expr.h revision 225736
1/* Definitions for code generation pass of GNU compiler.
2   Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
4   Free Software Foundation, Inc.
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 2, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING.  If not, write to the Free
20Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2102110-1301, USA.  */
22
23#ifndef GCC_EXPR_H
24#define GCC_EXPR_H
25
26/* For inhibit_defer_pop */
27#include "function.h"
28/* For XEXP, GEN_INT, rtx_code */
29#include "rtl.h"
30/* For optimize_size */
31#include "flags.h"
32/* For host_integerp, tree_low_cst, fold_convert, size_binop, ssize_int,
33   TREE_CODE, TYPE_SIZE, int_size_in_bytes,    */
34#include "tree.h"
35/* For GET_MODE_BITSIZE, word_mode */
36#include "machmode.h"
37
38/* The default branch cost is 1.  */
39#ifndef BRANCH_COST
40#define BRANCH_COST 1
41#endif
42
43/* This is the 4th arg to `expand_expr'.
44   EXPAND_STACK_PARM means we are possibly expanding a call param onto
45   the stack.
46   EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
47   EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
48   EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
49    is a constant that is not a legitimate address.
50   EXPAND_WRITE means we are only going to write to the resulting rtx.
51   EXPAND_MEMORY means we are interested in a memory result, even if
52    the memory is constant and we could have propagated a constant value.  */
53enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
54		      EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
55		      EXPAND_MEMORY};
56
57/* Prevent the compiler from deferring stack pops.  See
58   inhibit_defer_pop for more information.  */
59#define NO_DEFER_POP (inhibit_defer_pop += 1)
60
61/* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
62   more information.  */
63#define OK_DEFER_POP (inhibit_defer_pop -= 1)
64
65/* If a memory-to-memory move would take MOVE_RATIO or more simple
66   move-instruction sequences, we will do a movmem or libcall instead.  */
67
68#ifndef MOVE_RATIO
69#if defined (HAVE_movmemqi) || defined (HAVE_movmemhi) || defined (HAVE_movmemsi) || defined (HAVE_movmemdi) || defined (HAVE_movmemti)
70#define MOVE_RATIO 2
71#else
72/* If we are optimizing for space (-Os), cut down the default move ratio.  */
73#define MOVE_RATIO (optimize_size ? 3 : 15)
74#endif
75#endif
76
77/* If a clear memory operation would take CLEAR_RATIO or more simple
78   move-instruction sequences, we will do a setmem or libcall instead.  */
79
80#ifndef CLEAR_RATIO
81#if defined (HAVE_setmemqi) || defined (HAVE_setmemhi) || defined (HAVE_setmemsi) || defined (HAVE_setmemdi) || defined (HAVE_setmemti)
82#define CLEAR_RATIO 2
83#else
84/* If we are optimizing for space, cut down the default clear ratio.  */
85#define CLEAR_RATIO (optimize_size ? 3 : 15)
86#endif
87#endif
88
89enum direction {none, upward, downward};
90
91/* Structure to record the size of a sequence of arguments
92   as the sum of a tree-expression and a constant.  This structure is
93   also used to store offsets from the stack, which might be negative,
94   so the variable part must be ssizetype, not sizetype.  */
95
96struct args_size
97{
98  HOST_WIDE_INT constant;
99  tree var;
100};
101
102/* Package up various arg related fields of struct args for
103   locate_and_pad_parm.  */
104struct locate_and_pad_arg_data
105{
106  /* Size of this argument on the stack, rounded up for any padding it
107     gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
108     counted here, otherwise they aren't.  */
109  struct args_size size;
110  /* Offset of this argument from beginning of stack-args.  */
111  struct args_size offset;
112  /* Offset to the start of the stack slot.  Different from OFFSET
113     if this arg pads downward.  */
114  struct args_size slot_offset;
115  /* The amount that the stack pointer needs to be adjusted to
116     force alignment for the next argument.  */
117  struct args_size alignment_pad;
118  /* Which way we should pad this arg.  */
119  enum direction where_pad;
120  /* slot_offset is at least this aligned.  */
121  unsigned int boundary;
122};
123
124/* Add the value of the tree INC to the `struct args_size' TO.  */
125
126#define ADD_PARM_SIZE(TO, INC)					\
127do {								\
128  tree inc = (INC);						\
129  if (host_integerp (inc, 0))					\
130    (TO).constant += tree_low_cst (inc, 0);			\
131  else if ((TO).var == 0)					\
132    (TO).var = fold_convert (ssizetype, inc);			\
133  else								\
134    (TO).var = size_binop (PLUS_EXPR, (TO).var,			\
135			   fold_convert (ssizetype, inc));	\
136} while (0)
137
138#define SUB_PARM_SIZE(TO, DEC)					\
139do {								\
140  tree dec = (DEC);						\
141  if (host_integerp (dec, 0))					\
142    (TO).constant -= tree_low_cst (dec, 0);			\
143  else if ((TO).var == 0)					\
144    (TO).var = size_binop (MINUS_EXPR, ssize_int (0),		\
145			   fold_convert (ssizetype, dec));	\
146  else								\
147    (TO).var = size_binop (MINUS_EXPR, (TO).var,		\
148			   fold_convert (ssizetype, dec));	\
149} while (0)
150
151/* Convert the implicit sum in a `struct args_size' into a tree
152   of type ssizetype.  */
153#define ARGS_SIZE_TREE(SIZE)					\
154((SIZE).var == 0 ? ssize_int ((SIZE).constant)			\
155 : size_binop (PLUS_EXPR, fold_convert (ssizetype, (SIZE).var),	\
156	       ssize_int ((SIZE).constant)))
157
158/* Convert the implicit sum in a `struct args_size' into an rtx.  */
159#define ARGS_SIZE_RTX(SIZE)					\
160((SIZE).var == 0 ? GEN_INT ((SIZE).constant)			\
161 : expand_normal (ARGS_SIZE_TREE (SIZE)))
162
163/* Supply a default definition for FUNCTION_ARG_PADDING:
164   usually pad upward, but pad short args downward on
165   big-endian machines.  */
166
167#define DEFAULT_FUNCTION_ARG_PADDING(MODE, TYPE)			\
168  (! BYTES_BIG_ENDIAN							\
169   ? upward								\
170   : (((MODE) == BLKmode						\
171       ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST		\
172	  && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
173       : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)			\
174      ? downward : upward))
175
176#ifndef FUNCTION_ARG_PADDING
177#define FUNCTION_ARG_PADDING(MODE, TYPE)	\
178  DEFAULT_FUNCTION_ARG_PADDING ((MODE), (TYPE))
179#endif
180
181/* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
182   FUNCTION_ARG_PADDING, which also pads the length, handle any needed
183   alignment.  */
184
185#ifndef FUNCTION_ARG_BOUNDARY
186#define FUNCTION_ARG_BOUNDARY(MODE, TYPE)	PARM_BOUNDARY
187#endif
188
189/* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
190   Normally move_insn, so Pmode stack pointer.  */
191
192#ifndef STACK_SAVEAREA_MODE
193#define STACK_SAVEAREA_MODE(LEVEL) Pmode
194#endif
195
196/* Supply a default definition of STACK_SIZE_MODE for
197   allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
198
199#ifndef STACK_SIZE_MODE
200#define STACK_SIZE_MODE word_mode
201#endif
202
203/* Provide default values for the macros controlling stack checking.  */
204
205#ifndef STACK_CHECK_BUILTIN
206#define STACK_CHECK_BUILTIN 0
207#endif
208
209/* The default interval is one page.  */
210#ifndef STACK_CHECK_PROBE_INTERVAL
211#define STACK_CHECK_PROBE_INTERVAL 4096
212#endif
213
214/* The default is to do a store into the stack.  */
215#ifndef STACK_CHECK_PROBE_LOAD
216#define STACK_CHECK_PROBE_LOAD 0
217#endif
218
219/* This value is arbitrary, but should be sufficient for most machines.  */
220#ifndef STACK_CHECK_PROTECT
221#define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
222#endif
223
224/* Make the maximum frame size be the largest we can and still only need
225   one probe per function.  */
226#ifndef STACK_CHECK_MAX_FRAME_SIZE
227#define STACK_CHECK_MAX_FRAME_SIZE \
228  (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
229#endif
230
231/* This is arbitrary, but should be large enough everywhere.  */
232#ifndef STACK_CHECK_FIXED_FRAME_SIZE
233#define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
234#endif
235
236/* Provide a reasonable default for the maximum size of an object to
237   allocate in the fixed frame.  We may need to be able to make this
238   controllable by the user at some point.  */
239#ifndef STACK_CHECK_MAX_VAR_SIZE
240#define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
241#endif
242
243/* Functions from optabs.c, commonly used, and without need for the optabs
244   tables:  */
245
246/* Passed to expand_simple_binop and expand_binop to say which options
247   to try to use if the requested operation can't be open-coded on the
248   requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
249   a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
250   using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
251   try anything else.  */
252
253enum optab_methods
254{
255  OPTAB_DIRECT,
256  OPTAB_LIB,
257  OPTAB_WIDEN,
258  OPTAB_LIB_WIDEN,
259  OPTAB_MUST_WIDEN
260};
261
262/* Generate code for a simple binary or unary operation.  "Simple" in
263   this case means "can be unambiguously described by a (mode, code)
264   pair and mapped to a single optab."  */
265extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
266				rtx, rtx, int, enum optab_methods);
267extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
268			       int);
269
270/* Report whether the machine description contains an insn which can
271   perform the operation described by CODE and MODE.  */
272extern int have_insn_for (enum rtx_code, enum machine_mode);
273
274/* Emit code to make a call to a constant function or a library call.  */
275extern void emit_libcall_block (rtx, rtx, rtx, rtx);
276
277/* Create but don't emit one rtl instruction to perform certain operations.
278   Modes must match; operands must meet the operation's predicates.
279   Likewise for subtraction and for just copying.  */
280extern rtx gen_add2_insn (rtx, rtx);
281extern rtx gen_add3_insn (rtx, rtx, rtx);
282extern rtx gen_sub2_insn (rtx, rtx);
283extern rtx gen_sub3_insn (rtx, rtx, rtx);
284extern rtx gen_move_insn (rtx, rtx);
285extern int have_add2_insn (rtx, rtx);
286extern int have_sub2_insn (rtx, rtx);
287
288/* Emit a pair of rtl insns to compare two rtx's and to jump
289   to a label if the comparison is true.  */
290extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
291				     enum machine_mode, int, rtx);
292
293/* Generate code to indirectly jump to a location given in the rtx LOC.  */
294extern void emit_indirect_jump (rtx);
295
296/* Generate a conditional trap instruction.  */
297extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
298
299#include "insn-config.h"
300
301#ifdef HAVE_conditional_move
302/* Emit a conditional move operation.  */
303rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
304			   rtx, rtx, enum machine_mode, int);
305
306/* Return nonzero if the conditional move is supported.  */
307int can_conditionally_move_p (enum machine_mode mode);
308
309#endif
310rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
311			  rtx, rtx, enum machine_mode, int);
312
313rtx expand_val_compare_and_swap (rtx, rtx, rtx, rtx);
314rtx expand_bool_compare_and_swap (rtx, rtx, rtx, rtx);
315rtx expand_sync_operation (rtx, rtx, enum rtx_code);
316rtx expand_sync_fetch_operation (rtx, rtx, enum rtx_code, bool, rtx);
317rtx expand_sync_lock_test_and_set (rtx, rtx, rtx);
318
319/* Functions from expmed.c:  */
320
321/* Arguments MODE, RTX: return an rtx for the negation of that value.
322   May emit insns.  */
323extern rtx negate_rtx (enum machine_mode, rtx);
324
325/* Expand a logical AND operation.  */
326extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
327
328/* Emit a store-flag operation.  */
329extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
330			    int, int);
331
332/* Like emit_store_flag, but always succeeds.  */
333extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
334				  enum machine_mode, int, int);
335
336/* Functions from builtins.c:  */
337extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
338extern tree std_build_builtin_va_list (void);
339extern void std_expand_builtin_va_start (tree, rtx);
340extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
341extern void expand_builtin_setjmp_setup (rtx, rtx);
342extern void expand_builtin_setjmp_receiver (rtx);
343extern rtx expand_builtin_saveregs (void);
344extern void expand_builtin_trap (void);
345
346/* Functions from expr.c:  */
347
348/* This is run once per compilation to set up which modes can be used
349   directly in memory and to initialize the block move optab.  */
350extern void init_expr_once (void);
351
352/* This is run at the start of compiling a function.  */
353extern void init_expr (void);
354
355/* Emit some rtl insns to move data between rtx's, converting machine modes.
356   Both modes must be floating or both fixed.  */
357extern void convert_move (rtx, rtx, int);
358
359/* Convert an rtx to specified machine mode and return the result.  */
360extern rtx convert_to_mode (enum machine_mode, rtx, int);
361
362/* Convert an rtx to MODE from OLDMODE and return the result.  */
363extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
364
365/* Emit code to move a block Y to a block X.  */
366
367enum block_op_methods
368{
369  BLOCK_OP_NORMAL,
370  BLOCK_OP_NO_LIBCALL,
371  BLOCK_OP_CALL_PARM,
372  /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized.  */
373  BLOCK_OP_TAILCALL
374};
375
376extern void init_block_move_fn (const char *);
377extern void init_block_clear_fn (const char *);
378
379extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
380
381/* Copy all or part of a value X into registers starting at REGNO.
382   The number of registers to be filled is NREGS.  */
383extern void move_block_to_reg (int, rtx, int, enum machine_mode);
384
385/* Copy all or part of a BLKmode value X out of registers starting at REGNO.
386   The number of registers to be filled is NREGS.  */
387extern void move_block_from_reg (int, rtx, int);
388
389/* Generate a non-consecutive group of registers represented by a PARALLEL.  */
390extern rtx gen_group_rtx (rtx);
391
392/* Load a BLKmode value into non-consecutive registers represented by a
393   PARALLEL.  */
394extern void emit_group_load (rtx, rtx, tree, int);
395
396/* Similarly, but load into new temporaries.  */
397extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
398
399/* Move a non-consecutive group of registers represented by a PARALLEL into
400   a non-consecutive group of registers represented by a PARALLEL.  */
401extern void emit_group_move (rtx, rtx);
402
403/* Move a group of registers represented by a PARALLEL into pseudos.  */
404extern rtx emit_group_move_into_temps (rtx);
405
406/* Store a BLKmode value from non-consecutive registers represented by a
407   PARALLEL.  */
408extern void emit_group_store (rtx, rtx, tree, int);
409
410/* Copy BLKmode object from a set of registers.  */
411extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
412
413/* Mark REG as holding a parameter for the next CALL_INSN.  */
414extern void use_reg (rtx *, rtx);
415
416/* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
417   for the next CALL_INSN.  */
418extern void use_regs (rtx *, int, int);
419
420/* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
421extern void use_group_regs (rtx *, rtx);
422
423/* Write zeros through the storage of OBJECT.
424   If OBJECT has BLKmode, SIZE is its length in bytes.  */
425extern rtx clear_storage (rtx, rtx, enum block_op_methods);
426
427/* Expand a setmem pattern; return true if successful.  */
428extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int);
429
430/* Determine whether the LEN bytes can be moved by using several move
431   instructions.  Return nonzero if a call to move_by_pieces should
432   succeed.  */
433extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
434
435/* Return nonzero if it is desirable to store LEN bytes generated by
436   CONSTFUN with several move instructions by store_by_pieces
437   function.  CONSTFUNDATA is a pointer which will be passed as argument
438   in every CONSTFUN call.
439   ALIGN is maximum alignment we can assume.  */
440extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
441				rtx (*) (void *, HOST_WIDE_INT,
442					 enum machine_mode),
443				void *, unsigned int);
444
445/* Generate several move instructions to store LEN bytes generated by
446   CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
447   pointer which will be passed as argument in every CONSTFUN call.
448   ALIGN is maximum alignment we can assume.
449   Returns TO + LEN.  */
450extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
451			    rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
452			    void *, unsigned int, int);
453
454/* Emit insns to set X from Y.  */
455extern rtx emit_move_insn (rtx, rtx);
456
457/* Emit insns to set X from Y, with no frills.  */
458extern rtx emit_move_insn_1 (rtx, rtx);
459
460/* Push a block of length SIZE (perhaps variable)
461   and return an rtx to address the beginning of the block.  */
462extern rtx push_block (rtx, int, int);
463
464/* Generate code to push something onto the stack, given its mode and type.  */
465extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
466			    int, rtx, int, rtx, rtx, int, rtx);
467
468/* Expand an assignment that stores the value of FROM into TO.  */
469extern void expand_assignment (tree, tree);
470
471/* Generate code for computing expression EXP,
472   and storing the value into TARGET.
473   If SUGGEST_REG is nonzero, copy the value through a register
474   and return that register, if that is possible.  */
475extern rtx store_expr (tree, rtx, int);
476
477/* Given an rtx that may include add and multiply operations,
478   generate them as insns and return a pseudo-reg containing the value.
479   Useful after calling expand_expr with 1 as sum_ok.  */
480extern rtx force_operand (rtx, rtx);
481
482/* Work horse for expand_expr.  */
483extern rtx expand_expr_real (tree, rtx, enum machine_mode,
484			     enum expand_modifier, rtx *);
485
486/* Generate code for computing expression EXP.
487   An rtx for the computed value is returned.  The value is never null.
488   In the case of a void EXP, const0_rtx is returned.  */
489static inline rtx
490expand_expr (tree exp, rtx target, enum machine_mode mode,
491	     enum expand_modifier modifier)
492{
493  return expand_expr_real (exp, target, mode, modifier, NULL);
494}
495
496static inline rtx
497expand_normal (tree exp)
498{
499  return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL);
500}
501
502extern void expand_var (tree);
503
504/* At the start of a function, record that we have no previously-pushed
505   arguments waiting to be popped.  */
506extern void init_pending_stack_adjust (void);
507
508/* Discard any pending stack adjustment.  */
509extern void discard_pending_stack_adjust (void);
510
511/* When exiting from function, if safe, clear out any pending stack adjust
512   so the adjustment won't get done.  */
513extern void clear_pending_stack_adjust (void);
514
515/* Pop any previously-pushed arguments that have not been popped yet.  */
516extern void do_pending_stack_adjust (void);
517
518/* Return the tree node and offset if a given argument corresponds to
519   a string constant.  */
520extern tree string_constant (tree, tree *);
521
522/* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
523extern void jumpifnot (tree, rtx);
524
525/* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
526extern void jumpif (tree, rtx);
527
528/* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
529   the result is zero, or IF_TRUE_LABEL if the result is one.  */
530extern void do_jump (tree, rtx, rtx);
531
532/* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
533extern rtx compare_from_rtx (rtx, rtx, enum rtx_code, int, enum machine_mode,
534			     rtx);
535extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
536				     enum machine_mode, rtx, rtx, rtx);
537
538/* Two different ways of generating switch statements.  */
539extern int try_casesi (tree, tree, tree, tree, rtx, rtx);
540extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
541
542/* Smallest number of adjacent cases before we use a jump table.
543   XXX Should be a target hook.  */
544extern unsigned int case_values_threshold (void);
545
546/* Functions from alias.c */
547#include "alias.h"
548
549
550/* rtl.h and tree.h were included.  */
551/* Return an rtx for the size in bytes of the value of an expr.  */
552extern rtx expr_size (tree);
553
554/* Return a wide integer for the size in bytes of the value of EXP, or -1
555   if the size can vary or is larger than an integer.  */
556extern HOST_WIDE_INT int_expr_size (tree);
557
558/* Return an rtx that refers to the value returned by a function
559   in its original home.  This becomes invalid if any more code is emitted.  */
560extern rtx hard_function_value (tree, tree, tree, int);
561
562extern rtx prepare_call_address (rtx, rtx, rtx *, int, int);
563
564extern bool shift_return_value (enum machine_mode, bool, rtx);
565
566extern rtx expand_call (tree, rtx, int);
567
568extern void fixup_tail_calls (void);
569
570#ifdef TREE_CODE
571extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
572			 int);
573extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
574			  rtx, int);
575#endif
576
577extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
578				 struct args_size *,
579				 struct locate_and_pad_arg_data *);
580
581/* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
582extern rtx label_rtx (tree);
583
584/* As label_rtx, but additionally the label is placed on the forced label
585   list of its containing function (i.e. it is treated as reachable even
586   if how is not obvious).  */
587extern rtx force_label_rtx (tree);
588
589/* Indicate how an input argument register was promoted.  */
590extern rtx promoted_input_arg (unsigned int, enum machine_mode *, int *);
591
592/* Return an rtx like arg but sans any constant terms.
593   Returns the original rtx if it has no constant terms.
594   The constant terms are added and stored via a second arg.  */
595extern rtx eliminate_constant_term (rtx, rtx *);
596
597/* Convert arg to a valid memory address for specified machine mode,
598   by emitting insns to perform arithmetic if nec.  */
599extern rtx memory_address (enum machine_mode, rtx);
600
601/* Like `memory_address' but pretend `flag_force_addr' is 0.  */
602extern rtx memory_address_noforce (enum machine_mode, rtx);
603
604/* Return a memory reference like MEMREF, but with its mode changed
605   to MODE and its address changed to ADDR.
606   (VOIDmode means don't change the mode.
607   NULL for ADDR means don't change the address.)  */
608extern rtx change_address (rtx, enum machine_mode, rtx);
609
610/* Return a memory reference like MEMREF, but with its mode changed
611   to MODE and its address offset by OFFSET bytes.  */
612#define adjust_address(MEMREF, MODE, OFFSET) \
613  adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
614
615/* Likewise, but the reference is not required to be valid.  */
616#define adjust_address_nv(MEMREF, MODE, OFFSET) \
617  adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
618
619/* Return a memory reference like MEMREF, but with its mode changed
620   to MODE and its address changed to ADDR, which is assumed to be
621   increased by OFFSET bytes from MEMREF.  */
622#define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
623  adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
624
625/* Likewise, but the reference is not required to be valid.  */
626#define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
627  adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
628
629extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
630extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
631					HOST_WIDE_INT, int);
632
633/* Return a memory reference like MEMREF, but whose address is changed by
634   adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
635   known to be in OFFSET (possibly 1).  */
636extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
637
638/* Definitions from emit-rtl.c */
639#include "emit-rtl.h"
640
641/* Return a memory reference like MEMREF, but with its mode widened to
642   MODE and adjusted by OFFSET.  */
643extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
644
645/* Return a memory reference like MEMREF, but which is known to have a
646   valid address.  */
647extern rtx validize_mem (rtx);
648
649extern rtx use_anchored_address (rtx);
650
651/* Given REF, a MEM, and T, either the type of X or the expression
652   corresponding to REF, set the memory attributes.  OBJECTP is nonzero
653   if we are making a new object of this type.  */
654extern void set_mem_attributes (rtx, tree, int);
655
656/* Similar, except that BITPOS has not yet been applied to REF, so if
657   we alter MEM_OFFSET according to T then we should subtract BITPOS
658   expecting that it'll be added back in later.  */
659extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
660
661/* Assemble the static constant template for function entry trampolines.  */
662extern rtx assemble_trampoline_template (void);
663
664/* Copy given rtx to a new temp reg and return that.  */
665extern rtx copy_to_reg (rtx);
666
667/* Like copy_to_reg but always make the reg Pmode.  */
668extern rtx copy_addr_to_reg (rtx);
669
670/* Like copy_to_reg but always make the reg the specified mode MODE.  */
671extern rtx copy_to_mode_reg (enum machine_mode, rtx);
672
673/* Copy given rtx to given temp reg and return that.  */
674extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
675
676/* Copy a value to a register if it isn't already a register.
677   Args are mode (in case value is a constant) and the value.  */
678extern rtx force_reg (enum machine_mode, rtx);
679
680/* Return given rtx, copied into a new temp reg if it was in memory.  */
681extern rtx force_not_mem (rtx);
682
683/* Return mode and signedness to use when object is promoted.  */
684extern enum machine_mode promote_mode (tree, enum machine_mode, int *, int);
685
686/* Remove some bytes from the stack.  An rtx says how many.  */
687extern void adjust_stack (rtx);
688
689/* Add some bytes to the stack.  An rtx says how many.  */
690extern void anti_adjust_stack (rtx);
691
692/* This enum is used for the following two functions.  */
693enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
694
695/* Save the stack pointer at the specified level.  */
696extern void emit_stack_save (enum save_level, rtx *, rtx);
697
698/* Restore the stack pointer from a save area of the specified level.  */
699extern void emit_stack_restore (enum save_level, rtx, rtx);
700
701/* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
702extern void update_nonlocal_goto_save_area (void);
703
704/* Allocate some space on the stack dynamically and return its address.  An rtx
705   says how many bytes.  */
706extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
707
708/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
709   FIRST is a constant and size is a Pmode RTX.  These are offsets from the
710   current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
711   subtract from the stack.  If SIZE is constant, this is done
712   with a fixed number of probes.  Otherwise, we must make a loop.  */
713extern void probe_stack_range (HOST_WIDE_INT, rtx);
714
715/* Return an rtx that refers to the value returned by a library call
716   in its original home.  This becomes invalid if any more code is emitted.  */
717extern rtx hard_libcall_value (enum machine_mode);
718
719/* Return the mode desired by operand N of a particular bitfield
720   insert/extract insn, or MAX_MACHINE_MODE if no such insn is
721   available.  */
722
723enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
724extern enum machine_mode
725mode_for_extraction (enum extraction_pattern, int);
726
727extern rtx store_bit_field (rtx, unsigned HOST_WIDE_INT,
728			    unsigned HOST_WIDE_INT, enum machine_mode, rtx);
729extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
730			      unsigned HOST_WIDE_INT, int, rtx,
731			      enum machine_mode, enum machine_mode);
732extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
733extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
734
735extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
736extern int safe_from_p (rtx, tree, int);
737
738/* Call this once to initialize the contents of the optabs
739   appropriately for the current target machine.  */
740extern void init_optabs (void);
741extern void init_all_optabs (void);
742
743/* Call this to initialize an optab function entry.  */
744extern rtx init_one_libfunc (const char *);
745
746extern int vector_mode_valid_p (enum machine_mode);
747
748#endif /* GCC_EXPR_H */
749