1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 88, 89, 91-96, 1997 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. */
48 #include "insn-flags.h"
50 #include "insn-codes.h"
52 #include "hard-reg-set.h"
53 #include "insn-config.h"
56 #include "basic-block.h"
61 #ifndef TRAMPOLINE_ALIGNMENT
62 #define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
65 /* Some systems use __main in a way incompatible with its use in gcc, in these
66 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
67 give the same symbol without quotes for an alternative entry point. You
68 must define both, or neither. */
70 #define NAME__MAIN "__main"
71 #define SYMBOL__MAIN __main
74 /* Round a value to the lowest integer less than it that is a multiple of
75 the required alignment. Avoid using division in case the value is
76 negative. Assume the alignment is a power of two. */
77 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
79 /* Similar, but round to the next highest integer that meets the
81 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
83 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
84 during rtl generation. If they are different register numbers, this is
85 always true. It may also be true if
86 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
87 generation. See fix_lexical_addr for details. */
89 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
90 #define NEED_SEPARATE_AP
93 /* Number of bytes of args popped by function being compiled on its return.
94 Zero if no bytes are to be popped.
95 May affect compilation of return insn or of function epilogue. */
97 int current_function_pops_args;
99 /* Nonzero if function being compiled needs to be given an address
100 where the value should be stored. */
102 int current_function_returns_struct;
104 /* Nonzero if function being compiled needs to
105 return the address of where it has put a structure value. */
107 int current_function_returns_pcc_struct;
109 /* Nonzero if function being compiled needs to be passed a static chain. */
111 int current_function_needs_context;
113 /* Nonzero if function being compiled can call setjmp. */
115 int current_function_calls_setjmp;
117 /* Nonzero if function being compiled can call longjmp. */
119 int current_function_calls_longjmp;
121 /* Nonzero if function being compiled receives nonlocal gotos
122 from nested functions. */
124 int current_function_has_nonlocal_label;
126 /* Nonzero if function being compiled has nonlocal gotos to parent
129 int current_function_has_nonlocal_goto;
131 /* Nonzero if function being compiled contains nested functions. */
133 int current_function_contains_functions;
135 /* Nonzero if function being compiled can call alloca,
136 either as a subroutine or builtin. */
138 int current_function_calls_alloca;
140 /* Nonzero if the current function returns a pointer type */
142 int current_function_returns_pointer;
144 /* If some insns can be deferred to the delay slots of the epilogue, the
145 delay list for them is recorded here. */
147 rtx current_function_epilogue_delay_list;
149 /* If function's args have a fixed size, this is that size, in bytes.
151 May affect compilation of return insn or of function epilogue. */
153 int current_function_args_size;
155 /* # bytes the prologue should push and pretend that the caller pushed them.
156 The prologue must do this, but only if parms can be passed in registers. */
158 int current_function_pretend_args_size;
160 /* # of bytes of outgoing arguments. If ACCUMULATE_OUTGOING_ARGS is
161 defined, the needed space is pushed by the prologue. */
163 int current_function_outgoing_args_size;
165 /* This is the offset from the arg pointer to the place where the first
166 anonymous arg can be found, if there is one. */
168 rtx current_function_arg_offset_rtx;
170 /* Nonzero if current function uses varargs.h or equivalent.
171 Zero for functions that use stdarg.h. */
173 int current_function_varargs;
175 /* Nonzero if current function uses stdarg.h or equivalent.
176 Zero for functions that use varargs.h. */
178 int current_function_stdarg;
180 /* Quantities of various kinds of registers
181 used for the current function's args. */
183 CUMULATIVE_ARGS current_function_args_info;
185 /* Name of function now being compiled. */
187 char *current_function_name;
189 /* If non-zero, an RTL expression for that location at which the current
190 function returns its result. Always equal to
191 DECL_RTL (DECL_RESULT (current_function_decl)), but provided
192 independently of the tree structures. */
194 rtx current_function_return_rtx;
196 /* Nonzero if the current function uses the constant pool. */
198 int current_function_uses_const_pool;
200 /* Nonzero if the current function uses pic_offset_table_rtx. */
201 int current_function_uses_pic_offset_table;
203 /* The arg pointer hard register, or the pseudo into which it was copied. */
204 rtx current_function_internal_arg_pointer;
206 /* The FUNCTION_DECL for an inline function currently being expanded. */
207 tree inline_function_decl;
209 /* Number of function calls seen so far in current function. */
211 int function_call_count;
213 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
214 (labels to which there can be nonlocal gotos from nested functions)
217 tree nonlocal_labels;
219 /* RTX for stack slot that holds the current handler for nonlocal gotos.
220 Zero when function does not have nonlocal labels. */
222 rtx nonlocal_goto_handler_slot;
224 /* RTX for stack slot that holds the stack pointer value to restore
226 Zero when function does not have nonlocal labels. */
228 rtx nonlocal_goto_stack_level;
230 /* Label that will go on parm cleanup code, if any.
231 Jumping to this label runs cleanup code for parameters, if
232 such code must be run. Following this code is the logical return label. */
236 /* Label that will go on function epilogue.
237 Jumping to this label serves as a "return" instruction
238 on machines which require execution of the epilogue on all returns. */
242 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
243 So we can mark them all live at the end of the function, if nonopt. */
246 /* List (chain of EXPR_LISTs) of all stack slots in this function.
247 Made for the sake of unshare_all_rtl. */
250 /* Chain of all RTL_EXPRs that have insns in them. */
253 /* Label to jump back to for tail recursion, or 0 if we have
254 not yet needed one for this function. */
255 rtx tail_recursion_label;
257 /* Place after which to insert the tail_recursion_label if we need one. */
258 rtx tail_recursion_reentry;
260 /* Location at which to save the argument pointer if it will need to be
261 referenced. There are two cases where this is done: if nonlocal gotos
262 exist, or if vars stored at an offset from the argument pointer will be
263 needed by inner routines. */
265 rtx arg_pointer_save_area;
267 /* Offset to end of allocated area of stack frame.
268 If stack grows down, this is the address of the last stack slot allocated.
269 If stack grows up, this is the address for the next slot. */
270 HOST_WIDE_INT frame_offset;
272 /* List (chain of TREE_LISTs) of static chains for containing functions.
273 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
274 in an RTL_EXPR in the TREE_VALUE. */
275 static tree context_display;
277 /* List (chain of TREE_LISTs) of trampolines for nested functions.
278 The trampoline sets up the static chain and jumps to the function.
279 We supply the trampoline's address when the function's address is requested.
281 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
282 in an RTL_EXPR in the TREE_VALUE. */
283 static tree trampoline_list;
285 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
286 static rtx parm_birth_insn;
289 /* Nonzero if a stack slot has been generated whose address is not
290 actually valid. It means that the generated rtl must all be scanned
291 to detect and correct the invalid addresses where they occur. */
292 static int invalid_stack_slot;
295 /* Last insn of those whose job was to put parms into their nominal homes. */
296 static rtx last_parm_insn;
298 /* 1 + last pseudo register number used for loading a copy
299 of a parameter of this function. */
300 static int max_parm_reg;
302 /* Vector indexed by REGNO, containing location on stack in which
303 to put the parm which is nominally in pseudo register REGNO,
304 if we discover that that parm must go in the stack. */
305 static rtx *parm_reg_stack_loc;
307 /* Nonzero once virtual register instantiation has been done.
308 assign_stack_local uses frame_pointer_rtx when this is nonzero. */
309 static int virtuals_instantiated;
311 /* These variables hold pointers to functions to
312 save and restore machine-specific data,
313 in push_function_context and pop_function_context. */
314 void (*save_machine_status) PROTO((struct function *));
315 void (*restore_machine_status) PROTO((struct function *));
317 /* Nonzero if we need to distinguish between the return value of this function
318 and the return value of a function called by this function. This helps
321 extern int rtx_equal_function_value_matters;
322 extern tree sequence_rtl_expr;
324 /* In order to evaluate some expressions, such as function calls returning
325 structures in memory, we need to temporarily allocate stack locations.
326 We record each allocated temporary in the following structure.
328 Associated with each temporary slot is a nesting level. When we pop up
329 one level, all temporaries associated with the previous level are freed.
330 Normally, all temporaries are freed after the execution of the statement
331 in which they were created. However, if we are inside a ({...}) grouping,
332 the result may be in a temporary and hence must be preserved. If the
333 result could be in a temporary, we preserve it if we can determine which
334 one it is in. If we cannot determine which temporary may contain the
335 result, all temporaries are preserved. A temporary is preserved by
336 pretending it was allocated at the previous nesting level.
338 Automatic variables are also assigned temporary slots, at the nesting
339 level where they are defined. They are marked a "kept" so that
340 free_temp_slots will not free them. */
344 /* Points to next temporary slot. */
345 struct temp_slot *next;
346 /* The rtx to used to reference the slot. */
348 /* The rtx used to represent the address if not the address of the
349 slot above. May be an EXPR_LIST if multiple addresses exist. */
351 /* The size, in units, of the slot. */
353 /* The value of `sequence_rtl_expr' when this temporary is allocated. */
355 /* Non-zero if this temporary is currently in use. */
357 /* Non-zero if this temporary has its address taken. */
359 /* Nesting level at which this slot is being used. */
361 /* Non-zero if this should survive a call to free_temp_slots. */
363 /* The offset of the slot from the frame_pointer, including extra space
364 for alignment. This info is for combine_temp_slots. */
366 /* The size of the slot, including extra space for alignment. This
367 info is for combine_temp_slots. */
371 /* List of all temporaries allocated, both available and in use. */
373 struct temp_slot *temp_slots;
375 /* Current nesting level for temporaries. */
379 /* The FUNCTION_DECL node for the current function. */
380 static tree this_function_decl;
382 /* Callinfo pointer for the current function. */
383 static rtx this_function_callinfo;
385 /* The label in the bytecode file of this function's actual bytecode.
387 static char *this_function_bytecode;
389 /* The call description vector for the current function. */
390 static rtx this_function_calldesc;
392 /* Size of the local variables allocated for the current function. */
395 /* Current depth of the bytecode evaluation stack. */
398 /* Maximum depth of the evaluation stack in this function. */
401 /* Current depth in statement expressions. */
402 static int stmt_expr_depth;
404 /* This structure is used to record MEMs or pseudos used to replace VAR, any
405 SUBREGs of VAR, and any MEMs containing VAR as an address. We need to
406 maintain this list in case two operands of an insn were required to match;
407 in that case we must ensure we use the same replacement. */
409 struct fixup_replacement
413 struct fixup_replacement *next;
416 /* Forward declarations. */
418 static struct temp_slot *find_temp_slot_from_address PROTO((rtx));
419 static void put_reg_into_stack PROTO((struct function *, rtx, tree,
420 enum machine_mode, enum machine_mode,
422 static void fixup_var_refs PROTO((rtx, enum machine_mode, int));
423 static struct fixup_replacement
424 *find_fixup_replacement PROTO((struct fixup_replacement **, rtx));
425 static void fixup_var_refs_insns PROTO((rtx, enum machine_mode, int,
427 static void fixup_var_refs_1 PROTO((rtx, enum machine_mode, rtx *, rtx,
428 struct fixup_replacement **));
429 static rtx fixup_memory_subreg PROTO((rtx, rtx, int));
430 static rtx walk_fixup_memory_subreg PROTO((rtx, rtx, int));
431 static rtx fixup_stack_1 PROTO((rtx, rtx));
432 static void optimize_bit_field PROTO((rtx, rtx, rtx *));
433 static void instantiate_decls PROTO((tree, int));
434 static void instantiate_decls_1 PROTO((tree, int));
435 static void instantiate_decl PROTO((rtx, int, int));
436 static int instantiate_virtual_regs_1 PROTO((rtx *, rtx, int));
437 static void delete_handlers PROTO((void));
438 static void pad_to_arg_alignment PROTO((struct args_size *, int));
439 static void pad_below PROTO((struct args_size *, enum machine_mode,
441 static tree round_down PROTO((tree, int));
442 static rtx round_trampoline_addr PROTO((rtx));
443 static tree blocks_nreverse PROTO((tree));
444 static int all_blocks PROTO((tree, tree *));
445 static int *record_insns PROTO((rtx));
446 static int contains PROTO((rtx, int *));
448 /* Pointer to chain of `struct function' for containing functions. */
449 struct function *outer_function_chain;
451 /* Given a function decl for a containing function,
452 return the `struct function' for it. */
455 find_function_data (decl)
459 for (p = outer_function_chain; p; p = p->next)
465 /* Save the current context for compilation of a nested function.
466 This is called from language-specific code.
467 The caller is responsible for saving any language-specific status,
468 since this function knows only about language-independent variables. */
471 push_function_context_to (context)
474 struct function *p = (struct function *) xmalloc (sizeof (struct function));
476 p->next = outer_function_chain;
477 outer_function_chain = p;
479 p->name = current_function_name;
480 p->decl = current_function_decl;
481 p->pops_args = current_function_pops_args;
482 p->returns_struct = current_function_returns_struct;
483 p->returns_pcc_struct = current_function_returns_pcc_struct;
484 p->returns_pointer = current_function_returns_pointer;
485 p->needs_context = current_function_needs_context;
486 p->calls_setjmp = current_function_calls_setjmp;
487 p->calls_longjmp = current_function_calls_longjmp;
488 p->calls_alloca = current_function_calls_alloca;
489 p->has_nonlocal_label = current_function_has_nonlocal_label;
490 p->has_nonlocal_goto = current_function_has_nonlocal_goto;
491 p->contains_functions = current_function_contains_functions;
492 p->args_size = current_function_args_size;
493 p->pretend_args_size = current_function_pretend_args_size;
494 p->arg_offset_rtx = current_function_arg_offset_rtx;
495 p->varargs = current_function_varargs;
496 p->stdarg = current_function_stdarg;
497 p->uses_const_pool = current_function_uses_const_pool;
498 p->uses_pic_offset_table = current_function_uses_pic_offset_table;
499 p->internal_arg_pointer = current_function_internal_arg_pointer;
500 p->max_parm_reg = max_parm_reg;
501 p->parm_reg_stack_loc = parm_reg_stack_loc;
502 p->outgoing_args_size = current_function_outgoing_args_size;
503 p->return_rtx = current_function_return_rtx;
504 p->nonlocal_goto_handler_slot = nonlocal_goto_handler_slot;
505 p->nonlocal_goto_stack_level = nonlocal_goto_stack_level;
506 p->nonlocal_labels = nonlocal_labels;
507 p->cleanup_label = cleanup_label;
508 p->return_label = return_label;
509 p->save_expr_regs = save_expr_regs;
510 p->stack_slot_list = stack_slot_list;
511 p->parm_birth_insn = parm_birth_insn;
512 p->frame_offset = frame_offset;
513 p->tail_recursion_label = tail_recursion_label;
514 p->tail_recursion_reentry = tail_recursion_reentry;
515 p->arg_pointer_save_area = arg_pointer_save_area;
516 p->rtl_expr_chain = rtl_expr_chain;
517 p->last_parm_insn = last_parm_insn;
518 p->context_display = context_display;
519 p->trampoline_list = trampoline_list;
520 p->function_call_count = function_call_count;
521 p->temp_slots = temp_slots;
522 p->temp_slot_level = temp_slot_level;
523 p->fixup_var_refs_queue = 0;
524 p->epilogue_delay_list = current_function_epilogue_delay_list;
525 p->args_info = current_function_args_info;
527 save_tree_status (p, context);
528 save_storage_status (p);
529 save_emit_status (p);
531 save_expr_status (p);
532 save_stmt_status (p);
533 save_varasm_status (p);
535 if (save_machine_status)
536 (*save_machine_status) (p);
540 push_function_context ()
542 push_function_context_to (current_function_decl);
545 /* Restore the last saved context, at the end of a nested function.
546 This function is called from language-specific code. */
549 pop_function_context_from (context)
552 struct function *p = outer_function_chain;
554 outer_function_chain = p->next;
556 current_function_contains_functions
557 = p->contains_functions || p->inline_obstacks
558 || context == current_function_decl;
559 current_function_name = p->name;
560 current_function_decl = p->decl;
561 current_function_pops_args = p->pops_args;
562 current_function_returns_struct = p->returns_struct;
563 current_function_returns_pcc_struct = p->returns_pcc_struct;
564 current_function_returns_pointer = p->returns_pointer;
565 current_function_needs_context = p->needs_context;
566 current_function_calls_setjmp = p->calls_setjmp;
567 current_function_calls_longjmp = p->calls_longjmp;
568 current_function_calls_alloca = p->calls_alloca;
569 current_function_has_nonlocal_label = p->has_nonlocal_label;
570 current_function_has_nonlocal_goto = p->has_nonlocal_goto;
571 current_function_args_size = p->args_size;
572 current_function_pretend_args_size = p->pretend_args_size;
573 current_function_arg_offset_rtx = p->arg_offset_rtx;
574 current_function_varargs = p->varargs;
575 current_function_stdarg = p->stdarg;
576 current_function_uses_const_pool = p->uses_const_pool;
577 current_function_uses_pic_offset_table = p->uses_pic_offset_table;
578 current_function_internal_arg_pointer = p->internal_arg_pointer;
579 max_parm_reg = p->max_parm_reg;
580 parm_reg_stack_loc = p->parm_reg_stack_loc;
581 current_function_outgoing_args_size = p->outgoing_args_size;
582 current_function_return_rtx = p->return_rtx;
583 nonlocal_goto_handler_slot = p->nonlocal_goto_handler_slot;
584 nonlocal_goto_stack_level = p->nonlocal_goto_stack_level;
585 nonlocal_labels = p->nonlocal_labels;
586 cleanup_label = p->cleanup_label;
587 return_label = p->return_label;
588 save_expr_regs = p->save_expr_regs;
589 stack_slot_list = p->stack_slot_list;
590 parm_birth_insn = p->parm_birth_insn;
591 frame_offset = p->frame_offset;
592 tail_recursion_label = p->tail_recursion_label;
593 tail_recursion_reentry = p->tail_recursion_reentry;
594 arg_pointer_save_area = p->arg_pointer_save_area;
595 rtl_expr_chain = p->rtl_expr_chain;
596 last_parm_insn = p->last_parm_insn;
597 context_display = p->context_display;
598 trampoline_list = p->trampoline_list;
599 function_call_count = p->function_call_count;
600 temp_slots = p->temp_slots;
601 temp_slot_level = p->temp_slot_level;
602 current_function_epilogue_delay_list = p->epilogue_delay_list;
604 current_function_args_info = p->args_info;
606 restore_tree_status (p);
607 restore_storage_status (p);
608 restore_expr_status (p);
609 restore_emit_status (p);
610 restore_stmt_status (p);
611 restore_varasm_status (p);
613 if (restore_machine_status)
614 (*restore_machine_status) (p);
616 /* Finish doing put_var_into_stack for any of our variables
617 which became addressable during the nested function. */
619 struct var_refs_queue *queue = p->fixup_var_refs_queue;
620 for (; queue; queue = queue->next)
621 fixup_var_refs (queue->modified, queue->promoted_mode, queue->unsignedp);
626 /* Reset variables that have known state during rtx generation. */
627 rtx_equal_function_value_matters = 1;
628 virtuals_instantiated = 0;
631 void pop_function_context ()
633 pop_function_context_from (current_function_decl);
636 /* Allocate fixed slots in the stack frame of the current function. */
638 /* Return size needed for stack frame based on slots so far allocated.
639 This size counts from zero. It is not rounded to STACK_BOUNDARY;
640 the caller may have to do that. */
645 #ifdef FRAME_GROWS_DOWNWARD
646 return -frame_offset;
652 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
653 with machine mode MODE.
655 ALIGN controls the amount of alignment for the address of the slot:
656 0 means according to MODE,
657 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
658 positive specifies alignment boundary in bits.
660 We do not round to stack_boundary here. */
663 assign_stack_local (mode, size, align)
664 enum machine_mode mode;
668 register rtx x, addr;
669 int bigend_correction = 0;
674 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
676 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
678 else if (align == -1)
680 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
681 size = CEIL_ROUND (size, alignment);
684 alignment = align / BITS_PER_UNIT;
686 /* Round frame offset to that alignment.
687 We must be careful here, since FRAME_OFFSET might be negative and
688 division with a negative dividend isn't as well defined as we might
689 like. So we instead assume that ALIGNMENT is a power of two and
690 use logical operations which are unambiguous. */
691 #ifdef FRAME_GROWS_DOWNWARD
692 frame_offset = FLOOR_ROUND (frame_offset, alignment);
694 frame_offset = CEIL_ROUND (frame_offset, alignment);
697 /* On a big-endian machine, if we are allocating more space than we will use,
698 use the least significant bytes of those that are allocated. */
699 if (BYTES_BIG_ENDIAN && mode != BLKmode)
700 bigend_correction = size - GET_MODE_SIZE (mode);
702 #ifdef FRAME_GROWS_DOWNWARD
703 frame_offset -= size;
706 /* If we have already instantiated virtual registers, return the actual
707 address relative to the frame pointer. */
708 if (virtuals_instantiated)
709 addr = plus_constant (frame_pointer_rtx,
710 (frame_offset + bigend_correction
711 + STARTING_FRAME_OFFSET));
713 addr = plus_constant (virtual_stack_vars_rtx,
714 frame_offset + bigend_correction);
716 #ifndef FRAME_GROWS_DOWNWARD
717 frame_offset += size;
720 x = gen_rtx (MEM, mode, addr);
722 stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, x, stack_slot_list);
727 /* Assign a stack slot in a containing function.
728 First three arguments are same as in preceding function.
729 The last argument specifies the function to allocate in. */
732 assign_outer_stack_local (mode, size, align, function)
733 enum machine_mode mode;
736 struct function *function;
738 register rtx x, addr;
739 int bigend_correction = 0;
742 /* Allocate in the memory associated with the function in whose frame
744 push_obstacks (function->function_obstack,
745 function->function_maybepermanent_obstack);
749 alignment = GET_MODE_ALIGNMENT (mode) / BITS_PER_UNIT;
751 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
753 else if (align == -1)
755 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
756 size = CEIL_ROUND (size, alignment);
759 alignment = align / BITS_PER_UNIT;
761 /* Round frame offset to that alignment. */
762 #ifdef FRAME_GROWS_DOWNWARD
763 function->frame_offset = FLOOR_ROUND (function->frame_offset, alignment);
765 function->frame_offset = CEIL_ROUND (function->frame_offset, alignment);
768 /* On a big-endian machine, if we are allocating more space than we will use,
769 use the least significant bytes of those that are allocated. */
770 if (BYTES_BIG_ENDIAN && mode != BLKmode)
771 bigend_correction = size - GET_MODE_SIZE (mode);
773 #ifdef FRAME_GROWS_DOWNWARD
774 function->frame_offset -= size;
776 addr = plus_constant (virtual_stack_vars_rtx,
777 function->frame_offset + bigend_correction);
778 #ifndef FRAME_GROWS_DOWNWARD
779 function->frame_offset += size;
782 x = gen_rtx (MEM, mode, addr);
784 function->stack_slot_list
785 = gen_rtx (EXPR_LIST, VOIDmode, x, function->stack_slot_list);
792 /* Allocate a temporary stack slot and record it for possible later
795 MODE is the machine mode to be given to the returned rtx.
797 SIZE is the size in units of the space required. We do no rounding here
798 since assign_stack_local will do any required rounding.
800 KEEP is 1 if this slot is to be retained after a call to
801 free_temp_slots. Automatic variables for a block are allocated
802 with this flag. KEEP is 2, if we allocate a longer term temporary,
803 whose lifetime is controlled by CLEANUP_POINT_EXPRs. */
806 assign_stack_temp (mode, size, keep)
807 enum machine_mode mode;
811 struct temp_slot *p, *best_p = 0;
813 /* If SIZE is -1 it means that somebody tried to allocate a temporary
814 of a variable size. */
818 /* First try to find an available, already-allocated temporary that is the
819 exact size we require. */
820 for (p = temp_slots; p; p = p->next)
821 if (p->size == size && GET_MODE (p->slot) == mode && ! p->in_use)
824 /* If we didn't find, one, try one that is larger than what we want. We
825 find the smallest such. */
827 for (p = temp_slots; p; p = p->next)
828 if (p->size > size && GET_MODE (p->slot) == mode && ! p->in_use
829 && (best_p == 0 || best_p->size > p->size))
832 /* Make our best, if any, the one to use. */
835 /* If there are enough aligned bytes left over, make them into a new
836 temp_slot so that the extra bytes don't get wasted. Do this only
837 for BLKmode slots, so that we can be sure of the alignment. */
838 if (GET_MODE (best_p->slot) == BLKmode)
840 int alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
841 int rounded_size = CEIL_ROUND (size, alignment);
843 if (best_p->size - rounded_size >= alignment)
845 p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
846 p->in_use = p->addr_taken = 0;
847 p->size = best_p->size - rounded_size;
848 p->base_offset = best_p->base_offset + rounded_size;
849 p->full_size = best_p->full_size - rounded_size;
850 p->slot = gen_rtx (MEM, BLKmode,
851 plus_constant (XEXP (best_p->slot, 0),
855 p->next = temp_slots;
858 stack_slot_list = gen_rtx (EXPR_LIST, VOIDmode, p->slot,
861 best_p->size = rounded_size;
862 best_p->full_size = rounded_size;
869 /* If we still didn't find one, make a new temporary. */
872 int frame_offset_old = frame_offset;
873 p = (struct temp_slot *) oballoc (sizeof (struct temp_slot));
874 /* If the temp slot mode doesn't indicate the alignment,
875 use the largest possible, so no one will be disappointed. */
876 p->slot = assign_stack_local (mode, size, mode == BLKmode ? -1 : 0);
877 /* The following slot size computation is necessary because we don't
878 know the actual size of the temporary slot until assign_stack_local
879 has performed all the frame alignment and size rounding for the
880 requested temporary. Note that extra space added for alignment
881 can be either above or below this stack slot depending on which
882 way the frame grows. We include the extra space if and only if it
883 is above this slot. */
884 #ifdef FRAME_GROWS_DOWNWARD
885 p->size = frame_offset_old - frame_offset;
889 /* Now define the fields used by combine_temp_slots. */
890 #ifdef FRAME_GROWS_DOWNWARD
891 p->base_offset = frame_offset;
892 p->full_size = frame_offset_old - frame_offset;
894 p->base_offset = frame_offset_old;
895 p->full_size = frame_offset - frame_offset_old;
898 p->next = temp_slots;
904 p->rtl_expr = sequence_rtl_expr;
908 p->level = target_temp_slot_level;
913 p->level = temp_slot_level;
919 /* Assign a temporary of given TYPE.
920 KEEP is as for assign_stack_temp.
921 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
922 it is 0 if a register is OK.
923 DONT_PROMOTE is 1 if we should not promote values in register
927 assign_temp (type, keep, memory_required, dont_promote)
933 enum machine_mode mode = TYPE_MODE (type);
934 int unsignedp = TREE_UNSIGNED (type);
936 if (mode == BLKmode || memory_required)
938 int size = int_size_in_bytes (type);
941 /* Unfortunately, we don't yet know how to allocate variable-sized
942 temporaries. However, sometimes we have a fixed upper limit on
943 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
944 instead. This is the case for Chill variable-sized strings. */
945 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
946 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
947 && TREE_CODE (TYPE_ARRAY_MAX_SIZE (type)) == INTEGER_CST)
948 size = TREE_INT_CST_LOW (TYPE_ARRAY_MAX_SIZE (type));
950 tmp = assign_stack_temp (mode, size, keep);
951 MEM_IN_STRUCT_P (tmp) = AGGREGATE_TYPE_P (type);
955 #ifndef PROMOTE_FOR_CALL_ONLY
957 mode = promote_mode (type, mode, &unsignedp, 0);
960 return gen_reg_rtx (mode);
963 /* Combine temporary stack slots which are adjacent on the stack.
965 This allows for better use of already allocated stack space. This is only
966 done for BLKmode slots because we can be sure that we won't have alignment
967 problems in this case. */
970 combine_temp_slots ()
972 struct temp_slot *p, *q;
973 struct temp_slot *prev_p, *prev_q;
974 /* Determine where to free back to after this function. */
975 rtx free_pointer = rtx_alloc (CONST_INT);
977 for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
980 if (! p->in_use && GET_MODE (p->slot) == BLKmode)
981 for (q = p->next, prev_q = p; q; q = prev_q->next)
984 if (! q->in_use && GET_MODE (q->slot) == BLKmode)
986 if (p->base_offset + p->full_size == q->base_offset)
988 /* Q comes after P; combine Q into P. */
990 p->full_size += q->full_size;
993 else if (q->base_offset + q->full_size == p->base_offset)
995 /* P comes after Q; combine P into Q. */
997 q->full_size += p->full_size;
1002 /* Either delete Q or advance past it. */
1004 prev_q->next = q->next;
1008 /* Either delete P or advance past it. */
1012 prev_p->next = p->next;
1014 temp_slots = p->next;
1020 /* Free all the RTL made by plus_constant. */
1021 rtx_free (free_pointer);
1024 /* Find the temp slot corresponding to the object at address X. */
1026 static struct temp_slot *
1027 find_temp_slot_from_address (x)
1030 struct temp_slot *p;
1033 for (p = temp_slots; p; p = p->next)
1037 else if (XEXP (p->slot, 0) == x
1039 || (GET_CODE (x) == PLUS
1040 && XEXP (x, 0) == virtual_stack_vars_rtx
1041 && GET_CODE (XEXP (x, 1)) == CONST_INT
1042 && INTVAL (XEXP (x, 1)) >= p->base_offset
1043 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
1046 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
1047 for (next = p->address; next; next = XEXP (next, 1))
1048 if (XEXP (next, 0) == x)
1055 /* Indicate that NEW is an alternate way of referring to the temp slot
1056 that previous was known by OLD. */
1059 update_temp_slot_address (old, new)
1062 struct temp_slot *p = find_temp_slot_from_address (old);
1064 /* If none, return. Else add NEW as an alias. */
1067 else if (p->address == 0)
1071 if (GET_CODE (p->address) != EXPR_LIST)
1072 p->address = gen_rtx (EXPR_LIST, VOIDmode, p->address, NULL_RTX);
1074 p->address = gen_rtx (EXPR_LIST, VOIDmode, new, p->address);
1078 /* If X could be a reference to a temporary slot, mark the fact that its
1079 address was taken. */
1082 mark_temp_addr_taken (x)
1085 struct temp_slot *p;
1090 /* If X is not in memory or is at a constant address, it cannot be in
1091 a temporary slot. */
1092 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1095 p = find_temp_slot_from_address (XEXP (x, 0));
1100 /* If X could be a reference to a temporary slot, mark that slot as
1101 belonging to the to one level higher than the current level. If X
1102 matched one of our slots, just mark that one. Otherwise, we can't
1103 easily predict which it is, so upgrade all of them. Kept slots
1104 need not be touched.
1106 This is called when an ({...}) construct occurs and a statement
1107 returns a value in memory. */
1110 preserve_temp_slots (x)
1113 struct temp_slot *p = 0;
1115 /* If there is no result, we still might have some objects whose address
1116 were taken, so we need to make sure they stay around. */
1119 for (p = temp_slots; p; p = p->next)
1120 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1126 /* If X is a register that is being used as a pointer, see if we have
1127 a temporary slot we know it points to. To be consistent with
1128 the code below, we really should preserve all non-kept slots
1129 if we can't find a match, but that seems to be much too costly. */
1130 if (GET_CODE (x) == REG && REGNO_POINTER_FLAG (REGNO (x)))
1131 p = find_temp_slot_from_address (x);
1133 /* If X is not in memory or is at a constant address, it cannot be in
1134 a temporary slot, but it can contain something whose address was
1136 if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
1138 for (p = temp_slots; p; p = p->next)
1139 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1145 /* First see if we can find a match. */
1147 p = find_temp_slot_from_address (XEXP (x, 0));
1151 /* Move everything at our level whose address was taken to our new
1152 level in case we used its address. */
1153 struct temp_slot *q;
1155 if (p->level == temp_slot_level)
1157 for (q = temp_slots; q; q = q->next)
1158 if (q != p && q->addr_taken && q->level == p->level)
1167 /* Otherwise, preserve all non-kept slots at this level. */
1168 for (p = temp_slots; p; p = p->next)
1169 if (p->in_use && p->level == temp_slot_level && ! p->keep)
1173 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
1174 with that RTL_EXPR, promote it into a temporary slot at the present
1175 level so it will not be freed when we free slots made in the
1179 preserve_rtl_expr_result (x)
1182 struct temp_slot *p;
1184 /* If X is not in memory or is at a constant address, it cannot be in
1185 a temporary slot. */
1186 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1189 /* If we can find a match, move it to our level unless it is already at
1191 p = find_temp_slot_from_address (XEXP (x, 0));
1194 p->level = MIN (p->level, temp_slot_level);
1201 /* Free all temporaries used so far. This is normally called at the end
1202 of generating code for a statement. Don't free any temporaries
1203 currently in use for an RTL_EXPR that hasn't yet been emitted.
1204 We could eventually do better than this since it can be reused while
1205 generating the same RTL_EXPR, but this is complex and probably not
1211 struct temp_slot *p;
1213 for (p = temp_slots; p; p = p->next)
1214 if (p->in_use && p->level == temp_slot_level && ! p->keep
1215 && p->rtl_expr == 0)
1218 combine_temp_slots ();
1221 /* Free all temporary slots used in T, an RTL_EXPR node. */
1224 free_temps_for_rtl_expr (t)
1227 struct temp_slot *p;
1229 for (p = temp_slots; p; p = p->next)
1230 if (p->rtl_expr == t)
1233 combine_temp_slots ();
1236 /* Mark all temporaries ever allocated in this functon as not suitable
1237 for reuse until the current level is exited. */
1240 mark_all_temps_used ()
1242 struct temp_slot *p;
1244 for (p = temp_slots; p; p = p->next)
1246 p->in_use = p->keep = 1;
1247 p->level = MIN (p->level, temp_slot_level);
1251 /* Push deeper into the nesting level for stack temporaries. */
1259 /* Pop a temporary nesting level. All slots in use in the current level
1265 struct temp_slot *p;
1267 for (p = temp_slots; p; p = p->next)
1268 if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
1271 combine_temp_slots ();
1276 /* Initialize temporary slots. */
1281 /* We have not allocated any temporaries yet. */
1283 temp_slot_level = 0;
1284 target_temp_slot_level = 0;
1287 /* Retroactively move an auto variable from a register to a stack slot.
1288 This is done when an address-reference to the variable is seen. */
1291 put_var_into_stack (decl)
1295 enum machine_mode promoted_mode, decl_mode;
1296 struct function *function = 0;
1299 if (output_bytecode)
1302 context = decl_function_context (decl);
1304 /* Get the current rtl used for this object and it's original mode. */
1305 reg = TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl) : DECL_RTL (decl);
1307 /* No need to do anything if decl has no rtx yet
1308 since in that case caller is setting TREE_ADDRESSABLE
1309 and a stack slot will be assigned when the rtl is made. */
1313 /* Get the declared mode for this object. */
1314 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1315 : DECL_MODE (decl));
1316 /* Get the mode it's actually stored in. */
1317 promoted_mode = GET_MODE (reg);
1319 /* If this variable comes from an outer function,
1320 find that function's saved context. */
1321 if (context != current_function_decl)
1322 for (function = outer_function_chain; function; function = function->next)
1323 if (function->decl == context)
1326 /* If this is a variable-size object with a pseudo to address it,
1327 put that pseudo into the stack, if the var is nonlocal. */
1328 if (DECL_NONLOCAL (decl)
1329 && GET_CODE (reg) == MEM
1330 && GET_CODE (XEXP (reg, 0)) == REG
1331 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1333 reg = XEXP (reg, 0);
1334 decl_mode = promoted_mode = GET_MODE (reg);
1337 /* Now we should have a value that resides in one or more pseudo regs. */
1339 if (GET_CODE (reg) == REG)
1340 put_reg_into_stack (function, reg, TREE_TYPE (decl),
1341 promoted_mode, decl_mode, TREE_SIDE_EFFECTS (decl));
1342 else if (GET_CODE (reg) == CONCAT)
1344 /* A CONCAT contains two pseudos; put them both in the stack.
1345 We do it so they end up consecutive. */
1346 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1347 tree part_type = TREE_TYPE (TREE_TYPE (decl));
1348 #ifdef FRAME_GROWS_DOWNWARD
1349 /* Since part 0 should have a lower address, do it second. */
1350 put_reg_into_stack (function, XEXP (reg, 1), part_type, part_mode,
1351 part_mode, TREE_SIDE_EFFECTS (decl));
1352 put_reg_into_stack (function, XEXP (reg, 0), part_type, part_mode,
1353 part_mode, TREE_SIDE_EFFECTS (decl));
1355 put_reg_into_stack (function, XEXP (reg, 0), part_type, part_mode,
1356 part_mode, TREE_SIDE_EFFECTS (decl));
1357 put_reg_into_stack (function, XEXP (reg, 1), part_type, part_mode,
1358 part_mode, TREE_SIDE_EFFECTS (decl));
1361 /* Change the CONCAT into a combined MEM for both parts. */
1362 PUT_CODE (reg, MEM);
1363 MEM_VOLATILE_P (reg) = MEM_VOLATILE_P (XEXP (reg, 0));
1365 /* The two parts are in memory order already.
1366 Use the lower parts address as ours. */
1367 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1368 /* Prevent sharing of rtl that might lose. */
1369 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1370 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1374 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1375 into the stack frame of FUNCTION (0 means the current function).
1376 DECL_MODE is the machine mode of the user-level data type.
1377 PROMOTED_MODE is the machine mode of the register.
1378 VOLATILE_P is nonzero if this is for a "volatile" decl. */
1381 put_reg_into_stack (function, reg, type, promoted_mode, decl_mode, volatile_p)
1382 struct function *function;
1385 enum machine_mode promoted_mode, decl_mode;
1392 if (REGNO (reg) < function->max_parm_reg)
1393 new = function->parm_reg_stack_loc[REGNO (reg)];
1395 new = assign_outer_stack_local (decl_mode, GET_MODE_SIZE (decl_mode),
1400 if (REGNO (reg) < max_parm_reg)
1401 new = parm_reg_stack_loc[REGNO (reg)];
1403 new = assign_stack_local (decl_mode, GET_MODE_SIZE (decl_mode), 0);
1406 PUT_MODE (reg, decl_mode);
1407 XEXP (reg, 0) = XEXP (new, 0);
1408 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1409 MEM_VOLATILE_P (reg) = volatile_p;
1410 PUT_CODE (reg, MEM);
1412 /* If this is a memory ref that contains aggregate components,
1413 mark it as such for cse and loop optimize. */
1414 MEM_IN_STRUCT_P (reg) = AGGREGATE_TYPE_P (type);
1416 /* Now make sure that all refs to the variable, previously made
1417 when it was a register, are fixed up to be valid again. */
1420 struct var_refs_queue *temp;
1422 /* Variable is inherited; fix it up when we get back to its function. */
1423 push_obstacks (function->function_obstack,
1424 function->function_maybepermanent_obstack);
1426 /* See comment in restore_tree_status in tree.c for why this needs to be
1427 on saveable obstack. */
1429 = (struct var_refs_queue *) savealloc (sizeof (struct var_refs_queue));
1430 temp->modified = reg;
1431 temp->promoted_mode = promoted_mode;
1432 temp->unsignedp = TREE_UNSIGNED (type);
1433 temp->next = function->fixup_var_refs_queue;
1434 function->fixup_var_refs_queue = temp;
1438 /* Variable is local; fix it up now. */
1439 fixup_var_refs (reg, promoted_mode, TREE_UNSIGNED (type));
1443 fixup_var_refs (var, promoted_mode, unsignedp)
1445 enum machine_mode promoted_mode;
1449 rtx first_insn = get_insns ();
1450 struct sequence_stack *stack = sequence_stack;
1451 tree rtl_exps = rtl_expr_chain;
1453 /* Must scan all insns for stack-refs that exceed the limit. */
1454 fixup_var_refs_insns (var, promoted_mode, unsignedp, first_insn, stack == 0);
1456 /* Scan all pending sequences too. */
1457 for (; stack; stack = stack->next)
1459 push_to_sequence (stack->first);
1460 fixup_var_refs_insns (var, promoted_mode, unsignedp,
1461 stack->first, stack->next != 0);
1462 /* Update remembered end of sequence
1463 in case we added an insn at the end. */
1464 stack->last = get_last_insn ();
1468 /* Scan all waiting RTL_EXPRs too. */
1469 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1471 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1472 if (seq != const0_rtx && seq != 0)
1474 push_to_sequence (seq);
1475 fixup_var_refs_insns (var, promoted_mode, unsignedp, seq, 0);
1481 /* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
1482 some part of an insn. Return a struct fixup_replacement whose OLD
1483 value is equal to X. Allocate a new structure if no such entry exists. */
1485 static struct fixup_replacement *
1486 find_fixup_replacement (replacements, x)
1487 struct fixup_replacement **replacements;
1490 struct fixup_replacement *p;
1492 /* See if we have already replaced this. */
1493 for (p = *replacements; p && p->old != x; p = p->next)
1498 p = (struct fixup_replacement *) oballoc (sizeof (struct fixup_replacement));
1501 p->next = *replacements;
1508 /* Scan the insn-chain starting with INSN for refs to VAR
1509 and fix them up. TOPLEVEL is nonzero if this chain is the
1510 main chain of insns for the current function. */
1513 fixup_var_refs_insns (var, promoted_mode, unsignedp, insn, toplevel)
1515 enum machine_mode promoted_mode;
1524 rtx next = NEXT_INSN (insn);
1526 if (GET_RTX_CLASS (GET_CODE (insn)) == 'i')
1528 /* If this is a CLOBBER of VAR, delete it.
1530 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1531 and REG_RETVAL notes too. */
1532 if (GET_CODE (PATTERN (insn)) == CLOBBER
1533 && XEXP (PATTERN (insn), 0) == var)
1535 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1536 /* The REG_LIBCALL note will go away since we are going to
1537 turn INSN into a NOTE, so just delete the
1538 corresponding REG_RETVAL note. */
1539 remove_note (XEXP (note, 0),
1540 find_reg_note (XEXP (note, 0), REG_RETVAL,
1543 /* In unoptimized compilation, we shouldn't call delete_insn
1544 except in jump.c doing warnings. */
1545 PUT_CODE (insn, NOTE);
1546 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1547 NOTE_SOURCE_FILE (insn) = 0;
1550 /* The insn to load VAR from a home in the arglist
1551 is now a no-op. When we see it, just delete it. */
1553 && GET_CODE (PATTERN (insn)) == SET
1554 && SET_DEST (PATTERN (insn)) == var
1555 /* If this represents the result of an insn group,
1556 don't delete the insn. */
1557 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1558 && rtx_equal_p (SET_SRC (PATTERN (insn)), var))
1560 /* In unoptimized compilation, we shouldn't call delete_insn
1561 except in jump.c doing warnings. */
1562 PUT_CODE (insn, NOTE);
1563 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1564 NOTE_SOURCE_FILE (insn) = 0;
1565 if (insn == last_parm_insn)
1566 last_parm_insn = PREV_INSN (next);
1570 struct fixup_replacement *replacements = 0;
1571 rtx next_insn = NEXT_INSN (insn);
1573 #ifdef SMALL_REGISTER_CLASSES
1574 /* If the insn that copies the results of a CALL_INSN
1575 into a pseudo now references VAR, we have to use an
1576 intermediate pseudo since we want the life of the
1577 return value register to be only a single insn.
1579 If we don't use an intermediate pseudo, such things as
1580 address computations to make the address of VAR valid
1581 if it is not can be placed between the CALL_INSN and INSN.
1583 To make sure this doesn't happen, we record the destination
1584 of the CALL_INSN and see if the next insn uses both that
1587 if (SMALL_REGISTER_CLASSES)
1589 if (call_dest != 0 && GET_CODE (insn) == INSN
1590 && reg_mentioned_p (var, PATTERN (insn))
1591 && reg_mentioned_p (call_dest, PATTERN (insn)))
1593 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1595 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1597 PATTERN (insn) = replace_rtx (PATTERN (insn),
1601 if (GET_CODE (insn) == CALL_INSN
1602 && GET_CODE (PATTERN (insn)) == SET)
1603 call_dest = SET_DEST (PATTERN (insn));
1604 else if (GET_CODE (insn) == CALL_INSN
1605 && GET_CODE (PATTERN (insn)) == PARALLEL
1606 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1607 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1613 /* See if we have to do anything to INSN now that VAR is in
1614 memory. If it needs to be loaded into a pseudo, use a single
1615 pseudo for the entire insn in case there is a MATCH_DUP
1616 between two operands. We pass a pointer to the head of
1617 a list of struct fixup_replacements. If fixup_var_refs_1
1618 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1619 it will record them in this list.
1621 If it allocated a pseudo for any replacement, we copy into
1624 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1627 /* If this is last_parm_insn, and any instructions were output
1628 after it to fix it up, then we must set last_parm_insn to
1629 the last such instruction emitted. */
1630 if (insn == last_parm_insn)
1631 last_parm_insn = PREV_INSN (next_insn);
1633 while (replacements)
1635 if (GET_CODE (replacements->new) == REG)
1640 /* OLD might be a (subreg (mem)). */
1641 if (GET_CODE (replacements->old) == SUBREG)
1643 = fixup_memory_subreg (replacements->old, insn, 0);
1646 = fixup_stack_1 (replacements->old, insn);
1648 insert_before = insn;
1650 /* If we are changing the mode, do a conversion.
1651 This might be wasteful, but combine.c will
1652 eliminate much of the waste. */
1654 if (GET_MODE (replacements->new)
1655 != GET_MODE (replacements->old))
1658 convert_move (replacements->new,
1659 replacements->old, unsignedp);
1660 seq = gen_sequence ();
1664 seq = gen_move_insn (replacements->new,
1667 emit_insn_before (seq, insert_before);
1670 replacements = replacements->next;
1674 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1675 But don't touch other insns referred to by reg-notes;
1676 we will get them elsewhere. */
1677 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
1678 if (GET_CODE (note) != INSN_LIST)
1680 = walk_fixup_memory_subreg (XEXP (note, 0), insn, 1);
1686 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1687 See if the rtx expression at *LOC in INSN needs to be changed.
1689 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1690 contain a list of original rtx's and replacements. If we find that we need
1691 to modify this insn by replacing a memory reference with a pseudo or by
1692 making a new MEM to implement a SUBREG, we consult that list to see if
1693 we have already chosen a replacement. If none has already been allocated,
1694 we allocate it and update the list. fixup_var_refs_insns will copy VAR
1695 or the SUBREG, as appropriate, to the pseudo. */
1698 fixup_var_refs_1 (var, promoted_mode, loc, insn, replacements)
1700 enum machine_mode promoted_mode;
1703 struct fixup_replacement **replacements;
1706 register rtx x = *loc;
1707 RTX_CODE code = GET_CODE (x);
1709 register rtx tem, tem1;
1710 struct fixup_replacement *replacement;
1717 /* If we already have a replacement, use it. Otherwise,
1718 try to fix up this address in case it is invalid. */
1720 replacement = find_fixup_replacement (replacements, var);
1721 if (replacement->new)
1723 *loc = replacement->new;
1727 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1729 /* Unless we are forcing memory to register or we changed the mode,
1730 we can leave things the way they are if the insn is valid. */
1732 INSN_CODE (insn) = -1;
1733 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1734 && recog_memoized (insn) >= 0)
1737 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1741 /* If X contains VAR, we need to unshare it here so that we update
1742 each occurrence separately. But all identical MEMs in one insn
1743 must be replaced with the same rtx because of the possibility of
1746 if (reg_mentioned_p (var, x))
1748 replacement = find_fixup_replacement (replacements, x);
1749 if (replacement->new == 0)
1750 replacement->new = copy_most_rtx (x, var);
1752 *loc = x = replacement->new;
1768 /* Note that in some cases those types of expressions are altered
1769 by optimize_bit_field, and do not survive to get here. */
1770 if (XEXP (x, 0) == var
1771 || (GET_CODE (XEXP (x, 0)) == SUBREG
1772 && SUBREG_REG (XEXP (x, 0)) == var))
1774 /* Get TEM as a valid MEM in the mode presently in the insn.
1776 We don't worry about the possibility of MATCH_DUP here; it
1777 is highly unlikely and would be tricky to handle. */
1780 if (GET_CODE (tem) == SUBREG)
1782 if (GET_MODE_BITSIZE (GET_MODE (tem))
1783 > GET_MODE_BITSIZE (GET_MODE (var)))
1785 replacement = find_fixup_replacement (replacements, var);
1786 if (replacement->new == 0)
1787 replacement->new = gen_reg_rtx (GET_MODE (var));
1788 SUBREG_REG (tem) = replacement->new;
1791 tem = fixup_memory_subreg (tem, insn, 0);
1794 tem = fixup_stack_1 (tem, insn);
1796 /* Unless we want to load from memory, get TEM into the proper mode
1797 for an extract from memory. This can only be done if the
1798 extract is at a constant position and length. */
1800 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
1801 && GET_CODE (XEXP (x, 2)) == CONST_INT
1802 && ! mode_dependent_address_p (XEXP (tem, 0))
1803 && ! MEM_VOLATILE_P (tem))
1805 enum machine_mode wanted_mode = VOIDmode;
1806 enum machine_mode is_mode = GET_MODE (tem);
1807 int width = INTVAL (XEXP (x, 1));
1808 int pos = INTVAL (XEXP (x, 2));
1811 if (GET_CODE (x) == ZERO_EXTRACT)
1812 wanted_mode = insn_operand_mode[(int) CODE_FOR_extzv][1];
1815 if (GET_CODE (x) == SIGN_EXTRACT)
1816 wanted_mode = insn_operand_mode[(int) CODE_FOR_extv][1];
1818 /* If we have a narrower mode, we can do something. */
1819 if (wanted_mode != VOIDmode
1820 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
1822 int offset = pos / BITS_PER_UNIT;
1823 rtx old_pos = XEXP (x, 2);
1826 /* If the bytes and bits are counted differently, we
1827 must adjust the offset. */
1828 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
1829 offset = (GET_MODE_SIZE (is_mode)
1830 - GET_MODE_SIZE (wanted_mode) - offset);
1832 pos %= GET_MODE_BITSIZE (wanted_mode);
1834 newmem = gen_rtx (MEM, wanted_mode,
1835 plus_constant (XEXP (tem, 0), offset));
1836 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
1837 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
1838 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
1840 /* Make the change and see if the insn remains valid. */
1841 INSN_CODE (insn) = -1;
1842 XEXP (x, 0) = newmem;
1843 XEXP (x, 2) = GEN_INT (pos);
1845 if (recog_memoized (insn) >= 0)
1848 /* Otherwise, restore old position. XEXP (x, 0) will be
1850 XEXP (x, 2) = old_pos;
1854 /* If we get here, the bitfield extract insn can't accept a memory
1855 reference. Copy the input into a register. */
1857 tem1 = gen_reg_rtx (GET_MODE (tem));
1858 emit_insn_before (gen_move_insn (tem1, tem), insn);
1865 if (SUBREG_REG (x) == var)
1867 /* If this is a special SUBREG made because VAR was promoted
1868 from a wider mode, replace it with VAR and call ourself
1869 recursively, this time saying that the object previously
1870 had its current mode (by virtue of the SUBREG). */
1872 if (SUBREG_PROMOTED_VAR_P (x))
1875 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements);
1879 /* If this SUBREG makes VAR wider, it has become a paradoxical
1880 SUBREG with VAR in memory, but these aren't allowed at this
1881 stage of the compilation. So load VAR into a pseudo and take
1882 a SUBREG of that pseudo. */
1883 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
1885 replacement = find_fixup_replacement (replacements, var);
1886 if (replacement->new == 0)
1887 replacement->new = gen_reg_rtx (GET_MODE (var));
1888 SUBREG_REG (x) = replacement->new;
1892 /* See if we have already found a replacement for this SUBREG.
1893 If so, use it. Otherwise, make a MEM and see if the insn
1894 is recognized. If not, or if we should force MEM into a register,
1895 make a pseudo for this SUBREG. */
1896 replacement = find_fixup_replacement (replacements, x);
1897 if (replacement->new)
1899 *loc = replacement->new;
1903 replacement->new = *loc = fixup_memory_subreg (x, insn, 0);
1905 INSN_CODE (insn) = -1;
1906 if (! flag_force_mem && recog_memoized (insn) >= 0)
1909 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
1915 /* First do special simplification of bit-field references. */
1916 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
1917 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
1918 optimize_bit_field (x, insn, 0);
1919 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
1920 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
1921 optimize_bit_field (x, insn, NULL_PTR);
1923 /* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
1924 into a register and then store it back out. */
1925 if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
1926 && GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
1927 && SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
1928 && (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
1929 > GET_MODE_SIZE (GET_MODE (var))))
1931 replacement = find_fixup_replacement (replacements, var);
1932 if (replacement->new == 0)
1933 replacement->new = gen_reg_rtx (GET_MODE (var));
1935 SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
1936 emit_insn_after (gen_move_insn (var, replacement->new), insn);
1939 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
1940 insn into a pseudo and store the low part of the pseudo into VAR. */
1941 if (GET_CODE (SET_DEST (x)) == SUBREG
1942 && SUBREG_REG (SET_DEST (x)) == var
1943 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
1944 > GET_MODE_SIZE (GET_MODE (var))))
1946 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
1947 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
1954 rtx dest = SET_DEST (x);
1955 rtx src = SET_SRC (x);
1956 rtx outerdest = dest;
1958 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
1959 || GET_CODE (dest) == SIGN_EXTRACT
1960 || GET_CODE (dest) == ZERO_EXTRACT)
1961 dest = XEXP (dest, 0);
1963 if (GET_CODE (src) == SUBREG)
1964 src = XEXP (src, 0);
1966 /* If VAR does not appear at the top level of the SET
1967 just scan the lower levels of the tree. */
1969 if (src != var && dest != var)
1972 /* We will need to rerecognize this insn. */
1973 INSN_CODE (insn) = -1;
1976 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var)
1978 /* Since this case will return, ensure we fixup all the
1980 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
1981 insn, replacements);
1982 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
1983 insn, replacements);
1984 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
1985 insn, replacements);
1987 tem = XEXP (outerdest, 0);
1989 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
1990 that may appear inside a ZERO_EXTRACT.
1991 This was legitimate when the MEM was a REG. */
1992 if (GET_CODE (tem) == SUBREG
1993 && SUBREG_REG (tem) == var)
1994 tem = fixup_memory_subreg (tem, insn, 0);
1996 tem = fixup_stack_1 (tem, insn);
1998 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
1999 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
2000 && ! mode_dependent_address_p (XEXP (tem, 0))
2001 && ! MEM_VOLATILE_P (tem))
2003 enum machine_mode wanted_mode
2004 = insn_operand_mode[(int) CODE_FOR_insv][0];
2005 enum machine_mode is_mode = GET_MODE (tem);
2006 int width = INTVAL (XEXP (outerdest, 1));
2007 int pos = INTVAL (XEXP (outerdest, 2));
2009 /* If we have a narrower mode, we can do something. */
2010 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2012 int offset = pos / BITS_PER_UNIT;
2013 rtx old_pos = XEXP (outerdest, 2);
2016 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2017 offset = (GET_MODE_SIZE (is_mode)
2018 - GET_MODE_SIZE (wanted_mode) - offset);
2020 pos %= GET_MODE_BITSIZE (wanted_mode);
2022 newmem = gen_rtx (MEM, wanted_mode,
2023 plus_constant (XEXP (tem, 0), offset));
2024 RTX_UNCHANGING_P (newmem) = RTX_UNCHANGING_P (tem);
2025 MEM_VOLATILE_P (newmem) = MEM_VOLATILE_P (tem);
2026 MEM_IN_STRUCT_P (newmem) = MEM_IN_STRUCT_P (tem);
2028 /* Make the change and see if the insn remains valid. */
2029 INSN_CODE (insn) = -1;
2030 XEXP (outerdest, 0) = newmem;
2031 XEXP (outerdest, 2) = GEN_INT (pos);
2033 if (recog_memoized (insn) >= 0)
2036 /* Otherwise, restore old position. XEXP (x, 0) will be
2038 XEXP (outerdest, 2) = old_pos;
2042 /* If we get here, the bit-field store doesn't allow memory
2043 or isn't located at a constant position. Load the value into
2044 a register, do the store, and put it back into memory. */
2046 tem1 = gen_reg_rtx (GET_MODE (tem));
2047 emit_insn_before (gen_move_insn (tem1, tem), insn);
2048 emit_insn_after (gen_move_insn (tem, tem1), insn);
2049 XEXP (outerdest, 0) = tem1;
2054 /* STRICT_LOW_PART is a no-op on memory references
2055 and it can cause combinations to be unrecognizable,
2058 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2059 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2061 /* A valid insn to copy VAR into or out of a register
2062 must be left alone, to avoid an infinite loop here.
2063 If the reference to VAR is by a subreg, fix that up,
2064 since SUBREG is not valid for a memref.
2065 Also fix up the address of the stack slot.
2067 Note that we must not try to recognize the insn until
2068 after we know that we have valid addresses and no
2069 (subreg (mem ...) ...) constructs, since these interfere
2070 with determining the validity of the insn. */
2072 if ((SET_SRC (x) == var
2073 || (GET_CODE (SET_SRC (x)) == SUBREG
2074 && SUBREG_REG (SET_SRC (x)) == var))
2075 && (GET_CODE (SET_DEST (x)) == REG
2076 || (GET_CODE (SET_DEST (x)) == SUBREG
2077 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
2078 && GET_MODE (var) == promoted_mode
2079 && x == single_set (insn))
2083 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2084 if (replacement->new)
2085 SET_SRC (x) = replacement->new;
2086 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2087 SET_SRC (x) = replacement->new
2088 = fixup_memory_subreg (SET_SRC (x), insn, 0);
2090 SET_SRC (x) = replacement->new
2091 = fixup_stack_1 (SET_SRC (x), insn);
2093 if (recog_memoized (insn) >= 0)
2096 /* INSN is not valid, but we know that we want to
2097 copy SET_SRC (x) to SET_DEST (x) in some way. So
2098 we generate the move and see whether it requires more
2099 than one insn. If it does, we emit those insns and
2100 delete INSN. Otherwise, we an just replace the pattern
2101 of INSN; we have already verified above that INSN has
2102 no other function that to do X. */
2104 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2105 if (GET_CODE (pat) == SEQUENCE)
2107 emit_insn_after (pat, insn);
2108 PUT_CODE (insn, NOTE);
2109 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
2110 NOTE_SOURCE_FILE (insn) = 0;
2113 PATTERN (insn) = pat;
2118 if ((SET_DEST (x) == var
2119 || (GET_CODE (SET_DEST (x)) == SUBREG
2120 && SUBREG_REG (SET_DEST (x)) == var))
2121 && (GET_CODE (SET_SRC (x)) == REG
2122 || (GET_CODE (SET_SRC (x)) == SUBREG
2123 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
2124 && GET_MODE (var) == promoted_mode
2125 && x == single_set (insn))
2129 if (GET_CODE (SET_DEST (x)) == SUBREG)
2130 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn, 0);
2132 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2134 if (recog_memoized (insn) >= 0)
2137 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2138 if (GET_CODE (pat) == SEQUENCE)
2140 emit_insn_after (pat, insn);
2141 PUT_CODE (insn, NOTE);
2142 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
2143 NOTE_SOURCE_FILE (insn) = 0;
2146 PATTERN (insn) = pat;
2151 /* Otherwise, storing into VAR must be handled specially
2152 by storing into a temporary and copying that into VAR
2153 with a new insn after this one. Note that this case
2154 will be used when storing into a promoted scalar since
2155 the insn will now have different modes on the input
2156 and output and hence will be invalid (except for the case
2157 of setting it to a constant, which does not need any
2158 change if it is valid). We generate extra code in that case,
2159 but combine.c will eliminate it. */
2164 rtx fixeddest = SET_DEST (x);
2166 /* STRICT_LOW_PART can be discarded, around a MEM. */
2167 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2168 fixeddest = XEXP (fixeddest, 0);
2169 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2170 if (GET_CODE (fixeddest) == SUBREG)
2172 fixeddest = fixup_memory_subreg (fixeddest, insn, 0);
2173 promoted_mode = GET_MODE (fixeddest);
2176 fixeddest = fixup_stack_1 (fixeddest, insn);
2178 temp = gen_reg_rtx (promoted_mode);
2180 emit_insn_after (gen_move_insn (fixeddest,
2181 gen_lowpart (GET_MODE (fixeddest),
2185 SET_DEST (x) = temp;
2190 /* Nothing special about this RTX; fix its operands. */
2192 fmt = GET_RTX_FORMAT (code);
2193 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2196 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements);
2200 for (j = 0; j < XVECLEN (x, i); j++)
2201 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2202 insn, replacements);
2207 /* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
2208 return an rtx (MEM:m1 newaddr) which is equivalent.
2209 If any insns must be emitted to compute NEWADDR, put them before INSN.
2211 UNCRITICAL nonzero means accept paradoxical subregs.
2212 This is used for subregs found inside REG_NOTES. */
2215 fixup_memory_subreg (x, insn, uncritical)
2220 int offset = SUBREG_WORD (x) * UNITS_PER_WORD;
2221 rtx addr = XEXP (SUBREG_REG (x), 0);
2222 enum machine_mode mode = GET_MODE (x);
2225 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2226 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
2230 if (BYTES_BIG_ENDIAN)
2231 offset += (MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2232 - MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)));
2233 addr = plus_constant (addr, offset);
2234 if (!flag_force_addr && memory_address_p (mode, addr))
2235 /* Shortcut if no insns need be emitted. */
2236 return change_address (SUBREG_REG (x), mode, addr);
2238 result = change_address (SUBREG_REG (x), mode, addr);
2239 emit_insn_before (gen_sequence (), insn);
2244 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
2245 Replace subexpressions of X in place.
2246 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
2247 Otherwise return X, with its contents possibly altered.
2249 If any insns must be emitted to compute NEWADDR, put them before INSN.
2251 UNCRITICAL is as in fixup_memory_subreg. */
2254 walk_fixup_memory_subreg (x, insn, uncritical)
2259 register enum rtx_code code;
2266 code = GET_CODE (x);
2268 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
2269 return fixup_memory_subreg (x, insn, uncritical);
2271 /* Nothing special about this RTX; fix its operands. */
2273 fmt = GET_RTX_FORMAT (code);
2274 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2277 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn, uncritical);
2281 for (j = 0; j < XVECLEN (x, i); j++)
2283 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn, uncritical);
2289 /* For each memory ref within X, if it refers to a stack slot
2290 with an out of range displacement, put the address in a temp register
2291 (emitting new insns before INSN to load these registers)
2292 and alter the memory ref to use that register.
2293 Replace each such MEM rtx with a copy, to avoid clobberage. */
2296 fixup_stack_1 (x, insn)
2301 register RTX_CODE code = GET_CODE (x);
2306 register rtx ad = XEXP (x, 0);
2307 /* If we have address of a stack slot but it's not valid
2308 (displacement is too large), compute the sum in a register. */
2309 if (GET_CODE (ad) == PLUS
2310 && GET_CODE (XEXP (ad, 0)) == REG
2311 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2312 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2313 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2314 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2317 if (memory_address_p (GET_MODE (x), ad))
2321 temp = copy_to_reg (ad);
2322 seq = gen_sequence ();
2324 emit_insn_before (seq, insn);
2325 return change_address (x, VOIDmode, temp);
2330 fmt = GET_RTX_FORMAT (code);
2331 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2334 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2338 for (j = 0; j < XVECLEN (x, i); j++)
2339 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2345 /* Optimization: a bit-field instruction whose field
2346 happens to be a byte or halfword in memory
2347 can be changed to a move instruction.
2349 We call here when INSN is an insn to examine or store into a bit-field.
2350 BODY is the SET-rtx to be altered.
2352 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2353 (Currently this is called only from function.c, and EQUIV_MEM
2357 optimize_bit_field (body, insn, equiv_mem)
2362 register rtx bitfield;
2365 enum machine_mode mode;
2367 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2368 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2369 bitfield = SET_DEST (body), destflag = 1;
2371 bitfield = SET_SRC (body), destflag = 0;
2373 /* First check that the field being stored has constant size and position
2374 and is in fact a byte or halfword suitably aligned. */
2376 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2377 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2378 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2380 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2382 register rtx memref = 0;
2384 /* Now check that the containing word is memory, not a register,
2385 and that it is safe to change the machine mode. */
2387 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2388 memref = XEXP (bitfield, 0);
2389 else if (GET_CODE (XEXP (bitfield, 0)) == REG
2391 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2392 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2393 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2394 memref = SUBREG_REG (XEXP (bitfield, 0));
2395 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2397 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
2398 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2401 && ! mode_dependent_address_p (XEXP (memref, 0))
2402 && ! MEM_VOLATILE_P (memref))
2404 /* Now adjust the address, first for any subreg'ing
2405 that we are now getting rid of,
2406 and then for which byte of the word is wanted. */
2408 register int offset = INTVAL (XEXP (bitfield, 2));
2411 /* Adjust OFFSET to count bits from low-address byte. */
2412 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2413 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2414 - offset - INTVAL (XEXP (bitfield, 1)));
2416 /* Adjust OFFSET to count bytes from low-address byte. */
2417 offset /= BITS_PER_UNIT;
2418 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2420 offset += SUBREG_WORD (XEXP (bitfield, 0)) * UNITS_PER_WORD;
2421 if (BYTES_BIG_ENDIAN)
2422 offset -= (MIN (UNITS_PER_WORD,
2423 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2424 - MIN (UNITS_PER_WORD,
2425 GET_MODE_SIZE (GET_MODE (memref))));
2429 memref = change_address (memref, mode,
2430 plus_constant (XEXP (memref, 0), offset));
2431 insns = get_insns ();
2433 emit_insns_before (insns, insn);
2435 /* Store this memory reference where
2436 we found the bit field reference. */
2440 validate_change (insn, &SET_DEST (body), memref, 1);
2441 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2443 rtx src = SET_SRC (body);
2444 while (GET_CODE (src) == SUBREG
2445 && SUBREG_WORD (src) == 0)
2446 src = SUBREG_REG (src);
2447 if (GET_MODE (src) != GET_MODE (memref))
2448 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2449 validate_change (insn, &SET_SRC (body), src, 1);
2451 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2452 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2453 /* This shouldn't happen because anything that didn't have
2454 one of these modes should have got converted explicitly
2455 and then referenced through a subreg.
2456 This is so because the original bit-field was
2457 handled by agg_mode and so its tree structure had
2458 the same mode that memref now has. */
2463 rtx dest = SET_DEST (body);
2465 while (GET_CODE (dest) == SUBREG
2466 && SUBREG_WORD (dest) == 0
2467 && (GET_MODE_CLASS (GET_MODE (dest))
2468 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest)))))
2469 dest = SUBREG_REG (dest);
2471 validate_change (insn, &SET_DEST (body), dest, 1);
2473 if (GET_MODE (dest) == GET_MODE (memref))
2474 validate_change (insn, &SET_SRC (body), memref, 1);
2477 /* Convert the mem ref to the destination mode. */
2478 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2481 convert_move (newreg, memref,
2482 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2486 validate_change (insn, &SET_SRC (body), newreg, 1);
2490 /* See if we can convert this extraction or insertion into
2491 a simple move insn. We might not be able to do so if this
2492 was, for example, part of a PARALLEL.
2494 If we succeed, write out any needed conversions. If we fail,
2495 it is hard to guess why we failed, so don't do anything
2496 special; just let the optimization be suppressed. */
2498 if (apply_change_group () && seq)
2499 emit_insns_before (seq, insn);
2504 /* These routines are responsible for converting virtual register references
2505 to the actual hard register references once RTL generation is complete.
2507 The following four variables are used for communication between the
2508 routines. They contain the offsets of the virtual registers from their
2509 respective hard registers. */
2511 static int in_arg_offset;
2512 static int var_offset;
2513 static int dynamic_offset;
2514 static int out_arg_offset;
2516 /* In most machines, the stack pointer register is equivalent to the bottom
2519 #ifndef STACK_POINTER_OFFSET
2520 #define STACK_POINTER_OFFSET 0
2523 /* If not defined, pick an appropriate default for the offset of dynamically
2524 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2525 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2527 #ifndef STACK_DYNAMIC_OFFSET
2529 #ifdef ACCUMULATE_OUTGOING_ARGS
2530 /* The bottom of the stack points to the actual arguments. If
2531 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2532 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2533 stack space for register parameters is not pushed by the caller, but
2534 rather part of the fixed stack areas and hence not included in
2535 `current_function_outgoing_args_size'. Nevertheless, we must allow
2536 for it when allocating stack dynamic objects. */
2538 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2539 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2540 (current_function_outgoing_args_size \
2541 + REG_PARM_STACK_SPACE (FNDECL) + (STACK_POINTER_OFFSET))
2544 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2545 (current_function_outgoing_args_size + (STACK_POINTER_OFFSET))
2549 #define STACK_DYNAMIC_OFFSET(FNDECL) STACK_POINTER_OFFSET
2553 /* Pass through the INSNS of function FNDECL and convert virtual register
2554 references to hard register references. */
2557 instantiate_virtual_regs (fndecl, insns)
2563 /* Compute the offsets to use for this function. */
2564 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
2565 var_offset = STARTING_FRAME_OFFSET;
2566 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
2567 out_arg_offset = STACK_POINTER_OFFSET;
2569 /* Scan all variables and parameters of this function. For each that is
2570 in memory, instantiate all virtual registers if the result is a valid
2571 address. If not, we do it later. That will handle most uses of virtual
2572 regs on many machines. */
2573 instantiate_decls (fndecl, 1);
2575 /* Initialize recognition, indicating that volatile is OK. */
2578 /* Scan through all the insns, instantiating every virtual register still
2580 for (insn = insns; insn; insn = NEXT_INSN (insn))
2581 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
2582 || GET_CODE (insn) == CALL_INSN)
2584 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
2585 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
2588 /* Now instantiate the remaining register equivalences for debugging info.
2589 These will not be valid addresses. */
2590 instantiate_decls (fndecl, 0);
2592 /* Indicate that, from now on, assign_stack_local should use
2593 frame_pointer_rtx. */
2594 virtuals_instantiated = 1;
2597 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
2598 all virtual registers in their DECL_RTL's.
2600 If VALID_ONLY, do this only if the resulting address is still valid.
2601 Otherwise, always do it. */
2604 instantiate_decls (fndecl, valid_only)
2610 if (DECL_SAVED_INSNS (fndecl))
2611 /* When compiling an inline function, the obstack used for
2612 rtl allocation is the maybepermanent_obstack. Calling
2613 `resume_temporary_allocation' switches us back to that
2614 obstack while we process this function's parameters. */
2615 resume_temporary_allocation ();
2617 /* Process all parameters of the function. */
2618 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
2620 instantiate_decl (DECL_RTL (decl), int_size_in_bytes (TREE_TYPE (decl)),
2622 instantiate_decl (DECL_INCOMING_RTL (decl),
2623 int_size_in_bytes (TREE_TYPE (decl)), valid_only);
2626 /* Now process all variables defined in the function or its subblocks. */
2627 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
2629 if (DECL_INLINE (fndecl) || DECL_DEFER_OUTPUT (fndecl))
2631 /* Save all rtl allocated for this function by raising the
2632 high-water mark on the maybepermanent_obstack. */
2634 /* All further rtl allocation is now done in the current_obstack. */
2635 rtl_in_current_obstack ();
2639 /* Subroutine of instantiate_decls: Process all decls in the given
2640 BLOCK node and all its subblocks. */
2643 instantiate_decls_1 (let, valid_only)
2649 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
2650 instantiate_decl (DECL_RTL (t), int_size_in_bytes (TREE_TYPE (t)),
2653 /* Process all subblocks. */
2654 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
2655 instantiate_decls_1 (t, valid_only);
2658 /* Subroutine of the preceding procedures: Given RTL representing a
2659 decl and the size of the object, do any instantiation required.
2661 If VALID_ONLY is non-zero, it means that the RTL should only be
2662 changed if the new address is valid. */
2665 instantiate_decl (x, size, valid_only)
2670 enum machine_mode mode;
2673 /* If this is not a MEM, no need to do anything. Similarly if the
2674 address is a constant or a register that is not a virtual register. */
2676 if (x == 0 || GET_CODE (x) != MEM)
2680 if (CONSTANT_P (addr)
2681 || (GET_CODE (addr) == REG
2682 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
2683 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
2686 /* If we should only do this if the address is valid, copy the address.
2687 We need to do this so we can undo any changes that might make the
2688 address invalid. This copy is unfortunate, but probably can't be
2692 addr = copy_rtx (addr);
2694 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
2698 /* Now verify that the resulting address is valid for every integer or
2699 floating-point mode up to and including SIZE bytes long. We do this
2700 since the object might be accessed in any mode and frame addresses
2703 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
2704 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2705 mode = GET_MODE_WIDER_MODE (mode))
2706 if (! memory_address_p (mode, addr))
2709 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
2710 mode != VOIDmode && GET_MODE_SIZE (mode) <= size;
2711 mode = GET_MODE_WIDER_MODE (mode))
2712 if (! memory_address_p (mode, addr))
2716 /* Put back the address now that we have updated it and we either know
2717 it is valid or we don't care whether it is valid. */
2722 /* Given a pointer to a piece of rtx and an optional pointer to the
2723 containing object, instantiate any virtual registers present in it.
2725 If EXTRA_INSNS, we always do the replacement and generate
2726 any extra insns before OBJECT. If it zero, we do nothing if replacement
2729 Return 1 if we either had nothing to do or if we were able to do the
2730 needed replacement. Return 0 otherwise; we only return zero if
2731 EXTRA_INSNS is zero.
2733 We first try some simple transformations to avoid the creation of extra
2737 instantiate_virtual_regs_1 (loc, object, extra_insns)
2751 /* Re-start here to avoid recursion in common cases. */
2758 code = GET_CODE (x);
2760 /* Check for some special cases. */
2777 /* We are allowed to set the virtual registers. This means that
2778 that the actual register should receive the source minus the
2779 appropriate offset. This is used, for example, in the handling
2780 of non-local gotos. */
2781 if (SET_DEST (x) == virtual_incoming_args_rtx)
2782 new = arg_pointer_rtx, offset = - in_arg_offset;
2783 else if (SET_DEST (x) == virtual_stack_vars_rtx)
2784 new = frame_pointer_rtx, offset = - var_offset;
2785 else if (SET_DEST (x) == virtual_stack_dynamic_rtx)
2786 new = stack_pointer_rtx, offset = - dynamic_offset;
2787 else if (SET_DEST (x) == virtual_outgoing_args_rtx)
2788 new = stack_pointer_rtx, offset = - out_arg_offset;
2792 /* The only valid sources here are PLUS or REG. Just do
2793 the simplest possible thing to handle them. */
2794 if (GET_CODE (SET_SRC (x)) != REG
2795 && GET_CODE (SET_SRC (x)) != PLUS)
2799 if (GET_CODE (SET_SRC (x)) != REG)
2800 temp = force_operand (SET_SRC (x), NULL_RTX);
2803 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
2807 emit_insns_before (seq, object);
2810 if (!validate_change (object, &SET_SRC (x), temp, 0)
2817 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
2822 /* Handle special case of virtual register plus constant. */
2823 if (CONSTANT_P (XEXP (x, 1)))
2825 rtx old, new_offset;
2827 /* Check for (plus (plus VIRT foo) (const_int)) first. */
2828 if (GET_CODE (XEXP (x, 0)) == PLUS)
2830 rtx inner = XEXP (XEXP (x, 0), 0);
2832 if (inner == virtual_incoming_args_rtx)
2833 new = arg_pointer_rtx, offset = in_arg_offset;
2834 else if (inner == virtual_stack_vars_rtx)
2835 new = frame_pointer_rtx, offset = var_offset;
2836 else if (inner == virtual_stack_dynamic_rtx)
2837 new = stack_pointer_rtx, offset = dynamic_offset;
2838 else if (inner == virtual_outgoing_args_rtx)
2839 new = stack_pointer_rtx, offset = out_arg_offset;
2846 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
2848 new = gen_rtx (PLUS, Pmode, new, XEXP (XEXP (x, 0), 1));
2851 else if (XEXP (x, 0) == virtual_incoming_args_rtx)
2852 new = arg_pointer_rtx, offset = in_arg_offset;
2853 else if (XEXP (x, 0) == virtual_stack_vars_rtx)
2854 new = frame_pointer_rtx, offset = var_offset;
2855 else if (XEXP (x, 0) == virtual_stack_dynamic_rtx)
2856 new = stack_pointer_rtx, offset = dynamic_offset;
2857 else if (XEXP (x, 0) == virtual_outgoing_args_rtx)
2858 new = stack_pointer_rtx, offset = out_arg_offset;
2861 /* We know the second operand is a constant. Unless the
2862 first operand is a REG (which has been already checked),
2863 it needs to be checked. */
2864 if (GET_CODE (XEXP (x, 0)) != REG)
2872 new_offset = plus_constant (XEXP (x, 1), offset);
2874 /* If the new constant is zero, try to replace the sum with just
2876 if (new_offset == const0_rtx
2877 && validate_change (object, loc, new, 0))
2880 /* Next try to replace the register and new offset.
2881 There are two changes to validate here and we can't assume that
2882 in the case of old offset equals new just changing the register
2883 will yield a valid insn. In the interests of a little efficiency,
2884 however, we only call validate change once (we don't queue up the
2885 changes and then call apply_change_group). */
2889 ? ! validate_change (object, &XEXP (x, 0), new, 0)
2890 : (XEXP (x, 0) = new,
2891 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
2899 /* Otherwise copy the new constant into a register and replace
2900 constant with that register. */
2901 temp = gen_reg_rtx (Pmode);
2903 if (validate_change (object, &XEXP (x, 1), temp, 0))
2904 emit_insn_before (gen_move_insn (temp, new_offset), object);
2907 /* If that didn't work, replace this expression with a
2908 register containing the sum. */
2911 new = gen_rtx (PLUS, Pmode, new, new_offset);
2914 temp = force_operand (new, NULL_RTX);
2918 emit_insns_before (seq, object);
2919 if (! validate_change (object, loc, temp, 0)
2920 && ! validate_replace_rtx (x, temp, object))
2928 /* Fall through to generic two-operand expression case. */
2934 case DIV: case UDIV:
2935 case MOD: case UMOD:
2936 case AND: case IOR: case XOR:
2937 case ROTATERT: case ROTATE:
2938 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
2940 case GE: case GT: case GEU: case GTU:
2941 case LE: case LT: case LEU: case LTU:
2942 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
2943 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
2948 /* Most cases of MEM that convert to valid addresses have already been
2949 handled by our scan of decls. The only special handling we
2950 need here is to make a copy of the rtx to ensure it isn't being
2951 shared if we have to change it to a pseudo.
2953 If the rtx is a simple reference to an address via a virtual register,
2954 it can potentially be shared. In such cases, first try to make it
2955 a valid address, which can also be shared. Otherwise, copy it and
2958 First check for common cases that need no processing. These are
2959 usually due to instantiation already being done on a previous instance
2963 if (CONSTANT_ADDRESS_P (temp)
2964 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2965 || temp == arg_pointer_rtx
2967 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2968 || temp == hard_frame_pointer_rtx
2970 || temp == frame_pointer_rtx)
2973 if (GET_CODE (temp) == PLUS
2974 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2975 && (XEXP (temp, 0) == frame_pointer_rtx
2976 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2977 || XEXP (temp, 0) == hard_frame_pointer_rtx
2979 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2980 || XEXP (temp, 0) == arg_pointer_rtx
2985 if (temp == virtual_stack_vars_rtx
2986 || temp == virtual_incoming_args_rtx
2987 || (GET_CODE (temp) == PLUS
2988 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
2989 && (XEXP (temp, 0) == virtual_stack_vars_rtx
2990 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
2992 /* This MEM may be shared. If the substitution can be done without
2993 the need to generate new pseudos, we want to do it in place
2994 so all copies of the shared rtx benefit. The call below will
2995 only make substitutions if the resulting address is still
2998 Note that we cannot pass X as the object in the recursive call
2999 since the insn being processed may not allow all valid
3000 addresses. However, if we were not passed on object, we can
3001 only modify X without copying it if X will have a valid
3004 ??? Also note that this can still lose if OBJECT is an insn that
3005 has less restrictions on an address that some other insn.
3006 In that case, we will modify the shared address. This case
3007 doesn't seem very likely, though. One case where this could
3008 happen is in the case of a USE or CLOBBER reference, but we
3009 take care of that below. */
3011 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
3012 object ? object : x, 0))
3015 /* Otherwise make a copy and process that copy. We copy the entire
3016 RTL expression since it might be a PLUS which could also be
3018 *loc = x = copy_rtx (x);
3021 /* Fall through to generic unary operation case. */
3023 case STRICT_LOW_PART:
3025 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
3026 case SIGN_EXTEND: case ZERO_EXTEND:
3027 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
3028 case FLOAT: case FIX:
3029 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
3033 /* These case either have just one operand or we know that we need not
3034 check the rest of the operands. */
3040 /* If the operand is a MEM, see if the change is a valid MEM. If not,
3041 go ahead and make the invalid one, but do it to a copy. For a REG,
3042 just make the recursive call, since there's no chance of a problem. */
3044 if ((GET_CODE (XEXP (x, 0)) == MEM
3045 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
3047 || (GET_CODE (XEXP (x, 0)) == REG
3048 && instantiate_virtual_regs_1 (&XEXP (x, 0), 0, 0)))
3051 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
3056 /* Try to replace with a PLUS. If that doesn't work, compute the sum
3057 in front of this insn and substitute the temporary. */
3058 if (x == virtual_incoming_args_rtx)
3059 new = arg_pointer_rtx, offset = in_arg_offset;
3060 else if (x == virtual_stack_vars_rtx)
3061 new = frame_pointer_rtx, offset = var_offset;
3062 else if (x == virtual_stack_dynamic_rtx)
3063 new = stack_pointer_rtx, offset = dynamic_offset;
3064 else if (x == virtual_outgoing_args_rtx)
3065 new = stack_pointer_rtx, offset = out_arg_offset;
3069 temp = plus_constant (new, offset);
3070 if (!validate_change (object, loc, temp, 0))
3076 temp = force_operand (temp, NULL_RTX);
3080 emit_insns_before (seq, object);
3081 if (! validate_change (object, loc, temp, 0)
3082 && ! validate_replace_rtx (x, temp, object))
3090 /* Scan all subexpressions. */
3091 fmt = GET_RTX_FORMAT (code);
3092 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3095 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
3098 else if (*fmt == 'E')
3099 for (j = 0; j < XVECLEN (x, i); j++)
3100 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
3107 /* Optimization: assuming this function does not receive nonlocal gotos,
3108 delete the handlers for such, as well as the insns to establish
3109 and disestablish them. */
3115 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3117 /* Delete the handler by turning off the flag that would
3118 prevent jump_optimize from deleting it.
3119 Also permit deletion of the nonlocal labels themselves
3120 if nothing local refers to them. */
3121 if (GET_CODE (insn) == CODE_LABEL)
3125 LABEL_PRESERVE_P (insn) = 0;
3127 /* Remove it from the nonlocal_label list, to avoid confusing
3129 for (t = nonlocal_labels, last_t = 0; t;
3130 last_t = t, t = TREE_CHAIN (t))
3131 if (DECL_RTL (TREE_VALUE (t)) == insn)
3136 nonlocal_labels = TREE_CHAIN (nonlocal_labels);
3138 TREE_CHAIN (last_t) = TREE_CHAIN (t);
3141 if (GET_CODE (insn) == INSN
3142 && ((nonlocal_goto_handler_slot != 0
3143 && reg_mentioned_p (nonlocal_goto_handler_slot, PATTERN (insn)))
3144 || (nonlocal_goto_stack_level != 0
3145 && reg_mentioned_p (nonlocal_goto_stack_level,
3151 /* Return a list (chain of EXPR_LIST nodes) for the nonlocal labels
3152 of the current function. */
3155 nonlocal_label_rtx_list ()
3160 for (t = nonlocal_labels; t; t = TREE_CHAIN (t))
3161 x = gen_rtx (EXPR_LIST, VOIDmode, label_rtx (TREE_VALUE (t)), x);
3166 /* Output a USE for any register use in RTL.
3167 This is used with -noreg to mark the extent of lifespan
3168 of any registers used in a user-visible variable's DECL_RTL. */
3174 if (GET_CODE (rtl) == REG)
3175 /* This is a register variable. */
3176 emit_insn (gen_rtx (USE, VOIDmode, rtl));
3177 else if (GET_CODE (rtl) == MEM
3178 && GET_CODE (XEXP (rtl, 0)) == REG
3179 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
3180 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
3181 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
3182 /* This is a variable-sized structure. */
3183 emit_insn (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)));
3186 /* Like use_variable except that it outputs the USEs after INSN
3187 instead of at the end of the insn-chain. */
3190 use_variable_after (rtl, insn)
3193 if (GET_CODE (rtl) == REG)
3194 /* This is a register variable. */
3195 emit_insn_after (gen_rtx (USE, VOIDmode, rtl), insn);
3196 else if (GET_CODE (rtl) == MEM
3197 && GET_CODE (XEXP (rtl, 0)) == REG
3198 && (REGNO (XEXP (rtl, 0)) < FIRST_VIRTUAL_REGISTER
3199 || REGNO (XEXP (rtl, 0)) > LAST_VIRTUAL_REGISTER)
3200 && XEXP (rtl, 0) != current_function_internal_arg_pointer)
3201 /* This is a variable-sized structure. */
3202 emit_insn_after (gen_rtx (USE, VOIDmode, XEXP (rtl, 0)), insn);
3208 return max_parm_reg;
3211 /* Return the first insn following those generated by `assign_parms'. */
3214 get_first_nonparm_insn ()
3217 return NEXT_INSN (last_parm_insn);
3218 return get_insns ();
3221 /* Return the first NOTE_INSN_BLOCK_BEG note in the function.
3222 Crash if there is none. */
3225 get_first_block_beg ()
3227 register rtx searcher;
3228 register rtx insn = get_first_nonparm_insn ();
3230 for (searcher = insn; searcher; searcher = NEXT_INSN (searcher))
3231 if (GET_CODE (searcher) == NOTE
3232 && NOTE_LINE_NUMBER (searcher) == NOTE_INSN_BLOCK_BEG)
3235 abort (); /* Invalid call to this function. (See comments above.) */
3239 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
3240 This means a type for which function calls must pass an address to the
3241 function or get an address back from the function.
3242 EXP may be a type node or an expression (whose type is tested). */
3245 aggregate_value_p (exp)
3248 int i, regno, nregs;
3251 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 't')
3254 type = TREE_TYPE (exp);
3256 if (RETURN_IN_MEMORY (type))
3258 /* Types that are TREE_ADDRESSABLE must be contructed in memory,
3259 and thus can't be returned in registers. */
3260 if (TREE_ADDRESSABLE (type))
3262 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
3264 /* Make sure we have suitable call-clobbered regs to return
3265 the value in; if not, we must return it in memory. */
3266 reg = hard_function_value (type, 0);
3268 /* If we have something other than a REG (e.g. a PARALLEL), then assume
3270 if (GET_CODE (reg) != REG)
3273 regno = REGNO (reg);
3274 nregs = HARD_REGNO_NREGS (regno, TYPE_MODE (type));
3275 for (i = 0; i < nregs; i++)
3276 if (! call_used_regs[regno + i])
3281 /* Assign RTL expressions to the function's parameters.
3282 This may involve copying them into registers and using
3283 those registers as the RTL for them.
3285 If SECOND_TIME is non-zero it means that this function is being
3286 called a second time. This is done by integrate.c when a function's
3287 compilation is deferred. We need to come back here in case the
3288 FUNCTION_ARG macro computes items needed for the rest of the compilation
3289 (such as changing which registers are fixed or caller-saved). But suppress
3290 writing any insns or setting DECL_RTL of anything in this case. */
3293 assign_parms (fndecl, second_time)
3298 register rtx entry_parm = 0;
3299 register rtx stack_parm = 0;
3300 CUMULATIVE_ARGS args_so_far;
3301 enum machine_mode promoted_mode, passed_mode;
3302 enum machine_mode nominal_mode, promoted_nominal_mode;
3304 /* Total space needed so far for args on the stack,
3305 given as a constant and a tree-expression. */
3306 struct args_size stack_args_size;
3307 tree fntype = TREE_TYPE (fndecl);
3308 tree fnargs = DECL_ARGUMENTS (fndecl);
3309 /* This is used for the arg pointer when referring to stack args. */
3310 rtx internal_arg_pointer;
3311 /* This is a dummy PARM_DECL that we used for the function result if
3312 the function returns a structure. */
3313 tree function_result_decl = 0;
3314 int nparmregs = list_length (fnargs) + LAST_VIRTUAL_REGISTER + 1;
3315 int varargs_setup = 0;
3316 rtx conversion_insns = 0;
3318 /* Nonzero if the last arg is named `__builtin_va_alist',
3319 which is used on some machines for old-fashioned non-ANSI varargs.h;
3320 this should be stuck onto the stack as if it had arrived there. */
3322 = (current_function_varargs
3324 && (parm = tree_last (fnargs)) != 0
3326 && (! strcmp (IDENTIFIER_POINTER (DECL_NAME (parm)),
3327 "__builtin_va_alist")));
3329 /* Nonzero if function takes extra anonymous args.
3330 This means the last named arg must be on the stack
3331 right before the anonymous ones. */
3333 = (TYPE_ARG_TYPES (fntype) != 0
3334 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3335 != void_type_node));
3337 current_function_stdarg = stdarg;
3339 /* If the reg that the virtual arg pointer will be translated into is
3340 not a fixed reg or is the stack pointer, make a copy of the virtual
3341 arg pointer, and address parms via the copy. The frame pointer is
3342 considered fixed even though it is not marked as such.
3344 The second time through, simply use ap to avoid generating rtx. */
3346 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
3347 || ! (fixed_regs[ARG_POINTER_REGNUM]
3348 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM))
3350 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
3352 internal_arg_pointer = virtual_incoming_args_rtx;
3353 current_function_internal_arg_pointer = internal_arg_pointer;
3355 stack_args_size.constant = 0;
3356 stack_args_size.var = 0;
3358 /* If struct value address is treated as the first argument, make it so. */
3359 if (aggregate_value_p (DECL_RESULT (fndecl))
3360 && ! current_function_returns_pcc_struct
3361 && struct_value_incoming_rtx == 0)
3363 tree type = build_pointer_type (TREE_TYPE (fntype));
3365 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
3367 DECL_ARG_TYPE (function_result_decl) = type;
3368 TREE_CHAIN (function_result_decl) = fnargs;
3369 fnargs = function_result_decl;
3372 parm_reg_stack_loc = (rtx *) oballoc (nparmregs * sizeof (rtx));
3373 bzero ((char *) parm_reg_stack_loc, nparmregs * sizeof (rtx));
3375 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
3376 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
3378 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, 0);
3381 /* We haven't yet found an argument that we must push and pretend the
3383 current_function_pretend_args_size = 0;
3385 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3387 int aggregate = AGGREGATE_TYPE_P (TREE_TYPE (parm));
3388 struct args_size stack_offset;
3389 struct args_size arg_size;
3390 int passed_pointer = 0;
3391 int did_conversion = 0;
3392 tree passed_type = DECL_ARG_TYPE (parm);
3393 tree nominal_type = TREE_TYPE (parm);
3395 /* Set LAST_NAMED if this is last named arg before some
3396 anonymous args. We treat it as if it were anonymous too. */
3397 int last_named = ((TREE_CHAIN (parm) == 0
3398 || DECL_NAME (TREE_CHAIN (parm)) == 0)
3399 && (stdarg || current_function_varargs));
3401 if (TREE_TYPE (parm) == error_mark_node
3402 /* This can happen after weird syntax errors
3403 or if an enum type is defined among the parms. */
3404 || TREE_CODE (parm) != PARM_DECL
3405 || passed_type == NULL)
3407 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = gen_rtx (MEM, BLKmode,
3409 TREE_USED (parm) = 1;
3413 /* For varargs.h function, save info about regs and stack space
3414 used by the individual args, not including the va_alist arg. */
3415 if (hide_last_arg && last_named)
3416 current_function_args_info = args_so_far;
3418 /* Find mode of arg as it is passed, and mode of arg
3419 as it should be during execution of this function. */
3420 passed_mode = TYPE_MODE (passed_type);
3421 nominal_mode = TYPE_MODE (nominal_type);
3423 /* If the parm's mode is VOID, its value doesn't matter,
3424 and avoid the usual things like emit_move_insn that could crash. */
3425 if (nominal_mode == VOIDmode)
3427 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = const0_rtx;
3431 /* If the parm is to be passed as a transparent union, use the
3432 type of the first field for the tests below. We have already
3433 verified that the modes are the same. */
3434 if (DECL_TRANSPARENT_UNION (parm)
3435 || TYPE_TRANSPARENT_UNION (passed_type))
3436 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
3438 /* See if this arg was passed by invisible reference. It is if
3439 it is an object whose size depends on the contents of the
3440 object itself or if the machine requires these objects be passed
3443 if ((TREE_CODE (TYPE_SIZE (passed_type)) != INTEGER_CST
3444 && contains_placeholder_p (TYPE_SIZE (passed_type)))
3445 || TREE_ADDRESSABLE (passed_type)
3446 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3447 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
3448 passed_type, ! last_named)
3452 passed_type = nominal_type = build_pointer_type (passed_type);
3454 passed_mode = nominal_mode = Pmode;
3457 promoted_mode = passed_mode;
3459 #ifdef PROMOTE_FUNCTION_ARGS
3460 /* Compute the mode in which the arg is actually extended to. */
3461 promoted_mode = promote_mode (passed_type, promoted_mode, &unsignedp, 1);
3464 /* Let machine desc say which reg (if any) the parm arrives in.
3465 0 means it arrives on the stack. */
3466 #ifdef FUNCTION_INCOMING_ARG
3467 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
3468 passed_type, ! last_named);
3470 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
3471 passed_type, ! last_named);
3474 if (entry_parm == 0)
3475 promoted_mode = passed_mode;
3477 #ifdef SETUP_INCOMING_VARARGS
3478 /* If this is the last named parameter, do any required setup for
3479 varargs or stdargs. We need to know about the case of this being an
3480 addressable type, in which case we skip the registers it
3481 would have arrived in.
3483 For stdargs, LAST_NAMED will be set for two parameters, the one that
3484 is actually the last named, and the dummy parameter. We only
3485 want to do this action once.
3487 Also, indicate when RTL generation is to be suppressed. */
3488 if (last_named && !varargs_setup)
3490 SETUP_INCOMING_VARARGS (args_so_far, promoted_mode, passed_type,
3491 current_function_pretend_args_size,
3497 /* Determine parm's home in the stack,
3498 in case it arrives in the stack or we should pretend it did.
3500 Compute the stack position and rtx where the argument arrives
3503 There is one complexity here: If this was a parameter that would
3504 have been passed in registers, but wasn't only because it is
3505 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
3506 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
3507 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
3508 0 as it was the previous time. */
3510 locate_and_pad_parm (promoted_mode, passed_type,
3511 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3514 #ifdef FUNCTION_INCOMING_ARG
3515 FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
3518 || varargs_setup)) != 0,
3520 FUNCTION_ARG (args_so_far, promoted_mode,
3522 ! last_named || varargs_setup) != 0,
3525 fndecl, &stack_args_size, &stack_offset, &arg_size);
3529 rtx offset_rtx = ARGS_SIZE_RTX (stack_offset);
3531 if (offset_rtx == const0_rtx)
3532 stack_parm = gen_rtx (MEM, promoted_mode, internal_arg_pointer);
3534 stack_parm = gen_rtx (MEM, promoted_mode,
3535 gen_rtx (PLUS, Pmode,
3536 internal_arg_pointer, offset_rtx));
3538 /* If this is a memory ref that contains aggregate components,
3539 mark it as such for cse and loop optimize. Likewise if it
3541 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3542 RTX_UNCHANGING_P (stack_parm) = TREE_READONLY (parm);
3545 /* If this parameter was passed both in registers and in the stack,
3546 use the copy on the stack. */
3547 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
3550 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3551 /* If this parm was passed part in regs and part in memory,
3552 pretend it arrived entirely in memory
3553 by pushing the register-part onto the stack.
3555 In the special case of a DImode or DFmode that is split,
3556 we could put it together in a pseudoreg directly,
3557 but for now that's not worth bothering with. */
3561 int nregs = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
3562 passed_type, ! last_named);
3566 current_function_pretend_args_size
3567 = (((nregs * UNITS_PER_WORD) + (PARM_BOUNDARY / BITS_PER_UNIT) - 1)
3568 / (PARM_BOUNDARY / BITS_PER_UNIT)
3569 * (PARM_BOUNDARY / BITS_PER_UNIT));
3573 /* Handle calls that pass values in multiple non-contiguous
3574 locations. The Irix 6 ABI has examples of this. */
3575 if (GET_CODE (entry_parm) == PARALLEL)
3576 emit_group_store (validize_mem (stack_parm),
3579 move_block_from_reg (REGNO (entry_parm),
3580 validize_mem (stack_parm), nregs,
3581 int_size_in_bytes (TREE_TYPE (parm)));
3583 entry_parm = stack_parm;
3588 /* If we didn't decide this parm came in a register,
3589 by default it came on the stack. */
3590 if (entry_parm == 0)
3591 entry_parm = stack_parm;
3593 /* Record permanently how this parm was passed. */
3595 DECL_INCOMING_RTL (parm) = entry_parm;
3597 /* If there is actually space on the stack for this parm,
3598 count it in stack_args_size; otherwise set stack_parm to 0
3599 to indicate there is no preallocated stack slot for the parm. */
3601 if (entry_parm == stack_parm
3602 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
3603 /* On some machines, even if a parm value arrives in a register
3604 there is still an (uninitialized) stack slot allocated for it.
3606 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
3607 whether this parameter already has a stack slot allocated,
3608 because an arg block exists only if current_function_args_size
3609 is larger than some threshold, and we haven't calculated that
3610 yet. So, for now, we just assume that stack slots never exist
3612 || REG_PARM_STACK_SPACE (fndecl) > 0
3616 stack_args_size.constant += arg_size.constant;
3618 ADD_PARM_SIZE (stack_args_size, arg_size.var);
3621 /* No stack slot was pushed for this parm. */
3624 /* Update info on where next arg arrives in registers. */
3626 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
3627 passed_type, ! last_named);
3629 /* If this is our second time through, we are done with this parm. */
3633 /* If we can't trust the parm stack slot to be aligned enough
3634 for its ultimate type, don't use that slot after entry.
3635 We'll make another stack slot, if we need one. */
3637 int thisparm_boundary
3638 = FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type);
3640 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
3644 /* If parm was passed in memory, and we need to convert it on entry,
3645 don't store it back in that same slot. */
3647 && nominal_mode != BLKmode && nominal_mode != passed_mode)
3651 /* Now adjust STACK_PARM to the mode and precise location
3652 where this parameter should live during execution,
3653 if we discover that it must live in the stack during execution.
3654 To make debuggers happier on big-endian machines, we store
3655 the value in the last bytes of the space available. */
3657 if (nominal_mode != BLKmode && nominal_mode != passed_mode
3662 if (BYTES_BIG_ENDIAN
3663 && GET_MODE_SIZE (nominal_mode) < UNITS_PER_WORD)
3664 stack_offset.constant += (GET_MODE_SIZE (passed_mode)
3665 - GET_MODE_SIZE (nominal_mode));
3667 offset_rtx = ARGS_SIZE_RTX (stack_offset);
3668 if (offset_rtx == const0_rtx)
3669 stack_parm = gen_rtx (MEM, nominal_mode, internal_arg_pointer);
3671 stack_parm = gen_rtx (MEM, nominal_mode,
3672 gen_rtx (PLUS, Pmode,
3673 internal_arg_pointer, offset_rtx));
3675 /* If this is a memory ref that contains aggregate components,
3676 mark it as such for cse and loop optimize. */
3677 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3682 /* We need this "use" info, because the gcc-register->stack-register
3683 converter in reg-stack.c needs to know which registers are active
3684 at the start of the function call. The actual parameter loading
3685 instructions are not always available then anymore, since they might
3686 have been optimised away. */
3688 if (GET_CODE (entry_parm) == REG && !(hide_last_arg && last_named))
3689 emit_insn (gen_rtx (USE, GET_MODE (entry_parm), entry_parm));
3692 /* ENTRY_PARM is an RTX for the parameter as it arrives,
3693 in the mode in which it arrives.
3694 STACK_PARM is an RTX for a stack slot where the parameter can live
3695 during the function (in case we want to put it there).
3696 STACK_PARM is 0 if no stack slot was pushed for it.
3698 Now output code if necessary to convert ENTRY_PARM to
3699 the type in which this function declares it,
3700 and store that result in an appropriate place,
3701 which may be a pseudo reg, may be STACK_PARM,
3702 or may be a local stack slot if STACK_PARM is 0.
3704 Set DECL_RTL to that place. */
3706 if (nominal_mode == BLKmode || GET_CODE (entry_parm) == PARALLEL)
3708 /* If a BLKmode arrives in registers, copy it to a stack slot.
3709 Handle calls that pass values in multiple non-contiguous
3710 locations. The Irix 6 ABI has examples of this. */
3711 if (GET_CODE (entry_parm) == REG
3712 || GET_CODE (entry_parm) == PARALLEL)
3715 = CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm)),
3718 /* Note that we will be storing an integral number of words.
3719 So we have to be careful to ensure that we allocate an
3720 integral number of words. We do this below in the
3721 assign_stack_local if space was not allocated in the argument
3722 list. If it was, this will not work if PARM_BOUNDARY is not
3723 a multiple of BITS_PER_WORD. It isn't clear how to fix this
3724 if it becomes a problem. */
3726 if (stack_parm == 0)
3729 = assign_stack_local (GET_MODE (entry_parm),
3732 /* If this is a memory ref that contains aggregate
3733 components, mark it as such for cse and loop optimize. */
3734 MEM_IN_STRUCT_P (stack_parm) = aggregate;
3737 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
3740 if (TREE_READONLY (parm))
3741 RTX_UNCHANGING_P (stack_parm) = 1;
3743 /* Handle calls that pass values in multiple non-contiguous
3744 locations. The Irix 6 ABI has examples of this. */
3745 if (GET_CODE (entry_parm) == PARALLEL)
3746 emit_group_store (validize_mem (stack_parm), entry_parm);
3748 move_block_from_reg (REGNO (entry_parm),
3749 validize_mem (stack_parm),
3750 size_stored / UNITS_PER_WORD,
3751 int_size_in_bytes (TREE_TYPE (parm)));
3753 DECL_RTL (parm) = stack_parm;
3755 else if (! ((obey_regdecls && ! DECL_REGISTER (parm)
3756 && ! DECL_INLINE (fndecl))
3757 /* layout_decl may set this. */
3758 || TREE_ADDRESSABLE (parm)
3759 || TREE_SIDE_EFFECTS (parm)
3760 /* If -ffloat-store specified, don't put explicit
3761 float variables into registers. */
3762 || (flag_float_store
3763 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
3764 /* Always assign pseudo to structure return or item passed
3765 by invisible reference. */
3766 || passed_pointer || parm == function_result_decl)
3768 /* Store the parm in a pseudoregister during the function, but we
3769 may need to do it in a wider mode. */
3771 register rtx parmreg;
3772 int regno, regnoi, regnor;
3774 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
3776 promoted_nominal_mode
3777 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
3779 parmreg = gen_reg_rtx (promoted_nominal_mode);
3780 mark_user_reg (parmreg);
3782 /* If this was an item that we received a pointer to, set DECL_RTL
3787 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (passed_type)), parmreg);
3788 MEM_IN_STRUCT_P (DECL_RTL (parm)) = aggregate;
3791 DECL_RTL (parm) = parmreg;
3793 /* Copy the value into the register. */
3794 if (nominal_mode != passed_mode
3795 || promoted_nominal_mode != promoted_mode)
3797 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3798 mode, by the caller. We now have to convert it to
3799 NOMINAL_MODE, if different. However, PARMREG may be in
3800 a diffent mode than NOMINAL_MODE if it is being stored
3803 If ENTRY_PARM is a hard register, it might be in a register
3804 not valid for operating in its mode (e.g., an odd-numbered
3805 register for a DFmode). In that case, moves are the only
3806 thing valid, so we can't do a convert from there. This
3807 occurs when the calling sequence allow such misaligned
3810 In addition, the conversion may involve a call, which could
3811 clobber parameters which haven't been copied to pseudo
3812 registers yet. Therefore, we must first copy the parm to
3813 a pseudo reg here, and save the conversion until after all
3814 parameters have been moved. */
3816 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
3818 emit_move_insn (tempreg, validize_mem (entry_parm));
3820 push_to_sequence (conversion_insns);
3821 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
3823 expand_assignment (parm,
3824 make_tree (nominal_type, tempreg), 0, 0);
3825 conversion_insns = get_insns ();
3830 emit_move_insn (parmreg, validize_mem (entry_parm));
3832 /* If we were passed a pointer but the actual value
3833 can safely live in a register, put it in one. */
3834 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
3835 && ! ((obey_regdecls && ! DECL_REGISTER (parm)
3836 && ! DECL_INLINE (fndecl))
3837 /* layout_decl may set this. */
3838 || TREE_ADDRESSABLE (parm)
3839 || TREE_SIDE_EFFECTS (parm)
3840 /* If -ffloat-store specified, don't put explicit
3841 float variables into registers. */
3842 || (flag_float_store
3843 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE)))
3845 /* We can't use nominal_mode, because it will have been set to
3846 Pmode above. We must use the actual mode of the parm. */
3847 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3848 mark_user_reg (parmreg);
3849 emit_move_insn (parmreg, DECL_RTL (parm));
3850 DECL_RTL (parm) = parmreg;
3851 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3855 #ifdef FUNCTION_ARG_CALLEE_COPIES
3856 /* If we are passed an arg by reference and it is our responsibility
3857 to make a copy, do it now.
3858 PASSED_TYPE and PASSED mode now refer to the pointer, not the
3859 original argument, so we must recreate them in the call to
3860 FUNCTION_ARG_CALLEE_COPIES. */
3861 /* ??? Later add code to handle the case that if the argument isn't
3862 modified, don't do the copy. */
3864 else if (passed_pointer
3865 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
3866 TYPE_MODE (DECL_ARG_TYPE (parm)),
3867 DECL_ARG_TYPE (parm),
3869 && ! TREE_ADDRESSABLE (DECL_ARG_TYPE (parm)))
3872 tree type = DECL_ARG_TYPE (parm);
3874 /* This sequence may involve a library call perhaps clobbering
3875 registers that haven't been copied to pseudos yet. */
3877 push_to_sequence (conversion_insns);
3879 if (TYPE_SIZE (type) == 0
3880 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
3881 /* This is a variable sized object. */
3882 copy = gen_rtx (MEM, BLKmode,
3883 allocate_dynamic_stack_space
3884 (expr_size (parm), NULL_RTX,
3885 TYPE_ALIGN (type)));
3887 copy = assign_stack_temp (TYPE_MODE (type),
3888 int_size_in_bytes (type), 1);
3889 MEM_IN_STRUCT_P (copy) = AGGREGATE_TYPE_P (type);
3891 store_expr (parm, copy, 0);
3892 emit_move_insn (parmreg, XEXP (copy, 0));
3893 conversion_insns = get_insns ();
3897 #endif /* FUNCTION_ARG_CALLEE_COPIES */
3899 /* In any case, record the parm's desired stack location
3900 in case we later discover it must live in the stack.
3902 If it is a COMPLEX value, store the stack location for both
3905 if (GET_CODE (parmreg) == CONCAT)
3906 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
3908 regno = REGNO (parmreg);
3910 if (regno >= nparmregs)
3913 int old_nparmregs = nparmregs;
3915 nparmregs = regno + 5;
3916 new = (rtx *) oballoc (nparmregs * sizeof (rtx));
3917 bcopy ((char *) parm_reg_stack_loc, (char *) new,
3918 old_nparmregs * sizeof (rtx));
3919 bzero ((char *) (new + old_nparmregs),
3920 (nparmregs - old_nparmregs) * sizeof (rtx));
3921 parm_reg_stack_loc = new;
3924 if (GET_CODE (parmreg) == CONCAT)
3926 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
3928 regnor = REGNO (gen_realpart (submode, parmreg));
3929 regnoi = REGNO (gen_imagpart (submode, parmreg));
3931 if (stack_parm != 0)
3933 parm_reg_stack_loc[regnor]
3934 = gen_realpart (submode, stack_parm);
3935 parm_reg_stack_loc[regnoi]
3936 = gen_imagpart (submode, stack_parm);
3940 parm_reg_stack_loc[regnor] = 0;
3941 parm_reg_stack_loc[regnoi] = 0;
3945 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
3947 /* Mark the register as eliminable if we did no conversion
3948 and it was copied from memory at a fixed offset,
3949 and the arg pointer was not copied to a pseudo-reg.
3950 If the arg pointer is a pseudo reg or the offset formed
3951 an invalid address, such memory-equivalences
3952 as we make here would screw up life analysis for it. */
3953 if (nominal_mode == passed_mode
3955 && GET_CODE (entry_parm) == MEM
3956 && entry_parm == stack_parm
3957 && stack_offset.var == 0
3958 && reg_mentioned_p (virtual_incoming_args_rtx,
3959 XEXP (entry_parm, 0)))
3961 rtx linsn = get_last_insn ();
3964 /* Mark complex types separately. */
3965 if (GET_CODE (parmreg) == CONCAT)
3966 /* Scan backwards for the set of the real and
3968 for (sinsn = linsn; sinsn != 0;
3969 sinsn = prev_nonnote_insn (sinsn))
3971 set = single_set (sinsn);
3973 && SET_DEST (set) == regno_reg_rtx [regnoi])
3975 = gen_rtx (EXPR_LIST, REG_EQUIV,
3976 parm_reg_stack_loc[regnoi],
3979 && SET_DEST (set) == regno_reg_rtx [regnor])
3981 = gen_rtx (EXPR_LIST, REG_EQUIV,
3982 parm_reg_stack_loc[regnor],
3985 else if ((set = single_set (linsn)) != 0
3986 && SET_DEST (set) == parmreg)
3988 = gen_rtx (EXPR_LIST, REG_EQUIV,
3989 entry_parm, REG_NOTES (linsn));
3992 /* For pointer data type, suggest pointer register. */
3993 if (TREE_CODE (TREE_TYPE (parm)) == POINTER_TYPE)
3994 mark_reg_pointer (parmreg,
3995 (TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm)))
4000 /* Value must be stored in the stack slot STACK_PARM
4001 during function execution. */
4003 if (promoted_mode != nominal_mode)
4005 /* Conversion is required. */
4006 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4008 emit_move_insn (tempreg, validize_mem (entry_parm));
4010 push_to_sequence (conversion_insns);
4011 entry_parm = convert_to_mode (nominal_mode, tempreg,
4012 TREE_UNSIGNED (TREE_TYPE (parm)));
4013 conversion_insns = get_insns ();
4018 if (entry_parm != stack_parm)
4020 if (stack_parm == 0)
4023 = assign_stack_local (GET_MODE (entry_parm),
4024 GET_MODE_SIZE (GET_MODE (entry_parm)), 0);
4025 /* If this is a memory ref that contains aggregate components,
4026 mark it as such for cse and loop optimize. */
4027 MEM_IN_STRUCT_P (stack_parm) = aggregate;
4030 if (promoted_mode != nominal_mode)
4032 push_to_sequence (conversion_insns);
4033 emit_move_insn (validize_mem (stack_parm),
4034 validize_mem (entry_parm));
4035 conversion_insns = get_insns ();
4039 emit_move_insn (validize_mem (stack_parm),
4040 validize_mem (entry_parm));
4043 DECL_RTL (parm) = stack_parm;
4046 /* If this "parameter" was the place where we are receiving the
4047 function's incoming structure pointer, set up the result. */
4048 if (parm == function_result_decl)
4050 tree result = DECL_RESULT (fndecl);
4051 tree restype = TREE_TYPE (result);
4054 = gen_rtx (MEM, DECL_MODE (result), DECL_RTL (parm));
4056 MEM_IN_STRUCT_P (DECL_RTL (result)) = AGGREGATE_TYPE_P (restype);
4059 if (TREE_THIS_VOLATILE (parm))
4060 MEM_VOLATILE_P (DECL_RTL (parm)) = 1;
4061 if (TREE_READONLY (parm))
4062 RTX_UNCHANGING_P (DECL_RTL (parm)) = 1;
4065 /* Output all parameter conversion instructions (possibly including calls)
4066 now that all parameters have been copied out of hard registers. */
4067 emit_insns (conversion_insns);
4069 max_parm_reg = max_reg_num ();
4070 last_parm_insn = get_last_insn ();
4072 current_function_args_size = stack_args_size.constant;
4074 /* Adjust function incoming argument size for alignment and
4077 #ifdef REG_PARM_STACK_SPACE
4078 #ifndef MAYBE_REG_PARM_STACK_SPACE
4079 current_function_args_size = MAX (current_function_args_size,
4080 REG_PARM_STACK_SPACE (fndecl));
4084 #ifdef STACK_BOUNDARY
4085 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
4087 current_function_args_size
4088 = ((current_function_args_size + STACK_BYTES - 1)
4089 / STACK_BYTES) * STACK_BYTES;
4092 #ifdef ARGS_GROW_DOWNWARD
4093 current_function_arg_offset_rtx
4094 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
4095 : expand_expr (size_binop (MINUS_EXPR, stack_args_size.var,
4096 size_int (-stack_args_size.constant)),
4097 NULL_RTX, VOIDmode, 0));
4099 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
4102 /* See how many bytes, if any, of its args a function should try to pop
4105 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
4106 current_function_args_size);
4108 /* For stdarg.h function, save info about
4109 regs and stack space used by the named args. */
4112 current_function_args_info = args_so_far;
4114 /* Set the rtx used for the function return value. Put this in its
4115 own variable so any optimizers that need this information don't have
4116 to include tree.h. Do this here so it gets done when an inlined
4117 function gets output. */
4119 current_function_return_rtx = DECL_RTL (DECL_RESULT (fndecl));
4122 /* Indicate whether REGNO is an incoming argument to the current function
4123 that was promoted to a wider mode. If so, return the RTX for the
4124 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
4125 that REGNO is promoted from and whether the promotion was signed or
4128 #ifdef PROMOTE_FUNCTION_ARGS
4131 promoted_input_arg (regno, pmode, punsignedp)
4133 enum machine_mode *pmode;
4138 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
4139 arg = TREE_CHAIN (arg))
4140 if (GET_CODE (DECL_INCOMING_RTL (arg)) == REG
4141 && REGNO (DECL_INCOMING_RTL (arg)) == regno
4142 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
4144 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
4145 int unsignedp = TREE_UNSIGNED (TREE_TYPE (arg));
4147 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
4148 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
4149 && mode != DECL_MODE (arg))
4151 *pmode = DECL_MODE (arg);
4152 *punsignedp = unsignedp;
4153 return DECL_INCOMING_RTL (arg);
4162 /* Compute the size and offset from the start of the stacked arguments for a
4163 parm passed in mode PASSED_MODE and with type TYPE.
4165 INITIAL_OFFSET_PTR points to the current offset into the stacked
4168 The starting offset and size for this parm are returned in *OFFSET_PTR
4169 and *ARG_SIZE_PTR, respectively.
4171 IN_REGS is non-zero if the argument will be passed in registers. It will
4172 never be set if REG_PARM_STACK_SPACE is not defined.
4174 FNDECL is the function in which the argument was defined.
4176 There are two types of rounding that are done. The first, controlled by
4177 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
4178 list to be aligned to the specific boundary (in bits). This rounding
4179 affects the initial and starting offsets, but not the argument size.
4181 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
4182 optionally rounds the size of the parm to PARM_BOUNDARY. The
4183 initial offset is not affected by this rounding, while the size always
4184 is and the starting offset may be. */
4186 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
4187 initial_offset_ptr is positive because locate_and_pad_parm's
4188 callers pass in the total size of args so far as
4189 initial_offset_ptr. arg_size_ptr is always positive.*/
4192 locate_and_pad_parm (passed_mode, type, in_regs, fndecl,
4193 initial_offset_ptr, offset_ptr, arg_size_ptr)
4194 enum machine_mode passed_mode;
4198 struct args_size *initial_offset_ptr;
4199 struct args_size *offset_ptr;
4200 struct args_size *arg_size_ptr;
4203 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
4204 enum direction where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
4205 int boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
4206 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4207 int reg_parm_stack_space = 0;
4209 #ifdef REG_PARM_STACK_SPACE
4210 /* If we have found a stack parm before we reach the end of the
4211 area reserved for registers, skip that area. */
4214 #ifdef MAYBE_REG_PARM_STACK_SPACE
4215 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
4217 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
4219 if (reg_parm_stack_space > 0)
4221 if (initial_offset_ptr->var)
4223 initial_offset_ptr->var
4224 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4225 size_int (reg_parm_stack_space));
4226 initial_offset_ptr->constant = 0;
4228 else if (initial_offset_ptr->constant < reg_parm_stack_space)
4229 initial_offset_ptr->constant = reg_parm_stack_space;
4232 #endif /* REG_PARM_STACK_SPACE */
4234 arg_size_ptr->var = 0;
4235 arg_size_ptr->constant = 0;
4237 #ifdef ARGS_GROW_DOWNWARD
4238 if (initial_offset_ptr->var)
4240 offset_ptr->constant = 0;
4241 offset_ptr->var = size_binop (MINUS_EXPR, integer_zero_node,
4242 initial_offset_ptr->var);
4246 offset_ptr->constant = - initial_offset_ptr->constant;
4247 offset_ptr->var = 0;
4249 if (where_pad != none
4250 && (TREE_CODE (sizetree) != INTEGER_CST
4251 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
4252 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4253 SUB_PARM_SIZE (*offset_ptr, sizetree);
4254 if (where_pad != downward)
4255 pad_to_arg_alignment (offset_ptr, boundary);
4256 if (initial_offset_ptr->var)
4258 arg_size_ptr->var = size_binop (MINUS_EXPR,
4259 size_binop (MINUS_EXPR,
4261 initial_offset_ptr->var),
4266 arg_size_ptr->constant = (- initial_offset_ptr->constant -
4267 offset_ptr->constant);
4269 #else /* !ARGS_GROW_DOWNWARD */
4270 pad_to_arg_alignment (initial_offset_ptr, boundary);
4271 *offset_ptr = *initial_offset_ptr;
4273 #ifdef PUSH_ROUNDING
4274 if (passed_mode != BLKmode)
4275 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4278 /* Pad_below needs the pre-rounded size to know how much to pad below
4279 so this must be done before rounding up. */
4280 if (where_pad == downward
4281 /* However, BLKmode args passed in regs have their padding done elsewhere.
4282 The stack slot must be able to hold the entire register. */
4283 && !(in_regs && passed_mode == BLKmode))
4284 pad_below (offset_ptr, passed_mode, sizetree);
4286 if (where_pad != none
4287 && (TREE_CODE (sizetree) != INTEGER_CST
4288 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
4289 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4291 ADD_PARM_SIZE (*arg_size_ptr, sizetree);
4292 #endif /* ARGS_GROW_DOWNWARD */
4295 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4296 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4299 pad_to_arg_alignment (offset_ptr, boundary)
4300 struct args_size *offset_ptr;
4303 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4305 if (boundary > BITS_PER_UNIT)
4307 if (offset_ptr->var)
4310 #ifdef ARGS_GROW_DOWNWARD
4315 (ARGS_SIZE_TREE (*offset_ptr),
4316 boundary / BITS_PER_UNIT);
4317 offset_ptr->constant = 0; /*?*/
4320 offset_ptr->constant =
4321 #ifdef ARGS_GROW_DOWNWARD
4322 FLOOR_ROUND (offset_ptr->constant, boundary_in_bytes);
4324 CEIL_ROUND (offset_ptr->constant, boundary_in_bytes);
4330 pad_below (offset_ptr, passed_mode, sizetree)
4331 struct args_size *offset_ptr;
4332 enum machine_mode passed_mode;
4335 if (passed_mode != BLKmode)
4337 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
4338 offset_ptr->constant
4339 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
4340 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
4341 - GET_MODE_SIZE (passed_mode));
4345 if (TREE_CODE (sizetree) != INTEGER_CST
4346 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
4348 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4349 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4351 ADD_PARM_SIZE (*offset_ptr, s2);
4352 SUB_PARM_SIZE (*offset_ptr, sizetree);
4358 round_down (value, divisor)
4362 return size_binop (MULT_EXPR,
4363 size_binop (FLOOR_DIV_EXPR, value, size_int (divisor)),
4364 size_int (divisor));
4367 /* Walk the tree of blocks describing the binding levels within a function
4368 and warn about uninitialized variables.
4369 This is done after calling flow_analysis and before global_alloc
4370 clobbers the pseudo-regs to hard regs. */
4373 uninitialized_vars_warning (block)
4376 register tree decl, sub;
4377 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
4379 if (TREE_CODE (decl) == VAR_DECL
4380 /* These warnings are unreliable for and aggregates
4381 because assigning the fields one by one can fail to convince
4382 flow.c that the entire aggregate was initialized.
4383 Unions are troublesome because members may be shorter. */
4384 && ! AGGREGATE_TYPE_P (TREE_TYPE (decl))
4385 && DECL_RTL (decl) != 0
4386 && GET_CODE (DECL_RTL (decl)) == REG
4387 && regno_uninitialized (REGNO (DECL_RTL (decl))))
4388 warning_with_decl (decl,
4389 "`%s' might be used uninitialized in this function");
4390 if (TREE_CODE (decl) == VAR_DECL
4391 && DECL_RTL (decl) != 0
4392 && GET_CODE (DECL_RTL (decl)) == REG
4393 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
4394 warning_with_decl (decl,
4395 "variable `%s' might be clobbered by `longjmp' or `vfork'");
4397 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
4398 uninitialized_vars_warning (sub);
4401 /* Do the appropriate part of uninitialized_vars_warning
4402 but for arguments instead of local variables. */
4405 setjmp_args_warning ()
4408 for (decl = DECL_ARGUMENTS (current_function_decl);
4409 decl; decl = TREE_CHAIN (decl))
4410 if (DECL_RTL (decl) != 0
4411 && GET_CODE (DECL_RTL (decl)) == REG
4412 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
4413 warning_with_decl (decl, "argument `%s' might be clobbered by `longjmp' or `vfork'");
4416 /* If this function call setjmp, put all vars into the stack
4417 unless they were declared `register'. */
4420 setjmp_protect (block)
4423 register tree decl, sub;
4424 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
4425 if ((TREE_CODE (decl) == VAR_DECL
4426 || TREE_CODE (decl) == PARM_DECL)
4427 && DECL_RTL (decl) != 0
4428 && GET_CODE (DECL_RTL (decl)) == REG
4429 /* If this variable came from an inline function, it must be
4430 that it's life doesn't overlap the setjmp. If there was a
4431 setjmp in the function, it would already be in memory. We
4432 must exclude such variable because their DECL_RTL might be
4433 set to strange things such as virtual_stack_vars_rtx. */
4434 && ! DECL_FROM_INLINE (decl)
4436 #ifdef NON_SAVING_SETJMP
4437 /* If longjmp doesn't restore the registers,
4438 don't put anything in them. */
4442 ! DECL_REGISTER (decl)))
4443 put_var_into_stack (decl);
4444 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
4445 setjmp_protect (sub);
4448 /* Like the previous function, but for args instead of local variables. */
4451 setjmp_protect_args ()
4453 register tree decl, sub;
4454 for (decl = DECL_ARGUMENTS (current_function_decl);
4455 decl; decl = TREE_CHAIN (decl))
4456 if ((TREE_CODE (decl) == VAR_DECL
4457 || TREE_CODE (decl) == PARM_DECL)
4458 && DECL_RTL (decl) != 0
4459 && GET_CODE (DECL_RTL (decl)) == REG
4461 /* If longjmp doesn't restore the registers,
4462 don't put anything in them. */
4463 #ifdef NON_SAVING_SETJMP
4467 ! DECL_REGISTER (decl)))
4468 put_var_into_stack (decl);
4471 /* Return the context-pointer register corresponding to DECL,
4472 or 0 if it does not need one. */
4475 lookup_static_chain (decl)
4478 tree context = decl_function_context (decl);
4482 || (TREE_CODE (decl) == FUNCTION_DECL && DECL_NO_STATIC_CHAIN (decl)))
4485 /* We treat inline_function_decl as an alias for the current function
4486 because that is the inline function whose vars, types, etc.
4487 are being merged into the current function.
4488 See expand_inline_function. */
4489 if (context == current_function_decl || context == inline_function_decl)
4490 return virtual_stack_vars_rtx;
4492 for (link = context_display; link; link = TREE_CHAIN (link))
4493 if (TREE_PURPOSE (link) == context)
4494 return RTL_EXPR_RTL (TREE_VALUE (link));
4499 /* Convert a stack slot address ADDR for variable VAR
4500 (from a containing function)
4501 into an address valid in this function (using a static chain). */
4504 fix_lexical_addr (addr, var)
4510 tree context = decl_function_context (var);
4511 struct function *fp;
4514 /* If this is the present function, we need not do anything. */
4515 if (context == current_function_decl || context == inline_function_decl)
4518 for (fp = outer_function_chain; fp; fp = fp->next)
4519 if (fp->decl == context)
4525 /* Decode given address as base reg plus displacement. */
4526 if (GET_CODE (addr) == REG)
4527 basereg = addr, displacement = 0;
4528 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
4529 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
4533 /* We accept vars reached via the containing function's
4534 incoming arg pointer and via its stack variables pointer. */
4535 if (basereg == fp->internal_arg_pointer)
4537 /* If reached via arg pointer, get the arg pointer value
4538 out of that function's stack frame.
4540 There are two cases: If a separate ap is needed, allocate a
4541 slot in the outer function for it and dereference it that way.
4542 This is correct even if the real ap is actually a pseudo.
4543 Otherwise, just adjust the offset from the frame pointer to
4546 #ifdef NEED_SEPARATE_AP
4549 if (fp->arg_pointer_save_area == 0)
4550 fp->arg_pointer_save_area
4551 = assign_outer_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0, fp);
4553 addr = fix_lexical_addr (XEXP (fp->arg_pointer_save_area, 0), var);
4554 addr = memory_address (Pmode, addr);
4556 base = copy_to_reg (gen_rtx (MEM, Pmode, addr));
4558 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
4559 base = lookup_static_chain (var);
4563 else if (basereg == virtual_stack_vars_rtx)
4565 /* This is the same code as lookup_static_chain, duplicated here to
4566 avoid an extra call to decl_function_context. */
4569 for (link = context_display; link; link = TREE_CHAIN (link))
4570 if (TREE_PURPOSE (link) == context)
4572 base = RTL_EXPR_RTL (TREE_VALUE (link));
4580 /* Use same offset, relative to appropriate static chain or argument
4582 return plus_constant (base, displacement);
4585 /* Return the address of the trampoline for entering nested fn FUNCTION.
4586 If necessary, allocate a trampoline (in the stack frame)
4587 and emit rtl to initialize its contents (at entry to this function). */
4590 trampoline_address (function)
4596 struct function *fp;
4599 /* Find an existing trampoline and return it. */
4600 for (link = trampoline_list; link; link = TREE_CHAIN (link))
4601 if (TREE_PURPOSE (link) == function)
4603 round_trampoline_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0));
4605 for (fp = outer_function_chain; fp; fp = fp->next)
4606 for (link = fp->trampoline_list; link; link = TREE_CHAIN (link))
4607 if (TREE_PURPOSE (link) == function)
4609 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
4611 return round_trampoline_addr (tramp);
4614 /* None exists; we must make one. */
4616 /* Find the `struct function' for the function containing FUNCTION. */
4618 fn_context = decl_function_context (function);
4619 if (fn_context != current_function_decl)
4620 for (fp = outer_function_chain; fp; fp = fp->next)
4621 if (fp->decl == fn_context)
4624 /* Allocate run-time space for this trampoline
4625 (usually in the defining function's stack frame). */
4626 #ifdef ALLOCATE_TRAMPOLINE
4627 tramp = ALLOCATE_TRAMPOLINE (fp);
4629 /* If rounding needed, allocate extra space
4630 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
4631 #ifdef TRAMPOLINE_ALIGNMENT
4632 #define TRAMPOLINE_REAL_SIZE \
4633 (TRAMPOLINE_SIZE + (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT) - 1)
4635 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE)
4638 tramp = assign_outer_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0, fp);
4640 tramp = assign_stack_local (BLKmode, TRAMPOLINE_REAL_SIZE, 0);
4643 /* Record the trampoline for reuse and note it for later initialization
4644 by expand_function_end. */
4647 push_obstacks (fp->function_maybepermanent_obstack,
4648 fp->function_maybepermanent_obstack);
4649 rtlexp = make_node (RTL_EXPR);
4650 RTL_EXPR_RTL (rtlexp) = tramp;
4651 fp->trampoline_list = tree_cons (function, rtlexp, fp->trampoline_list);
4656 /* Make the RTL_EXPR node temporary, not momentary, so that the
4657 trampoline_list doesn't become garbage. */
4658 int momentary = suspend_momentary ();
4659 rtlexp = make_node (RTL_EXPR);
4660 resume_momentary (momentary);
4662 RTL_EXPR_RTL (rtlexp) = tramp;
4663 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
4666 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
4667 return round_trampoline_addr (tramp);
4670 /* Given a trampoline address,
4671 round it to multiple of TRAMPOLINE_ALIGNMENT. */
4674 round_trampoline_addr (tramp)
4677 #ifdef TRAMPOLINE_ALIGNMENT
4678 /* Round address up to desired boundary. */
4679 rtx temp = gen_reg_rtx (Pmode);
4680 temp = expand_binop (Pmode, add_optab, tramp,
4681 GEN_INT (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT - 1),
4682 temp, 0, OPTAB_LIB_WIDEN);
4683 tramp = expand_binop (Pmode, and_optab, temp,
4684 GEN_INT (- TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT),
4685 temp, 0, OPTAB_LIB_WIDEN);
4690 /* The functions identify_blocks and reorder_blocks provide a way to
4691 reorder the tree of BLOCK nodes, for optimizers that reshuffle or
4692 duplicate portions of the RTL code. Call identify_blocks before
4693 changing the RTL, and call reorder_blocks after. */
4695 /* Put all this function's BLOCK nodes including those that are chained
4696 onto the first block into a vector, and return it.
4697 Also store in each NOTE for the beginning or end of a block
4698 the index of that block in the vector.
4699 The arguments are BLOCK, the chain of top-level blocks of the function,
4700 and INSNS, the insn chain of the function. */
4703 identify_blocks (block, insns)
4711 int next_block_number = 1;
4712 int current_block_number = 1;
4718 n_blocks = all_blocks (block, 0);
4719 block_vector = (tree *) xmalloc (n_blocks * sizeof (tree));
4720 block_stack = (int *) alloca (n_blocks * sizeof (int));
4722 all_blocks (block, block_vector);
4724 for (insn = insns; insn; insn = NEXT_INSN (insn))
4725 if (GET_CODE (insn) == NOTE)
4727 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
4729 block_stack[depth++] = current_block_number;
4730 current_block_number = next_block_number;
4731 NOTE_BLOCK_NUMBER (insn) = next_block_number++;
4733 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
4735 current_block_number = block_stack[--depth];
4736 NOTE_BLOCK_NUMBER (insn) = current_block_number;
4740 if (n_blocks != next_block_number)
4743 return block_vector;
4746 /* Given BLOCK_VECTOR which was returned by identify_blocks,
4747 and a revised instruction chain, rebuild the tree structure
4748 of BLOCK nodes to correspond to the new order of RTL.
4749 The new block tree is inserted below TOP_BLOCK.
4750 Returns the current top-level block. */
4753 reorder_blocks (block_vector, block, insns)
4758 tree current_block = block;
4761 if (block_vector == 0)
4764 /* Prune the old trees away, so that it doesn't get in the way. */
4765 BLOCK_SUBBLOCKS (current_block) = 0;
4766 BLOCK_CHAIN (current_block) = 0;
4768 for (insn = insns; insn; insn = NEXT_INSN (insn))
4769 if (GET_CODE (insn) == NOTE)
4771 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
4773 tree block = block_vector[NOTE_BLOCK_NUMBER (insn)];
4774 /* If we have seen this block before, copy it. */
4775 if (TREE_ASM_WRITTEN (block))
4776 block = copy_node (block);
4777 BLOCK_SUBBLOCKS (block) = 0;
4778 TREE_ASM_WRITTEN (block) = 1;
4779 BLOCK_SUPERCONTEXT (block) = current_block;
4780 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4781 BLOCK_SUBBLOCKS (current_block) = block;
4782 current_block = block;
4783 NOTE_SOURCE_FILE (insn) = 0;
4785 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
4787 BLOCK_SUBBLOCKS (current_block)
4788 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
4789 current_block = BLOCK_SUPERCONTEXT (current_block);
4790 NOTE_SOURCE_FILE (insn) = 0;
4794 BLOCK_SUBBLOCKS (current_block)
4795 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
4796 return current_block;
4799 /* Reverse the order of elements in the chain T of blocks,
4800 and return the new head of the chain (old last element). */
4806 register tree prev = 0, decl, next;
4807 for (decl = t; decl; decl = next)
4809 next = BLOCK_CHAIN (decl);
4810 BLOCK_CHAIN (decl) = prev;
4816 /* Count the subblocks of the list starting with BLOCK, and list them
4817 all into the vector VECTOR. Also clear TREE_ASM_WRITTEN in all
4821 all_blocks (block, vector)
4829 TREE_ASM_WRITTEN (block) = 0;
4831 /* Record this block. */
4833 vector[n_blocks] = block;
4837 /* Record the subblocks, and their subblocks... */
4838 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4839 vector ? vector + n_blocks : 0);
4840 block = BLOCK_CHAIN (block);
4846 /* Build bytecode call descriptor for function SUBR. */
4849 bc_build_calldesc (subr)
4852 tree calldesc = 0, arg;
4855 /* Build the argument description vector in reverse order. */
4856 DECL_ARGUMENTS (subr) = nreverse (DECL_ARGUMENTS (subr));
4859 for (arg = DECL_ARGUMENTS (subr); arg; arg = TREE_CHAIN (arg))
4863 calldesc = tree_cons ((tree) 0, size_in_bytes (TREE_TYPE (arg)), calldesc);
4864 calldesc = tree_cons ((tree) 0, bc_runtime_type_code (TREE_TYPE (arg)), calldesc);
4867 DECL_ARGUMENTS (subr) = nreverse (DECL_ARGUMENTS (subr));
4869 /* Prepend the function's return type. */
4870 calldesc = tree_cons ((tree) 0,
4871 size_in_bytes (TREE_TYPE (TREE_TYPE (subr))),
4874 calldesc = tree_cons ((tree) 0,
4875 bc_runtime_type_code (TREE_TYPE (TREE_TYPE (subr))),
4878 /* Prepend the arg count. */
4879 calldesc = tree_cons ((tree) 0, build_int_2 (nargs, 0), calldesc);
4881 /* Output the call description vector and get its address. */
4882 calldesc = build_nt (CONSTRUCTOR, (tree) 0, calldesc);
4883 TREE_TYPE (calldesc) = build_array_type (integer_type_node,
4884 build_index_type (build_int_2 (nargs * 2, 0)));
4886 return output_constant_def (calldesc);
4890 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4891 and initialize static variables for generating RTL for the statements
4895 init_function_start (subr, filename, line)
4902 if (output_bytecode)
4904 this_function_decl = subr;
4905 this_function_calldesc = bc_build_calldesc (subr);
4906 local_vars_size = 0;
4908 max_stack_depth = 0;
4909 stmt_expr_depth = 0;
4913 init_stmt_for_function ();
4915 cse_not_expected = ! optimize;
4917 /* Caller save not needed yet. */
4918 caller_save_needed = 0;
4920 /* No stack slots have been made yet. */
4921 stack_slot_list = 0;
4923 /* There is no stack slot for handling nonlocal gotos. */
4924 nonlocal_goto_handler_slot = 0;
4925 nonlocal_goto_stack_level = 0;
4927 /* No labels have been declared for nonlocal use. */
4928 nonlocal_labels = 0;
4930 /* No function calls so far in this function. */
4931 function_call_count = 0;
4933 /* No parm regs have been allocated.
4934 (This is important for output_inline_function.) */
4935 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4937 /* Initialize the RTL mechanism. */
4940 /* Initialize the queue of pending postincrement and postdecrements,
4941 and some other info in expr.c. */
4944 /* We haven't done register allocation yet. */
4947 init_const_rtx_hash_table ();
4949 current_function_name = (*decl_printable_name) (subr, &junk);
4951 /* Nonzero if this is a nested function that uses a static chain. */
4953 current_function_needs_context
4954 = (decl_function_context (current_function_decl) != 0
4955 && ! DECL_NO_STATIC_CHAIN (current_function_decl));
4957 /* Set if a call to setjmp is seen. */
4958 current_function_calls_setjmp = 0;
4960 /* Set if a call to longjmp is seen. */
4961 current_function_calls_longjmp = 0;
4963 current_function_calls_alloca = 0;
4964 current_function_has_nonlocal_label = 0;
4965 current_function_has_nonlocal_goto = 0;
4966 current_function_contains_functions = 0;
4968 current_function_returns_pcc_struct = 0;
4969 current_function_returns_struct = 0;
4970 current_function_epilogue_delay_list = 0;
4971 current_function_uses_const_pool = 0;
4972 current_function_uses_pic_offset_table = 0;
4974 /* We have not yet needed to make a label to jump to for tail-recursion. */
4975 tail_recursion_label = 0;
4977 /* We haven't had a need to make a save area for ap yet. */
4979 arg_pointer_save_area = 0;
4981 /* No stack slots allocated yet. */
4984 /* No SAVE_EXPRs in this function yet. */
4987 /* No RTL_EXPRs in this function yet. */
4990 /* Set up to allocate temporaries. */
4993 /* Within function body, compute a type's size as soon it is laid out. */
4994 immediate_size_expand++;
4996 /* We haven't made any trampolines for this function yet. */
4997 trampoline_list = 0;
4999 init_pending_stack_adjust ();
5000 inhibit_defer_pop = 0;
5002 current_function_outgoing_args_size = 0;
5004 /* Prevent ever trying to delete the first instruction of a function.
5005 Also tell final how to output a linenum before the function prologue. */
5006 emit_line_note (filename, line);
5008 /* Make sure first insn is a note even if we don't want linenums.
5009 This makes sure the first insn will never be deleted.
5010 Also, final expects a note to appear there. */
5011 emit_note (NULL_PTR, NOTE_INSN_DELETED);
5013 /* Set flags used by final.c. */
5014 if (aggregate_value_p (DECL_RESULT (subr)))
5016 #ifdef PCC_STATIC_STRUCT_RETURN
5017 current_function_returns_pcc_struct = 1;
5019 current_function_returns_struct = 1;
5022 /* Warn if this value is an aggregate type,
5023 regardless of which calling convention we are using for it. */
5024 if (warn_aggregate_return
5025 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
5026 warning ("function returns an aggregate");
5028 current_function_returns_pointer
5029 = POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (subr)));
5031 /* Indicate that we need to distinguish between the return value of the
5032 present function and the return value of a function being called. */
5033 rtx_equal_function_value_matters = 1;
5035 /* Indicate that we have not instantiated virtual registers yet. */
5036 virtuals_instantiated = 0;
5038 /* Indicate we have no need of a frame pointer yet. */
5039 frame_pointer_needed = 0;
5041 /* By default assume not varargs or stdarg. */
5042 current_function_varargs = 0;
5043 current_function_stdarg = 0;
5046 /* Indicate that the current function uses extra args
5047 not explicitly mentioned in the argument list in any fashion. */
5052 current_function_varargs = 1;
5055 /* Expand a call to __main at the beginning of a possible main function. */
5057 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
5058 #undef HAS_INIT_SECTION
5059 #define HAS_INIT_SECTION
5063 expand_main_function ()
5065 if (!output_bytecode)
5067 /* The zero below avoids a possible parse error */
5069 #if !defined (HAS_INIT_SECTION)
5070 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, NAME__MAIN), 0,
5072 #endif /* not HAS_INIT_SECTION */
5076 extern struct obstack permanent_obstack;
5078 /* Expand start of bytecode function. See comment at
5079 expand_function_start below for details. */
5082 bc_expand_function_start (subr, parms_have_cleanups)
5084 int parms_have_cleanups;
5086 char label[20], *name;
5091 if (TREE_PUBLIC (subr))
5092 bc_globalize_label (IDENTIFIER_POINTER (DECL_NAME (subr)));
5094 #ifdef DEBUG_PRINT_CODE
5095 fprintf (stderr, "\n<func %s>\n", IDENTIFIER_POINTER (DECL_NAME (subr)));
5098 for (argsz = 0, thisarg = DECL_ARGUMENTS (subr); thisarg; thisarg = TREE_CHAIN (thisarg))
5100 if (DECL_RTL (thisarg))
5101 abort (); /* Should be NULL here I think. */
5102 else if (TREE_CONSTANT (DECL_SIZE (thisarg)))
5104 DECL_RTL (thisarg) = bc_gen_rtx ((char *) 0, argsz, (struct bc_label *) 0);
5105 argsz += TREE_INT_CST_LOW (DECL_SIZE (thisarg));
5109 /* Variable-sized objects are pointers to their storage. */
5110 DECL_RTL (thisarg) = bc_gen_rtx ((char *) 0, argsz, (struct bc_label *) 0);
5111 argsz += POINTER_SIZE;
5115 bc_begin_function (xstrdup (IDENTIFIER_POINTER (DECL_NAME (subr))));
5117 ASM_GENERATE_INTERNAL_LABEL (label, "LX", nlab);
5120 name = (char *) obstack_copy0 (&permanent_obstack, label, strlen (label));
5121 this_function_callinfo = bc_gen_rtx (name, 0, (struct bc_label *) 0);
5122 this_function_bytecode =
5123 bc_emit_trampoline (BYTECODE_LABEL (this_function_callinfo));
5127 /* Expand end of bytecode function. See details the comment of
5128 expand_function_end(), below. */
5131 bc_expand_function_end ()
5135 expand_null_return ();
5137 /* Emit any fixup code. This must be done before the call to
5138 to BC_END_FUNCTION (), since that will cause the bytecode
5139 segment to be finished off and closed. */
5141 expand_fixups (NULL_RTX);
5143 ptrconsts = bc_end_function ();
5145 bc_align_const (2 /* INT_ALIGN */);
5147 /* If this changes also make sure to change bc-interp.h! */
5149 bc_emit_const_labeldef (BYTECODE_LABEL (this_function_callinfo));
5150 bc_emit_const ((char *) &max_stack_depth, sizeof max_stack_depth);
5151 bc_emit_const ((char *) &local_vars_size, sizeof local_vars_size);
5152 bc_emit_const_labelref (this_function_bytecode, 0);
5153 bc_emit_const_labelref (ptrconsts, 0);
5154 bc_emit_const_labelref (BYTECODE_LABEL (this_function_calldesc), 0);
5158 /* Start the RTL for a new function, and set variables used for
5160 SUBR is the FUNCTION_DECL node.
5161 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
5162 the function's parameters, which must be run at any return statement. */
5165 expand_function_start (subr, parms_have_cleanups)
5167 int parms_have_cleanups;
5173 if (output_bytecode)
5175 bc_expand_function_start (subr, parms_have_cleanups);
5179 /* Make sure volatile mem refs aren't considered
5180 valid operands of arithmetic insns. */
5181 init_recog_no_volatile ();
5183 /* If function gets a static chain arg, store it in the stack frame.
5184 Do this first, so it gets the first stack slot offset. */
5185 if (current_function_needs_context)
5187 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5189 #ifdef SMALL_REGISTER_CLASSES
5190 /* Delay copying static chain if it is not a register to avoid
5191 conflicts with regs used for parameters. */
5192 if (! SMALL_REGISTER_CLASSES
5193 || GET_CODE (static_chain_incoming_rtx) == REG)
5195 emit_move_insn (last_ptr, static_chain_incoming_rtx);
5198 /* If the parameters of this function need cleaning up, get a label
5199 for the beginning of the code which executes those cleanups. This must
5200 be done before doing anything with return_label. */
5201 if (parms_have_cleanups)
5202 cleanup_label = gen_label_rtx ();
5206 /* Make the label for return statements to jump to, if this machine
5207 does not have a one-instruction return and uses an epilogue,
5208 or if it returns a structure, or if it has parm cleanups. */
5210 if (cleanup_label == 0 && HAVE_return
5211 && ! current_function_returns_pcc_struct
5212 && ! (current_function_returns_struct && ! optimize))
5215 return_label = gen_label_rtx ();
5217 return_label = gen_label_rtx ();
5220 /* Initialize rtx used to return the value. */
5221 /* Do this before assign_parms so that we copy the struct value address
5222 before any library calls that assign parms might generate. */
5224 /* Decide whether to return the value in memory or in a register. */
5225 if (aggregate_value_p (DECL_RESULT (subr)))
5227 /* Returning something that won't go in a register. */
5228 register rtx value_address = 0;
5230 #ifdef PCC_STATIC_STRUCT_RETURN
5231 if (current_function_returns_pcc_struct)
5233 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
5234 value_address = assemble_static_space (size);
5239 /* Expect to be passed the address of a place to store the value.
5240 If it is passed as an argument, assign_parms will take care of
5242 if (struct_value_incoming_rtx)
5244 value_address = gen_reg_rtx (Pmode);
5245 emit_move_insn (value_address, struct_value_incoming_rtx);
5250 DECL_RTL (DECL_RESULT (subr))
5251 = gen_rtx (MEM, DECL_MODE (DECL_RESULT (subr)), value_address);
5252 MEM_IN_STRUCT_P (DECL_RTL (DECL_RESULT (subr)))
5253 = AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr)));
5256 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
5257 /* If return mode is void, this decl rtl should not be used. */
5258 DECL_RTL (DECL_RESULT (subr)) = 0;
5259 else if (parms_have_cleanups)
5261 /* If function will end with cleanup code for parms,
5262 compute the return values into a pseudo reg,
5263 which we will copy into the true return register
5264 after the cleanups are done. */
5266 enum machine_mode mode = DECL_MODE (DECL_RESULT (subr));
5268 #ifdef PROMOTE_FUNCTION_RETURN
5269 tree type = TREE_TYPE (DECL_RESULT (subr));
5270 int unsignedp = TREE_UNSIGNED (type);
5272 mode = promote_mode (type, mode, &unsignedp, 1);
5275 DECL_RTL (DECL_RESULT (subr)) = gen_reg_rtx (mode);
5278 /* Scalar, returned in a register. */
5280 #ifdef FUNCTION_OUTGOING_VALUE
5281 DECL_RTL (DECL_RESULT (subr))
5282 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
5284 DECL_RTL (DECL_RESULT (subr))
5285 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (subr)), subr);
5288 /* Mark this reg as the function's return value. */
5289 if (GET_CODE (DECL_RTL (DECL_RESULT (subr))) == REG)
5291 REG_FUNCTION_VALUE_P (DECL_RTL (DECL_RESULT (subr))) = 1;
5292 /* Needed because we may need to move this to memory
5293 in case it's a named return value whose address is taken. */
5294 DECL_REGISTER (DECL_RESULT (subr)) = 1;
5298 /* Initialize rtx for parameters and local variables.
5299 In some cases this requires emitting insns. */
5301 assign_parms (subr, 0);
5303 #ifdef SMALL_REGISTER_CLASSES
5304 /* Copy the static chain now if it wasn't a register. The delay is to
5305 avoid conflicts with the parameter passing registers. */
5307 if (SMALL_REGISTER_CLASSES && current_function_needs_context)
5308 if (GET_CODE (static_chain_incoming_rtx) != REG)
5309 emit_move_insn (last_ptr, static_chain_incoming_rtx);
5312 /* The following was moved from init_function_start.
5313 The move is supposed to make sdb output more accurate. */
5314 /* Indicate the beginning of the function body,
5315 as opposed to parm setup. */
5316 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_BEG);
5318 /* If doing stupid allocation, mark parms as born here. */
5320 if (GET_CODE (get_last_insn ()) != NOTE)
5321 emit_note (NULL_PTR, NOTE_INSN_DELETED);
5322 parm_birth_insn = get_last_insn ();
5326 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
5327 use_variable (regno_reg_rtx[i]);
5329 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
5330 use_variable (current_function_internal_arg_pointer);
5333 context_display = 0;
5334 if (current_function_needs_context)
5336 /* Fetch static chain values for containing functions. */
5337 tem = decl_function_context (current_function_decl);
5338 /* If not doing stupid register allocation copy the static chain
5339 pointer into a pseudo. If we have small register classes, copy
5340 the value from memory if static_chain_incoming_rtx is a REG. If
5341 we do stupid register allocation, we use the stack address
5343 if (tem && ! obey_regdecls)
5345 #ifdef SMALL_REGISTER_CLASSES
5346 /* If the static chain originally came in a register, put it back
5347 there, then move it out in the next insn. The reason for
5348 this peculiar code is to satisfy function integration. */
5349 if (SMALL_REGISTER_CLASSES
5350 && GET_CODE (static_chain_incoming_rtx) == REG)
5351 emit_move_insn (static_chain_incoming_rtx, last_ptr);
5354 last_ptr = copy_to_reg (static_chain_incoming_rtx);
5359 tree rtlexp = make_node (RTL_EXPR);
5361 RTL_EXPR_RTL (rtlexp) = last_ptr;
5362 context_display = tree_cons (tem, rtlexp, context_display);
5363 tem = decl_function_context (tem);
5366 /* Chain thru stack frames, assuming pointer to next lexical frame
5367 is found at the place we always store it. */
5368 #ifdef FRAME_GROWS_DOWNWARD
5369 last_ptr = plus_constant (last_ptr, - GET_MODE_SIZE (Pmode));
5371 last_ptr = copy_to_reg (gen_rtx (MEM, Pmode,
5372 memory_address (Pmode, last_ptr)));
5374 /* If we are not optimizing, ensure that we know that this
5375 piece of context is live over the entire function. */
5377 save_expr_regs = gen_rtx (EXPR_LIST, VOIDmode, last_ptr,
5382 /* After the display initializations is where the tail-recursion label
5383 should go, if we end up needing one. Ensure we have a NOTE here
5384 since some things (like trampolines) get placed before this. */
5385 tail_recursion_reentry = emit_note (NULL_PTR, NOTE_INSN_DELETED);
5387 /* Evaluate now the sizes of any types declared among the arguments. */
5388 for (tem = nreverse (get_pending_sizes ()); tem; tem = TREE_CHAIN (tem))
5389 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
5391 /* Make sure there is a line number after the function entry setup code. */
5392 force_next_line_note ();
5395 /* Generate RTL for the end of the current function.
5396 FILENAME and LINE are the current position in the source file.
5398 It is up to language-specific callers to do cleanups for parameters--
5399 or else, supply 1 for END_BINDINGS and we will call expand_end_bindings. */
5402 expand_function_end (filename, line, end_bindings)
5410 #ifdef TRAMPOLINE_TEMPLATE
5411 static rtx initial_trampoline;
5414 if (output_bytecode)
5416 bc_expand_function_end ();
5420 #ifdef NON_SAVING_SETJMP
5421 /* Don't put any variables in registers if we call setjmp
5422 on a machine that fails to restore the registers. */
5423 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
5425 if (DECL_INITIAL (current_function_decl) != error_mark_node)
5426 setjmp_protect (DECL_INITIAL (current_function_decl));
5428 setjmp_protect_args ();
5432 /* Save the argument pointer if a save area was made for it. */
5433 if (arg_pointer_save_area)
5435 rtx x = gen_move_insn (arg_pointer_save_area, virtual_incoming_args_rtx);
5436 emit_insn_before (x, tail_recursion_reentry);
5439 /* Initialize any trampolines required by this function. */
5440 for (link = trampoline_list; link; link = TREE_CHAIN (link))
5442 tree function = TREE_PURPOSE (link);
5443 rtx context = lookup_static_chain (function);
5444 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
5448 #ifdef TRAMPOLINE_TEMPLATE
5449 /* First make sure this compilation has a template for
5450 initializing trampolines. */
5451 if (initial_trampoline == 0)
5453 end_temporary_allocation ();
5455 = gen_rtx (MEM, BLKmode, assemble_trampoline_template ());
5456 resume_temporary_allocation ();
5460 /* Generate insns to initialize the trampoline. */
5462 tramp = round_trampoline_addr (XEXP (tramp, 0));
5463 #ifdef TRAMPOLINE_TEMPLATE
5464 blktramp = change_address (initial_trampoline, BLKmode, tramp);
5465 emit_block_move (blktramp, initial_trampoline,
5466 GEN_INT (TRAMPOLINE_SIZE),
5467 TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
5469 INITIALIZE_TRAMPOLINE (tramp, XEXP (DECL_RTL (function), 0), context);
5473 /* Put those insns at entry to the containing function (this one). */
5474 emit_insns_before (seq, tail_recursion_reentry);
5477 /* Warn about unused parms if extra warnings were specified. */
5478 if (warn_unused && extra_warnings)
5482 for (decl = DECL_ARGUMENTS (current_function_decl);
5483 decl; decl = TREE_CHAIN (decl))
5484 if (! TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
5485 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
5486 warning_with_decl (decl, "unused parameter `%s'");
5489 /* Delete handlers for nonlocal gotos if nothing uses them. */
5490 if (nonlocal_goto_handler_slot != 0 && !current_function_has_nonlocal_label)
5493 /* End any sequences that failed to be closed due to syntax errors. */
5494 while (in_sequence_p ())
5497 /* Outside function body, can't compute type's actual size
5498 until next function's body starts. */
5499 immediate_size_expand--;
5501 /* If doing stupid register allocation,
5502 mark register parms as dying here. */
5507 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_parm_reg; i++)
5508 use_variable (regno_reg_rtx[i]);
5510 /* Likewise for the regs of all the SAVE_EXPRs in the function. */
5512 for (tem = save_expr_regs; tem; tem = XEXP (tem, 1))
5514 use_variable (XEXP (tem, 0));
5515 use_variable_after (XEXP (tem, 0), parm_birth_insn);
5518 if (current_function_internal_arg_pointer != virtual_incoming_args_rtx)
5519 use_variable (current_function_internal_arg_pointer);
5522 clear_pending_stack_adjust ();
5523 do_pending_stack_adjust ();
5525 /* Mark the end of the function body.
5526 If control reaches this insn, the function can drop through
5527 without returning a value. */
5528 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_END);
5530 /* Output a linenumber for the end of the function.
5531 SDB depends on this. */
5532 emit_line_note_force (filename, line);
5534 /* Output the label for the actual return from the function,
5535 if one is expected. This happens either because a function epilogue
5536 is used instead of a return instruction, or because a return was done
5537 with a goto in order to run local cleanups, or because of pcc-style
5538 structure returning. */
5541 emit_label (return_label);
5543 /* C++ uses this. */
5545 expand_end_bindings (0, 0, 0);
5547 /* If we had calls to alloca, and this machine needs
5548 an accurate stack pointer to exit the function,
5549 insert some code to save and restore the stack pointer. */
5550 #ifdef EXIT_IGNORE_STACK
5551 if (! EXIT_IGNORE_STACK)
5553 if (current_function_calls_alloca)
5557 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
5558 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
5561 /* If scalar return value was computed in a pseudo-reg,
5562 copy that to the hard return register. */
5563 if (DECL_RTL (DECL_RESULT (current_function_decl)) != 0
5564 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG
5565 && (REGNO (DECL_RTL (DECL_RESULT (current_function_decl)))
5566 >= FIRST_PSEUDO_REGISTER))
5568 rtx real_decl_result;
5570 #ifdef FUNCTION_OUTGOING_VALUE
5572 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
5573 current_function_decl);
5576 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
5577 current_function_decl);
5579 REG_FUNCTION_VALUE_P (real_decl_result) = 1;
5580 /* If this is a BLKmode structure being returned in registers, then use
5581 the mode computed in expand_return. */
5582 if (GET_MODE (real_decl_result) == BLKmode)
5583 PUT_MODE (real_decl_result,
5584 GET_MODE (DECL_RTL (DECL_RESULT (current_function_decl))));
5585 emit_move_insn (real_decl_result,
5586 DECL_RTL (DECL_RESULT (current_function_decl)));
5587 emit_insn (gen_rtx (USE, VOIDmode, real_decl_result));
5590 /* If returning a structure, arrange to return the address of the value
5591 in a place where debuggers expect to find it.
5593 If returning a structure PCC style,
5594 the caller also depends on this value.
5595 And current_function_returns_pcc_struct is not necessarily set. */
5596 if (current_function_returns_struct
5597 || current_function_returns_pcc_struct)
5599 rtx value_address = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
5600 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5601 #ifdef FUNCTION_OUTGOING_VALUE
5603 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
5604 current_function_decl);
5607 = FUNCTION_VALUE (build_pointer_type (type),
5608 current_function_decl);
5611 /* Mark this as a function return value so integrate will delete the
5612 assignment and USE below when inlining this function. */
5613 REG_FUNCTION_VALUE_P (outgoing) = 1;
5615 emit_move_insn (outgoing, value_address);
5616 use_variable (outgoing);
5619 /* Output a return insn if we are using one.
5620 Otherwise, let the rtl chain end here, to drop through
5621 into the epilogue. */
5626 emit_jump_insn (gen_return ());
5631 /* Fix up any gotos that jumped out to the outermost
5632 binding level of the function.
5633 Must follow emitting RETURN_LABEL. */
5635 /* If you have any cleanups to do at this point,
5636 and they need to create temporary variables,
5637 then you will lose. */
5638 expand_fixups (get_insns ());
5641 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
5643 static int *prologue;
5644 static int *epilogue;
5646 /* Create an array that records the INSN_UIDs of INSNS (either a sequence
5647 or a single insn). */
5650 record_insns (insns)
5655 if (GET_CODE (insns) == SEQUENCE)
5657 int len = XVECLEN (insns, 0);
5658 vec = (int *) oballoc ((len + 1) * sizeof (int));
5661 vec[len] = INSN_UID (XVECEXP (insns, 0, len));
5665 vec = (int *) oballoc (2 * sizeof (int));
5666 vec[0] = INSN_UID (insns);
5672 /* Determine how many INSN_UIDs in VEC are part of INSN. */
5675 contains (insn, vec)
5681 if (GET_CODE (insn) == INSN
5682 && GET_CODE (PATTERN (insn)) == SEQUENCE)
5685 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
5686 for (j = 0; vec[j]; j++)
5687 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == vec[j])
5693 for (j = 0; vec[j]; j++)
5694 if (INSN_UID (insn) == vec[j])
5700 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5701 this into place with notes indicating where the prologue ends and where
5702 the epilogue begins. Update the basic block information when possible. */
5705 thread_prologue_and_epilogue_insns (f)
5708 #ifdef HAVE_prologue
5711 rtx head, seq, insn;
5713 /* The first insn (a NOTE_INSN_DELETED) is followed by zero or more
5714 prologue insns and a NOTE_INSN_PROLOGUE_END. */
5715 emit_note_after (NOTE_INSN_PROLOGUE_END, f);
5716 seq = gen_prologue ();
5717 head = emit_insn_after (seq, f);
5719 /* Include the new prologue insns in the first block. Ignore them
5720 if they form a basic block unto themselves. */
5721 if (basic_block_head && n_basic_blocks
5722 && GET_CODE (basic_block_head[0]) != CODE_LABEL)
5723 basic_block_head[0] = NEXT_INSN (f);
5725 /* Retain a map of the prologue insns. */
5726 prologue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : head);
5732 #ifdef HAVE_epilogue
5735 rtx insn = get_last_insn ();
5736 rtx prev = prev_nonnote_insn (insn);
5738 /* If we end with a BARRIER, we don't need an epilogue. */
5739 if (! (prev && GET_CODE (prev) == BARRIER))
5745 /* The last basic block ends with a NOTE_INSN_EPILOGUE_BEG, the
5746 epilogue insns, the USE insns at the end of a function,
5747 the jump insn that returns, and then a BARRIER. */
5749 /* Move the USE insns at the end of a function onto a list. */
5751 && GET_CODE (prev) == INSN
5752 && GET_CODE (PATTERN (prev)) == USE)
5755 prev = prev_nonnote_insn (prev);
5757 NEXT_INSN (PREV_INSN (tem)) = NEXT_INSN (tem);
5758 PREV_INSN (NEXT_INSN (tem)) = PREV_INSN (tem);
5761 NEXT_INSN (tem) = first_use;
5762 PREV_INSN (first_use) = tem;
5769 emit_barrier_after (insn);
5771 seq = gen_epilogue ();
5772 tail = emit_jump_insn_after (seq, insn);
5774 /* Insert the USE insns immediately before the return insn, which
5775 must be the first instruction before the final barrier. */
5778 tem = prev_nonnote_insn (get_last_insn ());
5779 NEXT_INSN (PREV_INSN (tem)) = first_use;
5780 PREV_INSN (first_use) = PREV_INSN (tem);
5781 PREV_INSN (tem) = last_use;
5782 NEXT_INSN (last_use) = tem;
5785 emit_note_after (NOTE_INSN_EPILOGUE_BEG, insn);
5787 /* Include the new epilogue insns in the last block. Ignore
5788 them if they form a basic block unto themselves. */
5789 if (basic_block_end && n_basic_blocks
5790 && GET_CODE (basic_block_end[n_basic_blocks - 1]) != JUMP_INSN)
5791 basic_block_end[n_basic_blocks - 1] = tail;
5793 /* Retain a map of the epilogue insns. */
5794 epilogue = record_insns (GET_CODE (seq) == SEQUENCE ? seq : tail);
5802 /* Reposition the prologue-end and epilogue-begin notes after instruction
5803 scheduling and delayed branch scheduling. */
5806 reposition_prologue_and_epilogue_notes (f)
5809 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5810 /* Reposition the prologue and epilogue notes. */
5818 register rtx insn, note = 0;
5820 /* Scan from the beginning until we reach the last prologue insn.
5821 We apparently can't depend on basic_block_{head,end} after
5823 for (len = 0; prologue[len]; len++)
5825 for (insn = f; len && insn; insn = NEXT_INSN (insn))
5827 if (GET_CODE (insn) == NOTE)
5829 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
5832 else if ((len -= contains (insn, prologue)) == 0)
5834 /* Find the prologue-end note if we haven't already, and
5835 move it to just after the last prologue insn. */
5838 for (note = insn; note = NEXT_INSN (note);)
5839 if (GET_CODE (note) == NOTE
5840 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
5843 next = NEXT_INSN (note);
5844 prev = PREV_INSN (note);
5846 NEXT_INSN (prev) = next;
5848 PREV_INSN (next) = prev;
5849 add_insn_after (note, insn);
5856 register rtx insn, note = 0;
5858 /* Scan from the end until we reach the first epilogue insn.
5859 We apparently can't depend on basic_block_{head,end} after
5861 for (len = 0; epilogue[len]; len++)
5863 for (insn = get_last_insn (); len && insn; insn = PREV_INSN (insn))
5865 if (GET_CODE (insn) == NOTE)
5867 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
5870 else if ((len -= contains (insn, epilogue)) == 0)
5872 /* Find the epilogue-begin note if we haven't already, and
5873 move it to just before the first epilogue insn. */
5876 for (note = insn; note = PREV_INSN (note);)
5877 if (GET_CODE (note) == NOTE
5878 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
5881 next = NEXT_INSN (note);
5882 prev = PREV_INSN (note);
5884 NEXT_INSN (prev) = next;
5886 PREV_INSN (next) = prev;
5887 add_insn_after (note, PREV_INSN (insn));
5892 #endif /* HAVE_prologue or HAVE_epilogue */