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, 2007, 2008, 2009, 2010
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 3, 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 COPYING3.  If not see
20<http://www.gnu.org/licenses/>.  */
21
22#ifndef GCC_EXPR_H
23#define GCC_EXPR_H
24
25/* For inhibit_defer_pop */
26#include "function.h"
27/* For XEXP, GEN_INT, rtx_code */
28#include "rtl.h"
29/* For optimize_size */
30#include "flags.h"
31/* For host_integerp, tree_low_cst, fold_convert, size_binop, ssize_int,
32   TREE_CODE, TYPE_SIZE, int_size_in_bytes,    */
33#include "tree.h"
34/* For GET_MODE_BITSIZE, word_mode */
35#include "machmode.h"
36
37/* The default branch cost is 1.  */
38#ifndef BRANCH_COST
39#define BRANCH_COST(speed_p, predictable_p) 1
40#endif
41
42/* This is the 4th arg to `expand_expr'.
43   EXPAND_STACK_PARM means we are possibly expanding a call param onto
44   the stack.
45   EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
46   EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
47   EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
48    is a constant that is not a legitimate address.
49   EXPAND_WRITE means we are only going to write to the resulting rtx.
50   EXPAND_MEMORY means we are interested in a memory result, even if
51    the memory is constant and we could have propagated a constant value.  */
52enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
53		      EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
54		      EXPAND_MEMORY};
55
56/* Prevent the compiler from deferring stack pops.  See
57   inhibit_defer_pop for more information.  */
58#define NO_DEFER_POP (inhibit_defer_pop += 1)
59
60/* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
61   more information.  */
62#define OK_DEFER_POP (inhibit_defer_pop -= 1)
63
64/* If a memory-to-memory move would take MOVE_RATIO or more simple
65   move-instruction sequences, we will do a movmem or libcall instead.  */
66
67#ifndef MOVE_RATIO
68#if defined (HAVE_movmemqi) || defined (HAVE_movmemhi) || defined (HAVE_movmemsi) || defined (HAVE_movmemdi) || defined (HAVE_movmemti)
69#define MOVE_RATIO(speed) 2
70#else
71/* If we are optimizing for space (-Os), cut down the default move ratio.  */
72#define MOVE_RATIO(speed) ((speed) ? 15 : 3)
73#endif
74#endif
75
76/* If a clear memory operation would take CLEAR_RATIO or more simple
77   move-instruction sequences, we will do a setmem or libcall instead.  */
78
79#ifndef CLEAR_RATIO
80#if defined (HAVE_setmemqi) || defined (HAVE_setmemhi) || defined (HAVE_setmemsi) || defined (HAVE_setmemdi) || defined (HAVE_setmemti)
81#define CLEAR_RATIO(speed) 2
82#else
83/* If we are optimizing for space, cut down the default clear ratio.  */
84#define CLEAR_RATIO(speed) ((speed) ? 15 :3)
85#endif
86#endif
87
88/* If a memory set (to value other than zero) operation would take
89   SET_RATIO or more simple move-instruction sequences, we will do a movmem
90   or libcall instead.  */
91#ifndef SET_RATIO
92#define SET_RATIO(speed) MOVE_RATIO(speed)
93#endif
94
95enum direction {none, upward, downward};
96
97/* Structure to record the size of a sequence of arguments
98   as the sum of a tree-expression and a constant.  This structure is
99   also used to store offsets from the stack, which might be negative,
100   so the variable part must be ssizetype, not sizetype.  */
101
102struct args_size
103{
104  HOST_WIDE_INT constant;
105  tree var;
106};
107
108/* Package up various arg related fields of struct args for
109   locate_and_pad_parm.  */
110struct locate_and_pad_arg_data
111{
112  /* Size of this argument on the stack, rounded up for any padding it
113     gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
114     counted here, otherwise they aren't.  */
115  struct args_size size;
116  /* Offset of this argument from beginning of stack-args.  */
117  struct args_size offset;
118  /* Offset to the start of the stack slot.  Different from OFFSET
119     if this arg pads downward.  */
120  struct args_size slot_offset;
121  /* The amount that the stack pointer needs to be adjusted to
122     force alignment for the next argument.  */
123  struct args_size alignment_pad;
124  /* Which way we should pad this arg.  */
125  enum direction where_pad;
126  /* slot_offset is at least this aligned.  */
127  unsigned int boundary;
128};
129
130/* Add the value of the tree INC to the `struct args_size' TO.  */
131
132#define ADD_PARM_SIZE(TO, INC)					\
133do {								\
134  tree inc = (INC);						\
135  if (host_integerp (inc, 0))					\
136    (TO).constant += tree_low_cst (inc, 0);			\
137  else if ((TO).var == 0)					\
138    (TO).var = fold_convert (ssizetype, inc);			\
139  else								\
140    (TO).var = size_binop (PLUS_EXPR, (TO).var,			\
141			   fold_convert (ssizetype, inc));	\
142} while (0)
143
144#define SUB_PARM_SIZE(TO, DEC)					\
145do {								\
146  tree dec = (DEC);						\
147  if (host_integerp (dec, 0))					\
148    (TO).constant -= tree_low_cst (dec, 0);			\
149  else if ((TO).var == 0)					\
150    (TO).var = size_binop (MINUS_EXPR, ssize_int (0),		\
151			   fold_convert (ssizetype, dec));	\
152  else								\
153    (TO).var = size_binop (MINUS_EXPR, (TO).var,		\
154			   fold_convert (ssizetype, dec));	\
155} while (0)
156
157/* Convert the implicit sum in a `struct args_size' into a tree
158   of type ssizetype.  */
159#define ARGS_SIZE_TREE(SIZE)					\
160((SIZE).var == 0 ? ssize_int ((SIZE).constant)			\
161 : size_binop (PLUS_EXPR, fold_convert (ssizetype, (SIZE).var),	\
162	       ssize_int ((SIZE).constant)))
163
164/* Convert the implicit sum in a `struct args_size' into an rtx.  */
165#define ARGS_SIZE_RTX(SIZE)					\
166((SIZE).var == 0 ? GEN_INT ((SIZE).constant)			\
167 : expand_normal (ARGS_SIZE_TREE (SIZE)))
168
169/* Supply a default definition for FUNCTION_ARG_PADDING:
170   usually pad upward, but pad short args downward on
171   big-endian machines.  */
172
173#define DEFAULT_FUNCTION_ARG_PADDING(MODE, TYPE)			\
174  (! BYTES_BIG_ENDIAN							\
175   ? upward								\
176   : (((MODE) == BLKmode						\
177       ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST		\
178	  && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
179       : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)			\
180      ? downward : upward))
181
182#ifndef FUNCTION_ARG_PADDING
183#define FUNCTION_ARG_PADDING(MODE, TYPE)	\
184  DEFAULT_FUNCTION_ARG_PADDING ((MODE), (TYPE))
185#endif
186
187/* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
188   FUNCTION_ARG_PADDING, which also pads the length, handle any needed
189   alignment.  */
190
191#ifndef FUNCTION_ARG_BOUNDARY
192#define FUNCTION_ARG_BOUNDARY(MODE, TYPE)	PARM_BOUNDARY
193#endif
194
195/* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
196   Normally move_insn, so Pmode stack pointer.  */
197
198#ifndef STACK_SAVEAREA_MODE
199#define STACK_SAVEAREA_MODE(LEVEL) Pmode
200#endif
201
202/* Supply a default definition of STACK_SIZE_MODE for
203   allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
204
205#ifndef STACK_SIZE_MODE
206#define STACK_SIZE_MODE word_mode
207#endif
208
209/* Provide default values for the macros controlling stack checking.  */
210
211/* The default is neither full builtin stack checking...  */
212#ifndef STACK_CHECK_BUILTIN
213#define STACK_CHECK_BUILTIN 0
214#endif
215
216/* ...nor static builtin stack checking.  */
217#ifndef STACK_CHECK_STATIC_BUILTIN
218#define STACK_CHECK_STATIC_BUILTIN 0
219#endif
220
221/* The default interval is one page (4096 bytes).  */
222#ifndef STACK_CHECK_PROBE_INTERVAL_EXP
223#define STACK_CHECK_PROBE_INTERVAL_EXP 12
224#endif
225
226/* The default is not to move the stack pointer.  */
227#ifndef STACK_CHECK_MOVING_SP
228#define STACK_CHECK_MOVING_SP 0
229#endif
230
231/* This is a kludge to try to capture the discrepancy between the old
232   mechanism (generic stack checking) and the new mechanism (static
233   builtin stack checking).  STACK_CHECK_PROTECT needs to be bumped
234   for the latter because part of the protection area is effectively
235   included in STACK_CHECK_MAX_FRAME_SIZE for the former.  */
236#ifdef STACK_CHECK_PROTECT
237#define STACK_OLD_CHECK_PROTECT STACK_CHECK_PROTECT
238#else
239#define STACK_OLD_CHECK_PROTECT \
240 (USING_SJLJ_EXCEPTIONS ? 75 * UNITS_PER_WORD : 8 * 1024)
241#endif
242
243/* Minimum amount of stack required to recover from an anticipated stack
244   overflow detection.  The default value conveys an estimate of the amount
245   of stack required to propagate an exception.  */
246#ifndef STACK_CHECK_PROTECT
247#define STACK_CHECK_PROTECT \
248 (USING_SJLJ_EXCEPTIONS ? 75 * UNITS_PER_WORD : 12 * 1024)
249#endif
250
251/* Make the maximum frame size be the largest we can and still only need
252   one probe per function.  */
253#ifndef STACK_CHECK_MAX_FRAME_SIZE
254#define STACK_CHECK_MAX_FRAME_SIZE \
255  ((1 << STACK_CHECK_PROBE_INTERVAL_EXP) - UNITS_PER_WORD)
256#endif
257
258/* This is arbitrary, but should be large enough everywhere.  */
259#ifndef STACK_CHECK_FIXED_FRAME_SIZE
260#define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
261#endif
262
263/* Provide a reasonable default for the maximum size of an object to
264   allocate in the fixed frame.  We may need to be able to make this
265   controllable by the user at some point.  */
266#ifndef STACK_CHECK_MAX_VAR_SIZE
267#define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
268#endif
269
270/* This structure is used to pass around information about exploded
271   unary, binary and trinary expressions between expand_expr_real_1 and
272   friends.  */
273typedef struct separate_ops
274{
275  enum tree_code code;
276  tree type;
277  tree op0, op1, op2;
278  location_t location;
279} *sepops;
280
281/* Functions from optabs.c, commonly used, and without need for the optabs
282   tables:  */
283
284/* Passed to expand_simple_binop and expand_binop to say which options
285   to try to use if the requested operation can't be open-coded on the
286   requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
287   a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
288   using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
289   try anything else.  */
290
291enum optab_methods
292{
293  OPTAB_DIRECT,
294  OPTAB_LIB,
295  OPTAB_WIDEN,
296  OPTAB_LIB_WIDEN,
297  OPTAB_MUST_WIDEN
298};
299
300/* Generate code for a simple binary or unary operation.  "Simple" in
301   this case means "can be unambiguously described by a (mode, code)
302   pair and mapped to a single optab."  */
303extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
304				rtx, rtx, int, enum optab_methods);
305extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
306			       int);
307
308/* Report whether the machine description contains an insn which can
309   perform the operation described by CODE and MODE.  */
310extern int have_insn_for (enum rtx_code, enum machine_mode);
311
312extern rtx prepare_operand (int, rtx, int, enum machine_mode, enum machine_mode,
313			    int);
314
315/* Emit code to make a call to a constant function or a library call.  */
316extern void emit_libcall_block (rtx, rtx, rtx, rtx);
317
318/* Create but don't emit one rtl instruction to perform certain operations.
319   Modes must match; operands must meet the operation's predicates.
320   Likewise for subtraction and for just copying.  */
321extern rtx gen_add2_insn (rtx, rtx);
322extern rtx gen_add3_insn (rtx, rtx, rtx);
323extern rtx gen_sub2_insn (rtx, rtx);
324extern rtx gen_sub3_insn (rtx, rtx, rtx);
325extern rtx gen_move_insn (rtx, rtx);
326extern int have_add2_insn (rtx, rtx);
327extern int have_sub2_insn (rtx, rtx);
328
329/* Emit a pair of rtl insns to compare two rtx's and to jump
330   to a label if the comparison is true.  */
331extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
332				     enum machine_mode, int, rtx);
333
334/* Generate code to indirectly jump to a location given in the rtx LOC.  */
335extern void emit_indirect_jump (rtx);
336
337/* Generate a conditional trap instruction.  */
338extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
339
340#include "insn-config.h"
341
342#ifdef HAVE_conditional_move
343/* Emit a conditional move operation.  */
344rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
345			   rtx, rtx, enum machine_mode, int);
346
347/* Return nonzero if the conditional move is supported.  */
348int can_conditionally_move_p (enum machine_mode mode);
349
350#endif
351rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
352			  rtx, rtx, enum machine_mode, int);
353
354rtx expand_val_compare_and_swap (rtx, rtx, rtx, rtx);
355rtx expand_bool_compare_and_swap (rtx, rtx, rtx, rtx);
356rtx expand_sync_operation (rtx, rtx, enum rtx_code);
357rtx expand_sync_fetch_operation (rtx, rtx, enum rtx_code, bool, rtx);
358rtx expand_sync_lock_test_and_set (rtx, rtx, rtx);
359
360/* Functions from expmed.c:  */
361
362/* Arguments MODE, RTX: return an rtx for the negation of that value.
363   May emit insns.  */
364extern rtx negate_rtx (enum machine_mode, rtx);
365
366/* Expand a logical AND operation.  */
367extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
368
369/* Emit a store-flag operation.  */
370extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
371			    int, int);
372
373/* Like emit_store_flag, but always succeeds.  */
374extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
375				  enum machine_mode, int, int);
376
377/* Functions from builtins.c:  */
378extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
379extern tree std_build_builtin_va_list (void);
380extern tree std_fn_abi_va_list (tree);
381extern tree std_canonical_va_list_type (tree);
382
383extern void std_expand_builtin_va_start (tree, rtx);
384extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
385extern void expand_builtin_setjmp_setup (rtx, rtx);
386extern void expand_builtin_setjmp_receiver (rtx);
387extern rtx expand_builtin_saveregs (void);
388extern void expand_builtin_trap (void);
389extern rtx builtin_strncpy_read_str (void *, HOST_WIDE_INT, enum machine_mode);
390
391/* Functions from expr.c:  */
392
393/* This is run during target initialization to set up which modes can be
394   used directly in memory and to initialize the block move optab.  */
395extern void init_expr_target (void);
396
397/* This is run at the start of compiling a function.  */
398extern void init_expr (void);
399
400/* Emit some rtl insns to move data between rtx's, converting machine modes.
401   Both modes must be floating or both fixed.  */
402extern void convert_move (rtx, rtx, int);
403
404/* Convert an rtx to specified machine mode and return the result.  */
405extern rtx convert_to_mode (enum machine_mode, rtx, int);
406
407/* Convert an rtx to MODE from OLDMODE and return the result.  */
408extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
409
410/* Emit code to move a block Y to a block X.  */
411
412enum block_op_methods
413{
414  BLOCK_OP_NORMAL,
415  BLOCK_OP_NO_LIBCALL,
416  BLOCK_OP_CALL_PARM,
417  /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized.  */
418  BLOCK_OP_TAILCALL
419};
420
421extern GTY(()) tree block_clear_fn;
422extern void init_block_move_fn (const char *);
423extern void init_block_clear_fn (const char *);
424
425extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
426extern rtx emit_block_move_via_libcall (rtx, rtx, rtx, bool);
427extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
428			          unsigned int, HOST_WIDE_INT);
429extern bool emit_storent_insn (rtx to, rtx from);
430
431/* Copy all or part of a value X into registers starting at REGNO.
432   The number of registers to be filled is NREGS.  */
433extern void move_block_to_reg (int, rtx, int, enum machine_mode);
434
435/* Copy all or part of a BLKmode value X out of registers starting at REGNO.
436   The number of registers to be filled is NREGS.  */
437extern void move_block_from_reg (int, rtx, int);
438
439/* Generate a non-consecutive group of registers represented by a PARALLEL.  */
440extern rtx gen_group_rtx (rtx);
441
442/* Load a BLKmode value into non-consecutive registers represented by a
443   PARALLEL.  */
444extern void emit_group_load (rtx, rtx, tree, int);
445
446/* Similarly, but load into new temporaries.  */
447extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
448
449/* Move a non-consecutive group of registers represented by a PARALLEL into
450   a non-consecutive group of registers represented by a PARALLEL.  */
451extern void emit_group_move (rtx, rtx);
452
453/* Move a group of registers represented by a PARALLEL into pseudos.  */
454extern rtx emit_group_move_into_temps (rtx);
455
456/* Store a BLKmode value from non-consecutive registers represented by a
457   PARALLEL.  */
458extern void emit_group_store (rtx, rtx, tree, int);
459
460/* Copy BLKmode object from a set of registers.  */
461extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
462
463/* Mark REG as holding a parameter for the next CALL_INSN.  */
464extern void use_reg (rtx *, rtx);
465
466/* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
467   for the next CALL_INSN.  */
468extern void use_regs (rtx *, int, int);
469
470/* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
471extern void use_group_regs (rtx *, rtx);
472
473/* Write zeros through the storage of OBJECT.
474   If OBJECT has BLKmode, SIZE is its length in bytes.  */
475extern rtx clear_storage (rtx, rtx, enum block_op_methods);
476extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
477			        unsigned int, HOST_WIDE_INT);
478/* The same, but always output an library call.  */
479rtx set_storage_via_libcall (rtx, rtx, rtx, bool);
480
481/* Expand a setmem pattern; return true if successful.  */
482extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
483				    unsigned int, HOST_WIDE_INT);
484
485/* Determine whether the LEN bytes can be moved by using several move
486   instructions.  Return nonzero if a call to move_by_pieces should
487   succeed.  */
488extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
489
490/* Return nonzero if it is desirable to store LEN bytes generated by
491   CONSTFUN with several move instructions by store_by_pieces
492   function.  CONSTFUNDATA is a pointer which will be passed as argument
493   in every CONSTFUN call.
494   ALIGN is maximum alignment we can assume.
495   MEMSETP is true if this is a real memset/bzero, not a copy
496   of a const string.  */
497extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
498				rtx (*) (void *, HOST_WIDE_INT,
499					 enum machine_mode),
500				void *, unsigned int, bool);
501
502/* Generate several move instructions to store LEN bytes generated by
503   CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
504   pointer which will be passed as argument in every CONSTFUN call.
505   ALIGN is maximum alignment we can assume.
506   MEMSETP is true if this is a real memset/bzero, not a copy.
507   Returns TO + LEN.  */
508extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
509			    rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
510			    void *, unsigned int, bool, int);
511
512/* Emit insns to set X from Y.  */
513extern rtx emit_move_insn (rtx, rtx);
514
515/* Emit insns to set X from Y, with no frills.  */
516extern rtx emit_move_insn_1 (rtx, rtx);
517
518extern rtx emit_move_complex_push (enum machine_mode, rtx, rtx);
519extern rtx emit_move_complex_parts (rtx, rtx);
520
521/* Push a block of length SIZE (perhaps variable)
522   and return an rtx to address the beginning of the block.  */
523extern rtx push_block (rtx, int, int);
524
525/* Generate code to push something onto the stack, given its mode and type.  */
526extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
527			    int, rtx, int, rtx, rtx, int, rtx);
528
529/* Expand an assignment that stores the value of FROM into TO.  */
530extern void expand_assignment (tree, tree, bool);
531
532/* Generate code for computing expression EXP,
533   and storing the value into TARGET.
534   If SUGGEST_REG is nonzero, copy the value through a register
535   and return that register, if that is possible.  */
536extern rtx store_expr (tree, rtx, int, bool);
537
538/* Given an rtx that may include add and multiply operations,
539   generate them as insns and return a pseudo-reg containing the value.
540   Useful after calling expand_expr with 1 as sum_ok.  */
541extern rtx force_operand (rtx, rtx);
542
543/* Work horses for expand_expr.  */
544extern rtx expand_expr_real (tree, rtx, enum machine_mode,
545			     enum expand_modifier, rtx *);
546extern rtx expand_expr_real_1 (tree, rtx, enum machine_mode,
547			       enum expand_modifier, rtx *);
548extern rtx expand_expr_real_2 (sepops, rtx, enum machine_mode,
549			       enum expand_modifier);
550
551/* Generate code for computing expression EXP.
552   An rtx for the computed value is returned.  The value is never null.
553   In the case of a void EXP, const0_rtx is returned.  */
554static inline rtx
555expand_expr (tree exp, rtx target, enum machine_mode mode,
556	     enum expand_modifier modifier)
557{
558  return expand_expr_real (exp, target, mode, modifier, NULL);
559}
560
561static inline rtx
562expand_normal (tree exp)
563{
564  return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL);
565}
566
567/* At the start of a function, record that we have no previously-pushed
568   arguments waiting to be popped.  */
569extern void init_pending_stack_adjust (void);
570
571/* Discard any pending stack adjustment.  */
572extern void discard_pending_stack_adjust (void);
573
574/* When exiting from function, if safe, clear out any pending stack adjust
575   so the adjustment won't get done.  */
576extern void clear_pending_stack_adjust (void);
577
578/* Pop any previously-pushed arguments that have not been popped yet.  */
579extern void do_pending_stack_adjust (void);
580
581/* Return the tree node and offset if a given argument corresponds to
582   a string constant.  */
583extern tree string_constant (tree, tree *);
584
585/* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
586extern void jumpifnot (tree, rtx, int);
587extern void jumpifnot_1 (enum tree_code, tree, tree, rtx, int);
588
589/* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
590extern void jumpif (tree, rtx, int);
591extern void jumpif_1 (enum tree_code, tree, tree, rtx, int);
592
593/* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
594   the result is zero, or IF_TRUE_LABEL if the result is one.  */
595extern void do_jump (tree, rtx, rtx, int);
596extern void do_jump_1 (enum tree_code, tree, tree, rtx, rtx, int);
597
598extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
599				     enum machine_mode, rtx, rtx, rtx, int);
600
601/* Two different ways of generating switch statements.  */
602extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx);
603extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
604
605/* Functions from alias.c */
606#include "alias.h"
607
608
609/* rtl.h and tree.h were included.  */
610/* Return an rtx for the size in bytes of the value of an expr.  */
611extern rtx expr_size (tree);
612
613/* Return a wide integer for the size in bytes of the value of EXP, or -1
614   if the size can vary or is larger than an integer.  */
615extern HOST_WIDE_INT int_expr_size (tree);
616
617/* Return an rtx that refers to the value returned by a function
618   in its original home.  This becomes invalid if any more code is emitted.  */
619extern rtx hard_function_value (const_tree, const_tree, const_tree, int);
620
621extern rtx prepare_call_address (tree, rtx, rtx, rtx *, int, int);
622
623extern bool shift_return_value (enum machine_mode, bool, rtx);
624
625extern rtx expand_call (tree, rtx, int);
626
627extern void fixup_tail_calls (void);
628
629#ifdef TREE_CODE
630extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
631			 int);
632extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
633			  rtx, int);
634#endif
635
636extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
637				 struct args_size *,
638				 struct locate_and_pad_arg_data *);
639
640/* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
641extern rtx label_rtx (tree);
642
643/* As label_rtx, but additionally the label is placed on the forced label
644   list of its containing function (i.e. it is treated as reachable even
645   if how is not obvious).  */
646extern rtx force_label_rtx (tree);
647
648/* Return an rtx like arg but sans any constant terms.
649   Returns the original rtx if it has no constant terms.
650   The constant terms are added and stored via a second arg.  */
651extern rtx eliminate_constant_term (rtx, rtx *);
652
653/* Convert arg to a valid memory address for specified machine mode that points
654   to a specific named address space, by emitting insns to perform arithmetic
655   if necessary.  */
656extern rtx memory_address_addr_space (enum machine_mode, rtx, addr_space_t);
657
658/* Like memory_address_addr_space, except assume the memory address points to
659   the generic named address space.  */
660#define memory_address(MODE,RTX) \
661	memory_address_addr_space ((MODE), (RTX), ADDR_SPACE_GENERIC)
662
663/* Return a memory reference like MEMREF, but with its mode changed
664   to MODE and its address changed to ADDR.
665   (VOIDmode means don't change the mode.
666   NULL for ADDR means don't change the address.)  */
667extern rtx change_address (rtx, enum machine_mode, rtx);
668
669/* Return a memory reference like MEMREF, but with its mode changed
670   to MODE and its address offset by OFFSET bytes.  */
671#define adjust_address(MEMREF, MODE, OFFSET) \
672  adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
673
674/* Likewise, but the reference is not required to be valid.  */
675#define adjust_address_nv(MEMREF, MODE, OFFSET) \
676  adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
677
678/* Return a memory reference like MEMREF, but with its mode changed
679   to MODE and its address changed to ADDR, which is assumed to be
680   increased by OFFSET bytes from MEMREF.  */
681#define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
682  adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
683
684/* Likewise, but the reference is not required to be valid.  */
685#define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
686  adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
687
688extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
689extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
690					HOST_WIDE_INT, int);
691
692/* Return a memory reference like MEMREF, but whose address is changed by
693   adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
694   known to be in OFFSET (possibly 1).  */
695extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
696
697/* Definitions from emit-rtl.c */
698#include "emit-rtl.h"
699
700/* Return a memory reference like MEMREF, but with its mode widened to
701   MODE and adjusted by OFFSET.  */
702extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
703
704/* Return a memory reference like MEMREF, but which is known to have a
705   valid address.  */
706extern rtx validize_mem (rtx);
707
708extern rtx use_anchored_address (rtx);
709
710/* Given REF, a MEM, and T, either the type of X or the expression
711   corresponding to REF, set the memory attributes.  OBJECTP is nonzero
712   if we are making a new object of this type.  */
713extern void set_mem_attributes (rtx, tree, int);
714
715/* Similar, except that BITPOS has not yet been applied to REF, so if
716   we alter MEM_OFFSET according to T then we should subtract BITPOS
717   expecting that it'll be added back in later.  */
718extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
719
720/* Return OFFSET if XEXP (MEM, 0) - OFFSET is known to be ALIGN
721   bits aligned for 0 <= OFFSET < ALIGN / BITS_PER_UNIT, or
722   -1 if not known.  */
723extern int get_mem_align_offset (rtx, unsigned int);
724
725/* Assemble the static constant template for function entry trampolines.  */
726extern rtx assemble_trampoline_template (void);
727
728/* Copy given rtx to a new temp reg and return that.  */
729extern rtx copy_to_reg (rtx);
730
731/* Like copy_to_reg but always make the reg Pmode.  */
732extern rtx copy_addr_to_reg (rtx);
733
734/* Like copy_to_reg but always make the reg the specified mode MODE.  */
735extern rtx copy_to_mode_reg (enum machine_mode, rtx);
736
737/* Copy given rtx to given temp reg and return that.  */
738extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
739
740/* Copy a value to a register if it isn't already a register.
741   Args are mode (in case value is a constant) and the value.  */
742extern rtx force_reg (enum machine_mode, rtx);
743
744/* Return given rtx, copied into a new temp reg if it was in memory.  */
745extern rtx force_not_mem (rtx);
746
747/* Return mode and signedness to use when an argument or result in the
748   given mode is promoted.  */
749extern enum machine_mode promote_function_mode (const_tree, enum machine_mode, int *,
750					        const_tree, int);
751
752/* Return mode and signedness to use when an object in the given mode
753   is promoted.  */
754extern enum machine_mode promote_mode (const_tree, enum machine_mode, int *);
755
756/* Return mode and signedness to use when object is promoted.  */
757enum machine_mode promote_decl_mode (const_tree, int *);
758
759/* Remove some bytes from the stack.  An rtx says how many.  */
760extern void adjust_stack (rtx);
761
762/* Add some bytes to the stack.  An rtx says how many.  */
763extern void anti_adjust_stack (rtx);
764
765/* Add some bytes to the stack while probing it.  An rtx says how many. */
766extern void anti_adjust_stack_and_probe (rtx, bool);
767
768/* This enum is used for the following two functions.  */
769enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
770
771/* Save the stack pointer at the specified level.  */
772extern void emit_stack_save (enum save_level, rtx *, rtx);
773
774/* Restore the stack pointer from a save area of the specified level.  */
775extern void emit_stack_restore (enum save_level, rtx, rtx);
776
777/* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
778extern void update_nonlocal_goto_save_area (void);
779
780/* Allocate some space on the stack dynamically and return its address.  An rtx
781   says how many bytes.  */
782extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
783
784/* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
785   FIRST is a constant and size is a Pmode RTX.  These are offsets from
786   the current stack pointer.  STACK_GROWS_DOWNWARD says whether to add
787   or subtract them from the stack pointer.  */
788extern void probe_stack_range (HOST_WIDE_INT, rtx);
789
790/* Return an rtx that refers to the value returned by a library call
791   in its original home.  This becomes invalid if any more code is emitted.  */
792extern rtx hard_libcall_value (enum machine_mode, rtx);
793
794/* Return the mode desired by operand N of a particular bitfield
795   insert/extract insn, or MAX_MACHINE_MODE if no such insn is
796   available.  */
797
798enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
799extern enum machine_mode
800mode_for_extraction (enum extraction_pattern, int);
801
802extern void store_bit_field (rtx, unsigned HOST_WIDE_INT,
803			     unsigned HOST_WIDE_INT, enum machine_mode, rtx);
804extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
805			      unsigned HOST_WIDE_INT, int, rtx,
806			      enum machine_mode, enum machine_mode);
807extern rtx extract_low_bits (enum machine_mode, enum machine_mode, rtx);
808extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
809extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
810
811extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
812extern int safe_from_p (const_rtx, tree, int);
813extern bool split_comparison (enum rtx_code, enum machine_mode,
814			      enum rtx_code *, enum rtx_code *);
815
816/* Call this once to initialize the contents of the optabs
817   appropriately for the current target machine.  */
818extern void init_optabs (void);
819extern void init_all_optabs (void);
820
821/* Call this to initialize an optab function entry.  */
822extern rtx init_one_libfunc (const char *);
823extern rtx set_user_assembler_libfunc (const char *, const char *);
824
825/* Build a decl for a libfunc named NAME. */
826extern tree build_libfunc_function (const char *);
827
828/* Get the personality libfunc for a function decl.  */
829rtx get_personality_function (tree);
830
831extern int vector_mode_valid_p (enum machine_mode);
832
833#endif /* GCC_EXPR_H */
834