1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 91-95, 1996 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, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register.
36 Call `put_var_into_stack' when you learn, belatedly, that a variable
37 previously given a pseudo-register must in fact go in the stack.
38 This function changes the DECL_RTL to be a stack slot instead of a reg
39 then scans all the RTL instructions so far generated to correct them. */
49 #include "insn-flags.h"
51 #include "insn-codes.h"
53 #include "hard-reg-set.h"
54 #include "insn-config.h"
57 #include "basic-block.h"
61 /* Some systems use __main in a way incompatible with its use in gcc, in these
62 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
63 give the same symbol without quotes for an alternative entry point. You
64 must define both, or neither. */
66 #define NAME__MAIN "__main"
67 #define SYMBOL__MAIN __main
70 /* Round a value to the lowest integer less than it that is a multiple of
71 the required alignment. Avoid using division in case the value is
72 negative. Assume the alignment is a power of two. */
73 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
75 /* Similar, but round to the next highest integer that meets the
77 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
79 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
80 during rtl generation. If they are different register numbers, this is
81 always true. It may also be true if
82 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
83 generation. See fix_lexical_addr for details. */
85 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
86 #define NEED_SEPARATE_AP
89 /* Number of bytes of args popped by function being compiled on its return.
90 Zero if no bytes are to be popped.
91 May affect compilation of return insn or of function epilogue. */
93 int current_function_pops_args;
95 /* Nonzero if function being compiled needs to be given an address
96 where the value should be stored. */
98 int current_function_returns_struct;
100 /* Nonzero if function being compiled needs to
101 return the address of where it has put a structure value. */
103 int current_function_returns_pcc_struct;
105 /* Nonzero if function being compiled needs to be passed a static chain. */
107 int current_function_needs_context;
109 /* Nonzero if function being compiled can call setjmp. */
111 int current_function_calls_setjmp;
113 /* Nonzero if function being compiled can call longjmp. */
115 int current_function_calls_longjmp;
117 /* Nonzero if function being compiled receives nonlocal gotos
118 from nested functions. */
120 int current_function_has_nonlocal_label;
122 /* Nonzero if function being compiled has nonlocal gotos to parent
125 int current_function_has_nonlocal_goto;
127 /* Nonzero if function being compiled contains nested functions. */
129 int current_function_contains_functions;
131 /* Nonzero if function being compiled can call alloca,
132 either as a subroutine or builtin. */
134 int current_function_calls_alloca;
136 /* Nonzero if the current function returns a pointer type */
138 int current_function_returns_pointer;
140 /* If some insns can be deferred to the delay slots of the epilogue, the
141 delay list for them is recorded here. */
143 rtx current_function_epilogue_delay_list;
145 /* If function's args have a fixed size, this is that size, in bytes.
147 May affect compilation of return insn or of function epilogue. */
149 int current_function_args_size;
151 /* # bytes the prologue should push and pretend that the caller pushed them.
152 The prologue must do this, but only if parms can be passed in registers. */
154 int current_function_pretend_args_size;
156 /* # of bytes of outgoing arguments. If ACCUMULATE_OUTGOING_ARGS is
157 defined, the needed space is pushed by the prologue. */
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 /* Nonzero if current function uses stdarg.h or equivalent.
172 Zero for functions that use varargs.h. */
174 int current_function_stdarg;
176 /* Quantities of various kinds of registers
177 used for the current function's args. */
179 CUMULATIVE_ARGS current_function_args_info;
181 /* Name of function now being compiled. */
183 char *current_function_name;
185 /* If non-zero, an RTL expression for that location at which the current
186 function returns its result. Always equal to
187 DECL_RTL (DECL_RESULT (current_function_decl)), but provided
188 independently of the tree structures. */
190 rtx current_function_return_rtx;
192 /* Nonzero if the current function uses the constant pool. */
194 int current_function_uses_const_pool;
196 /* Nonzero if the current function uses pic_offset_table_rtx. */
197 int current_function_uses_pic_offset_table;
199 /* The arg pointer hard register, or the pseudo into which it was copied. */
200 rtx current_function_internal_arg_pointer;
202 /* The FUNCTION_DECL for an inline function currently being expanded. */
203 tree inline_function_decl;
205 /* Number of function calls seen so far in current function. */
207 int function_call_count;
209 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
210 (labels to which there can be nonlocal gotos from nested functions)
213 tree nonlocal_labels;
215 /* RTX for stack slot that holds the current handler for nonlocal gotos.
216 Zero when function does not have nonlocal labels. */
218 rtx nonlocal_goto_handler_slot;
220 /* RTX for stack slot that holds the stack pointer value to restore
222 Zero when function does not have nonlocal labels. */
224 rtx nonlocal_goto_stack_level;
226 /* Label that will go on parm cleanup code, if any.
227 Jumping to this label runs cleanup code for parameters, if
228 such code must be run. Following this code is the logical return label. */
232 /* Label that will go on function epilogue.
233 Jumping to this label serves as a "return" instruction
234 on machines which require execution of the epilogue on all returns. */
238 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
239 So we can mark them all live at the end of the function, if nonopt. */
242 /* List (chain of EXPR_LISTs) of all stack slots in this function.
243 Made for the sake of unshare_all_rtl. */
246 /* Chain of all RTL_EXPRs that have insns in them. */
249 /* Label to jump back to for tail recursion, or 0 if we have
250 not yet needed one for this function. */
251 rtx tail_recursion_label;
253 /* Place after which to insert the tail_recursion_label if we need one. */
254 rtx tail_recursion_reentry;
256 /* Location at which to save the argument pointer if it will need to be
257 referenced. There are two cases where this is done: if nonlocal gotos
258 exist, or if vars stored at an offset from the argument pointer will be
259 needed by inner routines. */
261 rtx arg_pointer_save_area;
263 /* Offset to end of allocated area of stack frame.
264 If stack grows down, this is the address of the last stack slot allocated.
265 If stack grows up, this is the address for the next slot. */
268 /* List (chain of TREE_LISTs) of static chains for containing functions.
269 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
270 in an RTL_EXPR in the TREE_VALUE. */
271 static tree context_display;
273 /* List (chain of TREE_LISTs) of trampolines for nested functions.
274 The trampoline sets up the static chain and jumps to the function.
275 We supply the trampoline's address when the function's address is requested.
277 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
278 in an RTL_EXPR in the TREE_VALUE. */
279 static tree trampoline_list;
281 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
282 static rtx parm_birth_insn;
285 /* Nonzero if a stack slot has been generated whose address is not
286 actually valid. It means that the generated rtl must all be scanned
287 to detect and correct the invalid addresses where they occur. */
288 static int invalid_stack_slot;
291 /* Last insn of those whose job was to put parms into their nominal homes. */
292 static rtx last_parm_insn;
294 /* 1 + last pseudo register number used for loading a copy
295 of a parameter of this function. */
296 static int max_parm_reg;
298 /* Vector indexed by REGNO, containing location on stack in which
299 to put the parm which is nominally in pseudo register REGNO,
300 if we discover that that parm must go in the stack. */
301 static rtx *parm_reg_stack_loc;
303 #if 0 /* Turned off because 0 seems to work just as well. */
304 /* Cleanup lists are required for binding levels regardless of whether
305 that binding level has cleanups or not. This node serves as the
306 cleanup list whenever an empty list is required. */
307 static tree empty_cleanup_list;
310 /* Nonzero once virtual register instantiation has been done.
311 assign_stack_local uses frame_pointer_rtx when this is nonzero. */
312 static int virtuals_instantiated;
314 /* These variables hold pointers to functions to
315 save and restore machine-specific data,
316 in push_function_context and pop_function_context. */
317 void (*save_machine_status) ();
318 void (*restore_machine_status) ();
320 /* Nonzero if we need to distinguish between the return value of this function
321 and the return value of a function called by this function. This helps
324 extern int rtx_equal_function_value_matters;
325 extern tree sequence_rtl_expr;
326 extern tree bc_runtime_type_code ();
327 extern rtx bc_build_calldesc ();
328 extern char *bc_emit_trampoline ();
329 extern char *bc_end_function ();
331 /* In order to evaluate some expressions, such as function calls returning
332 structures in memory, we need to temporarily allocate stack locations.
333 We record each allocated temporary in the following structure.
335 Associated with each temporary slot is a nesting level. When we pop up
336 one level, all temporaries associated with the previous level are freed.
337 Normally, all temporaries are freed after the execution of the statement
338 in which they were created. However, if we are inside a ({...}) grouping,
339 the result may be in a temporary and hence must be preserved. If the
340 result could be in a temporary, we preserve it if we can determine which
341 one it is in. If we cannot determine which temporary may contain the
342 result, all temporaries are preserved. A temporary is preserved by
343 pretending it was allocated at the previous nesting level.
345 Automatic variables are also assigned temporary slots, at the nesting
346 level where they are defined. They are marked a "kept" so that
347 free_temp_slots will not free them. */
351 /* Points to next temporary slot. */
352 struct temp_slot *next;
353 /* The rtx to used to reference the slot. */
355 /* The rtx used to represent the address if not the address of the
356 slot above. May be an EXPR_LIST if multiple addresses exist. */
358 /* The size, in units, of the slot. */
360 /* The value of `sequence_rtl_expr' when this temporary is allocated. */
362 /* Non-zero if this temporary is currently in use. */
364 /* Non-zero if this temporary has its address taken. */
366 /* Nesting level at which this slot is being used. */
368 /* Non-zero if this should survive a call to free_temp_slots. */
370 /* The offset of the slot from the frame_pointer, including extra space
371 for alignment. This info is for combine_temp_slots. */
373 /* The size of the slot, including extra space for alignment. This
374 info is for combine_temp_slots. */
378 /* List of all temporaries allocated, both available and in use. */
380 struct temp_slot *temp_slots;
382 /* Current nesting level for temporaries. */
386 /* The FUNCTION_DECL node for the current function. */
387 static tree this_function_decl;
389 /* Callinfo pointer for the current function. */
390 static rtx this_function_callinfo;
392 /* The label in the bytecode file of this function's actual bytecode.
394 static char *this_function_bytecode;
396 /* The call description vector for the current function. */
397 static rtx this_function_calldesc;
399 /* Size of the local variables allocated for the current function. */
402 /* Current depth of the bytecode evaluation stack. */
405 /* Maximum depth of the evaluation stack in this function. */
408 /* Current depth in statement expressions. */
409 static int stmt_expr_depth;
411 /* This structure is used to record MEMs or pseudos used to replace VAR, any
412 SUBREGs of VAR, and any MEMs containing VAR as an address. We need to
413 maintain this list in case two operands of an insn were required to match;
414 in that case we must ensure we use the same replacement. */
416 struct fixup_replacement
420 struct fixup_replacement *next;
423 /* Forward declarations. */
425 static struct temp_slot *find_temp_slot_from_address PROTO((rtx));
426 static void put_reg_into_stack PROTO((struct function *, rtx, tree,
427 enum machine_mode, enum machine_mode,
429 static void fixup_var_refs PROTO((rtx, enum machine_mode, int));
430 static struct fixup_replacement
431 *find_fixup_replacement PROTO((struct fixup_replacement **, rtx));
432 static void fixup_var_refs_insns PROTO((rtx, enum machine_mode, int,
434 static void fixup_var_refs_1 PROTO((rtx, enum machine_mode, rtx *, rtx,
435 struct fixup_replacement **));
436 static rtx fixup_memory_subreg PROTO((rtx, rtx, int));
437 static rtx walk_fixup_memory_subreg PROTO((rtx, rtx, int));
438 static rtx fixup_stack_1 PROTO((rtx, rtx));
439 static void optimize_bit_field PROTO((rtx, rtx, rtx *));
440 static void instantiate_decls PROTO((tree, int));
441 static void instantiate_decls_1 PROTO((tree, int));
442 static void instantiate_decl PROTO((rtx, int, int));
443 static int instantiate_virtual_regs_1 PROTO((rtx *, rtx, int));
444 static void delete_handlers PROTO((void));
445 static void pad_to_arg_alignment PROTO((struct args_size *, int));
446 static void pad_below PROTO((struct args_size *, enum machine_mode,
448 static tree round_down PROTO((tree, int));
449 static rtx round_trampoline_addr PROTO((rtx));
450 static tree blocks_nreverse PROTO((tree));
451 static int all_blocks PROTO((tree, tree *));
452 static int *record_insns PROTO((rtx));
453 static int contains PROTO((rtx, int *));
455 /* Pointer to chain of `struct function' for containing functions. */
456 struct function *outer_function_chain;
458 /* Given a function decl for a containing function,
459 return the `struct function' for it. */
462 find_function_data (decl)
466 for (p = outer_function_chain; p; p = p->next)
472 /* Save the current context for compilation of a nested function.
473 This is called from language-specific code.
474 The caller is responsible for saving any language-specific status,
475 since this function knows only about language-independent variables. */
478 push_function_context_to (context)
481 struct function *p = (struct function *) xmalloc (sizeof (struct function));
483 p->next = outer_function_chain;
484 outer_function_chain = p;
486 p->name = current_function_name;
487 p->decl = current_function_decl;
488 p->pops_args = current_function_pops_args;
489 p->returns_struct = current_function_returns_struct;
490 p->returns_pcc_struct = current_function_returns_pcc_struct;
491 p->needs_context = current_function_needs_context;
492 p->calls_setjmp = current_function_calls_setjmp;
493 p->calls_longjmp = current_function_calls_longjmp;
494 p->calls_alloca = current_function_calls_alloca;
495 p->has_nonlocal_label = current_function_has_nonlocal_label;
496 p->has_nonlocal_goto = current_function_has_nonlocal_goto;
497 p->contains_functions = current_function_contains_functions;
498 p->args_size = current_function_args_size;
499 p->pretend_args_size = current_function_pretend_args_size;
500 p->arg_offset_rtx = current_function_arg_offset_rtx;
501 p->varargs = current_function_varargs;
502 p->stdarg = current_function_stdarg;
503 p->uses_const_pool = current_function_uses_const_pool;
504 p->uses_pic_offset_table = current_function_uses_pic_offset_table;
505 p->internal_arg_pointer = current_function_internal_arg_pointer;
506 p->max_parm_reg = max_parm_reg;
507 p->parm_reg_stack_loc = parm_reg_stack_loc;
508 p->outgoing_args_size = current_function_outgoing_args_size;
509 p->return_rtx = current_function_return_rtx;
510 p->nonlocal_goto_handler_slot = nonlocal_goto_handler_slot;
511 p->nonlocal_goto_stack_level = nonlocal_goto_stack_level;
512 p->nonlocal_labels = nonlocal_labels;
513 p->cleanup_label = cleanup_label;
514 p->return_label = return_label;
515 p->save_expr_regs = save_expr_regs;
516 p->stack_slot_list = stack_slot_list;
517 p->parm_birth_insn = parm_birth_insn;
518 p->frame_offset = frame_offset;
519 p->tail_recursion_label = tail_recursion_label;
520 p->tail_recursion_reentry = tail_recursion_reentry;
521 p->arg_pointer_save_area = arg_pointer_save_area;
522 p->rtl_expr_chain = rtl_expr_chain;
523 p->last_parm_insn = last_parm_insn;
524 p->context_display = context_display;
525 p->trampoline_list = trampoline_list;
526 p->function_call_count = function_call_count;
527 p->temp_slots = temp_slots;
528 p->temp_slot_level = temp_slot_level;
529 p->fixup_var_refs_queue = 0;
530 p->epilogue_delay_list = current_function_epilogue_delay_list;
532 save_tree_status (p, context);
533 save_storage_status (p);
534 save_emit_status (p);
536 save_expr_status (p);
537 save_stmt_status (p);
538 save_varasm_status (p);
540 if (save_machine_status)
541 (*save_machine_status) (p);
545 push_function_context ()
547 push_function_context_to (current_function_decl);
550 /* Restore the last saved context, at the end of a nested function.
551 This function is called from language-specific code. */
554 pop_function_context_from (context)
557 struct function *p = outer_function_chain;
559 outer_function_chain = p->next;
561 current_function_contains_functions
562 = p->contains_functions || p->inline_obstacks
563 || context == current_function_decl;
564 current_function_name = p->name;
565 current_function_decl = p->decl;
566 current_function_pops_args = p->pops_args;
567 current_function_returns_struct = p->returns_struct;
568 current_function_returns_pcc_struct = p->returns_pcc_struct;
569 current_function_needs_context = p->needs_context;
570 current_function_calls_setjmp = p->calls_setjmp;
571 current_function_calls_longjmp = p->calls_longjmp;
572 current_function_calls_alloca = p->calls_alloca;
573 current_function_has_nonlocal_label = p->has_nonlocal_label;
574 current_function_has_nonlocal_goto = p->has_nonlocal_goto;
575 current_function_args_size = p->args_size;
576 current_function_pretend_args_size = p->pretend_args_size;
577 current_function_arg_offset_rtx = p->arg_offset_rtx;
578 current_function_varargs = p->varargs;
579 current_function_stdarg = p->stdarg;
580 current_function_uses_const_pool = p->uses_const_pool;
581 current_function_uses_pic_offset_table = p->uses_pic_offset_table;
582 current_function_internal_arg_pointer = p->internal_arg_pointer;
583 max_parm_reg = p->max_parm_reg;
584 parm_reg_stack_loc = p->parm_reg_stack_loc;
585 current_function_outgoing_args_size = p->outgoing_args_size;
586 current_function_return_rtx = p->return_rtx;
587 nonlocal_goto_handler_slot = p->nonlocal_goto_handler_slot;
588 nonlocal_goto_stack_level = p->nonlocal_goto_stack_level;
589 nonlocal_labels = p->nonlocal_labels;
590 cleanup_label = p->cleanup_label;
591 return_label = p->return_label;
592 save_expr_regs = p->save_expr_regs;
593 stack_slot_list = p->stack_slot_list;
594 parm_birth_insn = p->parm_birth_insn;
595 frame_offset = p->frame_offset;
596 tail_recursion_label = p->tail_recursion_label;
597 tail_recursion_reentry = p->tail_recursion_reentry;
598 arg_pointer_save_area = p->arg_pointer_save_area;
599 rtl_expr_chain = p->rtl_expr_chain;
600 last_parm_insn = p->last_parm_insn;
601 context_display = p->context_display;
602 trampoline_list = p->trampoline_list;
603 function_call_count = p->function_call_count;
604 temp_slots = p->temp_slots;
605 temp_slot_level = p->temp_slot_level;
606 current_function_epilogue_delay_list = p->epilogue_delay_list;
609 restore_tree_status (p);
610 restore_storage_status (p);
611 restore_expr_status (p);
612 restore_emit_status (p);
613 restore_stmt_status (p);
614 restore_varasm_status (p);
616 if (restore_machine_status)
617 (*restore_machine_status) (p);
619 /* Finish doing put_var_into_stack for any of our variables
620 which became addressable during the nested function. */
622 struct var_refs_queue *queue = p->fixup_var_refs_queue;
623 for (; queue; queue = queue->next)
624 fixup_var_refs (queue->modified, queue->promoted_mode, queue->unsignedp);
629 /* Reset variables that have known state during rtx generation. */
630 rtx_equal_function_value_matters = 1;
631 virtuals_instantiated = 0;
634 void pop_function_context ()
636 pop_function_context_from (current_function_decl);
639 /* Allocate fixed slots in the stack frame of the current function. */
641 /* Return size needed for stack frame based on slots so far allocated.
642 This size counts from zero. It is not rounded to STACK_BOUNDARY;
643 the caller may have to do that. */
648 #ifdef FRAME_GROWS_DOWNWARD
649 return -frame_offset;
655 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
656 with machine mode MODE.
658 ALIGN controls the amount of alignment for the address of the slot:
659 0 means according to MODE,
660 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
661 positive specifies alignment boundary in bits.
663 We do not round to stack_boundary here. */
666 assign_stack_local (mode, size, align)
667 enum machine_mode mode;
671 register rtx x, addr;
672 int bigend_correction = 0;
677 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
679 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
681 else if (align == -1)
683 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
684 size = CEIL_ROUND (size, alignment);
687 alignment = align / BITS_PER_UNIT;
689 /* Round frame offset to that alignment.
690 We must be careful here, since FRAME_OFFSET might be negative and
691 division with a negative dividend isn't as well defined as we might
692 like. So we instead assume that ALIGNMENT is a power of two and
693 use logical operations which are unambiguous. */
694 #ifdef FRAME_GROWS_DOWNWARD
695 frame_offset = FLOOR_ROUND (frame_offset, alignment);
697 frame_offset = CEIL_ROUND (frame_offset, alignment);
700 /* On a big-endian machine, if we are allocating more space than we will use,
701 use the least significant bytes of those that are allocated. */
702 if (BYTES_BIG_ENDIAN && mode != BLKmode)
703 bigend_correction = size - GET_MODE_SIZE (mode);
705 #ifdef FRAME_GROWS_DOWNWARD
706 frame_offset -= size;
709 /* If we have already instantiated virtual registers, return the actual
710 address relative to the frame pointer. */
711 if (virtuals_instantiated)
712 addr = plus_constant (frame_pointer_rtx,
713 (frame_offset + bigend_correction
714 + STARTING_FRAME_OFFSET));
716 addr = plus_constant (virtual_stack_vars_rtx,
717 frame_offset + bigend_correction);
719 #ifndef FRAME_GROWS_DOWNWARD
720 frame_offset += size;
723 x = gen_rtx (MEM, mode, addr);
725 stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, x, stack_slot_list);
730 /* Assign a stack slot in a containing function.
731 First three arguments are same as in preceding function.
732 The last argument specifies the function to allocate in. */
735 assign_outer_stack_local (mode, size, align, function)
736 enum machine_mode mode;
739 struct function *function;
741 register rtx x, addr;
742 int bigend_correction = 0;
745 /* Allocate in the memory associated with the function in whose frame
747 push_obstacks (function->function_obstack,
748 function->function_maybepermanent_obstack);
752 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
754 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
756 else if (align == -1)
758 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
759 size = CEIL_ROUND (size, alignment);
762 alignment = align / BITS_PER_UNIT;
764 /* Round frame offset to that alignment. */
765 #ifdef FRAME_GROWS_DOWNWARD
766 function->frame_offset = FLOOR_ROUND (function->frame_offset, alignment);
768 function->frame_offset = CEIL_ROUND (function->frame_offset, alignment);
771 /* On a big-endian machine, if we are allocating more space than we will use,
772 use the least significant bytes of those that are allocated. */
773 if (BYTES_BIG_ENDIAN && mode != BLKmode)
774 bigend_correction = size - GET_MODE_SIZE (mode);
776 #ifdef FRAME_GROWS_DOWNWARD
777 function->frame_offset -= size;
779 addr = plus_constant (virtual_stack_vars_rtx,
780 function->frame_offset + bigend_correction);
781 #ifndef FRAME_GROWS_DOWNWARD
782 function->frame_offset += size;
785 x = gen_rtx (MEM, mode, addr);
787 function->stack_slot_list
788 = gen_rtx (EXPR_LIST, VOIDmode, x, function->stack_slot_list);
795 /* Allocate a temporary stack slot and record it for possible later
798 MODE is the machine mode to be given to the returned rtx.
800 SIZE is the size in units of the space required. We do no rounding here
801 since assign_stack_local will do any required rounding.
803 KEEP is 1 if this slot is to be retained after a call to
804 free_temp_slots. Automatic variables for a block are allocated
805 with this flag. KEEP is 2, if we allocate a longer term temporary,
806 whose lifetime is controlled by CLEANUP_POINT_EXPRs. */
809 assign_stack_temp (mode, size, keep)
810 enum machine_mode mode;
814 struct temp_slot *p, *best_p = 0;
816 /* If SIZE is -1 it means that somebody tried to allocate a temporary
817 of a variable size. */
821 /* First try to find an available, already-allocated temporary that is the
822 exact size we require. */
823 for (p = temp_slots; p; p = p->next)
824 if (p->size == size && GET_MODE (p->slot) == mode && ! p->in_use)
827 /* If we didn't find, one, try one that is larger than what we want. We
828 find the smallest such. */
830 for (p = temp_slots; p; p = p->next)
831 if (p->size > size && GET_MODE (p->slot) == mode && ! p->in_use
832 && (best_p == 0 || best_p->size > p->size))
835 /* Make our best, if any, the one to use. */
838 /* If there are enough aligned bytes left over, make them into a new
839 temp_slot so that the extra bytes don't get wasted. Do this only
840 for BLKmode slots, so that we can be sure of the alignment. */
841 if (GET_MODE (best_p->slot) == BLKmode)
843 int alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
844 int rounded_size = CEIL_ROUND (size, alignment);
846 if (best_p->size - rounded_size >= alignment)
848 p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
849 p->in_use = p->addr_taken = 0;
850 p->size = best_p->size - rounded_size;
851 p->base_offset = best_p->base_offset + rounded_size;
852 p->full_size = best_p->full_size - rounded_size;
853 p->slot = gen_rtx (MEM, BLKmode,
854 plus_constant (XEXP (best_p->slot, 0),
858 p->next = temp_slots;
861 stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, p->slot,
864 best_p->size = rounded_size;
865 best_p->full_size = rounded_size;
872 /* If we still didn't find one, make a new temporary. */
875 int frame_offset_old = frame_offset;
876 p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
877 /* If the temp slot mode doesn't indicate the alignment,
878 use the largest possible, so no one will be disappointed. */
879 p->slot = assign_stack_local (mode, size, mode == BLKmode ? -1 : 0);
880 /* The following slot size computation is necessary because we don't
881 know the actual size of the temporary slot until assign_stack_local
882 has performed all the frame alignment and size rounding for the
883 requested temporary. Note that extra space added for alignment
884 can be either above or below this stack slot depending on which
885 way the frame grows. We include the extra space if and only if it
886 is above this slot. */
887 #ifdef FRAME_GROWS_DOWNWARD
888 p->size = frame_offset_old - frame_offset;
892 /* Now define the fields used by combine_temp_slots. */
893 #ifdef FRAME_GROWS_DOWNWARD
894 p->base_offset = frame_offset;
895 p->full_size = frame_offset_old - frame_offset;
897 p->base_offset = frame_offset_old;
898 p->full_size = frame_offset - frame_offset_old;
901 p->next = temp_slots;
907 p->rtl_expr = sequence_rtl_expr;
911 p->level = target_temp_slot_level;
916 p->level = temp_slot_level;
922 /* Assign a temporary of given TYPE.
923 KEEP is as for assign_stack_temp.
924 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
925 it is 0 if a register is OK.
926 DONT_PROMOTE is 1 if we should not promote values in register
930 assign_temp (type, keep, memory_required, dont_promote)
936 enum machine_mode mode = TYPE_MODE (type);
937 int unsignedp = TREE_UNSIGNED (type);
939 if (mode == BLKmode || memory_required)
941 int size = int_size_in_bytes (type);
944 /* Unfortunately, we don't yet know how to allocate variable-sized
945 temporaries. However, sometimes we have a fixed upper limit on
946 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
947 instead. This is the case for Chill variable-sized strings. */
948 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
949 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
950 && TREE_CODE (TYPE_ARRAY_MAX_SIZE (type)) == INTEGER_CST)
951 size = TREE_INT_CST_LOW (TYPE_ARRAY_MAX_SIZE (type));
953 tmp = assign_stack_temp (mode, size, keep);
954 MEM_IN_STRUCT_P (tmp) = AGGREGATE_TYPE_P (type);
958 #ifndef PROMOTE_FOR_CALL_ONLY
960 mode = promote_mode (type, mode, &unsignedp, 0);
963 return gen_reg_rtx (mode);
966 /* Combine temporary stack slots which are adjacent on the stack.
968 This allows for better use of already allocated stack space. This is only
969 done for BLKmode slots because we can be sure that we won't have alignment
970 problems in this case. */
973 combine_temp_slots ()
975 struct temp_slot *p, *q;
976 struct temp_slot *prev_p, *prev_q;
977 /* Determine where to free back to after this function. */
978 rtx free_pointer = rtx_alloc (CONST_INT);
980 for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
983 if (! p->in_use && GET_MODE (p->slot) == BLKmode)
984 for (q = p->next, prev_q = p; q; q = prev_q->next)
987 if (! q->in_use && GET_MODE (q->slot) == BLKmode)
989 if (p->base_offset + p->full_size == q->base_offset)
991 /* Q comes after P; combine Q into P. */
993 p->full_size += q->full_size;
996 else if (q->base_offset + q->full_size == p->base_offset)
998 /* P comes after Q; combine P into Q. */
1000 q->full_size += p->full_size;
1005 /* Either delete Q or advance past it. */
1007 prev_q->next = q->next;
1011 /* Either delete P or advance past it. */
1015 prev_p->next = p->next;
1017 temp_slots = p->next;
1023 /* Free all the RTL made by plus_constant. */
1024 rtx_free (free_pointer);
1027 /* Find the temp slot corresponding to the object at address X. */
1029 static struct temp_slot *
1030 find_temp_slot_from_address (x)
1033 struct temp_slot *p;
1036 for (p = temp_slots; p; p = p->next)
1040 else if (XEXP (p->slot, 0) == x
1044 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
1045 for (next = p->address; next; next = XEXP (next, 1))
1046 if (XEXP (next, 0) == x)
1053 /* Indicate that NEW is an alternate way of referring to the temp slot
1054 that previous was known by OLD. */
1057 update_temp_slot_address (old, new)
1060 struct temp_slot *p = find_temp_slot_from_address (old);
1062 /* If none, return. Else add NEW as an alias. */
1065 else if (p->address == 0)
1069 if (GET_CODE (p->address) != EXPR_LIST)
1070 p->address = gen_rtx (EXPR_LIST, VOIDmode, p->address, NULL_RTX);
1072 p->address = gen_rtx (EXPR_LIST, VOIDmode, new, p->address);
1076 /* If X could be a reference to a temporary slot, mark the fact that its
1077 address was taken. */
1080 mark_temp_addr_taken (x)
1083 struct temp_slot *p;
1088 /* If X is not in memory or is at a constant address, it cannot be in
1089 a temporary slot. */
1090 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1093 p = find_temp_slot_from_address (XEXP (x, 0));
1098 /* If X could be a reference to a temporary slot, mark that slot as belonging
1099 to the to one level higher. If X matched one of our slots, just mark that
1100 one. Otherwise, we can't easily predict which it is, so upgrade all of
1101 them. Kept slots need not be touched.
1103 This is called when an ({...}) construct occurs and a statement
1104 returns a value in memory. */
1107 preserve_temp_slots (x)
1110 struct temp_slot *p = 0;
1112 /* If there is no result, we still might have some objects whose address
1113 were taken, so we need to make sure they stay around. */
1116 for (p = temp_slots; p; p = p->next)
1117 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1123 /* If X is a register that is being used as a pointer, see if we have
1124 a temporary slot we know it points to. To be consistent with
1125 the code below, we really should preserve all non-kept slots
1126 if we can't find a match, but that seems to be much too costly. */
1127 if (GET_CODE (x) == REG && REGNO_POINTER_FLAG (REGNO (x)))
1128 p = find_temp_slot_from_address (x);
1130 /* If X is not in memory or is at a constant address, it cannot be in
1131 a temporary slot, but it can contain something whose address was
1133 if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
1135 for (p = temp_slots; p; p = p->next)
1136 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1142 /* First see if we can find a match. */
1144 p = find_temp_slot_from_address (XEXP (x, 0));
1148 /* Move everything at our level whose address was taken to our new
1149 level in case we used its address. */
1150 struct temp_slot *q;
1152 for (q = temp_slots; q; q = q->next)
1153 if (q != p && q->addr_taken && q->level == p->level)
1161 /* Otherwise, preserve all non-kept slots at this level. */
1162 for (p = temp_slots; p; p = p->next)
1163 if (p->in_use && p->level == temp_slot_level && ! p->keep)
1167 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
1168 with that RTL_EXPR, promote it into a temporary slot at the present
1169 level so it will not be freed when we free slots made in the
1173 preserve_rtl_expr_result (x)
1176 struct temp_slot *p;
1178 /* If X is not in memory or is at a constant address, it cannot be in
1179 a temporary slot. */
1180 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1183 /* If we can find a match, move it to our level unless it is already at
1185 p = find_temp_slot_from_address (XEXP (x, 0));
1188 p->level = MIN (p->level, temp_slot_level);
1195 /* Free all temporaries used so far. This is normally called at the end
1196 of generating code for a statement. Don't free any temporaries
1197 currently in use for an RTL_EXPR that hasn't yet been emitted.
1198 We could eventually do better than this since it can be reused while
1199 generating the same RTL_EXPR, but this is complex and probably not
1205 struct temp_slot *p;
1207 for (p = temp_slots; p; p = p->next)
1208 if (p->in_use && p->level == temp_slot_level && ! p->keep
1209 && p->rtl_expr == 0)
1212 combine_temp_slots ();
1215 /* Free all temporary slots used in T, an RTL_EXPR node. */
1218 free_temps_for_rtl_expr (t)
1221 struct temp_slot *p;
1223 for (p = temp_slots; p; p = p->next)
1224 if (p->rtl_expr == t)
1227 combine_temp_slots ();
1230 /* Push deeper into the nesting level for stack temporaries. */
1238 /* Pop a temporary nesting level. All slots in use in the current level
1244 struct temp_slot *p;
1246 for (p = temp_slots; p; p = p->next)
1247 if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
1250 combine_temp_slots ();
1255 /* Initialize temporary slots. */
1260 /* We have not allocated any temporaries yet. */
1262 temp_slot_level = 0;
1263 target_temp_slot_level = 0;
1266 /* Retroactively move an auto variable from a register to a stack slot.
1267 This is done when an address-reference to the variable is seen. */
1270 put_var_into_stack (decl)
1274 enum machine_mode promoted_mode, decl_mode;
1275 struct function *function = 0;
1278 if (output_bytecode)
1281 context = decl_function_context (decl);
1283 /* Get the current rtl used for this object and it's original mode. */
1284 reg = TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl) : DECL_RTL (decl);
1286 /* No need to do anything if decl has no rtx yet
1287 since in that case caller is setting TREE_ADDRESSABLE
1288 and a stack slot will be assigned when the rtl is made. */
1292 /* Get the declared mode for this object. */
1293 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1294 : DECL_MODE (decl));
1295 /* Get the mode it's actually stored in. */
1296 promoted_mode = GET_MODE (reg);
1298 /* If this variable comes from an outer function,
1299 find that function's saved context. */
1300 if (context != current_function_decl)
1301 for (function = outer_function_chain; function; function = function->next)
1302 if (function->decl == context)
1305 /* If this is a variable-size object with a pseudo to address it,
1306 put that pseudo into the stack, if the var is nonlocal. */
1307 if (DECL_NONLOCAL (decl)
1308 && GET_CODE (reg) == MEM
1309 && GET_CODE (XEXP (reg, 0)) == REG
1310 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1312 reg = XEXP (reg, 0);
1313 decl_mode = promoted_mode = GET_MODE (reg);
1316 /* Now we should have a value that resides in one or more pseudo regs. */
1318 if (GET_CODE (reg) == REG)
1319 put_reg_into_stack (function, reg, TREE_TYPE (decl),
1320 promoted_mode, decl_mode, TREE_SIDE_EFFECTS (decl));
1321 else if (GET_CODE (reg) == CONCAT)
1323 /* A CONCAT contains two pseudos; put them both in the stack.
1324 We do it so they end up consecutive. */
1325 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1326 tree part_type = TREE_TYPE (TREE_TYPE (decl));
1327 #ifdef FRAME_GROWS_DOWNWARD
1328 /* Since part 0 should have a lower address, do it second. */
1329 put_reg_into_stack (function, XEXP (reg, 1), part_type, part_mode,
1330 part_mode, TREE_SIDE_EFFECTS (decl));
1331 put_reg_into_stack (function, XEXP (reg, 0), part_type, part_mode,
1332 part_mode, TREE_SIDE_EFFECTS (decl));
1334 put_reg_into_stack (function, XEXP (reg, 0), part_type, part_mode,
1335 part_mode, TREE_SIDE_EFFECTS (decl));
1336 put_reg_into_stack (function, XEXP (reg, 1), part_type, part_mode,
1337 part_mode, TREE_SIDE_EFFECTS (decl));
1340 /* Change the CONCAT into a combined MEM for both parts. */
1341 PUT_CODE (reg, MEM);
1342 MEM_VOLATILE_P (reg) = MEM_VOLATILE_P (XEXP (reg, 0));
1344 /* The two parts are in memory order already.
1345 Use the lower parts address as ours. */
1346 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1347 /* Prevent sharing of rtl that might lose. */
1348 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1349 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1353 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1354 into the stack frame of FUNCTION (0 means the current function).
1355 DECL_MODE is the machine mode of the user-level data type.
1356 PROMOTED_MODE is the machine mode of the register.
1357 VOLATILE_P is nonzero if this is for a "volatile" decl. */
1360 put_reg_into_stack (function, reg, type, promoted_mode, decl_mode, volatile_p)
1361 struct function *function;
1364 enum machine_mode promoted_mode, decl_mode;
1371 if (REGNO (reg) < function->max_parm_reg)
1372 new = function->parm_reg_stack_loc[REGNO (reg)];
1374 new = assign_outer_stack_local (decl_mode, GET_MODE_SIZE (decl_mode),
1379 if (REGNO (reg) < max_parm_reg)
1380 new = parm_reg_stack_loc[REGNO (reg)];
1382 new = assign_stack_local (decl_mode, GET_MODE_SIZE (decl_mode), 0);
1385 PUT_MODE (reg, decl_mode);
1386 XEXP (reg, 0) = XEXP (new, 0);
1387 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1388 MEM_VOLATILE_P (reg) = volatile_p;
1389 PUT_CODE (reg, MEM);
1391 /* If this is a memory ref that contains aggregate components,
1392 mark it as such for cse and loop optimize. */
1393 MEM_IN_STRUCT_P (reg) = AGGREGATE_TYPE_P (type);
1395 /* Now make sure that all refs to the variable, previously made
1396 when it was a register, are fixed up to be valid again. */
1399 struct var_refs_queue *temp;
1401 /* Variable is inherited; fix it up when we get back to its function. */
1402 push_obstacks (function->function_obstack,
1403 function->function_maybepermanent_obstack);
1405 /* See comment in restore_tree_status in tree.c for why this needs to be
1406 on saveable obstack. */
1408 = (struct var_refs_queue *) savealloc (sizeof (struct var_refs_queue));
1409 temp->modified = reg;
1410 temp->promoted_mode = promoted_mode;
1411 temp->unsignedp = TREE_UNSIGNED (type);
1412 temp->next = function->fixup_var_refs_queue;
1413 function->fixup_var_refs_queue = temp;
1417 /* Variable is local; fix it up now. */
1418 fixup_var_refs (reg, promoted_mode, TREE_UNSIGNED (type));
1422 fixup_var_refs (var, promoted_mode, unsignedp)
1424 enum machine_mode promoted_mode;
1428 rtx first_insn = get_insns ();
1429 struct sequence_stack *stack = sequence_stack;
1430 tree rtl_exps = rtl_expr_chain;
1432 /* Must scan all insns for stack-refs that exceed the limit. */
1433 fixup_var_refs_insns (var, promoted_mode, unsignedp, first_insn, stack == 0);
1435 /* Scan all pending sequences too. */
1436 for (; stack; stack = stack->next)
1438 push_to_sequence (stack->first);
1439 fixup_var_refs_insns (var, promoted_mode, unsignedp,
1440 stack->first, stack->next != 0);
1441 /* Update remembered end of sequence
1442 in case we added an insn at the end. */
1443 stack->last = get_last_insn ();
1447 /* Scan all waiting RTL_EXPRs too. */
1448 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1450 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1451 if (seq != const0_rtx && seq != 0)
1453 push_to_sequence (seq);
1454 fixup_var_refs_insns (var, promoted_mode, unsignedp, seq, 0);
1460 /* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
1461 some part of an insn. Return a struct fixup_replacement whose OLD
1462 value is equal to X. Allocate a new structure if no such entry exists. */
1464 static struct fixup_replacement *
1465 find_fixup_replacement (replacements, x)
1466 struct fixup_replacement **replacements;
1469 struct fixup_replacement *p;
1471 /* See if we have already replaced this. */
1472 for (p = *replacements; p && p->old != x; p = p->next)
1477 p = (struct fixup_replacement *) oballoc (sizeof (struct fixup_replacement));
1480 p->next = *replacements;
1487 /* Scan the insn-chain starting with INSN for refs to VAR
1488 and fix them up. TOPLEVEL is nonzero if this chain is the
1489 main chain of insns for the current function. */
1492 fixup_var_refs_insns (var, promoted_mode, unsignedp, insn, toplevel)
1494 enum machine_mode promoted_mode;
1503 rtx next = NEXT_INSN (insn);
1505 if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
1507 /* If this is a CLOBBER of VAR, delete it.
1509 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1510 and REG_RETVAL notes too. */
1511 if (GET_CODE (PATTERN (insn)) == CLOBBER
1512 && XEXP (PATTERN (insn), 0) == var)
1514 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1515 /* The REG_LIBCALL note will go away since we are going to
1516 turn INSN into a NOTE, so just delete the
1517 corresponding REG_RETVAL note. */
1518 remove_note (XEXP (note, 0),
1519 find_reg_note (XEXP (note, 0), REG_RETVAL,
1522 /* In unoptimized compilation, we shouldn't call delete_insn
1523 except in jump.c doing warnings. */
1524 PUT_CODE (insn, NOTE);
1525 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1526 NOTE_SOURCE_FILE (insn) = 0;
1529 /* The insn to load VAR from a home in the arglist
1530 is now a no-op. When we see it, just delete it. */
1532 && GET_CODE (PATTERN (insn)) == SET
1533 && SET_DEST (PATTERN (insn)) == var
1534 /* If this represents the result of an insn group,
1535 don't delete the insn. */
1536 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1537 && rtx_equal_p (SET_SRC (PATTERN (insn)), var))
1539 /* In unoptimized compilation, we shouldn't call delete_insn
1540 except in jump.c doing warnings. */
1541 PUT_CODE (insn, NOTE);
1542 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1543 NOTE_SOURCE_FILE (insn) = 0;
1544 if (insn == last_parm_insn)
1545 last_parm_insn = PREV_INSN (next);
1549 struct fixup_replacement *replacements = 0;
1550 rtx next_insn = NEXT_INSN (insn);
1552 #ifdef SMALL_REGISTER_CLASSES
1553 /* If the insn that copies the results of a CALL_INSN
1554 into a pseudo now references VAR, we have to use an
1555 intermediate pseudo since we want the life of the
1556 return value register to be only a single insn.
1558 If we don't use an intermediate pseudo, such things as
1559 address computations to make the address of VAR valid
1560 if it is not can be placed between the CALL_INSN and INSN.
1562 To make sure this doesn't happen, we record the destination
1563 of the CALL_INSN and see if the next insn uses both that
1566 if (call_dest != 0 && GET_CODE (insn) == INSN
1567 && reg_mentioned_p (var, PATTERN (insn))
1568 && reg_mentioned_p (call_dest, PATTERN (insn)))
1570 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1572 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1574 PATTERN (insn) = replace_rtx (PATTERN (insn),
1578 if (GET_CODE (insn) == CALL_INSN
1579 && GET_CODE (PATTERN (insn)) == SET)
1580 call_dest = SET_DEST (PATTERN (insn));
1581 else if (GET_CODE (insn) == CALL_INSN
1582 && GET_CODE (PATTERN (insn)) == PARALLEL
1583 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1584 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1589 /* See if we have to do anything to INSN now that VAR is in
1590 memory. If it needs to be loaded into a pseudo, use a single
1591 pseudo for the entire insn in case there is a MATCH_DUP
1592 between two operands. We pass a pointer to the head of
1593 a list of struct fixup_replacements. If fixup_var_refs_1
1594 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1595 it will record them in this list.
1597 If it allocated a pseudo for any replacement, we copy into
1600 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1603 /* If this is last_parm_insn, and any instructions were output
1604 after it to fix it up, then we must set last_parm_insn to
1605 the last such instruction emitted. */
1606 if (insn == last_parm_insn)
1607 last_parm_insn = PREV_INSN (next_insn);
1609 while (replacements)
1611 if (GET_CODE (replacements->new) == REG)
1616 /* OLD might be a (subreg (mem)). */
1617 if (GET_CODE (replacements->old) == SUBREG)
1619 = fixup_memory_subreg (replacements->old, insn, 0);
1622 = fixup_stack_1 (replacements->old, insn);
1624 insert_before = insn;
1626 /* If we are changing the mode, do a conversion.
1627 This might be wasteful, but combine.c will
1628 eliminate much of the waste. */
1630 if (GET_MODE (replacements->new)
1631 != GET_MODE (replacements->old))
1634 convert_move (replacements->new,
1635 replacements->old, unsignedp);
1636 seq = gen_sequence ();
1640 seq = gen_move_insn (replacements->new,
1643 emit_insn_before (seq, insert_before);
1646 replacements = replacements->next;
1650 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1651 But don't touch other insns referred to by reg-notes;
1652 we will get them elsewhere. */
1653 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1654 if (GET_CODE (note) != INSN_LIST)
1656 = walk_fixup_memory_subreg (XEXP (note, 0), insn, 1);
1662 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1663 See if the rtx expression at *LOC in INSN needs to be changed.
1665 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1666 contain a list of original rtx's and replacements. If we find that we need
1667 to modify this insn by replacing a memory reference with a pseudo or by
1668 making a new MEM to implement a SUBREG, we consult that list to see if
1669 we have already chosen a replacement. If none has already been allocated,
1670 we allocate it and update the list. fixup_var_refs_insns will copy VAR
1671 or the SUBREG, as appropriate, to the pseudo. */
1674 fixup_var_refs_1 (var, promoted_mode, loc, insn, replacements)
1676 enum machine_mode promoted_mode;
1679 struct fixup_replacement **replacements;
1682 register rtx x = *loc;
1683 RTX_CODE code = GET_CODE (x);
1685 register rtx tem, tem1;
1686 struct fixup_replacement *replacement;
1693 /* If we already have a replacement, use it. Otherwise,
1694 try to fix up this address in case it is invalid. */
1696 replacement = find_fixup_replacement (replacements, var);
1697 if (replacement->new)
1699 *loc = replacement->new;
1703 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1705 /* Unless we are forcing memory to register or we changed the mode,
1706 we can leave things the way they are if the insn is valid. */
1708 INSN_CODE (insn) = -1;
1709 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1710 && recog_memoized (insn) >= 0)
1713 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1717 /* If X contains VAR, we need to unshare it here so that we update
1718 each occurrence separately. But all identical MEMs in one insn
1719 must be replaced with the same rtx because of the possibility of
1722 if (reg_mentioned_p (var, x))
1724 replacement = find_fixup_replacement (replacements, x);
1725 if (replacement->new == 0)
1726 replacement->new = copy_most_rtx (x, var);
1728 *loc = x = replacement->new;
1744 /* Note that in some cases those types of expressions are altered
1745 by optimize_bit_field, and do not survive to get here. */
1746 if (XEXP (x, 0) == var
1747 || (GET_CODE (XEXP (x, 0)) == SUBREG
1748 && SUBREG_REG (XEXP (x, 0)) == var))
1750 /* Get TEM as a valid MEM in the mode presently in the insn.
1752 We don't worry about the possibility of MATCH_DUP here; it
1753 is highly unlikely and would be tricky to handle. */
1756 if (GET_CODE (tem) == SUBREG)
1757 tem = fixup_memory_subreg (tem, insn, 1);
1758 tem = fixup_stack_1 (tem, insn);
1760 /* Unless we want to load from memory, get TEM into the proper mode
1761 for an extract from memory. This can only be done if the
1762 extract is at a constant position and length. */
1764 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
1765 && GET_CODE (XEXP (x, 2)) == CONST_INT
1766 && ! mode_dependent_address_p (XEXP (tem, 0))
1767 && ! MEM_VOLATILE_P (tem))
1769 enum machine_mode wanted_mode = VOIDmode;
1770 enum machine_mode is_mode = GET_MODE (tem);
1771 int width = INTVAL (XEXP (x, 1));
1772 int pos = INTVAL (XEXP (x, 2));
1775 if (GET_CODE (x) == ZERO_EXTRACT)
1776 wanted_mode = insn_operand_mode[(int) CODE_FOR_extzv][1];
1779 if (GET_CODE (x) == SIGN_EXTRACT)
1780 wanted_mode = insn_operand_mode[(int) CODE_FOR_extv][1];
1782 /* If we have a narrower mode, we can do something. */
1783 if (wanted_mode != VOIDmode
1784 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
1786 int offset = pos / BITS_PER_UNIT;
1787 rtx old_pos = XEXP (x, 2);
1790 /* If the bytes and bits are counted differently, we
1791 must adjust the offset. */
1792 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
1793 offset = (GET_MODE_SIZE (is_mode)
1794 - GET_MODE_SIZE (wanted_mode) - offset);
1796 pos %= GET_MODE_BITSIZE (wanted_mode);
1798 newmem = gen_rtx (MEM, wanted_mode,
1799 plus_constant (XEXP (tem, 0), offset));
1800 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
1801 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
1802 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
1804 /* Make the change and see if the insn remains valid. */
1805 INSN_CODE (insn) = -1;
1806 XEXP (x, 0) = newmem;
1807 XEXP (x, 2) = GEN_INT (pos);
1809 if (recog_memoized (insn) >= 0)
1812 /* Otherwise, restore old position. XEXP (x, 0) will be
1814 XEXP (x, 2) = old_pos;
1818 /* If we get here, the bitfield extract insn can't accept a memory
1819 reference. Copy the input into a register. */
1821 tem1 = gen_reg_rtx (GET_MODE (tem));
1822 emit_insn_before (gen_move_insn (tem1, tem), insn);
1829 if (SUBREG_REG (x) == var)
1831 /* If this is a special SUBREG made because VAR was promoted
1832 from a wider mode, replace it with VAR and call ourself
1833 recursively, this time saying that the object previously
1834 had its current mode (by virtue of the SUBREG). */
1836 if (SUBREG_PROMOTED_VAR_P (x))
1839 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements);
1843 /* If this SUBREG makes VAR wider, it has become a paradoxical
1844 SUBREG with VAR in memory, but these aren't allowed at this
1845 stage of the compilation. So load VAR into a pseudo and take
1846 a SUBREG of that pseudo. */
1847 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
1849 replacement = find_fixup_replacement (replacements, var);
1850 if (replacement->new == 0)
1851 replacement->new = gen_reg_rtx (GET_MODE (var));
1852 SUBREG_REG (x) = replacement->new;
1856 /* See if we have already found a replacement for this SUBREG.
1857 If so, use it. Otherwise, make a MEM and see if the insn
1858 is recognized. If not, or if we should force MEM into a register,
1859 make a pseudo for this SUBREG. */
1860 replacement = find_fixup_replacement (replacements, x);
1861 if (replacement->new)
1863 *loc = replacement->new;
1867 replacement->new = *loc = fixup_memory_subreg (x, insn, 0);
1869 INSN_CODE (insn) = -1;
1870 if (! flag_force_mem && recog_memoized (insn) >= 0)
1873 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
1879 /* First do special simplification of bit-field references. */
1880 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
1881 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
1882 optimize_bit_field (x, insn, 0);
1883 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
1884 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
1885 optimize_bit_field (x, insn, NULL_PTR);
1887 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
1888 insn into a pseudo and store the low part of the pseudo into VAR. */
1889 if (GET_CODE (SET_DEST (x)) == SUBREG
1890 && SUBREG_REG (SET_DEST (x)) == var
1891 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
1892 > GET_MODE_SIZE (GET_MODE (var))))
1894 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
1895 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
1902 rtx dest = SET_DEST (x);
1903 rtx src = SET_SRC (x);
1904 rtx outerdest = dest;
1906 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
1907 || GET_CODE (dest) == SIGN_EXTRACT
1908 || GET_CODE (dest) == ZERO_EXTRACT)
1909 dest = XEXP (dest, 0);
1911 if (GET_CODE (src) == SUBREG)
1912 src = XEXP (src, 0);
1914 /* If VAR does not appear at the top level of the SET
1915 just scan the lower levels of the tree. */
1917 if (src != var && dest != var)
1920 /* We will need to rerecognize this insn. */
1921 INSN_CODE (insn) = -1;
1924 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var)
1926 /* Since this case will return, ensure we fixup all the
1928 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
1929 insn, replacements);
1930 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
1931 insn, replacements);
1932 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
1933 insn, replacements);
1935 tem = XEXP (outerdest, 0);
1937 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
1938 that may appear inside a ZERO_EXTRACT.
1939 This was legitimate when the MEM was a REG. */
1940 if (GET_CODE (tem) == SUBREG
1941 && SUBREG_REG (tem) == var)
1942 tem = fixup_memory_subreg (tem, insn, 1);
1944 tem = fixup_stack_1 (tem, insn);
1946 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
1947 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
1948 && ! mode_dependent_address_p (XEXP (tem, 0))
1949 && ! MEM_VOLATILE_P (tem))
1951 enum machine_mode wanted_mode
1952 = insn_operand_mode[(int) CODE_FOR_insv][0];
1953 enum machine_mode is_mode = GET_MODE (tem);
1954 int width = INTVAL (XEXP (outerdest, 1));
1955 int pos = INTVAL (XEXP (outerdest, 2));
1957 /* If we have a narrower mode, we can do something. */
1958 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
1960 int offset = pos / BITS_PER_UNIT;
1961 rtx old_pos = XEXP (outerdest, 2);
1964 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
1965 offset = (GET_MODE_SIZE (is_mode)
1966 - GET_MODE_SIZE (wanted_mode) - offset);
1968 pos %= GET_MODE_BITSIZE (wanted_mode);
1970 newmem = gen_rtx (MEM, wanted_mode,
1971 plus_constant (XEXP (tem, 0), offset));
1972 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
1973 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
1974 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
1976 /* Make the change and see if the insn remains valid. */
1977 INSN_CODE (insn) = -1;
1978 XEXP (outerdest, 0) = newmem;
1979 XEXP (outerdest, 2) = GEN_INT (pos);
1981 if (recog_memoized (insn) >= 0)
1984 /* Otherwise, restore old position. XEXP (x, 0) will be
1986 XEXP (outerdest, 2) = old_pos;
1990 /* If we get here, the bit-field store doesn't allow memory
1991 or isn't located at a constant position. Load the value into
1992 a register, do the store, and put it back into memory. */
1994 tem1 = gen_reg_rtx (GET_MODE (tem));
1995 emit_insn_before (gen_move_insn (tem1, tem), insn);
1996 emit_insn_after (gen_move_insn (tem, tem1), insn);
1997 XEXP (outerdest, 0) = tem1;
2002 /* STRICT_LOW_PART is a no-op on memory references
2003 and it can cause combinations to be unrecognizable,
2006 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2007 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2009 /* A valid insn to copy VAR into or out of a register
2010 must be left alone, to avoid an infinite loop here.
2011 If the reference to VAR is by a subreg, fix that up,
2012 since SUBREG is not valid for a memref.
2013 Also fix up the address of the stack slot.
2015 Note that we must not try to recognize the insn until
2016 after we know that we have valid addresses and no
2017 (subreg (mem ...) ...) constructs, since these interfere
2018 with determining the validity of the insn. */
2020 if ((SET_SRC (x) == var
2021 || (GET_CODE (SET_SRC (x)) == SUBREG
2022 && SUBREG_REG (SET_SRC (x)) == var))
2023 && (GET_CODE (SET_DEST (x)) == REG
2024 || (GET_CODE (SET_DEST (x)) == SUBREG
2025 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
2026 && GET_MODE (var) == promoted_mode
2027 && x == single_set (insn))
2031 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2032 if (replacement->new)
2033 SET_SRC (x) = replacement->new;
2034 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2035 SET_SRC (x) = replacement->new
2036 = fixup_memory_subreg (SET_SRC (x), insn, 0);
2038 SET_SRC (x) = replacement->new
2039 = fixup_stack_1 (SET_SRC (x), insn);
2041 if (recog_memoized (insn) >= 0)
2044 /* INSN is not valid, but we know that we want to
2045 copy SET_SRC (x) to SET_DEST (x) in some way. So
2046 we generate the move and see whether it requires more
2047 than one insn. If it does, we emit those insns and
2048 delete INSN. Otherwise, we an just replace the pattern
2049 of INSN; we have already verified above that INSN has
2050 no other function that to do X. */
2052 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2053 if (GET_CODE (pat) == SEQUENCE)
2055 emit_insn_after (pat, insn);
2056 PUT_CODE (insn, NOTE);
2057 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
2058 NOTE_SOURCE_FILE (insn) = 0;
2061 PATTERN (insn) = pat;
2066 if ((SET_DEST (x) == var
2067 || (GET_CODE (SET_DEST (x)) == SUBREG
2068 && SUBREG_REG (SET_DEST (x)) == var))
2069 && (GET_CODE (SET_SRC (x)) == REG
2070 || (GET_CODE (SET_SRC (x)) == SUBREG
2071 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
2072 && GET_MODE (var) == promoted_mode
2073 && x == single_set (insn))
2077 if (GET_CODE (SET_DEST (x)) == SUBREG)
2078 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn, 0);
2080 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2082 if (recog_memoized (insn) >= 0)
2085 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2086 if (GET_CODE (pat) == SEQUENCE)
2088 emit_insn_after (pat, insn);
2089 PUT_CODE (insn, NOTE);
2090 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
2091 NOTE_SOURCE_FILE (insn) = 0;
2094 PATTERN (insn) = pat;
2099 /* Otherwise, storing into VAR must be handled specially
2100 by storing into a temporary and copying that into VAR
2101 with a new insn after this one. Note that this case
2102 will be used when storing into a promoted scalar since
2103 the insn will now have different modes on the input
2104 and output and hence will be invalid (except for the case
2105 of setting it to a constant, which does not need any
2106 change if it is valid). We generate extra code in that case,
2107 but combine.c will eliminate it. */
2112 rtx fixeddest = SET_DEST (x);
2114 /* STRICT_LOW_PART can be discarded, around a MEM. */
2115 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2116 fixeddest = XEXP (fixeddest, 0);
2117 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2118 if (GET_CODE (fixeddest) == SUBREG)
2120 fixeddest = fixup_memory_subreg (fixeddest, insn, 0);
2121 promoted_mode = GET_MODE (fixeddest);
2124 fixeddest = fixup_stack_1 (fixeddest, insn);
2126 temp = gen_reg_rtx (promoted_mode);
2128 emit_insn_after (gen_move_insn (fixeddest,
2129 gen_lowpart (GET_MODE (fixeddest),
2133 SET_DEST (x) = temp;
2138 /* Nothing special about this RTX; fix its operands. */
2140 fmt = GET_RTX_FORMAT (code);
2141 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2144 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements);
2148 for (j = 0; j < XVECLEN (x, i); j++)
2149 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2150 insn, replacements);
2155 /* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
2156 return an rtx (MEM:m1 newaddr) which is equivalent.
2157 If any insns must be emitted to compute NEWADDR, put them before INSN.
2159 UNCRITICAL nonzero means accept paradoxical subregs.
2160 This is used for subregs found inside of ZERO_EXTRACTs and in REG_NOTES. */
2163 fixup_memory_subreg (x, insn, uncritical)
2168 int offset = SUBREG_WORD (x) * UNITS_PER_WORD;
2169 rtx addr = XEXP (SUBREG_REG (x), 0);
2170 enum machine_mode mode = GET_MODE (x);
2173 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2174 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
2178 if (BYTES_BIG_ENDIAN)
2179 offset += (MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2180 - MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)));
2181 addr = plus_constant (addr, offset);
2182 if (!flag_force_addr && memory_address_p (mode, addr))
2183 /* Shortcut if no insns need be emitted. */
2184 return change_address (SUBREG_REG (x), mode, addr);
2186 result = change_address (SUBREG_REG (x), mode, addr);
2187 emit_insn_before (gen_sequence (), insn);
2192 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
2193 Replace subexpressions of X in place.
2194 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
2195 Otherwise return X, with its contents possibly altered.
2197 If any insns must be emitted to compute NEWADDR, put them before INSN.
2199 UNCRITICAL is as in fixup_memory_subreg. */
2202 walk_fixup_memory_subreg (x, insn, uncritical)
2207 register enum rtx_code code;
2214 code = GET_CODE (x);
2216 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
2217 return fixup_memory_subreg (x, insn, uncritical);
2219 /* Nothing special about this RTX; fix its operands. */
2221 fmt = GET_RTX_FORMAT (code);
2222 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2225 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn, uncritical);
2229 for (j = 0; j < XVECLEN (x, i); j++)
2231 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn, uncritical);
2237 /* For each memory ref within X, if it refers to a stack slot
2238 with an out of range displacement, put the address in a temp register
2239 (emitting new insns before INSN to load these registers)
2240 and alter the memory ref to use that register.
2241 Replace each such MEM rtx with a copy, to avoid clobberage. */
2244 fixup_stack_1 (x, insn)
2249 register RTX_CODE code = GET_CODE (x);
2254 register rtx ad = XEXP (x, 0);
2255 /* If we have address of a stack slot but it's not valid
2256 (displacement is too large), compute the sum in a register. */
2257 if (GET_CODE (ad) == PLUS
2258 && GET_CODE (XEXP (ad, 0)) == REG
2259 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2260 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2261 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2262 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2265 if (memory_address_p (GET_MODE (x), ad))
2269 temp = copy_to_reg (ad);
2270 seq = gen_sequence ();
2272 emit_insn_before (seq, insn);
2273 return change_address (x, VOIDmode, temp);
2278 fmt = GET_RTX_FORMAT (code);
2279 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2282 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2286 for (j = 0; j < XVECLEN (x, i); j++)
2287 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2293 /* Optimization: a bit-field instruction whose field
2294 happens to be a byte or halfword in memory
2295 can be changed to a move instruction.
2297 We call here when INSN is an insn to examine or store into a bit-field.
2298 BODY is the SET-rtx to be altered.
2300 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2301 (Currently this is called only from function.c, and EQUIV_MEM
2305 optimize_bit_field (body, insn, equiv_mem)
2310 register rtx bitfield;
2313 enum machine_mode mode;
2315 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2316 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2317 bitfield = SET_DEST (body), destflag = 1;
2319 bitfield = SET_SRC (body), destflag = 0;
2321 /* First check that the field being stored has constant size and position
2322 and is in fact a byte or halfword suitably aligned. */
2324 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2325 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2326 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2328 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2330 register rtx memref = 0;
2332 /* Now check that the containing word is memory, not a register,
2333 and that it is safe to change the machine mode. */
2335 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2336 memref = XEXP (bitfield, 0);
2337 else if (GET_CODE (XEXP (bitfield, 0)) == REG
2339 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2340 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2341 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2342 memref = SUBREG_REG (XEXP (bitfield, 0));
2343 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2345 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
2346 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2349 && ! mode_dependent_address_p (XEXP (memref, 0))
2350 && ! MEM_VOLATILE_P (memref))
2352 /* Now adjust the address, first for any subreg'ing
2353 that we are now getting rid of,
2354 and then for which byte of the word is wanted. */
2356 register int offset = INTVAL (XEXP (bitfield, 2));
2359 /* Adjust OFFSET to count bits from low-address byte. */
2360 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2361 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2362 - offset - INTVAL (XEXP (bitfield, 1)));
2364 /* Adjust OFFSET to count bytes from low-address byte. */
2365 offset /= BITS_PER_UNIT;
2366 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2368 offset += SUBREG_WORD (XEXP (bitfield, 0)) * UNITS_PER_WORD;
2369 if (BYTES_BIG_ENDIAN)
2370 offset -= (MIN (UNITS_PER_WORD,
2371 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2372 - MIN (UNITS_PER_WORD,
2373 GET_MODE_SIZE (GET_MODE (memref))));
2377 memref = change_address (memref, mode,
2378 plus_constant (XEXP (memref, 0), offset));
2379 insns = get_insns ();
2381 emit_insns_before (insns, insn);
2383 /* Store this memory reference where
2384 we found the bit field reference. */
2388 validate_change (insn, &SET_DEST (body), memref, 1);
2389 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2391 rtx src = SET_SRC (body);
2392 while (GET_CODE (src) == SUBREG
2393 && SUBREG_WORD (src) == 0)
2394 src = SUBREG_REG (src);
2395 if (GET_MODE (src) != GET_MODE (memref))
2396 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2397 validate_change (insn, &SET_SRC (body), src, 1);
2399 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2400 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2401 /* This shouldn't happen because anything that didn't have
2402 one of these modes should have got converted explicitly
2403 and then referenced through a subreg.
2404 This is so because the original bit-field was
2405 handled by agg_mode and so its tree structure had
2406 the same mode that memref now has. */
2411 rtx dest = SET_DEST (body);
2413 while (GET_CODE (dest) == SUBREG
2414 && SUBREG_WORD (dest) == 0
2415 && (GET_MODE_CLASS (GET_MODE (dest))
2416 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest)))))
2417 dest = SUBREG_REG (dest);
2419 validate_change (insn, &SET_DEST (body), dest, 1);
2421 if (GET_MODE (dest) == GET_MODE (memref))
2422 validate_change (insn, &SET_SRC (body), memref, 1);
2425 /* Convert the mem ref to the destination mode. */
2426 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2429 convert_move (newreg, memref,
2430 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2434 validate_change (insn, &SET_SRC (body), newreg, 1);
2438 /* See if we can convert this extraction or insertion into
2439 a simple move insn. We might not be able to do so if this
2440 was, for example, part of a PARALLEL.
2442 If we succeed, write out any needed conversions. If we fail,
2443 it is hard to guess why we failed, so don't do anything
2444 special; just let the optimization be suppressed. */
2446 if (apply_change_group () && seq)
2447 emit_insns_before (seq, insn);
2452 /* These routines are responsible for converting virtual register references
2453 to the actual hard register references once RTL generation is complete.
2455 The following four variables are used for communication between the
2456 routines. They contain the offsets of the virtual registers from their
2457 respective hard registers. */
2459 static int in_arg_offset;
2460 static int var_offset;
2461 static int dynamic_offset;
2462 static int out_arg_offset;
2464 /* In most machines, the stack pointer register is equivalent to the bottom
2467 #ifndef STACK_POINTER_OFFSET
2468 #define STACK_POINTER_OFFSET 0
2471 /* If not defined, pick an appropriate default for the offset of dynamically
2472 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2473 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2475 #ifndef STACK_DYNAMIC_OFFSET
2477 #ifdef ACCUMULATE_OUTGOING_ARGS
2478 /* The bottom of the stack points to the actual arguments. If
2479 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2480 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2481 stack space for register parameters is not pushed by the caller, but
2482 rather part of the fixed stack areas and hence not included in
2483 `current_function_outgoing_args_size'. Nevertheless, we must allow
2484 for it when allocating stack dynamic objects. */
2486 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2487 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2488 (current_function_outgoing_args_size \
2489 + REG_PARM_STACK_SPACE (FNDECL) + (STACK_POINTER_OFFSET))
2492 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2493 (current_function_outgoing_args_size + (STACK_POINTER_OFFSET))
2497 #define STACK_DYNAMIC_OFFSET(FNDECL) STACK_POINTER_OFFSET
2501 /* Pass through the INSNS of function FNDECL and convert virtual register
2502 references to hard register references. */
2505 instantiate_virtual_regs (fndecl, insns)
2511 /* Compute the offsets to use for this function. */
2512 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
2513 var_offset = STARTING_FRAME_OFFSET;
2514 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
2515 out_arg_offset = STACK_POINTER_OFFSET;
2517 /* Scan all variables and parameters of this function. For each that is
2518 in memory, instantiate all virtual registers if the result is a valid
2519 address. If not, we do it later. That will handle most uses of virtual
2520 regs on many machines. */
2521 instantiate_decls (fndecl, 1);
2523 /* Initialize recognition, indicating that volatile is OK. */
2526 /* Scan through all the insns, instantiating every virtual register still
2528 for (insn = insns; insn; insn = NEXT_INSN (insn))
2529 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
2530 || GET_CODE (insn) == CALL_INSN)
2532 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
2533 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
2536 /* Now instantiate the remaining register equivalences for debugging info.
2537 These will not be valid addresses. */
2538 instantiate_decls (fndecl, 0);
2540 /* Indicate that, from now on, assign_stack_local should use
2541 frame_pointer_rtx. */
2542 virtuals_instantiated = 1;
2545 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
2546 all virtual registers in their DECL_RTL's.
2548 If VALID_ONLY, do this only if the resulting address is still valid.
2549 Otherwise, always do it. */
2552 instantiate_decls (fndecl, valid_only)
2558 if (DECL_SAVED_INSNS (fndecl))
2559 /* When compiling an inline function, the obstack used for
2560 rtl allocation is the maybepermanent_obstack. Calling
2561 `resume_temporary_allocation' switches us back to that
2562 obstack while we process this function's parameters. */
2563 resume_temporary_allocation ();
2565 /* Process all parameters of the function. */
2566 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
2568 instantiate_decl (DECL_RTL (decl), int_size_in_bytes (TREE_TYPE (decl)),
2570 instantiate_decl (DECL_INCOMING_RTL (decl),
2571 int_size_in_bytes (TREE_TYPE (decl)), valid_only);
2574 /* Now process all variables defined in the function or its subblocks. */
2575 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
2577 if (DECL_INLINE (fndecl) || DECL_DEFER_OUTPUT (fndecl))
2579 /* Save all rtl allocated for this function by raising the
2580 high-water mark on the maybepermanent_obstack. */
2582 /* All further rtl allocation is now done in the current_obstack. */
2583 rtl_in_current_obstack ();
2587 /* Subroutine of instantiate_decls: Process all decls in the given
2588 BLOCK node and all its subblocks. */
2591 instantiate_decls_1 (let, valid_only)
2597 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
2598 instantiate_decl (DECL_RTL (t), int_size_in_bytes (TREE_TYPE (t)),
2601 /* Process all subblocks. */
2602 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
2603 instantiate_decls_1 (t, valid_only);
2606 /* Subroutine of the preceding procedures: Given RTL representing a
2607 decl and the size of the object, do any instantiation required.
2609 If VALID_ONLY is non-zero, it means that the RTL should only be
2610 changed if the new address is valid. */
2613 instantiate_decl (x, size, valid_only)
2618 enum machine_mode mode;
2621 /* If this is not a MEM, no need to do anything. Similarly if the
2622 address is a constant or a register that is not a virtual register. */
2624 if (x == 0 || GET_CODE (x) != MEM)
2628 if (CONSTANT_P (addr)
2629 || (GET_CODE (addr) == REG
2630 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
2631 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
2634 /* If we should only do this if the address is valid, copy the address.
2635 We need to do this so we can undo any changes that might make the
2636 address invalid. This copy is unfortunate, but probably can't be
2640 addr = copy_rtx (addr);
2642 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
2647 /* Now verify that the resulting address is valid for every integer or
2648 floating-point mode up to and including SIZE bytes long. We do this
2649 since the object might be accessed in any mode and frame addresses
2652 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2653 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2654 mode = GET_MODE_WIDER_MODE (mode))
2655 if (! memory_address_p (mode, addr))
2658 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
2659 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2660 mode = GET_MODE_WIDER_MODE (mode))
2661 if (! memory_address_p (mode, addr))
2664 /* Otherwise, put back the address, now that we have updated it and we
2665 know it is valid. */
2670 /* Given a pointer to a piece of rtx and an optional pointer to the
2671 containing object, instantiate any virtual registers present in it.
2673 If EXTRA_INSNS, we always do the replacement and generate
2674 any extra insns before OBJECT. If it zero, we do nothing if replacement
2677 Return 1 if we either had nothing to do or if we were able to do the
2678 needed replacement. Return 0 otherwise; we only return zero if
2679 EXTRA_INSNS is zero.
2681 We first try some simple transformations to avoid the creation of extra
2685 instantiate_virtual_regs_1 (loc, object, extra_insns)
2699 /* Re-start here to avoid recursion in common cases. */
2706 code = GET_CODE (x);
2708 /* Check for some special cases. */
2725 /* We are allowed to set the virtual registers. This means that
2726 that the actual register should receive the source minus the
2727 appropriate offset. This is used, for example, in the handling
2728 of non-local gotos. */
2729 if (SET_DEST (x) == virtual_incoming_args_rtx)
2730 new = arg_pointer_rtx, offset = - in_arg_offset;
2731 else if (SET_DEST (x) == virtual_stack_vars_rtx)
2732 new = frame_pointer_rtx, offset = - var_offset;
2733 else if (SET_DEST (x) == virtual_stack_dynamic_rtx)
2734 new = stack_pointer_rtx, offset = - dynamic_offset;
2735 else if (SET_DEST (x) == virtual_outgoing_args_rtx)
2736 new = stack_pointer_rtx, offset = - out_arg_offset;
2740 /* The only valid sources here are PLUS or REG. Just do
2741 the simplest possible thing to handle them. */
2742 if (GET_CODE (SET_SRC (x)) != REG
2743 && GET_CODE (SET_SRC (x)) != PLUS)
2747 if (GET_CODE (SET_SRC (x)) != REG)
2748 temp = force_operand (SET_SRC (x), NULL_RTX);
2751 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
2755 emit_insns_before (seq, object);
2758 if (!validate_change (object, &SET_SRC (x), temp, 0)
2765 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
2770 /* Handle special case of virtual register plus constant. */
2771 if (CONSTANT_P (XEXP (x, 1)))
2773 rtx old, new_offset;
2775 /* Check for (plus (plus VIRT foo) (const_int)) first. */
2776 if (GET_CODE (XEXP (x, 0)) == PLUS)
2778 rtx inner = XEXP (XEXP (x, 0), 0);
2780 if (inner == virtual_incoming_args_rtx)
2781 new = arg_pointer_rtx, offset = in_arg_offset;
2782 else if (inner == virtual_stack_vars_rtx)
2783 new = frame_pointer_rtx, offset = var_offset;
2784 else if (inner == virtual_stack_dynamic_rtx)
2785 new = stack_pointer_rtx, offset = dynamic_offset;
2786 else if (inner == virtual_outgoing_args_rtx)
2787 new = stack_pointer_rtx, offset = out_arg_offset;
2794 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
2796 new = gen_rtx (PLUS, Pmode, new, XEXP (XEXP (x, 0), 1));
2799 else if (XEXP (x, 0) == virtual_incoming_args_rtx)
2800 new = arg_pointer_rtx, offset = in_arg_offset;
2801 else if (XEXP (x, 0) == virtual_stack_vars_rtx)
2802 new = frame_pointer_rtx, offset = var_offset;
2803 else if (XEXP (x, 0) == virtual_stack_dynamic_rtx)
2804 new = stack_pointer_rtx, offset = dynamic_offset;
2805 else if (XEXP (x, 0) == virtual_outgoing_args_rtx)
2806 new = stack_pointer_rtx, offset = out_arg_offset;
2809 /* We know the second operand is a constant. Unless the
2810 first operand is a REG (which has been already checked),
2811 it needs to be checked. */
2812 if (GET_CODE (XEXP (x, 0)) != REG)
2820 new_offset = plus_constant (XEXP (x, 1), offset);
2822 /* If the new constant is zero, try to replace the sum with just
2824 if (new_offset == const0_rtx
2825 && validate_change (object, loc, new, 0))
2828 /* Next try to replace the register and new offset.
2829 There are two changes to validate here and we can't assume that
2830 in the case of old offset equals new just changing the register
2831 will yield a valid insn. In the interests of a little efficiency,
2832 however, we only call validate change once (we don't queue up the
2833 changes and then call apply_change_group). */
2837 ? ! validate_change (object, &XEXP (x, 0), new, 0)
2838 : (XEXP (x, 0) = new,
2839 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
2847 /* Otherwise copy the new constant into a register and replace
2848 constant with that register. */
2849 temp = gen_reg_rtx (Pmode);
2851 if (validate_change (object, &XEXP (x, 1), temp, 0))
2852 emit_insn_before (gen_move_insn (temp, new_offset), object);
2855 /* If that didn't work, replace this expression with a
2856 register containing the sum. */
2859 new = gen_rtx (PLUS, Pmode, new, new_offset);
2862 temp = force_operand (new, NULL_RTX);
2866 emit_insns_before (seq, object);
2867 if (! validate_change (object, loc, temp, 0)
2868 && ! validate_replace_rtx (x, temp, object))
2876 /* Fall through to generic two-operand expression case. */
2882 case DIV: case UDIV:
2883 case MOD: case UMOD:
2884 case AND: case IOR: case XOR:
2885 case ROTATERT: case ROTATE:
2886 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
2888 case GE: case GT: case GEU: case GTU:
2889 case LE: case LT: case LEU: case LTU:
2890 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
2891 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
2896 /* Most cases of MEM that convert to valid addresses have already been
2897 handled by our scan of regno_reg_rtx. The only special handling we
2898 need here is to make a copy of the rtx to ensure it isn't being
2899 shared if we have to change it to a pseudo.
2901 If the rtx is a simple reference to an address via a virtual register,
2902 it can potentially be shared. In such cases, first try to make it
2903 a valid address, which can also be shared. Otherwise, copy it and
2906 First check for common cases that need no processing. These are
2907 usually due to instantiation already being done on a previous instance
2911 if (CONSTANT_ADDRESS_P (temp)
2912 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2913 || temp == arg_pointer_rtx
2915 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2916 || temp == hard_frame_pointer_rtx
2918 || temp == frame_pointer_rtx)
2921 if (GET_CODE (temp) == PLUS
2922 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2923 && (XEXP (temp, 0) == frame_pointer_rtx
2924 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2925 || XEXP (temp, 0) == hard_frame_pointer_rtx
2927 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2928 || XEXP (temp, 0) == arg_pointer_rtx
2933 if (temp == virtual_stack_vars_rtx
2934 || temp == virtual_incoming_args_rtx
2935 || (GET_CODE (temp) == PLUS
2936 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2937 && (XEXP (temp, 0) == virtual_stack_vars_rtx
2938 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
2940 /* This MEM may be shared. If the substitution can be done without
2941 the need to generate new pseudos, we want to do it in place
2942 so all copies of the shared rtx benefit. The call below will
2943 only make substitutions if the resulting address is still
2946 Note that we cannot pass X as the object in the recursive call
2947 since the insn being processed may not allow all valid
2948 addresses. However, if we were not passed on object, we can
2949 only modify X without copying it if X will have a valid
2952 ??? Also note that this can still lose if OBJECT is an insn that
2953 has less restrictions on an address that some other insn.
2954 In that case, we will modify the shared address. This case
2955 doesn't seem very likely, though. */
2957 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
2958 object ? object : x, 0))
2961 /* Otherwise make a copy and process that copy. We copy the entire
2962 RTL expression since it might be a PLUS which could also be
2964 *loc = x = copy_rtx (x);
2967 /* Fall through to generic unary operation case. */
2971 case STRICT_LOW_PART:
2973 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
2974 case SIGN_EXTEND: case ZERO_EXTEND:
2975 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2976 case FLOAT: case FIX:
2977 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2981 /* These case either have just one operand or we know that we need not
2982 check the rest of the operands. */
2987 /* Try to replace with a PLUS. If that doesn't work, compute the sum
2988 in front of this insn and substitute the temporary. */
2989 if (x == virtual_incoming_args_rtx)
2990 new = arg_pointer_rtx, offset = in_arg_offset;
2991 else if (x == virtual_stack_vars_rtx)
2992 new = frame_pointer_rtx, offset = var_offset;
2993 else if (x == virtual_stack_dynamic_rtx)
2994 new = stack_pointer_rtx, offset = dynamic_offset;
2995 else if (x == virtual_outgoing_args_rtx)
2996 new = stack_pointer_rtx, offset = out_arg_offset;
3000 temp = plus_constant (new, offset);
3001 if (!validate_change (object, loc, temp, 0))
3007 temp = force_operand (temp, NULL_RTX);
3011 emit_insns_before (seq, object);
3012 if (! validate_change (object, loc, temp, 0)
3013 && ! validate_replace_rtx (x, temp, object))
3021 /* Scan all subexpressions. */
3022 fmt = GET_RTX_FORMAT (code);
3023 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3026 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
3029 else if (*fmt == 'E')
3030 for (j = 0; j < XVECLEN (x, i); j++)
3031 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
3038 /* Optimization: assuming this function does not receive nonlocal gotos,
3039 delete the handlers for such, as well as the insns to establish
3040 and disestablish them. */
3046 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3048 /* Delete the handler by turning off the flag that would
3049 prevent jump_optimize from deleting it.
3050 Also permit deletion of the nonlocal labels themselves
3051 if nothing local refers to them. */
3052 if (GET_CODE (insn) == CODE_LABEL)
3056 LABEL_PRESERVE_P (insn) = 0;
3058 /* Remove it from the nonlocal_label list, to avoid confusing
3060 for (t = nonlocal_labels, last_t = 0; t;
3061 last_t = t, t = TREE_CHAIN (t))
3062 if (DECL_RTL (TREE_VALUE (t)) == insn)
3067 nonlocal_labels = TREE_CHAIN (nonlocal_labels);
3069 TREE_CHAIN (last_t) = TREE_CHAIN (t);
3072 if (GET_CODE (insn) == INSN
3073 && ((nonlocal_goto_handler_slot != 0
3074 && reg_mentioned_p (nonlocal_goto_handler_slot, PATTERN (insn)))
3075 || (nonlocal_goto_stack_level != 0
3076 && reg_mentioned_p (nonlocal_goto_stack_level,
3082 /* Return a list (chain of EXPR_LIST nodes) for the nonlocal labels
3083 of the current function. */
3086 nonlocal_label_rtx_list ()
3091 for (t = nonlocal_labels; t; t = TREE_CHAIN (t))
3092 x = gen_rtx (EXPR_LIST, VOIDmode, label_rtx (TREE_VALUE (t)), x);
3097 /* Output a USE for any register use in RTL.
3098 This is used with -noreg to mark the extent of lifespan
3099 of any registers used in a user-visible variable's DECL_RTL. */
3105 if (GET_CODE (rtl) == REG)
3106 /* This is a register variable. */
3107 emit_insn (gen_rtx (USE, VOIDmode, rtl));
3108 else if (GET_CODE (rtl) == MEM
3109 && GET_CODE (XEXP (rtl, 0)) == REG
3110 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
3111 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
3112 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
3113 /* This is a variable-sized structure. */
3114 emit_insn (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)));
3117 /* Like use_variable except that it outputs the USEs after INSN
3118 instead of at the end of the insn-chain. */
3121 use_variable_after (rtl, insn)
3124 if (GET_CODE (rtl) == REG)
3125 /* This is a register variable. */
3126 emit_insn_after (gen_rtx (USE, VOIDmode, rtl), insn);
3127 else if (GET_CODE (rtl) == MEM
3128 && GET_CODE (XEXP (rtl, 0)) == REG
3129 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
3130 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
3131 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
3132 /* This is a variable-sized structure. */
3133 emit_insn_after (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)), insn);
3139 return max_parm_reg;
3142 /* Return the first insn following those generated by `assign_parms'. */
3145 get_first_nonparm_insn ()
3148 return NEXT_INSN (last_parm_insn);
3149 return get_insns ();
3152 /* Return the first NOTE_INSN_BLOCK_BEG note in the function.
3153 Crash if there is none. */
3156 get_first_block_beg ()
3158 register rtx searcher;
3159 register rtx insn = get_first_nonparm_insn ();
3161 for (searcher = insn; searcher; searcher = NEXT_INSN (searcher))
3162 if (GET_CODE (searcher) == NOTE
3163 && NOTE_LINE_NUMBER (searcher) == NOTE_INSN_BLOCK_BEG)
3166 abort (); /* Invalid call to this function. (See comments above.) */
3170 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
3171 This means a type for which function calls must pass an address to the
3172 function or get an address back from the function.
3173 EXP may be a type node or an expression (whose type is tested). */
3176 aggregate_value_p (exp)
3179 int i, regno, nregs;
3182 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 't')
3185 type = TREE_TYPE (exp);
3187 if (RETURN_IN_MEMORY (type))
3189 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
3191 /* Make sure we have suitable call-clobbered regs to return
3192 the value in; if not, we must return it in memory. */
3193 reg = hard_function_value (type, 0);
3194 regno = REGNO (reg);
3195 nregs = HARD_REGNO_NREGS (regno, TYPE_MODE (type));
3196 for (i = 0; i < nregs; i++)
3197 if (! call_used_regs[regno + i])
3202 /* Assign RTL expressions to the function's parameters.
3203 This may involve copying them into registers and using
3204 those registers as the RTL for them.
3206 If SECOND_TIME is non-zero it means that this function is being
3207 called a second time. This is done by integrate.c when a function's
3208 compilation is deferred. We need to come back here in case the
3209 FUNCTION_ARG macro computes items needed for the rest of the compilation
3210 (such as changing which registers are fixed or caller-saved). But suppress
3211 writing any insns or setting DECL_RTL of anything in this case. */
3214 assign_parms (fndecl, second_time)
3219 register rtx entry_parm = 0;
3220 register rtx stack_parm = 0;
3221 CUMULATIVE_ARGS args_so_far;
3222 enum machine_mode promoted_mode, passed_mode;
3223 enum machine_mode nominal_mode, promoted_nominal_mode;
3225 /* Total space needed so far for args on the stack,
3226 given as a constant and a tree-expression. */
3227 struct args_size stack_args_size;
3228 tree fntype = TREE_TYPE (fndecl);
3229 tree fnargs = DECL_ARGUMENTS (fndecl);
3230 /* This is used for the arg pointer when referring to stack args. */
3231 rtx internal_arg_pointer;
3232 /* This is a dummy PARM_DECL that we used for the function result if
3233 the function returns a structure. */
3234 tree function_result_decl = 0;
3235 int nparmregs = list_length (fnargs) + LAST_VIRTUAL_REGISTER + 1;
3236 int varargs_setup = 0;
3237 rtx conversion_insns = 0;
3238 /* FUNCTION_ARG may look at this variable. Since this is not
3239 expanding a call it will always be zero in this function. */
3240 int current_call_is_indirect = 0;
3242 /* Nonzero if the last arg is named `__builtin_va_alist',
3243 which is used on some machines for old-fashioned non-ANSI varargs.h;
3244 this should be stuck onto the stack as if it had arrived there. */
3246 = (current_function_varargs
3248 && (parm = tree_last (fnargs)) != 0
3250 && (! strcmp (IDENTIFIER_POINTER (DECL_NAME (parm)),
3251 "__builtin_va_alist")));
3253 /* Nonzero if function takes extra anonymous args.
3254 This means the last named arg must be on the stack
3255 right before the anonymous ones. */
3257 = (TYPE_ARG_TYPES (fntype) != 0
3258 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3259 != void_type_node));
3261 current_function_stdarg = stdarg;
3263 /* If the reg that the virtual arg pointer will be translated into is
3264 not a fixed reg or is the stack pointer, make a copy of the virtual
3265 arg pointer, and address parms via the copy. The frame pointer is
3266 considered fixed even though it is not marked as such.
3268 The second time through, simply use ap to avoid generating rtx. */
3270 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
3271 || ! (fixed_regs[ARG_POINTER_REGNUM]
3272 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM))
3274 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
3276 internal_arg_pointer = virtual_incoming_args_rtx;
3277 current_function_internal_arg_pointer = internal_arg_pointer;
3279 stack_args_size.constant = 0;
3280 stack_args_size.var = 0;
3282 /* If struct value address is treated as the first argument, make it so. */
3283 if (aggregate_value_p (DECL_RESULT (fndecl))
3284 && ! current_function_returns_pcc_struct
3285 && struct_value_incoming_rtx == 0)
3287 tree type = build_pointer_type (TREE_TYPE (fntype));
3289 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
3291 DECL_ARG_TYPE (function_result_decl) = type;
3292 TREE_CHAIN (function_result_decl) = fnargs;
3293 fnargs = function_result_decl;
3296 parm_reg_stack_loc = (rtx *) oballoc (nparmregs * sizeof (rtx));
3297 bzero ((char *) parm_reg_stack_loc, nparmregs * sizeof (rtx));
3299 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
3300 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
3302 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX);
3305 /* We haven't yet found an argument that we must push and pretend the
3307 current_function_pretend_args_size = 0;
3309 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3311 int aggregate = AGGREGATE_TYPE_P (TREE_TYPE (parm));
3312 struct args_size stack_offset;
3313 struct args_size arg_size;
3314 int passed_pointer = 0;
3315 int did_conversion = 0;
3316 tree passed_type = DECL_ARG_TYPE (parm);
3317 tree nominal_type = TREE_TYPE (parm);
3319 /* Set LAST_NAMED if this is last named arg before some
3320 anonymous args. We treat it as if it were anonymous too. */
3321 int last_named = ((TREE_CHAIN (parm) == 0
3322 || DECL_NAME (TREE_CHAIN (parm)) == 0)
3323 && (stdarg || current_function_varargs));
3325 if (TREE_TYPE (parm) == error_mark_node
3326 /* This can happen after weird syntax errors
3327 or if an enum type is defined among the parms. */
3328 || TREE_CODE (parm) != PARM_DECL
3329 || passed_type == NULL)
3331 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = gen_rtx (MEM, BLKmode,
3333 TREE_USED (parm) = 1;
3337 /* For varargs.h function, save info about regs and stack space
3338 used by the individual args, not including the va_alist arg. */
3339 if (hide_last_arg && last_named)
3340 current_function_args_info = args_so_far;
3342 /* Find mode of arg as it is passed, and mode of arg
3343 as it should be during execution of this function. */
3344 passed_mode = TYPE_MODE (passed_type);
3345 nominal_mode = TYPE_MODE (nominal_type);
3347 /* If the parm's mode is VOID, its value doesn't matter,
3348 and avoid the usual things like emit_move_insn that could crash. */
3349 if (nominal_mode == VOIDmode)
3351 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = const0_rtx;
3355 /* If the parm is to be passed as a transparent union, use the
3356 type of the first field for the tests below. We have already
3357 verified that the modes are the same. */
3358 if (DECL_TRANSPARENT_UNION (parm)
3359 || TYPE_TRANSPARENT_UNION (passed_type))
3360 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
3362 /* See if this arg was passed by invisible reference. It is if
3363 it is an object whose size depends on the contents of the
3364 object itself or if the machine requires these objects be passed
3367 if ((TREE_CODE (TYPE_SIZE (passed_type)) != INTEGER_CST
3368 && contains_placeholder_p (TYPE_SIZE (passed_type)))
3369 || TREE_ADDRESSABLE (passed_type)
3370 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3371 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
3372 passed_type, ! last_named)
3376 passed_type = nominal_type = build_pointer_type (passed_type);
3378 passed_mode = nominal_mode = Pmode;
3381 promoted_mode = passed_mode;
3383 #ifdef PROMOTE_FUNCTION_ARGS
3384 /* Compute the mode in which the arg is actually extended to. */
3385 promoted_mode = promote_mode (passed_type, promoted_mode, &unsignedp, 1);
3388 /* Let machine desc say which reg (if any) the parm arrives in.
3389 0 means it arrives on the stack. */
3390 #ifdef FUNCTION_INCOMING_ARG
3391 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
3392 passed_type, ! last_named);
3394 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
3395 passed_type, ! last_named);
3398 if (entry_parm == 0)
3399 promoted_mode = passed_mode;
3401 #ifdef SETUP_INCOMING_VARARGS
3402 /* If this is the last named parameter, do any required setup for
3403 varargs or stdargs. We need to know about the case of this being an
3404 addressable type, in which case we skip the registers it
3405 would have arrived in.
3407 For stdargs, LAST_NAMED will be set for two parameters, the one that
3408 is actually the last named, and the dummy parameter. We only
3409 want to do this action once.
3411 Also, indicate when RTL generation is to be suppressed. */
3412 if (last_named && !varargs_setup)
3414 SETUP_INCOMING_VARARGS (args_so_far, promoted_mode, passed_type,
3415 current_function_pretend_args_size,
3421 /* Determine parm's home in the stack,
3422 in case it arrives in the stack or we should pretend it did.
3424 Compute the stack position and rtx where the argument arrives
3427 There is one complexity here: If this was a parameter that would
3428 have been passed in registers, but wasn't only because it is
3429 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
3430 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
3431 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
3432 0 as it was the previous time. */
3434 locate_and_pad_parm (promoted_mode, passed_type,
3435 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3438 #ifdef FUNCTION_INCOMING_ARG
3439 FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
3442 || varargs_setup)) != 0,
3444 FUNCTION_ARG (args_so_far, promoted_mode,
3446 ! last_named || varargs_setup) != 0,
3449 fndecl, &stack_args_size, &stack_offset, &arg_size);
3453 rtx offset_rtx = ARGS_SIZE_RTX (stack_offset);
3455 if (offset_rtx == const0_rtx)
3456 stack_parm = gen_rtx (MEM, promoted_mode, internal_arg_pointer);
3458 stack_parm = gen_rtx (MEM, promoted_mode,
3459 gen_rtx (PLUS, Pmode,
3460 internal_arg_pointer, offset_rtx));
3462 /* If this is a memory ref that contains aggregate components,
3463 mark it as such for cse and loop optimize. */
3464 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3467 /* If this parameter was passed both in registers and in the stack,
3468 use the copy on the stack. */
3469 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
3472 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3473 /* If this parm was passed part in regs and part in memory,
3474 pretend it arrived entirely in memory
3475 by pushing the register-part onto the stack.
3477 In the special case of a DImode or DFmode that is split,
3478 we could put it together in a pseudoreg directly,
3479 but for now that's not worth bothering with. */
3483 int nregs = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
3484 passed_type, ! last_named);
3488 current_function_pretend_args_size
3489 = (((nregs * UNITS_PER_WORD) + (PARM_BOUNDARY / BITS_PER_UNIT) - 1)
3490 / (PARM_BOUNDARY / BITS_PER_UNIT)
3491 * (PARM_BOUNDARY / BITS_PER_UNIT));
3494 move_block_from_reg (REGNO (entry_parm),
3495 validize_mem (stack_parm), nregs,
3496 int_size_in_bytes (TREE_TYPE (parm)));
3497 entry_parm = stack_parm;
3502 /* If we didn't decide this parm came in a register,
3503 by default it came on the stack. */
3504 if (entry_parm == 0)
3505 entry_parm = stack_parm;
3507 /* Record permanently how this parm was passed. */
3509 DECL_INCOMING_RTL (parm) = entry_parm;
3511 /* If there is actually space on the stack for this parm,
3512 count it in stack_args_size; otherwise set stack_parm to 0
3513 to indicate there is no preallocated stack slot for the parm. */
3515 if (entry_parm == stack_parm
3516 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
3517 /* On some machines, even if a parm value arrives in a register
3518 there is still an (uninitialized) stack slot allocated for it.
3520 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
3521 whether this parameter already has a stack slot allocated,
3522 because an arg block exists only if current_function_args_size
3523 is larger than some threshold, and we haven't calculated that
3524 yet. So, for now, we just assume that stack slots never exist
3526 || REG_PARM_STACK_SPACE (fndecl) > 0
3530 stack_args_size.constant += arg_size.constant;
3532 ADD_PARM_SIZE (stack_args_size, arg_size.var);
3535 /* No stack slot was pushed for this parm. */
3538 /* Update info on where next arg arrives in registers. */
3540 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
3541 passed_type, ! last_named);
3543 /* If this is our second time through, we are done with this parm. */
3547 /* If we can't trust the parm stack slot to be aligned enough
3548 for its ultimate type, don't use that slot after entry.
3549 We'll make another stack slot, if we need one. */
3551 int thisparm_boundary
3552 = FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type);
3554 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
3558 /* If parm was passed in memory, and we need to convert it on entry,
3559 don't store it back in that same slot. */
3561 && nominal_mode != BLKmode && nominal_mode != passed_mode)
3565 /* Now adjust STACK_PARM to the mode and precise location
3566 where this parameter should live during execution,
3567 if we discover that it must live in the stack during execution.
3568 To make debuggers happier on big-endian machines, we store
3569 the value in the last bytes of the space available. */
3571 if (nominal_mode != BLKmode && nominal_mode != passed_mode
3576 if (BYTES_BIG_ENDIAN
3577 && GET_MODE_SIZE (nominal_mode) < UNITS_PER_WORD)
3578 stack_offset.constant += (GET_MODE_SIZE (passed_mode)
3579 - GET_MODE_SIZE (nominal_mode));
3581 offset_rtx = ARGS_SIZE_RTX (stack_offset);
3582 if (offset_rtx == const0_rtx)
3583 stack_parm = gen_rtx (MEM, nominal_mode, internal_arg_pointer);
3585 stack_parm = gen_rtx (MEM, nominal_mode,
3586 gen_rtx (PLUS, Pmode,
3587 internal_arg_pointer, offset_rtx));
3589 /* If this is a memory ref that contains aggregate components,
3590 mark it as such for cse and loop optimize. */
3591 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3596 /* We need this "use" info, because the gcc-register->stack-register
3597 converter in reg-stack.c needs to know which registers are active
3598 at the start of the function call. The actual parameter loading
3599 instructions are not always available then anymore, since they might
3600 have been optimised away. */
3602 if (GET_CODE (entry_parm) == REG && !(hide_last_arg && last_named))
3603 emit_insn (gen_rtx (USE, GET_MODE (entry_parm), entry_parm));
3606 /* ENTRY_PARM is an RTX for the parameter as it arrives,
3607 in the mode in which it arrives.
3608 STACK_PARM is an RTX for a stack slot where the parameter can live
3609 during the function (in case we want to put it there).
3610 STACK_PARM is 0 if no stack slot was pushed for it.
3612 Now output code if necessary to convert ENTRY_PARM to
3613 the type in which this function declares it,
3614 and store that result in an appropriate place,
3615 which may be a pseudo reg, may be STACK_PARM,
3616 or may be a local stack slot if STACK_PARM is 0.
3618 Set DECL_RTL to that place. */
3620 if (nominal_mode == BLKmode)
3622 /* If a BLKmode arrives in registers, copy it to a stack slot. */
3623 if (GET_CODE (entry_parm) == REG)
3626 = CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm)),
3629 /* Note that we will be storing an integral number of words.
3630 So we have to be careful to ensure that we allocate an
3631 integral number of words. We do this below in the
3632 assign_stack_local if space was not allocated in the argument
3633 list. If it was, this will not work if PARM_BOUNDARY is not
3634 a multiple of BITS_PER_WORD. It isn't clear how to fix this
3635 if it becomes a problem. */
3637 if (stack_parm == 0)
3640 = assign_stack_local (GET_MODE (entry_parm),
3643 /* If this is a memory ref that contains aggregate
3644 components, mark it as such for cse and loop optimize. */
3645 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3648 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
3651 if (TREE_READONLY (parm))
3652 RTX_UNCHANGING_P (stack_parm) = 1;
3654 move_block_from_reg (REGNO (entry_parm),
3655 validize_mem (stack_parm),
3656 size_stored / UNITS_PER_WORD,
3657 int_size_in_bytes (TREE_TYPE (parm)));
3659 DECL_RTL (parm) = stack_parm;
3661 else if (! ((obey_regdecls && ! DECL_REGISTER (parm)
3662 && ! DECL_INLINE (fndecl))
3663 /* layout_decl may set this. */
3664 || TREE_ADDRESSABLE (parm)
3665 || TREE_SIDE_EFFECTS (parm)
3666 /* If -ffloat-store specified, don't put explicit
3667 float variables into registers. */
3668 || (flag_float_store
3669 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
3670 /* Always assign pseudo to structure return or item passed
3671 by invisible reference. */
3672 || passed_pointer || parm == function_result_decl)
3674 /* Store the parm in a pseudoregister during the function, but we
3675 may need to do it in a wider mode. */
3677 register rtx parmreg;
3678 int regno, regnoi, regnor;
3680 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
3682 promoted_nominal_mode
3683 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
3685 parmreg = gen_reg_rtx (promoted_nominal_mode);
3686 REG_USERVAR_P (parmreg) = 1;
3688 /* If this was an item that we received a pointer to, set DECL_RTL
3693 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (passed_type)), parmreg);
3694 MEM_IN_STRUCT_P (DECL_RTL (parm)) = aggregate;
3697 DECL_RTL (parm) = parmreg;
3699 /* Copy the value into the register. */
3700 if (nominal_mode != passed_mode
3701 || promoted_nominal_mode != promoted_mode)
3703 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3704 mode, by the caller. We now have to convert it to
3705 NOMINAL_MODE, if different. However, PARMREG may be in
3706 a diffent mode than NOMINAL_MODE if it is being stored
3709 If ENTRY_PARM is a hard register, it might be in a register
3710 not valid for operating in its mode (e.g., an odd-numbered
3711 register for a DFmode). In that case, moves are the only
3712 thing valid, so we can't do a convert from there. This
3713 occurs when the calling sequence allow such misaligned
3716 In addition, the conversion may involve a call, which could
3717 clobber parameters which haven't been copied to pseudo
3718 registers yet. Therefore, we must first copy the parm to
3719 a pseudo reg here, and save the conversion until after all
3720 parameters have been moved. */
3722 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
3724 emit_move_insn (tempreg, validize_mem (entry_parm));
3726 push_to_sequence (conversion_insns);
3727 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
3729 expand_assignment (parm,
3730 make_tree (nominal_type, tempreg), 0, 0);
3731 conversion_insns = get_insns ();
3736 emit_move_insn (parmreg, validize_mem (entry_parm));
3738 /* If we were passed a pointer but the actual value
3739 can safely live in a register, put it in one. */
3740 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
3741 && ! ((obey_regdecls && ! DECL_REGISTER (parm)
3742 && ! DECL_INLINE (fndecl))
3743 /* layout_decl may set this. */
3744 || TREE_ADDRESSABLE (parm)
3745 || TREE_SIDE_EFFECTS (parm)
3746 /* If -ffloat-store specified, don't put explicit
3747 float variables into registers. */
3748 || (flag_float_store
3749 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE)))
3751 /* We can't use nominal_mode, because it will have been set to
3752 Pmode above. We must use the actual mode of the parm. */
3753 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3754 REG_USERVAR_P (parmreg) = 1;
3755 emit_move_insn (parmreg, DECL_RTL (parm));
3756 DECL_RTL (parm) = parmreg;
3757 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3761 #ifdef FUNCTION_ARG_CALLEE_COPIES
3762 /* If we are passed an arg by reference and it is our responsibility
3763 to make a copy, do it now.
3764 PASSED_TYPE and PASSED mode now refer to the pointer, not the
3765 original argument, so we must recreate them in the call to
3766 FUNCTION_ARG_CALLEE_COPIES. */
3767 /* ??? Later add code to handle the case that if the argument isn't
3768 modified, don't do the copy. */
3770 else if (passed_pointer
3771 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
3772 TYPE_MODE (DECL_ARG_TYPE (parm)),
3773 DECL_ARG_TYPE (parm),
3775 && ! TREE_ADDRESSABLE (DECL_ARG_TYPE (parm)))
3778 tree type = DECL_ARG_TYPE (parm);
3780 /* This sequence may involve a library call perhaps clobbering
3781 registers that haven't been copied to pseudos yet. */
3783 push_to_sequence (conversion_insns);
3785 if (TYPE_SIZE (type) == 0
3786 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
3787 /* This is a variable sized object. */
3788 copy = gen_rtx (MEM, BLKmode,
3789 allocate_dynamic_stack_space
3790 (expr_size (parm), NULL_RTX,
3791 TYPE_ALIGN (type)));
3793 copy = assign_stack_temp (TYPE_MODE (type),
3794 int_size_in_bytes (type), 1);
3795 MEM_IN_STRUCT_P (copy) = AGGREGATE_TYPE_P (type);
3797 store_expr (parm, copy, 0);
3798 emit_move_insn (parmreg, XEXP (copy, 0));
3799 conversion_insns = get_insns ();
3803 #endif /* FUNCTION_ARG_CALLEE_COPIES */
3805 /* In any case, record the parm's desired stack location
3806 in case we later discover it must live in the stack.
3808 If it is a COMPLEX value, store the stack location for both
3811 if (GET_CODE (parmreg) == CONCAT)
3812 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
3814 regno = REGNO (parmreg);
3816 if (regno >= nparmregs)
3819 int old_nparmregs = nparmregs;
3821 nparmregs = regno + 5;
3822 new = (rtx *) oballoc (nparmregs * sizeof (rtx));
3823 bcopy ((char *) parm_reg_stack_loc, (char *) new,
3824 old_nparmregs * sizeof (rtx));
3825 bzero ((char *) (new + old_nparmregs),
3826 (nparmregs - old_nparmregs) * sizeof (rtx));
3827 parm_reg_stack_loc = new;
3830 if (GET_CODE (parmreg) == CONCAT)
3832 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
3834 regnor = REGNO (gen_realpart (submode, parmreg));
3835 regnoi = REGNO (gen_imagpart (submode, parmreg));
3837 if (stack_parm != 0)
3839 parm_reg_stack_loc[regnor]
3840 = gen_realpart (submode, stack_parm);
3841 parm_reg_stack_loc[regnoi]
3842 = gen_imagpart (submode, stack_parm);
3846 parm_reg_stack_loc[regnor] = 0;
3847 parm_reg_stack_loc[regnoi] = 0;
3851 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
3853 /* Mark the register as eliminable if we did no conversion
3854 and it was copied from memory at a fixed offset,
3855 and the arg pointer was not copied to a pseudo-reg.
3856 If the arg pointer is a pseudo reg or the offset formed
3857 an invalid address, such memory-equivalences
3858 as we make here would screw up life analysis for it. */
3859 if (nominal_mode == passed_mode
3861 && GET_CODE (entry_parm) == MEM
3862 && entry_parm == stack_parm
3863 && stack_offset.var == 0
3864 && reg_mentioned_p (virtual_incoming_args_rtx,
3865 XEXP (entry_parm, 0)))
3867 rtx linsn = get_last_insn ();
3869 /* Mark complex types separately. */
3870 if (GET_CODE (parmreg) == CONCAT)
3873 = gen_rtx (EXPR_LIST, REG_EQUIV,
3874 parm_reg_stack_loc[regnoi], REG_NOTES (linsn));
3876 /* Now search backward for where we set the real part. */
3878 && ! reg_referenced_p (parm_reg_stack_loc[regnor],
3880 linsn = prev_nonnote_insn (linsn))
3884 = gen_rtx (EXPR_LIST, REG_EQUIV,
3885 parm_reg_stack_loc[regnor], REG_NOTES (linsn));
3889 = gen_rtx (EXPR_LIST, REG_EQUIV,
3890 entry_parm, REG_NOTES (linsn));
3893 /* For pointer data type, suggest pointer register. */
3894 if (TREE_CODE (TREE_TYPE (parm)) == POINTER_TYPE)
3895 mark_reg_pointer (parmreg,
3896 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm)))
3901 /* Value must be stored in the stack slot STACK_PARM
3902 during function execution. */
3904 if (promoted_mode != nominal_mode)
3906 /* Conversion is required. */
3907 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
3909 emit_move_insn (tempreg, validize_mem (entry_parm));
3911 push_to_sequence (conversion_insns);
3912 entry_parm = convert_to_mode (nominal_mode, tempreg,
3913 TREE_UNSIGNED (TREE_TYPE (parm)));
3914 conversion_insns = get_insns ();
3919 if (entry_parm != stack_parm)
3921 if (stack_parm == 0)
3924 = assign_stack_local (GET_MODE (entry_parm),
3925 GET_MODE_SIZE (GET_MODE (entry_parm)), 0);
3926 /* If this is a memory ref that contains aggregate components,
3927 mark it as such for cse and loop optimize. */
3928 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3931 if (promoted_mode != nominal_mode)
3933 push_to_sequence (conversion_insns);
3934 emit_move_insn (validize_mem (stack_parm),
3935 validize_mem (entry_parm));
3936 conversion_insns = get_insns ();
3940 emit_move_insn (validize_mem (stack_parm),
3941 validize_mem (entry_parm));
3944 DECL_RTL (parm) = stack_parm;
3947 /* If this "parameter" was the place where we are receiving the
3948 function's incoming structure pointer, set up the result. */
3949 if (parm == function_result_decl)
3951 tree result = DECL_RESULT (fndecl);
3952 tree restype = TREE_TYPE (result);
3955 = gen_rtx (MEM, DECL_MODE (result), DECL_RTL (parm));
3957 MEM_IN_STRUCT_P (DECL_RTL (result)) = AGGREGATE_TYPE_P (restype);
3960 if (TREE_THIS_VOLATILE (parm))
3961 MEM_VOLATILE_P (DECL_RTL (parm)) = 1;
3962 if (TREE_READONLY (parm))
3963 RTX_UNCHANGING_P (DECL_RTL (parm)) = 1;
3966 /* Output all parameter conversion instructions (possibly including calls)
3967 now that all parameters have been copied out of hard registers. */
3968 emit_insns (conversion_insns);
3970 max_parm_reg = max_reg_num ();
3971 last_parm_insn = get_last_insn ();
3973 current_function_args_size = stack_args_size.constant;
3975 /* Adjust function incoming argument size for alignment and
3978 #ifdef REG_PARM_STACK_SPACE
3979 #ifndef MAYBE_REG_PARM_STACK_SPACE
3980 current_function_args_size = MAX (current_function_args_size,
3981 REG_PARM_STACK_SPACE (fndecl));
3985 #ifdef STACK_BOUNDARY
3986 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
3988 current_function_args_size
3989 = ((current_function_args_size + STACK_BYTES - 1)
3990 / STACK_BYTES) * STACK_BYTES;
3993 #ifdef ARGS_GROW_DOWNWARD
3994 current_function_arg_offset_rtx
3995 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
3996 : expand_expr (size_binop (MINUS_EXPR, stack_args_size.var,
3997 size_int (-stack_args_size.constant)),
3998 NULL_RTX, VOIDmode, 0));
4000 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
4003 /* See how many bytes, if any, of its args a function should try to pop
4006 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
4007 current_function_args_size);
4009 /* For stdarg.h function, save info about
4010 regs and stack space used by the named args. */
4013 current_function_args_info = args_so_far;
4015 /* Set the rtx used for the function return value. Put this in its
4016 own variable so any optimizers that need this information don't have
4017 to include tree.h. Do this here so it gets done when an inlined
4018 function gets output. */
4020 current_function_return_rtx = DECL_RTL (DECL_RESULT (fndecl));
4023 /* Indicate whether REGNO is an incoming argument to the current function
4024 that was promoted to a wider mode. If so, return the RTX for the
4025 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
4026 that REGNO is promoted from and whether the promotion was signed or
4029 #ifdef PROMOTE_FUNCTION_ARGS
4032 promoted_input_arg (regno, pmode, punsignedp)
4034 enum machine_mode *pmode;
4039 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
4040 arg = TREE_CHAIN (arg))
4041 if (GET_CODE (DECL_INCOMING_RTL (arg)) == REG
4042 && REGNO (DECL_INCOMING_RTL (arg)) == regno
4043 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
4045 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
4046 int unsignedp = TREE_UNSIGNED (TREE_TYPE (arg));
4048 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
4049 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
4050 && mode != DECL_MODE (arg))
4052 *pmode = DECL_MODE (arg);
4053 *punsignedp = unsignedp;
4054 return DECL_INCOMING_RTL (arg);
4063 /* Compute the size and offset from the start of the stacked arguments for a
4064 parm passed in mode PASSED_MODE and with type TYPE.
4066 INITIAL_OFFSET_PTR points to the current offset into the stacked
4069 The starting offset and size for this parm are returned in *OFFSET_PTR
4070 and *ARG_SIZE_PTR, respectively.
4072 IN_REGS is non-zero if the argument will be passed in registers. It will
4073 never be set if REG_PARM_STACK_SPACE is not defined.
4075 FNDECL is the function in which the argument was defined.
4077 There are two types of rounding that are done. The first, controlled by
4078 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
4079 list to be aligned to the specific boundary (in bits). This rounding
4080 affects the initial and starting offsets, but not the argument size.
4082 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
4083 optionally rounds the size of the parm to PARM_BOUNDARY. The
4084 initial offset is not affected by this rounding, while the size always
4085 is and the starting offset may be. */
4087 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
4088 initial_offset_ptr is positive because locate_and_pad_parm's
4089 callers pass in the total size of args so far as
4090 initial_offset_ptr. arg_size_ptr is always positive.*/
4093 locate_and_pad_parm (passed_mode, type, in_regs, fndecl,
4094 initial_offset_ptr, offset_ptr, arg_size_ptr)
4095 enum machine_mode passed_mode;
4099 struct args_size *initial_offset_ptr;
4100 struct args_size *offset_ptr;
4101 struct args_size *arg_size_ptr;
4104 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
4105 enum direction where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
4106 int boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
4107 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4108 int reg_parm_stack_space = 0;
4110 #ifdef REG_PARM_STACK_SPACE
4111 /* If we have found a stack parm before we reach the end of the
4112 area reserved for registers, skip that area. */
4115 #ifdef MAYBE_REG_PARM_STACK_SPACE
4116 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
4118 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
4120 if (reg_parm_stack_space > 0)
4122 if (initial_offset_ptr->var)
4124 initial_offset_ptr->var
4125 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4126 size_int (reg_parm_stack_space));
4127 initial_offset_ptr->constant = 0;
4129 else if (initial_offset_ptr->constant < reg_parm_stack_space)
4130 initial_offset_ptr->constant = reg_parm_stack_space;
4133 #endif /* REG_PARM_STACK_SPACE */
4135 arg_size_ptr->var = 0;
4136 arg_size_ptr->constant = 0;
4138 #ifdef ARGS_GROW_DOWNWARD
4139 if (initial_offset_ptr->var)
4141 offset_ptr->constant = 0;
4142 offset_ptr->var = size_binop (MINUS_EXPR, integer_zero_node,
4143 initial_offset_ptr->var);
4147 offset_ptr->constant = - initial_offset_ptr->constant;
4148 offset_ptr->var = 0;
4150 if (where_pad != none
4151 && (TREE_CODE (sizetree) != INTEGER_CST
4152 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
4153 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4154 SUB_PARM_SIZE (*offset_ptr, sizetree);
4155 if (where_pad != downward)
4156 pad_to_arg_alignment (offset_ptr, boundary);
4157 if (initial_offset_ptr->var)
4159 arg_size_ptr->var = size_binop (MINUS_EXPR,
4160 size_binop (MINUS_EXPR,
4162 initial_offset_ptr->var),
4167 arg_size_ptr->constant = (- initial_offset_ptr->constant -
4168 offset_ptr->constant);
4170 #else /* !ARGS_GROW_DOWNWARD */
4171 pad_to_arg_alignment (initial_offset_ptr, boundary);
4172 *offset_ptr = *initial_offset_ptr;
4174 #ifdef PUSH_ROUNDING
4175 if (passed_mode != BLKmode)
4176 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4179 /* Pad_below needs the pre-rounded size to know how much to pad below
4180 so this must be done before rounding up. */
4181 if (where_pad == downward
4182 /* However, BLKmode args passed in regs have their padding done elsewhere.
4183 The stack slot must be able to hold the entire register. */
4184 && !(in_regs && passed_mode == BLKmode))
4185 pad_below (offset_ptr, passed_mode, sizetree);
4187 if (where_pad != none
4188 && (TREE_CODE (sizetree) != INTEGER_CST
4189 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
4190 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4192 ADD_PARM_SIZE (*arg_size_ptr, sizetree);
4193 #endif /* ARGS_GROW_DOWNWARD */
4196 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4197 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4200 pad_to_arg_alignment (offset_ptr, boundary)
4201 struct args_size *offset_ptr;
4204 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4206 if (boundary > BITS_PER_UNIT)
4208 if (offset_ptr->var)
4211 #ifdef ARGS_GROW_DOWNWARD
4216 (ARGS_SIZE_TREE (*offset_ptr),
4217 boundary / BITS_PER_UNIT);
4218 offset_ptr->constant = 0; /*?*/
4221 offset_ptr->constant =
4222 #ifdef ARGS_GROW_DOWNWARD
4223 FLOOR_ROUND (offset_ptr->constant, boundary_in_bytes);
4225 CEIL_ROUND (offset_ptr->constant, boundary_in_bytes);
4231 pad_below (offset_ptr, passed_mode, sizetree)
4232 struct args_size *offset_ptr;
4233 enum machine_mode passed_mode;
4236 if (passed_mode != BLKmode)
4238 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
4239 offset_ptr->constant
4240 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
4241 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
4242 - GET_MODE_SIZE (passed_mode));
4246 if (TREE_CODE (sizetree) != INTEGER_CST
4247 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
4249 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4250 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4252 ADD_PARM_SIZE (*offset_ptr, s2);
4253 SUB_PARM_SIZE (*offset_ptr, sizetree);
4259 round_down (value, divisor)
4263 return size_binop (MULT_EXPR,
4264 size_binop (FLOOR_DIV_EXPR, value, size_int (divisor)),
4265 size_int (divisor));
4268 /* Walk the tree of blocks describing the binding levels within a function
4269 and warn about uninitialized variables.
4270 This is done after calling flow_analysis and before global_alloc
4271 clobbers the pseudo-regs to hard regs. */
4274 uninitialized_vars_warning (block)
4277 register tree decl, sub;
4278 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
4280 if (TREE_CODE (decl) == VAR_DECL
4281 /* These warnings are unreliable for and aggregates
4282 because assigning the fields one by one can fail to convince
4283 flow.c that the entire aggregate was initialized.
4284 Unions are troublesome because members may be shorter. */
4285 && ! AGGREGATE_TYPE_P (TREE_TYPE (decl))
4286 && DECL_RTL (decl) != 0
4287 && GET_CODE (DECL_RTL (decl)) == REG
4288 && regno_uninitialized (REGNO (DECL_RTL (decl))))
4289 warning_with_decl (decl,
4290 "`%s' might be used uninitialized in this function");
4291 if (TREE_CODE (decl) == VAR_DECL
4292 && DECL_RTL (decl) != 0
4293 && GET_CODE (DECL_RTL (decl)) == REG
4294 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
4295 warning_with_decl (decl,
4296 "variable `%s' might be clobbered by `longjmp' or `vfork'");
4298 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
4299 uninitialized_vars_warning (sub);
4302 /* Do the appropriate part of uninitialized_vars_warning
4303 but for arguments instead of local variables. */
4306 setjmp_args_warning ()
4309 for (decl = DECL_ARGUMENTS (current_function_decl);
4310 decl; decl = TREE_CHAIN (decl))
4311 if (DECL_RTL (decl) != 0
4312 && GET_CODE (DECL_RTL (decl)) == REG
4313 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
4314 warning_with_decl (decl, "argument `%s' might be clobbered by `longjmp' or `vfork'");
4317 /* If this function call setjmp, put all vars into the stack
4318 unless they were declared `register'. */
4321 setjmp_protect (block)
4324 register tree decl, sub;
4325 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
4326 if ((TREE_CODE (decl) == VAR_DECL
4327 || TREE_CODE (decl) == PARM_DECL)
4328 && DECL_RTL (decl) != 0
4329 && GET_CODE (DECL_RTL (decl)) == REG
4330 /* If this variable came from an inline function, it must be
4331 that it's life doesn't overlap the setjmp. If there was a
4332 setjmp in the function, it would already be in memory. We
4333 must exclude such variable because their DECL_RTL might be
4334 set to strange things such as virtual_stack_vars_rtx. */
4335 && ! DECL_FROM_INLINE (decl)
4337 #ifdef NON_SAVING_SETJMP
4338 /* If longjmp doesn't restore the registers,
4339 don't put anything in them. */
4343 ! DECL_REGISTER (decl)))
4344 put_var_into_stack (decl);
4345 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
4346 setjmp_protect (sub);
4349 /* Like the previous function, but for args instead of local variables. */
4352 setjmp_protect_args ()
4354 register tree decl, sub;
4355 for (decl = DECL_ARGUMENTS (current_function_decl);
4356 decl; decl = TREE_CHAIN (decl))
4357 if ((TREE_CODE (decl) == VAR_DECL
4358 || TREE_CODE (decl) == PARM_DECL)
4359 && DECL_RTL (decl) != 0
4360 && GET_CODE (DECL_RTL (decl)) == REG
4362 /* If longjmp doesn't restore the registers,
4363 don't put anything in them. */
4364 #ifdef NON_SAVING_SETJMP
4368 ! DECL_REGISTER (decl)))
4369 put_var_into_stack (decl);
4372 /* Return the context-pointer register corresponding to DECL,
4373 or 0 if it does not need one. */
4376 lookup_static_chain (decl)
4379 tree context = decl_function_context (decl);
4385 /* We treat inline_function_decl as an alias for the current function
4386 because that is the inline function whose vars, types, etc.
4387 are being merged into the current function.
4388 See expand_inline_function. */
4389 if (context == current_function_decl || context == inline_function_decl)
4390 return virtual_stack_vars_rtx;
4392 for (link = context_display; link; link = TREE_CHAIN (link))
4393 if (TREE_PURPOSE (link) == context)
4394 return RTL_EXPR_RTL (TREE_VALUE (link));
4399 /* Convert a stack slot address ADDR for variable VAR
4400 (from a containing function)
4401 into an address valid in this function (using a static chain). */
4404 fix_lexical_addr (addr, var)
4410 tree context = decl_function_context (var);
4411 struct function *fp;
4414 /* If this is the present function, we need not do anything. */
4415 if (context == current_function_decl || context == inline_function_decl)
4418 for (fp = outer_function_chain; fp; fp = fp->next)
4419 if (fp->decl == context)
4425 /* Decode given address as base reg plus displacement. */
4426 if (GET_CODE (addr) == REG)
4427 basereg = addr, displacement = 0;
4428 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
4429 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
4433 /* We accept vars reached via the containing function's
4434 incoming arg pointer and via its stack variables pointer. */
4435 if (basereg == fp->internal_arg_pointer)
4437 /* If reached via arg pointer, get the arg pointer value
4438 out of that function's stack frame.
4440 There are two cases: If a separate ap is needed, allocate a
4441 slot in the outer function for it and dereference it that way.
4442 This is correct even if the real ap is actually a pseudo.
4443 Otherwise, just adjust the offset from the frame pointer to
4446 #ifdef NEED_SEPARATE_AP
4449 if (fp->arg_pointer_save_area == 0)
4450 fp->arg_pointer_save_area
4451 = assign_outer_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0, fp);
4453 addr = fix_lexical_addr (XEXP (fp->arg_pointer_save_area, 0), var);
4454 addr = memory_address (Pmode, addr);
4456 base = copy_to_reg (gen_rtx (MEM, Pmode, addr));
4458 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
4459 base = lookup_static_chain (var);
4463 else if (basereg == virtual_stack_vars_rtx)
4465 /* This is the same code as lookup_static_chain, duplicated here to
4466 avoid an extra call to decl_function_context. */
4469 for (link = context_display; link; link = TREE_CHAIN (link))
4470 if (TREE_PURPOSE (link) == context)
4472 base = RTL_EXPR_RTL (TREE_VALUE (link));
4480 /* Use same offset, relative to appropriate static chain or argument
4482 return plus_constant (base, displacement);
4485 /* Return the address of the trampoline for entering nested fn FUNCTION.
4486 If necessary, allocate a trampoline (in the stack frame)
4487 and emit rtl to initialize its contents (at entry to this function). */
4490 trampoline_address (function)
4496 struct function *fp;
4499 /* Find an existing trampoline and return it. */
4500 for (link = trampoline_list; link; link = TREE_CHAIN (link))
4501 if (TREE_PURPOSE (link) == function)
4503 round_trampoline_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0));
4505 for (fp = outer_function_chain; fp; fp = fp->next)
4506 for (link = fp->trampoline_list; link; link = TREE_CHAIN (link))
4507 if (TREE_PURPOSE (link) == function)
4509 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
4511 return round_trampoline_addr (tramp);
4514 /* None exists; we must make one. */
4516 /* Find the `struct function' for the function containing FUNCTION. */
4518 fn_context = decl_function_context (function);
4519 if (fn_context != current_function_decl)
4520 for (fp = outer_function_chain; fp; fp = fp->next)
4521 if (fp->decl == fn_context)
4524 /* Allocate run-time space for this trampoline
4525 (usually in the defining function's stack frame). */
4526 #ifdef ALLOCATE_TRAMPOLINE
4527 tramp = ALLOCATE_TRAMPOLINE (fp);
4529 /* If rounding needed, allocate extra space
4530 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
4531 #ifdef TRAMPOLINE_ALIGNMENT
4532 #define TRAMPOLINE_REAL_SIZE \
4533 (TRAMPOLINE_SIZE + (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT) - 1)
4535 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE)
4538 tramp = assign_outer_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0, fp);
4540 tramp = assign_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0);
4543 /* Record the trampoline for reuse and note it for later initialization
4544 by expand_function_end. */
4547 push_obstacks (fp->function_maybepermanent_obstack,
4548 fp->function_maybepermanent_obstack);
4549 rtlexp = make_node (RTL_EXPR);
4550 RTL_EXPR_RTL (rtlexp) = tramp;
4551 fp->trampoline_list = tree_cons (function, rtlexp, fp->trampoline_list);
4556 /* Make the RTL_EXPR node temporary, not momentary, so that the
4557 trampoline_list doesn't become garbage. */
4558 int momentary = suspend_momentary ();
4559 rtlexp = make_node (RTL_EXPR);
4560 resume_momentary (momentary);
4562 RTL_EXPR_RTL (rtlexp) = tramp;
4563 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
4566 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
4567 return round_trampoline_addr (tramp);
4570 /* Given a trampoline address,
4571 round it to multiple of TRAMPOLINE_ALIGNMENT. */
4574 round_trampoline_addr (tramp)
4577 #ifdef TRAMPOLINE_ALIGNMENT
4578 /* Round address up to desired boundary. */
4579 rtx temp = gen_reg_rtx (Pmode);
4580 temp = expand_binop (Pmode, add_optab, tramp,
4581 GEN_INT (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT - 1),
4582 temp, 0, OPTAB_LIB_WIDEN);
4583 tramp = expand_binop (Pmode, and_optab, temp,
4584 GEN_INT (- TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT),
4585 temp, 0, OPTAB_LIB_WIDEN);
4590 /* The functions identify_blocks and reorder_blocks provide a way to
4591 reorder the tree of BLOCK nodes, for optimizers that reshuffle or
4592 duplicate portions of the RTL code. Call identify_blocks before
4593 changing the RTL, and call reorder_blocks after. */
4595 /* Put all this function's BLOCK nodes including those that are chained
4596 onto the first block into a vector, and return it.
4597 Also store in each NOTE for the beginning or end of a block
4598 the index of that block in the vector.
4599 The arguments are BLOCK, the chain of top-level blocks of the function,
4600 and INSNS, the insn chain of the function. */
4603 identify_blocks (block, insns)
4611 int next_block_number = 1;
4612 int current_block_number = 1;
4618 n_blocks = all_blocks (block, 0);
4619 block_vector = (tree *) xmalloc (n_blocks * sizeof (tree));
4620 block_stack = (int *) alloca (n_blocks * sizeof (int));
4622 all_blocks (block, block_vector);
4624 for (insn = insns; insn; insn = NEXT_INSN (insn))
4625 if (GET_CODE (insn) == NOTE)
4627 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
4629 block_stack[depth++] = current_block_number;
4630 current_block_number = next_block_number;
4631 NOTE_BLOCK_NUMBER (insn) = next_block_number++;
4633 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
4635 current_block_number = block_stack[--depth];
4636 NOTE_BLOCK_NUMBER (insn) = current_block_number;
4640 if (n_blocks != next_block_number)
4643 return block_vector;
4646 /* Given BLOCK_VECTOR which was returned by identify_blocks,
4647 and a revised instruction chain, rebuild the tree structure
4648 of BLOCK nodes to correspond to the new order of RTL.
4649 The new block tree is inserted below TOP_BLOCK.
4650 Returns the current top-level block. */
4653 reorder_blocks (block_vector, block, insns)
4658 tree current_block = block;
4661 if (block_vector == 0)
4664 /* Prune the old trees away, so that it doesn't get in the way. */
4665 BLOCK_SUBBLOCKS (current_block) = 0;
4666 BLOCK_CHAIN (current_block) = 0;
4668 for (insn = insns; insn; insn = NEXT_INSN (insn))
4669 if (GET_CODE (insn) == NOTE)
4671 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
4673 tree block = block_vector[NOTE_BLOCK_NUMBER (insn)];
4674 /* If we have seen this block before, copy it. */
4675 if (TREE_ASM_WRITTEN (block))
4676 block = copy_node (block);
4677 BLOCK_SUBBLOCKS (block) = 0;
4678 TREE_ASM_WRITTEN (block) = 1;
4679 BLOCK_SUPERCONTEXT (block) = current_block;
4680 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4681 BLOCK_SUBBLOCKS (current_block) = block;
4682 current_block = block;
4683 NOTE_SOURCE_FILE (insn) = 0;
4685 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
4687 BLOCK_SUBBLOCKS (current_block)
4688 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
4689 current_block = BLOCK_SUPERCONTEXT (current_block);
4690 NOTE_SOURCE_FILE (insn) = 0;
4694 BLOCK_SUBBLOCKS (current_block)
4695 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
4696 return current_block;
4699 /* Reverse the order of elements in the chain T of blocks,
4700 and return the new head of the chain (old last element). */
4706 register tree prev = 0, decl, next;
4707 for (decl = t; decl; decl = next)
4709 next = BLOCK_CHAIN (decl);
4710 BLOCK_CHAIN (decl) = prev;
4716 /* Count the subblocks of the list starting with BLOCK, and list them
4717 all into the vector VECTOR. Also clear TREE_ASM_WRITTEN in all
4721 all_blocks (block, vector)
4729 TREE_ASM_WRITTEN (block) = 0;
4731 /* Record this block. */
4733 vector[n_blocks] = block;
4737 /* Record the subblocks, and their subblocks... */
4738 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4739 vector ? vector + n_blocks : 0);
4740 block = BLOCK_CHAIN (block);
4746 /* Build bytecode call descriptor for function SUBR. */
4749 bc_build_calldesc (subr)
4752 tree calldesc = 0, arg;
4755 /* Build the argument description vector in reverse order. */
4756 DECL_ARGUMENTS (subr) = nreverse (DECL_ARGUMENTS (subr));
4759 for (arg = DECL_ARGUMENTS (subr); arg; arg = TREE_CHAIN (arg))
4763 calldesc = tree_cons ((tree) 0, size_in_bytes (TREE_TYPE (arg)), calldesc);
4764 calldesc = tree_cons ((tree) 0, bc_runtime_type_code (TREE_TYPE (arg)), calldesc);
4767 DECL_ARGUMENTS (subr) = nreverse (DECL_ARGUMENTS (subr));
4769 /* Prepend the function's return type. */
4770 calldesc = tree_cons ((tree) 0,
4771 size_in_bytes (TREE_TYPE (TREE_TYPE (subr))),
4774 calldesc = tree_cons ((tree) 0,
4775 bc_runtime_type_code (TREE_TYPE (TREE_TYPE (subr))),
4778 /* Prepend the arg count. */
4779 calldesc = tree_cons ((tree) 0, build_int_2 (nargs, 0), calldesc);
4781 /* Output the call description vector and get its address. */
4782 calldesc = build_nt (CONSTRUCTOR, (tree) 0, calldesc);
4783 TREE_TYPE (calldesc) = build_array_type (integer_type_node,
4784 build_index_type (build_int_2 (nargs * 2, 0)));
4786 return output_constant_def (calldesc);
4790 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4791 and initialize static variables for generating RTL for the statements
4795 init_function_start (subr, filename, line)
4802 if (output_bytecode)
4804 this_function_decl = subr;
4805 this_function_calldesc = bc_build_calldesc (subr);
4806 local_vars_size = 0;
4808 max_stack_depth = 0;
4809 stmt_expr_depth = 0;
4813 init_stmt_for_function ();
4815 cse_not_expected = ! optimize;
4817 /* Caller save not needed yet. */
4818 caller_save_needed = 0;
4820 /* No stack slots have been made yet. */
4821 stack_slot_list = 0;
4823 /* There is no stack slot for handling nonlocal gotos. */
4824 nonlocal_goto_handler_slot = 0;
4825 nonlocal_goto_stack_level = 0;
4827 /* No labels have been declared for nonlocal use. */
4828 nonlocal_labels = 0;
4830 /* No function calls so far in this function. */
4831 function_call_count = 0;
4833 /* No parm regs have been allocated.
4834 (This is important for output_inline_function.) */
4835 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4837 /* Initialize the RTL mechanism. */
4840 /* Initialize the queue of pending postincrement and postdecrements,
4841 and some other info in expr.c. */
4844 /* We haven't done register allocation yet. */
4847 init_const_rtx_hash_table ();
4849 current_function_name = (*decl_printable_name) (subr, &junk);
4851 /* Nonzero if this is a nested function that uses a static chain. */
4853 current_function_needs_context
4854 = (decl_function_context (current_function_decl) != 0);
4856 /* Set if a call to setjmp is seen. */
4857 current_function_calls_setjmp = 0;
4859 /* Set if a call to longjmp is seen. */
4860 current_function_calls_longjmp = 0;
4862 current_function_calls_alloca = 0;
4863 current_function_has_nonlocal_label = 0;
4864 current_function_has_nonlocal_goto = 0;
4865 current_function_contains_functions = 0;
4867 current_function_returns_pcc_struct = 0;
4868 current_function_returns_struct = 0;
4869 current_function_epilogue_delay_list = 0;
4870 current_function_uses_const_pool = 0;
4871 current_function_uses_pic_offset_table = 0;
4873 /* We have not yet needed to make a label to jump to for tail-recursion. */
4874 tail_recursion_label = 0;
4876 /* We haven't had a need to make a save area for ap yet. */
4878 arg_pointer_save_area = 0;
4880 /* No stack slots allocated yet. */
4883 /* No SAVE_EXPRs in this function yet. */
4886 /* No RTL_EXPRs in this function yet. */
4889 /* Set up to allocate temporaries. */
4892 /* Within function body, compute a type's size as soon it is laid out. */
4893 immediate_size_expand++;
4895 /* We haven't made any trampolines for this function yet. */
4896 trampoline_list = 0;
4898 init_pending_stack_adjust ();
4899 inhibit_defer_pop = 0;
4901 current_function_outgoing_args_size = 0;
4903 /* Prevent ever trying to delete the first instruction of a function.
4904 Also tell final how to output a linenum before the function prologue. */
4905 emit_line_note (filename, line);
4907 /* Make sure first insn is a note even if we don't want linenums.
4908 This makes sure the first insn will never be deleted.
4909 Also, final expects a note to appear there. */
4910 emit_note (NULL_PTR, NOTE_INSN_DELETED);
4912 /* Set flags used by final.c. */
4913 if (aggregate_value_p (DECL_RESULT (subr)))
4915 #ifdef PCC_STATIC_STRUCT_RETURN
4916 current_function_returns_pcc_struct = 1;
4918 current_function_returns_struct = 1;
4921 /* Warn if this value is an aggregate type,
4922 regardless of which calling convention we are using for it. */
4923 if (warn_aggregate_return
4924 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4925 warning ("function returns an aggregate");
4927 current_function_returns_pointer
4928 = POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (subr)));
4930 /* Indicate that we need to distinguish between the return value of the
4931 present function and the return value of a function being called. */
4932 rtx_equal_function_value_matters = 1;
4934 /* Indicate that we have not instantiated virtual registers yet. */
4935 virtuals_instantiated = 0;
4937 /* Indicate we have no need of a frame pointer yet. */
4938 frame_pointer_needed = 0;
4940 /* By default assume not varargs or stdarg. */
4941 current_function_varargs = 0;
4942 current_function_stdarg = 0;
4945 /* Indicate that the current function uses extra args
4946 not explicitly mentioned in the argument list in any fashion. */
4951 current_function_varargs = 1;
4954 /* Expand a call to __main at the beginning of a possible main function. */
4956 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
4957 #undef HAS_INIT_SECTION
4958 #define HAS_INIT_SECTION
4962 expand_main_function ()
4964 if (!output_bytecode)
4966 /* The zero below avoids a possible parse error */
4968 #if !defined (HAS_INIT_SECTION)
4969 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, NAME__MAIN), 0,
4971 #endif /* not HAS_INIT_SECTION */
4975 extern struct obstack permanent_obstack;
4977 /* Expand start of bytecode function. See comment at
4978 expand_function_start below for details. */
4981 bc_expand_function_start (subr, parms_have_cleanups)
4983 int parms_have_cleanups;
4985 char label[20], *name;
4990 if (TREE_PUBLIC (subr))
4991 bc_globalize_label (IDENTIFIER_POINTER (DECL_NAME (subr)));
4993 #ifdef DEBUG_PRINT_CODE
4994 fprintf (stderr, "\n<func %s>\n", IDENTIFIER_POINTER (DECL_NAME (subr)));
4997 for (argsz = 0, thisarg = DECL_ARGUMENTS (subr); thisarg; thisarg = TREE_CHAIN (thisarg))
4999 if (DECL_RTL (thisarg))
5000 abort (); /* Should be NULL here I think. */
5001 else if (TREE_CONSTANT (DECL_SIZE (thisarg)))
5003 DECL_RTL (thisarg) = bc_gen_rtx ((char *) 0, argsz, (struct bc_label *) 0);
5004 argsz += TREE_INT_CST_LOW (DECL_SIZE (thisarg));
5008 /* Variable-sized objects are pointers to their storage. */
5009 DECL_RTL (thisarg) = bc_gen_rtx ((char *) 0, argsz, (struct bc_label *) 0);
5010 argsz += POINTER_SIZE;
5014 bc_begin_function (bc_xstrdup (IDENTIFIER_POINTER (DECL_NAME (subr))));
5016 ASM_GENERATE_INTERNAL_LABEL (label, "LX", nlab);
5019 name = (char *) obstack_copy0 (&permanent_obstack, label, strlen (label));
5020 this_function_callinfo = bc_gen_rtx (name, 0, (struct bc_label *) 0);
5021 this_function_bytecode =
5022 bc_emit_trampoline (BYTECODE_LABEL (this_function_callinfo));
5026 /* Expand end of bytecode function. See details the comment of
5027 expand_function_end(), below. */
5030 bc_expand_function_end ()
5034 expand_null_return ();
5036 /* Emit any fixup code. This must be done before the call to
5037 to BC_END_FUNCTION (), since that will cause the bytecode
5038 segment to be finished off and closed. */
5040 expand_fixups (NULL_RTX);
5042 ptrconsts = bc_end_function ();
5044 bc_align_const (2 /* INT_ALIGN */);
5046 /* If this changes also make sure to change bc-interp.h! */
5048 bc_emit_const_labeldef (BYTECODE_LABEL (this_function_callinfo));
5049 bc_emit_const ((char *) &max_stack_depth, sizeof max_stack_depth);
5050 bc_emit_const ((char *) &local_vars_size, sizeof local_vars_size);
5051 bc_emit_const_labelref (this_function_bytecode, 0);
5052 bc_emit_const_labelref (ptrconsts, 0);
5053 bc_emit_const_labelref (BYTECODE_LABEL (this_function_calldesc), 0);
5057 /* Start the RTL for a new function, and set variables used for
5059 SUBR is the FUNCTION_DECL node.
5060 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
5061 the function's parameters, which must be run at any return statement. */
5064 expand_function_start (subr, parms_have_cleanups)
5066 int parms_have_cleanups;
5072 if (output_bytecode)
5074 bc_expand_function_start (subr, parms_have_cleanups);
5078 /* Make sure volatile mem refs aren't considered
5079 valid operands of arithmetic insns. */
5080 init_recog_no_volatile ();
5082 /* If function gets a static chain arg, store it in the stack frame.
5083 Do this first, so it gets the first stack slot offset. */
5084 if (current_function_needs_context)
5086 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5088 #ifdef SMALL_REGISTER_CLASSES
5089 /* Delay copying static chain if it is not a register to avoid
5090 conflicts with regs used for parameters. */
5091 if (GET_CODE (static_chain_incoming_rtx) == REG)
5093 emit_move_insn (last_ptr, static_chain_incoming_rtx);
5096 /* If the parameters of this function need cleaning up, get a label
5097 for the beginning of the code which executes those cleanups. This must
5098 be done before doing anything with return_label. */
5099 if (parms_have_cleanups)
5100 cleanup_label = gen_label_rtx ();
5104 /* Make the label for return statements to jump to, if this machine
5105 does not have a one-instruction return and uses an epilogue,
5106 or if it returns a structure, or if it has parm cleanups. */
5108 if (cleanup_label == 0 && HAVE_return
5109 && ! current_function_returns_pcc_struct
5110 && ! (current_function_returns_struct && ! optimize))
5113 return_label = gen_label_rtx ();
5115 return_label = gen_label_rtx ();
5118 /* Initialize rtx used to return the value. */
5119 /* Do this before assign_parms so that we copy the struct value address
5120 before any library calls that assign parms might generate. */
5122 /* Decide whether to return the value in memory or in a register. */
5123 if (aggregate_value_p (DECL_RESULT (subr)))
5125 /* Returning something that won't go in a register. */
5126 register rtx value_address = 0;
5128 #ifdef PCC_STATIC_STRUCT_RETURN
5129 if (current_function_returns_pcc_struct)
5131 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
5132 value_address = assemble_static_space (size);
5137 /* Expect to be passed the address of a place to store the value.
5138 If it is passed as an argument, assign_parms will take care of
5140 if (struct_value_incoming_rtx)
5142 value_address = gen_reg_rtx (Pmode);
5143 emit_move_insn (value_address, struct_value_incoming_rtx);
5148 DECL_RTL (DECL_RESULT (subr))
5149 = gen_rtx (MEM, DECL_MODE (DECL_RESULT (subr)), value_address);
5150 MEM_IN_STRUCT_P (DECL_RTL (DECL_RESULT (subr)))
5151 = AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr)));
5154 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
5155 /* If return mode is void, this decl rtl should not be used. */
5156 DECL_RTL (DECL_RESULT (subr)) = 0;
5157 else if (parms_have_cleanups)
5159 /* If function will end with cleanup code for parms,
5160 compute the return values into a pseudo reg,
5161 which we will copy into the true return register
5162 after the cleanups are done. */
5164 enum machine_mode mode = DECL_MODE (DECL_RESULT (subr));
5166 #ifdef PROMOTE_FUNCTION_RETURN
5167 tree type = TREE_TYPE (DECL_RESULT (subr));
5168 int unsignedp = TREE_UNSIGNED (type);
5170 mode = promote_mode (type, mode, &unsignedp, 1);
5173 DECL_RTL (DECL_RESULT (subr)) = gen_reg_rtx (mode);
5176 /* Scalar, returned in a register. */
5178 #ifdef FUNCTION_OUTGOING_VALUE
5179 DECL_RTL (DECL_RESULT (subr))
5180 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
5182 DECL_RTL (DECL_RESULT (subr))
5183 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
5186 /* Mark this reg as the function's return value. */
5187 if (GET_CODE (DECL_RTL (DECL_RESULT (subr))) == REG)
5189 REG_FUNCTION_VALUE_P (DECL_RTL (DECL_RESULT (subr))) = 1;
5190 /* Needed because we may need to move this to memory
5191 in case it's a named return value whose address is taken. */
5192 DECL_REGISTER (DECL_RESULT (subr)) = 1;
5196 /* Initialize rtx for parameters and local variables.
5197 In some cases this requires emitting insns. */
5199 assign_parms (subr, 0);
5201 #ifdef SMALL_REGISTER_CLASSES
5202 /* Copy the static chain now if it wasn't a register. The delay is to
5203 avoid conflicts with the parameter passing registers. */
5205 if (current_function_needs_context)
5206 if (GET_CODE (static_chain_incoming_rtx) != REG)
5207 emit_move_insn (last_ptr, static_chain_incoming_rtx);
5210 /* The following was moved from init_function_start.
5211 The move is supposed to make sdb output more accurate. */
5212 /* Indicate the beginning of the function body,
5213 as opposed to parm setup. */
5214 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_BEG);
5216 /* If doing stupid allocation, mark parms as born here. */
5218 if (GET_CODE (get_last_insn ()) != NOTE)
5219 emit_note (NULL_PTR, NOTE_INSN_DELETED);
5220 parm_birth_insn = get_last_insn ();
5224 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
5225 use_variable (regno_reg_rtx[i]);
5227 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
5228 use_variable (current_function_internal_arg_pointer);
5231 /* Fetch static chain values for containing functions. */
5232 tem = decl_function_context (current_function_decl);
5233 /* If not doing stupid register allocation copy the static chain
5234 pointer into a pseudo. If we have small register classes, copy the
5235 value from memory if static_chain_incoming_rtx is a REG. If we do
5236 stupid register allocation, we use the stack address generated above. */
5237 if (tem && ! obey_regdecls)
5239 #ifdef SMALL_REGISTER_CLASSES
5240 /* If the static chain originally came in a register, put it back
5241 there, then move it out in the next insn. The reason for
5242 this peculiar code is to satisfy function integration. */
5243 if (GET_CODE (static_chain_incoming_rtx) == REG)
5244 emit_move_insn (static_chain_incoming_rtx, last_ptr);
5247 last_ptr = copy_to_reg (static_chain_incoming_rtx);
5250 context_display = 0;
5253 tree rtlexp = make_node (RTL_EXPR);
5255 RTL_EXPR_RTL (rtlexp) = last_ptr;
5256 context_display = tree_cons (tem, rtlexp, context_display);
5257 tem = decl_function_context (tem);
5260 /* Chain thru stack frames, assuming pointer to next lexical frame
5261 is found at the place we always store it. */
5262 #ifdef FRAME_GROWS_DOWNWARD
5263 last_ptr = plus_constant (last_ptr, - GET_MODE_SIZE (Pmode));
5265 last_ptr = copy_to_reg (gen_rtx (MEM, Pmode,
5266 memory_address (Pmode, last_ptr)));
5268 /* If we are not optimizing, ensure that we know that this
5269 piece of context is live over the entire function. */
5271 save_expr_regs = gen_rtx (EXPR_LIST, VOIDmode, last_ptr,
5275 /* After the display initializations is where the tail-recursion label
5276 should go, if we end up needing one. Ensure we have a NOTE here
5277 since some things (like trampolines) get placed before this. */
5278 tail_recursion_reentry = emit_note (NULL_PTR, NOTE_INSN_DELETED);
5280 /* Evaluate now the sizes of any types declared among the arguments. */
5281 for (tem = nreverse (get_pending_sizes ()); tem; tem = TREE_CHAIN (tem))
5282 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
5284 /* Make sure there is a line number after the function entry setup code. */
5285 force_next_line_note ();
5288 /* Generate RTL for the end of the current function.
5289 FILENAME and LINE are the current position in the source file.
5291 It is up to language-specific callers to do cleanups for parameters--
5292 or else, supply 1 for END_BINDINGS and we will call expand_end_bindings. */
5295 expand_function_end (filename, line, end_bindings)
5303 static rtx initial_trampoline;
5305 if (output_bytecode)
5307 bc_expand_function_end ();
5311 #ifdef NON_SAVING_SETJMP
5312 /* Don't put any variables in registers if we call setjmp
5313 on a machine that fails to restore the registers. */
5314 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
5316 if (DECL_INITIAL (current_function_decl) != error_mark_node)
5317 setjmp_protect (DECL_INITIAL (current_function_decl));
5319 setjmp_protect_args ();
5323 /* Save the argument pointer if a save area was made for it. */
5324 if (arg_pointer_save_area)
5326 rtx x = gen_move_insn (arg_pointer_save_area, virtual_incoming_args_rtx);
5327 emit_insn_before (x, tail_recursion_reentry);
5330 /* Initialize any trampolines required by this function. */
5331 for (link = trampoline_list; link; link = TREE_CHAIN (link))
5333 tree function = TREE_PURPOSE (link);
5334 rtx context = lookup_static_chain (function);
5335 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
5338 /* First make sure this compilation has a template for
5339 initializing trampolines. */
5340 if (initial_trampoline == 0)
5342 end_temporary_allocation ();
5344 = gen_rtx (MEM, BLKmode, assemble_trampoline_template ());
5345 resume_temporary_allocation ();
5348 /* Generate insns to initialize the trampoline. */
5350 tramp = change_address (initial_trampoline, BLKmode,
5351 round_trampoline_addr (XEXP (tramp, 0)));
5352 emit_block_move (tramp, initial_trampoline, GEN_INT (TRAMPOLINE_SIZE),
5353 FUNCTION_BOUNDARY / BITS_PER_UNIT);
5354 INITIALIZE_TRAMPOLINE (XEXP (tramp, 0),
5355 XEXP (DECL_RTL (function), 0), context);
5359 /* Put those insns at entry to the containing function (this one). */
5360 emit_insns_before (seq, tail_recursion_reentry);
5363 /* Warn about unused parms if extra warnings were specified. */
5364 if (warn_unused && extra_warnings)
5368 for (decl = DECL_ARGUMENTS (current_function_decl);
5369 decl; decl = TREE_CHAIN (decl))
5370 if (! TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
5371 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
5372 warning_with_decl (decl, "unused parameter `%s'");
5375 /* Delete handlers for nonlocal gotos if nothing uses them. */
5376 if (nonlocal_goto_handler_slot != 0 && !current_function_has_nonlocal_label)
5379 /* End any sequences that failed to be closed due to syntax errors. */
5380 while (in_sequence_p ())
5383 /* Outside function body, can't compute type's actual size
5384 until next function's body starts. */
5385 immediate_size_expand--;
5387 /* If doing stupid register allocation,
5388 mark register parms as dying here. */
5393 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
5394 use_variable (regno_reg_rtx[i]);
5396 /* Likewise for the regs of all the SAVE_EXPRs in the function. */
5398 for (tem = save_expr_regs; tem; tem = XEXP (tem, 1))
5400 use_variable (XEXP (tem, 0));
5401 use_variable_after (XEXP (tem, 0), parm_birth_insn);
5404 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
5405 use_variable (current_function_internal_arg_pointer);
5408 clear_pending_stack_adjust ();
5409 do_pending_stack_adjust ();
5411 /* Mark the end of the function body.
5412 If control reaches this insn, the function can drop through
5413 without returning a value. */
5414 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_END);
5416 /* Output a linenumber for the end of the function.
5417 SDB depends on this. */
5418 emit_line_note_force (filename, line);
5420 /* Output the label for the actual return from the function,
5421 if one is expected. This happens either because a function epilogue
5422 is used instead of a return instruction, or because a return was done
5423 with a goto in order to run local cleanups, or because of pcc-style
5424 structure returning. */
5427 emit_label (return_label);
5429 /* C++ uses this. */
5431 expand_end_bindings (0, 0, 0);
5433 /* If we had calls to alloca, and this machine needs
5434 an accurate stack pointer to exit the function,
5435 insert some code to save and restore the stack pointer. */
5436 #ifdef EXIT_IGNORE_STACK
5437 if (! EXIT_IGNORE_STACK)
5439 if (current_function_calls_alloca)
5443 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
5444 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
5447 /* If scalar return value was computed in a pseudo-reg,
5448 copy that to the hard return register. */
5449 if (DECL_RTL (DECL_RESULT (current_function_decl)) != 0
5450 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG
5451 && (REGNO (DECL_RTL (DECL_RESULT (current_function_decl)))
5452 >= FIRST_PSEUDO_REGISTER))
5454 rtx real_decl_result;
5456 #ifdef FUNCTION_OUTGOING_VALUE
5458 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
5459 current_function_decl);
5462 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
5463 current_function_decl);
5465 REG_FUNCTION_VALUE_P (real_decl_result) = 1;
5466 emit_move_insn (real_decl_result,
5467 DECL_RTL (DECL_RESULT (current_function_decl)));
5468 emit_insn (gen_rtx (USE, VOIDmode, real_decl_result));
5471 /* If returning a structure, arrange to return the address of the value
5472 in a place where debuggers expect to find it.
5474 If returning a structure PCC style,
5475 the caller also depends on this value.
5476 And current_function_returns_pcc_struct is not necessarily set. */
5477 if (current_function_returns_struct
5478 || current_function_returns_pcc_struct)
5480 rtx value_address = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
5481 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5482 #ifdef FUNCTION_OUTGOING_VALUE
5484 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
5485 current_function_decl);
5488 = FUNCTION_VALUE (build_pointer_type (type),
5489 current_function_decl);
5492 /* Mark this as a function return value so integrate will delete the
5493 assignment and USE below when inlining this function. */
5494 REG_FUNCTION_VALUE_P (outgoing) = 1;
5496 emit_move_insn (outgoing, value_address);
5497 use_variable (outgoing);
5500 /* Output a return insn if we are using one.
5501 Otherwise, let the rtl chain end here, to drop through
5502 into the epilogue. */
5507 emit_jump_insn (gen_return ());
5512 /* Fix up any gotos that jumped out to the outermost
5513 binding level of the function.
5514 Must follow emitting RETURN_LABEL. */
5516 /* If you have any cleanups to do at this point,
5517 and they need to create temporary variables,
5518 then you will lose. */
5519 expand_fixups (get_insns ());
5522 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
5524 static int *prologue;
5525 static int *epilogue;
5527 /* Create an array that records the INSN_UIDs of INSNS (either a sequence
5528 or a single insn). */
5531 record_insns (insns)
5536 if (GET_CODE (insns) == SEQUENCE)
5538 int len = XVECLEN (insns, 0);
5539 vec = (int *) oballoc ((len + 1) * sizeof (int));
5542 vec[len] = INSN_UID (XVECEXP (insns, 0, len));
5546 vec = (int *) oballoc (2 * sizeof (int));
5547 vec[0] = INSN_UID (insns);
5553 /* Determine how many INSN_UIDs in VEC are part of INSN. */
5556 contains (insn, vec)
5562 if (GET_CODE (insn) == INSN
5563 && GET_CODE (PATTERN (insn)) == SEQUENCE)
5566 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
5567 for (j = 0; vec[j]; j++)
5568 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == vec[j])
5574 for (j = 0; vec[j]; j++)
5575 if (INSN_UID (insn) == vec[j])
5581 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5582 this into place with notes indicating where the prologue ends and where
5583 the epilogue begins. Update the basic block information when possible. */
5586 thread_prologue_and_epilogue_insns (f)
5589 #ifdef HAVE_prologue
5592 rtx head, seq, insn;
5594 /* The first insn (a NOTE_INSN_DELETED) is followed by zero or more
5595 prologue insns and a NOTE_INSN_PROLOGUE_END. */
5596 emit_note_after (NOTE_INSN_PROLOGUE_END, f);
5597 seq = gen_prologue ();
5598 head = emit_insn_after (seq, f);
5600 /* Include the new prologue insns in the first block. Ignore them
5601 if they form a basic block unto themselves. */
5602 if (basic_block_head && n_basic_blocks
5603 && GET_CODE (basic_block_head[0]) != CODE_LABEL)
5604 basic_block_head[0] = NEXT_INSN (f);
5606 /* Retain a map of the prologue insns. */
5607 prologue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : head);
5613 #ifdef HAVE_epilogue
5616 rtx insn = get_last_insn ();
5617 rtx prev = prev_nonnote_insn (insn);
5619 /* If we end with a BARRIER, we don't need an epilogue. */
5620 if (! (prev && GET_CODE (prev) == BARRIER))
5626 /* The last basic block ends with a NOTE_INSN_EPILOGUE_BEG, the
5627 epilogue insns, the USE insns at the end of a function,
5628 the jump insn that returns, and then a BARRIER. */
5630 /* Move the USE insns at the end of a function onto a list. */
5632 && GET_CODE (prev) == INSN
5633 && GET_CODE (PATTERN (prev)) == USE)
5636 prev = prev_nonnote_insn (prev);
5638 NEXT_INSN (PREV_INSN (tem)) = NEXT_INSN (tem);
5639 PREV_INSN (NEXT_INSN (tem)) = PREV_INSN (tem);
5642 NEXT_INSN (tem) = first_use;
5643 PREV_INSN (first_use) = tem;
5650 emit_barrier_after (insn);
5652 seq = gen_epilogue ();
5653 tail = emit_jump_insn_after (seq, insn);
5655 /* Insert the USE insns immediately before the return insn, which
5656 must be the first instruction before the final barrier. */
5659 tem = prev_nonnote_insn (get_last_insn ());
5660 NEXT_INSN (PREV_INSN (tem)) = first_use;
5661 PREV_INSN (first_use) = PREV_INSN (tem);
5662 PREV_INSN (tem) = last_use;
5663 NEXT_INSN (last_use) = tem;
5666 emit_note_after (NOTE_INSN_EPILOGUE_BEG, insn);
5668 /* Include the new epilogue insns in the last block. Ignore
5669 them if they form a basic block unto themselves. */
5670 if (basic_block_end && n_basic_blocks
5671 && GET_CODE (basic_block_end[n_basic_blocks - 1]) != JUMP_INSN)
5672 basic_block_end[n_basic_blocks - 1] = tail;
5674 /* Retain a map of the epilogue insns. */
5675 epilogue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : tail);
5683 /* Reposition the prologue-end and epilogue-begin notes after instruction
5684 scheduling and delayed branch scheduling. */
5687 reposition_prologue_and_epilogue_notes (f)
5690 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5691 /* Reposition the prologue and epilogue notes. */
5699 register rtx insn, note = 0;
5701 /* Scan from the beginning until we reach the last prologue insn.
5702 We apparently can't depend on basic_block_{head,end} after
5704 for (len = 0; prologue[len]; len++)
5706 for (insn = f; len && insn; insn = NEXT_INSN (insn))
5708 if (GET_CODE (insn) == NOTE)
5710 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
5713 else if ((len -= contains (insn, prologue)) == 0)
5715 /* Find the prologue-end note if we haven't already, and
5716 move it to just after the last prologue insn. */
5719 for (note = insn; note = NEXT_INSN (note);)
5720 if (GET_CODE (note) == NOTE
5721 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
5724 next = NEXT_INSN (note);
5725 prev = PREV_INSN (note);
5727 NEXT_INSN (prev) = next;
5729 PREV_INSN (next) = prev;
5730 add_insn_after (note, insn);
5737 register rtx insn, note = 0;
5739 /* Scan from the end until we reach the first epilogue insn.
5740 We apparently can't depend on basic_block_{head,end} after
5742 for (len = 0; epilogue[len]; len++)
5744 for (insn = get_last_insn (); len && insn; insn = PREV_INSN (insn))
5746 if (GET_CODE (insn) == NOTE)
5748 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
5751 else if ((len -= contains (insn, epilogue)) == 0)
5753 /* Find the epilogue-begin note if we haven't already, and
5754 move it to just before the first epilogue insn. */
5757 for (note = insn; note = PREV_INSN (note);)
5758 if (GET_CODE (note) == NOTE
5759 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
5762 next = NEXT_INSN (note);
5763 prev = PREV_INSN (note);
5765 NEXT_INSN (prev) = next;
5767 PREV_INSN (next) = prev;
5768 add_insn_after (note, PREV_INSN (insn));
5773 #endif /* HAVE_prologue or HAVE_epilogue */