1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 91, 92, 93, 1994 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"
60 /* Some systems use __main in a way incompatible with its use in gcc, in these
61 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
62 give the same symbol without quotes for an alternative entry point. You
63 must define both, or niether. */
65 #define NAME__MAIN "__main"
66 #define SYMBOL__MAIN __main
69 /* Round a value to the lowest integer less than it that is a multiple of
70 the required alignment. Avoid using division in case the value is
71 negative. Assume the alignment is a power of two. */
72 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
74 /* Similar, but round to the next highest integer that meets the
76 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
78 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
79 during rtl generation. If they are different register numbers, this is
80 always true. It may also be true if
81 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
82 generation. See fix_lexical_addr for details. */
84 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
85 #define NEED_SEPARATE_AP
88 /* Number of bytes of args popped by function being compiled on its return.
89 Zero if no bytes are to be popped.
90 May affect compilation of return insn or of function epilogue. */
92 int current_function_pops_args;
94 /* Nonzero if function being compiled needs to be given an address
95 where the value should be stored. */
97 int current_function_returns_struct;
99 /* Nonzero if function being compiled needs to
100 return the address of where it has put a structure value. */
102 int current_function_returns_pcc_struct;
104 /* Nonzero if function being compiled needs to be passed a static chain. */
106 int current_function_needs_context;
108 /* Nonzero if function being compiled can call setjmp. */
110 int current_function_calls_setjmp;
112 /* Nonzero if function being compiled can call longjmp. */
114 int current_function_calls_longjmp;
116 /* Nonzero if function being compiled receives nonlocal gotos
117 from nested functions. */
119 int current_function_has_nonlocal_label;
121 /* Nonzero if function being compiled has nonlocal gotos to parent
124 int current_function_has_nonlocal_goto;
126 /* Nonzero if function being compiled contains nested functions. */
128 int current_function_contains_functions;
130 /* Nonzero if function being compiled can call alloca,
131 either as a subroutine or builtin. */
133 int current_function_calls_alloca;
135 /* Nonzero if the current function returns a pointer type */
137 int current_function_returns_pointer;
139 /* If some insns can be deferred to the delay slots of the epilogue, the
140 delay list for them is recorded here. */
142 rtx current_function_epilogue_delay_list;
144 /* If function's args have a fixed size, this is that size, in bytes.
146 May affect compilation of return insn or of function epilogue. */
148 int current_function_args_size;
150 /* # bytes the prologue should push and pretend that the caller pushed them.
151 The prologue must do this, but only if parms can be passed in registers. */
153 int current_function_pretend_args_size;
155 /* # of bytes of outgoing arguments required to be pushed by the prologue.
156 If this is non-zero, it means that ACCUMULATE_OUTGOING_ARGS was defined
157 and no stack adjusts will be done on function calls. */
159 int current_function_outgoing_args_size;
161 /* This is the offset from the arg pointer to the place where the first
162 anonymous arg can be found, if there is one. */
164 rtx current_function_arg_offset_rtx;
166 /* Nonzero if current function uses varargs.h or equivalent.
167 Zero for functions that use stdarg.h. */
169 int current_function_varargs;
171 /* Quantities of various kinds of registers
172 used for the current function's args. */
174 CUMULATIVE_ARGS current_function_args_info;
176 /* Name of function now being compiled. */
178 char *current_function_name;
180 /* If non-zero, an RTL expression for that location at which the current
181 function returns its result. Always equal to
182 DECL_RTL (DECL_RESULT (current_function_decl)), but provided
183 independently of the tree structures. */
185 rtx current_function_return_rtx;
187 /* Nonzero if the current function uses the constant pool. */
189 int current_function_uses_const_pool;
191 /* Nonzero if the current function uses pic_offset_table_rtx. */
192 int current_function_uses_pic_offset_table;
194 /* The arg pointer hard register, or the pseudo into which it was copied. */
195 rtx current_function_internal_arg_pointer;
197 /* The FUNCTION_DECL for an inline function currently being expanded. */
198 tree inline_function_decl;
200 /* Number of function calls seen so far in current function. */
202 int function_call_count;
204 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
205 (labels to which there can be nonlocal gotos from nested functions)
208 tree nonlocal_labels;
210 /* RTX for stack slot that holds the current handler for nonlocal gotos.
211 Zero when function does not have nonlocal labels. */
213 rtx nonlocal_goto_handler_slot;
215 /* RTX for stack slot that holds the stack pointer value to restore
217 Zero when function does not have nonlocal labels. */
219 rtx nonlocal_goto_stack_level;
221 /* Label that will go on parm cleanup code, if any.
222 Jumping to this label runs cleanup code for parameters, if
223 such code must be run. Following this code is the logical return label. */
227 /* Label that will go on function epilogue.
228 Jumping to this label serves as a "return" instruction
229 on machines which require execution of the epilogue on all returns. */
233 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
234 So we can mark them all live at the end of the function, if nonopt. */
237 /* List (chain of EXPR_LISTs) of all stack slots in this function.
238 Made for the sake of unshare_all_rtl. */
241 /* Chain of all RTL_EXPRs that have insns in them. */
244 /* Label to jump back to for tail recursion, or 0 if we have
245 not yet needed one for this function. */
246 rtx tail_recursion_label;
248 /* Place after which to insert the tail_recursion_label if we need one. */
249 rtx tail_recursion_reentry;
251 /* Location at which to save the argument pointer if it will need to be
252 referenced. There are two cases where this is done: if nonlocal gotos
253 exist, or if vars stored at an offset from the argument pointer will be
254 needed by inner routines. */
256 rtx arg_pointer_save_area;
258 /* Offset to end of allocated area of stack frame.
259 If stack grows down, this is the address of the last stack slot allocated.
260 If stack grows up, this is the address for the next slot. */
263 /* List (chain of TREE_LISTs) of static chains for containing functions.
264 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
265 in an RTL_EXPR in the TREE_VALUE. */
266 static tree context_display;
268 /* List (chain of TREE_LISTs) of trampolines for nested functions.
269 The trampoline sets up the static chain and jumps to the function.
270 We supply the trampoline's address when the function's address is requested.
272 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
273 in an RTL_EXPR in the TREE_VALUE. */
274 static tree trampoline_list;
276 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
277 static rtx parm_birth_insn;
280 /* Nonzero if a stack slot has been generated whose address is not
281 actually valid. It means that the generated rtl must all be scanned
282 to detect and correct the invalid addresses where they occur. */
283 static int invalid_stack_slot;
286 /* Last insn of those whose job was to put parms into their nominal homes. */
287 static rtx last_parm_insn;
289 /* 1 + last pseudo register number used for loading a copy
290 of a parameter of this function. */
291 static int max_parm_reg;
293 /* Vector indexed by REGNO, containing location on stack in which
294 to put the parm which is nominally in pseudo register REGNO,
295 if we discover that that parm must go in the stack. */
296 static rtx *parm_reg_stack_loc;
298 #if 0 /* Turned off because 0 seems to work just as well. */
299 /* Cleanup lists are required for binding levels regardless of whether
300 that binding level has cleanups or not. This node serves as the
301 cleanup list whenever an empty list is required. */
302 static tree empty_cleanup_list;
305 /* Nonzero once virtual register instantiation has been done.
306 assign_stack_local uses frame_pointer_rtx when this is nonzero. */
307 static int virtuals_instantiated;
309 /* These variables hold pointers to functions to
310 save and restore machine-specific data,
311 in push_function_context and pop_function_context. */
312 void (*save_machine_status) ();
313 void (*restore_machine_status) ();
315 /* Nonzero if we need to distinguish between the return value of this function
316 and the return value of a function called by this function. This helps
319 extern int rtx_equal_function_value_matters;
320 extern tree sequence_rtl_expr;
321 extern tree bc_runtime_type_code ();
322 extern rtx bc_build_calldesc ();
323 extern char *bc_emit_trampoline ();
324 extern char *bc_end_function ();
328 static tree round_down ();
329 static rtx round_trampoline_addr ();
330 static rtx fixup_stack_1 ();
331 static void put_reg_into_stack ();
332 static void fixup_var_refs ();
333 static void fixup_var_refs_insns ();
334 static void fixup_var_refs_1 ();
335 static void optimize_bit_field ();
336 static void instantiate_decls ();
337 static void instantiate_decls_1 ();
338 static void instantiate_decl ();
339 static int instantiate_virtual_regs_1 ();
340 static rtx fixup_memory_subreg ();
341 static rtx walk_fixup_memory_subreg ();
343 /* In order to evaluate some expressions, such as function calls returning
344 structures in memory, we need to temporarily allocate stack locations.
345 We record each allocated temporary in the following structure.
347 Associated with each temporary slot is a nesting level. When we pop up
348 one level, all temporaries associated with the previous level are freed.
349 Normally, all temporaries are freed after the execution of the statement
350 in which they were created. However, if we are inside a ({...}) grouping,
351 the result may be in a temporary and hence must be preserved. If the
352 result could be in a temporary, we preserve it if we can determine which
353 one it is in. If we cannot determine which temporary may contain the
354 result, all temporaries are preserved. A temporary is preserved by
355 pretending it was allocated at the previous nesting level.
357 Automatic variables are also assigned temporary slots, at the nesting
358 level where they are defined. They are marked a "kept" so that
359 free_temp_slots will not free them. */
363 /* Points to next temporary slot. */
364 struct temp_slot *next;
365 /* The rtx to used to reference the slot. */
367 /* The rtx used to represent the address if not the address of the
368 slot above. May be an EXPR_LIST if multiple addresses exist. */
370 /* The size, in units, of the slot. */
372 /* The value of `sequence_rtl_expr' when this temporary is allocated. */
374 /* Non-zero if this temporary is currently in use. */
376 /* Nesting level at which this slot is being used. */
378 /* Non-zero if this should survive a call to free_temp_slots. */
382 /* List of all temporaries allocated, both available and in use. */
384 struct temp_slot *temp_slots;
386 /* Current nesting level for temporaries. */
390 /* The FUNCTION_DECL node for the current function. */
391 static tree this_function_decl;
393 /* Callinfo pointer for the current function. */
394 static rtx this_function_callinfo;
396 /* The label in the bytecode file of this function's actual bytecode.
398 static char *this_function_bytecode;
400 /* The call description vector for the current function. */
401 static rtx this_function_calldesc;
403 /* Size of the local variables allocated for the current function. */
406 /* Current depth of the bytecode evaluation stack. */
409 /* Maximum depth of the evaluation stack in this function. */
412 /* Current depth in statement expressions. */
413 static int stmt_expr_depth;
415 /* Pointer to chain of `struct function' for containing functions. */
416 struct function *outer_function_chain;
418 /* Given a function decl for a containing function,
419 return the `struct function' for it. */
422 find_function_data (decl)
426 for (p = outer_function_chain; p; p = p->next)
432 /* Save the current context for compilation of a nested function.
433 This is called from language-specific code.
434 The caller is responsible for saving any language-specific status,
435 since this function knows only about language-independent variables. */
438 push_function_context ()
440 struct function *p = (struct function *) xmalloc (sizeof (struct function));
442 p->next = outer_function_chain;
443 outer_function_chain = p;
445 p->name = current_function_name;
446 p->decl = current_function_decl;
447 p->pops_args = current_function_pops_args;
448 p->returns_struct = current_function_returns_struct;
449 p->returns_pcc_struct = current_function_returns_pcc_struct;
450 p->needs_context = current_function_needs_context;
451 p->calls_setjmp = current_function_calls_setjmp;
452 p->calls_longjmp = current_function_calls_longjmp;
453 p->calls_alloca = current_function_calls_alloca;
454 p->has_nonlocal_label = current_function_has_nonlocal_label;
455 p->has_nonlocal_goto = current_function_has_nonlocal_goto;
456 p->args_size = current_function_args_size;
457 p->pretend_args_size = current_function_pretend_args_size;
458 p->arg_offset_rtx = current_function_arg_offset_rtx;
459 p->varargs = current_function_varargs;
460 p->uses_const_pool = current_function_uses_const_pool;
461 p->uses_pic_offset_table = current_function_uses_pic_offset_table;
462 p->internal_arg_pointer = current_function_internal_arg_pointer;
463 p->max_parm_reg = max_parm_reg;
464 p->parm_reg_stack_loc = parm_reg_stack_loc;
465 p->outgoing_args_size = current_function_outgoing_args_size;
466 p->return_rtx = current_function_return_rtx;
467 p->nonlocal_goto_handler_slot = nonlocal_goto_handler_slot;
468 p->nonlocal_goto_stack_level = nonlocal_goto_stack_level;
469 p->nonlocal_labels = nonlocal_labels;
470 p->cleanup_label = cleanup_label;
471 p->return_label = return_label;
472 p->save_expr_regs = save_expr_regs;
473 p->stack_slot_list = stack_slot_list;
474 p->parm_birth_insn = parm_birth_insn;
475 p->frame_offset = frame_offset;
476 p->tail_recursion_label = tail_recursion_label;
477 p->tail_recursion_reentry = tail_recursion_reentry;
478 p->arg_pointer_save_area = arg_pointer_save_area;
479 p->rtl_expr_chain = rtl_expr_chain;
480 p->last_parm_insn = last_parm_insn;
481 p->context_display = context_display;
482 p->trampoline_list = trampoline_list;
483 p->function_call_count = function_call_count;
484 p->temp_slots = temp_slots;
485 p->temp_slot_level = temp_slot_level;
486 p->fixup_var_refs_queue = 0;
487 p->epilogue_delay_list = current_function_epilogue_delay_list;
489 save_tree_status (p);
490 save_storage_status (p);
491 save_emit_status (p);
493 save_expr_status (p);
494 save_stmt_status (p);
495 save_varasm_status (p);
497 if (save_machine_status)
498 (*save_machine_status) (p);
501 /* Restore the last saved context, at the end of a nested function.
502 This function is called from language-specific code. */
505 pop_function_context ()
507 struct function *p = outer_function_chain;
509 outer_function_chain = p->next;
511 current_function_name = p->name;
512 current_function_decl = p->decl;
513 current_function_pops_args = p->pops_args;
514 current_function_returns_struct = p->returns_struct;
515 current_function_returns_pcc_struct = p->returns_pcc_struct;
516 current_function_needs_context = p->needs_context;
517 current_function_calls_setjmp = p->calls_setjmp;
518 current_function_calls_longjmp = p->calls_longjmp;
519 current_function_calls_alloca = p->calls_alloca;
520 current_function_has_nonlocal_label = p->has_nonlocal_label;
521 current_function_has_nonlocal_goto = p->has_nonlocal_goto;
522 current_function_contains_functions = 1;
523 current_function_args_size = p->args_size;
524 current_function_pretend_args_size = p->pretend_args_size;
525 current_function_arg_offset_rtx = p->arg_offset_rtx;
526 current_function_varargs = p->varargs;
527 current_function_uses_const_pool = p->uses_const_pool;
528 current_function_uses_pic_offset_table = p->uses_pic_offset_table;
529 current_function_internal_arg_pointer = p->internal_arg_pointer;
530 max_parm_reg = p->max_parm_reg;
531 parm_reg_stack_loc = p->parm_reg_stack_loc;
532 current_function_outgoing_args_size = p->outgoing_args_size;
533 current_function_return_rtx = p->return_rtx;
534 nonlocal_goto_handler_slot = p->nonlocal_goto_handler_slot;
535 nonlocal_goto_stack_level = p->nonlocal_goto_stack_level;
536 nonlocal_labels = p->nonlocal_labels;
537 cleanup_label = p->cleanup_label;
538 return_label = p->return_label;
539 save_expr_regs = p->save_expr_regs;
540 stack_slot_list = p->stack_slot_list;
541 parm_birth_insn = p->parm_birth_insn;
542 frame_offset = p->frame_offset;
543 tail_recursion_label = p->tail_recursion_label;
544 tail_recursion_reentry = p->tail_recursion_reentry;
545 arg_pointer_save_area = p->arg_pointer_save_area;
546 rtl_expr_chain = p->rtl_expr_chain;
547 last_parm_insn = p->last_parm_insn;
548 context_display = p->context_display;
549 trampoline_list = p->trampoline_list;
550 function_call_count = p->function_call_count;
551 temp_slots = p->temp_slots;
552 temp_slot_level = p->temp_slot_level;
553 current_function_epilogue_delay_list = p->epilogue_delay_list;
555 restore_tree_status (p);
556 restore_storage_status (p);
557 restore_expr_status (p);
558 restore_emit_status (p);
559 restore_stmt_status (p);
560 restore_varasm_status (p);
562 if (restore_machine_status)
563 (*restore_machine_status) (p);
565 /* Finish doing put_var_into_stack for any of our variables
566 which became addressable during the nested function. */
568 struct var_refs_queue *queue = p->fixup_var_refs_queue;
569 for (; queue; queue = queue->next)
570 fixup_var_refs (queue->modified, queue->promoted_mode, queue->unsignedp);
575 /* Reset variables that have known state during rtx generation. */
576 rtx_equal_function_value_matters = 1;
577 virtuals_instantiated = 0;
580 /* Allocate fixed slots in the stack frame of the current function. */
582 /* Return size needed for stack frame based on slots so far allocated.
583 This size counts from zero. It is not rounded to STACK_BOUNDARY;
584 the caller may have to do that. */
589 #ifdef FRAME_GROWS_DOWNWARD
590 return -frame_offset;
596 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
597 with machine mode MODE.
599 ALIGN controls the amount of alignment for the address of the slot:
600 0 means according to MODE,
601 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
602 positive specifies alignment boundary in bits.
604 We do not round to stack_boundary here. */
607 assign_stack_local (mode, size, align)
608 enum machine_mode mode;
612 register rtx x, addr;
613 int bigend_correction = 0;
618 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
620 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
622 else if (align == -1)
624 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
625 size = CEIL_ROUND (size, alignment);
628 alignment = align / BITS_PER_UNIT;
630 /* Round frame offset to that alignment.
631 We must be careful here, since FRAME_OFFSET might be negative and
632 division with a negative dividend isn't as well defined as we might
633 like. So we instead assume that ALIGNMENT is a power of two and
634 use logical operations which are unambiguous. */
635 #ifdef FRAME_GROWS_DOWNWARD
636 frame_offset = FLOOR_ROUND (frame_offset, alignment);
638 frame_offset = CEIL_ROUND (frame_offset, alignment);
641 /* On a big-endian machine, if we are allocating more space than we will use,
642 use the least significant bytes of those that are allocated. */
645 bigend_correction = size - GET_MODE_SIZE (mode);
648 #ifdef FRAME_GROWS_DOWNWARD
649 frame_offset -= size;
652 /* If we have already instantiated virtual registers, return the actual
653 address relative to the frame pointer. */
654 if (virtuals_instantiated)
655 addr = plus_constant (frame_pointer_rtx,
656 (frame_offset + bigend_correction
657 + STARTING_FRAME_OFFSET));
659 addr = plus_constant (virtual_stack_vars_rtx,
660 frame_offset + bigend_correction);
662 #ifndef FRAME_GROWS_DOWNWARD
663 frame_offset += size;
666 x = gen_rtx (MEM, mode, addr);
668 stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, x, stack_slot_list);
673 /* Assign a stack slot in a containing function.
674 First three arguments are same as in preceding function.
675 The last argument specifies the function to allocate in. */
678 assign_outer_stack_local (mode, size, align, function)
679 enum machine_mode mode;
682 struct function *function;
684 register rtx x, addr;
685 int bigend_correction = 0;
688 /* Allocate in the memory associated with the function in whose frame
690 push_obstacks (function->function_obstack,
691 function->function_maybepermanent_obstack);
695 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
697 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
699 else if (align == -1)
701 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
702 size = CEIL_ROUND (size, alignment);
705 alignment = align / BITS_PER_UNIT;
707 /* Round frame offset to that alignment. */
708 #ifdef FRAME_GROWS_DOWNWARD
709 function->frame_offset = FLOOR_ROUND (function->frame_offset, alignment);
711 function->frame_offset = CEIL_ROUND (function->frame_offset, alignment);
714 /* On a big-endian machine, if we are allocating more space than we will use,
715 use the least significant bytes of those that are allocated. */
718 bigend_correction = size - GET_MODE_SIZE (mode);
721 #ifdef FRAME_GROWS_DOWNWARD
722 function->frame_offset -= size;
724 addr = plus_constant (virtual_stack_vars_rtx,
725 function->frame_offset + bigend_correction);
726 #ifndef FRAME_GROWS_DOWNWARD
727 function->frame_offset += size;
730 x = gen_rtx (MEM, mode, addr);
732 function->stack_slot_list
733 = gen_rtx (EXPR_LIST, VOIDmode, x, function->stack_slot_list);
740 /* Allocate a temporary stack slot and record it for possible later
743 MODE is the machine mode to be given to the returned rtx.
745 SIZE is the size in units of the space required. We do no rounding here
746 since assign_stack_local will do any required rounding.
748 KEEP is non-zero if this slot is to be retained after a call to
749 free_temp_slots. Automatic variables for a block are allocated with this
753 assign_stack_temp (mode, size, keep)
754 enum machine_mode mode;
758 struct temp_slot *p, *best_p = 0;
760 /* First try to find an available, already-allocated temporary that is the
761 exact size we require. */
762 for (p = temp_slots; p; p = p->next)
763 if (p->size == size && GET_MODE (p->slot) == mode && ! p->in_use)
766 /* If we didn't find, one, try one that is larger than what we want. We
767 find the smallest such. */
769 for (p = temp_slots; p; p = p->next)
770 if (p->size > size && GET_MODE (p->slot) == mode && ! p->in_use
771 && (best_p == 0 || best_p->size > p->size))
774 /* Make our best, if any, the one to use. */
777 /* If there are enough aligned bytes left over, make them into a new
778 temp_slot so that the extra bytes don't get wasted. Do this only
779 for BLKmode slots, so that we can be sure of the alignment. */
780 if (GET_MODE (best_p->slot) == BLKmode)
782 int alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
783 int rounded_size = CEIL_ROUND (size, alignment);
785 if (best_p->size - rounded_size >= alignment)
787 p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
789 p->size = best_p->size - rounded_size;
790 p->slot = gen_rtx (MEM, BLKmode,
791 plus_constant (XEXP (best_p->slot, 0),
794 p->next = temp_slots;
797 stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, p->slot,
800 best_p->size = rounded_size;
807 /* If we still didn't find one, make a new temporary. */
810 p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
812 /* If the temp slot mode doesn't indicate the alignment,
813 use the largest possible, so no one will be disappointed. */
814 p->slot = assign_stack_local (mode, size, mode == BLKmode ? -1 : 0);
816 p->next = temp_slots;
821 p->rtl_expr = sequence_rtl_expr;
822 p->level = temp_slot_level;
827 /* Combine temporary stack slots which are adjacent on the stack.
829 This allows for better use of already allocated stack space. This is only
830 done for BLKmode slots because we can be sure that we won't have alignment
831 problems in this case. */
834 combine_temp_slots ()
836 struct temp_slot *p, *q;
837 struct temp_slot *prev_p, *prev_q;
838 /* Determine where to free back to after this function. */
839 rtx free_pointer = rtx_alloc (CONST_INT);
841 for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
844 if (! p->in_use && GET_MODE (p->slot) == BLKmode)
845 for (q = p->next, prev_q = p; q; q = prev_q->next)
848 if (! q->in_use && GET_MODE (q->slot) == BLKmode)
850 if (rtx_equal_p (plus_constant (XEXP (p->slot, 0), p->size),
853 /* Q comes after P; combine Q into P. */
857 else if (rtx_equal_p (plus_constant (XEXP (q->slot, 0), q->size),
860 /* P comes after Q; combine P into Q. */
866 /* Either delete Q or advance past it. */
868 prev_q->next = q->next;
872 /* Either delete P or advance past it. */
876 prev_p->next = p->next;
878 temp_slots = p->next;
884 /* Free all the RTL made by plus_constant. */
885 rtx_free (free_pointer);
888 /* Find the temp slot corresponding to the object at address X. */
890 static struct temp_slot *
891 find_temp_slot_from_address (x)
897 for (p = temp_slots; p; p = p->next)
901 else if (XEXP (p->slot, 0) == x
905 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
906 for (next = p->address; next; next = XEXP (next, 1))
907 if (XEXP (next, 0) == x)
914 /* Indicate that NEW is an alternate way of refering to the temp slot
915 that previous was known by OLD. */
918 update_temp_slot_address (old, new)
921 struct temp_slot *p = find_temp_slot_from_address (old);
923 /* If none, return. Else add NEW as an alias. */
926 else if (p->address == 0)
930 if (GET_CODE (p->address) != EXPR_LIST)
931 p->address = gen_rtx (EXPR_LIST, VOIDmode, p->address, NULL_RTX);
933 p->address = gen_rtx (EXPR_LIST, VOIDmode, new, p->address);
937 /* If X could be a reference to a temporary slot, mark that slot as belonging
938 to the to one level higher. If X matched one of our slots, just mark that
939 one. Otherwise, we can't easily predict which it is, so upgrade all of
940 them. Kept slots need not be touched.
942 This is called when an ({...}) construct occurs and a statement
943 returns a value in memory. */
946 preserve_temp_slots (x)
954 /* If X is a register that is being used as a pointer, see if we have
955 a temporary slot we know it points to. To be consistent with
956 the code below, we really should preserve all non-kept slots
957 if we can't find a match, but that seems to be much too costly. */
958 if (GET_CODE (x) == REG && REGNO_POINTER_FLAG (REGNO (x))
959 && (p = find_temp_slot_from_address (x)) != 0)
965 /* If X is not in memory or is at a constant address, it cannot be in
967 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
970 /* First see if we can find a match. */
971 p = find_temp_slot_from_address (XEXP (x, 0));
978 /* Otherwise, preserve all non-kept slots at this level. */
979 for (p = temp_slots; p; p = p->next)
980 if (p->in_use && p->level == temp_slot_level && ! p->keep)
984 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
985 with that RTL_EXPR, promote it into a temporary slot at the present
986 level so it will not be freed when we free slots made in the
990 preserve_rtl_expr_result (x)
995 /* If X is not in memory or is at a constant address, it cannot be in
997 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1000 /* If we can find a match, move it to our level. */
1001 for (p = temp_slots; p; p = p->next)
1002 if (p->in_use && rtx_equal_p (x, p->slot))
1004 p->level = temp_slot_level;
1012 /* Free all temporaries used so far. This is normally called at the end
1013 of generating code for a statement. Don't free any temporaries
1014 currently in use for an RTL_EXPR that hasn't yet been emitted.
1015 We could eventually do better than this since it can be reused while
1016 generating the same RTL_EXPR, but this is complex and probably not
1022 struct temp_slot *p;
1024 for (p = temp_slots; p; p = p->next)
1025 if (p->in_use && p->level == temp_slot_level && ! p->keep
1026 && p->rtl_expr == 0)
1029 combine_temp_slots ();
1032 /* Free all temporary slots used in T, an RTL_EXPR node. */
1035 free_temps_for_rtl_expr (t)
1038 struct temp_slot *p;
1040 for (p = temp_slots; p; p = p->next)
1041 if (p->rtl_expr == t)
1044 combine_temp_slots ();
1047 /* Push deeper into the nesting level for stack temporaries. */
1055 /* Pop a temporary nesting level. All slots in use in the current level
1061 struct temp_slot *p;
1063 for (p = temp_slots; p; p = p->next)
1064 if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
1067 combine_temp_slots ();
1072 /* Retroactively move an auto variable from a register to a stack slot.
1073 This is done when an address-reference to the variable is seen. */
1076 put_var_into_stack (decl)
1080 enum machine_mode promoted_mode, decl_mode;
1081 struct function *function = 0;
1084 if (output_bytecode)
1087 context = decl_function_context (decl);
1089 /* Get the current rtl used for this object and it's original mode. */
1090 reg = TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl) : DECL_RTL (decl);
1092 /* No need to do anything if decl has no rtx yet
1093 since in that case caller is setting TREE_ADDRESSABLE
1094 and a stack slot will be assigned when the rtl is made. */
1098 /* Get the declared mode for this object. */
1099 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1100 : DECL_MODE (decl));
1101 /* Get the mode it's actually stored in. */
1102 promoted_mode = GET_MODE (reg);
1104 /* If this variable comes from an outer function,
1105 find that function's saved context. */
1106 if (context != current_function_decl)
1107 for (function = outer_function_chain; function; function = function->next)
1108 if (function->decl == context)
1111 /* If this is a variable-size object with a pseudo to address it,
1112 put that pseudo into the stack, if the var is nonlocal. */
1113 if (DECL_NONLOCAL (decl)
1114 && GET_CODE (reg) == MEM
1115 && GET_CODE (XEXP (reg, 0)) == REG
1116 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1118 reg = XEXP (reg, 0);
1119 decl_mode = promoted_mode = GET_MODE (reg);
1122 /* Now we should have a value that resides in one or more pseudo regs. */
1124 if (GET_CODE (reg) == REG)
1125 put_reg_into_stack (function, reg, TREE_TYPE (decl),
1126 promoted_mode, decl_mode);
1127 else if (GET_CODE (reg) == CONCAT)
1129 /* A CONCAT contains two pseudos; put them both in the stack.
1130 We do it so they end up consecutive. */
1131 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1132 tree part_type = TREE_TYPE (TREE_TYPE (decl));
1133 #ifdef STACK_GROWS_DOWNWARD
1134 /* Since part 0 should have a lower address, do it second. */
1135 put_reg_into_stack (function, XEXP (reg, 1),
1136 part_type, part_mode, part_mode);
1137 put_reg_into_stack (function, XEXP (reg, 0),
1138 part_type, part_mode, part_mode);
1140 put_reg_into_stack (function, XEXP (reg, 0),
1141 part_type, part_mode, part_mode);
1142 put_reg_into_stack (function, XEXP (reg, 1),
1143 part_type, part_mode, part_mode);
1146 /* Change the CONCAT into a combined MEM for both parts. */
1147 PUT_CODE (reg, MEM);
1148 /* The two parts are in memory order already.
1149 Use the lower parts address as ours. */
1150 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1151 /* Prevent sharing of rtl that might lose. */
1152 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1153 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1157 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1158 into the stack frame of FUNCTION (0 means the current function).
1159 DECL_MODE is the machine mode of the user-level data type.
1160 PROMOTED_MODE is the machine mode of the register. */
1163 put_reg_into_stack (function, reg, type, promoted_mode, decl_mode)
1164 struct function *function;
1167 enum machine_mode promoted_mode, decl_mode;
1173 if (REGNO (reg) < function->max_parm_reg)
1174 new = function->parm_reg_stack_loc[REGNO (reg)];
1176 new = assign_outer_stack_local (decl_mode, GET_MODE_SIZE (decl_mode),
1181 if (REGNO (reg) < max_parm_reg)
1182 new = parm_reg_stack_loc[REGNO (reg)];
1184 new = assign_stack_local (decl_mode, GET_MODE_SIZE (decl_mode), 0);
1187 XEXP (reg, 0) = XEXP (new, 0);
1188 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1189 REG_USERVAR_P (reg) = 0;
1190 PUT_CODE (reg, MEM);
1191 PUT_MODE (reg, decl_mode);
1193 /* If this is a memory ref that contains aggregate components,
1194 mark it as such for cse and loop optimize. */
1195 MEM_IN_STRUCT_P (reg)
1196 = (TREE_CODE (type) == ARRAY_TYPE
1197 || TREE_CODE (type) == RECORD_TYPE
1198 || TREE_CODE (type) == UNION_TYPE
1199 || TREE_CODE (type) == QUAL_UNION_TYPE);
1201 /* Now make sure that all refs to the variable, previously made
1202 when it was a register, are fixed up to be valid again. */
1205 struct var_refs_queue *temp;
1207 /* Variable is inherited; fix it up when we get back to its function. */
1208 push_obstacks (function->function_obstack,
1209 function->function_maybepermanent_obstack);
1211 /* See comment in restore_tree_status in tree.c for why this needs to be
1212 on saveable obstack. */
1214 = (struct var_refs_queue *) savealloc (sizeof (struct var_refs_queue));
1215 temp->modified = reg;
1216 temp->promoted_mode = promoted_mode;
1217 temp->unsignedp = TREE_UNSIGNED (type);
1218 temp->next = function->fixup_var_refs_queue;
1219 function->fixup_var_refs_queue = temp;
1223 /* Variable is local; fix it up now. */
1224 fixup_var_refs (reg, promoted_mode, TREE_UNSIGNED (type));
1228 fixup_var_refs (var, promoted_mode, unsignedp)
1230 enum machine_mode promoted_mode;
1234 rtx first_insn = get_insns ();
1235 struct sequence_stack *stack = sequence_stack;
1236 tree rtl_exps = rtl_expr_chain;
1238 /* Must scan all insns for stack-refs that exceed the limit. */
1239 fixup_var_refs_insns (var, promoted_mode, unsignedp, first_insn, stack == 0);
1241 /* Scan all pending sequences too. */
1242 for (; stack; stack = stack->next)
1244 push_to_sequence (stack->first);
1245 fixup_var_refs_insns (var, promoted_mode, unsignedp,
1246 stack->first, stack->next != 0);
1247 /* Update remembered end of sequence
1248 in case we added an insn at the end. */
1249 stack->last = get_last_insn ();
1253 /* Scan all waiting RTL_EXPRs too. */
1254 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1256 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1257 if (seq != const0_rtx && seq != 0)
1259 push_to_sequence (seq);
1260 fixup_var_refs_insns (var, promoted_mode, unsignedp, seq, 0);
1266 /* This structure is used by the following two functions to record MEMs or
1267 pseudos used to replace VAR, any SUBREGs of VAR, and any MEMs containing
1268 VAR as an address. We need to maintain this list in case two operands of
1269 an insn were required to match; in that case we must ensure we use the
1270 same replacement. */
1272 struct fixup_replacement
1276 struct fixup_replacement *next;
1279 /* REPLACEMENTS is a pointer to a list of the above structures and X is
1280 some part of an insn. Return a struct fixup_replacement whose OLD
1281 value is equal to X. Allocate a new structure if no such entry exists. */
1283 static struct fixup_replacement *
1284 find_fixup_replacement (replacements, x)
1285 struct fixup_replacement **replacements;
1288 struct fixup_replacement *p;
1290 /* See if we have already replaced this. */
1291 for (p = *replacements; p && p->old != x; p = p->next)
1296 p = (struct fixup_replacement *) oballoc (sizeof (struct fixup_replacement));
1299 p->next = *replacements;
1306 /* Scan the insn-chain starting with INSN for refs to VAR
1307 and fix them up. TOPLEVEL is nonzero if this chain is the
1308 main chain of insns for the current function. */
1311 fixup_var_refs_insns (var, promoted_mode, unsignedp, insn, toplevel)
1313 enum machine_mode promoted_mode;
1322 rtx next = NEXT_INSN (insn);
1324 if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
1326 /* If this is a CLOBBER of VAR, delete it.
1328 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1329 and REG_RETVAL notes too. */
1330 if (GET_CODE (PATTERN (insn)) == CLOBBER
1331 && XEXP (PATTERN (insn), 0) == var)
1333 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1334 /* The REG_LIBCALL note will go away since we are going to
1335 turn INSN into a NOTE, so just delete the
1336 corresponding REG_RETVAL note. */
1337 remove_note (XEXP (note, 0),
1338 find_reg_note (XEXP (note, 0), REG_RETVAL,
1341 /* In unoptimized compilation, we shouldn't call delete_insn
1342 except in jump.c doing warnings. */
1343 PUT_CODE (insn, NOTE);
1344 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1345 NOTE_SOURCE_FILE (insn) = 0;
1348 /* The insn to load VAR from a home in the arglist
1349 is now a no-op. When we see it, just delete it. */
1351 && GET_CODE (PATTERN (insn)) == SET
1352 && SET_DEST (PATTERN (insn)) == var
1353 /* If this represents the result of an insn group,
1354 don't delete the insn. */
1355 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1356 && rtx_equal_p (SET_SRC (PATTERN (insn)), var))
1358 /* In unoptimized compilation, we shouldn't call delete_insn
1359 except in jump.c doing warnings. */
1360 PUT_CODE (insn, NOTE);
1361 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1362 NOTE_SOURCE_FILE (insn) = 0;
1363 if (insn == last_parm_insn)
1364 last_parm_insn = PREV_INSN (next);
1368 struct fixup_replacement *replacements = 0;
1369 rtx next_insn = NEXT_INSN (insn);
1371 #ifdef SMALL_REGISTER_CLASSES
1372 /* If the insn that copies the results of a CALL_INSN
1373 into a pseudo now references VAR, we have to use an
1374 intermediate pseudo since we want the life of the
1375 return value register to be only a single insn.
1377 If we don't use an intermediate pseudo, such things as
1378 address computations to make the address of VAR valid
1379 if it is not can be placed beween the CALL_INSN and INSN.
1381 To make sure this doesn't happen, we record the destination
1382 of the CALL_INSN and see if the next insn uses both that
1385 if (call_dest != 0 && GET_CODE (insn) == INSN
1386 && reg_mentioned_p (var, PATTERN (insn))
1387 && reg_mentioned_p (call_dest, PATTERN (insn)))
1389 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1391 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1393 PATTERN (insn) = replace_rtx (PATTERN (insn),
1397 if (GET_CODE (insn) == CALL_INSN
1398 && GET_CODE (PATTERN (insn)) == SET)
1399 call_dest = SET_DEST (PATTERN (insn));
1400 else if (GET_CODE (insn) == CALL_INSN
1401 && GET_CODE (PATTERN (insn)) == PARALLEL
1402 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1403 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1408 /* See if we have to do anything to INSN now that VAR is in
1409 memory. If it needs to be loaded into a pseudo, use a single
1410 pseudo for the entire insn in case there is a MATCH_DUP
1411 between two operands. We pass a pointer to the head of
1412 a list of struct fixup_replacements. If fixup_var_refs_1
1413 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1414 it will record them in this list.
1416 If it allocated a pseudo for any replacement, we copy into
1419 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1422 /* If this is last_parm_insn, and any instructions were output
1423 after it to fix it up, then we must set last_parm_insn to
1424 the last such instruction emitted. */
1425 if (insn == last_parm_insn)
1426 last_parm_insn = PREV_INSN (next_insn);
1428 while (replacements)
1430 if (GET_CODE (replacements->new) == REG)
1435 /* OLD might be a (subreg (mem)). */
1436 if (GET_CODE (replacements->old) == SUBREG)
1438 = fixup_memory_subreg (replacements->old, insn, 0);
1441 = fixup_stack_1 (replacements->old, insn);
1443 /* We can not separate USE insns from the CALL_INSN
1444 that they belong to. If this is a CALL_INSN, insert
1445 the move insn before the USE insns preceding it
1446 instead of immediately before the insn. */
1447 if (GET_CODE (insn) == CALL_INSN)
1449 insert_before = insn;
1450 while (GET_CODE (PREV_INSN (insert_before)) == INSN
1451 && GET_CODE (PATTERN (PREV_INSN (insert_before))) == USE)
1452 insert_before = PREV_INSN (insert_before);
1455 insert_before = insn;
1457 /* If we are changing the mode, do a conversion.
1458 This might be wasteful, but combine.c will
1459 eliminate much of the waste. */
1461 if (GET_MODE (replacements->new)
1462 != GET_MODE (replacements->old))
1465 convert_move (replacements->new,
1466 replacements->old, unsignedp);
1467 seq = gen_sequence ();
1471 seq = gen_move_insn (replacements->new,
1474 emit_insn_before (seq, insert_before);
1477 replacements = replacements->next;
1481 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1482 But don't touch other insns referred to by reg-notes;
1483 we will get them elsewhere. */
1484 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1485 if (GET_CODE (note) != INSN_LIST)
1487 = walk_fixup_memory_subreg (XEXP (note, 0), insn, 1);
1493 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1494 See if the rtx expression at *LOC in INSN needs to be changed.
1496 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1497 contain a list of original rtx's and replacements. If we find that we need
1498 to modify this insn by replacing a memory reference with a pseudo or by
1499 making a new MEM to implement a SUBREG, we consult that list to see if
1500 we have already chosen a replacement. If none has already been allocated,
1501 we allocate it and update the list. fixup_var_refs_insns will copy VAR
1502 or the SUBREG, as appropriate, to the pseudo. */
1505 fixup_var_refs_1 (var, promoted_mode, loc, insn, replacements)
1507 enum machine_mode promoted_mode;
1510 struct fixup_replacement **replacements;
1513 register rtx x = *loc;
1514 RTX_CODE code = GET_CODE (x);
1516 register rtx tem, tem1;
1517 struct fixup_replacement *replacement;
1524 /* If we already have a replacement, use it. Otherwise,
1525 try to fix up this address in case it is invalid. */
1527 replacement = find_fixup_replacement (replacements, var);
1528 if (replacement->new)
1530 *loc = replacement->new;
1534 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1536 /* Unless we are forcing memory to register or we changed the mode,
1537 we can leave things the way they are if the insn is valid. */
1539 INSN_CODE (insn) = -1;
1540 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1541 && recog_memoized (insn) >= 0)
1544 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1548 /* If X contains VAR, we need to unshare it here so that we update
1549 each occurrence separately. But all identical MEMs in one insn
1550 must be replaced with the same rtx because of the possibility of
1553 if (reg_mentioned_p (var, x))
1555 replacement = find_fixup_replacement (replacements, x);
1556 if (replacement->new == 0)
1557 replacement->new = copy_most_rtx (x, var);
1559 *loc = x = replacement->new;
1575 /* Note that in some cases those types of expressions are altered
1576 by optimize_bit_field, and do not survive to get here. */
1577 if (XEXP (x, 0) == var
1578 || (GET_CODE (XEXP (x, 0)) == SUBREG
1579 && SUBREG_REG (XEXP (x, 0)) == var))
1581 /* Get TEM as a valid MEM in the mode presently in the insn.
1583 We don't worry about the possibility of MATCH_DUP here; it
1584 is highly unlikely and would be tricky to handle. */
1587 if (GET_CODE (tem) == SUBREG)
1588 tem = fixup_memory_subreg (tem, insn, 1);
1589 tem = fixup_stack_1 (tem, insn);
1591 /* Unless we want to load from memory, get TEM into the proper mode
1592 for an extract from memory. This can only be done if the
1593 extract is at a constant position and length. */
1595 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
1596 && GET_CODE (XEXP (x, 2)) == CONST_INT
1597 && ! mode_dependent_address_p (XEXP (tem, 0))
1598 && ! MEM_VOLATILE_P (tem))
1600 enum machine_mode wanted_mode = VOIDmode;
1601 enum machine_mode is_mode = GET_MODE (tem);
1602 int width = INTVAL (XEXP (x, 1));
1603 int pos = INTVAL (XEXP (x, 2));
1606 if (GET_CODE (x) == ZERO_EXTRACT)
1607 wanted_mode = insn_operand_mode[(int) CODE_FOR_extzv][1];
1610 if (GET_CODE (x) == SIGN_EXTRACT)
1611 wanted_mode = insn_operand_mode[(int) CODE_FOR_extv][1];
1613 /* If we have a narrower mode, we can do something. */
1614 if (wanted_mode != VOIDmode
1615 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
1617 int offset = pos / BITS_PER_UNIT;
1618 rtx old_pos = XEXP (x, 2);
1621 /* If the bytes and bits are counted differently, we
1622 must adjust the offset. */
1623 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1624 offset = (GET_MODE_SIZE (is_mode)
1625 - GET_MODE_SIZE (wanted_mode) - offset);
1628 pos %= GET_MODE_BITSIZE (wanted_mode);
1630 newmem = gen_rtx (MEM, wanted_mode,
1631 plus_constant (XEXP (tem, 0), offset));
1632 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
1633 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
1634 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
1636 /* Make the change and see if the insn remains valid. */
1637 INSN_CODE (insn) = -1;
1638 XEXP (x, 0) = newmem;
1639 XEXP (x, 2) = GEN_INT (pos);
1641 if (recog_memoized (insn) >= 0)
1644 /* Otherwise, restore old position. XEXP (x, 0) will be
1646 XEXP (x, 2) = old_pos;
1650 /* If we get here, the bitfield extract insn can't accept a memory
1651 reference. Copy the input into a register. */
1653 tem1 = gen_reg_rtx (GET_MODE (tem));
1654 emit_insn_before (gen_move_insn (tem1, tem), insn);
1661 if (SUBREG_REG (x) == var)
1663 /* If this is a special SUBREG made because VAR was promoted
1664 from a wider mode, replace it with VAR and call ourself
1665 recursively, this time saying that the object previously
1666 had its current mode (by virtue of the SUBREG). */
1668 if (SUBREG_PROMOTED_VAR_P (x))
1671 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements);
1675 /* If this SUBREG makes VAR wider, it has become a paradoxical
1676 SUBREG with VAR in memory, but these aren't allowed at this
1677 stage of the compilation. So load VAR into a pseudo and take
1678 a SUBREG of that pseudo. */
1679 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
1681 replacement = find_fixup_replacement (replacements, var);
1682 if (replacement->new == 0)
1683 replacement->new = gen_reg_rtx (GET_MODE (var));
1684 SUBREG_REG (x) = replacement->new;
1688 /* See if we have already found a replacement for this SUBREG.
1689 If so, use it. Otherwise, make a MEM and see if the insn
1690 is recognized. If not, or if we should force MEM into a register,
1691 make a pseudo for this SUBREG. */
1692 replacement = find_fixup_replacement (replacements, x);
1693 if (replacement->new)
1695 *loc = replacement->new;
1699 replacement->new = *loc = fixup_memory_subreg (x, insn, 0);
1701 INSN_CODE (insn) = -1;
1702 if (! flag_force_mem && recog_memoized (insn) >= 0)
1705 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
1711 /* First do special simplification of bit-field references. */
1712 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
1713 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
1714 optimize_bit_field (x, insn, 0);
1715 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
1716 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
1717 optimize_bit_field (x, insn, NULL_PTR);
1719 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
1720 insn into a pseudo and store the low part of the pseudo into VAR. */
1721 if (GET_CODE (SET_DEST (x)) == SUBREG
1722 && SUBREG_REG (SET_DEST (x)) == var
1723 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
1724 > GET_MODE_SIZE (GET_MODE (var))))
1726 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
1727 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
1734 rtx dest = SET_DEST (x);
1735 rtx src = SET_SRC (x);
1736 rtx outerdest = dest;
1738 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
1739 || GET_CODE (dest) == SIGN_EXTRACT
1740 || GET_CODE (dest) == ZERO_EXTRACT)
1741 dest = XEXP (dest, 0);
1743 if (GET_CODE (src) == SUBREG)
1744 src = XEXP (src, 0);
1746 /* If VAR does not appear at the top level of the SET
1747 just scan the lower levels of the tree. */
1749 if (src != var && dest != var)
1752 /* We will need to rerecognize this insn. */
1753 INSN_CODE (insn) = -1;
1756 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var)
1758 /* Since this case will return, ensure we fixup all the
1760 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
1761 insn, replacements);
1762 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
1763 insn, replacements);
1764 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
1765 insn, replacements);
1767 tem = XEXP (outerdest, 0);
1769 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
1770 that may appear inside a ZERO_EXTRACT.
1771 This was legitimate when the MEM was a REG. */
1772 if (GET_CODE (tem) == SUBREG
1773 && SUBREG_REG (tem) == var)
1774 tem = fixup_memory_subreg (tem, insn, 1);
1776 tem = fixup_stack_1 (tem, insn);
1778 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
1779 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
1780 && ! mode_dependent_address_p (XEXP (tem, 0))
1781 && ! MEM_VOLATILE_P (tem))
1783 enum machine_mode wanted_mode
1784 = insn_operand_mode[(int) CODE_FOR_insv][0];
1785 enum machine_mode is_mode = GET_MODE (tem);
1786 int width = INTVAL (XEXP (outerdest, 1));
1787 int pos = INTVAL (XEXP (outerdest, 2));
1789 /* If we have a narrower mode, we can do something. */
1790 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
1792 int offset = pos / BITS_PER_UNIT;
1793 rtx old_pos = XEXP (outerdest, 2);
1796 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1797 offset = (GET_MODE_SIZE (is_mode)
1798 - GET_MODE_SIZE (wanted_mode) - offset);
1801 pos %= GET_MODE_BITSIZE (wanted_mode);
1803 newmem = gen_rtx (MEM, wanted_mode,
1804 plus_constant (XEXP (tem, 0), offset));
1805 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
1806 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
1807 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
1809 /* Make the change and see if the insn remains valid. */
1810 INSN_CODE (insn) = -1;
1811 XEXP (outerdest, 0) = newmem;
1812 XEXP (outerdest, 2) = GEN_INT (pos);
1814 if (recog_memoized (insn) >= 0)
1817 /* Otherwise, restore old position. XEXP (x, 0) will be
1819 XEXP (outerdest, 2) = old_pos;
1823 /* If we get here, the bit-field store doesn't allow memory
1824 or isn't located at a constant position. Load the value into
1825 a register, do the store, and put it back into memory. */
1827 tem1 = gen_reg_rtx (GET_MODE (tem));
1828 emit_insn_before (gen_move_insn (tem1, tem), insn);
1829 emit_insn_after (gen_move_insn (tem, tem1), insn);
1830 XEXP (outerdest, 0) = tem1;
1835 /* STRICT_LOW_PART is a no-op on memory references
1836 and it can cause combinations to be unrecognizable,
1839 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
1840 SET_DEST (x) = XEXP (SET_DEST (x), 0);
1842 /* A valid insn to copy VAR into or out of a register
1843 must be left alone, to avoid an infinite loop here.
1844 If the reference to VAR is by a subreg, fix that up,
1845 since SUBREG is not valid for a memref.
1846 Also fix up the address of the stack slot.
1848 Note that we must not try to recognize the insn until
1849 after we know that we have valid addresses and no
1850 (subreg (mem ...) ...) constructs, since these interfere
1851 with determining the validity of the insn. */
1853 if ((SET_SRC (x) == var
1854 || (GET_CODE (SET_SRC (x)) == SUBREG
1855 && SUBREG_REG (SET_SRC (x)) == var))
1856 && (GET_CODE (SET_DEST (x)) == REG
1857 || (GET_CODE (SET_DEST (x)) == SUBREG
1858 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
1859 && x == single_set (PATTERN (insn)))
1863 replacement = find_fixup_replacement (replacements, SET_SRC (x));
1864 if (replacement->new)
1865 SET_SRC (x) = replacement->new;
1866 else if (GET_CODE (SET_SRC (x)) == SUBREG)
1867 SET_SRC (x) = replacement->new
1868 = fixup_memory_subreg (SET_SRC (x), insn, 0);
1870 SET_SRC (x) = replacement->new
1871 = fixup_stack_1 (SET_SRC (x), insn);
1873 if (recog_memoized (insn) >= 0)
1876 /* INSN is not valid, but we know that we want to
1877 copy SET_SRC (x) to SET_DEST (x) in some way. So
1878 we generate the move and see whether it requires more
1879 than one insn. If it does, we emit those insns and
1880 delete INSN. Otherwise, we an just replace the pattern
1881 of INSN; we have already verified above that INSN has
1882 no other function that to do X. */
1884 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
1885 if (GET_CODE (pat) == SEQUENCE)
1887 emit_insn_after (pat, insn);
1888 PUT_CODE (insn, NOTE);
1889 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1890 NOTE_SOURCE_FILE (insn) = 0;
1893 PATTERN (insn) = pat;
1898 if ((SET_DEST (x) == var
1899 || (GET_CODE (SET_DEST (x)) == SUBREG
1900 && SUBREG_REG (SET_DEST (x)) == var))
1901 && (GET_CODE (SET_SRC (x)) == REG
1902 || (GET_CODE (SET_SRC (x)) == SUBREG
1903 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
1904 && x == single_set (PATTERN (insn)))
1908 if (GET_CODE (SET_DEST (x)) == SUBREG)
1909 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn, 0);
1911 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
1913 if (recog_memoized (insn) >= 0)
1916 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
1917 if (GET_CODE (pat) == SEQUENCE)
1919 emit_insn_after (pat, insn);
1920 PUT_CODE (insn, NOTE);
1921 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1922 NOTE_SOURCE_FILE (insn) = 0;
1925 PATTERN (insn) = pat;
1930 /* Otherwise, storing into VAR must be handled specially
1931 by storing into a temporary and copying that into VAR
1932 with a new insn after this one. Note that this case
1933 will be used when storing into a promoted scalar since
1934 the insn will now have different modes on the input
1935 and output and hence will be invalid (except for the case
1936 of setting it to a constant, which does not need any
1937 change if it is valid). We generate extra code in that case,
1938 but combine.c will eliminate it. */
1943 rtx fixeddest = SET_DEST (x);
1945 /* STRICT_LOW_PART can be discarded, around a MEM. */
1946 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
1947 fixeddest = XEXP (fixeddest, 0);
1948 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
1949 if (GET_CODE (fixeddest) == SUBREG)
1950 fixeddest = fixup_memory_subreg (fixeddest, insn, 0);
1952 fixeddest = fixup_stack_1 (fixeddest, insn);
1954 temp = gen_reg_rtx (GET_MODE (SET_SRC (x)) == VOIDmode
1955 ? GET_MODE (fixeddest)
1956 : GET_MODE (SET_SRC (x)));
1958 emit_insn_after (gen_move_insn (fixeddest,
1959 gen_lowpart (GET_MODE (fixeddest),
1963 SET_DEST (x) = temp;
1968 /* Nothing special about this RTX; fix its operands. */
1970 fmt = GET_RTX_FORMAT (code);
1971 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1974 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements);
1978 for (j = 0; j < XVECLEN (x, i); j++)
1979 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
1980 insn, replacements);
1985 /* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
1986 return an rtx (MEM:m1 newaddr) which is equivalent.
1987 If any insns must be emitted to compute NEWADDR, put them before INSN.
1989 UNCRITICAL nonzero means accept paradoxical subregs.
1990 This is used for subregs found inside of ZERO_EXTRACTs and in REG_NOTES. */
1993 fixup_memory_subreg (x, insn, uncritical)
1998 int offset = SUBREG_WORD (x) * UNITS_PER_WORD;
1999 rtx addr = XEXP (SUBREG_REG (x), 0);
2000 enum machine_mode mode = GET_MODE (x);
2003 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2004 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
2008 #if BYTES_BIG_ENDIAN
2009 offset += (MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2010 - MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)));
2012 addr = plus_constant (addr, offset);
2013 if (!flag_force_addr && memory_address_p (mode, addr))
2014 /* Shortcut if no insns need be emitted. */
2015 return change_address (SUBREG_REG (x), mode, addr);
2017 result = change_address (SUBREG_REG (x), mode, addr);
2018 emit_insn_before (gen_sequence (), insn);
2023 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
2024 Replace subexpressions of X in place.
2025 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
2026 Otherwise return X, with its contents possibly altered.
2028 If any insns must be emitted to compute NEWADDR, put them before INSN.
2030 UNCRITICAL is as in fixup_memory_subreg. */
2033 walk_fixup_memory_subreg (x, insn, uncritical)
2038 register enum rtx_code code;
2045 code = GET_CODE (x);
2047 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
2048 return fixup_memory_subreg (x, insn, uncritical);
2050 /* Nothing special about this RTX; fix its operands. */
2052 fmt = GET_RTX_FORMAT (code);
2053 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2056 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn, uncritical);
2060 for (j = 0; j < XVECLEN (x, i); j++)
2062 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn, uncritical);
2069 /* Fix up any references to stack slots that are invalid memory addresses
2070 because they exceed the maximum range of a displacement. */
2073 fixup_stack_slots ()
2077 /* Did we generate a stack slot that is out of range
2078 or otherwise has an invalid address? */
2079 if (invalid_stack_slot)
2081 /* Yes. Must scan all insns for stack-refs that exceed the limit. */
2082 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
2083 if (GET_CODE (insn) == INSN || GET_CODE (insn) == CALL_INSN
2084 || GET_CODE (insn) == JUMP_INSN)
2085 fixup_stack_1 (PATTERN (insn), insn);
2090 /* For each memory ref within X, if it refers to a stack slot
2091 with an out of range displacement, put the address in a temp register
2092 (emitting new insns before INSN to load these registers)
2093 and alter the memory ref to use that register.
2094 Replace each such MEM rtx with a copy, to avoid clobberage. */
2097 fixup_stack_1 (x, insn)
2102 register RTX_CODE code = GET_CODE (x);
2107 register rtx ad = XEXP (x, 0);
2108 /* If we have address of a stack slot but it's not valid
2109 (displacement is too large), compute the sum in a register. */
2110 if (GET_CODE (ad) == PLUS
2111 && GET_CODE (XEXP (ad, 0)) == REG
2112 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2113 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2114 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2115 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2118 if (memory_address_p (GET_MODE (x), ad))
2122 temp = copy_to_reg (ad);
2123 seq = gen_sequence ();
2125 emit_insn_before (seq, insn);
2126 return change_address (x, VOIDmode, temp);
2131 fmt = GET_RTX_FORMAT (code);
2132 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2135 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2139 for (j = 0; j < XVECLEN (x, i); j++)
2140 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2146 /* Optimization: a bit-field instruction whose field
2147 happens to be a byte or halfword in memory
2148 can be changed to a move instruction.
2150 We call here when INSN is an insn to examine or store into a bit-field.
2151 BODY is the SET-rtx to be altered.
2153 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2154 (Currently this is called only from function.c, and EQUIV_MEM
2158 optimize_bit_field (body, insn, equiv_mem)
2163 register rtx bitfield;
2166 enum machine_mode mode;
2168 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2169 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2170 bitfield = SET_DEST (body), destflag = 1;
2172 bitfield = SET_SRC (body), destflag = 0;
2174 /* First check that the field being stored has constant size and position
2175 and is in fact a byte or halfword suitably aligned. */
2177 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2178 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2179 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2181 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2183 register rtx memref = 0;
2185 /* Now check that the containing word is memory, not a register,
2186 and that it is safe to change the machine mode. */
2188 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2189 memref = XEXP (bitfield, 0);
2190 else if (GET_CODE (XEXP (bitfield, 0)) == REG
2192 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2193 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2194 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2195 memref = SUBREG_REG (XEXP (bitfield, 0));
2196 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2198 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
2199 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2202 && ! mode_dependent_address_p (XEXP (memref, 0))
2203 && ! MEM_VOLATILE_P (memref))
2205 /* Now adjust the address, first for any subreg'ing
2206 that we are now getting rid of,
2207 and then for which byte of the word is wanted. */
2209 register int offset = INTVAL (XEXP (bitfield, 2));
2210 /* Adjust OFFSET to count bits from low-address byte. */
2211 #if BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN
2212 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2213 - offset - INTVAL (XEXP (bitfield, 1)));
2215 /* Adjust OFFSET to count bytes from low-address byte. */
2216 offset /= BITS_PER_UNIT;
2217 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2219 offset += SUBREG_WORD (XEXP (bitfield, 0)) * UNITS_PER_WORD;
2220 #if BYTES_BIG_ENDIAN
2221 offset -= (MIN (UNITS_PER_WORD,
2222 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2223 - MIN (UNITS_PER_WORD,
2224 GET_MODE_SIZE (GET_MODE (memref))));
2228 memref = change_address (memref, mode,
2229 plus_constant (XEXP (memref, 0), offset));
2231 /* Store this memory reference where
2232 we found the bit field reference. */
2236 validate_change (insn, &SET_DEST (body), memref, 1);
2237 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2239 rtx src = SET_SRC (body);
2240 while (GET_CODE (src) == SUBREG
2241 && SUBREG_WORD (src) == 0)
2242 src = SUBREG_REG (src);
2243 if (GET_MODE (src) != GET_MODE (memref))
2244 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2245 validate_change (insn, &SET_SRC (body), src, 1);
2247 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2248 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2249 /* This shouldn't happen because anything that didn't have
2250 one of these modes should have got converted explicitly
2251 and then referenced through a subreg.
2252 This is so because the original bit-field was
2253 handled by agg_mode and so its tree structure had
2254 the same mode that memref now has. */
2259 rtx dest = SET_DEST (body);
2261 while (GET_CODE (dest) == SUBREG
2262 && SUBREG_WORD (dest) == 0)
2263 dest = SUBREG_REG (dest);
2265 validate_change (insn, &SET_DEST (body), dest, 1);
2267 if (GET_MODE (dest) == GET_MODE (memref))
2268 validate_change (insn, &SET_SRC (body), memref, 1);
2271 /* Convert the mem ref to the destination mode. */
2272 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2275 convert_move (newreg, memref,
2276 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2280 validate_change (insn, &SET_SRC (body), newreg, 1);
2284 /* See if we can convert this extraction or insertion into
2285 a simple move insn. We might not be able to do so if this
2286 was, for example, part of a PARALLEL.
2288 If we succeed, write out any needed conversions. If we fail,
2289 it is hard to guess why we failed, so don't do anything
2290 special; just let the optimization be suppressed. */
2292 if (apply_change_group () && seq)
2293 emit_insns_before (seq, insn);
2298 /* These routines are responsible for converting virtual register references
2299 to the actual hard register references once RTL generation is complete.
2301 The following four variables are used for communication between the
2302 routines. They contain the offsets of the virtual registers from their
2303 respective hard registers. */
2305 static int in_arg_offset;
2306 static int var_offset;
2307 static int dynamic_offset;
2308 static int out_arg_offset;
2310 /* In most machines, the stack pointer register is equivalent to the bottom
2313 #ifndef STACK_POINTER_OFFSET
2314 #define STACK_POINTER_OFFSET 0
2317 /* If not defined, pick an appropriate default for the offset of dynamically
2318 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2319 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2321 #ifndef STACK_DYNAMIC_OFFSET
2323 #ifdef ACCUMULATE_OUTGOING_ARGS
2324 /* The bottom of the stack points to the actual arguments. If
2325 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2326 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2327 stack space for register parameters is not pushed by the caller, but
2328 rather part of the fixed stack areas and hence not included in
2329 `current_function_outgoing_args_size'. Nevertheless, we must allow
2330 for it when allocating stack dynamic objects. */
2332 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2333 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2334 (current_function_outgoing_args_size \
2335 + REG_PARM_STACK_SPACE (FNDECL) + (STACK_POINTER_OFFSET))
2338 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2339 (current_function_outgoing_args_size + (STACK_POINTER_OFFSET))
2343 #define STACK_DYNAMIC_OFFSET(FNDECL) STACK_POINTER_OFFSET
2347 /* Pass through the INSNS of function FNDECL and convert virtual register
2348 references to hard register references. */
2351 instantiate_virtual_regs (fndecl, insns)
2357 /* Compute the offsets to use for this function. */
2358 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
2359 var_offset = STARTING_FRAME_OFFSET;
2360 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
2361 out_arg_offset = STACK_POINTER_OFFSET;
2363 /* Scan all variables and parameters of this function. For each that is
2364 in memory, instantiate all virtual registers if the result is a valid
2365 address. If not, we do it later. That will handle most uses of virtual
2366 regs on many machines. */
2367 instantiate_decls (fndecl, 1);
2369 /* Initialize recognition, indicating that volatile is OK. */
2372 /* Scan through all the insns, instantiating every virtual register still
2374 for (insn = insns; insn; insn = NEXT_INSN (insn))
2375 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
2376 || GET_CODE (insn) == CALL_INSN)
2378 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
2379 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
2382 /* Now instantiate the remaining register equivalences for debugging info.
2383 These will not be valid addresses. */
2384 instantiate_decls (fndecl, 0);
2386 /* Indicate that, from now on, assign_stack_local should use
2387 frame_pointer_rtx. */
2388 virtuals_instantiated = 1;
2391 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
2392 all virtual registers in their DECL_RTL's.
2394 If VALID_ONLY, do this only if the resulting address is still valid.
2395 Otherwise, always do it. */
2398 instantiate_decls (fndecl, valid_only)
2404 if (DECL_INLINE (fndecl))
2405 /* When compiling an inline function, the obstack used for
2406 rtl allocation is the maybepermanent_obstack. Calling
2407 `resume_temporary_allocation' switches us back to that
2408 obstack while we process this function's parameters. */
2409 resume_temporary_allocation ();
2411 /* Process all parameters of the function. */
2412 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
2414 instantiate_decl (DECL_RTL (decl), int_size_in_bytes (TREE_TYPE (decl)),
2416 instantiate_decl (DECL_INCOMING_RTL (decl),
2417 int_size_in_bytes (TREE_TYPE (decl)), valid_only);
2420 /* Now process all variables defined in the function or its subblocks. */
2421 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
2423 if (DECL_INLINE (fndecl))
2425 /* Save all rtl allocated for this function by raising the
2426 high-water mark on the maybepermanent_obstack. */
2428 /* All further rtl allocation is now done in the current_obstack. */
2429 rtl_in_current_obstack ();
2433 /* Subroutine of instantiate_decls: Process all decls in the given
2434 BLOCK node and all its subblocks. */
2437 instantiate_decls_1 (let, valid_only)
2443 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
2444 instantiate_decl (DECL_RTL (t), int_size_in_bytes (TREE_TYPE (t)),
2447 /* Process all subblocks. */
2448 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
2449 instantiate_decls_1 (t, valid_only);
2452 /* Subroutine of the preceding procedures: Given RTL representing a
2453 decl and the size of the object, do any instantiation required.
2455 If VALID_ONLY is non-zero, it means that the RTL should only be
2456 changed if the new address is valid. */
2459 instantiate_decl (x, size, valid_only)
2464 enum machine_mode mode;
2467 /* If this is not a MEM, no need to do anything. Similarly if the
2468 address is a constant or a register that is not a virtual register. */
2470 if (x == 0 || GET_CODE (x) != MEM)
2474 if (CONSTANT_P (addr)
2475 || (GET_CODE (addr) == REG
2476 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
2477 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
2480 /* If we should only do this if the address is valid, copy the address.
2481 We need to do this so we can undo any changes that might make the
2482 address invalid. This copy is unfortunate, but probably can't be
2486 addr = copy_rtx (addr);
2488 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
2493 /* Now verify that the resulting address is valid for every integer or
2494 floating-point mode up to and including SIZE bytes long. We do this
2495 since the object might be accessed in any mode and frame addresses
2498 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2499 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2500 mode = GET_MODE_WIDER_MODE (mode))
2501 if (! memory_address_p (mode, addr))
2504 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
2505 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2506 mode = GET_MODE_WIDER_MODE (mode))
2507 if (! memory_address_p (mode, addr))
2510 /* Otherwise, put back the address, now that we have updated it and we
2511 know it is valid. */
2516 /* Given a pointer to a piece of rtx and an optional pointer to the
2517 containing object, instantiate any virtual registers present in it.
2519 If EXTRA_INSNS, we always do the replacement and generate
2520 any extra insns before OBJECT. If it zero, we do nothing if replacement
2523 Return 1 if we either had nothing to do or if we were able to do the
2524 needed replacement. Return 0 otherwise; we only return zero if
2525 EXTRA_INSNS is zero.
2527 We first try some simple transformations to avoid the creation of extra
2531 instantiate_virtual_regs_1 (loc, object, extra_insns)
2545 /* Re-start here to avoid recursion in common cases. */
2552 code = GET_CODE (x);
2554 /* Check for some special cases. */
2571 /* We are allowed to set the virtual registers. This means that
2572 that the actual register should receive the source minus the
2573 appropriate offset. This is used, for example, in the handling
2574 of non-local gotos. */
2575 if (SET_DEST (x) == virtual_incoming_args_rtx)
2576 new = arg_pointer_rtx, offset = - in_arg_offset;
2577 else if (SET_DEST (x) == virtual_stack_vars_rtx)
2578 new = frame_pointer_rtx, offset = - var_offset;
2579 else if (SET_DEST (x) == virtual_stack_dynamic_rtx)
2580 new = stack_pointer_rtx, offset = - dynamic_offset;
2581 else if (SET_DEST (x) == virtual_outgoing_args_rtx)
2582 new = stack_pointer_rtx, offset = - out_arg_offset;
2586 /* The only valid sources here are PLUS or REG. Just do
2587 the simplest possible thing to handle them. */
2588 if (GET_CODE (SET_SRC (x)) != REG
2589 && GET_CODE (SET_SRC (x)) != PLUS)
2593 if (GET_CODE (SET_SRC (x)) != REG)
2594 temp = force_operand (SET_SRC (x), NULL_RTX);
2597 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
2601 emit_insns_before (seq, object);
2604 if (!validate_change (object, &SET_SRC (x), temp, 0)
2611 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
2616 /* Handle special case of virtual register plus constant. */
2617 if (CONSTANT_P (XEXP (x, 1)))
2621 /* Check for (plus (plus VIRT foo) (const_int)) first. */
2622 if (GET_CODE (XEXP (x, 0)) == PLUS)
2624 rtx inner = XEXP (XEXP (x, 0), 0);
2626 if (inner == virtual_incoming_args_rtx)
2627 new = arg_pointer_rtx, offset = in_arg_offset;
2628 else if (inner == virtual_stack_vars_rtx)
2629 new = frame_pointer_rtx, offset = var_offset;
2630 else if (inner == virtual_stack_dynamic_rtx)
2631 new = stack_pointer_rtx, offset = dynamic_offset;
2632 else if (inner == virtual_outgoing_args_rtx)
2633 new = stack_pointer_rtx, offset = out_arg_offset;
2640 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
2642 new = gen_rtx (PLUS, Pmode, new, XEXP (XEXP (x, 0), 1));
2645 else if (XEXP (x, 0) == virtual_incoming_args_rtx)
2646 new = arg_pointer_rtx, offset = in_arg_offset;
2647 else if (XEXP (x, 0) == virtual_stack_vars_rtx)
2648 new = frame_pointer_rtx, offset = var_offset;
2649 else if (XEXP (x, 0) == virtual_stack_dynamic_rtx)
2650 new = stack_pointer_rtx, offset = dynamic_offset;
2651 else if (XEXP (x, 0) == virtual_outgoing_args_rtx)
2652 new = stack_pointer_rtx, offset = out_arg_offset;
2655 /* We know the second operand is a constant. Unless the
2656 first operand is a REG (which has been already checked),
2657 it needs to be checked. */
2658 if (GET_CODE (XEXP (x, 0)) != REG)
2668 new = plus_constant (XEXP (x, 1), offset);
2670 /* If the new constant is zero, try to replace the sum with its
2672 if (new == const0_rtx
2673 && validate_change (object, loc, XEXP (x, 0), 0))
2676 /* Next try to replace constant with new one. */
2677 if (!validate_change (object, &XEXP (x, 1), new, 0))
2685 /* Otherwise copy the new constant into a register and replace
2686 constant with that register. */
2687 temp = gen_reg_rtx (Pmode);
2688 if (validate_change (object, &XEXP (x, 1), temp, 0))
2689 emit_insn_before (gen_move_insn (temp, new), object);
2692 /* If that didn't work, replace this expression with a
2693 register containing the sum. */
2695 new = gen_rtx (PLUS, Pmode, XEXP (x, 0), new);
2699 temp = force_operand (new, NULL_RTX);
2703 emit_insns_before (seq, object);
2704 if (! validate_change (object, loc, temp, 0)
2705 && ! validate_replace_rtx (x, temp, object))
2713 /* Fall through to generic two-operand expression case. */
2719 case DIV: case UDIV:
2720 case MOD: case UMOD:
2721 case AND: case IOR: case XOR:
2722 case LSHIFT: case ASHIFT: case ROTATE:
2723 case ASHIFTRT: case LSHIFTRT: case ROTATERT:
2725 case GE: case GT: case GEU: case GTU:
2726 case LE: case LT: case LEU: case LTU:
2727 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
2728 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
2733 /* Most cases of MEM that convert to valid addresses have already been
2734 handled by our scan of regno_reg_rtx. The only special handling we
2735 need here is to make a copy of the rtx to ensure it isn't being
2736 shared if we have to change it to a pseudo.
2738 If the rtx is a simple reference to an address via a virtual register,
2739 it can potentially be shared. In such cases, first try to make it
2740 a valid address, which can also be shared. Otherwise, copy it and
2743 First check for common cases that need no processing. These are
2744 usually due to instantiation already being done on a previous instance
2748 if (CONSTANT_ADDRESS_P (temp)
2749 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2750 || temp == arg_pointer_rtx
2752 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2753 || temp == hard_frame_pointer_rtx
2755 || temp == frame_pointer_rtx)
2758 if (GET_CODE (temp) == PLUS
2759 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2760 && (XEXP (temp, 0) == frame_pointer_rtx
2761 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2762 || XEXP (temp, 0) == hard_frame_pointer_rtx
2764 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2765 || XEXP (temp, 0) == arg_pointer_rtx
2770 if (temp == virtual_stack_vars_rtx
2771 || temp == virtual_incoming_args_rtx
2772 || (GET_CODE (temp) == PLUS
2773 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2774 && (XEXP (temp, 0) == virtual_stack_vars_rtx
2775 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
2777 /* This MEM may be shared. If the substitution can be done without
2778 the need to generate new pseudos, we want to do it in place
2779 so all copies of the shared rtx benefit. The call below will
2780 only make substitutions if the resulting address is still
2783 Note that we cannot pass X as the object in the recursive call
2784 since the insn being processed may not allow all valid
2785 addresses. However, if we were not passed on object, we can
2786 only modify X without copying it if X will have a valid
2789 ??? Also note that this can still lose if OBJECT is an insn that
2790 has less restrictions on an address that some other insn.
2791 In that case, we will modify the shared address. This case
2792 doesn't seem very likely, though. */
2794 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
2795 object ? object : x, 0))
2798 /* Otherwise make a copy and process that copy. We copy the entire
2799 RTL expression since it might be a PLUS which could also be
2801 *loc = x = copy_rtx (x);
2804 /* Fall through to generic unary operation case. */
2808 case STRICT_LOW_PART:
2810 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
2811 case SIGN_EXTEND: case ZERO_EXTEND:
2812 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2813 case FLOAT: case FIX:
2814 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2818 /* These case either have just one operand or we know that we need not
2819 check the rest of the operands. */
2824 /* Try to replace with a PLUS. If that doesn't work, compute the sum
2825 in front of this insn and substitute the temporary. */
2826 if (x == virtual_incoming_args_rtx)
2827 new = arg_pointer_rtx, offset = in_arg_offset;
2828 else if (x == virtual_stack_vars_rtx)
2829 new = frame_pointer_rtx, offset = var_offset;
2830 else if (x == virtual_stack_dynamic_rtx)
2831 new = stack_pointer_rtx, offset = dynamic_offset;
2832 else if (x == virtual_outgoing_args_rtx)
2833 new = stack_pointer_rtx, offset = out_arg_offset;
2837 temp = plus_constant (new, offset);
2838 if (!validate_change (object, loc, temp, 0))
2844 temp = force_operand (temp, NULL_RTX);
2848 emit_insns_before (seq, object);
2849 if (! validate_change (object, loc, temp, 0)
2850 && ! validate_replace_rtx (x, temp, object))
2858 /* Scan all subexpressions. */
2859 fmt = GET_RTX_FORMAT (code);
2860 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2863 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
2866 else if (*fmt == 'E')
2867 for (j = 0; j < XVECLEN (x, i); j++)
2868 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
2875 /* Optimization: assuming this function does not receive nonlocal gotos,
2876 delete the handlers for such, as well as the insns to establish
2877 and disestablish them. */
2883 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
2885 /* Delete the handler by turning off the flag that would
2886 prevent jump_optimize from deleting it.
2887 Also permit deletion of the nonlocal labels themselves
2888 if nothing local refers to them. */
2889 if (GET_CODE (insn) == CODE_LABEL)
2890 LABEL_PRESERVE_P (insn) = 0;
2891 if (GET_CODE (insn) == INSN
2892 && ((nonlocal_goto_handler_slot != 0
2893 && reg_mentioned_p (nonlocal_goto_handler_slot, PATTERN (insn)))
2894 || (nonlocal_goto_stack_level != 0
2895 && reg_mentioned_p (nonlocal_goto_stack_level,
2901 /* Return a list (chain of EXPR_LIST nodes) for the nonlocal labels
2902 of the current function. */
2905 nonlocal_label_rtx_list ()
2910 for (t = nonlocal_labels; t; t = TREE_CHAIN (t))
2911 x = gen_rtx (EXPR_LIST, VOIDmode, label_rtx (TREE_VALUE (t)), x);
2916 /* Output a USE for any register use in RTL.
2917 This is used with -noreg to mark the extent of lifespan
2918 of any registers used in a user-visible variable's DECL_RTL. */
2924 if (GET_CODE (rtl) == REG)
2925 /* This is a register variable. */
2926 emit_insn (gen_rtx (USE, VOIDmode, rtl));
2927 else if (GET_CODE (rtl) == MEM
2928 && GET_CODE (XEXP (rtl, 0)) == REG
2929 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
2930 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
2931 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
2932 /* This is a variable-sized structure. */
2933 emit_insn (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)));
2936 /* Like use_variable except that it outputs the USEs after INSN
2937 instead of at the end of the insn-chain. */
2940 use_variable_after (rtl, insn)
2943 if (GET_CODE (rtl) == REG)
2944 /* This is a register variable. */
2945 emit_insn_after (gen_rtx (USE, VOIDmode, rtl), insn);
2946 else if (GET_CODE (rtl) == MEM
2947 && GET_CODE (XEXP (rtl, 0)) == REG
2948 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
2949 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
2950 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
2951 /* This is a variable-sized structure. */
2952 emit_insn_after (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)), insn);
2958 return max_parm_reg;
2961 /* Return the first insn following those generated by `assign_parms'. */
2964 get_first_nonparm_insn ()
2967 return NEXT_INSN (last_parm_insn);
2968 return get_insns ();
2971 /* Return the first NOTE_INSN_BLOCK_BEG note in the function.
2972 Crash if there is none. */
2975 get_first_block_beg ()
2977 register rtx searcher;
2978 register rtx insn = get_first_nonparm_insn ();
2980 for (searcher = insn; searcher; searcher = NEXT_INSN (searcher))
2981 if (GET_CODE (searcher) == NOTE
2982 && NOTE_LINE_NUMBER (searcher) == NOTE_INSN_BLOCK_BEG)
2985 abort (); /* Invalid call to this function. (See comments above.) */
2989 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2990 This means a type for which function calls must pass an address to the
2991 function or get an address back from the function.
2992 EXP may be a type node or an expression (whose type is tested). */
2995 aggregate_value_p (exp)
2998 int i, regno, nregs;
3001 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 't')
3004 type = TREE_TYPE (exp);
3006 if (RETURN_IN_MEMORY (type))
3008 if (flag_pcc_struct_return
3009 && (TREE_CODE (type) == RECORD_TYPE
3010 || TREE_CODE (type) == UNION_TYPE
3011 || TREE_CODE (type) == QUAL_UNION_TYPE
3012 || TREE_CODE (type) == ARRAY_TYPE))
3014 /* Make sure we have suitable call-clobbered regs to return
3015 the value in; if not, we must return it in memory. */
3016 reg = hard_function_value (type, 0);
3017 regno = REGNO (reg);
3018 nregs = HARD_REGNO_NREGS (regno, TYPE_MODE (type));
3019 for (i = 0; i < nregs; i++)
3020 if (! call_used_regs[regno + i])
3025 /* Assign RTL expressions to the function's parameters.
3026 This may involve copying them into registers and using
3027 those registers as the RTL for them.
3029 If SECOND_TIME is non-zero it means that this function is being
3030 called a second time. This is done by integrate.c when a function's
3031 compilation is deferred. We need to come back here in case the
3032 FUNCTION_ARG macro computes items needed for the rest of the compilation
3033 (such as changing which registers are fixed or caller-saved). But suppress
3034 writing any insns or setting DECL_RTL of anything in this case. */
3037 assign_parms (fndecl, second_time)
3042 register rtx entry_parm = 0;
3043 register rtx stack_parm = 0;
3044 CUMULATIVE_ARGS args_so_far;
3045 enum machine_mode promoted_mode, passed_mode, nominal_mode;
3047 /* Total space needed so far for args on the stack,
3048 given as a constant and a tree-expression. */
3049 struct args_size stack_args_size;
3050 tree fntype = TREE_TYPE (fndecl);
3051 tree fnargs = DECL_ARGUMENTS (fndecl);
3052 /* This is used for the arg pointer when referring to stack args. */
3053 rtx internal_arg_pointer;
3054 /* This is a dummy PARM_DECL that we used for the function result if
3055 the function returns a structure. */
3056 tree function_result_decl = 0;
3057 int nparmregs = list_length (fnargs) + LAST_VIRTUAL_REGISTER + 1;
3058 int varargs_setup = 0;
3059 rtx conversion_insns = 0;
3060 /* FUNCTION_ARG may look at this variable. Since this is not
3061 expanding a call it will always be zero in this function. */
3062 int current_call_is_indirect = 0;
3064 /* Nonzero if the last arg is named `__builtin_va_alist',
3065 which is used on some machines for old-fashioned non-ANSI varargs.h;
3066 this should be stuck onto the stack as if it had arrived there. */
3068 = (current_function_varargs
3070 && (parm = tree_last (fnargs)) != 0
3072 && (! strcmp (IDENTIFIER_POINTER (DECL_NAME (parm)),
3073 "__builtin_va_alist")));
3075 /* Nonzero if function takes extra anonymous args.
3076 This means the last named arg must be on the stack
3077 right before the anonymous ones. */
3079 = (TYPE_ARG_TYPES (fntype) != 0
3080 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3081 != void_type_node));
3083 /* If the reg that the virtual arg pointer will be translated into is
3084 not a fixed reg or is the stack pointer, make a copy of the virtual
3085 arg pointer, and address parms via the copy. The frame pointer is
3086 considered fixed even though it is not marked as such.
3088 The second time through, simply use ap to avoid generating rtx. */
3090 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
3091 || ! (fixed_regs[ARG_POINTER_REGNUM]
3092 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM))
3094 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
3096 internal_arg_pointer = virtual_incoming_args_rtx;
3097 current_function_internal_arg_pointer = internal_arg_pointer;
3099 stack_args_size.constant = 0;
3100 stack_args_size.var = 0;
3102 /* If struct value address is treated as the first argument, make it so. */
3103 if (aggregate_value_p (DECL_RESULT (fndecl))
3104 && ! current_function_returns_pcc_struct
3105 && struct_value_incoming_rtx == 0)
3107 tree type = build_pointer_type (fntype);
3109 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
3111 DECL_ARG_TYPE (function_result_decl) = type;
3112 TREE_CHAIN (function_result_decl) = fnargs;
3113 fnargs = function_result_decl;
3116 parm_reg_stack_loc = (rtx *) oballoc (nparmregs * sizeof (rtx));
3117 bzero (parm_reg_stack_loc, nparmregs * sizeof (rtx));
3119 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
3120 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
3122 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX);
3125 /* We haven't yet found an argument that we must push and pretend the
3127 current_function_pretend_args_size = 0;
3129 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3132 = (TREE_CODE (TREE_TYPE (parm)) == ARRAY_TYPE
3133 || TREE_CODE (TREE_TYPE (parm)) == RECORD_TYPE
3134 || TREE_CODE (TREE_TYPE (parm)) == UNION_TYPE
3135 || TREE_CODE (TREE_TYPE (parm)) == QUAL_UNION_TYPE);
3136 struct args_size stack_offset;
3137 struct args_size arg_size;
3138 int passed_pointer = 0;
3139 tree passed_type = DECL_ARG_TYPE (parm);
3141 /* Set LAST_NAMED if this is last named arg before some
3142 anonymous args. We treat it as if it were anonymous too. */
3143 int last_named = ((TREE_CHAIN (parm) == 0
3144 || DECL_NAME (TREE_CHAIN (parm)) == 0)
3145 && (stdarg || current_function_varargs));
3147 if (TREE_TYPE (parm) == error_mark_node
3148 /* This can happen after weird syntax errors
3149 or if an enum type is defined among the parms. */
3150 || TREE_CODE (parm) != PARM_DECL
3151 || passed_type == NULL)
3153 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = gen_rtx (MEM, BLKmode,
3155 TREE_USED (parm) = 1;
3159 /* For varargs.h function, save info about regs and stack space
3160 used by the individual args, not including the va_alist arg. */
3161 if (hide_last_arg && last_named)
3162 current_function_args_info = args_so_far;
3164 /* Find mode of arg as it is passed, and mode of arg
3165 as it should be during execution of this function. */
3166 passed_mode = TYPE_MODE (passed_type);
3167 nominal_mode = TYPE_MODE (TREE_TYPE (parm));
3169 /* If the parm's mode is VOID, its value doesn't matter,
3170 and avoid the usual things like emit_move_insn that could crash. */
3171 if (nominal_mode == VOIDmode)
3173 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = const0_rtx;
3177 /* See if this arg was passed by invisible reference. It is if
3178 it is an object whose size depends on the contents of the
3179 object itself or if the machine requires these objects be passed
3182 if ((TREE_CODE (TYPE_SIZE (passed_type)) != INTEGER_CST
3183 && contains_placeholder_p (TYPE_SIZE (passed_type)))
3184 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3185 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
3186 passed_type, ! last_named)
3190 passed_type = build_pointer_type (passed_type);
3192 passed_mode = nominal_mode = Pmode;
3195 promoted_mode = passed_mode;
3197 #ifdef PROMOTE_FUNCTION_ARGS
3198 /* Compute the mode in which the arg is actually extended to. */
3199 if (TREE_CODE (passed_type) == INTEGER_TYPE
3200 || TREE_CODE (passed_type) == ENUMERAL_TYPE
3201 || TREE_CODE (passed_type) == BOOLEAN_TYPE
3202 || TREE_CODE (passed_type) == CHAR_TYPE
3203 || TREE_CODE (passed_type) == REAL_TYPE
3204 || TREE_CODE (passed_type) == POINTER_TYPE
3205 || TREE_CODE (passed_type) == OFFSET_TYPE)
3207 unsignedp = TREE_UNSIGNED (passed_type);
3208 PROMOTE_MODE (promoted_mode, unsignedp, passed_type);
3212 /* Let machine desc say which reg (if any) the parm arrives in.
3213 0 means it arrives on the stack. */
3214 #ifdef FUNCTION_INCOMING_ARG
3215 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
3216 passed_type, ! last_named);
3218 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
3219 passed_type, ! last_named);
3223 passed_mode = promoted_mode;
3225 #ifdef SETUP_INCOMING_VARARGS
3226 /* If this is the last named parameter, do any required setup for
3227 varargs or stdargs. We need to know about the case of this being an
3228 addressable type, in which case we skip the registers it
3229 would have arrived in.
3231 For stdargs, LAST_NAMED will be set for two parameters, the one that
3232 is actually the last named, and the dummy parameter. We only
3233 want to do this action once.
3235 Also, indicate when RTL generation is to be suppressed. */
3236 if (last_named && !varargs_setup)
3238 SETUP_INCOMING_VARARGS (args_so_far, passed_mode, passed_type,
3239 current_function_pretend_args_size,
3245 /* Determine parm's home in the stack,
3246 in case it arrives in the stack or we should pretend it did.
3248 Compute the stack position and rtx where the argument arrives
3251 There is one complexity here: If this was a parameter that would
3252 have been passed in registers, but wasn't only because it is
3253 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
3254 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
3255 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
3256 0 as it was the previous time. */
3258 locate_and_pad_parm (passed_mode, passed_type,
3259 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3262 #ifdef FUNCTION_INCOMING_ARG
3263 FUNCTION_INCOMING_ARG (args_so_far, passed_mode,
3266 || varargs_setup)) != 0,
3268 FUNCTION_ARG (args_so_far, passed_mode,
3270 ! last_named || varargs_setup) != 0,
3273 fndecl, &stack_args_size, &stack_offset, &arg_size);
3277 rtx offset_rtx = ARGS_SIZE_RTX (stack_offset);
3279 if (offset_rtx == const0_rtx)
3280 stack_parm = gen_rtx (MEM, passed_mode, internal_arg_pointer);
3282 stack_parm = gen_rtx (MEM, passed_mode,
3283 gen_rtx (PLUS, Pmode,
3284 internal_arg_pointer, offset_rtx));
3286 /* If this is a memory ref that contains aggregate components,
3287 mark it as such for cse and loop optimize. */
3288 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3291 /* If this parameter was passed both in registers and in the stack,
3292 use the copy on the stack. */
3293 if (MUST_PASS_IN_STACK (passed_mode, passed_type))
3296 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3297 /* If this parm was passed part in regs and part in memory,
3298 pretend it arrived entirely in memory
3299 by pushing the register-part onto the stack.
3301 In the special case of a DImode or DFmode that is split,
3302 we could put it together in a pseudoreg directly,
3303 but for now that's not worth bothering with. */
3307 int nregs = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, passed_mode,
3308 passed_type, ! last_named);
3312 current_function_pretend_args_size
3313 = (((nregs * UNITS_PER_WORD) + (PARM_BOUNDARY / BITS_PER_UNIT) - 1)
3314 / (PARM_BOUNDARY / BITS_PER_UNIT)
3315 * (PARM_BOUNDARY / BITS_PER_UNIT));
3318 move_block_from_reg (REGNO (entry_parm),
3319 validize_mem (stack_parm), nregs,
3320 int_size_in_bytes (TREE_TYPE (parm)));
3321 entry_parm = stack_parm;
3326 /* If we didn't decide this parm came in a register,
3327 by default it came on the stack. */
3328 if (entry_parm == 0)
3329 entry_parm = stack_parm;
3331 /* Record permanently how this parm was passed. */
3333 DECL_INCOMING_RTL (parm) = entry_parm;
3335 /* If there is actually space on the stack for this parm,
3336 count it in stack_args_size; otherwise set stack_parm to 0
3337 to indicate there is no preallocated stack slot for the parm. */
3339 if (entry_parm == stack_parm
3340 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
3341 /* On some machines, even if a parm value arrives in a register
3342 there is still an (uninitialized) stack slot allocated for it.
3344 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
3345 whether this parameter already has a stack slot allocated,
3346 because an arg block exists only if current_function_args_size
3347 is larger than some threshhold, and we haven't calculated that
3348 yet. So, for now, we just assume that stack slots never exist
3350 || REG_PARM_STACK_SPACE (fndecl) > 0
3354 stack_args_size.constant += arg_size.constant;
3356 ADD_PARM_SIZE (stack_args_size, arg_size.var);
3359 /* No stack slot was pushed for this parm. */
3362 /* Update info on where next arg arrives in registers. */
3364 FUNCTION_ARG_ADVANCE (args_so_far, passed_mode,
3365 passed_type, ! last_named);
3367 /* If this is our second time through, we are done with this parm. */
3371 /* If we can't trust the parm stack slot to be aligned enough
3372 for its ultimate type, don't use that slot after entry.
3373 We'll make another stack slot, if we need one. */
3375 int thisparm_boundary
3376 = FUNCTION_ARG_BOUNDARY (passed_mode, passed_type);
3378 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
3382 /* If parm was passed in memory, and we need to convert it on entry,
3383 don't store it back in that same slot. */
3385 && nominal_mode != BLKmode && nominal_mode != passed_mode)
3389 /* Now adjust STACK_PARM to the mode and precise location
3390 where this parameter should live during execution,
3391 if we discover that it must live in the stack during execution.
3392 To make debuggers happier on big-endian machines, we store
3393 the value in the last bytes of the space available. */
3395 if (nominal_mode != BLKmode && nominal_mode != passed_mode
3400 #if BYTES_BIG_ENDIAN
3401 if (GET_MODE_SIZE (nominal_mode) < UNITS_PER_WORD)
3402 stack_offset.constant += (GET_MODE_SIZE (passed_mode)
3403 - GET_MODE_SIZE (nominal_mode));
3406 offset_rtx = ARGS_SIZE_RTX (stack_offset);
3407 if (offset_rtx == const0_rtx)
3408 stack_parm = gen_rtx (MEM, nominal_mode, internal_arg_pointer);
3410 stack_parm = gen_rtx (MEM, nominal_mode,
3411 gen_rtx (PLUS, Pmode,
3412 internal_arg_pointer, offset_rtx));
3414 /* If this is a memory ref that contains aggregate components,
3415 mark it as such for cse and loop optimize. */
3416 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3420 /* ENTRY_PARM is an RTX for the parameter as it arrives,
3421 in the mode in which it arrives.
3422 STACK_PARM is an RTX for a stack slot where the parameter can live
3423 during the function (in case we want to put it there).
3424 STACK_PARM is 0 if no stack slot was pushed for it.
3426 Now output code if necessary to convert ENTRY_PARM to
3427 the type in which this function declares it,
3428 and store that result in an appropriate place,
3429 which may be a pseudo reg, may be STACK_PARM,
3430 or may be a local stack slot if STACK_PARM is 0.
3432 Set DECL_RTL to that place. */
3434 if (nominal_mode == BLKmode)
3436 /* If a BLKmode arrives in registers, copy it to a stack slot. */
3437 if (GET_CODE (entry_parm) == REG)
3439 int size_stored = CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm)),
3442 /* Note that we will be storing an integral number of words.
3443 So we have to be careful to ensure that we allocate an
3444 integral number of words. We do this below in the
3445 assign_stack_local if space was not allocated in the argument
3446 list. If it was, this will not work if PARM_BOUNDARY is not
3447 a multiple of BITS_PER_WORD. It isn't clear how to fix this
3448 if it becomes a problem. */
3450 if (stack_parm == 0)
3453 = assign_stack_local (GET_MODE (entry_parm), size_stored, 0);
3454 /* If this is a memory ref that contains aggregate components,
3455 mark it as such for cse and loop optimize. */
3456 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3459 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
3462 move_block_from_reg (REGNO (entry_parm),
3463 validize_mem (stack_parm),
3464 size_stored / UNITS_PER_WORD,
3465 int_size_in_bytes (TREE_TYPE (parm)));
3467 DECL_RTL (parm) = stack_parm;
3469 else if (! ((obey_regdecls && ! DECL_REGISTER (parm)
3470 && ! DECL_INLINE (fndecl))
3471 /* layout_decl may set this. */
3472 || TREE_ADDRESSABLE (parm)
3473 || TREE_SIDE_EFFECTS (parm)
3474 /* If -ffloat-store specified, don't put explicit
3475 float variables into registers. */
3476 || (flag_float_store
3477 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
3478 /* Always assign pseudo to structure return or item passed
3479 by invisible reference. */
3480 || passed_pointer || parm == function_result_decl)
3482 /* Store the parm in a pseudoregister during the function, but we
3483 may need to do it in a wider mode. */
3485 register rtx parmreg;
3488 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
3489 if (TREE_CODE (TREE_TYPE (parm)) == INTEGER_TYPE
3490 || TREE_CODE (TREE_TYPE (parm)) == ENUMERAL_TYPE
3491 || TREE_CODE (TREE_TYPE (parm)) == BOOLEAN_TYPE
3492 || TREE_CODE (TREE_TYPE (parm)) == CHAR_TYPE
3493 || TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE
3494 || TREE_CODE (TREE_TYPE (parm)) == POINTER_TYPE
3495 || TREE_CODE (TREE_TYPE (parm)) == OFFSET_TYPE)
3497 PROMOTE_MODE (nominal_mode, unsignedp, TREE_TYPE (parm));
3500 parmreg = gen_reg_rtx (nominal_mode);
3501 REG_USERVAR_P (parmreg) = 1;
3503 /* If this was an item that we received a pointer to, set DECL_RTL
3507 DECL_RTL (parm) = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (passed_type)), parmreg);
3508 MEM_IN_STRUCT_P (DECL_RTL (parm)) = aggregate;
3511 DECL_RTL (parm) = parmreg;
3513 /* Copy the value into the register. */
3514 if (GET_MODE (parmreg) != GET_MODE (entry_parm))
3516 /* If ENTRY_PARM is a hard register, it might be in a register
3517 not valid for operating in its mode (e.g., an odd-numbered
3518 register for a DFmode). In that case, moves are the only
3519 thing valid, so we can't do a convert from there. This
3520 occurs when the calling sequence allow such misaligned
3523 In addition, the conversion may involve a call, which could
3524 clobber parameters which haven't been copied to pseudo
3525 registers yet. Therefore, we must first copy the parm to
3526 a pseudo reg here, and save the conversion until after all
3527 parameters have been moved. */
3529 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
3531 emit_move_insn (tempreg, validize_mem (entry_parm));
3533 push_to_sequence (conversion_insns);
3534 convert_move (parmreg, tempreg, unsignedp);
3535 conversion_insns = get_insns ();
3539 emit_move_insn (parmreg, validize_mem (entry_parm));
3541 /* If we were passed a pointer but the actual value
3542 can safely live in a register, put it in one. */
3543 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
3544 && ! ((obey_regdecls && ! DECL_REGISTER (parm)
3545 && ! DECL_INLINE (fndecl))
3546 /* layout_decl may set this. */
3547 || TREE_ADDRESSABLE (parm)
3548 || TREE_SIDE_EFFECTS (parm)
3549 /* If -ffloat-store specified, don't put explicit
3550 float variables into registers. */
3551 || (flag_float_store
3552 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE)))
3554 /* We can't use nominal_mode, because it will have been set to
3555 Pmode above. We must use the actual mode of the parm. */
3556 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3557 emit_move_insn (parmreg, DECL_RTL (parm));
3558 DECL_RTL (parm) = parmreg;
3559 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3563 #ifdef FUNCTION_ARG_CALLEE_COPIES
3564 /* If we are passed an arg by reference and it is our responsibility
3565 to make a copy, do it now.
3566 PASSED_TYPE and PASSED mode now refer to the pointer, not the
3567 original argument, so we must recreate them in the call to
3568 FUNCTION_ARG_CALLEE_COPIES. */
3569 /* ??? Later add code to handle the case that if the argument isn't
3570 modified, don't do the copy. */
3572 else if (passed_pointer
3573 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
3574 TYPE_MODE (DECL_ARG_TYPE (parm)),
3575 DECL_ARG_TYPE (parm),
3579 tree type = DECL_ARG_TYPE (parm);
3581 /* This sequence may involve a library call perhaps clobbering
3582 registers that haven't been copied to pseudos yet. */
3584 push_to_sequence (conversion_insns);
3586 if (TYPE_SIZE (type) == 0
3587 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
3589 /* This is a variable sized object. */
3590 /* ??? Can we use expr_size here? */
3591 rtx size_rtx = expand_expr (size_in_bytes (type), NULL_RTX,
3592 TYPE_MODE (sizetype), 0);
3594 copy = gen_rtx (MEM, BLKmode,
3595 allocate_dynamic_stack_space (size_rtx, NULL_RTX,
3596 TYPE_ALIGN (type)));
3600 int size = int_size_in_bytes (type);
3601 copy = assign_stack_temp (TYPE_MODE (type), size, 1);
3604 store_expr (parm, copy, 0);
3605 emit_move_insn (parmreg, XEXP (copy, 0));
3606 conversion_insns = get_insns ();
3609 #endif /* FUNCTION_ARG_CALLEE_COPIES */
3611 /* In any case, record the parm's desired stack location
3612 in case we later discover it must live in the stack.
3614 If it is a COMPLEX value, store the stack location for both
3617 if (GET_CODE (parmreg) == CONCAT)
3618 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
3620 regno = REGNO (parmreg);
3622 if (regno >= nparmregs)
3625 int old_nparmregs = nparmregs;
3627 nparmregs = regno + 5;
3628 new = (rtx *) oballoc (nparmregs * sizeof (rtx));
3629 bcopy (parm_reg_stack_loc, new, old_nparmregs * sizeof (rtx));
3630 bzero (new + old_nparmregs,
3631 (nparmregs - old_nparmregs) * sizeof (rtx));
3632 parm_reg_stack_loc = new;
3635 if (GET_CODE (parmreg) == CONCAT)
3637 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
3639 if (stack_parm != 0)
3641 parm_reg_stack_loc[REGNO (gen_realpart (submode, parmreg))]
3642 = gen_realpart (submode, stack_parm);
3643 parm_reg_stack_loc[REGNO (gen_imagpart (submode, parmreg))]
3644 = gen_imagpart (submode, stack_parm);
3648 parm_reg_stack_loc[REGNO (gen_realpart (submode, parmreg))]
3650 parm_reg_stack_loc[REGNO (gen_imagpart (submode, parmreg))]
3655 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
3657 /* Mark the register as eliminable if we did no conversion
3658 and it was copied from memory at a fixed offset,
3659 and the arg pointer was not copied to a pseudo-reg.
3660 If the arg pointer is a pseudo reg or the offset formed
3661 an invalid address, such memory-equivalences
3662 as we make here would screw up life analysis for it. */
3663 if (nominal_mode == passed_mode
3664 && GET_CODE (entry_parm) == MEM
3665 && entry_parm == stack_parm
3666 && stack_offset.var == 0
3667 && reg_mentioned_p (virtual_incoming_args_rtx,
3668 XEXP (entry_parm, 0)))
3669 REG_NOTES (get_last_insn ())
3670 = gen_rtx (EXPR_LIST, REG_EQUIV,
3671 entry_parm, REG_NOTES (get_last_insn ()));
3673 /* For pointer data type, suggest pointer register. */
3674 if (TREE_CODE (TREE_TYPE (parm)) == POINTER_TYPE)
3675 mark_reg_pointer (parmreg);
3679 /* Value must be stored in the stack slot STACK_PARM
3680 during function execution. */
3682 if (passed_mode != nominal_mode)
3684 /* Conversion is required. */
3685 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
3687 emit_move_insn (tempreg, validize_mem (entry_parm));
3689 push_to_sequence (conversion_insns);
3690 entry_parm = convert_to_mode (nominal_mode, tempreg,
3691 TREE_UNSIGNED (TREE_TYPE (parm)));
3692 conversion_insns = get_insns ();
3696 if (entry_parm != stack_parm)
3698 if (stack_parm == 0)
3701 = assign_stack_local (GET_MODE (entry_parm),
3702 GET_MODE_SIZE (GET_MODE (entry_parm)), 0);
3703 /* If this is a memory ref that contains aggregate components,
3704 mark it as such for cse and loop optimize. */
3705 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3708 if (passed_mode != nominal_mode)
3710 push_to_sequence (conversion_insns);
3711 emit_move_insn (validize_mem (stack_parm),
3712 validize_mem (entry_parm));
3713 conversion_insns = get_insns ();
3717 emit_move_insn (validize_mem (stack_parm),
3718 validize_mem (entry_parm));
3721 DECL_RTL (parm) = stack_parm;
3724 /* If this "parameter" was the place where we are receiving the
3725 function's incoming structure pointer, set up the result. */
3726 if (parm == function_result_decl)
3728 tree result = DECL_RESULT (fndecl);
3729 tree restype = TREE_TYPE (result);
3732 = gen_rtx (MEM, DECL_MODE (result), DECL_RTL (parm));
3734 MEM_IN_STRUCT_P (DECL_RTL (result))
3735 = (TREE_CODE (restype) == RECORD_TYPE
3736 || TREE_CODE (restype) == UNION_TYPE
3737 || TREE_CODE (restype) == QUAL_UNION_TYPE
3738 || TREE_CODE (restype) == ARRAY_TYPE);
3741 if (TREE_THIS_VOLATILE (parm))
3742 MEM_VOLATILE_P (DECL_RTL (parm)) = 1;
3743 if (TREE_READONLY (parm))
3744 RTX_UNCHANGING_P (DECL_RTL (parm)) = 1;
3747 /* Output all parameter conversion instructions (possibly including calls)
3748 now that all parameters have been copied out of hard registers. */
3749 emit_insns (conversion_insns);
3751 max_parm_reg = max_reg_num ();
3752 last_parm_insn = get_last_insn ();
3754 current_function_args_size = stack_args_size.constant;
3756 /* Adjust function incoming argument size for alignment and
3759 #ifdef REG_PARM_STACK_SPACE
3760 #ifndef MAYBE_REG_PARM_STACK_SPACE
3761 current_function_args_size = MAX (current_function_args_size,
3762 REG_PARM_STACK_SPACE (fndecl));
3766 #ifdef STACK_BOUNDARY
3767 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
3769 current_function_args_size
3770 = ((current_function_args_size + STACK_BYTES - 1)
3771 / STACK_BYTES) * STACK_BYTES;
3774 #ifdef ARGS_GROW_DOWNWARD
3775 current_function_arg_offset_rtx
3776 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
3777 : expand_expr (size_binop (MINUS_EXPR, stack_args_size.var,
3778 size_int (-stack_args_size.constant)),
3779 NULL_RTX, VOIDmode, 0));
3781 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
3784 /* See how many bytes, if any, of its args a function should try to pop
3787 current_function_pops_args = RETURN_POPS_ARGS (TREE_TYPE (fndecl),
3788 current_function_args_size);
3790 /* For stdarg.h function, save info about
3791 regs and stack space used by the named args. */
3794 current_function_args_info = args_so_far;
3796 /* Set the rtx used for the function return value. Put this in its
3797 own variable so any optimizers that need this information don't have
3798 to include tree.h. Do this here so it gets done when an inlined
3799 function gets output. */
3801 current_function_return_rtx = DECL_RTL (DECL_RESULT (fndecl));
3804 /* Indicate whether REGNO is an incoming argument to the current function
3805 that was promoted to a wider mode. If so, return the RTX for the
3806 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
3807 that REGNO is promoted from and whether the promotion was signed or
3810 #ifdef PROMOTE_FUNCTION_ARGS
3813 promoted_input_arg (regno, pmode, punsignedp)
3815 enum machine_mode *pmode;
3820 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
3821 arg = TREE_CHAIN (arg))
3822 if (GET_CODE (DECL_INCOMING_RTL (arg)) == REG
3823 && REGNO (DECL_INCOMING_RTL (arg)) == regno
3824 && (TREE_CODE (TREE_TYPE (arg)) == INTEGER_TYPE
3825 || TREE_CODE (TREE_TYPE (arg)) == ENUMERAL_TYPE
3826 || TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE
3827 || TREE_CODE (TREE_TYPE (arg)) == CHAR_TYPE
3828 || TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE
3829 || TREE_CODE (TREE_TYPE (arg)) == POINTER_TYPE
3830 || TREE_CODE (TREE_TYPE (arg)) == OFFSET_TYPE))
3832 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
3833 int unsignedp = TREE_UNSIGNED (TREE_TYPE (arg));
3835 PROMOTE_MODE (mode, unsignedp, TREE_TYPE (arg));
3836 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
3837 && mode != DECL_MODE (arg))
3839 *pmode = DECL_MODE (arg);
3840 *punsignedp = unsignedp;
3841 return DECL_INCOMING_RTL (arg);
3850 /* Compute the size and offset from the start of the stacked arguments for a
3851 parm passed in mode PASSED_MODE and with type TYPE.
3853 INITIAL_OFFSET_PTR points to the current offset into the stacked
3856 The starting offset and size for this parm are returned in *OFFSET_PTR
3857 and *ARG_SIZE_PTR, respectively.
3859 IN_REGS is non-zero if the argument will be passed in registers. It will
3860 never be set if REG_PARM_STACK_SPACE is not defined.
3862 FNDECL is the function in which the argument was defined.
3864 There are two types of rounding that are done. The first, controlled by
3865 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3866 list to be aligned to the specific boundary (in bits). This rounding
3867 affects the initial and starting offsets, but not the argument size.
3869 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3870 optionally rounds the size of the parm to PARM_BOUNDARY. The
3871 initial offset is not affected by this rounding, while the size always
3872 is and the starting offset may be. */
3874 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
3875 initial_offset_ptr is positive because locate_and_pad_parm's
3876 callers pass in the total size of args so far as
3877 initial_offset_ptr. arg_size_ptr is always positive.*/
3879 static void pad_to_arg_alignment (), pad_below ();
3882 locate_and_pad_parm (passed_mode, type, in_regs, fndecl,
3883 initial_offset_ptr, offset_ptr, arg_size_ptr)
3884 enum machine_mode passed_mode;
3888 struct args_size *initial_offset_ptr;
3889 struct args_size *offset_ptr;
3890 struct args_size *arg_size_ptr;
3893 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3894 enum direction where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3895 int boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3896 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3897 int reg_parm_stack_space = 0;
3899 #ifdef REG_PARM_STACK_SPACE
3900 /* If we have found a stack parm before we reach the end of the
3901 area reserved for registers, skip that area. */
3904 #ifdef MAYBE_REG_PARM_STACK_SPACE
3905 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3907 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3909 if (reg_parm_stack_space > 0)
3911 if (initial_offset_ptr->var)
3913 initial_offset_ptr->var
3914 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3915 size_int (reg_parm_stack_space));
3916 initial_offset_ptr->constant = 0;
3918 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3919 initial_offset_ptr->constant = reg_parm_stack_space;
3922 #endif /* REG_PARM_STACK_SPACE */
3924 arg_size_ptr->var = 0;
3925 arg_size_ptr->constant = 0;
3927 #ifdef ARGS_GROW_DOWNWARD
3928 if (initial_offset_ptr->var)
3930 offset_ptr->constant = 0;
3931 offset_ptr->var = size_binop (MINUS_EXPR, integer_zero_node,
3932 initial_offset_ptr->var);
3936 offset_ptr->constant = - initial_offset_ptr->constant;
3937 offset_ptr->var = 0;
3939 if (where_pad == upward
3940 && (TREE_CODE (sizetree) != INTEGER_CST
3941 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
3942 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3943 SUB_PARM_SIZE (*offset_ptr, sizetree);
3944 if (where_pad != downward)
3945 pad_to_arg_alignment (offset_ptr, boundary);
3946 if (initial_offset_ptr->var)
3948 arg_size_ptr->var = size_binop (MINUS_EXPR,
3949 size_binop (MINUS_EXPR,
3951 initial_offset_ptr->var),
3956 arg_size_ptr->constant = (- initial_offset_ptr->constant -
3957 offset_ptr->constant);
3959 /* ADD_PARM_SIZE (*arg_size_ptr, sizetree); */
3960 if (where_pad == downward)
3961 pad_below (arg_size_ptr, passed_mode, sizetree);
3962 #else /* !ARGS_GROW_DOWNWARD */
3963 pad_to_arg_alignment (initial_offset_ptr, boundary);
3964 *offset_ptr = *initial_offset_ptr;
3966 #ifdef PUSH_ROUNDING
3967 if (passed_mode != BLKmode)
3968 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3971 if (where_pad != none
3972 && (TREE_CODE (sizetree) != INTEGER_CST
3973 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
3974 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3976 /* This must be done after rounding sizetree, so that it will subtract
3977 the same value that we explicitly add below. */
3978 if (where_pad == downward)
3979 pad_below (offset_ptr, passed_mode, sizetree);
3980 ADD_PARM_SIZE (*arg_size_ptr, sizetree);
3981 #endif /* ARGS_GROW_DOWNWARD */
3984 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3985 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3988 pad_to_arg_alignment (offset_ptr, boundary)
3989 struct args_size *offset_ptr;
3992 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3994 if (boundary > BITS_PER_UNIT)
3996 if (offset_ptr->var)
3999 #ifdef ARGS_GROW_DOWNWARD
4004 (ARGS_SIZE_TREE (*offset_ptr),
4005 boundary / BITS_PER_UNIT);
4006 offset_ptr->constant = 0; /*?*/
4009 offset_ptr->constant =
4010 #ifdef ARGS_GROW_DOWNWARD
4011 FLOOR_ROUND (offset_ptr->constant, boundary_in_bytes);
4013 CEIL_ROUND (offset_ptr->constant, boundary_in_bytes);
4019 pad_below (offset_ptr, passed_mode, sizetree)
4020 struct args_size *offset_ptr;
4021 enum machine_mode passed_mode;
4024 if (passed_mode != BLKmode)
4026 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
4027 offset_ptr->constant
4028 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
4029 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
4030 - GET_MODE_SIZE (passed_mode));
4034 if (TREE_CODE (sizetree) != INTEGER_CST
4035 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
4037 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4038 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4040 ADD_PARM_SIZE (*offset_ptr, s2);
4041 SUB_PARM_SIZE (*offset_ptr, sizetree);
4047 round_down (value, divisor)
4051 return size_binop (MULT_EXPR,
4052 size_binop (FLOOR_DIV_EXPR, value, size_int (divisor)),
4053 size_int (divisor));
4056 /* Walk the tree of blocks describing the binding levels within a function
4057 and warn about uninitialized variables.
4058 This is done after calling flow_analysis and before global_alloc
4059 clobbers the pseudo-regs to hard regs. */
4062 uninitialized_vars_warning (block)
4065 register tree decl, sub;
4066 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
4068 if (TREE_CODE (decl) == VAR_DECL
4069 /* These warnings are unreliable for and aggregates
4070 because assigning the fields one by one can fail to convince
4071 flow.c that the entire aggregate was initialized.
4072 Unions are troublesome because members may be shorter. */
4073 && TREE_CODE (TREE_TYPE (decl)) != RECORD_TYPE
4074 && TREE_CODE (TREE_TYPE (decl)) != UNION_TYPE
4075 && TREE_CODE (TREE_TYPE (decl)) != QUAL_UNION_TYPE
4076 && TREE_CODE (TREE_TYPE (decl)) != ARRAY_TYPE
4077 && DECL_RTL (decl) != 0
4078 && GET_CODE (DECL_RTL (decl)) == REG
4079 && regno_uninitialized (REGNO (DECL_RTL (decl))))
4080 warning_with_decl (decl,
4081 "`%s' may be used uninitialized in this function");
4082 if (TREE_CODE (decl) == VAR_DECL
4083 && DECL_RTL (decl) != 0
4084 && GET_CODE (DECL_RTL (decl)) == REG
4085 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
4086 warning_with_decl (decl,
4087 "variable `%s' may be clobbered by `longjmp' or `vfork'");
4089 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
4090 uninitialized_vars_warning (sub);
4093 /* Do the appropriate part of uninitialized_vars_warning
4094 but for arguments instead of local variables. */
4097 setjmp_args_warning (block)
4101 for (decl = DECL_ARGUMENTS (current_function_decl);
4102 decl; decl = TREE_CHAIN (decl))
4103 if (DECL_RTL (decl) != 0
4104 && GET_CODE (DECL_RTL (decl)) == REG
4105 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
4106 warning_with_decl (decl, "argument `%s' may be clobbered by `longjmp' or `vfork'");
4109 /* If this function call setjmp, put all vars into the stack
4110 unless they were declared `register'. */
4113 setjmp_protect (block)
4116 register tree decl, sub;
4117 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
4118 if ((TREE_CODE (decl) == VAR_DECL
4119 || TREE_CODE (decl) == PARM_DECL)
4120 && DECL_RTL (decl) != 0
4121 && GET_CODE (DECL_RTL (decl)) == REG
4122 /* If this variable came from an inline function, it must be
4123 that it's life doesn't overlap the setjmp. If there was a
4124 setjmp in the function, it would already be in memory. We
4125 must exclude such variable because their DECL_RTL might be
4126 set to strange things such as virtual_stack_vars_rtx. */
4127 && ! DECL_FROM_INLINE (decl)
4129 #ifdef NON_SAVING_SETJMP
4130 /* If longjmp doesn't restore the registers,
4131 don't put anything in them. */
4135 ! DECL_REGISTER (decl)))
4136 put_var_into_stack (decl);
4137 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
4138 setjmp_protect (sub);
4141 /* Like the previous function, but for args instead of local variables. */
4144 setjmp_protect_args ()
4146 register tree decl, sub;
4147 for (decl = DECL_ARGUMENTS (current_function_decl);
4148 decl; decl = TREE_CHAIN (decl))
4149 if ((TREE_CODE (decl) == VAR_DECL
4150 || TREE_CODE (decl) == PARM_DECL)
4151 && DECL_RTL (decl) != 0
4152 && GET_CODE (DECL_RTL (decl)) == REG
4154 /* If longjmp doesn't restore the registers,
4155 don't put anything in them. */
4156 #ifdef NON_SAVING_SETJMP
4160 ! DECL_REGISTER (decl)))
4161 put_var_into_stack (decl);
4164 /* Return the context-pointer register corresponding to DECL,
4165 or 0 if it does not need one. */
4168 lookup_static_chain (decl)
4171 tree context = decl_function_context (decl);
4177 /* We treat inline_function_decl as an alias for the current function
4178 because that is the inline function whose vars, types, etc.
4179 are being merged into the current function.
4180 See expand_inline_function. */
4181 if (context == current_function_decl || context == inline_function_decl)
4182 return virtual_stack_vars_rtx;
4184 for (link = context_display; link; link = TREE_CHAIN (link))
4185 if (TREE_PURPOSE (link) == context)
4186 return RTL_EXPR_RTL (TREE_VALUE (link));
4191 /* Convert a stack slot address ADDR for variable VAR
4192 (from a containing function)
4193 into an address valid in this function (using a static chain). */
4196 fix_lexical_addr (addr, var)
4202 tree context = decl_function_context (var);
4203 struct function *fp;
4206 /* If this is the present function, we need not do anything. */
4207 if (context == current_function_decl || context == inline_function_decl)
4210 for (fp = outer_function_chain; fp; fp = fp->next)
4211 if (fp->decl == context)
4217 /* Decode given address as base reg plus displacement. */
4218 if (GET_CODE (addr) == REG)
4219 basereg = addr, displacement = 0;
4220 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
4221 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
4225 /* We accept vars reached via the containing function's
4226 incoming arg pointer and via its stack variables pointer. */
4227 if (basereg == fp->internal_arg_pointer)
4229 /* If reached via arg pointer, get the arg pointer value
4230 out of that function's stack frame.
4232 There are two cases: If a separate ap is needed, allocate a
4233 slot in the outer function for it and dereference it that way.
4234 This is correct even if the real ap is actually a pseudo.
4235 Otherwise, just adjust the offset from the frame pointer to
4238 #ifdef NEED_SEPARATE_AP
4241 if (fp->arg_pointer_save_area == 0)
4242 fp->arg_pointer_save_area
4243 = assign_outer_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0, fp);
4245 addr = fix_lexical_addr (XEXP (fp->arg_pointer_save_area, 0), var);
4246 addr = memory_address (Pmode, addr);
4248 base = copy_to_reg (gen_rtx (MEM, Pmode, addr));
4250 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
4251 base = lookup_static_chain (var);
4255 else if (basereg == virtual_stack_vars_rtx)
4257 /* This is the same code as lookup_static_chain, duplicated here to
4258 avoid an extra call to decl_function_context. */
4261 for (link = context_display; link; link = TREE_CHAIN (link))
4262 if (TREE_PURPOSE (link) == context)
4264 base = RTL_EXPR_RTL (TREE_VALUE (link));
4272 /* Use same offset, relative to appropriate static chain or argument
4274 return plus_constant (base, displacement);
4277 /* Return the address of the trampoline for entering nested fn FUNCTION.
4278 If necessary, allocate a trampoline (in the stack frame)
4279 and emit rtl to initialize its contents (at entry to this function). */
4282 trampoline_address (function)
4288 struct function *fp;
4291 /* Find an existing trampoline and return it. */
4292 for (link = trampoline_list; link; link = TREE_CHAIN (link))
4293 if (TREE_PURPOSE (link) == function)
4294 return XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0);
4295 for (fp = outer_function_chain; fp; fp = fp->next)
4296 for (link = fp->trampoline_list; link; link = TREE_CHAIN (link))
4297 if (TREE_PURPOSE (link) == function)
4299 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
4301 return round_trampoline_addr (tramp);
4304 /* None exists; we must make one. */
4306 /* Find the `struct function' for the function containing FUNCTION. */
4308 fn_context = decl_function_context (function);
4309 if (fn_context != current_function_decl)
4310 for (fp = outer_function_chain; fp; fp = fp->next)
4311 if (fp->decl == fn_context)
4314 /* Allocate run-time space for this trampoline
4315 (usually in the defining function's stack frame). */
4316 #ifdef ALLOCATE_TRAMPOLINE
4317 tramp = ALLOCATE_TRAMPOLINE (fp);
4319 /* If rounding needed, allocate extra space
4320 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
4321 #ifdef TRAMPOLINE_ALIGNMENT
4322 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE + TRAMPOLINE_ALIGNMENT - 1)
4324 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE)
4327 tramp = assign_outer_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0, fp);
4329 tramp = assign_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0);
4332 /* Record the trampoline for reuse and note it for later initialization
4333 by expand_function_end. */
4336 push_obstacks (fp->function_maybepermanent_obstack,
4337 fp->function_maybepermanent_obstack);
4338 rtlexp = make_node (RTL_EXPR);
4339 RTL_EXPR_RTL (rtlexp) = tramp;
4340 fp->trampoline_list = tree_cons (function, rtlexp, fp->trampoline_list);
4345 /* Make the RTL_EXPR node temporary, not momentary, so that the
4346 trampoline_list doesn't become garbage. */
4347 int momentary = suspend_momentary ();
4348 rtlexp = make_node (RTL_EXPR);
4349 resume_momentary (momentary);
4351 RTL_EXPR_RTL (rtlexp) = tramp;
4352 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
4355 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
4356 return round_trampoline_addr (tramp);
4359 /* Given a trampoline address,
4360 round it to multiple of TRAMPOLINE_ALIGNMENT. */
4363 round_trampoline_addr (tramp)
4366 #ifdef TRAMPOLINE_ALIGNMENT
4367 /* Round address up to desired boundary. */
4368 rtx temp = gen_reg_rtx (Pmode);
4369 temp = expand_binop (Pmode, add_optab, tramp,
4370 GEN_INT (TRAMPOLINE_ALIGNMENT - 1),
4371 temp, 0, OPTAB_LIB_WIDEN);
4372 tramp = expand_binop (Pmode, and_optab, temp,
4373 GEN_INT (- TRAMPOLINE_ALIGNMENT),
4374 temp, 0, OPTAB_LIB_WIDEN);
4379 /* The functions identify_blocks and reorder_blocks provide a way to
4380 reorder the tree of BLOCK nodes, for optimizers that reshuffle or
4381 duplicate portions of the RTL code. Call identify_blocks before
4382 changing the RTL, and call reorder_blocks after. */
4384 static int all_blocks ();
4385 static tree blocks_nreverse ();
4387 /* Put all this function's BLOCK nodes into a vector, and return it.
4388 Also store in each NOTE for the beginning or end of a block
4389 the index of that block in the vector.
4390 The arguments are TOP_BLOCK, the top-level block of the function,
4391 and INSNS, the insn chain of the function. */
4394 identify_blocks (top_block, insns)
4402 int next_block_number = 0;
4403 int current_block_number = 0;
4409 n_blocks = all_blocks (top_block, 0);
4410 block_vector = (tree *) xmalloc (n_blocks * sizeof (tree));
4411 block_stack = (int *) alloca (n_blocks * sizeof (int));
4413 all_blocks (top_block, block_vector);
4415 for (insn = insns; insn; insn = NEXT_INSN (insn))
4416 if (GET_CODE (insn) == NOTE)
4418 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
4420 block_stack[depth++] = current_block_number;
4421 current_block_number = next_block_number;
4422 NOTE_BLOCK_NUMBER (insn) = next_block_number++;
4424 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
4426 current_block_number = block_stack[--depth];
4427 NOTE_BLOCK_NUMBER (insn) = current_block_number;
4431 return block_vector;
4434 /* Given BLOCK_VECTOR which was returned by identify_blocks,
4435 and a revised instruction chain, rebuild the tree structure
4436 of BLOCK nodes to correspond to the new order of RTL.
4437 The new block tree is inserted below TOP_BLOCK.
4438 Returns the current top-level block. */
4441 reorder_blocks (block_vector, top_block, insns)
4446 tree current_block = top_block;
4449 if (block_vector == 0)
4452 /* Prune the old tree away, so that it doesn't get in the way. */
4453 BLOCK_SUBBLOCKS (current_block) = 0;
4455 for (insn = insns; insn; insn = NEXT_INSN (insn))
4456 if (GET_CODE (insn) == NOTE)
4458 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
4460 tree block = block_vector[NOTE_BLOCK_NUMBER (insn)];
4461 /* If we have seen this block before, copy it. */
4462 if (TREE_ASM_WRITTEN (block))
4463 block = copy_node (block);
4464 BLOCK_SUBBLOCKS (block) = 0;
4465 TREE_ASM_WRITTEN (block) = 1;
4466 BLOCK_SUPERCONTEXT (block) = current_block;
4467 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4468 BLOCK_SUBBLOCKS (current_block) = block;
4469 current_block = block;
4470 NOTE_SOURCE_FILE (insn) = 0;
4472 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
4474 BLOCK_SUBBLOCKS (current_block)
4475 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
4476 current_block = BLOCK_SUPERCONTEXT (current_block);
4477 NOTE_SOURCE_FILE (insn) = 0;
4481 return current_block;
4484 /* Reverse the order of elements in the chain T of blocks,
4485 and return the new head of the chain (old last element). */
4491 register tree prev = 0, decl, next;
4492 for (decl = t; decl; decl = next)
4494 next = BLOCK_CHAIN (decl);
4495 BLOCK_CHAIN (decl) = prev;
4501 /* Count the subblocks of BLOCK, and list them all into the vector VECTOR.
4502 Also clear TREE_ASM_WRITTEN in all blocks. */
4505 all_blocks (block, vector)
4512 TREE_ASM_WRITTEN (block) = 0;
4513 /* Record this block. */
4517 /* Record the subblocks, and their subblocks. */
4518 for (subblocks = BLOCK_SUBBLOCKS (block);
4519 subblocks; subblocks = BLOCK_CHAIN (subblocks))
4520 n_blocks += all_blocks (subblocks, vector ? vector + n_blocks : 0);
4525 /* Build bytecode call descriptor for function SUBR. */
4527 bc_build_calldesc (subr)
4530 tree calldesc = 0, arg;
4533 /* Build the argument description vector in reverse order. */
4534 DECL_ARGUMENTS (subr) = nreverse (DECL_ARGUMENTS (subr));
4537 for (arg = DECL_ARGUMENTS (subr); arg; arg = TREE_CHAIN (arg))
4541 calldesc = tree_cons ((tree) 0, size_in_bytes (TREE_TYPE (arg)), calldesc);
4542 calldesc = tree_cons ((tree) 0, bc_runtime_type_code (TREE_TYPE (arg)), calldesc);
4545 DECL_ARGUMENTS (subr) = nreverse (DECL_ARGUMENTS (subr));
4547 /* Prepend the function's return type. */
4548 calldesc = tree_cons ((tree) 0,
4549 size_in_bytes (TREE_TYPE (TREE_TYPE (subr))),
4552 calldesc = tree_cons ((tree) 0,
4553 bc_runtime_type_code (TREE_TYPE (TREE_TYPE (subr))),
4556 /* Prepend the arg count. */
4557 calldesc = tree_cons ((tree) 0, build_int_2 (nargs, 0), calldesc);
4559 /* Output the call description vector and get its address. */
4560 calldesc = build_nt (CONSTRUCTOR, (tree) 0, calldesc);
4561 TREE_TYPE (calldesc) = build_array_type (integer_type_node,
4562 build_index_type (build_int_2 (nargs * 2, 0)));
4564 return output_constant_def (calldesc);
4568 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4569 and initialize static variables for generating RTL for the statements
4573 init_function_start (subr, filename, line)
4580 if (output_bytecode)
4582 this_function_decl = subr;
4583 this_function_calldesc = bc_build_calldesc (subr);
4584 local_vars_size = 0;
4586 max_stack_depth = 0;
4587 stmt_expr_depth = 0;
4591 init_stmt_for_function ();
4593 cse_not_expected = ! optimize;
4595 /* Caller save not needed yet. */
4596 caller_save_needed = 0;
4598 /* No stack slots have been made yet. */
4599 stack_slot_list = 0;
4601 /* There is no stack slot for handling nonlocal gotos. */
4602 nonlocal_goto_handler_slot = 0;
4603 nonlocal_goto_stack_level = 0;
4605 /* No labels have been declared for nonlocal use. */
4606 nonlocal_labels = 0;
4608 /* No function calls so far in this function. */
4609 function_call_count = 0;
4611 /* No parm regs have been allocated.
4612 (This is important for output_inline_function.) */
4613 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4615 /* Initialize the RTL mechanism. */
4618 /* Initialize the queue of pending postincrement and postdecrements,
4619 and some other info in expr.c. */
4622 /* We haven't done register allocation yet. */
4625 init_const_rtx_hash_table ();
4627 current_function_name = (*decl_printable_name) (subr, &junk);
4629 /* Nonzero if this is a nested function that uses a static chain. */
4631 current_function_needs_context
4632 = (decl_function_context (current_function_decl) != 0);
4634 /* Set if a call to setjmp is seen. */
4635 current_function_calls_setjmp = 0;
4637 /* Set if a call to longjmp is seen. */
4638 current_function_calls_longjmp = 0;
4640 current_function_calls_alloca = 0;
4641 current_function_has_nonlocal_label = 0;
4642 current_function_has_nonlocal_goto = 0;
4643 current_function_contains_functions = 0;
4645 current_function_returns_pcc_struct = 0;
4646 current_function_returns_struct = 0;
4647 current_function_epilogue_delay_list = 0;
4648 current_function_uses_const_pool = 0;
4649 current_function_uses_pic_offset_table = 0;
4651 /* We have not yet needed to make a label to jump to for tail-recursion. */
4652 tail_recursion_label = 0;
4654 /* We haven't had a need to make a save area for ap yet. */
4656 arg_pointer_save_area = 0;
4658 /* No stack slots allocated yet. */
4661 /* No SAVE_EXPRs in this function yet. */
4664 /* No RTL_EXPRs in this function yet. */
4667 /* We have not allocated any temporaries yet. */
4669 temp_slot_level = 0;
4671 /* Within function body, compute a type's size as soon it is laid out. */
4672 immediate_size_expand++;
4674 /* We haven't made any trampolines for this function yet. */
4675 trampoline_list = 0;
4677 init_pending_stack_adjust ();
4678 inhibit_defer_pop = 0;
4680 current_function_outgoing_args_size = 0;
4682 /* Initialize the insn lengths. */
4683 init_insn_lengths ();
4685 /* Prevent ever trying to delete the first instruction of a function.
4686 Also tell final how to output a linenum before the function prologue. */
4687 emit_line_note (filename, line);
4689 /* Make sure first insn is a note even if we don't want linenums.
4690 This makes sure the first insn will never be deleted.
4691 Also, final expects a note to appear there. */
4692 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4694 /* Set flags used by final.c. */
4695 if (aggregate_value_p (DECL_RESULT (subr)))
4697 #ifdef PCC_STATIC_STRUCT_RETURN
4698 current_function_returns_pcc_struct = 1;
4700 current_function_returns_struct = 1;
4703 /* Warn if this value is an aggregate type,
4704 regardless of which calling convention we are using for it. */
4705 if (warn_aggregate_return
4706 && (TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == RECORD_TYPE
4707 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == UNION_TYPE
4708 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == QUAL_UNION_TYPE
4709 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == ARRAY_TYPE))
4710 warning ("function returns an aggregate");
4712 current_function_returns_pointer
4713 = (TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == POINTER_TYPE);
4715 /* Indicate that we need to distinguish between the return value of the
4716 present function and the return value of a function being called. */
4717 rtx_equal_function_value_matters = 1;
4719 /* Indicate that we have not instantiated virtual registers yet. */
4720 virtuals_instantiated = 0;
4722 /* Indicate we have no need of a frame pointer yet. */
4723 frame_pointer_needed = 0;
4725 /* By default assume not varargs. */
4726 current_function_varargs = 0;
4729 /* Indicate that the current function uses extra args
4730 not explicitly mentioned in the argument list in any fashion. */
4735 current_function_varargs = 1;
4738 /* Expand a call to __main at the beginning of a possible main function. */
4741 expand_main_function ()
4743 if (!output_bytecode)
4745 /* The zero below avoids a possible parse error */
4747 #if !defined (INIT_SECTION_ASM_OP) || defined (INVOKE__main)
4748 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, NAME__MAIN), 0,
4750 #endif /* not INIT_SECTION_ASM_OP or INVOKE__main */
4754 extern struct obstack permanent_obstack;
4756 /* Expand start of bytecode function. See comment at
4757 expand_function_start below for details. */
4760 bc_expand_function_start (subr, parms_have_cleanups)
4762 int parms_have_cleanups;
4764 char label[20], *name;
4769 if (TREE_PUBLIC (subr))
4770 bc_globalize_label (IDENTIFIER_POINTER (DECL_NAME (subr)));
4772 #ifdef DEBUG_PRINT_CODE
4773 fprintf (stderr, "\n<func %s>\n", IDENTIFIER_POINTER (DECL_NAME (subr)));
4776 for (argsz = 0, thisarg = DECL_ARGUMENTS (subr); thisarg; thisarg = TREE_CHAIN (thisarg))
4778 if (DECL_RTL (thisarg))
4779 abort (); /* Should be NULL here I think. */
4780 else if (TREE_CONSTANT (DECL_SIZE (thisarg)))
4782 DECL_RTL (thisarg) = bc_gen_rtx ((char *) 0, argsz, (struct bc_label *) 0);
4783 argsz += TREE_INT_CST_LOW (DECL_SIZE (thisarg));
4787 /* Variable-sized objects are pointers to their storage. */
4788 DECL_RTL (thisarg) = bc_gen_rtx ((char *) 0, argsz, (struct bc_label *) 0);
4789 argsz += POINTER_SIZE;
4793 bc_begin_function (bc_xstrdup (IDENTIFIER_POINTER (DECL_NAME (subr))));
4795 ASM_GENERATE_INTERNAL_LABEL (label, "LX", nlab);
4798 name = (char *) obstack_copy0 (&permanent_obstack, label, strlen (label));
4799 this_function_callinfo = bc_gen_rtx (name, 0, (struct bc_label *) 0);
4800 this_function_bytecode =
4801 bc_emit_trampoline (BYTECODE_LABEL (this_function_callinfo));
4805 /* Expand end of bytecode function. See details the comment of
4806 expand_function_end(), below. */
4809 bc_expand_function_end ()
4813 expand_null_return ();
4815 /* Emit any fixup code. This must be done before the call to
4816 to BC_END_FUNCTION (), since that will cause the bytecode
4817 segment to be finished off and closed. */
4819 fixup_gotos (0, 0, 0, 0, 0);
4821 ptrconsts = bc_end_function ();
4823 bc_align_const (2 /* INT_ALIGN */);
4825 /* If this changes also make sure to change bc-interp.h! */
4827 bc_emit_const_labeldef (BYTECODE_LABEL (this_function_callinfo));
4828 bc_emit_const ((char *) &max_stack_depth, sizeof max_stack_depth);
4829 bc_emit_const ((char *) &local_vars_size, sizeof local_vars_size);
4830 bc_emit_const_labelref (this_function_bytecode, 0);
4831 bc_emit_const_labelref (ptrconsts, 0);
4832 bc_emit_const_labelref (BYTECODE_LABEL (this_function_calldesc), 0);
4836 /* Start the RTL for a new function, and set variables used for
4838 SUBR is the FUNCTION_DECL node.
4839 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4840 the function's parameters, which must be run at any return statement. */
4843 expand_function_start (subr, parms_have_cleanups)
4845 int parms_have_cleanups;
4851 if (output_bytecode)
4853 bc_expand_function_start (subr, parms_have_cleanups);
4857 /* Make sure volatile mem refs aren't considered
4858 valid operands of arithmetic insns. */
4859 init_recog_no_volatile ();
4861 /* If function gets a static chain arg, store it in the stack frame.
4862 Do this first, so it gets the first stack slot offset. */
4863 if (current_function_needs_context)
4865 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4867 #ifdef SMALL_REGISTER_CLASSES
4868 /* Delay copying static chain if it is not a register to avoid
4869 conflicts with regs used for parameters. */
4870 if (GET_CODE (static_chain_incoming_rtx) == REG)
4872 emit_move_insn (last_ptr, static_chain_incoming_rtx);
4875 /* If the parameters of this function need cleaning up, get a label
4876 for the beginning of the code which executes those cleanups. This must
4877 be done before doing anything with return_label. */
4878 if (parms_have_cleanups)
4879 cleanup_label = gen_label_rtx ();
4883 /* Make the label for return statements to jump to, if this machine
4884 does not have a one-instruction return and uses an epilogue,
4885 or if it returns a structure, or if it has parm cleanups. */
4887 if (cleanup_label == 0 && HAVE_return
4888 && ! current_function_returns_pcc_struct
4889 && ! (current_function_returns_struct && ! optimize))
4892 return_label = gen_label_rtx ();
4894 return_label = gen_label_rtx ();
4897 /* Initialize rtx used to return the value. */
4898 /* Do this before assign_parms so that we copy the struct value address
4899 before any library calls that assign parms might generate. */
4901 /* Decide whether to return the value in memory or in a register. */
4902 if (aggregate_value_p (DECL_RESULT (subr)))
4904 /* Returning something that won't go in a register. */
4905 register rtx value_address;
4907 #ifdef PCC_STATIC_STRUCT_RETURN
4908 if (current_function_returns_pcc_struct)
4910 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4911 value_address = assemble_static_space (size);
4916 /* Expect to be passed the address of a place to store the value.
4917 If it is passed as an argument, assign_parms will take care of
4919 if (struct_value_incoming_rtx)
4921 value_address = gen_reg_rtx (Pmode);
4922 emit_move_insn (value_address, struct_value_incoming_rtx);
4927 DECL_RTL (DECL_RESULT (subr))
4928 = gen_rtx (MEM, DECL_MODE (DECL_RESULT (subr)), value_address);
4929 MEM_IN_STRUCT_P (DECL_RTL (DECL_RESULT (subr)))
4930 = (TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == RECORD_TYPE
4931 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == UNION_TYPE
4932 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == QUAL_UNION_TYPE
4933 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr))) == ARRAY_TYPE);
4936 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4937 /* If return mode is void, this decl rtl should not be used. */
4938 DECL_RTL (DECL_RESULT (subr)) = 0;
4939 else if (parms_have_cleanups)
4941 /* If function will end with cleanup code for parms,
4942 compute the return values into a pseudo reg,
4943 which we will copy into the true return register
4944 after the cleanups are done. */
4946 enum machine_mode mode = DECL_MODE (DECL_RESULT (subr));
4947 #ifdef PROMOTE_FUNCTION_RETURN
4948 tree type = TREE_TYPE (DECL_RESULT (subr));
4949 int unsignedp = TREE_UNSIGNED (type);
4951 if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE
4952 || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE
4953 || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE
4954 || TREE_CODE (type) == OFFSET_TYPE)
4956 PROMOTE_MODE (mode, unsignedp, type);
4960 DECL_RTL (DECL_RESULT (subr)) = gen_reg_rtx (mode);
4963 /* Scalar, returned in a register. */
4965 #ifdef FUNCTION_OUTGOING_VALUE
4966 DECL_RTL (DECL_RESULT (subr))
4967 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
4969 DECL_RTL (DECL_RESULT (subr))
4970 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
4973 /* Mark this reg as the function's return value. */
4974 if (GET_CODE (DECL_RTL (DECL_RESULT (subr))) == REG)
4976 REG_FUNCTION_VALUE_P (DECL_RTL (DECL_RESULT (subr))) = 1;
4977 /* Needed because we may need to move this to memory
4978 in case it's a named return value whose address is taken. */
4979 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4983 /* Initialize rtx for parameters and local variables.
4984 In some cases this requires emitting insns. */
4986 assign_parms (subr, 0);
4988 #ifdef SMALL_REGISTER_CLASSES
4989 /* Copy the static chain now if it wasn't a register. The delay is to
4990 avoid conflicts with the parameter passing registers. */
4992 if (current_function_needs_context)
4993 if (GET_CODE (static_chain_incoming_rtx) != REG)
4994 emit_move_insn (last_ptr, static_chain_incoming_rtx);
4997 /* The following was moved from init_function_start.
4998 The move is supposed to make sdb output more accurate. */
4999 /* Indicate the beginning of the function body,
5000 as opposed to parm setup. */
5001 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_BEG);
5003 /* If doing stupid allocation, mark parms as born here. */
5005 if (GET_CODE (get_last_insn ()) != NOTE)
5006 emit_note (NULL_PTR, NOTE_INSN_DELETED);
5007 parm_birth_insn = get_last_insn ();
5011 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
5012 use_variable (regno_reg_rtx[i]);
5014 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
5015 use_variable (current_function_internal_arg_pointer);
5018 /* Fetch static chain values for containing functions. */
5019 tem = decl_function_context (current_function_decl);
5020 /* If not doing stupid register allocation, then start off with the static
5021 chain pointer in a pseudo register. Otherwise, we use the stack
5022 address that was generated above. */
5023 if (tem && ! obey_regdecls)
5024 last_ptr = copy_to_reg (static_chain_incoming_rtx);
5025 context_display = 0;
5028 tree rtlexp = make_node (RTL_EXPR);
5030 RTL_EXPR_RTL (rtlexp) = last_ptr;
5031 context_display = tree_cons (tem, rtlexp, context_display);
5032 tem = decl_function_context (tem);
5035 /* Chain thru stack frames, assuming pointer to next lexical frame
5036 is found at the place we always store it. */
5037 #ifdef FRAME_GROWS_DOWNWARD
5038 last_ptr = plus_constant (last_ptr, - GET_MODE_SIZE (Pmode));
5040 last_ptr = copy_to_reg (gen_rtx (MEM, Pmode,
5041 memory_address (Pmode, last_ptr)));
5043 /* If we are not optimizing, ensure that we know that this
5044 piece of context is live over the entire function. */
5046 save_expr_regs = gen_rtx (EXPR_LIST, VOIDmode, last_ptr,
5050 /* After the display initializations is where the tail-recursion label
5051 should go, if we end up needing one. Ensure we have a NOTE here
5052 since some things (like trampolines) get placed before this. */
5053 tail_recursion_reentry = emit_note (NULL_PTR, NOTE_INSN_DELETED);
5055 /* Evaluate now the sizes of any types declared among the arguments. */
5056 for (tem = nreverse (get_pending_sizes ()); tem; tem = TREE_CHAIN (tem))
5057 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
5059 /* Make sure there is a line number after the function entry setup code. */
5060 force_next_line_note ();
5063 /* Generate RTL for the end of the current function.
5064 FILENAME and LINE are the current position in the source file.
5066 It is up to language-specific callers to do cleanups for parameters--
5067 or else, supply 1 for END_BINDINGS and we will call expand_end_bindings. */
5070 expand_function_end (filename, line, end_bindings)
5078 static rtx initial_trampoline;
5080 if (output_bytecode)
5082 bc_expand_function_end ();
5086 #ifdef NON_SAVING_SETJMP
5087 /* Don't put any variables in registers if we call setjmp
5088 on a machine that fails to restore the registers. */
5089 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
5091 setjmp_protect (DECL_INITIAL (current_function_decl));
5092 setjmp_protect_args ();
5096 /* Save the argument pointer if a save area was made for it. */
5097 if (arg_pointer_save_area)
5099 rtx x = gen_move_insn (arg_pointer_save_area, virtual_incoming_args_rtx);
5100 emit_insn_before (x, tail_recursion_reentry);
5103 /* Initialize any trampolines required by this function. */
5104 for (link = trampoline_list; link; link = TREE_CHAIN (link))
5106 tree function = TREE_PURPOSE (link);
5107 rtx context = lookup_static_chain (function);
5108 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
5111 /* First make sure this compilation has a template for
5112 initializing trampolines. */
5113 if (initial_trampoline == 0)
5115 end_temporary_allocation ();
5117 = gen_rtx (MEM, BLKmode, assemble_trampoline_template ());
5118 resume_temporary_allocation ();
5121 /* Generate insns to initialize the trampoline. */
5123 tramp = change_address (initial_trampoline, BLKmode,
5124 round_trampoline_addr (XEXP (tramp, 0)));
5125 emit_block_move (tramp, initial_trampoline, GEN_INT (TRAMPOLINE_SIZE),
5126 FUNCTION_BOUNDARY / BITS_PER_UNIT);
5127 INITIALIZE_TRAMPOLINE (XEXP (tramp, 0),
5128 XEXP (DECL_RTL (function), 0), context);
5132 /* Put those insns at entry to the containing function (this one). */
5133 emit_insns_before (seq, tail_recursion_reentry);
5136 #if 0 /* I think unused parms are legitimate enough. */
5137 /* Warn about unused parms. */
5142 for (decl = DECL_ARGUMENTS (current_function_decl);
5143 decl; decl = TREE_CHAIN (decl))
5144 if (! TREE_USED (decl) && TREE_CODE (decl) == VAR_DECL)
5145 warning_with_decl (decl, "unused parameter `%s'");
5149 /* Delete handlers for nonlocal gotos if nothing uses them. */
5150 if (nonlocal_goto_handler_slot != 0 && !current_function_has_nonlocal_label)
5153 /* End any sequences that failed to be closed due to syntax errors. */
5154 while (in_sequence_p ())
5157 /* Outside function body, can't compute type's actual size
5158 until next function's body starts. */
5159 immediate_size_expand--;
5161 /* If doing stupid register allocation,
5162 mark register parms as dying here. */
5167 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
5168 use_variable (regno_reg_rtx[i]);
5170 /* Likewise for the regs of all the SAVE_EXPRs in the function. */
5172 for (tem = save_expr_regs; tem; tem = XEXP (tem, 1))
5174 use_variable (XEXP (tem, 0));
5175 use_variable_after (XEXP (tem, 0), parm_birth_insn);
5178 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
5179 use_variable (current_function_internal_arg_pointer);
5182 clear_pending_stack_adjust ();
5183 do_pending_stack_adjust ();
5185 /* Mark the end of the function body.
5186 If control reaches this insn, the function can drop through
5187 without returning a value. */
5188 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_END);
5190 /* Output a linenumber for the end of the function.
5191 SDB depends on this. */
5192 emit_line_note_force (filename, line);
5194 /* Output the label for the actual return from the function,
5195 if one is expected. This happens either because a function epilogue
5196 is used instead of a return instruction, or because a return was done
5197 with a goto in order to run local cleanups, or because of pcc-style
5198 structure returning. */
5201 emit_label (return_label);
5203 /* C++ uses this. */
5205 expand_end_bindings (0, 0, 0);
5207 /* If we had calls to alloca, and this machine needs
5208 an accurate stack pointer to exit the function,
5209 insert some code to save and restore the stack pointer. */
5210 #ifdef EXIT_IGNORE_STACK
5211 if (! EXIT_IGNORE_STACK)
5213 if (current_function_calls_alloca)
5217 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
5218 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
5221 /* If scalar return value was computed in a pseudo-reg,
5222 copy that to the hard return register. */
5223 if (DECL_RTL (DECL_RESULT (current_function_decl)) != 0
5224 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG
5225 && (REGNO (DECL_RTL (DECL_RESULT (current_function_decl)))
5226 >= FIRST_PSEUDO_REGISTER))
5228 rtx real_decl_result;
5230 #ifdef FUNCTION_OUTGOING_VALUE
5232 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
5233 current_function_decl);
5236 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
5237 current_function_decl);
5239 REG_FUNCTION_VALUE_P (real_decl_result) = 1;
5240 emit_move_insn (real_decl_result,
5241 DECL_RTL (DECL_RESULT (current_function_decl)));
5242 emit_insn (gen_rtx (USE, VOIDmode, real_decl_result));
5245 /* If returning a structure, arrange to return the address of the value
5246 in a place where debuggers expect to find it.
5248 If returning a structure PCC style,
5249 the caller also depends on this value.
5250 And current_function_returns_pcc_struct is not necessarily set. */
5251 if (current_function_returns_struct
5252 || current_function_returns_pcc_struct)
5254 rtx value_address = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
5255 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5256 #ifdef FUNCTION_OUTGOING_VALUE
5258 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
5259 current_function_decl);
5262 = FUNCTION_VALUE (build_pointer_type (type),
5263 current_function_decl);
5266 /* Mark this as a function return value so integrate will delete the
5267 assignment and USE below when inlining this function. */
5268 REG_FUNCTION_VALUE_P (outgoing) = 1;
5270 emit_move_insn (outgoing, value_address);
5271 use_variable (outgoing);
5274 /* Output a return insn if we are using one.
5275 Otherwise, let the rtl chain end here, to drop through
5276 into the epilogue. */
5281 emit_jump_insn (gen_return ());
5286 /* Fix up any gotos that jumped out to the outermost
5287 binding level of the function.
5288 Must follow emitting RETURN_LABEL. */
5290 /* If you have any cleanups to do at this point,
5291 and they need to create temporary variables,
5292 then you will lose. */
5293 fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, get_insns (), 0);
5296 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
5298 static int *prologue;
5299 static int *epilogue;
5301 /* Create an array that records the INSN_UIDs of INSNS (either a sequence
5302 or a single insn). */
5305 record_insns (insns)
5310 if (GET_CODE (insns) == SEQUENCE)
5312 int len = XVECLEN (insns, 0);
5313 vec = (int *) oballoc ((len + 1) * sizeof (int));
5316 vec[len] = INSN_UID (XVECEXP (insns, 0, len));
5320 vec = (int *) oballoc (2 * sizeof (int));
5321 vec[0] = INSN_UID (insns);
5327 /* Determine how many INSN_UIDs in VEC are part of INSN. */
5330 contains (insn, vec)
5336 if (GET_CODE (insn) == INSN
5337 && GET_CODE (PATTERN (insn)) == SEQUENCE)
5340 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
5341 for (j = 0; vec[j]; j++)
5342 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == vec[j])
5348 for (j = 0; vec[j]; j++)
5349 if (INSN_UID (insn) == vec[j])
5355 /* Generate the prologe and epilogue RTL if the machine supports it. Thread
5356 this into place with notes indicating where the prologue ends and where
5357 the epilogue begins. Update the basic block information when possible. */
5360 thread_prologue_and_epilogue_insns (f)
5363 #ifdef HAVE_prologue
5366 rtx head, seq, insn;
5368 /* The first insn (a NOTE_INSN_DELETED) is followed by zero or more
5369 prologue insns and a NOTE_INSN_PROLOGUE_END. */
5370 emit_note_after (NOTE_INSN_PROLOGUE_END, f);
5371 seq = gen_prologue ();
5372 head = emit_insn_after (seq, f);
5374 /* Include the new prologue insns in the first block. Ignore them
5375 if they form a basic block unto themselves. */
5376 if (basic_block_head && n_basic_blocks
5377 && GET_CODE (basic_block_head[0]) != CODE_LABEL)
5378 basic_block_head[0] = NEXT_INSN (f);
5380 /* Retain a map of the prologue insns. */
5381 prologue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : head);
5387 #ifdef HAVE_epilogue
5390 rtx insn = get_last_insn ();
5391 rtx prev = prev_nonnote_insn (insn);
5393 /* If we end with a BARRIER, we don't need an epilogue. */
5394 if (! (prev && GET_CODE (prev) == BARRIER))
5400 /* The last basic block ends with a NOTE_INSN_EPILOGUE_BEG, the
5401 epilogue insns, the USE insns at the end of a function,
5402 the jump insn that returns, and then a BARRIER. */
5404 /* Move the USE insns at the end of a function onto a list. */
5406 && GET_CODE (prev) == INSN
5407 && GET_CODE (PATTERN (prev)) == USE)
5410 prev = prev_nonnote_insn (prev);
5412 NEXT_INSN (PREV_INSN (tem)) = NEXT_INSN (tem);
5413 PREV_INSN (NEXT_INSN (tem)) = PREV_INSN (tem);
5416 NEXT_INSN (tem) = first_use;
5417 PREV_INSN (first_use) = tem;
5424 emit_barrier_after (insn);
5426 seq = gen_epilogue ();
5427 tail = emit_jump_insn_after (seq, insn);
5429 /* Insert the USE insns immediately before the return insn, which
5430 must be the first instruction before the final barrier. */
5433 tem = prev_nonnote_insn (get_last_insn ());
5434 NEXT_INSN (PREV_INSN (tem)) = first_use;
5435 PREV_INSN (first_use) = PREV_INSN (tem);
5436 PREV_INSN (tem) = last_use;
5437 NEXT_INSN (last_use) = tem;
5440 emit_note_after (NOTE_INSN_EPILOGUE_BEG, insn);
5442 /* Include the new epilogue insns in the last block. Ignore
5443 them if they form a basic block unto themselves. */
5444 if (basic_block_end && n_basic_blocks
5445 && GET_CODE (basic_block_end[n_basic_blocks - 1]) != JUMP_INSN)
5446 basic_block_end[n_basic_blocks - 1] = tail;
5448 /* Retain a map of the epilogue insns. */
5449 epilogue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : tail);
5457 /* Reposition the prologue-end and epilogue-begin notes after instruction
5458 scheduling and delayed branch scheduling. */
5461 reposition_prologue_and_epilogue_notes (f)
5464 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5465 /* Reposition the prologue and epilogue notes. */
5473 register rtx insn, note = 0;
5475 /* Scan from the beginning until we reach the last prologue insn.
5476 We apparently can't depend on basic_block_{head,end} after
5478 for (len = 0; prologue[len]; len++)
5480 for (insn = f; len && insn; insn = NEXT_INSN (insn))
5482 if (GET_CODE (insn) == NOTE)
5484 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
5487 else if ((len -= contains (insn, prologue)) == 0)
5489 /* Find the prologue-end note if we haven't already, and
5490 move it to just after the last prologue insn. */
5493 for (note = insn; note = NEXT_INSN (note);)
5494 if (GET_CODE (note) == NOTE
5495 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
5498 next = NEXT_INSN (note);
5499 prev = PREV_INSN (note);
5501 NEXT_INSN (prev) = next;
5503 PREV_INSN (next) = prev;
5504 add_insn_after (note, insn);
5511 register rtx insn, note = 0;
5513 /* Scan from the end until we reach the first epilogue insn.
5514 We apparently can't depend on basic_block_{head,end} after
5516 for (len = 0; epilogue[len]; len++)
5518 for (insn = get_last_insn (); len && insn; insn = PREV_INSN (insn))
5520 if (GET_CODE (insn) == NOTE)
5522 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
5525 else if ((len -= contains (insn, epilogue)) == 0)
5527 /* Find the epilogue-begin note if we haven't already, and
5528 move it to just before the first epilogue insn. */
5531 for (note = insn; note = PREV_INSN (note);)
5532 if (GET_CODE (note) == NOTE
5533 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
5536 next = NEXT_INSN (note);
5537 prev = PREV_INSN (note);
5539 NEXT_INSN (prev) = next;
5541 PREV_INSN (next) = prev;
5542 add_insn_after (note, PREV_INSN (insn));
5547 #endif /* HAVE_prologue or HAVE_epilogue */