 else if (code == ADDRESSOF)
3005 if (GET_CODE (XEXP (x, 0)) != MEM)
3006 put_addressof_into_stack (x, ht);
3008 /* We must create a copy of the rtx because it was created by
3009 overwriting a REG rtx which is always shared. */
3010 sub = copy_rtx (XEXP (XEXP (x, 0), 0));
3011 if (validate_change (insn, loc, sub, 0)
3012 || validate_replace_rtx (x, sub, insn))
3017 /* If SUB is a hard or virtual register, try it as a pseudo-register.
3018 Otherwise, perhaps SUB is an expression, so generate code to compute
3020 if (GET_CODE (sub) == REG && REGNO (sub) <= LAST_VIRTUAL_REGISTER)
3021 sub = copy_to_reg (sub);
3023 sub = force_operand (sub, NULL_RTX);
3025 if (! validate_change (insn, loc, sub, 0)
3026 && ! validate_replace_rtx (x, sub, insn))
3029 insns = get_insns ();
3031 emit_insn_before (insns, insn);
3035 else if (code == MEM && GET_CODE (XEXP (x, 0)) == ADDRESSOF && ! force)
3037 rtx sub = XEXP (XEXP (x, 0), 0);
3039 if (GET_CODE (sub) == MEM)
3040 sub = adjust_address_nv (sub, GET_MODE (x), 0);
3041 else if (GET_CODE (sub) == REG
3042 && (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode))
3044 else if (GET_CODE (sub) == REG && GET_MODE (x) != GET_MODE (sub))
3046 int size_x, size_sub;
3050 /* Postpone for now, so that we do not emit bitfield arithmetics
3051 unless there is some benefit from it. */
3052 if (!postponed_insns || XEXP (postponed_insns, 0) != insn)
3053 postponed_insns = alloc_INSN_LIST (insn, postponed_insns);
3059 /* When processing REG_NOTES look at the list of
3060 replacements done on the insn to find the register that X
3064 for (tem = purge_bitfield_addressof_replacements;
3066 tem = XEXP (XEXP (tem, 1), 1))
3067 if (rtx_equal_p (x, XEXP (tem, 0)))
3069 *loc = XEXP (XEXP (tem, 1), 0);
3073 /* See comment for purge_addressof_replacements. */
3074 for (tem = purge_addressof_replacements;
3076 tem = XEXP (XEXP (tem, 1), 1))
3077 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3079 rtx z = XEXP (XEXP (tem, 1), 0);
3081 if (GET_MODE (x) == GET_MODE (z)
3082 || (GET_CODE (XEXP (XEXP (tem, 1), 0)) != REG
3083 && GET_CODE (XEXP (XEXP (tem, 1), 0)) != SUBREG))
3086 /* It can happen that the note may speak of things
3087 in a wider (or just different) mode than the
3088 code did. This is especially true of
3091 if (GET_CODE (z) == SUBREG && SUBREG_BYTE (z) == 0)
3094 if (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3095 && (GET_MODE_SIZE (GET_MODE (x))
3096 > GET_MODE_SIZE (GET_MODE (z))))
3098 /* This can occur as a result in invalid
3099 pointer casts, e.g. float f; ...
3100 *(long long int *)&f.
3101 ??? We could emit a warning here, but
3102 without a line number that wouldn't be
3104 z = gen_rtx_SUBREG (GET_MODE (x), z, 0);
3107 z = gen_lowpart (GET_MODE (x), z);
3113 /* When we are processing the REG_NOTES of the last instruction
3114 of a libcall, there will be typically no replacements
3115 for that insn; the replacements happened before, piecemeal
3116 fashion. OTOH we are not interested in the details of
3117 this for the REG_EQUAL note, we want to know the big picture,
3118 which can be succinctly described with a simple SUBREG.
3119 Note that removing the REG_EQUAL note is not an option
3120 on the last insn of a libcall, so we must do a replacement. */
3122 /* In compile/990107-1.c:7 compiled at -O1 -m1 for sh-elf,
3124 (mem:DI (addressof:SI (reg/v:DF 160) 159 0x401c8510)
3125 [0 S8 A32]), which can be expressed with a simple
3127 if ((GET_MODE_SIZE (GET_MODE (x))
3128 <= GET_MODE_SIZE (GET_MODE (sub)))
3129 /* Again, invalid pointer casts (as in
3130 compile/990203-1.c) can require paradoxical
3132 || (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3133 && (GET_MODE_SIZE (GET_MODE (x))
3134 > GET_MODE_SIZE (GET_MODE (sub)))
3137 *loc = gen_rtx_SUBREG (GET_MODE (x), sub, 0);
3140 /* ??? Are there other cases we should handle? */
3142 /* Sometimes we may not be able to find the replacement. For
3143 example when the original insn was a MEM in a wider mode,
3144 and the note is part of a sign extension of a narrowed
3145 version of that MEM. Gcc testcase compile/990829-1.c can
3146 generate an example of this situation. Rather than complain
3147 we return false, which will prompt our caller to remove the
3152 size_x = GET_MODE_BITSIZE (GET_MODE (x));
3153 size_sub = GET_MODE_BITSIZE (GET_MODE (sub));
3155 /* Do not frob unchanging MEMs. If a later reference forces the
3156 pseudo to the stack, we can wind up with multiple writes to
3157 an unchanging memory, which is invalid. */
3158 if (RTX_UNCHANGING_P (x) && size_x != size_sub)
3161 /* Don't even consider working with paradoxical subregs,
3162 or the moral equivalent seen here. */
3163 else if (size_x <= size_sub
3164 && int_mode_for_mode (GET_MODE (sub)) != BLKmode)
3166 /* Do a bitfield insertion to mirror what would happen
3173 rtx p = PREV_INSN (insn);
3176 val = gen_reg_rtx (GET_MODE (x));
3177 if (! validate_change (insn, loc, val, 0))
3179 /* Discard the current sequence and put the
3180 ADDRESSOF on stack. */
3186 emit_insn_before (seq, insn);
3187 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3191 store_bit_field (sub, size_x, 0, GET_MODE (x),
3192 val, GET_MODE_SIZE (GET_MODE (sub)));
3194 /* Make sure to unshare any shared rtl that store_bit_field
3195 might have created. */
3196 unshare_all_rtl_again (get_insns ());
3200 p = emit_insn_after (seq, insn);
3201 if (NEXT_INSN (insn))
3202 compute_insns_for_mem (NEXT_INSN (insn),
3203 p ? NEXT_INSN (p) : NULL_RTX,
3208 rtx p = PREV_INSN (insn);
3211 val = extract_bit_field (sub, size_x, 0, 1, NULL_RTX,
3212 GET_MODE (x), GET_MODE (x),
3213 GET_MODE_SIZE (GET_MODE (sub)));
3215 if (! validate_change (insn, loc, val, 0))
3217 /* Discard the current sequence and put the
3218 ADDRESSOF on stack. */
3225 emit_insn_before (seq, insn);
3226 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3230 /* Remember the replacement so that the same one can be done
3231 on the REG_NOTES. */
3232 purge_bitfield_addressof_replacements
3233 = gen_rtx_EXPR_LIST (VOIDmode, x,
3236 purge_bitfield_addressof_replacements));
3238 /* We replaced with a reg -- all done. */
3243 else if (validate_change (insn, loc, sub, 0))
3245 /* Remember the replacement so that the same one can be done
3246 on the REG_NOTES. */
3247 if (GET_CODE (sub) == REG || GET_CODE (sub) == SUBREG)
3251 for (tem = purge_addressof_replacements;
3253 tem = XEXP (XEXP (tem, 1), 1))
3254 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3256 XEXP (XEXP (tem, 1), 0) = sub;
3259 purge_addressof_replacements
3260 = gen_rtx_EXPR_LIST (VOIDmode, XEXP (x, 0),
3261 gen_rtx_EXPR_LIST (VOIDmode, sub,
3262 purge_addressof_replacements));
3270 /* Scan all subexpressions. */
3271 fmt = GET_RTX_FORMAT (code);
3272 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3275 result &= purge_addressof_1 (&XEXP (x, i), insn, force, 0,
3277 else if (*fmt == 'E')
3278 for (j = 0; j < XVECLEN (x, i); j++)
3279 result &= purge_addressof_1 (&XVECEXP (x, i, j), insn, force, 0,
3286 /* Return a hash value for K, a REG. */
3289 insns_for_mem_hash (const void *k)
3291 /* Use the address of the key for the hash value. */
3292 struct insns_for_mem_entry *m = (struct insns_for_mem_entry *) k;
3293 return htab_hash_pointer (m->key);
3296 /* Return nonzero if K1 and K2 (two REGs) are the same. */
3299 insns_for_mem_comp (const void *k1, const void *k2)
3301 struct insns_for_mem_entry *m1 = (struct insns_for_mem_entry *) k1;
3302 struct insns_for_mem_entry *m2 = (struct insns_for_mem_entry *) k2;
3303 return m1->key == m2->key;
3306 struct insns_for_mem_walk_info
3308 /* The hash table that we are using to record which INSNs use which
3312 /* The INSN we are currently processing. */
3315 /* Zero if we are walking to find ADDRESSOFs, one if we are walking
3316 to find the insns that use the REGs in the ADDRESSOFs. */
3320 /* Called from compute_insns_for_mem via for_each_rtx. If R is a REG
3321 that might be used in an ADDRESSOF expression, record this INSN in
3322 the hash table given by DATA (which is really a pointer to an
3323 insns_for_mem_walk_info structure). */
3326 insns_for_mem_walk (rtx *r, void *data)
3328 struct insns_for_mem_walk_info *ifmwi
3329 = (struct insns_for_mem_walk_info *) data;
3330 struct insns_for_mem_entry tmp;
3331 tmp.insns = NULL_RTX;
3333 if (ifmwi->pass == 0 && *r && GET_CODE (*r) == ADDRESSOF
3334 && GET_CODE (XEXP (*r, 0)) == REG)
3337 tmp.key = XEXP (*r, 0);
3338 e = htab_find_slot (ifmwi->ht, &tmp, INSERT);
3341 *e = ggc_alloc (sizeof (tmp));
3342 memcpy (*e, &tmp, sizeof (tmp));
3345 else if (ifmwi->pass == 1 && *r && GET_CODE (*r) == REG)
3347 struct insns_for_mem_entry *ifme;
3349 ifme = htab_find (ifmwi->ht, &tmp);
3351 /* If we have not already recorded this INSN, do so now. Since
3352 we process the INSNs in order, we know that if we have
3353 recorded it it must be at the front of the list. */
3354 if (ifme && (!ifme->insns || XEXP (ifme->insns, 0) != ifmwi->insn))
3355 ifme->insns = gen_rtx_EXPR_LIST (VOIDmode, ifmwi->insn,
3362 /* Walk the INSNS, until we reach LAST_INSN, recording which INSNs use
3363 which REGs in HT. */
3366 compute_insns_for_mem (rtx insns, rtx last_insn, htab_t ht)
3369 struct insns_for_mem_walk_info ifmwi;
3372 for (ifmwi.pass = 0; ifmwi.pass < 2; ++ifmwi.pass)
3373 for (insn = insns; insn != last_insn; insn = NEXT_INSN (insn))
3377 for_each_rtx (&insn, insns_for_mem_walk, &ifmwi);
3381 /* Helper function for purge_addressof called through for_each_rtx.
3382 Returns true iff the rtl is an ADDRESSOF. */
3385 is_addressof (rtx *rtl, void *data ATTRIBUTE_UNUSED)
3387 return GET_CODE (*rtl) == ADDRESSOF;
3390 /* Eliminate all occurrences of ADDRESSOF from INSNS. Elide any remaining
3391 (MEM (ADDRESSOF)) patterns, and force any needed registers into the
3395 purge_addressof (rtx insns)
3400 /* When we actually purge ADDRESSOFs, we turn REGs into MEMs. That
3401 requires a fixup pass over the instruction stream to correct
3402 INSNs that depended on the REG being a REG, and not a MEM. But,
3403 these fixup passes are slow. Furthermore, most MEMs are not
3404 mentioned in very many instructions. So, we speed up the process
3405 by pre-calculating which REGs occur in which INSNs; that allows
3406 us to perform the fixup passes much more quickly. */
3407 ht = htab_create_ggc (1000, insns_for_mem_hash, insns_for_mem_comp, NULL);
3408 compute_insns_for_mem (insns, NULL_RTX, ht);
3410 postponed_insns = NULL;
3412 for (insn = insns; insn; insn = NEXT_INSN (insn))
3415 if (! purge_addressof_1 (&PATTERN (insn), insn,
3416 asm_noperands (PATTERN (insn)) > 0, 0, 1, ht))
3417 /* If we could not replace the ADDRESSOFs in the insn,
3418 something is wrong. */
3421 if (! purge_addressof_1 (®_NOTES (insn), NULL_RTX, 0, 0, 0, ht))
3423 /* If we could not replace the ADDRESSOFs in the insn's notes,
3424 we can just remove the offending notes instead. */
3427 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
3429 /* If we find a REG_RETVAL note then the insn is a libcall.
3430 Such insns must have REG_EQUAL notes as well, in order
3431 for later passes of the compiler to work. So it is not
3432 safe to delete the notes here, and instead we abort. */
3433 if (REG_NOTE_KIND (note) == REG_RETVAL)
3435 if (for_each_rtx (¬e, is_addressof, NULL))
3436 remove_note (insn, note);
3441 /* Process the postponed insns. */
3442 while (postponed_insns)
3444 insn = XEXP (postponed_insns, 0);
3445 tmp = postponed_insns;
3446 postponed_insns = XEXP (postponed_insns, 1);
3447 free_INSN_LIST_node (tmp);
3449 if (! purge_addressof_1 (&PATTERN (insn), insn,
3450 asm_noperands (PATTERN (insn)) > 0, 0, 0, ht))
3455 purge_bitfield_addressof_replacements = 0;
3456 purge_addressof_replacements = 0;
3458 /* REGs are shared. purge_addressof will destructively replace a REG
3459 with a MEM, which creates shared MEMs.
3461 Unfortunately, the children of put_reg_into_stack assume that MEMs
3462 referring to the same stack slot are shared (fixup_var_refs and
3463 the associated hash table code).
3465 So, we have to do another unsharing pass after we have flushed any
3466 REGs that had their address taken into the stack.
3468 It may be worth tracking whether or not we converted any REGs into
3469 MEMs to avoid this overhead when it is not needed. */
3470 unshare_all_rtl_again (get_insns ());
3473 /* Convert a SET of a hard subreg to a set of the appropriate hard
3474 register. A subroutine of purge_hard_subreg_sets. */
3477 purge_single_hard_subreg_set (rtx pattern)
3479 rtx reg = SET_DEST (pattern);
3480 enum machine_mode mode = GET_MODE (SET_DEST (pattern));
3483 if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG
3484 && REGNO (SUBREG_REG (reg)) < FIRST_PSEUDO_REGISTER)
3486 offset = subreg_regno_offset (REGNO (SUBREG_REG (reg)),
3487 GET_MODE (SUBREG_REG (reg)),
3490 reg = SUBREG_REG (reg);
3494 if (GET_CODE (reg) == REG && REGNO (reg) < FIRST_PSEUDO_REGISTER)
3496 reg = gen_rtx_REG (mode, REGNO (reg) + offset);
3497 SET_DEST (pattern) = reg;
3501 /* Eliminate all occurrences of SETs of hard subregs from INSNS. The
3502 only such SETs that we expect to see are those left in because
3503 integrate can't handle sets of parts of a return value register.
3505 We don't use alter_subreg because we only want to eliminate subregs
3506 of hard registers. */
3509 purge_hard_subreg_sets (rtx insn)
3511 for (; insn; insn = NEXT_INSN (insn))
3515 rtx pattern = PATTERN (insn);
3516 switch (GET_CODE (pattern))
3519 if (GET_CODE (SET_DEST (pattern)) == SUBREG)
3520 purge_single_hard_subreg_set (pattern);
3525 for (j = XVECLEN (pattern, 0) - 1; j >= 0; j--)
3527 rtx inner_pattern = XVECEXP (pattern, 0, j);
3528 if (GET_CODE (inner_pattern) == SET
3529 && GET_CODE (SET_DEST (inner_pattern)) == SUBREG)
3530 purge_single_hard_subreg_set (inner_pattern);
3541 /* Pass through the INSNS of function FNDECL and convert virtual register
3542 references to hard register references. */
3545 instantiate_virtual_regs (tree fndecl, rtx insns)
3550 /* Compute the offsets to use for this function. */
3551 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
3552 var_offset = STARTING_FRAME_OFFSET;
3553 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
3554 out_arg_offset = STACK_POINTER_OFFSET;
3555 cfa_offset = ARG_POINTER_CFA_OFFSET (fndecl);
3557 /* Scan all variables and parameters of this function. For each that is
3558 in memory, instantiate all virtual registers if the result is a valid
3559 address. If not, we do it later. That will handle most uses of virtual
3560 regs on many machines. */
3561 instantiate_decls (fndecl, 1);
3563 /* Initialize recognition, indicating that volatile is OK. */
3566 /* Scan through all the insns, instantiating every virtual register still
3568 for (insn = insns; insn; insn = NEXT_INSN (insn))
3569 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3570 || GET_CODE (insn) == CALL_INSN)
3572 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
3573 if (INSN_DELETED_P (insn))
3575 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
3576 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
3577 if (GET_CODE (insn) == CALL_INSN)
3578 instantiate_virtual_regs_1 (&CALL_INSN_FUNCTION_USAGE (insn),
3581 /* Past this point all ASM statements should match. Verify that
3582 to avoid failures later in the compilation process. */
3583 if (asm_noperands (PATTERN (insn)) >= 0
3584 && ! check_asm_operands (PATTERN (insn)))
3585 instantiate_virtual_regs_lossage (insn);
3588 /* Instantiate the stack slots for the parm registers, for later use in
3589 addressof elimination. */
3590 for (i = 0; i < max_parm_reg; ++i)
3591 if (parm_reg_stack_loc[i])
3592 instantiate_virtual_regs_1 (&parm_reg_stack_loc[i], NULL_RTX, 0);
3594 /* Now instantiate the remaining register equivalences for debugging info.
3595 These will not be valid addresses. */
3596 instantiate_decls (fndecl, 0);
3598 /* Indicate that, from now on, assign_stack_local should use
3599 frame_pointer_rtx. */
3600 virtuals_instantiated = 1;
3603 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
3604 all virtual registers in their DECL_RTL's.
3606 If VALID_ONLY, do this only if the resulting address is still valid.
3607 Otherwise, always do it. */
3610 instantiate_decls (tree fndecl, int valid_only)
3614 /* Process all parameters of the function. */
3615 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
3617 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));
3618 HOST_WIDE_INT size_rtl;
3620 instantiate_decl (DECL_RTL (decl), size, valid_only);
3622 /* If the parameter was promoted, then the incoming RTL mode may be
3623 larger than the declared type size. We must use the larger of
3625 size_rtl = GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl)));
3626 size = MAX (size_rtl, size);
3627 instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
3630 /* Now process all variables defined in the function or its subblocks. */
3631 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
3634 /* Subroutine of instantiate_decls: Process all decls in the given
3635 BLOCK node and all its subblocks. */
3638 instantiate_decls_1 (tree let, int valid_only)
3642 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
3643 if (DECL_RTL_SET_P (t))
3644 instantiate_decl (DECL_RTL (t),
3645 int_size_in_bytes (TREE_TYPE (t)),
3648 /* Process all subblocks. */
3649 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
3650 instantiate_decls_1 (t, valid_only);
3653 /* Subroutine of the preceding procedures: Given RTL representing a
3654 decl and the size of the object, do any instantiation required.
3656 If VALID_ONLY is nonzero, it means that the RTL should only be
3657 changed if the new address is valid. */
3660 instantiate_decl (rtx x, HOST_WIDE_INT size, int valid_only)
3662 enum machine_mode mode;
3665 /* If this is not a MEM, no need to do anything. Similarly if the
3666 address is a constant or a register that is not a virtual register. */
3668 if (x == 0 || GET_CODE (x) != MEM)
3672 if (CONSTANT_P (addr)
3673 || (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == REG)
3674 || (GET_CODE (addr) == REG
3675 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
3676 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
3679 /* If we should only do this if the address is valid, copy the address.
3680 We need to do this so we can undo any changes that might make the
3681 address invalid. This copy is unfortunate, but probably can't be
3685 addr = copy_rtx (addr);
3687 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
3689 if (valid_only && size >= 0)
3691 unsigned HOST_WIDE_INT decl_size = size;
3693 /* Now verify that the resulting address is valid for every integer or
3694 floating-point mode up to and including SIZE bytes long. We do this
3695 since the object might be accessed in any mode and frame addresses
3698 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3699 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3700 mode = GET_MODE_WIDER_MODE (mode))
3701 if (! memory_address_p (mode, addr))
3704 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
3705 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3706 mode = GET_MODE_WIDER_MODE (mode))
3707 if (! memory_address_p (mode, addr))
3711 /* Put back the address now that we have updated it and we either know
3712 it is valid or we don't care whether it is valid. */
3717 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
3718 is a virtual register, return the equivalent hard register and set the
3719 offset indirectly through the pointer. Otherwise, return 0. */
3722 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
3725 HOST_WIDE_INT offset;
3727 if (x == virtual_incoming_args_rtx)
3728 new = arg_pointer_rtx, offset = in_arg_offset;
3729 else if (x == virtual_stack_vars_rtx)
3730 new = frame_pointer_rtx, offset = var_offset;
3731 else if (x == virtual_stack_dynamic_rtx)
3732 new = stack_pointer_rtx, offset = dynamic_offset;
3733 else if (x == virtual_outgoing_args_rtx)
3734 new = stack_pointer_rtx, offset = out_arg_offset;
3735 else if (x == virtual_cfa_rtx)
3736 new = arg_pointer_rtx, offset = cfa_offset;
3745 /* Called when instantiate_virtual_regs has failed to update the instruction.
3746 Usually this means that non-matching instruction has been emit, however for
3747 asm statements it may be the problem in the constraints. */
3749 instantiate_virtual_regs_lossage (rtx insn)
3751 if (asm_noperands (PATTERN (insn)) >= 0)
3753 error_for_asm (insn, "impossible constraint in `asm'");
3759 /* Given a pointer to a piece of rtx and an optional pointer to the
3760 containing object, instantiate any virtual registers present in it.
3762 If EXTRA_INSNS, we always do the replacement and generate
3763 any extra insns before OBJECT. If it zero, we do nothing if replacement
3766 Return 1 if we either had nothing to do or if we were able to do the
3767 needed replacement. Return 0 otherwise; we only return zero if
3768 EXTRA_INSNS is zero.
3770 We first try some simple transformations to avoid the creation of extra
3774 instantiate_virtual_regs_1 (rtx *loc, rtx object, int extra_insns)
3779 HOST_WIDE_INT offset = 0;
3785 /* Re-start here to avoid recursion in common cases. */
3792 /* We may have detected and deleted invalid asm statements. */
3793 if (object && INSN_P (object) && INSN_DELETED_P (object))
3796 code = GET_CODE (x);
3798 /* Check for some special cases. */
3816 /* We are allowed to set the virtual registers. This means that
3817 the actual register should receive the source minus the
3818 appropriate offset. This is used, for example, in the handling
3819 of non-local gotos. */
3820 if ((new = instantiate_new_reg (SET_DEST (x), &offset)) != 0)
3822 rtx src = SET_SRC (x);
3824 /* We are setting the register, not using it, so the relevant
3825 offset is the negative of the offset to use were we using
3828 instantiate_virtual_regs_1 (&src, NULL_RTX, 0);
3830 /* The only valid sources here are PLUS or REG. Just do
3831 the simplest possible thing to handle them. */
3832 if (GET_CODE (src) != REG && GET_CODE (src) != PLUS)
3834 instantiate_virtual_regs_lossage (object);
3839 if (GET_CODE (src) != REG)
3840 temp = force_operand (src, NULL_RTX);
3843 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
3847 emit_insn_before (seq, object);
3850 if (! validate_change (object, &SET_SRC (x), temp, 0)
3852 instantiate_virtual_regs_lossage (object);
3857 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
3862 /* Handle special case of virtual register plus constant. */
3863 if (CONSTANT_P (XEXP (x, 1)))
3865 rtx old, new_offset;
3867 /* Check for (plus (plus VIRT foo) (const_int)) first. */
3868 if (GET_CODE (XEXP (x, 0)) == PLUS)
3870 if ((new = instantiate_new_reg (XEXP (XEXP (x, 0), 0), &offset)))
3872 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
3874 new = gen_rtx_PLUS (Pmode, new, XEXP (XEXP (x, 0), 1));
3883 #ifdef POINTERS_EXTEND_UNSIGNED
3884 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
3885 we can commute the PLUS and SUBREG because pointers into the
3886 frame are well-behaved. */
3887 else if (GET_CODE (XEXP (x, 0)) == SUBREG && GET_MODE (x) == ptr_mode
3888 && GET_CODE (XEXP (x, 1)) == CONST_INT
3890 = instantiate_new_reg (SUBREG_REG (XEXP (x, 0)),
3892 && validate_change (object, loc,
3893 plus_constant (gen_lowpart (ptr_mode,
3896 + INTVAL (XEXP (x, 1))),
3900 else if ((new = instantiate_new_reg (XEXP (x, 0), &offset)) == 0)
3902 /* We know the second operand is a constant. Unless the
3903 first operand is a REG (which has been already checked),
3904 it needs to be checked. */
3905 if (GET_CODE (XEXP (x, 0)) != REG)
3913 new_offset = plus_constant (XEXP (x, 1), offset);
3915 /* If the new constant is zero, try to replace the sum with just
3917 if (new_offset == const0_rtx
3918 && validate_change (object, loc, new, 0))
3921 /* Next try to replace the register and new offset.
3922 There are two changes to validate here and we can't assume that
3923 in the case of old offset equals new just changing the register
3924 will yield a valid insn. In the interests of a little efficiency,
3925 however, we only call validate change once (we don't queue up the
3926 changes and then call apply_change_group). */
3930 ? ! validate_change (object, &XEXP (x, 0), new, 0)
3931 : (XEXP (x, 0) = new,
3932 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
3940 /* Otherwise copy the new constant into a register and replace
3941 constant with that register. */
3942 temp = gen_reg_rtx (Pmode);
3944 if (validate_change (object, &XEXP (x, 1), temp, 0))
3945 emit_insn_before (gen_move_insn (temp, new_offset), object);
3948 /* If that didn't work, replace this expression with a
3949 register containing the sum. */
3952 new = gen_rtx_PLUS (Pmode, new, new_offset);
3955 temp = force_operand (new, NULL_RTX);
3959 emit_insn_before (seq, object);
3960 if (! validate_change (object, loc, temp, 0)
3961 && ! validate_replace_rtx (x, temp, object))
3963 instantiate_virtual_regs_lossage (object);
3972 /* Fall through to generic two-operand expression case. */
3978 case DIV: case UDIV:
3979 case MOD: case UMOD:
3980 case AND: case IOR: case XOR:
3981 case ROTATERT: case ROTATE:
3982 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
3984 case GE: case GT: case GEU: case GTU:
3985 case LE: case LT: case LEU: case LTU:
3986 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
3987 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
3992 /* Most cases of MEM that convert to valid addresses have already been
3993 handled by our scan of decls. The only special handling we
3994 need here is to make a copy of the rtx to ensure it isn't being
3995 shared if we have to change it to a pseudo.
3997 If the rtx is a simple reference to an address via a virtual register,
3998 it can potentially be shared. In such cases, first try to make it
3999 a valid address, which can also be shared. Otherwise, copy it and
4002 First check for common cases that need no processing. These are
4003 usually due to instantiation already being done on a previous instance
4007 if (CONSTANT_ADDRESS_P (temp)
4008 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4009 || temp == arg_pointer_rtx
4011 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4012 || temp == hard_frame_pointer_rtx
4014 || temp == frame_pointer_rtx)
4017 if (GET_CODE (temp) == PLUS
4018 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4019 && (XEXP (temp, 0) == frame_pointer_rtx
4020 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4021 || XEXP (temp, 0) == hard_frame_pointer_rtx
4023 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4024 || XEXP (temp, 0) == arg_pointer_rtx
4029 if (temp == virtual_stack_vars_rtx
4030 || temp == virtual_incoming_args_rtx
4031 || (GET_CODE (temp) == PLUS
4032 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4033 && (XEXP (temp, 0) == virtual_stack_vars_rtx
4034 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
4036 /* This MEM may be shared. If the substitution can be done without
4037 the need to generate new pseudos, we want to do it in place
4038 so all copies of the shared rtx benefit. The call below will
4039 only make substitutions if the resulting address is still
4042 Note that we cannot pass X as the object in the recursive call
4043 since the insn being processed may not allow all valid
4044 addresses. However, if we were not passed on object, we can
4045 only modify X without copying it if X will have a valid
4048 ??? Also note that this can still lose if OBJECT is an insn that
4049 has less restrictions on an address that some other insn.
4050 In that case, we will modify the shared address. This case
4051 doesn't seem very likely, though. One case where this could
4052 happen is in the case of a USE or CLOBBER reference, but we
4053 take care of that below. */
4055 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
4056 object ? object : x, 0))
4059 /* Otherwise make a copy and process that copy. We copy the entire
4060 RTL expression since it might be a PLUS which could also be
4062 *loc = x = copy_rtx (x);
4065 /* Fall through to generic unary operation case. */
4068 case STRICT_LOW_PART:
4070 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
4071 case SIGN_EXTEND: case ZERO_EXTEND:
4072 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
4073 case FLOAT: case FIX:
4074 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
4079 case POPCOUNT: case PARITY:
4080 /* These case either have just one operand or we know that we need not
4081 check the rest of the operands. */
4087 /* If the operand is a MEM, see if the change is a valid MEM. If not,
4088 go ahead and make the invalid one, but do it to a copy. For a REG,
4089 just make the recursive call, since there's no chance of a problem. */
4091 if ((GET_CODE (XEXP (x, 0)) == MEM
4092 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
4094 || (GET_CODE (XEXP (x, 0)) == REG
4095 && instantiate_virtual_regs_1 (&XEXP (x, 0), object, 0)))
4098 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
4103 /* Try to replace with a PLUS. If that doesn't work, compute the sum
4104 in front of this insn and substitute the temporary. */
4105 if ((new = instantiate_new_reg (x, &offset)) != 0)
4107 temp = plus_constant (new, offset);
4108 if (!validate_change (object, loc, temp, 0))
4114 temp = force_operand (temp, NULL_RTX);
4118 emit_insn_before (seq, object);
4119 if (! validate_change (object, loc, temp, 0)
4120 && ! validate_replace_rtx (x, temp, object))
4121 instantiate_virtual_regs_lossage (object);
4128 if (GET_CODE (XEXP (x, 0)) == REG)
4131 else if (GET_CODE (XEXP (x, 0)) == MEM)
4133 /* If we have a (addressof (mem ..)), do any instantiation inside
4134 since we know we'll be making the inside valid when we finally
4135 remove the ADDRESSOF. */
4136 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), NULL_RTX, 0);
4145 /* Scan all subexpressions. */
4146 fmt = GET_RTX_FORMAT (code);
4147 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
4150 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
4153 else if (*fmt == 'E')
4154 for (j = 0; j < XVECLEN (x, i); j++)
4155 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
4162 /* Optimization: assuming this function does not receive nonlocal gotos,
4163 delete the handlers for such, as well as the insns to establish
4164 and disestablish them. */
4167 delete_handlers (void)
4170 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4172 /* Delete the handler by turning off the flag that would
4173 prevent jump_optimize from deleting it.
4174 Also permit deletion of the nonlocal labels themselves
4175 if nothing local refers to them. */
4176 if (GET_CODE (insn) == CODE_LABEL)
4180 LABEL_PRESERVE_P (insn) = 0;
4182 /* Remove it from the nonlocal_label list, to avoid confusing
4184 for (t = nonlocal_labels, last_t = 0; t;
4185 last_t = t, t = TREE_CHAIN (t))
4186 if (DECL_RTL (TREE_VALUE (t)) == insn)
4191 nonlocal_labels = TREE_CHAIN (nonlocal_labels);
4193 TREE_CHAIN (last_t) = TREE_CHAIN (t);
4196 if (GET_CODE (insn) == INSN)
4200 for (t = nonlocal_goto_handler_slots; t != 0; t = XEXP (t, 1))
4201 if (reg_mentioned_p (t, PATTERN (insn)))
4207 || (nonlocal_goto_stack_level != 0
4208 && reg_mentioned_p (nonlocal_goto_stack_level,
4210 delete_related_insns (insn);
4215 /* Return the first insn following those generated by `assign_parms'. */
4218 get_first_nonparm_insn (void)
4221 return NEXT_INSN (last_parm_insn);
4222 return get_insns ();
4225 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
4226 This means a type for which function calls must pass an address to the
4227 function or get an address back from the function.
4228 EXP may be a type node or an expression (whose type is tested). */
4231 aggregate_value_p (tree exp, tree fntype)
4233 int i, regno, nregs;
4236 tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
4239 switch (TREE_CODE (fntype))
4242 fntype = get_callee_fndecl (fntype);
4243 fntype = fntype ? TREE_TYPE (fntype) : 0;
4246 fntype = TREE_TYPE (fntype);
4251 case IDENTIFIER_NODE:
4255 /* We don't expect other rtl types here. */
4259 if (TREE_CODE (type) == VOID_TYPE)
4261 if (targetm.calls.return_in_memory (type, fntype))
4263 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
4264 and thus can't be returned in registers. */
4265 if (TREE_ADDRESSABLE (type))
4267 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
4269 /* Make sure we have suitable call-clobbered regs to return
4270 the value in; if not, we must return it in memory. */
4271 reg = hard_function_value (type, 0, 0);
4273 /* If we have something other than a REG (e.g. a PARALLEL), then assume
4275 if (GET_CODE (reg) != REG)
4278 regno = REGNO (reg);
4279 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
4280 for (i = 0; i < nregs; i++)
4281 if (! call_used_regs[regno + i])
4286 /* Assign RTL expressions to the function's parameters.
4287 This may involve copying them into registers and using
4288 those registers as the RTL for them. */
4291 assign_parms (tree fndecl)
4294 CUMULATIVE_ARGS args_so_far;
4295 /* Total space needed so far for args on the stack,
4296 given as a constant and a tree-expression. */
4297 struct args_size stack_args_size;
4298 HOST_WIDE_INT extra_pretend_bytes = 0;
4299 tree fntype = TREE_TYPE (fndecl);
4300 tree fnargs = DECL_ARGUMENTS (fndecl), orig_fnargs;
4301 /* This is used for the arg pointer when referring to stack args. */
4302 rtx internal_arg_pointer;
4303 /* This is a dummy PARM_DECL that we used for the function result if
4304 the function returns a structure. */
4305 tree function_result_decl = 0;
4306 int varargs_setup = 0;
4307 int reg_parm_stack_space ATTRIBUTE_UNUSED = 0;
4308 rtx conversion_insns = 0;
4310 /* Nonzero if function takes extra anonymous args.
4311 This means the last named arg must be on the stack
4312 right before the anonymous ones. */
4314 = (TYPE_ARG_TYPES (fntype) != 0
4315 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
4316 != void_type_node));
4318 current_function_stdarg = stdarg;
4320 /* If the reg that the virtual arg pointer will be translated into is
4321 not a fixed reg or is the stack pointer, make a copy of the virtual
4322 arg pointer, and address parms via the copy. The frame pointer is
4323 considered fixed even though it is not marked as such.
4325 The second time through, simply use ap to avoid generating rtx. */
4327 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
4328 || ! (fixed_regs[ARG_POINTER_REGNUM]
4329 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
4330 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
4332 internal_arg_pointer = virtual_incoming_args_rtx;
4333 current_function_internal_arg_pointer = internal_arg_pointer;
4335 stack_args_size.constant = 0;
4336 stack_args_size.var = 0;
4338 /* If struct value address is treated as the first argument, make it so. */
4339 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
4340 && ! current_function_returns_pcc_struct
4341 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
4343 tree type = build_pointer_type (TREE_TYPE (fntype));
4345 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
4347 DECL_ARG_TYPE (function_result_decl) = type;
4348 TREE_CHAIN (function_result_decl) = fnargs;
4349 fnargs = function_result_decl;
4352 orig_fnargs = fnargs;
4354 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4355 parm_reg_stack_loc = ggc_alloc_cleared (max_parm_reg * sizeof (rtx));
4357 /* If the target wants to split complex arguments into scalars, do so. */
4358 if (targetm.calls.split_complex_arg)
4359 fnargs = split_complex_args (fnargs);
4361 #ifdef REG_PARM_STACK_SPACE
4362 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
4365 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
4366 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
4368 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, fndecl, -1);
4371 /* We haven't yet found an argument that we must push and pretend the
4373 current_function_pretend_args_size = 0;
4375 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
4379 enum machine_mode promoted_mode, passed_mode;
4380 enum machine_mode nominal_mode, promoted_nominal_mode;
4382 struct locate_and_pad_arg_data locate;
4383 int passed_pointer = 0;
4384 int did_conversion = 0;
4385 tree passed_type = DECL_ARG_TYPE (parm);
4386 tree nominal_type = TREE_TYPE (parm);
4387 int last_named = 0, named_arg;
4390 int pretend_bytes = 0;
4391 int loaded_in_reg = 0;
4393 /* Set LAST_NAMED if this is last named arg before last
4399 for (tem = TREE_CHAIN (parm); tem; tem = TREE_CHAIN (tem))
4400 if (DECL_NAME (tem))
4406 /* Set NAMED_ARG if this arg should be treated as a named arg. For
4407 most machines, if this is a varargs/stdarg function, then we treat
4408 the last named arg as if it were anonymous too. */
4409 named_arg = (targetm.calls.strict_argument_naming (&args_so_far)
4412 if (TREE_TYPE (parm) == error_mark_node
4413 /* This can happen after weird syntax errors
4414 or if an enum type is defined among the parms. */
4415 || TREE_CODE (parm) != PARM_DECL
4416 || passed_type == NULL)
4418 SET_DECL_RTL (parm, gen_rtx_MEM (BLKmode, const0_rtx));
4419 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4420 TREE_USED (parm) = 1;
4424 /* Find mode of arg as it is passed, and mode of arg
4425 as it should be during execution of this function. */
4426 passed_mode = TYPE_MODE (passed_type);
4427 nominal_mode = TYPE_MODE (nominal_type);
4429 /* If the parm's mode is VOID, its value doesn't matter,
4430 and avoid the usual things like emit_move_insn that could crash. */
4431 if (nominal_mode == VOIDmode)
4433 SET_DECL_RTL (parm, const0_rtx);
4434 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4438 /* If the parm is to be passed as a transparent union, use the
4439 type of the first field for the tests below. We have already
4440 verified that the modes are the same. */
4441 if (DECL_TRANSPARENT_UNION (parm)
4442 || (TREE_CODE (passed_type) == UNION_TYPE
4443 && TYPE_TRANSPARENT_UNION (passed_type)))
4444 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
4446 /* See if this arg was passed by invisible reference. It is if
4447 it is an object whose size depends on the contents of the
4448 object itself or if the machine requires these objects be passed
4451 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (passed_type))
4452 || TREE_ADDRESSABLE (passed_type)
4453 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
4454 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
4455 passed_type, named_arg)
4459 passed_type = nominal_type = build_pointer_type (passed_type);
4461 passed_mode = nominal_mode = Pmode;
4463 /* See if the frontend wants to pass this by invisible reference. */
4464 else if (passed_type != nominal_type
4465 && POINTER_TYPE_P (passed_type)
4466 && TREE_TYPE (passed_type) == nominal_type)
4468 nominal_type = passed_type;
4470 passed_mode = nominal_mode = Pmode;
4473 promoted_mode = passed_mode;
4475 if (targetm.calls.promote_function_args (TREE_TYPE (fndecl)))
4477 /* Compute the mode in which the arg is actually extended to. */
4478 unsignedp = TYPE_UNSIGNED (passed_type);
4479 promoted_mode = promote_mode (passed_type, promoted_mode,
4483 /* Let machine desc say which reg (if any) the parm arrives in.
4484 0 means it arrives on the stack. */
4485 #ifdef FUNCTION_INCOMING_ARG
4486 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4487 passed_type, named_arg);
4489 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
4490 passed_type, named_arg);
4493 if (entry_parm == 0)
4494 promoted_mode = passed_mode;
4496 /* If this is the last named parameter, do any required setup for
4497 varargs or stdargs. We need to know about the case of this being an
4498 addressable type, in which case we skip the registers it
4499 would have arrived in.
4501 For stdargs, LAST_NAMED will be set for two parameters, the one that
4502 is actually the last named, and the dummy parameter. We only
4503 want to do this action once.
4505 Also, indicate when RTL generation is to be suppressed. */
4506 if (last_named && !varargs_setup)
4508 int varargs_pretend_bytes = 0;
4509 targetm.calls.setup_incoming_varargs (&args_so_far, promoted_mode,
4511 &varargs_pretend_bytes, 0);
4514 /* If the back-end has requested extra stack space, record how
4515 much is needed. Do not change pretend_args_size otherwise
4516 since it may be nonzero from an earlier partial argument. */
4517 if (varargs_pretend_bytes > 0)
4518 current_function_pretend_args_size = varargs_pretend_bytes;
4521 /* Determine parm's home in the stack,
4522 in case it arrives in the stack or we should pretend it did.
4524 Compute the stack position and rtx where the argument arrives
4527 There is one complexity here: If this was a parameter that would
4528 have been passed in registers, but wasn't only because it is
4529 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
4530 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
4531 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
4532 0 as it was the previous time. */
4533 in_regs = entry_parm != 0;
4534 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4537 if (!in_regs && !named_arg)
4540 targetm.calls.pretend_outgoing_varargs_named (&args_so_far);
4543 #ifdef FUNCTION_INCOMING_ARG
4544 in_regs = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4546 pretend_named) != 0;
4548 in_regs = FUNCTION_ARG (args_so_far, promoted_mode,
4550 pretend_named) != 0;
4555 /* If this parameter was passed both in registers and in the stack,
4556 use the copy on the stack. */
4557 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
4560 #ifdef FUNCTION_ARG_PARTIAL_NREGS
4563 partial = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
4564 passed_type, named_arg);
4566 /* The caller might already have allocated stack space
4567 for the register parameters. */
4568 && reg_parm_stack_space == 0)
4570 /* Part of this argument is passed in registers and part
4571 is passed on the stack. Ask the prologue code to extend
4572 the stack part so that we can recreate the full value.
4574 PRETEND_BYTES is the size of the registers we need to store.
4575 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
4576 stack space that the prologue should allocate.
4578 Internally, gcc assumes that the argument pointer is
4579 aligned to STACK_BOUNDARY bits. This is used both for
4580 alignment optimizations (see init_emit) and to locate
4581 arguments that are aligned to more than PARM_BOUNDARY
4582 bits. We must preserve this invariant by rounding
4583 CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to a stack
4586 /* We assume at most one partial arg, and it must be the first
4587 argument on the stack. */
4588 if (extra_pretend_bytes || current_function_pretend_args_size)
4591 pretend_bytes = partial * UNITS_PER_WORD;
4592 current_function_pretend_args_size
4593 = CEIL_ROUND (pretend_bytes, STACK_BYTES);
4595 /* We want to align relative to the actual stack pointer, so
4596 don't include this in the stack size until later. */
4597 extra_pretend_bytes = current_function_pretend_args_size;
4602 memset (&locate, 0, sizeof (locate));
4603 locate_and_pad_parm (promoted_mode, passed_type, in_regs,
4604 entry_parm ? partial : 0, fndecl,
4605 &stack_args_size, &locate);
4606 /* Adjust offsets to include the pretend args. */
4607 locate.slot_offset.constant += extra_pretend_bytes - pretend_bytes;
4608 locate.offset.constant += extra_pretend_bytes - pretend_bytes;
4613 /* If we're passing this arg using a reg, make its stack home
4614 the aligned stack slot. */
4616 offset_rtx = ARGS_SIZE_RTX (locate.slot_offset);
4618 offset_rtx = ARGS_SIZE_RTX (locate.offset);
4620 if (offset_rtx == const0_rtx)
4621 stack_parm = gen_rtx_MEM (promoted_mode, internal_arg_pointer);
4623 stack_parm = gen_rtx_MEM (promoted_mode,
4624 gen_rtx_PLUS (Pmode,
4625 internal_arg_pointer,
4628 set_mem_attributes (stack_parm, parm, 1);
4629 if (entry_parm && MEM_ATTRS (stack_parm)->align < PARM_BOUNDARY)
4630 set_mem_align (stack_parm, PARM_BOUNDARY);
4632 /* Set also REG_ATTRS if parameter was passed in a register. */
4634 set_reg_attrs_for_parm (entry_parm, stack_parm);
4637 /* If this parm was passed part in regs and part in memory,
4638 pretend it arrived entirely in memory
4639 by pushing the register-part onto the stack.
4641 In the special case of a DImode or DFmode that is split,
4642 we could put it together in a pseudoreg directly,
4643 but for now that's not worth bothering with. */
4647 /* Handle calls that pass values in multiple non-contiguous
4648 locations. The Irix 6 ABI has examples of this. */
4649 if (GET_CODE (entry_parm) == PARALLEL)
4650 emit_group_store (validize_mem (stack_parm), entry_parm,
4652 int_size_in_bytes (TREE_TYPE (parm)));
4655 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
4658 entry_parm = stack_parm;
4661 /* If we didn't decide this parm came in a register,
4662 by default it came on the stack. */
4663 if (entry_parm == 0)
4664 entry_parm = stack_parm;
4666 /* Record permanently how this parm was passed. */
4667 set_decl_incoming_rtl (parm, entry_parm);
4669 /* If there is actually space on the stack for this parm,
4670 count it in stack_args_size; otherwise set stack_parm to 0
4671 to indicate there is no preallocated stack slot for the parm. */
4673 if (entry_parm == stack_parm
4674 || (GET_CODE (entry_parm) == PARALLEL
4675 && XEXP (XVECEXP (entry_parm, 0, 0), 0) == NULL_RTX)
4676 #if defined (REG_PARM_STACK_SPACE)
4677 /* On some machines, even if a parm value arrives in a register
4678 there is still an (uninitialized) stack slot allocated
4680 || REG_PARM_STACK_SPACE (fndecl) > 0
4684 stack_args_size.constant += locate.size.constant;
4685 if (locate.size.var)
4686 ADD_PARM_SIZE (stack_args_size, locate.size.var);
4689 /* No stack slot was pushed for this parm. */
4692 /* Update info on where next arg arrives in registers. */
4694 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
4695 passed_type, named_arg);
4697 /* If we can't trust the parm stack slot to be aligned enough
4698 for its ultimate type, don't use that slot after entry.
4699 We'll make another stack slot, if we need one. */
4701 unsigned int thisparm_boundary
4702 = FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type);
4704 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
4708 /* If parm was passed in memory, and we need to convert it on entry,
4709 don't store it back in that same slot. */
4710 if (entry_parm == stack_parm
4711 && nominal_mode != BLKmode && nominal_mode != passed_mode)
4714 /* When an argument is passed in multiple locations, we can't
4715 make use of this information, but we can save some copying if
4716 the whole argument is passed in a single register. */
4717 if (GET_CODE (entry_parm) == PARALLEL
4718 && nominal_mode != BLKmode && passed_mode != BLKmode)
4720 int i, len = XVECLEN (entry_parm, 0);
4722 for (i = 0; i < len; i++)
4723 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
4724 && GET_CODE (XEXP (XVECEXP (entry_parm, 0, i), 0)) == REG
4725 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
4727 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
4729 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
4730 set_decl_incoming_rtl (parm, entry_parm);
4735 /* ENTRY_PARM is an RTX for the parameter as it arrives,
4736 in the mode in which it arrives.
4737 STACK_PARM is an RTX for a stack slot where the parameter can live
4738 during the function (in case we want to put it there).
4739 STACK_PARM is 0 if no stack slot was pushed for it.
4741 Now output code if necessary to convert ENTRY_PARM to
4742 the type in which this function declares it,
4743 and store that result in an appropriate place,
4744 which may be a pseudo reg, may be STACK_PARM,
4745 or may be a local stack slot if STACK_PARM is 0.
4747 Set DECL_RTL to that place. */
4749 if (GET_CODE (entry_parm) == PARALLEL && nominal_mode != BLKmode
4750 && XVECLEN (entry_parm, 0) > 1)
4752 /* Reconstitute objects the size of a register or larger using
4753 register operations instead of the stack. */
4754 rtx parmreg = gen_reg_rtx (nominal_mode);
4756 if (REG_P (parmreg))
4758 unsigned int regno = REGNO (parmreg);
4760 emit_group_store (parmreg, entry_parm, TREE_TYPE (parm),
4761 int_size_in_bytes (TREE_TYPE (parm)));
4762 SET_DECL_RTL (parm, parmreg);
4765 if (regno >= max_parm_reg)
4768 int old_max_parm_reg = max_parm_reg;
4770 /* It's slow to expand this one register at a time,
4771 but it's also rare and we need max_parm_reg to be
4772 precisely correct. */
4773 max_parm_reg = regno + 1;
4774 new = ggc_realloc (parm_reg_stack_loc,
4775 max_parm_reg * sizeof (rtx));
4776 memset (new + old_max_parm_reg, 0,
4777 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
4778 parm_reg_stack_loc = new;
4779 parm_reg_stack_loc[regno] = stack_parm;
4784 if (nominal_mode == BLKmode
4785 #ifdef BLOCK_REG_PADDING
4786 || (locate.where_pad == (BYTES_BIG_ENDIAN ? upward : downward)
4787 && GET_MODE_SIZE (promoted_mode) < UNITS_PER_WORD)
4789 || GET_CODE (entry_parm) == PARALLEL)
4791 /* If a BLKmode arrives in registers, copy it to a stack slot.
4792 Handle calls that pass values in multiple non-contiguous
4793 locations. The Irix 6 ABI has examples of this. */
4794 if (GET_CODE (entry_parm) == REG
4795 || (GET_CODE (entry_parm) == PARALLEL
4796 && (!loaded_in_reg || !optimize)))
4798 int size = int_size_in_bytes (TREE_TYPE (parm));
4799 int size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
4802 /* Note that we will be storing an integral number of words.
4803 So we have to be careful to ensure that we allocate an
4804 integral number of words. We do this below in the
4805 assign_stack_local if space was not allocated in the argument
4806 list. If it was, this will not work if PARM_BOUNDARY is not
4807 a multiple of BITS_PER_WORD. It isn't clear how to fix this
4808 if it becomes a problem. Exception is when BLKmode arrives
4809 with arguments not conforming to word_mode. */
4811 if (stack_parm == 0)
4813 stack_parm = assign_stack_local (BLKmode, size_stored, 0);
4814 PUT_MODE (stack_parm, GET_MODE (entry_parm));
4815 set_mem_attributes (stack_parm, parm, 1);
4817 else if (GET_CODE (entry_parm) == PARALLEL
4818 && GET_MODE(entry_parm) == BLKmode)
4820 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
4823 mem = validize_mem (stack_parm);
4825 /* Handle calls that pass values in multiple non-contiguous
4826 locations. The Irix 6 ABI has examples of this. */
4827 if (GET_CODE (entry_parm) == PARALLEL)
4828 emit_group_store (mem, entry_parm, TREE_TYPE (parm), size);
4833 /* If SIZE is that of a mode no bigger than a word, just use
4834 that mode's store operation. */
4835 else if (size <= UNITS_PER_WORD)
4837 enum machine_mode mode
4838 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
4841 #ifdef BLOCK_REG_PADDING
4842 && (size == UNITS_PER_WORD
4843 || (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4844 != (BYTES_BIG_ENDIAN ? upward : downward)))
4848 rtx reg = gen_rtx_REG (mode, REGNO (entry_parm));
4849 emit_move_insn (change_address (mem, mode, 0), reg);
4852 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
4853 machine must be aligned to the left before storing
4854 to memory. Note that the previous test doesn't
4855 handle all cases (e.g. SIZE == 3). */
4856 else if (size != UNITS_PER_WORD
4857 #ifdef BLOCK_REG_PADDING
4858 && (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4866 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
4867 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
4869 x = expand_binop (word_mode, ashl_optab, reg,
4870 GEN_INT (by), 0, 1, OPTAB_WIDEN);
4871 tem = change_address (mem, word_mode, 0);
4872 emit_move_insn (tem, x);
4875 move_block_from_reg (REGNO (entry_parm), mem,
4876 size_stored / UNITS_PER_WORD);
4879 move_block_from_reg (REGNO (entry_parm), mem,
4880 size_stored / UNITS_PER_WORD);
4882 /* If parm is already bound to register pair, don't change
4884 if (! DECL_RTL_SET_P (parm))
4885 SET_DECL_RTL (parm, stack_parm);
4887 else if (! ((! optimize
4888 && ! DECL_REGISTER (parm))
4889 || TREE_SIDE_EFFECTS (parm)
4890 /* If -ffloat-store specified, don't put explicit
4891 float variables into registers. */
4892 || (flag_float_store
4893 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
4894 /* Always assign pseudo to structure return or item passed
4895 by invisible reference. */
4896 || passed_pointer || parm == function_result_decl)
4898 /* Store the parm in a pseudoregister during the function, but we
4899 may need to do it in a wider mode. */
4902 unsigned int regno, regnoi = 0, regnor = 0;
4904 unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
4906 promoted_nominal_mode
4907 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
4909 parmreg = gen_reg_rtx (promoted_nominal_mode);
4910 mark_user_reg (parmreg);
4912 /* If this was an item that we received a pointer to, set DECL_RTL
4916 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (passed_type)),
4918 set_mem_attributes (x, parm, 1);
4919 SET_DECL_RTL (parm, x);
4923 SET_DECL_RTL (parm, parmreg);
4924 maybe_set_unchanging (DECL_RTL (parm), parm);
4927 /* Copy the value into the register. */
4928 if (nominal_mode != passed_mode
4929 || promoted_nominal_mode != promoted_mode)
4932 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
4933 mode, by the caller. We now have to convert it to
4934 NOMINAL_MODE, if different. However, PARMREG may be in
4935 a different mode than NOMINAL_MODE if it is being stored
4938 If ENTRY_PARM is a hard register, it might be in a register
4939 not valid for operating in its mode (e.g., an odd-numbered
4940 register for a DFmode). In that case, moves are the only
4941 thing valid, so we can't do a convert from there. This
4942 occurs when the calling sequence allow such misaligned
4945 In addition, the conversion may involve a call, which could
4946 clobber parameters which haven't been copied to pseudo
4947 registers yet. Therefore, we must first copy the parm to
4948 a pseudo reg here, and save the conversion until after all
4949 parameters have been moved. */
4951 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4953 emit_move_insn (tempreg, validize_mem (entry_parm));
4955 push_to_sequence (conversion_insns);
4956 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
4958 if (GET_CODE (tempreg) == SUBREG
4959 && GET_MODE (tempreg) == nominal_mode
4960 && GET_CODE (SUBREG_REG (tempreg)) == REG
4961 && nominal_mode == passed_mode
4962 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (entry_parm)
4963 && GET_MODE_SIZE (GET_MODE (tempreg))
4964 < GET_MODE_SIZE (GET_MODE (entry_parm)))
4966 /* The argument is already sign/zero extended, so note it
4968 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
4969 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
4972 /* TREE_USED gets set erroneously during expand_assignment. */
4973 save_tree_used = TREE_USED (parm);
4974 expand_assignment (parm,
4975 make_tree (nominal_type, tempreg), 0);
4976 TREE_USED (parm) = save_tree_used;
4977 conversion_insns = get_insns ();
4982 emit_move_insn (parmreg, validize_mem (entry_parm));
4984 /* If we were passed a pointer but the actual value
4985 can safely live in a register, put it in one. */
4986 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
4987 /* If by-reference argument was promoted, demote it. */
4988 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
4990 && ! DECL_REGISTER (parm))
4991 || TREE_SIDE_EFFECTS (parm)
4992 /* If -ffloat-store specified, don't put explicit
4993 float variables into registers. */
4994 || (flag_float_store
4995 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))))
4997 /* We can't use nominal_mode, because it will have been set to
4998 Pmode above. We must use the actual mode of the parm. */
4999 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
5000 mark_user_reg (parmreg);
5001 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
5003 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
5004 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
5005 push_to_sequence (conversion_insns);
5006 emit_move_insn (tempreg, DECL_RTL (parm));
5008 convert_to_mode (GET_MODE (parmreg),
5011 emit_move_insn (parmreg, DECL_RTL (parm));
5012 conversion_insns = get_insns();
5017 emit_move_insn (parmreg, DECL_RTL (parm));
5018 SET_DECL_RTL (parm, parmreg);
5019 /* STACK_PARM is the pointer, not the parm, and PARMREG is
5023 #ifdef FUNCTION_ARG_CALLEE_COPIES
5024 /* If we are passed an arg by reference and it is our responsibility
5025 to make a copy, do it now.
5026 PASSED_TYPE and PASSED mode now refer to the pointer, not the
5027 original argument, so we must recreate them in the call to
5028 FUNCTION_ARG_CALLEE_COPIES. */
5029 /* ??? Later add code to handle the case that if the argument isn't
5030 modified, don't do the copy. */
5032 else if (passed_pointer
5033 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
5034 TYPE_MODE (TREE_TYPE (passed_type)),
5035 TREE_TYPE (passed_type),
5037 && ! TREE_ADDRESSABLE (TREE_TYPE (passed_type)))
5040 tree type = TREE_TYPE (passed_type);
5042 /* This sequence may involve a library call perhaps clobbering
5043 registers that haven't been copied to pseudos yet. */
5045 push_to_sequence (conversion_insns);
5047 if (!COMPLETE_TYPE_P (type)
5048 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5049 /* This is a variable sized object. */
5050 copy = gen_rtx_MEM (BLKmode,
5051 allocate_dynamic_stack_space
5052 (expr_size (parm), NULL_RTX,
5053 TYPE_ALIGN (type)));
5055 copy = assign_stack_temp (TYPE_MODE (type),
5056 int_size_in_bytes (type), 1);
5057 set_mem_attributes (copy, parm, 1);
5059 store_expr (parm, copy, 0);
5060 emit_move_insn (parmreg, XEXP (copy, 0));
5061 conversion_insns = get_insns ();
5065 #endif /* FUNCTION_ARG_CALLEE_COPIES */
5067 /* In any case, record the parm's desired stack location
5068 in case we later discover it must live in the stack.
5070 If it is a COMPLEX value, store the stack location for both
5073 if (GET_CODE (parmreg) == CONCAT)
5074 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
5076 regno = REGNO (parmreg);
5078 if (regno >= max_parm_reg)
5081 int old_max_parm_reg = max_parm_reg;
5083 /* It's slow to expand this one register at a time,
5084 but it's also rare and we need max_parm_reg to be
5085 precisely correct. */
5086 max_parm_reg = regno + 1;
5087 new = ggc_realloc (parm_reg_stack_loc,
5088 max_parm_reg * sizeof (rtx));
5089 memset (new + old_max_parm_reg, 0,
5090 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
5091 parm_reg_stack_loc = new;
5094 if (GET_CODE (parmreg) == CONCAT)
5096 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
5098 regnor = REGNO (gen_realpart (submode, parmreg));
5099 regnoi = REGNO (gen_imagpart (submode, parmreg));
5101 if (stack_parm != 0)
5103 parm_reg_stack_loc[regnor]
5104 = gen_realpart (submode, stack_parm);
5105 parm_reg_stack_loc[regnoi]
5106 = gen_imagpart (submode, stack_parm);
5110 parm_reg_stack_loc[regnor] = 0;
5111 parm_reg_stack_loc[regnoi] = 0;
5115 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
5117 /* Mark the register as eliminable if we did no conversion
5118 and it was copied from memory at a fixed offset,
5119 and the arg pointer was not copied to a pseudo-reg.
5120 If the arg pointer is a pseudo reg or the offset formed
5121 an invalid address, such memory-equivalences
5122 as we make here would screw up life analysis for it. */
5123 if (nominal_mode == passed_mode
5126 && GET_CODE (stack_parm) == MEM
5127 && locate.offset.var == 0
5128 && reg_mentioned_p (virtual_incoming_args_rtx,
5129 XEXP (stack_parm, 0)))
5131 rtx linsn = get_last_insn ();
5134 /* Mark complex types separately. */
5135 if (GET_CODE (parmreg) == CONCAT)
5136 /* Scan backwards for the set of the real and
5138 for (sinsn = linsn; sinsn != 0;
5139 sinsn = prev_nonnote_insn (sinsn))
5141 set = single_set (sinsn);
5143 && SET_DEST (set) == regno_reg_rtx [regnoi])
5145 = gen_rtx_EXPR_LIST (REG_EQUIV,
5146 parm_reg_stack_loc[regnoi],
5149 && SET_DEST (set) == regno_reg_rtx [regnor])
5151 = gen_rtx_EXPR_LIST (REG_EQUIV,
5152 parm_reg_stack_loc[regnor],
5155 else if ((set = single_set (linsn)) != 0
5156 && SET_DEST (set) == parmreg)
5158 = gen_rtx_EXPR_LIST (REG_EQUIV,
5159 stack_parm, REG_NOTES (linsn));
5162 /* For pointer data type, suggest pointer register. */
5163 if (POINTER_TYPE_P (TREE_TYPE (parm)))
5164 mark_reg_pointer (parmreg,
5165 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5167 /* If something wants our address, try to use ADDRESSOF. */
5168 if (TREE_ADDRESSABLE (parm))
5170 /* If we end up putting something into the stack,
5171 fixup_var_refs_insns will need to make a pass over
5172 all the instructions. It looks through the pending
5173 sequences -- but it can't see the ones in the
5174 CONVERSION_INSNS, if they're not on the sequence
5175 stack. So, we go back to that sequence, just so that
5176 the fixups will happen. */
5177 push_to_sequence (conversion_insns);
5178 put_var_into_stack (parm, /*rescan=*/true);
5179 conversion_insns = get_insns ();
5185 /* Value must be stored in the stack slot STACK_PARM
5186 during function execution. */
5188 if (promoted_mode != nominal_mode)
5190 /* Conversion is required. */
5191 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
5193 emit_move_insn (tempreg, validize_mem (entry_parm));
5195 push_to_sequence (conversion_insns);
5196 entry_parm = convert_to_mode (nominal_mode, tempreg,
5197 TYPE_UNSIGNED (TREE_TYPE (parm)));
5199 /* ??? This may need a big-endian conversion on sparc64. */
5200 stack_parm = adjust_address (stack_parm, nominal_mode, 0);
5202 conversion_insns = get_insns ();
5207 if (entry_parm != stack_parm)
5209 if (stack_parm == 0)
5212 = assign_stack_local (GET_MODE (entry_parm),
5213 GET_MODE_SIZE (GET_MODE (entry_parm)),
5215 set_mem_attributes (stack_parm, parm, 1);
5218 if (promoted_mode != nominal_mode)
5220 push_to_sequence (conversion_insns);
5221 emit_move_insn (validize_mem (stack_parm),
5222 validize_mem (entry_parm));
5223 conversion_insns = get_insns ();
5227 emit_move_insn (validize_mem (stack_parm),
5228 validize_mem (entry_parm));
5231 SET_DECL_RTL (parm, stack_parm);
5235 if (targetm.calls.split_complex_arg && fnargs != orig_fnargs)
5237 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
5239 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
5240 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
5242 rtx tmp, real, imag;
5243 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
5245 real = DECL_RTL (fnargs);
5246 imag = DECL_RTL (TREE_CHAIN (fnargs));
5247 if (inner != GET_MODE (real))
5249 real = gen_lowpart_SUBREG (inner, real);
5250 imag = gen_lowpart_SUBREG (inner, imag);
5252 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
5253 SET_DECL_RTL (parm, tmp);
5255 real = DECL_INCOMING_RTL (fnargs);
5256 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
5257 if (inner != GET_MODE (real))
5259 real = gen_lowpart_SUBREG (inner, real);
5260 imag = gen_lowpart_SUBREG (inner, imag);
5262 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
5263 set_decl_incoming_rtl (parm, tmp);
5264 fnargs = TREE_CHAIN (fnargs);
5268 SET_DECL_RTL (parm, DECL_RTL (fnargs));
5269 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs));
5271 /* Set MEM_EXPR to the original decl, i.e. to PARM,
5272 instead of the copy of decl, i.e. FNARGS. */
5273 if (DECL_INCOMING_RTL (parm)
5274 && GET_CODE (DECL_INCOMING_RTL (parm)) == MEM)
5275 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
5277 fnargs = TREE_CHAIN (fnargs);
5281 /* Output all parameter conversion instructions (possibly including calls)
5282 now that all parameters have been copied out of hard registers. */
5283 emit_insn (conversion_insns);
5285 /* If we are receiving a struct value address as the first argument, set up
5286 the RTL for the function result. As this might require code to convert
5287 the transmitted address to Pmode, we do this here to ensure that possible
5288 preliminary conversions of the address have been emitted already. */
5289 if (function_result_decl)
5291 tree result = DECL_RESULT (fndecl);
5292 rtx addr = DECL_RTL (function_result_decl);
5295 addr = convert_memory_address (Pmode, addr);
5296 x = gen_rtx_MEM (DECL_MODE (result), addr);
5297 set_mem_attributes (x, result, 1);
5298 SET_DECL_RTL (result, x);
5301 last_parm_insn = get_last_insn ();
5303 /* We have aligned all the args, so add space for the pretend args. */
5304 stack_args_size.constant += extra_pretend_bytes;
5305 current_function_args_size = stack_args_size.constant;
5307 /* Adjust function incoming argument size for alignment and
5310 #ifdef REG_PARM_STACK_SPACE
5311 current_function_args_size = MAX (current_function_args_size,
5312 REG_PARM_STACK_SPACE (fndecl));
5315 current_function_args_size
5316 = ((current_function_args_size + STACK_BYTES - 1)
5317 / STACK_BYTES) * STACK_BYTES;
5319 #ifdef ARGS_GROW_DOWNWARD
5320 current_function_arg_offset_rtx
5321 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
5322 : expand_expr (size_diffop (stack_args_size.var,
5323 size_int (-stack_args_size.constant)),
5324 NULL_RTX, VOIDmode, 0));
5326 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
5329 /* See how many bytes, if any, of its args a function should try to pop
5332 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
5333 current_function_args_size);
5335 /* For stdarg.h function, save info about
5336 regs and stack space used by the named args. */
5338 current_function_args_info = args_so_far;
5340 /* Set the rtx used for the function return value. Put this in its
5341 own variable so any optimizers that need this information don't have
5342 to include tree.h. Do this here so it gets done when an inlined
5343 function gets output. */
5345 current_function_return_rtx
5346 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
5347 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
5349 /* If scalar return value was computed in a pseudo-reg, or was a named
5350 return value that got dumped to the stack, copy that to the hard
5352 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
5354 tree decl_result = DECL_RESULT (fndecl);
5355 rtx decl_rtl = DECL_RTL (decl_result);
5357 if (REG_P (decl_rtl)
5358 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5359 : DECL_REGISTER (decl_result))
5363 #ifdef FUNCTION_OUTGOING_VALUE
5364 real_decl_rtl = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl_result),
5367 real_decl_rtl = FUNCTION_VALUE (TREE_TYPE (decl_result),
5370 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
5371 /* The delay slot scheduler assumes that current_function_return_rtx
5372 holds the hard register containing the return value, not a
5373 temporary pseudo. */
5374 current_function_return_rtx = real_decl_rtl;
5379 /* If ARGS contains entries with complex types, split the entry into two
5380 entries of the component type. Return a new list of substitutions are
5381 needed, else the old list. */
5384 split_complex_args (tree args)
5388 /* Before allocating memory, check for the common case of no complex. */
5389 for (p = args; p; p = TREE_CHAIN (p))
5391 tree type = TREE_TYPE (p);
5392 if (TREE_CODE (type) == COMPLEX_TYPE
5393 && targetm.calls.split_complex_arg (type))
5399 args = copy_list (args);
5401 for (p = args; p; p = TREE_CHAIN (p))
5403 tree type = TREE_TYPE (p);
5404 if (TREE_CODE (type) == COMPLEX_TYPE
5405 && targetm.calls.split_complex_arg (type))
5408 tree subtype = TREE_TYPE (type);
5410 /* Rewrite the PARM_DECL's type with its component. */
5411 TREE_TYPE (p) = subtype;
5412 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
5413 DECL_MODE (p) = VOIDmode;
5414 DECL_SIZE (p) = NULL;
5415 DECL_SIZE_UNIT (p) = NULL;
5418 /* Build a second synthetic decl. */
5419 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
5420 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
5421 layout_decl (decl, 0);
5423 /* Splice it in; skip the new decl. */
5424 TREE_CHAIN (decl) = TREE_CHAIN (p);
5425 TREE_CHAIN (p) = decl;
5433 /* Indicate whether REGNO is an incoming argument to the current function
5434 that was promoted to a wider mode. If so, return the RTX for the
5435 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
5436 that REGNO is promoted from and whether the promotion was signed or
5440 promoted_input_arg (unsigned int regno, enum machine_mode *pmode, int *punsignedp)
5444 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
5445 arg = TREE_CHAIN (arg))
5446 if (GET_CODE (DECL_INCOMING_RTL (arg)) == REG
5447 && REGNO (DECL_INCOMING_RTL (arg)) == regno
5448 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
5450 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
5451 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (arg));
5453 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
5454 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
5455 && mode != DECL_MODE (arg))
5457 *pmode = DECL_MODE (arg);
5458 *punsignedp = unsignedp;
5459 return DECL_INCOMING_RTL (arg);
5467 /* Compute the size and offset from the start of the stacked arguments for a
5468 parm passed in mode PASSED_MODE and with type TYPE.
5470 INITIAL_OFFSET_PTR points to the current offset into the stacked
5473 The starting offset and size for this parm are returned in
5474 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
5475 nonzero, the offset is that of stack slot, which is returned in
5476 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
5477 padding required from the initial offset ptr to the stack slot.
5479 IN_REGS is nonzero if the argument will be passed in registers. It will
5480 never be set if REG_PARM_STACK_SPACE is not defined.
5482 FNDECL is the function in which the argument was defined.
5484 There are two types of rounding that are done. The first, controlled by
5485 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
5486 list to be aligned to the specific boundary (in bits). This rounding
5487 affects the initial and starting offsets, but not the argument size.
5489 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
5490 optionally rounds the size of the parm to PARM_BOUNDARY. The
5491 initial offset is not affected by this rounding, while the size always
5492 is and the starting offset may be. */
5494 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
5495 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
5496 callers pass in the total size of args so far as
5497 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
5500 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
5501 int partial, tree fndecl ATTRIBUTE_UNUSED,
5502 struct args_size *initial_offset_ptr,
5503 struct locate_and_pad_arg_data *locate)
5506 enum direction where_pad;
5508 int reg_parm_stack_space = 0;
5509 int part_size_in_regs;
5511 #ifdef REG_PARM_STACK_SPACE
5512 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
5514 /* If we have found a stack parm before we reach the end of the
5515 area reserved for registers, skip that area. */
5518 if (reg_parm_stack_space > 0)
5520 if (initial_offset_ptr->var)
5522 initial_offset_ptr->var
5523 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
5524 ssize_int (reg_parm_stack_space));
5525 initial_offset_ptr->constant = 0;
5527 else if (initial_offset_ptr->constant < reg_parm_stack_space)
5528 initial_offset_ptr->constant = reg_parm_stack_space;
5531 #endif /* REG_PARM_STACK_SPACE */
5533 part_size_in_regs = 0;
5534 if (reg_parm_stack_space == 0)
5535 part_size_in_regs = ((partial * UNITS_PER_WORD)
5536 / (PARM_BOUNDARY / BITS_PER_UNIT)
5537 * (PARM_BOUNDARY / BITS_PER_UNIT));
5540 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
5541 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
5542 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
5543 locate->where_pad = where_pad;
5545 #ifdef ARGS_GROW_DOWNWARD
5546 locate->slot_offset.constant = -initial_offset_ptr->constant;
5547 if (initial_offset_ptr->var)
5548 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
5549 initial_offset_ptr->var);
5553 if (where_pad != none
5554 && (!host_integerp (sizetree, 1)
5555 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5556 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
5557 SUB_PARM_SIZE (locate->slot_offset, s2);
5560 locate->slot_offset.constant += part_size_in_regs;
5563 #ifdef REG_PARM_STACK_SPACE
5564 || REG_PARM_STACK_SPACE (fndecl) > 0
5567 pad_to_arg_alignment (&locate->slot_offset, boundary,
5568 &locate->alignment_pad);
5570 locate->size.constant = (-initial_offset_ptr->constant
5571 - locate->slot_offset.constant);
5572 if (initial_offset_ptr->var)
5573 locate->size.var = size_binop (MINUS_EXPR,
5574 size_binop (MINUS_EXPR,
5576 initial_offset_ptr->var),
5577 locate->slot_offset.var);
5579 /* Pad_below needs the pre-rounded size to know how much to pad
5581 locate->offset = locate->slot_offset;
5582 if (where_pad == downward)
5583 pad_below (&locate->offset, passed_mode, sizetree);
5585 #else /* !ARGS_GROW_DOWNWARD */
5587 #ifdef REG_PARM_STACK_SPACE
5588 || REG_PARM_STACK_SPACE (fndecl) > 0
5591 pad_to_arg_alignment (initial_offset_ptr, boundary,
5592 &locate->alignment_pad);
5593 locate->slot_offset = *initial_offset_ptr;
5595 #ifdef PUSH_ROUNDING
5596 if (passed_mode != BLKmode)
5597 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
5600 /* Pad_below needs the pre-rounded size to know how much to pad below
5601 so this must be done before rounding up. */
5602 locate->offset = locate->slot_offset;
5603 if (where_pad == downward)
5604 pad_below (&locate->offset, passed_mode, sizetree);
5606 if (where_pad != none
5607 && (!host_integerp (sizetree, 1)
5608 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5609 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5611 ADD_PARM_SIZE (locate->size, sizetree);
5613 locate->size.constant -= part_size_in_regs;
5614 #endif /* ARGS_GROW_DOWNWARD */
5617 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
5618 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
5621 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
5622 struct args_size *alignment_pad)
5624 tree save_var = NULL_TREE;
5625 HOST_WIDE_INT save_constant = 0;
5626 int boundary_in_bytes = boundary / BITS_PER_UNIT;
5627 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
5629 #ifdef SPARC_STACK_BOUNDARY_HACK
5630 /* The sparc port has a bug. It sometimes claims a STACK_BOUNDARY
5631 higher than the real alignment of %sp. However, when it does this,
5632 the alignment of %sp+STACK_POINTER_OFFSET will be STACK_BOUNDARY.
5633 This is a temporary hack while the sparc port is fixed. */
5634 if (SPARC_STACK_BOUNDARY_HACK)
5638 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5640 save_var = offset_ptr->var;
5641 save_constant = offset_ptr->constant;
5644 alignment_pad->var = NULL_TREE;
5645 alignment_pad->constant = 0;
5647 if (boundary > BITS_PER_UNIT)
5649 if (offset_ptr->var)
5651 tree sp_offset_tree = ssize_int (sp_offset);
5652 tree offset = size_binop (PLUS_EXPR,
5653 ARGS_SIZE_TREE (*offset_ptr),
5655 #ifdef ARGS_GROW_DOWNWARD
5656 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
5658 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
5661 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
5662 /* ARGS_SIZE_TREE includes constant term. */
5663 offset_ptr->constant = 0;
5664 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5665 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
5670 offset_ptr->constant = -sp_offset +
5671 #ifdef ARGS_GROW_DOWNWARD
5672 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5674 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5676 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5677 alignment_pad->constant = offset_ptr->constant - save_constant;
5683 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
5685 if (passed_mode != BLKmode)
5687 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
5688 offset_ptr->constant
5689 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
5690 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
5691 - GET_MODE_SIZE (passed_mode));
5695 if (TREE_CODE (sizetree) != INTEGER_CST
5696 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
5698 /* Round the size up to multiple of PARM_BOUNDARY bits. */
5699 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5701 ADD_PARM_SIZE (*offset_ptr, s2);
5702 SUB_PARM_SIZE (*offset_ptr, sizetree);
5707 /* Walk the tree of blocks describing the binding levels within a function
5708 and warn about uninitialized variables.
5709 This is done after calling flow_analysis and before global_alloc
5710 clobbers the pseudo-regs to hard regs. */
5713 uninitialized_vars_warning (tree block)
5716 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5718 if (warn_uninitialized
5719 && TREE_CODE (decl) == VAR_DECL
5720 /* These warnings are unreliable for and aggregates
5721 because assigning the fields one by one can fail to convince
5722 flow.c that the entire aggregate was initialized.
5723 Unions are troublesome because members may be shorter. */
5724 && ! AGGREGATE_TYPE_P (TREE_TYPE (decl))
5725 && DECL_RTL_SET_P (decl)
5726 && GET_CODE (DECL_RTL (decl)) == REG
5727 /* Global optimizations can make it difficult to determine if a
5728 particular variable has been initialized. However, a VAR_DECL
5729 with a nonzero DECL_INITIAL had an initializer, so do not
5730 claim it is potentially uninitialized.
5732 When the DECL_INITIAL is NULL call the language hook to tell us
5733 if we want to warn. */
5734 && (DECL_INITIAL (decl) == NULL_TREE || lang_hooks.decl_uninit (decl))
5735 && regno_uninitialized (REGNO (DECL_RTL (decl))))
5736 warning ("%J'%D' might be used uninitialized in this function",
5739 && TREE_CODE (decl) == VAR_DECL
5740 && DECL_RTL_SET_P (decl)
5741 && GET_CODE (DECL_RTL (decl)) == REG
5742 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5743 warning ("%Jvariable '%D' might be clobbered by `longjmp' or `vfork'",
5746 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5747 uninitialized_vars_warning (sub);
5750 /* Do the appropriate part of uninitialized_vars_warning
5751 but for arguments instead of local variables. */
5754 setjmp_args_warning (void)
5757 for (decl = DECL_ARGUMENTS (current_function_decl);
5758 decl; decl = TREE_CHAIN (decl))
5759 if (DECL_RTL (decl) != 0
5760 && GET_CODE (DECL_RTL (decl)) == REG
5761 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5762 warning ("%Jargument '%D' might be clobbered by `longjmp' or `vfork'",
5766 /* If this function call setjmp, put all vars into the stack
5767 unless they were declared `register'. */
5770 setjmp_protect (tree block)
5773 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5774 if ((TREE_CODE (decl) == VAR_DECL
5775 || TREE_CODE (decl) == PARM_DECL)
5776 && DECL_RTL (decl) != 0
5777 && (GET_CODE (DECL_RTL (decl)) == REG
5778 || (GET_CODE (DECL_RTL (decl)) == MEM
5779 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5780 /* If this variable came from an inline function, it must be
5781 that its life doesn't overlap the setjmp. If there was a
5782 setjmp in the function, it would already be in memory. We
5783 must exclude such variable because their DECL_RTL might be
5784 set to strange things such as virtual_stack_vars_rtx. */
5785 && ! DECL_FROM_INLINE (decl)
5787 #ifdef NON_SAVING_SETJMP
5788 /* If longjmp doesn't restore the registers,
5789 don't put anything in them. */
5793 ! DECL_REGISTER (decl)))
5794 put_var_into_stack (decl, /*rescan=*/true);
5795 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5796 setjmp_protect (sub);
5799 /* Like the previous function, but for args instead of local variables. */
5802 setjmp_protect_args (void)
5805 for (decl = DECL_ARGUMENTS (current_function_decl);
5806 decl; decl = TREE_CHAIN (decl))
5807 if ((TREE_CODE (decl) == VAR_DECL
5808 || TREE_CODE (decl) == PARM_DECL)
5809 && DECL_RTL (decl) != 0
5810 && (GET_CODE (DECL_RTL (decl)) == REG
5811 || (GET_CODE (DECL_RTL (decl)) == MEM
5812 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5814 /* If longjmp doesn't restore the registers,
5815 don't put anything in them. */
5816 #ifdef NON_SAVING_SETJMP
5820 ! DECL_REGISTER (decl)))
5821 put_var_into_stack (decl, /*rescan=*/true);
5824 /* Return the context-pointer register corresponding to DECL,
5825 or 0 if it does not need one. */
5828 lookup_static_chain (tree decl)
5830 tree context = decl_function_context (decl);
5834 || (TREE_CODE (decl) == FUNCTION_DECL && DECL_NO_STATIC_CHAIN (decl)))
5837 /* We treat inline_function_decl as an alias for the current function
5838 because that is the inline function whose vars, types, etc.
5839 are being merged into the current function.
5840 See expand_inline_function. */
5841 if (context == current_function_decl || context == inline_function_decl)
5842 return virtual_stack_vars_rtx;
5844 for (link = context_display; link; link = TREE_CHAIN (link))
5845 if (TREE_PURPOSE (link) == context)
5846 return RTL_EXPR_RTL (TREE_VALUE (link));
5851 /* Convert a stack slot address ADDR for variable VAR
5852 (from a containing function)
5853 into an address valid in this function (using a static chain). */
5856 fix_lexical_addr (rtx addr, tree var)
5859 HOST_WIDE_INT displacement;
5860 tree context = decl_function_context (var);
5861 struct function *fp;
5864 /* If this is the present function, we need not do anything. */
5865 if (context == current_function_decl || context == inline_function_decl)
5868 fp = find_function_data (context);
5870 if (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == MEM)
5871 addr = XEXP (XEXP (addr, 0), 0);
5873 /* Decode given address as base reg plus displacement. */
5874 if (GET_CODE (addr) == REG)
5875 basereg = addr, displacement = 0;
5876 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
5877 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
5881 /* We accept vars reached via the containing function's
5882 incoming arg pointer and via its stack variables pointer. */
5883 if (basereg == fp->internal_arg_pointer)
5885 /* If reached via arg pointer, get the arg pointer value
5886 out of that function's stack frame.
5888 There are two cases: If a separate ap is needed, allocate a
5889 slot in the outer function for it and dereference it that way.
5890 This is correct even if the real ap is actually a pseudo.
5891 Otherwise, just adjust the offset from the frame pointer to
5894 #ifdef NEED_SEPARATE_AP
5897 addr = get_arg_pointer_save_area (fp);
5898 addr = fix_lexical_addr (XEXP (addr, 0), var);
5899 addr = memory_address (Pmode, addr);
5901 base = gen_rtx_MEM (Pmode, addr);
5902 set_mem_alias_set (base, get_frame_alias_set ());
5903 base = copy_to_reg (base);
5905 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
5906 base = lookup_static_chain (var);
5910 else if (basereg == virtual_stack_vars_rtx)
5912 /* This is the same code as lookup_static_chain, duplicated here to
5913 avoid an extra call to decl_function_context. */
5916 for (link = context_display; link; link = TREE_CHAIN (link))
5917 if (TREE_PURPOSE (link) == context)
5919 base = RTL_EXPR_RTL (TREE_VALUE (link));
5927 /* Use same offset, relative to appropriate static chain or argument
5929 return plus_constant (base, displacement);
5932 /* Return the address of the trampoline for entering nested fn FUNCTION.
5933 If necessary, allocate a trampoline (in the stack frame)
5934 and emit rtl to initialize its contents (at entry to this function). */
5937 trampoline_address (tree function)
5942 struct function *fp;
5945 /* Find an existing trampoline and return it. */
5946 for (link = trampoline_list; link; link = TREE_CHAIN (link))
5947 if (TREE_PURPOSE (link) == function)
5949 adjust_trampoline_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0));
5951 for (fp = outer_function_chain; fp; fp = fp->outer)
5952 for (link = fp->x_trampoline_list; link; link = TREE_CHAIN (link))
5953 if (TREE_PURPOSE (link) == function)
5955 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
5957 return adjust_trampoline_addr (tramp);
5960 /* None exists; we must make one. */
5962 /* Find the `struct function' for the function containing FUNCTION. */
5964 fn_context = decl_function_context (function);
5965 if (fn_context != current_function_decl
5966 && fn_context != inline_function_decl)
5967 fp = find_function_data (fn_context);
5969 /* Allocate run-time space for this trampoline. */
5970 /* If rounding needed, allocate extra space
5971 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
5972 #define TRAMPOLINE_REAL_SIZE \
5973 (TRAMPOLINE_SIZE + (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT) - 1)
5974 tramp = assign_stack_local_1 (BLKmode, TRAMPOLINE_REAL_SIZE, 0,
5976 /* Record the trampoline for reuse and note it for later initialization
5977 by expand_function_end. */
5980 rtlexp = make_node (RTL_EXPR);
5981 RTL_EXPR_RTL (rtlexp) = tramp;
5982 fp->x_trampoline_list = tree_cons (function, rtlexp,
5983 fp->x_trampoline_list);
5987 /* Make the RTL_EXPR node temporary, not momentary, so that the
5988 trampoline_list doesn't become garbage. */
5989 rtlexp = make_node (RTL_EXPR);
5991 RTL_EXPR_RTL (rtlexp) = tramp;
5992 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
5995 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
5996 return adjust_trampoline_addr (tramp);
5999 /* Given a trampoline address,
6000 round it to multiple of TRAMPOLINE_ALIGNMENT. */
6003 round_trampoline_addr (rtx tramp)
6005 /* Round address up to desired boundary. */
6006 rtx temp = gen_reg_rtx (Pmode);
6007 rtx addend = GEN_INT (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT - 1);
6008 rtx mask = GEN_INT (-TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
6010 temp = expand_simple_binop (Pmode, PLUS, tramp, addend,
6011 temp, 0, OPTAB_LIB_WIDEN);
6012 tramp = expand_simple_binop (Pmode, AND, temp, mask,
6013 temp, 0, OPTAB_LIB_WIDEN);
6018 /* Given a trampoline address, round it then apply any
6019 platform-specific adjustments so that the result can be used for a
6023 adjust_trampoline_addr (rtx tramp)
6025 tramp = round_trampoline_addr (tramp);
6026 #ifdef TRAMPOLINE_ADJUST_ADDRESS
6027 TRAMPOLINE_ADJUST_ADDRESS (tramp);
6032 /* Put all this function's BLOCK nodes including those that are chained
6033 onto the first block into a vector, and return it.
6034 Also store in each NOTE for the beginning or end of a block
6035 the index of that block in the vector.
6036 The arguments are BLOCK, the chain of top-level blocks of the function,
6037 and INSNS, the insn chain of the function. */
6040 identify_blocks (void)
6043 tree *block_vector, *last_block_vector;
6045 tree block = DECL_INITIAL (current_function_decl);
6050 /* Fill the BLOCK_VECTOR with all of the BLOCKs in this function, in
6051 depth-first order. */
6052 block_vector = get_block_vector (block, &n_blocks);
6053 block_stack = xmalloc (n_blocks * sizeof (tree));
6055 last_block_vector = identify_blocks_1 (get_insns (),
6057 block_vector + n_blocks,
6060 /* If we didn't use all of the subblocks, we've misplaced block notes. */
6061 /* ??? This appears to happen all the time. Latent bugs elsewhere? */
6062 if (0 && last_block_vector != block_vector + n_blocks)
6065 free (block_vector);
6069 /* Subroutine of identify_blocks. Do the block substitution on the
6070 insn chain beginning with INSNS. Recurse for CALL_PLACEHOLDER chains.
6072 BLOCK_STACK is pushed and popped for each BLOCK_BEGIN/BLOCK_END pair.
6073 BLOCK_VECTOR is incremented for each block seen. */
6076 identify_blocks_1 (rtx insns, tree *block_vector, tree *end_block_vector,
6077 tree *orig_block_stack)
6080 tree *block_stack = orig_block_stack;
6082 for (insn = insns; insn; insn = NEXT_INSN (insn))
6084 if (GET_CODE (insn) == NOTE)
6086 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
6090 /* If there are more block notes than BLOCKs, something
6092 if (block_vector == end_block_vector)
6095 b = *block_vector++;
6096 NOTE_BLOCK (insn) = b;
6099 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
6101 /* If there are more NOTE_INSN_BLOCK_ENDs than
6102 NOTE_INSN_BLOCK_BEGs, something is badly wrong. */
6103 if (block_stack == orig_block_stack)
6106 NOTE_BLOCK (insn) = *--block_stack;
6109 else if (GET_CODE (insn) == CALL_INSN
6110 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
6112 rtx cp = PATTERN (insn);
6114 block_vector = identify_blocks_1 (XEXP (cp, 0), block_vector,
6115 end_block_vector, block_stack);
6117 block_vector = identify_blocks_1 (XEXP (cp, 1), block_vector,
6118 end_block_vector, block_stack);
6120 block_vector = identify_blocks_1 (XEXP (cp, 2), block_vector,
6121 end_block_vector, block_stack);
6125 /* If there are more NOTE_INSN_BLOCK_BEGINs than NOTE_INSN_BLOCK_ENDs,
6126 something is badly wrong. */
6127 if (block_stack != orig_block_stack)
6130 return block_vector;
6133 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
6134 and create duplicate blocks. */
6135 /* ??? Need an option to either create block fragments or to create
6136 abstract origin duplicates of a source block. It really depends
6137 on what optimization has been performed. */
6140 reorder_blocks (void)
6142 tree block = DECL_INITIAL (current_function_decl);
6143 varray_type block_stack;
6145 if (block == NULL_TREE)
6148 VARRAY_TREE_INIT (block_stack, 10, "block_stack");
6150 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
6151 reorder_blocks_0 (block);
6153 /* Prune the old trees away, so that they don't get in the way. */
6154 BLOCK_SUBBLOCKS (block) = NULL_TREE;
6155 BLOCK_CHAIN (block) = NULL_TREE;
6157 /* Recreate the block tree from the note nesting. */
6158 reorder_blocks_1 (get_insns (), block, &block_stack);
6159 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
6161 /* Remove deleted blocks from the block fragment chains. */
6162 reorder_fix_fragments (block);
6165 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
6168 reorder_blocks_0 (tree block)
6172 TREE_ASM_WRITTEN (block) = 0;
6173 reorder_blocks_0 (BLOCK_SUBBLOCKS (block));
6174 block = BLOCK_CHAIN (block);
6179 reorder_blocks_1 (rtx insns, tree current_block, varray_type *p_block_stack)
6183 for (insn = insns; insn; insn = NEXT_INSN (insn))
6185 if (GET_CODE (insn) == NOTE)
6187 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
6189 tree block = NOTE_BLOCK (insn);
6191 /* If we have seen this block before, that means it now
6192 spans multiple address regions. Create a new fragment. */
6193 if (TREE_ASM_WRITTEN (block))
6195 tree new_block = copy_node (block);
6198 origin = (BLOCK_FRAGMENT_ORIGIN (block)
6199 ? BLOCK_FRAGMENT_ORIGIN (block)
6201 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
6202 BLOCK_FRAGMENT_CHAIN (new_block)
6203 = BLOCK_FRAGMENT_CHAIN (origin);
6204 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
6206 NOTE_BLOCK (insn) = new_block;
6210 BLOCK_SUBBLOCKS (block) = 0;
6211 TREE_ASM_WRITTEN (block) = 1;
6212 /* When there's only one block for the entire function,
6213 current_block == block and we mustn't do this, it
6214 will cause infinite recursion. */
6215 if (block != current_block)
6217 BLOCK_SUPERCONTEXT (block) = current_block;
6218 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
6219 BLOCK_SUBBLOCKS (current_block) = block;
6220 current_block = block;
6222 VARRAY_PUSH_TREE (*p_block_stack, block);
6224 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
6226 NOTE_BLOCK (insn) = VARRAY_TOP_TREE (*p_block_stack);
6227 VARRAY_POP (*p_block_stack);
6228 BLOCK_SUBBLOCKS (current_block)
6229 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
6230 current_block = BLOCK_SUPERCONTEXT (current_block);
6233 else if (GET_CODE (insn) == CALL_INSN
6234 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
6236 rtx cp = PATTERN (insn);
6237 reorder_blocks_1 (XEXP (cp, 0), current_block, p_block_stack);
6239 reorder_blocks_1 (XEXP (cp, 1), current_block, p_block_stack);
6241 reorder_blocks_1 (XEXP (cp, 2), current_block, p_block_stack);
6246 /* Rationalize BLOCK_FRAGMENT_ORIGIN. If an origin block no longer
6247 appears in the block tree, select one of the fragments to become
6248 the new origin block. */
6251 reorder_fix_fragments (tree block)
6255 tree dup_origin = BLOCK_FRAGMENT_ORIGIN (block);
6256 tree new_origin = NULL_TREE;
6260 if (! TREE_ASM_WRITTEN (dup_origin))
6262 new_origin = BLOCK_FRAGMENT_CHAIN (dup_origin);
6264 /* Find the first of the remaining fragments. There must
6265 be at least one -- the current block. */
6266 while (! TREE_ASM_WRITTEN (new_origin))
6267 new_origin = BLOCK_FRAGMENT_CHAIN (new_origin);
6268 BLOCK_FRAGMENT_ORIGIN (new_origin) = NULL_TREE;
6271 else if (! dup_origin)
6274 /* Re-root the rest of the fragments to the new origin. In the
6275 case that DUP_ORIGIN was null, that means BLOCK was the origin
6276 of a chain of fragments and we want to remove those fragments
6277 that didn't make it to the output. */
6280 tree *pp = &BLOCK_FRAGMENT_CHAIN (new_origin);
6285 if (TREE_ASM_WRITTEN (chain))
6287 BLOCK_FRAGMENT_ORIGIN (chain) = new_origin;
6289 pp = &BLOCK_FRAGMENT_CHAIN (chain);
6291 chain = BLOCK_FRAGMENT_CHAIN (chain);
6296 reorder_fix_fragments (BLOCK_SUBBLOCKS (block));
6297 block = BLOCK_CHAIN (block);
6301 /* Reverse the order of elements in the chain T of blocks,
6302 and return the new head of the chain (old last element). */
6305 blocks_nreverse (tree t)
6307 tree prev = 0, decl, next;
6308 for (decl = t; decl; decl = next)
6310 next = BLOCK_CHAIN (decl);
6311 BLOCK_CHAIN (decl) = prev;
6317 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
6318 non-NULL, list them all into VECTOR, in a depth-first preorder
6319 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
6323 all_blocks (tree block, tree *vector)
6329 TREE_ASM_WRITTEN (block) = 0;
6331 /* Record this block. */
6333 vector[n_blocks] = block;
6337 /* Record the subblocks, and their subblocks... */
6338 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
6339 vector ? vector + n_blocks : 0);
6340 block = BLOCK_CHAIN (block);
6346 /* Return a vector containing all the blocks rooted at BLOCK. The
6347 number of elements in the vector is stored in N_BLOCKS_P. The
6348 vector is dynamically allocated; it is the caller's responsibility
6349 to call `free' on the pointer returned. */
6352 get_block_vector (tree block, int *n_blocks_p)
6356 *n_blocks_p = all_blocks (block, NULL);
6357 block_vector = xmalloc (*n_blocks_p * sizeof (tree));
6358 all_blocks (block, block_vector);
6360 return block_vector;
6363 static GTY(()) int next_block_index = 2;
6365 /* Set BLOCK_NUMBER for all the blocks in FN. */
6368 number_blocks (tree fn)
6374 /* For SDB and XCOFF debugging output, we start numbering the blocks
6375 from 1 within each function, rather than keeping a running
6377 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
6378 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
6379 next_block_index = 1;
6382 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
6384 /* The top-level BLOCK isn't numbered at all. */
6385 for (i = 1; i < n_blocks; ++i)
6386 /* We number the blocks from two. */
6387 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
6389 free (block_vector);
6394 /* If VAR is present in a subblock of BLOCK, return the subblock. */
6397 debug_find_var_in_block_tree (tree var, tree block)
6401 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
6405 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
6407 tree ret = debug_find_var_in_block_tree (var, t);
6415 /* Allocate a function structure for FNDECL and set its contents
6419 allocate_struct_function (tree fndecl)
6423 cfun = ggc_alloc_cleared (sizeof (struct function));
6425 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
6427 cfun->stack_alignment_needed = STACK_BOUNDARY;
6428 cfun->preferred_stack_boundary = STACK_BOUNDARY;
6430 current_function_funcdef_no = funcdef_no++;
6432 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
6434 init_stmt_for_function ();
6435 init_eh_for_function ();
6437 lang_hooks.function.init (cfun);
6438 if (init_machine_status)
6439 cfun->machine = (*init_machine_status) ();
6444 DECL_STRUCT_FUNCTION (fndecl) = cfun;
6445 cfun->decl = fndecl;
6447 result = DECL_RESULT (fndecl);
6448 if (aggregate_value_p (result, fndecl))
6450 #ifdef PCC_STATIC_STRUCT_RETURN
6451 current_function_returns_pcc_struct = 1;
6453 current_function_returns_struct = 1;
6456 current_function_returns_pointer = POINTER_TYPE_P (TREE_TYPE (result));
6458 current_function_needs_context
6459 = (decl_function_context (current_function_decl) != 0
6460 && ! DECL_NO_STATIC_CHAIN (current_function_decl));
6463 /* Reset cfun, and other non-struct-function variables to defaults as
6464 appropriate for emitting rtl at the start of a function. */
6467 prepare_function_start (tree fndecl)
6469 if (fndecl && DECL_STRUCT_FUNCTION (fndecl))
6470 cfun = DECL_STRUCT_FUNCTION (fndecl);
6472 allocate_struct_function (fndecl);
6474 init_varasm_status (cfun);
6477 cse_not_expected = ! optimize;
6479 /* Caller save not needed yet. */
6480 caller_save_needed = 0;
6482 /* We haven't done register allocation yet. */
6485 /* Indicate that we need to distinguish between the return value of the
6486 present function and the return value of a function being called. */
6487 rtx_equal_function_value_matters = 1;
6489 /* Indicate that we have not instantiated virtual registers yet. */
6490 virtuals_instantiated = 0;
6492 /* Indicate that we want CONCATs now. */
6493 generating_concat_p = 1;
6495 /* Indicate we have no need of a frame pointer yet. */
6496 frame_pointer_needed = 0;
6499 /* Initialize the rtl expansion mechanism so that we can do simple things
6500 like generate sequences. This is used to provide a context during global
6501 initialization of some passes. */
6503 init_dummy_function_start (void)
6505 prepare_function_start (NULL);
6508 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
6509 and initialize static variables for generating RTL for the statements
6513 init_function_start (tree subr)
6515 prepare_function_start (subr);
6517 /* Within function body, compute a type's size as soon it is laid out. */
6518 immediate_size_expand++;
6520 /* Prevent ever trying to delete the first instruction of a
6521 function. Also tell final how to output a linenum before the
6522 function prologue. Note linenums could be missing, e.g. when
6523 compiling a Java .class file. */
6524 if (DECL_SOURCE_LINE (subr))
6525 emit_line_note (DECL_SOURCE_LOCATION (subr));
6527 /* Make sure first insn is a note even if we don't want linenums.
6528 This makes sure the first insn will never be deleted.
6529 Also, final expects a note to appear there. */
6530 emit_note (NOTE_INSN_DELETED);
6532 /* Warn if this value is an aggregate type,
6533 regardless of which calling convention we are using for it. */
6534 if (warn_aggregate_return
6535 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
6536 warning ("function returns an aggregate");
6539 /* Make sure all values used by the optimization passes have sane
6542 init_function_for_compilation (void)
6546 /* No prologue/epilogue insns yet. */
6547 VARRAY_GROW (prologue, 0);
6548 VARRAY_GROW (epilogue, 0);
6549 VARRAY_GROW (sibcall_epilogue, 0);
6552 /* Expand a call to __main at the beginning of a possible main function. */
6554 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
6555 #undef HAS_INIT_SECTION
6556 #define HAS_INIT_SECTION
6560 expand_main_function (void)
6562 #ifdef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN
6563 if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN)
6565 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
6569 /* Forcibly align the stack. */
6570 #ifdef STACK_GROWS_DOWNWARD
6571 tmp = expand_simple_binop (Pmode, AND, stack_pointer_rtx, GEN_INT(-align),
6572 stack_pointer_rtx, 1, OPTAB_WIDEN);
6574 tmp = expand_simple_binop (Pmode, PLUS, stack_pointer_rtx,
6575 GEN_INT (align - 1), NULL_RTX, 1, OPTAB_WIDEN);
6576 tmp = expand_simple_binop (Pmode, AND, tmp, GEN_INT (-align),
6577 stack_pointer_rtx, 1, OPTAB_WIDEN);
6579 if (tmp != stack_pointer_rtx)
6580 emit_move_insn (stack_pointer_rtx, tmp);
6582 /* Enlist allocate_dynamic_stack_space to pick up the pieces. */
6583 tmp = force_reg (Pmode, const0_rtx);
6584 allocate_dynamic_stack_space (tmp, NULL_RTX, BIGGEST_ALIGNMENT);
6588 for (tmp = get_last_insn (); tmp; tmp = PREV_INSN (tmp))
6589 if (NOTE_P (tmp) && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_FUNCTION_BEG)
6592 emit_insn_before (seq, tmp);
6598 #ifndef HAS_INIT_SECTION
6599 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
6603 /* The PENDING_SIZES represent the sizes of variable-sized types.
6604 Create RTL for the various sizes now (using temporary variables),
6605 so that we can refer to the sizes from the RTL we are generating
6606 for the current function. The PENDING_SIZES are a TREE_LIST. The
6607 TREE_VALUE of each node is a SAVE_EXPR. */
6610 expand_pending_sizes (tree pending_sizes)
6614 /* Evaluate now the sizes of any types declared among the arguments. */
6615 for (tem = pending_sizes; tem; tem = TREE_CHAIN (tem))
6617 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
6618 /* Flush the queue in case this parameter declaration has
6624 /* Start the RTL for a new function, and set variables used for
6626 SUBR is the FUNCTION_DECL node.
6627 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
6628 the function's parameters, which must be run at any return statement. */
6631 expand_function_start (tree subr, int parms_have_cleanups)
6634 rtx last_ptr = NULL_RTX;
6636 /* Make sure volatile mem refs aren't considered
6637 valid operands of arithmetic insns. */
6638 init_recog_no_volatile ();
6640 current_function_instrument_entry_exit
6641 = (flag_instrument_function_entry_exit
6642 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6644 current_function_profile
6646 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6648 current_function_limit_stack
6649 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
6651 /* If function gets a static chain arg, store it in the stack frame.
6652 Do this first, so it gets the first stack slot offset. */
6653 if (current_function_needs_context)
6655 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
6657 /* Delay copying static chain if it is not a register to avoid
6658 conflicts with regs used for parameters. */
6659 if (! SMALL_REGISTER_CLASSES
6660 || GET_CODE (static_chain_incoming_rtx) == REG)
6661 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6664 /* If the parameters of this function need cleaning up, get a label
6665 for the beginning of the code which executes those cleanups. This must
6666 be done before doing anything with return_label. */
6667 if (parms_have_cleanups)
6668 cleanup_label = gen_label_rtx ();
6672 /* Make the label for return statements to jump to. Do not special
6673 case machines with special return instructions -- they will be
6674 handled later during jump, ifcvt, or epilogue creation. */
6675 return_label = gen_label_rtx ();
6677 /* Initialize rtx used to return the value. */
6678 /* Do this before assign_parms so that we copy the struct value address
6679 before any library calls that assign parms might generate. */
6681 /* Decide whether to return the value in memory or in a register. */
6682 if (aggregate_value_p (DECL_RESULT (subr), subr))
6684 /* Returning something that won't go in a register. */
6685 rtx value_address = 0;
6687 #ifdef PCC_STATIC_STRUCT_RETURN
6688 if (current_function_returns_pcc_struct)
6690 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
6691 value_address = assemble_static_space (size);
6696 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 1);
6697 /* Expect to be passed the address of a place to store the value.
6698 If it is passed as an argument, assign_parms will take care of
6702 value_address = gen_reg_rtx (Pmode);
6703 emit_move_insn (value_address, sv);
6708 rtx x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), value_address);
6709 set_mem_attributes (x, DECL_RESULT (subr), 1);
6710 SET_DECL_RTL (DECL_RESULT (subr), x);
6713 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
6714 /* If return mode is void, this decl rtl should not be used. */
6715 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
6718 /* Compute the return values into a pseudo reg, which we will copy
6719 into the true return register after the cleanups are done. */
6721 /* In order to figure out what mode to use for the pseudo, we
6722 figure out what the mode of the eventual return register will
6723 actually be, and use that. */
6725 = hard_function_value (TREE_TYPE (DECL_RESULT (subr)),
6728 /* Structures that are returned in registers are not aggregate_value_p,
6729 so we may see a PARALLEL or a REG. */
6730 if (REG_P (hard_reg))
6731 SET_DECL_RTL (DECL_RESULT (subr), gen_reg_rtx (GET_MODE (hard_reg)));
6732 else if (GET_CODE (hard_reg) == PARALLEL)
6733 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
6737 /* Set DECL_REGISTER flag so that expand_function_end will copy the
6738 result to the real return register(s). */
6739 DECL_REGISTER (DECL_RESULT (subr)) = 1;
6742 /* Initialize rtx for parameters and local variables.
6743 In some cases this requires emitting insns. */
6745 assign_parms (subr);
6747 /* Copy the static chain now if it wasn't a register. The delay is to
6748 avoid conflicts with the parameter passing registers. */
6750 if (SMALL_REGISTER_CLASSES && current_function_needs_context)
6751 if (GET_CODE (static_chain_incoming_rtx) != REG)
6752 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6754 /* The following was moved from init_function_start.
6755 The move is supposed to make sdb output more accurate. */
6756 /* Indicate the beginning of the function body,
6757 as opposed to parm setup. */
6758 emit_note (NOTE_INSN_FUNCTION_BEG);
6760 if (GET_CODE (get_last_insn ()) != NOTE)
6761 emit_note (NOTE_INSN_DELETED);
6762 parm_birth_insn = get_last_insn ();
6764 context_display = 0;
6765 if (current_function_needs_context)
6767 /* Fetch static chain values for containing functions. */
6768 tem = decl_function_context (current_function_decl);
6769 /* Copy the static chain pointer into a pseudo. If we have
6770 small register classes, copy the value from memory if
6771 static_chain_incoming_rtx is a REG. */
6774 /* If the static chain originally came in a register, put it back
6775 there, then move it out in the next insn. The reason for
6776 this peculiar code is to satisfy function integration. */
6777 if (SMALL_REGISTER_CLASSES
6778 && GET_CODE (static_chain_incoming_rtx) == REG)
6779 emit_move_insn (static_chain_incoming_rtx, last_ptr);
6780 last_ptr = copy_to_reg (static_chain_incoming_rtx);
6785 tree rtlexp = make_node (RTL_EXPR);
6787 RTL_EXPR_RTL (rtlexp) = last_ptr;
6788 context_display = tree_cons (tem, rtlexp, context_display);
6789 tem = decl_function_context (tem);
6792 /* Chain through stack frames, assuming pointer to next lexical frame
6793 is found at the place we always store it. */
6794 #ifdef FRAME_GROWS_DOWNWARD
6795 last_ptr = plus_constant (last_ptr,
6796 -(HOST_WIDE_INT) GET_MODE_SIZE (Pmode));
6798 last_ptr = gen_rtx_MEM (Pmode, memory_address (Pmode, last_ptr));
6799 set_mem_alias_set (last_ptr, get_frame_alias_set ());
6800 last_ptr = copy_to_reg (last_ptr);
6802 /* If we are not optimizing, ensure that we know that this
6803 piece of context is live over the entire function. */
6805 save_expr_regs = gen_rtx_EXPR_LIST (VOIDmode, last_ptr,
6810 if (current_function_instrument_entry_exit)
6812 rtx fun = DECL_RTL (current_function_decl);
6813 if (GET_CODE (fun) == MEM)
6814 fun = XEXP (fun, 0);
6817 emit_library_call (profile_function_entry_libfunc, LCT_NORMAL, VOIDmode,
6819 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
6821 hard_frame_pointer_rtx),
6825 if (current_function_profile)
6828 PROFILE_HOOK (current_function_funcdef_no);
6832 /* After the display initializations is where the tail-recursion label
6833 should go, if we end up needing one. Ensure we have a NOTE here
6834 since some things (like trampolines) get placed before this. */
6835 tail_recursion_reentry = emit_note (NOTE_INSN_DELETED);
6837 /* Evaluate now the sizes of any types declared among the arguments. */
6838 expand_pending_sizes (nreverse (get_pending_sizes ()));
6840 /* Make sure there is a line number after the function entry setup code. */
6841 force_next_line_note ();
6844 /* Undo the effects of init_dummy_function_start. */
6846 expand_dummy_function_end (void)
6848 /* End any sequences that failed to be closed due to syntax errors. */
6849 while (in_sequence_p ())
6852 /* Outside function body, can't compute type's actual size
6853 until next function's body starts. */
6855 free_after_parsing (cfun);
6856 free_after_compilation (cfun);
6860 /* Call DOIT for each hard register used as a return value from
6861 the current function. */
6864 diddle_return_value (void (*doit) (rtx, void *), void *arg)
6866 rtx outgoing = current_function_return_rtx;
6871 if (GET_CODE (outgoing) == REG)
6872 (*doit) (outgoing, arg);
6873 else if (GET_CODE (outgoing) == PARALLEL)
6877 for (i = 0; i < XVECLEN (outgoing, 0); i++)
6879 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
6881 if (GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
6888 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6890 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
6894 clobber_return_register (void)
6896 diddle_return_value (do_clobber_return_reg, NULL);
6898 /* In case we do use pseudo to return value, clobber it too. */
6899 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
6901 tree decl_result = DECL_RESULT (current_function_decl);
6902 rtx decl_rtl = DECL_RTL (decl_result);
6903 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
6905 do_clobber_return_reg (decl_rtl, NULL);
6911 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6913 emit_insn (gen_rtx_USE (VOIDmode, reg));
6917 use_return_register (void)
6919 diddle_return_value (do_use_return_reg, NULL);
6922 /* Possibly warn about unused parameters. */
6924 do_warn_unused_parameter (tree fn)
6928 for (decl = DECL_ARGUMENTS (fn);
6929 decl; decl = TREE_CHAIN (decl))
6930 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
6931 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl))
6932 warning ("%Junused parameter '%D'", decl, decl);
6935 static GTY(()) rtx initial_trampoline;
6937 /* Generate RTL for the end of the current function. */
6940 expand_function_end (void)
6945 finish_expr_for_function ();
6947 /* If arg_pointer_save_area was referenced only from a nested
6948 function, we will not have initialized it yet. Do that now. */
6949 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
6950 get_arg_pointer_save_area (cfun);
6952 #ifdef NON_SAVING_SETJMP
6953 /* Don't put any variables in registers if we call setjmp
6954 on a machine that fails to restore the registers. */
6955 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
6957 if (DECL_INITIAL (current_function_decl) != error_mark_node)
6958 setjmp_protect (DECL_INITIAL (current_function_decl));
6960 setjmp_protect_args ();
6964 /* Initialize any trampolines required by this function. */
6965 for (link = trampoline_list; link; link = TREE_CHAIN (link))
6967 tree function = TREE_PURPOSE (link);
6968 rtx context ATTRIBUTE_UNUSED = lookup_static_chain (function);
6969 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
6970 #ifdef TRAMPOLINE_TEMPLATE
6975 #ifdef TRAMPOLINE_TEMPLATE
6976 /* First make sure this compilation has a template for
6977 initializing trampolines. */
6978 if (initial_trampoline == 0)
6981 = gen_rtx_MEM (BLKmode, assemble_trampoline_template ());
6982 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
6986 /* Generate insns to initialize the trampoline. */
6988 tramp = round_trampoline_addr (XEXP (tramp, 0));
6989 #ifdef TRAMPOLINE_TEMPLATE
6990 blktramp = replace_equiv_address (initial_trampoline, tramp);
6991 emit_block_move (blktramp, initial_trampoline,
6992 GEN_INT (TRAMPOLINE_SIZE), BLOCK_OP_NORMAL);
6994 trampolines_created = 1;
6995 INITIALIZE_TRAMPOLINE (tramp, XEXP (DECL_RTL (function), 0), context);
6999 /* Put those insns at entry to the containing function (this one). */
7000 emit_insn_before (seq, tail_recursion_reentry);
7003 /* If we are doing stack checking and this function makes calls,
7004 do a stack probe at the start of the function to ensure we have enough
7005 space for another stack frame. */
7006 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
7010 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
7011 if (GET_CODE (insn) == CALL_INSN)
7014 probe_stack_range (STACK_CHECK_PROTECT,
7015 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
7018 emit_insn_before (seq, tail_recursion_reentry);
7023 /* Possibly warn about unused parameters.
7024 When frontend does unit-at-a-time, the warning is already
7025 issued at finalization time. */
7026 if (warn_unused_parameter
7027 && !lang_hooks.callgraph.expand_function)
7028 do_warn_unused_parameter (current_function_decl);
7030 /* Delete handlers for nonlocal gotos if nothing uses them. */
7031 if (nonlocal_goto_handler_slots != 0
7032 && ! current_function_has_nonlocal_label)
7035 /* End any sequences that failed to be closed due to syntax errors. */
7036 while (in_sequence_p ())
7039 /* Outside function body, can't compute type's actual size
7040 until next function's body starts. */
7041 immediate_size_expand--;
7043 clear_pending_stack_adjust ();
7044 do_pending_stack_adjust ();
7046 /* @@@ This is a kludge. We want to ensure that instructions that
7047 may trap are not moved into the epilogue by scheduling, because
7048 we don't always emit unwind information for the epilogue.
7049 However, not all machine descriptions define a blockage insn, so
7050 emit an ASM_INPUT to act as one. */
7051 if (flag_non_call_exceptions)
7052 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
7054 /* Mark the end of the function body.
7055 If control reaches this insn, the function can drop through
7056 without returning a value. */
7057 emit_note (NOTE_INSN_FUNCTION_END);
7059 /* Must mark the last line number note in the function, so that the test
7060 coverage code can avoid counting the last line twice. This just tells
7061 the code to ignore the immediately following line note, since there
7062 already exists a copy of this note somewhere above. This line number
7063 note is still needed for debugging though, so we can't delete it. */
7064 if (flag_test_coverage)
7065 emit_note (NOTE_INSN_REPEATED_LINE_NUMBER);
7067 /* Output a linenumber for the end of the function.
7068 SDB depends on this. */
7069 force_next_line_note ();
7070 emit_line_note (input_location);
7072 /* Before the return label (if any), clobber the return
7073 registers so that they are not propagated live to the rest of
7074 the function. This can only happen with functions that drop
7075 through; if there had been a return statement, there would
7076 have either been a return rtx, or a jump to the return label.
7078 We delay actual code generation after the current_function_value_rtx
7080 clobber_after = get_last_insn ();
7082 /* Output the label for the actual return from the function,
7083 if one is expected. This happens either because a function epilogue
7084 is used instead of a return instruction, or because a return was done
7085 with a goto in order to run local cleanups, or because of pcc-style
7086 structure returning. */
7088 emit_label (return_label);
7090 if (current_function_instrument_entry_exit)
7092 rtx fun = DECL_RTL (current_function_decl);
7093 if (GET_CODE (fun) == MEM)
7094 fun = XEXP (fun, 0);
7097 emit_library_call (profile_function_exit_libfunc, LCT_NORMAL, VOIDmode,
7099 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
7101 hard_frame_pointer_rtx),
7105 /* Let except.c know where it should emit the call to unregister
7106 the function context for sjlj exceptions. */
7107 if (flag_exceptions && USING_SJLJ_EXCEPTIONS)
7108 sjlj_emit_function_exit_after (get_last_insn ());
7110 /* If we had calls to alloca, and this machine needs
7111 an accurate stack pointer to exit the function,
7112 insert some code to save and restore the stack pointer. */
7113 if (! EXIT_IGNORE_STACK
7114 && current_function_calls_alloca)
7118 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
7119 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
7122 /* If scalar return value was computed in a pseudo-reg, or was a named
7123 return value that got dumped to the stack, copy that to the hard
7125 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
7127 tree decl_result = DECL_RESULT (current_function_decl);
7128 rtx decl_rtl = DECL_RTL (decl_result);
7130 if (REG_P (decl_rtl)
7131 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
7132 : DECL_REGISTER (decl_result))
7134 rtx real_decl_rtl = current_function_return_rtx;
7136 /* This should be set in assign_parms. */
7137 if (! REG_FUNCTION_VALUE_P (real_decl_rtl))
7140 /* If this is a BLKmode structure being returned in registers,
7141 then use the mode computed in expand_return. Note that if
7142 decl_rtl is memory, then its mode may have been changed,
7143 but that current_function_return_rtx has not. */
7144 if (GET_MODE (real_decl_rtl) == BLKmode)
7145 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
7147 /* If a named return value dumped decl_return to memory, then
7148 we may need to re-do the PROMOTE_MODE signed/unsigned
7150 if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
7152 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
7154 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
7155 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
7158 convert_move (real_decl_rtl, decl_rtl, unsignedp);
7160 else if (GET_CODE (real_decl_rtl) == PARALLEL)
7162 /* If expand_function_start has created a PARALLEL for decl_rtl,
7163 move the result to the real return registers. Otherwise, do
7164 a group load from decl_rtl for a named return. */
7165 if (GET_CODE (decl_rtl) == PARALLEL)
7166 emit_group_move (real_decl_rtl, decl_rtl);
7168 emit_group_load (real_decl_rtl, decl_rtl,
7169 TREE_TYPE (decl_result),
7170 int_size_in_bytes (TREE_TYPE (decl_result)));
7173 emit_move_insn (real_decl_rtl, decl_rtl);
7177 /* If returning a structure, arrange to return the address of the value
7178 in a place where debuggers expect to find it.
7180 If returning a structure PCC style,
7181 the caller also depends on this value.
7182 And current_function_returns_pcc_struct is not necessarily set. */
7183 if (current_function_returns_struct
7184 || current_function_returns_pcc_struct)
7187 = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
7188 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
7189 #ifdef FUNCTION_OUTGOING_VALUE
7191 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
7192 current_function_decl);
7195 = FUNCTION_VALUE (build_pointer_type (type), current_function_decl);
7198 /* Mark this as a function return value so integrate will delete the
7199 assignment and USE below when inlining this function. */
7200 REG_FUNCTION_VALUE_P (outgoing) = 1;
7202 /* The address may be ptr_mode and OUTGOING may be Pmode. */
7203 value_address = convert_memory_address (GET_MODE (outgoing),
7206 emit_move_insn (outgoing, value_address);
7208 /* Show return register used to hold result (in this case the address
7210 current_function_return_rtx = outgoing;
7213 /* If this is an implementation of throw, do what's necessary to
7214 communicate between __builtin_eh_return and the epilogue. */
7215 expand_eh_return ();
7217 /* Emit the actual code to clobber return register. */
7222 clobber_return_register ();
7226 after = emit_insn_after (seq, clobber_after);
7228 if (clobber_after != after)
7229 cfun->x_clobber_return_insn = after;
7232 /* Output the label for the naked return from the function, if one is
7233 expected. This is currently used only by __builtin_return. */
7234 if (naked_return_label)
7235 emit_label (naked_return_label);
7237 /* ??? This should no longer be necessary since stupid is no longer with
7238 us, but there are some parts of the compiler (eg reload_combine, and
7239 sh mach_dep_reorg) that still try and compute their own lifetime info
7240 instead of using the general framework. */
7241 use_return_register ();
7243 /* Fix up any gotos that jumped out to the outermost
7244 binding level of the function.
7245 Must follow emitting RETURN_LABEL. */
7247 /* If you have any cleanups to do at this point,
7248 and they need to create temporary variables,
7249 then you will lose. */
7250 expand_fixups (get_insns ());
7254 get_arg_pointer_save_area (struct function *f)
7256 rtx ret = f->x_arg_pointer_save_area;
7260 ret = assign_stack_local_1 (Pmode, GET_MODE_SIZE (Pmode), 0, f);
7261 f->x_arg_pointer_save_area = ret;
7264 if (f == cfun && ! f->arg_pointer_save_area_init)
7268 /* Save the arg pointer at the beginning of the function. The
7269 generated stack slot may not be a valid memory address, so we
7270 have to check it and fix it if necessary. */
7272 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
7276 push_topmost_sequence ();
7277 emit_insn_after (seq, get_insns ());
7278 pop_topmost_sequence ();
7284 /* Extend a vector that records the INSN_UIDs of INSNS
7285 (a list of one or more insns). */
7288 record_insns (rtx insns, varray_type *vecp)
7295 while (tmp != NULL_RTX)
7298 tmp = NEXT_INSN (tmp);
7301 i = VARRAY_SIZE (*vecp);
7302 VARRAY_GROW (*vecp, i + len);
7304 while (tmp != NULL_RTX)
7306 VARRAY_INT (*vecp, i) = INSN_UID (tmp);
7308 tmp = NEXT_INSN (tmp);
7312 /* Set the locator of the insn chain starting at INSN to LOC. */
7314 set_insn_locators (rtx insn, int loc)
7316 while (insn != NULL_RTX)
7319 INSN_LOCATOR (insn) = loc;
7320 insn = NEXT_INSN (insn);
7324 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
7325 be running after reorg, SEQUENCE rtl is possible. */
7328 contains (rtx insn, varray_type vec)
7332 if (GET_CODE (insn) == INSN
7333 && GET_CODE (PATTERN (insn)) == SEQUENCE)
7336 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
7337 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
7338 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == VARRAY_INT (vec, j))
7344 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
7345 if (INSN_UID (insn) == VARRAY_INT (vec, j))
7352 prologue_epilogue_contains (rtx insn)
7354 if (contains (insn, prologue))
7356 if (contains (insn, epilogue))
7362 sibcall_epilogue_contains (rtx insn)
7364 if (sibcall_epilogue)
7365 return contains (insn, sibcall_epilogue);
7370 /* Insert gen_return at the end of block BB. This also means updating
7371 block_for_insn appropriately. */
7374 emit_return_into_block (basic_block bb, rtx line_note)
7376 emit_jump_insn_after (gen_return (), BB_END (bb));
7378 emit_note_copy_after (line_note, PREV_INSN (BB_END (bb)));
7380 #endif /* HAVE_return */
7382 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
7384 /* These functions convert the epilogue into a variant that does not modify the
7385 stack pointer. This is used in cases where a function returns an object
7386 whose size is not known until it is computed. The called function leaves the
7387 object on the stack, leaves the stack depressed, and returns a pointer to
7390 What we need to do is track all modifications and references to the stack
7391 pointer, deleting the modifications and changing the references to point to
7392 the location the stack pointer would have pointed to had the modifications
7395 These functions need to be portable so we need to make as few assumptions
7396 about the epilogue as we can. However, the epilogue basically contains
7397 three things: instructions to reset the stack pointer, instructions to
7398 reload registers, possibly including the frame pointer, and an
7399 instruction to return to the caller.
7401 If we can't be sure of what a relevant epilogue insn is doing, we abort.
7402 We also make no attempt to validate the insns we make since if they are
7403 invalid, we probably can't do anything valid. The intent is that these
7404 routines get "smarter" as more and more machines start to use them and
7405 they try operating on different epilogues.
7407 We use the following structure to track what the part of the epilogue that
7408 we've already processed has done. We keep two copies of the SP equivalence,
7409 one for use during the insn we are processing and one for use in the next
7410 insn. The difference is because one part of a PARALLEL may adjust SP
7411 and the other may use it. */
7415 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
7416 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
7417 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
7418 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
7419 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
7420 should be set to once we no longer need
7422 rtx const_equiv[FIRST_PSEUDO_REGISTER]; /* Any known constant equivalences
7426 static void handle_epilogue_set (rtx, struct epi_info *);
7427 static void update_epilogue_consts (rtx, rtx, void *);
7428 static void emit_equiv_load (struct epi_info *);
7430 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
7431 no modifications to the stack pointer. Return the new list of insns. */
7434 keep_stack_depressed (rtx insns)
7437 struct epi_info info;
7440 /* If the epilogue is just a single instruction, it must be OK as is. */
7441 if (NEXT_INSN (insns) == NULL_RTX)
7444 /* Otherwise, start a sequence, initialize the information we have, and
7445 process all the insns we were given. */
7448 info.sp_equiv_reg = stack_pointer_rtx;
7450 info.equiv_reg_src = 0;
7452 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
7453 info.const_equiv[j] = 0;
7457 while (insn != NULL_RTX)
7459 next = NEXT_INSN (insn);
7468 /* If this insn references the register that SP is equivalent to and
7469 we have a pending load to that register, we must force out the load
7470 first and then indicate we no longer know what SP's equivalent is. */
7471 if (info.equiv_reg_src != 0
7472 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
7474 emit_equiv_load (&info);
7475 info.sp_equiv_reg = 0;
7478 info.new_sp_equiv_reg = info.sp_equiv_reg;
7479 info.new_sp_offset = info.sp_offset;
7481 /* If this is a (RETURN) and the return address is on the stack,
7482 update the address and change to an indirect jump. */
7483 if (GET_CODE (PATTERN (insn)) == RETURN
7484 || (GET_CODE (PATTERN (insn)) == PARALLEL
7485 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
7487 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
7489 HOST_WIDE_INT offset = 0;
7490 rtx jump_insn, jump_set;
7492 /* If the return address is in a register, we can emit the insn
7493 unchanged. Otherwise, it must be a MEM and we see what the
7494 base register and offset are. In any case, we have to emit any
7495 pending load to the equivalent reg of SP, if any. */
7496 if (GET_CODE (retaddr) == REG)
7498 emit_equiv_load (&info);
7503 else if (GET_CODE (retaddr) == MEM
7504 && GET_CODE (XEXP (retaddr, 0)) == REG)
7505 base = gen_rtx_REG (Pmode, REGNO (XEXP (retaddr, 0))), offset = 0;
7506 else if (GET_CODE (retaddr) == MEM
7507 && GET_CODE (XEXP (retaddr, 0)) == PLUS
7508 && GET_CODE (XEXP (XEXP (retaddr, 0), 0)) == REG
7509 && GET_CODE (XEXP (XEXP (retaddr, 0), 1)) == CONST_INT)
7511 base = gen_rtx_REG (Pmode, REGNO (XEXP (XEXP (retaddr, 0), 0)));
7512 offset = INTVAL (XEXP (XEXP (retaddr, 0), 1));
7517 /* If the base of the location containing the return pointer
7518 is SP, we must update it with the replacement address. Otherwise,
7519 just build the necessary MEM. */
7520 retaddr = plus_constant (base, offset);
7521 if (base == stack_pointer_rtx)
7522 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
7523 plus_constant (info.sp_equiv_reg,
7526 retaddr = gen_rtx_MEM (Pmode, retaddr);
7528 /* If there is a pending load to the equivalent register for SP
7529 and we reference that register, we must load our address into
7530 a scratch register and then do that load. */
7531 if (info.equiv_reg_src
7532 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
7537 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
7538 if (HARD_REGNO_MODE_OK (regno, Pmode)
7539 && !fixed_regs[regno]
7540 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
7541 && !REGNO_REG_SET_P (EXIT_BLOCK_PTR->global_live_at_start,
7543 && !refers_to_regno_p (regno,
7544 regno + hard_regno_nregs[regno]
7546 info.equiv_reg_src, NULL)
7547 && info.const_equiv[regno] == 0)
7550 if (regno == FIRST_PSEUDO_REGISTER)
7553 reg = gen_rtx_REG (Pmode, regno);
7554 emit_move_insn (reg, retaddr);
7558 emit_equiv_load (&info);
7559 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
7561 /* Show the SET in the above insn is a RETURN. */
7562 jump_set = single_set (jump_insn);
7566 SET_IS_RETURN_P (jump_set) = 1;
7569 /* If SP is not mentioned in the pattern and its equivalent register, if
7570 any, is not modified, just emit it. Otherwise, if neither is set,
7571 replace the reference to SP and emit the insn. If none of those are
7572 true, handle each SET individually. */
7573 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
7574 && (info.sp_equiv_reg == stack_pointer_rtx
7575 || !reg_set_p (info.sp_equiv_reg, insn)))
7577 else if (! reg_set_p (stack_pointer_rtx, insn)
7578 && (info.sp_equiv_reg == stack_pointer_rtx
7579 || !reg_set_p (info.sp_equiv_reg, insn)))
7581 if (! validate_replace_rtx (stack_pointer_rtx,
7582 plus_constant (info.sp_equiv_reg,
7589 else if (GET_CODE (PATTERN (insn)) == SET)
7590 handle_epilogue_set (PATTERN (insn), &info);
7591 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
7593 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
7594 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
7595 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
7600 info.sp_equiv_reg = info.new_sp_equiv_reg;
7601 info.sp_offset = info.new_sp_offset;
7603 /* Now update any constants this insn sets. */
7604 note_stores (PATTERN (insn), update_epilogue_consts, &info);
7608 insns = get_insns ();
7613 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
7614 structure that contains information about what we've seen so far. We
7615 process this SET by either updating that data or by emitting one or
7619 handle_epilogue_set (rtx set, struct epi_info *p)
7621 /* First handle the case where we are setting SP. Record what it is being
7622 set from. If unknown, abort. */
7623 if (reg_set_p (stack_pointer_rtx, set))
7625 if (SET_DEST (set) != stack_pointer_rtx)
7628 if (GET_CODE (SET_SRC (set)) == PLUS)
7630 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
7631 if (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
7632 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
7633 else if (GET_CODE (XEXP (SET_SRC (set), 1)) == REG
7634 && REGNO (XEXP (SET_SRC (set), 1)) < FIRST_PSEUDO_REGISTER
7635 && p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))] != 0)
7637 = INTVAL (p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
7642 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
7644 /* If we are adjusting SP, we adjust from the old data. */
7645 if (p->new_sp_equiv_reg == stack_pointer_rtx)
7647 p->new_sp_equiv_reg = p->sp_equiv_reg;
7648 p->new_sp_offset += p->sp_offset;
7651 if (p->new_sp_equiv_reg == 0 || GET_CODE (p->new_sp_equiv_reg) != REG)
7657 /* Next handle the case where we are setting SP's equivalent register.
7658 If we already have a value to set it to, abort. We could update, but
7659 there seems little point in handling that case. Note that we have
7660 to allow for the case where we are setting the register set in
7661 the previous part of a PARALLEL inside a single insn. But use the
7662 old offset for any updates within this insn. We must allow for the case
7663 where the register is being set in a different (usually wider) mode than
7665 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
7667 if (p->equiv_reg_src != 0
7668 || GET_CODE (p->new_sp_equiv_reg) != REG
7669 || GET_CODE (SET_DEST (set)) != REG
7670 || GET_MODE_BITSIZE (GET_MODE (SET_DEST (set))) > BITS_PER_WORD
7671 || REGNO (p->new_sp_equiv_reg) != REGNO (SET_DEST (set)))
7675 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7676 plus_constant (p->sp_equiv_reg,
7680 /* Otherwise, replace any references to SP in the insn to its new value
7681 and emit the insn. */
7684 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7685 plus_constant (p->sp_equiv_reg,
7687 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
7688 plus_constant (p->sp_equiv_reg,
7694 /* Update the tracking information for registers set to constants. */
7697 update_epilogue_consts (rtx dest, rtx x, void *data)
7699 struct epi_info *p = (struct epi_info *) data;
7702 if (GET_CODE (dest) != REG || REGNO (dest) >= FIRST_PSEUDO_REGISTER)
7705 /* If we are either clobbering a register or doing a partial set,
7706 show we don't know the value. */
7707 else if (GET_CODE (x) == CLOBBER || ! rtx_equal_p (dest, SET_DEST (x)))
7708 p->const_equiv[REGNO (dest)] = 0;
7710 /* If we are setting it to a constant, record that constant. */
7711 else if (GET_CODE (SET_SRC (x)) == CONST_INT)
7712 p->const_equiv[REGNO (dest)] = SET_SRC (x);
7714 /* If this is a binary operation between a register we have been tracking
7715 and a constant, see if we can compute a new constant value. */
7716 else if (ARITHMETIC_P (SET_SRC (x))
7717 && GET_CODE (XEXP (SET_SRC (x), 0)) == REG
7718 && REGNO (XEXP (SET_SRC (x), 0)) < FIRST_PSEUDO_REGISTER
7719 && p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))] != 0
7720 && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT
7721 && 0 != (new = simplify_binary_operation
7722 (GET_CODE (SET_SRC (x)), GET_MODE (dest),
7723 p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))],
7724 XEXP (SET_SRC (x), 1)))
7725 && GET_CODE (new) == CONST_INT)
7726 p->const_equiv[REGNO (dest)] = new;
7728 /* Otherwise, we can't do anything with this value. */
7730 p->const_equiv[REGNO (dest)] = 0;
7733 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
7736 emit_equiv_load (struct epi_info *p)
7738 if (p->equiv_reg_src != 0)
7740 rtx dest = p->sp_equiv_reg;
7742 if (GET_MODE (p->equiv_reg_src) != GET_MODE (dest))
7743 dest = gen_rtx_REG (GET_MODE (p->equiv_reg_src),
7744 REGNO (p->sp_equiv_reg));
7746 emit_move_insn (dest, p->equiv_reg_src);
7747 p->equiv_reg_src = 0;
7752 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
7753 this into place with notes indicating where the prologue ends and where
7754 the epilogue begins. Update the basic block information when possible. */
7757 thread_prologue_and_epilogue_insns (rtx f ATTRIBUTE_UNUSED)
7761 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
7764 #ifdef HAVE_prologue
7765 rtx prologue_end = NULL_RTX;
7767 #if defined (HAVE_epilogue) || defined(HAVE_return)
7768 rtx epilogue_end = NULL_RTX;
7771 #ifdef HAVE_prologue
7775 seq = gen_prologue ();
7778 /* Retain a map of the prologue insns. */
7779 record_insns (seq, &prologue);
7780 prologue_end = emit_note (NOTE_INSN_PROLOGUE_END);
7784 set_insn_locators (seq, prologue_locator);
7786 /* Can't deal with multiple successors of the entry block
7787 at the moment. Function should always have at least one
7789 if (!ENTRY_BLOCK_PTR->succ || ENTRY_BLOCK_PTR->succ->succ_next)
7792 insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
7797 /* If the exit block has no non-fake predecessors, we don't need
7799 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7800 if ((e->flags & EDGE_FAKE) == 0)
7806 if (optimize && HAVE_return)
7808 /* If we're allowed to generate a simple return instruction,
7809 then by definition we don't need a full epilogue. Examine
7810 the block that falls through to EXIT. If it does not
7811 contain any code, examine its predecessors and try to
7812 emit (conditional) return instructions. */
7818 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7819 if (e->flags & EDGE_FALLTHRU)
7825 /* Verify that there are no active instructions in the last block. */
7826 label = BB_END (last);
7827 while (label && GET_CODE (label) != CODE_LABEL)
7829 if (active_insn_p (label))
7831 label = PREV_INSN (label);
7834 if (BB_HEAD (last) == label && GET_CODE (label) == CODE_LABEL)
7836 rtx epilogue_line_note = NULL_RTX;
7838 /* Locate the line number associated with the closing brace,
7839 if we can find one. */
7840 for (seq = get_last_insn ();
7841 seq && ! active_insn_p (seq);
7842 seq = PREV_INSN (seq))
7843 if (GET_CODE (seq) == NOTE && NOTE_LINE_NUMBER (seq) > 0)
7845 epilogue_line_note = seq;
7849 for (e = last->pred; e; e = e_next)
7851 basic_block bb = e->src;
7854 e_next = e->pred_next;
7855 if (bb == ENTRY_BLOCK_PTR)
7859 if ((GET_CODE (jump) != JUMP_INSN) || JUMP_LABEL (jump) != label)
7862 /* If we have an unconditional jump, we can replace that
7863 with a simple return instruction. */
7864 if (simplejump_p (jump))
7866 emit_return_into_block (bb, epilogue_line_note);
7870 /* If we have a conditional jump, we can try to replace
7871 that with a conditional return instruction. */
7872 else if (condjump_p (jump))
7874 if (! redirect_jump (jump, 0, 0))
7877 /* If this block has only one successor, it both jumps
7878 and falls through to the fallthru block, so we can't
7880 if (bb->succ->succ_next == NULL)
7886 /* Fix up the CFG for the successful change we just made. */
7887 redirect_edge_succ (e, EXIT_BLOCK_PTR);
7890 /* Emit a return insn for the exit fallthru block. Whether
7891 this is still reachable will be determined later. */
7893 emit_barrier_after (BB_END (last));
7894 emit_return_into_block (last, epilogue_line_note);
7895 epilogue_end = BB_END (last);
7896 last->succ->flags &= ~EDGE_FALLTHRU;
7901 #ifdef HAVE_epilogue
7904 /* Find the edge that falls through to EXIT. Other edges may exist
7905 due to RETURN instructions, but those don't need epilogues.
7906 There really shouldn't be a mixture -- either all should have
7907 been converted or none, however... */
7909 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7910 if (e->flags & EDGE_FALLTHRU)
7916 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
7918 seq = gen_epilogue ();
7920 #ifdef INCOMING_RETURN_ADDR_RTX
7921 /* If this function returns with the stack depressed and we can support
7922 it, massage the epilogue to actually do that. */
7923 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
7924 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
7925 seq = keep_stack_depressed (seq);
7928 emit_jump_insn (seq);
7930 /* Retain a map of the epilogue insns. */
7931 record_insns (seq, &epilogue);
7932 set_insn_locators (seq, epilogue_locator);
7937 insert_insn_on_edge (seq, e);
7944 commit_edge_insertions ();
7946 #ifdef HAVE_sibcall_epilogue
7947 /* Emit sibling epilogues before any sibling call sites. */
7948 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7950 basic_block bb = e->src;
7951 rtx insn = BB_END (bb);
7955 if (GET_CODE (insn) != CALL_INSN
7956 || ! SIBLING_CALL_P (insn))
7960 emit_insn (gen_sibcall_epilogue ());
7964 /* Retain a map of the epilogue insns. Used in life analysis to
7965 avoid getting rid of sibcall epilogue insns. Do this before we
7966 actually emit the sequence. */
7967 record_insns (seq, &sibcall_epilogue);
7968 set_insn_locators (seq, epilogue_locator);
7970 i = PREV_INSN (insn);
7971 newinsn = emit_insn_before (seq, insn);
7975 #ifdef HAVE_prologue
7976 /* This is probably all useless now that we use locators. */
7981 /* GDB handles `break f' by setting a breakpoint on the first
7982 line note after the prologue. Which means (1) that if
7983 there are line number notes before where we inserted the
7984 prologue we should move them, and (2) we should generate a
7985 note before the end of the first basic block, if there isn't
7988 ??? This behavior is completely broken when dealing with
7989 multiple entry functions. We simply place the note always
7990 into first basic block and let alternate entry points
7994 for (insn = prologue_end; insn; insn = prev)
7996 prev = PREV_INSN (insn);
7997 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7999 /* Note that we cannot reorder the first insn in the
8000 chain, since rest_of_compilation relies on that
8001 remaining constant. */
8004 reorder_insns (insn, insn, prologue_end);
8008 /* Find the last line number note in the first block. */
8009 for (insn = BB_END (ENTRY_BLOCK_PTR->next_bb);
8010 insn != prologue_end && insn;
8011 insn = PREV_INSN (insn))
8012 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
8015 /* If we didn't find one, make a copy of the first line number
8019 for (insn = next_active_insn (prologue_end);
8021 insn = PREV_INSN (insn))
8022 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
8024 emit_note_copy_after (insn, prologue_end);
8030 #ifdef HAVE_epilogue
8035 /* Similarly, move any line notes that appear after the epilogue.
8036 There is no need, however, to be quite so anal about the existence
8037 of such a note. Also move the NOTE_INSN_FUNCTION_END and (possibly)
8038 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
8040 for (insn = epilogue_end; insn; insn = next)
8042 next = NEXT_INSN (insn);
8043 if (GET_CODE (insn) == NOTE
8044 && (NOTE_LINE_NUMBER (insn) > 0
8045 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG
8046 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END))
8047 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
8053 /* Reposition the prologue-end and epilogue-begin notes after instruction
8054 scheduling and delayed branch scheduling. */
8057 reposition_prologue_and_epilogue_notes (rtx f ATTRIBUTE_UNUSED)
8059 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
8060 rtx insn, last, note;
8063 if ((len = VARRAY_SIZE (prologue)) > 0)
8067 /* Scan from the beginning until we reach the last prologue insn.
8068 We apparently can't depend on basic_block_{head,end} after
8070 for (insn = f; insn; insn = NEXT_INSN (insn))
8072 if (GET_CODE (insn) == NOTE)
8074 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
8077 else if (contains (insn, prologue))
8087 /* Find the prologue-end note if we haven't already, and
8088 move it to just after the last prologue insn. */
8091 for (note = last; (note = NEXT_INSN (note));)
8092 if (GET_CODE (note) == NOTE
8093 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
8097 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
8098 if (GET_CODE (last) == CODE_LABEL)
8099 last = NEXT_INSN (last);
8100 reorder_insns (note, note, last);
8104 if ((len = VARRAY_SIZE (epilogue)) > 0)
8108 /* Scan from the end until we reach the first epilogue insn.
8109 We apparently can't depend on basic_block_{head,end} after
8111 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
8113 if (GET_CODE (insn) == NOTE)
8115 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
8118 else if (contains (insn, epilogue))
8128 /* Find the epilogue-begin note if we haven't already, and
8129 move it to just before the first epilogue insn. */
8132 for (note = insn; (note = PREV_INSN (note));)
8133 if (GET_CODE (note) == NOTE
8134 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
8138 if (PREV_INSN (last) != note)
8139 reorder_insns (note, note, PREV_INSN (last));
8142 #endif /* HAVE_prologue or HAVE_epilogue */
8145 /* Called once, at initialization, to initialize function.c. */
8148 init_function_once (void)
8150 VARRAY_INT_INIT (prologue, 0, "prologue");
8151 VARRAY_INT_INIT (epilogue, 0, "epilogue");
8152 VARRAY_INT_INIT (sibcall_epilogue, 0, "sibcall_epilogue");
8155 /* Returns the name of the current function. */
8157 current_function_name (void)
8159 return lang_hooks.decl_printable_name (cfun->decl, 2);
8162 #include "gt-function.h"