Add sh2e support:
[official-gcc.git] / gcc / function.c
blobc240788e30a8746332410248061fae94ee257b35
1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register.
36 Call `put_var_into_stack' when you learn, belatedly, that a variable
37 previously given a pseudo-register must in fact go in the stack.
38 This function changes the DECL_RTL to be a stack slot instead of a reg
39 then scans all the RTL instructions so far generated to correct them. */
41 #include "config.h"
42 #include "system.h"
43 #include "coretypes.h"
44 #include "tm.h"
45 #include "rtl.h"
46 #include "tree.h"
47 #include "flags.h"
48 #include "except.h"
49 #include "function.h"
50 #include "expr.h"
51 #include "libfuncs.h"
52 #include "regs.h"
53 #include "hard-reg-set.h"
54 #include "insn-config.h"
55 #include "recog.h"
56 #include "output.h"
57 #include "basic-block.h"
58 #include "toplev.h"
59 #include "hashtab.h"
60 #include "ggc.h"
61 #include "tm_p.h"
62 #include "integrate.h"
63 #include "langhooks.h"
65 #ifndef TRAMPOLINE_ALIGNMENT
66 #define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
67 #endif
69 #ifndef LOCAL_ALIGNMENT
70 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
71 #endif
73 /* Some systems use __main in a way incompatible with its use in gcc, in these
74 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
75 give the same symbol without quotes for an alternative entry point. You
76 must define both, or neither. */
77 #ifndef NAME__MAIN
78 #define NAME__MAIN "__main"
79 #endif
81 /* Round a value to the lowest integer less than it that is a multiple of
82 the required alignment. Avoid using division in case the value is
83 negative. Assume the alignment is a power of two. */
84 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
86 /* Similar, but round to the next highest integer that meets the
87 alignment. */
88 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
90 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
91 during rtl generation. If they are different register numbers, this is
92 always true. It may also be true if
93 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
94 generation. See fix_lexical_addr for details. */
96 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
97 #define NEED_SEPARATE_AP
98 #endif
100 /* Nonzero if function being compiled doesn't contain any calls
101 (ignoring the prologue and epilogue). This is set prior to
102 local register allocation and is valid for the remaining
103 compiler passes. */
104 int current_function_is_leaf;
106 /* Nonzero if function being compiled doesn't contain any instructions
107 that can throw an exception. This is set prior to final. */
109 int current_function_nothrow;
111 /* Nonzero if function being compiled doesn't modify the stack pointer
112 (ignoring the prologue and epilogue). This is only valid after
113 life_analysis has run. */
114 int current_function_sp_is_unchanging;
116 /* Nonzero if the function being compiled is a leaf function which only
117 uses leaf registers. This is valid after reload (specifically after
118 sched2) and is useful only if the port defines LEAF_REGISTERS. */
119 int current_function_uses_only_leaf_regs;
121 /* Nonzero once virtual register instantiation has been done.
122 assign_stack_local uses frame_pointer_rtx when this is nonzero.
123 calls.c:emit_library_call_value_1 uses it to set up
124 post-instantiation libcalls. */
125 int virtuals_instantiated;
127 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
128 static GTY(()) int funcdef_no;
130 /* These variables hold pointers to functions to create and destroy
131 target specific, per-function data structures. */
132 struct machine_function * (*init_machine_status) PARAMS ((void));
134 /* The FUNCTION_DECL for an inline function currently being expanded. */
135 tree inline_function_decl;
137 /* The currently compiled function. */
138 struct function *cfun = 0;
140 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
141 static GTY(()) varray_type prologue;
142 static GTY(()) varray_type epilogue;
144 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
145 in this function. */
146 static GTY(()) varray_type sibcall_epilogue;
148 /* In order to evaluate some expressions, such as function calls returning
149 structures in memory, we need to temporarily allocate stack locations.
150 We record each allocated temporary in the following structure.
152 Associated with each temporary slot is a nesting level. When we pop up
153 one level, all temporaries associated with the previous level are freed.
154 Normally, all temporaries are freed after the execution of the statement
155 in which they were created. However, if we are inside a ({...}) grouping,
156 the result may be in a temporary and hence must be preserved. If the
157 result could be in a temporary, we preserve it if we can determine which
158 one it is in. If we cannot determine which temporary may contain the
159 result, all temporaries are preserved. A temporary is preserved by
160 pretending it was allocated at the previous nesting level.
162 Automatic variables are also assigned temporary slots, at the nesting
163 level where they are defined. They are marked a "kept" so that
164 free_temp_slots will not free them. */
166 struct temp_slot GTY(())
168 /* Points to next temporary slot. */
169 struct temp_slot *next;
170 /* The rtx to used to reference the slot. */
171 rtx slot;
172 /* The rtx used to represent the address if not the address of the
173 slot above. May be an EXPR_LIST if multiple addresses exist. */
174 rtx address;
175 /* The alignment (in bits) of the slot. */
176 unsigned int align;
177 /* The size, in units, of the slot. */
178 HOST_WIDE_INT size;
179 /* The type of the object in the slot, or zero if it doesn't correspond
180 to a type. We use this to determine whether a slot can be reused.
181 It can be reused if objects of the type of the new slot will always
182 conflict with objects of the type of the old slot. */
183 tree type;
184 /* The value of `sequence_rtl_expr' when this temporary is allocated. */
185 tree rtl_expr;
186 /* Nonzero if this temporary is currently in use. */
187 char in_use;
188 /* Nonzero if this temporary has its address taken. */
189 char addr_taken;
190 /* Nesting level at which this slot is being used. */
191 int level;
192 /* Nonzero if this should survive a call to free_temp_slots. */
193 int keep;
194 /* The offset of the slot from the frame_pointer, including extra space
195 for alignment. This info is for combine_temp_slots. */
196 HOST_WIDE_INT base_offset;
197 /* The size of the slot, including extra space for alignment. This
198 info is for combine_temp_slots. */
199 HOST_WIDE_INT full_size;
202 /* This structure is used to record MEMs or pseudos used to replace VAR, any
203 SUBREGs of VAR, and any MEMs containing VAR as an address. We need to
204 maintain this list in case two operands of an insn were required to match;
205 in that case we must ensure we use the same replacement. */
207 struct fixup_replacement GTY(())
209 rtx old;
210 rtx new;
211 struct fixup_replacement *next;
214 struct insns_for_mem_entry
216 /* A MEM. */
217 rtx key;
218 /* These are the INSNs which reference the MEM. */
219 rtx insns;
222 /* Forward declarations. */
224 static rtx assign_stack_local_1 PARAMS ((enum machine_mode, HOST_WIDE_INT,
225 int, struct function *));
226 static struct temp_slot *find_temp_slot_from_address PARAMS ((rtx));
227 static void put_reg_into_stack PARAMS ((struct function *, rtx, tree,
228 enum machine_mode, enum machine_mode,
229 int, unsigned int, int,
230 htab_t));
231 static void schedule_fixup_var_refs PARAMS ((struct function *, rtx, tree,
232 enum machine_mode,
233 htab_t));
234 static void fixup_var_refs PARAMS ((rtx, enum machine_mode, int, rtx,
235 htab_t));
236 static struct fixup_replacement
237 *find_fixup_replacement PARAMS ((struct fixup_replacement **, rtx));
238 static void fixup_var_refs_insns PARAMS ((rtx, rtx, enum machine_mode,
239 int, int, rtx));
240 static void fixup_var_refs_insns_with_hash
241 PARAMS ((htab_t, rtx,
242 enum machine_mode, int, rtx));
243 static void fixup_var_refs_insn PARAMS ((rtx, rtx, enum machine_mode,
244 int, int, rtx));
245 static void fixup_var_refs_1 PARAMS ((rtx, enum machine_mode, rtx *, rtx,
246 struct fixup_replacement **, rtx));
247 static rtx fixup_memory_subreg PARAMS ((rtx, rtx, enum machine_mode, int));
248 static rtx walk_fixup_memory_subreg PARAMS ((rtx, rtx, enum machine_mode,
249 int));
250 static rtx fixup_stack_1 PARAMS ((rtx, rtx));
251 static void optimize_bit_field PARAMS ((rtx, rtx, rtx *));
252 static void instantiate_decls PARAMS ((tree, int));
253 static void instantiate_decls_1 PARAMS ((tree, int));
254 static void instantiate_decl PARAMS ((rtx, HOST_WIDE_INT, int));
255 static rtx instantiate_new_reg PARAMS ((rtx, HOST_WIDE_INT *));
256 static int instantiate_virtual_regs_1 PARAMS ((rtx *, rtx, int));
257 static void delete_handlers PARAMS ((void));
258 static void pad_to_arg_alignment PARAMS ((struct args_size *, int,
259 struct args_size *));
260 static void pad_below PARAMS ((struct args_size *, enum machine_mode,
261 tree));
262 static rtx round_trampoline_addr PARAMS ((rtx));
263 static rtx adjust_trampoline_addr PARAMS ((rtx));
264 static tree *identify_blocks_1 PARAMS ((rtx, tree *, tree *, tree *));
265 static void reorder_blocks_0 PARAMS ((tree));
266 static void reorder_blocks_1 PARAMS ((rtx, tree, varray_type *));
267 static void reorder_fix_fragments PARAMS ((tree));
268 static tree blocks_nreverse PARAMS ((tree));
269 static int all_blocks PARAMS ((tree, tree *));
270 static tree *get_block_vector PARAMS ((tree, int *));
271 extern tree debug_find_var_in_block_tree PARAMS ((tree, tree));
272 /* We always define `record_insns' even if its not used so that we
273 can always export `prologue_epilogue_contains'. */
274 static void record_insns PARAMS ((rtx, varray_type *)) ATTRIBUTE_UNUSED;
275 static int contains PARAMS ((rtx, varray_type));
276 #ifdef HAVE_return
277 static void emit_return_into_block PARAMS ((basic_block, rtx));
278 #endif
279 static void put_addressof_into_stack PARAMS ((rtx, htab_t));
280 static bool purge_addressof_1 PARAMS ((rtx *, rtx, int, int,
281 htab_t));
282 static void purge_single_hard_subreg_set PARAMS ((rtx));
283 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
284 static rtx keep_stack_depressed PARAMS ((rtx));
285 #endif
286 static int is_addressof PARAMS ((rtx *, void *));
287 static hashval_t insns_for_mem_hash PARAMS ((const void *));
288 static int insns_for_mem_comp PARAMS ((const void *, const void *));
289 static int insns_for_mem_walk PARAMS ((rtx *, void *));
290 static void compute_insns_for_mem PARAMS ((rtx, rtx, htab_t));
291 static void prepare_function_start PARAMS ((void));
292 static void do_clobber_return_reg PARAMS ((rtx, void *));
293 static void do_use_return_reg PARAMS ((rtx, void *));
295 /* Pointer to chain of `struct function' for containing functions. */
296 static GTY(()) struct function *outer_function_chain;
298 /* Given a function decl for a containing function,
299 return the `struct function' for it. */
301 struct function *
302 find_function_data (decl)
303 tree decl;
305 struct function *p;
307 for (p = outer_function_chain; p; p = p->outer)
308 if (p->decl == decl)
309 return p;
311 abort ();
314 /* Save the current context for compilation of a nested function.
315 This is called from language-specific code. The caller should use
316 the enter_nested langhook to save any language-specific state,
317 since this function knows only about language-independent
318 variables. */
320 void
321 push_function_context_to (context)
322 tree context;
324 struct function *p;
326 if (context)
328 if (context == current_function_decl)
329 cfun->contains_functions = 1;
330 else
332 struct function *containing = find_function_data (context);
333 containing->contains_functions = 1;
337 if (cfun == 0)
338 init_dummy_function_start ();
339 p = cfun;
341 p->outer = outer_function_chain;
342 outer_function_chain = p;
343 p->fixup_var_refs_queue = 0;
345 (*lang_hooks.function.enter_nested) (p);
347 cfun = 0;
350 void
351 push_function_context ()
353 push_function_context_to (current_function_decl);
356 /* Restore the last saved context, at the end of a nested function.
357 This function is called from language-specific code. */
359 void
360 pop_function_context_from (context)
361 tree context ATTRIBUTE_UNUSED;
363 struct function *p = outer_function_chain;
364 struct var_refs_queue *queue;
366 cfun = p;
367 outer_function_chain = p->outer;
369 current_function_decl = p->decl;
370 reg_renumber = 0;
372 restore_emit_status (p);
374 (*lang_hooks.function.leave_nested) (p);
376 /* Finish doing put_var_into_stack for any of our variables which became
377 addressable during the nested function. If only one entry has to be
378 fixed up, just do that one. Otherwise, first make a list of MEMs that
379 are not to be unshared. */
380 if (p->fixup_var_refs_queue == 0)
382 else if (p->fixup_var_refs_queue->next == 0)
383 fixup_var_refs (p->fixup_var_refs_queue->modified,
384 p->fixup_var_refs_queue->promoted_mode,
385 p->fixup_var_refs_queue->unsignedp,
386 p->fixup_var_refs_queue->modified, 0);
387 else
389 rtx list = 0;
391 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
392 list = gen_rtx_EXPR_LIST (VOIDmode, queue->modified, list);
394 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
395 fixup_var_refs (queue->modified, queue->promoted_mode,
396 queue->unsignedp, list, 0);
400 p->fixup_var_refs_queue = 0;
402 /* Reset variables that have known state during rtx generation. */
403 rtx_equal_function_value_matters = 1;
404 virtuals_instantiated = 0;
405 generating_concat_p = 1;
408 void
409 pop_function_context ()
411 pop_function_context_from (current_function_decl);
414 /* Clear out all parts of the state in F that can safely be discarded
415 after the function has been parsed, but not compiled, to let
416 garbage collection reclaim the memory. */
418 void
419 free_after_parsing (f)
420 struct function *f;
422 /* f->expr->forced_labels is used by code generation. */
423 /* f->emit->regno_reg_rtx is used by code generation. */
424 /* f->varasm is used by code generation. */
425 /* f->eh->eh_return_stub_label is used by code generation. */
427 (*lang_hooks.function.final) (f);
428 f->stmt = NULL;
431 /* Clear out all parts of the state in F that can safely be discarded
432 after the function has been compiled, to let garbage collection
433 reclaim the memory. */
435 void
436 free_after_compilation (f)
437 struct function *f;
439 f->eh = NULL;
440 f->expr = NULL;
441 f->emit = NULL;
442 f->varasm = NULL;
443 f->machine = NULL;
445 f->x_temp_slots = NULL;
446 f->arg_offset_rtx = NULL;
447 f->return_rtx = NULL;
448 f->internal_arg_pointer = NULL;
449 f->x_nonlocal_labels = NULL;
450 f->x_nonlocal_goto_handler_slots = NULL;
451 f->x_nonlocal_goto_handler_labels = NULL;
452 f->x_nonlocal_goto_stack_level = NULL;
453 f->x_cleanup_label = NULL;
454 f->x_return_label = NULL;
455 f->x_save_expr_regs = NULL;
456 f->x_stack_slot_list = NULL;
457 f->x_rtl_expr_chain = NULL;
458 f->x_tail_recursion_label = NULL;
459 f->x_tail_recursion_reentry = NULL;
460 f->x_arg_pointer_save_area = NULL;
461 f->x_clobber_return_insn = NULL;
462 f->x_context_display = NULL;
463 f->x_trampoline_list = NULL;
464 f->x_parm_birth_insn = NULL;
465 f->x_last_parm_insn = NULL;
466 f->x_parm_reg_stack_loc = NULL;
467 f->fixup_var_refs_queue = NULL;
468 f->original_arg_vector = NULL;
469 f->original_decl_initial = NULL;
470 f->inl_last_parm_insn = NULL;
471 f->epilogue_delay_list = NULL;
474 /* Allocate fixed slots in the stack frame of the current function. */
476 /* Return size needed for stack frame based on slots so far allocated in
477 function F.
478 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
479 the caller may have to do that. */
481 HOST_WIDE_INT
482 get_func_frame_size (f)
483 struct function *f;
485 #ifdef FRAME_GROWS_DOWNWARD
486 return -f->x_frame_offset;
487 #else
488 return f->x_frame_offset;
489 #endif
492 /* Return size needed for stack frame based on slots so far allocated.
493 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
494 the caller may have to do that. */
495 HOST_WIDE_INT
496 get_frame_size ()
498 return get_func_frame_size (cfun);
501 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
502 with machine mode MODE.
504 ALIGN controls the amount of alignment for the address of the slot:
505 0 means according to MODE,
506 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
507 positive specifies alignment boundary in bits.
509 We do not round to stack_boundary here.
511 FUNCTION specifies the function to allocate in. */
513 static rtx
514 assign_stack_local_1 (mode, size, align, function)
515 enum machine_mode mode;
516 HOST_WIDE_INT size;
517 int align;
518 struct function *function;
520 rtx x, addr;
521 int bigend_correction = 0;
522 int alignment;
523 int frame_off, frame_alignment, frame_phase;
525 if (align == 0)
527 tree type;
529 if (mode == BLKmode)
530 alignment = BIGGEST_ALIGNMENT;
531 else
532 alignment = GET_MODE_ALIGNMENT (mode);
534 /* Allow the target to (possibly) increase the alignment of this
535 stack slot. */
536 type = (*lang_hooks.types.type_for_mode) (mode, 0);
537 if (type)
538 alignment = LOCAL_ALIGNMENT (type, alignment);
540 alignment /= BITS_PER_UNIT;
542 else if (align == -1)
544 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
545 size = CEIL_ROUND (size, alignment);
547 else
548 alignment = align / BITS_PER_UNIT;
550 #ifdef FRAME_GROWS_DOWNWARD
551 function->x_frame_offset -= size;
552 #endif
554 /* Ignore alignment we can't do with expected alignment of the boundary. */
555 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
556 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
558 if (function->stack_alignment_needed < alignment * BITS_PER_UNIT)
559 function->stack_alignment_needed = alignment * BITS_PER_UNIT;
561 /* Calculate how many bytes the start of local variables is off from
562 stack alignment. */
563 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
564 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
565 frame_phase = frame_off ? frame_alignment - frame_off : 0;
567 /* Round frame offset to that alignment.
568 We must be careful here, since FRAME_OFFSET might be negative and
569 division with a negative dividend isn't as well defined as we might
570 like. So we instead assume that ALIGNMENT is a power of two and
571 use logical operations which are unambiguous. */
572 #ifdef FRAME_GROWS_DOWNWARD
573 function->x_frame_offset = FLOOR_ROUND (function->x_frame_offset - frame_phase, alignment) + frame_phase;
574 #else
575 function->x_frame_offset = CEIL_ROUND (function->x_frame_offset - frame_phase, alignment) + frame_phase;
576 #endif
578 /* On a big-endian machine, if we are allocating more space than we will use,
579 use the least significant bytes of those that are allocated. */
580 if (BYTES_BIG_ENDIAN && mode != BLKmode)
581 bigend_correction = size - GET_MODE_SIZE (mode);
583 /* If we have already instantiated virtual registers, return the actual
584 address relative to the frame pointer. */
585 if (function == cfun && virtuals_instantiated)
586 addr = plus_constant (frame_pointer_rtx,
587 (frame_offset + bigend_correction
588 + STARTING_FRAME_OFFSET));
589 else
590 addr = plus_constant (virtual_stack_vars_rtx,
591 function->x_frame_offset + bigend_correction);
593 #ifndef FRAME_GROWS_DOWNWARD
594 function->x_frame_offset += size;
595 #endif
597 x = gen_rtx_MEM (mode, addr);
599 function->x_stack_slot_list
600 = gen_rtx_EXPR_LIST (VOIDmode, x, function->x_stack_slot_list);
602 return x;
605 /* Wrapper around assign_stack_local_1; assign a local stack slot for the
606 current function. */
609 assign_stack_local (mode, size, align)
610 enum machine_mode mode;
611 HOST_WIDE_INT size;
612 int align;
614 return assign_stack_local_1 (mode, size, align, cfun);
617 /* Allocate a temporary stack slot and record it for possible later
618 reuse.
620 MODE is the machine mode to be given to the returned rtx.
622 SIZE is the size in units of the space required. We do no rounding here
623 since assign_stack_local will do any required rounding.
625 KEEP is 1 if this slot is to be retained after a call to
626 free_temp_slots. Automatic variables for a block are allocated
627 with this flag. KEEP is 2 if we allocate a longer term temporary,
628 whose lifetime is controlled by CLEANUP_POINT_EXPRs. KEEP is 3
629 if we are to allocate something at an inner level to be treated as
630 a variable in the block (e.g., a SAVE_EXPR).
632 TYPE is the type that will be used for the stack slot. */
635 assign_stack_temp_for_type (mode, size, keep, type)
636 enum machine_mode mode;
637 HOST_WIDE_INT size;
638 int keep;
639 tree type;
641 unsigned int align;
642 struct temp_slot *p, *best_p = 0;
643 rtx slot;
645 /* If SIZE is -1 it means that somebody tried to allocate a temporary
646 of a variable size. */
647 if (size == -1)
648 abort ();
650 if (mode == BLKmode)
651 align = BIGGEST_ALIGNMENT;
652 else
653 align = GET_MODE_ALIGNMENT (mode);
655 if (! type)
656 type = (*lang_hooks.types.type_for_mode) (mode, 0);
658 if (type)
659 align = LOCAL_ALIGNMENT (type, align);
661 /* Try to find an available, already-allocated temporary of the proper
662 mode which meets the size and alignment requirements. Choose the
663 smallest one with the closest alignment. */
664 for (p = temp_slots; p; p = p->next)
665 if (p->align >= align && p->size >= size && GET_MODE (p->slot) == mode
666 && ! p->in_use
667 && objects_must_conflict_p (p->type, type)
668 && (best_p == 0 || best_p->size > p->size
669 || (best_p->size == p->size && best_p->align > p->align)))
671 if (p->align == align && p->size == size)
673 best_p = 0;
674 break;
676 best_p = p;
679 /* Make our best, if any, the one to use. */
680 if (best_p)
682 /* If there are enough aligned bytes left over, make them into a new
683 temp_slot so that the extra bytes don't get wasted. Do this only
684 for BLKmode slots, so that we can be sure of the alignment. */
685 if (GET_MODE (best_p->slot) == BLKmode)
687 int alignment = best_p->align / BITS_PER_UNIT;
688 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
690 if (best_p->size - rounded_size >= alignment)
692 p = (struct temp_slot *) ggc_alloc (sizeof (struct temp_slot));
693 p->in_use = p->addr_taken = 0;
694 p->size = best_p->size - rounded_size;
695 p->base_offset = best_p->base_offset + rounded_size;
696 p->full_size = best_p->full_size - rounded_size;
697 p->slot = gen_rtx_MEM (BLKmode,
698 plus_constant (XEXP (best_p->slot, 0),
699 rounded_size));
700 p->align = best_p->align;
701 p->address = 0;
702 p->rtl_expr = 0;
703 p->type = best_p->type;
704 p->next = temp_slots;
705 temp_slots = p;
707 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
708 stack_slot_list);
710 best_p->size = rounded_size;
711 best_p->full_size = rounded_size;
715 p = best_p;
718 /* If we still didn't find one, make a new temporary. */
719 if (p == 0)
721 HOST_WIDE_INT frame_offset_old = frame_offset;
723 p = (struct temp_slot *) ggc_alloc (sizeof (struct temp_slot));
725 /* We are passing an explicit alignment request to assign_stack_local.
726 One side effect of that is assign_stack_local will not round SIZE
727 to ensure the frame offset remains suitably aligned.
729 So for requests which depended on the rounding of SIZE, we go ahead
730 and round it now. We also make sure ALIGNMENT is at least
731 BIGGEST_ALIGNMENT. */
732 if (mode == BLKmode && align < BIGGEST_ALIGNMENT)
733 abort ();
734 p->slot = assign_stack_local (mode,
735 (mode == BLKmode
736 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
737 : size),
738 align);
740 p->align = align;
742 /* The following slot size computation is necessary because we don't
743 know the actual size of the temporary slot until assign_stack_local
744 has performed all the frame alignment and size rounding for the
745 requested temporary. Note that extra space added for alignment
746 can be either above or below this stack slot depending on which
747 way the frame grows. We include the extra space if and only if it
748 is above this slot. */
749 #ifdef FRAME_GROWS_DOWNWARD
750 p->size = frame_offset_old - frame_offset;
751 #else
752 p->size = size;
753 #endif
755 /* Now define the fields used by combine_temp_slots. */
756 #ifdef FRAME_GROWS_DOWNWARD
757 p->base_offset = frame_offset;
758 p->full_size = frame_offset_old - frame_offset;
759 #else
760 p->base_offset = frame_offset_old;
761 p->full_size = frame_offset - frame_offset_old;
762 #endif
763 p->address = 0;
764 p->next = temp_slots;
765 temp_slots = p;
768 p->in_use = 1;
769 p->addr_taken = 0;
770 p->rtl_expr = seq_rtl_expr;
771 p->type = type;
773 if (keep == 2)
775 p->level = target_temp_slot_level;
776 p->keep = 0;
778 else if (keep == 3)
780 p->level = var_temp_slot_level;
781 p->keep = 0;
783 else
785 p->level = temp_slot_level;
786 p->keep = keep;
790 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
791 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
792 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
794 /* If we know the alias set for the memory that will be used, use
795 it. If there's no TYPE, then we don't know anything about the
796 alias set for the memory. */
797 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
798 set_mem_align (slot, align);
800 /* If a type is specified, set the relevant flags. */
801 if (type != 0)
803 RTX_UNCHANGING_P (slot) = (lang_hooks.honor_readonly
804 && TYPE_READONLY (type));
805 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
806 MEM_SET_IN_STRUCT_P (slot, AGGREGATE_TYPE_P (type));
809 return slot;
812 /* Allocate a temporary stack slot and record it for possible later
813 reuse. First three arguments are same as in preceding function. */
816 assign_stack_temp (mode, size, keep)
817 enum machine_mode mode;
818 HOST_WIDE_INT size;
819 int keep;
821 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
824 /* Assign a temporary.
825 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
826 and so that should be used in error messages. In either case, we
827 allocate of the given type.
828 KEEP is as for assign_stack_temp.
829 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
830 it is 0 if a register is OK.
831 DONT_PROMOTE is 1 if we should not promote values in register
832 to wider modes. */
835 assign_temp (type_or_decl, keep, memory_required, dont_promote)
836 tree type_or_decl;
837 int keep;
838 int memory_required;
839 int dont_promote ATTRIBUTE_UNUSED;
841 tree type, decl;
842 enum machine_mode mode;
843 #ifndef PROMOTE_FOR_CALL_ONLY
844 int unsignedp;
845 #endif
847 if (DECL_P (type_or_decl))
848 decl = type_or_decl, type = TREE_TYPE (decl);
849 else
850 decl = NULL, type = type_or_decl;
852 mode = TYPE_MODE (type);
853 #ifndef PROMOTE_FOR_CALL_ONLY
854 unsignedp = TREE_UNSIGNED (type);
855 #endif
857 if (mode == BLKmode || memory_required)
859 HOST_WIDE_INT size = int_size_in_bytes (type);
860 rtx tmp;
862 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
863 problems with allocating the stack space. */
864 if (size == 0)
865 size = 1;
867 /* Unfortunately, we don't yet know how to allocate variable-sized
868 temporaries. However, sometimes we have a fixed upper limit on
869 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
870 instead. This is the case for Chill variable-sized strings. */
871 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
872 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
873 && host_integerp (TYPE_ARRAY_MAX_SIZE (type), 1))
874 size = tree_low_cst (TYPE_ARRAY_MAX_SIZE (type), 1);
876 /* The size of the temporary may be too large to fit into an integer. */
877 /* ??? Not sure this should happen except for user silliness, so limit
878 this to things that aren't compiler-generated temporaries. The
879 rest of the time we'll abort in assign_stack_temp_for_type. */
880 if (decl && size == -1
881 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
883 error_with_decl (decl, "size of variable `%s' is too large");
884 size = 1;
887 tmp = assign_stack_temp_for_type (mode, size, keep, type);
888 return tmp;
891 #ifndef PROMOTE_FOR_CALL_ONLY
892 if (! dont_promote)
893 mode = promote_mode (type, mode, &unsignedp, 0);
894 #endif
896 return gen_reg_rtx (mode);
899 /* Combine temporary stack slots which are adjacent on the stack.
901 This allows for better use of already allocated stack space. This is only
902 done for BLKmode slots because we can be sure that we won't have alignment
903 problems in this case. */
905 void
906 combine_temp_slots ()
908 struct temp_slot *p, *q;
909 struct temp_slot *prev_p, *prev_q;
910 int num_slots;
912 /* We can't combine slots, because the information about which slot
913 is in which alias set will be lost. */
914 if (flag_strict_aliasing)
915 return;
917 /* If there are a lot of temp slots, don't do anything unless
918 high levels of optimization. */
919 if (! flag_expensive_optimizations)
920 for (p = temp_slots, num_slots = 0; p; p = p->next, num_slots++)
921 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
922 return;
924 for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
926 int delete_p = 0;
928 if (! p->in_use && GET_MODE (p->slot) == BLKmode)
929 for (q = p->next, prev_q = p; q; q = prev_q->next)
931 int delete_q = 0;
932 if (! q->in_use && GET_MODE (q->slot) == BLKmode)
934 if (p->base_offset + p->full_size == q->base_offset)
936 /* Q comes after P; combine Q into P. */
937 p->size += q->size;
938 p->full_size += q->full_size;
939 delete_q = 1;
941 else if (q->base_offset + q->full_size == p->base_offset)
943 /* P comes after Q; combine P into Q. */
944 q->size += p->size;
945 q->full_size += p->full_size;
946 delete_p = 1;
947 break;
950 /* Either delete Q or advance past it. */
951 if (delete_q)
952 prev_q->next = q->next;
953 else
954 prev_q = q;
956 /* Either delete P or advance past it. */
957 if (delete_p)
959 if (prev_p)
960 prev_p->next = p->next;
961 else
962 temp_slots = p->next;
964 else
965 prev_p = p;
969 /* Find the temp slot corresponding to the object at address X. */
971 static struct temp_slot *
972 find_temp_slot_from_address (x)
973 rtx x;
975 struct temp_slot *p;
976 rtx next;
978 for (p = temp_slots; p; p = p->next)
980 if (! p->in_use)
981 continue;
983 else if (XEXP (p->slot, 0) == x
984 || p->address == x
985 || (GET_CODE (x) == PLUS
986 && XEXP (x, 0) == virtual_stack_vars_rtx
987 && GET_CODE (XEXP (x, 1)) == CONST_INT
988 && INTVAL (XEXP (x, 1)) >= p->base_offset
989 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
990 return p;
992 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
993 for (next = p->address; next; next = XEXP (next, 1))
994 if (XEXP (next, 0) == x)
995 return p;
998 /* If we have a sum involving a register, see if it points to a temp
999 slot. */
1000 if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == REG
1001 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
1002 return p;
1003 else if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == REG
1004 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
1005 return p;
1007 return 0;
1010 /* Indicate that NEW is an alternate way of referring to the temp slot
1011 that previously was known by OLD. */
1013 void
1014 update_temp_slot_address (old, new)
1015 rtx old, new;
1017 struct temp_slot *p;
1019 if (rtx_equal_p (old, new))
1020 return;
1022 p = find_temp_slot_from_address (old);
1024 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
1025 is a register, see if one operand of the PLUS is a temporary
1026 location. If so, NEW points into it. Otherwise, if both OLD and
1027 NEW are a PLUS and if there is a register in common between them.
1028 If so, try a recursive call on those values. */
1029 if (p == 0)
1031 if (GET_CODE (old) != PLUS)
1032 return;
1034 if (GET_CODE (new) == REG)
1036 update_temp_slot_address (XEXP (old, 0), new);
1037 update_temp_slot_address (XEXP (old, 1), new);
1038 return;
1040 else if (GET_CODE (new) != PLUS)
1041 return;
1043 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
1044 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
1045 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
1046 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
1047 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
1048 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
1049 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
1050 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
1052 return;
1055 /* Otherwise add an alias for the temp's address. */
1056 else if (p->address == 0)
1057 p->address = new;
1058 else
1060 if (GET_CODE (p->address) != EXPR_LIST)
1061 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
1063 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
1067 /* If X could be a reference to a temporary slot, mark the fact that its
1068 address was taken. */
1070 void
1071 mark_temp_addr_taken (x)
1072 rtx x;
1074 struct temp_slot *p;
1076 if (x == 0)
1077 return;
1079 /* If X is not in memory or is at a constant address, it cannot be in
1080 a temporary slot. */
1081 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1082 return;
1084 p = find_temp_slot_from_address (XEXP (x, 0));
1085 if (p != 0)
1086 p->addr_taken = 1;
1089 /* If X could be a reference to a temporary slot, mark that slot as
1090 belonging to the to one level higher than the current level. If X
1091 matched one of our slots, just mark that one. Otherwise, we can't
1092 easily predict which it is, so upgrade all of them. Kept slots
1093 need not be touched.
1095 This is called when an ({...}) construct occurs and a statement
1096 returns a value in memory. */
1098 void
1099 preserve_temp_slots (x)
1100 rtx x;
1102 struct temp_slot *p = 0;
1104 /* If there is no result, we still might have some objects whose address
1105 were taken, so we need to make sure they stay around. */
1106 if (x == 0)
1108 for (p = temp_slots; p; p = p->next)
1109 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1110 p->level--;
1112 return;
1115 /* If X is a register that is being used as a pointer, see if we have
1116 a temporary slot we know it points to. To be consistent with
1117 the code below, we really should preserve all non-kept slots
1118 if we can't find a match, but that seems to be much too costly. */
1119 if (GET_CODE (x) == REG && REG_POINTER (x))
1120 p = find_temp_slot_from_address (x);
1122 /* If X is not in memory or is at a constant address, it cannot be in
1123 a temporary slot, but it can contain something whose address was
1124 taken. */
1125 if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
1127 for (p = temp_slots; p; p = p->next)
1128 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1129 p->level--;
1131 return;
1134 /* First see if we can find a match. */
1135 if (p == 0)
1136 p = find_temp_slot_from_address (XEXP (x, 0));
1138 if (p != 0)
1140 /* Move everything at our level whose address was taken to our new
1141 level in case we used its address. */
1142 struct temp_slot *q;
1144 if (p->level == temp_slot_level)
1146 for (q = temp_slots; q; q = q->next)
1147 if (q != p && q->addr_taken && q->level == p->level)
1148 q->level--;
1150 p->level--;
1151 p->addr_taken = 0;
1153 return;
1156 /* Otherwise, preserve all non-kept slots at this level. */
1157 for (p = temp_slots; p; p = p->next)
1158 if (p->in_use && p->level == temp_slot_level && ! p->keep)
1159 p->level--;
1162 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
1163 with that RTL_EXPR, promote it into a temporary slot at the present
1164 level so it will not be freed when we free slots made in the
1165 RTL_EXPR. */
1167 void
1168 preserve_rtl_expr_result (x)
1169 rtx x;
1171 struct temp_slot *p;
1173 /* If X is not in memory or is at a constant address, it cannot be in
1174 a temporary slot. */
1175 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1176 return;
1178 /* If we can find a match, move it to our level unless it is already at
1179 an upper level. */
1180 p = find_temp_slot_from_address (XEXP (x, 0));
1181 if (p != 0)
1183 p->level = MIN (p->level, temp_slot_level);
1184 p->rtl_expr = 0;
1187 return;
1190 /* Free all temporaries used so far. This is normally called at the end
1191 of generating code for a statement. Don't free any temporaries
1192 currently in use for an RTL_EXPR that hasn't yet been emitted.
1193 We could eventually do better than this since it can be reused while
1194 generating the same RTL_EXPR, but this is complex and probably not
1195 worthwhile. */
1197 void
1198 free_temp_slots ()
1200 struct temp_slot *p;
1202 for (p = temp_slots; p; p = p->next)
1203 if (p->in_use && p->level == temp_slot_level && ! p->keep
1204 && p->rtl_expr == 0)
1205 p->in_use = 0;
1207 combine_temp_slots ();
1210 /* Free all temporary slots used in T, an RTL_EXPR node. */
1212 void
1213 free_temps_for_rtl_expr (t)
1214 tree t;
1216 struct temp_slot *p;
1218 for (p = temp_slots; p; p = p->next)
1219 if (p->rtl_expr == t)
1221 /* If this slot is below the current TEMP_SLOT_LEVEL, then it
1222 needs to be preserved. This can happen if a temporary in
1223 the RTL_EXPR was addressed; preserve_temp_slots will move
1224 the temporary into a higher level. */
1225 if (temp_slot_level <= p->level)
1226 p->in_use = 0;
1227 else
1228 p->rtl_expr = NULL_TREE;
1231 combine_temp_slots ();
1234 /* Mark all temporaries ever allocated in this function as not suitable
1235 for reuse until the current level is exited. */
1237 void
1238 mark_all_temps_used ()
1240 struct temp_slot *p;
1242 for (p = temp_slots; p; p = p->next)
1244 p->in_use = p->keep = 1;
1245 p->level = MIN (p->level, temp_slot_level);
1249 /* Push deeper into the nesting level for stack temporaries. */
1251 void
1252 push_temp_slots ()
1254 temp_slot_level++;
1257 /* Pop a temporary nesting level. All slots in use in the current level
1258 are freed. */
1260 void
1261 pop_temp_slots ()
1263 struct temp_slot *p;
1265 for (p = temp_slots; p; p = p->next)
1266 if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
1267 p->in_use = 0;
1269 combine_temp_slots ();
1271 temp_slot_level--;
1274 /* Initialize temporary slots. */
1276 void
1277 init_temp_slots ()
1279 /* We have not allocated any temporaries yet. */
1280 temp_slots = 0;
1281 temp_slot_level = 0;
1282 var_temp_slot_level = 0;
1283 target_temp_slot_level = 0;
1286 /* Retroactively move an auto variable from a register to a stack slot.
1287 This is done when an address-reference to the variable is seen. */
1289 void
1290 put_var_into_stack (decl)
1291 tree decl;
1293 rtx reg;
1294 enum machine_mode promoted_mode, decl_mode;
1295 struct function *function = 0;
1296 tree context;
1297 int can_use_addressof;
1298 int volatilep = TREE_CODE (decl) != SAVE_EXPR && TREE_THIS_VOLATILE (decl);
1299 int usedp = (TREE_USED (decl)
1300 || (TREE_CODE (decl) != SAVE_EXPR && DECL_INITIAL (decl) != 0));
1302 context = decl_function_context (decl);
1304 /* Get the current rtl used for this object and its original mode. */
1305 reg = (TREE_CODE (decl) == SAVE_EXPR
1306 ? SAVE_EXPR_RTL (decl)
1307 : DECL_RTL_IF_SET (decl));
1309 /* No need to do anything if decl has no rtx yet
1310 since in that case caller is setting TREE_ADDRESSABLE
1311 and a stack slot will be assigned when the rtl is made. */
1312 if (reg == 0)
1313 return;
1315 /* Get the declared mode for this object. */
1316 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1317 : DECL_MODE (decl));
1318 /* Get the mode it's actually stored in. */
1319 promoted_mode = GET_MODE (reg);
1321 /* If this variable comes from an outer function, find that
1322 function's saved context. Don't use find_function_data here,
1323 because it might not be in any active function.
1324 FIXME: Is that really supposed to happen?
1325 It does in ObjC at least. */
1326 if (context != current_function_decl && context != inline_function_decl)
1327 for (function = outer_function_chain; function; function = function->outer)
1328 if (function->decl == context)
1329 break;
1331 /* If this is a variable-size object with a pseudo to address it,
1332 put that pseudo into the stack, if the var is nonlocal. */
1333 if (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl)
1334 && GET_CODE (reg) == MEM
1335 && GET_CODE (XEXP (reg, 0)) == REG
1336 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1338 reg = XEXP (reg, 0);
1339 decl_mode = promoted_mode = GET_MODE (reg);
1342 can_use_addressof
1343 = (function == 0
1344 && optimize > 0
1345 /* FIXME make it work for promoted modes too */
1346 && decl_mode == promoted_mode
1347 #ifdef NON_SAVING_SETJMP
1348 && ! (NON_SAVING_SETJMP && current_function_calls_setjmp)
1349 #endif
1352 /* If we can't use ADDRESSOF, make sure we see through one we already
1353 generated. */
1354 if (! can_use_addressof && GET_CODE (reg) == MEM
1355 && GET_CODE (XEXP (reg, 0)) == ADDRESSOF)
1356 reg = XEXP (XEXP (reg, 0), 0);
1358 /* Now we should have a value that resides in one or more pseudo regs. */
1360 if (GET_CODE (reg) == REG)
1362 /* If this variable lives in the current function and we don't need
1363 to put things in the stack for the sake of setjmp, try to keep it
1364 in a register until we know we actually need the address. */
1365 if (can_use_addressof)
1366 gen_mem_addressof (reg, decl);
1367 else
1368 put_reg_into_stack (function, reg, TREE_TYPE (decl), promoted_mode,
1369 decl_mode, volatilep, 0, usedp, 0);
1371 else if (GET_CODE (reg) == CONCAT)
1373 /* A CONCAT contains two pseudos; put them both in the stack.
1374 We do it so they end up consecutive.
1375 We fixup references to the parts only after we fixup references
1376 to the whole CONCAT, lest we do double fixups for the latter
1377 references. */
1378 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1379 tree part_type = (*lang_hooks.types.type_for_mode) (part_mode, 0);
1380 rtx lopart = XEXP (reg, 0);
1381 rtx hipart = XEXP (reg, 1);
1382 #ifdef FRAME_GROWS_DOWNWARD
1383 /* Since part 0 should have a lower address, do it second. */
1384 put_reg_into_stack (function, hipart, part_type, part_mode,
1385 part_mode, volatilep, 0, 0, 0);
1386 put_reg_into_stack (function, lopart, part_type, part_mode,
1387 part_mode, volatilep, 0, 0, 0);
1388 #else
1389 put_reg_into_stack (function, lopart, part_type, part_mode,
1390 part_mode, volatilep, 0, 0, 0);
1391 put_reg_into_stack (function, hipart, part_type, part_mode,
1392 part_mode, volatilep, 0, 0, 0);
1393 #endif
1395 /* Change the CONCAT into a combined MEM for both parts. */
1396 PUT_CODE (reg, MEM);
1397 MEM_ATTRS (reg) = 0;
1399 /* set_mem_attributes uses DECL_RTL to avoid re-generating of
1400 already computed alias sets. Here we want to re-generate. */
1401 if (DECL_P (decl))
1402 SET_DECL_RTL (decl, NULL);
1403 set_mem_attributes (reg, decl, 1);
1404 if (DECL_P (decl))
1405 SET_DECL_RTL (decl, reg);
1407 /* The two parts are in memory order already.
1408 Use the lower parts address as ours. */
1409 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1410 /* Prevent sharing of rtl that might lose. */
1411 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1412 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1413 if (usedp)
1415 schedule_fixup_var_refs (function, reg, TREE_TYPE (decl),
1416 promoted_mode, 0);
1417 schedule_fixup_var_refs (function, lopart, part_type, part_mode, 0);
1418 schedule_fixup_var_refs (function, hipart, part_type, part_mode, 0);
1421 else
1422 return;
1425 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1426 into the stack frame of FUNCTION (0 means the current function).
1427 DECL_MODE is the machine mode of the user-level data type.
1428 PROMOTED_MODE is the machine mode of the register.
1429 VOLATILE_P is nonzero if this is for a "volatile" decl.
1430 USED_P is nonzero if this reg might have already been used in an insn. */
1432 static void
1433 put_reg_into_stack (function, reg, type, promoted_mode, decl_mode, volatile_p,
1434 original_regno, used_p, ht)
1435 struct function *function;
1436 rtx reg;
1437 tree type;
1438 enum machine_mode promoted_mode, decl_mode;
1439 int volatile_p;
1440 unsigned int original_regno;
1441 int used_p;
1442 htab_t ht;
1444 struct function *func = function ? function : cfun;
1445 rtx new = 0;
1446 unsigned int regno = original_regno;
1448 if (regno == 0)
1449 regno = REGNO (reg);
1451 if (regno < func->x_max_parm_reg)
1452 new = func->x_parm_reg_stack_loc[regno];
1454 if (new == 0)
1455 new = assign_stack_local_1 (decl_mode, GET_MODE_SIZE (decl_mode), 0, func);
1457 PUT_CODE (reg, MEM);
1458 PUT_MODE (reg, decl_mode);
1459 XEXP (reg, 0) = XEXP (new, 0);
1460 MEM_ATTRS (reg) = 0;
1461 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1462 MEM_VOLATILE_P (reg) = volatile_p;
1464 /* If this is a memory ref that contains aggregate components,
1465 mark it as such for cse and loop optimize. If we are reusing a
1466 previously generated stack slot, then we need to copy the bit in
1467 case it was set for other reasons. For instance, it is set for
1468 __builtin_va_alist. */
1469 if (type)
1471 MEM_SET_IN_STRUCT_P (reg,
1472 AGGREGATE_TYPE_P (type) || MEM_IN_STRUCT_P (new));
1473 set_mem_alias_set (reg, get_alias_set (type));
1476 if (used_p)
1477 schedule_fixup_var_refs (function, reg, type, promoted_mode, ht);
1480 /* Make sure that all refs to the variable, previously made
1481 when it was a register, are fixed up to be valid again.
1482 See function above for meaning of arguments. */
1484 static void
1485 schedule_fixup_var_refs (function, reg, type, promoted_mode, ht)
1486 struct function *function;
1487 rtx reg;
1488 tree type;
1489 enum machine_mode promoted_mode;
1490 htab_t ht;
1492 int unsigned_p = type ? TREE_UNSIGNED (type) : 0;
1494 if (function != 0)
1496 struct var_refs_queue *temp;
1498 temp
1499 = (struct var_refs_queue *) ggc_alloc (sizeof (struct var_refs_queue));
1500 temp->modified = reg;
1501 temp->promoted_mode = promoted_mode;
1502 temp->unsignedp = unsigned_p;
1503 temp->next = function->fixup_var_refs_queue;
1504 function->fixup_var_refs_queue = temp;
1506 else
1507 /* Variable is local; fix it up now. */
1508 fixup_var_refs (reg, promoted_mode, unsigned_p, reg, ht);
1511 static void
1512 fixup_var_refs (var, promoted_mode, unsignedp, may_share, ht)
1513 rtx var;
1514 enum machine_mode promoted_mode;
1515 int unsignedp;
1516 htab_t ht;
1517 rtx may_share;
1519 tree pending;
1520 rtx first_insn = get_insns ();
1521 struct sequence_stack *stack = seq_stack;
1522 tree rtl_exps = rtl_expr_chain;
1524 /* If there's a hash table, it must record all uses of VAR. */
1525 if (ht)
1527 if (stack != 0)
1528 abort ();
1529 fixup_var_refs_insns_with_hash (ht, var, promoted_mode, unsignedp,
1530 may_share);
1531 return;
1534 fixup_var_refs_insns (first_insn, var, promoted_mode, unsignedp,
1535 stack == 0, may_share);
1537 /* Scan all pending sequences too. */
1538 for (; stack; stack = stack->next)
1540 push_to_full_sequence (stack->first, stack->last);
1541 fixup_var_refs_insns (stack->first, var, promoted_mode, unsignedp,
1542 stack->next != 0, may_share);
1543 /* Update remembered end of sequence
1544 in case we added an insn at the end. */
1545 stack->last = get_last_insn ();
1546 end_sequence ();
1549 /* Scan all waiting RTL_EXPRs too. */
1550 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1552 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1553 if (seq != const0_rtx && seq != 0)
1555 push_to_sequence (seq);
1556 fixup_var_refs_insns (seq, var, promoted_mode, unsignedp, 0,
1557 may_share);
1558 end_sequence ();
1563 /* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
1564 some part of an insn. Return a struct fixup_replacement whose OLD
1565 value is equal to X. Allocate a new structure if no such entry exists. */
1567 static struct fixup_replacement *
1568 find_fixup_replacement (replacements, x)
1569 struct fixup_replacement **replacements;
1570 rtx x;
1572 struct fixup_replacement *p;
1574 /* See if we have already replaced this. */
1575 for (p = *replacements; p != 0 && ! rtx_equal_p (p->old, x); p = p->next)
1578 if (p == 0)
1580 p = (struct fixup_replacement *) xmalloc (sizeof (struct fixup_replacement));
1581 p->old = x;
1582 p->new = 0;
1583 p->next = *replacements;
1584 *replacements = p;
1587 return p;
1590 /* Scan the insn-chain starting with INSN for refs to VAR and fix them
1591 up. TOPLEVEL is nonzero if this chain is the main chain of insns
1592 for the current function. MAY_SHARE is either a MEM that is not
1593 to be unshared or a list of them. */
1595 static void
1596 fixup_var_refs_insns (insn, var, promoted_mode, unsignedp, toplevel, may_share)
1597 rtx insn;
1598 rtx var;
1599 enum machine_mode promoted_mode;
1600 int unsignedp;
1601 int toplevel;
1602 rtx may_share;
1604 while (insn)
1606 /* fixup_var_refs_insn might modify insn, so save its next
1607 pointer now. */
1608 rtx next = NEXT_INSN (insn);
1610 /* CALL_PLACEHOLDERs are special; we have to switch into each of
1611 the three sequences they (potentially) contain, and process
1612 them recursively. The CALL_INSN itself is not interesting. */
1614 if (GET_CODE (insn) == CALL_INSN
1615 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
1617 int i;
1619 /* Look at the Normal call, sibling call and tail recursion
1620 sequences attached to the CALL_PLACEHOLDER. */
1621 for (i = 0; i < 3; i++)
1623 rtx seq = XEXP (PATTERN (insn), i);
1624 if (seq)
1626 push_to_sequence (seq);
1627 fixup_var_refs_insns (seq, var, promoted_mode, unsignedp, 0,
1628 may_share);
1629 XEXP (PATTERN (insn), i) = get_insns ();
1630 end_sequence ();
1635 else if (INSN_P (insn))
1636 fixup_var_refs_insn (insn, var, promoted_mode, unsignedp, toplevel,
1637 may_share);
1639 insn = next;
1643 /* Look up the insns which reference VAR in HT and fix them up. Other
1644 arguments are the same as fixup_var_refs_insns.
1646 N.B. No need for special processing of CALL_PLACEHOLDERs here,
1647 because the hash table will point straight to the interesting insn
1648 (inside the CALL_PLACEHOLDER). */
1650 static void
1651 fixup_var_refs_insns_with_hash (ht, var, promoted_mode, unsignedp, may_share)
1652 htab_t ht;
1653 rtx var;
1654 enum machine_mode promoted_mode;
1655 int unsignedp;
1656 rtx may_share;
1658 struct insns_for_mem_entry tmp;
1659 struct insns_for_mem_entry *ime;
1660 rtx insn_list;
1662 tmp.key = var;
1663 ime = (struct insns_for_mem_entry *) htab_find (ht, &tmp);
1664 for (insn_list = ime->insns; insn_list != 0; insn_list = XEXP (insn_list, 1))
1665 if (INSN_P (XEXP (insn_list, 0)))
1666 fixup_var_refs_insn (XEXP (insn_list, 0), var, promoted_mode,
1667 unsignedp, 1, may_share);
1671 /* Per-insn processing by fixup_var_refs_insns(_with_hash). INSN is
1672 the insn under examination, VAR is the variable to fix up
1673 references to, PROMOTED_MODE and UNSIGNEDP describe VAR, and
1674 TOPLEVEL is nonzero if this is the main insn chain for this
1675 function. */
1677 static void
1678 fixup_var_refs_insn (insn, var, promoted_mode, unsignedp, toplevel, no_share)
1679 rtx insn;
1680 rtx var;
1681 enum machine_mode promoted_mode;
1682 int unsignedp;
1683 int toplevel;
1684 rtx no_share;
1686 rtx call_dest = 0;
1687 rtx set, prev, prev_set;
1688 rtx note;
1690 /* Remember the notes in case we delete the insn. */
1691 note = REG_NOTES (insn);
1693 /* If this is a CLOBBER of VAR, delete it.
1695 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1696 and REG_RETVAL notes too. */
1697 if (GET_CODE (PATTERN (insn)) == CLOBBER
1698 && (XEXP (PATTERN (insn), 0) == var
1699 || (GET_CODE (XEXP (PATTERN (insn), 0)) == CONCAT
1700 && (XEXP (XEXP (PATTERN (insn), 0), 0) == var
1701 || XEXP (XEXP (PATTERN (insn), 0), 1) == var))))
1703 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1704 /* The REG_LIBCALL note will go away since we are going to
1705 turn INSN into a NOTE, so just delete the
1706 corresponding REG_RETVAL note. */
1707 remove_note (XEXP (note, 0),
1708 find_reg_note (XEXP (note, 0), REG_RETVAL,
1709 NULL_RTX));
1711 delete_insn (insn);
1714 /* The insn to load VAR from a home in the arglist
1715 is now a no-op. When we see it, just delete it.
1716 Similarly if this is storing VAR from a register from which
1717 it was loaded in the previous insn. This will occur
1718 when an ADDRESSOF was made for an arglist slot. */
1719 else if (toplevel
1720 && (set = single_set (insn)) != 0
1721 && SET_DEST (set) == var
1722 /* If this represents the result of an insn group,
1723 don't delete the insn. */
1724 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1725 && (rtx_equal_p (SET_SRC (set), var)
1726 || (GET_CODE (SET_SRC (set)) == REG
1727 && (prev = prev_nonnote_insn (insn)) != 0
1728 && (prev_set = single_set (prev)) != 0
1729 && SET_DEST (prev_set) == SET_SRC (set)
1730 && rtx_equal_p (SET_SRC (prev_set), var))))
1732 delete_insn (insn);
1734 else
1736 struct fixup_replacement *replacements = 0;
1737 rtx next_insn = NEXT_INSN (insn);
1739 if (SMALL_REGISTER_CLASSES)
1741 /* If the insn that copies the results of a CALL_INSN
1742 into a pseudo now references VAR, we have to use an
1743 intermediate pseudo since we want the life of the
1744 return value register to be only a single insn.
1746 If we don't use an intermediate pseudo, such things as
1747 address computations to make the address of VAR valid
1748 if it is not can be placed between the CALL_INSN and INSN.
1750 To make sure this doesn't happen, we record the destination
1751 of the CALL_INSN and see if the next insn uses both that
1752 and VAR. */
1754 if (call_dest != 0 && GET_CODE (insn) == INSN
1755 && reg_mentioned_p (var, PATTERN (insn))
1756 && reg_mentioned_p (call_dest, PATTERN (insn)))
1758 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1760 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1762 PATTERN (insn) = replace_rtx (PATTERN (insn),
1763 call_dest, temp);
1766 if (GET_CODE (insn) == CALL_INSN
1767 && GET_CODE (PATTERN (insn)) == SET)
1768 call_dest = SET_DEST (PATTERN (insn));
1769 else if (GET_CODE (insn) == CALL_INSN
1770 && GET_CODE (PATTERN (insn)) == PARALLEL
1771 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1772 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1773 else
1774 call_dest = 0;
1777 /* See if we have to do anything to INSN now that VAR is in
1778 memory. If it needs to be loaded into a pseudo, use a single
1779 pseudo for the entire insn in case there is a MATCH_DUP
1780 between two operands. We pass a pointer to the head of
1781 a list of struct fixup_replacements. If fixup_var_refs_1
1782 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1783 it will record them in this list.
1785 If it allocated a pseudo for any replacement, we copy into
1786 it here. */
1788 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1789 &replacements, no_share);
1791 /* If this is last_parm_insn, and any instructions were output
1792 after it to fix it up, then we must set last_parm_insn to
1793 the last such instruction emitted. */
1794 if (insn == last_parm_insn)
1795 last_parm_insn = PREV_INSN (next_insn);
1797 while (replacements)
1799 struct fixup_replacement *next;
1801 if (GET_CODE (replacements->new) == REG)
1803 rtx insert_before;
1804 rtx seq;
1806 /* OLD might be a (subreg (mem)). */
1807 if (GET_CODE (replacements->old) == SUBREG)
1808 replacements->old
1809 = fixup_memory_subreg (replacements->old, insn,
1810 promoted_mode, 0);
1811 else
1812 replacements->old
1813 = fixup_stack_1 (replacements->old, insn);
1815 insert_before = insn;
1817 /* If we are changing the mode, do a conversion.
1818 This might be wasteful, but combine.c will
1819 eliminate much of the waste. */
1821 if (GET_MODE (replacements->new)
1822 != GET_MODE (replacements->old))
1824 start_sequence ();
1825 convert_move (replacements->new,
1826 replacements->old, unsignedp);
1827 seq = get_insns ();
1828 end_sequence ();
1830 else
1831 seq = gen_move_insn (replacements->new,
1832 replacements->old);
1834 emit_insn_before (seq, insert_before);
1837 next = replacements->next;
1838 free (replacements);
1839 replacements = next;
1843 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1844 But don't touch other insns referred to by reg-notes;
1845 we will get them elsewhere. */
1846 while (note)
1848 if (GET_CODE (note) != INSN_LIST)
1849 XEXP (note, 0)
1850 = walk_fixup_memory_subreg (XEXP (note, 0), insn,
1851 promoted_mode, 1);
1852 note = XEXP (note, 1);
1856 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1857 See if the rtx expression at *LOC in INSN needs to be changed.
1859 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1860 contain a list of original rtx's and replacements. If we find that we need
1861 to modify this insn by replacing a memory reference with a pseudo or by
1862 making a new MEM to implement a SUBREG, we consult that list to see if
1863 we have already chosen a replacement. If none has already been allocated,
1864 we allocate it and update the list. fixup_var_refs_insn will copy VAR
1865 or the SUBREG, as appropriate, to the pseudo. */
1867 static void
1868 fixup_var_refs_1 (var, promoted_mode, loc, insn, replacements, no_share)
1869 rtx var;
1870 enum machine_mode promoted_mode;
1871 rtx *loc;
1872 rtx insn;
1873 struct fixup_replacement **replacements;
1874 rtx no_share;
1876 int i;
1877 rtx x = *loc;
1878 RTX_CODE code = GET_CODE (x);
1879 const char *fmt;
1880 rtx tem, tem1;
1881 struct fixup_replacement *replacement;
1883 switch (code)
1885 case ADDRESSOF:
1886 if (XEXP (x, 0) == var)
1888 /* Prevent sharing of rtl that might lose. */
1889 rtx sub = copy_rtx (XEXP (var, 0));
1891 if (! validate_change (insn, loc, sub, 0))
1893 rtx y = gen_reg_rtx (GET_MODE (sub));
1894 rtx seq, new_insn;
1896 /* We should be able to replace with a register or all is lost.
1897 Note that we can't use validate_change to verify this, since
1898 we're not caring for replacing all dups simultaneously. */
1899 if (! validate_replace_rtx (*loc, y, insn))
1900 abort ();
1902 /* Careful! First try to recognize a direct move of the
1903 value, mimicking how things are done in gen_reload wrt
1904 PLUS. Consider what happens when insn is a conditional
1905 move instruction and addsi3 clobbers flags. */
1907 start_sequence ();
1908 new_insn = emit_insn (gen_rtx_SET (VOIDmode, y, sub));
1909 seq = get_insns ();
1910 end_sequence ();
1912 if (recog_memoized (new_insn) < 0)
1914 /* That failed. Fall back on force_operand and hope. */
1916 start_sequence ();
1917 sub = force_operand (sub, y);
1918 if (sub != y)
1919 emit_insn (gen_move_insn (y, sub));
1920 seq = get_insns ();
1921 end_sequence ();
1924 #ifdef HAVE_cc0
1925 /* Don't separate setter from user. */
1926 if (PREV_INSN (insn) && sets_cc0_p (PREV_INSN (insn)))
1927 insn = PREV_INSN (insn);
1928 #endif
1930 emit_insn_before (seq, insn);
1933 return;
1935 case MEM:
1936 if (var == x)
1938 /* If we already have a replacement, use it. Otherwise,
1939 try to fix up this address in case it is invalid. */
1941 replacement = find_fixup_replacement (replacements, var);
1942 if (replacement->new)
1944 *loc = replacement->new;
1945 return;
1948 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1950 /* Unless we are forcing memory to register or we changed the mode,
1951 we can leave things the way they are if the insn is valid. */
1953 INSN_CODE (insn) = -1;
1954 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1955 && recog_memoized (insn) >= 0)
1956 return;
1958 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1959 return;
1962 /* If X contains VAR, we need to unshare it here so that we update
1963 each occurrence separately. But all identical MEMs in one insn
1964 must be replaced with the same rtx because of the possibility of
1965 MATCH_DUPs. */
1967 if (reg_mentioned_p (var, x))
1969 replacement = find_fixup_replacement (replacements, x);
1970 if (replacement->new == 0)
1971 replacement->new = copy_most_rtx (x, no_share);
1973 *loc = x = replacement->new;
1974 code = GET_CODE (x);
1976 break;
1978 case REG:
1979 case CC0:
1980 case PC:
1981 case CONST_INT:
1982 case CONST:
1983 case SYMBOL_REF:
1984 case LABEL_REF:
1985 case CONST_DOUBLE:
1986 case CONST_VECTOR:
1987 return;
1989 case SIGN_EXTRACT:
1990 case ZERO_EXTRACT:
1991 /* Note that in some cases those types of expressions are altered
1992 by optimize_bit_field, and do not survive to get here. */
1993 if (XEXP (x, 0) == var
1994 || (GET_CODE (XEXP (x, 0)) == SUBREG
1995 && SUBREG_REG (XEXP (x, 0)) == var))
1997 /* Get TEM as a valid MEM in the mode presently in the insn.
1999 We don't worry about the possibility of MATCH_DUP here; it
2000 is highly unlikely and would be tricky to handle. */
2002 tem = XEXP (x, 0);
2003 if (GET_CODE (tem) == SUBREG)
2005 if (GET_MODE_BITSIZE (GET_MODE (tem))
2006 > GET_MODE_BITSIZE (GET_MODE (var)))
2008 replacement = find_fixup_replacement (replacements, var);
2009 if (replacement->new == 0)
2010 replacement->new = gen_reg_rtx (GET_MODE (var));
2011 SUBREG_REG (tem) = replacement->new;
2013 /* The following code works only if we have a MEM, so we
2014 need to handle the subreg here. We directly substitute
2015 it assuming that a subreg must be OK here. We already
2016 scheduled a replacement to copy the mem into the
2017 subreg. */
2018 XEXP (x, 0) = tem;
2019 return;
2021 else
2022 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2024 else
2025 tem = fixup_stack_1 (tem, insn);
2027 /* Unless we want to load from memory, get TEM into the proper mode
2028 for an extract from memory. This can only be done if the
2029 extract is at a constant position and length. */
2031 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
2032 && GET_CODE (XEXP (x, 2)) == CONST_INT
2033 && ! mode_dependent_address_p (XEXP (tem, 0))
2034 && ! MEM_VOLATILE_P (tem))
2036 enum machine_mode wanted_mode = VOIDmode;
2037 enum machine_mode is_mode = GET_MODE (tem);
2038 HOST_WIDE_INT pos = INTVAL (XEXP (x, 2));
2040 if (GET_CODE (x) == ZERO_EXTRACT)
2042 enum machine_mode new_mode
2043 = mode_for_extraction (EP_extzv, 1);
2044 if (new_mode != MAX_MACHINE_MODE)
2045 wanted_mode = new_mode;
2047 else if (GET_CODE (x) == SIGN_EXTRACT)
2049 enum machine_mode new_mode
2050 = mode_for_extraction (EP_extv, 1);
2051 if (new_mode != MAX_MACHINE_MODE)
2052 wanted_mode = new_mode;
2055 /* If we have a narrower mode, we can do something. */
2056 if (wanted_mode != VOIDmode
2057 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2059 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2060 rtx old_pos = XEXP (x, 2);
2061 rtx newmem;
2063 /* If the bytes and bits are counted differently, we
2064 must adjust the offset. */
2065 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2066 offset = (GET_MODE_SIZE (is_mode)
2067 - GET_MODE_SIZE (wanted_mode) - offset);
2069 pos %= GET_MODE_BITSIZE (wanted_mode);
2071 newmem = adjust_address_nv (tem, wanted_mode, offset);
2073 /* Make the change and see if the insn remains valid. */
2074 INSN_CODE (insn) = -1;
2075 XEXP (x, 0) = newmem;
2076 XEXP (x, 2) = GEN_INT (pos);
2078 if (recog_memoized (insn) >= 0)
2079 return;
2081 /* Otherwise, restore old position. XEXP (x, 0) will be
2082 restored later. */
2083 XEXP (x, 2) = old_pos;
2087 /* If we get here, the bitfield extract insn can't accept a memory
2088 reference. Copy the input into a register. */
2090 tem1 = gen_reg_rtx (GET_MODE (tem));
2091 emit_insn_before (gen_move_insn (tem1, tem), insn);
2092 XEXP (x, 0) = tem1;
2093 return;
2095 break;
2097 case SUBREG:
2098 if (SUBREG_REG (x) == var)
2100 /* If this is a special SUBREG made because VAR was promoted
2101 from a wider mode, replace it with VAR and call ourself
2102 recursively, this time saying that the object previously
2103 had its current mode (by virtue of the SUBREG). */
2105 if (SUBREG_PROMOTED_VAR_P (x))
2107 *loc = var;
2108 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements,
2109 no_share);
2110 return;
2113 /* If this SUBREG makes VAR wider, it has become a paradoxical
2114 SUBREG with VAR in memory, but these aren't allowed at this
2115 stage of the compilation. So load VAR into a pseudo and take
2116 a SUBREG of that pseudo. */
2117 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
2119 replacement = find_fixup_replacement (replacements, var);
2120 if (replacement->new == 0)
2121 replacement->new = gen_reg_rtx (promoted_mode);
2122 SUBREG_REG (x) = replacement->new;
2123 return;
2126 /* See if we have already found a replacement for this SUBREG.
2127 If so, use it. Otherwise, make a MEM and see if the insn
2128 is recognized. If not, or if we should force MEM into a register,
2129 make a pseudo for this SUBREG. */
2130 replacement = find_fixup_replacement (replacements, x);
2131 if (replacement->new)
2133 *loc = replacement->new;
2134 return;
2137 replacement->new = *loc = fixup_memory_subreg (x, insn,
2138 promoted_mode, 0);
2140 INSN_CODE (insn) = -1;
2141 if (! flag_force_mem && recog_memoized (insn) >= 0)
2142 return;
2144 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
2145 return;
2147 break;
2149 case SET:
2150 /* First do special simplification of bit-field references. */
2151 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
2152 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
2153 optimize_bit_field (x, insn, 0);
2154 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
2155 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
2156 optimize_bit_field (x, insn, 0);
2158 /* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
2159 into a register and then store it back out. */
2160 if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
2161 && GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
2162 && SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
2163 && (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
2164 > GET_MODE_SIZE (GET_MODE (var))))
2166 replacement = find_fixup_replacement (replacements, var);
2167 if (replacement->new == 0)
2168 replacement->new = gen_reg_rtx (GET_MODE (var));
2170 SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
2171 emit_insn_after (gen_move_insn (var, replacement->new), insn);
2174 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
2175 insn into a pseudo and store the low part of the pseudo into VAR. */
2176 if (GET_CODE (SET_DEST (x)) == SUBREG
2177 && SUBREG_REG (SET_DEST (x)) == var
2178 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
2179 > GET_MODE_SIZE (GET_MODE (var))))
2181 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
2182 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
2183 tem)),
2184 insn);
2185 break;
2189 rtx dest = SET_DEST (x);
2190 rtx src = SET_SRC (x);
2191 rtx outerdest = dest;
2193 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
2194 || GET_CODE (dest) == SIGN_EXTRACT
2195 || GET_CODE (dest) == ZERO_EXTRACT)
2196 dest = XEXP (dest, 0);
2198 if (GET_CODE (src) == SUBREG)
2199 src = SUBREG_REG (src);
2201 /* If VAR does not appear at the top level of the SET
2202 just scan the lower levels of the tree. */
2204 if (src != var && dest != var)
2205 break;
2207 /* We will need to rerecognize this insn. */
2208 INSN_CODE (insn) = -1;
2210 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var
2211 && mode_for_extraction (EP_insv, -1) != MAX_MACHINE_MODE)
2213 /* Since this case will return, ensure we fixup all the
2214 operands here. */
2215 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
2216 insn, replacements, no_share);
2217 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
2218 insn, replacements, no_share);
2219 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
2220 insn, replacements, no_share);
2222 tem = XEXP (outerdest, 0);
2224 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
2225 that may appear inside a ZERO_EXTRACT.
2226 This was legitimate when the MEM was a REG. */
2227 if (GET_CODE (tem) == SUBREG
2228 && SUBREG_REG (tem) == var)
2229 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2230 else
2231 tem = fixup_stack_1 (tem, insn);
2233 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
2234 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
2235 && ! mode_dependent_address_p (XEXP (tem, 0))
2236 && ! MEM_VOLATILE_P (tem))
2238 enum machine_mode wanted_mode;
2239 enum machine_mode is_mode = GET_MODE (tem);
2240 HOST_WIDE_INT pos = INTVAL (XEXP (outerdest, 2));
2242 wanted_mode = mode_for_extraction (EP_insv, 0);
2244 /* If we have a narrower mode, we can do something. */
2245 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2247 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2248 rtx old_pos = XEXP (outerdest, 2);
2249 rtx newmem;
2251 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2252 offset = (GET_MODE_SIZE (is_mode)
2253 - GET_MODE_SIZE (wanted_mode) - offset);
2255 pos %= GET_MODE_BITSIZE (wanted_mode);
2257 newmem = adjust_address_nv (tem, wanted_mode, offset);
2259 /* Make the change and see if the insn remains valid. */
2260 INSN_CODE (insn) = -1;
2261 XEXP (outerdest, 0) = newmem;
2262 XEXP (outerdest, 2) = GEN_INT (pos);
2264 if (recog_memoized (insn) >= 0)
2265 return;
2267 /* Otherwise, restore old position. XEXP (x, 0) will be
2268 restored later. */
2269 XEXP (outerdest, 2) = old_pos;
2273 /* If we get here, the bit-field store doesn't allow memory
2274 or isn't located at a constant position. Load the value into
2275 a register, do the store, and put it back into memory. */
2277 tem1 = gen_reg_rtx (GET_MODE (tem));
2278 emit_insn_before (gen_move_insn (tem1, tem), insn);
2279 emit_insn_after (gen_move_insn (tem, tem1), insn);
2280 XEXP (outerdest, 0) = tem1;
2281 return;
2284 /* STRICT_LOW_PART is a no-op on memory references
2285 and it can cause combinations to be unrecognizable,
2286 so eliminate it. */
2288 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2289 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2291 /* A valid insn to copy VAR into or out of a register
2292 must be left alone, to avoid an infinite loop here.
2293 If the reference to VAR is by a subreg, fix that up,
2294 since SUBREG is not valid for a memref.
2295 Also fix up the address of the stack slot.
2297 Note that we must not try to recognize the insn until
2298 after we know that we have valid addresses and no
2299 (subreg (mem ...) ...) constructs, since these interfere
2300 with determining the validity of the insn. */
2302 if ((SET_SRC (x) == var
2303 || (GET_CODE (SET_SRC (x)) == SUBREG
2304 && SUBREG_REG (SET_SRC (x)) == var))
2305 && (GET_CODE (SET_DEST (x)) == REG
2306 || (GET_CODE (SET_DEST (x)) == SUBREG
2307 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
2308 && GET_MODE (var) == promoted_mode
2309 && x == single_set (insn))
2311 rtx pat, last;
2313 if (GET_CODE (SET_SRC (x)) == SUBREG
2314 && (GET_MODE_SIZE (GET_MODE (SET_SRC (x)))
2315 > GET_MODE_SIZE (GET_MODE (var))))
2317 /* This (subreg VAR) is now a paradoxical subreg. We need
2318 to replace VAR instead of the subreg. */
2319 replacement = find_fixup_replacement (replacements, var);
2320 if (replacement->new == NULL_RTX)
2321 replacement->new = gen_reg_rtx (GET_MODE (var));
2322 SUBREG_REG (SET_SRC (x)) = replacement->new;
2324 else
2326 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2327 if (replacement->new)
2328 SET_SRC (x) = replacement->new;
2329 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2330 SET_SRC (x) = replacement->new
2331 = fixup_memory_subreg (SET_SRC (x), insn, promoted_mode,
2333 else
2334 SET_SRC (x) = replacement->new
2335 = fixup_stack_1 (SET_SRC (x), insn);
2338 if (recog_memoized (insn) >= 0)
2339 return;
2341 /* INSN is not valid, but we know that we want to
2342 copy SET_SRC (x) to SET_DEST (x) in some way. So
2343 we generate the move and see whether it requires more
2344 than one insn. If it does, we emit those insns and
2345 delete INSN. Otherwise, we can just replace the pattern
2346 of INSN; we have already verified above that INSN has
2347 no other function that to do X. */
2349 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2350 if (NEXT_INSN (pat) != NULL_RTX)
2352 last = emit_insn_before (pat, insn);
2354 /* INSN might have REG_RETVAL or other important notes, so
2355 we need to store the pattern of the last insn in the
2356 sequence into INSN similarly to the normal case. LAST
2357 should not have REG_NOTES, but we allow them if INSN has
2358 no REG_NOTES. */
2359 if (REG_NOTES (last) && REG_NOTES (insn))
2360 abort ();
2361 if (REG_NOTES (last))
2362 REG_NOTES (insn) = REG_NOTES (last);
2363 PATTERN (insn) = PATTERN (last);
2365 delete_insn (last);
2367 else
2368 PATTERN (insn) = PATTERN (pat);
2370 return;
2373 if ((SET_DEST (x) == var
2374 || (GET_CODE (SET_DEST (x)) == SUBREG
2375 && SUBREG_REG (SET_DEST (x)) == var))
2376 && (GET_CODE (SET_SRC (x)) == REG
2377 || (GET_CODE (SET_SRC (x)) == SUBREG
2378 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
2379 && GET_MODE (var) == promoted_mode
2380 && x == single_set (insn))
2382 rtx pat, last;
2384 if (GET_CODE (SET_DEST (x)) == SUBREG)
2385 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn,
2386 promoted_mode, 0);
2387 else
2388 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2390 if (recog_memoized (insn) >= 0)
2391 return;
2393 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2394 if (NEXT_INSN (pat) != NULL_RTX)
2396 last = emit_insn_before (pat, insn);
2398 /* INSN might have REG_RETVAL or other important notes, so
2399 we need to store the pattern of the last insn in the
2400 sequence into INSN similarly to the normal case. LAST
2401 should not have REG_NOTES, but we allow them if INSN has
2402 no REG_NOTES. */
2403 if (REG_NOTES (last) && REG_NOTES (insn))
2404 abort ();
2405 if (REG_NOTES (last))
2406 REG_NOTES (insn) = REG_NOTES (last);
2407 PATTERN (insn) = PATTERN (last);
2409 delete_insn (last);
2411 else
2412 PATTERN (insn) = PATTERN (pat);
2414 return;
2417 /* Otherwise, storing into VAR must be handled specially
2418 by storing into a temporary and copying that into VAR
2419 with a new insn after this one. Note that this case
2420 will be used when storing into a promoted scalar since
2421 the insn will now have different modes on the input
2422 and output and hence will be invalid (except for the case
2423 of setting it to a constant, which does not need any
2424 change if it is valid). We generate extra code in that case,
2425 but combine.c will eliminate it. */
2427 if (dest == var)
2429 rtx temp;
2430 rtx fixeddest = SET_DEST (x);
2431 enum machine_mode temp_mode;
2433 /* STRICT_LOW_PART can be discarded, around a MEM. */
2434 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2435 fixeddest = XEXP (fixeddest, 0);
2436 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2437 if (GET_CODE (fixeddest) == SUBREG)
2439 fixeddest = fixup_memory_subreg (fixeddest, insn,
2440 promoted_mode, 0);
2441 temp_mode = GET_MODE (fixeddest);
2443 else
2445 fixeddest = fixup_stack_1 (fixeddest, insn);
2446 temp_mode = promoted_mode;
2449 temp = gen_reg_rtx (temp_mode);
2451 emit_insn_after (gen_move_insn (fixeddest,
2452 gen_lowpart (GET_MODE (fixeddest),
2453 temp)),
2454 insn);
2456 SET_DEST (x) = temp;
2460 default:
2461 break;
2464 /* Nothing special about this RTX; fix its operands. */
2466 fmt = GET_RTX_FORMAT (code);
2467 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2469 if (fmt[i] == 'e')
2470 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements,
2471 no_share);
2472 else if (fmt[i] == 'E')
2474 int j;
2475 for (j = 0; j < XVECLEN (x, i); j++)
2476 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2477 insn, replacements, no_share);
2482 /* Previously, X had the form (SUBREG:m1 (REG:PROMOTED_MODE ...)).
2483 The REG was placed on the stack, so X now has the form (SUBREG:m1
2484 (MEM:m2 ...)).
2486 Return an rtx (MEM:m1 newaddr) which is equivalent. If any insns
2487 must be emitted to compute NEWADDR, put them before INSN.
2489 UNCRITICAL nonzero means accept paradoxical subregs.
2490 This is used for subregs found inside REG_NOTES. */
2492 static rtx
2493 fixup_memory_subreg (x, insn, promoted_mode, uncritical)
2494 rtx x;
2495 rtx insn;
2496 enum machine_mode promoted_mode;
2497 int uncritical;
2499 int offset;
2500 rtx mem = SUBREG_REG (x);
2501 rtx addr = XEXP (mem, 0);
2502 enum machine_mode mode = GET_MODE (x);
2503 rtx result, seq;
2505 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2506 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (mem)) && ! uncritical)
2507 abort ();
2509 offset = SUBREG_BYTE (x);
2510 if (BYTES_BIG_ENDIAN)
2511 /* If the PROMOTED_MODE is wider than the mode of the MEM, adjust
2512 the offset so that it points to the right location within the
2513 MEM. */
2514 offset -= (GET_MODE_SIZE (promoted_mode) - GET_MODE_SIZE (GET_MODE (mem)));
2516 if (!flag_force_addr
2517 && memory_address_p (mode, plus_constant (addr, offset)))
2518 /* Shortcut if no insns need be emitted. */
2519 return adjust_address (mem, mode, offset);
2521 start_sequence ();
2522 result = adjust_address (mem, mode, offset);
2523 seq = get_insns ();
2524 end_sequence ();
2526 emit_insn_before (seq, insn);
2527 return result;
2530 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
2531 Replace subexpressions of X in place.
2532 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
2533 Otherwise return X, with its contents possibly altered.
2535 INSN, PROMOTED_MODE and UNCRITICAL are as for
2536 fixup_memory_subreg. */
2538 static rtx
2539 walk_fixup_memory_subreg (x, insn, promoted_mode, uncritical)
2540 rtx x;
2541 rtx insn;
2542 enum machine_mode promoted_mode;
2543 int uncritical;
2545 enum rtx_code code;
2546 const char *fmt;
2547 int i;
2549 if (x == 0)
2550 return 0;
2552 code = GET_CODE (x);
2554 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
2555 return fixup_memory_subreg (x, insn, promoted_mode, uncritical);
2557 /* Nothing special about this RTX; fix its operands. */
2559 fmt = GET_RTX_FORMAT (code);
2560 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2562 if (fmt[i] == 'e')
2563 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn,
2564 promoted_mode, uncritical);
2565 else if (fmt[i] == 'E')
2567 int j;
2568 for (j = 0; j < XVECLEN (x, i); j++)
2569 XVECEXP (x, i, j)
2570 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn,
2571 promoted_mode, uncritical);
2574 return x;
2577 /* For each memory ref within X, if it refers to a stack slot
2578 with an out of range displacement, put the address in a temp register
2579 (emitting new insns before INSN to load these registers)
2580 and alter the memory ref to use that register.
2581 Replace each such MEM rtx with a copy, to avoid clobberage. */
2583 static rtx
2584 fixup_stack_1 (x, insn)
2585 rtx x;
2586 rtx insn;
2588 int i;
2589 RTX_CODE code = GET_CODE (x);
2590 const char *fmt;
2592 if (code == MEM)
2594 rtx ad = XEXP (x, 0);
2595 /* If we have address of a stack slot but it's not valid
2596 (displacement is too large), compute the sum in a register. */
2597 if (GET_CODE (ad) == PLUS
2598 && GET_CODE (XEXP (ad, 0)) == REG
2599 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2600 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2601 || REGNO (XEXP (ad, 0)) == FRAME_POINTER_REGNUM
2602 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2603 || REGNO (XEXP (ad, 0)) == HARD_FRAME_POINTER_REGNUM
2604 #endif
2605 || REGNO (XEXP (ad, 0)) == STACK_POINTER_REGNUM
2606 || REGNO (XEXP (ad, 0)) == ARG_POINTER_REGNUM
2607 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2608 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2610 rtx temp, seq;
2611 if (memory_address_p (GET_MODE (x), ad))
2612 return x;
2614 start_sequence ();
2615 temp = copy_to_reg (ad);
2616 seq = get_insns ();
2617 end_sequence ();
2618 emit_insn_before (seq, insn);
2619 return replace_equiv_address (x, temp);
2621 return x;
2624 fmt = GET_RTX_FORMAT (code);
2625 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2627 if (fmt[i] == 'e')
2628 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2629 else if (fmt[i] == 'E')
2631 int j;
2632 for (j = 0; j < XVECLEN (x, i); j++)
2633 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2636 return x;
2639 /* Optimization: a bit-field instruction whose field
2640 happens to be a byte or halfword in memory
2641 can be changed to a move instruction.
2643 We call here when INSN is an insn to examine or store into a bit-field.
2644 BODY is the SET-rtx to be altered.
2646 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2647 (Currently this is called only from function.c, and EQUIV_MEM
2648 is always 0.) */
2650 static void
2651 optimize_bit_field (body, insn, equiv_mem)
2652 rtx body;
2653 rtx insn;
2654 rtx *equiv_mem;
2656 rtx bitfield;
2657 int destflag;
2658 rtx seq = 0;
2659 enum machine_mode mode;
2661 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2662 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2663 bitfield = SET_DEST (body), destflag = 1;
2664 else
2665 bitfield = SET_SRC (body), destflag = 0;
2667 /* First check that the field being stored has constant size and position
2668 and is in fact a byte or halfword suitably aligned. */
2670 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2671 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2672 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2673 != BLKmode)
2674 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2676 rtx memref = 0;
2678 /* Now check that the containing word is memory, not a register,
2679 and that it is safe to change the machine mode. */
2681 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2682 memref = XEXP (bitfield, 0);
2683 else if (GET_CODE (XEXP (bitfield, 0)) == REG
2684 && equiv_mem != 0)
2685 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2686 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2687 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2688 memref = SUBREG_REG (XEXP (bitfield, 0));
2689 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2690 && equiv_mem != 0
2691 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
2692 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2694 if (memref
2695 && ! mode_dependent_address_p (XEXP (memref, 0))
2696 && ! MEM_VOLATILE_P (memref))
2698 /* Now adjust the address, first for any subreg'ing
2699 that we are now getting rid of,
2700 and then for which byte of the word is wanted. */
2702 HOST_WIDE_INT offset = INTVAL (XEXP (bitfield, 2));
2703 rtx insns;
2705 /* Adjust OFFSET to count bits from low-address byte. */
2706 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2707 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2708 - offset - INTVAL (XEXP (bitfield, 1)));
2710 /* Adjust OFFSET to count bytes from low-address byte. */
2711 offset /= BITS_PER_UNIT;
2712 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2714 offset += (SUBREG_BYTE (XEXP (bitfield, 0))
2715 / UNITS_PER_WORD) * UNITS_PER_WORD;
2716 if (BYTES_BIG_ENDIAN)
2717 offset -= (MIN (UNITS_PER_WORD,
2718 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2719 - MIN (UNITS_PER_WORD,
2720 GET_MODE_SIZE (GET_MODE (memref))));
2723 start_sequence ();
2724 memref = adjust_address (memref, mode, offset);
2725 insns = get_insns ();
2726 end_sequence ();
2727 emit_insn_before (insns, insn);
2729 /* Store this memory reference where
2730 we found the bit field reference. */
2732 if (destflag)
2734 validate_change (insn, &SET_DEST (body), memref, 1);
2735 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2737 rtx src = SET_SRC (body);
2738 while (GET_CODE (src) == SUBREG
2739 && SUBREG_BYTE (src) == 0)
2740 src = SUBREG_REG (src);
2741 if (GET_MODE (src) != GET_MODE (memref))
2742 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2743 validate_change (insn, &SET_SRC (body), src, 1);
2745 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2746 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2747 /* This shouldn't happen because anything that didn't have
2748 one of these modes should have got converted explicitly
2749 and then referenced through a subreg.
2750 This is so because the original bit-field was
2751 handled by agg_mode and so its tree structure had
2752 the same mode that memref now has. */
2753 abort ();
2755 else
2757 rtx dest = SET_DEST (body);
2759 while (GET_CODE (dest) == SUBREG
2760 && SUBREG_BYTE (dest) == 0
2761 && (GET_MODE_CLASS (GET_MODE (dest))
2762 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest))))
2763 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
2764 <= UNITS_PER_WORD))
2765 dest = SUBREG_REG (dest);
2767 validate_change (insn, &SET_DEST (body), dest, 1);
2769 if (GET_MODE (dest) == GET_MODE (memref))
2770 validate_change (insn, &SET_SRC (body), memref, 1);
2771 else
2773 /* Convert the mem ref to the destination mode. */
2774 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2776 start_sequence ();
2777 convert_move (newreg, memref,
2778 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2779 seq = get_insns ();
2780 end_sequence ();
2782 validate_change (insn, &SET_SRC (body), newreg, 1);
2786 /* See if we can convert this extraction or insertion into
2787 a simple move insn. We might not be able to do so if this
2788 was, for example, part of a PARALLEL.
2790 If we succeed, write out any needed conversions. If we fail,
2791 it is hard to guess why we failed, so don't do anything
2792 special; just let the optimization be suppressed. */
2794 if (apply_change_group () && seq)
2795 emit_insn_before (seq, insn);
2800 /* These routines are responsible for converting virtual register references
2801 to the actual hard register references once RTL generation is complete.
2803 The following four variables are used for communication between the
2804 routines. They contain the offsets of the virtual registers from their
2805 respective hard registers. */
2807 static int in_arg_offset;
2808 static int var_offset;
2809 static int dynamic_offset;
2810 static int out_arg_offset;
2811 static int cfa_offset;
2813 /* In most machines, the stack pointer register is equivalent to the bottom
2814 of the stack. */
2816 #ifndef STACK_POINTER_OFFSET
2817 #define STACK_POINTER_OFFSET 0
2818 #endif
2820 /* If not defined, pick an appropriate default for the offset of dynamically
2821 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2822 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2824 #ifndef STACK_DYNAMIC_OFFSET
2826 /* The bottom of the stack points to the actual arguments. If
2827 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2828 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2829 stack space for register parameters is not pushed by the caller, but
2830 rather part of the fixed stack areas and hence not included in
2831 `current_function_outgoing_args_size'. Nevertheless, we must allow
2832 for it when allocating stack dynamic objects. */
2834 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2835 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2836 ((ACCUMULATE_OUTGOING_ARGS \
2837 ? (current_function_outgoing_args_size + REG_PARM_STACK_SPACE (FNDECL)) : 0)\
2838 + (STACK_POINTER_OFFSET)) \
2840 #else
2841 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2842 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
2843 + (STACK_POINTER_OFFSET))
2844 #endif
2845 #endif
2847 /* On most machines, the CFA coincides with the first incoming parm. */
2849 #ifndef ARG_POINTER_CFA_OFFSET
2850 #define ARG_POINTER_CFA_OFFSET(FNDECL) FIRST_PARM_OFFSET (FNDECL)
2851 #endif
2853 /* Build up a (MEM (ADDRESSOF (REG))) rtx for a register REG that just had its
2854 address taken. DECL is the decl or SAVE_EXPR for the object stored in the
2855 register, for later use if we do need to force REG into the stack. REG is
2856 overwritten by the MEM like in put_reg_into_stack. */
2859 gen_mem_addressof (reg, decl)
2860 rtx reg;
2861 tree decl;
2863 rtx r = gen_rtx_ADDRESSOF (Pmode, gen_reg_rtx (GET_MODE (reg)),
2864 REGNO (reg), decl);
2866 /* Calculate this before we start messing with decl's RTL. */
2867 HOST_WIDE_INT set = decl ? get_alias_set (decl) : 0;
2869 /* If the original REG was a user-variable, then so is the REG whose
2870 address is being taken. Likewise for unchanging. */
2871 REG_USERVAR_P (XEXP (r, 0)) = REG_USERVAR_P (reg);
2872 RTX_UNCHANGING_P (XEXP (r, 0)) = RTX_UNCHANGING_P (reg);
2874 PUT_CODE (reg, MEM);
2875 MEM_ATTRS (reg) = 0;
2876 XEXP (reg, 0) = r;
2878 if (decl)
2880 tree type = TREE_TYPE (decl);
2881 enum machine_mode decl_mode
2882 = (DECL_P (decl) ? DECL_MODE (decl) : TYPE_MODE (TREE_TYPE (decl)));
2883 rtx decl_rtl = (TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl)
2884 : DECL_RTL_IF_SET (decl));
2886 PUT_MODE (reg, decl_mode);
2888 /* Clear DECL_RTL momentarily so functions below will work
2889 properly, then set it again. */
2890 if (DECL_P (decl) && decl_rtl == reg)
2891 SET_DECL_RTL (decl, 0);
2893 set_mem_attributes (reg, decl, 1);
2894 set_mem_alias_set (reg, set);
2896 if (DECL_P (decl) && decl_rtl == reg)
2897 SET_DECL_RTL (decl, reg);
2899 if (TREE_USED (decl) || (DECL_P (decl) && DECL_INITIAL (decl) != 0))
2900 fixup_var_refs (reg, GET_MODE (reg), TREE_UNSIGNED (type), reg, 0);
2902 else
2903 fixup_var_refs (reg, GET_MODE (reg), 0, reg, 0);
2905 return reg;
2908 /* If DECL has an RTL that is an ADDRESSOF rtx, put it into the stack. */
2910 void
2911 flush_addressof (decl)
2912 tree decl;
2914 if ((TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL)
2915 && DECL_RTL (decl) != 0
2916 && GET_CODE (DECL_RTL (decl)) == MEM
2917 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF
2918 && GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == REG)
2919 put_addressof_into_stack (XEXP (DECL_RTL (decl), 0), 0);
2922 /* Force the register pointed to by R, an ADDRESSOF rtx, into the stack. */
2924 static void
2925 put_addressof_into_stack (r, ht)
2926 rtx r;
2927 htab_t ht;
2929 tree decl, type;
2930 int volatile_p, used_p;
2932 rtx reg = XEXP (r, 0);
2934 if (GET_CODE (reg) != REG)
2935 abort ();
2937 decl = ADDRESSOF_DECL (r);
2938 if (decl)
2940 type = TREE_TYPE (decl);
2941 volatile_p = (TREE_CODE (decl) != SAVE_EXPR
2942 && TREE_THIS_VOLATILE (decl));
2943 used_p = (TREE_USED (decl)
2944 || (DECL_P (decl) && DECL_INITIAL (decl) != 0));
2946 else
2948 type = NULL_TREE;
2949 volatile_p = 0;
2950 used_p = 1;
2953 put_reg_into_stack (0, reg, type, GET_MODE (reg), GET_MODE (reg),
2954 volatile_p, ADDRESSOF_REGNO (r), used_p, ht);
2957 /* List of replacements made below in purge_addressof_1 when creating
2958 bitfield insertions. */
2959 static rtx purge_bitfield_addressof_replacements;
2961 /* List of replacements made below in purge_addressof_1 for patterns
2962 (MEM (ADDRESSOF (REG ...))). The key of the list entry is the
2963 corresponding (ADDRESSOF (REG ...)) and value is a substitution for
2964 the all pattern. List PURGE_BITFIELD_ADDRESSOF_REPLACEMENTS is not
2965 enough in complex cases, e.g. when some field values can be
2966 extracted by usage MEM with narrower mode. */
2967 static rtx purge_addressof_replacements;
2969 /* Helper function for purge_addressof. See if the rtx expression at *LOC
2970 in INSN needs to be changed. If FORCE, always put any ADDRESSOFs into
2971 the stack. If the function returns FALSE then the replacement could not
2972 be made. */
2974 static bool
2975 purge_addressof_1 (loc, insn, force, store, ht)
2976 rtx *loc;
2977 rtx insn;
2978 int force, store;
2979 htab_t ht;
2981 rtx x;
2982 RTX_CODE code;
2983 int i, j;
2984 const char *fmt;
2985 bool result = true;
2987 /* Re-start here to avoid recursion in common cases. */
2988 restart:
2990 x = *loc;
2991 if (x == 0)
2992 return true;
2994 code = GET_CODE (x);
2996 /* If we don't return in any of the cases below, we will recurse inside
2997 the RTX, which will normally result in any ADDRESSOF being forced into
2998 memory. */
2999 if (code == SET)
3001 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1, ht);
3002 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0, ht);
3003 return result;
3005 else if (code == ADDRESSOF)
3007 rtx sub, insns;
3009 if (GET_CODE (XEXP (x, 0)) != MEM)
3011 put_addressof_into_stack (x, ht);
3012 return true;
3015 /* We must create a copy of the rtx because it was created by
3016 overwriting a REG rtx which is always shared. */
3017 sub = copy_rtx (XEXP (XEXP (x, 0), 0));
3018 if (validate_change (insn, loc, sub, 0)
3019 || validate_replace_rtx (x, sub, insn))
3020 return true;
3022 start_sequence ();
3023 sub = force_operand (sub, NULL_RTX);
3024 if (! validate_change (insn, loc, sub, 0)
3025 && ! validate_replace_rtx (x, sub, insn))
3026 abort ();
3028 insns = get_insns ();
3029 end_sequence ();
3030 emit_insn_before (insns, insn);
3031 return true;
3034 else if (code == MEM && GET_CODE (XEXP (x, 0)) == ADDRESSOF && ! force)
3036 rtx sub = XEXP (XEXP (x, 0), 0);
3038 if (GET_CODE (sub) == MEM)
3039 sub = adjust_address_nv (sub, GET_MODE (x), 0);
3040 else if (GET_CODE (sub) == REG
3041 && (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode))
3043 else if (GET_CODE (sub) == REG && GET_MODE (x) != GET_MODE (sub))
3045 int size_x, size_sub;
3047 if (!insn)
3049 /* When processing REG_NOTES look at the list of
3050 replacements done on the insn to find the register that X
3051 was replaced by. */
3052 rtx tem;
3054 for (tem = purge_bitfield_addressof_replacements;
3055 tem != NULL_RTX;
3056 tem = XEXP (XEXP (tem, 1), 1))
3057 if (rtx_equal_p (x, XEXP (tem, 0)))
3059 *loc = XEXP (XEXP (tem, 1), 0);
3060 return true;
3063 /* See comment for purge_addressof_replacements. */
3064 for (tem = purge_addressof_replacements;
3065 tem != NULL_RTX;
3066 tem = XEXP (XEXP (tem, 1), 1))
3067 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3069 rtx z = XEXP (XEXP (tem, 1), 0);
3071 if (GET_MODE (x) == GET_MODE (z)
3072 || (GET_CODE (XEXP (XEXP (tem, 1), 0)) != REG
3073 && GET_CODE (XEXP (XEXP (tem, 1), 0)) != SUBREG))
3074 abort ();
3076 /* It can happen that the note may speak of things
3077 in a wider (or just different) mode than the
3078 code did. This is especially true of
3079 REG_RETVAL. */
3081 if (GET_CODE (z) == SUBREG && SUBREG_BYTE (z) == 0)
3082 z = SUBREG_REG (z);
3084 if (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3085 && (GET_MODE_SIZE (GET_MODE (x))
3086 > GET_MODE_SIZE (GET_MODE (z))))
3088 /* This can occur as a result in invalid
3089 pointer casts, e.g. float f; ...
3090 *(long long int *)&f.
3091 ??? We could emit a warning here, but
3092 without a line number that wouldn't be
3093 very helpful. */
3094 z = gen_rtx_SUBREG (GET_MODE (x), z, 0);
3096 else
3097 z = gen_lowpart (GET_MODE (x), z);
3099 *loc = z;
3100 return true;
3103 /* Sometimes we may not be able to find the replacement. For
3104 example when the original insn was a MEM in a wider mode,
3105 and the note is part of a sign extension of a narrowed
3106 version of that MEM. Gcc testcase compile/990829-1.c can
3107 generate an example of this situation. Rather than complain
3108 we return false, which will prompt our caller to remove the
3109 offending note. */
3110 return false;
3113 size_x = GET_MODE_BITSIZE (GET_MODE (x));
3114 size_sub = GET_MODE_BITSIZE (GET_MODE (sub));
3116 /* Don't even consider working with paradoxical subregs,
3117 or the moral equivalent seen here. */
3118 if (size_x <= size_sub
3119 && int_mode_for_mode (GET_MODE (sub)) != BLKmode)
3121 /* Do a bitfield insertion to mirror what would happen
3122 in memory. */
3124 rtx val, seq;
3126 if (store)
3128 rtx p = PREV_INSN (insn);
3130 start_sequence ();
3131 val = gen_reg_rtx (GET_MODE (x));
3132 if (! validate_change (insn, loc, val, 0))
3134 /* Discard the current sequence and put the
3135 ADDRESSOF on stack. */
3136 end_sequence ();
3137 goto give_up;
3139 seq = get_insns ();
3140 end_sequence ();
3141 emit_insn_before (seq, insn);
3142 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3143 insn, ht);
3145 start_sequence ();
3146 store_bit_field (sub, size_x, 0, GET_MODE (x),
3147 val, GET_MODE_SIZE (GET_MODE (sub)));
3149 /* Make sure to unshare any shared rtl that store_bit_field
3150 might have created. */
3151 unshare_all_rtl_again (get_insns ());
3153 seq = get_insns ();
3154 end_sequence ();
3155 p = emit_insn_after (seq, insn);
3156 if (NEXT_INSN (insn))
3157 compute_insns_for_mem (NEXT_INSN (insn),
3158 p ? NEXT_INSN (p) : NULL_RTX,
3159 ht);
3161 else
3163 rtx p = PREV_INSN (insn);
3165 start_sequence ();
3166 val = extract_bit_field (sub, size_x, 0, 1, NULL_RTX,
3167 GET_MODE (x), GET_MODE (x),
3168 GET_MODE_SIZE (GET_MODE (sub)));
3170 if (! validate_change (insn, loc, val, 0))
3172 /* Discard the current sequence and put the
3173 ADDRESSOF on stack. */
3174 end_sequence ();
3175 goto give_up;
3178 seq = get_insns ();
3179 end_sequence ();
3180 emit_insn_before (seq, insn);
3181 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3182 insn, ht);
3185 /* Remember the replacement so that the same one can be done
3186 on the REG_NOTES. */
3187 purge_bitfield_addressof_replacements
3188 = gen_rtx_EXPR_LIST (VOIDmode, x,
3189 gen_rtx_EXPR_LIST
3190 (VOIDmode, val,
3191 purge_bitfield_addressof_replacements));
3193 /* We replaced with a reg -- all done. */
3194 return true;
3198 else if (validate_change (insn, loc, sub, 0))
3200 /* Remember the replacement so that the same one can be done
3201 on the REG_NOTES. */
3202 if (GET_CODE (sub) == REG || GET_CODE (sub) == SUBREG)
3204 rtx tem;
3206 for (tem = purge_addressof_replacements;
3207 tem != NULL_RTX;
3208 tem = XEXP (XEXP (tem, 1), 1))
3209 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3211 XEXP (XEXP (tem, 1), 0) = sub;
3212 return true;
3214 purge_addressof_replacements
3215 = gen_rtx (EXPR_LIST, VOIDmode, XEXP (x, 0),
3216 gen_rtx_EXPR_LIST (VOIDmode, sub,
3217 purge_addressof_replacements));
3218 return true;
3220 goto restart;
3224 give_up:
3225 /* Scan all subexpressions. */
3226 fmt = GET_RTX_FORMAT (code);
3227 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3229 if (*fmt == 'e')
3230 result &= purge_addressof_1 (&XEXP (x, i), insn, force, 0, ht);
3231 else if (*fmt == 'E')
3232 for (j = 0; j < XVECLEN (x, i); j++)
3233 result &= purge_addressof_1 (&XVECEXP (x, i, j), insn, force, 0, ht);
3236 return result;
3239 /* Return a hash value for K, a REG. */
3241 static hashval_t
3242 insns_for_mem_hash (k)
3243 const void * k;
3245 /* Use the address of the key for the hash value. */
3246 struct insns_for_mem_entry *m = (struct insns_for_mem_entry *) k;
3247 return htab_hash_pointer (m->key);
3250 /* Return nonzero if K1 and K2 (two REGs) are the same. */
3252 static int
3253 insns_for_mem_comp (k1, k2)
3254 const void * k1;
3255 const void * k2;
3257 struct insns_for_mem_entry *m1 = (struct insns_for_mem_entry *) k1;
3258 struct insns_for_mem_entry *m2 = (struct insns_for_mem_entry *) k2;
3259 return m1->key == m2->key;
3262 struct insns_for_mem_walk_info
3264 /* The hash table that we are using to record which INSNs use which
3265 MEMs. */
3266 htab_t ht;
3268 /* The INSN we are currently processing. */
3269 rtx insn;
3271 /* Zero if we are walking to find ADDRESSOFs, one if we are walking
3272 to find the insns that use the REGs in the ADDRESSOFs. */
3273 int pass;
3276 /* Called from compute_insns_for_mem via for_each_rtx. If R is a REG
3277 that might be used in an ADDRESSOF expression, record this INSN in
3278 the hash table given by DATA (which is really a pointer to an
3279 insns_for_mem_walk_info structure). */
3281 static int
3282 insns_for_mem_walk (r, data)
3283 rtx *r;
3284 void *data;
3286 struct insns_for_mem_walk_info *ifmwi
3287 = (struct insns_for_mem_walk_info *) data;
3288 struct insns_for_mem_entry tmp;
3289 tmp.insns = NULL_RTX;
3291 if (ifmwi->pass == 0 && *r && GET_CODE (*r) == ADDRESSOF
3292 && GET_CODE (XEXP (*r, 0)) == REG)
3294 PTR *e;
3295 tmp.key = XEXP (*r, 0);
3296 e = htab_find_slot (ifmwi->ht, &tmp, INSERT);
3297 if (*e == NULL)
3299 *e = ggc_alloc (sizeof (tmp));
3300 memcpy (*e, &tmp, sizeof (tmp));
3303 else if (ifmwi->pass == 1 && *r && GET_CODE (*r) == REG)
3305 struct insns_for_mem_entry *ifme;
3306 tmp.key = *r;
3307 ifme = (struct insns_for_mem_entry *) htab_find (ifmwi->ht, &tmp);
3309 /* If we have not already recorded this INSN, do so now. Since
3310 we process the INSNs in order, we know that if we have
3311 recorded it it must be at the front of the list. */
3312 if (ifme && (!ifme->insns || XEXP (ifme->insns, 0) != ifmwi->insn))
3313 ifme->insns = gen_rtx_EXPR_LIST (VOIDmode, ifmwi->insn,
3314 ifme->insns);
3317 return 0;
3320 /* Walk the INSNS, until we reach LAST_INSN, recording which INSNs use
3321 which REGs in HT. */
3323 static void
3324 compute_insns_for_mem (insns, last_insn, ht)
3325 rtx insns;
3326 rtx last_insn;
3327 htab_t ht;
3329 rtx insn;
3330 struct insns_for_mem_walk_info ifmwi;
3331 ifmwi.ht = ht;
3333 for (ifmwi.pass = 0; ifmwi.pass < 2; ++ifmwi.pass)
3334 for (insn = insns; insn != last_insn; insn = NEXT_INSN (insn))
3335 if (INSN_P (insn))
3337 ifmwi.insn = insn;
3338 for_each_rtx (&insn, insns_for_mem_walk, &ifmwi);
3342 /* Helper function for purge_addressof called through for_each_rtx.
3343 Returns true iff the rtl is an ADDRESSOF. */
3345 static int
3346 is_addressof (rtl, data)
3347 rtx *rtl;
3348 void *data ATTRIBUTE_UNUSED;
3350 return GET_CODE (*rtl) == ADDRESSOF;
3353 /* Eliminate all occurrences of ADDRESSOF from INSNS. Elide any remaining
3354 (MEM (ADDRESSOF)) patterns, and force any needed registers into the
3355 stack. */
3357 void
3358 purge_addressof (insns)
3359 rtx insns;
3361 rtx insn;
3362 htab_t ht;
3364 /* When we actually purge ADDRESSOFs, we turn REGs into MEMs. That
3365 requires a fixup pass over the instruction stream to correct
3366 INSNs that depended on the REG being a REG, and not a MEM. But,
3367 these fixup passes are slow. Furthermore, most MEMs are not
3368 mentioned in very many instructions. So, we speed up the process
3369 by pre-calculating which REGs occur in which INSNs; that allows
3370 us to perform the fixup passes much more quickly. */
3371 ht = htab_create_ggc (1000, insns_for_mem_hash, insns_for_mem_comp, NULL);
3372 compute_insns_for_mem (insns, NULL_RTX, ht);
3374 for (insn = insns; insn; insn = NEXT_INSN (insn))
3375 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3376 || GET_CODE (insn) == CALL_INSN)
3378 if (! purge_addressof_1 (&PATTERN (insn), insn,
3379 asm_noperands (PATTERN (insn)) > 0, 0, ht))
3380 /* If we could not replace the ADDRESSOFs in the insn,
3381 something is wrong. */
3382 abort ();
3384 if (! purge_addressof_1 (&REG_NOTES (insn), NULL_RTX, 0, 0, ht))
3386 /* If we could not replace the ADDRESSOFs in the insn's notes,
3387 we can just remove the offending notes instead. */
3388 rtx note;
3390 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
3392 /* If we find a REG_RETVAL note then the insn is a libcall.
3393 Such insns must have REG_EQUAL notes as well, in order
3394 for later passes of the compiler to work. So it is not
3395 safe to delete the notes here, and instead we abort. */
3396 if (REG_NOTE_KIND (note) == REG_RETVAL)
3397 abort ();
3398 if (for_each_rtx (&note, is_addressof, NULL))
3399 remove_note (insn, note);
3404 /* Clean up. */
3405 purge_bitfield_addressof_replacements = 0;
3406 purge_addressof_replacements = 0;
3408 /* REGs are shared. purge_addressof will destructively replace a REG
3409 with a MEM, which creates shared MEMs.
3411 Unfortunately, the children of put_reg_into_stack assume that MEMs
3412 referring to the same stack slot are shared (fixup_var_refs and
3413 the associated hash table code).
3415 So, we have to do another unsharing pass after we have flushed any
3416 REGs that had their address taken into the stack.
3418 It may be worth tracking whether or not we converted any REGs into
3419 MEMs to avoid this overhead when it is not needed. */
3420 unshare_all_rtl_again (get_insns ());
3423 /* Convert a SET of a hard subreg to a set of the appropriate hard
3424 register. A subroutine of purge_hard_subreg_sets. */
3426 static void
3427 purge_single_hard_subreg_set (pattern)
3428 rtx pattern;
3430 rtx reg = SET_DEST (pattern);
3431 enum machine_mode mode = GET_MODE (SET_DEST (pattern));
3432 int offset = 0;
3434 if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG
3435 && REGNO (SUBREG_REG (reg)) < FIRST_PSEUDO_REGISTER)
3437 offset = subreg_regno_offset (REGNO (SUBREG_REG (reg)),
3438 GET_MODE (SUBREG_REG (reg)),
3439 SUBREG_BYTE (reg),
3440 GET_MODE (reg));
3441 reg = SUBREG_REG (reg);
3445 if (GET_CODE (reg) == REG && REGNO (reg) < FIRST_PSEUDO_REGISTER)
3447 reg = gen_rtx_REG (mode, REGNO (reg) + offset);
3448 SET_DEST (pattern) = reg;
3452 /* Eliminate all occurrences of SETs of hard subregs from INSNS. The
3453 only such SETs that we expect to see are those left in because
3454 integrate can't handle sets of parts of a return value register.
3456 We don't use alter_subreg because we only want to eliminate subregs
3457 of hard registers. */
3459 void
3460 purge_hard_subreg_sets (insn)
3461 rtx insn;
3463 for (; insn; insn = NEXT_INSN (insn))
3465 if (INSN_P (insn))
3467 rtx pattern = PATTERN (insn);
3468 switch (GET_CODE (pattern))
3470 case SET:
3471 if (GET_CODE (SET_DEST (pattern)) == SUBREG)
3472 purge_single_hard_subreg_set (pattern);
3473 break;
3474 case PARALLEL:
3476 int j;
3477 for (j = XVECLEN (pattern, 0) - 1; j >= 0; j--)
3479 rtx inner_pattern = XVECEXP (pattern, 0, j);
3480 if (GET_CODE (inner_pattern) == SET
3481 && GET_CODE (SET_DEST (inner_pattern)) == SUBREG)
3482 purge_single_hard_subreg_set (inner_pattern);
3485 break;
3486 default:
3487 break;
3493 /* Pass through the INSNS of function FNDECL and convert virtual register
3494 references to hard register references. */
3496 void
3497 instantiate_virtual_regs (fndecl, insns)
3498 tree fndecl;
3499 rtx insns;
3501 rtx insn;
3502 unsigned int i;
3504 /* Compute the offsets to use for this function. */
3505 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
3506 var_offset = STARTING_FRAME_OFFSET;
3507 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
3508 out_arg_offset = STACK_POINTER_OFFSET;
3509 cfa_offset = ARG_POINTER_CFA_OFFSET (fndecl);
3511 /* Scan all variables and parameters of this function. For each that is
3512 in memory, instantiate all virtual registers if the result is a valid
3513 address. If not, we do it later. That will handle most uses of virtual
3514 regs on many machines. */
3515 instantiate_decls (fndecl, 1);
3517 /* Initialize recognition, indicating that volatile is OK. */
3518 init_recog ();
3520 /* Scan through all the insns, instantiating every virtual register still
3521 present. */
3522 for (insn = insns; insn; insn = NEXT_INSN (insn))
3523 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3524 || GET_CODE (insn) == CALL_INSN)
3526 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
3527 instantiate_virtual_regs_1 (&REG_NOTES (insn), NULL_RTX, 0);
3528 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
3529 if (GET_CODE (insn) == CALL_INSN)
3530 instantiate_virtual_regs_1 (&CALL_INSN_FUNCTION_USAGE (insn),
3531 NULL_RTX, 0);
3534 /* Instantiate the stack slots for the parm registers, for later use in
3535 addressof elimination. */
3536 for (i = 0; i < max_parm_reg; ++i)
3537 if (parm_reg_stack_loc[i])
3538 instantiate_virtual_regs_1 (&parm_reg_stack_loc[i], NULL_RTX, 0);
3540 /* Now instantiate the remaining register equivalences for debugging info.
3541 These will not be valid addresses. */
3542 instantiate_decls (fndecl, 0);
3544 /* Indicate that, from now on, assign_stack_local should use
3545 frame_pointer_rtx. */
3546 virtuals_instantiated = 1;
3549 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
3550 all virtual registers in their DECL_RTL's.
3552 If VALID_ONLY, do this only if the resulting address is still valid.
3553 Otherwise, always do it. */
3555 static void
3556 instantiate_decls (fndecl, valid_only)
3557 tree fndecl;
3558 int valid_only;
3560 tree decl;
3562 /* Process all parameters of the function. */
3563 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
3565 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));
3566 HOST_WIDE_INT size_rtl;
3568 instantiate_decl (DECL_RTL (decl), size, valid_only);
3570 /* If the parameter was promoted, then the incoming RTL mode may be
3571 larger than the declared type size. We must use the larger of
3572 the two sizes. */
3573 size_rtl = GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl)));
3574 size = MAX (size_rtl, size);
3575 instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
3578 /* Now process all variables defined in the function or its subblocks. */
3579 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
3582 /* Subroutine of instantiate_decls: Process all decls in the given
3583 BLOCK node and all its subblocks. */
3585 static void
3586 instantiate_decls_1 (let, valid_only)
3587 tree let;
3588 int valid_only;
3590 tree t;
3592 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
3593 if (DECL_RTL_SET_P (t))
3594 instantiate_decl (DECL_RTL (t),
3595 int_size_in_bytes (TREE_TYPE (t)),
3596 valid_only);
3598 /* Process all subblocks. */
3599 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
3600 instantiate_decls_1 (t, valid_only);
3603 /* Subroutine of the preceding procedures: Given RTL representing a
3604 decl and the size of the object, do any instantiation required.
3606 If VALID_ONLY is nonzero, it means that the RTL should only be
3607 changed if the new address is valid. */
3609 static void
3610 instantiate_decl (x, size, valid_only)
3611 rtx x;
3612 HOST_WIDE_INT size;
3613 int valid_only;
3615 enum machine_mode mode;
3616 rtx addr;
3618 /* If this is not a MEM, no need to do anything. Similarly if the
3619 address is a constant or a register that is not a virtual register. */
3621 if (x == 0 || GET_CODE (x) != MEM)
3622 return;
3624 addr = XEXP (x, 0);
3625 if (CONSTANT_P (addr)
3626 || (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == REG)
3627 || (GET_CODE (addr) == REG
3628 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
3629 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
3630 return;
3632 /* If we should only do this if the address is valid, copy the address.
3633 We need to do this so we can undo any changes that might make the
3634 address invalid. This copy is unfortunate, but probably can't be
3635 avoided. */
3637 if (valid_only)
3638 addr = copy_rtx (addr);
3640 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
3642 if (valid_only && size >= 0)
3644 unsigned HOST_WIDE_INT decl_size = size;
3646 /* Now verify that the resulting address is valid for every integer or
3647 floating-point mode up to and including SIZE bytes long. We do this
3648 since the object might be accessed in any mode and frame addresses
3649 are shared. */
3651 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3652 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3653 mode = GET_MODE_WIDER_MODE (mode))
3654 if (! memory_address_p (mode, addr))
3655 return;
3657 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
3658 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3659 mode = GET_MODE_WIDER_MODE (mode))
3660 if (! memory_address_p (mode, addr))
3661 return;
3664 /* Put back the address now that we have updated it and we either know
3665 it is valid or we don't care whether it is valid. */
3667 XEXP (x, 0) = addr;
3670 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
3671 is a virtual register, return the equivalent hard register and set the
3672 offset indirectly through the pointer. Otherwise, return 0. */
3674 static rtx
3675 instantiate_new_reg (x, poffset)
3676 rtx x;
3677 HOST_WIDE_INT *poffset;
3679 rtx new;
3680 HOST_WIDE_INT offset;
3682 if (x == virtual_incoming_args_rtx)
3683 new = arg_pointer_rtx, offset = in_arg_offset;
3684 else if (x == virtual_stack_vars_rtx)
3685 new = frame_pointer_rtx, offset = var_offset;
3686 else if (x == virtual_stack_dynamic_rtx)
3687 new = stack_pointer_rtx, offset = dynamic_offset;
3688 else if (x == virtual_outgoing_args_rtx)
3689 new = stack_pointer_rtx, offset = out_arg_offset;
3690 else if (x == virtual_cfa_rtx)
3691 new = arg_pointer_rtx, offset = cfa_offset;
3692 else
3693 return 0;
3695 *poffset = offset;
3696 return new;
3699 /* Given a pointer to a piece of rtx and an optional pointer to the
3700 containing object, instantiate any virtual registers present in it.
3702 If EXTRA_INSNS, we always do the replacement and generate
3703 any extra insns before OBJECT. If it zero, we do nothing if replacement
3704 is not valid.
3706 Return 1 if we either had nothing to do or if we were able to do the
3707 needed replacement. Return 0 otherwise; we only return zero if
3708 EXTRA_INSNS is zero.
3710 We first try some simple transformations to avoid the creation of extra
3711 pseudos. */
3713 static int
3714 instantiate_virtual_regs_1 (loc, object, extra_insns)
3715 rtx *loc;
3716 rtx object;
3717 int extra_insns;
3719 rtx x;
3720 RTX_CODE code;
3721 rtx new = 0;
3722 HOST_WIDE_INT offset = 0;
3723 rtx temp;
3724 rtx seq;
3725 int i, j;
3726 const char *fmt;
3728 /* Re-start here to avoid recursion in common cases. */
3729 restart:
3731 x = *loc;
3732 if (x == 0)
3733 return 1;
3735 code = GET_CODE (x);
3737 /* Check for some special cases. */
3738 switch (code)
3740 case CONST_INT:
3741 case CONST_DOUBLE:
3742 case CONST_VECTOR:
3743 case CONST:
3744 case SYMBOL_REF:
3745 case CODE_LABEL:
3746 case PC:
3747 case CC0:
3748 case ASM_INPUT:
3749 case ADDR_VEC:
3750 case ADDR_DIFF_VEC:
3751 case RETURN:
3752 return 1;
3754 case SET:
3755 /* We are allowed to set the virtual registers. This means that
3756 the actual register should receive the source minus the
3757 appropriate offset. This is used, for example, in the handling
3758 of non-local gotos. */
3759 if ((new = instantiate_new_reg (SET_DEST (x), &offset)) != 0)
3761 rtx src = SET_SRC (x);
3763 /* We are setting the register, not using it, so the relevant
3764 offset is the negative of the offset to use were we using
3765 the register. */
3766 offset = - offset;
3767 instantiate_virtual_regs_1 (&src, NULL_RTX, 0);
3769 /* The only valid sources here are PLUS or REG. Just do
3770 the simplest possible thing to handle them. */
3771 if (GET_CODE (src) != REG && GET_CODE (src) != PLUS)
3772 abort ();
3774 start_sequence ();
3775 if (GET_CODE (src) != REG)
3776 temp = force_operand (src, NULL_RTX);
3777 else
3778 temp = src;
3779 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
3780 seq = get_insns ();
3781 end_sequence ();
3783 emit_insn_before (seq, object);
3784 SET_DEST (x) = new;
3786 if (! validate_change (object, &SET_SRC (x), temp, 0)
3787 || ! extra_insns)
3788 abort ();
3790 return 1;
3793 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
3794 loc = &SET_SRC (x);
3795 goto restart;
3797 case PLUS:
3798 /* Handle special case of virtual register plus constant. */
3799 if (CONSTANT_P (XEXP (x, 1)))
3801 rtx old, new_offset;
3803 /* Check for (plus (plus VIRT foo) (const_int)) first. */
3804 if (GET_CODE (XEXP (x, 0)) == PLUS)
3806 if ((new = instantiate_new_reg (XEXP (XEXP (x, 0), 0), &offset)))
3808 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
3809 extra_insns);
3810 new = gen_rtx_PLUS (Pmode, new, XEXP (XEXP (x, 0), 1));
3812 else
3814 loc = &XEXP (x, 0);
3815 goto restart;
3819 #ifdef POINTERS_EXTEND_UNSIGNED
3820 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
3821 we can commute the PLUS and SUBREG because pointers into the
3822 frame are well-behaved. */
3823 else if (GET_CODE (XEXP (x, 0)) == SUBREG && GET_MODE (x) == ptr_mode
3824 && GET_CODE (XEXP (x, 1)) == CONST_INT
3825 && 0 != (new
3826 = instantiate_new_reg (SUBREG_REG (XEXP (x, 0)),
3827 &offset))
3828 && validate_change (object, loc,
3829 plus_constant (gen_lowpart (ptr_mode,
3830 new),
3831 offset
3832 + INTVAL (XEXP (x, 1))),
3834 return 1;
3835 #endif
3836 else if ((new = instantiate_new_reg (XEXP (x, 0), &offset)) == 0)
3838 /* We know the second operand is a constant. Unless the
3839 first operand is a REG (which has been already checked),
3840 it needs to be checked. */
3841 if (GET_CODE (XEXP (x, 0)) != REG)
3843 loc = &XEXP (x, 0);
3844 goto restart;
3846 return 1;
3849 new_offset = plus_constant (XEXP (x, 1), offset);
3851 /* If the new constant is zero, try to replace the sum with just
3852 the register. */
3853 if (new_offset == const0_rtx
3854 && validate_change (object, loc, new, 0))
3855 return 1;
3857 /* Next try to replace the register and new offset.
3858 There are two changes to validate here and we can't assume that
3859 in the case of old offset equals new just changing the register
3860 will yield a valid insn. In the interests of a little efficiency,
3861 however, we only call validate change once (we don't queue up the
3862 changes and then call apply_change_group). */
3864 old = XEXP (x, 0);
3865 if (offset == 0
3866 ? ! validate_change (object, &XEXP (x, 0), new, 0)
3867 : (XEXP (x, 0) = new,
3868 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
3870 if (! extra_insns)
3872 XEXP (x, 0) = old;
3873 return 0;
3876 /* Otherwise copy the new constant into a register and replace
3877 constant with that register. */
3878 temp = gen_reg_rtx (Pmode);
3879 XEXP (x, 0) = new;
3880 if (validate_change (object, &XEXP (x, 1), temp, 0))
3881 emit_insn_before (gen_move_insn (temp, new_offset), object);
3882 else
3884 /* If that didn't work, replace this expression with a
3885 register containing the sum. */
3887 XEXP (x, 0) = old;
3888 new = gen_rtx_PLUS (Pmode, new, new_offset);
3890 start_sequence ();
3891 temp = force_operand (new, NULL_RTX);
3892 seq = get_insns ();
3893 end_sequence ();
3895 emit_insn_before (seq, object);
3896 if (! validate_change (object, loc, temp, 0)
3897 && ! validate_replace_rtx (x, temp, object))
3898 abort ();
3902 return 1;
3905 /* Fall through to generic two-operand expression case. */
3906 case EXPR_LIST:
3907 case CALL:
3908 case COMPARE:
3909 case MINUS:
3910 case MULT:
3911 case DIV: case UDIV:
3912 case MOD: case UMOD:
3913 case AND: case IOR: case XOR:
3914 case ROTATERT: case ROTATE:
3915 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
3916 case NE: case EQ:
3917 case GE: case GT: case GEU: case GTU:
3918 case LE: case LT: case LEU: case LTU:
3919 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
3920 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
3921 loc = &XEXP (x, 0);
3922 goto restart;
3924 case MEM:
3925 /* Most cases of MEM that convert to valid addresses have already been
3926 handled by our scan of decls. The only special handling we
3927 need here is to make a copy of the rtx to ensure it isn't being
3928 shared if we have to change it to a pseudo.
3930 If the rtx is a simple reference to an address via a virtual register,
3931 it can potentially be shared. In such cases, first try to make it
3932 a valid address, which can also be shared. Otherwise, copy it and
3933 proceed normally.
3935 First check for common cases that need no processing. These are
3936 usually due to instantiation already being done on a previous instance
3937 of a shared rtx. */
3939 temp = XEXP (x, 0);
3940 if (CONSTANT_ADDRESS_P (temp)
3941 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3942 || temp == arg_pointer_rtx
3943 #endif
3944 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
3945 || temp == hard_frame_pointer_rtx
3946 #endif
3947 || temp == frame_pointer_rtx)
3948 return 1;
3950 if (GET_CODE (temp) == PLUS
3951 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
3952 && (XEXP (temp, 0) == frame_pointer_rtx
3953 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
3954 || XEXP (temp, 0) == hard_frame_pointer_rtx
3955 #endif
3956 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3957 || XEXP (temp, 0) == arg_pointer_rtx
3958 #endif
3960 return 1;
3962 if (temp == virtual_stack_vars_rtx
3963 || temp == virtual_incoming_args_rtx
3964 || (GET_CODE (temp) == PLUS
3965 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
3966 && (XEXP (temp, 0) == virtual_stack_vars_rtx
3967 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
3969 /* This MEM may be shared. If the substitution can be done without
3970 the need to generate new pseudos, we want to do it in place
3971 so all copies of the shared rtx benefit. The call below will
3972 only make substitutions if the resulting address is still
3973 valid.
3975 Note that we cannot pass X as the object in the recursive call
3976 since the insn being processed may not allow all valid
3977 addresses. However, if we were not passed on object, we can
3978 only modify X without copying it if X will have a valid
3979 address.
3981 ??? Also note that this can still lose if OBJECT is an insn that
3982 has less restrictions on an address that some other insn.
3983 In that case, we will modify the shared address. This case
3984 doesn't seem very likely, though. One case where this could
3985 happen is in the case of a USE or CLOBBER reference, but we
3986 take care of that below. */
3988 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
3989 object ? object : x, 0))
3990 return 1;
3992 /* Otherwise make a copy and process that copy. We copy the entire
3993 RTL expression since it might be a PLUS which could also be
3994 shared. */
3995 *loc = x = copy_rtx (x);
3998 /* Fall through to generic unary operation case. */
3999 case PREFETCH:
4000 case SUBREG:
4001 case STRICT_LOW_PART:
4002 case NEG: case NOT:
4003 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
4004 case SIGN_EXTEND: case ZERO_EXTEND:
4005 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
4006 case FLOAT: case FIX:
4007 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
4008 case ABS:
4009 case SQRT:
4010 case FFS:
4011 /* These case either have just one operand or we know that we need not
4012 check the rest of the operands. */
4013 loc = &XEXP (x, 0);
4014 goto restart;
4016 case USE:
4017 case CLOBBER:
4018 /* If the operand is a MEM, see if the change is a valid MEM. If not,
4019 go ahead and make the invalid one, but do it to a copy. For a REG,
4020 just make the recursive call, since there's no chance of a problem. */
4022 if ((GET_CODE (XEXP (x, 0)) == MEM
4023 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
4025 || (GET_CODE (XEXP (x, 0)) == REG
4026 && instantiate_virtual_regs_1 (&XEXP (x, 0), object, 0)))
4027 return 1;
4029 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
4030 loc = &XEXP (x, 0);
4031 goto restart;
4033 case REG:
4034 /* Try to replace with a PLUS. If that doesn't work, compute the sum
4035 in front of this insn and substitute the temporary. */
4036 if ((new = instantiate_new_reg (x, &offset)) != 0)
4038 temp = plus_constant (new, offset);
4039 if (!validate_change (object, loc, temp, 0))
4041 if (! extra_insns)
4042 return 0;
4044 start_sequence ();
4045 temp = force_operand (temp, NULL_RTX);
4046 seq = get_insns ();
4047 end_sequence ();
4049 emit_insn_before (seq, object);
4050 if (! validate_change (object, loc, temp, 0)
4051 && ! validate_replace_rtx (x, temp, object))
4052 abort ();
4056 return 1;
4058 case ADDRESSOF:
4059 if (GET_CODE (XEXP (x, 0)) == REG)
4060 return 1;
4062 else if (GET_CODE (XEXP (x, 0)) == MEM)
4064 /* If we have a (addressof (mem ..)), do any instantiation inside
4065 since we know we'll be making the inside valid when we finally
4066 remove the ADDRESSOF. */
4067 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), NULL_RTX, 0);
4068 return 1;
4070 break;
4072 default:
4073 break;
4076 /* Scan all subexpressions. */
4077 fmt = GET_RTX_FORMAT (code);
4078 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
4079 if (*fmt == 'e')
4081 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
4082 return 0;
4084 else if (*fmt == 'E')
4085 for (j = 0; j < XVECLEN (x, i); j++)
4086 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
4087 extra_insns))
4088 return 0;
4090 return 1;
4093 /* Optimization: assuming this function does not receive nonlocal gotos,
4094 delete the handlers for such, as well as the insns to establish
4095 and disestablish them. */
4097 static void
4098 delete_handlers ()
4100 rtx insn;
4101 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4103 /* Delete the handler by turning off the flag that would
4104 prevent jump_optimize from deleting it.
4105 Also permit deletion of the nonlocal labels themselves
4106 if nothing local refers to them. */
4107 if (GET_CODE (insn) == CODE_LABEL)
4109 tree t, last_t;
4111 LABEL_PRESERVE_P (insn) = 0;
4113 /* Remove it from the nonlocal_label list, to avoid confusing
4114 flow. */
4115 for (t = nonlocal_labels, last_t = 0; t;
4116 last_t = t, t = TREE_CHAIN (t))
4117 if (DECL_RTL (TREE_VALUE (t)) == insn)
4118 break;
4119 if (t)
4121 if (! last_t)
4122 nonlocal_labels = TREE_CHAIN (nonlocal_labels);
4123 else
4124 TREE_CHAIN (last_t) = TREE_CHAIN (t);
4127 if (GET_CODE (insn) == INSN)
4129 int can_delete = 0;
4130 rtx t;
4131 for (t = nonlocal_goto_handler_slots; t != 0; t = XEXP (t, 1))
4132 if (reg_mentioned_p (t, PATTERN (insn)))
4134 can_delete = 1;
4135 break;
4137 if (can_delete
4138 || (nonlocal_goto_stack_level != 0
4139 && reg_mentioned_p (nonlocal_goto_stack_level,
4140 PATTERN (insn))))
4141 delete_related_insns (insn);
4146 /* Return the first insn following those generated by `assign_parms'. */
4149 get_first_nonparm_insn ()
4151 if (last_parm_insn)
4152 return NEXT_INSN (last_parm_insn);
4153 return get_insns ();
4156 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
4157 This means a type for which function calls must pass an address to the
4158 function or get an address back from the function.
4159 EXP may be a type node or an expression (whose type is tested). */
4162 aggregate_value_p (exp)
4163 tree exp;
4165 int i, regno, nregs;
4166 rtx reg;
4168 tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
4170 if (TREE_CODE (type) == VOID_TYPE)
4171 return 0;
4172 if (RETURN_IN_MEMORY (type))
4173 return 1;
4174 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
4175 and thus can't be returned in registers. */
4176 if (TREE_ADDRESSABLE (type))
4177 return 1;
4178 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
4179 return 1;
4180 /* Make sure we have suitable call-clobbered regs to return
4181 the value in; if not, we must return it in memory. */
4182 reg = hard_function_value (type, 0, 0);
4184 /* If we have something other than a REG (e.g. a PARALLEL), then assume
4185 it is OK. */
4186 if (GET_CODE (reg) != REG)
4187 return 0;
4189 regno = REGNO (reg);
4190 nregs = HARD_REGNO_NREGS (regno, TYPE_MODE (type));
4191 for (i = 0; i < nregs; i++)
4192 if (! call_used_regs[regno + i])
4193 return 1;
4194 return 0;
4197 /* Assign RTL expressions to the function's parameters.
4198 This may involve copying them into registers and using
4199 those registers as the RTL for them. */
4201 void
4202 assign_parms (fndecl)
4203 tree fndecl;
4205 tree parm;
4206 rtx entry_parm = 0;
4207 rtx stack_parm = 0;
4208 CUMULATIVE_ARGS args_so_far;
4209 enum machine_mode promoted_mode, passed_mode;
4210 enum machine_mode nominal_mode, promoted_nominal_mode;
4211 int unsignedp;
4212 /* Total space needed so far for args on the stack,
4213 given as a constant and a tree-expression. */
4214 struct args_size stack_args_size;
4215 tree fntype = TREE_TYPE (fndecl);
4216 tree fnargs = DECL_ARGUMENTS (fndecl);
4217 /* This is used for the arg pointer when referring to stack args. */
4218 rtx internal_arg_pointer;
4219 /* This is a dummy PARM_DECL that we used for the function result if
4220 the function returns a structure. */
4221 tree function_result_decl = 0;
4222 #ifdef SETUP_INCOMING_VARARGS
4223 int varargs_setup = 0;
4224 #endif
4225 rtx conversion_insns = 0;
4226 struct args_size alignment_pad;
4228 /* Nonzero if function takes extra anonymous args.
4229 This means the last named arg must be on the stack
4230 right before the anonymous ones. */
4231 int stdarg
4232 = (TYPE_ARG_TYPES (fntype) != 0
4233 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
4234 != void_type_node));
4236 current_function_stdarg = stdarg;
4238 /* If the reg that the virtual arg pointer will be translated into is
4239 not a fixed reg or is the stack pointer, make a copy of the virtual
4240 arg pointer, and address parms via the copy. The frame pointer is
4241 considered fixed even though it is not marked as such.
4243 The second time through, simply use ap to avoid generating rtx. */
4245 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
4246 || ! (fixed_regs[ARG_POINTER_REGNUM]
4247 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
4248 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
4249 else
4250 internal_arg_pointer = virtual_incoming_args_rtx;
4251 current_function_internal_arg_pointer = internal_arg_pointer;
4253 stack_args_size.constant = 0;
4254 stack_args_size.var = 0;
4256 /* If struct value address is treated as the first argument, make it so. */
4257 if (aggregate_value_p (DECL_RESULT (fndecl))
4258 && ! current_function_returns_pcc_struct
4259 && struct_value_incoming_rtx == 0)
4261 tree type = build_pointer_type (TREE_TYPE (fntype));
4263 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
4265 DECL_ARG_TYPE (function_result_decl) = type;
4266 TREE_CHAIN (function_result_decl) = fnargs;
4267 fnargs = function_result_decl;
4270 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4271 parm_reg_stack_loc = (rtx *) ggc_alloc_cleared (max_parm_reg * sizeof (rtx));
4273 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
4274 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
4275 #else
4276 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, 0);
4277 #endif
4279 /* We haven't yet found an argument that we must push and pretend the
4280 caller did. */
4281 current_function_pretend_args_size = 0;
4283 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
4285 struct args_size stack_offset;
4286 struct args_size arg_size;
4287 int passed_pointer = 0;
4288 int did_conversion = 0;
4289 tree passed_type = DECL_ARG_TYPE (parm);
4290 tree nominal_type = TREE_TYPE (parm);
4291 int pretend_named;
4292 int last_named = 0, named_arg;
4294 /* Set LAST_NAMED if this is last named arg before last
4295 anonymous args. */
4296 if (stdarg)
4298 tree tem;
4300 for (tem = TREE_CHAIN (parm); tem; tem = TREE_CHAIN (tem))
4301 if (DECL_NAME (tem))
4302 break;
4304 if (tem == 0)
4305 last_named = 1;
4307 /* Set NAMED_ARG if this arg should be treated as a named arg. For
4308 most machines, if this is a varargs/stdarg function, then we treat
4309 the last named arg as if it were anonymous too. */
4310 named_arg = STRICT_ARGUMENT_NAMING ? 1 : ! last_named;
4312 if (TREE_TYPE (parm) == error_mark_node
4313 /* This can happen after weird syntax errors
4314 or if an enum type is defined among the parms. */
4315 || TREE_CODE (parm) != PARM_DECL
4316 || passed_type == NULL)
4318 SET_DECL_RTL (parm, gen_rtx_MEM (BLKmode, const0_rtx));
4319 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4320 TREE_USED (parm) = 1;
4321 continue;
4324 /* Find mode of arg as it is passed, and mode of arg
4325 as it should be during execution of this function. */
4326 passed_mode = TYPE_MODE (passed_type);
4327 nominal_mode = TYPE_MODE (nominal_type);
4329 /* If the parm's mode is VOID, its value doesn't matter,
4330 and avoid the usual things like emit_move_insn that could crash. */
4331 if (nominal_mode == VOIDmode)
4333 SET_DECL_RTL (parm, const0_rtx);
4334 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4335 continue;
4338 /* If the parm is to be passed as a transparent union, use the
4339 type of the first field for the tests below. We have already
4340 verified that the modes are the same. */
4341 if (DECL_TRANSPARENT_UNION (parm)
4342 || (TREE_CODE (passed_type) == UNION_TYPE
4343 && TYPE_TRANSPARENT_UNION (passed_type)))
4344 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
4346 /* See if this arg was passed by invisible reference. It is if
4347 it is an object whose size depends on the contents of the
4348 object itself or if the machine requires these objects be passed
4349 that way. */
4351 if ((TREE_CODE (TYPE_SIZE (passed_type)) != INTEGER_CST
4352 && contains_placeholder_p (TYPE_SIZE (passed_type)))
4353 || TREE_ADDRESSABLE (passed_type)
4354 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
4355 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
4356 passed_type, named_arg)
4357 #endif
4360 passed_type = nominal_type = build_pointer_type (passed_type);
4361 passed_pointer = 1;
4362 passed_mode = nominal_mode = Pmode;
4364 /* See if the frontend wants to pass this by invisible reference. */
4365 else if (passed_type != nominal_type
4366 && POINTER_TYPE_P (passed_type)
4367 && TREE_TYPE (passed_type) == nominal_type)
4369 nominal_type = passed_type;
4370 passed_pointer = 1;
4371 passed_mode = nominal_mode = Pmode;
4374 promoted_mode = passed_mode;
4376 #ifdef PROMOTE_FUNCTION_ARGS
4377 /* Compute the mode in which the arg is actually extended to. */
4378 unsignedp = TREE_UNSIGNED (passed_type);
4379 promoted_mode = promote_mode (passed_type, promoted_mode, &unsignedp, 1);
4380 #endif
4382 /* Let machine desc say which reg (if any) the parm arrives in.
4383 0 means it arrives on the stack. */
4384 #ifdef FUNCTION_INCOMING_ARG
4385 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4386 passed_type, named_arg);
4387 #else
4388 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
4389 passed_type, named_arg);
4390 #endif
4392 if (entry_parm == 0)
4393 promoted_mode = passed_mode;
4395 #ifdef SETUP_INCOMING_VARARGS
4396 /* If this is the last named parameter, do any required setup for
4397 varargs or stdargs. We need to know about the case of this being an
4398 addressable type, in which case we skip the registers it
4399 would have arrived in.
4401 For stdargs, LAST_NAMED will be set for two parameters, the one that
4402 is actually the last named, and the dummy parameter. We only
4403 want to do this action once.
4405 Also, indicate when RTL generation is to be suppressed. */
4406 if (last_named && !varargs_setup)
4408 SETUP_INCOMING_VARARGS (args_so_far, promoted_mode, passed_type,
4409 current_function_pretend_args_size, 0);
4410 varargs_setup = 1;
4412 #endif
4414 /* Determine parm's home in the stack,
4415 in case it arrives in the stack or we should pretend it did.
4417 Compute the stack position and rtx where the argument arrives
4418 and its size.
4420 There is one complexity here: If this was a parameter that would
4421 have been passed in registers, but wasn't only because it is
4422 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
4423 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
4424 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
4425 0 as it was the previous time. */
4427 pretend_named = named_arg || PRETEND_OUTGOING_VARARGS_NAMED;
4428 locate_and_pad_parm (promoted_mode, passed_type,
4429 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4431 #else
4432 #ifdef FUNCTION_INCOMING_ARG
4433 FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4434 passed_type,
4435 pretend_named) != 0,
4436 #else
4437 FUNCTION_ARG (args_so_far, promoted_mode,
4438 passed_type,
4439 pretend_named) != 0,
4440 #endif
4441 #endif
4442 fndecl, &stack_args_size, &stack_offset, &arg_size,
4443 &alignment_pad);
4446 rtx offset_rtx = ARGS_SIZE_RTX (stack_offset);
4448 if (offset_rtx == const0_rtx)
4449 stack_parm = gen_rtx_MEM (promoted_mode, internal_arg_pointer);
4450 else
4451 stack_parm = gen_rtx_MEM (promoted_mode,
4452 gen_rtx_PLUS (Pmode,
4453 internal_arg_pointer,
4454 offset_rtx));
4456 set_mem_attributes (stack_parm, parm, 1);
4459 /* If this parameter was passed both in registers and in the stack,
4460 use the copy on the stack. */
4461 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
4462 entry_parm = 0;
4464 #ifdef FUNCTION_ARG_PARTIAL_NREGS
4465 /* If this parm was passed part in regs and part in memory,
4466 pretend it arrived entirely in memory
4467 by pushing the register-part onto the stack.
4469 In the special case of a DImode or DFmode that is split,
4470 we could put it together in a pseudoreg directly,
4471 but for now that's not worth bothering with. */
4473 if (entry_parm)
4475 int nregs = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
4476 passed_type, named_arg);
4478 if (nregs > 0)
4480 #if defined (REG_PARM_STACK_SPACE) && !defined (MAYBE_REG_PARM_STACK_SPACE)
4481 /* When REG_PARM_STACK_SPACE is nonzero, stack space for
4482 split parameters was allocated by our caller, so we
4483 won't be pushing it in the prolog. */
4484 if (REG_PARM_STACK_SPACE (fndecl) == 0)
4485 #endif
4486 current_function_pretend_args_size
4487 = (((nregs * UNITS_PER_WORD) + (PARM_BOUNDARY / BITS_PER_UNIT) - 1)
4488 / (PARM_BOUNDARY / BITS_PER_UNIT)
4489 * (PARM_BOUNDARY / BITS_PER_UNIT));
4491 /* Handle calls that pass values in multiple non-contiguous
4492 locations. The Irix 6 ABI has examples of this. */
4493 if (GET_CODE (entry_parm) == PARALLEL)
4494 emit_group_store (validize_mem (stack_parm), entry_parm,
4495 int_size_in_bytes (TREE_TYPE (parm)));
4497 else
4498 move_block_from_reg (REGNO (entry_parm),
4499 validize_mem (stack_parm), nregs,
4500 int_size_in_bytes (TREE_TYPE (parm)));
4502 entry_parm = stack_parm;
4505 #endif
4507 /* If we didn't decide this parm came in a register,
4508 by default it came on the stack. */
4509 if (entry_parm == 0)
4510 entry_parm = stack_parm;
4512 /* Record permanently how this parm was passed. */
4513 DECL_INCOMING_RTL (parm) = entry_parm;
4515 /* If there is actually space on the stack for this parm,
4516 count it in stack_args_size; otherwise set stack_parm to 0
4517 to indicate there is no preallocated stack slot for the parm. */
4519 if (entry_parm == stack_parm
4520 || (GET_CODE (entry_parm) == PARALLEL
4521 && XEXP (XVECEXP (entry_parm, 0, 0), 0) == NULL_RTX)
4522 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
4523 /* On some machines, even if a parm value arrives in a register
4524 there is still an (uninitialized) stack slot allocated for it.
4526 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
4527 whether this parameter already has a stack slot allocated,
4528 because an arg block exists only if current_function_args_size
4529 is larger than some threshold, and we haven't calculated that
4530 yet. So, for now, we just assume that stack slots never exist
4531 in this case. */
4532 || REG_PARM_STACK_SPACE (fndecl) > 0
4533 #endif
4536 stack_args_size.constant += arg_size.constant;
4537 if (arg_size.var)
4538 ADD_PARM_SIZE (stack_args_size, arg_size.var);
4540 else
4541 /* No stack slot was pushed for this parm. */
4542 stack_parm = 0;
4544 /* Update info on where next arg arrives in registers. */
4546 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
4547 passed_type, named_arg);
4549 /* If we can't trust the parm stack slot to be aligned enough
4550 for its ultimate type, don't use that slot after entry.
4551 We'll make another stack slot, if we need one. */
4553 unsigned int thisparm_boundary
4554 = FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type);
4556 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
4557 stack_parm = 0;
4560 /* If parm was passed in memory, and we need to convert it on entry,
4561 don't store it back in that same slot. */
4562 if (entry_parm != 0
4563 && nominal_mode != BLKmode && nominal_mode != passed_mode)
4564 stack_parm = 0;
4566 /* When an argument is passed in multiple locations, we can't
4567 make use of this information, but we can save some copying if
4568 the whole argument is passed in a single register. */
4569 if (GET_CODE (entry_parm) == PARALLEL
4570 && nominal_mode != BLKmode && passed_mode != BLKmode)
4572 int i, len = XVECLEN (entry_parm, 0);
4574 for (i = 0; i < len; i++)
4575 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
4576 && GET_CODE (XEXP (XVECEXP (entry_parm, 0, i), 0)) == REG
4577 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
4578 == passed_mode)
4579 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
4581 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
4582 DECL_INCOMING_RTL (parm) = entry_parm;
4583 break;
4587 /* ENTRY_PARM is an RTX for the parameter as it arrives,
4588 in the mode in which it arrives.
4589 STACK_PARM is an RTX for a stack slot where the parameter can live
4590 during the function (in case we want to put it there).
4591 STACK_PARM is 0 if no stack slot was pushed for it.
4593 Now output code if necessary to convert ENTRY_PARM to
4594 the type in which this function declares it,
4595 and store that result in an appropriate place,
4596 which may be a pseudo reg, may be STACK_PARM,
4597 or may be a local stack slot if STACK_PARM is 0.
4599 Set DECL_RTL to that place. */
4601 if (nominal_mode == BLKmode || GET_CODE (entry_parm) == PARALLEL)
4603 /* If a BLKmode arrives in registers, copy it to a stack slot.
4604 Handle calls that pass values in multiple non-contiguous
4605 locations. The Irix 6 ABI has examples of this. */
4606 if (GET_CODE (entry_parm) == REG
4607 || GET_CODE (entry_parm) == PARALLEL)
4609 int size_stored
4610 = CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm)),
4611 UNITS_PER_WORD);
4613 /* Note that we will be storing an integral number of words.
4614 So we have to be careful to ensure that we allocate an
4615 integral number of words. We do this below in the
4616 assign_stack_local if space was not allocated in the argument
4617 list. If it was, this will not work if PARM_BOUNDARY is not
4618 a multiple of BITS_PER_WORD. It isn't clear how to fix this
4619 if it becomes a problem. */
4621 if (stack_parm == 0)
4623 stack_parm
4624 = assign_stack_local (GET_MODE (entry_parm),
4625 size_stored, 0);
4626 set_mem_attributes (stack_parm, parm, 1);
4629 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
4630 abort ();
4632 /* Handle calls that pass values in multiple non-contiguous
4633 locations. The Irix 6 ABI has examples of this. */
4634 if (GET_CODE (entry_parm) == PARALLEL)
4635 emit_group_store (validize_mem (stack_parm), entry_parm,
4636 int_size_in_bytes (TREE_TYPE (parm)));
4637 else
4638 move_block_from_reg (REGNO (entry_parm),
4639 validize_mem (stack_parm),
4640 size_stored / UNITS_PER_WORD,
4641 int_size_in_bytes (TREE_TYPE (parm)));
4643 SET_DECL_RTL (parm, stack_parm);
4645 else if (! ((! optimize
4646 && ! DECL_REGISTER (parm))
4647 || TREE_SIDE_EFFECTS (parm)
4648 /* If -ffloat-store specified, don't put explicit
4649 float variables into registers. */
4650 || (flag_float_store
4651 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
4652 /* Always assign pseudo to structure return or item passed
4653 by invisible reference. */
4654 || passed_pointer || parm == function_result_decl)
4656 /* Store the parm in a pseudoregister during the function, but we
4657 may need to do it in a wider mode. */
4659 rtx parmreg;
4660 unsigned int regno, regnoi = 0, regnor = 0;
4662 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
4664 promoted_nominal_mode
4665 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
4667 parmreg = gen_reg_rtx (promoted_nominal_mode);
4668 mark_user_reg (parmreg);
4670 /* If this was an item that we received a pointer to, set DECL_RTL
4671 appropriately. */
4672 if (passed_pointer)
4674 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (passed_type)),
4675 parmreg);
4676 set_mem_attributes (x, parm, 1);
4677 SET_DECL_RTL (parm, x);
4679 else
4681 SET_DECL_RTL (parm, parmreg);
4682 maybe_set_unchanging (DECL_RTL (parm), parm);
4685 /* Copy the value into the register. */
4686 if (nominal_mode != passed_mode
4687 || promoted_nominal_mode != promoted_mode)
4689 int save_tree_used;
4690 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
4691 mode, by the caller. We now have to convert it to
4692 NOMINAL_MODE, if different. However, PARMREG may be in
4693 a different mode than NOMINAL_MODE if it is being stored
4694 promoted.
4696 If ENTRY_PARM is a hard register, it might be in a register
4697 not valid for operating in its mode (e.g., an odd-numbered
4698 register for a DFmode). In that case, moves are the only
4699 thing valid, so we can't do a convert from there. This
4700 occurs when the calling sequence allow such misaligned
4701 usages.
4703 In addition, the conversion may involve a call, which could
4704 clobber parameters which haven't been copied to pseudo
4705 registers yet. Therefore, we must first copy the parm to
4706 a pseudo reg here, and save the conversion until after all
4707 parameters have been moved. */
4709 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4711 emit_move_insn (tempreg, validize_mem (entry_parm));
4713 push_to_sequence (conversion_insns);
4714 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
4716 if (GET_CODE (tempreg) == SUBREG
4717 && GET_MODE (tempreg) == nominal_mode
4718 && GET_CODE (SUBREG_REG (tempreg)) == REG
4719 && nominal_mode == passed_mode
4720 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (entry_parm)
4721 && GET_MODE_SIZE (GET_MODE (tempreg))
4722 < GET_MODE_SIZE (GET_MODE (entry_parm)))
4724 /* The argument is already sign/zero extended, so note it
4725 into the subreg. */
4726 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
4727 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
4730 /* TREE_USED gets set erroneously during expand_assignment. */
4731 save_tree_used = TREE_USED (parm);
4732 expand_assignment (parm,
4733 make_tree (nominal_type, tempreg), 0, 0);
4734 TREE_USED (parm) = save_tree_used;
4735 conversion_insns = get_insns ();
4736 did_conversion = 1;
4737 end_sequence ();
4739 else
4740 emit_move_insn (parmreg, validize_mem (entry_parm));
4742 /* If we were passed a pointer but the actual value
4743 can safely live in a register, put it in one. */
4744 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
4745 /* If by-reference argument was promoted, demote it. */
4746 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
4747 || ! ((! optimize
4748 && ! DECL_REGISTER (parm))
4749 || TREE_SIDE_EFFECTS (parm)
4750 /* If -ffloat-store specified, don't put explicit
4751 float variables into registers. */
4752 || (flag_float_store
4753 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))))
4755 /* We can't use nominal_mode, because it will have been set to
4756 Pmode above. We must use the actual mode of the parm. */
4757 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
4758 mark_user_reg (parmreg);
4759 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
4761 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
4762 int unsigned_p = TREE_UNSIGNED (TREE_TYPE (parm));
4763 push_to_sequence (conversion_insns);
4764 emit_move_insn (tempreg, DECL_RTL (parm));
4765 SET_DECL_RTL (parm,
4766 convert_to_mode (GET_MODE (parmreg),
4767 tempreg,
4768 unsigned_p));
4769 emit_move_insn (parmreg, DECL_RTL (parm));
4770 conversion_insns = get_insns();
4771 did_conversion = 1;
4772 end_sequence ();
4774 else
4775 emit_move_insn (parmreg, DECL_RTL (parm));
4776 SET_DECL_RTL (parm, parmreg);
4777 /* STACK_PARM is the pointer, not the parm, and PARMREG is
4778 now the parm. */
4779 stack_parm = 0;
4781 #ifdef FUNCTION_ARG_CALLEE_COPIES
4782 /* If we are passed an arg by reference and it is our responsibility
4783 to make a copy, do it now.
4784 PASSED_TYPE and PASSED mode now refer to the pointer, not the
4785 original argument, so we must recreate them in the call to
4786 FUNCTION_ARG_CALLEE_COPIES. */
4787 /* ??? Later add code to handle the case that if the argument isn't
4788 modified, don't do the copy. */
4790 else if (passed_pointer
4791 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
4792 TYPE_MODE (DECL_ARG_TYPE (parm)),
4793 DECL_ARG_TYPE (parm),
4794 named_arg)
4795 && ! TREE_ADDRESSABLE (DECL_ARG_TYPE (parm)))
4797 rtx copy;
4798 tree type = DECL_ARG_TYPE (parm);
4800 /* This sequence may involve a library call perhaps clobbering
4801 registers that haven't been copied to pseudos yet. */
4803 push_to_sequence (conversion_insns);
4805 if (!COMPLETE_TYPE_P (type)
4806 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4807 /* This is a variable sized object. */
4808 copy = gen_rtx_MEM (BLKmode,
4809 allocate_dynamic_stack_space
4810 (expr_size (parm), NULL_RTX,
4811 TYPE_ALIGN (type)));
4812 else
4813 copy = assign_stack_temp (TYPE_MODE (type),
4814 int_size_in_bytes (type), 1);
4815 set_mem_attributes (copy, parm, 1);
4817 store_expr (parm, copy, 0);
4818 emit_move_insn (parmreg, XEXP (copy, 0));
4819 conversion_insns = get_insns ();
4820 did_conversion = 1;
4821 end_sequence ();
4823 #endif /* FUNCTION_ARG_CALLEE_COPIES */
4825 /* In any case, record the parm's desired stack location
4826 in case we later discover it must live in the stack.
4828 If it is a COMPLEX value, store the stack location for both
4829 halves. */
4831 if (GET_CODE (parmreg) == CONCAT)
4832 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
4833 else
4834 regno = REGNO (parmreg);
4836 if (regno >= max_parm_reg)
4838 rtx *new;
4839 int old_max_parm_reg = max_parm_reg;
4841 /* It's slow to expand this one register at a time,
4842 but it's also rare and we need max_parm_reg to be
4843 precisely correct. */
4844 max_parm_reg = regno + 1;
4845 new = (rtx *) ggc_realloc (parm_reg_stack_loc,
4846 max_parm_reg * sizeof (rtx));
4847 memset ((char *) (new + old_max_parm_reg), 0,
4848 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
4849 parm_reg_stack_loc = new;
4852 if (GET_CODE (parmreg) == CONCAT)
4854 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
4856 regnor = REGNO (gen_realpart (submode, parmreg));
4857 regnoi = REGNO (gen_imagpart (submode, parmreg));
4859 if (stack_parm != 0)
4861 parm_reg_stack_loc[regnor]
4862 = gen_realpart (submode, stack_parm);
4863 parm_reg_stack_loc[regnoi]
4864 = gen_imagpart (submode, stack_parm);
4866 else
4868 parm_reg_stack_loc[regnor] = 0;
4869 parm_reg_stack_loc[regnoi] = 0;
4872 else
4873 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
4875 /* Mark the register as eliminable if we did no conversion
4876 and it was copied from memory at a fixed offset,
4877 and the arg pointer was not copied to a pseudo-reg.
4878 If the arg pointer is a pseudo reg or the offset formed
4879 an invalid address, such memory-equivalences
4880 as we make here would screw up life analysis for it. */
4881 if (nominal_mode == passed_mode
4882 && ! did_conversion
4883 && stack_parm != 0
4884 && GET_CODE (stack_parm) == MEM
4885 && stack_offset.var == 0
4886 && reg_mentioned_p (virtual_incoming_args_rtx,
4887 XEXP (stack_parm, 0)))
4889 rtx linsn = get_last_insn ();
4890 rtx sinsn, set;
4892 /* Mark complex types separately. */
4893 if (GET_CODE (parmreg) == CONCAT)
4894 /* Scan backwards for the set of the real and
4895 imaginary parts. */
4896 for (sinsn = linsn; sinsn != 0;
4897 sinsn = prev_nonnote_insn (sinsn))
4899 set = single_set (sinsn);
4900 if (set != 0
4901 && SET_DEST (set) == regno_reg_rtx [regnoi])
4902 REG_NOTES (sinsn)
4903 = gen_rtx_EXPR_LIST (REG_EQUIV,
4904 parm_reg_stack_loc[regnoi],
4905 REG_NOTES (sinsn));
4906 else if (set != 0
4907 && SET_DEST (set) == regno_reg_rtx [regnor])
4908 REG_NOTES (sinsn)
4909 = gen_rtx_EXPR_LIST (REG_EQUIV,
4910 parm_reg_stack_loc[regnor],
4911 REG_NOTES (sinsn));
4913 else if ((set = single_set (linsn)) != 0
4914 && SET_DEST (set) == parmreg)
4915 REG_NOTES (linsn)
4916 = gen_rtx_EXPR_LIST (REG_EQUIV,
4917 stack_parm, REG_NOTES (linsn));
4920 /* For pointer data type, suggest pointer register. */
4921 if (POINTER_TYPE_P (TREE_TYPE (parm)))
4922 mark_reg_pointer (parmreg,
4923 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4925 /* If something wants our address, try to use ADDRESSOF. */
4926 if (TREE_ADDRESSABLE (parm))
4928 /* If we end up putting something into the stack,
4929 fixup_var_refs_insns will need to make a pass over
4930 all the instructions. It looks through the pending
4931 sequences -- but it can't see the ones in the
4932 CONVERSION_INSNS, if they're not on the sequence
4933 stack. So, we go back to that sequence, just so that
4934 the fixups will happen. */
4935 push_to_sequence (conversion_insns);
4936 put_var_into_stack (parm);
4937 conversion_insns = get_insns ();
4938 end_sequence ();
4941 else
4943 /* Value must be stored in the stack slot STACK_PARM
4944 during function execution. */
4946 if (promoted_mode != nominal_mode)
4948 /* Conversion is required. */
4949 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4951 emit_move_insn (tempreg, validize_mem (entry_parm));
4953 push_to_sequence (conversion_insns);
4954 entry_parm = convert_to_mode (nominal_mode, tempreg,
4955 TREE_UNSIGNED (TREE_TYPE (parm)));
4956 if (stack_parm)
4957 /* ??? This may need a big-endian conversion on sparc64. */
4958 stack_parm = adjust_address (stack_parm, nominal_mode, 0);
4960 conversion_insns = get_insns ();
4961 did_conversion = 1;
4962 end_sequence ();
4965 if (entry_parm != stack_parm)
4967 if (stack_parm == 0)
4969 stack_parm
4970 = assign_stack_local (GET_MODE (entry_parm),
4971 GET_MODE_SIZE (GET_MODE (entry_parm)), 0);
4972 set_mem_attributes (stack_parm, parm, 1);
4975 if (promoted_mode != nominal_mode)
4977 push_to_sequence (conversion_insns);
4978 emit_move_insn (validize_mem (stack_parm),
4979 validize_mem (entry_parm));
4980 conversion_insns = get_insns ();
4981 end_sequence ();
4983 else
4984 emit_move_insn (validize_mem (stack_parm),
4985 validize_mem (entry_parm));
4988 SET_DECL_RTL (parm, stack_parm);
4991 /* If this "parameter" was the place where we are receiving the
4992 function's incoming structure pointer, set up the result. */
4993 if (parm == function_result_decl)
4995 tree result = DECL_RESULT (fndecl);
4996 rtx addr = DECL_RTL (parm);
4997 rtx x;
4999 #ifdef POINTERS_EXTEND_UNSIGNED
5000 if (GET_MODE (addr) != Pmode)
5001 addr = convert_memory_address (Pmode, addr);
5002 #endif
5004 x = gen_rtx_MEM (DECL_MODE (result), addr);
5005 set_mem_attributes (x, result, 1);
5006 SET_DECL_RTL (result, x);
5009 if (GET_CODE (DECL_RTL (parm)) == REG)
5010 REGNO_DECL (REGNO (DECL_RTL (parm))) = parm;
5011 else if (GET_CODE (DECL_RTL (parm)) == CONCAT)
5013 REGNO_DECL (REGNO (XEXP (DECL_RTL (parm), 0))) = parm;
5014 REGNO_DECL (REGNO (XEXP (DECL_RTL (parm), 1))) = parm;
5019 /* Output all parameter conversion instructions (possibly including calls)
5020 now that all parameters have been copied out of hard registers. */
5021 emit_insn (conversion_insns);
5023 last_parm_insn = get_last_insn ();
5025 current_function_args_size = stack_args_size.constant;
5027 /* Adjust function incoming argument size for alignment and
5028 minimum length. */
5030 #ifdef REG_PARM_STACK_SPACE
5031 #ifndef MAYBE_REG_PARM_STACK_SPACE
5032 current_function_args_size = MAX (current_function_args_size,
5033 REG_PARM_STACK_SPACE (fndecl));
5034 #endif
5035 #endif
5037 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
5039 current_function_args_size
5040 = ((current_function_args_size + STACK_BYTES - 1)
5041 / STACK_BYTES) * STACK_BYTES;
5043 #ifdef ARGS_GROW_DOWNWARD
5044 current_function_arg_offset_rtx
5045 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
5046 : expand_expr (size_diffop (stack_args_size.var,
5047 size_int (-stack_args_size.constant)),
5048 NULL_RTX, VOIDmode, 0));
5049 #else
5050 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
5051 #endif
5053 /* See how many bytes, if any, of its args a function should try to pop
5054 on return. */
5056 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
5057 current_function_args_size);
5059 /* For stdarg.h function, save info about
5060 regs and stack space used by the named args. */
5062 current_function_args_info = args_so_far;
5064 /* Set the rtx used for the function return value. Put this in its
5065 own variable so any optimizers that need this information don't have
5066 to include tree.h. Do this here so it gets done when an inlined
5067 function gets output. */
5069 current_function_return_rtx
5070 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
5071 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
5073 /* If scalar return value was computed in a pseudo-reg, or was a named
5074 return value that got dumped to the stack, copy that to the hard
5075 return register. */
5076 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
5078 tree decl_result = DECL_RESULT (fndecl);
5079 rtx decl_rtl = DECL_RTL (decl_result);
5081 if (REG_P (decl_rtl)
5082 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5083 : DECL_REGISTER (decl_result))
5085 rtx real_decl_rtl;
5087 #ifdef FUNCTION_OUTGOING_VALUE
5088 real_decl_rtl = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl_result),
5089 fndecl);
5090 #else
5091 real_decl_rtl = FUNCTION_VALUE (TREE_TYPE (decl_result),
5092 fndecl);
5093 #endif
5094 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
5095 /* The delay slot scheduler assumes that current_function_return_rtx
5096 holds the hard register containing the return value, not a
5097 temporary pseudo. */
5098 current_function_return_rtx = real_decl_rtl;
5103 /* Indicate whether REGNO is an incoming argument to the current function
5104 that was promoted to a wider mode. If so, return the RTX for the
5105 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
5106 that REGNO is promoted from and whether the promotion was signed or
5107 unsigned. */
5109 #ifdef PROMOTE_FUNCTION_ARGS
5112 promoted_input_arg (regno, pmode, punsignedp)
5113 unsigned int regno;
5114 enum machine_mode *pmode;
5115 int *punsignedp;
5117 tree arg;
5119 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
5120 arg = TREE_CHAIN (arg))
5121 if (GET_CODE (DECL_INCOMING_RTL (arg)) == REG
5122 && REGNO (DECL_INCOMING_RTL (arg)) == regno
5123 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
5125 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
5126 int unsignedp = TREE_UNSIGNED (TREE_TYPE (arg));
5128 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
5129 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
5130 && mode != DECL_MODE (arg))
5132 *pmode = DECL_MODE (arg);
5133 *punsignedp = unsignedp;
5134 return DECL_INCOMING_RTL (arg);
5138 return 0;
5141 #endif
5143 /* Compute the size and offset from the start of the stacked arguments for a
5144 parm passed in mode PASSED_MODE and with type TYPE.
5146 INITIAL_OFFSET_PTR points to the current offset into the stacked
5147 arguments.
5149 The starting offset and size for this parm are returned in *OFFSET_PTR
5150 and *ARG_SIZE_PTR, respectively.
5152 IN_REGS is nonzero if the argument will be passed in registers. It will
5153 never be set if REG_PARM_STACK_SPACE is not defined.
5155 FNDECL is the function in which the argument was defined.
5157 There are two types of rounding that are done. The first, controlled by
5158 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
5159 list to be aligned to the specific boundary (in bits). This rounding
5160 affects the initial and starting offsets, but not the argument size.
5162 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
5163 optionally rounds the size of the parm to PARM_BOUNDARY. The
5164 initial offset is not affected by this rounding, while the size always
5165 is and the starting offset may be. */
5167 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
5168 initial_offset_ptr is positive because locate_and_pad_parm's
5169 callers pass in the total size of args so far as
5170 initial_offset_ptr. arg_size_ptr is always positive. */
5172 void
5173 locate_and_pad_parm (passed_mode, type, in_regs, fndecl,
5174 initial_offset_ptr, offset_ptr, arg_size_ptr,
5175 alignment_pad)
5176 enum machine_mode passed_mode;
5177 tree type;
5178 int in_regs ATTRIBUTE_UNUSED;
5179 tree fndecl ATTRIBUTE_UNUSED;
5180 struct args_size *initial_offset_ptr;
5181 struct args_size *offset_ptr;
5182 struct args_size *arg_size_ptr;
5183 struct args_size *alignment_pad;
5186 tree sizetree
5187 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
5188 enum direction where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
5189 int boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
5190 #ifdef ARGS_GROW_DOWNWARD
5191 tree s2 = sizetree;
5192 #endif
5194 #ifdef REG_PARM_STACK_SPACE
5195 /* If we have found a stack parm before we reach the end of the
5196 area reserved for registers, skip that area. */
5197 if (! in_regs)
5199 int reg_parm_stack_space = 0;
5201 #ifdef MAYBE_REG_PARM_STACK_SPACE
5202 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
5203 #else
5204 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
5205 #endif
5206 if (reg_parm_stack_space > 0)
5208 if (initial_offset_ptr->var)
5210 initial_offset_ptr->var
5211 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
5212 ssize_int (reg_parm_stack_space));
5213 initial_offset_ptr->constant = 0;
5215 else if (initial_offset_ptr->constant < reg_parm_stack_space)
5216 initial_offset_ptr->constant = reg_parm_stack_space;
5219 #endif /* REG_PARM_STACK_SPACE */
5221 arg_size_ptr->var = 0;
5222 arg_size_ptr->constant = 0;
5223 alignment_pad->var = 0;
5224 alignment_pad->constant = 0;
5226 #ifdef ARGS_GROW_DOWNWARD
5227 if (initial_offset_ptr->var)
5229 offset_ptr->constant = 0;
5230 offset_ptr->var = size_binop (MINUS_EXPR, ssize_int (0),
5231 initial_offset_ptr->var);
5233 else
5235 offset_ptr->constant = -initial_offset_ptr->constant;
5236 offset_ptr->var = 0;
5239 if (where_pad != none
5240 && (!host_integerp (sizetree, 1)
5241 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5242 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
5243 SUB_PARM_SIZE (*offset_ptr, s2);
5245 if (!in_regs
5246 #ifdef REG_PARM_STACK_SPACE
5247 || REG_PARM_STACK_SPACE (fndecl) > 0
5248 #endif
5250 pad_to_arg_alignment (offset_ptr, boundary, alignment_pad);
5252 if (initial_offset_ptr->var)
5253 arg_size_ptr->var = size_binop (MINUS_EXPR,
5254 size_binop (MINUS_EXPR,
5255 ssize_int (0),
5256 initial_offset_ptr->var),
5257 offset_ptr->var);
5259 else
5260 arg_size_ptr->constant = (-initial_offset_ptr->constant
5261 - offset_ptr->constant);
5263 /* Pad_below needs the pre-rounded size to know how much to pad below.
5264 We only pad parameters which are not in registers as they have their
5265 padding done elsewhere. */
5266 if (where_pad == downward
5267 && !in_regs)
5268 pad_below (offset_ptr, passed_mode, sizetree);
5270 #else /* !ARGS_GROW_DOWNWARD */
5271 if (!in_regs
5272 #ifdef REG_PARM_STACK_SPACE
5273 || REG_PARM_STACK_SPACE (fndecl) > 0
5274 #endif
5276 pad_to_arg_alignment (initial_offset_ptr, boundary, alignment_pad);
5277 *offset_ptr = *initial_offset_ptr;
5279 #ifdef PUSH_ROUNDING
5280 if (passed_mode != BLKmode)
5281 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
5282 #endif
5284 /* Pad_below needs the pre-rounded size to know how much to pad below
5285 so this must be done before rounding up. */
5286 if (where_pad == downward
5287 /* However, BLKmode args passed in regs have their padding done elsewhere.
5288 The stack slot must be able to hold the entire register. */
5289 && !(in_regs && passed_mode == BLKmode))
5290 pad_below (offset_ptr, passed_mode, sizetree);
5292 if (where_pad != none
5293 && (!host_integerp (sizetree, 1)
5294 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5295 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5297 ADD_PARM_SIZE (*arg_size_ptr, sizetree);
5298 #endif /* ARGS_GROW_DOWNWARD */
5301 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
5302 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
5304 static void
5305 pad_to_arg_alignment (offset_ptr, boundary, alignment_pad)
5306 struct args_size *offset_ptr;
5307 int boundary;
5308 struct args_size *alignment_pad;
5310 tree save_var = NULL_TREE;
5311 HOST_WIDE_INT save_constant = 0;
5313 int boundary_in_bytes = boundary / BITS_PER_UNIT;
5315 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5317 save_var = offset_ptr->var;
5318 save_constant = offset_ptr->constant;
5321 alignment_pad->var = NULL_TREE;
5322 alignment_pad->constant = 0;
5324 if (boundary > BITS_PER_UNIT)
5326 if (offset_ptr->var)
5328 offset_ptr->var =
5329 #ifdef ARGS_GROW_DOWNWARD
5330 round_down
5331 #else
5332 round_up
5333 #endif
5334 (ARGS_SIZE_TREE (*offset_ptr),
5335 boundary / BITS_PER_UNIT);
5336 offset_ptr->constant = 0; /*?*/
5337 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5338 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
5339 save_var);
5341 else
5343 offset_ptr->constant =
5344 #ifdef ARGS_GROW_DOWNWARD
5345 FLOOR_ROUND (offset_ptr->constant, boundary_in_bytes);
5346 #else
5347 CEIL_ROUND (offset_ptr->constant, boundary_in_bytes);
5348 #endif
5349 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5350 alignment_pad->constant = offset_ptr->constant - save_constant;
5355 static void
5356 pad_below (offset_ptr, passed_mode, sizetree)
5357 struct args_size *offset_ptr;
5358 enum machine_mode passed_mode;
5359 tree sizetree;
5361 if (passed_mode != BLKmode)
5363 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
5364 offset_ptr->constant
5365 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
5366 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
5367 - GET_MODE_SIZE (passed_mode));
5369 else
5371 if (TREE_CODE (sizetree) != INTEGER_CST
5372 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
5374 /* Round the size up to multiple of PARM_BOUNDARY bits. */
5375 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5376 /* Add it in. */
5377 ADD_PARM_SIZE (*offset_ptr, s2);
5378 SUB_PARM_SIZE (*offset_ptr, sizetree);
5383 /* Walk the tree of blocks describing the binding levels within a function
5384 and warn about uninitialized variables.
5385 This is done after calling flow_analysis and before global_alloc
5386 clobbers the pseudo-regs to hard regs. */
5388 void
5389 uninitialized_vars_warning (block)
5390 tree block;
5392 tree decl, sub;
5393 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5395 if (warn_uninitialized
5396 && TREE_CODE (decl) == VAR_DECL
5397 /* These warnings are unreliable for and aggregates
5398 because assigning the fields one by one can fail to convince
5399 flow.c that the entire aggregate was initialized.
5400 Unions are troublesome because members may be shorter. */
5401 && ! AGGREGATE_TYPE_P (TREE_TYPE (decl))
5402 && DECL_RTL (decl) != 0
5403 && GET_CODE (DECL_RTL (decl)) == REG
5404 /* Global optimizations can make it difficult to determine if a
5405 particular variable has been initialized. However, a VAR_DECL
5406 with a nonzero DECL_INITIAL had an initializer, so do not
5407 claim it is potentially uninitialized.
5409 We do not care about the actual value in DECL_INITIAL, so we do
5410 not worry that it may be a dangling pointer. */
5411 && DECL_INITIAL (decl) == NULL_TREE
5412 && regno_uninitialized (REGNO (DECL_RTL (decl))))
5413 warning_with_decl (decl,
5414 "`%s' might be used uninitialized in this function");
5415 if (extra_warnings
5416 && TREE_CODE (decl) == VAR_DECL
5417 && DECL_RTL (decl) != 0
5418 && GET_CODE (DECL_RTL (decl)) == REG
5419 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5420 warning_with_decl (decl,
5421 "variable `%s' might be clobbered by `longjmp' or `vfork'");
5423 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5424 uninitialized_vars_warning (sub);
5427 /* Do the appropriate part of uninitialized_vars_warning
5428 but for arguments instead of local variables. */
5430 void
5431 setjmp_args_warning ()
5433 tree decl;
5434 for (decl = DECL_ARGUMENTS (current_function_decl);
5435 decl; decl = TREE_CHAIN (decl))
5436 if (DECL_RTL (decl) != 0
5437 && GET_CODE (DECL_RTL (decl)) == REG
5438 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5439 warning_with_decl (decl,
5440 "argument `%s' might be clobbered by `longjmp' or `vfork'");
5443 /* If this function call setjmp, put all vars into the stack
5444 unless they were declared `register'. */
5446 void
5447 setjmp_protect (block)
5448 tree block;
5450 tree decl, sub;
5451 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5452 if ((TREE_CODE (decl) == VAR_DECL
5453 || TREE_CODE (decl) == PARM_DECL)
5454 && DECL_RTL (decl) != 0
5455 && (GET_CODE (DECL_RTL (decl)) == REG
5456 || (GET_CODE (DECL_RTL (decl)) == MEM
5457 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5458 /* If this variable came from an inline function, it must be
5459 that its life doesn't overlap the setjmp. If there was a
5460 setjmp in the function, it would already be in memory. We
5461 must exclude such variable because their DECL_RTL might be
5462 set to strange things such as virtual_stack_vars_rtx. */
5463 && ! DECL_FROM_INLINE (decl)
5464 && (
5465 #ifdef NON_SAVING_SETJMP
5466 /* If longjmp doesn't restore the registers,
5467 don't put anything in them. */
5468 NON_SAVING_SETJMP
5470 #endif
5471 ! DECL_REGISTER (decl)))
5472 put_var_into_stack (decl);
5473 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5474 setjmp_protect (sub);
5477 /* Like the previous function, but for args instead of local variables. */
5479 void
5480 setjmp_protect_args ()
5482 tree decl;
5483 for (decl = DECL_ARGUMENTS (current_function_decl);
5484 decl; decl = TREE_CHAIN (decl))
5485 if ((TREE_CODE (decl) == VAR_DECL
5486 || TREE_CODE (decl) == PARM_DECL)
5487 && DECL_RTL (decl) != 0
5488 && (GET_CODE (DECL_RTL (decl)) == REG
5489 || (GET_CODE (DECL_RTL (decl)) == MEM
5490 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5491 && (
5492 /* If longjmp doesn't restore the registers,
5493 don't put anything in them. */
5494 #ifdef NON_SAVING_SETJMP
5495 NON_SAVING_SETJMP
5497 #endif
5498 ! DECL_REGISTER (decl)))
5499 put_var_into_stack (decl);
5502 /* Return the context-pointer register corresponding to DECL,
5503 or 0 if it does not need one. */
5506 lookup_static_chain (decl)
5507 tree decl;
5509 tree context = decl_function_context (decl);
5510 tree link;
5512 if (context == 0
5513 || (TREE_CODE (decl) == FUNCTION_DECL && DECL_NO_STATIC_CHAIN (decl)))
5514 return 0;
5516 /* We treat inline_function_decl as an alias for the current function
5517 because that is the inline function whose vars, types, etc.
5518 are being merged into the current function.
5519 See expand_inline_function. */
5520 if (context == current_function_decl || context == inline_function_decl)
5521 return virtual_stack_vars_rtx;
5523 for (link = context_display; link; link = TREE_CHAIN (link))
5524 if (TREE_PURPOSE (link) == context)
5525 return RTL_EXPR_RTL (TREE_VALUE (link));
5527 abort ();
5530 /* Convert a stack slot address ADDR for variable VAR
5531 (from a containing function)
5532 into an address valid in this function (using a static chain). */
5535 fix_lexical_addr (addr, var)
5536 rtx addr;
5537 tree var;
5539 rtx basereg;
5540 HOST_WIDE_INT displacement;
5541 tree context = decl_function_context (var);
5542 struct function *fp;
5543 rtx base = 0;
5545 /* If this is the present function, we need not do anything. */
5546 if (context == current_function_decl || context == inline_function_decl)
5547 return addr;
5549 fp = find_function_data (context);
5551 if (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == MEM)
5552 addr = XEXP (XEXP (addr, 0), 0);
5554 /* Decode given address as base reg plus displacement. */
5555 if (GET_CODE (addr) == REG)
5556 basereg = addr, displacement = 0;
5557 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
5558 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
5559 else
5560 abort ();
5562 /* We accept vars reached via the containing function's
5563 incoming arg pointer and via its stack variables pointer. */
5564 if (basereg == fp->internal_arg_pointer)
5566 /* If reached via arg pointer, get the arg pointer value
5567 out of that function's stack frame.
5569 There are two cases: If a separate ap is needed, allocate a
5570 slot in the outer function for it and dereference it that way.
5571 This is correct even if the real ap is actually a pseudo.
5572 Otherwise, just adjust the offset from the frame pointer to
5573 compensate. */
5575 #ifdef NEED_SEPARATE_AP
5576 rtx addr;
5578 addr = get_arg_pointer_save_area (fp);
5579 addr = fix_lexical_addr (XEXP (addr, 0), var);
5580 addr = memory_address (Pmode, addr);
5582 base = gen_rtx_MEM (Pmode, addr);
5583 set_mem_alias_set (base, get_frame_alias_set ());
5584 base = copy_to_reg (base);
5585 #else
5586 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
5587 base = lookup_static_chain (var);
5588 #endif
5591 else if (basereg == virtual_stack_vars_rtx)
5593 /* This is the same code as lookup_static_chain, duplicated here to
5594 avoid an extra call to decl_function_context. */
5595 tree link;
5597 for (link = context_display; link; link = TREE_CHAIN (link))
5598 if (TREE_PURPOSE (link) == context)
5600 base = RTL_EXPR_RTL (TREE_VALUE (link));
5601 break;
5605 if (base == 0)
5606 abort ();
5608 /* Use same offset, relative to appropriate static chain or argument
5609 pointer. */
5610 return plus_constant (base, displacement);
5613 /* Return the address of the trampoline for entering nested fn FUNCTION.
5614 If necessary, allocate a trampoline (in the stack frame)
5615 and emit rtl to initialize its contents (at entry to this function). */
5618 trampoline_address (function)
5619 tree function;
5621 tree link;
5622 tree rtlexp;
5623 rtx tramp;
5624 struct function *fp;
5625 tree fn_context;
5627 /* Find an existing trampoline and return it. */
5628 for (link = trampoline_list; link; link = TREE_CHAIN (link))
5629 if (TREE_PURPOSE (link) == function)
5630 return
5631 adjust_trampoline_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0));
5633 for (fp = outer_function_chain; fp; fp = fp->outer)
5634 for (link = fp->x_trampoline_list; link; link = TREE_CHAIN (link))
5635 if (TREE_PURPOSE (link) == function)
5637 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
5638 function);
5639 return adjust_trampoline_addr (tramp);
5642 /* None exists; we must make one. */
5644 /* Find the `struct function' for the function containing FUNCTION. */
5645 fp = 0;
5646 fn_context = decl_function_context (function);
5647 if (fn_context != current_function_decl
5648 && fn_context != inline_function_decl)
5649 fp = find_function_data (fn_context);
5651 /* Allocate run-time space for this trampoline
5652 (usually in the defining function's stack frame). */
5653 #ifdef ALLOCATE_TRAMPOLINE
5654 tramp = ALLOCATE_TRAMPOLINE (fp);
5655 #else
5656 /* If rounding needed, allocate extra space
5657 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
5658 #define TRAMPOLINE_REAL_SIZE \
5659 (TRAMPOLINE_SIZE + (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT) - 1)
5660 tramp = assign_stack_local_1 (BLKmode, TRAMPOLINE_REAL_SIZE, 0,
5661 fp ? fp : cfun);
5662 #endif
5664 /* Record the trampoline for reuse and note it for later initialization
5665 by expand_function_end. */
5666 if (fp != 0)
5668 rtlexp = make_node (RTL_EXPR);
5669 RTL_EXPR_RTL (rtlexp) = tramp;
5670 fp->x_trampoline_list = tree_cons (function, rtlexp,
5671 fp->x_trampoline_list);
5673 else
5675 /* Make the RTL_EXPR node temporary, not momentary, so that the
5676 trampoline_list doesn't become garbage. */
5677 rtlexp = make_node (RTL_EXPR);
5679 RTL_EXPR_RTL (rtlexp) = tramp;
5680 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
5683 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
5684 return adjust_trampoline_addr (tramp);
5687 /* Given a trampoline address,
5688 round it to multiple of TRAMPOLINE_ALIGNMENT. */
5690 static rtx
5691 round_trampoline_addr (tramp)
5692 rtx tramp;
5694 /* Round address up to desired boundary. */
5695 rtx temp = gen_reg_rtx (Pmode);
5696 rtx addend = GEN_INT (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT - 1);
5697 rtx mask = GEN_INT (-TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
5699 temp = expand_simple_binop (Pmode, PLUS, tramp, addend,
5700 temp, 0, OPTAB_LIB_WIDEN);
5701 tramp = expand_simple_binop (Pmode, AND, temp, mask,
5702 temp, 0, OPTAB_LIB_WIDEN);
5704 return tramp;
5707 /* Given a trampoline address, round it then apply any
5708 platform-specific adjustments so that the result can be used for a
5709 function call . */
5711 static rtx
5712 adjust_trampoline_addr (tramp)
5713 rtx tramp;
5715 tramp = round_trampoline_addr (tramp);
5716 #ifdef TRAMPOLINE_ADJUST_ADDRESS
5717 TRAMPOLINE_ADJUST_ADDRESS (tramp);
5718 #endif
5719 return tramp;
5722 /* Put all this function's BLOCK nodes including those that are chained
5723 onto the first block into a vector, and return it.
5724 Also store in each NOTE for the beginning or end of a block
5725 the index of that block in the vector.
5726 The arguments are BLOCK, the chain of top-level blocks of the function,
5727 and INSNS, the insn chain of the function. */
5729 void
5730 identify_blocks ()
5732 int n_blocks;
5733 tree *block_vector, *last_block_vector;
5734 tree *block_stack;
5735 tree block = DECL_INITIAL (current_function_decl);
5737 if (block == 0)
5738 return;
5740 /* Fill the BLOCK_VECTOR with all of the BLOCKs in this function, in
5741 depth-first order. */
5742 block_vector = get_block_vector (block, &n_blocks);
5743 block_stack = (tree *) xmalloc (n_blocks * sizeof (tree));
5745 last_block_vector = identify_blocks_1 (get_insns (),
5746 block_vector + 1,
5747 block_vector + n_blocks,
5748 block_stack);
5750 /* If we didn't use all of the subblocks, we've misplaced block notes. */
5751 /* ??? This appears to happen all the time. Latent bugs elsewhere? */
5752 if (0 && last_block_vector != block_vector + n_blocks)
5753 abort ();
5755 free (block_vector);
5756 free (block_stack);
5759 /* Subroutine of identify_blocks. Do the block substitution on the
5760 insn chain beginning with INSNS. Recurse for CALL_PLACEHOLDER chains.
5762 BLOCK_STACK is pushed and popped for each BLOCK_BEGIN/BLOCK_END pair.
5763 BLOCK_VECTOR is incremented for each block seen. */
5765 static tree *
5766 identify_blocks_1 (insns, block_vector, end_block_vector, orig_block_stack)
5767 rtx insns;
5768 tree *block_vector;
5769 tree *end_block_vector;
5770 tree *orig_block_stack;
5772 rtx insn;
5773 tree *block_stack = orig_block_stack;
5775 for (insn = insns; insn; insn = NEXT_INSN (insn))
5777 if (GET_CODE (insn) == NOTE)
5779 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5781 tree b;
5783 /* If there are more block notes than BLOCKs, something
5784 is badly wrong. */
5785 if (block_vector == end_block_vector)
5786 abort ();
5788 b = *block_vector++;
5789 NOTE_BLOCK (insn) = b;
5790 *block_stack++ = b;
5792 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
5794 /* If there are more NOTE_INSN_BLOCK_ENDs than
5795 NOTE_INSN_BLOCK_BEGs, something is badly wrong. */
5796 if (block_stack == orig_block_stack)
5797 abort ();
5799 NOTE_BLOCK (insn) = *--block_stack;
5802 else if (GET_CODE (insn) == CALL_INSN
5803 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
5805 rtx cp = PATTERN (insn);
5807 block_vector = identify_blocks_1 (XEXP (cp, 0), block_vector,
5808 end_block_vector, block_stack);
5809 if (XEXP (cp, 1))
5810 block_vector = identify_blocks_1 (XEXP (cp, 1), block_vector,
5811 end_block_vector, block_stack);
5812 if (XEXP (cp, 2))
5813 block_vector = identify_blocks_1 (XEXP (cp, 2), block_vector,
5814 end_block_vector, block_stack);
5818 /* If there are more NOTE_INSN_BLOCK_BEGINs than NOTE_INSN_BLOCK_ENDs,
5819 something is badly wrong. */
5820 if (block_stack != orig_block_stack)
5821 abort ();
5823 return block_vector;
5826 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
5827 and create duplicate blocks. */
5828 /* ??? Need an option to either create block fragments or to create
5829 abstract origin duplicates of a source block. It really depends
5830 on what optimization has been performed. */
5832 void
5833 reorder_blocks ()
5835 tree block = DECL_INITIAL (current_function_decl);
5836 varray_type block_stack;
5838 if (block == NULL_TREE)
5839 return;
5841 VARRAY_TREE_INIT (block_stack, 10, "block_stack");
5843 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
5844 reorder_blocks_0 (block);
5846 /* Prune the old trees away, so that they don't get in the way. */
5847 BLOCK_SUBBLOCKS (block) = NULL_TREE;
5848 BLOCK_CHAIN (block) = NULL_TREE;
5850 /* Recreate the block tree from the note nesting. */
5851 reorder_blocks_1 (get_insns (), block, &block_stack);
5852 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
5854 /* Remove deleted blocks from the block fragment chains. */
5855 reorder_fix_fragments (block);
5858 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
5860 static void
5861 reorder_blocks_0 (block)
5862 tree block;
5864 while (block)
5866 TREE_ASM_WRITTEN (block) = 0;
5867 reorder_blocks_0 (BLOCK_SUBBLOCKS (block));
5868 block = BLOCK_CHAIN (block);
5872 static void
5873 reorder_blocks_1 (insns, current_block, p_block_stack)
5874 rtx insns;
5875 tree current_block;
5876 varray_type *p_block_stack;
5878 rtx insn;
5880 for (insn = insns; insn; insn = NEXT_INSN (insn))
5882 if (GET_CODE (insn) == NOTE)
5884 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5886 tree block = NOTE_BLOCK (insn);
5888 /* If we have seen this block before, that means it now
5889 spans multiple address regions. Create a new fragment. */
5890 if (TREE_ASM_WRITTEN (block))
5892 tree new_block = copy_node (block);
5893 tree origin;
5895 origin = (BLOCK_FRAGMENT_ORIGIN (block)
5896 ? BLOCK_FRAGMENT_ORIGIN (block)
5897 : block);
5898 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
5899 BLOCK_FRAGMENT_CHAIN (new_block)
5900 = BLOCK_FRAGMENT_CHAIN (origin);
5901 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
5903 NOTE_BLOCK (insn) = new_block;
5904 block = new_block;
5907 BLOCK_SUBBLOCKS (block) = 0;
5908 TREE_ASM_WRITTEN (block) = 1;
5909 BLOCK_SUPERCONTEXT (block) = current_block;
5910 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
5911 BLOCK_SUBBLOCKS (current_block) = block;
5912 current_block = block;
5913 VARRAY_PUSH_TREE (*p_block_stack, block);
5915 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
5917 NOTE_BLOCK (insn) = VARRAY_TOP_TREE (*p_block_stack);
5918 VARRAY_POP (*p_block_stack);
5919 BLOCK_SUBBLOCKS (current_block)
5920 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
5921 current_block = BLOCK_SUPERCONTEXT (current_block);
5924 else if (GET_CODE (insn) == CALL_INSN
5925 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
5927 rtx cp = PATTERN (insn);
5928 reorder_blocks_1 (XEXP (cp, 0), current_block, p_block_stack);
5929 if (XEXP (cp, 1))
5930 reorder_blocks_1 (XEXP (cp, 1), current_block, p_block_stack);
5931 if (XEXP (cp, 2))
5932 reorder_blocks_1 (XEXP (cp, 2), current_block, p_block_stack);
5937 /* Rationalize BLOCK_FRAGMENT_ORIGIN. If an origin block no longer
5938 appears in the block tree, select one of the fragments to become
5939 the new origin block. */
5941 static void
5942 reorder_fix_fragments (block)
5943 tree block;
5945 while (block)
5947 tree dup_origin = BLOCK_FRAGMENT_ORIGIN (block);
5948 tree new_origin = NULL_TREE;
5950 if (dup_origin)
5952 if (! TREE_ASM_WRITTEN (dup_origin))
5954 new_origin = BLOCK_FRAGMENT_CHAIN (dup_origin);
5956 /* Find the first of the remaining fragments. There must
5957 be at least one -- the current block. */
5958 while (! TREE_ASM_WRITTEN (new_origin))
5959 new_origin = BLOCK_FRAGMENT_CHAIN (new_origin);
5960 BLOCK_FRAGMENT_ORIGIN (new_origin) = NULL_TREE;
5963 else if (! dup_origin)
5964 new_origin = block;
5966 /* Re-root the rest of the fragments to the new origin. In the
5967 case that DUP_ORIGIN was null, that means BLOCK was the origin
5968 of a chain of fragments and we want to remove those fragments
5969 that didn't make it to the output. */
5970 if (new_origin)
5972 tree *pp = &BLOCK_FRAGMENT_CHAIN (new_origin);
5973 tree chain = *pp;
5975 while (chain)
5977 if (TREE_ASM_WRITTEN (chain))
5979 BLOCK_FRAGMENT_ORIGIN (chain) = new_origin;
5980 *pp = chain;
5981 pp = &BLOCK_FRAGMENT_CHAIN (chain);
5983 chain = BLOCK_FRAGMENT_CHAIN (chain);
5985 *pp = NULL_TREE;
5988 reorder_fix_fragments (BLOCK_SUBBLOCKS (block));
5989 block = BLOCK_CHAIN (block);
5993 /* Reverse the order of elements in the chain T of blocks,
5994 and return the new head of the chain (old last element). */
5996 static tree
5997 blocks_nreverse (t)
5998 tree t;
6000 tree prev = 0, decl, next;
6001 for (decl = t; decl; decl = next)
6003 next = BLOCK_CHAIN (decl);
6004 BLOCK_CHAIN (decl) = prev;
6005 prev = decl;
6007 return prev;
6010 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
6011 non-NULL, list them all into VECTOR, in a depth-first preorder
6012 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
6013 blocks. */
6015 static int
6016 all_blocks (block, vector)
6017 tree block;
6018 tree *vector;
6020 int n_blocks = 0;
6022 while (block)
6024 TREE_ASM_WRITTEN (block) = 0;
6026 /* Record this block. */
6027 if (vector)
6028 vector[n_blocks] = block;
6030 ++n_blocks;
6032 /* Record the subblocks, and their subblocks... */
6033 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
6034 vector ? vector + n_blocks : 0);
6035 block = BLOCK_CHAIN (block);
6038 return n_blocks;
6041 /* Return a vector containing all the blocks rooted at BLOCK. The
6042 number of elements in the vector is stored in N_BLOCKS_P. The
6043 vector is dynamically allocated; it is the caller's responsibility
6044 to call `free' on the pointer returned. */
6046 static tree *
6047 get_block_vector (block, n_blocks_p)
6048 tree block;
6049 int *n_blocks_p;
6051 tree *block_vector;
6053 *n_blocks_p = all_blocks (block, NULL);
6054 block_vector = (tree *) xmalloc (*n_blocks_p * sizeof (tree));
6055 all_blocks (block, block_vector);
6057 return block_vector;
6060 static int next_block_index = 2;
6062 /* Set BLOCK_NUMBER for all the blocks in FN. */
6064 void
6065 number_blocks (fn)
6066 tree fn;
6068 int i;
6069 int n_blocks;
6070 tree *block_vector;
6072 /* For SDB and XCOFF debugging output, we start numbering the blocks
6073 from 1 within each function, rather than keeping a running
6074 count. */
6075 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
6076 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
6077 next_block_index = 1;
6078 #endif
6080 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
6082 /* The top-level BLOCK isn't numbered at all. */
6083 for (i = 1; i < n_blocks; ++i)
6084 /* We number the blocks from two. */
6085 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
6087 free (block_vector);
6089 return;
6092 /* If VAR is present in a subblock of BLOCK, return the subblock. */
6094 tree
6095 debug_find_var_in_block_tree (var, block)
6096 tree var;
6097 tree block;
6099 tree t;
6101 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
6102 if (t == var)
6103 return block;
6105 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
6107 tree ret = debug_find_var_in_block_tree (var, t);
6108 if (ret)
6109 return ret;
6112 return NULL_TREE;
6115 /* Allocate a function structure and reset its contents to the defaults. */
6117 static void
6118 prepare_function_start ()
6120 cfun = (struct function *) ggc_alloc_cleared (sizeof (struct function));
6122 init_stmt_for_function ();
6123 init_eh_for_function ();
6125 cse_not_expected = ! optimize;
6127 /* Caller save not needed yet. */
6128 caller_save_needed = 0;
6130 /* No stack slots have been made yet. */
6131 stack_slot_list = 0;
6133 current_function_has_nonlocal_label = 0;
6134 current_function_has_nonlocal_goto = 0;
6136 /* There is no stack slot for handling nonlocal gotos. */
6137 nonlocal_goto_handler_slots = 0;
6138 nonlocal_goto_stack_level = 0;
6140 /* No labels have been declared for nonlocal use. */
6141 nonlocal_labels = 0;
6142 nonlocal_goto_handler_labels = 0;
6144 /* No function calls so far in this function. */
6145 function_call_count = 0;
6147 /* No parm regs have been allocated.
6148 (This is important for output_inline_function.) */
6149 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
6151 /* Initialize the RTL mechanism. */
6152 init_emit ();
6154 /* Initialize the queue of pending postincrement and postdecrements,
6155 and some other info in expr.c. */
6156 init_expr ();
6158 /* We haven't done register allocation yet. */
6159 reg_renumber = 0;
6161 init_varasm_status (cfun);
6163 /* Clear out data used for inlining. */
6164 cfun->inlinable = 0;
6165 cfun->original_decl_initial = 0;
6166 cfun->original_arg_vector = 0;
6168 cfun->stack_alignment_needed = STACK_BOUNDARY;
6169 cfun->preferred_stack_boundary = STACK_BOUNDARY;
6171 /* Set if a call to setjmp is seen. */
6172 current_function_calls_setjmp = 0;
6174 /* Set if a call to longjmp is seen. */
6175 current_function_calls_longjmp = 0;
6177 current_function_calls_alloca = 0;
6178 current_function_contains_functions = 0;
6179 current_function_is_leaf = 0;
6180 current_function_nothrow = 0;
6181 current_function_sp_is_unchanging = 0;
6182 current_function_uses_only_leaf_regs = 0;
6183 current_function_has_computed_jump = 0;
6184 current_function_is_thunk = 0;
6186 current_function_returns_pcc_struct = 0;
6187 current_function_returns_struct = 0;
6188 current_function_epilogue_delay_list = 0;
6189 current_function_uses_const_pool = 0;
6190 current_function_uses_pic_offset_table = 0;
6191 current_function_cannot_inline = 0;
6193 /* We have not yet needed to make a label to jump to for tail-recursion. */
6194 tail_recursion_label = 0;
6196 /* We haven't had a need to make a save area for ap yet. */
6197 arg_pointer_save_area = 0;
6199 /* No stack slots allocated yet. */
6200 frame_offset = 0;
6202 /* No SAVE_EXPRs in this function yet. */
6203 save_expr_regs = 0;
6205 /* No RTL_EXPRs in this function yet. */
6206 rtl_expr_chain = 0;
6208 /* Set up to allocate temporaries. */
6209 init_temp_slots ();
6211 /* Indicate that we need to distinguish between the return value of the
6212 present function and the return value of a function being called. */
6213 rtx_equal_function_value_matters = 1;
6215 /* Indicate that we have not instantiated virtual registers yet. */
6216 virtuals_instantiated = 0;
6218 /* Indicate that we want CONCATs now. */
6219 generating_concat_p = 1;
6221 /* Indicate we have no need of a frame pointer yet. */
6222 frame_pointer_needed = 0;
6224 /* By default assume not stdarg. */
6225 current_function_stdarg = 0;
6227 /* We haven't made any trampolines for this function yet. */
6228 trampoline_list = 0;
6230 init_pending_stack_adjust ();
6231 inhibit_defer_pop = 0;
6233 current_function_outgoing_args_size = 0;
6235 current_function_funcdef_no = funcdef_no++;
6237 cfun->arc_profile = profile_arc_flag || flag_test_coverage;
6239 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
6241 cfun->max_jumptable_ents = 0;
6243 (*lang_hooks.function.init) (cfun);
6244 if (init_machine_status)
6245 cfun->machine = (*init_machine_status) ();
6248 /* Initialize the rtl expansion mechanism so that we can do simple things
6249 like generate sequences. This is used to provide a context during global
6250 initialization of some passes. */
6251 void
6252 init_dummy_function_start ()
6254 prepare_function_start ();
6257 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
6258 and initialize static variables for generating RTL for the statements
6259 of the function. */
6261 void
6262 init_function_start (subr, filename, line)
6263 tree subr;
6264 const char *filename;
6265 int line;
6267 prepare_function_start ();
6269 current_function_name = (*lang_hooks.decl_printable_name) (subr, 2);
6270 cfun->decl = subr;
6272 /* Nonzero if this is a nested function that uses a static chain. */
6274 current_function_needs_context
6275 = (decl_function_context (current_function_decl) != 0
6276 && ! DECL_NO_STATIC_CHAIN (current_function_decl));
6278 /* Within function body, compute a type's size as soon it is laid out. */
6279 immediate_size_expand++;
6281 /* Prevent ever trying to delete the first instruction of a function.
6282 Also tell final how to output a linenum before the function prologue.
6283 Note linenums could be missing, e.g. when compiling a Java .class file. */
6284 if (line > 0)
6285 emit_line_note (filename, line);
6287 /* Make sure first insn is a note even if we don't want linenums.
6288 This makes sure the first insn will never be deleted.
6289 Also, final expects a note to appear there. */
6290 emit_note (NULL, NOTE_INSN_DELETED);
6292 /* Set flags used by final.c. */
6293 if (aggregate_value_p (DECL_RESULT (subr)))
6295 #ifdef PCC_STATIC_STRUCT_RETURN
6296 current_function_returns_pcc_struct = 1;
6297 #endif
6298 current_function_returns_struct = 1;
6301 /* Warn if this value is an aggregate type,
6302 regardless of which calling convention we are using for it. */
6303 if (warn_aggregate_return
6304 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
6305 warning ("function returns an aggregate");
6307 current_function_returns_pointer
6308 = POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (subr)));
6311 /* Make sure all values used by the optimization passes have sane
6312 defaults. */
6313 void
6314 init_function_for_compilation ()
6316 reg_renumber = 0;
6318 /* No prologue/epilogue insns yet. */
6319 VARRAY_GROW (prologue, 0);
6320 VARRAY_GROW (epilogue, 0);
6321 VARRAY_GROW (sibcall_epilogue, 0);
6324 /* Expand a call to __main at the beginning of a possible main function. */
6326 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
6327 #undef HAS_INIT_SECTION
6328 #define HAS_INIT_SECTION
6329 #endif
6331 void
6332 expand_main_function ()
6334 #ifdef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN
6335 if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN)
6337 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
6338 rtx tmp, seq;
6340 start_sequence ();
6341 /* Forcibly align the stack. */
6342 #ifdef STACK_GROWS_DOWNWARD
6343 tmp = expand_simple_binop (Pmode, AND, stack_pointer_rtx, GEN_INT(-align),
6344 stack_pointer_rtx, 1, OPTAB_WIDEN);
6345 #else
6346 tmp = expand_simple_binop (Pmode, PLUS, stack_pointer_rtx,
6347 GEN_INT (align - 1), NULL_RTX, 1, OPTAB_WIDEN);
6348 tmp = expand_simple_binop (Pmode, AND, tmp, GEN_INT (-align),
6349 stack_pointer_rtx, 1, OPTAB_WIDEN);
6350 #endif
6351 if (tmp != stack_pointer_rtx)
6352 emit_move_insn (stack_pointer_rtx, tmp);
6354 /* Enlist allocate_dynamic_stack_space to pick up the pieces. */
6355 tmp = force_reg (Pmode, const0_rtx);
6356 allocate_dynamic_stack_space (tmp, NULL_RTX, BIGGEST_ALIGNMENT);
6357 seq = get_insns ();
6358 end_sequence ();
6360 for (tmp = get_last_insn (); tmp; tmp = PREV_INSN (tmp))
6361 if (NOTE_P (tmp) && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_FUNCTION_BEG)
6362 break;
6363 if (tmp)
6364 emit_insn_before (seq, tmp);
6365 else
6366 emit_insn (seq);
6368 #endif
6370 #ifndef HAS_INIT_SECTION
6371 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, NAME__MAIN), LCT_NORMAL,
6372 VOIDmode, 0);
6373 #endif
6376 /* The PENDING_SIZES represent the sizes of variable-sized types.
6377 Create RTL for the various sizes now (using temporary variables),
6378 so that we can refer to the sizes from the RTL we are generating
6379 for the current function. The PENDING_SIZES are a TREE_LIST. The
6380 TREE_VALUE of each node is a SAVE_EXPR. */
6382 void
6383 expand_pending_sizes (pending_sizes)
6384 tree pending_sizes;
6386 tree tem;
6388 /* Evaluate now the sizes of any types declared among the arguments. */
6389 for (tem = pending_sizes; tem; tem = TREE_CHAIN (tem))
6391 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
6392 /* Flush the queue in case this parameter declaration has
6393 side-effects. */
6394 emit_queue ();
6398 /* Start the RTL for a new function, and set variables used for
6399 emitting RTL.
6400 SUBR is the FUNCTION_DECL node.
6401 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
6402 the function's parameters, which must be run at any return statement. */
6404 void
6405 expand_function_start (subr, parms_have_cleanups)
6406 tree subr;
6407 int parms_have_cleanups;
6409 tree tem;
6410 rtx last_ptr = NULL_RTX;
6412 /* Make sure volatile mem refs aren't considered
6413 valid operands of arithmetic insns. */
6414 init_recog_no_volatile ();
6416 current_function_instrument_entry_exit
6417 = (flag_instrument_function_entry_exit
6418 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6420 current_function_profile
6421 = (profile_flag
6422 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6424 current_function_limit_stack
6425 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
6427 /* If function gets a static chain arg, store it in the stack frame.
6428 Do this first, so it gets the first stack slot offset. */
6429 if (current_function_needs_context)
6431 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
6433 /* Delay copying static chain if it is not a register to avoid
6434 conflicts with regs used for parameters. */
6435 if (! SMALL_REGISTER_CLASSES
6436 || GET_CODE (static_chain_incoming_rtx) == REG)
6437 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6440 /* If the parameters of this function need cleaning up, get a label
6441 for the beginning of the code which executes those cleanups. This must
6442 be done before doing anything with return_label. */
6443 if (parms_have_cleanups)
6444 cleanup_label = gen_label_rtx ();
6445 else
6446 cleanup_label = 0;
6448 /* Make the label for return statements to jump to. Do not special
6449 case machines with special return instructions -- they will be
6450 handled later during jump, ifcvt, or epilogue creation. */
6451 return_label = gen_label_rtx ();
6453 /* Initialize rtx used to return the value. */
6454 /* Do this before assign_parms so that we copy the struct value address
6455 before any library calls that assign parms might generate. */
6457 /* Decide whether to return the value in memory or in a register. */
6458 if (aggregate_value_p (DECL_RESULT (subr)))
6460 /* Returning something that won't go in a register. */
6461 rtx value_address = 0;
6463 #ifdef PCC_STATIC_STRUCT_RETURN
6464 if (current_function_returns_pcc_struct)
6466 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
6467 value_address = assemble_static_space (size);
6469 else
6470 #endif
6472 /* Expect to be passed the address of a place to store the value.
6473 If it is passed as an argument, assign_parms will take care of
6474 it. */
6475 if (struct_value_incoming_rtx)
6477 value_address = gen_reg_rtx (Pmode);
6478 emit_move_insn (value_address, struct_value_incoming_rtx);
6481 if (value_address)
6483 rtx x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), value_address);
6484 set_mem_attributes (x, DECL_RESULT (subr), 1);
6485 SET_DECL_RTL (DECL_RESULT (subr), x);
6488 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
6489 /* If return mode is void, this decl rtl should not be used. */
6490 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
6491 else
6493 /* Compute the return values into a pseudo reg, which we will copy
6494 into the true return register after the cleanups are done. */
6496 /* In order to figure out what mode to use for the pseudo, we
6497 figure out what the mode of the eventual return register will
6498 actually be, and use that. */
6499 rtx hard_reg
6500 = hard_function_value (TREE_TYPE (DECL_RESULT (subr)),
6501 subr, 1);
6503 /* Structures that are returned in registers are not aggregate_value_p,
6504 so we may see a PARALLEL or a REG. */
6505 if (REG_P (hard_reg))
6506 SET_DECL_RTL (DECL_RESULT (subr), gen_reg_rtx (GET_MODE (hard_reg)));
6507 else if (GET_CODE (hard_reg) == PARALLEL)
6508 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
6509 else
6510 abort ();
6512 /* Set DECL_REGISTER flag so that expand_function_end will copy the
6513 result to the real return register(s). */
6514 DECL_REGISTER (DECL_RESULT (subr)) = 1;
6517 /* Initialize rtx for parameters and local variables.
6518 In some cases this requires emitting insns. */
6520 assign_parms (subr);
6522 /* Copy the static chain now if it wasn't a register. The delay is to
6523 avoid conflicts with the parameter passing registers. */
6525 if (SMALL_REGISTER_CLASSES && current_function_needs_context)
6526 if (GET_CODE (static_chain_incoming_rtx) != REG)
6527 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6529 /* The following was moved from init_function_start.
6530 The move is supposed to make sdb output more accurate. */
6531 /* Indicate the beginning of the function body,
6532 as opposed to parm setup. */
6533 emit_note (NULL, NOTE_INSN_FUNCTION_BEG);
6535 if (GET_CODE (get_last_insn ()) != NOTE)
6536 emit_note (NULL, NOTE_INSN_DELETED);
6537 parm_birth_insn = get_last_insn ();
6539 context_display = 0;
6540 if (current_function_needs_context)
6542 /* Fetch static chain values for containing functions. */
6543 tem = decl_function_context (current_function_decl);
6544 /* Copy the static chain pointer into a pseudo. If we have
6545 small register classes, copy the value from memory if
6546 static_chain_incoming_rtx is a REG. */
6547 if (tem)
6549 /* If the static chain originally came in a register, put it back
6550 there, then move it out in the next insn. The reason for
6551 this peculiar code is to satisfy function integration. */
6552 if (SMALL_REGISTER_CLASSES
6553 && GET_CODE (static_chain_incoming_rtx) == REG)
6554 emit_move_insn (static_chain_incoming_rtx, last_ptr);
6555 last_ptr = copy_to_reg (static_chain_incoming_rtx);
6558 while (tem)
6560 tree rtlexp = make_node (RTL_EXPR);
6562 RTL_EXPR_RTL (rtlexp) = last_ptr;
6563 context_display = tree_cons (tem, rtlexp, context_display);
6564 tem = decl_function_context (tem);
6565 if (tem == 0)
6566 break;
6567 /* Chain thru stack frames, assuming pointer to next lexical frame
6568 is found at the place we always store it. */
6569 #ifdef FRAME_GROWS_DOWNWARD
6570 last_ptr = plus_constant (last_ptr,
6571 -(HOST_WIDE_INT) GET_MODE_SIZE (Pmode));
6572 #endif
6573 last_ptr = gen_rtx_MEM (Pmode, memory_address (Pmode, last_ptr));
6574 set_mem_alias_set (last_ptr, get_frame_alias_set ());
6575 last_ptr = copy_to_reg (last_ptr);
6577 /* If we are not optimizing, ensure that we know that this
6578 piece of context is live over the entire function. */
6579 if (! optimize)
6580 save_expr_regs = gen_rtx_EXPR_LIST (VOIDmode, last_ptr,
6581 save_expr_regs);
6585 if (current_function_instrument_entry_exit)
6587 rtx fun = DECL_RTL (current_function_decl);
6588 if (GET_CODE (fun) == MEM)
6589 fun = XEXP (fun, 0);
6590 else
6591 abort ();
6592 emit_library_call (profile_function_entry_libfunc, LCT_NORMAL, VOIDmode,
6593 2, fun, Pmode,
6594 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
6596 hard_frame_pointer_rtx),
6597 Pmode);
6600 if (current_function_profile)
6602 #ifdef PROFILE_HOOK
6603 PROFILE_HOOK (current_function_funcdef_no);
6604 #endif
6607 /* After the display initializations is where the tail-recursion label
6608 should go, if we end up needing one. Ensure we have a NOTE here
6609 since some things (like trampolines) get placed before this. */
6610 tail_recursion_reentry = emit_note (NULL, NOTE_INSN_DELETED);
6612 /* Evaluate now the sizes of any types declared among the arguments. */
6613 expand_pending_sizes (nreverse (get_pending_sizes ()));
6615 /* Make sure there is a line number after the function entry setup code. */
6616 force_next_line_note ();
6619 /* Undo the effects of init_dummy_function_start. */
6620 void
6621 expand_dummy_function_end ()
6623 /* End any sequences that failed to be closed due to syntax errors. */
6624 while (in_sequence_p ())
6625 end_sequence ();
6627 /* Outside function body, can't compute type's actual size
6628 until next function's body starts. */
6630 free_after_parsing (cfun);
6631 free_after_compilation (cfun);
6632 cfun = 0;
6635 /* Call DOIT for each hard register used as a return value from
6636 the current function. */
6638 void
6639 diddle_return_value (doit, arg)
6640 void (*doit) PARAMS ((rtx, void *));
6641 void *arg;
6643 rtx outgoing = current_function_return_rtx;
6645 if (! outgoing)
6646 return;
6648 if (GET_CODE (outgoing) == REG)
6649 (*doit) (outgoing, arg);
6650 else if (GET_CODE (outgoing) == PARALLEL)
6652 int i;
6654 for (i = 0; i < XVECLEN (outgoing, 0); i++)
6656 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
6658 if (GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
6659 (*doit) (x, arg);
6664 static void
6665 do_clobber_return_reg (reg, arg)
6666 rtx reg;
6667 void *arg ATTRIBUTE_UNUSED;
6669 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
6672 void
6673 clobber_return_register ()
6675 diddle_return_value (do_clobber_return_reg, NULL);
6677 /* In case we do use pseudo to return value, clobber it too. */
6678 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
6680 tree decl_result = DECL_RESULT (current_function_decl);
6681 rtx decl_rtl = DECL_RTL (decl_result);
6682 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
6684 do_clobber_return_reg (decl_rtl, NULL);
6689 static void
6690 do_use_return_reg (reg, arg)
6691 rtx reg;
6692 void *arg ATTRIBUTE_UNUSED;
6694 emit_insn (gen_rtx_USE (VOIDmode, reg));
6697 void
6698 use_return_register ()
6700 diddle_return_value (do_use_return_reg, NULL);
6703 static GTY(()) rtx initial_trampoline;
6705 /* Generate RTL for the end of the current function.
6706 FILENAME and LINE are the current position in the source file.
6708 It is up to language-specific callers to do cleanups for parameters--
6709 or else, supply 1 for END_BINDINGS and we will call expand_end_bindings. */
6711 void
6712 expand_function_end (filename, line, end_bindings)
6713 const char *filename;
6714 int line;
6715 int end_bindings;
6717 tree link;
6718 rtx clobber_after;
6720 finish_expr_for_function ();
6722 /* If arg_pointer_save_area was referenced only from a nested
6723 function, we will not have initialized it yet. Do that now. */
6724 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
6725 get_arg_pointer_save_area (cfun);
6727 #ifdef NON_SAVING_SETJMP
6728 /* Don't put any variables in registers if we call setjmp
6729 on a machine that fails to restore the registers. */
6730 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
6732 if (DECL_INITIAL (current_function_decl) != error_mark_node)
6733 setjmp_protect (DECL_INITIAL (current_function_decl));
6735 setjmp_protect_args ();
6737 #endif
6739 /* Initialize any trampolines required by this function. */
6740 for (link = trampoline_list; link; link = TREE_CHAIN (link))
6742 tree function = TREE_PURPOSE (link);
6743 rtx context ATTRIBUTE_UNUSED = lookup_static_chain (function);
6744 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
6745 #ifdef TRAMPOLINE_TEMPLATE
6746 rtx blktramp;
6747 #endif
6748 rtx seq;
6750 #ifdef TRAMPOLINE_TEMPLATE
6751 /* First make sure this compilation has a template for
6752 initializing trampolines. */
6753 if (initial_trampoline == 0)
6755 initial_trampoline
6756 = gen_rtx_MEM (BLKmode, assemble_trampoline_template ());
6757 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
6759 #endif
6761 /* Generate insns to initialize the trampoline. */
6762 start_sequence ();
6763 tramp = round_trampoline_addr (XEXP (tramp, 0));
6764 #ifdef TRAMPOLINE_TEMPLATE
6765 blktramp = replace_equiv_address (initial_trampoline, tramp);
6766 emit_block_move (blktramp, initial_trampoline,
6767 GEN_INT (TRAMPOLINE_SIZE), BLOCK_OP_NORMAL);
6768 #endif
6769 INITIALIZE_TRAMPOLINE (tramp, XEXP (DECL_RTL (function), 0), context);
6770 seq = get_insns ();
6771 end_sequence ();
6773 /* Put those insns at entry to the containing function (this one). */
6774 emit_insn_before (seq, tail_recursion_reentry);
6777 /* If we are doing stack checking and this function makes calls,
6778 do a stack probe at the start of the function to ensure we have enough
6779 space for another stack frame. */
6780 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
6782 rtx insn, seq;
6784 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6785 if (GET_CODE (insn) == CALL_INSN)
6787 start_sequence ();
6788 probe_stack_range (STACK_CHECK_PROTECT,
6789 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
6790 seq = get_insns ();
6791 end_sequence ();
6792 emit_insn_before (seq, tail_recursion_reentry);
6793 break;
6797 /* Warn about unused parms if extra warnings were specified. */
6798 /* Either ``-Wextra -Wunused'' or ``-Wunused-parameter'' enables this
6799 warning. WARN_UNUSED_PARAMETER is negative when set by
6800 -Wunused. Note that -Wall implies -Wunused, so ``-Wall -Wextra'' will
6801 also give these warnings. */
6802 if (warn_unused_parameter > 0
6803 || (warn_unused_parameter < 0 && extra_warnings))
6805 tree decl;
6807 for (decl = DECL_ARGUMENTS (current_function_decl);
6808 decl; decl = TREE_CHAIN (decl))
6809 if (! TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
6810 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
6811 warning_with_decl (decl, "unused parameter `%s'");
6814 /* Delete handlers for nonlocal gotos if nothing uses them. */
6815 if (nonlocal_goto_handler_slots != 0
6816 && ! current_function_has_nonlocal_label)
6817 delete_handlers ();
6819 /* End any sequences that failed to be closed due to syntax errors. */
6820 while (in_sequence_p ())
6821 end_sequence ();
6823 /* Outside function body, can't compute type's actual size
6824 until next function's body starts. */
6825 immediate_size_expand--;
6827 clear_pending_stack_adjust ();
6828 do_pending_stack_adjust ();
6830 /* Mark the end of the function body.
6831 If control reaches this insn, the function can drop through
6832 without returning a value. */
6833 emit_note (NULL, NOTE_INSN_FUNCTION_END);
6835 /* Must mark the last line number note in the function, so that the test
6836 coverage code can avoid counting the last line twice. This just tells
6837 the code to ignore the immediately following line note, since there
6838 already exists a copy of this note somewhere above. This line number
6839 note is still needed for debugging though, so we can't delete it. */
6840 if (flag_test_coverage)
6841 emit_note (NULL, NOTE_INSN_REPEATED_LINE_NUMBER);
6843 /* Output a linenumber for the end of the function.
6844 SDB depends on this. */
6845 emit_line_note_force (filename, line);
6847 /* Before the return label (if any), clobber the return
6848 registers so that they are not propagated live to the rest of
6849 the function. This can only happen with functions that drop
6850 through; if there had been a return statement, there would
6851 have either been a return rtx, or a jump to the return label.
6853 We delay actual code generation after the current_function_value_rtx
6854 is computed. */
6855 clobber_after = get_last_insn ();
6857 /* Output the label for the actual return from the function,
6858 if one is expected. This happens either because a function epilogue
6859 is used instead of a return instruction, or because a return was done
6860 with a goto in order to run local cleanups, or because of pcc-style
6861 structure returning. */
6862 if (return_label)
6863 emit_label (return_label);
6865 /* C++ uses this. */
6866 if (end_bindings)
6867 expand_end_bindings (0, 0, 0);
6869 if (current_function_instrument_entry_exit)
6871 rtx fun = DECL_RTL (current_function_decl);
6872 if (GET_CODE (fun) == MEM)
6873 fun = XEXP (fun, 0);
6874 else
6875 abort ();
6876 emit_library_call (profile_function_exit_libfunc, LCT_NORMAL, VOIDmode,
6877 2, fun, Pmode,
6878 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
6880 hard_frame_pointer_rtx),
6881 Pmode);
6884 /* Let except.c know where it should emit the call to unregister
6885 the function context for sjlj exceptions. */
6886 if (flag_exceptions && USING_SJLJ_EXCEPTIONS)
6887 sjlj_emit_function_exit_after (get_last_insn ());
6889 /* If we had calls to alloca, and this machine needs
6890 an accurate stack pointer to exit the function,
6891 insert some code to save and restore the stack pointer. */
6892 #ifdef EXIT_IGNORE_STACK
6893 if (! EXIT_IGNORE_STACK)
6894 #endif
6895 if (current_function_calls_alloca)
6897 rtx tem = 0;
6899 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
6900 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
6903 /* If scalar return value was computed in a pseudo-reg, or was a named
6904 return value that got dumped to the stack, copy that to the hard
6905 return register. */
6906 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
6908 tree decl_result = DECL_RESULT (current_function_decl);
6909 rtx decl_rtl = DECL_RTL (decl_result);
6911 if (REG_P (decl_rtl)
6912 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
6913 : DECL_REGISTER (decl_result))
6915 rtx real_decl_rtl = current_function_return_rtx;
6917 /* This should be set in assign_parms. */
6918 if (! REG_FUNCTION_VALUE_P (real_decl_rtl))
6919 abort ();
6921 /* If this is a BLKmode structure being returned in registers,
6922 then use the mode computed in expand_return. Note that if
6923 decl_rtl is memory, then its mode may have been changed,
6924 but that current_function_return_rtx has not. */
6925 if (GET_MODE (real_decl_rtl) == BLKmode)
6926 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
6928 /* If a named return value dumped decl_return to memory, then
6929 we may need to re-do the PROMOTE_MODE signed/unsigned
6930 extension. */
6931 if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
6933 int unsignedp = TREE_UNSIGNED (TREE_TYPE (decl_result));
6935 #ifdef PROMOTE_FUNCTION_RETURN
6936 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
6937 &unsignedp, 1);
6938 #endif
6940 convert_move (real_decl_rtl, decl_rtl, unsignedp);
6942 else if (GET_CODE (real_decl_rtl) == PARALLEL)
6944 /* If expand_function_start has created a PARALLEL for decl_rtl,
6945 move the result to the real return registers. Otherwise, do
6946 a group load from decl_rtl for a named return. */
6947 if (GET_CODE (decl_rtl) == PARALLEL)
6948 emit_group_move (real_decl_rtl, decl_rtl);
6949 else
6950 emit_group_load (real_decl_rtl, decl_rtl,
6951 int_size_in_bytes (TREE_TYPE (decl_result)));
6953 else
6954 emit_move_insn (real_decl_rtl, decl_rtl);
6958 /* If returning a structure, arrange to return the address of the value
6959 in a place where debuggers expect to find it.
6961 If returning a structure PCC style,
6962 the caller also depends on this value.
6963 And current_function_returns_pcc_struct is not necessarily set. */
6964 if (current_function_returns_struct
6965 || current_function_returns_pcc_struct)
6967 rtx value_address
6968 = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
6969 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
6970 #ifdef FUNCTION_OUTGOING_VALUE
6971 rtx outgoing
6972 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
6973 current_function_decl);
6974 #else
6975 rtx outgoing
6976 = FUNCTION_VALUE (build_pointer_type (type), current_function_decl);
6977 #endif
6979 /* Mark this as a function return value so integrate will delete the
6980 assignment and USE below when inlining this function. */
6981 REG_FUNCTION_VALUE_P (outgoing) = 1;
6983 #ifdef POINTERS_EXTEND_UNSIGNED
6984 /* The address may be ptr_mode and OUTGOING may be Pmode. */
6985 if (GET_MODE (outgoing) != GET_MODE (value_address))
6986 value_address = convert_memory_address (GET_MODE (outgoing),
6987 value_address);
6988 #endif
6990 emit_move_insn (outgoing, value_address);
6992 /* Show return register used to hold result (in this case the address
6993 of the result. */
6994 current_function_return_rtx = outgoing;
6997 /* If this is an implementation of throw, do what's necessary to
6998 communicate between __builtin_eh_return and the epilogue. */
6999 expand_eh_return ();
7001 /* Emit the actual code to clobber return register. */
7003 rtx seq, after;
7005 start_sequence ();
7006 clobber_return_register ();
7007 seq = get_insns ();
7008 end_sequence ();
7010 after = emit_insn_after (seq, clobber_after);
7012 if (clobber_after != after)
7013 cfun->x_clobber_return_insn = after;
7016 /* ??? This should no longer be necessary since stupid is no longer with
7017 us, but there are some parts of the compiler (eg reload_combine, and
7018 sh mach_dep_reorg) that still try and compute their own lifetime info
7019 instead of using the general framework. */
7020 use_return_register ();
7022 /* Fix up any gotos that jumped out to the outermost
7023 binding level of the function.
7024 Must follow emitting RETURN_LABEL. */
7026 /* If you have any cleanups to do at this point,
7027 and they need to create temporary variables,
7028 then you will lose. */
7029 expand_fixups (get_insns ());
7033 get_arg_pointer_save_area (f)
7034 struct function *f;
7036 rtx ret = f->x_arg_pointer_save_area;
7038 if (! ret)
7040 ret = assign_stack_local_1 (Pmode, GET_MODE_SIZE (Pmode), 0, f);
7041 f->x_arg_pointer_save_area = ret;
7044 if (f == cfun && ! f->arg_pointer_save_area_init)
7046 rtx seq;
7048 /* Save the arg pointer at the beginning of the function. The
7049 generated stack slot may not be a valid memory address, so we
7050 have to check it and fix it if necessary. */
7051 start_sequence ();
7052 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
7053 seq = get_insns ();
7054 end_sequence ();
7056 push_topmost_sequence ();
7057 emit_insn_after (seq, get_insns ());
7058 pop_topmost_sequence ();
7061 return ret;
7064 /* Extend a vector that records the INSN_UIDs of INSNS
7065 (a list of one or more insns). */
7067 static void
7068 record_insns (insns, vecp)
7069 rtx insns;
7070 varray_type *vecp;
7072 int i, len;
7073 rtx tmp;
7075 tmp = insns;
7076 len = 0;
7077 while (tmp != NULL_RTX)
7079 len++;
7080 tmp = NEXT_INSN (tmp);
7083 i = VARRAY_SIZE (*vecp);
7084 VARRAY_GROW (*vecp, i + len);
7085 tmp = insns;
7086 while (tmp != NULL_RTX)
7088 VARRAY_INT (*vecp, i) = INSN_UID (tmp);
7089 i++;
7090 tmp = NEXT_INSN (tmp);
7094 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
7095 be running after reorg, SEQUENCE rtl is possible. */
7097 static int
7098 contains (insn, vec)
7099 rtx insn;
7100 varray_type vec;
7102 int i, j;
7104 if (GET_CODE (insn) == INSN
7105 && GET_CODE (PATTERN (insn)) == SEQUENCE)
7107 int count = 0;
7108 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
7109 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
7110 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == VARRAY_INT (vec, j))
7111 count++;
7112 return count;
7114 else
7116 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
7117 if (INSN_UID (insn) == VARRAY_INT (vec, j))
7118 return 1;
7120 return 0;
7124 prologue_epilogue_contains (insn)
7125 rtx insn;
7127 if (contains (insn, prologue))
7128 return 1;
7129 if (contains (insn, epilogue))
7130 return 1;
7131 return 0;
7135 sibcall_epilogue_contains (insn)
7136 rtx insn;
7138 if (sibcall_epilogue)
7139 return contains (insn, sibcall_epilogue);
7140 return 0;
7143 #ifdef HAVE_return
7144 /* Insert gen_return at the end of block BB. This also means updating
7145 block_for_insn appropriately. */
7147 static void
7148 emit_return_into_block (bb, line_note)
7149 basic_block bb;
7150 rtx line_note;
7152 emit_jump_insn_after (gen_return (), bb->end);
7153 if (line_note)
7154 emit_line_note_after (NOTE_SOURCE_FILE (line_note),
7155 NOTE_LINE_NUMBER (line_note), PREV_INSN (bb->end));
7157 #endif /* HAVE_return */
7159 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
7161 /* These functions convert the epilogue into a variant that does not modify the
7162 stack pointer. This is used in cases where a function returns an object
7163 whose size is not known until it is computed. The called function leaves the
7164 object on the stack, leaves the stack depressed, and returns a pointer to
7165 the object.
7167 What we need to do is track all modifications and references to the stack
7168 pointer, deleting the modifications and changing the references to point to
7169 the location the stack pointer would have pointed to had the modifications
7170 taken place.
7172 These functions need to be portable so we need to make as few assumptions
7173 about the epilogue as we can. However, the epilogue basically contains
7174 three things: instructions to reset the stack pointer, instructions to
7175 reload registers, possibly including the frame pointer, and an
7176 instruction to return to the caller.
7178 If we can't be sure of what a relevant epilogue insn is doing, we abort.
7179 We also make no attempt to validate the insns we make since if they are
7180 invalid, we probably can't do anything valid. The intent is that these
7181 routines get "smarter" as more and more machines start to use them and
7182 they try operating on different epilogues.
7184 We use the following structure to track what the part of the epilogue that
7185 we've already processed has done. We keep two copies of the SP equivalence,
7186 one for use during the insn we are processing and one for use in the next
7187 insn. The difference is because one part of a PARALLEL may adjust SP
7188 and the other may use it. */
7190 struct epi_info
7192 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
7193 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
7194 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
7195 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
7196 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
7197 should be set to once we no longer need
7198 its value. */
7201 static void handle_epilogue_set PARAMS ((rtx, struct epi_info *));
7202 static void emit_equiv_load PARAMS ((struct epi_info *));
7204 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
7205 no modifications to the stack pointer. Return the new list of insns. */
7207 static rtx
7208 keep_stack_depressed (insns)
7209 rtx insns;
7211 int j;
7212 struct epi_info info;
7213 rtx insn, next;
7215 /* If the epilogue is just a single instruction, it ust be OK as is. */
7217 if (NEXT_INSN (insns) == NULL_RTX)
7218 return insns;
7220 /* Otherwise, start a sequence, initialize the information we have, and
7221 process all the insns we were given. */
7222 start_sequence ();
7224 info.sp_equiv_reg = stack_pointer_rtx;
7225 info.sp_offset = 0;
7226 info.equiv_reg_src = 0;
7228 insn = insns;
7229 next = NULL_RTX;
7230 while (insn != NULL_RTX)
7232 next = NEXT_INSN (insn);
7234 if (!INSN_P (insn))
7236 add_insn (insn);
7237 insn = next;
7238 continue;
7241 /* If this insn references the register that SP is equivalent to and
7242 we have a pending load to that register, we must force out the load
7243 first and then indicate we no longer know what SP's equivalent is. */
7244 if (info.equiv_reg_src != 0
7245 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
7247 emit_equiv_load (&info);
7248 info.sp_equiv_reg = 0;
7251 info.new_sp_equiv_reg = info.sp_equiv_reg;
7252 info.new_sp_offset = info.sp_offset;
7254 /* If this is a (RETURN) and the return address is on the stack,
7255 update the address and change to an indirect jump. */
7256 if (GET_CODE (PATTERN (insn)) == RETURN
7257 || (GET_CODE (PATTERN (insn)) == PARALLEL
7258 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
7260 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
7261 rtx base = 0;
7262 HOST_WIDE_INT offset = 0;
7263 rtx jump_insn, jump_set;
7265 /* If the return address is in a register, we can emit the insn
7266 unchanged. Otherwise, it must be a MEM and we see what the
7267 base register and offset are. In any case, we have to emit any
7268 pending load to the equivalent reg of SP, if any. */
7269 if (GET_CODE (retaddr) == REG)
7271 emit_equiv_load (&info);
7272 add_insn (insn);
7273 insn = next;
7274 continue;
7276 else if (GET_CODE (retaddr) == MEM
7277 && GET_CODE (XEXP (retaddr, 0)) == REG)
7278 base = gen_rtx_REG (Pmode, REGNO (XEXP (retaddr, 0))), offset = 0;
7279 else if (GET_CODE (retaddr) == MEM
7280 && GET_CODE (XEXP (retaddr, 0)) == PLUS
7281 && GET_CODE (XEXP (XEXP (retaddr, 0), 0)) == REG
7282 && GET_CODE (XEXP (XEXP (retaddr, 0), 1)) == CONST_INT)
7284 base = gen_rtx_REG (Pmode, REGNO (XEXP (XEXP (retaddr, 0), 0)));
7285 offset = INTVAL (XEXP (XEXP (retaddr, 0), 1));
7287 else
7288 abort ();
7290 /* If the base of the location containing the return pointer
7291 is SP, we must update it with the replacement address. Otherwise,
7292 just build the necessary MEM. */
7293 retaddr = plus_constant (base, offset);
7294 if (base == stack_pointer_rtx)
7295 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
7296 plus_constant (info.sp_equiv_reg,
7297 info.sp_offset));
7299 retaddr = gen_rtx_MEM (Pmode, retaddr);
7301 /* If there is a pending load to the equivalent register for SP
7302 and we reference that register, we must load our address into
7303 a scratch register and then do that load. */
7304 if (info.equiv_reg_src
7305 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
7307 unsigned int regno;
7308 rtx reg;
7310 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
7311 if (HARD_REGNO_MODE_OK (regno, Pmode)
7312 && !fixed_regs[regno]
7313 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
7314 && !REGNO_REG_SET_P (EXIT_BLOCK_PTR->global_live_at_start,
7315 regno)
7316 && !refers_to_regno_p (regno,
7317 regno + HARD_REGNO_NREGS (regno,
7318 Pmode),
7319 info.equiv_reg_src, NULL))
7320 break;
7322 if (regno == FIRST_PSEUDO_REGISTER)
7323 abort ();
7325 reg = gen_rtx_REG (Pmode, regno);
7326 emit_move_insn (reg, retaddr);
7327 retaddr = reg;
7330 emit_equiv_load (&info);
7331 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
7333 /* Show the SET in the above insn is a RETURN. */
7334 jump_set = single_set (jump_insn);
7335 if (jump_set == 0)
7336 abort ();
7337 else
7338 SET_IS_RETURN_P (jump_set) = 1;
7341 /* If SP is not mentioned in the pattern and its equivalent register, if
7342 any, is not modified, just emit it. Otherwise, if neither is set,
7343 replace the reference to SP and emit the insn. If none of those are
7344 true, handle each SET individually. */
7345 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
7346 && (info.sp_equiv_reg == stack_pointer_rtx
7347 || !reg_set_p (info.sp_equiv_reg, insn)))
7348 add_insn (insn);
7349 else if (! reg_set_p (stack_pointer_rtx, insn)
7350 && (info.sp_equiv_reg == stack_pointer_rtx
7351 || !reg_set_p (info.sp_equiv_reg, insn)))
7353 if (! validate_replace_rtx (stack_pointer_rtx,
7354 plus_constant (info.sp_equiv_reg,
7355 info.sp_offset),
7356 insn))
7357 abort ();
7359 add_insn (insn);
7361 else if (GET_CODE (PATTERN (insn)) == SET)
7362 handle_epilogue_set (PATTERN (insn), &info);
7363 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
7365 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
7366 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
7367 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
7369 else
7370 add_insn (insn);
7372 info.sp_equiv_reg = info.new_sp_equiv_reg;
7373 info.sp_offset = info.new_sp_offset;
7375 insn = next;
7378 insns = get_insns ();
7379 end_sequence ();
7380 return insns;
7383 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
7384 structure that contains information about what we've seen so far. We
7385 process this SET by either updating that data or by emitting one or
7386 more insns. */
7388 static void
7389 handle_epilogue_set (set, p)
7390 rtx set;
7391 struct epi_info *p;
7393 /* First handle the case where we are setting SP. Record what it is being
7394 set from. If unknown, abort. */
7395 if (reg_set_p (stack_pointer_rtx, set))
7397 if (SET_DEST (set) != stack_pointer_rtx)
7398 abort ();
7400 if (GET_CODE (SET_SRC (set)) == PLUS
7401 && GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
7403 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
7404 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
7406 else
7407 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
7409 /* If we are adjusting SP, we adjust from the old data. */
7410 if (p->new_sp_equiv_reg == stack_pointer_rtx)
7412 p->new_sp_equiv_reg = p->sp_equiv_reg;
7413 p->new_sp_offset += p->sp_offset;
7416 if (p->new_sp_equiv_reg == 0 || GET_CODE (p->new_sp_equiv_reg) != REG)
7417 abort ();
7419 return;
7422 /* Next handle the case where we are setting SP's equivalent register.
7423 If we already have a value to set it to, abort. We could update, but
7424 there seems little point in handling that case. Note that we have
7425 to allow for the case where we are setting the register set in
7426 the previous part of a PARALLEL inside a single insn. But use the
7427 old offset for any updates within this insn. */
7428 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
7430 if (!rtx_equal_p (p->new_sp_equiv_reg, SET_DEST (set))
7431 || p->equiv_reg_src != 0)
7432 abort ();
7433 else
7434 p->equiv_reg_src
7435 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7436 plus_constant (p->sp_equiv_reg,
7437 p->sp_offset));
7440 /* Otherwise, replace any references to SP in the insn to its new value
7441 and emit the insn. */
7442 else
7444 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7445 plus_constant (p->sp_equiv_reg,
7446 p->sp_offset));
7447 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
7448 plus_constant (p->sp_equiv_reg,
7449 p->sp_offset));
7450 emit_insn (set);
7454 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
7456 static void
7457 emit_equiv_load (p)
7458 struct epi_info *p;
7460 if (p->equiv_reg_src != 0)
7461 emit_move_insn (p->sp_equiv_reg, p->equiv_reg_src);
7463 p->equiv_reg_src = 0;
7465 #endif
7467 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
7468 this into place with notes indicating where the prologue ends and where
7469 the epilogue begins. Update the basic block information when possible. */
7471 void
7472 thread_prologue_and_epilogue_insns (f)
7473 rtx f ATTRIBUTE_UNUSED;
7475 int inserted = 0;
7476 edge e;
7477 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
7478 rtx seq;
7479 #endif
7480 #ifdef HAVE_prologue
7481 rtx prologue_end = NULL_RTX;
7482 #endif
7483 #if defined (HAVE_epilogue) || defined(HAVE_return)
7484 rtx epilogue_end = NULL_RTX;
7485 #endif
7487 #ifdef HAVE_prologue
7488 if (HAVE_prologue)
7490 start_sequence ();
7491 seq = gen_prologue ();
7492 emit_insn (seq);
7494 /* Retain a map of the prologue insns. */
7495 record_insns (seq, &prologue);
7496 prologue_end = emit_note (NULL, NOTE_INSN_PROLOGUE_END);
7498 seq = get_insns ();
7499 end_sequence ();
7501 /* Can't deal with multiple successors of the entry block
7502 at the moment. Function should always have at least one
7503 entry point. */
7504 if (!ENTRY_BLOCK_PTR->succ || ENTRY_BLOCK_PTR->succ->succ_next)
7505 abort ();
7507 insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
7508 inserted = 1;
7510 #endif
7512 /* If the exit block has no non-fake predecessors, we don't need
7513 an epilogue. */
7514 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7515 if ((e->flags & EDGE_FAKE) == 0)
7516 break;
7517 if (e == NULL)
7518 goto epilogue_done;
7520 #ifdef HAVE_return
7521 if (optimize && HAVE_return)
7523 /* If we're allowed to generate a simple return instruction,
7524 then by definition we don't need a full epilogue. Examine
7525 the block that falls through to EXIT. If it does not
7526 contain any code, examine its predecessors and try to
7527 emit (conditional) return instructions. */
7529 basic_block last;
7530 edge e_next;
7531 rtx label;
7533 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7534 if (e->flags & EDGE_FALLTHRU)
7535 break;
7536 if (e == NULL)
7537 goto epilogue_done;
7538 last = e->src;
7540 /* Verify that there are no active instructions in the last block. */
7541 label = last->end;
7542 while (label && GET_CODE (label) != CODE_LABEL)
7544 if (active_insn_p (label))
7545 break;
7546 label = PREV_INSN (label);
7549 if (last->head == label && GET_CODE (label) == CODE_LABEL)
7551 rtx epilogue_line_note = NULL_RTX;
7553 /* Locate the line number associated with the closing brace,
7554 if we can find one. */
7555 for (seq = get_last_insn ();
7556 seq && ! active_insn_p (seq);
7557 seq = PREV_INSN (seq))
7558 if (GET_CODE (seq) == NOTE && NOTE_LINE_NUMBER (seq) > 0)
7560 epilogue_line_note = seq;
7561 break;
7564 for (e = last->pred; e; e = e_next)
7566 basic_block bb = e->src;
7567 rtx jump;
7569 e_next = e->pred_next;
7570 if (bb == ENTRY_BLOCK_PTR)
7571 continue;
7573 jump = bb->end;
7574 if ((GET_CODE (jump) != JUMP_INSN) || JUMP_LABEL (jump) != label)
7575 continue;
7577 /* If we have an unconditional jump, we can replace that
7578 with a simple return instruction. */
7579 if (simplejump_p (jump))
7581 emit_return_into_block (bb, epilogue_line_note);
7582 delete_insn (jump);
7585 /* If we have a conditional jump, we can try to replace
7586 that with a conditional return instruction. */
7587 else if (condjump_p (jump))
7589 rtx ret, *loc;
7591 ret = SET_SRC (PATTERN (jump));
7592 if (GET_CODE (XEXP (ret, 1)) == LABEL_REF)
7593 loc = &XEXP (ret, 1);
7594 else
7595 loc = &XEXP (ret, 2);
7596 ret = gen_rtx_RETURN (VOIDmode);
7598 if (! validate_change (jump, loc, ret, 0))
7599 continue;
7600 if (JUMP_LABEL (jump))
7601 LABEL_NUSES (JUMP_LABEL (jump))--;
7603 /* If this block has only one successor, it both jumps
7604 and falls through to the fallthru block, so we can't
7605 delete the edge. */
7606 if (bb->succ->succ_next == NULL)
7607 continue;
7609 else
7610 continue;
7612 /* Fix up the CFG for the successful change we just made. */
7613 redirect_edge_succ (e, EXIT_BLOCK_PTR);
7616 /* Emit a return insn for the exit fallthru block. Whether
7617 this is still reachable will be determined later. */
7619 emit_barrier_after (last->end);
7620 emit_return_into_block (last, epilogue_line_note);
7621 epilogue_end = last->end;
7622 last->succ->flags &= ~EDGE_FALLTHRU;
7623 goto epilogue_done;
7626 #endif
7627 #ifdef HAVE_epilogue
7628 if (HAVE_epilogue)
7630 /* Find the edge that falls through to EXIT. Other edges may exist
7631 due to RETURN instructions, but those don't need epilogues.
7632 There really shouldn't be a mixture -- either all should have
7633 been converted or none, however... */
7635 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7636 if (e->flags & EDGE_FALLTHRU)
7637 break;
7638 if (e == NULL)
7639 goto epilogue_done;
7641 start_sequence ();
7642 epilogue_end = emit_note (NULL, NOTE_INSN_EPILOGUE_BEG);
7644 seq = gen_epilogue ();
7646 #ifdef INCOMING_RETURN_ADDR_RTX
7647 /* If this function returns with the stack depressed and we can support
7648 it, massage the epilogue to actually do that. */
7649 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
7650 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
7651 seq = keep_stack_depressed (seq);
7652 #endif
7654 emit_jump_insn (seq);
7656 /* Retain a map of the epilogue insns. */
7657 record_insns (seq, &epilogue);
7659 seq = get_insns ();
7660 end_sequence ();
7662 insert_insn_on_edge (seq, e);
7663 inserted = 1;
7665 #endif
7666 epilogue_done:
7668 if (inserted)
7669 commit_edge_insertions ();
7671 #ifdef HAVE_sibcall_epilogue
7672 /* Emit sibling epilogues before any sibling call sites. */
7673 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7675 basic_block bb = e->src;
7676 rtx insn = bb->end;
7677 rtx i;
7678 rtx newinsn;
7680 if (GET_CODE (insn) != CALL_INSN
7681 || ! SIBLING_CALL_P (insn))
7682 continue;
7684 start_sequence ();
7685 emit_insn (gen_sibcall_epilogue ());
7686 seq = get_insns ();
7687 end_sequence ();
7689 /* Retain a map of the epilogue insns. Used in life analysis to
7690 avoid getting rid of sibcall epilogue insns. Do this before we
7691 actually emit the sequence. */
7692 record_insns (seq, &sibcall_epilogue);
7694 i = PREV_INSN (insn);
7695 newinsn = emit_insn_before (seq, insn);
7697 #endif
7699 #ifdef HAVE_prologue
7700 if (prologue_end)
7702 rtx insn, prev;
7704 /* GDB handles `break f' by setting a breakpoint on the first
7705 line note after the prologue. Which means (1) that if
7706 there are line number notes before where we inserted the
7707 prologue we should move them, and (2) we should generate a
7708 note before the end of the first basic block, if there isn't
7709 one already there.
7711 ??? This behavior is completely broken when dealing with
7712 multiple entry functions. We simply place the note always
7713 into first basic block and let alternate entry points
7714 to be missed.
7717 for (insn = prologue_end; insn; insn = prev)
7719 prev = PREV_INSN (insn);
7720 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7722 /* Note that we cannot reorder the first insn in the
7723 chain, since rest_of_compilation relies on that
7724 remaining constant. */
7725 if (prev == NULL)
7726 break;
7727 reorder_insns (insn, insn, prologue_end);
7731 /* Find the last line number note in the first block. */
7732 for (insn = ENTRY_BLOCK_PTR->next_bb->end;
7733 insn != prologue_end && insn;
7734 insn = PREV_INSN (insn))
7735 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7736 break;
7738 /* If we didn't find one, make a copy of the first line number
7739 we run across. */
7740 if (! insn)
7742 for (insn = next_active_insn (prologue_end);
7743 insn;
7744 insn = PREV_INSN (insn))
7745 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7747 emit_line_note_after (NOTE_SOURCE_FILE (insn),
7748 NOTE_LINE_NUMBER (insn),
7749 prologue_end);
7750 break;
7754 #endif
7755 #ifdef HAVE_epilogue
7756 if (epilogue_end)
7758 rtx insn, next;
7760 /* Similarly, move any line notes that appear after the epilogue.
7761 There is no need, however, to be quite so anal about the existence
7762 of such a note. */
7763 for (insn = epilogue_end; insn; insn = next)
7765 next = NEXT_INSN (insn);
7766 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7767 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
7770 #endif
7773 /* Reposition the prologue-end and epilogue-begin notes after instruction
7774 scheduling and delayed branch scheduling. */
7776 void
7777 reposition_prologue_and_epilogue_notes (f)
7778 rtx f ATTRIBUTE_UNUSED;
7780 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
7781 rtx insn, last, note;
7782 int len;
7784 if ((len = VARRAY_SIZE (prologue)) > 0)
7786 last = 0, note = 0;
7788 /* Scan from the beginning until we reach the last prologue insn.
7789 We apparently can't depend on basic_block_{head,end} after
7790 reorg has run. */
7791 for (insn = f; insn; insn = NEXT_INSN (insn))
7793 if (GET_CODE (insn) == NOTE)
7795 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
7796 note = insn;
7798 else if (contains (insn, prologue))
7800 last = insn;
7801 if (--len == 0)
7802 break;
7806 if (last)
7808 /* Find the prologue-end note if we haven't already, and
7809 move it to just after the last prologue insn. */
7810 if (note == 0)
7812 for (note = last; (note = NEXT_INSN (note));)
7813 if (GET_CODE (note) == NOTE
7814 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
7815 break;
7818 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
7819 if (GET_CODE (last) == CODE_LABEL)
7820 last = NEXT_INSN (last);
7821 reorder_insns (note, note, last);
7825 if ((len = VARRAY_SIZE (epilogue)) > 0)
7827 last = 0, note = 0;
7829 /* Scan from the end until we reach the first epilogue insn.
7830 We apparently can't depend on basic_block_{head,end} after
7831 reorg has run. */
7832 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
7834 if (GET_CODE (insn) == NOTE)
7836 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
7837 note = insn;
7839 else if (contains (insn, epilogue))
7841 last = insn;
7842 if (--len == 0)
7843 break;
7847 if (last)
7849 /* Find the epilogue-begin note if we haven't already, and
7850 move it to just before the first epilogue insn. */
7851 if (note == 0)
7853 for (note = insn; (note = PREV_INSN (note));)
7854 if (GET_CODE (note) == NOTE
7855 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
7856 break;
7859 if (PREV_INSN (last) != note)
7860 reorder_insns (note, note, PREV_INSN (last));
7863 #endif /* HAVE_prologue or HAVE_epilogue */
7866 /* Called once, at initialization, to initialize function.c. */
7868 void
7869 init_function_once ()
7871 VARRAY_INT_INIT (prologue, 0, "prologue");
7872 VARRAY_INT_INIT (epilogue, 0, "epilogue");
7873 VARRAY_INT_INIT (sibcall_epilogue, 0, "sibcall_epilogue");
7876 #include "gt-function.h"