xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/expr.h (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
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 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12 
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16 for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along 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.  */
52 enum 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 
95 enum 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 
102 struct 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.  */
110 struct 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)					\
133 do {								\
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)					\
145 do {								\
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.  */
273 typedef 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 
291 enum 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."  */
303 extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
304 				rtx, rtx, int, enum optab_methods);
305 extern 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.  */
310 extern int have_insn_for (enum rtx_code, enum machine_mode);
311 
312 extern 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.  */
316 extern 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.  */
321 extern rtx gen_add2_insn (rtx, rtx);
322 extern rtx gen_add3_insn (rtx, rtx, rtx);
323 extern rtx gen_sub2_insn (rtx, rtx);
324 extern rtx gen_sub3_insn (rtx, rtx, rtx);
325 extern rtx gen_move_insn (rtx, rtx);
326 extern int have_add2_insn (rtx, rtx);
327 extern 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.  */
331 extern 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.  */
335 extern void emit_indirect_jump (rtx);
336 
337 /* Generate a conditional trap instruction.  */
338 extern 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.  */
344 rtx 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.  */
348 int can_conditionally_move_p (enum machine_mode mode);
349 
350 #endif
351 rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
352 			  rtx, rtx, enum machine_mode, int);
353 
354 rtx expand_val_compare_and_swap (rtx, rtx, rtx, rtx);
355 rtx expand_bool_compare_and_swap (rtx, rtx, rtx, rtx);
356 rtx expand_sync_operation (rtx, rtx, enum rtx_code);
357 rtx expand_sync_fetch_operation (rtx, rtx, enum rtx_code, bool, rtx);
358 rtx 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.  */
364 extern rtx negate_rtx (enum machine_mode, rtx);
365 
366 /* Expand a logical AND operation.  */
367 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
368 
369 /* Emit a store-flag operation.  */
370 extern 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.  */
374 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
375 				  enum machine_mode, int, int);
376 
377 /* Functions from builtins.c:  */
378 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
379 extern tree std_build_builtin_va_list (void);
380 extern tree std_fn_abi_va_list (tree);
381 extern tree std_canonical_va_list_type (tree);
382 
383 extern void std_expand_builtin_va_start (tree, rtx);
384 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
385 extern void expand_builtin_setjmp_setup (rtx, rtx);
386 extern void expand_builtin_setjmp_receiver (rtx);
387 extern rtx expand_builtin_saveregs (void);
388 extern void expand_builtin_trap (void);
389 extern 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.  */
395 extern void init_expr_target (void);
396 
397 /* This is run at the start of compiling a function.  */
398 extern 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.  */
402 extern void convert_move (rtx, rtx, int);
403 
404 /* Convert an rtx to specified machine mode and return the result.  */
405 extern rtx convert_to_mode (enum machine_mode, rtx, int);
406 
407 /* Convert an rtx to MODE from OLDMODE and return the result.  */
408 extern 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 
412 enum 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 
421 extern GTY(()) tree block_clear_fn;
422 extern void init_block_move_fn (const char *);
423 extern void init_block_clear_fn (const char *);
424 
425 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
426 extern rtx emit_block_move_via_libcall (rtx, rtx, rtx, bool);
427 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
428 			          unsigned int, HOST_WIDE_INT);
429 extern 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.  */
433 extern 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.  */
437 extern void move_block_from_reg (int, rtx, int);
438 
439 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
440 extern rtx gen_group_rtx (rtx);
441 
442 /* Load a BLKmode value into non-consecutive registers represented by a
443    PARALLEL.  */
444 extern void emit_group_load (rtx, rtx, tree, int);
445 
446 /* Similarly, but load into new temporaries.  */
447 extern 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.  */
451 extern void emit_group_move (rtx, rtx);
452 
453 /* Move a group of registers represented by a PARALLEL into pseudos.  */
454 extern rtx emit_group_move_into_temps (rtx);
455 
456 /* Store a BLKmode value from non-consecutive registers represented by a
457    PARALLEL.  */
458 extern void emit_group_store (rtx, rtx, tree, int);
459 
460 /* Copy BLKmode object from a set of registers.  */
461 extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
462 
463 extern rtx copy_blkmode_to_reg (enum machine_mode, tree);
464 
465 /* Mark REG as holding a parameter for the next CALL_INSN.  */
466 extern void use_reg (rtx *, rtx);
467 
468 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
469    for the next CALL_INSN.  */
470 extern void use_regs (rtx *, int, int);
471 
472 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
473 extern void use_group_regs (rtx *, rtx);
474 
475 /* Write zeros through the storage of OBJECT.
476    If OBJECT has BLKmode, SIZE is its length in bytes.  */
477 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
478 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
479 			        unsigned int, HOST_WIDE_INT);
480 /* The same, but always output an library call.  */
481 rtx set_storage_via_libcall (rtx, rtx, rtx, bool);
482 
483 /* Expand a setmem pattern; return true if successful.  */
484 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
485 				    unsigned int, HOST_WIDE_INT);
486 
487 /* Determine whether the LEN bytes can be moved by using several move
488    instructions.  Return nonzero if a call to move_by_pieces should
489    succeed.  */
490 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
491 
492 /* Return nonzero if it is desirable to store LEN bytes generated by
493    CONSTFUN with several move instructions by store_by_pieces
494    function.  CONSTFUNDATA is a pointer which will be passed as argument
495    in every CONSTFUN call.
496    ALIGN is maximum alignment we can assume.
497    MEMSETP is true if this is a real memset/bzero, not a copy
498    of a const string.  */
499 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
500 				rtx (*) (void *, HOST_WIDE_INT,
501 					 enum machine_mode),
502 				void *, unsigned int, bool);
503 
504 /* Generate several move instructions to store LEN bytes generated by
505    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
506    pointer which will be passed as argument in every CONSTFUN call.
507    ALIGN is maximum alignment we can assume.
508    MEMSETP is true if this is a real memset/bzero, not a copy.
509    Returns TO + LEN.  */
510 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
511 			    rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
512 			    void *, unsigned int, bool, int);
513 
514 /* Emit insns to set X from Y.  */
515 extern rtx emit_move_insn (rtx, rtx);
516 
517 /* Emit insns to set X from Y, with no frills.  */
518 extern rtx emit_move_insn_1 (rtx, rtx);
519 
520 extern rtx emit_move_complex_push (enum machine_mode, rtx, rtx);
521 extern rtx emit_move_complex_parts (rtx, rtx);
522 
523 /* Push a block of length SIZE (perhaps variable)
524    and return an rtx to address the beginning of the block.  */
525 extern rtx push_block (rtx, int, int);
526 
527 /* Generate code to push something onto the stack, given its mode and type.  */
528 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
529 			    int, rtx, int, rtx, rtx, int, rtx);
530 
531 /* Expand an assignment that stores the value of FROM into TO.  */
532 extern void expand_assignment (tree, tree, bool);
533 
534 /* Generate code for computing expression EXP,
535    and storing the value into TARGET.
536    If SUGGEST_REG is nonzero, copy the value through a register
537    and return that register, if that is possible.  */
538 extern rtx store_expr (tree, rtx, int, bool);
539 
540 /* Given an rtx that may include add and multiply operations,
541    generate them as insns and return a pseudo-reg containing the value.
542    Useful after calling expand_expr with 1 as sum_ok.  */
543 extern rtx force_operand (rtx, rtx);
544 
545 /* Work horses for expand_expr.  */
546 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
547 			     enum expand_modifier, rtx *);
548 extern rtx expand_expr_real_1 (tree, rtx, enum machine_mode,
549 			       enum expand_modifier, rtx *);
550 extern rtx expand_expr_real_2 (sepops, rtx, enum machine_mode,
551 			       enum expand_modifier);
552 
553 /* Generate code for computing expression EXP.
554    An rtx for the computed value is returned.  The value is never null.
555    In the case of a void EXP, const0_rtx is returned.  */
556 static inline rtx
557 expand_expr (tree exp, rtx target, enum machine_mode mode,
558 	     enum expand_modifier modifier)
559 {
560   return expand_expr_real (exp, target, mode, modifier, NULL);
561 }
562 
563 static inline rtx
564 expand_normal (tree exp)
565 {
566   return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL);
567 }
568 
569 /* At the start of a function, record that we have no previously-pushed
570    arguments waiting to be popped.  */
571 extern void init_pending_stack_adjust (void);
572 
573 /* Discard any pending stack adjustment.  */
574 extern void discard_pending_stack_adjust (void);
575 
576 /* When exiting from function, if safe, clear out any pending stack adjust
577    so the adjustment won't get done.  */
578 extern void clear_pending_stack_adjust (void);
579 
580 /* Pop any previously-pushed arguments that have not been popped yet.  */
581 extern void do_pending_stack_adjust (void);
582 
583 /* Return the tree node and offset if a given argument corresponds to
584    a string constant.  */
585 extern tree string_constant (tree, tree *);
586 
587 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
588 extern void jumpifnot (tree, rtx, int);
589 extern void jumpifnot_1 (enum tree_code, tree, tree, rtx, int);
590 
591 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
592 extern void jumpif (tree, rtx, int);
593 extern void jumpif_1 (enum tree_code, tree, tree, rtx, int);
594 
595 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
596    the result is zero, or IF_TRUE_LABEL if the result is one.  */
597 extern void do_jump (tree, rtx, rtx, int);
598 extern void do_jump_1 (enum tree_code, tree, tree, rtx, rtx, int);
599 
600 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
601 				     enum machine_mode, rtx, rtx, rtx, int);
602 
603 /* Two different ways of generating switch statements.  */
604 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx);
605 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
606 
607 /* Functions from alias.c */
608 #include "alias.h"
609 
610 
611 /* rtl.h and tree.h were included.  */
612 /* Return an rtx for the size in bytes of the value of an expr.  */
613 extern rtx expr_size (tree);
614 
615 /* Return a wide integer for the size in bytes of the value of EXP, or -1
616    if the size can vary or is larger than an integer.  */
617 extern HOST_WIDE_INT int_expr_size (tree);
618 
619 /* Return an rtx that refers to the value returned by a function
620    in its original home.  This becomes invalid if any more code is emitted.  */
621 extern rtx hard_function_value (const_tree, const_tree, const_tree, int);
622 
623 extern rtx prepare_call_address (tree, rtx, rtx, rtx *, int, int);
624 
625 extern bool shift_return_value (enum machine_mode, bool, rtx);
626 
627 extern rtx expand_call (tree, rtx, int);
628 
629 extern void fixup_tail_calls (void);
630 
631 #ifdef TREE_CODE
632 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
633 			 int);
634 extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
635 			  rtx, int);
636 #endif
637 
638 extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
639 				 struct args_size *,
640 				 struct locate_and_pad_arg_data *);
641 
642 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
643 extern rtx label_rtx (tree);
644 
645 /* As label_rtx, but additionally the label is placed on the forced label
646    list of its containing function (i.e. it is treated as reachable even
647    if how is not obvious).  */
648 extern rtx force_label_rtx (tree);
649 
650 /* Return an rtx like arg but sans any constant terms.
651    Returns the original rtx if it has no constant terms.
652    The constant terms are added and stored via a second arg.  */
653 extern rtx eliminate_constant_term (rtx, rtx *);
654 
655 /* Convert arg to a valid memory address for specified machine mode that points
656    to a specific named address space, by emitting insns to perform arithmetic
657    if necessary.  */
658 extern rtx memory_address_addr_space (enum machine_mode, rtx, addr_space_t);
659 
660 /* Like memory_address_addr_space, except assume the memory address points to
661    the generic named address space.  */
662 #define memory_address(MODE,RTX) \
663 	memory_address_addr_space ((MODE), (RTX), ADDR_SPACE_GENERIC)
664 
665 /* Return a memory reference like MEMREF, but with its mode changed
666    to MODE and its address changed to ADDR.
667    (VOIDmode means don't change the mode.
668    NULL for ADDR means don't change the address.)  */
669 extern rtx change_address (rtx, enum machine_mode, rtx);
670 
671 /* Return a memory reference like MEMREF, but with its mode changed
672    to MODE and its address offset by OFFSET bytes.  */
673 #define adjust_address(MEMREF, MODE, OFFSET) \
674   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
675 
676 /* Likewise, but the reference is not required to be valid.  */
677 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
678   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
679 
680 /* Return a memory reference like MEMREF, but with its mode changed
681    to MODE and its address changed to ADDR, which is assumed to be
682    increased by OFFSET bytes from MEMREF.  */
683 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
684   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
685 
686 /* Likewise, but the reference is not required to be valid.  */
687 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
688   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
689 
690 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
691 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
692 					HOST_WIDE_INT, int);
693 
694 /* Return a memory reference like MEMREF, but whose address is changed by
695    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
696    known to be in OFFSET (possibly 1).  */
697 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
698 
699 /* Definitions from emit-rtl.c */
700 #include "emit-rtl.h"
701 
702 /* Return a memory reference like MEMREF, but with its mode widened to
703    MODE and adjusted by OFFSET.  */
704 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
705 
706 /* Return a memory reference like MEMREF, but which is known to have a
707    valid address.  */
708 extern rtx validize_mem (rtx);
709 
710 extern rtx use_anchored_address (rtx);
711 
712 /* Given REF, a MEM, and T, either the type of X or the expression
713    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
714    if we are making a new object of this type.  */
715 extern void set_mem_attributes (rtx, tree, int);
716 
717 /* Similar, except that BITPOS has not yet been applied to REF, so if
718    we alter MEM_OFFSET according to T then we should subtract BITPOS
719    expecting that it'll be added back in later.  */
720 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
721 
722 /* Return OFFSET if XEXP (MEM, 0) - OFFSET is known to be ALIGN
723    bits aligned for 0 <= OFFSET < ALIGN / BITS_PER_UNIT, or
724    -1 if not known.  */
725 extern int get_mem_align_offset (rtx, unsigned int);
726 
727 /* Assemble the static constant template for function entry trampolines.  */
728 extern rtx assemble_trampoline_template (void);
729 
730 /* Copy given rtx to a new temp reg and return that.  */
731 extern rtx copy_to_reg (rtx);
732 
733 /* Like copy_to_reg but always make the reg Pmode.  */
734 extern rtx copy_addr_to_reg (rtx);
735 
736 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
737 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
738 
739 /* Copy given rtx to given temp reg and return that.  */
740 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
741 
742 /* Copy a value to a register if it isn't already a register.
743    Args are mode (in case value is a constant) and the value.  */
744 extern rtx force_reg (enum machine_mode, rtx);
745 
746 /* Return given rtx, copied into a new temp reg if it was in memory.  */
747 extern rtx force_not_mem (rtx);
748 
749 /* Return mode and signedness to use when an argument or result in the
750    given mode is promoted.  */
751 extern enum machine_mode promote_function_mode (const_tree, enum machine_mode, int *,
752 					        const_tree, int);
753 
754 /* Return mode and signedness to use when an object in the given mode
755    is promoted.  */
756 extern enum machine_mode promote_mode (const_tree, enum machine_mode, int *);
757 
758 /* Return mode and signedness to use when object is promoted.  */
759 enum machine_mode promote_decl_mode (const_tree, int *);
760 
761 /* Remove some bytes from the stack.  An rtx says how many.  */
762 extern void adjust_stack (rtx);
763 
764 /* Add some bytes to the stack.  An rtx says how many.  */
765 extern void anti_adjust_stack (rtx);
766 
767 /* Add some bytes to the stack while probing it.  An rtx says how many. */
768 extern void anti_adjust_stack_and_probe (rtx, bool);
769 
770 /* This enum is used for the following two functions.  */
771 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
772 
773 /* Save the stack pointer at the specified level.  */
774 extern void emit_stack_save (enum save_level, rtx *, rtx);
775 
776 /* Restore the stack pointer from a save area of the specified level.  */
777 extern void emit_stack_restore (enum save_level, rtx, rtx);
778 
779 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
780 extern void update_nonlocal_goto_save_area (void);
781 
782 /* Allocate some space on the stack dynamically and return its address.  An rtx
783    says how many bytes.  */
784 extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
785 
786 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
787    FIRST is a constant and size is a Pmode RTX.  These are offsets from
788    the current stack pointer.  STACK_GROWS_DOWNWARD says whether to add
789    or subtract them from the stack pointer.  */
790 extern void probe_stack_range (HOST_WIDE_INT, rtx);
791 
792 /* Return an rtx that refers to the value returned by a library call
793    in its original home.  This becomes invalid if any more code is emitted.  */
794 extern rtx hard_libcall_value (enum machine_mode, rtx);
795 
796 /* Return the mode desired by operand N of a particular bitfield
797    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
798    available.  */
799 
800 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
801 extern enum machine_mode
802 mode_for_extraction (enum extraction_pattern, int);
803 
804 extern void store_bit_field (rtx, unsigned HOST_WIDE_INT,
805 			     unsigned HOST_WIDE_INT, enum machine_mode, rtx);
806 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
807 			      unsigned HOST_WIDE_INT, int, rtx,
808 			      enum machine_mode, enum machine_mode);
809 extern rtx extract_low_bits (enum machine_mode, enum machine_mode, rtx);
810 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
811 extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
812 
813 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
814 extern int safe_from_p (const_rtx, tree, int);
815 extern bool split_comparison (enum rtx_code, enum machine_mode,
816 			      enum rtx_code *, enum rtx_code *);
817 
818 /* Call this once to initialize the contents of the optabs
819    appropriately for the current target machine.  */
820 extern void init_optabs (void);
821 extern void init_all_optabs (void);
822 
823 /* Call this to initialize an optab function entry.  */
824 extern rtx init_one_libfunc (const char *);
825 extern rtx set_user_assembler_libfunc (const char *, const char *);
826 
827 /* Build a decl for a libfunc named NAME. */
828 extern tree build_libfunc_function (const char *);
829 
830 /* Get the personality libfunc for a function decl.  */
831 rtx get_personality_function (tree);
832 
833 extern int vector_mode_valid_p (enum machine_mode);
834 
835 #endif /* GCC_EXPR_H */
836