gcc/expr.h

   1 /* Definitions for code generation pass of GNU compiler.
   2    Copyright (C) 1987-2014 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_EXPR_H
  21 #define GCC_EXPR_H
  22
  23 /* For inhibit_defer_pop */
  24 #include "hashtab.h"
  25 #include "hash-set.h"
  26 #include "vec.h"
  27 #include "machmode.h"
  28 #include "tm.h"
  29 #include "hard-reg-set.h"
  30 #include "input.h"
  31 #include "function.h"
  32 /* For XEXP, GEN_INT, rtx_code */
  33 #include "rtl.h"
  34 /* For optimize_size */
  35 #include "flags.h"
  36 /* For tree_fits_[su]hwi_p, tree_to_[su]hwi, fold_convert, size_binop,
  37    ssize_int, TREE_CODE, TYPE_SIZE, int_size_in_bytes,    */
  38 #include "tree-core.h"
  39 /* For GET_MODE_BITSIZE, word_mode */
  40 #include "insn-config.h"
  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     or the memory is unaligned on a STRICT_ALIGNMENT target.  */
  53 enum 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 \f
  65 /* This structure is used to pass around information about exploded
  66    unary, binary and trinary expressions between expand_expr_real_1 and
  67    friends.  */
  68 typedef struct separate_ops
  69 {
  70   enum tree_code code;
  71   location_t location;
  72   tree type;
  73   tree op0, op1, op2;
  74 } *sepops;
  75 \f
  76 /* Functions from expmed.c:  */
  77
  78 /* Arguments MODE, RTX: return an rtx for the negation of that value.
  79    May emit insns.  */
  80 extern rtx negate_rtx (machine_mode, rtx);
  81
  82 /* Expand a logical AND operation.  */
  83 extern rtx expand_and (machine_mode, rtx, rtx, rtx);
  84
  85 /* Emit a store-flag operation.  */
  86 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, machine_mode,
  87                             int, int);
  88
  89 /* Like emit_store_flag, but always succeeds.  */
  90 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
  91                                   machine_mode, int, int);
  92
  93 /* Choose a minimal N + 1 bit approximation to 1/D that can be used to
  94    replace division by D, and put the least significant N bits of the result
  95    in *MULTIPLIER_PTR and return the most significant bit.  */
  96 extern unsigned HOST_WIDE_INT choose_multiplier (unsigned HOST_WIDE_INT, int,
  97                                                  int, unsigned HOST_WIDE_INT *,
  98                                                  int *, int *);
  99 \f
 100 /* Functions from expr.c:  */
 101
 102 /* This is run during target initialization to set up which modes can be
 103    used directly in memory and to initialize the block move optab.  */
 104 extern void init_expr_target (void);
 105
 106 /* This is run at the start of compiling a function.  */
 107 extern void init_expr (void);
 108
 109 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 110    Both modes must be floating or both fixed.  */
 111 extern void convert_move (rtx, rtx, int);
 112
 113 /* Convert an rtx to specified machine mode and return the result.  */
 114 extern rtx convert_to_mode (machine_mode, rtx, int);
 115
 116 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 117 extern rtx convert_modes (machine_mode, machine_mode, rtx, int);
 118
 119 /* Emit code to move a block Y to a block X.  */
 120
 121 enum block_op_methods
 122 {
 123   BLOCK_OP_NORMAL,
 124   BLOCK_OP_NO_LIBCALL,
 125   BLOCK_OP_CALL_PARM,
 126   /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized.  */
 127   BLOCK_OP_TAILCALL
 128 };
 129
 130 extern GTY(()) tree block_clear_fn;
 131 extern void init_block_move_fn (const char *);
 132 extern void init_block_clear_fn (const char *);
 133
 134 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 135 extern rtx emit_block_move_via_libcall (rtx, rtx, rtx, bool);
 136 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
 137                                   unsigned int, HOST_WIDE_INT,
 138                                   unsigned HOST_WIDE_INT,
 139                                   unsigned HOST_WIDE_INT,
 140                                   unsigned HOST_WIDE_INT);
 141 extern bool emit_storent_insn (rtx to, rtx from);
 142
 143 /* Copy all or part of a value X into registers starting at REGNO.
 144    The number of registers to be filled is NREGS.  */
 145 extern void move_block_to_reg (int, rtx, int, machine_mode);
 146
 147 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 148    The number of registers to be filled is NREGS.  */
 149 extern void move_block_from_reg (int, rtx, int);
 150
 151 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 152 extern rtx gen_group_rtx (rtx);
 153
 154 /* Load a BLKmode value into non-consecutive registers represented by a
 155    PARALLEL.  */
 156 extern void emit_group_load (rtx, rtx, tree, int);
 157
 158 /* Similarly, but load into new temporaries.  */
 159 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
 160
 161 /* Move a non-consecutive group of registers represented by a PARALLEL into
 162    a non-consecutive group of registers represented by a PARALLEL.  */
 163 extern void emit_group_move (rtx, rtx);
 164
 165 /* Move a group of registers represented by a PARALLEL into pseudos.  */
 166 extern rtx emit_group_move_into_temps (rtx);
 167
 168 /* Store a BLKmode value from non-consecutive registers represented by a
 169    PARALLEL.  */
 170 extern void emit_group_store (rtx, rtx, tree, int);
 171
 172 extern rtx maybe_emit_group_store (rtx, tree);
 173
 174 /* Copy BLKmode object from a set of registers.  */
 175 extern void copy_blkmode_from_reg (rtx, rtx, tree);
 176
 177 /* Mark REG as holding a parameter for the next CALL_INSN.
 178    Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode.  */
 179 extern void use_reg_mode (rtx *, rtx, machine_mode);
 180 extern void clobber_reg_mode (rtx *, rtx, machine_mode);
 181
 182 extern rtx copy_blkmode_to_reg (machine_mode, tree);
 183
 184 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 185 static inline void
 186 use_reg (rtx *fusage, rtx reg)
 187 {
 188   use_reg_mode (fusage, reg, VOIDmode);
 189 }
 190
 191 /* Mark REG as clobbered by the call with FUSAGE as CALL_INSN_FUNCTION_USAGE.  */
 192 static inline void
 193 clobber_reg (rtx *fusage, rtx reg)
 194 {
 195   clobber_reg_mode (fusage, reg, VOIDmode);
 196 }
 197
 198 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 199    for the next CALL_INSN.  */
 200 extern void use_regs (rtx *, int, int);
 201
 202 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 203 extern void use_group_regs (rtx *, rtx);
 204
 205 /* Write zeros through the storage of OBJECT.
 206    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 207 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
 208 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
 209                                 unsigned int, HOST_WIDE_INT,
 210                                 unsigned HOST_WIDE_INT,
 211                                 unsigned HOST_WIDE_INT,
 212                                 unsigned HOST_WIDE_INT);
 213 /* The same, but always output an library call.  */
 214 rtx set_storage_via_libcall (rtx, rtx, rtx, bool);
 215
 216 /* Expand a setmem pattern; return true if successful.  */
 217 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
 218                                     unsigned int, HOST_WIDE_INT,
 219                                     unsigned HOST_WIDE_INT,
 220                                     unsigned HOST_WIDE_INT,
 221                                     unsigned HOST_WIDE_INT);
 222
 223 extern unsigned HOST_WIDE_INT move_by_pieces_ninsns (unsigned HOST_WIDE_INT,
 224                                                      unsigned int,
 225                                                      unsigned int);
 226
 227 /* Return nonzero if it is desirable to store LEN bytes generated by
 228    CONSTFUN with several move instructions by store_by_pieces
 229    function.  CONSTFUNDATA is a pointer which will be passed as argument
 230    in every CONSTFUN call.
 231    ALIGN is maximum alignment we can assume.
 232    MEMSETP is true if this is a real memset/bzero, not a copy
 233    of a const string.  */
 234 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 235                                 rtx (*) (void *, HOST_WIDE_INT,
 236                                          machine_mode),
 237                                 void *, unsigned int, bool);
 238
 239 /* Generate several move instructions to store LEN bytes generated by
 240    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 241    pointer which will be passed as argument in every CONSTFUN call.
 242    ALIGN is maximum alignment we can assume.
 243    MEMSETP is true if this is a real memset/bzero, not a copy.
 244    Returns TO + LEN.  */
 245 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 246                             rtx (*) (void *, HOST_WIDE_INT, machine_mode),
 247                             void *, unsigned int, bool, int);
 248
 249 /* Emit insns to set X from Y.  */
 250 extern rtx_insn *emit_move_insn (rtx, rtx);
 251 extern rtx gen_move_insn (rtx, rtx);
 252
 253 /* Emit insns to set X from Y, with no frills.  */
 254 extern rtx_insn *emit_move_insn_1 (rtx, rtx);
 255
 256 extern rtx_insn *emit_move_complex_push (machine_mode, rtx, rtx);
 257 extern rtx_insn *emit_move_complex_parts (rtx, rtx);
 258 extern rtx emit_move_resolve_push (machine_mode, rtx);
 259
 260 /* Push a block of length SIZE (perhaps variable)
 261    and return an rtx to address the beginning of the block.  */
 262 extern rtx push_block (rtx, int, int);
 263
 264 /* Generate code to push something onto the stack, given its mode and type.  */
 265 extern void emit_push_insn (rtx, machine_mode, tree, rtx, unsigned int,
 266                             int, rtx, int, rtx, rtx, int, rtx);
 267
 268 /* Expand an assignment that stores the value of FROM into TO.  */
 269 extern void expand_assignment (tree, tree, bool);
 270
 271 /* Generate code for computing expression EXP,
 272    and storing the value into TARGET.
 273    If SUGGEST_REG is nonzero, copy the value through a register
 274    and return that register, if that is possible.  */
 275 extern rtx store_expr (tree, rtx, int, bool);
 276
 277 /* Given an rtx that may include add and multiply operations,
 278    generate them as insns and return a pseudo-reg containing the value.
 279    Useful after calling expand_expr with 1 as sum_ok.  */
 280 extern rtx force_operand (rtx, rtx);
 281
 282 /* Work horses for expand_expr.  */
 283 extern rtx expand_expr_real (tree, rtx, machine_mode,
 284                              enum expand_modifier, rtx *, bool);
 285 extern rtx expand_expr_real_1 (tree, rtx, machine_mode,
 286                                enum expand_modifier, rtx *, bool);
 287 extern rtx expand_expr_real_2 (sepops, rtx, machine_mode,
 288                                enum expand_modifier);
 289
 290 /* Generate code for computing expression EXP.
 291    An rtx for the computed value is returned.  The value is never null.
 292    In the case of a void EXP, const0_rtx is returned.  */
 293 static inline rtx
 294 expand_expr (tree exp, rtx target, machine_mode mode,
 295              enum expand_modifier modifier)
 296 {
 297   return expand_expr_real (exp, target, mode, modifier, NULL, false);
 298 }
 299
 300 static inline rtx
 301 expand_normal (tree exp)
 302 {
 303   return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL, false);
 304 }
 305
 306 /* At the start of a function, record that we have no previously-pushed
 307    arguments waiting to be popped.  */
 308 extern void init_pending_stack_adjust (void);
 309
 310 /* Discard any pending stack adjustment.  */
 311 extern void discard_pending_stack_adjust (void);
 312
 313 /* When exiting from function, if safe, clear out any pending stack adjust
 314    so the adjustment won't get done.  */
 315 extern void clear_pending_stack_adjust (void);
 316
 317 /* Pop any previously-pushed arguments that have not been popped yet.  */
 318 extern void do_pending_stack_adjust (void);
 319
 320 /* Struct for saving/restoring of pending_stack_adjust/stack_pointer_delta
 321    values.  */
 322
 323 struct saved_pending_stack_adjust
 324 {
 325   /* Saved value of pending_stack_adjust.  */
 326   int x_pending_stack_adjust;
 327
 328   /* Saved value of stack_pointer_delta.  */
 329   int x_stack_pointer_delta;
 330 };
 331
 332 /* Remember pending_stack_adjust/stack_pointer_delta.
 333    To be used around code that may call do_pending_stack_adjust (),
 334    but the generated code could be discarded e.g. using delete_insns_since.  */
 335
 336 extern void save_pending_stack_adjust (saved_pending_stack_adjust *);
 337
 338 /* Restore the saved pending_stack_adjust/stack_pointer_delta.  */
 339
 340 extern void restore_pending_stack_adjust (saved_pending_stack_adjust *);
 341
 342 /* Return the tree node and offset if a given argument corresponds to
 343    a string constant.  */
 344 extern tree string_constant (tree, tree *);
 345
 346 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 347 extern void jumpifnot (tree, rtx, int);
 348 extern void jumpifnot_1 (enum tree_code, tree, tree, rtx, int);
 349
 350 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 351 extern void jumpif (tree, rtx, int);
 352 extern void jumpif_1 (enum tree_code, tree, tree, rtx, int);
 353
 354 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 355    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 356 extern void do_jump (tree, rtx, rtx, int);
 357 extern void do_jump_1 (enum tree_code, tree, tree, rtx, rtx, int);
 358
 359 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 360                                      machine_mode, rtx, rtx, rtx, int);
 361
 362 /* Two different ways of generating switch statements.  */
 363 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx, int);
 364 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx, int);
 365
 366 /* Functions from alias.c */
 367 #include "alias.h"
 368
 369 \f
 370 /* rtl.h and tree.h were included.  */
 371 /* Return an rtx for the size in bytes of the value of an expr.  */
 372 extern rtx expr_size (tree);
 373
 374 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 375    if the size can vary or is larger than an integer.  */
 376 extern HOST_WIDE_INT int_expr_size (tree);
 377
 378 /* Return an rtx that refers to the value returned by a function
 379    in its original home.  This becomes invalid if any more code is emitted.  */
 380 extern rtx hard_function_value (const_tree, const_tree, const_tree, int);
 381
 382 extern rtx prepare_call_address (tree, rtx, rtx, rtx *, int, int);
 383
 384 extern bool shift_return_value (machine_mode, bool, rtx);
 385
 386 extern rtx expand_call (tree, rtx, int);
 387
 388 extern void fixup_tail_calls (void);
 389
 390 #ifdef TREE_CODE
 391 extern rtx expand_variable_shift (enum tree_code, machine_mode,
 392                                   rtx, tree, rtx, int);
 393 extern rtx expand_shift (enum tree_code, machine_mode, rtx, int, rtx,
 394                              int);
 395 extern rtx expand_divmod (int, enum tree_code, machine_mode, rtx, rtx,
 396                           rtx, int);
 397 #endif
 398
 399 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 400 extern rtx label_rtx (tree);
 401
 402 /* As label_rtx, but additionally the label is placed on the forced label
 403    list of its containing function (i.e. it is treated as reachable even
 404    if how is not obvious).  */
 405 extern rtx force_label_rtx (tree);
 406
 407 /* Return an rtx like arg but sans any constant terms.
 408    Returns the original rtx if it has no constant terms.
 409    The constant terms are added and stored via a second arg.  */
 410 extern rtx eliminate_constant_term (rtx, rtx *);
 411
 412 /* Convert arg to a valid memory address for specified machine mode that points
 413    to a specific named address space, by emitting insns to perform arithmetic
 414    if necessary.  */
 415 extern rtx memory_address_addr_space (machine_mode, rtx, addr_space_t);
 416
 417 /* Like memory_address_addr_space, except assume the memory address points to
 418    the generic named address space.  */
 419 #define memory_address(MODE,RTX) \
 420         memory_address_addr_space ((MODE), (RTX), ADDR_SPACE_GENERIC)
 421
 422 /* Return a memory reference like MEMREF, but with its mode changed
 423    to MODE and its address changed to ADDR.
 424    (VOIDmode means don't change the mode.
 425    NULL for ADDR means don't change the address.)  */
 426 extern rtx change_address (rtx, machine_mode, rtx);
 427
 428 /* Return a memory reference like MEMREF, but with its mode changed
 429    to MODE and its address offset by OFFSET bytes.  */
 430 #define adjust_address(MEMREF, MODE, OFFSET) \
 431   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 0, 0)
 432
 433 /* Likewise, but the reference is not required to be valid.  */
 434 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 435   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1, 0, 0)
 436
 437 /* Return a memory reference like MEMREF, but with its mode changed
 438    to MODE and its address offset by OFFSET bytes.  Assume that it's
 439    for a bitfield and conservatively drop the underlying object if we
 440    cannot be sure to stay within its bounds.  */
 441 #define adjust_bitfield_address(MEMREF, MODE, OFFSET) \
 442   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 1, 0)
 443
 444 /* As for adjust_bitfield_address, but specify that the width of
 445    BLKmode accesses is SIZE bytes.  */
 446 #define adjust_bitfield_address_size(MEMREF, MODE, OFFSET, SIZE) \
 447   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 1, SIZE)
 448
 449 /* Likewise, but the reference is not required to be valid.  */
 450 #define adjust_bitfield_address_nv(MEMREF, MODE, OFFSET) \
 451   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1, 1, 0)
 452
 453 /* Return a memory reference like MEMREF, but with its mode changed
 454    to MODE and its address changed to ADDR, which is assumed to be
 455    increased by OFFSET bytes from MEMREF.  */
 456 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 457   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 458
 459 /* Likewise, but the reference is not required to be valid.  */
 460 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 461   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 462
 463 extern rtx adjust_address_1 (rtx, machine_mode, HOST_WIDE_INT, int, int,
 464                              int, HOST_WIDE_INT);
 465 extern rtx adjust_automodify_address_1 (rtx, machine_mode, rtx,
 466                                         HOST_WIDE_INT, int);
 467
 468 /* Return a memory reference like MEMREF, but whose address is changed by
 469    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 470    known to be in OFFSET (possibly 1).  */
 471 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 472
 473 /* Definitions from emit-rtl.c */
 474 #include "emit-rtl.h"
 475
 476 /* Return a memory reference like MEMREF, but with its mode widened to
 477    MODE and adjusted by OFFSET.  */
 478 extern rtx widen_memory_access (rtx, machine_mode, HOST_WIDE_INT);
 479
 480 /* Return a memory reference like MEMREF, but which is known to have a
 481    valid address.  */
 482 extern rtx validize_mem (rtx);
 483
 484 extern rtx use_anchored_address (rtx);
 485
 486 /* Given REF, a MEM, and T, either the type of X or the expression
 487    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 488    if we are making a new object of this type.  */
 489 extern void set_mem_attributes (rtx, tree, int);
 490
 491 /* Similar, except that BITPOS has not yet been applied to REF, so if
 492    we alter MEM_OFFSET according to T then we should subtract BITPOS
 493    expecting that it'll be added back in later.  */
 494 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 495
 496 /* Return OFFSET if XEXP (MEM, 0) - OFFSET is known to be ALIGN
 497    bits aligned for 0 <= OFFSET < ALIGN / BITS_PER_UNIT, or
 498    -1 if not known.  */
 499 extern int get_mem_align_offset (rtx, unsigned int);
 500
 501 /* Assemble the static constant template for function entry trampolines.  */
 502 extern rtx assemble_trampoline_template (void);
 503
 504 /* Copy given rtx to a new temp reg and return that.  */
 505 extern rtx copy_to_reg (rtx);
 506
 507 /* Like copy_to_reg but always make the reg Pmode.  */
 508 extern rtx copy_addr_to_reg (rtx);
 509
 510 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 511 extern rtx copy_to_mode_reg (machine_mode, rtx);
 512
 513 /* Copy given rtx to given temp reg and return that.  */
 514 extern rtx copy_to_suggested_reg (rtx, rtx, machine_mode);
 515
 516 /* Copy a value to a register if it isn't already a register.
 517    Args are mode (in case value is a constant) and the value.  */
 518 extern rtx force_reg (machine_mode, rtx);
 519
 520 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 521 extern rtx force_not_mem (rtx);
 522
 523 /* Return mode and signedness to use when an argument or result in the
 524    given mode is promoted.  */
 525 extern machine_mode promote_function_mode (const_tree, machine_mode, int *,
 526                                                 const_tree, int);
 527
 528 /* Return mode and signedness to use when an object in the given mode
 529    is promoted.  */
 530 extern machine_mode promote_mode (const_tree, machine_mode, int *);
 531
 532 /* Return mode and signedness to use when object is promoted.  */
 533 machine_mode promote_decl_mode (const_tree, int *);
 534
 535 /* Remove some bytes from the stack.  An rtx says how many.  */
 536 extern void adjust_stack (rtx);
 537
 538 /* Add some bytes to the stack.  An rtx says how many.  */
 539 extern void anti_adjust_stack (rtx);
 540
 541 /* Add some bytes to the stack while probing it.  An rtx says how many. */
 542 extern void anti_adjust_stack_and_probe (rtx, bool);
 543
 544 /* This enum is used for the following two functions.  */
 545 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 546
 547 /* Save the stack pointer at the specified level.  */
 548 extern void emit_stack_save (enum save_level, rtx *);
 549
 550 /* Restore the stack pointer from a save area of the specified level.  */
 551 extern void emit_stack_restore (enum save_level, rtx);
 552
 553 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 554 extern void update_nonlocal_goto_save_area (void);
 555
 556 /* Allocate some space on the stack dynamically and return its address.  */
 557 extern rtx allocate_dynamic_stack_space (rtx, unsigned, unsigned, bool);
 558
 559 /* Emit one stack probe at ADDRESS, an address within the stack.  */
 560 extern void emit_stack_probe (rtx);
 561
 562 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 563    FIRST is a constant and size is a Pmode RTX.  These are offsets from
 564    the current stack pointer.  STACK_GROWS_DOWNWARD says whether to add
 565    or subtract them from the stack pointer.  */
 566 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 567
 568 /* Return an rtx that refers to the value returned by a library call
 569    in its original home.  This becomes invalid if any more code is emitted.  */
 570 extern rtx hard_libcall_value (machine_mode, rtx);
 571
 572 extern void store_bit_field (rtx, unsigned HOST_WIDE_INT,
 573                              unsigned HOST_WIDE_INT,
 574                              unsigned HOST_WIDE_INT,
 575                              unsigned HOST_WIDE_INT,
 576                              machine_mode, rtx);
 577 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 578                               unsigned HOST_WIDE_INT, int, rtx,
 579                               machine_mode, machine_mode);
 580 extern rtx extract_low_bits (machine_mode, machine_mode, rtx);
 581 extern rtx expand_mult (machine_mode, rtx, rtx, rtx, int);
 582 extern rtx expand_mult_highpart_adjust (machine_mode, rtx, rtx, rtx, rtx, int);
 583
 584 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
 585 extern int safe_from_p (const_rtx, tree, int);
 586 extern bool split_comparison (enum rtx_code, machine_mode,
 587                               enum rtx_code *, enum rtx_code *);
 588
 589 /* Get the personality libfunc for a function decl.  */
 590 rtx get_personality_function (tree);
 591
 592
 593 /* In stmt.c */
 594
 595 /* Expand a GIMPLE_SWITCH statement.  */
 596 extern void expand_case (gimple);
 597
 598 /* Like expand_case but special-case for SJLJ exception dispatching.  */
 599 extern void expand_sjlj_dispatch_table (rtx, vec<tree> );
 600
 601 /* Determine whether the LEN bytes can be moved by using several move
 602    instructions.  Return nonzero if a call to move_by_pieces should
 603    succeed.  */
 604 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 605
 606 extern unsigned HOST_WIDE_INT highest_pow2_factor (const_tree);
 607 bool array_at_struct_end_p (tree);
 608
 609 /* Return a tree of sizetype representing the size, in bytes, of the element
 610    of EXP, an ARRAY_REF or an ARRAY_RANGE_REF.  */
 611 extern tree array_ref_element_size (tree);
 612
 613 extern bool categorize_ctor_elements (const_tree, HOST_WIDE_INT *,
 614                                       HOST_WIDE_INT *, bool *);
 615
 616 /* Return a tree representing the offset, in bytes, of the field referenced
 617    by EXP.  This does not include any offset in DECL_FIELD_BIT_OFFSET.  */
 618 extern tree component_ref_field_offset (tree);
 619
 620 #endif /* GCC_EXPR_H */