1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1991, 1992 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file handles the generation of rtl code from tree structure
22 at the level of the function as a whole.
23 It creates the rtl expressions for parameters and auto variables
24 and has full responsibility for allocating stack slots.
26 `expand_function_start' is called at the beginning of a function,
27 before the function body is parsed, and `expand_function_end' is
28 called after parsing the body.
30 Call `assign_stack_local' to allocate a stack slot for a local variable.
31 This is usually done during the RTL generation for the function body,
32 but it can also be done in the reload pass when a pseudo-register does
33 not get a hard register.
35 Call `put_var_into_stack' when you learn, belatedly, that a variable
36 previously given a pseudo-register must in fact go in the stack.
37 This function changes the DECL_RTL to be a stack slot instead of a reg
38 then scans all the RTL instructions so far generated to correct them. */
48 #include "insn-flags.h"
50 #include "insn-codes.h"
52 #include "hard-reg-set.h"
53 #include "insn-config.h"
56 #include "basic-block.h"
58 /* Round a value to the lowest integer less than it that is a multiple of
59 the required alignment. Avoid using division in case the value is
60 negative. Assume the alignment is a power of two. */
61 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
63 /* Similar, but round to the next highest integer that meets the
65 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
67 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
68 during rtl generation. If they are different register numbers, this is
69 always true. It may also be true if
70 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
71 generation. See fix_lexical_addr for details. */
73 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
74 #define NEED_SEPARATE_AP
77 /* Number of bytes of args popped by function being compiled on its return.
78 Zero if no bytes are to be popped.
79 May affect compilation of return insn or of function epilogue. */
81 int current_function_pops_args
;
83 /* Nonzero if function being compiled needs to be given an address
84 where the value should be stored. */
86 int current_function_returns_struct
;
88 /* Nonzero if function being compiled needs to
89 return the address of where it has put a structure value. */
91 int current_function_returns_pcc_struct
;
93 /* Nonzero if function being compiled needs to be passed a static chain. */
95 int current_function_needs_context
;
97 /* Nonzero if function being compiled can call setjmp. */
99 int current_function_calls_setjmp
;
101 /* Nonzero if function being compiled can call longjmp. */
103 int current_function_calls_longjmp
;
105 /* Nonzero if function being compiled receives nonlocal gotos
106 from nested functions. */
108 int current_function_has_nonlocal_label
;
110 /* Nonzero if function being compiled contains nested functions. */
112 int current_function_contains_functions
;
114 /* Nonzero if function being compiled can call alloca,
115 either as a subroutine or builtin. */
117 int current_function_calls_alloca
;
119 /* Nonzero if the current function returns a pointer type */
121 int current_function_returns_pointer
;
123 /* If some insns can be deferred to the delay slots of the epilogue, the
124 delay list for them is recorded here. */
126 rtx current_function_epilogue_delay_list
;
128 /* If function's args have a fixed size, this is that size, in bytes.
130 May affect compilation of return insn or of function epilogue. */
132 int current_function_args_size
;
134 /* # bytes the prologue should push and pretend that the caller pushed them.
135 The prologue must do this, but only if parms can be passed in registers. */
137 int current_function_pretend_args_size
;
139 /* # of bytes of outgoing arguments required to be pushed by the prologue.
140 If this is non-zero, it means that ACCUMULATE_OUTGOING_ARGS was defined
141 and no stack adjusts will be done on function calls. */
143 int current_function_outgoing_args_size
;
145 /* This is the offset from the arg pointer to the place where the first
146 anonymous arg can be found, if there is one. */
148 rtx current_function_arg_offset_rtx
;
150 /* Nonzero if current function uses varargs.h or equivalent.
151 Zero for functions that use stdarg.h. */
153 int current_function_varargs
;
155 /* Quantities of various kinds of registers
156 used for the current function's args. */
158 CUMULATIVE_ARGS current_function_args_info
;
160 /* Name of function now being compiled. */
162 char *current_function_name
;
164 /* If non-zero, an RTL expression for that location at which the current
165 function returns its result. Always equal to
166 DECL_RTL (DECL_RESULT (current_function_decl)), but provided
167 independently of the tree structures. */
169 rtx current_function_return_rtx
;
171 /* Nonzero if the current function uses the constant pool. */
173 int current_function_uses_const_pool
;
175 /* Nonzero if the current function uses pic_offset_table_rtx. */
176 int current_function_uses_pic_offset_table
;
178 /* The arg pointer hard register, or the pseudo into which it was copied. */
179 rtx current_function_internal_arg_pointer
;
181 /* The FUNCTION_DECL for an inline function currently being expanded. */
182 tree inline_function_decl
;
184 /* Number of function calls seen so far in current function. */
186 int function_call_count
;
188 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
189 (labels to which there can be nonlocal gotos from nested functions)
192 tree nonlocal_labels
;
194 /* RTX for stack slot that holds the current handler for nonlocal gotos.
195 Zero when function does not have nonlocal labels. */
197 rtx nonlocal_goto_handler_slot
;
199 /* RTX for stack slot that holds the stack pointer value to restore
201 Zero when function does not have nonlocal labels. */
203 rtx nonlocal_goto_stack_level
;
205 /* Label that will go on parm cleanup code, if any.
206 Jumping to this label runs cleanup code for parameters, if
207 such code must be run. Following this code is the logical return label. */
211 /* Label that will go on function epilogue.
212 Jumping to this label serves as a "return" instruction
213 on machines which require execution of the epilogue on all returns. */
217 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
218 So we can mark them all live at the end of the function, if nonopt. */
221 /* List (chain of EXPR_LISTs) of all stack slots in this function.
222 Made for the sake of unshare_all_rtl. */
225 /* Chain of all RTL_EXPRs that have insns in them. */
228 /* Label to jump back to for tail recursion, or 0 if we have
229 not yet needed one for this function. */
230 rtx tail_recursion_label
;
232 /* Place after which to insert the tail_recursion_label if we need one. */
233 rtx tail_recursion_reentry
;
235 /* Location at which to save the argument pointer if it will need to be
236 referenced. There are two cases where this is done: if nonlocal gotos
237 exist, or if vars stored at an offset from the argument pointer will be
238 needed by inner routines. */
240 rtx arg_pointer_save_area
;
242 /* Offset to end of allocated area of stack frame.
243 If stack grows down, this is the address of the last stack slot allocated.
244 If stack grows up, this is the address for the next slot. */
247 /* List (chain of TREE_LISTs) of static chains for containing functions.
248 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
249 in an RTL_EXPR in the TREE_VALUE. */
250 static tree context_display
;
252 /* List (chain of TREE_LISTs) of trampolines for nested functions.
253 The trampoline sets up the static chain and jumps to the function.
254 We supply the trampoline's address when the function's address is requested.
256 Each link has a FUNCTION_DECL in the TREE_PURPOSE and a reg rtx
257 in an RTL_EXPR in the TREE_VALUE. */
258 static tree trampoline_list
;
260 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */
261 static rtx parm_birth_insn
;
264 /* Nonzero if a stack slot has been generated whose address is not
265 actually valid. It means that the generated rtl must all be scanned
266 to detect and correct the invalid addresses where they occur. */
267 static int invalid_stack_slot
;
270 /* Last insn of those whose job was to put parms into their nominal homes. */
271 static rtx last_parm_insn
;
273 /* 1 + last pseudo register number used for loading a copy
274 of a parameter of this function. */
275 static int max_parm_reg
;
277 /* Vector indexed by REGNO, containing location on stack in which
278 to put the parm which is nominally in pseudo register REGNO,
279 if we discover that that parm must go in the stack. */
280 static rtx
*parm_reg_stack_loc
;
282 #if 0 /* Turned off because 0 seems to work just as well. */
283 /* Cleanup lists are required for binding levels regardless of whether
284 that binding level has cleanups or not. This node serves as the
285 cleanup list whenever an empty list is required. */
286 static tree empty_cleanup_list
;
289 /* Nonzero once virtual register instantiation has been done.
290 assign_stack_local uses frame_pointer_rtx when this is nonzero. */
291 static int virtuals_instantiated
;
293 /* Nonzero if we need to distinguish between the return value of this function
294 and the return value of a function called by this function. This helps
297 extern int rtx_equal_function_value_matters
;
301 static tree
round_down ();
302 static rtx
round_trampoline_addr ();
303 static rtx
fixup_stack_1 ();
304 static void fixup_var_refs ();
305 static void fixup_var_refs_insns ();
306 static void fixup_var_refs_1 ();
307 static void optimize_bit_field ();
308 static void instantiate_decls ();
309 static void instantiate_decls_1 ();
310 static void instantiate_decl ();
311 static int instantiate_virtual_regs_1 ();
312 static rtx
fixup_memory_subreg ();
313 static rtx
walk_fixup_memory_subreg ();
315 /* In order to evaluate some expressions, such as function calls returning
316 structures in memory, we need to temporarily allocate stack locations.
317 We record each allocated temporary in the following structure.
319 Associated with each temporary slot is a nesting level. When we pop up
320 one level, all temporaries associated with the previous level are freed.
321 Normally, all temporaries are freed after the execution of the statement
322 in which they were created. However, if we are inside a ({...}) grouping,
323 the result may be in a temporary and hence must be preserved. If the
324 result could be in a temporary, we preserve it if we can determine which
325 one it is in. If we cannot determine which temporary may contain the
326 result, all temporaries are preserved. A temporary is preserved by
327 pretending it was allocated at the previous nesting level.
329 Automatic variables are also assigned temporary slots, at the nesting
330 level where they are defined. They are marked a "kept" so that
331 free_temp_slots will not free them. */
335 /* Points to next temporary slot. */
336 struct temp_slot
*next
;
337 /* The rtx to used to reference the slot. */
339 /* The size, in units, of the slot. */
341 /* Non-zero if this temporary is currently in use. */
343 /* Nesting level at which this slot is being used. */
345 /* Non-zero if this should survive a call to free_temp_slots. */
349 /* List of all temporaries allocated, both available and in use. */
351 struct temp_slot
*temp_slots
;
353 /* Current nesting level for temporaries. */
357 /* Pointer to chain of `struct function' for containing functions. */
358 struct function
*outer_function_chain
;
360 /* Given a function decl for a containing function,
361 return the `struct function' for it. */
364 find_function_data (decl
)
368 for (p
= outer_function_chain
; p
; p
= p
->next
)
374 /* Save the current context for compilation of a nested function.
375 This is called from language-specific code.
376 The caller is responsible for saving any language-specific status,
377 since this function knows only about language-independent variables. */
380 push_function_context ()
382 struct function
*p
= (struct function
*) xmalloc (sizeof (struct function
));
384 p
->next
= outer_function_chain
;
385 outer_function_chain
= p
;
387 p
->name
= current_function_name
;
388 p
->decl
= current_function_decl
;
389 p
->pops_args
= current_function_pops_args
;
390 p
->returns_struct
= current_function_returns_struct
;
391 p
->returns_pcc_struct
= current_function_returns_pcc_struct
;
392 p
->needs_context
= current_function_needs_context
;
393 p
->calls_setjmp
= current_function_calls_setjmp
;
394 p
->calls_longjmp
= current_function_calls_longjmp
;
395 p
->calls_alloca
= current_function_calls_alloca
;
396 p
->has_nonlocal_label
= current_function_has_nonlocal_label
;
397 p
->args_size
= current_function_args_size
;
398 p
->pretend_args_size
= current_function_pretend_args_size
;
399 p
->arg_offset_rtx
= current_function_arg_offset_rtx
;
400 p
->uses_const_pool
= current_function_uses_const_pool
;
401 p
->uses_pic_offset_table
= current_function_uses_pic_offset_table
;
402 p
->internal_arg_pointer
= current_function_internal_arg_pointer
;
403 p
->max_parm_reg
= max_parm_reg
;
404 p
->parm_reg_stack_loc
= parm_reg_stack_loc
;
405 p
->outgoing_args_size
= current_function_outgoing_args_size
;
406 p
->return_rtx
= current_function_return_rtx
;
407 p
->nonlocal_goto_handler_slot
= nonlocal_goto_handler_slot
;
408 p
->nonlocal_goto_stack_level
= nonlocal_goto_stack_level
;
409 p
->nonlocal_labels
= nonlocal_labels
;
410 p
->cleanup_label
= cleanup_label
;
411 p
->return_label
= return_label
;
412 p
->save_expr_regs
= save_expr_regs
;
413 p
->stack_slot_list
= stack_slot_list
;
414 p
->parm_birth_insn
= parm_birth_insn
;
415 p
->frame_offset
= frame_offset
;
416 p
->tail_recursion_label
= tail_recursion_label
;
417 p
->tail_recursion_reentry
= tail_recursion_reentry
;
418 p
->arg_pointer_save_area
= arg_pointer_save_area
;
419 p
->rtl_expr_chain
= rtl_expr_chain
;
420 p
->last_parm_insn
= last_parm_insn
;
421 p
->context_display
= context_display
;
422 p
->trampoline_list
= trampoline_list
;
423 p
->function_call_count
= function_call_count
;
424 p
->temp_slots
= temp_slots
;
425 p
->temp_slot_level
= temp_slot_level
;
426 p
->fixup_var_refs_queue
= 0;
427 p
->epilogue_delay_list
= current_function_epilogue_delay_list
;
429 save_tree_status (p
);
430 save_storage_status (p
);
431 save_emit_status (p
);
433 save_expr_status (p
);
434 save_stmt_status (p
);
435 save_varasm_status (p
);
438 /* Restore the last saved context, at the end of a nested function.
439 This function is called from language-specific code. */
442 pop_function_context ()
444 struct function
*p
= outer_function_chain
;
446 outer_function_chain
= p
->next
;
448 current_function_name
= p
->name
;
449 current_function_decl
= p
->decl
;
450 current_function_pops_args
= p
->pops_args
;
451 current_function_returns_struct
= p
->returns_struct
;
452 current_function_returns_pcc_struct
= p
->returns_pcc_struct
;
453 current_function_needs_context
= p
->needs_context
;
454 current_function_calls_setjmp
= p
->calls_setjmp
;
455 current_function_calls_longjmp
= p
->calls_longjmp
;
456 current_function_calls_alloca
= p
->calls_alloca
;
457 current_function_has_nonlocal_label
= p
->has_nonlocal_label
;
458 current_function_contains_functions
= 1;
459 current_function_args_size
= p
->args_size
;
460 current_function_pretend_args_size
= p
->pretend_args_size
;
461 current_function_arg_offset_rtx
= p
->arg_offset_rtx
;
462 current_function_uses_const_pool
= p
->uses_const_pool
;
463 current_function_uses_pic_offset_table
= p
->uses_pic_offset_table
;
464 current_function_internal_arg_pointer
= p
->internal_arg_pointer
;
465 max_parm_reg
= p
->max_parm_reg
;
466 parm_reg_stack_loc
= p
->parm_reg_stack_loc
;
467 current_function_outgoing_args_size
= p
->outgoing_args_size
;
468 current_function_return_rtx
= p
->return_rtx
;
469 nonlocal_goto_handler_slot
= p
->nonlocal_goto_handler_slot
;
470 nonlocal_goto_stack_level
= p
->nonlocal_goto_stack_level
;
471 nonlocal_labels
= p
->nonlocal_labels
;
472 cleanup_label
= p
->cleanup_label
;
473 return_label
= p
->return_label
;
474 save_expr_regs
= p
->save_expr_regs
;
475 stack_slot_list
= p
->stack_slot_list
;
476 parm_birth_insn
= p
->parm_birth_insn
;
477 frame_offset
= p
->frame_offset
;
478 tail_recursion_label
= p
->tail_recursion_label
;
479 tail_recursion_reentry
= p
->tail_recursion_reentry
;
480 arg_pointer_save_area
= p
->arg_pointer_save_area
;
481 rtl_expr_chain
= p
->rtl_expr_chain
;
482 last_parm_insn
= p
->last_parm_insn
;
483 context_display
= p
->context_display
;
484 trampoline_list
= p
->trampoline_list
;
485 function_call_count
= p
->function_call_count
;
486 temp_slots
= p
->temp_slots
;
487 temp_slot_level
= p
->temp_slot_level
;
488 current_function_epilogue_delay_list
= p
->epilogue_delay_list
;
490 restore_tree_status (p
);
491 restore_storage_status (p
);
492 restore_expr_status (p
);
493 restore_emit_status (p
);
494 restore_stmt_status (p
);
495 restore_varasm_status (p
);
497 /* Finish doing put_var_into_stack for any of our variables
498 which became addressable during the nested function. */
500 struct var_refs_queue
*queue
= p
->fixup_var_refs_queue
;
501 for (; queue
; queue
= queue
->next
)
502 fixup_var_refs (queue
->modified
, queue
->promoted_mode
, queue
->unsignedp
);
507 /* Reset variables that have known state during rtx generation. */
508 rtx_equal_function_value_matters
= 1;
509 virtuals_instantiated
= 0;
512 /* Allocate fixed slots in the stack frame of the current function. */
514 /* Return size needed for stack frame based on slots so far allocated.
515 This size counts from zero. It is not rounded to STACK_BOUNDARY;
516 the caller may have to do that. */
521 #ifdef FRAME_GROWS_DOWNWARD
522 return -frame_offset
;
528 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
529 with machine mode MODE.
531 ALIGN controls the amount of alignment for the address of the slot:
532 0 means according to MODE,
533 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
534 positive specifies alignment boundary in bits.
536 We do not round to stack_boundary here. */
539 assign_stack_local (mode
, size
, align
)
540 enum machine_mode mode
;
544 register rtx x
, addr
;
545 int bigend_correction
= 0;
550 alignment
= GET_MODE_ALIGNMENT (mode
) / BITS_PER_UNIT
;
552 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
554 else if (align
== -1)
556 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
557 size
= CEIL_ROUND (size
, alignment
);
560 alignment
= align
/ BITS_PER_UNIT
;
562 /* Round frame offset to that alignment.
563 We must be careful here, since FRAME_OFFSET might be negative and
564 division with a negative dividend isn't as well defined as we might
565 like. So we instead assume that ALIGNMENT is a power of two and
566 use logical operations which are unambiguous. */
567 #ifdef FRAME_GROWS_DOWNWARD
568 frame_offset
= FLOOR_ROUND (frame_offset
, alignment
);
570 frame_offset
= CEIL_ROUND (frame_offset
, alignment
);
573 /* On a big-endian machine, if we are allocating more space than we will use,
574 use the least significant bytes of those that are allocated. */
577 bigend_correction
= size
- GET_MODE_SIZE (mode
);
580 #ifdef FRAME_GROWS_DOWNWARD
581 frame_offset
-= size
;
584 /* If we have already instantiated virtual registers, return the actual
585 address relative to the frame pointer. */
586 if (virtuals_instantiated
)
587 addr
= plus_constant (frame_pointer_rtx
,
588 (frame_offset
+ bigend_correction
589 + STARTING_FRAME_OFFSET
));
591 addr
= plus_constant (virtual_stack_vars_rtx
,
592 frame_offset
+ bigend_correction
);
594 #ifndef FRAME_GROWS_DOWNWARD
595 frame_offset
+= size
;
598 x
= gen_rtx (MEM
, mode
, addr
);
600 stack_slot_list
= gen_rtx (EXPR_LIST
, VOIDmode
, x
, stack_slot_list
);
605 /* Assign a stack slot in a containing function.
606 First three arguments are same as in preceding function.
607 The last argument specifies the function to allocate in. */
610 assign_outer_stack_local (mode
, size
, align
, function
)
611 enum machine_mode mode
;
614 struct function
*function
;
616 register rtx x
, addr
;
617 int bigend_correction
= 0;
620 /* Allocate in the memory associated with the function in whose frame
622 push_obstacks (function
->function_obstack
,
623 function
->function_maybepermanent_obstack
);
627 alignment
= GET_MODE_ALIGNMENT (mode
) / BITS_PER_UNIT
;
629 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
631 else if (align
== -1)
633 alignment
= BIGGEST_ALIGNMENT
/ BITS_PER_UNIT
;
634 size
= CEIL_ROUND (size
, alignment
);
637 alignment
= align
/ BITS_PER_UNIT
;
639 /* Round frame offset to that alignment. */
640 #ifdef FRAME_GROWS_DOWNWARD
641 function
->frame_offset
= FLOOR_ROUND (function
->frame_offset
, alignment
);
643 function
->frame_offset
= CEIL_ROUND (function
->frame_offset
, alignment
);
646 /* On a big-endian machine, if we are allocating more space than we will use,
647 use the least significant bytes of those that are allocated. */
650 bigend_correction
= size
- GET_MODE_SIZE (mode
);
653 #ifdef FRAME_GROWS_DOWNWARD
654 function
->frame_offset
-= size
;
656 addr
= plus_constant (virtual_stack_vars_rtx
,
657 function
->frame_offset
+ bigend_correction
);
658 #ifndef FRAME_GROWS_DOWNWARD
659 function
->frame_offset
+= size
;
662 x
= gen_rtx (MEM
, mode
, addr
);
664 function
->stack_slot_list
665 = gen_rtx (EXPR_LIST
, VOIDmode
, x
, function
->stack_slot_list
);
672 /* Allocate a temporary stack slot and record it for possible later
675 MODE is the machine mode to be given to the returned rtx.
677 SIZE is the size in units of the space required. We do no rounding here
678 since assign_stack_local will do any required rounding.
680 KEEP is non-zero if this slot is to be retained after a call to
681 free_temp_slots. Automatic variables for a block are allocated with this
685 assign_stack_temp (mode
, size
, keep
)
686 enum machine_mode mode
;
690 struct temp_slot
*p
, *best_p
= 0;
692 /* First try to find an available, already-allocated temporary that is the
693 exact size we require. */
694 for (p
= temp_slots
; p
; p
= p
->next
)
695 if (p
->size
== size
&& GET_MODE (p
->slot
) == mode
&& ! p
->in_use
)
698 /* If we didn't find, one, try one that is larger than what we want. We
699 find the smallest such. */
701 for (p
= temp_slots
; p
; p
= p
->next
)
702 if (p
->size
> size
&& GET_MODE (p
->slot
) == mode
&& ! p
->in_use
703 && (best_p
== 0 || best_p
->size
> p
->size
))
706 /* Make our best, if any, the one to use. */
710 /* If we still didn't find one, make a new temporary. */
713 p
= (struct temp_slot
*) oballoc (sizeof (struct temp_slot
));
715 /* If the temp slot mode doesn't indicate the alignment,
716 use the largest possible, so no one will be disappointed. */
717 p
->slot
= assign_stack_local (mode
, size
, mode
== BLKmode
? -1 : 0);
718 p
->next
= temp_slots
;
723 p
->level
= temp_slot_level
;
728 /* If X could be a reference to a temporary slot, mark that slot as belonging
729 to the to one level higher. If X matched one of our slots, just mark that
730 one. Otherwise, we can't easily predict which it is, so upgrade all of
731 them. Kept slots need not be touched.
733 This is called when an ({...}) construct occurs and a statement
734 returns a value in memory. */
737 preserve_temp_slots (x
)
742 /* If X is not in memory or is at a constant address, it cannot be in
744 if (x
== 0 || GET_CODE (x
) != MEM
|| CONSTANT_P (XEXP (x
, 0)))
747 /* First see if we can find a match. */
748 for (p
= temp_slots
; p
; p
= p
->next
)
749 if (p
->in_use
&& x
== p
->slot
)
755 /* Otherwise, preserve all non-kept slots at this level. */
756 for (p
= temp_slots
; p
; p
= p
->next
)
757 if (p
->in_use
&& p
->level
== temp_slot_level
&& ! p
->keep
)
761 /* Free all temporaries used so far. This is normally called at the end
762 of generating code for a statement. */
769 for (p
= temp_slots
; p
; p
= p
->next
)
770 if (p
->in_use
&& p
->level
== temp_slot_level
&& ! p
->keep
)
774 /* Push deeper into the nesting level for stack temporaries. */
779 /* For GNU C++, we must allow a sequence to be emitted anywhere in
780 the level where the sequence was started. By not changing levels
781 when the compiler is inside a sequence, the temporaries for the
782 sequence and the temporaries will not unwittingly conflict with
783 the temporaries for other sequences and/or code at that level. */
784 if (in_sequence_p ())
790 /* Pop a temporary nesting level. All slots in use in the current level
798 /* See comment in push_temp_slots about why we don't change levels
800 if (in_sequence_p ())
803 for (p
= temp_slots
; p
; p
= p
->next
)
804 if (p
->in_use
&& p
->level
== temp_slot_level
)
810 /* Retroactively move an auto variable from a register to a stack slot.
811 This is done when an address-reference to the variable is seen. */
814 put_var_into_stack (decl
)
818 register rtx
new = 0;
819 enum machine_mode promoted_mode
, decl_mode
;
820 struct function
*function
= 0;
821 tree context
= decl_function_context (decl
);
823 /* Get the current rtl used for this object and it's original mode. */
824 reg
= TREE_CODE (decl
) == SAVE_EXPR
? SAVE_EXPR_RTL (decl
) : DECL_RTL (decl
);
826 /* No need to do anything if decl has no rtx yet
827 since in that case caller is setting TREE_ADDRESSABLE
828 and a stack slot will be assigned when the rtl is made. */
832 /* Get the declared mode for this object. */
833 decl_mode
= (TREE_CODE (decl
) == SAVE_EXPR
? TYPE_MODE (TREE_TYPE (decl
))
835 /* Get the mode it's actually stored in. */
836 promoted_mode
= GET_MODE (reg
);
838 /* If this variable comes from an outer function,
839 find that function's saved context. */
840 if (context
!= current_function_decl
)
841 for (function
= outer_function_chain
; function
; function
= function
->next
)
842 if (function
->decl
== context
)
845 /* If this is a variable-size object with a pseudo to address it,
846 put that pseudo into the stack, if the var is nonlocal. */
847 if (DECL_NONLOCAL (decl
)
848 && GET_CODE (reg
) == MEM
849 && GET_CODE (XEXP (reg
, 0)) == REG
850 && REGNO (XEXP (reg
, 0)) > LAST_VIRTUAL_REGISTER
)
853 decl_mode
= promoted_mode
= GET_MODE (reg
);
856 if (GET_CODE (reg
) != REG
)
861 if (REGNO (reg
) < function
->max_parm_reg
)
862 new = function
->parm_reg_stack_loc
[REGNO (reg
)];
864 new = assign_outer_stack_local (decl_mode
, GET_MODE_SIZE (decl_mode
),
869 if (REGNO (reg
) < max_parm_reg
)
870 new = parm_reg_stack_loc
[REGNO (reg
)];
872 new = assign_stack_local (decl_mode
, GET_MODE_SIZE (decl_mode
), 0);
875 XEXP (reg
, 0) = XEXP (new, 0);
876 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
877 REG_USERVAR_P (reg
) = 0;
879 PUT_MODE (reg
, decl_mode
);
881 /* If this is a memory ref that contains aggregate components,
882 mark it as such for cse and loop optimize. */
883 MEM_IN_STRUCT_P (reg
)
884 = (TREE_CODE (TREE_TYPE (decl
)) == ARRAY_TYPE
885 || TREE_CODE (TREE_TYPE (decl
)) == RECORD_TYPE
886 || TREE_CODE (TREE_TYPE (decl
)) == UNION_TYPE
);
888 /* Now make sure that all refs to the variable, previously made
889 when it was a register, are fixed up to be valid again. */
892 struct var_refs_queue
*temp
;
894 /* Variable is inherited; fix it up when we get back to its function. */
895 push_obstacks (function
->function_obstack
,
896 function
->function_maybepermanent_obstack
);
898 = (struct var_refs_queue
*) oballoc (sizeof (struct var_refs_queue
));
899 temp
->modified
= reg
;
900 temp
->promoted_mode
= promoted_mode
;
901 temp
->unsignedp
= TREE_UNSIGNED (TREE_TYPE (decl
));
902 temp
->next
= function
->fixup_var_refs_queue
;
903 function
->fixup_var_refs_queue
= temp
;
907 /* Variable is local; fix it up now. */
908 fixup_var_refs (reg
, promoted_mode
, TREE_UNSIGNED (TREE_TYPE (decl
)));
912 fixup_var_refs (var
, promoted_mode
, unsignedp
)
914 enum machine_mode promoted_mode
;
918 rtx first_insn
= get_insns ();
919 struct sequence_stack
*stack
= sequence_stack
;
920 tree rtl_exps
= rtl_expr_chain
;
922 /* Must scan all insns for stack-refs that exceed the limit. */
923 fixup_var_refs_insns (var
, promoted_mode
, unsignedp
, first_insn
, stack
== 0);
925 /* Scan all pending sequences too. */
926 for (; stack
; stack
= stack
->next
)
928 push_to_sequence (stack
->first
);
929 fixup_var_refs_insns (var
, promoted_mode
, unsignedp
,
930 stack
->first
, stack
->next
!= 0);
931 /* Update remembered end of sequence
932 in case we added an insn at the end. */
933 stack
->last
= get_last_insn ();
937 /* Scan all waiting RTL_EXPRs too. */
938 for (pending
= rtl_exps
; pending
; pending
= TREE_CHAIN (pending
))
940 rtx seq
= RTL_EXPR_SEQUENCE (TREE_VALUE (pending
));
941 if (seq
!= const0_rtx
&& seq
!= 0)
943 push_to_sequence (seq
);
944 fixup_var_refs_insns (var
, promoted_mode
, unsignedp
, seq
, 0);
950 /* This structure is used by the following two functions to record MEMs or
951 pseudos used to replace VAR, any SUBREGs of VAR, and any MEMs containing
952 VAR as an address. We need to maintain this list in case two operands of
953 an insn were required to match; in that case we must ensure we use the
956 struct fixup_replacement
960 struct fixup_replacement
*next
;
963 /* REPLACEMENTS is a pointer to a list of the above structures and X is
964 some part of an insn. Return a struct fixup_replacement whose OLD
965 value is equal to X. Allocate a new structure if no such entry exists. */
967 static struct fixup_replacement
*
968 find_fixup_replacement (replacements
, x
)
969 struct fixup_replacement
**replacements
;
972 struct fixup_replacement
*p
;
974 /* See if we have already replaced this. */
975 for (p
= *replacements
; p
&& p
->old
!= x
; p
= p
->next
)
980 p
= (struct fixup_replacement
*) oballoc (sizeof (struct fixup_replacement
));
983 p
->next
= *replacements
;
990 /* Scan the insn-chain starting with INSN for refs to VAR
991 and fix them up. TOPLEVEL is nonzero if this chain is the
992 main chain of insns for the current function. */
995 fixup_var_refs_insns (var
, promoted_mode
, unsignedp
, insn
, toplevel
)
997 enum machine_mode promoted_mode
;
1004 rtx next
= NEXT_INSN (insn
);
1006 if (GET_RTX_CLASS (GET_CODE (insn
)) == 'i')
1008 /* The insn to load VAR from a home in the arglist
1009 is now a no-op. When we see it, just delete it. */
1011 && GET_CODE (PATTERN (insn
)) == SET
1012 && SET_DEST (PATTERN (insn
)) == var
1013 && rtx_equal_p (SET_SRC (PATTERN (insn
)), var
))
1015 /* In unoptimized compilation, we shouldn't call delete_insn
1016 except in jump.c doing warnings. */
1017 PUT_CODE (insn
, NOTE
);
1018 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
1019 NOTE_SOURCE_FILE (insn
) = 0;
1020 if (insn
== last_parm_insn
)
1021 last_parm_insn
= PREV_INSN (next
);
1025 /* See if we have to do anything to INSN now that VAR is in
1026 memory. If it needs to be loaded into a pseudo, use a single
1027 pseudo for the entire insn in case there is a MATCH_DUP
1028 between two operands. We pass a pointer to the head of
1029 a list of struct fixup_replacements. If fixup_var_refs_1
1030 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1031 it will record them in this list.
1033 If it allocated a pseudo for any replacement, we copy into
1036 struct fixup_replacement
*replacements
= 0;
1037 rtx next_insn
= NEXT_INSN (insn
);
1039 fixup_var_refs_1 (var
, promoted_mode
, &PATTERN (insn
), insn
,
1042 /* If this is last_parm_insn, and any instructions were output
1043 after it to fix it up, then we must set last_parm_insn to
1044 the last such instruction emitted. */
1045 if (insn
== last_parm_insn
)
1046 last_parm_insn
= PREV_INSN (next_insn
);
1048 while (replacements
)
1050 if (GET_CODE (replacements
->new) == REG
)
1055 /* OLD might be a (subreg (mem)). */
1056 if (GET_CODE (replacements
->old
) == SUBREG
)
1058 = fixup_memory_subreg (replacements
->old
, insn
, 0);
1061 = fixup_stack_1 (replacements
->old
, insn
);
1063 /* We can not separate USE insns from the CALL_INSN
1064 that they belong to. If this is a CALL_INSN, insert
1065 the move insn before the USE insns preceding it
1066 instead of immediately before the insn. */
1067 if (GET_CODE (insn
) == CALL_INSN
)
1069 insert_before
= insn
;
1070 while (GET_CODE (PREV_INSN (insert_before
)) == INSN
1071 && GET_CODE (PATTERN (PREV_INSN (insert_before
))) == USE
)
1072 insert_before
= PREV_INSN (insert_before
);
1075 insert_before
= insn
;
1077 /* If we are changing the mode, do a conversion.
1078 This might be wasteful, but combine.c will
1079 eliminate much of the waste. */
1081 if (GET_MODE (replacements
->new)
1082 != GET_MODE (replacements
->old
))
1085 convert_move (replacements
->new,
1086 replacements
->old
, unsignedp
);
1087 seq
= gen_sequence ();
1091 seq
= gen_move_insn (replacements
->new,
1094 emit_insn_before (seq
, insert_before
);
1097 replacements
= replacements
->next
;
1101 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1102 But don't touch other insns referred to by reg-notes;
1103 we will get them elsewhere. */
1104 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
1105 if (GET_CODE (note
) != INSN_LIST
)
1106 XEXP (note
, 0) = walk_fixup_memory_subreg (XEXP (note
, 0), insn
);
1112 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1113 See if the rtx expression at *LOC in INSN needs to be changed.
1115 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1116 contain a list of original rtx's and replacements. If we find that we need
1117 to modify this insn by replacing a memory reference with a pseudo or by
1118 making a new MEM to implement a SUBREG, we consult that list to see if
1119 we have already chosen a replacement. If none has already been allocated,
1120 we allocate it and update the list. fixup_var_refs_insns will copy VAR
1121 or the SUBREG, as appropriate, to the pseudo. */
1124 fixup_var_refs_1 (var
, promoted_mode
, loc
, insn
, replacements
)
1126 enum machine_mode promoted_mode
;
1129 struct fixup_replacement
**replacements
;
1132 register rtx x
= *loc
;
1133 RTX_CODE code
= GET_CODE (x
);
1135 register rtx tem
, tem1
;
1136 struct fixup_replacement
*replacement
;
1143 /* If we already have a replacement, use it. Otherwise,
1144 try to fix up this address in case it is invalid. */
1146 replacement
= find_fixup_replacement (replacements
, var
);
1147 if (replacement
->new)
1149 *loc
= replacement
->new;
1153 *loc
= replacement
->new = x
= fixup_stack_1 (x
, insn
);
1155 /* Unless we are forcing memory to register or we changed the mode,
1156 we can leave things the way they are if the insn is valid. */
1158 INSN_CODE (insn
) = -1;
1159 if (! flag_force_mem
&& GET_MODE (x
) == promoted_mode
1160 && recog_memoized (insn
) >= 0)
1163 *loc
= replacement
->new = gen_reg_rtx (promoted_mode
);
1167 /* If X contains VAR, we need to unshare it here so that we update
1168 each occurrence separately. But all identical MEMs in one insn
1169 must be replaced with the same rtx because of the possibility of
1172 if (reg_mentioned_p (var
, x
))
1174 replacement
= find_fixup_replacement (replacements
, x
);
1175 if (replacement
->new == 0)
1176 replacement
->new = copy_most_rtx (x
, var
);
1178 *loc
= x
= replacement
->new;
1194 /* Note that in some cases those types of expressions are altered
1195 by optimize_bit_field, and do not survive to get here. */
1196 if (XEXP (x
, 0) == var
1197 || (GET_CODE (XEXP (x
, 0)) == SUBREG
1198 && SUBREG_REG (XEXP (x
, 0)) == var
))
1200 /* Get TEM as a valid MEM in the mode presently in the insn.
1202 We don't worry about the possibility of MATCH_DUP here; it
1203 is highly unlikely and would be tricky to handle. */
1206 if (GET_CODE (tem
) == SUBREG
)
1207 tem
= fixup_memory_subreg (tem
, insn
, 1);
1208 tem
= fixup_stack_1 (tem
, insn
);
1210 /* Unless we want to load from memory, get TEM into the proper mode
1211 for an extract from memory. This can only be done if the
1212 extract is at a constant position and length. */
1214 if (! flag_force_mem
&& GET_CODE (XEXP (x
, 1)) == CONST_INT
1215 && GET_CODE (XEXP (x
, 2)) == CONST_INT
1216 && ! mode_dependent_address_p (XEXP (tem
, 0))
1217 && ! MEM_VOLATILE_P (tem
))
1219 enum machine_mode wanted_mode
= VOIDmode
;
1220 enum machine_mode is_mode
= GET_MODE (tem
);
1221 int width
= INTVAL (XEXP (x
, 1));
1222 int pos
= INTVAL (XEXP (x
, 2));
1225 if (GET_CODE (x
) == ZERO_EXTRACT
)
1226 wanted_mode
= insn_operand_mode
[(int) CODE_FOR_extzv
][1];
1229 if (GET_CODE (x
) == SIGN_EXTRACT
)
1230 wanted_mode
= insn_operand_mode
[(int) CODE_FOR_extv
][1];
1232 /* If we have a narrower mode, we can do something. */
1233 if (wanted_mode
!= VOIDmode
1234 && GET_MODE_SIZE (wanted_mode
) < GET_MODE_SIZE (is_mode
))
1236 int offset
= pos
/ BITS_PER_UNIT
;
1237 rtx old_pos
= XEXP (x
, 2);
1240 /* If the bytes and bits are counted differently, we
1241 must adjust the offset. */
1242 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1243 offset
= (GET_MODE_SIZE (is_mode
)
1244 - GET_MODE_SIZE (wanted_mode
) - offset
);
1247 pos
%= GET_MODE_BITSIZE (wanted_mode
);
1249 newmem
= gen_rtx (MEM
, wanted_mode
,
1250 plus_constant (XEXP (tem
, 0), offset
));
1251 RTX_UNCHANGING_P (newmem
) = RTX_UNCHANGING_P (tem
);
1252 MEM_VOLATILE_P (newmem
) = MEM_VOLATILE_P (tem
);
1253 MEM_IN_STRUCT_P (newmem
) = MEM_IN_STRUCT_P (tem
);
1255 /* Make the change and see if the insn remains valid. */
1256 INSN_CODE (insn
) = -1;
1257 XEXP (x
, 0) = newmem
;
1258 XEXP (x
, 2) = GEN_INT (pos
);
1260 if (recog_memoized (insn
) >= 0)
1263 /* Otherwise, restore old position. XEXP (x, 0) will be
1265 XEXP (x
, 2) = old_pos
;
1269 /* If we get here, the bitfield extract insn can't accept a memory
1270 reference. Copy the input into a register. */
1272 tem1
= gen_reg_rtx (GET_MODE (tem
));
1273 emit_insn_before (gen_move_insn (tem1
, tem
), insn
);
1280 if (SUBREG_REG (x
) == var
)
1282 /* If this is a special SUBREG made because VAR was promoted
1283 from a wider mode, replace it with VAR and call ourself
1284 recursively, this time saying that the object previously
1285 had its current mode (by virtue of the SUBREG). */
1287 if (SUBREG_PROMOTED_VAR_P (x
))
1290 fixup_var_refs_1 (var
, GET_MODE (var
), loc
, insn
, replacements
);
1294 /* If this SUBREG makes VAR wider, it has become a paradoxical
1295 SUBREG with VAR in memory, but these aren't allowed at this
1296 stage of the compilation. So load VAR into a pseudo and take
1297 a SUBREG of that pseudo. */
1298 if (GET_MODE_SIZE (GET_MODE (x
)) > GET_MODE_SIZE (GET_MODE (var
)))
1300 replacement
= find_fixup_replacement (replacements
, var
);
1301 if (replacement
->new == 0)
1302 replacement
->new = gen_reg_rtx (GET_MODE (var
));
1303 SUBREG_REG (x
) = replacement
->new;
1307 /* See if we have already found a replacement for this SUBREG.
1308 If so, use it. Otherwise, make a MEM and see if the insn
1309 is recognized. If not, or if we should force MEM into a register,
1310 make a pseudo for this SUBREG. */
1311 replacement
= find_fixup_replacement (replacements
, x
);
1312 if (replacement
->new)
1314 *loc
= replacement
->new;
1318 replacement
->new = *loc
= fixup_memory_subreg (x
, insn
, 0);
1320 INSN_CODE (insn
) = -1;
1321 if (! flag_force_mem
&& recog_memoized (insn
) >= 0)
1324 *loc
= replacement
->new = gen_reg_rtx (GET_MODE (x
));
1330 /* First do special simplification of bit-field references. */
1331 if (GET_CODE (SET_DEST (x
)) == SIGN_EXTRACT
1332 || GET_CODE (SET_DEST (x
)) == ZERO_EXTRACT
)
1333 optimize_bit_field (x
, insn
, 0);
1334 if (GET_CODE (SET_SRC (x
)) == SIGN_EXTRACT
1335 || GET_CODE (SET_SRC (x
)) == ZERO_EXTRACT
)
1336 optimize_bit_field (x
, insn
, NULL_PTR
);
1338 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
1339 insn into a pseudo and store the low part of the pseudo into VAR. */
1340 if (GET_CODE (SET_DEST (x
)) == SUBREG
1341 && SUBREG_REG (SET_DEST (x
)) == var
1342 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x
)))
1343 > GET_MODE_SIZE (GET_MODE (var
))))
1345 SET_DEST (x
) = tem
= gen_reg_rtx (GET_MODE (SET_DEST (x
)));
1346 emit_insn_after (gen_move_insn (var
, gen_lowpart (GET_MODE (var
),
1353 rtx dest
= SET_DEST (x
);
1354 rtx src
= SET_SRC (x
);
1355 rtx outerdest
= dest
;
1357 while (GET_CODE (dest
) == SUBREG
|| GET_CODE (dest
) == STRICT_LOW_PART
1358 || GET_CODE (dest
) == SIGN_EXTRACT
1359 || GET_CODE (dest
) == ZERO_EXTRACT
)
1360 dest
= XEXP (dest
, 0);
1362 if (GET_CODE (src
) == SUBREG
)
1363 src
= XEXP (src
, 0);
1365 /* If VAR does not appear at the top level of the SET
1366 just scan the lower levels of the tree. */
1368 if (src
!= var
&& dest
!= var
)
1371 /* We will need to rerecognize this insn. */
1372 INSN_CODE (insn
) = -1;
1375 if (GET_CODE (outerdest
) == ZERO_EXTRACT
&& dest
== var
)
1377 /* Since this case will return, ensure we fixup all the
1379 fixup_var_refs_1 (var
, promoted_mode
, &XEXP (outerdest
, 1),
1380 insn
, replacements
);
1381 fixup_var_refs_1 (var
, promoted_mode
, &XEXP (outerdest
, 2),
1382 insn
, replacements
);
1383 fixup_var_refs_1 (var
, promoted_mode
, &SET_SRC (x
),
1384 insn
, replacements
);
1386 tem
= XEXP (outerdest
, 0);
1388 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
1389 that may appear inside a ZERO_EXTRACT.
1390 This was legitimate when the MEM was a REG. */
1391 if (GET_CODE (tem
) == SUBREG
1392 && SUBREG_REG (tem
) == var
)
1393 tem
= fixup_memory_subreg (tem
, insn
, 1);
1395 tem
= fixup_stack_1 (tem
, insn
);
1397 if (GET_CODE (XEXP (outerdest
, 1)) == CONST_INT
1398 && GET_CODE (XEXP (outerdest
, 2)) == CONST_INT
1399 && ! mode_dependent_address_p (XEXP (tem
, 0))
1400 && ! MEM_VOLATILE_P (tem
))
1402 enum machine_mode wanted_mode
1403 = insn_operand_mode
[(int) CODE_FOR_insv
][0];
1404 enum machine_mode is_mode
= GET_MODE (tem
);
1405 int width
= INTVAL (XEXP (outerdest
, 1));
1406 int pos
= INTVAL (XEXP (outerdest
, 2));
1408 /* If we have a narrower mode, we can do something. */
1409 if (GET_MODE_SIZE (wanted_mode
) < GET_MODE_SIZE (is_mode
))
1411 int offset
= pos
/ BITS_PER_UNIT
;
1412 rtx old_pos
= XEXP (outerdest
, 2);
1415 #if BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN
1416 offset
= (GET_MODE_SIZE (is_mode
)
1417 - GET_MODE_SIZE (wanted_mode
) - offset
);
1420 pos
%= GET_MODE_BITSIZE (wanted_mode
);
1422 newmem
= gen_rtx (MEM
, wanted_mode
,
1423 plus_constant (XEXP (tem
, 0), offset
));
1424 RTX_UNCHANGING_P (newmem
) = RTX_UNCHANGING_P (tem
);
1425 MEM_VOLATILE_P (newmem
) = MEM_VOLATILE_P (tem
);
1426 MEM_IN_STRUCT_P (newmem
) = MEM_IN_STRUCT_P (tem
);
1428 /* Make the change and see if the insn remains valid. */
1429 INSN_CODE (insn
) = -1;
1430 XEXP (outerdest
, 0) = newmem
;
1431 XEXP (outerdest
, 2) = GEN_INT (pos
);
1433 if (recog_memoized (insn
) >= 0)
1436 /* Otherwise, restore old position. XEXP (x, 0) will be
1438 XEXP (outerdest
, 2) = old_pos
;
1442 /* If we get here, the bit-field store doesn't allow memory
1443 or isn't located at a constant position. Load the value into
1444 a register, do the store, and put it back into memory. */
1446 tem1
= gen_reg_rtx (GET_MODE (tem
));
1447 emit_insn_before (gen_move_insn (tem1
, tem
), insn
);
1448 emit_insn_after (gen_move_insn (tem
, tem1
), insn
);
1449 XEXP (outerdest
, 0) = tem1
;
1454 /* STRICT_LOW_PART is a no-op on memory references
1455 and it can cause combinations to be unrecognizable,
1458 if (dest
== var
&& GET_CODE (SET_DEST (x
)) == STRICT_LOW_PART
)
1459 SET_DEST (x
) = XEXP (SET_DEST (x
), 0);
1461 /* A valid insn to copy VAR into or out of a register
1462 must be left alone, to avoid an infinite loop here.
1463 If the reference to VAR is by a subreg, fix that up,
1464 since SUBREG is not valid for a memref.
1465 Also fix up the address of the stack slot.
1467 Note that we must not try to recognize the insn until
1468 after we know that we have valid addresses and no
1469 (subreg (mem ...) ...) constructs, since these interfere
1470 with determining the validity of the insn. */
1472 if ((SET_SRC (x
) == var
1473 || (GET_CODE (SET_SRC (x
)) == SUBREG
1474 && SUBREG_REG (SET_SRC (x
)) == var
))
1475 && (GET_CODE (SET_DEST (x
)) == REG
1476 || (GET_CODE (SET_DEST (x
)) == SUBREG
1477 && GET_CODE (SUBREG_REG (SET_DEST (x
))) == REG
))
1478 && x
== single_set (PATTERN (insn
)))
1482 replacement
= find_fixup_replacement (replacements
, SET_SRC (x
));
1483 if (replacement
->new)
1484 SET_SRC (x
) = replacement
->new;
1485 else if (GET_CODE (SET_SRC (x
)) == SUBREG
)
1486 SET_SRC (x
) = replacement
->new
1487 = fixup_memory_subreg (SET_SRC (x
), insn
, 0);
1489 SET_SRC (x
) = replacement
->new
1490 = fixup_stack_1 (SET_SRC (x
), insn
);
1492 if (recog_memoized (insn
) >= 0)
1495 /* INSN is not valid, but we know that we want to
1496 copy SET_SRC (x) to SET_DEST (x) in some way. So
1497 we generate the move and see whether it requires more
1498 than one insn. If it does, we emit those insns and
1499 delete INSN. Otherwise, we an just replace the pattern
1500 of INSN; we have already verified above that INSN has
1501 no other function that to do X. */
1503 pat
= gen_move_insn (SET_DEST (x
), SET_SRC (x
));
1504 if (GET_CODE (pat
) == SEQUENCE
)
1506 emit_insn_after (pat
, insn
);
1507 PUT_CODE (insn
, NOTE
);
1508 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
1509 NOTE_SOURCE_FILE (insn
) = 0;
1512 PATTERN (insn
) = pat
;
1517 if ((SET_DEST (x
) == var
1518 || (GET_CODE (SET_DEST (x
)) == SUBREG
1519 && SUBREG_REG (SET_DEST (x
)) == var
))
1520 && (GET_CODE (SET_SRC (x
)) == REG
1521 || (GET_CODE (SET_SRC (x
)) == SUBREG
1522 && GET_CODE (SUBREG_REG (SET_SRC (x
))) == REG
))
1523 && x
== single_set (PATTERN (insn
)))
1527 if (GET_CODE (SET_DEST (x
)) == SUBREG
)
1528 SET_DEST (x
) = fixup_memory_subreg (SET_DEST (x
), insn
, 0);
1530 SET_DEST (x
) = fixup_stack_1 (SET_DEST (x
), insn
);
1532 if (recog_memoized (insn
) >= 0)
1535 pat
= gen_move_insn (SET_DEST (x
), SET_SRC (x
));
1536 if (GET_CODE (pat
) == SEQUENCE
)
1538 emit_insn_after (pat
, insn
);
1539 PUT_CODE (insn
, NOTE
);
1540 NOTE_LINE_NUMBER (insn
) = NOTE_INSN_DELETED
;
1541 NOTE_SOURCE_FILE (insn
) = 0;
1544 PATTERN (insn
) = pat
;
1549 /* Otherwise, storing into VAR must be handled specially
1550 by storing into a temporary and copying that into VAR
1551 with a new insn after this one. Note that this case
1552 will be used when storing into a promoted scalar since
1553 the insn will now have different modes on the input
1554 and output and hence will be invalid (except for the case
1555 of setting it to a constant, which does not need any
1556 change if it is valid). We generate extra code in that case,
1557 but combine.c will eliminate it. */
1562 rtx fixeddest
= SET_DEST (x
);
1564 /* STRICT_LOW_PART can be discarded, around a MEM. */
1565 if (GET_CODE (fixeddest
) == STRICT_LOW_PART
)
1566 fixeddest
= XEXP (fixeddest
, 0);
1567 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
1568 if (GET_CODE (fixeddest
) == SUBREG
)
1569 fixeddest
= fixup_memory_subreg (fixeddest
, insn
, 0);
1571 fixeddest
= fixup_stack_1 (fixeddest
, insn
);
1573 temp
= gen_reg_rtx (GET_MODE (SET_SRC (x
)) == VOIDmode
1574 ? GET_MODE (fixeddest
)
1575 : GET_MODE (SET_SRC (x
)));
1577 emit_insn_after (gen_move_insn (fixeddest
,
1578 gen_lowpart (GET_MODE (fixeddest
),
1582 SET_DEST (x
) = temp
;
1587 /* Nothing special about this RTX; fix its operands. */
1589 fmt
= GET_RTX_FORMAT (code
);
1590 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1593 fixup_var_refs_1 (var
, promoted_mode
, &XEXP (x
, i
), insn
, replacements
);
1597 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1598 fixup_var_refs_1 (var
, promoted_mode
, &XVECEXP (x
, i
, j
),
1599 insn
, replacements
);
1604 /* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
1605 return an rtx (MEM:m1 newaddr) which is equivalent.
1606 If any insns must be emitted to compute NEWADDR, put them before INSN.
1608 UNCRITICAL nonzero means accept paradoxical subregs.
1609 This is used for subregs found inside of ZERO_EXTRACTs. */
1612 fixup_memory_subreg (x
, insn
, uncritical
)
1617 int offset
= SUBREG_WORD (x
) * UNITS_PER_WORD
;
1618 rtx addr
= XEXP (SUBREG_REG (x
), 0);
1619 enum machine_mode mode
= GET_MODE (x
);
1622 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
1623 if (GET_MODE_SIZE (mode
) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x
)))
1627 #if BYTES_BIG_ENDIAN
1628 offset
+= (MIN (UNITS_PER_WORD
, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x
))))
1629 - MIN (UNITS_PER_WORD
, GET_MODE_SIZE (mode
)));
1631 addr
= plus_constant (addr
, offset
);
1632 if (!flag_force_addr
&& memory_address_p (mode
, addr
))
1633 /* Shortcut if no insns need be emitted. */
1634 return change_address (SUBREG_REG (x
), mode
, addr
);
1636 result
= change_address (SUBREG_REG (x
), mode
, addr
);
1637 emit_insn_before (gen_sequence (), insn
);
1642 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
1643 Replace subexpressions of X in place.
1644 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
1645 Otherwise return X, with its contents possibly altered.
1647 If any insns must be emitted to compute NEWADDR, put them before INSN. */
1650 walk_fixup_memory_subreg (x
, insn
)
1654 register enum rtx_code code
;
1661 code
= GET_CODE (x
);
1663 if (code
== SUBREG
&& GET_CODE (SUBREG_REG (x
)) == MEM
)
1664 return fixup_memory_subreg (x
, insn
, 0);
1666 /* Nothing special about this RTX; fix its operands. */
1668 fmt
= GET_RTX_FORMAT (code
);
1669 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1672 XEXP (x
, i
) = walk_fixup_memory_subreg (XEXP (x
, i
), insn
);
1676 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1678 = walk_fixup_memory_subreg (XVECEXP (x
, i
, j
), insn
);
1685 /* Fix up any references to stack slots that are invalid memory addresses
1686 because they exceed the maximum range of a displacement. */
1689 fixup_stack_slots ()
1693 /* Did we generate a stack slot that is out of range
1694 or otherwise has an invalid address? */
1695 if (invalid_stack_slot
)
1697 /* Yes. Must scan all insns for stack-refs that exceed the limit. */
1698 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
1699 if (GET_CODE (insn
) == INSN
|| GET_CODE (insn
) == CALL_INSN
1700 || GET_CODE (insn
) == JUMP_INSN
)
1701 fixup_stack_1 (PATTERN (insn
), insn
);
1706 /* For each memory ref within X, if it refers to a stack slot
1707 with an out of range displacement, put the address in a temp register
1708 (emitting new insns before INSN to load these registers)
1709 and alter the memory ref to use that register.
1710 Replace each such MEM rtx with a copy, to avoid clobberage. */
1713 fixup_stack_1 (x
, insn
)
1718 register RTX_CODE code
= GET_CODE (x
);
1723 register rtx ad
= XEXP (x
, 0);
1724 /* If we have address of a stack slot but it's not valid
1725 (displacement is too large), compute the sum in a register. */
1726 if (GET_CODE (ad
) == PLUS
1727 && GET_CODE (XEXP (ad
, 0)) == REG
1728 && REGNO (XEXP (ad
, 0)) >= FIRST_VIRTUAL_REGISTER
1729 && REGNO (XEXP (ad
, 0)) <= LAST_VIRTUAL_REGISTER
1730 && GET_CODE (XEXP (ad
, 1)) == CONST_INT
)
1733 if (memory_address_p (GET_MODE (x
), ad
))
1737 temp
= copy_to_reg (ad
);
1738 seq
= gen_sequence ();
1740 emit_insn_before (seq
, insn
);
1741 return change_address (x
, VOIDmode
, temp
);
1746 fmt
= GET_RTX_FORMAT (code
);
1747 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1750 XEXP (x
, i
) = fixup_stack_1 (XEXP (x
, i
), insn
);
1754 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1755 XVECEXP (x
, i
, j
) = fixup_stack_1 (XVECEXP (x
, i
, j
), insn
);
1761 /* Optimization: a bit-field instruction whose field
1762 happens to be a byte or halfword in memory
1763 can be changed to a move instruction.
1765 We call here when INSN is an insn to examine or store into a bit-field.
1766 BODY is the SET-rtx to be altered.
1768 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
1769 (Currently this is called only from function.c, and EQUIV_MEM
1773 optimize_bit_field (body
, insn
, equiv_mem
)
1778 register rtx bitfield
;
1781 enum machine_mode mode
;
1783 if (GET_CODE (SET_DEST (body
)) == SIGN_EXTRACT
1784 || GET_CODE (SET_DEST (body
)) == ZERO_EXTRACT
)
1785 bitfield
= SET_DEST (body
), destflag
= 1;
1787 bitfield
= SET_SRC (body
), destflag
= 0;
1789 /* First check that the field being stored has constant size and position
1790 and is in fact a byte or halfword suitably aligned. */
1792 if (GET_CODE (XEXP (bitfield
, 1)) == CONST_INT
1793 && GET_CODE (XEXP (bitfield
, 2)) == CONST_INT
1794 && ((mode
= mode_for_size (INTVAL (XEXP (bitfield
, 1)), MODE_INT
, 1))
1796 && INTVAL (XEXP (bitfield
, 2)) % INTVAL (XEXP (bitfield
, 1)) == 0)
1798 register rtx memref
= 0;
1800 /* Now check that the containing word is memory, not a register,
1801 and that it is safe to change the machine mode. */
1803 if (GET_CODE (XEXP (bitfield
, 0)) == MEM
)
1804 memref
= XEXP (bitfield
, 0);
1805 else if (GET_CODE (XEXP (bitfield
, 0)) == REG
1807 memref
= equiv_mem
[REGNO (XEXP (bitfield
, 0))];
1808 else if (GET_CODE (XEXP (bitfield
, 0)) == SUBREG
1809 && GET_CODE (SUBREG_REG (XEXP (bitfield
, 0))) == MEM
)
1810 memref
= SUBREG_REG (XEXP (bitfield
, 0));
1811 else if (GET_CODE (XEXP (bitfield
, 0)) == SUBREG
1813 && GET_CODE (SUBREG_REG (XEXP (bitfield
, 0))) == REG
)
1814 memref
= equiv_mem
[REGNO (SUBREG_REG (XEXP (bitfield
, 0)))];
1817 && ! mode_dependent_address_p (XEXP (memref
, 0))
1818 && ! MEM_VOLATILE_P (memref
))
1820 /* Now adjust the address, first for any subreg'ing
1821 that we are now getting rid of,
1822 and then for which byte of the word is wanted. */
1824 register int offset
= INTVAL (XEXP (bitfield
, 2));
1825 /* Adjust OFFSET to count bits from low-address byte. */
1826 #if BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN
1827 offset
= (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield
, 0)))
1828 - offset
- INTVAL (XEXP (bitfield
, 1)));
1830 /* Adjust OFFSET to count bytes from low-address byte. */
1831 offset
/= BITS_PER_UNIT
;
1832 if (GET_CODE (XEXP (bitfield
, 0)) == SUBREG
)
1834 offset
+= SUBREG_WORD (XEXP (bitfield
, 0)) * UNITS_PER_WORD
;
1835 #if BYTES_BIG_ENDIAN
1836 offset
-= (MIN (UNITS_PER_WORD
,
1837 GET_MODE_SIZE (GET_MODE (XEXP (bitfield
, 0))))
1838 - MIN (UNITS_PER_WORD
,
1839 GET_MODE_SIZE (GET_MODE (memref
))));
1843 memref
= change_address (memref
, mode
,
1844 plus_constant (XEXP (memref
, 0), offset
));
1846 /* Store this memory reference where
1847 we found the bit field reference. */
1851 validate_change (insn
, &SET_DEST (body
), memref
, 1);
1852 if (! CONSTANT_ADDRESS_P (SET_SRC (body
)))
1854 rtx src
= SET_SRC (body
);
1855 while (GET_CODE (src
) == SUBREG
1856 && SUBREG_WORD (src
) == 0)
1857 src
= SUBREG_REG (src
);
1858 if (GET_MODE (src
) != GET_MODE (memref
))
1859 src
= gen_lowpart (GET_MODE (memref
), SET_SRC (body
));
1860 validate_change (insn
, &SET_SRC (body
), src
, 1);
1862 else if (GET_MODE (SET_SRC (body
)) != VOIDmode
1863 && GET_MODE (SET_SRC (body
)) != GET_MODE (memref
))
1864 /* This shouldn't happen because anything that didn't have
1865 one of these modes should have got converted explicitly
1866 and then referenced through a subreg.
1867 This is so because the original bit-field was
1868 handled by agg_mode and so its tree structure had
1869 the same mode that memref now has. */
1874 rtx dest
= SET_DEST (body
);
1876 while (GET_CODE (dest
) == SUBREG
1877 && SUBREG_WORD (dest
) == 0)
1878 dest
= SUBREG_REG (dest
);
1880 validate_change (insn
, &SET_DEST (body
), dest
, 1);
1882 if (GET_MODE (dest
) == GET_MODE (memref
))
1883 validate_change (insn
, &SET_SRC (body
), memref
, 1);
1886 /* Convert the mem ref to the destination mode. */
1887 rtx newreg
= gen_reg_rtx (GET_MODE (dest
));
1890 convert_move (newreg
, memref
,
1891 GET_CODE (SET_SRC (body
)) == ZERO_EXTRACT
);
1895 validate_change (insn
, &SET_SRC (body
), newreg
, 1);
1899 /* See if we can convert this extraction or insertion into
1900 a simple move insn. We might not be able to do so if this
1901 was, for example, part of a PARALLEL.
1903 If we succeed, write out any needed conversions. If we fail,
1904 it is hard to guess why we failed, so don't do anything
1905 special; just let the optimization be suppressed. */
1907 if (apply_change_group () && seq
)
1908 emit_insns_before (seq
, insn
);
1913 /* These routines are responsible for converting virtual register references
1914 to the actual hard register references once RTL generation is complete.
1916 The following four variables are used for communication between the
1917 routines. They contain the offsets of the virtual registers from their
1918 respective hard registers. */
1920 static int in_arg_offset
;
1921 static int var_offset
;
1922 static int dynamic_offset
;
1923 static int out_arg_offset
;
1925 /* In most machines, the stack pointer register is equivalent to the bottom
1928 #ifndef STACK_POINTER_OFFSET
1929 #define STACK_POINTER_OFFSET 0
1932 /* If not defined, pick an appropriate default for the offset of dynamically
1933 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1934 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1936 #ifndef STACK_DYNAMIC_OFFSET
1938 #ifdef ACCUMULATE_OUTGOING_ARGS
1939 /* The bottom of the stack points to the actual arguments. If
1940 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1941 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1942 stack space for register parameters is not pushed by the caller, but
1943 rather part of the fixed stack areas and hence not included in
1944 `current_function_outgoing_args_size'. Nevertheless, we must allow
1945 for it when allocating stack dynamic objects. */
1947 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1948 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1949 (current_function_outgoing_args_size \
1950 + REG_PARM_STACK_SPACE (FNDECL) + (STACK_POINTER_OFFSET))
1953 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1954 (current_function_outgoing_args_size + (STACK_POINTER_OFFSET))
1958 #define STACK_DYNAMIC_OFFSET(FNDECL) STACK_POINTER_OFFSET
1962 /* Pass through the INSNS of function FNDECL and convert virtual register
1963 references to hard register references. */
1966 instantiate_virtual_regs (fndecl
, insns
)
1972 /* Compute the offsets to use for this function. */
1973 in_arg_offset
= FIRST_PARM_OFFSET (fndecl
);
1974 var_offset
= STARTING_FRAME_OFFSET
;
1975 dynamic_offset
= STACK_DYNAMIC_OFFSET (fndecl
);
1976 out_arg_offset
= STACK_POINTER_OFFSET
;
1978 /* Scan all variables and parameters of this function. For each that is
1979 in memory, instantiate all virtual registers if the result is a valid
1980 address. If not, we do it later. That will handle most uses of virtual
1981 regs on many machines. */
1982 instantiate_decls (fndecl
, 1);
1984 /* Initialize recognition, indicating that volatile is OK. */
1987 /* Scan through all the insns, instantiating every virtual register still
1989 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
1990 if (GET_CODE (insn
) == INSN
|| GET_CODE (insn
) == JUMP_INSN
1991 || GET_CODE (insn
) == CALL_INSN
)
1993 instantiate_virtual_regs_1 (&PATTERN (insn
), insn
, 1);
1994 instantiate_virtual_regs_1 (®_NOTES (insn
), NULL_RTX
, 0);
1997 /* Now instantiate the remaining register equivalences for debugging info.
1998 These will not be valid addresses. */
1999 instantiate_decls (fndecl
, 0);
2001 /* Indicate that, from now on, assign_stack_local should use
2002 frame_pointer_rtx. */
2003 virtuals_instantiated
= 1;
2006 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
2007 all virtual registers in their DECL_RTL's.
2009 If VALID_ONLY, do this only if the resulting address is still valid.
2010 Otherwise, always do it. */
2013 instantiate_decls (fndecl
, valid_only
)
2019 if (DECL_INLINE (fndecl
))
2020 /* When compiling an inline function, the obstack used for
2021 rtl allocation is the maybepermanent_obstack. Calling
2022 `resume_temporary_allocation' switches us back to that
2023 obstack while we process this function's parameters. */
2024 resume_temporary_allocation ();
2026 /* Process all parameters of the function. */
2027 for (decl
= DECL_ARGUMENTS (fndecl
); decl
; decl
= TREE_CHAIN (decl
))
2029 instantiate_decl (DECL_RTL (decl
), int_size_in_bytes (TREE_TYPE (decl
)),
2031 instantiate_decl (DECL_INCOMING_RTL (decl
),
2032 int_size_in_bytes (TREE_TYPE (decl
)), valid_only
);
2035 /* Now process all variables defined in the function or its subblocks. */
2036 instantiate_decls_1 (DECL_INITIAL (fndecl
), valid_only
);
2038 if (DECL_INLINE (fndecl
))
2040 /* Save all rtl allocated for this function by raising the
2041 high-water mark on the maybepermanent_obstack. */
2043 /* All further rtl allocation is now done in the current_obstack. */
2044 rtl_in_current_obstack ();
2048 /* Subroutine of instantiate_decls: Process all decls in the given
2049 BLOCK node and all its subblocks. */
2052 instantiate_decls_1 (let
, valid_only
)
2058 for (t
= BLOCK_VARS (let
); t
; t
= TREE_CHAIN (t
))
2059 instantiate_decl (DECL_RTL (t
), int_size_in_bytes (TREE_TYPE (t
)),
2062 /* Process all subblocks. */
2063 for (t
= BLOCK_SUBBLOCKS (let
); t
; t
= TREE_CHAIN (t
))
2064 instantiate_decls_1 (t
, valid_only
);
2067 /* Subroutine of the preceding procedures: Given RTL representing a
2068 decl and the size of the object, do any instantiation required.
2070 If VALID_ONLY is non-zero, it means that the RTL should only be
2071 changed if the new address is valid. */
2074 instantiate_decl (x
, size
, valid_only
)
2079 enum machine_mode mode
;
2082 /* If this is not a MEM, no need to do anything. Similarly if the
2083 address is a constant or a register that is not a virtual register. */
2085 if (x
== 0 || GET_CODE (x
) != MEM
)
2089 if (CONSTANT_P (addr
)
2090 || (GET_CODE (addr
) == REG
2091 && (REGNO (addr
) < FIRST_VIRTUAL_REGISTER
2092 || REGNO (addr
) > LAST_VIRTUAL_REGISTER
)))
2095 /* If we should only do this if the address is valid, copy the address.
2096 We need to do this so we can undo any changes that might make the
2097 address invalid. This copy is unfortunate, but probably can't be
2101 addr
= copy_rtx (addr
);
2103 instantiate_virtual_regs_1 (&addr
, NULL_RTX
, 0);
2108 /* Now verify that the resulting address is valid for every integer or
2109 floating-point mode up to and including SIZE bytes long. We do this
2110 since the object might be accessed in any mode and frame addresses
2113 for (mode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
2114 mode
!= VOIDmode
&& GET_MODE_SIZE (mode
) <= size
;
2115 mode
= GET_MODE_WIDER_MODE (mode
))
2116 if (! memory_address_p (mode
, addr
))
2119 for (mode
= GET_CLASS_NARROWEST_MODE (MODE_FLOAT
);
2120 mode
!= VOIDmode
&& GET_MODE_SIZE (mode
) <= size
;
2121 mode
= GET_MODE_WIDER_MODE (mode
))
2122 if (! memory_address_p (mode
, addr
))
2125 /* Otherwise, put back the address, now that we have updated it and we
2126 know it is valid. */
2131 /* Given a pointer to a piece of rtx and an optional pointer to the
2132 containing object, instantiate any virtual registers present in it.
2134 If EXTRA_INSNS, we always do the replacement and generate
2135 any extra insns before OBJECT. If it zero, we do nothing if replacement
2138 Return 1 if we either had nothing to do or if we were able to do the
2139 needed replacement. Return 0 otherwise; we only return zero if
2140 EXTRA_INSNS is zero.
2142 We first try some simple transformations to avoid the creation of extra
2146 instantiate_virtual_regs_1 (loc
, object
, extra_insns
)
2160 /* Re-start here to avoid recursion in common cases. */
2167 code
= GET_CODE (x
);
2169 /* Check for some special cases. */
2186 /* We are allowed to set the virtual registers. This means that
2187 that the actual register should receive the source minus the
2188 appropriate offset. This is used, for example, in the handling
2189 of non-local gotos. */
2190 if (SET_DEST (x
) == virtual_incoming_args_rtx
)
2191 new = arg_pointer_rtx
, offset
= - in_arg_offset
;
2192 else if (SET_DEST (x
) == virtual_stack_vars_rtx
)
2193 new = frame_pointer_rtx
, offset
= - var_offset
;
2194 else if (SET_DEST (x
) == virtual_stack_dynamic_rtx
)
2195 new = stack_pointer_rtx
, offset
= - dynamic_offset
;
2196 else if (SET_DEST (x
) == virtual_outgoing_args_rtx
)
2197 new = stack_pointer_rtx
, offset
= - out_arg_offset
;
2201 /* The only valid sources here are PLUS or REG. Just do
2202 the simplest possible thing to handle them. */
2203 if (GET_CODE (SET_SRC (x
)) != REG
2204 && GET_CODE (SET_SRC (x
)) != PLUS
)
2208 if (GET_CODE (SET_SRC (x
)) != REG
)
2209 temp
= force_operand (SET_SRC (x
), NULL_RTX
);
2212 temp
= force_operand (plus_constant (temp
, offset
), NULL_RTX
);
2216 emit_insns_before (seq
, object
);
2219 if (!validate_change (object
, &SET_SRC (x
), temp
, 0)
2226 instantiate_virtual_regs_1 (&SET_DEST (x
), object
, extra_insns
);
2231 /* Handle special case of virtual register plus constant. */
2232 if (CONSTANT_P (XEXP (x
, 1)))
2236 /* Check for (plus (plus VIRT foo) (const_int)) first. */
2237 if (GET_CODE (XEXP (x
, 0)) == PLUS
)
2239 rtx inner
= XEXP (XEXP (x
, 0), 0);
2241 if (inner
== virtual_incoming_args_rtx
)
2242 new = arg_pointer_rtx
, offset
= in_arg_offset
;
2243 else if (inner
== virtual_stack_vars_rtx
)
2244 new = frame_pointer_rtx
, offset
= var_offset
;
2245 else if (inner
== virtual_stack_dynamic_rtx
)
2246 new = stack_pointer_rtx
, offset
= dynamic_offset
;
2247 else if (inner
== virtual_outgoing_args_rtx
)
2248 new = stack_pointer_rtx
, offset
= out_arg_offset
;
2255 instantiate_virtual_regs_1 (&XEXP (XEXP (x
, 0), 1), object
,
2257 new = gen_rtx (PLUS
, Pmode
, new, XEXP (XEXP (x
, 0), 1));
2260 else if (XEXP (x
, 0) == virtual_incoming_args_rtx
)
2261 new = arg_pointer_rtx
, offset
= in_arg_offset
;
2262 else if (XEXP (x
, 0) == virtual_stack_vars_rtx
)
2263 new = frame_pointer_rtx
, offset
= var_offset
;
2264 else if (XEXP (x
, 0) == virtual_stack_dynamic_rtx
)
2265 new = stack_pointer_rtx
, offset
= dynamic_offset
;
2266 else if (XEXP (x
, 0) == virtual_outgoing_args_rtx
)
2267 new = stack_pointer_rtx
, offset
= out_arg_offset
;
2270 /* We know the second operand is a constant. Unless the
2271 first operand is a REG (which has been already checked),
2272 it needs to be checked. */
2273 if (GET_CODE (XEXP (x
, 0)) != REG
)
2283 new = plus_constant (XEXP (x
, 1), offset
);
2285 /* If the new constant is zero, try to replace the sum with its
2287 if (new == const0_rtx
2288 && validate_change (object
, loc
, XEXP (x
, 0), 0))
2291 /* Next try to replace constant with new one. */
2292 if (!validate_change (object
, &XEXP (x
, 1), new, 0))
2300 /* Otherwise copy the new constant into a register and replace
2301 constant with that register. */
2302 temp
= gen_reg_rtx (Pmode
);
2303 if (validate_change (object
, &XEXP (x
, 1), temp
, 0))
2304 emit_insn_before (gen_move_insn (temp
, new), object
);
2307 /* If that didn't work, replace this expression with a
2308 register containing the sum. */
2310 new = gen_rtx (PLUS
, Pmode
, XEXP (x
, 0), new);
2314 temp
= force_operand (new, NULL_RTX
);
2318 emit_insns_before (seq
, object
);
2319 if (! validate_change (object
, loc
, temp
, 0)
2320 && ! validate_replace_rtx (x
, temp
, object
))
2328 /* Fall through to generic two-operand expression case. */
2334 case DIV
: case UDIV
:
2335 case MOD
: case UMOD
:
2336 case AND
: case IOR
: case XOR
:
2337 case LSHIFT
: case ASHIFT
: case ROTATE
:
2338 case ASHIFTRT
: case LSHIFTRT
: case ROTATERT
:
2340 case GE
: case GT
: case GEU
: case GTU
:
2341 case LE
: case LT
: case LEU
: case LTU
:
2342 if (XEXP (x
, 1) && ! CONSTANT_P (XEXP (x
, 1)))
2343 instantiate_virtual_regs_1 (&XEXP (x
, 1), object
, extra_insns
);
2348 /* Most cases of MEM that convert to valid addresses have already been
2349 handled by our scan of regno_reg_rtx. The only special handling we
2350 need here is to make a copy of the rtx to ensure it isn't being
2351 shared if we have to change it to a pseudo.
2353 If the rtx is a simple reference to an address via a virtual register,
2354 it can potentially be shared. In such cases, first try to make it
2355 a valid address, which can also be shared. Otherwise, copy it and
2358 First check for common cases that need no processing. These are
2359 usually due to instantiation already being done on a previous instance
2363 if (CONSTANT_ADDRESS_P (temp
)
2364 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2365 || temp
== arg_pointer_rtx
2367 || temp
== frame_pointer_rtx
)
2370 if (GET_CODE (temp
) == PLUS
2371 && CONSTANT_ADDRESS_P (XEXP (temp
, 1))
2372 && (XEXP (temp
, 0) == frame_pointer_rtx
2373 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
2374 || XEXP (temp
, 0) == arg_pointer_rtx
2379 if (temp
== virtual_stack_vars_rtx
2380 || temp
== virtual_incoming_args_rtx
2381 || (GET_CODE (temp
) == PLUS
2382 && CONSTANT_ADDRESS_P (XEXP (temp
, 1))
2383 && (XEXP (temp
, 0) == virtual_stack_vars_rtx
2384 || XEXP (temp
, 0) == virtual_incoming_args_rtx
)))
2386 /* This MEM may be shared. If the substitution can be done without
2387 the need to generate new pseudos, we want to do it in place
2388 so all copies of the shared rtx benefit. The call below will
2389 only make substitutions if the resulting address is still
2392 Note that we cannot pass X as the object in the recursive call
2393 since the insn being processed may not allow all valid
2394 addresses. However, if we were not passed on object, we can
2395 only modify X without copying it if X will have a valid
2398 ??? Also note that this can still lose if OBJECT is an insn that
2399 has less restrictions on an address that some other insn.
2400 In that case, we will modify the shared address. This case
2401 doesn't seem very likely, though. */
2403 if (instantiate_virtual_regs_1 (&XEXP (x
, 0),
2404 object
? object
: x
, 0))
2407 /* Otherwise make a copy and process that copy. We copy the entire
2408 RTL expression since it might be a PLUS which could also be
2410 *loc
= x
= copy_rtx (x
);
2413 /* Fall through to generic unary operation case. */
2417 case STRICT_LOW_PART
:
2419 case PRE_DEC
: case PRE_INC
: case POST_DEC
: case POST_INC
:
2420 case SIGN_EXTEND
: case ZERO_EXTEND
:
2421 case TRUNCATE
: case FLOAT_EXTEND
: case FLOAT_TRUNCATE
:
2422 case FLOAT
: case FIX
:
2423 case UNSIGNED_FIX
: case UNSIGNED_FLOAT
:
2427 /* These case either have just one operand or we know that we need not
2428 check the rest of the operands. */
2433 /* Try to replace with a PLUS. If that doesn't work, compute the sum
2434 in front of this insn and substitute the temporary. */
2435 if (x
== virtual_incoming_args_rtx
)
2436 new = arg_pointer_rtx
, offset
= in_arg_offset
;
2437 else if (x
== virtual_stack_vars_rtx
)
2438 new = frame_pointer_rtx
, offset
= var_offset
;
2439 else if (x
== virtual_stack_dynamic_rtx
)
2440 new = stack_pointer_rtx
, offset
= dynamic_offset
;
2441 else if (x
== virtual_outgoing_args_rtx
)
2442 new = stack_pointer_rtx
, offset
= out_arg_offset
;
2446 temp
= plus_constant (new, offset
);
2447 if (!validate_change (object
, loc
, temp
, 0))
2453 temp
= force_operand (temp
, NULL_RTX
);
2457 emit_insns_before (seq
, object
);
2458 if (! validate_change (object
, loc
, temp
, 0)
2459 && ! validate_replace_rtx (x
, temp
, object
))
2467 /* Scan all subexpressions. */
2468 fmt
= GET_RTX_FORMAT (code
);
2469 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++, fmt
++)
2472 if (!instantiate_virtual_regs_1 (&XEXP (x
, i
), object
, extra_insns
))
2475 else if (*fmt
== 'E')
2476 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
2477 if (! instantiate_virtual_regs_1 (&XVECEXP (x
, i
, j
), object
,
2484 /* Optimization: assuming this function does not receive nonlocal gotos,
2485 delete the handlers for such, as well as the insns to establish
2486 and disestablish them. */
2492 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
2494 /* Delete the handler by turning off the flag that would
2495 prevent jump_optimize from deleting it.
2496 Also permit deletion of the nonlocal labels themselves
2497 if nothing local refers to them. */
2498 if (GET_CODE (insn
) == CODE_LABEL
)
2499 LABEL_PRESERVE_P (insn
) = 0;
2500 if (GET_CODE (insn
) == INSN
2501 && ((nonlocal_goto_handler_slot
!= 0
2502 && reg_mentioned_p (nonlocal_goto_handler_slot
, PATTERN (insn
)))
2503 || (nonlocal_goto_stack_level
!= 0
2504 && reg_mentioned_p (nonlocal_goto_stack_level
,
2510 /* Return a list (chain of EXPR_LIST nodes) for the nonlocal labels
2511 of the current function. */
2514 nonlocal_label_rtx_list ()
2519 for (t
= nonlocal_labels
; t
; t
= TREE_CHAIN (t
))
2520 x
= gen_rtx (EXPR_LIST
, VOIDmode
, label_rtx (TREE_VALUE (t
)), x
);
2525 /* Output a USE for any register use in RTL.
2526 This is used with -noreg to mark the extent of lifespan
2527 of any registers used in a user-visible variable's DECL_RTL. */
2533 if (GET_CODE (rtl
) == REG
)
2534 /* This is a register variable. */
2535 emit_insn (gen_rtx (USE
, VOIDmode
, rtl
));
2536 else if (GET_CODE (rtl
) == MEM
2537 && GET_CODE (XEXP (rtl
, 0)) == REG
2538 && (REGNO (XEXP (rtl
, 0)) < FIRST_VIRTUAL_REGISTER
2539 || REGNO (XEXP (rtl
, 0)) > LAST_VIRTUAL_REGISTER
)
2540 && XEXP (rtl
, 0) != current_function_internal_arg_pointer
)
2541 /* This is a variable-sized structure. */
2542 emit_insn (gen_rtx (USE
, VOIDmode
, XEXP (rtl
, 0)));
2545 /* Like use_variable except that it outputs the USEs after INSN
2546 instead of at the end of the insn-chain. */
2549 use_variable_after (rtl
, insn
)
2552 if (GET_CODE (rtl
) == REG
)
2553 /* This is a register variable. */
2554 emit_insn_after (gen_rtx (USE
, VOIDmode
, rtl
), insn
);
2555 else if (GET_CODE (rtl
) == MEM
2556 && GET_CODE (XEXP (rtl
, 0)) == REG
2557 && (REGNO (XEXP (rtl
, 0)) < FIRST_VIRTUAL_REGISTER
2558 || REGNO (XEXP (rtl
, 0)) > LAST_VIRTUAL_REGISTER
)
2559 && XEXP (rtl
, 0) != current_function_internal_arg_pointer
)
2560 /* This is a variable-sized structure. */
2561 emit_insn_after (gen_rtx (USE
, VOIDmode
, XEXP (rtl
, 0)), insn
);
2567 return max_parm_reg
;
2570 /* Return the first insn following those generated by `assign_parms'. */
2573 get_first_nonparm_insn ()
2576 return NEXT_INSN (last_parm_insn
);
2577 return get_insns ();
2580 /* Return the first NOTE_INSN_BLOCK_BEG note in the function.
2581 Crash if there is none. */
2584 get_first_block_beg ()
2586 register rtx searcher
;
2587 register rtx insn
= get_first_nonparm_insn ();
2589 for (searcher
= insn
; searcher
; searcher
= NEXT_INSN (searcher
))
2590 if (GET_CODE (searcher
) == NOTE
2591 && NOTE_LINE_NUMBER (searcher
) == NOTE_INSN_BLOCK_BEG
)
2594 abort (); /* Invalid call to this function. (See comments above.) */
2598 /* Return 1 if EXP returns an aggregate value, for which an address
2599 must be passed to the function or returned by the function. */
2602 aggregate_value_p (exp
)
2605 int i
, regno
, nregs
;
2607 if (TYPE_MODE (TREE_TYPE (exp
)) == BLKmode
)
2609 if (RETURN_IN_MEMORY (TREE_TYPE (exp
)))
2611 if (flag_pcc_struct_return
2612 && (TREE_CODE (TREE_TYPE (exp
)) == RECORD_TYPE
2613 || TREE_CODE (TREE_TYPE (exp
)) == UNION_TYPE
))
2615 /* Make sure we have suitable call-clobbered regs to return
2616 the value in; if not, we must return it in memory. */
2617 reg
= hard_function_value (TREE_TYPE (exp
), 0);
2618 regno
= REGNO (reg
);
2619 nregs
= HARD_REGNO_NREGS (regno
, TYPE_MODE (TREE_TYPE (exp
)));
2620 for (i
= 0; i
< nregs
; i
++)
2621 if (! call_used_regs
[regno
+ i
])
2626 /* Assign RTL expressions to the function's parameters.
2627 This may involve copying them into registers and using
2628 those registers as the RTL for them.
2630 If SECOND_TIME is non-zero it means that this function is being
2631 called a second time. This is done by integrate.c when a function's
2632 compilation is deferred. We need to come back here in case the
2633 FUNCTION_ARG macro computes items needed for the rest of the compilation
2634 (such as changing which registers are fixed or caller-saved). But suppress
2635 writing any insns or setting DECL_RTL of anything in this case. */
2638 assign_parms (fndecl
, second_time
)
2643 register rtx entry_parm
= 0;
2644 register rtx stack_parm
= 0;
2645 CUMULATIVE_ARGS args_so_far
;
2646 enum machine_mode promoted_mode
, passed_mode
, nominal_mode
;
2648 /* Total space needed so far for args on the stack,
2649 given as a constant and a tree-expression. */
2650 struct args_size stack_args_size
;
2651 tree fntype
= TREE_TYPE (fndecl
);
2652 tree fnargs
= DECL_ARGUMENTS (fndecl
);
2653 /* This is used for the arg pointer when referring to stack args. */
2654 rtx internal_arg_pointer
;
2655 /* This is a dummy PARM_DECL that we used for the function result if
2656 the function returns a structure. */
2657 tree function_result_decl
= 0;
2658 int nparmregs
= list_length (fnargs
) + LAST_VIRTUAL_REGISTER
+ 1;
2659 int varargs_setup
= 0;
2660 rtx conversion_insns
= 0;
2662 /* Nonzero if the last arg is named `__builtin_va_alist',
2663 which is used on some machines for old-fashioned non-ANSI varargs.h;
2664 this should be stuck onto the stack as if it had arrived there. */
2667 && (parm
= tree_last (fnargs
)) != 0
2669 && (! strcmp (IDENTIFIER_POINTER (DECL_NAME (parm
)),
2670 "__builtin_va_alist")));
2672 /* Nonzero if function takes extra anonymous args.
2673 This means the last named arg must be on the stack
2674 right before the anonymous ones. */
2676 = (TYPE_ARG_TYPES (fntype
) != 0
2677 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype
)))
2678 != void_type_node
));
2680 /* If the reg that the virtual arg pointer will be translated into is
2681 not a fixed reg or is the stack pointer, make a copy of the virtual
2682 arg pointer, and address parms via the copy. The frame pointer is
2683 considered fixed even though it is not marked as such.
2685 The second time through, simply use ap to avoid generating rtx. */
2687 if ((ARG_POINTER_REGNUM
== STACK_POINTER_REGNUM
2688 || ! (fixed_regs
[ARG_POINTER_REGNUM
]
2689 || ARG_POINTER_REGNUM
== FRAME_POINTER_REGNUM
))
2691 internal_arg_pointer
= copy_to_reg (virtual_incoming_args_rtx
);
2693 internal_arg_pointer
= virtual_incoming_args_rtx
;
2694 current_function_internal_arg_pointer
= internal_arg_pointer
;
2696 stack_args_size
.constant
= 0;
2697 stack_args_size
.var
= 0;
2699 /* If struct value address is treated as the first argument, make it so. */
2700 if (aggregate_value_p (DECL_RESULT (fndecl
))
2701 && ! current_function_returns_pcc_struct
2702 && struct_value_incoming_rtx
== 0)
2704 tree type
= build_pointer_type (fntype
);
2706 function_result_decl
= build_decl (PARM_DECL
, NULL_TREE
, type
);
2708 DECL_ARG_TYPE (function_result_decl
) = type
;
2709 TREE_CHAIN (function_result_decl
) = fnargs
;
2710 fnargs
= function_result_decl
;
2713 parm_reg_stack_loc
= (rtx
*) oballoc (nparmregs
* sizeof (rtx
));
2714 bzero (parm_reg_stack_loc
, nparmregs
* sizeof (rtx
));
2716 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2717 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far
, fntype
, NULL_RTX
);
2719 INIT_CUMULATIVE_ARGS (args_so_far
, fntype
, NULL_RTX
);
2722 /* We haven't yet found an argument that we must push and pretend the
2724 current_function_pretend_args_size
= 0;
2726 for (parm
= fnargs
; parm
; parm
= TREE_CHAIN (parm
))
2729 = (TREE_CODE (TREE_TYPE (parm
)) == ARRAY_TYPE
2730 || TREE_CODE (TREE_TYPE (parm
)) == RECORD_TYPE
2731 || TREE_CODE (TREE_TYPE (parm
)) == UNION_TYPE
);
2732 struct args_size stack_offset
;
2733 struct args_size arg_size
;
2734 int passed_pointer
= 0;
2735 tree passed_type
= DECL_ARG_TYPE (parm
);
2737 /* Set LAST_NAMED if this is last named arg before some
2738 anonymous args. We treat it as if it were anonymous too. */
2739 int last_named
= ((TREE_CHAIN (parm
) == 0
2740 || DECL_NAME (TREE_CHAIN (parm
)) == 0)
2741 && (vararg
|| stdarg
));
2743 if (TREE_TYPE (parm
) == error_mark_node
2744 /* This can happen after weird syntax errors
2745 or if an enum type is defined among the parms. */
2746 || TREE_CODE (parm
) != PARM_DECL
2747 || passed_type
== NULL
)
2749 DECL_INCOMING_RTL (parm
) = DECL_RTL (parm
) = gen_rtx (MEM
, BLKmode
,
2751 TREE_USED (parm
) = 1;
2755 /* For varargs.h function, save info about regs and stack space
2756 used by the individual args, not including the va_alist arg. */
2757 if (vararg
&& last_named
)
2758 current_function_args_info
= args_so_far
;
2760 /* Find mode of arg as it is passed, and mode of arg
2761 as it should be during execution of this function. */
2762 passed_mode
= TYPE_MODE (passed_type
);
2763 nominal_mode
= TYPE_MODE (TREE_TYPE (parm
));
2765 /* If the parm's mode is VOID, its value doesn't matter,
2766 and avoid the usual things like emit_move_insn that could crash. */
2767 if (nominal_mode
== VOIDmode
)
2769 DECL_INCOMING_RTL (parm
) = DECL_RTL (parm
) = const0_rtx
;
2773 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
2774 /* See if this arg was passed by invisible reference. */
2775 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far
, passed_mode
,
2776 passed_type
, ! last_named
))
2778 passed_type
= build_pointer_type (passed_type
);
2780 passed_mode
= nominal_mode
= Pmode
;
2784 promoted_mode
= passed_mode
;
2786 #ifdef PROMOTE_FUNCTION_ARGS
2787 /* Compute the mode in which the arg is actually extended to. */
2788 if (TREE_CODE (passed_type
) == INTEGER_TYPE
2789 || TREE_CODE (passed_type
) == ENUMERAL_TYPE
2790 || TREE_CODE (passed_type
) == BOOLEAN_TYPE
2791 || TREE_CODE (passed_type
) == CHAR_TYPE
2792 || TREE_CODE (passed_type
) == REAL_TYPE
2793 || TREE_CODE (passed_type
) == POINTER_TYPE
2794 || TREE_CODE (passed_type
) == OFFSET_TYPE
)
2796 unsignedp
= TREE_UNSIGNED (passed_type
);
2797 PROMOTE_MODE (promoted_mode
, unsignedp
, passed_type
);
2801 /* Let machine desc say which reg (if any) the parm arrives in.
2802 0 means it arrives on the stack. */
2803 #ifdef FUNCTION_INCOMING_ARG
2804 entry_parm
= FUNCTION_INCOMING_ARG (args_so_far
, promoted_mode
,
2805 passed_type
, ! last_named
);
2807 entry_parm
= FUNCTION_ARG (args_so_far
, promoted_mode
,
2808 passed_type
, ! last_named
);
2812 passed_mode
= promoted_mode
;
2814 #ifdef SETUP_INCOMING_VARARGS
2815 /* If this is the last named parameter, do any required setup for
2816 varargs or stdargs. We need to know about the case of this being an
2817 addressable type, in which case we skip the registers it
2818 would have arrived in.
2820 For stdargs, LAST_NAMED will be set for two parameters, the one that
2821 is actually the last named, and the dummy parameter. We only
2822 want to do this action once.
2824 Also, indicate when RTL generation is to be suppressed. */
2825 if (last_named
&& !varargs_setup
)
2827 SETUP_INCOMING_VARARGS (args_so_far
, passed_mode
, passed_type
,
2828 current_function_pretend_args_size
,
2834 /* Determine parm's home in the stack,
2835 in case it arrives in the stack or we should pretend it did.
2837 Compute the stack position and rtx where the argument arrives
2840 There is one complexity here: If this was a parameter that would
2841 have been passed in registers, but wasn't only because it is
2842 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2843 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2844 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
2845 0 as it was the previous time. */
2847 locate_and_pad_parm (passed_mode
, passed_type
,
2848 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2851 #ifdef FUNCTION_INCOMING_ARG
2852 FUNCTION_INCOMING_ARG (args_so_far
, passed_mode
,
2855 || varargs_setup
)) != 0,
2857 FUNCTION_ARG (args_so_far
, passed_mode
,
2859 ! last_named
|| varargs_setup
) != 0,
2862 fndecl
, &stack_args_size
, &stack_offset
, &arg_size
);
2866 rtx offset_rtx
= ARGS_SIZE_RTX (stack_offset
);
2868 if (offset_rtx
== const0_rtx
)
2869 stack_parm
= gen_rtx (MEM
, passed_mode
, internal_arg_pointer
);
2871 stack_parm
= gen_rtx (MEM
, passed_mode
,
2872 gen_rtx (PLUS
, Pmode
,
2873 internal_arg_pointer
, offset_rtx
));
2875 /* If this is a memory ref that contains aggregate components,
2876 mark it as such for cse and loop optimize. */
2877 MEM_IN_STRUCT_P (stack_parm
) = aggregate
;
2880 /* If this parameter was passed both in registers and in the stack,
2881 use the copy on the stack. */
2882 if (MUST_PASS_IN_STACK (passed_mode
, passed_type
))
2885 /* If this parm was passed part in regs and part in memory,
2886 pretend it arrived entirely in memory
2887 by pushing the register-part onto the stack.
2889 In the special case of a DImode or DFmode that is split,
2890 we could put it together in a pseudoreg directly,
2891 but for now that's not worth bothering with. */
2896 #ifdef FUNCTION_ARG_PARTIAL_NREGS
2897 nregs
= FUNCTION_ARG_PARTIAL_NREGS (args_so_far
, passed_mode
,
2898 passed_type
, ! last_named
);
2903 current_function_pretend_args_size
2904 = (((nregs
* UNITS_PER_WORD
) + (PARM_BOUNDARY
/ BITS_PER_UNIT
) - 1)
2905 / (PARM_BOUNDARY
/ BITS_PER_UNIT
)
2906 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
2909 move_block_from_reg (REGNO (entry_parm
),
2910 validize_mem (stack_parm
), nregs
);
2911 entry_parm
= stack_parm
;
2915 /* If we didn't decide this parm came in a register,
2916 by default it came on the stack. */
2917 if (entry_parm
== 0)
2918 entry_parm
= stack_parm
;
2920 /* Record permanently how this parm was passed. */
2922 DECL_INCOMING_RTL (parm
) = entry_parm
;
2924 /* If there is actually space on the stack for this parm,
2925 count it in stack_args_size; otherwise set stack_parm to 0
2926 to indicate there is no preallocated stack slot for the parm. */
2928 if (entry_parm
== stack_parm
2929 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
2930 /* On some machines, even if a parm value arrives in a register
2931 there is still an (uninitialized) stack slot allocated for it.
2933 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
2934 whether this parameter already has a stack slot allocated,
2935 because an arg block exists only if current_function_args_size
2936 is larger than some threshhold, and we haven't calculated that
2937 yet. So, for now, we just assume that stack slots never exist
2939 || REG_PARM_STACK_SPACE (fndecl
) > 0
2943 stack_args_size
.constant
+= arg_size
.constant
;
2945 ADD_PARM_SIZE (stack_args_size
, arg_size
.var
);
2948 /* No stack slot was pushed for this parm. */
2951 /* Update info on where next arg arrives in registers. */
2953 FUNCTION_ARG_ADVANCE (args_so_far
, passed_mode
,
2954 passed_type
, ! last_named
);
2956 /* If this is our second time through, we are done with this parm. */
2960 /* If we can't trust the parm stack slot to be aligned enough
2961 for its ultimate type, don't use that slot after entry.
2962 We'll make another stack slot, if we need one. */
2964 #ifdef FUNCTION_ARG_BOUNDARY
2965 int thisparm_boundary
2966 = FUNCTION_ARG_BOUNDARY (passed_mode
, passed_type
);
2968 int thisparm_boundary
= PARM_BOUNDARY
;
2971 if (GET_MODE_ALIGNMENT (nominal_mode
) > thisparm_boundary
)
2975 /* Now adjust STACK_PARM to the mode and precise location
2976 where this parameter should live during execution,
2977 if we discover that it must live in the stack during execution.
2978 To make debuggers happier on big-endian machines, we store
2979 the value in the last bytes of the space available. */
2981 if (nominal_mode
!= BLKmode
&& nominal_mode
!= passed_mode
2986 #if BYTES_BIG_ENDIAN
2987 if (GET_MODE_SIZE (nominal_mode
) < UNITS_PER_WORD
)
2988 stack_offset
.constant
+= (GET_MODE_SIZE (passed_mode
)
2989 - GET_MODE_SIZE (nominal_mode
));
2992 offset_rtx
= ARGS_SIZE_RTX (stack_offset
);
2993 if (offset_rtx
== const0_rtx
)
2994 stack_parm
= gen_rtx (MEM
, nominal_mode
, internal_arg_pointer
);
2996 stack_parm
= gen_rtx (MEM
, nominal_mode
,
2997 gen_rtx (PLUS
, Pmode
,
2998 internal_arg_pointer
, offset_rtx
));
3000 /* If this is a memory ref that contains aggregate components,
3001 mark it as such for cse and loop optimize. */
3002 MEM_IN_STRUCT_P (stack_parm
) = aggregate
;
3005 /* ENTRY_PARM is an RTX for the parameter as it arrives,
3006 in the mode in which it arrives.
3007 STACK_PARM is an RTX for a stack slot where the parameter can live
3008 during the function (in case we want to put it there).
3009 STACK_PARM is 0 if no stack slot was pushed for it.
3011 Now output code if necessary to convert ENTRY_PARM to
3012 the type in which this function declares it,
3013 and store that result in an appropriate place,
3014 which may be a pseudo reg, may be STACK_PARM,
3015 or may be a local stack slot if STACK_PARM is 0.
3017 Set DECL_RTL to that place. */
3019 if (nominal_mode
== BLKmode
)
3021 /* If a BLKmode arrives in registers, copy it to a stack slot. */
3022 if (GET_CODE (entry_parm
) == REG
)
3024 int size_stored
= CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm
)),
3027 /* Note that we will be storing an integral number of words.
3028 So we have to be careful to ensure that we allocate an
3029 integral number of words. We do this below in the
3030 assign_stack_local if space was not allocated in the argument
3031 list. If it was, this will not work if PARM_BOUNDARY is not
3032 a multiple of BITS_PER_WORD. It isn't clear how to fix this
3033 if it becomes a problem. */
3035 if (stack_parm
== 0)
3038 = assign_stack_local (GET_MODE (entry_parm
), size_stored
, 0);
3039 /* If this is a memory ref that contains aggregate components,
3040 mark it as such for cse and loop optimize. */
3041 MEM_IN_STRUCT_P (stack_parm
) = aggregate
;
3044 else if (PARM_BOUNDARY
% BITS_PER_WORD
!= 0)
3047 move_block_from_reg (REGNO (entry_parm
),
3048 validize_mem (stack_parm
),
3049 size_stored
/ UNITS_PER_WORD
);
3051 DECL_RTL (parm
) = stack_parm
;
3053 else if (! ((obey_regdecls
&& ! DECL_REGISTER (parm
)
3054 && ! DECL_INLINE (fndecl
))
3055 /* layout_decl may set this. */
3056 || TREE_ADDRESSABLE (parm
)
3057 || TREE_SIDE_EFFECTS (parm
)
3058 /* If -ffloat-store specified, don't put explicit
3059 float variables into registers. */
3060 || (flag_float_store
3061 && TREE_CODE (TREE_TYPE (parm
)) == REAL_TYPE
))
3062 /* Always assign pseudo to structure return or item passed
3063 by invisible reference. */
3064 || passed_pointer
|| parm
== function_result_decl
)
3066 /* Store the parm in a pseudoregister during the function, but we
3067 may need to do it in a wider mode. */
3069 register rtx parmreg
;
3071 unsignedp
= TREE_UNSIGNED (TREE_TYPE (parm
));
3072 if (TREE_CODE (TREE_TYPE (parm
)) == INTEGER_TYPE
3073 || TREE_CODE (TREE_TYPE (parm
)) == ENUMERAL_TYPE
3074 || TREE_CODE (TREE_TYPE (parm
)) == BOOLEAN_TYPE
3075 || TREE_CODE (TREE_TYPE (parm
)) == CHAR_TYPE
3076 || TREE_CODE (TREE_TYPE (parm
)) == REAL_TYPE
3077 || TREE_CODE (TREE_TYPE (parm
)) == POINTER_TYPE
3078 || TREE_CODE (TREE_TYPE (parm
)) == OFFSET_TYPE
)
3080 PROMOTE_MODE (nominal_mode
, unsignedp
, TREE_TYPE (parm
));
3083 parmreg
= gen_reg_rtx (nominal_mode
);
3084 REG_USERVAR_P (parmreg
) = 1;
3086 /* If this was an item that we received a pointer to, set DECL_RTL
3090 DECL_RTL (parm
) = gen_rtx (MEM
, TYPE_MODE (TREE_TYPE (passed_type
)), parmreg
);
3091 MEM_IN_STRUCT_P (DECL_RTL (parm
)) = aggregate
;
3094 DECL_RTL (parm
) = parmreg
;
3096 /* Copy the value into the register. */
3097 if (GET_MODE (parmreg
) != GET_MODE (entry_parm
))
3099 /* If ENTRY_PARM is a hard register, it might be in a register
3100 not valid for operating in its mode (e.g., an odd-numbered
3101 register for a DFmode). In that case, moves are the only
3102 thing valid, so we can't do a convert from there. This
3103 occurs when the calling sequence allow such misaligned
3106 In addition, the conversion may involve a call, which could
3107 clobber parameters which haven't been copied to pseudo
3108 registers yet. Therefore, we must first copy the parm to
3109 a pseudo reg here, and save the conversion until after all
3110 parameters have been moved. */
3112 rtx tempreg
= gen_reg_rtx (GET_MODE (entry_parm
));
3114 emit_move_insn (tempreg
, validize_mem (entry_parm
));
3116 push_to_sequence (conversion_insns
);
3117 convert_move (parmreg
, tempreg
, unsignedp
);
3118 conversion_insns
= get_insns ();
3122 emit_move_insn (parmreg
, validize_mem (entry_parm
));
3124 /* If we were passed a pointer but the actual value
3125 can safely live in a register, put it in one. */
3126 if (passed_pointer
&& TYPE_MODE (TREE_TYPE (parm
)) != BLKmode
3127 && ! ((obey_regdecls
&& ! DECL_REGISTER (parm
)
3128 && ! DECL_INLINE (fndecl
))
3129 /* layout_decl may set this. */
3130 || TREE_ADDRESSABLE (parm
)
3131 || TREE_SIDE_EFFECTS (parm
)
3132 /* If -ffloat-store specified, don't put explicit
3133 float variables into registers. */
3134 || (flag_float_store
3135 && TREE_CODE (TREE_TYPE (parm
)) == REAL_TYPE
)))
3137 /* We can't use nominal_mode, because it will have been set to
3138 Pmode above. We must use the actual mode of the parm. */
3139 parmreg
= gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm
)));
3140 emit_move_insn (parmreg
, DECL_RTL (parm
));
3141 DECL_RTL (parm
) = parmreg
;
3144 /* In any case, record the parm's desired stack location
3145 in case we later discover it must live in the stack. */
3146 if (REGNO (parmreg
) >= nparmregs
)
3149 nparmregs
= REGNO (parmreg
) + 5;
3150 new = (rtx
*) oballoc (nparmregs
* sizeof (rtx
));
3151 bcopy (parm_reg_stack_loc
, new, nparmregs
* sizeof (rtx
));
3152 parm_reg_stack_loc
= new;
3154 parm_reg_stack_loc
[REGNO (parmreg
)] = stack_parm
;
3156 /* Mark the register as eliminable if we did no conversion
3157 and it was copied from memory at a fixed offset,
3158 and the arg pointer was not copied to a pseudo-reg.
3159 If the arg pointer is a pseudo reg or the offset formed
3160 an invalid address, such memory-equivalences
3161 as we make here would screw up life analysis for it. */
3162 if (nominal_mode
== passed_mode
3163 && GET_CODE (entry_parm
) == MEM
3164 && entry_parm
== stack_parm
3165 && stack_offset
.var
== 0
3166 && reg_mentioned_p (virtual_incoming_args_rtx
,
3167 XEXP (entry_parm
, 0)))
3168 REG_NOTES (get_last_insn ())
3169 = gen_rtx (EXPR_LIST
, REG_EQUIV
,
3170 entry_parm
, REG_NOTES (get_last_insn ()));
3172 /* For pointer data type, suggest pointer register. */
3173 if (TREE_CODE (TREE_TYPE (parm
)) == POINTER_TYPE
)
3174 mark_reg_pointer (parmreg
);
3178 /* Value must be stored in the stack slot STACK_PARM
3179 during function execution. */
3181 if (passed_mode
!= nominal_mode
)
3183 /* Conversion is required. */
3184 rtx tempreg
= gen_reg_rtx (GET_MODE (entry_parm
));
3186 emit_move_insn (tempreg
, validize_mem (entry_parm
));
3188 push_to_sequence (conversion_insns
);
3189 entry_parm
= convert_to_mode (nominal_mode
, tempreg
,
3190 TREE_UNSIGNED (TREE_TYPE (parm
)));
3191 conversion_insns
= get_insns ();
3195 if (entry_parm
!= stack_parm
)
3197 if (stack_parm
== 0)
3200 = assign_stack_local (GET_MODE (entry_parm
),
3201 GET_MODE_SIZE (GET_MODE (entry_parm
)), 0);
3202 /* If this is a memory ref that contains aggregate components,
3203 mark it as such for cse and loop optimize. */
3204 MEM_IN_STRUCT_P (stack_parm
) = aggregate
;
3207 if (passed_mode
!= nominal_mode
)
3209 push_to_sequence (conversion_insns
);
3210 emit_move_insn (validize_mem (stack_parm
),
3211 validize_mem (entry_parm
));
3212 conversion_insns
= get_insns ();
3216 emit_move_insn (validize_mem (stack_parm
),
3217 validize_mem (entry_parm
));
3220 DECL_RTL (parm
) = stack_parm
;
3223 /* If this "parameter" was the place where we are receiving the
3224 function's incoming structure pointer, set up the result. */
3225 if (parm
== function_result_decl
)
3226 DECL_RTL (DECL_RESULT (fndecl
))
3227 = gen_rtx (MEM
, DECL_MODE (DECL_RESULT (fndecl
)), DECL_RTL (parm
));
3229 if (TREE_THIS_VOLATILE (parm
))
3230 MEM_VOLATILE_P (DECL_RTL (parm
)) = 1;
3231 if (TREE_READONLY (parm
))
3232 RTX_UNCHANGING_P (DECL_RTL (parm
)) = 1;
3235 /* Output all parameter conversion instructions (possibly including calls)
3236 now that all parameters have been copied out of hard registers. */
3237 emit_insns (conversion_insns
);
3239 max_parm_reg
= max_reg_num ();
3240 last_parm_insn
= get_last_insn ();
3242 current_function_args_size
= stack_args_size
.constant
;
3244 /* Adjust function incoming argument size for alignment and
3247 #ifdef REG_PARM_STACK_SPACE
3248 #ifndef MAYBE_REG_PARM_STACK_SPACE
3249 current_function_args_size
= MAX (current_function_args_size
,
3250 REG_PARM_STACK_SPACE (fndecl
));
3254 #ifdef STACK_BOUNDARY
3255 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
3257 current_function_args_size
3258 = ((current_function_args_size
+ STACK_BYTES
- 1)
3259 / STACK_BYTES
) * STACK_BYTES
;
3262 #ifdef ARGS_GROW_DOWNWARD
3263 current_function_arg_offset_rtx
3264 = (stack_args_size
.var
== 0 ? GEN_INT (-stack_args_size
.constant
)
3265 : expand_expr (size_binop (MINUS_EXPR
, stack_args_size
.var
,
3266 size_int (-stack_args_size
.constant
)),
3267 NULL_RTX
, VOIDmode
, 0));
3269 current_function_arg_offset_rtx
= ARGS_SIZE_RTX (stack_args_size
);
3272 /* See how many bytes, if any, of its args a function should try to pop
3275 current_function_pops_args
= RETURN_POPS_ARGS (TREE_TYPE (fndecl
),
3276 current_function_args_size
);
3278 /* For stdarg.h function, save info about regs and stack space
3279 used by the named args. */
3282 current_function_args_info
= args_so_far
;
3284 /* Set the rtx used for the function return value. Put this in its
3285 own variable so any optimizers that need this information don't have
3286 to include tree.h. Do this here so it gets done when an inlined
3287 function gets output. */
3289 current_function_return_rtx
= DECL_RTL (DECL_RESULT (fndecl
));
3292 /* Compute the size and offset from the start of the stacked arguments for a
3293 parm passed in mode PASSED_MODE and with type TYPE.
3295 INITIAL_OFFSET_PTR points to the current offset into the stacked
3298 The starting offset and size for this parm are returned in *OFFSET_PTR
3299 and *ARG_SIZE_PTR, respectively.
3301 IN_REGS is non-zero if the argument will be passed in registers. It will
3302 never be set if REG_PARM_STACK_SPACE is not defined.
3304 FNDECL is the function in which the argument was defined.
3306 There are two types of rounding that are done. The first, controlled by
3307 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3308 list to be aligned to the specific boundary (in bits). This rounding
3309 affects the initial and starting offsets, but not the argument size.
3311 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3312 optionally rounds the size of the parm to PARM_BOUNDARY. The
3313 initial offset is not affected by this rounding, while the size always
3314 is and the starting offset may be. */
3316 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
3317 initial_offset_ptr is positive because locate_and_pad_parm's
3318 callers pass in the total size of args so far as
3319 initial_offset_ptr. arg_size_ptr is always positive.*/
3321 static void pad_to_arg_alignment (), pad_below ();
3324 locate_and_pad_parm (passed_mode
, type
, in_regs
, fndecl
,
3325 initial_offset_ptr
, offset_ptr
, arg_size_ptr
)
3326 enum machine_mode passed_mode
;
3330 struct args_size
*initial_offset_ptr
;
3331 struct args_size
*offset_ptr
;
3332 struct args_size
*arg_size_ptr
;
3335 = type
? size_in_bytes (type
) : size_int (GET_MODE_SIZE (passed_mode
));
3336 enum direction where_pad
= FUNCTION_ARG_PADDING (passed_mode
, type
);
3337 int boundary
= FUNCTION_ARG_BOUNDARY (passed_mode
, type
);
3338 int boundary_in_bytes
= boundary
/ BITS_PER_UNIT
;
3339 int reg_parm_stack_space
= 0;
3341 #ifdef REG_PARM_STACK_SPACE
3342 /* If we have found a stack parm before we reach the end of the
3343 area reserved for registers, skip that area. */
3346 #ifdef MAYBE_REG_PARM_STACK_SPACE
3347 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
3349 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
3351 if (reg_parm_stack_space
> 0)
3353 if (initial_offset_ptr
->var
)
3355 initial_offset_ptr
->var
3356 = size_binop (MAX_EXPR
, ARGS_SIZE_TREE (*initial_offset_ptr
),
3357 size_int (reg_parm_stack_space
));
3358 initial_offset_ptr
->constant
= 0;
3360 else if (initial_offset_ptr
->constant
< reg_parm_stack_space
)
3361 initial_offset_ptr
->constant
= reg_parm_stack_space
;
3364 #endif /* REG_PARM_STACK_SPACE */
3366 arg_size_ptr
->var
= 0;
3367 arg_size_ptr
->constant
= 0;
3369 #ifdef ARGS_GROW_DOWNWARD
3370 if (initial_offset_ptr
->var
)
3372 offset_ptr
->constant
= 0;
3373 offset_ptr
->var
= size_binop (MINUS_EXPR
, integer_zero_node
,
3374 initial_offset_ptr
->var
);
3378 offset_ptr
->constant
= - initial_offset_ptr
->constant
;
3379 offset_ptr
->var
= 0;
3381 if (where_pad
== upward
3382 && (TREE_CODE (sizetree
) != INTEGER_CST
3383 || ((TREE_INT_CST_LOW (sizetree
) * BITS_PER_UNIT
) % PARM_BOUNDARY
)))
3384 sizetree
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3385 SUB_PARM_SIZE (*offset_ptr
, sizetree
);
3386 if (where_pad
!= downward
)
3387 pad_to_arg_alignment (offset_ptr
, boundary
);
3388 if (initial_offset_ptr
->var
)
3390 arg_size_ptr
->var
= size_binop (MINUS_EXPR
,
3391 size_binop (MINUS_EXPR
,
3393 initial_offset_ptr
->var
),
3398 arg_size_ptr
->constant
= (- initial_offset_ptr
->constant
-
3399 offset_ptr
->constant
);
3401 /* ADD_PARM_SIZE (*arg_size_ptr, sizetree); */
3402 if (where_pad
== downward
)
3403 pad_below (arg_size_ptr
, passed_mode
, sizetree
);
3404 #else /* !ARGS_GROW_DOWNWARD */
3405 pad_to_arg_alignment (initial_offset_ptr
, boundary
);
3406 *offset_ptr
= *initial_offset_ptr
;
3407 if (where_pad
== downward
)
3408 pad_below (offset_ptr
, passed_mode
, sizetree
);
3410 #ifdef PUSH_ROUNDING
3411 if (passed_mode
!= BLKmode
)
3412 sizetree
= size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree
)));
3415 if (where_pad
!= none
3416 && (TREE_CODE (sizetree
) != INTEGER_CST
3417 || ((TREE_INT_CST_LOW (sizetree
) * BITS_PER_UNIT
) % PARM_BOUNDARY
)))
3418 sizetree
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3420 ADD_PARM_SIZE (*arg_size_ptr
, sizetree
);
3421 #endif /* ARGS_GROW_DOWNWARD */
3424 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3425 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3428 pad_to_arg_alignment (offset_ptr
, boundary
)
3429 struct args_size
*offset_ptr
;
3432 int boundary_in_bytes
= boundary
/ BITS_PER_UNIT
;
3434 if (boundary
> BITS_PER_UNIT
)
3436 if (offset_ptr
->var
)
3439 #ifdef ARGS_GROW_DOWNWARD
3444 (ARGS_SIZE_TREE (*offset_ptr
),
3445 boundary
/ BITS_PER_UNIT
);
3446 offset_ptr
->constant
= 0; /*?*/
3449 offset_ptr
->constant
=
3450 #ifdef ARGS_GROW_DOWNWARD
3451 FLOOR_ROUND (offset_ptr
->constant
, boundary_in_bytes
);
3453 CEIL_ROUND (offset_ptr
->constant
, boundary_in_bytes
);
3459 pad_below (offset_ptr
, passed_mode
, sizetree
)
3460 struct args_size
*offset_ptr
;
3461 enum machine_mode passed_mode
;
3464 if (passed_mode
!= BLKmode
)
3466 if (GET_MODE_BITSIZE (passed_mode
) % PARM_BOUNDARY
)
3467 offset_ptr
->constant
3468 += (((GET_MODE_BITSIZE (passed_mode
) + PARM_BOUNDARY
- 1)
3469 / PARM_BOUNDARY
* PARM_BOUNDARY
/ BITS_PER_UNIT
)
3470 - GET_MODE_SIZE (passed_mode
));
3474 if (TREE_CODE (sizetree
) != INTEGER_CST
3475 || (TREE_INT_CST_LOW (sizetree
) * BITS_PER_UNIT
) % PARM_BOUNDARY
)
3477 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3478 tree s2
= round_up (sizetree
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
3480 ADD_PARM_SIZE (*offset_ptr
, s2
);
3481 SUB_PARM_SIZE (*offset_ptr
, sizetree
);
3487 round_down (value
, divisor
)
3491 return size_binop (MULT_EXPR
,
3492 size_binop (FLOOR_DIV_EXPR
, value
, size_int (divisor
)),
3493 size_int (divisor
));
3496 /* Walk the tree of blocks describing the binding levels within a function
3497 and warn about uninitialized variables.
3498 This is done after calling flow_analysis and before global_alloc
3499 clobbers the pseudo-regs to hard regs. */
3502 uninitialized_vars_warning (block
)
3505 register tree decl
, sub
;
3506 for (decl
= BLOCK_VARS (block
); decl
; decl
= TREE_CHAIN (decl
))
3508 if (TREE_CODE (decl
) == VAR_DECL
3509 /* These warnings are unreliable for and aggregates
3510 because assigning the fields one by one can fail to convince
3511 flow.c that the entire aggregate was initialized.
3512 Unions are troublesome because members may be shorter. */
3513 && TREE_CODE (TREE_TYPE (decl
)) != RECORD_TYPE
3514 && TREE_CODE (TREE_TYPE (decl
)) != UNION_TYPE
3515 && TREE_CODE (TREE_TYPE (decl
)) != ARRAY_TYPE
3516 && DECL_RTL (decl
) != 0
3517 && GET_CODE (DECL_RTL (decl
)) == REG
3518 && regno_uninitialized (REGNO (DECL_RTL (decl
))))
3519 warning_with_decl (decl
,
3520 "`%s' may be used uninitialized in this function");
3521 if (TREE_CODE (decl
) == VAR_DECL
3522 && DECL_RTL (decl
) != 0
3523 && GET_CODE (DECL_RTL (decl
)) == REG
3524 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl
))))
3525 warning_with_decl (decl
,
3526 "variable `%s' may be clobbered by `longjmp'");
3528 for (sub
= BLOCK_SUBBLOCKS (block
); sub
; sub
= TREE_CHAIN (sub
))
3529 uninitialized_vars_warning (sub
);
3532 /* Do the appropriate part of uninitialized_vars_warning
3533 but for arguments instead of local variables. */
3536 setjmp_args_warning (block
)
3540 for (decl
= DECL_ARGUMENTS (current_function_decl
);
3541 decl
; decl
= TREE_CHAIN (decl
))
3542 if (DECL_RTL (decl
) != 0
3543 && GET_CODE (DECL_RTL (decl
)) == REG
3544 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl
))))
3545 warning_with_decl (decl
, "argument `%s' may be clobbered by `longjmp'");
3548 /* If this function call setjmp, put all vars into the stack
3549 unless they were declared `register'. */
3552 setjmp_protect (block
)
3555 register tree decl
, sub
;
3556 for (decl
= BLOCK_VARS (block
); decl
; decl
= TREE_CHAIN (decl
))
3557 if ((TREE_CODE (decl
) == VAR_DECL
3558 || TREE_CODE (decl
) == PARM_DECL
)
3559 && DECL_RTL (decl
) != 0
3560 && GET_CODE (DECL_RTL (decl
)) == REG
3561 /* If this variable came from an inline function, it must be
3562 that it's life doesn't overlap the setjmp. If there was a
3563 setjmp in the function, it would already be in memory. We
3564 must exclude such variable because their DECL_RTL might be
3565 set to strange things such as virtual_stack_vars_rtx. */
3566 && ! DECL_FROM_INLINE (decl
)
3568 #ifdef NON_SAVING_SETJMP
3569 /* If longjmp doesn't restore the registers,
3570 don't put anything in them. */
3574 ! DECL_REGISTER (decl
)))
3575 put_var_into_stack (decl
);
3576 for (sub
= BLOCK_SUBBLOCKS (block
); sub
; sub
= TREE_CHAIN (sub
))
3577 setjmp_protect (sub
);
3580 /* Like the previous function, but for args instead of local variables. */
3583 setjmp_protect_args ()
3585 register tree decl
, sub
;
3586 for (decl
= DECL_ARGUMENTS (current_function_decl
);
3587 decl
; decl
= TREE_CHAIN (decl
))
3588 if ((TREE_CODE (decl
) == VAR_DECL
3589 || TREE_CODE (decl
) == PARM_DECL
)
3590 && DECL_RTL (decl
) != 0
3591 && GET_CODE (DECL_RTL (decl
)) == REG
3593 /* If longjmp doesn't restore the registers,
3594 don't put anything in them. */
3595 #ifdef NON_SAVING_SETJMP
3599 ! DECL_REGISTER (decl
)))
3600 put_var_into_stack (decl
);
3603 /* Return the context-pointer register corresponding to DECL,
3604 or 0 if it does not need one. */
3607 lookup_static_chain (decl
)
3610 tree context
= decl_function_context (decl
);
3616 /* We treat inline_function_decl as an alias for the current function
3617 because that is the inline function whose vars, types, etc.
3618 are being merged into the current function.
3619 See expand_inline_function. */
3620 if (context
== current_function_decl
|| context
== inline_function_decl
)
3621 return virtual_stack_vars_rtx
;
3623 for (link
= context_display
; link
; link
= TREE_CHAIN (link
))
3624 if (TREE_PURPOSE (link
) == context
)
3625 return RTL_EXPR_RTL (TREE_VALUE (link
));
3630 /* Convert a stack slot address ADDR for variable VAR
3631 (from a containing function)
3632 into an address valid in this function (using a static chain). */
3635 fix_lexical_addr (addr
, var
)
3641 tree context
= decl_function_context (var
);
3642 struct function
*fp
;
3645 /* If this is the present function, we need not do anything. */
3646 if (context
== current_function_decl
|| context
== inline_function_decl
)
3649 for (fp
= outer_function_chain
; fp
; fp
= fp
->next
)
3650 if (fp
->decl
== context
)
3656 /* Decode given address as base reg plus displacement. */
3657 if (GET_CODE (addr
) == REG
)
3658 basereg
= addr
, displacement
= 0;
3659 else if (GET_CODE (addr
) == PLUS
&& GET_CODE (XEXP (addr
, 1)) == CONST_INT
)
3660 basereg
= XEXP (addr
, 0), displacement
= INTVAL (XEXP (addr
, 1));
3664 /* We accept vars reached via the containing function's
3665 incoming arg pointer and via its stack variables pointer. */
3666 if (basereg
== fp
->internal_arg_pointer
)
3668 /* If reached via arg pointer, get the arg pointer value
3669 out of that function's stack frame.
3671 There are two cases: If a separate ap is needed, allocate a
3672 slot in the outer function for it and dereference it that way.
3673 This is correct even if the real ap is actually a pseudo.
3674 Otherwise, just adjust the offset from the frame pointer to
3677 #ifdef NEED_SEPARATE_AP
3680 if (fp
->arg_pointer_save_area
== 0)
3681 fp
->arg_pointer_save_area
3682 = assign_outer_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0, fp
);
3684 addr
= fix_lexical_addr (XEXP (fp
->arg_pointer_save_area
, 0), var
);
3685 addr
= memory_address (Pmode
, addr
);
3687 base
= copy_to_reg (gen_rtx (MEM
, Pmode
, addr
));
3689 displacement
+= (FIRST_PARM_OFFSET (context
) - STARTING_FRAME_OFFSET
);
3690 base
= lookup_static_chain (var
);
3694 else if (basereg
== virtual_stack_vars_rtx
)
3696 /* This is the same code as lookup_static_chain, duplicated here to
3697 avoid an extra call to decl_function_context. */
3700 for (link
= context_display
; link
; link
= TREE_CHAIN (link
))
3701 if (TREE_PURPOSE (link
) == context
)
3703 base
= RTL_EXPR_RTL (TREE_VALUE (link
));
3711 /* Use same offset, relative to appropriate static chain or argument
3713 return plus_constant (base
, displacement
);
3716 /* Return the address of the trampoline for entering nested fn FUNCTION.
3717 If necessary, allocate a trampoline (in the stack frame)
3718 and emit rtl to initialize its contents (at entry to this function). */
3721 trampoline_address (function
)
3727 struct function
*fp
;
3730 /* Find an existing trampoline and return it. */
3731 for (link
= trampoline_list
; link
; link
= TREE_CHAIN (link
))
3732 if (TREE_PURPOSE (link
) == function
)
3733 return XEXP (RTL_EXPR_RTL (TREE_VALUE (link
)), 0);
3734 for (fp
= outer_function_chain
; fp
; fp
= fp
->next
)
3735 for (link
= fp
->trampoline_list
; link
; link
= TREE_CHAIN (link
))
3736 if (TREE_PURPOSE (link
) == function
)
3738 tramp
= fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link
)), 0),
3740 return round_trampoline_addr (tramp
);
3743 /* None exists; we must make one. */
3745 /* Find the `struct function' for the function containing FUNCTION. */
3747 fn_context
= decl_function_context (function
);
3748 if (fn_context
!= current_function_decl
)
3749 for (fp
= outer_function_chain
; fp
; fp
= fp
->next
)
3750 if (fp
->decl
== fn_context
)
3753 /* Allocate run-time space for this trampoline
3754 (usually in the defining function's stack frame). */
3755 #ifdef ALLOCATE_TRAMPOLINE
3756 tramp
= ALLOCATE_TRAMPOLINE (fp
);
3758 /* If rounding needed, allocate extra space
3759 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
3760 #ifdef TRAMPOLINE_ALIGNMENT
3761 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE + TRAMPOLINE_ALIGNMENT - 1)
3763 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE)
3766 tramp
= assign_outer_stack_local (BLKmode
, TRAMPOLINE_REAL_SIZE
, 0, fp
);
3768 tramp
= assign_stack_local (BLKmode
, TRAMPOLINE_REAL_SIZE
, 0);
3771 /* Record the trampoline for reuse and note it for later initialization
3772 by expand_function_end. */
3775 push_obstacks (fp
->current_obstack
, fp
->function_maybepermanent_obstack
);
3776 rtlexp
= make_node (RTL_EXPR
);
3777 RTL_EXPR_RTL (rtlexp
) = tramp
;
3778 fp
->trampoline_list
= tree_cons (function
, rtlexp
, fp
->trampoline_list
);
3783 /* Make the RTL_EXPR node temporary, not momentary, so that the
3784 trampoline_list doesn't become garbage. */
3785 int momentary
= suspend_momentary ();
3786 rtlexp
= make_node (RTL_EXPR
);
3787 resume_momentary (momentary
);
3789 RTL_EXPR_RTL (rtlexp
) = tramp
;
3790 trampoline_list
= tree_cons (function
, rtlexp
, trampoline_list
);
3793 tramp
= fix_lexical_addr (XEXP (tramp
, 0), function
);
3794 return round_trampoline_addr (tramp
);
3797 /* Given a trampoline address,
3798 round it to multiple of TRAMPOLINE_ALIGNMENT. */
3801 round_trampoline_addr (tramp
)
3804 #ifdef TRAMPOLINE_ALIGNMENT
3805 /* Round address up to desired boundary. */
3806 rtx temp
= gen_reg_rtx (Pmode
);
3807 temp
= expand_binop (Pmode
, add_optab
, tramp
,
3808 GEN_INT (TRAMPOLINE_ALIGNMENT
- 1),
3809 temp
, 0, OPTAB_LIB_WIDEN
);
3810 tramp
= expand_binop (Pmode
, and_optab
, temp
,
3811 GEN_INT (- TRAMPOLINE_ALIGNMENT
),
3812 temp
, 0, OPTAB_LIB_WIDEN
);
3817 /* The functions identify_blocks and reorder_blocks provide a way to
3818 reorder the tree of BLOCK nodes, for optimizers that reshuffle or
3819 duplicate portions of the RTL code. Call identify_blocks before
3820 changing the RTL, and call reorder_blocks after. */
3822 static int all_blocks ();
3823 static tree
blocks_nreverse ();
3825 /* Put all this function's BLOCK nodes into a vector, and return it.
3826 Also store in each NOTE for the beginning or end of a block
3827 the index of that block in the vector.
3828 The arguments are TOP_BLOCK, the top-level block of the function,
3829 and INSNS, the insn chain of the function. */
3832 identify_blocks (top_block
, insns
)
3840 int next_block_number
= 0;
3841 int current_block_number
= 0;
3847 n_blocks
= all_blocks (top_block
, 0);
3848 block_vector
= (tree
*) xmalloc (n_blocks
* sizeof (tree
));
3849 block_stack
= (int *) alloca (n_blocks
* sizeof (int));
3851 all_blocks (top_block
, block_vector
);
3853 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
3854 if (GET_CODE (insn
) == NOTE
)
3856 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
)
3858 block_stack
[depth
++] = current_block_number
;
3859 current_block_number
= next_block_number
;
3860 NOTE_BLOCK_NUMBER (insn
) = next_block_number
++;
3862 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
)
3864 current_block_number
= block_stack
[--depth
];
3865 NOTE_BLOCK_NUMBER (insn
) = current_block_number
;
3869 return block_vector
;
3872 /* Given BLOCK_VECTOR which was returned by identify_blocks,
3873 and a revised instruction chain, rebuild the tree structure
3874 of BLOCK nodes to correspond to the new order of RTL.
3875 The new block tree is inserted below TOP_BLOCK.
3876 Returns the current top-level block. */
3879 reorder_blocks (block_vector
, top_block
, insns
)
3884 tree current_block
= top_block
;
3887 if (block_vector
== 0)
3890 /* Prune the old tree away, so that it doesn't get in the way. */
3891 BLOCK_SUBBLOCKS (current_block
) = 0;
3893 for (insn
= insns
; insn
; insn
= NEXT_INSN (insn
))
3894 if (GET_CODE (insn
) == NOTE
)
3896 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_BEG
)
3898 tree block
= block_vector
[NOTE_BLOCK_NUMBER (insn
)];
3899 /* If we have seen this block before, copy it. */
3900 if (TREE_ASM_WRITTEN (block
))
3901 block
= copy_node (block
);
3902 BLOCK_SUBBLOCKS (block
) = 0;
3903 TREE_ASM_WRITTEN (block
) = 1;
3904 BLOCK_SUPERCONTEXT (block
) = current_block
;
3905 BLOCK_CHAIN (block
) = BLOCK_SUBBLOCKS (current_block
);
3906 BLOCK_SUBBLOCKS (current_block
) = block
;
3907 current_block
= block
;
3908 NOTE_SOURCE_FILE (insn
) = 0;
3910 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_BLOCK_END
)
3912 BLOCK_SUBBLOCKS (current_block
)
3913 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block
));
3914 current_block
= BLOCK_SUPERCONTEXT (current_block
);
3915 NOTE_SOURCE_FILE (insn
) = 0;
3919 return current_block
;
3922 /* Reverse the order of elements in the chain T of blocks,
3923 and return the new head of the chain (old last element). */
3929 register tree prev
= 0, decl
, next
;
3930 for (decl
= t
; decl
; decl
= next
)
3932 next
= BLOCK_CHAIN (decl
);
3933 BLOCK_CHAIN (decl
) = prev
;
3939 /* Count the subblocks of BLOCK, and list them all into the vector VECTOR.
3940 Also clear TREE_ASM_WRITTEN in all blocks. */
3943 all_blocks (block
, vector
)
3950 TREE_ASM_WRITTEN (block
) = 0;
3951 /* Record this block. */
3955 /* Record the subblocks, and their subblocks. */
3956 for (subblocks
= BLOCK_SUBBLOCKS (block
);
3957 subblocks
; subblocks
= BLOCK_CHAIN (subblocks
))
3958 n_blocks
+= all_blocks (subblocks
, vector
? vector
+ n_blocks
: 0);
3963 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
3964 and initialize static variables for generating RTL for the statements
3968 init_function_start (subr
, filename
, line
)
3975 init_stmt_for_function ();
3977 cse_not_expected
= ! optimize
;
3979 /* Caller save not needed yet. */
3980 caller_save_needed
= 0;
3982 /* No stack slots have been made yet. */
3983 stack_slot_list
= 0;
3985 /* There is no stack slot for handling nonlocal gotos. */
3986 nonlocal_goto_handler_slot
= 0;
3987 nonlocal_goto_stack_level
= 0;
3989 /* No labels have been declared for nonlocal use. */
3990 nonlocal_labels
= 0;
3992 /* No function calls so far in this function. */
3993 function_call_count
= 0;
3995 /* No parm regs have been allocated.
3996 (This is important for output_inline_function.) */
3997 max_parm_reg
= LAST_VIRTUAL_REGISTER
+ 1;
3999 /* Initialize the RTL mechanism. */
4002 /* Initialize the queue of pending postincrement and postdecrements,
4003 and some other info in expr.c. */
4006 /* We haven't done register allocation yet. */
4009 init_const_rtx_hash_table ();
4011 current_function_name
= (*decl_printable_name
) (subr
, &junk
);
4013 /* Nonzero if this is a nested function that uses a static chain. */
4015 current_function_needs_context
4016 = (decl_function_context (current_function_decl
) != 0);
4018 /* Set if a call to setjmp is seen. */
4019 current_function_calls_setjmp
= 0;
4021 /* Set if a call to longjmp is seen. */
4022 current_function_calls_longjmp
= 0;
4024 current_function_calls_alloca
= 0;
4025 current_function_has_nonlocal_label
= 0;
4026 current_function_contains_functions
= 0;
4028 current_function_returns_pcc_struct
= 0;
4029 current_function_returns_struct
= 0;
4030 current_function_epilogue_delay_list
= 0;
4031 current_function_uses_const_pool
= 0;
4032 current_function_uses_pic_offset_table
= 0;
4034 /* We have not yet needed to make a label to jump to for tail-recursion. */
4035 tail_recursion_label
= 0;
4037 /* We haven't had a need to make a save area for ap yet. */
4039 arg_pointer_save_area
= 0;
4041 /* No stack slots allocated yet. */
4044 /* No SAVE_EXPRs in this function yet. */
4047 /* No RTL_EXPRs in this function yet. */
4050 /* We have not allocated any temporaries yet. */
4052 temp_slot_level
= 0;
4054 /* Within function body, compute a type's size as soon it is laid out. */
4055 immediate_size_expand
++;
4057 init_pending_stack_adjust ();
4058 inhibit_defer_pop
= 0;
4060 current_function_outgoing_args_size
= 0;
4062 /* Initialize the insn lengths. */
4063 init_insn_lengths ();
4065 /* Prevent ever trying to delete the first instruction of a function.
4066 Also tell final how to output a linenum before the function prologue. */
4067 emit_line_note (filename
, line
);
4069 /* Make sure first insn is a note even if we don't want linenums.
4070 This makes sure the first insn will never be deleted.
4071 Also, final expects a note to appear there. */
4072 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4074 /* Set flags used by final.c. */
4075 if (aggregate_value_p (DECL_RESULT (subr
)))
4077 #ifdef PCC_STATIC_STRUCT_RETURN
4078 if (flag_pcc_struct_return
)
4079 current_function_returns_pcc_struct
= 1;
4082 current_function_returns_struct
= 1;
4085 /* Warn if this value is an aggregate type,
4086 regardless of which calling convention we are using for it. */
4087 if (warn_aggregate_return
4088 && (TREE_CODE (TREE_TYPE (DECL_RESULT (subr
))) == RECORD_TYPE
4089 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr
))) == UNION_TYPE
4090 || TREE_CODE (TREE_TYPE (DECL_RESULT (subr
))) == ARRAY_TYPE
))
4091 warning ("function returns an aggregate");
4093 current_function_returns_pointer
4094 = (TREE_CODE (TREE_TYPE (DECL_RESULT (subr
))) == POINTER_TYPE
);
4096 /* Indicate that we need to distinguish between the return value of the
4097 present function and the return value of a function being called. */
4098 rtx_equal_function_value_matters
= 1;
4100 /* Indicate that we have not instantiated virtual registers yet. */
4101 virtuals_instantiated
= 0;
4103 /* Indicate we have no need of a frame pointer yet. */
4104 frame_pointer_needed
= 0;
4106 /* By default assume not varargs. */
4107 current_function_varargs
= 0;
4110 /* Indicate that the current function uses extra args
4111 not explicitly mentioned in the argument list in any fashion. */
4116 current_function_varargs
= 1;
4119 /* Expand a call to __main at the beginning of a possible main function. */
4122 expand_main_function ()
4124 #if !defined (INIT_SECTION_ASM_OP) || defined (INVOKE__main)
4125 emit_library_call (gen_rtx (SYMBOL_REF
, Pmode
, "__main"), 0,
4127 #endif /* not INIT_SECTION_ASM_OP or INVOKE__main */
4130 /* Start the RTL for a new function, and set variables used for
4132 SUBR is the FUNCTION_DECL node.
4133 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4134 the function's parameters, which must be run at any return statement. */
4137 expand_function_start (subr
, parms_have_cleanups
)
4139 int parms_have_cleanups
;
4145 /* Make sure volatile mem refs aren't considered
4146 valid operands of arithmetic insns. */
4147 init_recog_no_volatile ();
4149 /* If function gets a static chain arg, store it in the stack frame.
4150 Do this first, so it gets the first stack slot offset. */
4151 if (current_function_needs_context
)
4153 last_ptr
= assign_stack_local (Pmode
, GET_MODE_SIZE (Pmode
), 0);
4154 emit_move_insn (last_ptr
, static_chain_incoming_rtx
);
4157 /* If the parameters of this function need cleaning up, get a label
4158 for the beginning of the code which executes those cleanups. This must
4159 be done before doing anything with return_label. */
4160 if (parms_have_cleanups
)
4161 cleanup_label
= gen_label_rtx ();
4165 /* Make the label for return statements to jump to, if this machine
4166 does not have a one-instruction return and uses an epilogue,
4167 or if it returns a structure, or if it has parm cleanups. */
4169 if (cleanup_label
== 0 && HAVE_return
4170 && ! current_function_returns_pcc_struct
4171 && ! (current_function_returns_struct
&& ! optimize
))
4174 return_label
= gen_label_rtx ();
4176 return_label
= gen_label_rtx ();
4179 /* Initialize rtx used to return the value. */
4180 /* Do this before assign_parms so that we copy the struct value address
4181 before any library calls that assign parms might generate. */
4183 /* Decide whether to return the value in memory or in a register. */
4184 if (aggregate_value_p (DECL_RESULT (subr
)))
4186 /* Returning something that won't go in a register. */
4187 register rtx value_address
;
4189 #ifdef PCC_STATIC_STRUCT_RETURN
4190 if (current_function_returns_pcc_struct
)
4192 int size
= int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr
)));
4193 value_address
= assemble_static_space (size
);
4198 /* Expect to be passed the address of a place to store the value.
4199 If it is passed as an argument, assign_parms will take care of
4201 if (struct_value_incoming_rtx
)
4203 value_address
= gen_reg_rtx (Pmode
);
4204 emit_move_insn (value_address
, struct_value_incoming_rtx
);
4208 DECL_RTL (DECL_RESULT (subr
))
4209 = gen_rtx (MEM
, DECL_MODE (DECL_RESULT (subr
)),
4212 else if (DECL_MODE (DECL_RESULT (subr
)) == VOIDmode
)
4213 /* If return mode is void, this decl rtl should not be used. */
4214 DECL_RTL (DECL_RESULT (subr
)) = 0;
4215 else if (parms_have_cleanups
)
4217 /* If function will end with cleanup code for parms,
4218 compute the return values into a pseudo reg,
4219 which we will copy into the true return register
4220 after the cleanups are done. */
4222 enum machine_mode mode
= DECL_MODE (DECL_RESULT (subr
));
4223 #ifdef PROMOTE_FUNCTION_RETURN
4224 tree type
= TREE_TYPE (DECL_RESULT (subr
));
4225 int unsignedp
= TREE_UNSIGNED (type
);
4227 if (TREE_CODE (type
) == INTEGER_TYPE
|| TREE_CODE (type
) == ENUMERAL_TYPE
4228 || TREE_CODE (type
) == BOOLEAN_TYPE
|| TREE_CODE (type
) == CHAR_TYPE
4229 || TREE_CODE (type
) == REAL_TYPE
|| TREE_CODE (type
) == POINTER_TYPE
4230 || TREE_CODE (type
) == OFFSET_TYPE
)
4232 PROMOTE_MODE (mode
, unsignedp
, type
);
4236 DECL_RTL (DECL_RESULT (subr
)) = gen_reg_rtx (mode
);
4239 /* Scalar, returned in a register. */
4241 #ifdef FUNCTION_OUTGOING_VALUE
4242 DECL_RTL (DECL_RESULT (subr
))
4243 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (subr
)), subr
);
4245 DECL_RTL (DECL_RESULT (subr
))
4246 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (subr
)), subr
);
4249 /* Mark this reg as the function's return value. */
4250 if (GET_CODE (DECL_RTL (DECL_RESULT (subr
))) == REG
)
4252 REG_FUNCTION_VALUE_P (DECL_RTL (DECL_RESULT (subr
))) = 1;
4253 /* Needed because we may need to move this to memory
4254 in case it's a named return value whose address is taken. */
4255 DECL_REGISTER (DECL_RESULT (subr
)) = 1;
4259 /* Initialize rtx for parameters and local variables.
4260 In some cases this requires emitting insns. */
4262 assign_parms (subr
, 0);
4264 /* The following was moved from init_function_start.
4265 The move is supposed to make sdb output more accurate. */
4266 /* Indicate the beginning of the function body,
4267 as opposed to parm setup. */
4268 emit_note (NULL_PTR
, NOTE_INSN_FUNCTION_BEG
);
4270 /* If doing stupid allocation, mark parms as born here. */
4272 if (GET_CODE (get_last_insn ()) != NOTE
)
4273 emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4274 parm_birth_insn
= get_last_insn ();
4278 for (i
= LAST_VIRTUAL_REGISTER
+ 1; i
< max_parm_reg
; i
++)
4279 use_variable (regno_reg_rtx
[i
]);
4281 if (current_function_internal_arg_pointer
!= virtual_incoming_args_rtx
)
4282 use_variable (current_function_internal_arg_pointer
);
4285 /* Fetch static chain values for containing functions. */
4286 tem
= decl_function_context (current_function_decl
);
4287 /* If not doing stupid register allocation, then start off with the static
4288 chain pointer in a pseudo register. Otherwise, we use the stack
4289 address that was generated above. */
4290 if (tem
&& ! obey_regdecls
)
4291 last_ptr
= copy_to_reg (static_chain_incoming_rtx
);
4292 context_display
= 0;
4295 tree rtlexp
= make_node (RTL_EXPR
);
4297 RTL_EXPR_RTL (rtlexp
) = last_ptr
;
4298 context_display
= tree_cons (tem
, rtlexp
, context_display
);
4299 tem
= decl_function_context (tem
);
4302 /* Chain thru stack frames, assuming pointer to next lexical frame
4303 is found at the place we always store it. */
4304 #ifdef FRAME_GROWS_DOWNWARD
4305 last_ptr
= plus_constant (last_ptr
, - GET_MODE_SIZE (Pmode
));
4307 last_ptr
= copy_to_reg (gen_rtx (MEM
, Pmode
,
4308 memory_address (Pmode
, last_ptr
)));
4311 /* After the display initializations is where the tail-recursion label
4312 should go, if we end up needing one. Ensure we have a NOTE here
4313 since some things (like trampolines) get placed before this. */
4314 tail_recursion_reentry
= emit_note (NULL_PTR
, NOTE_INSN_DELETED
);
4316 /* Evaluate now the sizes of any types declared among the arguments. */
4317 for (tem
= nreverse (get_pending_sizes ()); tem
; tem
= TREE_CHAIN (tem
))
4318 expand_expr (TREE_VALUE (tem
), NULL_RTX
, VOIDmode
, 0);
4320 /* Make sure there is a line number after the function entry setup code. */
4321 force_next_line_note ();
4324 /* Generate RTL for the end of the current function.
4325 FILENAME and LINE are the current position in the source file. */
4327 /* It is up to language-specific callers to do cleanups for parameters. */
4330 expand_function_end (filename
, line
)
4337 static rtx initial_trampoline
;
4339 #ifdef NON_SAVING_SETJMP
4340 /* Don't put any variables in registers if we call setjmp
4341 on a machine that fails to restore the registers. */
4342 if (NON_SAVING_SETJMP
&& current_function_calls_setjmp
)
4344 setjmp_protect (DECL_INITIAL (current_function_decl
));
4345 setjmp_protect_args ();
4349 /* Save the argument pointer if a save area was made for it. */
4350 if (arg_pointer_save_area
)
4352 rtx x
= gen_move_insn (arg_pointer_save_area
, virtual_incoming_args_rtx
);
4353 emit_insn_before (x
, tail_recursion_reentry
);
4356 /* Initialize any trampolines required by this function. */
4357 for (link
= trampoline_list
; link
; link
= TREE_CHAIN (link
))
4359 tree function
= TREE_PURPOSE (link
);
4360 rtx context
= lookup_static_chain (function
);
4361 rtx tramp
= RTL_EXPR_RTL (TREE_VALUE (link
));
4364 /* First make sure this compilation has a template for
4365 initializing trampolines. */
4366 if (initial_trampoline
== 0)
4368 end_temporary_allocation ();
4370 = gen_rtx (MEM
, BLKmode
, assemble_trampoline_template ());
4371 resume_temporary_allocation ();
4374 /* Generate insns to initialize the trampoline. */
4376 tramp
= change_address (initial_trampoline
, BLKmode
,
4377 round_trampoline_addr (XEXP (tramp
, 0)));
4378 emit_block_move (tramp
, initial_trampoline
, GEN_INT (TRAMPOLINE_SIZE
),
4379 FUNCTION_BOUNDARY
/ BITS_PER_UNIT
);
4380 INITIALIZE_TRAMPOLINE (XEXP (tramp
, 0),
4381 XEXP (DECL_RTL (function
), 0), context
);
4385 /* Put those insns at entry to the containing function (this one). */
4386 emit_insns_before (seq
, tail_recursion_reentry
);
4388 /* Clear the trampoline_list for the next function. */
4389 trampoline_list
= 0;
4391 #if 0 /* I think unused parms are legitimate enough. */
4392 /* Warn about unused parms. */
4397 for (decl
= DECL_ARGUMENTS (current_function_decl
);
4398 decl
; decl
= TREE_CHAIN (decl
))
4399 if (! TREE_USED (decl
) && TREE_CODE (decl
) == VAR_DECL
)
4400 warning_with_decl (decl
, "unused parameter `%s'");
4404 /* Delete handlers for nonlocal gotos if nothing uses them. */
4405 if (nonlocal_goto_handler_slot
!= 0 && !current_function_has_nonlocal_label
)
4408 /* End any sequences that failed to be closed due to syntax errors. */
4409 while (in_sequence_p ())
4412 /* Outside function body, can't compute type's actual size
4413 until next function's body starts. */
4414 immediate_size_expand
--;
4416 /* If doing stupid register allocation,
4417 mark register parms as dying here. */
4422 for (i
= LAST_VIRTUAL_REGISTER
+ 1; i
< max_parm_reg
; i
++)
4423 use_variable (regno_reg_rtx
[i
]);
4425 /* Likewise for the regs of all the SAVE_EXPRs in the function. */
4427 for (tem
= save_expr_regs
; tem
; tem
= XEXP (tem
, 1))
4429 use_variable (XEXP (tem
, 0));
4430 use_variable_after (XEXP (tem
, 0), parm_birth_insn
);
4433 if (current_function_internal_arg_pointer
!= virtual_incoming_args_rtx
)
4434 use_variable (current_function_internal_arg_pointer
);
4437 clear_pending_stack_adjust ();
4438 do_pending_stack_adjust ();
4440 /* Mark the end of the function body.
4441 If control reaches this insn, the function can drop through
4442 without returning a value. */
4443 emit_note (NULL_PTR
, NOTE_INSN_FUNCTION_END
);
4445 /* Output a linenumber for the end of the function.
4446 SDB depends on this. */
4447 emit_line_note_force (filename
, line
);
4449 /* Output the label for the actual return from the function,
4450 if one is expected. This happens either because a function epilogue
4451 is used instead of a return instruction, or because a return was done
4452 with a goto in order to run local cleanups, or because of pcc-style
4453 structure returning. */
4456 emit_label (return_label
);
4458 /* If we had calls to alloca, and this machine needs
4459 an accurate stack pointer to exit the function,
4460 insert some code to save and restore the stack pointer. */
4461 #ifdef EXIT_IGNORE_STACK
4462 if (! EXIT_IGNORE_STACK
)
4464 if (current_function_calls_alloca
)
4468 emit_stack_save (SAVE_FUNCTION
, &tem
, parm_birth_insn
);
4469 emit_stack_restore (SAVE_FUNCTION
, tem
, NULL_RTX
);
4472 /* If scalar return value was computed in a pseudo-reg,
4473 copy that to the hard return register. */
4474 if (DECL_RTL (DECL_RESULT (current_function_decl
)) != 0
4475 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl
))) == REG
4476 && (REGNO (DECL_RTL (DECL_RESULT (current_function_decl
)))
4477 >= FIRST_PSEUDO_REGISTER
))
4479 rtx real_decl_result
;
4481 #ifdef FUNCTION_OUTGOING_VALUE
4483 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl
)),
4484 current_function_decl
);
4487 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl
)),
4488 current_function_decl
);
4490 REG_FUNCTION_VALUE_P (real_decl_result
) = 1;
4491 emit_move_insn (real_decl_result
,
4492 DECL_RTL (DECL_RESULT (current_function_decl
)));
4493 emit_insn (gen_rtx (USE
, VOIDmode
, real_decl_result
));
4496 /* If returning a structure, arrange to return the address of the value
4497 in a place where debuggers expect to find it.
4499 If returning a structure PCC style,
4500 the caller also depends on this value.
4501 And current_function_returns_pcc_struct is not necessarily set. */
4502 if (current_function_returns_struct
4503 || current_function_returns_pcc_struct
)
4505 rtx value_address
= XEXP (DECL_RTL (DECL_RESULT (current_function_decl
)), 0);
4506 tree type
= TREE_TYPE (DECL_RESULT (current_function_decl
));
4507 #ifdef FUNCTION_OUTGOING_VALUE
4509 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type
),
4510 current_function_decl
);
4513 = FUNCTION_VALUE (build_pointer_type (type
),
4514 current_function_decl
);
4517 /* Mark this as a function return value so integrate will delete the
4518 assignment and USE below when inlining this function. */
4519 REG_FUNCTION_VALUE_P (outgoing
) = 1;
4521 emit_move_insn (outgoing
, value_address
);
4522 use_variable (outgoing
);
4525 /* Output a return insn if we are using one.
4526 Otherwise, let the rtl chain end here, to drop through
4527 into the epilogue. */
4532 emit_jump_insn (gen_return ());
4537 /* Fix up any gotos that jumped out to the outermost
4538 binding level of the function.
4539 Must follow emitting RETURN_LABEL. */
4541 /* If you have any cleanups to do at this point,
4542 and they need to create temporary variables,
4543 then you will lose. */
4544 fixup_gotos (NULL_PTR
, NULL_RTX
, NULL_TREE
, get_insns (), 0);
4547 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
4549 static int *prologue
;
4550 static int *epilogue
;
4552 /* Create an array that records the INSN_UIDs of INSNS (either a sequence
4553 or a single insn). */
4556 record_insns (insns
)
4561 if (GET_CODE (insns
) == SEQUENCE
)
4563 int len
= XVECLEN (insns
, 0);
4564 vec
= (int *) oballoc ((len
+ 1) * sizeof (int));
4567 vec
[len
] = INSN_UID (XVECEXP (insns
, 0, len
));
4571 vec
= (int *) oballoc (2 * sizeof (int));
4572 vec
[0] = INSN_UID (insns
);
4578 /* Determine how many INSN_UIDs in VEC are part of INSN. */
4581 contains (insn
, vec
)
4587 if (GET_CODE (insn
) == INSN
4588 && GET_CODE (PATTERN (insn
)) == SEQUENCE
)
4591 for (i
= XVECLEN (PATTERN (insn
), 0) - 1; i
>= 0; i
--)
4592 for (j
= 0; vec
[j
]; j
++)
4593 if (INSN_UID (XVECEXP (PATTERN (insn
), 0, i
)) == vec
[j
])
4599 for (j
= 0; vec
[j
]; j
++)
4600 if (INSN_UID (insn
) == vec
[j
])
4606 /* Generate the prologe and epilogue RTL if the machine supports it. Thread
4607 this into place with notes indicating where the prologue ends and where
4608 the epilogue begins. Update the basic block information when possible. */
4611 thread_prologue_and_epilogue_insns (f
)
4614 #ifdef HAVE_prologue
4617 rtx head
, seq
, insn
;
4619 /* The first insn (a NOTE_INSN_DELETED) is followed by zero or more
4620 prologue insns and a NOTE_INSN_PROLOGUE_END. */
4621 emit_note_after (NOTE_INSN_PROLOGUE_END
, f
);
4622 seq
= gen_prologue ();
4623 head
= emit_insn_after (seq
, f
);
4625 /* Include the new prologue insns in the first block. Ignore them
4626 if they form a basic block unto themselves. */
4627 if (basic_block_head
&& n_basic_blocks
4628 && GET_CODE (basic_block_head
[0]) != CODE_LABEL
)
4629 basic_block_head
[0] = NEXT_INSN (f
);
4631 /* Retain a map of the prologue insns. */
4632 prologue
= record_insns (GET_CODE (seq
) == SEQUENCE
? seq
: head
);
4638 #ifdef HAVE_epilogue
4641 rtx insn
= get_last_insn ();
4642 rtx prev
= prev_nonnote_insn (insn
);
4644 /* If we end with a BARRIER, we don't need an epilogue. */
4645 if (! (prev
&& GET_CODE (prev
) == BARRIER
))
4649 /* The last basic block ends with a NOTE_INSN_EPILOGUE_BEG,
4650 the epilogue insns (this must include the jump insn that
4651 returns), USE insns ad the end of a function, and a BARRIER. */
4653 emit_barrier_after (insn
);
4655 /* Place the epilogue before the USE insns at the end of a
4658 && GET_CODE (prev
) == INSN
4659 && GET_CODE (PATTERN (prev
)) == USE
)
4661 insn
= PREV_INSN (prev
);
4662 prev
= prev_nonnote_insn (prev
);
4665 seq
= gen_epilogue ();
4666 tail
= emit_jump_insn_after (seq
, insn
);
4667 emit_note_after (NOTE_INSN_EPILOGUE_BEG
, insn
);
4669 /* Include the new epilogue insns in the last block. Ignore
4670 them if they form a basic block unto themselves. */
4671 if (basic_block_end
&& n_basic_blocks
4672 && GET_CODE (basic_block_end
[n_basic_blocks
- 1]) != JUMP_INSN
)
4673 basic_block_end
[n_basic_blocks
- 1] = tail
;
4675 /* Retain a map of the epilogue insns. */
4676 epilogue
= record_insns (GET_CODE (seq
) == SEQUENCE
? seq
: tail
);
4684 /* Reposition the prologue-end and epilogue-begin notes after instruction
4685 scheduling and delayed branch scheduling. */
4688 reposition_prologue_and_epilogue_notes (f
)
4691 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
4692 /* Reposition the prologue and epilogue notes. */
4700 register rtx insn
, note
= 0;
4702 /* Scan from the beginning until we reach the last prologue insn.
4703 We apparently can't depend on basic_block_{head,end} after
4705 for (len
= 0; prologue
[len
]; len
++)
4707 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
4708 if (GET_CODE (insn
) == NOTE
)
4710 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_PROLOGUE_END
)
4713 else if ((len
-= contains (insn
, prologue
)) == 0)
4715 /* Find the prologue-end note if we haven't already, and
4716 move it to just after the last prologue insn. */
4718 for (note
= insn
; note
= NEXT_INSN (note
);)
4719 if (GET_CODE (note
) == NOTE
4720 && NOTE_LINE_NUMBER (note
) == NOTE_INSN_PROLOGUE_END
)
4722 next
= NEXT_INSN (note
);
4723 prev
= PREV_INSN (note
);
4725 NEXT_INSN (prev
) = next
;
4727 PREV_INSN (next
) = prev
;
4728 add_insn_after (note
, insn
);
4735 register rtx insn
, note
= 0;
4737 /* Scan from the end until we reach the first epilogue insn.
4738 We apparently can't depend on basic_block_{head,end} after
4740 for (len
= 0; epilogue
[len
]; len
++)
4742 for (insn
= get_last_insn (); insn
; insn
= PREV_INSN (insn
))
4743 if (GET_CODE (insn
) == NOTE
)
4745 if (NOTE_LINE_NUMBER (insn
) == NOTE_INSN_EPILOGUE_BEG
)
4748 else if ((len
-= contains (insn
, epilogue
)) == 0)
4750 /* Find the epilogue-begin note if we haven't already, and
4751 move it to just before the first epilogue insn. */
4753 for (note
= insn
; note
= PREV_INSN (note
);)
4754 if (GET_CODE (note
) == NOTE
4755 && NOTE_LINE_NUMBER (note
) == NOTE_INSN_EPILOGUE_BEG
)
4757 next
= NEXT_INSN (note
);
4758 prev
= PREV_INSN (note
);
4760 NEXT_INSN (prev
) = next
;
4762 PREV_INSN (next
) = prev
;
4763 add_insn_after (note
, PREV_INSN (insn
));
4768 #endif /* HAVE_prologue or HAVE_epilogue */