1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1991, 1992 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file handles the generation of rtl code from tree structure
22 at the level of the function as a whole.
23 It creates the rtl expressions for parameters and auto variables
24 and has full responsibility for allocating stack slots.
26 `expand_function_start' is called at the beginning of a function,
27 before the function body is parsed, and `expand_function_end' is
28 called after parsing the body.
30 Call `assign_stack_local' to allocate a stack slot for a local variable.
31 This is usually done during the RTL generation for the function body,
32 but it can also be done in the reload pass when a pseudo-register does
33 not get a hard register.
35 Call `put_var_into_stack' when you learn, belatedly, that a variable
36 previously given a pseudo-register must in fact go in the stack.
37 This function changes the DECL_RTL to be a stack slot instead of a reg
38 then scans all the RTL instructions so far generated to correct them. */
48 #include "insn-flags.h"
50 #include "insn-codes.h"
52 #include "hard-reg-set.h"
53 #include "insn-config.h"
56 #include "basic-block.h"
58 /* Round a value to the lowest integer less than it that is a multiple of
59 the required alignment. Avoid using division in case the value is
60 negative. Assume the alignment is a power of two. */
61 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
63 /* Similar, but round to the next highest integer that meets the
65 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
67 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
68 during rtl generation. If they are different register numbers, this is
69 always true. It may also be true if
70 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
71 generation. See fix_lexical_addr for details. */
73 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
74 #define NEED_SEPARATE_AP
77 /* Number of bytes of args popped by function being compiled on its return.
78 Zero if no bytes are to be popped.
79 May affect compilation of return insn or of function epilogue. */
81 int current_function_pops_args;
83 /* Nonzero if function being compiled needs to be given an address
84 where the value should be stored. */
86 int current_function_returns_struct;
88 /* Nonzero if function being compiled needs to
89 return the address of where it has put a structure value. */
91 int current_function_returns_pcc_struct;
93 /* Nonzero if function being compiled needs to be passed a static chain. */
95 int current_function_needs_context;
97 /* Nonzero if function being compiled can call setjmp. */
99 int current_function_calls_setjmp;
101 /* Nonzero if function being compiled can call longjmp. */
103 int current_function_calls_longjmp;
105 /* Nonzero if function being compiled receives nonlocal gotos
106 from nested functions. */
108 int current_function_has_nonlocal_label;
110 /* Nonzero if function being compiled contains nested functions. */
112 int current_function_contains_functions;
114 /* Nonzero if function being compiled can call alloca,
115 either as a subroutine or builtin. */
117 int current_function_calls_alloca;
119 /* Nonzero if the current function returns a pointer type */
121 int current_function_returns_pointer;
123 /* If some insns can be deferred to the delay slots of the epilogue, the
124 delay list for them is recorded here. */
126 rtx current_function_epilogue_delay_list;
128 /* If function's args have a fixed size, this is that size, in bytes.
130 May affect compilation of return insn or of function epilogue. */
132 int current_function_args_size;
134 /* # bytes the prologue should push and pretend that the caller pushed them.
135 The prologue must do this, but only if parms can be passed in registers. */
137 int current_function_pretend_args_size;
139 /* # of bytes of outgoing arguments required to be pushed by the prologue.
140 If this is non-zero, it means that ACCUMULATE_OUTGOING_ARGS was defined
141 and no stack adjusts will be done on function calls. */
143 int current_function_outgoing_args_size;
145 /* This is the offset from the arg pointer to the place where the first
146 anonymous arg can be found, if there is one. */
148 rtx current_function_arg_offset_rtx;
150 /* Nonzero if current function uses varargs.h or equivalent.
151 Zero for functions that use stdarg.h. */
153 int current_function_varargs;
155 /* Quantities of various kinds of registers
156 used for the current function's args. */
158 CUMULATIVE_ARGS current_function_args_info;
160 /* Name of function now being compiled. */
162 char *current_function_name;
164 /* If non-zero, an RTL expression for that location at which the current
165 function returns its result. Always equal to
166 DECL_RTL (DECL_RESULT (current_function_decl)), but provided
167 independently of the tree structures. */
169 rtx current_function_return_rtx;
171 /* Nonzero if the current function uses the constant pool. */
173 int current_function_uses_const_pool;
175 /* Nonzero if the current function uses pic_offset_table_rtx. */
176 int current_function_uses_pic_offset_table;
178 /* The arg pointer hard register, or the pseudo into which it was copied. */
179 rtx current_function_internal_arg_pointer;
181 /* The FUNCTION_DECL for an inline function currently being expanded. */
182 tree inline_function_decl;
184 /* Number of function calls seen so far in current function. */
186 int function_call_count;
188 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
189 (labels to which there can be nonlocal gotos from nested functions)
192 tree nonlocal_labels;
194 /* RTX for stack slot that holds the current handler for nonlocal gotos.
195 Zero when function does not have nonlocal labels. */
197 rtx nonlocal_goto_handler_slot;
199 /* RTX for stack slot that holds the stack pointer value to restore
201 Zero when function does not have nonlocal labels. */
203 rtx nonlocal_goto_stack_level;
205 /* Label that will go on parm cleanup code, if any.
206 Jumping to this label runs cleanup code for parameters, if
207 such code must be run. Following this code is the logical return label. */
211 /* Label that will go on function epilogue.
212 Jumping to this label serves as a "return" instruction
213 on machines which require execution of the epilogue on all returns. */
217 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
218 So we can mark them all live at the end of the function, if nonopt. */
221 /* List (chain of EXPR_LISTs) of all stack slots in this function.
222 Made for the sake of unshare_all_rtl. */
225 /* Chain of all RTL_EXPRs that have insns in them. */
228 /* Label to jump back to for tail recursion, or 0 if we have
229 not yet needed one for this function. */
230 rtx tail_recursion_label;
232 /* Place after which to insert the tail_recursion_label if we need one. */
233 rtx tail_recursion_reentry;
235 /* Location at which to save the argument pointer if it will need to be
236 referenced. There are two cases where this is done: if nonlocal gotos
237 exist, or if vars stored at an offset from the argument pointer will be
238 needed by inner routines. */
240 rtx arg_pointer_save_area;
242 /* Offset to end of allocated area of stack frame.
243 If stack grows down, this is the address of the last stack slot allocated.
244 If stack grows up, this is the address for the next slot. */
247 /* List (chain of TREE_LISTs) of static chains for containing functions.
248 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
249 in an RTL_EXPR in the TREE_VALUE. */
250 static tree context_display;
252 /* List (chain of TREE_LISTs) of trampolines for nested functions.
253 The trampoline sets up the static chain and jumps to the function.
254 We supply the trampoline's address when the function's address is requested.
256 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
257 in an RTL_EXPR in the TREE_VALUE. */
258 static tree trampoline_list;
260 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
261 static rtx parm_birth_insn;
264 /* Nonzero if a stack slot has been generated whose address is not
265 actually valid. It means that the generated rtl must all be scanned
266 to detect and correct the invalid addresses where they occur. */
267 static int invalid_stack_slot;
270 /* Last insn of those whose job was to put parms into their nominal homes. */
271 static rtx last_parm_insn;
273 /* 1 + last pseudo register number used for loading a copy
274 of a parameter of this function. */
275 static int max_parm_reg;
277 /* Vector indexed by REGNO, containing location on stack in which
278 to put the parm which is nominally in pseudo register REGNO,
279 if we discover that that parm must go in the stack. */
280 static rtx *parm_reg_stack_loc;
282 #if 0 /* Turned off because 0 seems to work just as well. */
283 /* Cleanup lists are required for binding levels regardless of whether
284 that binding level has cleanups or not. This node serves as the
285 cleanup list whenever an empty list is required. */
286 static tree empty_cleanup_list;
289 /* Nonzero once virtual register instantiation has been done.
290 assign_stack_local uses frame_pointer_rtx when this is nonzero. */
291 static int virtuals_instantiated;
293 /* Nonzero if we need to distinguish between the return value of this function
294 and the return value of a function called by this function. This helps
297 extern int rtx_equal_function_value_matters;
301 static tree round_down ();
302 static rtx round_trampoline_addr ();
303 static rtx fixup_stack_1 ();
304 static void fixup_var_refs ();
305 static void fixup_var_refs_insns ();
306 static void fixup_var_refs_1 ();
307 static void optimize_bit_field ();
308 static void instantiate_decls ();
309 static void instantiate_decls_1 ();
310 static void instantiate_decl ();
311 static int instantiate_virtual_regs_1 ();
312 static rtx fixup_memory_subreg ();
313 static rtx walk_fixup_memory_subreg ();
315 /* In order to evaluate some expressions, such as function calls returning
316 structures in memory, we need to temporarily allocate stack locations.
317 We record each allocated temporary in the following structure.
319 Associated with each temporary slot is a nesting level. When we pop up
320 one level, all temporaries associated with the previous level are freed.
321 Normally, all temporaries are freed after the execution of the statement
322 in which they were created. However, if we are inside a ({...}) grouping,
323 the result may be in a temporary and hence must be preserved. If the
324 result could be in a temporary, we preserve it if we can determine which
325 one it is in. If we cannot determine which temporary may contain the
326 result, all temporaries are preserved. A temporary is preserved by
327 pretending it was allocated at the previous nesting level.
329 Automatic variables are also assigned temporary slots, at the nesting
330 level where they are defined. They are marked a "kept" so that
331 free_temp_slots will not free them. */
335 /* Points to next temporary slot. */
336 struct temp_slot *next;
337 /* The rtx to used to reference the slot. */
339 /* The size, in units, of the slot. */
341 /* Non-zero if this temporary is currently in use. */
343 /* Nesting level at which this slot is being used. */
345 /* Non-zero if this should survive a call to free_temp_slots. */
349 /* List of all temporaries allocated, both available and in use. */
351 struct temp_slot *temp_slots;
353 /* Current nesting level for temporaries. */
357 /* Pointer to chain of `struct function' for containing functions. */
358 struct function *outer_function_chain;
360 /* Given a function decl for a containing function,
361 return the `struct function' for it. */
364 find_function_data (decl)
368 for (p = outer_function_chain; p; p = p->next)
374 /* Save the current context for compilation of a nested function.
375 This is called from language-specific code.
376 The caller is responsible for saving any language-specific status,
377 since this function knows only about language-independent variables. */
380 push_function_context ()
382 struct function *p = (struct function *) xmalloc (sizeof (struct function));
384 p->next = outer_function_chain;
385 outer_function_chain = p;
387 p->name = current_function_name;
388 p->decl = current_function_decl;
389 p->pops_args = current_function_pops_args;
390 p->returns_struct = current_function_returns_struct;
391 p->returns_pcc_struct = current_function_returns_pcc_struct;
392 p->needs_context = current_function_needs_context;
393 p->calls_setjmp = current_function_calls_setjmp;
394 p->calls_longjmp = current_function_calls_longjmp;
395 p->calls_alloca = current_function_calls_alloca;
396 p->has_nonlocal_label = current_function_has_nonlocal_label;
397 p->args_size = current_function_args_size;
398 p->pretend_args_size = current_function_pretend_args_size;
399 p->arg_offset_rtx = current_function_arg_offset_rtx;
400 p->uses_const_pool = current_function_uses_const_pool;
401 p->uses_pic_offset_table = current_function_uses_pic_offset_table;
402 p->internal_arg_pointer = current_function_internal_arg_pointer;
403 p->max_parm_reg = max_parm_reg;
404 p->parm_reg_stack_loc = parm_reg_stack_loc;
405 p->outgoing_args_size = current_function_outgoing_args_size;
406 p->return_rtx = current_function_return_rtx;
407 p->nonlocal_goto_handler_slot = nonlocal_goto_handler_slot;
408 p->nonlocal_goto_stack_level = nonlocal_goto_stack_level;
409 p->nonlocal_labels = nonlocal_labels;
410 p->cleanup_label = cleanup_label;
411 p->return_label = return_label;
412 p->save_expr_regs = save_expr_regs;
413 p->stack_slot_list = stack_slot_list;
414 p->parm_birth_insn = parm_birth_insn;
415 p->frame_offset = frame_offset;
416 p->tail_recursion_label = tail_recursion_label;
417 p->tail_recursion_reentry = tail_recursion_reentry;
418 p->arg_pointer_save_area = arg_pointer_save_area;
419 p->rtl_expr_chain = rtl_expr_chain;
420 p->last_parm_insn = last_parm_insn;
421 p->context_display = context_display;
422 p->trampoline_list = trampoline_list;
423 p->function_call_count = function_call_count;
424 p->temp_slots = temp_slots;
425 p->temp_slot_level = temp_slot_level;
426 p->fixup_var_refs_queue = 0;
427 p->epilogue_delay_list = current_function_epilogue_delay_list;
429 save_tree_status (p);
430 save_storage_status (p);
431 save_emit_status (p);
433 save_expr_status (p);
434 save_stmt_status (p);
435 save_varasm_status (p);
438 /* Restore the last saved context, at the end of a nested function.
439 This function is called from language-specific code. */
442 pop_function_context ()
444 struct function *p = outer_function_chain;
446 outer_function_chain = p->next;
448 current_function_name = p->name;
449 current_function_decl = p->decl;
450 current_function_pops_args = p->pops_args;
451 current_function_returns_struct = p->returns_struct;
452 current_function_returns_pcc_struct = p->returns_pcc_struct;
453 current_function_needs_context = p->needs_context;
454 current_function_calls_setjmp = p->calls_setjmp;
455 current_function_calls_longjmp = p->calls_longjmp;
456 current_function_calls_alloca = p->calls_alloca;
457 current_function_has_nonlocal_label = p->has_nonlocal_label;
458 current_function_contains_functions = 1;
459 current_function_args_size = p->args_size;
460 current_function_pretend_args_size = p->pretend_args_size;
461 current_function_arg_offset_rtx = p->arg_offset_rtx;
462 current_function_uses_const_pool = p->uses_const_pool;
463 current_function_uses_pic_offset_table = p->uses_pic_offset_table;
464 current_function_internal_arg_pointer = p->internal_arg_pointer;
465 max_parm_reg = p->max_parm_reg;
466 parm_reg_stack_loc = p->parm_reg_stack_loc;
467 current_function_outgoing_args_size = p->outgoing_args_size;
468 current_function_return_rtx = p->return_rtx;
469 nonlocal_goto_handler_slot = p->nonlocal_goto_handler_slot;
470 nonlocal_goto_stack_level = p->nonlocal_goto_stack_level;
471 nonlocal_labels = p->nonlocal_labels;
472 cleanup_label = p->cleanup_label;
473 return_label = p->return_label;
474 save_expr_regs = p->save_expr_regs;
475 stack_slot_list = p->stack_slot_list;
476 parm_birth_insn = p->parm_birth_insn;
477 frame_offset = p->frame_offset;
478 tail_recursion_label = p->tail_recursion_label;
479 tail_recursion_reentry = p->tail_recursion_reentry;
480 arg_pointer_save_area = p->arg_pointer_save_area;
481 rtl_expr_chain = p->rtl_expr_chain;
482 last_parm_insn = p->last_parm_insn;
483 context_display = p->context_display;
484 trampoline_list = p->trampoline_list;
485 function_call_count = p->function_call_count;
486 temp_slots = p->temp_slots;
487 temp_slot_level = p->temp_slot_level;
488 current_function_epilogue_delay_list = p->epilogue_delay_list;
490 restore_tree_status (p);
491 restore_storage_status (p);
492 restore_expr_status (p);
493 restore_emit_status (p);
494 restore_stmt_status (p);
495 restore_varasm_status (p);
497 /* Finish doing put_var_into_stack for any of our variables
498 which became addressable during the nested function. */
500 struct var_refs_queue *queue = p->fixup_var_refs_queue;
501 for (; queue; queue = queue->next)
502 fixup_var_refs (queue->modified, queue->promoted_mode, queue->unsignedp);
507 /* Reset variables that have known state during rtx generation. */
508 rtx_equal_function_value_matters = 1;
509 virtuals_instantiated = 0;
512 /* Allocate fixed slots in the stack frame of the current function. */
514 /* Return size needed for stack frame based on slots so far allocated.
515 This size counts from zero. It is not rounded to STACK_BOUNDARY;
516 the caller may have to do that. */
521 #ifdef FRAME_GROWS_DOWNWARD
522 return -frame_offset;
528 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
529 with machine mode MODE.
531 ALIGN controls the amount of alignment for the address of the slot:
532 0 means according to MODE,
533 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
534 positive specifies alignment boundary in bits.
536 We do not round to stack_boundary here. */
539 assign_stack_local (mode, size, align)
540 enum machine_mode mode;
544 register rtx x, addr;
545 int bigend_correction = 0;
550 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
552 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
554 else if (align == -1)
556 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
557 size = CEIL_ROUND (size, alignment);
560 alignment = align / BITS_PER_UNIT;
562 /* Round frame offset to that alignment.
563 We must be careful here, since FRAME_OFFSET might be negative and
564 division with a negative dividend isn't as well defined as we might
565 like. So we instead assume that ALIGNMENT is a power of two and
566 use logical operations which are unambiguous. */
567 #ifdef FRAME_GROWS_DOWNWARD
568 frame_offset = FLOOR_ROUND (frame_offset, alignment);
570 frame_offset = CEIL_ROUND (frame_offset, alignment);
573 /* On a big-endian machine, if we are allocating more space than we will use,
574 use the least significant bytes of those that are allocated. */
577 bigend_correction = size - GET_MODE_SIZE (mode);
580 #ifdef FRAME_GROWS_DOWNWARD
581 frame_offset -= size;
584 /* If we have already instantiated virtual registers, return the actual
585 address relative to the frame pointer. */
586 if (virtuals_instantiated)
587 addr = plus_constant (frame_pointer_rtx,
588 (frame_offset + bigend_correction
589 + STARTING_FRAME_OFFSET));
591 addr = plus_constant (virtual_stack_vars_rtx,
592 frame_offset + bigend_correction);
594 #ifndef FRAME_GROWS_DOWNWARD
595 frame_offset += size;
598 x = gen_rtx (MEM, mode, addr);
600 stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, x, stack_slot_list);
605 /* Assign a stack slot in a containing function.
606 First three arguments are same as in preceding function.
607 The last argument specifies the function to allocate in. */
610 assign_outer_stack_local (mode, size, align, function)
611 enum machine_mode mode;
614 struct function *function;
616 register rtx x, addr;
617 int bigend_correction = 0;
620 /* Allocate in the memory associated with the function in whose frame
622 push_obstacks (function->function_obstack,
623 function->function_maybepermanent_obstack);
627 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
629 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
631 else if (align == -1)
633 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
634 size = CEIL_ROUND (size, alignment);
637 alignment = align / BITS_PER_UNIT;
639 /* Round frame offset to that alignment. */
640 #ifdef FRAME_GROWS_DOWNWARD
641 function->frame_offset = FLOOR_ROUND (function->frame_offset, alignment);
643 function->frame_offset = CEIL_ROUND (function->frame_offset, alignment);
646 /* On a big-endian machine, if we are allocating more space than we will use,
647 use the least significant bytes of those that are allocated. */
650 bigend_correction = size - GET_MODE_SIZE (mode);
653 #ifdef FRAME_GROWS_DOWNWARD
654 function->frame_offset -= size;
656 addr = plus_constant (virtual_stack_vars_rtx,
657 function->frame_offset + bigend_correction);
658 #ifndef FRAME_GROWS_DOWNWARD
659 function->frame_offset += size;
662 x = gen_rtx (MEM, mode, addr);
664 function->stack_slot_list
665 = gen_rtx (EXPR_LIST, VOIDmode, x, function->stack_slot_list);
672 /* Allocate a temporary stack slot and record it for possible later
675 MODE is the machine mode to be given to the returned rtx.
677 SIZE is the size in units of the space required. We do no rounding here
678 since assign_stack_local will do any required rounding.
680 KEEP is non-zero if this slot is to be retained after a call to
681 free_temp_slots. Automatic variables for a block are allocated with this
685 assign_stack_temp (mode, size, keep)
686 enum machine_mode mode;
690 struct temp_slot *p, *best_p = 0;
692 /* First try to find an available, already-allocated temporary that is the
693 exact size we require. */
694 for (p = temp_slots; p; p = p->next)
695 if (p->size == size && GET_MODE (p->slot) == mode && ! p->in_use)
698 /* If we didn't find, one, try one that is larger than what we want. We
699 find the smallest such. */
701 for (p = temp_slots; p; p = p->next)
702 if (p->size > size && GET_MODE (p->slot) == mode && ! p->in_use
703 && (best_p == 0 || best_p->size > p->size))
706 /* Make our best, if any, the one to use. */
710 /* If we still didn't find one, make a new temporary. */
713 p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
715 /* If the temp slot mode doesn't indicate the alignment,
716 use the largest possible, so no one will be disappointed. */
717 p->slot = assign_stack_local (mode, size, mode == BLKmode ? -1 : 0);
718 p->next = temp_slots;
723 p->level = temp_slot_level;
728 /* If X could be a reference to a temporary slot, mark that slot as belonging
729 to the to one level higher. If X matched one of our slots, just mark that
730 one. Otherwise, we can't easily predict which it is, so upgrade all of
731 them. Kept slots need not be touched.
733 This is called when an ({...}) construct occurs and a statement
734 returns a value in memory. */
737 preserve_temp_slots (x)
742 /* If X is not in memory or is at a constant address, it cannot be in
744 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
747 /* First see if we can find a match. */
748 for (p = temp_slots; p; p = p->next)
749 if (p->in_use && x == p->slot)
755 /* Otherwise, preserve all non-kept slots at this level. */
756 for (p = temp_slots; p; p = p->next)
757 if (p->in_use && p->level == temp_slot_level && ! p->keep)
761 /* Free all temporaries used so far. This is normally called at the end
762 of generating code for a statement. */
769 for (p = temp_slots; p; p = p->next)
770 if (p->in_use && p->level == temp_slot_level && ! p->keep)
774 /* Push deeper into the nesting level for stack temporaries. */
779 /* For GNU C++, we must allow a sequence to be emitted anywhere in
780 the level where the sequence was started. By not changing levels
781 when the compiler is inside a sequence, the temporaries for the
782 sequence and the temporaries will not unwittingly conflict with
783 the temporaries for other sequences and/or code at that level. */
784 if (in_sequence_p ())
790 /* Pop a temporary nesting level. All slots in use in the current level
798 /* See comment in push_temp_slots about why we don't change levels
800 if (in_sequence_p ())
803 for (p = temp_slots; p; p = p->next)
804 if (p->in_use && p->level == temp_slot_level)
810 /* Retroactively move an auto variable from a register to a stack slot.
811 This is done when an address-reference to the variable is seen. */
814 put_var_into_stack (decl)
818 register rtx new = 0;
819 enum machine_mode promoted_mode, decl_mode;
820 struct function *function = 0;
821 tree context = decl_function_context (decl);
823 /* Get the current rtl used for this object and it's original mode. */
824 reg = TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl) : DECL_RTL (decl);
826 /* No need to do anything if decl has no rtx yet
827 since in that case caller is setting TREE_ADDRESSABLE
828 and a stack slot will be assigned when the rtl is made. */
832 /* Get the declared mode for this object. */
833 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
835 /* Get the mode it's actually stored in. */
836 promoted_mode = GET_MODE (reg);
838 /* If this variable comes from an outer function,
839 find that function's saved context. */
840 if (context != current_function_decl)
841 for (function = outer_function_chain; function; function = function->next)
842 if (function->decl == context)
845 /* If this is a variable-size object with a pseudo to address it,
846 put that pseudo into the stack, if the var is nonlocal. */
847 if (DECL_NONLOCAL (decl)
848 && GET_CODE (reg) == MEM
849 && GET_CODE (XEXP (reg, 0)) == REG
850 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
853 decl_mode = promoted_mode = GET_MODE (reg);
855 if (GET_CODE (reg) != REG)
860 if (REGNO (reg) < function->max_parm_reg)
861 new = function->parm_reg_stack_loc[REGNO (reg)];
863 new = assign_outer_stack_local (GET_MODE (reg),
864 GET_MODE_SIZE (decl_mode),
869 if (REGNO (reg) < max_parm_reg)
870 new = parm_reg_stack_loc[REGNO (reg)];
872 new = assign_stack_local (GET_MODE (reg),
873 GET_MODE_SIZE (decl_mode), 0);
876 XEXP (reg, 0) = XEXP (new, 0);
877 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
878 REG_USERVAR_P (reg) = 0;
880 PUT_MODE (reg, decl_mode);
882 /* If this is a memory ref that contains aggregate components,
883 mark it as such for cse and loop optimize. */
884 MEM_IN_STRUCT_P (reg)
885 = (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
886 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
887 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE);
889 /* Now make sure that all refs to the variable, previously made
890 when it was a register, are fixed up to be valid again. */
893 struct var_refs_queue *temp;
895 /* Variable is inherited; fix it up when we get back to its function. */
896 push_obstacks (function->function_obstack,
897 function->function_maybepermanent_obstack);
899 = (struct var_refs_queue *) oballoc (sizeof (struct var_refs_queue));
900 temp->modified = reg;
901 temp->promoted_mode = promoted_mode;
902 temp->unsignedp = TREE_UNSIGNED (TREE_TYPE (decl));
903 temp->next = function->fixup_var_refs_queue;
904 function->fixup_var_refs_queue = temp;
908 /* Variable is local; fix it up now. */
909 fixup_var_refs (reg, promoted_mode, TREE_UNSIGNED (TREE_TYPE (decl)));
913 fixup_var_refs (var, promoted_mode, unsignedp)
915 enum machine_mode promoted_mode;
919 rtx first_insn = get_insns ();
920 struct sequence_stack *stack = sequence_stack;
921 tree rtl_exps = rtl_expr_chain;
923 /* Must scan all insns for stack-refs that exceed the limit. */
924 fixup_var_refs_insns (var, promoted_mode, unsignedp, first_insn, stack == 0);
926 /* Scan all pending sequences too. */
927 for (; stack; stack = stack->next)
929 push_to_sequence (stack->first);
930 fixup_var_refs_insns (var, promoted_mode, unsignedp,
931 stack->first, stack->next != 0);
932 /* Update remembered end of sequence
933 in case we added an insn at the end. */
934 stack->last = get_last_insn ();
938 /* Scan all waiting RTL_EXPRs too. */
939 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
941 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
942 if (seq != const0_rtx && seq != 0)
944 push_to_sequence (seq);
945 fixup_var_refs_insns (var, promoted_mode, unsignedp, seq, 0);
951 /* This structure is used by the following two functions to record MEMs or
952 pseudos used to replace VAR, any SUBREGs of VAR, and any MEMs containing
953 VAR as an address. We need to maintain this list in case two operands of
954 an insn were required to match; in that case we must ensure we use the
957 struct fixup_replacement
961 struct fixup_replacement *next;
964 /* REPLACEMENTS is a pointer to a list of the above structures and X is
965 some part of an insn. Return a struct fixup_replacement whose OLD
966 value is equal to X. Allocate a new structure if no such entry exists. */
968 static struct fixup_replacement *
969 find_fixup_replacement (replacements, x)
970 struct fixup_replacement **replacements;
973 struct fixup_replacement *p;
975 /* See if we have already replaced this. */
976 for (p = *replacements; p && p->old != x; p = p->next)
981 p = (struct fixup_replacement *) oballoc (sizeof (struct fixup_replacement));
984 p->next = *replacements;
991 /* Scan the insn-chain starting with INSN for refs to VAR
992 and fix them up. TOPLEVEL is nonzero if this chain is the
993 main chain of insns for the current function. */
996 fixup_var_refs_insns (var, promoted_mode, unsignedp, insn, toplevel)
998 enum machine_mode promoted_mode;
1005 rtx next = NEXT_INSN (insn);
1007 if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN
1008 || GET_CODE (insn) == JUMP_INSN)
1010 /* The insn to load VAR from a home in the arglist
1011 is now a no-op. When we see it, just delete it. */
1013 && GET_CODE (PATTERN (insn)) == SET
1014 && SET_DEST (PATTERN (insn)) == var
1015 && rtx_equal_p (SET_SRC (PATTERN (insn)), var))
1017 /* In unoptimized compilation, we shouldn't call delete_insn
1018 except in jump.c doing warnings. */
1019 PUT_CODE (insn, NOTE);
1020 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1021 NOTE_SOURCE_FILE (insn) = 0;
1022 if (insn == last_parm_insn)
1023 last_parm_insn = PREV_INSN (next);
1027 /* See if we have to do anything to INSN now that VAR is in
1028 memory. If it needs to be loaded into a pseudo, use a single
1029 pseudo for the entire insn in case there is a MATCH_DUP
1030 between two operands. We pass a pointer to the head of
1031 a list of struct fixup_replacements. If fixup_var_refs_1
1032 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1033 it will record them in this list.
1035 If it allocated a pseudo for any replacement, we copy into
1038 struct fixup_replacement *replacements = 0;
1039 rtx next_insn = NEXT_INSN (insn);
1041 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1044 /* If this is last_parm_insn, and any instructions were output
1045 after it to fix it up, then we must set last_parm_insn to
1046 the last such instruction emitted. */
1047 if (insn == last_parm_insn)
1048 last_parm_insn = PREV_INSN (next_insn);
1050 while (replacements)
1052 if (GET_CODE (replacements->new) == REG)
1057 /* OLD might be a (subreg (mem)). */
1058 if (GET_CODE (replacements->old) == SUBREG)
1060 = fixup_memory_subreg (replacements->old, insn, 0);
1063 = fixup_stack_1 (replacements->old, insn);
1065 /* We can not separate USE insns from the CALL_INSN
1066 that they belong to. If this is a CALL_INSN, insert
1067 the move insn before the USE insns preceding it
1068 instead of immediately before the insn. */
1069 if (GET_CODE (insn) == CALL_INSN)
1071 insert_before = insn;
1072 while (GET_CODE (PREV_INSN (insert_before)) == INSN
1073 && GET_CODE (PATTERN (PREV_INSN (insert_before))) == USE)
1074 insert_before = PREV_INSN (insert_before);
1077 insert_before = insn;
1079 /* If we are changing the mode, do a conversion.
1080 This might be wasteful, but combine.c will
1081 eliminate much of the waste. */
1083 if (GET_MODE (replacements->new)
1084 != GET_MODE (replacements->old))
1087 convert_move (replacements->new,
1088 replacements->old, unsignedp);
1089 seq = gen_sequence ();
1093 seq = gen_move_insn (replacements->new,
1096 emit_insn_before (seq, insert_before);
1099 replacements = replacements->next;
1103 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1104 But don't touch other insns referred to by reg-notes;
1105 we will get them elsewhere. */
1106 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1107 if (GET_CODE (note) != INSN_LIST)
1108 XEXP (note, 0) = walk_fixup_memory_subreg (XEXP (note, 0), insn);
1114 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1115 See if the rtx expression at *LOC in INSN needs to be changed.
1117 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1118 contain a list of original rtx's and replacements. If we find that we need
1119 to modify this insn by replacing a memory reference with a pseudo or by
1120 making a new MEM to implement a SUBREG, we consult that list to see if
1121 we have already chosen a replacement. If none has already been allocated,
1122 we allocate it and update the list. fixup_var_refs_insns will copy VAR
1123 or the SUBREG, as appropriate, to the pseudo. */
1126 fixup_var_refs_1 (var, promoted_mode, loc, insn, replacements)
1128 enum machine_mode promoted_mode;
1131 struct fixup_replacement **replacements;
1134 register rtx x = *loc;
1135 RTX_CODE code = GET_CODE (x);
1137 register rtx tem, tem1;
1138 struct fixup_replacement *replacement;
1145 /* If we already have a replacement, use it. Otherwise,
1146 try to fix up this address in case it is invalid. */
1148 replacement = find_fixup_replacement (replacements, var);
1149 if (replacement->new)
1151 *loc = replacement->new;
1155 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1157 /* Unless we are forcing memory to register or we changed the mode,
1158 we can leave things the way they are if the insn is valid. */
1160 INSN_CODE (insn) = -1;
1161 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1162 && recog_memoized (insn) >= 0)
1165 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1169 /* If X contains VAR, we need to unshare it here so that we update
1170 each occurrence separately. But all identical MEMs in one insn
1171 must be replaced with the same rtx because of the possibility of
1174 if (reg_mentioned_p (var, x))
1176 replacement = find_fixup_replacement (replacements, x);
1177 if (replacement->new == 0)
1178 replacement->new = copy_most_rtx (x, var);
1180 *loc = x = replacement->new;
1196 /* Note that in some cases those types of expressions are altered
1197 by optimize_bit_field, and do not survive to get here. */
1198 if (XEXP (x, 0) == var
1199 || (GET_CODE (XEXP (x, 0)) == SUBREG
1200 && SUBREG_REG (XEXP (x, 0)) == var))
1202 /* Get TEM as a valid MEM in the mode presently in the insn.
1204 We don't worry about the possibility of MATCH_DUP here; it
1205 is highly unlikely and would be tricky to handle. */
1208 if (GET_CODE (tem) == SUBREG)
1209 tem = fixup_memory_subreg (tem, insn, 1);
1210 tem = fixup_stack_1 (tem, insn);
1212 /* Unless we want to load from memory, get TEM into the proper mode
1213 for an extract from memory. This can only be done if the
1214 extract is at a constant position and length. */
1216 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
1217 && GET_CODE (XEXP (x, 2)) == CONST_INT
1218 && ! mode_dependent_address_p (XEXP (tem, 0))
1219 && ! MEM_VOLATILE_P (tem))
1221 enum machine_mode wanted_mode = VOIDmode;
1222 enum machine_mode is_mode = GET_MODE (tem);
1223 int width = INTVAL (XEXP (x, 1));
1224 int pos = INTVAL (XEXP (x, 2));
1227 if (GET_CODE (x) == ZERO_EXTRACT)
1228 wanted_mode = insn_operand_mode[(int) CODE_FOR_extzv][1];
1231 if (GET_CODE (x) == SIGN_EXTRACT)
1232 wanted_mode = insn_operand_mode[(int) CODE_FOR_extv][1];
1234 /* If we have a narrower mode, we can do something. */
1235 if (wanted_mode != VOIDmode
1236 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
1238 int offset = pos / BITS_PER_UNIT;
1239 rtx old_pos = XEXP (x, 2);
1242 /* If the bytes and bits are counted differently, we
1243 must adjust the offset. */
1244 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1245 offset = (GET_MODE_SIZE (is_mode)
1246 - GET_MODE_SIZE (wanted_mode) - offset);
1249 pos %= GET_MODE_BITSIZE (wanted_mode);
1251 newmem = gen_rtx (MEM, wanted_mode,
1252 plus_constant (XEXP (tem, 0), offset));
1253 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
1254 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
1255 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
1257 /* Make the change and see if the insn remains valid. */
1258 INSN_CODE (insn) = -1;
1259 XEXP (x, 0) = newmem;
1260 XEXP (x, 2) = GEN_INT (pos);
1262 if (recog_memoized (insn) >= 0)
1265 /* Otherwise, restore old position. XEXP (x, 0) will be
1267 XEXP (x, 2) = old_pos;
1271 /* If we get here, the bitfield extract insn can't accept a memory
1272 reference. Copy the input into a register. */
1274 tem1 = gen_reg_rtx (GET_MODE (tem));
1275 emit_insn_before (gen_move_insn (tem1, tem), insn);
1282 if (SUBREG_REG (x) == var)
1284 /* If this is a special SUBREG made because VAR was promoted
1285 from a wider mode, replace it with VAR and call ourself
1286 recursively, this time saying that the object previously
1287 had its current mode (by virtue of the SUBREG). */
1289 if (SUBREG_PROMOTED_VAR_P (x))
1292 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements);
1296 /* If this SUBREG makes VAR wider, it has become a paradoxical
1297 SUBREG with VAR in memory, but these aren't allowed at this
1298 stage of the compilation. So load VAR into a pseudo and take
1299 a SUBREG of that pseudo. */
1300 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
1302 replacement = find_fixup_replacement (replacements, var);
1303 if (replacement->new == 0)
1304 replacement->new = gen_reg_rtx (GET_MODE (var));
1305 SUBREG_REG (x) = replacement->new;
1309 /* See if we have already found a replacement for this SUBREG.
1310 If so, use it. Otherwise, make a MEM and see if the insn
1311 is recognized. If not, or if we should force MEM into a register,
1312 make a pseudo for this SUBREG. */
1313 replacement = find_fixup_replacement (replacements, x);
1314 if (replacement->new)
1316 *loc = replacement->new;
1320 replacement->new = *loc = fixup_memory_subreg (x, insn, 0);
1322 if (! flag_force_mem && recog_memoized (insn) >= 0)
1325 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
1331 /* First do special simplification of bit-field references. */
1332 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
1333 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
1334 optimize_bit_field (x, insn, 0);
1335 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
1336 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
1337 optimize_bit_field (x, insn, NULL_PTR);
1339 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
1340 insn into a pseudo and store the low part of the pseudo into VAR. */
1341 if (GET_CODE (SET_DEST (x)) == SUBREG
1342 && SUBREG_REG (SET_DEST (x)) == var
1343 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
1344 > GET_MODE_SIZE (GET_MODE (var))))
1346 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
1347 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
1354 rtx dest = SET_DEST (x);
1355 rtx src = SET_SRC (x);
1356 rtx outerdest = dest;
1358 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
1359 || GET_CODE (dest) == SIGN_EXTRACT
1360 || GET_CODE (dest) == ZERO_EXTRACT)
1361 dest = XEXP (dest, 0);
1363 if (GET_CODE (src) == SUBREG)
1364 src = XEXP (src, 0);
1366 /* If VAR does not appear at the top level of the SET
1367 just scan the lower levels of the tree. */
1369 if (src != var && dest != var)
1372 /* We will need to rerecognize this insn. */
1373 INSN_CODE (insn) = -1;
1376 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var)
1378 /* Since this case will return, ensure we fixup all the
1380 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
1381 insn, replacements);
1382 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
1383 insn, replacements);
1384 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
1385 insn, replacements);
1387 tem = XEXP (outerdest, 0);
1389 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
1390 that may appear inside a ZERO_EXTRACT.
1391 This was legitimate when the MEM was a REG. */
1392 if (GET_CODE (tem) == SUBREG
1393 && SUBREG_REG (tem) == var)
1394 tem = fixup_memory_subreg (tem, insn, 1);
1396 tem = fixup_stack_1 (tem, insn);
1398 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
1399 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
1400 && ! mode_dependent_address_p (XEXP (tem, 0))
1401 && ! MEM_VOLATILE_P (tem))
1403 enum machine_mode wanted_mode
1404 = insn_operand_mode[(int) CODE_FOR_insv][0];
1405 enum machine_mode is_mode = GET_MODE (tem);
1406 int width = INTVAL (XEXP (outerdest, 1));
1407 int pos = INTVAL (XEXP (outerdest, 2));
1409 /* If we have a narrower mode, we can do something. */
1410 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
1412 int offset = pos / BITS_PER_UNIT;
1413 rtx old_pos = XEXP (outerdest, 2);
1416 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1417 offset = (GET_MODE_SIZE (is_mode)
1418 - GET_MODE_SIZE (wanted_mode) - offset);
1421 pos %= GET_MODE_BITSIZE (wanted_mode);
1423 newmem = gen_rtx (MEM, wanted_mode,
1424 plus_constant (XEXP (tem, 0), offset));
1425 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
1426 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
1427 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
1429 /* Make the change and see if the insn remains valid. */
1430 INSN_CODE (insn) = -1;
1431 XEXP (outerdest, 0) = newmem;
1432 XEXP (outerdest, 2) = GEN_INT (pos);
1434 if (recog_memoized (insn) >= 0)
1437 /* Otherwise, restore old position. XEXP (x, 0) will be
1439 XEXP (outerdest, 2) = old_pos;
1443 /* If we get here, the bit-field store doesn't allow memory
1444 or isn't located at a constant position. Load the value into
1445 a register, do the store, and put it back into memory. */
1447 tem1 = gen_reg_rtx (GET_MODE (tem));
1448 emit_insn_before (gen_move_insn (tem1, tem), insn);
1449 emit_insn_after (gen_move_insn (tem, tem1), insn);
1450 XEXP (outerdest, 0) = tem1;
1455 /* STRICT_LOW_PART is a no-op on memory references
1456 and it can cause combinations to be unrecognizable,
1459 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
1460 SET_DEST (x) = XEXP (SET_DEST (x), 0);
1462 /* A valid insn to copy VAR into or out of a register
1463 must be left alone, to avoid an infinite loop here.
1464 If the reference to VAR is by a subreg, fix that up,
1465 since SUBREG is not valid for a memref.
1466 Also fix up the address of the stack slot. */
1468 if ((SET_SRC (x) == var
1469 || (GET_CODE (SET_SRC (x)) == SUBREG
1470 && SUBREG_REG (SET_SRC (x)) == var))
1471 && (GET_CODE (SET_DEST (x)) == REG
1472 || (GET_CODE (SET_DEST (x)) == SUBREG
1473 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
1474 && recog_memoized (insn) >= 0)
1476 replacement = find_fixup_replacement (replacements, SET_SRC (x));
1477 if (replacement->new)
1479 SET_SRC (x) = replacement->new;
1482 else if (GET_CODE (SET_SRC (x)) == SUBREG)
1483 SET_SRC (x) = replacement->new
1484 = fixup_memory_subreg (SET_SRC (x), insn, 0);
1486 SET_SRC (x) = replacement->new
1487 = fixup_stack_1 (SET_SRC (x), insn);
1491 if ((SET_DEST (x) == var
1492 || (GET_CODE (SET_DEST (x)) == SUBREG
1493 && SUBREG_REG (SET_DEST (x)) == var))
1494 && (GET_CODE (SET_SRC (x)) == REG
1495 || (GET_CODE (SET_SRC (x)) == SUBREG
1496 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
1497 && recog_memoized (insn) >= 0)
1499 if (GET_CODE (SET_DEST (x)) == SUBREG)
1500 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn, 0);
1502 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
1506 /* Otherwise, storing into VAR must be handled specially
1507 by storing into a temporary and copying that into VAR
1508 with a new insn after this one. Note that this case
1509 will be used when storing into a promoted scalar since
1510 the insn will now have different modes on the input
1511 and output and hence will be invalid (except for the case
1512 of setting it to a constant, which does not need any
1513 change if it is valid). We generate extra code in that case,
1514 but combine.c will eliminate it. */
1519 rtx fixeddest = SET_DEST (x);
1521 /* STRICT_LOW_PART can be discarded, around a MEM. */
1522 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
1523 fixeddest = XEXP (fixeddest, 0);
1524 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
1525 if (GET_CODE (fixeddest) == SUBREG)
1526 fixeddest = fixup_memory_subreg (fixeddest, insn, 0);
1528 fixeddest = fixup_stack_1 (fixeddest, insn);
1530 temp = gen_reg_rtx (GET_MODE (SET_SRC (x)) == VOIDmode
1531 ? GET_MODE (fixeddest)
1532 : GET_MODE (SET_SRC (x)));
1534 emit_insn_after (gen_move_insn (fixeddest,
1535 gen_lowpart (GET_MODE (fixeddest),
1539 SET_DEST (x) = temp;
1544 /* Nothing special about this RTX; fix its operands. */
1546 fmt = GET_RTX_FORMAT (code);
1547 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1550 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements);
1554 for (j = 0; j < XVECLEN (x, i); j++)
1555 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
1556 insn, replacements);
1561 /* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
1562 return an rtx (MEM:m1 newaddr) which is equivalent.
1563 If any insns must be emitted to compute NEWADDR, put them before INSN.
1565 UNCRITICAL nonzero means accept paradoxical subregs.
1566 This is used for subregs found inside of ZERO_EXTRACTs. */
1569 fixup_memory_subreg (x, insn, uncritical)
1574 int offset = SUBREG_WORD (x) * UNITS_PER_WORD;
1575 rtx addr = XEXP (SUBREG_REG (x), 0);
1576 enum machine_mode mode = GET_MODE (x);
1579 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
1580 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
1584 #if BYTES_BIG_ENDIAN
1585 offset += (MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
1586 - MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)));
1588 addr = plus_constant (addr, offset);
1589 if (!flag_force_addr && memory_address_p (mode, addr))
1590 /* Shortcut if no insns need be emitted. */
1591 return change_address (SUBREG_REG (x), mode, addr);
1593 result = change_address (SUBREG_REG (x), mode, addr);
1594 emit_insn_before (gen_sequence (), insn);
1599 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
1600 Replace subexpressions of X in place.
1601 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
1602 Otherwise return X, with its contents possibly altered.
1604 If any insns must be emitted to compute NEWADDR, put them before INSN. */
1607 walk_fixup_memory_subreg (x, insn)
1611 register enum rtx_code code;
1618 code = GET_CODE (x);
1620 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
1621 return fixup_memory_subreg (x, insn, 0);
1623 /* Nothing special about this RTX; fix its operands. */
1625 fmt = GET_RTX_FORMAT (code);
1626 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1629 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn);
1633 for (j = 0; j < XVECLEN (x, i); j++)
1635 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn);
1642 /* Fix up any references to stack slots that are invalid memory addresses
1643 because they exceed the maximum range of a displacement. */
1646 fixup_stack_slots ()
1650 /* Did we generate a stack slot that is out of range
1651 or otherwise has an invalid address? */
1652 if (invalid_stack_slot)
1654 /* Yes. Must scan all insns for stack-refs that exceed the limit. */
1655 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1656 if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN
1657 || GET_CODE (insn) == JUMP_INSN)
1658 fixup_stack_1 (PATTERN (insn), insn);
1663 /* For each memory ref within X, if it refers to a stack slot
1664 with an out of range displacement, put the address in a temp register
1665 (emitting new insns before INSN to load these registers)
1666 and alter the memory ref to use that register.
1667 Replace each such MEM rtx with a copy, to avoid clobberage. */
1670 fixup_stack_1 (x, insn)
1675 register RTX_CODE code = GET_CODE (x);
1680 register rtx ad = XEXP (x, 0);
1681 /* If we have address of a stack slot but it's not valid
1682 (displacement is too large), compute the sum in a register. */
1683 if (GET_CODE (ad) == PLUS
1684 && GET_CODE (XEXP (ad, 0)) == REG
1685 && REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
1686 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER
1687 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
1690 if (memory_address_p (GET_MODE (x), ad))
1694 temp = copy_to_reg (ad);
1695 seq = gen_sequence ();
1697 emit_insn_before (seq, insn);
1698 return change_address (x, VOIDmode, temp);
1703 fmt = GET_RTX_FORMAT (code);
1704 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1707 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
1711 for (j = 0; j < XVECLEN (x, i); j++)
1712 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
1718 /* Optimization: a bit-field instruction whose field
1719 happens to be a byte or halfword in memory
1720 can be changed to a move instruction.
1722 We call here when INSN is an insn to examine or store into a bit-field.
1723 BODY is the SET-rtx to be altered.
1725 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
1726 (Currently this is called only from function.c, and EQUIV_MEM
1730 optimize_bit_field (body, insn, equiv_mem)
1735 register rtx bitfield;
1738 enum machine_mode mode;
1740 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
1741 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
1742 bitfield = SET_DEST (body), destflag = 1;
1744 bitfield = SET_SRC (body), destflag = 0;
1746 /* First check that the field being stored has constant size and position
1747 and is in fact a byte or halfword suitably aligned. */
1749 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
1750 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
1751 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
1753 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
1755 register rtx memref = 0;
1757 /* Now check that the containing word is memory, not a register,
1758 and that it is safe to change the machine mode. */
1760 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
1761 memref = XEXP (bitfield, 0);
1762 else if (GET_CODE (XEXP (bitfield, 0)) == REG
1764 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
1765 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
1766 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
1767 memref = SUBREG_REG (XEXP (bitfield, 0));
1768 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
1770 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
1771 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
1774 && ! mode_dependent_address_p (XEXP (memref, 0))
1775 && ! MEM_VOLATILE_P (memref))
1777 /* Now adjust the address, first for any subreg'ing
1778 that we are now getting rid of,
1779 and then for which byte of the word is wanted. */
1781 register int offset = INTVAL (XEXP (bitfield, 2));
1782 /* Adjust OFFSET to count bits from low-address byte. */
1783 #if BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN
1784 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
1785 - offset - INTVAL (XEXP (bitfield, 1)));
1787 /* Adjust OFFSET to count bytes from low-address byte. */
1788 offset /= BITS_PER_UNIT;
1789 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
1791 offset += SUBREG_WORD (XEXP (bitfield, 0)) * UNITS_PER_WORD;
1792 #if BYTES_BIG_ENDIAN
1793 offset -= (MIN (UNITS_PER_WORD,
1794 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
1795 - MIN (UNITS_PER_WORD,
1796 GET_MODE_SIZE (GET_MODE (memref))));
1800 memref = change_address (memref, mode,
1801 plus_constant (XEXP (memref, 0), offset));
1803 /* Store this memory reference where
1804 we found the bit field reference. */
1808 validate_change (insn, &SET_DEST (body), memref, 1);
1809 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
1811 rtx src = SET_SRC (body);
1812 while (GET_CODE (src) == SUBREG
1813 && SUBREG_WORD (src) == 0)
1814 src = SUBREG_REG (src);
1815 if (GET_MODE (src) != GET_MODE (memref))
1816 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
1817 validate_change (insn, &SET_SRC (body), src, 1);
1819 else if (GET_MODE (SET_SRC (body)) != VOIDmode
1820 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
1821 /* This shouldn't happen because anything that didn't have
1822 one of these modes should have got converted explicitly
1823 and then referenced through a subreg.
1824 This is so because the original bit-field was
1825 handled by agg_mode and so its tree structure had
1826 the same mode that memref now has. */
1831 rtx dest = SET_DEST (body);
1833 while (GET_CODE (dest) == SUBREG
1834 && SUBREG_WORD (dest) == 0)
1835 dest = SUBREG_REG (dest);
1837 validate_change (insn, &SET_DEST (body), dest, 1);
1839 if (GET_MODE (dest) == GET_MODE (memref))
1840 validate_change (insn, &SET_SRC (body), memref, 1);
1843 /* Convert the mem ref to the destination mode. */
1844 rtx newreg = gen_reg_rtx (GET_MODE (dest));
1847 convert_move (newreg, memref,
1848 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
1852 validate_change (insn, &SET_SRC (body), newreg, 1);
1856 /* See if we can convert this extraction or insertion into
1857 a simple move insn. We might not be able to do so if this
1858 was, for example, part of a PARALLEL.
1860 If we succeed, write out any needed conversions. If we fail,
1861 it is hard to guess why we failed, so don't do anything
1862 special; just let the optimization be suppressed. */
1864 if (apply_change_group () && seq)
1865 emit_insns_before (seq, insn);
1870 /* These routines are responsible for converting virtual register references
1871 to the actual hard register references once RTL generation is complete.
1873 The following four variables are used for communication between the
1874 routines. They contain the offsets of the virtual registers from their
1875 respective hard registers. */
1877 static int in_arg_offset;
1878 static int var_offset;
1879 static int dynamic_offset;
1880 static int out_arg_offset;
1882 /* In most machines, the stack pointer register is equivalent to the bottom
1885 #ifndef STACK_POINTER_OFFSET
1886 #define STACK_POINTER_OFFSET 0
1889 /* If not defined, pick an appropriate default for the offset of dynamically
1890 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1891 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1893 #ifndef STACK_DYNAMIC_OFFSET
1895 #ifdef ACCUMULATE_OUTGOING_ARGS
1896 /* The bottom of the stack points to the actual arguments. If
1897 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1898 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1899 stack space for register parameters is not pushed by the caller, but
1900 rather part of the fixed stack areas and hence not included in
1901 `current_function_outgoing_args_size'. Nevertheless, we must allow
1902 for it when allocating stack dynamic objects. */
1904 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1905 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1906 (current_function_outgoing_args_size \
1907 + REG_PARM_STACK_SPACE (FNDECL) + (STACK_POINTER_OFFSET))
1910 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1911 (current_function_outgoing_args_size + (STACK_POINTER_OFFSET))
1915 #define STACK_DYNAMIC_OFFSET(FNDECL) STACK_POINTER_OFFSET
1919 /* Pass through the INSNS of function FNDECL and convert virtual register
1920 references to hard register references. */
1923 instantiate_virtual_regs (fndecl, insns)
1929 /* Compute the offsets to use for this function. */
1930 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
1931 var_offset = STARTING_FRAME_OFFSET;
1932 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
1933 out_arg_offset = STACK_POINTER_OFFSET;
1935 /* Scan all variables and parameters of this function. For each that is
1936 in memory, instantiate all virtual registers if the result is a valid
1937 address. If not, we do it later. That will handle most uses of virtual
1938 regs on many machines. */
1939 instantiate_decls (fndecl, 1);
1941 /* Initialize recognition, indicating that volatile is OK. */
1944 /* Scan through all the insns, instantiating every virtual register still
1946 for (insn = insns; insn; insn = NEXT_INSN (insn))
1947 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
1948 || GET_CODE (insn) == CALL_INSN)
1950 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
1951 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
1954 /* Now instantiate the remaining register equivalences for debugging info.
1955 These will not be valid addresses. */
1956 instantiate_decls (fndecl, 0);
1958 /* Indicate that, from now on, assign_stack_local should use
1959 frame_pointer_rtx. */
1960 virtuals_instantiated = 1;
1963 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1964 all virtual registers in their DECL_RTL's.
1966 If VALID_ONLY, do this only if the resulting address is still valid.
1967 Otherwise, always do it. */
1970 instantiate_decls (fndecl, valid_only)
1976 if (DECL_INLINE (fndecl))
1977 /* When compiling an inline function, the obstack used for
1978 rtl allocation is the maybepermanent_obstack. Calling
1979 `resume_temporary_allocation' switches us back to that
1980 obstack while we process this function's parameters. */
1981 resume_temporary_allocation ();
1983 /* Process all parameters of the function. */
1984 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1986 instantiate_decl (DECL_RTL (decl), int_size_in_bytes (TREE_TYPE (decl)),
1988 instantiate_decl (DECL_INCOMING_RTL (decl),
1989 int_size_in_bytes (TREE_TYPE (decl)), valid_only);
1992 /* Now process all variables defined in the function or its subblocks. */
1993 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
1995 if (DECL_INLINE (fndecl))
1997 /* Save all rtl allocated for this function by raising the
1998 high-water mark on the maybepermanent_obstack. */
2000 /* All further rtl allocation is now done in the current_obstack. */
2001 rtl_in_current_obstack ();
2005 /* Subroutine of instantiate_decls: Process all decls in the given
2006 BLOCK node and all its subblocks. */
2009 instantiate_decls_1 (let, valid_only)
2015 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
2016 instantiate_decl (DECL_RTL (t), int_size_in_bytes (TREE_TYPE (t)),
2019 /* Process all subblocks. */
2020 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
2021 instantiate_decls_1 (t, valid_only);
2024 /* Subroutine of the preceeding procedures: Given RTL representing a
2025 decl and the size of the object, do any instantiation required.
2027 If VALID_ONLY is non-zero, it means that the RTL should only be
2028 changed if the new address is valid. */
2031 instantiate_decl (x, size, valid_only)
2036 enum machine_mode mode;
2039 /* If this is not a MEM, no need to do anything. Similarly if the
2040 address is a constant or a register that is not a virtual register. */
2042 if (x == 0 || GET_CODE (x) != MEM)
2046 if (CONSTANT_P (addr)
2047 || (GET_CODE (addr) == REG
2048 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
2049 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
2052 /* If we should only do this if the address is valid, copy the address.
2053 We need to do this so we can undo any changes that might make the
2054 address invalid. This copy is unfortunate, but probably can't be
2058 addr = copy_rtx (addr);
2060 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
2065 /* Now verify that the resulting address is valid for every integer or
2066 floating-point mode up to and including SIZE bytes long. We do this
2067 since the object might be accessed in any mode and frame addresses
2070 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2071 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2072 mode = GET_MODE_WIDER_MODE (mode))
2073 if (! memory_address_p (mode, addr))
2076 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
2077 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2078 mode = GET_MODE_WIDER_MODE (mode))
2079 if (! memory_address_p (mode, addr))
2082 /* Otherwise, put back the address, now that we have updated it and we
2083 know it is valid. */
2088 /* Given a pointer to a piece of rtx and an optional pointer to the
2089 containing object, instantiate any virtual registers present in it.
2091 If EXTRA_INSNS, we always do the replacement and generate
2092 any extra insns before OBJECT. If it zero, we do nothing if replacement
2095 Return 1 if we either had nothing to do or if we were able to do the
2096 needed replacement. Return 0 otherwise; we only return zero if
2097 EXTRA_INSNS is zero.
2099 We first try some simple transformations to avoid the creation of extra
2103 instantiate_virtual_regs_1 (loc, object, extra_insns)
2117 /* Re-start here to avoid recursion in common cases. */
2124 code = GET_CODE (x);
2126 /* Check for some special cases. */
2143 /* We are allowed to set the virtual registers. This means that
2144 that the actual register should receive the source minus the
2145 appropriate offset. This is used, for example, in the handling
2146 of non-local gotos. */
2147 if (SET_DEST (x) == virtual_incoming_args_rtx)
2148 new = arg_pointer_rtx, offset = - in_arg_offset;
2149 else if (SET_DEST (x) == virtual_stack_vars_rtx)
2150 new = frame_pointer_rtx, offset = - var_offset;
2151 else if (SET_DEST (x) == virtual_stack_dynamic_rtx)
2152 new = stack_pointer_rtx, offset = - dynamic_offset;
2153 else if (SET_DEST (x) == virtual_outgoing_args_rtx)
2154 new = stack_pointer_rtx, offset = - out_arg_offset;
2158 /* The only valid sources here are PLUS or REG. Just do
2159 the simplest possible thing to handle them. */
2160 if (GET_CODE (SET_SRC (x)) != REG
2161 && GET_CODE (SET_SRC (x)) != PLUS)
2165 if (GET_CODE (SET_SRC (x)) != REG)
2166 temp = force_operand (SET_SRC (x), NULL_RTX);
2169 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
2173 emit_insns_before (seq, object);
2176 if (!validate_change (object, &SET_SRC (x), temp, 0)
2183 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
2188 /* Handle special case of virtual register plus constant. */
2189 if (CONSTANT_P (XEXP (x, 1)))
2193 /* Check for (plus (plus VIRT foo) (const_int)) first. */
2194 if (GET_CODE (XEXP (x, 0)) == PLUS)
2196 rtx inner = XEXP (XEXP (x, 0), 0);
2198 if (inner == virtual_incoming_args_rtx)
2199 new = arg_pointer_rtx, offset = in_arg_offset;
2200 else if (inner == virtual_stack_vars_rtx)
2201 new = frame_pointer_rtx, offset = var_offset;
2202 else if (inner == virtual_stack_dynamic_rtx)
2203 new = stack_pointer_rtx, offset = dynamic_offset;
2204 else if (inner == virtual_outgoing_args_rtx)
2205 new = stack_pointer_rtx, offset = out_arg_offset;
2212 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
2214 new = gen_rtx (PLUS, Pmode, new, XEXP (XEXP (x, 0), 1));
2217 else if (XEXP (x, 0) == virtual_incoming_args_rtx)
2218 new = arg_pointer_rtx, offset = in_arg_offset;
2219 else if (XEXP (x, 0) == virtual_stack_vars_rtx)
2220 new = frame_pointer_rtx, offset = var_offset;
2221 else if (XEXP (x, 0) == virtual_stack_dynamic_rtx)
2222 new = stack_pointer_rtx, offset = dynamic_offset;
2223 else if (XEXP (x, 0) == virtual_outgoing_args_rtx)
2224 new = stack_pointer_rtx, offset = out_arg_offset;
2227 /* We know the second operand is a constant. Unless the
2228 first operand is a REG (which has been already checked),
2229 it needs to be checked. */
2230 if (GET_CODE (XEXP (x, 0)) != REG)
2240 new = plus_constant (XEXP (x, 1), offset);
2242 /* If the new constant is zero, try to replace the sum with its
2244 if (new == const0_rtx
2245 && validate_change (object, loc, XEXP (x, 0), 0))
2248 /* Next try to replace constant with new one. */
2249 if (!validate_change (object, &XEXP (x, 1), new, 0))
2257 /* Otherwise copy the new constant into a register and replace
2258 constant with that register. */
2259 temp = gen_reg_rtx (Pmode);
2260 if (validate_change (object, &XEXP (x, 1), temp, 0))
2261 emit_insn_before (gen_move_insn (temp, new), object);
2264 /* If that didn't work, replace this expression with a
2265 register containing the sum. */
2267 new = gen_rtx (PLUS, Pmode, XEXP (x, 0), new);
2271 temp = force_operand (new, NULL_RTX);
2275 emit_insns_before (seq, object);
2276 if (! validate_change (object, loc, temp, 0)
2277 && ! validate_replace_rtx (x, temp, object))
2285 /* Fall through to generic two-operand expression case. */
2291 case DIV: case UDIV:
2292 case MOD: case UMOD:
2293 case AND: case IOR: case XOR:
2294 case LSHIFT: case ASHIFT: case ROTATE:
2295 case ASHIFTRT: case LSHIFTRT: case ROTATERT:
2297 case GE: case GT: case GEU: case GTU:
2298 case LE: case LT: case LEU: case LTU:
2299 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
2300 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
2305 /* Most cases of MEM that convert to valid addresses have already been
2306 handled by our scan of regno_reg_rtx. The only special handling we
2307 need here is to make a copy of the rtx to ensure it isn't being
2308 shared if we have to change it to a pseudo.
2310 If the rtx is a simple reference to an address via a virtual register,
2311 it can potentially be shared. In such cases, first try to make it
2312 a valid address, which can also be shared. Otherwise, copy it and
2315 First check for common cases that need no processing. These are
2316 usually due to instantiation already being done on a previous instance
2320 if (CONSTANT_ADDRESS_P (temp)
2321 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2322 || temp == arg_pointer_rtx
2324 || temp == frame_pointer_rtx)
2327 if (GET_CODE (temp) == PLUS
2328 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2329 && (XEXP (temp, 0) == frame_pointer_rtx
2330 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2331 || XEXP (temp, 0) == arg_pointer_rtx
2336 if (temp == virtual_stack_vars_rtx
2337 || temp == virtual_incoming_args_rtx
2338 || (GET_CODE (temp) == PLUS
2339 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2340 && (XEXP (temp, 0) == virtual_stack_vars_rtx
2341 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
2343 /* This MEM may be shared. If the substitution can be done without
2344 the need to generate new pseudos, we want to do it in place
2345 so all copies of the shared rtx benefit. The call below will
2346 only make substitutions if the resulting address is still
2349 Note that we cannot pass X as the object in the recursive call
2350 since the insn being processed may not allow all valid
2351 addresses. However, if we were not passed on object, we can
2352 only modify X without copying it if X will have a valid
2355 ??? Also note that this can still lose if OBJECT is an insn that
2356 has less restrictions on an address that some other insn.
2357 In that case, we will modify the shared address. This case
2358 doesn't seem very likely, though. */
2360 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
2361 object ? object : x, 0))
2364 /* Otherwise make a copy and process that copy. We copy the entire
2365 RTL expression since it might be a PLUS which could also be
2367 *loc = x = copy_rtx (x);
2370 /* Fall through to generic unary operation case. */
2374 case STRICT_LOW_PART:
2376 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
2377 case SIGN_EXTEND: case ZERO_EXTEND:
2378 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2379 case FLOAT: case FIX:
2380 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2384 /* These case either have just one operand or we know that we need not
2385 check the rest of the operands. */
2390 /* Try to replace with a PLUS. If that doesn't work, compute the sum
2391 in front of this insn and substitute the temporary. */
2392 if (x == virtual_incoming_args_rtx)
2393 new = arg_pointer_rtx, offset = in_arg_offset;
2394 else if (x == virtual_stack_vars_rtx)
2395 new = frame_pointer_rtx, offset = var_offset;
2396 else if (x == virtual_stack_dynamic_rtx)
2397 new = stack_pointer_rtx, offset = dynamic_offset;
2398 else if (x == virtual_outgoing_args_rtx)
2399 new = stack_pointer_rtx, offset = out_arg_offset;
2403 temp = plus_constant (new, offset);
2404 if (!validate_change (object, loc, temp, 0))
2410 temp = force_operand (temp, NULL_RTX);
2414 emit_insns_before (seq, object);
2415 if (! validate_change (object, loc, temp, 0)
2416 && ! validate_replace_rtx (x, temp, object))
2424 /* Scan all subexpressions. */
2425 fmt = GET_RTX_FORMAT (code);
2426 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2429 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
2432 else if (*fmt == 'E')
2433 for (j = 0; j < XVECLEN (x, i); j++)
2434 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
2441 /* Optimization: assuming this function does not receive nonlocal gotos,
2442 delete the handlers for such, as well as the insns to establish
2443 and disestablish them. */
2449 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
2451 /* Delete the handler by turning off the flag that would
2452 prevent jump_optimize from deleting it.
2453 Also permit deletion of the nonlocal labels themselves
2454 if nothing local refers to them. */
2455 if (GET_CODE (insn) == CODE_LABEL)
2456 LABEL_PRESERVE_P (insn) = 0;
2457 if (GET_CODE (insn) == INSN
2458 && ((nonlocal_goto_handler_slot != 0
2459 && reg_mentioned_p (nonlocal_goto_handler_slot, PATTERN (insn)))
2460 || (nonlocal_goto_stack_level != 0
2461 && reg_mentioned_p (nonlocal_goto_stack_level,
2467 /* Return a list (chain of EXPR_LIST nodes) for the nonlocal labels
2468 of the current function. */
2471 nonlocal_label_rtx_list ()
2476 for (t = nonlocal_labels; t; t = TREE_CHAIN (t))
2477 x = gen_rtx (EXPR_LIST, VOIDmode, label_rtx (TREE_VALUE (t)), x);
2482 /* Output a USE for any register use in RTL.
2483 This is used with -noreg to mark the extent of lifespan
2484 of any registers used in a user-visible variable's DECL_RTL. */
2490 if (GET_CODE (rtl) == REG)
2491 /* This is a register variable. */
2492 emit_insn (gen_rtx (USE, VOIDmode, rtl));
2493 else if (GET_CODE (rtl) == MEM
2494 && GET_CODE (XEXP (rtl, 0)) == REG
2495 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
2496 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
2497 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
2498 /* This is a variable-sized structure. */
2499 emit_insn (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)));
2502 /* Like use_variable except that it outputs the USEs after INSN
2503 instead of at the end of the insn-chain. */
2506 use_variable_after (rtl, insn)
2509 if (GET_CODE (rtl) == REG)
2510 /* This is a register variable. */
2511 emit_insn_after (gen_rtx (USE, VOIDmode, rtl), insn);
2512 else if (GET_CODE (rtl) == MEM
2513 && GET_CODE (XEXP (rtl, 0)) == REG
2514 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
2515 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
2516 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
2517 /* This is a variable-sized structure. */
2518 emit_insn_after (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)), insn);
2524 return max_parm_reg;
2527 /* Return the first insn following those generated by `assign_parms'. */
2530 get_first_nonparm_insn ()
2533 return NEXT_INSN (last_parm_insn);
2534 return get_insns ();
2537 /* Return the first NOTE_INSN_BLOCK_BEG note in the function.
2538 Crash if there is none. */
2541 get_first_block_beg ()
2543 register rtx searcher;
2544 register rtx insn = get_first_nonparm_insn ();
2546 for (searcher = insn; searcher; searcher = NEXT_INSN (searcher))
2547 if (GET_CODE (searcher) == NOTE
2548 && NOTE_LINE_NUMBER (searcher) == NOTE_INSN_BLOCK_BEG)
2551 abort (); /* Invalid call to this function. (See comments above.) */
2555 /* Return 1 if EXP returns an aggregate value, for which an address
2556 must be passed to the function or returned by the function. */
2559 aggregate_value_p (exp)
2562 int i, regno, nregs;
2564 if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2566 if (RETURN_IN_MEMORY (TREE_TYPE (exp)))
2568 if (flag_pcc_struct_return
2569 && (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
2570 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE))
2572 /* Make sure we have suitable call-clobbered regs to return
2573 the value in; if not, we must return it in memory. */
2574 reg = hard_function_value (TREE_TYPE (exp), 0);
2575 regno = REGNO (reg);
2576 nregs = HARD_REGNO_NREGS (regno, TYPE_MODE (TREE_TYPE (exp)));
2577 for (i = 0; i < nregs; i++)
2578 if (! call_used_regs[regno + i])
2583 /* Assign RTL expressions to the function's parameters.
2584 This may involve copying them into registers and using
2585 those registers as the RTL for them.
2587 If SECOND_TIME is non-zero it means that this function is being
2588 called a second time. This is done by integrate.c when a function's
2589 compilation is deferred. We need to come back here in case the
2590 FUNCTION_ARG macro computes items needed for the rest of the compilation
2591 (such as changing which registers are fixed or caller-saved). But suppress
2592 writing any insns or setting DECL_RTL of anything in this case. */
2595 assign_parms (fndecl, second_time)
2600 register rtx entry_parm = 0;
2601 register rtx stack_parm = 0;
2602 CUMULATIVE_ARGS args_so_far;
2603 enum machine_mode promoted_mode, passed_mode, nominal_mode;
2605 /* Total space needed so far for args on the stack,
2606 given as a constant and a tree-expression. */
2607 struct args_size stack_args_size;
2608 tree fntype = TREE_TYPE (fndecl);
2609 tree fnargs = DECL_ARGUMENTS (fndecl);
2610 /* This is used for the arg pointer when referring to stack args. */
2611 rtx internal_arg_pointer;
2612 /* This is a dummy PARM_DECL that we used for the function result if
2613 the function returns a structure. */
2614 tree function_result_decl = 0;
2615 int nparmregs = list_length (fnargs) + LAST_VIRTUAL_REGISTER + 1;
2616 int varargs_setup = 0;
2617 rtx conversion_insns = 0;
2619 /* Nonzero if the last arg is named `__builtin_va_alist',
2620 which is used on some machines for old-fashioned non-ANSI varargs.h;
2621 this should be stuck onto the stack as if it had arrived there. */
2624 && (parm = tree_last (fnargs)) != 0
2626 && (! strcmp (IDENTIFIER_POINTER (DECL_NAME (parm)),
2627 "__builtin_va_alist")));
2629 /* Nonzero if function takes extra anonymous args.
2630 This means the last named arg must be on the stack
2631 right before the anonymous ones. */
2633 = (TYPE_ARG_TYPES (fntype) != 0
2634 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
2635 != void_type_node));
2637 /* If the reg that the virtual arg pointer will be translated into is
2638 not a fixed reg or is the stack pointer, make a copy of the virtual
2639 arg pointer, and address parms via the copy. The frame pointer is
2640 considered fixed even though it is not marked as such.
2642 The second time through, simply use ap to avoid generating rtx. */
2644 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
2645 || ! (fixed_regs[ARG_POINTER_REGNUM]
2646 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM))
2648 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
2650 internal_arg_pointer = virtual_incoming_args_rtx;
2651 current_function_internal_arg_pointer = internal_arg_pointer;
2653 stack_args_size.constant = 0;
2654 stack_args_size.var = 0;
2656 /* If struct value address is treated as the first argument, make it so. */
2657 if (aggregate_value_p (DECL_RESULT (fndecl))
2658 && ! current_function_returns_pcc_struct
2659 && struct_value_incoming_rtx == 0)
2661 tree type = build_pointer_type (fntype);
2663 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
2665 DECL_ARG_TYPE (function_result_decl) = type;
2666 TREE_CHAIN (function_result_decl) = fnargs;
2667 fnargs = function_result_decl;
2670 parm_reg_stack_loc = (rtx *) oballoc (nparmregs * sizeof (rtx));
2671 bzero (parm_reg_stack_loc, nparmregs * sizeof (rtx));
2673 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2674 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
2676 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX);
2679 /* We haven't yet found an argument that we must push and pretend the
2681 current_function_pretend_args_size = 0;
2683 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
2686 = (TREE_CODE (TREE_TYPE (parm)) == ARRAY_TYPE
2687 || TREE_CODE (TREE_TYPE (parm)) == RECORD_TYPE
2688 || TREE_CODE (TREE_TYPE (parm)) == UNION_TYPE);
2689 struct args_size stack_offset;
2690 struct args_size arg_size;
2691 int passed_pointer = 0;
2692 tree passed_type = DECL_ARG_TYPE (parm);
2694 /* Set LAST_NAMED if this is last named arg before some
2695 anonymous args. We treat it as if it were anonymous too. */
2696 int last_named = ((TREE_CHAIN (parm) == 0
2697 || DECL_NAME (TREE_CHAIN (parm)) == 0)
2698 && (vararg || stdarg));
2700 if (TREE_TYPE (parm) == error_mark_node
2701 /* This can happen after weird syntax errors
2702 or if an enum type is defined among the parms. */
2703 || TREE_CODE (parm) != PARM_DECL
2704 || passed_type == NULL)
2706 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = gen_rtx (MEM, BLKmode,
2708 TREE_USED (parm) = 1;
2712 /* For varargs.h function, save info about regs and stack space
2713 used by the individual args, not including the va_alist arg. */
2714 if (vararg && last_named)
2715 current_function_args_info = args_so_far;
2717 /* Find mode of arg as it is passed, and mode of arg
2718 as it should be during execution of this function. */
2719 passed_mode = TYPE_MODE (passed_type);
2720 nominal_mode = TYPE_MODE (TREE_TYPE (parm));
2722 /* If the parm's mode is VOID, its value doesn't matter,
2723 and avoid the usual things like emit_move_insn that could crash. */
2724 if (nominal_mode == VOIDmode)
2726 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = const0_rtx;
2730 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
2731 /* See if this arg was passed by invisible reference. */
2732 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
2733 passed_type, ! last_named))
2735 passed_type = build_pointer_type (passed_type);
2737 passed_mode = nominal_mode = Pmode;
2741 promoted_mode = passed_mode;
2743 #ifdef PROMOTE_FUNCTION_ARGS
2744 /* Compute the mode in which the arg is actually extended to. */
2745 if (TREE_CODE (passed_type) == INTEGER_TYPE
2746 || TREE_CODE (passed_type) == ENUMERAL_TYPE
2747 || TREE_CODE (passed_type) == BOOLEAN_TYPE
2748 || TREE_CODE (passed_type) == CHAR_TYPE
2749 || TREE_CODE (passed_type) == REAL_TYPE
2750 || TREE_CODE (passed_type) == POINTER_TYPE
2751 || TREE_CODE (passed_type) == OFFSET_TYPE)
2753 unsignedp = TREE_UNSIGNED (passed_type);
2754 PROMOTE_MODE (promoted_mode, unsignedp, passed_type);
2758 /* Let machine desc say which reg (if any) the parm arrives in.
2759 0 means it arrives on the stack. */
2760 #ifdef FUNCTION_INCOMING_ARG
2761 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
2762 passed_type, ! last_named);
2764 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
2765 passed_type, ! last_named);
2769 passed_mode = promoted_mode;
2771 #ifdef SETUP_INCOMING_VARARGS
2772 /* If this is the last named parameter, do any required setup for
2773 varargs or stdargs. We need to know about the case of this being an
2774 addressable type, in which case we skip the registers it
2775 would have arrived in.
2777 For stdargs, LAST_NAMED will be set for two parameters, the one that
2778 is actually the last named, and the dummy parameter. We only
2779 want to do this action once.
2781 Also, indicate when RTL generation is to be suppressed. */
2782 if (last_named && !varargs_setup)
2784 SETUP_INCOMING_VARARGS (args_so_far, passed_mode, passed_type,
2785 current_function_pretend_args_size,
2791 /* Determine parm's home in the stack,
2792 in case it arrives in the stack or we should pretend it did.
2794 Compute the stack position and rtx where the argument arrives
2797 There is one complexity here: If this was a parameter that would
2798 have been passed in registers, but wasn't only because it is
2799 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2800 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2801 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
2802 0 as it was the previous time. */
2804 locate_and_pad_parm (passed_mode, passed_type,
2805 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2808 #ifdef FUNCTION_INCOMING_ARG
2809 FUNCTION_INCOMING_ARG (args_so_far, passed_mode,
2812 || varargs_setup)) != 0,
2814 FUNCTION_ARG (args_so_far, passed_mode,
2816 ! last_named || varargs_setup) != 0,
2819 fndecl, &stack_args_size, &stack_offset, &arg_size);
2823 rtx offset_rtx = ARGS_SIZE_RTX (stack_offset);
2825 if (offset_rtx == const0_rtx)
2826 stack_parm = gen_rtx (MEM, passed_mode, internal_arg_pointer);
2828 stack_parm = gen_rtx (MEM, passed_mode,
2829 gen_rtx (PLUS, Pmode,
2830 internal_arg_pointer, offset_rtx));
2832 /* If this is a memory ref that contains aggregate components,
2833 mark it as such for cse and loop optimize. */
2834 MEM_IN_STRUCT_P (stack_parm) = aggregate;
2837 /* If this parameter was passed both in registers and in the stack,
2838 use the copy on the stack. */
2839 if (MUST_PASS_IN_STACK (passed_mode, passed_type))
2842 /* If this parm was passed part in regs and part in memory,
2843 pretend it arrived entirely in memory
2844 by pushing the register-part onto the stack.
2846 In the special case of a DImode or DFmode that is split,
2847 we could put it together in a pseudoreg directly,
2848 but for now that's not worth bothering with. */
2853 #ifdef FUNCTION_ARG_PARTIAL_NREGS
2854 nregs = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, passed_mode,
2855 passed_type, ! last_named);
2860 current_function_pretend_args_size
2861 = (((nregs * UNITS_PER_WORD) + (PARM_BOUNDARY / BITS_PER_UNIT) - 1)
2862 / (PARM_BOUNDARY / BITS_PER_UNIT)
2863 * (PARM_BOUNDARY / BITS_PER_UNIT));
2866 move_block_from_reg (REGNO (entry_parm),
2867 validize_mem (stack_parm), nregs);
2868 entry_parm = stack_parm;
2872 /* If we didn't decide this parm came in a register,
2873 by default it came on the stack. */
2874 if (entry_parm == 0)
2875 entry_parm = stack_parm;
2877 /* Record permanently how this parm was passed. */
2879 DECL_INCOMING_RTL (parm) = entry_parm;
2881 /* If there is actually space on the stack for this parm,
2882 count it in stack_args_size; otherwise set stack_parm to 0
2883 to indicate there is no preallocated stack slot for the parm. */
2885 if (entry_parm == stack_parm
2886 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
2887 /* On some machines, even if a parm value arrives in a register
2888 there is still an (uninitialized) stack slot allocated for it.
2890 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
2891 whether this parameter already has a stack slot allocated,
2892 because an arg block exists only if current_function_args_size
2893 is larger than some threshhold, and we haven't calculated that
2894 yet. So, for now, we just assume that stack slots never exist
2896 || REG_PARM_STACK_SPACE (fndecl) > 0
2900 stack_args_size.constant += arg_size.constant;
2902 ADD_PARM_SIZE (stack_args_size, arg_size.var);
2905 /* No stack slot was pushed for this parm. */
2908 /* Update info on where next arg arrives in registers. */
2910 FUNCTION_ARG_ADVANCE (args_so_far, passed_mode,
2911 passed_type, ! last_named);
2913 /* If this is our second time through, we are done with this parm. */
2917 /* If we can't trust the parm stack slot to be aligned enough
2918 for its ultimate type, don't use that slot after entry.
2919 We'll make another stack slot, if we need one. */
2921 #ifdef FUNCTION_ARG_BOUNDARY
2922 int thisparm_boundary
2923 = FUNCTION_ARG_BOUNDARY (passed_mode, passed_type);
2925 int thisparm_boundary = PARM_BOUNDARY;
2928 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
2932 /* Now adjust STACK_PARM to the mode and precise location
2933 where this parameter should live during execution,
2934 if we discover that it must live in the stack during execution.
2935 To make debuggers happier on big-endian machines, we store
2936 the value in the last bytes of the space available. */
2938 if (nominal_mode != BLKmode && nominal_mode != passed_mode
2943 #if BYTES_BIG_ENDIAN
2944 if (GET_MODE_SIZE (nominal_mode) < UNITS_PER_WORD)
2945 stack_offset.constant += (GET_MODE_SIZE (passed_mode)
2946 - GET_MODE_SIZE (nominal_mode));
2949 offset_rtx = ARGS_SIZE_RTX (stack_offset);
2950 if (offset_rtx == const0_rtx)
2951 stack_parm = gen_rtx (MEM, nominal_mode, internal_arg_pointer);
2953 stack_parm = gen_rtx (MEM, nominal_mode,
2954 gen_rtx (PLUS, Pmode,
2955 internal_arg_pointer, offset_rtx));
2957 /* If this is a memory ref that contains aggregate components,
2958 mark it as such for cse and loop optimize. */
2959 MEM_IN_STRUCT_P (stack_parm) = aggregate;
2962 /* ENTRY_PARM is an RTX for the parameter as it arrives,
2963 in the mode in which it arrives.
2964 STACK_PARM is an RTX for a stack slot where the parameter can live
2965 during the function (in case we want to put it there).
2966 STACK_PARM is 0 if no stack slot was pushed for it.
2968 Now output code if necessary to convert ENTRY_PARM to
2969 the type in which this function declares it,
2970 and store that result in an appropriate place,
2971 which may be a pseudo reg, may be STACK_PARM,
2972 or may be a local stack slot if STACK_PARM is 0.
2974 Set DECL_RTL to that place. */
2976 if (nominal_mode == BLKmode)
2978 /* If a BLKmode arrives in registers, copy it to a stack slot. */
2979 if (GET_CODE (entry_parm) == REG)
2981 int size_stored = CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm)),
2984 /* Note that we will be storing an integral number of words.
2985 So we have to be careful to ensure that we allocate an
2986 integral number of words. We do this below in the
2987 assign_stack_local if space was not allocated in the argument
2988 list. If it was, this will not work if PARM_BOUNDARY is not
2989 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2990 if it becomes a problem. */
2992 if (stack_parm == 0)
2995 = assign_stack_local (GET_MODE (entry_parm), size_stored, 0);
2996 /* If this is a memory ref that contains aggregate components,
2997 mark it as such for cse and loop optimize. */
2998 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3001 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
3004 move_block_from_reg (REGNO (entry_parm),
3005 validize_mem (stack_parm),
3006 size_stored / UNITS_PER_WORD);
3008 DECL_RTL (parm) = stack_parm;
3010 else if (! ((obey_regdecls && ! DECL_REGISTER (parm)
3011 && ! DECL_INLINE (fndecl))
3012 /* layout_decl may set this. */
3013 || TREE_ADDRESSABLE (parm)
3014 || TREE_SIDE_EFFECTS (parm)
3015 /* If -ffloat-store specified, don't put explicit
3016 float variables into registers. */
3017 || (flag_float_store
3018 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
3019 /* Always assign pseudo to structure return or item passed
3020 by invisible reference. */
3021 || passed_pointer || parm == function_result_decl)
3023 /* Store the parm in a pseudoregister during the function, but we
3024 may need to do it in a wider mode. */
3026 register rtx parmreg;
3028 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
3029 if (TREE_CODE (TREE_TYPE (parm)) == INTEGER_TYPE
3030 || TREE_CODE (TREE_TYPE (parm)) == ENUMERAL_TYPE
3031 || TREE_CODE (TREE_TYPE (parm)) == BOOLEAN_TYPE
3032 || TREE_CODE (TREE_TYPE (parm)) == CHAR_TYPE
3033 || TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE
3034 || TREE_CODE (TREE_TYPE (parm)) == POINTER_TYPE
3035 || TREE_CODE (TREE_TYPE (parm)) == OFFSET_TYPE)
3037 PROMOTE_MODE (nominal_mode, unsignedp, TREE_TYPE (parm));
3040 parmreg = gen_reg_rtx (nominal_mode);
3041 REG_USERVAR_P (parmreg) = 1;
3043 /* If this was an item that we received a pointer to, set DECL_RTL
3047 DECL_RTL (parm) = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (passed_type)), parmreg);
3048 MEM_IN_STRUCT_P (DECL_RTL (parm)) = aggregate;
3051 DECL_RTL (parm) = parmreg;
3053 /* Copy the value into the register. */
3054 if (GET_MODE (parmreg) != GET_MODE (entry_parm))
3056 /* If ENTRY_PARM is a hard register, it might be in a register
3057 not valid for operating in its mode (e.g., an odd-numbered
3058 register for a DFmode). In that case, moves are the only
3059 thing valid, so we can't do a convert from there. This
3060 occurs when the calling sequence allow such misaligned
3063 In addition, the conversion may involve a call, which could
3064 clobber parameters which haven't been copied to pseudo
3065 registers yet. Therefore, we must first copy the parm to
3066 a pseudo reg here, and save the conversion until after all
3067 parameters have been moved. */
3069 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
3071 emit_move_insn (tempreg, validize_mem (entry_parm));
3073 push_to_sequence (conversion_insns);
3074 convert_move (parmreg, tempreg);
3075 conversion_insns = get_insns ();
3079 emit_move_insn (parmreg, validize_mem (entry_parm));
3081 /* If we were passed a pointer but the actual value
3082 can safely live in a register, put it in one. */
3083 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
3084 && ! ((obey_regdecls && ! DECL_REGISTER (parm)
3085 && ! DECL_INLINE (fndecl))
3086 /* layout_decl may set this. */
3087 || TREE_ADDRESSABLE (parm)
3088 || TREE_SIDE_EFFECTS (parm)
3089 /* If -ffloat-store specified, don't put explicit
3090 float variables into registers. */
3091 || (flag_float_store
3092 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE)))
3094 /* We can't use nominal_mode, because it will have been set to
3095 Pmode above. We must use the actual mode of the parm. */
3096 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3097 emit_move_insn (parmreg, DECL_RTL (parm));
3098 DECL_RTL (parm) = parmreg;
3101 /* In any case, record the parm's desired stack location
3102 in case we later discover it must live in the stack. */
3103 if (REGNO (parmreg) >= nparmregs)
3106 nparmregs = REGNO (parmreg) + 5;
3107 new = (rtx *) oballoc (nparmregs * sizeof (rtx));
3108 bcopy (parm_reg_stack_loc, new, nparmregs * sizeof (rtx));
3109 parm_reg_stack_loc = new;
3111 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
3113 /* Mark the register as eliminable if we did no conversion
3114 and it was copied from memory at a fixed offset,
3115 and the arg pointer was not copied to a pseudo-reg.
3116 If the arg pointer is a pseudo reg or the offset formed
3117 an invalid address, such memory-equivalences
3118 as we make here would screw up life analysis for it. */
3119 if (nominal_mode == passed_mode
3120 && GET_CODE (entry_parm) == MEM
3121 && entry_parm == stack_parm
3122 && stack_offset.var == 0
3123 && reg_mentioned_p (virtual_incoming_args_rtx,
3124 XEXP (entry_parm, 0)))
3125 REG_NOTES (get_last_insn ())
3126 = gen_rtx (EXPR_LIST, REG_EQUIV,
3127 entry_parm, REG_NOTES (get_last_insn ()));
3129 /* For pointer data type, suggest pointer register. */
3130 if (TREE_CODE (TREE_TYPE (parm)) == POINTER_TYPE)
3131 mark_reg_pointer (parmreg);
3135 /* Value must be stored in the stack slot STACK_PARM
3136 during function execution. */
3138 if (passed_mode != nominal_mode)
3140 /* Conversion is required. */
3141 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
3143 emit_move_insn (tempreg, validize_mem (entry_parm));
3145 push_to_sequence (conversion_insns);
3146 entry_parm = convert_to_mode (nominal_mode, tempreg,
3147 TREE_UNSIGNED (TREE_TYPE (parm)));
3148 conversion_insns = get_insns ();
3152 if (entry_parm != stack_parm)
3154 if (stack_parm == 0)
3157 = assign_stack_local (GET_MODE (entry_parm),
3158 GET_MODE_SIZE (GET_MODE (entry_parm)), 0);
3159 /* If this is a memory ref that contains aggregate components,
3160 mark it as such for cse and loop optimize. */
3161 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3164 if (passed_mode != nominal_mode)
3166 push_to_sequence (conversion_insns);
3167 emit_move_insn (validize_mem (stack_parm),
3168 validize_mem (entry_parm));
3169 conversion_insns = get_insns ();
3173 emit_move_insn (validize_mem (stack_parm),
3174 validize_mem (entry_parm));
3177 DECL_RTL (parm) = stack_parm;
3180 /* If this "parameter" was the place where we are receiving the
3181 function's incoming structure pointer, set up the result. */
3182 if (parm == function_result_decl)
3183 DECL_RTL (DECL_RESULT (fndecl))
3184 = gen_rtx (MEM, DECL_MODE (DECL_RESULT (fndecl)), DECL_RTL (parm));
3186 if (TREE_THIS_VOLATILE (parm))
3187 MEM_VOLATILE_P (DECL_RTL (parm)) = 1;
3188 if (TREE_READONLY (parm))
3189 RTX_UNCHANGING_P (DECL_RTL (parm)) = 1;
3192 /* Output all parameter conversion instructions (possibly including calls)
3193 now that all parameters have been copied out of hard registers. */
3194 emit_insns (conversion_insns);
3196 max_parm_reg = max_reg_num ();
3197 last_parm_insn = get_last_insn ();
3199 current_function_args_size = stack_args_size.constant;
3201 /* Adjust function incoming argument size for alignment and
3204 #ifdef REG_PARM_STACK_SPACE
3205 #ifndef MAYBE_REG_PARM_STACK_SPACE
3206 current_function_args_size = MAX (current_function_args_size,
3207 REG_PARM_STACK_SPACE (fndecl));
3211 #ifdef STACK_BOUNDARY
3212 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
3214 current_function_args_size
3215 = ((current_function_args_size + STACK_BYTES - 1)
3216 / STACK_BYTES) * STACK_BYTES;
3219 #ifdef ARGS_GROW_DOWNWARD
3220 current_function_arg_offset_rtx
3221 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
3222 : expand_expr (size_binop (MINUS_EXPR, stack_args_size.var,
3223 size_int (-stack_args_size.constant)),
3224 NULL_RTX, VOIDmode, 0));
3226 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
3229 /* See how many bytes, if any, of its args a function should try to pop
3232 current_function_pops_args = RETURN_POPS_ARGS (TREE_TYPE (fndecl),
3233 current_function_args_size);
3235 /* For stdarg.h function, save info about regs and stack space
3236 used by the named args. */
3239 current_function_args_info = args_so_far;
3241 /* Set the rtx used for the function return value. Put this in its
3242 own variable so any optimizers that need this information don't have
3243 to include tree.h. Do this here so it gets done when an inlined
3244 function gets output. */
3246 current_function_return_rtx = DECL_RTL (DECL_RESULT (fndecl));
3249 /* Compute the size and offset from the start of the stacked arguments for a
3250 parm passed in mode PASSED_MODE and with type TYPE.
3252 INITIAL_OFFSET_PTR points to the current offset into the stacked
3255 The starting offset and size for this parm are returned in *OFFSET_PTR
3256 and *ARG_SIZE_PTR, respectively.
3258 IN_REGS is non-zero if the argument will be passed in registers. It will
3259 never be set if REG_PARM_STACK_SPACE is not defined.
3261 FNDECL is the function in which the argument was defined.
3263 There are two types of rounding that are done. The first, controlled by
3264 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3265 list to be aligned to the specific boundary (in bits). This rounding
3266 affects the initial and starting offsets, but not the argument size.
3268 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3269 optionally rounds the size of the parm to PARM_BOUNDARY. The
3270 initial offset is not affected by this rounding, while the size always
3271 is and the starting offset may be. */
3273 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
3274 initial_offset_ptr is positive because locate_and_pad_parm's
3275 callers pass in the total size of args so far as
3276 initial_offset_ptr. arg_size_ptr is always positive.*/
3278 static void pad_to_arg_alignment (), pad_below ();
3281 locate_and_pad_parm (passed_mode, type, in_regs, fndecl,
3282 initial_offset_ptr, offset_ptr, arg_size_ptr)
3283 enum machine_mode passed_mode;
3287 struct args_size *initial_offset_ptr;
3288 struct args_size *offset_ptr;
3289 struct args_size *arg_size_ptr;
3292 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3293 enum direction where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3294 int boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3295 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3296 int reg_parm_stack_space = 0;
3298 #ifdef REG_PARM_STACK_SPACE
3299 /* If we have found a stack parm before we reach the end of the
3300 area reserved for registers, skip that area. */
3303 #ifdef MAYBE_REG_PARM_STACK_SPACE
3304 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3306 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3308 if (reg_parm_stack_space > 0)
3310 if (initial_offset_ptr->var)
3312 initial_offset_ptr->var
3313 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3314 size_int (reg_parm_stack_space));
3315 initial_offset_ptr->constant = 0;
3317 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3318 initial_offset_ptr->constant = reg_parm_stack_space;
3321 #endif /* REG_PARM_STACK_SPACE */
3323 arg_size_ptr->var = 0;
3324 arg_size_ptr->constant = 0;
3326 #ifdef ARGS_GROW_DOWNWARD
3327 if (initial_offset_ptr->var)
3329 offset_ptr->constant = 0;
3330 offset_ptr->var = size_binop (MINUS_EXPR, integer_zero_node,
3331 initial_offset_ptr->var);
3335 offset_ptr->constant = - initial_offset_ptr->constant;
3336 offset_ptr->var = 0;
3338 if (where_pad == upward
3339 && (TREE_CODE (sizetree) != INTEGER_CST
3340 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
3341 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3342 SUB_PARM_SIZE (*offset_ptr, sizetree);
3343 if (where_pad != downward)
3344 pad_to_arg_alignment (offset_ptr, boundary);
3345 if (initial_offset_ptr->var)
3347 arg_size_ptr->var = size_binop (MINUS_EXPR,
3348 size_binop (MINUS_EXPR,
3350 initial_offset_ptr->var),
3355 arg_size_ptr->constant = (- initial_offset_ptr->constant -
3356 offset_ptr->constant);
3358 /* ADD_PARM_SIZE (*arg_size_ptr, sizetree); */
3359 if (where_pad == downward)
3360 pad_below (arg_size_ptr, passed_mode, sizetree);
3361 #else /* !ARGS_GROW_DOWNWARD */
3362 pad_to_arg_alignment (initial_offset_ptr, boundary);
3363 *offset_ptr = *initial_offset_ptr;
3364 if (where_pad == downward)
3365 pad_below (offset_ptr, passed_mode, sizetree);
3367 #ifdef PUSH_ROUNDING
3368 if (passed_mode != BLKmode)
3369 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3372 if (where_pad != none
3373 && (TREE_CODE (sizetree) != INTEGER_CST
3374 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
3375 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3377 ADD_PARM_SIZE (*arg_size_ptr, sizetree);
3378 #endif /* ARGS_GROW_DOWNWARD */
3381 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3382 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3385 pad_to_arg_alignment (offset_ptr, boundary)
3386 struct args_size *offset_ptr;
3389 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3391 if (boundary > BITS_PER_UNIT)
3393 if (offset_ptr->var)
3396 #ifdef ARGS_GROW_DOWNWARD
3401 (ARGS_SIZE_TREE (*offset_ptr),
3402 boundary / BITS_PER_UNIT);
3403 offset_ptr->constant = 0; /*?*/
3406 offset_ptr->constant =
3407 #ifdef ARGS_GROW_DOWNWARD
3408 FLOOR_ROUND (offset_ptr->constant, boundary_in_bytes);
3410 CEIL_ROUND (offset_ptr->constant, boundary_in_bytes);
3416 pad_below (offset_ptr, passed_mode, sizetree)
3417 struct args_size *offset_ptr;
3418 enum machine_mode passed_mode;
3421 if (passed_mode != BLKmode)
3423 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3424 offset_ptr->constant
3425 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3426 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3427 - GET_MODE_SIZE (passed_mode));
3431 if (TREE_CODE (sizetree) != INTEGER_CST
3432 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3434 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3435 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3437 ADD_PARM_SIZE (*offset_ptr, s2);
3438 SUB_PARM_SIZE (*offset_ptr, sizetree);
3444 round_down (value, divisor)
3448 return size_binop (MULT_EXPR,
3449 size_binop (FLOOR_DIV_EXPR, value, size_int (divisor)),
3450 size_int (divisor));
3453 /* Walk the tree of blocks describing the binding levels within a function
3454 and warn about uninitialized variables.
3455 This is done after calling flow_analysis and before global_alloc
3456 clobbers the pseudo-regs to hard regs. */
3459 uninitialized_vars_warning (block)
3462 register tree decl, sub;
3463 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3465 if (TREE_CODE (decl) == VAR_DECL
3466 /* These warnings are unreliable for and aggregates
3467 because assigning the fields one by one can fail to convince
3468 flow.c that the entire aggregate was initialized.
3469 Unions are troublesome because members may be shorter. */
3470 && TREE_CODE (TREE_TYPE (decl)) != RECORD_TYPE
3471 && TREE_CODE (TREE_TYPE (decl)) != UNION_TYPE
3472 && TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE
3473 && DECL_RTL (decl) != 0
3474 && GET_CODE (DECL_RTL (decl)) == REG
3475 && regno_uninitialized (REGNO (DECL_RTL (decl))))
3476 warning_with_decl (decl,
3477 "`%s' may be used uninitialized in this function");
3478 if (TREE_CODE (decl) == VAR_DECL
3479 && DECL_RTL (decl) != 0
3480 && GET_CODE (DECL_RTL (decl)) == REG
3481 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
3482 warning_with_decl (decl,
3483 "variable `%s' may be clobbered by `longjmp'");
3485 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
3486 uninitialized_vars_warning (sub);
3489 /* Do the appropriate part of uninitialized_vars_warning
3490 but for arguments instead of local variables. */
3493 setjmp_args_warning (block)
3497 for (decl = DECL_ARGUMENTS (current_function_decl);
3498 decl; decl = TREE_CHAIN (decl))
3499 if (DECL_RTL (decl) != 0
3500 && GET_CODE (DECL_RTL (decl)) == REG
3501 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
3502 warning_with_decl (decl, "argument `%s' may be clobbered by `longjmp'");
3505 /* If this function call setjmp, put all vars into the stack
3506 unless they were declared `register'. */
3509 setjmp_protect (block)
3512 register tree decl, sub;
3513 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3514 if ((TREE_CODE (decl) == VAR_DECL
3515 || TREE_CODE (decl) == PARM_DECL)
3516 && DECL_RTL (decl) != 0
3517 && GET_CODE (DECL_RTL (decl)) == REG
3518 /* If this variable came from an inline function, it must be
3519 that it's life doesn't overlap the setjmp. If there was a
3520 setjmp in the function, it would already be in memory. We
3521 must exclude such variable because their DECL_RTL might be
3522 set to strange things such as virtual_stack_vars_rtx. */
3523 && ! DECL_FROM_INLINE (decl)
3525 #ifdef NON_SAVING_SETJMP
3526 /* If longjmp doesn't restore the registers,
3527 don't put anything in them. */
3531 ! DECL_REGISTER (decl)))
3532 put_var_into_stack (decl);
3533 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
3534 setjmp_protect (sub);
3537 /* Like the previous function, but for args instead of local variables. */
3540 setjmp_protect_args ()
3542 register tree decl, sub;
3543 for (decl = DECL_ARGUMENTS (current_function_decl);
3544 decl; decl = TREE_CHAIN (decl))
3545 if ((TREE_CODE (decl) == VAR_DECL
3546 || TREE_CODE (decl) == PARM_DECL)
3547 && DECL_RTL (decl) != 0
3548 && GET_CODE (DECL_RTL (decl)) == REG
3550 /* If longjmp doesn't restore the registers,
3551 don't put anything in them. */
3552 #ifdef NON_SAVING_SETJMP
3556 ! DECL_REGISTER (decl)))
3557 put_var_into_stack (decl);
3560 /* Return the context-pointer register corresponding to DECL,
3561 or 0 if it does not need one. */
3564 lookup_static_chain (decl)
3567 tree context = decl_function_context (decl);
3573 /* We treat inline_function_decl as an alias for the current function
3574 because that is the inline function whose vars, types, etc.
3575 are being merged into the current function.
3576 See expand_inline_function. */
3577 if (context == current_function_decl || context == inline_function_decl)
3578 return virtual_stack_vars_rtx;
3580 for (link = context_display; link; link = TREE_CHAIN (link))
3581 if (TREE_PURPOSE (link) == context)
3582 return RTL_EXPR_RTL (TREE_VALUE (link));
3587 /* Convert a stack slot address ADDR for variable VAR
3588 (from a containing function)
3589 into an address valid in this function (using a static chain). */
3592 fix_lexical_addr (addr, var)
3598 tree context = decl_function_context (var);
3599 struct function *fp;
3602 /* If this is the present function, we need not do anything. */
3603 if (context == current_function_decl || context == inline_function_decl)
3606 for (fp = outer_function_chain; fp; fp = fp->next)
3607 if (fp->decl == context)
3613 /* Decode given address as base reg plus displacement. */
3614 if (GET_CODE (addr) == REG)
3615 basereg = addr, displacement = 0;
3616 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
3617 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
3621 /* We accept vars reached via the containing function's
3622 incoming arg pointer and via its stack variables pointer. */
3623 if (basereg == fp->internal_arg_pointer)
3625 /* If reached via arg pointer, get the arg pointer value
3626 out of that function's stack frame.
3628 There are two cases: If a separate ap is needed, allocate a
3629 slot in the outer function for it and dereference it that way.
3630 This is correct even if the real ap is actually a pseudo.
3631 Otherwise, just adjust the offset from the frame pointer to
3634 #ifdef NEED_SEPARATE_AP
3637 if (fp->arg_pointer_save_area == 0)
3638 fp->arg_pointer_save_area
3639 = assign_outer_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0, fp);
3641 addr = fix_lexical_addr (XEXP (fp->arg_pointer_save_area, 0), var);
3642 addr = memory_address (Pmode, addr);
3644 base = copy_to_reg (gen_rtx (MEM, Pmode, addr));
3646 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
3647 base = lookup_static_chain (var);
3651 else if (basereg == virtual_stack_vars_rtx)
3653 /* This is the same code as lookup_static_chain, duplicated here to
3654 avoid an extra call to decl_function_context. */
3657 for (link = context_display; link; link = TREE_CHAIN (link))
3658 if (TREE_PURPOSE (link) == context)
3660 base = RTL_EXPR_RTL (TREE_VALUE (link));
3668 /* Use same offset, relative to appropriate static chain or argument
3670 return plus_constant (base, displacement);
3673 /* Return the address of the trampoline for entering nested fn FUNCTION.
3674 If necessary, allocate a trampoline (in the stack frame)
3675 and emit rtl to initialize its contents (at entry to this function). */
3678 trampoline_address (function)
3684 struct function *fp;
3687 /* Find an existing trampoline and return it. */
3688 for (link = trampoline_list; link; link = TREE_CHAIN (link))
3689 if (TREE_PURPOSE (link) == function)
3690 return XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0);
3691 for (fp = outer_function_chain; fp; fp = fp->next)
3692 for (link = fp->trampoline_list; link; link = TREE_CHAIN (link))
3693 if (TREE_PURPOSE (link) == function)
3695 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
3697 return round_trampoline_addr (tramp);
3700 /* None exists; we must make one. */
3702 /* Find the `struct function' for the function containing FUNCTION. */
3704 fn_context = decl_function_context (function);
3705 if (fn_context != current_function_decl)
3706 for (fp = outer_function_chain; fp; fp = fp->next)
3707 if (fp->decl == fn_context)
3710 /* Allocate run-time space for this trampoline
3711 (usually in the defining function's stack frame). */
3712 #ifdef ALLOCATE_TRAMPOLINE
3713 tramp = ALLOCATE_TRAMPOLINE (fp);
3715 /* If rounding needed, allocate extra space
3716 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
3717 #ifdef TRAMPOLINE_ALIGNMENT
3718 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE + TRAMPOLINE_ALIGNMENT - 1)
3720 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE)
3723 tramp = assign_outer_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0, fp);
3725 tramp = assign_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0);
3728 /* Record the trampoline for reuse and note it for later initialization
3729 by expand_function_end. */
3732 push_obstacks (fp->current_obstack, fp->function_maybepermanent_obstack);
3733 rtlexp = make_node (RTL_EXPR);
3734 RTL_EXPR_RTL (rtlexp) = tramp;
3735 fp->trampoline_list = tree_cons (function, rtlexp, fp->trampoline_list);
3740 /* Make the RTL_EXPR node temporary, not momentary, so that the
3741 trampoline_list doesn't become garbage. */
3742 int momentary = suspend_momentary ();
3743 rtlexp = make_node (RTL_EXPR);
3744 resume_momentary (momentary);
3746 RTL_EXPR_RTL (rtlexp) = tramp;
3747 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
3750 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
3751 return round_trampoline_addr (tramp);
3754 /* Given a trampoline address,
3755 round it to multiple of TRAMPOLINE_ALIGNMENT. */
3758 round_trampoline_addr (tramp)
3761 #ifdef TRAMPOLINE_ALIGNMENT
3762 /* Round address up to desired boundary. */
3763 rtx temp = gen_reg_rtx (Pmode);
3764 temp = expand_binop (Pmode, add_optab, tramp,
3765 GEN_INT (TRAMPOLINE_ALIGNMENT - 1),
3766 temp, 0, OPTAB_LIB_WIDEN);
3767 tramp = expand_binop (Pmode, and_optab, temp,
3768 GEN_INT (- TRAMPOLINE_ALIGNMENT),
3769 temp, 0, OPTAB_LIB_WIDEN);
3774 /* The functions identify_blocks and reorder_blocks provide a way to
3775 reorder the tree of BLOCK nodes, for optimizers that reshuffle or
3776 duplicate portions of the RTL code. Call identify_blocks before
3777 changing the RTL, and call reorder_blocks after. */
3779 static int all_blocks ();
3780 static tree blocks_nreverse ();
3782 /* Put all this function's BLOCK nodes into a vector, and return it.
3783 Also store in each NOTE for the beginning or end of a block
3784 the index of that block in the vector.
3785 The arguments are TOP_BLOCK, the top-level block of the function,
3786 and INSNS, the insn chain of the function. */
3789 identify_blocks (top_block, insns)
3797 int next_block_number = 0;
3798 int current_block_number = 0;
3804 n_blocks = all_blocks (top_block, 0);
3805 block_vector = (tree *) xmalloc (n_blocks * sizeof (tree));
3806 block_stack = (int *) alloca (n_blocks * sizeof (int));
3808 all_blocks (top_block, block_vector);
3810 for (insn = insns; insn; insn = NEXT_INSN (insn))
3811 if (GET_CODE (insn) == NOTE)
3813 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
3815 block_stack[depth++] = current_block_number;
3816 current_block_number = next_block_number;
3817 NOTE_BLOCK_NUMBER (insn) = next_block_number++;
3819 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
3821 current_block_number = block_stack[--depth];
3822 NOTE_BLOCK_NUMBER (insn) = current_block_number;
3826 return block_vector;
3829 /* Given BLOCK_VECTOR which was returned by identify_blocks,
3830 and a revised instruction chain, rebuild the tree structure
3831 of BLOCK nodes to correspond to the new order of RTL.
3832 The new block tree is inserted below TOP_BLOCK.
3833 Returns the current top-level block. */
3836 reorder_blocks (block_vector, top_block, insns)
3841 tree current_block = top_block;
3844 if (block_vector == 0)
3847 /* Prune the old tree away, so that it doesn't get in the way. */
3848 BLOCK_SUBBLOCKS (current_block) = 0;
3850 for (insn = insns; insn; insn = NEXT_INSN (insn))
3851 if (GET_CODE (insn) == NOTE)
3853 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
3855 tree block = block_vector[NOTE_BLOCK_NUMBER (insn)];
3856 /* If we have seen this block before, copy it. */
3857 if (TREE_ASM_WRITTEN (block))
3858 block = copy_node (block);
3859 BLOCK_SUBBLOCKS (block) = 0;
3860 TREE_ASM_WRITTEN (block) = 1;
3861 BLOCK_SUPERCONTEXT (block) = current_block;
3862 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3863 BLOCK_SUBBLOCKS (current_block) = block;
3864 current_block = block;
3865 NOTE_SOURCE_FILE (insn) = 0;
3867 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
3869 BLOCK_SUBBLOCKS (current_block)
3870 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3871 current_block = BLOCK_SUPERCONTEXT (current_block);
3872 NOTE_SOURCE_FILE (insn) = 0;
3876 return current_block;
3879 /* Reverse the order of elements in the chain T of blocks,
3880 and return the new head of the chain (old last element). */
3886 register tree prev = 0, decl, next;
3887 for (decl = t; decl; decl = next)
3889 next = BLOCK_CHAIN (decl);
3890 BLOCK_CHAIN (decl) = prev;
3896 /* Count the subblocks of BLOCK, and list them all into the vector VECTOR.
3897 Also clear TREE_ASM_WRITTEN in all blocks. */
3900 all_blocks (block, vector)
3907 TREE_ASM_WRITTEN (block) = 0;
3908 /* Record this block. */
3912 /* Record the subblocks, and their subblocks. */
3913 for (subblocks = BLOCK_SUBBLOCKS (block);
3914 subblocks; subblocks = BLOCK_CHAIN (subblocks))
3915 n_blocks += all_blocks (subblocks, vector ? vector + n_blocks : 0);
3920 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
3921 and initialize static variables for generating RTL for the statements
3925 init_function_start (subr, filename, line)
3932 init_stmt_for_function ();
3934 cse_not_expected = ! optimize;
3936 /* Caller save not needed yet. */
3937 caller_save_needed = 0;
3939 /* No stack slots have been made yet. */
3940 stack_slot_list = 0;
3942 /* There is no stack slot for handling nonlocal gotos. */
3943 nonlocal_goto_handler_slot = 0;
3944 nonlocal_goto_stack_level = 0;
3946 /* No labels have been declared for nonlocal use. */
3947 nonlocal_labels = 0;
3949 /* No function calls so far in this function. */
3950 function_call_count = 0;
3952 /* No parm regs have been allocated.
3953 (This is important for output_inline_function.) */
3954 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
3956 /* Initialize the RTL mechanism. */
3959 /* Initialize the queue of pending postincrement and postdecrements,
3960 and some other info in expr.c. */
3963 /* We haven't done register allocation yet. */
3966 init_const_rtx_hash_table ();
3968 current_function_name = (*decl_printable_name) (subr, &junk);
3970 /* Nonzero if this is a nested function that uses a static chain. */
3972 current_function_needs_context
3973 = (decl_function_context (current_function_decl) != 0);
3975 /* Set if a call to setjmp is seen. */
3976 current_function_calls_setjmp = 0;
3978 /* Set if a call to longjmp is seen. */
3979 current_function_calls_longjmp = 0;
3981 current_function_calls_alloca = 0;
3982 current_function_has_nonlocal_label = 0;
3983 current_function_contains_functions = 0;
3985 current_function_returns_pcc_struct = 0;
3986 current_function_returns_struct = 0;
3987 current_function_epilogue_delay_list = 0;
3988 current_function_uses_const_pool = 0;
3989 current_function_uses_pic_offset_table = 0;
3991 /* We have not yet needed to make a label to jump to for tail-recursion. */
3992 tail_recursion_label = 0;
3994 /* We haven't had a need to make a save area for ap yet. */
3996 arg_pointer_save_area = 0;
3998 /* No stack slots allocated yet. */
4001 /* No SAVE_EXPRs in this function yet. */
4004 /* No RTL_EXPRs in this function yet. */
4007 /* We have not allocated any temporaries yet. */
4009 temp_slot_level = 0;
4011 /* Within function body, compute a type's size as soon it is laid out. */
4012 immediate_size_expand++;
4014 init_pending_stack_adjust ();
4015 inhibit_defer_pop = 0;
4017 current_function_outgoing_args_size = 0;
4019 /* Initialize the insn lengths. */
4020 init_insn_lengths ();
4022 /* Prevent ever trying to delete the first instruction of a function.
4023 Also tell final how to output a linenum before the function prologue. */
4024 emit_line_note (filename, line);
4026 /* Make sure first insn is a note even if we don't want linenums.
4027 This makes sure the first insn will never be deleted.
4028 Also, final expects a note to appear there. */
4029 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4031 /* Set flags used by final.c. */
4032 if (aggregate_value_p (DECL_RESULT (subr)))
4034 #ifdef PCC_STATIC_STRUCT_RETURN
4035 if (flag_pcc_struct_return)
4036 current_function_returns_pcc_struct = 1;
4039 current_function_returns_struct = 1;
4042 /* Warn if this value is an aggregate type,
4043 regardless of which calling convention we are using for it. */
4044 if (warn_aggregate_return
4045 && (TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == RECORD_TYPE
4046 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == UNION_TYPE
4047 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == ARRAY_TYPE))
4048 warning ("function returns an aggregate");
4050 current_function_returns_pointer
4051 = (TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == POINTER_TYPE);
4053 /* Indicate that we need to distinguish between the return value of the
4054 present function and the return value of a function being called. */
4055 rtx_equal_function_value_matters = 1;
4057 /* Indicate that we have not instantiated virtual registers yet. */
4058 virtuals_instantiated = 0;
4060 /* Indicate we have no need of a frame pointer yet. */
4061 frame_pointer_needed = 0;
4063 /* By default assume not varargs. */
4064 current_function_varargs = 0;
4067 /* Indicate that the current function uses extra args
4068 not explicitly mentioned in the argument list in any fashion. */
4073 current_function_varargs = 1;
4076 /* Expand a call to __main at the beginning of a possible main function. */
4079 expand_main_function ()
4081 #if !defined (INIT_SECTION_ASM_OP) || defined (INVOKE__main)
4082 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__main"), 0,
4084 #endif /* not INIT_SECTION_ASM_OP or INVOKE__main */
4087 /* Start the RTL for a new function, and set variables used for
4089 SUBR is the FUNCTION_DECL node.
4090 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4091 the function's parameters, which must be run at any return statement. */
4094 expand_function_start (subr, parms_have_cleanups)
4096 int parms_have_cleanups;
4102 /* Make sure volatile mem refs aren't considered
4103 valid operands of arithmetic insns. */
4104 init_recog_no_volatile ();
4106 /* If function gets a static chain arg, store it in the stack frame.
4107 Do this first, so it gets the first stack slot offset. */
4108 if (current_function_needs_context)
4110 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4111 emit_move_insn (last_ptr, static_chain_incoming_rtx);
4114 /* If the parameters of this function need cleaning up, get a label
4115 for the beginning of the code which executes those cleanups. This must
4116 be done before doing anything with return_label. */
4117 if (parms_have_cleanups)
4118 cleanup_label = gen_label_rtx ();
4122 /* Make the label for return statements to jump to, if this machine
4123 does not have a one-instruction return and uses an epilogue,
4124 or if it returns a structure, or if it has parm cleanups. */
4126 if (cleanup_label == 0 && HAVE_return
4127 && ! current_function_returns_pcc_struct
4128 && ! (current_function_returns_struct && ! optimize))
4131 return_label = gen_label_rtx ();
4133 return_label = gen_label_rtx ();
4136 /* Initialize rtx used to return the value. */
4137 /* Do this before assign_parms so that we copy the struct value address
4138 before any library calls that assign parms might generate. */
4140 /* Decide whether to return the value in memory or in a register. */
4141 if (aggregate_value_p (DECL_RESULT (subr)))
4143 /* Returning something that won't go in a register. */
4144 register rtx value_address;
4146 #ifdef PCC_STATIC_STRUCT_RETURN
4147 if (current_function_returns_pcc_struct)
4149 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4150 value_address = assemble_static_space (size);
4155 /* Expect to be passed the address of a place to store the value.
4156 If it is passed as an argument, assign_parms will take care of
4158 if (struct_value_incoming_rtx)
4160 value_address = gen_reg_rtx (Pmode);
4161 emit_move_insn (value_address, struct_value_incoming_rtx);
4165 DECL_RTL (DECL_RESULT (subr))
4166 = gen_rtx (MEM, DECL_MODE (DECL_RESULT (subr)),
4169 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4170 /* If return mode is void, this decl rtl should not be used. */
4171 DECL_RTL (DECL_RESULT (subr)) = 0;
4172 else if (parms_have_cleanups)
4174 /* If function will end with cleanup code for parms,
4175 compute the return values into a pseudo reg,
4176 which we will copy into the true return register
4177 after the cleanups are done. */
4179 enum machine_mode mode = DECL_MODE (DECL_RESULT (subr));
4180 #ifdef PROMOTE_FUNCTION_RETURN
4181 tree type = TREE_TYPE (DECL_RESULT (subr));
4182 int unsignedp = TREE_UNSIGNED (type);
4184 if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE
4185 || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE
4186 || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE
4187 || TREE_CODE (type) == OFFSET_TYPE)
4189 PROMOTE_MODE (mode, unsignedp, type);
4193 DECL_RTL (DECL_RESULT (subr)) = gen_reg_rtx (mode);
4196 /* Scalar, returned in a register. */
4198 #ifdef FUNCTION_OUTGOING_VALUE
4199 DECL_RTL (DECL_RESULT (subr))
4200 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
4202 DECL_RTL (DECL_RESULT (subr))
4203 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
4206 /* Mark this reg as the function's return value. */
4207 if (GET_CODE (DECL_RTL (DECL_RESULT (subr))) == REG)
4209 REG_FUNCTION_VALUE_P (DECL_RTL (DECL_RESULT (subr))) = 1;
4210 /* Needed because we may need to move this to memory
4211 in case it's a named return value whose address is taken. */
4212 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4216 /* Initialize rtx for parameters and local variables.
4217 In some cases this requires emitting insns. */
4219 assign_parms (subr, 0);
4221 /* The following was moved from init_function_start.
4222 The move is supposed to make sdb output more accurate. */
4223 /* Indicate the beginning of the function body,
4224 as opposed to parm setup. */
4225 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_BEG);
4227 /* If doing stupid allocation, mark parms as born here. */
4229 if (GET_CODE (get_last_insn ()) != NOTE)
4230 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4231 parm_birth_insn = get_last_insn ();
4235 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
4236 use_variable (regno_reg_rtx[i]);
4238 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
4239 use_variable (current_function_internal_arg_pointer);
4242 /* Fetch static chain values for containing functions. */
4243 tem = decl_function_context (current_function_decl);
4244 /* If not doing stupid register allocation, then start off with the static
4245 chain pointer in a pseudo register. Otherwise, we use the stack
4246 address that was generated above. */
4247 if (tem && ! obey_regdecls)
4248 last_ptr = copy_to_reg (static_chain_incoming_rtx);
4249 context_display = 0;
4252 tree rtlexp = make_node (RTL_EXPR);
4254 RTL_EXPR_RTL (rtlexp) = last_ptr;
4255 context_display = tree_cons (tem, rtlexp, context_display);
4256 tem = decl_function_context (tem);
4259 /* Chain thru stack frames, assuming pointer to next lexical frame
4260 is found at the place we always store it. */
4261 #ifdef FRAME_GROWS_DOWNWARD
4262 last_ptr = plus_constant (last_ptr, - GET_MODE_SIZE (Pmode));
4264 last_ptr = copy_to_reg (gen_rtx (MEM, Pmode,
4265 memory_address (Pmode, last_ptr)));
4268 /* After the display initializations is where the tail-recursion label
4269 should go, if we end up needing one. Ensure we have a NOTE here
4270 since some things (like trampolines) get placed before this. */
4271 tail_recursion_reentry = emit_note (NULL_PTR, NOTE_INSN_DELETED);
4273 /* Evaluate now the sizes of any types declared among the arguments. */
4274 for (tem = nreverse (get_pending_sizes ()); tem; tem = TREE_CHAIN (tem))
4275 expand_expr (TREE_VALUE (tem), NULL_RTX, VOIDmode, 0);
4277 /* Make sure there is a line number after the function entry setup code. */
4278 force_next_line_note ();
4281 /* Generate RTL for the end of the current function.
4282 FILENAME and LINE are the current position in the source file. */
4284 /* It is up to language-specific callers to do cleanups for parameters. */
4287 expand_function_end (filename, line)
4294 static rtx initial_trampoline;
4296 #ifdef NON_SAVING_SETJMP
4297 /* Don't put any variables in registers if we call setjmp
4298 on a machine that fails to restore the registers. */
4299 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
4301 setjmp_protect (DECL_INITIAL (current_function_decl));
4302 setjmp_protect_args ();
4306 /* Save the argument pointer if a save area was made for it. */
4307 if (arg_pointer_save_area)
4309 rtx x = gen_move_insn (arg_pointer_save_area, virtual_incoming_args_rtx);
4310 emit_insn_before (x, tail_recursion_reentry);
4313 /* Initialize any trampolines required by this function. */
4314 for (link = trampoline_list; link; link = TREE_CHAIN (link))
4316 tree function = TREE_PURPOSE (link);
4317 rtx context = lookup_static_chain (function);
4318 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
4321 /* First make sure this compilation has a template for
4322 initializing trampolines. */
4323 if (initial_trampoline == 0)
4325 end_temporary_allocation ();
4327 = gen_rtx (MEM, BLKmode, assemble_trampoline_template ());
4328 resume_temporary_allocation ();
4331 /* Generate insns to initialize the trampoline. */
4333 tramp = change_address (initial_trampoline, BLKmode,
4334 round_trampoline_addr (XEXP (tramp, 0)));
4335 emit_block_move (tramp, initial_trampoline, GEN_INT (TRAMPOLINE_SIZE),
4336 FUNCTION_BOUNDARY / BITS_PER_UNIT);
4337 INITIALIZE_TRAMPOLINE (XEXP (tramp, 0),
4338 XEXP (DECL_RTL (function), 0), context);
4342 /* Put those insns at entry to the containing function (this one). */
4343 emit_insns_before (seq, tail_recursion_reentry);
4345 /* Clear the trampoline_list for the next function. */
4346 trampoline_list = 0;
4348 #if 0 /* I think unused parms are legitimate enough. */
4349 /* Warn about unused parms. */
4354 for (decl = DECL_ARGUMENTS (current_function_decl);
4355 decl; decl = TREE_CHAIN (decl))
4356 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL)
4357 warning_with_decl (decl, "unused parameter `%s'");
4361 /* Delete handlers for nonlocal gotos if nothing uses them. */
4362 if (nonlocal_goto_handler_slot != 0 && !current_function_has_nonlocal_label)
4365 /* End any sequences that failed to be closed due to syntax errors. */
4366 while (in_sequence_p ())
4369 /* Outside function body, can't compute type's actual size
4370 until next function's body starts. */
4371 immediate_size_expand--;
4373 /* If doing stupid register allocation,
4374 mark register parms as dying here. */
4379 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
4380 use_variable (regno_reg_rtx[i]);
4382 /* Likewise for the regs of all the SAVE_EXPRs in the function. */
4384 for (tem = save_expr_regs; tem; tem = XEXP (tem, 1))
4386 use_variable (XEXP (tem, 0));
4387 use_variable_after (XEXP (tem, 0), parm_birth_insn);
4390 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
4391 use_variable (current_function_internal_arg_pointer);
4394 clear_pending_stack_adjust ();
4395 do_pending_stack_adjust ();
4397 /* Mark the end of the function body.
4398 If control reaches this insn, the function can drop through
4399 without returning a value. */
4400 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_END);
4402 /* Output a linenumber for the end of the function.
4403 SDB depends on this. */
4404 emit_line_note_force (filename, line);
4406 /* Output the label for the actual return from the function,
4407 if one is expected. This happens either because a function epilogue
4408 is used instead of a return instruction, or because a return was done
4409 with a goto in order to run local cleanups, or because of pcc-style
4410 structure returning. */
4413 emit_label (return_label);
4415 /* If we had calls to alloca, and this machine needs
4416 an accurate stack pointer to exit the function,
4417 insert some code to save and restore the stack pointer. */
4418 #ifdef EXIT_IGNORE_STACK
4419 if (! EXIT_IGNORE_STACK)
4421 if (current_function_calls_alloca)
4425 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4426 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4429 /* If scalar return value was computed in a pseudo-reg,
4430 copy that to the hard return register. */
4431 if (DECL_RTL (DECL_RESULT (current_function_decl)) != 0
4432 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG
4433 && (REGNO (DECL_RTL (DECL_RESULT (current_function_decl)))
4434 >= FIRST_PSEUDO_REGISTER))
4436 rtx real_decl_result;
4438 #ifdef FUNCTION_OUTGOING_VALUE
4440 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
4441 current_function_decl);
4444 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
4445 current_function_decl);
4447 REG_FUNCTION_VALUE_P (real_decl_result) = 1;
4448 emit_move_insn (real_decl_result,
4449 DECL_RTL (DECL_RESULT (current_function_decl)));
4450 emit_insn (gen_rtx (USE, VOIDmode, real_decl_result));
4453 /* If returning a structure, arrange to return the address of the value
4454 in a place where debuggers expect to find it.
4456 If returning a structure PCC style,
4457 the caller also depends on this value.
4458 And current_function_returns_pcc_struct is not necessarily set. */
4459 if (current_function_returns_struct
4460 || current_function_returns_pcc_struct)
4462 rtx value_address = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
4463 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4464 #ifdef FUNCTION_OUTGOING_VALUE
4466 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
4467 current_function_decl);
4470 = FUNCTION_VALUE (build_pointer_type (type),
4471 current_function_decl);
4474 /* Mark this as a function return value so integrate will delete the
4475 assignment and USE below when inlining this function. */
4476 REG_FUNCTION_VALUE_P (outgoing) = 1;
4478 emit_move_insn (outgoing, value_address);
4479 use_variable (outgoing);
4482 /* Output a return insn if we are using one.
4483 Otherwise, let the rtl chain end here, to drop through
4484 into the epilogue. */
4489 emit_jump_insn (gen_return ());
4494 /* Fix up any gotos that jumped out to the outermost
4495 binding level of the function.
4496 Must follow emitting RETURN_LABEL. */
4498 /* If you have any cleanups to do at this point,
4499 and they need to create temporary variables,
4500 then you will lose. */
4501 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, get_insns (), 0);
4504 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
4506 static int *prologue;
4507 static int *epilogue;
4509 /* Create an array that records the INSN_UIDs of INSNS (either a sequence
4510 or a single insn). */
4513 record_insns (insns)
4518 if (GET_CODE (insns) == SEQUENCE)
4520 int len = XVECLEN (insns, 0);
4521 vec = (int *) oballoc ((len + 1) * sizeof (int));
4524 vec[len] = INSN_UID (XVECEXP (insns, 0, len));
4528 vec = (int *) oballoc (2 * sizeof (int));
4529 vec[0] = INSN_UID (insns);
4535 /* Determine how many INSN_UIDs in VEC are part of INSN. */
4538 contains (insn, vec)
4544 if (GET_CODE (insn) == INSN
4545 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4548 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4549 for (j = 0; vec[j]; j++)
4550 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == vec[j])
4556 for (j = 0; vec[j]; j++)
4557 if (INSN_UID (insn) == vec[j])
4563 /* Generate the prologe and epilogue RTL if the machine supports it. Thread
4564 this into place with notes indicating where the prologue ends and where
4565 the epilogue begins. Update the basic block information when possible. */
4568 thread_prologue_and_epilogue_insns (f)
4571 #ifdef HAVE_prologue
4574 rtx head, seq, insn;
4576 /* The first insn (a NOTE_INSN_DELETED) is followed by zero or more
4577 prologue insns and a NOTE_INSN_PROLOGUE_END. */
4578 emit_note_after (NOTE_INSN_PROLOGUE_END, f);
4579 seq = gen_prologue ();
4580 head = emit_insn_after (seq, f);
4582 /* Include the new prologue insns in the first block. Ignore them
4583 if they form a basic block unto themselves. */
4584 if (basic_block_head && n_basic_blocks
4585 && GET_CODE (basic_block_head[0]) != CODE_LABEL)
4586 basic_block_head[0] = NEXT_INSN (f);
4588 /* Retain a map of the prologue insns. */
4589 prologue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : head);
4595 #ifdef HAVE_epilogue
4598 rtx insn = get_last_insn ();
4599 rtx prev = prev_nonnote_insn (insn);
4601 /* If we end with a BARRIER, we don't need an epilogue. */
4602 if (! (prev && GET_CODE (prev) == BARRIER))
4606 /* The last basic block ends with a NOTE_INSN_EPILOGUE_BEG,
4607 the epilogue insns (this must include the jump insn that
4608 returns), USE insns ad the end of a function, and a BARRIER. */
4610 emit_barrier_after (insn);
4612 /* Place the epilogue before the USE insns at the end of a
4615 && GET_CODE (prev) == INSN
4616 && GET_CODE (PATTERN (prev)) == USE)
4618 insn = PREV_INSN (prev);
4619 prev = prev_nonnote_insn (prev);
4622 seq = gen_epilogue ();
4623 tail = emit_jump_insn_after (seq, insn);
4624 emit_note_after (NOTE_INSN_EPILOGUE_BEG, insn);
4626 /* Include the new epilogue insns in the last block. Ignore
4627 them if they form a basic block unto themselves. */
4628 if (basic_block_end && n_basic_blocks
4629 && GET_CODE (basic_block_end[n_basic_blocks - 1]) != JUMP_INSN)
4630 basic_block_end[n_basic_blocks - 1] = tail;
4632 /* Retain a map of the epilogue insns. */
4633 epilogue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : tail);
4641 /* Reposition the prologue-end and epilogue-begin notes after instruction
4642 scheduling and delayed branch scheduling. */
4645 reposition_prologue_and_epilogue_notes (f)
4648 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
4649 /* Reposition the prologue and epilogue notes. */
4657 register rtx insn, note = 0;
4659 /* Scan from the beginning until we reach the last prologue insn.
4660 We apparently can't depend on basic_block_{head,end} after
4662 for (len = 0; prologue[len]; len++)
4664 for (insn = f; insn; insn = NEXT_INSN (insn))
4665 if (GET_CODE (insn) == NOTE)
4667 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
4670 else if ((len -= contains (insn, prologue)) == 0)
4672 /* Find the prologue-end note if we haven't already, and
4673 move it to just after the last prologue insn. */
4675 for (note = insn; note = NEXT_INSN (note);)
4676 if (GET_CODE (note) == NOTE
4677 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
4679 next = NEXT_INSN (note);
4680 prev = PREV_INSN (note);
4682 NEXT_INSN (prev) = next;
4684 PREV_INSN (next) = prev;
4685 add_insn_after (note, insn);
4692 register rtx insn, note = 0;
4694 /* Scan from the end until we reach the first epilogue insn.
4695 We apparently can't depend on basic_block_{head,end} after
4697 for (len = 0; epilogue[len]; len++)
4699 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
4700 if (GET_CODE (insn) == NOTE)
4702 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
4705 else if ((len -= contains (insn, epilogue)) == 0)
4707 /* Find the epilogue-begin note if we haven't already, and
4708 move it to just before the first epilogue insn. */
4710 for (note = insn; note = PREV_INSN (note);)
4711 if (GET_CODE (note) == NOTE
4712 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
4714 next = NEXT_INSN (note);
4715 prev = PREV_INSN (note);
4717 NEXT_INSN (prev) = next;
4719 PREV_INSN (next) = prev;
4720 add_insn_after (note, PREV_INSN (insn));
4725 #endif /* HAVE_prologue or HAVE_epilogue */