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, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
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. */
38 #include "coretypes.h"
49 #include "hard-reg-set.h"
50 #include "insn-config.h"
53 #include "basic-block.h"
58 #include "integrate.h"
59 #include "langhooks.h"
61 #include "cfglayout.h"
62 #include "tree-gimple.h"
63 #include "tree-pass.h"
69 /* So we can assign to cfun in this file. */
72 #ifndef LOCAL_ALIGNMENT
73 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
76 #ifndef STACK_ALIGNMENT_NEEDED
77 #define STACK_ALIGNMENT_NEEDED 1
80 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
82 /* Some systems use __main in a way incompatible with its use in gcc, in these
83 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
84 give the same symbol without quotes for an alternative entry point. You
85 must define both, or neither. */
87 #define NAME__MAIN "__main"
90 /* Round a value to the lowest integer less than it that is a multiple of
91 the required alignment. Avoid using division in case the value is
92 negative. Assume the alignment is a power of two. */
93 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
95 /* Similar, but round to the next highest integer that meets the
97 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
99 /* Nonzero if function being compiled doesn't contain any calls
100 (ignoring the prologue and epilogue). This is set prior to
101 local register allocation and is valid for the remaining
103 int current_function_is_leaf;
105 /* Nonzero if function being compiled doesn't modify the stack pointer
106 (ignoring the prologue and epilogue). This is only valid after
107 pass_stack_ptr_mod has run. */
108 int current_function_sp_is_unchanging;
110 /* Nonzero if the function being compiled is a leaf function which only
111 uses leaf registers. This is valid after reload (specifically after
112 sched2) and is useful only if the port defines LEAF_REGISTERS. */
113 int current_function_uses_only_leaf_regs;
115 /* Nonzero once virtual register instantiation has been done.
116 assign_stack_local uses frame_pointer_rtx when this is nonzero.
117 calls.c:emit_library_call_value_1 uses it to set up
118 post-instantiation libcalls. */
119 int virtuals_instantiated;
121 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
122 static GTY(()) int funcdef_no;
124 /* These variables hold pointers to functions to create and destroy
125 target specific, per-function data structures. */
126 struct machine_function * (*init_machine_status) (void);
128 /* The currently compiled function. */
129 struct function *cfun = 0;
131 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
132 static VEC(int,heap) *prologue;
133 static VEC(int,heap) *epilogue;
135 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
137 static VEC(int,heap) *sibcall_epilogue;
139 /* In order to evaluate some expressions, such as function calls returning
140 structures in memory, we need to temporarily allocate stack locations.
141 We record each allocated temporary in the following structure.
143 Associated with each temporary slot is a nesting level. When we pop up
144 one level, all temporaries associated with the previous level are freed.
145 Normally, all temporaries are freed after the execution of the statement
146 in which they were created. However, if we are inside a ({...}) grouping,
147 the result may be in a temporary and hence must be preserved. If the
148 result could be in a temporary, we preserve it if we can determine which
149 one it is in. If we cannot determine which temporary may contain the
150 result, all temporaries are preserved. A temporary is preserved by
151 pretending it was allocated at the previous nesting level.
153 Automatic variables are also assigned temporary slots, at the nesting
154 level where they are defined. They are marked a "kept" so that
155 free_temp_slots will not free them. */
157 struct temp_slot GTY(())
159 /* Points to next temporary slot. */
160 struct temp_slot *next;
161 /* Points to previous temporary slot. */
162 struct temp_slot *prev;
164 /* The rtx to used to reference the slot. */
166 /* The rtx used to represent the address if not the address of the
167 slot above. May be an EXPR_LIST if multiple addresses exist. */
169 /* The alignment (in bits) of the slot. */
171 /* The size, in units, of the slot. */
173 /* The type of the object in the slot, or zero if it doesn't correspond
174 to a type. We use this to determine whether a slot can be reused.
175 It can be reused if objects of the type of the new slot will always
176 conflict with objects of the type of the old slot. */
178 /* Nonzero if this temporary is currently in use. */
180 /* Nonzero if this temporary has its address taken. */
182 /* Nesting level at which this slot is being used. */
184 /* Nonzero if this should survive a call to free_temp_slots. */
186 /* The offset of the slot from the frame_pointer, including extra space
187 for alignment. This info is for combine_temp_slots. */
188 HOST_WIDE_INT base_offset;
189 /* The size of the slot, including extra space for alignment. This
190 info is for combine_temp_slots. */
191 HOST_WIDE_INT full_size;
194 /* Forward declarations. */
196 static struct temp_slot *find_temp_slot_from_address (rtx);
197 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
198 static void pad_below (struct args_size *, enum machine_mode, tree);
199 static void reorder_blocks_1 (rtx, tree, VEC(tree,heap) **);
200 static int all_blocks (tree, tree *);
201 static tree *get_block_vector (tree, int *);
202 extern tree debug_find_var_in_block_tree (tree, tree);
203 /* We always define `record_insns' even if it's not used so that we
204 can always export `prologue_epilogue_contains'. */
205 static void record_insns (rtx, VEC(int,heap) **) ATTRIBUTE_UNUSED;
206 static int contains (const_rtx, VEC(int,heap) **);
208 static void emit_return_into_block (basic_block);
210 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
211 static rtx keep_stack_depressed (rtx);
213 static void prepare_function_start (void);
214 static void do_clobber_return_reg (rtx, void *);
215 static void do_use_return_reg (rtx, void *);
216 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
218 /* Pointer to chain of `struct function' for containing functions. */
219 struct function *outer_function_chain;
221 /* Given a function decl for a containing function,
222 return the `struct function' for it. */
225 find_function_data (tree decl)
229 for (p = outer_function_chain; p; p = p->outer)
236 /* Save the current context for compilation of a nested function.
237 This is called from language-specific code. */
240 push_function_context (void)
243 allocate_struct_function (NULL, false);
245 cfun->outer = outer_function_chain;
246 outer_function_chain = cfun;
250 /* Restore the last saved context, at the end of a nested function.
251 This function is called from language-specific code. */
254 pop_function_context (void)
256 struct function *p = outer_function_chain;
259 outer_function_chain = p->outer;
260 current_function_decl = p->decl;
262 /* Reset variables that have known state during rtx generation. */
263 virtuals_instantiated = 0;
264 generating_concat_p = 1;
267 /* Clear out all parts of the state in F that can safely be discarded
268 after the function has been parsed, but not compiled, to let
269 garbage collection reclaim the memory. */
272 free_after_parsing (struct function *f)
274 /* f->expr->forced_labels is used by code generation. */
275 /* f->emit->regno_reg_rtx is used by code generation. */
276 /* f->varasm is used by code generation. */
277 /* f->eh->eh_return_stub_label is used by code generation. */
279 lang_hooks.function.final (f);
282 /* Clear out all parts of the state in F that can safely be discarded
283 after the function has been compiled, to let garbage collection
284 reclaim the memory. */
287 free_after_compilation (struct function *f)
289 VEC_free (int, heap, prologue);
290 VEC_free (int, heap, epilogue);
291 VEC_free (int, heap, sibcall_epilogue);
292 if (rtl.emit.regno_pointer_align)
293 free (rtl.emit.regno_pointer_align);
295 memset (&rtl, 0, sizeof (rtl));
300 f->arg_offset_rtx = NULL;
301 f->return_rtx = NULL;
302 f->internal_arg_pointer = NULL;
303 f->epilogue_delay_list = NULL;
306 /* Return size needed for stack frame based on slots so far allocated.
307 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
308 the caller may have to do that. */
311 get_frame_size (void)
313 if (FRAME_GROWS_DOWNWARD)
314 return -frame_offset;
319 /* Issue an error message and return TRUE if frame OFFSET overflows in
320 the signed target pointer arithmetics for function FUNC. Otherwise
324 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
326 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
328 if (size > ((unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (Pmode) - 1))
329 /* Leave room for the fixed part of the frame. */
330 - 64 * UNITS_PER_WORD)
332 error ("%Jtotal size of local objects too large", func);
339 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
340 with machine mode MODE.
342 ALIGN controls the amount of alignment for the address of the slot:
343 0 means according to MODE,
344 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
345 -2 means use BITS_PER_UNIT,
346 positive specifies alignment boundary in bits.
348 We do not round to stack_boundary here. */
351 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
354 int bigend_correction = 0;
355 unsigned int alignment;
356 int frame_off, frame_alignment, frame_phase;
363 alignment = BIGGEST_ALIGNMENT;
365 alignment = GET_MODE_ALIGNMENT (mode);
367 /* Allow the target to (possibly) increase the alignment of this
369 type = lang_hooks.types.type_for_mode (mode, 0);
371 alignment = LOCAL_ALIGNMENT (type, alignment);
373 alignment /= BITS_PER_UNIT;
375 else if (align == -1)
377 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
378 size = CEIL_ROUND (size, alignment);
380 else if (align == -2)
381 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
383 alignment = align / BITS_PER_UNIT;
385 if (FRAME_GROWS_DOWNWARD)
386 frame_offset -= size;
388 /* Ignore alignment we can't do with expected alignment of the boundary. */
389 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
390 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
392 if (cfun->stack_alignment_needed < alignment * BITS_PER_UNIT)
393 cfun->stack_alignment_needed = alignment * BITS_PER_UNIT;
395 /* Calculate how many bytes the start of local variables is off from
397 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
398 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
399 frame_phase = frame_off ? frame_alignment - frame_off : 0;
401 /* Round the frame offset to the specified alignment. The default is
402 to always honor requests to align the stack but a port may choose to
403 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
404 if (STACK_ALIGNMENT_NEEDED
408 /* We must be careful here, since FRAME_OFFSET might be negative and
409 division with a negative dividend isn't as well defined as we might
410 like. So we instead assume that ALIGNMENT is a power of two and
411 use logical operations which are unambiguous. */
412 if (FRAME_GROWS_DOWNWARD)
414 = (FLOOR_ROUND (frame_offset - frame_phase,
415 (unsigned HOST_WIDE_INT) alignment)
419 = (CEIL_ROUND (frame_offset - frame_phase,
420 (unsigned HOST_WIDE_INT) alignment)
424 /* On a big-endian machine, if we are allocating more space than we will use,
425 use the least significant bytes of those that are allocated. */
426 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
427 bigend_correction = size - GET_MODE_SIZE (mode);
429 /* If we have already instantiated virtual registers, return the actual
430 address relative to the frame pointer. */
431 if (virtuals_instantiated)
432 addr = plus_constant (frame_pointer_rtx,
434 (frame_offset + bigend_correction
435 + STARTING_FRAME_OFFSET, Pmode));
437 addr = plus_constant (virtual_stack_vars_rtx,
439 (frame_offset + bigend_correction,
442 if (!FRAME_GROWS_DOWNWARD)
443 frame_offset += size;
445 x = gen_rtx_MEM (mode, addr);
446 MEM_NOTRAP_P (x) = 1;
449 = gen_rtx_EXPR_LIST (VOIDmode, x, stack_slot_list);
451 if (frame_offset_overflow (frame_offset, current_function_decl))
457 /* Removes temporary slot TEMP from LIST. */
460 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
463 temp->next->prev = temp->prev;
465 temp->prev->next = temp->next;
469 temp->prev = temp->next = NULL;
472 /* Inserts temporary slot TEMP to LIST. */
475 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
479 (*list)->prev = temp;
484 /* Returns the list of used temp slots at LEVEL. */
486 static struct temp_slot **
487 temp_slots_at_level (int level)
489 if (level >= (int) VEC_length (temp_slot_p, used_temp_slots))
490 VEC_safe_grow_cleared (temp_slot_p, gc, used_temp_slots, level + 1);
492 return &(VEC_address (temp_slot_p, used_temp_slots)[level]);
495 /* Returns the maximal temporary slot level. */
498 max_slot_level (void)
500 if (!used_temp_slots)
503 return VEC_length (temp_slot_p, used_temp_slots) - 1;
506 /* Moves temporary slot TEMP to LEVEL. */
509 move_slot_to_level (struct temp_slot *temp, int level)
511 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
512 insert_slot_to_list (temp, temp_slots_at_level (level));
516 /* Make temporary slot TEMP available. */
519 make_slot_available (struct temp_slot *temp)
521 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
522 insert_slot_to_list (temp, &avail_temp_slots);
527 /* Allocate a temporary stack slot and record it for possible later
530 MODE is the machine mode to be given to the returned rtx.
532 SIZE is the size in units of the space required. We do no rounding here
533 since assign_stack_local will do any required rounding.
535 KEEP is 1 if this slot is to be retained after a call to
536 free_temp_slots. Automatic variables for a block are allocated
537 with this flag. KEEP values of 2 or 3 were needed respectively
538 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
539 or for SAVE_EXPRs, but they are now unused.
541 TYPE is the type that will be used for the stack slot. */
544 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size,
548 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
551 /* If SIZE is -1 it means that somebody tried to allocate a temporary
552 of a variable size. */
553 gcc_assert (size != -1);
555 /* These are now unused. */
556 gcc_assert (keep <= 1);
559 align = BIGGEST_ALIGNMENT;
561 align = GET_MODE_ALIGNMENT (mode);
564 type = lang_hooks.types.type_for_mode (mode, 0);
567 align = LOCAL_ALIGNMENT (type, align);
569 /* Try to find an available, already-allocated temporary of the proper
570 mode which meets the size and alignment requirements. Choose the
571 smallest one with the closest alignment.
573 If assign_stack_temp is called outside of the tree->rtl expansion,
574 we cannot reuse the stack slots (that may still refer to
575 VIRTUAL_STACK_VARS_REGNUM). */
576 if (!virtuals_instantiated)
578 for (p = avail_temp_slots; p; p = p->next)
580 if (p->align >= align && p->size >= size
581 && GET_MODE (p->slot) == mode
582 && objects_must_conflict_p (p->type, type)
583 && (best_p == 0 || best_p->size > p->size
584 || (best_p->size == p->size && best_p->align > p->align)))
586 if (p->align == align && p->size == size)
589 cut_slot_from_list (selected, &avail_temp_slots);
598 /* Make our best, if any, the one to use. */
602 cut_slot_from_list (selected, &avail_temp_slots);
604 /* If there are enough aligned bytes left over, make them into a new
605 temp_slot so that the extra bytes don't get wasted. Do this only
606 for BLKmode slots, so that we can be sure of the alignment. */
607 if (GET_MODE (best_p->slot) == BLKmode)
609 int alignment = best_p->align / BITS_PER_UNIT;
610 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
612 if (best_p->size - rounded_size >= alignment)
614 p = ggc_alloc (sizeof (struct temp_slot));
615 p->in_use = p->addr_taken = 0;
616 p->size = best_p->size - rounded_size;
617 p->base_offset = best_p->base_offset + rounded_size;
618 p->full_size = best_p->full_size - rounded_size;
619 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
620 p->align = best_p->align;
622 p->type = best_p->type;
623 insert_slot_to_list (p, &avail_temp_slots);
625 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
628 best_p->size = rounded_size;
629 best_p->full_size = rounded_size;
634 /* If we still didn't find one, make a new temporary. */
637 HOST_WIDE_INT frame_offset_old = frame_offset;
639 p = ggc_alloc (sizeof (struct temp_slot));
641 /* We are passing an explicit alignment request to assign_stack_local.
642 One side effect of that is assign_stack_local will not round SIZE
643 to ensure the frame offset remains suitably aligned.
645 So for requests which depended on the rounding of SIZE, we go ahead
646 and round it now. We also make sure ALIGNMENT is at least
647 BIGGEST_ALIGNMENT. */
648 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
649 p->slot = assign_stack_local (mode,
651 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
657 /* The following slot size computation is necessary because we don't
658 know the actual size of the temporary slot until assign_stack_local
659 has performed all the frame alignment and size rounding for the
660 requested temporary. Note that extra space added for alignment
661 can be either above or below this stack slot depending on which
662 way the frame grows. We include the extra space if and only if it
663 is above this slot. */
664 if (FRAME_GROWS_DOWNWARD)
665 p->size = frame_offset_old - frame_offset;
669 /* Now define the fields used by combine_temp_slots. */
670 if (FRAME_GROWS_DOWNWARD)
672 p->base_offset = frame_offset;
673 p->full_size = frame_offset_old - frame_offset;
677 p->base_offset = frame_offset_old;
678 p->full_size = frame_offset - frame_offset_old;
689 p->level = temp_slot_level;
692 pp = temp_slots_at_level (p->level);
693 insert_slot_to_list (p, pp);
695 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
696 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
697 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
699 /* If we know the alias set for the memory that will be used, use
700 it. If there's no TYPE, then we don't know anything about the
701 alias set for the memory. */
702 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
703 set_mem_align (slot, align);
705 /* If a type is specified, set the relevant flags. */
708 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
709 MEM_SET_IN_STRUCT_P (slot, (AGGREGATE_TYPE_P (type)
710 || TREE_CODE (type) == COMPLEX_TYPE));
712 MEM_NOTRAP_P (slot) = 1;
717 /* Allocate a temporary stack slot and record it for possible later
718 reuse. First three arguments are same as in preceding function. */
721 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
723 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
726 /* Assign a temporary.
727 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
728 and so that should be used in error messages. In either case, we
729 allocate of the given type.
730 KEEP is as for assign_stack_temp.
731 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
732 it is 0 if a register is OK.
733 DONT_PROMOTE is 1 if we should not promote values in register
737 assign_temp (tree type_or_decl, int keep, int memory_required,
738 int dont_promote ATTRIBUTE_UNUSED)
741 enum machine_mode mode;
746 if (DECL_P (type_or_decl))
747 decl = type_or_decl, type = TREE_TYPE (decl);
749 decl = NULL, type = type_or_decl;
751 mode = TYPE_MODE (type);
753 unsignedp = TYPE_UNSIGNED (type);
756 if (mode == BLKmode || memory_required)
758 HOST_WIDE_INT size = int_size_in_bytes (type);
761 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
762 problems with allocating the stack space. */
766 /* Unfortunately, we don't yet know how to allocate variable-sized
767 temporaries. However, sometimes we can find a fixed upper limit on
768 the size, so try that instead. */
770 size = max_int_size_in_bytes (type);
772 /* The size of the temporary may be too large to fit into an integer. */
773 /* ??? Not sure this should happen except for user silliness, so limit
774 this to things that aren't compiler-generated temporaries. The
775 rest of the time we'll die in assign_stack_temp_for_type. */
776 if (decl && size == -1
777 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
779 error ("size of variable %q+D is too large", decl);
783 tmp = assign_stack_temp_for_type (mode, size, keep, type);
789 mode = promote_mode (type, mode, &unsignedp, 0);
792 return gen_reg_rtx (mode);
795 /* Combine temporary stack slots which are adjacent on the stack.
797 This allows for better use of already allocated stack space. This is only
798 done for BLKmode slots because we can be sure that we won't have alignment
799 problems in this case. */
802 combine_temp_slots (void)
804 struct temp_slot *p, *q, *next, *next_q;
807 /* We can't combine slots, because the information about which slot
808 is in which alias set will be lost. */
809 if (flag_strict_aliasing)
812 /* If there are a lot of temp slots, don't do anything unless
813 high levels of optimization. */
814 if (! flag_expensive_optimizations)
815 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
816 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
819 for (p = avail_temp_slots; p; p = next)
825 if (GET_MODE (p->slot) != BLKmode)
828 for (q = p->next; q; q = next_q)
834 if (GET_MODE (q->slot) != BLKmode)
837 if (p->base_offset + p->full_size == q->base_offset)
839 /* Q comes after P; combine Q into P. */
841 p->full_size += q->full_size;
844 else if (q->base_offset + q->full_size == p->base_offset)
846 /* P comes after Q; combine P into Q. */
848 q->full_size += p->full_size;
853 cut_slot_from_list (q, &avail_temp_slots);
856 /* Either delete P or advance past it. */
858 cut_slot_from_list (p, &avail_temp_slots);
862 /* Find the temp slot corresponding to the object at address X. */
864 static struct temp_slot *
865 find_temp_slot_from_address (rtx x)
871 for (i = max_slot_level (); i >= 0; i--)
872 for (p = *temp_slots_at_level (i); p; p = p->next)
874 if (XEXP (p->slot, 0) == x
876 || (GET_CODE (x) == PLUS
877 && XEXP (x, 0) == virtual_stack_vars_rtx
878 && GET_CODE (XEXP (x, 1)) == CONST_INT
879 && INTVAL (XEXP (x, 1)) >= p->base_offset
880 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
883 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
884 for (next = p->address; next; next = XEXP (next, 1))
885 if (XEXP (next, 0) == x)
889 /* If we have a sum involving a register, see if it points to a temp
891 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
892 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
894 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
895 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
901 /* Indicate that NEW is an alternate way of referring to the temp slot
902 that previously was known by OLD. */
905 update_temp_slot_address (rtx old, rtx new)
909 if (rtx_equal_p (old, new))
912 p = find_temp_slot_from_address (old);
914 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
915 is a register, see if one operand of the PLUS is a temporary
916 location. If so, NEW points into it. Otherwise, if both OLD and
917 NEW are a PLUS and if there is a register in common between them.
918 If so, try a recursive call on those values. */
921 if (GET_CODE (old) != PLUS)
926 update_temp_slot_address (XEXP (old, 0), new);
927 update_temp_slot_address (XEXP (old, 1), new);
930 else if (GET_CODE (new) != PLUS)
933 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
934 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
935 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
936 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
937 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
938 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
939 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
940 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
945 /* Otherwise add an alias for the temp's address. */
946 else if (p->address == 0)
950 if (GET_CODE (p->address) != EXPR_LIST)
951 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
953 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
957 /* If X could be a reference to a temporary slot, mark the fact that its
958 address was taken. */
961 mark_temp_addr_taken (rtx x)
968 /* If X is not in memory or is at a constant address, it cannot be in
970 if (!MEM_P (x) || CONSTANT_P (XEXP (x, 0)))
973 p = find_temp_slot_from_address (XEXP (x, 0));
978 /* If X could be a reference to a temporary slot, mark that slot as
979 belonging to the to one level higher than the current level. If X
980 matched one of our slots, just mark that one. Otherwise, we can't
981 easily predict which it is, so upgrade all of them. Kept slots
984 This is called when an ({...}) construct occurs and a statement
985 returns a value in memory. */
988 preserve_temp_slots (rtx x)
990 struct temp_slot *p = 0, *next;
992 /* If there is no result, we still might have some objects whose address
993 were taken, so we need to make sure they stay around. */
996 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1001 move_slot_to_level (p, temp_slot_level - 1);
1007 /* If X is a register that is being used as a pointer, see if we have
1008 a temporary slot we know it points to. To be consistent with
1009 the code below, we really should preserve all non-kept slots
1010 if we can't find a match, but that seems to be much too costly. */
1011 if (REG_P (x) && REG_POINTER (x))
1012 p = find_temp_slot_from_address (x);
1014 /* If X is not in memory or is at a constant address, it cannot be in
1015 a temporary slot, but it can contain something whose address was
1017 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1019 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1024 move_slot_to_level (p, temp_slot_level - 1);
1030 /* First see if we can find a match. */
1032 p = find_temp_slot_from_address (XEXP (x, 0));
1036 /* Move everything at our level whose address was taken to our new
1037 level in case we used its address. */
1038 struct temp_slot *q;
1040 if (p->level == temp_slot_level)
1042 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1046 if (p != q && q->addr_taken)
1047 move_slot_to_level (q, temp_slot_level - 1);
1050 move_slot_to_level (p, temp_slot_level - 1);
1056 /* Otherwise, preserve all non-kept slots at this level. */
1057 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1062 move_slot_to_level (p, temp_slot_level - 1);
1066 /* Free all temporaries used so far. This is normally called at the
1067 end of generating code for a statement. */
1070 free_temp_slots (void)
1072 struct temp_slot *p, *next;
1074 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1079 make_slot_available (p);
1082 combine_temp_slots ();
1085 /* Push deeper into the nesting level for stack temporaries. */
1088 push_temp_slots (void)
1093 /* Pop a temporary nesting level. All slots in use in the current level
1097 pop_temp_slots (void)
1099 struct temp_slot *p, *next;
1101 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1104 make_slot_available (p);
1107 combine_temp_slots ();
1112 /* Initialize temporary slots. */
1115 init_temp_slots (void)
1117 /* We have not allocated any temporaries yet. */
1118 avail_temp_slots = 0;
1119 used_temp_slots = 0;
1120 temp_slot_level = 0;
1123 /* These routines are responsible for converting virtual register references
1124 to the actual hard register references once RTL generation is complete.
1126 The following four variables are used for communication between the
1127 routines. They contain the offsets of the virtual registers from their
1128 respective hard registers. */
1130 static int in_arg_offset;
1131 static int var_offset;
1132 static int dynamic_offset;
1133 static int out_arg_offset;
1134 static int cfa_offset;
1136 /* In most machines, the stack pointer register is equivalent to the bottom
1139 #ifndef STACK_POINTER_OFFSET
1140 #define STACK_POINTER_OFFSET 0
1143 /* If not defined, pick an appropriate default for the offset of dynamically
1144 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1145 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1147 #ifndef STACK_DYNAMIC_OFFSET
1149 /* The bottom of the stack points to the actual arguments. If
1150 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1151 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1152 stack space for register parameters is not pushed by the caller, but
1153 rather part of the fixed stack areas and hence not included in
1154 `current_function_outgoing_args_size'. Nevertheless, we must allow
1155 for it when allocating stack dynamic objects. */
1157 #if defined(REG_PARM_STACK_SPACE)
1158 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1159 ((ACCUMULATE_OUTGOING_ARGS \
1160 ? (current_function_outgoing_args_size \
1161 + (OUTGOING_REG_PARM_STACK_SPACE ? 0 : REG_PARM_STACK_SPACE (FNDECL))) \
1162 : 0) + (STACK_POINTER_OFFSET))
1164 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1165 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
1166 + (STACK_POINTER_OFFSET))
1171 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1172 is a virtual register, return the equivalent hard register and set the
1173 offset indirectly through the pointer. Otherwise, return 0. */
1176 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1179 HOST_WIDE_INT offset;
1181 if (x == virtual_incoming_args_rtx)
1182 new = arg_pointer_rtx, offset = in_arg_offset;
1183 else if (x == virtual_stack_vars_rtx)
1184 new = frame_pointer_rtx, offset = var_offset;
1185 else if (x == virtual_stack_dynamic_rtx)
1186 new = stack_pointer_rtx, offset = dynamic_offset;
1187 else if (x == virtual_outgoing_args_rtx)
1188 new = stack_pointer_rtx, offset = out_arg_offset;
1189 else if (x == virtual_cfa_rtx)
1191 #ifdef FRAME_POINTER_CFA_OFFSET
1192 new = frame_pointer_rtx;
1194 new = arg_pointer_rtx;
1196 offset = cfa_offset;
1205 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1206 Instantiate any virtual registers present inside of *LOC. The expression
1207 is simplified, as much as possible, but is not to be considered "valid"
1208 in any sense implied by the target. If any change is made, set CHANGED
1212 instantiate_virtual_regs_in_rtx (rtx *loc, void *data)
1214 HOST_WIDE_INT offset;
1215 bool *changed = (bool *) data;
1222 switch (GET_CODE (x))
1225 new = instantiate_new_reg (x, &offset);
1228 *loc = plus_constant (new, offset);
1235 new = instantiate_new_reg (XEXP (x, 0), &offset);
1238 new = plus_constant (new, offset);
1239 *loc = simplify_gen_binary (PLUS, GET_MODE (x), new, XEXP (x, 1));
1245 /* FIXME -- from old code */
1246 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1247 we can commute the PLUS and SUBREG because pointers into the
1248 frame are well-behaved. */
1258 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1259 matches the predicate for insn CODE operand OPERAND. */
1262 safe_insn_predicate (int code, int operand, rtx x)
1264 const struct insn_operand_data *op_data;
1269 op_data = &insn_data[code].operand[operand];
1270 if (op_data->predicate == NULL)
1273 return op_data->predicate (x, op_data->mode);
1276 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1277 registers present inside of insn. The result will be a valid insn. */
1280 instantiate_virtual_regs_in_insn (rtx insn)
1282 HOST_WIDE_INT offset;
1284 bool any_change = false;
1285 rtx set, new, x, seq;
1287 /* There are some special cases to be handled first. */
1288 set = single_set (insn);
1291 /* We're allowed to assign to a virtual register. This is interpreted
1292 to mean that the underlying register gets assigned the inverse
1293 transformation. This is used, for example, in the handling of
1295 new = instantiate_new_reg (SET_DEST (set), &offset);
1300 for_each_rtx (&SET_SRC (set), instantiate_virtual_regs_in_rtx, NULL);
1301 x = simplify_gen_binary (PLUS, GET_MODE (new), SET_SRC (set),
1303 x = force_operand (x, new);
1305 emit_move_insn (new, x);
1310 emit_insn_before (seq, insn);
1315 /* Handle a straight copy from a virtual register by generating a
1316 new add insn. The difference between this and falling through
1317 to the generic case is avoiding a new pseudo and eliminating a
1318 move insn in the initial rtl stream. */
1319 new = instantiate_new_reg (SET_SRC (set), &offset);
1320 if (new && offset != 0
1321 && REG_P (SET_DEST (set))
1322 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1326 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS,
1327 new, GEN_INT (offset), SET_DEST (set),
1328 1, OPTAB_LIB_WIDEN);
1329 if (x != SET_DEST (set))
1330 emit_move_insn (SET_DEST (set), x);
1335 emit_insn_before (seq, insn);
1340 extract_insn (insn);
1341 insn_code = INSN_CODE (insn);
1343 /* Handle a plus involving a virtual register by determining if the
1344 operands remain valid if they're modified in place. */
1345 if (GET_CODE (SET_SRC (set)) == PLUS
1346 && recog_data.n_operands >= 3
1347 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1348 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1349 && GET_CODE (recog_data.operand[2]) == CONST_INT
1350 && (new = instantiate_new_reg (recog_data.operand[1], &offset)))
1352 offset += INTVAL (recog_data.operand[2]);
1354 /* If the sum is zero, then replace with a plain move. */
1356 && REG_P (SET_DEST (set))
1357 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1360 emit_move_insn (SET_DEST (set), new);
1364 emit_insn_before (seq, insn);
1369 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1371 /* Using validate_change and apply_change_group here leaves
1372 recog_data in an invalid state. Since we know exactly what
1373 we want to check, do those two by hand. */
1374 if (safe_insn_predicate (insn_code, 1, new)
1375 && safe_insn_predicate (insn_code, 2, x))
1377 *recog_data.operand_loc[1] = recog_data.operand[1] = new;
1378 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1381 /* Fall through into the regular operand fixup loop in
1382 order to take care of operands other than 1 and 2. */
1388 extract_insn (insn);
1389 insn_code = INSN_CODE (insn);
1392 /* In the general case, we expect virtual registers to appear only in
1393 operands, and then only as either bare registers or inside memories. */
1394 for (i = 0; i < recog_data.n_operands; ++i)
1396 x = recog_data.operand[i];
1397 switch (GET_CODE (x))
1401 rtx addr = XEXP (x, 0);
1402 bool changed = false;
1404 for_each_rtx (&addr, instantiate_virtual_regs_in_rtx, &changed);
1409 x = replace_equiv_address (x, addr);
1410 /* It may happen that the address with the virtual reg
1411 was valid (e.g. based on the virtual stack reg, which might
1412 be acceptable to the predicates with all offsets), whereas
1413 the address now isn't anymore, for instance when the address
1414 is still offsetted, but the base reg isn't virtual-stack-reg
1415 anymore. Below we would do a force_reg on the whole operand,
1416 but this insn might actually only accept memory. Hence,
1417 before doing that last resort, try to reload the address into
1418 a register, so this operand stays a MEM. */
1419 if (!safe_insn_predicate (insn_code, i, x))
1421 addr = force_reg (GET_MODE (addr), addr);
1422 x = replace_equiv_address (x, addr);
1427 emit_insn_before (seq, insn);
1432 new = instantiate_new_reg (x, &offset);
1441 /* Careful, special mode predicates may have stuff in
1442 insn_data[insn_code].operand[i].mode that isn't useful
1443 to us for computing a new value. */
1444 /* ??? Recognize address_operand and/or "p" constraints
1445 to see if (plus new offset) is a valid before we put
1446 this through expand_simple_binop. */
1447 x = expand_simple_binop (GET_MODE (x), PLUS, new,
1448 GEN_INT (offset), NULL_RTX,
1449 1, OPTAB_LIB_WIDEN);
1452 emit_insn_before (seq, insn);
1457 new = instantiate_new_reg (SUBREG_REG (x), &offset);
1463 new = expand_simple_binop (GET_MODE (new), PLUS, new,
1464 GEN_INT (offset), NULL_RTX,
1465 1, OPTAB_LIB_WIDEN);
1468 emit_insn_before (seq, insn);
1470 x = simplify_gen_subreg (recog_data.operand_mode[i], new,
1471 GET_MODE (new), SUBREG_BYTE (x));
1478 /* At this point, X contains the new value for the operand.
1479 Validate the new value vs the insn predicate. Note that
1480 asm insns will have insn_code -1 here. */
1481 if (!safe_insn_predicate (insn_code, i, x))
1484 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1488 emit_insn_before (seq, insn);
1491 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1497 /* Propagate operand changes into the duplicates. */
1498 for (i = 0; i < recog_data.n_dups; ++i)
1499 *recog_data.dup_loc[i]
1500 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1502 /* Force re-recognition of the instruction for validation. */
1503 INSN_CODE (insn) = -1;
1506 if (asm_noperands (PATTERN (insn)) >= 0)
1508 if (!check_asm_operands (PATTERN (insn)))
1510 error_for_asm (insn, "impossible constraint in %<asm%>");
1516 if (recog_memoized (insn) < 0)
1517 fatal_insn_not_found (insn);
1521 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1522 do any instantiation required. */
1525 instantiate_decl_rtl (rtx x)
1532 /* If this is a CONCAT, recurse for the pieces. */
1533 if (GET_CODE (x) == CONCAT)
1535 instantiate_decl_rtl (XEXP (x, 0));
1536 instantiate_decl_rtl (XEXP (x, 1));
1540 /* If this is not a MEM, no need to do anything. Similarly if the
1541 address is a constant or a register that is not a virtual register. */
1546 if (CONSTANT_P (addr)
1548 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1549 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1552 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1555 /* Helper for instantiate_decls called via walk_tree: Process all decls
1556 in the given DECL_VALUE_EXPR. */
1559 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1562 if (! EXPR_P (t) && ! GIMPLE_STMT_P (t))
1565 if (DECL_P (t) && DECL_RTL_SET_P (t))
1566 instantiate_decl_rtl (DECL_RTL (t));
1571 /* Subroutine of instantiate_decls: Process all decls in the given
1572 BLOCK node and all its subblocks. */
1575 instantiate_decls_1 (tree let)
1579 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1581 if (DECL_RTL_SET_P (t))
1582 instantiate_decl_rtl (DECL_RTL (t));
1583 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1585 tree v = DECL_VALUE_EXPR (t);
1586 walk_tree (&v, instantiate_expr, NULL, NULL);
1590 /* Process all subblocks. */
1591 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1592 instantiate_decls_1 (t);
1595 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1596 all virtual registers in their DECL_RTL's. */
1599 instantiate_decls (tree fndecl)
1603 /* Process all parameters of the function. */
1604 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1606 instantiate_decl_rtl (DECL_RTL (decl));
1607 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1608 if (DECL_HAS_VALUE_EXPR_P (decl))
1610 tree v = DECL_VALUE_EXPR (decl);
1611 walk_tree (&v, instantiate_expr, NULL, NULL);
1615 /* Now process all variables defined in the function or its subblocks. */
1616 instantiate_decls_1 (DECL_INITIAL (fndecl));
1619 /* Pass through the INSNS of function FNDECL and convert virtual register
1620 references to hard register references. */
1623 instantiate_virtual_regs (void)
1627 /* Compute the offsets to use for this function. */
1628 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1629 var_offset = STARTING_FRAME_OFFSET;
1630 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1631 out_arg_offset = STACK_POINTER_OFFSET;
1632 #ifdef FRAME_POINTER_CFA_OFFSET
1633 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1635 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1638 /* Initialize recognition, indicating that volatile is OK. */
1641 /* Scan through all the insns, instantiating every virtual register still
1643 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1646 /* These patterns in the instruction stream can never be recognized.
1647 Fortunately, they shouldn't contain virtual registers either. */
1648 if (GET_CODE (PATTERN (insn)) == USE
1649 || GET_CODE (PATTERN (insn)) == CLOBBER
1650 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1651 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1652 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1655 instantiate_virtual_regs_in_insn (insn);
1657 if (INSN_DELETED_P (insn))
1660 for_each_rtx (®_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1662 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1663 if (GET_CODE (insn) == CALL_INSN)
1664 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1665 instantiate_virtual_regs_in_rtx, NULL);
1668 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1669 instantiate_decls (current_function_decl);
1671 targetm.instantiate_decls ();
1673 /* Indicate that, from now on, assign_stack_local should use
1674 frame_pointer_rtx. */
1675 virtuals_instantiated = 1;
1679 struct rtl_opt_pass pass_instantiate_virtual_regs =
1685 instantiate_virtual_regs, /* execute */
1688 0, /* static_pass_number */
1690 0, /* properties_required */
1691 0, /* properties_provided */
1692 0, /* properties_destroyed */
1693 0, /* todo_flags_start */
1694 TODO_dump_func /* todo_flags_finish */
1699 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1700 This means a type for which function calls must pass an address to the
1701 function or get an address back from the function.
1702 EXP may be a type node or an expression (whose type is tested). */
1705 aggregate_value_p (const_tree exp, const_tree fntype)
1707 int i, regno, nregs;
1710 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1712 /* DECL node associated with FNTYPE when relevant, which we might need to
1713 check for by-invisible-reference returns, typically for CALL_EXPR input
1715 const_tree fndecl = NULL_TREE;
1718 switch (TREE_CODE (fntype))
1721 fndecl = get_callee_fndecl (fntype);
1722 fntype = fndecl ? TREE_TYPE (fndecl) : 0;
1726 fntype = TREE_TYPE (fndecl);
1731 case IDENTIFIER_NODE:
1735 /* We don't expect other rtl types here. */
1739 if (TREE_CODE (type) == VOID_TYPE)
1742 /* If the front end has decided that this needs to be passed by
1743 reference, do so. */
1744 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1745 && DECL_BY_REFERENCE (exp))
1748 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1749 called function RESULT_DECL, meaning the function returns in memory by
1750 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1751 on the function type, which used to be the way to request such a return
1752 mechanism but might now be causing troubles at gimplification time if
1753 temporaries with the function type need to be created. */
1754 if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
1755 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
1758 if (targetm.calls.return_in_memory (type, fntype))
1760 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1761 and thus can't be returned in registers. */
1762 if (TREE_ADDRESSABLE (type))
1764 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1766 /* Make sure we have suitable call-clobbered regs to return
1767 the value in; if not, we must return it in memory. */
1768 reg = hard_function_value (type, 0, fntype, 0);
1770 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1775 regno = REGNO (reg);
1776 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1777 for (i = 0; i < nregs; i++)
1778 if (! call_used_regs[regno + i])
1783 /* Return true if we should assign DECL a pseudo register; false if it
1784 should live on the local stack. */
1787 use_register_for_decl (const_tree decl)
1789 /* Honor volatile. */
1790 if (TREE_SIDE_EFFECTS (decl))
1793 /* Honor addressability. */
1794 if (TREE_ADDRESSABLE (decl))
1797 /* Only register-like things go in registers. */
1798 if (DECL_MODE (decl) == BLKmode)
1801 /* If -ffloat-store specified, don't put explicit float variables
1803 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1804 propagates values across these stores, and it probably shouldn't. */
1805 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1808 /* If we're not interested in tracking debugging information for
1809 this decl, then we can certainly put it in a register. */
1810 if (DECL_IGNORED_P (decl))
1813 return (optimize || DECL_REGISTER (decl));
1816 /* Return true if TYPE should be passed by invisible reference. */
1819 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1820 tree type, bool named_arg)
1824 /* If this type contains non-trivial constructors, then it is
1825 forbidden for the middle-end to create any new copies. */
1826 if (TREE_ADDRESSABLE (type))
1829 /* GCC post 3.4 passes *all* variable sized types by reference. */
1830 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1834 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1837 /* Return true if TYPE, which is passed by reference, should be callee
1838 copied instead of caller copied. */
1841 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1842 tree type, bool named_arg)
1844 if (type && TREE_ADDRESSABLE (type))
1846 return targetm.calls.callee_copies (ca, mode, type, named_arg);
1849 /* Structures to communicate between the subroutines of assign_parms.
1850 The first holds data persistent across all parameters, the second
1851 is cleared out for each parameter. */
1853 struct assign_parm_data_all
1855 CUMULATIVE_ARGS args_so_far;
1856 struct args_size stack_args_size;
1857 tree function_result_decl;
1859 rtx first_conversion_insn;
1860 rtx last_conversion_insn;
1861 HOST_WIDE_INT pretend_args_size;
1862 HOST_WIDE_INT extra_pretend_bytes;
1863 int reg_parm_stack_space;
1866 struct assign_parm_data_one
1872 enum machine_mode nominal_mode;
1873 enum machine_mode passed_mode;
1874 enum machine_mode promoted_mode;
1875 struct locate_and_pad_arg_data locate;
1877 BOOL_BITFIELD named_arg : 1;
1878 BOOL_BITFIELD passed_pointer : 1;
1879 BOOL_BITFIELD on_stack : 1;
1880 BOOL_BITFIELD loaded_in_reg : 1;
1883 /* A subroutine of assign_parms. Initialize ALL. */
1886 assign_parms_initialize_all (struct assign_parm_data_all *all)
1890 memset (all, 0, sizeof (*all));
1892 fntype = TREE_TYPE (current_function_decl);
1894 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
1895 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
1897 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
1898 current_function_decl, -1);
1901 #ifdef REG_PARM_STACK_SPACE
1902 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
1906 /* If ARGS contains entries with complex types, split the entry into two
1907 entries of the component type. Return a new list of substitutions are
1908 needed, else the old list. */
1911 split_complex_args (tree args)
1915 /* Before allocating memory, check for the common case of no complex. */
1916 for (p = args; p; p = TREE_CHAIN (p))
1918 tree type = TREE_TYPE (p);
1919 if (TREE_CODE (type) == COMPLEX_TYPE
1920 && targetm.calls.split_complex_arg (type))
1926 args = copy_list (args);
1928 for (p = args; p; p = TREE_CHAIN (p))
1930 tree type = TREE_TYPE (p);
1931 if (TREE_CODE (type) == COMPLEX_TYPE
1932 && targetm.calls.split_complex_arg (type))
1935 tree subtype = TREE_TYPE (type);
1936 bool addressable = TREE_ADDRESSABLE (p);
1938 /* Rewrite the PARM_DECL's type with its component. */
1939 TREE_TYPE (p) = subtype;
1940 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
1941 DECL_MODE (p) = VOIDmode;
1942 DECL_SIZE (p) = NULL;
1943 DECL_SIZE_UNIT (p) = NULL;
1944 /* If this arg must go in memory, put it in a pseudo here.
1945 We can't allow it to go in memory as per normal parms,
1946 because the usual place might not have the imag part
1947 adjacent to the real part. */
1948 DECL_ARTIFICIAL (p) = addressable;
1949 DECL_IGNORED_P (p) = addressable;
1950 TREE_ADDRESSABLE (p) = 0;
1953 /* Build a second synthetic decl. */
1954 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
1955 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
1956 DECL_ARTIFICIAL (decl) = addressable;
1957 DECL_IGNORED_P (decl) = addressable;
1958 layout_decl (decl, 0);
1960 /* Splice it in; skip the new decl. */
1961 TREE_CHAIN (decl) = TREE_CHAIN (p);
1962 TREE_CHAIN (p) = decl;
1970 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
1971 the hidden struct return argument, and (abi willing) complex args.
1972 Return the new parameter list. */
1975 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
1977 tree fndecl = current_function_decl;
1978 tree fntype = TREE_TYPE (fndecl);
1979 tree fnargs = DECL_ARGUMENTS (fndecl);
1981 /* If struct value address is treated as the first argument, make it so. */
1982 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
1983 && ! current_function_returns_pcc_struct
1984 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
1986 tree type = build_pointer_type (TREE_TYPE (fntype));
1989 decl = build_decl (PARM_DECL, NULL_TREE, type);
1990 DECL_ARG_TYPE (decl) = type;
1991 DECL_ARTIFICIAL (decl) = 1;
1992 DECL_IGNORED_P (decl) = 1;
1994 TREE_CHAIN (decl) = fnargs;
1996 all->function_result_decl = decl;
1999 all->orig_fnargs = fnargs;
2001 /* If the target wants to split complex arguments into scalars, do so. */
2002 if (targetm.calls.split_complex_arg)
2003 fnargs = split_complex_args (fnargs);
2008 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2009 data for the parameter. Incorporate ABI specifics such as pass-by-
2010 reference and type promotion. */
2013 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2014 struct assign_parm_data_one *data)
2016 tree nominal_type, passed_type;
2017 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2019 memset (data, 0, sizeof (*data));
2021 /* NAMED_ARG is a mis-nomer. We really mean 'non-varadic'. */
2022 if (!current_function_stdarg)
2023 data->named_arg = 1; /* No varadic parms. */
2024 else if (TREE_CHAIN (parm))
2025 data->named_arg = 1; /* Not the last non-varadic parm. */
2026 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2027 data->named_arg = 1; /* Only varadic ones are unnamed. */
2029 data->named_arg = 0; /* Treat as varadic. */
2031 nominal_type = TREE_TYPE (parm);
2032 passed_type = DECL_ARG_TYPE (parm);
2034 /* Look out for errors propagating this far. Also, if the parameter's
2035 type is void then its value doesn't matter. */
2036 if (TREE_TYPE (parm) == error_mark_node
2037 /* This can happen after weird syntax errors
2038 or if an enum type is defined among the parms. */
2039 || TREE_CODE (parm) != PARM_DECL
2040 || passed_type == NULL
2041 || VOID_TYPE_P (nominal_type))
2043 nominal_type = passed_type = void_type_node;
2044 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2048 /* Find mode of arg as it is passed, and mode of arg as it should be
2049 during execution of this function. */
2050 passed_mode = TYPE_MODE (passed_type);
2051 nominal_mode = TYPE_MODE (nominal_type);
2053 /* If the parm is to be passed as a transparent union, use the type of
2054 the first field for the tests below. We have already verified that
2055 the modes are the same. */
2056 if (TREE_CODE (passed_type) == UNION_TYPE
2057 && TYPE_TRANSPARENT_UNION (passed_type))
2058 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2060 /* See if this arg was passed by invisible reference. */
2061 if (pass_by_reference (&all->args_so_far, passed_mode,
2062 passed_type, data->named_arg))
2064 passed_type = nominal_type = build_pointer_type (passed_type);
2065 data->passed_pointer = true;
2066 passed_mode = nominal_mode = Pmode;
2069 /* Find mode as it is passed by the ABI. */
2070 promoted_mode = passed_mode;
2071 if (targetm.calls.promote_function_args (TREE_TYPE (current_function_decl)))
2073 int unsignedp = TYPE_UNSIGNED (passed_type);
2074 promoted_mode = promote_mode (passed_type, promoted_mode,
2079 data->nominal_type = nominal_type;
2080 data->passed_type = passed_type;
2081 data->nominal_mode = nominal_mode;
2082 data->passed_mode = passed_mode;
2083 data->promoted_mode = promoted_mode;
2086 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2089 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2090 struct assign_parm_data_one *data, bool no_rtl)
2092 int varargs_pretend_bytes = 0;
2094 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2095 data->promoted_mode,
2097 &varargs_pretend_bytes, no_rtl);
2099 /* If the back-end has requested extra stack space, record how much is
2100 needed. Do not change pretend_args_size otherwise since it may be
2101 nonzero from an earlier partial argument. */
2102 if (varargs_pretend_bytes > 0)
2103 all->pretend_args_size = varargs_pretend_bytes;
2106 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2107 the incoming location of the current parameter. */
2110 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2111 struct assign_parm_data_one *data)
2113 HOST_WIDE_INT pretend_bytes = 0;
2117 if (data->promoted_mode == VOIDmode)
2119 data->entry_parm = data->stack_parm = const0_rtx;
2123 #ifdef FUNCTION_INCOMING_ARG
2124 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2125 data->passed_type, data->named_arg);
2127 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2128 data->passed_type, data->named_arg);
2131 if (entry_parm == 0)
2132 data->promoted_mode = data->passed_mode;
2134 /* Determine parm's home in the stack, in case it arrives in the stack
2135 or we should pretend it did. Compute the stack position and rtx where
2136 the argument arrives and its size.
2138 There is one complexity here: If this was a parameter that would
2139 have been passed in registers, but wasn't only because it is
2140 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2141 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2142 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2143 as it was the previous time. */
2144 in_regs = entry_parm != 0;
2145 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2148 if (!in_regs && !data->named_arg)
2150 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2153 #ifdef FUNCTION_INCOMING_ARG
2154 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2155 data->passed_type, true);
2157 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2158 data->passed_type, true);
2160 in_regs = tem != NULL;
2164 /* If this parameter was passed both in registers and in the stack, use
2165 the copy on the stack. */
2166 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2174 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2175 data->promoted_mode,
2178 data->partial = partial;
2180 /* The caller might already have allocated stack space for the
2181 register parameters. */
2182 if (partial != 0 && all->reg_parm_stack_space == 0)
2184 /* Part of this argument is passed in registers and part
2185 is passed on the stack. Ask the prologue code to extend
2186 the stack part so that we can recreate the full value.
2188 PRETEND_BYTES is the size of the registers we need to store.
2189 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2190 stack space that the prologue should allocate.
2192 Internally, gcc assumes that the argument pointer is aligned
2193 to STACK_BOUNDARY bits. This is used both for alignment
2194 optimizations (see init_emit) and to locate arguments that are
2195 aligned to more than PARM_BOUNDARY bits. We must preserve this
2196 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2197 a stack boundary. */
2199 /* We assume at most one partial arg, and it must be the first
2200 argument on the stack. */
2201 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2203 pretend_bytes = partial;
2204 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2206 /* We want to align relative to the actual stack pointer, so
2207 don't include this in the stack size until later. */
2208 all->extra_pretend_bytes = all->pretend_args_size;
2212 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2213 entry_parm ? data->partial : 0, current_function_decl,
2214 &all->stack_args_size, &data->locate);
2216 /* Adjust offsets to include the pretend args. */
2217 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2218 data->locate.slot_offset.constant += pretend_bytes;
2219 data->locate.offset.constant += pretend_bytes;
2221 data->entry_parm = entry_parm;
2224 /* A subroutine of assign_parms. If there is actually space on the stack
2225 for this parm, count it in stack_args_size and return true. */
2228 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2229 struct assign_parm_data_one *data)
2231 /* Trivially true if we've no incoming register. */
2232 if (data->entry_parm == NULL)
2234 /* Also true if we're partially in registers and partially not,
2235 since we've arranged to drop the entire argument on the stack. */
2236 else if (data->partial != 0)
2238 /* Also true if the target says that it's passed in both registers
2239 and on the stack. */
2240 else if (GET_CODE (data->entry_parm) == PARALLEL
2241 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2243 /* Also true if the target says that there's stack allocated for
2244 all register parameters. */
2245 else if (all->reg_parm_stack_space > 0)
2247 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2251 all->stack_args_size.constant += data->locate.size.constant;
2252 if (data->locate.size.var)
2253 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2258 /* A subroutine of assign_parms. Given that this parameter is allocated
2259 stack space by the ABI, find it. */
2262 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2264 rtx offset_rtx, stack_parm;
2265 unsigned int align, boundary;
2267 /* If we're passing this arg using a reg, make its stack home the
2268 aligned stack slot. */
2269 if (data->entry_parm)
2270 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2272 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2274 stack_parm = current_function_internal_arg_pointer;
2275 if (offset_rtx != const0_rtx)
2276 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2277 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2279 set_mem_attributes (stack_parm, parm, 1);
2281 boundary = data->locate.boundary;
2282 align = BITS_PER_UNIT;
2284 /* If we're padding upward, we know that the alignment of the slot
2285 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2286 intentionally forcing upward padding. Otherwise we have to come
2287 up with a guess at the alignment based on OFFSET_RTX. */
2288 if (data->locate.where_pad != downward || data->entry_parm)
2290 else if (GET_CODE (offset_rtx) == CONST_INT)
2292 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2293 align = align & -align;
2295 set_mem_align (stack_parm, align);
2297 if (data->entry_parm)
2298 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2300 data->stack_parm = stack_parm;
2303 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2304 always valid and contiguous. */
2307 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2309 rtx entry_parm = data->entry_parm;
2310 rtx stack_parm = data->stack_parm;
2312 /* If this parm was passed part in regs and part in memory, pretend it
2313 arrived entirely in memory by pushing the register-part onto the stack.
2314 In the special case of a DImode or DFmode that is split, we could put
2315 it together in a pseudoreg directly, but for now that's not worth
2317 if (data->partial != 0)
2319 /* Handle calls that pass values in multiple non-contiguous
2320 locations. The Irix 6 ABI has examples of this. */
2321 if (GET_CODE (entry_parm) == PARALLEL)
2322 emit_group_store (validize_mem (stack_parm), entry_parm,
2324 int_size_in_bytes (data->passed_type));
2327 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2328 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2329 data->partial / UNITS_PER_WORD);
2332 entry_parm = stack_parm;
2335 /* If we didn't decide this parm came in a register, by default it came
2337 else if (entry_parm == NULL)
2338 entry_parm = stack_parm;
2340 /* When an argument is passed in multiple locations, we can't make use
2341 of this information, but we can save some copying if the whole argument
2342 is passed in a single register. */
2343 else if (GET_CODE (entry_parm) == PARALLEL
2344 && data->nominal_mode != BLKmode
2345 && data->passed_mode != BLKmode)
2347 size_t i, len = XVECLEN (entry_parm, 0);
2349 for (i = 0; i < len; i++)
2350 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2351 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2352 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2353 == data->passed_mode)
2354 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2356 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2361 data->entry_parm = entry_parm;
2364 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2365 always valid and properly aligned. */
2368 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2370 rtx stack_parm = data->stack_parm;
2372 /* If we can't trust the parm stack slot to be aligned enough for its
2373 ultimate type, don't use that slot after entry. We'll make another
2374 stack slot, if we need one. */
2376 && ((STRICT_ALIGNMENT
2377 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2378 || (data->nominal_type
2379 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2380 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2383 /* If parm was passed in memory, and we need to convert it on entry,
2384 don't store it back in that same slot. */
2385 else if (data->entry_parm == stack_parm
2386 && data->nominal_mode != BLKmode
2387 && data->nominal_mode != data->passed_mode)
2390 /* If stack protection is in effect for this function, don't leave any
2391 pointers in their passed stack slots. */
2392 else if (cfun->stack_protect_guard
2393 && (flag_stack_protect == 2
2394 || data->passed_pointer
2395 || POINTER_TYPE_P (data->nominal_type)))
2398 data->stack_parm = stack_parm;
2401 /* A subroutine of assign_parms. Return true if the current parameter
2402 should be stored as a BLKmode in the current frame. */
2405 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2407 if (data->nominal_mode == BLKmode)
2409 if (GET_CODE (data->entry_parm) == PARALLEL)
2412 #ifdef BLOCK_REG_PADDING
2413 /* Only assign_parm_setup_block knows how to deal with register arguments
2414 that are padded at the least significant end. */
2415 if (REG_P (data->entry_parm)
2416 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2417 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2418 == (BYTES_BIG_ENDIAN ? upward : downward)))
2425 /* A subroutine of assign_parms. Arrange for the parameter to be
2426 present and valid in DATA->STACK_RTL. */
2429 assign_parm_setup_block (struct assign_parm_data_all *all,
2430 tree parm, struct assign_parm_data_one *data)
2432 rtx entry_parm = data->entry_parm;
2433 rtx stack_parm = data->stack_parm;
2435 HOST_WIDE_INT size_stored;
2436 rtx orig_entry_parm = entry_parm;
2438 if (GET_CODE (entry_parm) == PARALLEL)
2439 entry_parm = emit_group_move_into_temps (entry_parm);
2441 /* If we've a non-block object that's nevertheless passed in parts,
2442 reconstitute it in register operations rather than on the stack. */
2443 if (GET_CODE (entry_parm) == PARALLEL
2444 && data->nominal_mode != BLKmode)
2446 rtx elt0 = XEXP (XVECEXP (orig_entry_parm, 0, 0), 0);
2448 if ((XVECLEN (entry_parm, 0) > 1
2449 || hard_regno_nregs[REGNO (elt0)][GET_MODE (elt0)] > 1)
2450 && use_register_for_decl (parm))
2452 rtx parmreg = gen_reg_rtx (data->nominal_mode);
2454 push_to_sequence2 (all->first_conversion_insn,
2455 all->last_conversion_insn);
2457 /* For values returned in multiple registers, handle possible
2458 incompatible calls to emit_group_store.
2460 For example, the following would be invalid, and would have to
2461 be fixed by the conditional below:
2463 emit_group_store ((reg:SF), (parallel:DF))
2464 emit_group_store ((reg:SI), (parallel:DI))
2466 An example of this are doubles in e500 v2:
2467 (parallel:DF (expr_list (reg:SI) (const_int 0))
2468 (expr_list (reg:SI) (const_int 4))). */
2469 if (data->nominal_mode != data->passed_mode)
2471 rtx t = gen_reg_rtx (GET_MODE (entry_parm));
2472 emit_group_store (t, entry_parm, NULL_TREE,
2473 GET_MODE_SIZE (GET_MODE (entry_parm)));
2474 convert_move (parmreg, t, 0);
2477 emit_group_store (parmreg, entry_parm, data->nominal_type,
2478 int_size_in_bytes (data->nominal_type));
2480 all->first_conversion_insn = get_insns ();
2481 all->last_conversion_insn = get_last_insn ();
2484 SET_DECL_RTL (parm, parmreg);
2489 size = int_size_in_bytes (data->passed_type);
2490 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2491 if (stack_parm == 0)
2493 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2494 stack_parm = assign_stack_local (BLKmode, size_stored,
2496 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2497 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2498 set_mem_attributes (stack_parm, parm, 1);
2501 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2502 calls that pass values in multiple non-contiguous locations. */
2503 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2507 /* Note that we will be storing an integral number of words.
2508 So we have to be careful to ensure that we allocate an
2509 integral number of words. We do this above when we call
2510 assign_stack_local if space was not allocated in the argument
2511 list. If it was, this will not work if PARM_BOUNDARY is not
2512 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2513 if it becomes a problem. Exception is when BLKmode arrives
2514 with arguments not conforming to word_mode. */
2516 if (data->stack_parm == 0)
2518 else if (GET_CODE (entry_parm) == PARALLEL)
2521 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2523 mem = validize_mem (stack_parm);
2525 /* Handle values in multiple non-contiguous locations. */
2526 if (GET_CODE (entry_parm) == PARALLEL)
2528 push_to_sequence2 (all->first_conversion_insn,
2529 all->last_conversion_insn);
2530 emit_group_store (mem, entry_parm, data->passed_type, size);
2531 all->first_conversion_insn = get_insns ();
2532 all->last_conversion_insn = get_last_insn ();
2539 /* If SIZE is that of a mode no bigger than a word, just use
2540 that mode's store operation. */
2541 else if (size <= UNITS_PER_WORD)
2543 enum machine_mode mode
2544 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2547 #ifdef BLOCK_REG_PADDING
2548 && (size == UNITS_PER_WORD
2549 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2550 != (BYTES_BIG_ENDIAN ? upward : downward)))
2556 /* We are really truncating a word_mode value containing
2557 SIZE bytes into a value of mode MODE. If such an
2558 operation requires no actual instructions, we can refer
2559 to the value directly in mode MODE, otherwise we must
2560 start with the register in word_mode and explicitly
2562 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2563 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2566 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2567 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2569 emit_move_insn (change_address (mem, mode, 0), reg);
2572 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2573 machine must be aligned to the left before storing
2574 to memory. Note that the previous test doesn't
2575 handle all cases (e.g. SIZE == 3). */
2576 else if (size != UNITS_PER_WORD
2577 #ifdef BLOCK_REG_PADDING
2578 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2586 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2587 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2589 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2590 build_int_cst (NULL_TREE, by),
2592 tem = change_address (mem, word_mode, 0);
2593 emit_move_insn (tem, x);
2596 move_block_from_reg (REGNO (entry_parm), mem,
2597 size_stored / UNITS_PER_WORD);
2600 move_block_from_reg (REGNO (entry_parm), mem,
2601 size_stored / UNITS_PER_WORD);
2603 else if (data->stack_parm == 0)
2605 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2606 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2608 all->first_conversion_insn = get_insns ();
2609 all->last_conversion_insn = get_last_insn ();
2613 data->stack_parm = stack_parm;
2614 SET_DECL_RTL (parm, stack_parm);
2617 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2618 parameter. Get it there. Perform all ABI specified conversions. */
2621 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2622 struct assign_parm_data_one *data)
2625 enum machine_mode promoted_nominal_mode;
2626 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2627 bool did_conversion = false;
2629 /* Store the parm in a pseudoregister during the function, but we may
2630 need to do it in a wider mode. */
2632 /* This is not really promoting for a call. However we need to be
2633 consistent with assign_parm_find_data_types and expand_expr_real_1. */
2634 promoted_nominal_mode
2635 = promote_mode (data->nominal_type, data->nominal_mode, &unsignedp, 1);
2637 parmreg = gen_reg_rtx (promoted_nominal_mode);
2639 if (!DECL_ARTIFICIAL (parm))
2640 mark_user_reg (parmreg);
2642 /* If this was an item that we received a pointer to,
2643 set DECL_RTL appropriately. */
2644 if (data->passed_pointer)
2646 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2647 set_mem_attributes (x, parm, 1);
2648 SET_DECL_RTL (parm, x);
2651 SET_DECL_RTL (parm, parmreg);
2653 /* Copy the value into the register. */
2654 if (data->nominal_mode != data->passed_mode
2655 || promoted_nominal_mode != data->promoted_mode)
2659 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2660 mode, by the caller. We now have to convert it to
2661 NOMINAL_MODE, if different. However, PARMREG may be in
2662 a different mode than NOMINAL_MODE if it is being stored
2665 If ENTRY_PARM is a hard register, it might be in a register
2666 not valid for operating in its mode (e.g., an odd-numbered
2667 register for a DFmode). In that case, moves are the only
2668 thing valid, so we can't do a convert from there. This
2669 occurs when the calling sequence allow such misaligned
2672 In addition, the conversion may involve a call, which could
2673 clobber parameters which haven't been copied to pseudo
2674 registers yet. Therefore, we must first copy the parm to
2675 a pseudo reg here, and save the conversion until after all
2676 parameters have been moved. */
2678 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2680 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2682 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2683 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2685 if (GET_CODE (tempreg) == SUBREG
2686 && GET_MODE (tempreg) == data->nominal_mode
2687 && REG_P (SUBREG_REG (tempreg))
2688 && data->nominal_mode == data->passed_mode
2689 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2690 && GET_MODE_SIZE (GET_MODE (tempreg))
2691 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2693 /* The argument is already sign/zero extended, so note it
2695 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2696 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2699 /* TREE_USED gets set erroneously during expand_assignment. */
2700 save_tree_used = TREE_USED (parm);
2701 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
2702 TREE_USED (parm) = save_tree_used;
2703 all->first_conversion_insn = get_insns ();
2704 all->last_conversion_insn = get_last_insn ();
2707 did_conversion = true;
2710 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2712 /* If we were passed a pointer but the actual value can safely live
2713 in a register, put it in one. */
2714 if (data->passed_pointer
2715 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2716 /* If by-reference argument was promoted, demote it. */
2717 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2718 || use_register_for_decl (parm)))
2720 /* We can't use nominal_mode, because it will have been set to
2721 Pmode above. We must use the actual mode of the parm. */
2722 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2723 mark_user_reg (parmreg);
2725 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2727 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2728 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2730 push_to_sequence2 (all->first_conversion_insn,
2731 all->last_conversion_insn);
2732 emit_move_insn (tempreg, DECL_RTL (parm));
2733 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2734 emit_move_insn (parmreg, tempreg);
2735 all->first_conversion_insn = get_insns ();
2736 all->last_conversion_insn = get_last_insn ();
2739 did_conversion = true;
2742 emit_move_insn (parmreg, DECL_RTL (parm));
2744 SET_DECL_RTL (parm, parmreg);
2746 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2748 data->stack_parm = NULL;
2751 /* Mark the register as eliminable if we did no conversion and it was
2752 copied from memory at a fixed offset, and the arg pointer was not
2753 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2754 offset formed an invalid address, such memory-equivalences as we
2755 make here would screw up life analysis for it. */
2756 if (data->nominal_mode == data->passed_mode
2758 && data->stack_parm != 0
2759 && MEM_P (data->stack_parm)
2760 && data->locate.offset.var == 0
2761 && reg_mentioned_p (virtual_incoming_args_rtx,
2762 XEXP (data->stack_parm, 0)))
2764 rtx linsn = get_last_insn ();
2767 /* Mark complex types separately. */
2768 if (GET_CODE (parmreg) == CONCAT)
2770 enum machine_mode submode
2771 = GET_MODE_INNER (GET_MODE (parmreg));
2772 int regnor = REGNO (XEXP (parmreg, 0));
2773 int regnoi = REGNO (XEXP (parmreg, 1));
2774 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
2775 rtx stacki = adjust_address_nv (data->stack_parm, submode,
2776 GET_MODE_SIZE (submode));
2778 /* Scan backwards for the set of the real and
2780 for (sinsn = linsn; sinsn != 0;
2781 sinsn = prev_nonnote_insn (sinsn))
2783 set = single_set (sinsn);
2787 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2788 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
2789 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2790 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
2793 else if ((set = single_set (linsn)) != 0
2794 && SET_DEST (set) == parmreg)
2795 set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm);
2798 /* For pointer data type, suggest pointer register. */
2799 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2800 mark_reg_pointer (parmreg,
2801 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2804 /* A subroutine of assign_parms. Allocate stack space to hold the current
2805 parameter. Get it there. Perform all ABI specified conversions. */
2808 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2809 struct assign_parm_data_one *data)
2811 /* Value must be stored in the stack slot STACK_PARM during function
2813 bool to_conversion = false;
2815 if (data->promoted_mode != data->nominal_mode)
2817 /* Conversion is required. */
2818 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2820 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2822 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2823 to_conversion = true;
2825 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2826 TYPE_UNSIGNED (TREE_TYPE (parm)));
2828 if (data->stack_parm)
2829 /* ??? This may need a big-endian conversion on sparc64. */
2831 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2834 if (data->entry_parm != data->stack_parm)
2838 if (data->stack_parm == 0)
2841 = assign_stack_local (GET_MODE (data->entry_parm),
2842 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
2843 TYPE_ALIGN (data->passed_type));
2844 set_mem_attributes (data->stack_parm, parm, 1);
2847 dest = validize_mem (data->stack_parm);
2848 src = validize_mem (data->entry_parm);
2852 /* Use a block move to handle potentially misaligned entry_parm. */
2854 push_to_sequence2 (all->first_conversion_insn,
2855 all->last_conversion_insn);
2856 to_conversion = true;
2858 emit_block_move (dest, src,
2859 GEN_INT (int_size_in_bytes (data->passed_type)),
2863 emit_move_insn (dest, src);
2868 all->first_conversion_insn = get_insns ();
2869 all->last_conversion_insn = get_last_insn ();
2873 SET_DECL_RTL (parm, data->stack_parm);
2876 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2877 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2880 assign_parms_unsplit_complex (struct assign_parm_data_all *all, tree fnargs)
2883 tree orig_fnargs = all->orig_fnargs;
2885 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
2887 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
2888 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
2890 rtx tmp, real, imag;
2891 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
2893 real = DECL_RTL (fnargs);
2894 imag = DECL_RTL (TREE_CHAIN (fnargs));
2895 if (inner != GET_MODE (real))
2897 real = gen_lowpart_SUBREG (inner, real);
2898 imag = gen_lowpart_SUBREG (inner, imag);
2901 if (TREE_ADDRESSABLE (parm))
2904 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
2906 /* split_complex_arg put the real and imag parts in
2907 pseudos. Move them to memory. */
2908 tmp = assign_stack_local (DECL_MODE (parm), size,
2909 TYPE_ALIGN (TREE_TYPE (parm)));
2910 set_mem_attributes (tmp, parm, 1);
2911 rmem = adjust_address_nv (tmp, inner, 0);
2912 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
2913 push_to_sequence2 (all->first_conversion_insn,
2914 all->last_conversion_insn);
2915 emit_move_insn (rmem, real);
2916 emit_move_insn (imem, imag);
2917 all->first_conversion_insn = get_insns ();
2918 all->last_conversion_insn = get_last_insn ();
2922 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2923 SET_DECL_RTL (parm, tmp);
2925 real = DECL_INCOMING_RTL (fnargs);
2926 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
2927 if (inner != GET_MODE (real))
2929 real = gen_lowpart_SUBREG (inner, real);
2930 imag = gen_lowpart_SUBREG (inner, imag);
2932 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2933 set_decl_incoming_rtl (parm, tmp, false);
2934 fnargs = TREE_CHAIN (fnargs);
2938 SET_DECL_RTL (parm, DECL_RTL (fnargs));
2939 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs), false);
2941 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2942 instead of the copy of decl, i.e. FNARGS. */
2943 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
2944 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
2947 fnargs = TREE_CHAIN (fnargs);
2951 /* Assign RTL expressions to the function's parameters. This may involve
2952 copying them into registers and using those registers as the DECL_RTL. */
2955 assign_parms (tree fndecl)
2957 struct assign_parm_data_all all;
2960 current_function_internal_arg_pointer
2961 = targetm.calls.internal_arg_pointer ();
2963 assign_parms_initialize_all (&all);
2964 fnargs = assign_parms_augmented_arg_list (&all);
2966 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
2968 struct assign_parm_data_one data;
2970 /* Extract the type of PARM; adjust it according to ABI. */
2971 assign_parm_find_data_types (&all, parm, &data);
2973 /* Early out for errors and void parameters. */
2974 if (data.passed_mode == VOIDmode)
2976 SET_DECL_RTL (parm, const0_rtx);
2977 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
2981 if (current_function_stdarg && !TREE_CHAIN (parm))
2982 assign_parms_setup_varargs (&all, &data, false);
2984 /* Find out where the parameter arrives in this function. */
2985 assign_parm_find_entry_rtl (&all, &data);
2987 /* Find out where stack space for this parameter might be. */
2988 if (assign_parm_is_stack_parm (&all, &data))
2990 assign_parm_find_stack_rtl (parm, &data);
2991 assign_parm_adjust_entry_rtl (&data);
2994 /* Record permanently how this parm was passed. */
2995 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
2997 /* Update info on where next arg arrives in registers. */
2998 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
2999 data.passed_type, data.named_arg);
3001 assign_parm_adjust_stack_rtl (&data);
3003 if (assign_parm_setup_block_p (&data))
3004 assign_parm_setup_block (&all, parm, &data);
3005 else if (data.passed_pointer || use_register_for_decl (parm))
3006 assign_parm_setup_reg (&all, parm, &data);
3008 assign_parm_setup_stack (&all, parm, &data);
3011 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3012 assign_parms_unsplit_complex (&all, fnargs);
3014 /* Output all parameter conversion instructions (possibly including calls)
3015 now that all parameters have been copied out of hard registers. */
3016 emit_insn (all.first_conversion_insn);
3018 /* If we are receiving a struct value address as the first argument, set up
3019 the RTL for the function result. As this might require code to convert
3020 the transmitted address to Pmode, we do this here to ensure that possible
3021 preliminary conversions of the address have been emitted already. */
3022 if (all.function_result_decl)
3024 tree result = DECL_RESULT (current_function_decl);
3025 rtx addr = DECL_RTL (all.function_result_decl);
3028 if (DECL_BY_REFERENCE (result))
3032 addr = convert_memory_address (Pmode, addr);
3033 x = gen_rtx_MEM (DECL_MODE (result), addr);
3034 set_mem_attributes (x, result, 1);
3036 SET_DECL_RTL (result, x);
3039 /* We have aligned all the args, so add space for the pretend args. */
3040 current_function_pretend_args_size = all.pretend_args_size;
3041 all.stack_args_size.constant += all.extra_pretend_bytes;
3042 current_function_args_size = all.stack_args_size.constant;
3044 /* Adjust function incoming argument size for alignment and
3047 #ifdef REG_PARM_STACK_SPACE
3048 current_function_args_size = MAX (current_function_args_size,
3049 REG_PARM_STACK_SPACE (fndecl));
3052 current_function_args_size = CEIL_ROUND (current_function_args_size,
3053 PARM_BOUNDARY / BITS_PER_UNIT);
3055 #ifdef ARGS_GROW_DOWNWARD
3056 current_function_arg_offset_rtx
3057 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3058 : expand_expr (size_diffop (all.stack_args_size.var,
3059 size_int (-all.stack_args_size.constant)),
3060 NULL_RTX, VOIDmode, 0));
3062 current_function_arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3065 /* See how many bytes, if any, of its args a function should try to pop
3068 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3069 current_function_args_size);
3071 /* For stdarg.h function, save info about
3072 regs and stack space used by the named args. */
3074 current_function_args_info = all.args_so_far;
3076 /* Set the rtx used for the function return value. Put this in its
3077 own variable so any optimizers that need this information don't have
3078 to include tree.h. Do this here so it gets done when an inlined
3079 function gets output. */
3081 current_function_return_rtx
3082 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3083 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3085 /* If scalar return value was computed in a pseudo-reg, or was a named
3086 return value that got dumped to the stack, copy that to the hard
3088 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3090 tree decl_result = DECL_RESULT (fndecl);
3091 rtx decl_rtl = DECL_RTL (decl_result);
3093 if (REG_P (decl_rtl)
3094 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3095 : DECL_REGISTER (decl_result))
3099 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3101 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3102 /* The delay slot scheduler assumes that current_function_return_rtx
3103 holds the hard register containing the return value, not a
3104 temporary pseudo. */
3105 current_function_return_rtx = real_decl_rtl;
3110 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3111 For all seen types, gimplify their sizes. */
3114 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3121 if (POINTER_TYPE_P (t))
3123 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3124 && !TYPE_SIZES_GIMPLIFIED (t))
3126 gimplify_type_sizes (t, (tree *) data);
3134 /* Gimplify the parameter list for current_function_decl. This involves
3135 evaluating SAVE_EXPRs of variable sized parameters and generating code
3136 to implement callee-copies reference parameters. Returns a list of
3137 statements to add to the beginning of the function, or NULL if nothing
3141 gimplify_parameters (void)
3143 struct assign_parm_data_all all;
3144 tree fnargs, parm, stmts = NULL;
3146 assign_parms_initialize_all (&all);
3147 fnargs = assign_parms_augmented_arg_list (&all);
3149 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3151 struct assign_parm_data_one data;
3153 /* Extract the type of PARM; adjust it according to ABI. */
3154 assign_parm_find_data_types (&all, parm, &data);
3156 /* Early out for errors and void parameters. */
3157 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3160 /* Update info on where next arg arrives in registers. */
3161 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3162 data.passed_type, data.named_arg);
3164 /* ??? Once upon a time variable_size stuffed parameter list
3165 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3166 turned out to be less than manageable in the gimple world.
3167 Now we have to hunt them down ourselves. */
3168 walk_tree_without_duplicates (&data.passed_type,
3169 gimplify_parm_type, &stmts);
3171 if (!TREE_CONSTANT (DECL_SIZE (parm)))
3173 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3174 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3177 if (data.passed_pointer)
3179 tree type = TREE_TYPE (data.passed_type);
3180 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3181 type, data.named_arg))
3185 /* For constant sized objects, this is trivial; for
3186 variable-sized objects, we have to play games. */
3187 if (TREE_CONSTANT (DECL_SIZE (parm)))
3189 local = create_tmp_var (type, get_name (parm));
3190 DECL_IGNORED_P (local) = 0;
3194 tree ptr_type, addr;
3196 ptr_type = build_pointer_type (type);
3197 addr = create_tmp_var (ptr_type, get_name (parm));
3198 DECL_IGNORED_P (addr) = 0;
3199 local = build_fold_indirect_ref (addr);
3201 t = built_in_decls[BUILT_IN_ALLOCA];
3202 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3203 t = fold_convert (ptr_type, t);
3204 t = build_gimple_modify_stmt (addr, t);
3205 gimplify_and_add (t, &stmts);
3208 t = build_gimple_modify_stmt (local, parm);
3209 gimplify_and_add (t, &stmts);
3211 SET_DECL_VALUE_EXPR (parm, local);
3212 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3220 /* Compute the size and offset from the start of the stacked arguments for a
3221 parm passed in mode PASSED_MODE and with type TYPE.
3223 INITIAL_OFFSET_PTR points to the current offset into the stacked
3226 The starting offset and size for this parm are returned in
3227 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3228 nonzero, the offset is that of stack slot, which is returned in
3229 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3230 padding required from the initial offset ptr to the stack slot.
3232 IN_REGS is nonzero if the argument will be passed in registers. It will
3233 never be set if REG_PARM_STACK_SPACE is not defined.
3235 FNDECL is the function in which the argument was defined.
3237 There are two types of rounding that are done. The first, controlled by
3238 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3239 list to be aligned to the specific boundary (in bits). This rounding
3240 affects the initial and starting offsets, but not the argument size.
3242 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3243 optionally rounds the size of the parm to PARM_BOUNDARY. The
3244 initial offset is not affected by this rounding, while the size always
3245 is and the starting offset may be. */
3247 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3248 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3249 callers pass in the total size of args so far as
3250 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3253 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3254 int partial, tree fndecl ATTRIBUTE_UNUSED,
3255 struct args_size *initial_offset_ptr,
3256 struct locate_and_pad_arg_data *locate)
3259 enum direction where_pad;
3260 unsigned int boundary;
3261 int reg_parm_stack_space = 0;
3262 int part_size_in_regs;
3264 #ifdef REG_PARM_STACK_SPACE
3265 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3267 /* If we have found a stack parm before we reach the end of the
3268 area reserved for registers, skip that area. */
3271 if (reg_parm_stack_space > 0)
3273 if (initial_offset_ptr->var)
3275 initial_offset_ptr->var
3276 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3277 ssize_int (reg_parm_stack_space));
3278 initial_offset_ptr->constant = 0;
3280 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3281 initial_offset_ptr->constant = reg_parm_stack_space;
3284 #endif /* REG_PARM_STACK_SPACE */
3286 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3289 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3290 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3291 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3292 locate->where_pad = where_pad;
3293 locate->boundary = boundary;
3295 /* Remember if the outgoing parameter requires extra alignment on the
3296 calling function side. */
3297 if (boundary > PREFERRED_STACK_BOUNDARY)
3298 boundary = PREFERRED_STACK_BOUNDARY;
3299 if (cfun->stack_alignment_needed < boundary)
3300 cfun->stack_alignment_needed = boundary;
3302 #ifdef ARGS_GROW_DOWNWARD
3303 locate->slot_offset.constant = -initial_offset_ptr->constant;
3304 if (initial_offset_ptr->var)
3305 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3306 initial_offset_ptr->var);
3310 if (where_pad != none
3311 && (!host_integerp (sizetree, 1)
3312 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3313 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3314 SUB_PARM_SIZE (locate->slot_offset, s2);
3317 locate->slot_offset.constant += part_size_in_regs;
3320 #ifdef REG_PARM_STACK_SPACE
3321 || REG_PARM_STACK_SPACE (fndecl) > 0
3324 pad_to_arg_alignment (&locate->slot_offset, boundary,
3325 &locate->alignment_pad);
3327 locate->size.constant = (-initial_offset_ptr->constant
3328 - locate->slot_offset.constant);
3329 if (initial_offset_ptr->var)
3330 locate->size.var = size_binop (MINUS_EXPR,
3331 size_binop (MINUS_EXPR,
3333 initial_offset_ptr->var),
3334 locate->slot_offset.var);
3336 /* Pad_below needs the pre-rounded size to know how much to pad
3338 locate->offset = locate->slot_offset;
3339 if (where_pad == downward)
3340 pad_below (&locate->offset, passed_mode, sizetree);
3342 #else /* !ARGS_GROW_DOWNWARD */
3344 #ifdef REG_PARM_STACK_SPACE
3345 || REG_PARM_STACK_SPACE (fndecl) > 0
3348 pad_to_arg_alignment (initial_offset_ptr, boundary,
3349 &locate->alignment_pad);
3350 locate->slot_offset = *initial_offset_ptr;
3352 #ifdef PUSH_ROUNDING
3353 if (passed_mode != BLKmode)
3354 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3357 /* Pad_below needs the pre-rounded size to know how much to pad below
3358 so this must be done before rounding up. */
3359 locate->offset = locate->slot_offset;
3360 if (where_pad == downward)
3361 pad_below (&locate->offset, passed_mode, sizetree);
3363 if (where_pad != none
3364 && (!host_integerp (sizetree, 1)
3365 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3366 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3368 ADD_PARM_SIZE (locate->size, sizetree);
3370 locate->size.constant -= part_size_in_regs;
3371 #endif /* ARGS_GROW_DOWNWARD */
3374 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3375 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3378 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3379 struct args_size *alignment_pad)
3381 tree save_var = NULL_TREE;
3382 HOST_WIDE_INT save_constant = 0;
3383 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3384 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3386 #ifdef SPARC_STACK_BOUNDARY_HACK
3387 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3388 the real alignment of %sp. However, when it does this, the
3389 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3390 if (SPARC_STACK_BOUNDARY_HACK)
3394 if (boundary > PARM_BOUNDARY)
3396 save_var = offset_ptr->var;
3397 save_constant = offset_ptr->constant;
3400 alignment_pad->var = NULL_TREE;
3401 alignment_pad->constant = 0;
3403 if (boundary > BITS_PER_UNIT)
3405 if (offset_ptr->var)
3407 tree sp_offset_tree = ssize_int (sp_offset);
3408 tree offset = size_binop (PLUS_EXPR,
3409 ARGS_SIZE_TREE (*offset_ptr),
3411 #ifdef ARGS_GROW_DOWNWARD
3412 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3414 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3417 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3418 /* ARGS_SIZE_TREE includes constant term. */
3419 offset_ptr->constant = 0;
3420 if (boundary > PARM_BOUNDARY)
3421 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3426 offset_ptr->constant = -sp_offset +
3427 #ifdef ARGS_GROW_DOWNWARD
3428 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3430 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3432 if (boundary > PARM_BOUNDARY)
3433 alignment_pad->constant = offset_ptr->constant - save_constant;
3439 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3441 if (passed_mode != BLKmode)
3443 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3444 offset_ptr->constant
3445 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3446 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3447 - GET_MODE_SIZE (passed_mode));
3451 if (TREE_CODE (sizetree) != INTEGER_CST
3452 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3454 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3455 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3457 ADD_PARM_SIZE (*offset_ptr, s2);
3458 SUB_PARM_SIZE (*offset_ptr, sizetree);
3464 /* True if register REGNO was alive at a place where `setjmp' was
3465 called and was set more than once or is an argument. Such regs may
3466 be clobbered by `longjmp'. */
3469 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3471 /* There appear to be cases where some local vars never reach the
3472 backend but have bogus regnos. */
3473 if (regno >= max_reg_num ())
3476 return ((REG_N_SETS (regno) > 1
3477 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3478 && REGNO_REG_SET_P (setjmp_crosses, regno));
3481 /* Walk the tree of blocks describing the binding levels within a
3482 function and warn about variables the might be killed by setjmp or
3483 vfork. This is done after calling flow_analysis before register
3484 allocation since that will clobber the pseudo-regs to hard
3488 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3492 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3494 if (TREE_CODE (decl) == VAR_DECL
3495 && DECL_RTL_SET_P (decl)
3496 && REG_P (DECL_RTL (decl))
3497 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3498 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3499 " %<longjmp%> or %<vfork%>", decl);
3502 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3503 setjmp_vars_warning (setjmp_crosses, sub);
3506 /* Do the appropriate part of setjmp_vars_warning
3507 but for arguments instead of local variables. */
3510 setjmp_args_warning (bitmap setjmp_crosses)
3513 for (decl = DECL_ARGUMENTS (current_function_decl);
3514 decl; decl = TREE_CHAIN (decl))
3515 if (DECL_RTL (decl) != 0
3516 && REG_P (DECL_RTL (decl))
3517 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3518 warning (OPT_Wclobbered,
3519 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3523 /* Generate warning messages for variables live across setjmp. */
3526 generate_setjmp_warnings (void)
3528 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
3530 if (n_basic_blocks == NUM_FIXED_BLOCKS
3531 || bitmap_empty_p (setjmp_crosses))
3534 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
3535 setjmp_args_warning (setjmp_crosses);
3539 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3540 and create duplicate blocks. */
3541 /* ??? Need an option to either create block fragments or to create
3542 abstract origin duplicates of a source block. It really depends
3543 on what optimization has been performed. */
3546 reorder_blocks (void)
3548 tree block = DECL_INITIAL (current_function_decl);
3549 VEC(tree,heap) *block_stack;
3551 if (block == NULL_TREE)
3554 block_stack = VEC_alloc (tree, heap, 10);
3556 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3557 clear_block_marks (block);
3559 /* Prune the old trees away, so that they don't get in the way. */
3560 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3561 BLOCK_CHAIN (block) = NULL_TREE;
3563 /* Recreate the block tree from the note nesting. */
3564 reorder_blocks_1 (get_insns (), block, &block_stack);
3565 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3567 VEC_free (tree, heap, block_stack);
3570 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3573 clear_block_marks (tree block)
3577 TREE_ASM_WRITTEN (block) = 0;
3578 clear_block_marks (BLOCK_SUBBLOCKS (block));
3579 block = BLOCK_CHAIN (block);
3584 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
3588 for (insn = insns; insn; insn = NEXT_INSN (insn))
3592 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
3594 tree block = NOTE_BLOCK (insn);
3597 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3598 ? BLOCK_FRAGMENT_ORIGIN (block)
3601 /* If we have seen this block before, that means it now
3602 spans multiple address regions. Create a new fragment. */
3603 if (TREE_ASM_WRITTEN (block))
3605 tree new_block = copy_node (block);
3607 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3608 BLOCK_FRAGMENT_CHAIN (new_block)
3609 = BLOCK_FRAGMENT_CHAIN (origin);
3610 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3612 NOTE_BLOCK (insn) = new_block;
3616 BLOCK_SUBBLOCKS (block) = 0;
3617 TREE_ASM_WRITTEN (block) = 1;
3618 /* When there's only one block for the entire function,
3619 current_block == block and we mustn't do this, it
3620 will cause infinite recursion. */
3621 if (block != current_block)
3623 if (block != origin)
3624 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
3626 BLOCK_SUPERCONTEXT (block) = current_block;
3627 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3628 BLOCK_SUBBLOCKS (current_block) = block;
3629 current_block = origin;
3631 VEC_safe_push (tree, heap, *p_block_stack, block);
3633 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
3635 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
3636 BLOCK_SUBBLOCKS (current_block)
3637 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3638 current_block = BLOCK_SUPERCONTEXT (current_block);
3644 /* Reverse the order of elements in the chain T of blocks,
3645 and return the new head of the chain (old last element). */
3648 blocks_nreverse (tree t)
3650 tree prev = 0, decl, next;
3651 for (decl = t; decl; decl = next)
3653 next = BLOCK_CHAIN (decl);
3654 BLOCK_CHAIN (decl) = prev;
3660 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3661 non-NULL, list them all into VECTOR, in a depth-first preorder
3662 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3666 all_blocks (tree block, tree *vector)
3672 TREE_ASM_WRITTEN (block) = 0;
3674 /* Record this block. */
3676 vector[n_blocks] = block;
3680 /* Record the subblocks, and their subblocks... */
3681 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3682 vector ? vector + n_blocks : 0);
3683 block = BLOCK_CHAIN (block);
3689 /* Return a vector containing all the blocks rooted at BLOCK. The
3690 number of elements in the vector is stored in N_BLOCKS_P. The
3691 vector is dynamically allocated; it is the caller's responsibility
3692 to call `free' on the pointer returned. */
3695 get_block_vector (tree block, int *n_blocks_p)
3699 *n_blocks_p = all_blocks (block, NULL);
3700 block_vector = XNEWVEC (tree, *n_blocks_p);
3701 all_blocks (block, block_vector);
3703 return block_vector;
3706 static GTY(()) int next_block_index = 2;
3708 /* Set BLOCK_NUMBER for all the blocks in FN. */
3711 number_blocks (tree fn)
3717 /* For SDB and XCOFF debugging output, we start numbering the blocks
3718 from 1 within each function, rather than keeping a running
3720 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3721 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3722 next_block_index = 1;
3725 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3727 /* The top-level BLOCK isn't numbered at all. */
3728 for (i = 1; i < n_blocks; ++i)
3729 /* We number the blocks from two. */
3730 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3732 free (block_vector);
3737 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3740 debug_find_var_in_block_tree (tree var, tree block)
3744 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3748 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3750 tree ret = debug_find_var_in_block_tree (var, t);
3758 /* Keep track of whether we're in a dummy function context. If we are,
3759 we don't want to invoke the set_current_function hook, because we'll
3760 get into trouble if the hook calls target_reinit () recursively or
3761 when the initial initialization is not yet complete. */
3763 static bool in_dummy_function;
3765 /* Invoke the target hook when setting cfun. */
3768 invoke_set_current_function_hook (tree fndecl)
3770 if (!in_dummy_function)
3771 targetm.set_current_function (fndecl);
3774 /* cfun should never be set directly; use this function. */
3777 set_cfun (struct function *new_cfun)
3779 if (cfun != new_cfun)
3782 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
3786 /* Keep track of the cfun stack. */
3788 typedef struct function *function_p;
3790 DEF_VEC_P(function_p);
3791 DEF_VEC_ALLOC_P(function_p,heap);
3793 /* Initialized with NOGC, making this poisonous to the garbage collector. */
3795 static VEC(function_p,heap) *cfun_stack;
3797 /* We save the value of in_system_header here when pushing the first
3798 function on the cfun stack, and we restore it from here when
3799 popping the last function. */
3801 static bool saved_in_system_header;
3803 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
3806 push_cfun (struct function *new_cfun)
3809 saved_in_system_header = in_system_header;
3810 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3812 in_system_header = DECL_IN_SYSTEM_HEADER (new_cfun->decl);
3813 set_cfun (new_cfun);
3816 /* Pop cfun from the stack. */
3821 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
3822 in_system_header = ((new_cfun == NULL) ? saved_in_system_header
3823 : DECL_IN_SYSTEM_HEADER (new_cfun->decl));
3824 set_cfun (new_cfun);
3827 /* Return value of funcdef and increase it. */
3829 get_next_funcdef_no (void)
3831 return funcdef_no++;
3834 /* Allocate a function structure for FNDECL and set its contents
3835 to the defaults. Set cfun to the newly-allocated object.
3836 Some of the helper functions invoked during initialization assume
3837 that cfun has already been set. Therefore, assign the new object
3838 directly into cfun and invoke the back end hook explicitly at the
3839 very end, rather than initializing a temporary and calling set_cfun
3842 ABSTRACT_P is true if this is a function that will never be seen by
3843 the middle-end. Such functions are front-end concepts (like C++
3844 function templates) that do not correspond directly to functions
3845 placed in object files. */
3848 allocate_struct_function (tree fndecl, bool abstract_p)
3851 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
3853 cfun = ggc_alloc_cleared (sizeof (struct function));
3855 cfun->stack_alignment_needed = STACK_BOUNDARY;
3856 cfun->preferred_stack_boundary = STACK_BOUNDARY;
3858 current_function_funcdef_no = get_next_funcdef_no ();
3860 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
3862 init_eh_for_function ();
3864 lang_hooks.function.init (cfun);
3865 if (init_machine_status)
3866 cfun->machine = (*init_machine_status) ();
3870 DECL_STRUCT_FUNCTION (fndecl) = cfun;
3871 cfun->decl = fndecl;
3873 result = DECL_RESULT (fndecl);
3874 if (!abstract_p && aggregate_value_p (result, fndecl))
3876 #ifdef PCC_STATIC_STRUCT_RETURN
3877 current_function_returns_pcc_struct = 1;
3879 current_function_returns_struct = 1;
3882 current_function_stdarg
3884 && TYPE_ARG_TYPES (fntype) != 0
3885 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3886 != void_type_node));
3888 /* Assume all registers in stdarg functions need to be saved. */
3889 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
3890 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
3893 invoke_set_current_function_hook (fndecl);
3896 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
3897 instead of just setting it. */
3900 push_struct_function (tree fndecl)
3903 saved_in_system_header = in_system_header;
3904 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3906 in_system_header = DECL_IN_SYSTEM_HEADER (fndecl);
3907 allocate_struct_function (fndecl, false);
3910 /* Reset cfun, and other non-struct-function variables to defaults as
3911 appropriate for emitting rtl at the start of a function. */
3914 prepare_function_start (void)
3916 gcc_assert (!rtl.emit.x_last_insn);
3918 init_varasm_status ();
3921 cse_not_expected = ! optimize;
3923 /* Caller save not needed yet. */
3924 caller_save_needed = 0;
3926 /* We haven't done register allocation yet. */
3929 /* Indicate that we have not instantiated virtual registers yet. */
3930 virtuals_instantiated = 0;
3932 /* Indicate that we want CONCATs now. */
3933 generating_concat_p = 1;
3935 /* Indicate we have no need of a frame pointer yet. */
3936 frame_pointer_needed = 0;
3939 /* Initialize the rtl expansion mechanism so that we can do simple things
3940 like generate sequences. This is used to provide a context during global
3941 initialization of some passes. You must call expand_dummy_function_end
3942 to exit this context. */
3945 init_dummy_function_start (void)
3947 gcc_assert (!in_dummy_function);
3948 in_dummy_function = true;
3949 push_struct_function (NULL_TREE);
3950 prepare_function_start ();
3953 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
3954 and initialize static variables for generating RTL for the statements
3958 init_function_start (tree subr)
3960 if (subr && DECL_STRUCT_FUNCTION (subr))
3961 set_cfun (DECL_STRUCT_FUNCTION (subr));
3963 allocate_struct_function (subr, false);
3964 prepare_function_start ();
3966 /* Warn if this value is an aggregate type,
3967 regardless of which calling convention we are using for it. */
3968 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
3969 warning (OPT_Waggregate_return, "function returns an aggregate");
3972 /* Make sure all values used by the optimization passes have sane
3975 init_function_for_compilation (void)
3979 /* No prologue/epilogue insns yet. Make sure that these vectors are
3981 gcc_assert (VEC_length (int, prologue) == 0);
3982 gcc_assert (VEC_length (int, epilogue) == 0);
3983 gcc_assert (VEC_length (int, sibcall_epilogue) == 0);
3987 struct rtl_opt_pass pass_init_function =
3993 init_function_for_compilation, /* execute */
3996 0, /* static_pass_number */
3998 0, /* properties_required */
3999 0, /* properties_provided */
4000 0, /* properties_destroyed */
4001 0, /* todo_flags_start */
4002 0 /* todo_flags_finish */
4008 expand_main_function (void)
4010 #if (defined(INVOKE__main) \
4011 || (!defined(HAS_INIT_SECTION) \
4012 && !defined(INIT_SECTION_ASM_OP) \
4013 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4014 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4018 /* Expand code to initialize the stack_protect_guard. This is invoked at
4019 the beginning of a function to be protected. */
4021 #ifndef HAVE_stack_protect_set
4022 # define HAVE_stack_protect_set 0
4023 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4027 stack_protect_prologue (void)
4029 tree guard_decl = targetm.stack_protect_guard ();
4032 /* Avoid expand_expr here, because we don't want guard_decl pulled
4033 into registers unless absolutely necessary. And we know that
4034 cfun->stack_protect_guard is a local stack slot, so this skips
4036 x = validize_mem (DECL_RTL (cfun->stack_protect_guard));
4037 y = validize_mem (DECL_RTL (guard_decl));
4039 /* Allow the target to copy from Y to X without leaking Y into a
4041 if (HAVE_stack_protect_set)
4043 rtx insn = gen_stack_protect_set (x, y);
4051 /* Otherwise do a straight move. */
4052 emit_move_insn (x, y);
4055 /* Expand code to verify the stack_protect_guard. This is invoked at
4056 the end of a function to be protected. */
4058 #ifndef HAVE_stack_protect_test
4059 # define HAVE_stack_protect_test 0
4060 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4064 stack_protect_epilogue (void)
4066 tree guard_decl = targetm.stack_protect_guard ();
4067 rtx label = gen_label_rtx ();
4070 /* Avoid expand_expr here, because we don't want guard_decl pulled
4071 into registers unless absolutely necessary. And we know that
4072 cfun->stack_protect_guard is a local stack slot, so this skips
4074 x = validize_mem (DECL_RTL (cfun->stack_protect_guard));
4075 y = validize_mem (DECL_RTL (guard_decl));
4077 /* Allow the target to compare Y with X without leaking either into
4079 switch (HAVE_stack_protect_test != 0)
4082 tmp = gen_stack_protect_test (x, y, label);
4091 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4095 /* The noreturn predictor has been moved to the tree level. The rtl-level
4096 predictors estimate this branch about 20%, which isn't enough to get
4097 things moved out of line. Since this is the only extant case of adding
4098 a noreturn function at the rtl level, it doesn't seem worth doing ought
4099 except adding the prediction by hand. */
4100 tmp = get_last_insn ();
4102 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4104 expand_expr_stmt (targetm.stack_protect_fail ());
4108 /* Start the RTL for a new function, and set variables used for
4110 SUBR is the FUNCTION_DECL node.
4111 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4112 the function's parameters, which must be run at any return statement. */
4115 expand_function_start (tree subr)
4117 /* Make sure volatile mem refs aren't considered
4118 valid operands of arithmetic insns. */
4119 init_recog_no_volatile ();
4121 current_function_profile
4123 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4125 current_function_limit_stack
4126 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4128 /* Make the label for return statements to jump to. Do not special
4129 case machines with special return instructions -- they will be
4130 handled later during jump, ifcvt, or epilogue creation. */
4131 return_label = gen_label_rtx ();
4133 /* Initialize rtx used to return the value. */
4134 /* Do this before assign_parms so that we copy the struct value address
4135 before any library calls that assign parms might generate. */
4137 /* Decide whether to return the value in memory or in a register. */
4138 if (aggregate_value_p (DECL_RESULT (subr), subr))
4140 /* Returning something that won't go in a register. */
4141 rtx value_address = 0;
4143 #ifdef PCC_STATIC_STRUCT_RETURN
4144 if (current_function_returns_pcc_struct)
4146 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4147 value_address = assemble_static_space (size);
4152 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4153 /* Expect to be passed the address of a place to store the value.
4154 If it is passed as an argument, assign_parms will take care of
4158 value_address = gen_reg_rtx (Pmode);
4159 emit_move_insn (value_address, sv);
4164 rtx x = value_address;
4165 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4167 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4168 set_mem_attributes (x, DECL_RESULT (subr), 1);
4170 SET_DECL_RTL (DECL_RESULT (subr), x);
4173 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4174 /* If return mode is void, this decl rtl should not be used. */
4175 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4178 /* Compute the return values into a pseudo reg, which we will copy
4179 into the true return register after the cleanups are done. */
4180 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4181 if (TYPE_MODE (return_type) != BLKmode
4182 && targetm.calls.return_in_msb (return_type))
4183 /* expand_function_end will insert the appropriate padding in
4184 this case. Use the return value's natural (unpadded) mode
4185 within the function proper. */
4186 SET_DECL_RTL (DECL_RESULT (subr),
4187 gen_reg_rtx (TYPE_MODE (return_type)));
4190 /* In order to figure out what mode to use for the pseudo, we
4191 figure out what the mode of the eventual return register will
4192 actually be, and use that. */
4193 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4195 /* Structures that are returned in registers are not
4196 aggregate_value_p, so we may see a PARALLEL or a REG. */
4197 if (REG_P (hard_reg))
4198 SET_DECL_RTL (DECL_RESULT (subr),
4199 gen_reg_rtx (GET_MODE (hard_reg)));
4202 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4203 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4207 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4208 result to the real return register(s). */
4209 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4212 /* Initialize rtx for parameters and local variables.
4213 In some cases this requires emitting insns. */
4214 assign_parms (subr);
4216 /* If function gets a static chain arg, store it. */
4217 if (cfun->static_chain_decl)
4219 tree parm = cfun->static_chain_decl;
4220 rtx local = gen_reg_rtx (Pmode);
4222 set_decl_incoming_rtl (parm, static_chain_incoming_rtx, false);
4223 SET_DECL_RTL (parm, local);
4224 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4226 emit_move_insn (local, static_chain_incoming_rtx);
4229 /* If the function receives a non-local goto, then store the
4230 bits we need to restore the frame pointer. */
4231 if (cfun->nonlocal_goto_save_area)
4236 /* ??? We need to do this save early. Unfortunately here is
4237 before the frame variable gets declared. Help out... */
4238 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
4239 if (!DECL_RTL_SET_P (var))
4242 t_save = build4 (ARRAY_REF, ptr_type_node,
4243 cfun->nonlocal_goto_save_area,
4244 integer_zero_node, NULL_TREE, NULL_TREE);
4245 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4246 r_save = convert_memory_address (Pmode, r_save);
4248 emit_move_insn (r_save, virtual_stack_vars_rtx);
4249 update_nonlocal_goto_save_area ();
4252 /* The following was moved from init_function_start.
4253 The move is supposed to make sdb output more accurate. */
4254 /* Indicate the beginning of the function body,
4255 as opposed to parm setup. */
4256 emit_note (NOTE_INSN_FUNCTION_BEG);
4258 gcc_assert (NOTE_P (get_last_insn ()));
4260 parm_birth_insn = get_last_insn ();
4262 if (current_function_profile)
4265 PROFILE_HOOK (current_function_funcdef_no);
4269 /* After the display initializations is where the stack checking
4271 if(flag_stack_check)
4272 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4274 /* Make sure there is a line number after the function entry setup code. */
4275 force_next_line_note ();
4278 /* Undo the effects of init_dummy_function_start. */
4280 expand_dummy_function_end (void)
4282 gcc_assert (in_dummy_function);
4284 /* End any sequences that failed to be closed due to syntax errors. */
4285 while (in_sequence_p ())
4288 /* Outside function body, can't compute type's actual size
4289 until next function's body starts. */
4291 free_after_parsing (cfun);
4292 free_after_compilation (cfun);
4294 in_dummy_function = false;
4297 /* Call DOIT for each hard register used as a return value from
4298 the current function. */
4301 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4303 rtx outgoing = current_function_return_rtx;
4308 if (REG_P (outgoing))
4309 (*doit) (outgoing, arg);
4310 else if (GET_CODE (outgoing) == PARALLEL)
4314 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4316 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4318 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4325 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4327 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
4331 clobber_return_register (void)
4333 diddle_return_value (do_clobber_return_reg, NULL);
4335 /* In case we do use pseudo to return value, clobber it too. */
4336 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4338 tree decl_result = DECL_RESULT (current_function_decl);
4339 rtx decl_rtl = DECL_RTL (decl_result);
4340 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4342 do_clobber_return_reg (decl_rtl, NULL);
4348 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4350 emit_insn (gen_rtx_USE (VOIDmode, reg));
4354 use_return_register (void)
4356 diddle_return_value (do_use_return_reg, NULL);
4359 /* Possibly warn about unused parameters. */
4361 do_warn_unused_parameter (tree fn)
4365 for (decl = DECL_ARGUMENTS (fn);
4366 decl; decl = TREE_CHAIN (decl))
4367 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4368 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4369 && !TREE_NO_WARNING (decl))
4370 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4373 static GTY(()) rtx initial_trampoline;
4375 /* Generate RTL for the end of the current function. */
4378 expand_function_end (void)
4382 /* If arg_pointer_save_area was referenced only from a nested
4383 function, we will not have initialized it yet. Do that now. */
4384 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
4385 get_arg_pointer_save_area ();
4387 /* If we are doing stack checking and this function makes calls,
4388 do a stack probe at the start of the function to ensure we have enough
4389 space for another stack frame. */
4390 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
4394 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4398 probe_stack_range (STACK_CHECK_PROTECT,
4399 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4402 emit_insn_before (seq, stack_check_probe_note);
4407 /* End any sequences that failed to be closed due to syntax errors. */
4408 while (in_sequence_p ())
4411 clear_pending_stack_adjust ();
4412 do_pending_stack_adjust ();
4414 /* Output a linenumber for the end of the function.
4415 SDB depends on this. */
4416 force_next_line_note ();
4417 set_curr_insn_source_location (input_location);
4419 /* Before the return label (if any), clobber the return
4420 registers so that they are not propagated live to the rest of
4421 the function. This can only happen with functions that drop
4422 through; if there had been a return statement, there would
4423 have either been a return rtx, or a jump to the return label.
4425 We delay actual code generation after the current_function_value_rtx
4427 clobber_after = get_last_insn ();
4429 /* Output the label for the actual return from the function. */
4430 emit_label (return_label);
4432 if (USING_SJLJ_EXCEPTIONS)
4434 /* Let except.c know where it should emit the call to unregister
4435 the function context for sjlj exceptions. */
4436 if (flag_exceptions)
4437 sjlj_emit_function_exit_after (get_last_insn ());
4441 /* We want to ensure that instructions that may trap are not
4442 moved into the epilogue by scheduling, because we don't
4443 always emit unwind information for the epilogue. */
4444 if (flag_non_call_exceptions)
4445 emit_insn (gen_blockage ());
4448 /* If this is an implementation of throw, do what's necessary to
4449 communicate between __builtin_eh_return and the epilogue. */
4450 expand_eh_return ();
4452 /* If scalar return value was computed in a pseudo-reg, or was a named
4453 return value that got dumped to the stack, copy that to the hard
4455 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4457 tree decl_result = DECL_RESULT (current_function_decl);
4458 rtx decl_rtl = DECL_RTL (decl_result);
4460 if (REG_P (decl_rtl)
4461 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4462 : DECL_REGISTER (decl_result))
4464 rtx real_decl_rtl = current_function_return_rtx;
4466 /* This should be set in assign_parms. */
4467 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4469 /* If this is a BLKmode structure being returned in registers,
4470 then use the mode computed in expand_return. Note that if
4471 decl_rtl is memory, then its mode may have been changed,
4472 but that current_function_return_rtx has not. */
4473 if (GET_MODE (real_decl_rtl) == BLKmode)
4474 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4476 /* If a non-BLKmode return value should be padded at the least
4477 significant end of the register, shift it left by the appropriate
4478 amount. BLKmode results are handled using the group load/store
4480 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4481 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4483 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4484 REGNO (real_decl_rtl)),
4486 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4488 /* If a named return value dumped decl_return to memory, then
4489 we may need to re-do the PROMOTE_MODE signed/unsigned
4491 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4493 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4495 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
4496 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
4499 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4501 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4503 /* If expand_function_start has created a PARALLEL for decl_rtl,
4504 move the result to the real return registers. Otherwise, do
4505 a group load from decl_rtl for a named return. */
4506 if (GET_CODE (decl_rtl) == PARALLEL)
4507 emit_group_move (real_decl_rtl, decl_rtl);
4509 emit_group_load (real_decl_rtl, decl_rtl,
4510 TREE_TYPE (decl_result),
4511 int_size_in_bytes (TREE_TYPE (decl_result)));
4513 /* In the case of complex integer modes smaller than a word, we'll
4514 need to generate some non-trivial bitfield insertions. Do that
4515 on a pseudo and not the hard register. */
4516 else if (GET_CODE (decl_rtl) == CONCAT
4517 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
4518 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
4520 int old_generating_concat_p;
4523 old_generating_concat_p = generating_concat_p;
4524 generating_concat_p = 0;
4525 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
4526 generating_concat_p = old_generating_concat_p;
4528 emit_move_insn (tmp, decl_rtl);
4529 emit_move_insn (real_decl_rtl, tmp);
4532 emit_move_insn (real_decl_rtl, decl_rtl);
4536 /* If returning a structure, arrange to return the address of the value
4537 in a place where debuggers expect to find it.
4539 If returning a structure PCC style,
4540 the caller also depends on this value.
4541 And current_function_returns_pcc_struct is not necessarily set. */
4542 if (current_function_returns_struct
4543 || current_function_returns_pcc_struct)
4545 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4546 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4549 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4550 type = TREE_TYPE (type);
4552 value_address = XEXP (value_address, 0);
4554 outgoing = targetm.calls.function_value (build_pointer_type (type),
4555 current_function_decl, true);
4557 /* Mark this as a function return value so integrate will delete the
4558 assignment and USE below when inlining this function. */
4559 REG_FUNCTION_VALUE_P (outgoing) = 1;
4561 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4562 value_address = convert_memory_address (GET_MODE (outgoing),
4565 emit_move_insn (outgoing, value_address);
4567 /* Show return register used to hold result (in this case the address
4569 current_function_return_rtx = outgoing;
4572 /* Emit the actual code to clobber return register. */
4577 clobber_return_register ();
4578 expand_naked_return ();
4582 emit_insn_after (seq, clobber_after);
4585 /* Output the label for the naked return from the function. */
4586 emit_label (naked_return_label);
4588 /* @@@ This is a kludge. We want to ensure that instructions that
4589 may trap are not moved into the epilogue by scheduling, because
4590 we don't always emit unwind information for the epilogue. */
4591 if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
4592 emit_insn (gen_blockage ());
4594 /* If stack protection is enabled for this function, check the guard. */
4595 if (cfun->stack_protect_guard)
4596 stack_protect_epilogue ();
4598 /* If we had calls to alloca, and this machine needs
4599 an accurate stack pointer to exit the function,
4600 insert some code to save and restore the stack pointer. */
4601 if (! EXIT_IGNORE_STACK
4602 && current_function_calls_alloca)
4606 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4607 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4610 /* ??? This should no longer be necessary since stupid is no longer with
4611 us, but there are some parts of the compiler (eg reload_combine, and
4612 sh mach_dep_reorg) that still try and compute their own lifetime info
4613 instead of using the general framework. */
4614 use_return_register ();
4618 get_arg_pointer_save_area (void)
4620 rtx ret = arg_pointer_save_area;
4624 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4625 arg_pointer_save_area = ret;
4628 if (! cfun->arg_pointer_save_area_init)
4632 /* Save the arg pointer at the beginning of the function. The
4633 generated stack slot may not be a valid memory address, so we
4634 have to check it and fix it if necessary. */
4636 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
4640 push_topmost_sequence ();
4641 emit_insn_after (seq, entry_of_function ());
4642 pop_topmost_sequence ();
4648 /* Extend a vector that records the INSN_UIDs of INSNS
4649 (a list of one or more insns). */
4652 record_insns (rtx insns, VEC(int,heap) **vecp)
4656 for (tmp = insns; tmp != NULL_RTX; tmp = NEXT_INSN (tmp))
4657 VEC_safe_push (int, heap, *vecp, INSN_UID (tmp));
4660 /* Set the locator of the insn chain starting at INSN to LOC. */
4662 set_insn_locators (rtx insn, int loc)
4664 while (insn != NULL_RTX)
4667 INSN_LOCATOR (insn) = loc;
4668 insn = NEXT_INSN (insn);
4672 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4673 be running after reorg, SEQUENCE rtl is possible. */
4676 contains (const_rtx insn, VEC(int,heap) **vec)
4680 if (NONJUMP_INSN_P (insn)
4681 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4684 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4685 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4686 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i))
4687 == VEC_index (int, *vec, j))
4693 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4694 if (INSN_UID (insn) == VEC_index (int, *vec, j))
4701 prologue_epilogue_contains (const_rtx insn)
4703 if (contains (insn, &prologue))
4705 if (contains (insn, &epilogue))
4711 sibcall_epilogue_contains (const_rtx insn)
4713 if (sibcall_epilogue)
4714 return contains (insn, &sibcall_epilogue);
4719 /* Insert gen_return at the end of block BB. This also means updating
4720 block_for_insn appropriately. */
4723 emit_return_into_block (basic_block bb)
4725 emit_jump_insn_after (gen_return (), BB_END (bb));
4727 #endif /* HAVE_return */
4729 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
4731 /* These functions convert the epilogue into a variant that does not
4732 modify the stack pointer. This is used in cases where a function
4733 returns an object whose size is not known until it is computed.
4734 The called function leaves the object on the stack, leaves the
4735 stack depressed, and returns a pointer to the object.
4737 What we need to do is track all modifications and references to the
4738 stack pointer, deleting the modifications and changing the
4739 references to point to the location the stack pointer would have
4740 pointed to had the modifications taken place.
4742 These functions need to be portable so we need to make as few
4743 assumptions about the epilogue as we can. However, the epilogue
4744 basically contains three things: instructions to reset the stack
4745 pointer, instructions to reload registers, possibly including the
4746 frame pointer, and an instruction to return to the caller.
4748 We must be sure of what a relevant epilogue insn is doing. We also
4749 make no attempt to validate the insns we make since if they are
4750 invalid, we probably can't do anything valid. The intent is that
4751 these routines get "smarter" as more and more machines start to use
4752 them and they try operating on different epilogues.
4754 We use the following structure to track what the part of the
4755 epilogue that we've already processed has done. We keep two copies
4756 of the SP equivalence, one for use during the insn we are
4757 processing and one for use in the next insn. The difference is
4758 because one part of a PARALLEL may adjust SP and the other may use
4763 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
4764 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
4765 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
4766 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
4767 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
4768 should be set to once we no longer need
4770 rtx const_equiv[FIRST_PSEUDO_REGISTER]; /* Any known constant equivalences
4774 static void handle_epilogue_set (rtx, struct epi_info *);
4775 static void update_epilogue_consts (rtx, const_rtx, void *);
4776 static void emit_equiv_load (struct epi_info *);
4778 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
4779 no modifications to the stack pointer. Return the new list of insns. */
4782 keep_stack_depressed (rtx insns)
4785 struct epi_info info;
4788 /* If the epilogue is just a single instruction, it must be OK as is. */
4789 if (NEXT_INSN (insns) == NULL_RTX)
4792 /* Otherwise, start a sequence, initialize the information we have, and
4793 process all the insns we were given. */
4796 info.sp_equiv_reg = stack_pointer_rtx;
4798 info.equiv_reg_src = 0;
4800 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
4801 info.const_equiv[j] = 0;
4805 while (insn != NULL_RTX)
4807 next = NEXT_INSN (insn);
4816 /* If this insn references the register that SP is equivalent to and
4817 we have a pending load to that register, we must force out the load
4818 first and then indicate we no longer know what SP's equivalent is. */
4819 if (info.equiv_reg_src != 0
4820 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
4822 emit_equiv_load (&info);
4823 info.sp_equiv_reg = 0;
4826 info.new_sp_equiv_reg = info.sp_equiv_reg;
4827 info.new_sp_offset = info.sp_offset;
4829 /* If this is a (RETURN) and the return address is on the stack,
4830 update the address and change to an indirect jump. */
4831 if (GET_CODE (PATTERN (insn)) == RETURN
4832 || (GET_CODE (PATTERN (insn)) == PARALLEL
4833 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
4835 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
4837 HOST_WIDE_INT offset = 0;
4838 rtx jump_insn, jump_set;
4840 /* If the return address is in a register, we can emit the insn
4841 unchanged. Otherwise, it must be a MEM and we see what the
4842 base register and offset are. In any case, we have to emit any
4843 pending load to the equivalent reg of SP, if any. */
4844 if (REG_P (retaddr))
4846 emit_equiv_load (&info);
4854 gcc_assert (MEM_P (retaddr));
4856 ret_ptr = XEXP (retaddr, 0);
4858 if (REG_P (ret_ptr))
4860 base = gen_rtx_REG (Pmode, REGNO (ret_ptr));
4865 gcc_assert (GET_CODE (ret_ptr) == PLUS
4866 && REG_P (XEXP (ret_ptr, 0))
4867 && GET_CODE (XEXP (ret_ptr, 1)) == CONST_INT);
4868 base = gen_rtx_REG (Pmode, REGNO (XEXP (ret_ptr, 0)));
4869 offset = INTVAL (XEXP (ret_ptr, 1));
4873 /* If the base of the location containing the return pointer
4874 is SP, we must update it with the replacement address. Otherwise,
4875 just build the necessary MEM. */
4876 retaddr = plus_constant (base, offset);
4877 if (base == stack_pointer_rtx)
4878 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
4879 plus_constant (info.sp_equiv_reg,
4882 retaddr = gen_rtx_MEM (Pmode, retaddr);
4883 MEM_NOTRAP_P (retaddr) = 1;
4885 /* If there is a pending load to the equivalent register for SP
4886 and we reference that register, we must load our address into
4887 a scratch register and then do that load. */
4888 if (info.equiv_reg_src
4889 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
4894 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
4895 if (HARD_REGNO_MODE_OK (regno, Pmode)
4896 && !fixed_regs[regno]
4897 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
4899 (DF_LR_IN (EXIT_BLOCK_PTR), regno)
4900 && !refers_to_regno_p (regno,
4901 end_hard_regno (Pmode, regno),
4902 info.equiv_reg_src, NULL)
4903 && info.const_equiv[regno] == 0)
4906 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
4908 reg = gen_rtx_REG (Pmode, regno);
4909 emit_move_insn (reg, retaddr);
4913 emit_equiv_load (&info);
4914 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
4916 /* Show the SET in the above insn is a RETURN. */
4917 jump_set = single_set (jump_insn);
4918 gcc_assert (jump_set);
4919 SET_IS_RETURN_P (jump_set) = 1;
4922 /* If SP is not mentioned in the pattern and its equivalent register, if
4923 any, is not modified, just emit it. Otherwise, if neither is set,
4924 replace the reference to SP and emit the insn. If none of those are
4925 true, handle each SET individually. */
4926 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
4927 && (info.sp_equiv_reg == stack_pointer_rtx
4928 || !reg_set_p (info.sp_equiv_reg, insn)))
4930 else if (! reg_set_p (stack_pointer_rtx, insn)
4931 && (info.sp_equiv_reg == stack_pointer_rtx
4932 || !reg_set_p (info.sp_equiv_reg, insn)))
4936 changed = validate_replace_rtx (stack_pointer_rtx,
4937 plus_constant (info.sp_equiv_reg,
4940 gcc_assert (changed);
4944 else if (GET_CODE (PATTERN (insn)) == SET)
4945 handle_epilogue_set (PATTERN (insn), &info);
4946 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
4948 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
4949 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
4950 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
4955 info.sp_equiv_reg = info.new_sp_equiv_reg;
4956 info.sp_offset = info.new_sp_offset;
4958 /* Now update any constants this insn sets. */
4959 note_stores (PATTERN (insn), update_epilogue_consts, &info);
4963 insns = get_insns ();
4968 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
4969 structure that contains information about what we've seen so far. We
4970 process this SET by either updating that data or by emitting one or
4974 handle_epilogue_set (rtx set, struct epi_info *p)
4976 /* First handle the case where we are setting SP. Record what it is being
4977 set from, which we must be able to determine */
4978 if (reg_set_p (stack_pointer_rtx, set))
4980 gcc_assert (SET_DEST (set) == stack_pointer_rtx);
4982 if (GET_CODE (SET_SRC (set)) == PLUS)
4984 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
4985 if (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
4986 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
4989 gcc_assert (REG_P (XEXP (SET_SRC (set), 1))
4990 && (REGNO (XEXP (SET_SRC (set), 1))
4991 < FIRST_PSEUDO_REGISTER)
4992 && p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
4994 = INTVAL (p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
4998 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
5000 /* If we are adjusting SP, we adjust from the old data. */
5001 if (p->new_sp_equiv_reg == stack_pointer_rtx)
5003 p->new_sp_equiv_reg = p->sp_equiv_reg;
5004 p->new_sp_offset += p->sp_offset;
5007 gcc_assert (p->new_sp_equiv_reg && REG_P (p->new_sp_equiv_reg));
5012 /* Next handle the case where we are setting SP's equivalent
5013 register. We must not already have a value to set it to. We
5014 could update, but there seems little point in handling that case.
5015 Note that we have to allow for the case where we are setting the
5016 register set in the previous part of a PARALLEL inside a single
5017 insn. But use the old offset for any updates within this insn.
5018 We must allow for the case where the register is being set in a
5019 different (usually wider) mode than Pmode). */
5020 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
5022 gcc_assert (!p->equiv_reg_src
5023 && REG_P (p->new_sp_equiv_reg)
5024 && REG_P (SET_DEST (set))
5025 && (GET_MODE_BITSIZE (GET_MODE (SET_DEST (set)))
5027 && REGNO (p->new_sp_equiv_reg) == REGNO (SET_DEST (set)));
5029 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
5030 plus_constant (p->sp_equiv_reg,
5034 /* Otherwise, replace any references to SP in the insn to its new value
5035 and emit the insn. */
5038 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
5039 plus_constant (p->sp_equiv_reg,
5041 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
5042 plus_constant (p->sp_equiv_reg,
5048 /* Update the tracking information for registers set to constants. */
5051 update_epilogue_consts (rtx dest, const_rtx x, void *data)
5053 struct epi_info *p = (struct epi_info *) data;
5056 if (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER)
5059 /* If we are either clobbering a register or doing a partial set,
5060 show we don't know the value. */
5061 else if (GET_CODE (x) == CLOBBER || ! rtx_equal_p (dest, SET_DEST (x)))
5062 p->const_equiv[REGNO (dest)] = 0;
5064 /* If we are setting it to a constant, record that constant. */
5065 else if (GET_CODE (SET_SRC (x)) == CONST_INT)
5066 p->const_equiv[REGNO (dest)] = SET_SRC (x);
5068 /* If this is a binary operation between a register we have been tracking
5069 and a constant, see if we can compute a new constant value. */
5070 else if (ARITHMETIC_P (SET_SRC (x))
5071 && REG_P (XEXP (SET_SRC (x), 0))
5072 && REGNO (XEXP (SET_SRC (x), 0)) < FIRST_PSEUDO_REGISTER
5073 && p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))] != 0
5074 && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT
5075 && 0 != (new = simplify_binary_operation
5076 (GET_CODE (SET_SRC (x)), GET_MODE (dest),
5077 p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))],
5078 XEXP (SET_SRC (x), 1)))
5079 && GET_CODE (new) == CONST_INT)
5080 p->const_equiv[REGNO (dest)] = new;
5082 /* Otherwise, we can't do anything with this value. */
5084 p->const_equiv[REGNO (dest)] = 0;
5087 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
5090 emit_equiv_load (struct epi_info *p)
5092 if (p->equiv_reg_src != 0)
5094 rtx dest = p->sp_equiv_reg;
5096 if (GET_MODE (p->equiv_reg_src) != GET_MODE (dest))
5097 dest = gen_rtx_REG (GET_MODE (p->equiv_reg_src),
5098 REGNO (p->sp_equiv_reg));
5100 emit_move_insn (dest, p->equiv_reg_src);
5101 p->equiv_reg_src = 0;
5106 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5107 this into place with notes indicating where the prologue ends and where
5108 the epilogue begins. Update the basic block information when possible. */
5111 thread_prologue_and_epilogue_insns (void)
5115 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
5118 #if defined (HAVE_epilogue) || defined(HAVE_return)
5119 rtx epilogue_end = NULL_RTX;
5123 #ifdef HAVE_prologue
5127 seq = gen_prologue ();
5130 /* Insert an explicit USE for the frame pointer
5131 if the profiling is on and the frame pointer is required. */
5132 if (current_function_profile && frame_pointer_needed)
5133 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
5135 /* Retain a map of the prologue insns. */
5136 record_insns (seq, &prologue);
5137 emit_note (NOTE_INSN_PROLOGUE_END);
5139 #ifndef PROFILE_BEFORE_PROLOGUE
5140 /* Ensure that instructions are not moved into the prologue when
5141 profiling is on. The call to the profiling routine can be
5142 emitted within the live range of a call-clobbered register. */
5143 if (current_function_profile)
5144 emit_insn (gen_blockage ());
5149 set_insn_locators (seq, prologue_locator);
5151 /* Can't deal with multiple successors of the entry block
5152 at the moment. Function should always have at least one
5154 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
5156 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
5161 /* If the exit block has no non-fake predecessors, we don't need
5163 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5164 if ((e->flags & EDGE_FAKE) == 0)
5170 if (optimize && HAVE_return)
5172 /* If we're allowed to generate a simple return instruction,
5173 then by definition we don't need a full epilogue. Examine
5174 the block that falls through to EXIT. If it does not
5175 contain any code, examine its predecessors and try to
5176 emit (conditional) return instructions. */
5181 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5182 if (e->flags & EDGE_FALLTHRU)
5188 /* Verify that there are no active instructions in the last block. */
5189 label = BB_END (last);
5190 while (label && !LABEL_P (label))
5192 if (active_insn_p (label))
5194 label = PREV_INSN (label);
5197 if (BB_HEAD (last) == label && LABEL_P (label))
5201 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
5203 basic_block bb = e->src;
5206 if (bb == ENTRY_BLOCK_PTR)
5213 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
5219 /* If we have an unconditional jump, we can replace that
5220 with a simple return instruction. */
5221 if (simplejump_p (jump))
5223 emit_return_into_block (bb);
5227 /* If we have a conditional jump, we can try to replace
5228 that with a conditional return instruction. */
5229 else if (condjump_p (jump))
5231 if (! redirect_jump (jump, 0, 0))
5237 /* If this block has only one successor, it both jumps
5238 and falls through to the fallthru block, so we can't
5240 if (single_succ_p (bb))
5252 /* Fix up the CFG for the successful change we just made. */
5253 redirect_edge_succ (e, EXIT_BLOCK_PTR);
5256 /* Emit a return insn for the exit fallthru block. Whether
5257 this is still reachable will be determined later. */
5259 emit_barrier_after (BB_END (last));
5260 emit_return_into_block (last);
5261 epilogue_end = BB_END (last);
5262 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
5267 /* Find the edge that falls through to EXIT. Other edges may exist
5268 due to RETURN instructions, but those don't need epilogues.
5269 There really shouldn't be a mixture -- either all should have
5270 been converted or none, however... */
5272 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5273 if (e->flags & EDGE_FALLTHRU)
5278 #ifdef HAVE_epilogue
5282 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5284 seq = gen_epilogue ();
5286 #ifdef INCOMING_RETURN_ADDR_RTX
5287 /* If this function returns with the stack depressed and we can support
5288 it, massage the epilogue to actually do that. */
5289 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
5290 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
5291 seq = keep_stack_depressed (seq);
5294 emit_jump_insn (seq);
5296 /* Retain a map of the epilogue insns. */
5297 record_insns (seq, &epilogue);
5298 set_insn_locators (seq, epilogue_locator);
5303 insert_insn_on_edge (seq, e);
5311 if (! next_active_insn (BB_END (e->src)))
5313 /* We have a fall-through edge to the exit block, the source is not
5314 at the end of the function, and there will be an assembler epilogue
5315 at the end of the function.
5316 We can't use force_nonfallthru here, because that would try to
5317 use return. Inserting a jump 'by hand' is extremely messy, so
5318 we take advantage of cfg_layout_finalize using
5319 fixup_fallthru_exit_predecessor. */
5320 cfg_layout_initialize (0);
5321 FOR_EACH_BB (cur_bb)
5322 if (cur_bb->index >= NUM_FIXED_BLOCKS
5323 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5324 cur_bb->aux = cur_bb->next_bb;
5325 cfg_layout_finalize ();
5331 commit_edge_insertions ();
5333 /* The epilogue insns we inserted may cause the exit edge to no longer
5335 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5337 if (((e->flags & EDGE_FALLTHRU) != 0)
5338 && returnjump_p (BB_END (e->src)))
5339 e->flags &= ~EDGE_FALLTHRU;
5343 #ifdef HAVE_sibcall_epilogue
5344 /* Emit sibling epilogues before any sibling call sites. */
5345 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5347 basic_block bb = e->src;
5348 rtx insn = BB_END (bb);
5351 || ! SIBLING_CALL_P (insn))
5358 emit_insn (gen_sibcall_epilogue ());
5362 /* Retain a map of the epilogue insns. Used in life analysis to
5363 avoid getting rid of sibcall epilogue insns. Do this before we
5364 actually emit the sequence. */
5365 record_insns (seq, &sibcall_epilogue);
5366 set_insn_locators (seq, epilogue_locator);
5368 emit_insn_before (seq, insn);
5373 #ifdef HAVE_epilogue
5378 /* Similarly, move any line notes that appear after the epilogue.
5379 There is no need, however, to be quite so anal about the existence
5380 of such a note. Also possibly move
5381 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5383 for (insn = epilogue_end; insn; insn = next)
5385 next = NEXT_INSN (insn);
5387 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5388 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5393 /* Threading the prologue and epilogue changes the artificial refs
5394 in the entry and exit blocks. */
5395 epilogue_completed = 1;
5396 df_update_entry_exit_and_calls ();
5399 /* Reposition the prologue-end and epilogue-begin notes after instruction
5400 scheduling and delayed branch scheduling. */
5403 reposition_prologue_and_epilogue_notes (void)
5405 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5406 rtx insn, last, note;
5409 if ((len = VEC_length (int, prologue)) > 0)
5413 /* Scan from the beginning until we reach the last prologue insn.
5414 We apparently can't depend on basic_block_{head,end} after
5416 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5420 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5423 else if (contains (insn, &prologue))
5433 /* Find the prologue-end note if we haven't already, and
5434 move it to just after the last prologue insn. */
5437 for (note = last; (note = NEXT_INSN (note));)
5439 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5443 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5445 last = NEXT_INSN (last);
5446 reorder_insns (note, note, last);
5450 if ((len = VEC_length (int, epilogue)) > 0)
5454 /* Scan from the end until we reach the first epilogue insn.
5455 We apparently can't depend on basic_block_{head,end} after
5457 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
5461 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5464 else if (contains (insn, &epilogue))
5474 /* Find the epilogue-begin note if we haven't already, and
5475 move it to just before the first epilogue insn. */
5478 for (note = insn; (note = PREV_INSN (note));)
5480 && NOTE_KIND (note) == NOTE_INSN_EPILOGUE_BEG)
5484 if (PREV_INSN (last) != note)
5485 reorder_insns (note, note, PREV_INSN (last));
5488 #endif /* HAVE_prologue or HAVE_epilogue */
5491 /* Returns the name of the current function. */
5493 current_function_name (void)
5495 return lang_hooks.decl_printable_name (cfun->decl, 2);
5498 /* Returns the raw (mangled) name of the current function. */
5500 current_function_assembler_name (void)
5502 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (cfun->decl));
5507 rest_of_handle_check_leaf_regs (void)
5509 #ifdef LEAF_REGISTERS
5510 current_function_uses_only_leaf_regs
5511 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5516 /* Insert a TYPE into the used types hash table of CFUN. */
5518 used_types_insert_helper (tree type, struct function *func)
5520 if (type != NULL && func != NULL)
5524 if (func->used_types_hash == NULL)
5525 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5526 htab_eq_pointer, NULL);
5527 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5533 /* Given a type, insert it into the used hash table in cfun. */
5535 used_types_insert (tree t)
5537 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5539 t = TYPE_MAIN_VARIANT (t);
5540 if (debug_info_level > DINFO_LEVEL_NONE)
5541 used_types_insert_helper (t, cfun);
5544 struct rtl_opt_pass pass_leaf_regs =
5550 rest_of_handle_check_leaf_regs, /* execute */
5553 0, /* static_pass_number */
5555 0, /* properties_required */
5556 0, /* properties_provided */
5557 0, /* properties_destroyed */
5558 0, /* todo_flags_start */
5559 0 /* todo_flags_finish */
5564 rest_of_handle_thread_prologue_and_epilogue (void)
5567 cleanup_cfg (CLEANUP_EXPENSIVE);
5568 /* On some machines, the prologue and epilogue code, or parts thereof,
5569 can be represented as RTL. Doing so lets us schedule insns between
5570 it and the rest of the code and also allows delayed branch
5571 scheduling to operate in the epilogue. */
5573 thread_prologue_and_epilogue_insns ();
5577 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5581 "pro_and_epilogue", /* name */
5583 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5586 0, /* static_pass_number */
5587 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5588 0, /* properties_required */
5589 0, /* properties_provided */
5590 0, /* properties_destroyed */
5591 TODO_verify_flow, /* todo_flags_start */
5594 TODO_df_finish | TODO_verify_rtl_sharing |
5595 TODO_ggc_collect /* todo_flags_finish */
5600 /* This mini-pass fixes fall-out from SSA in asm statements that have
5601 in-out constraints. Say you start with
5604 asm ("": "+mr" (inout));
5607 which is transformed very early to use explicit output and match operands:
5610 asm ("": "=mr" (inout) : "0" (inout));
5613 Or, after SSA and copyprop,
5615 asm ("": "=mr" (inout_2) : "0" (inout_1));
5618 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5619 they represent two separate values, so they will get different pseudo
5620 registers during expansion. Then, since the two operands need to match
5621 per the constraints, but use different pseudo registers, reload can
5622 only register a reload for these operands. But reloads can only be
5623 satisfied by hardregs, not by memory, so we need a register for this
5624 reload, just because we are presented with non-matching operands.
5625 So, even though we allow memory for this operand, no memory can be
5626 used for it, just because the two operands don't match. This can
5627 cause reload failures on register-starved targets.
5629 So it's a symptom of reload not being able to use memory for reloads
5630 or, alternatively it's also a symptom of both operands not coming into
5631 reload as matching (in which case the pseudo could go to memory just
5632 fine, as the alternative allows it, and no reload would be necessary).
5633 We fix the latter problem here, by transforming
5635 asm ("": "=mr" (inout_2) : "0" (inout_1));
5640 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5643 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5646 bool changed = false;
5647 rtx op = SET_SRC (p_sets[0]);
5648 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5649 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5650 bool *output_matched = alloca (noutputs * sizeof (bool));
5652 memset (output_matched, 0, noutputs * sizeof (bool));
5653 for (i = 0; i < ninputs; i++)
5655 rtx input, output, insns;
5656 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5660 match = strtoul (constraint, &end, 10);
5661 if (end == constraint)
5664 gcc_assert (match < noutputs);
5665 output = SET_DEST (p_sets[match]);
5666 input = RTVEC_ELT (inputs, i);
5667 /* Only do the transformation for pseudos. */
5668 if (! REG_P (output)
5669 || rtx_equal_p (output, input)
5670 || (GET_MODE (input) != VOIDmode
5671 && GET_MODE (input) != GET_MODE (output)))
5674 /* We can't do anything if the output is also used as input,
5675 as we're going to overwrite it. */
5676 for (j = 0; j < ninputs; j++)
5677 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5682 /* Avoid changing the same input several times. For
5683 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5684 only change in once (to out1), rather than changing it
5685 first to out1 and afterwards to out2. */
5688 for (j = 0; j < noutputs; j++)
5689 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5694 output_matched[match] = true;
5697 emit_move_insn (output, input);
5698 insns = get_insns ();
5700 emit_insn_before (insns, insn);
5702 /* Now replace all mentions of the input with output. We can't
5703 just replace the occurence in inputs[i], as the register might
5704 also be used in some other input (or even in an address of an
5705 output), which would mean possibly increasing the number of
5706 inputs by one (namely 'output' in addition), which might pose
5707 a too complicated problem for reload to solve. E.g. this situation:
5709 asm ("" : "=r" (output), "=m" (input) : "0" (input))
5711 Here 'input' is used in two occurrences as input (once for the
5712 input operand, once for the address in the second output operand).
5713 If we would replace only the occurence of the input operand (to
5714 make the matching) we would be left with this:
5717 asm ("" : "=r" (output), "=m" (input) : "0" (output))
5719 Now we suddenly have two different input values (containing the same
5720 value, but different pseudos) where we formerly had only one.
5721 With more complicated asms this might lead to reload failures
5722 which wouldn't have happen without this pass. So, iterate over
5723 all operands and replace all occurrences of the register used. */
5724 for (j = 0; j < noutputs; j++)
5725 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
5726 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
5727 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
5729 for (j = 0; j < ninputs; j++)
5730 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
5731 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
5738 df_insn_rescan (insn);
5742 rest_of_match_asm_constraints (void)
5745 rtx insn, pat, *p_sets;
5748 if (!cfun->has_asm_statement)
5751 df_set_flags (DF_DEFER_INSN_RESCAN);
5754 FOR_BB_INSNS (bb, insn)
5759 pat = PATTERN (insn);
5760 if (GET_CODE (pat) == PARALLEL)
5761 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
5762 else if (GET_CODE (pat) == SET)
5763 p_sets = &PATTERN (insn), noutputs = 1;
5767 if (GET_CODE (*p_sets) == SET
5768 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
5769 match_asm_constraints_1 (insn, p_sets, noutputs);
5773 return TODO_df_finish;
5776 struct rtl_opt_pass pass_match_asm_constraints =
5780 "asmcons", /* name */
5782 rest_of_match_asm_constraints, /* execute */
5785 0, /* static_pass_number */
5787 0, /* properties_required */
5788 0, /* properties_provided */
5789 0, /* properties_destroyed */
5790 0, /* todo_flags_start */
5791 TODO_dump_func /* todo_flags_finish */
5796 #include "gt-function.h"