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 "function.h"
  25 /* For XEXP, GEN_INT, rtx_code */
  26 #include "rtl.h"
  27 /* For optimize_size */
  28 #include "flags.h"
  29 /* For tree_fits_[su]hwi_p, tree_to_[su]hwi, fold_convert, size_binop,
  30    ssize_int, TREE_CODE, TYPE_SIZE, int_size_in_bytes,    */
  31 #include "tree-core.h"
  32 /* For GET_MODE_BITSIZE, word_mode */
  33 #include "machmode.h"
  34
  35 /* This is the 4th arg to `expand_expr'.
  36    EXPAND_STACK_PARM means we are possibly expanding a call param onto
  37    the stack.
  38    EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
  39    EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
  40    EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
  41     is a constant that is not a legitimate address.
  42    EXPAND_WRITE means we are only going to write to the resulting rtx.
  43    EXPAND_MEMORY means we are interested in a memory result, even if
  44     the memory is constant and we could have propagated a constant value,
  45     or the memory is unaligned on a STRICT_ALIGNMENT target.  */
  46 enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
  47                       EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
  48                       EXPAND_MEMORY};
  49
  50 /* Prevent the compiler from deferring stack pops.  See
  51    inhibit_defer_pop for more information.  */
  52 #define NO_DEFER_POP (inhibit_defer_pop += 1)
  53
  54 /* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
  55    more information.  */
  56 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
  57 \f
  58 enum direction {none, upward, downward};
  59
  60 /* Structure to record the size of a sequence of arguments
  61    as the sum of a tree-expression and a constant.  This structure is
  62    also used to store offsets from the stack, which might be negative,
  63    so the variable part must be ssizetype, not sizetype.  */
  64
  65 struct args_size
  66 {
  67   HOST_WIDE_INT constant;
  68   tree var;
  69 };
  70
  71 /* Package up various arg related fields of struct args for
  72    locate_and_pad_parm.  */
  73 struct locate_and_pad_arg_data
  74 {
  75   /* Size of this argument on the stack, rounded up for any padding it
  76      gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
  77      counted here, otherwise they aren't.  */
  78   struct args_size size;
  79   /* Offset of this argument from beginning of stack-args.  */
  80   struct args_size offset;
  81   /* Offset to the start of the stack slot.  Different from OFFSET
  82      if this arg pads downward.  */
  83   struct args_size slot_offset;
  84   /* The amount that the stack pointer needs to be adjusted to
  85      force alignment for the next argument.  */
  86   struct args_size alignment_pad;
  87   /* Which way we should pad this arg.  */
  88   enum direction where_pad;
  89   /* slot_offset is at least this aligned.  */
  90   unsigned int boundary;
  91 };
  92
  93 /* Add the value of the tree INC to the `struct args_size' TO.  */
  94
  95 #define ADD_PARM_SIZE(TO, INC)                                  \
  96 do {                                                            \
  97   tree inc = (INC);                                             \
  98   if (tree_fits_shwi_p (inc))                                   \
  99     (TO).constant += tree_to_shwi (inc);                        \
 100   else if ((TO).var == 0)                                       \
 101     (TO).var = fold_convert (ssizetype, inc);                   \
 102   else                                                          \
 103     (TO).var = size_binop (PLUS_EXPR, (TO).var,                 \
 104                            fold_convert (ssizetype, inc));      \
 105 } while (0)
 106
 107 #define SUB_PARM_SIZE(TO, DEC)                                  \
 108 do {                                                            \
 109   tree dec = (DEC);                                             \
 110   if (tree_fits_shwi_p (dec))                                   \
 111     (TO).constant -= tree_to_shwi (dec);                        \
 112   else if ((TO).var == 0)                                       \
 113     (TO).var = size_binop (MINUS_EXPR, ssize_int (0),           \
 114                            fold_convert (ssizetype, dec));      \
 115   else                                                          \
 116     (TO).var = size_binop (MINUS_EXPR, (TO).var,                \
 117                            fold_convert (ssizetype, dec));      \
 118 } while (0)
 119
 120 /* Convert the implicit sum in a `struct args_size' into a tree
 121    of type ssizetype.  */
 122 #define ARGS_SIZE_TREE(SIZE)                                    \
 123 ((SIZE).var == 0 ? ssize_int ((SIZE).constant)                  \
 124  : size_binop (PLUS_EXPR, fold_convert (ssizetype, (SIZE).var), \
 125                ssize_int ((SIZE).constant)))
 126
 127 /* Convert the implicit sum in a `struct args_size' into an rtx.  */
 128 #define ARGS_SIZE_RTX(SIZE)                                     \
 129 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant)                    \
 130  : expand_normal (ARGS_SIZE_TREE (SIZE)))
 131
 132 \f
 133 /* This structure is used to pass around information about exploded
 134    unary, binary and trinary expressions between expand_expr_real_1 and
 135    friends.  */
 136 typedef struct separate_ops
 137 {
 138   enum tree_code code;
 139   location_t location;
 140   tree type;
 141   tree op0, op1, op2;
 142 } *sepops;
 143 \f
 144 /* Functions from optabs.c, commonly used, and without need for the optabs
 145    tables:  */
 146
 147 /* Passed to expand_simple_binop and expand_binop to say which options
 148    to try to use if the requested operation can't be open-coded on the
 149    requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
 150    a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
 151    using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
 152    try anything else.  */
 153
 154 enum optab_methods
 155 {
 156   OPTAB_DIRECT,
 157   OPTAB_LIB,
 158   OPTAB_WIDEN,
 159   OPTAB_LIB_WIDEN,
 160   OPTAB_MUST_WIDEN
 161 };
 162
 163 /* Generate code for a simple binary or unary operation.  "Simple" in
 164    this case means "can be unambiguously described by a (mode, code)
 165    pair and mapped to a single optab."  */
 166 extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
 167                                 rtx, rtx, int, enum optab_methods);
 168 extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
 169                                int);
 170
 171 /* Report whether the machine description contains an insn which can
 172    perform the operation described by CODE and MODE.  */
 173 extern int have_insn_for (enum rtx_code, enum machine_mode);
 174
 175 /* Emit code to make a call to a constant function or a library call.  */
 176 extern void emit_libcall_block (rtx, rtx, rtx, rtx);
 177
 178 /* Create but don't emit one rtl instruction to perform certain operations.
 179    Modes must match; operands must meet the operation's predicates.
 180    Likewise for subtraction and for just copying.  */
 181 extern rtx gen_add2_insn (rtx, rtx);
 182 extern rtx gen_add3_insn (rtx, rtx, rtx);
 183 extern rtx gen_sub2_insn (rtx, rtx);
 184 extern rtx gen_sub3_insn (rtx, rtx, rtx);
 185 extern rtx gen_move_insn (rtx, rtx);
 186 extern int have_add2_insn (rtx, rtx);
 187 extern int have_sub2_insn (rtx, rtx);
 188
 189 /* Emit a pair of rtl insns to compare two rtx's and to jump
 190    to a label if the comparison is true.  */
 191 extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
 192                                      enum machine_mode, int, rtx, int prob=-1);
 193
 194 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 195 extern void emit_indirect_jump (rtx);
 196
 197 /* Generate a conditional trap instruction.  */
 198 extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
 199
 200 #include "insn-config.h"
 201
 202 #ifdef HAVE_conditional_move
 203 /* Emit a conditional move operation.  */
 204 rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 205                            rtx, rtx, enum machine_mode, int);
 206
 207 /* Return nonzero if the conditional move is supported.  */
 208 int can_conditionally_move_p (enum machine_mode mode);
 209
 210 #endif
 211 rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 212                           rtx, rtx, enum machine_mode, int);
 213
 214 rtx expand_sync_operation (rtx, rtx, enum rtx_code);
 215 rtx expand_sync_fetch_operation (rtx, rtx, enum rtx_code, bool, rtx);
 216 rtx expand_sync_lock_test_and_set (rtx, rtx, rtx);
 217
 218 rtx expand_atomic_exchange (rtx, rtx, rtx, enum memmodel);
 219 rtx expand_atomic_load (rtx, rtx, enum memmodel);
 220 rtx expand_atomic_store (rtx, rtx, enum memmodel, bool);
 221 rtx expand_atomic_fetch_op (rtx, rtx, rtx, enum rtx_code, enum memmodel,
 222                               bool);
 223 rtx expand_atomic_test_and_set (rtx, rtx, enum memmodel);
 224 rtx expand_atomic_clear (rtx, enum memmodel);
 225 void expand_atomic_thread_fence (enum memmodel);
 226 void expand_atomic_signal_fence (enum memmodel);
 227
 228 \f
 229 /* Functions from expmed.c:  */
 230
 231 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 232    May emit insns.  */
 233 extern rtx negate_rtx (enum machine_mode, rtx);
 234
 235 /* Expand a logical AND operation.  */
 236 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
 237
 238 /* Emit a store-flag operation.  */
 239 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 240                             int, int);
 241
 242 /* Like emit_store_flag, but always succeeds.  */
 243 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 244                                   enum machine_mode, int, int);
 245
 246 /* Choose a minimal N + 1 bit approximation to 1/D that can be used to
 247    replace division by D, and put the least significant N bits of the result
 248    in *MULTIPLIER_PTR and return the most significant bit.  */
 249 extern unsigned HOST_WIDE_INT choose_multiplier (unsigned HOST_WIDE_INT, int,
 250                                                  int, unsigned HOST_WIDE_INT *,
 251                                                  int *, int *);
 252 \f
 253 /* Functions from builtins.c:  */
 254 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 255 extern tree std_build_builtin_va_list (void);
 256 extern tree std_fn_abi_va_list (tree);
 257 extern tree std_canonical_va_list_type (tree);
 258
 259 extern void std_expand_builtin_va_start (tree, rtx);
 260 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 261 extern void expand_builtin_setjmp_setup (rtx, rtx);
 262 extern void expand_builtin_setjmp_receiver (rtx);
 263 extern rtx expand_builtin_saveregs (void);
 264 extern void expand_builtin_trap (void);
 265 extern rtx builtin_strncpy_read_str (void *, HOST_WIDE_INT, enum machine_mode);
 266 \f
 267 /* Functions from expr.c:  */
 268
 269 /* This is run during target initialization to set up which modes can be
 270    used directly in memory and to initialize the block move optab.  */
 271 extern void init_expr_target (void);
 272
 273 /* This is run at the start of compiling a function.  */
 274 extern void init_expr (void);
 275
 276 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 277    Both modes must be floating or both fixed.  */
 278 extern void convert_move (rtx, rtx, int);
 279
 280 /* Convert an rtx to specified machine mode and return the result.  */
 281 extern rtx convert_to_mode (enum machine_mode, rtx, int);
 282
 283 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 284 extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
 285
 286 /* Emit code to move a block Y to a block X.  */
 287
 288 enum block_op_methods
 289 {
 290   BLOCK_OP_NORMAL,
 291   BLOCK_OP_NO_LIBCALL,
 292   BLOCK_OP_CALL_PARM,
 293   /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized.  */
 294   BLOCK_OP_TAILCALL
 295 };
 296
 297 extern GTY(()) tree block_clear_fn;
 298 extern void init_block_move_fn (const char *);
 299 extern void init_block_clear_fn (const char *);
 300
 301 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 302 extern rtx emit_block_move_via_libcall (rtx, rtx, rtx, bool);
 303 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
 304                                   unsigned int, HOST_WIDE_INT,
 305                                   unsigned HOST_WIDE_INT,
 306                                   unsigned HOST_WIDE_INT,
 307                                   unsigned HOST_WIDE_INT);
 308 extern bool emit_storent_insn (rtx to, rtx from);
 309
 310 /* Copy all or part of a value X into registers starting at REGNO.
 311    The number of registers to be filled is NREGS.  */
 312 extern void move_block_to_reg (int, rtx, int, enum machine_mode);
 313
 314 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 315    The number of registers to be filled is NREGS.  */
 316 extern void move_block_from_reg (int, rtx, int);
 317
 318 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 319 extern rtx gen_group_rtx (rtx);
 320
 321 /* Load a BLKmode value into non-consecutive registers represented by a
 322    PARALLEL.  */
 323 extern void emit_group_load (rtx, rtx, tree, int);
 324
 325 /* Similarly, but load into new temporaries.  */
 326 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
 327
 328 /* Move a non-consecutive group of registers represented by a PARALLEL into
 329    a non-consecutive group of registers represented by a PARALLEL.  */
 330 extern void emit_group_move (rtx, rtx);
 331
 332 /* Move a group of registers represented by a PARALLEL into pseudos.  */
 333 extern rtx emit_group_move_into_temps (rtx);
 334
 335 /* Store a BLKmode value from non-consecutive registers represented by a
 336    PARALLEL.  */
 337 extern void emit_group_store (rtx, rtx, tree, int);
 338
 339 extern rtx maybe_emit_group_store (rtx, tree);
 340
 341 /* Copy BLKmode object from a set of registers.  */
 342 extern void copy_blkmode_from_reg (rtx, rtx, tree);
 343
 344 /* Mark REG as holding a parameter for the next CALL_INSN.
 345    Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode.  */
 346 extern void use_reg_mode (rtx *, rtx, enum machine_mode);
 347
 348 extern rtx copy_blkmode_to_reg (enum machine_mode, tree);
 349
 350 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 351 static inline void
 352 use_reg (rtx *fusage, rtx reg)
 353 {
 354   use_reg_mode (fusage, reg, VOIDmode);
 355 }
 356
 357 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 358    for the next CALL_INSN.  */
 359 extern void use_regs (rtx *, int, int);
 360
 361 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 362 extern void use_group_regs (rtx *, rtx);
 363
 364 /* Write zeros through the storage of OBJECT.
 365    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 366 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
 367 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
 368                                 unsigned int, HOST_WIDE_INT,
 369                                 unsigned HOST_WIDE_INT,
 370                                 unsigned HOST_WIDE_INT,
 371                                 unsigned HOST_WIDE_INT);
 372 /* The same, but always output an library call.  */
 373 rtx set_storage_via_libcall (rtx, rtx, rtx, bool);
 374
 375 /* Expand a setmem pattern; return true if successful.  */
 376 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
 377                                     unsigned int, HOST_WIDE_INT,
 378                                     unsigned HOST_WIDE_INT,
 379                                     unsigned HOST_WIDE_INT,
 380                                     unsigned HOST_WIDE_INT);
 381
 382 extern unsigned HOST_WIDE_INT move_by_pieces_ninsns (unsigned HOST_WIDE_INT,
 383                                                      unsigned int,
 384                                                      unsigned int);
 385
 386 /* Return nonzero if it is desirable to store LEN bytes generated by
 387    CONSTFUN with several move instructions by store_by_pieces
 388    function.  CONSTFUNDATA is a pointer which will be passed as argument
 389    in every CONSTFUN call.
 390    ALIGN is maximum alignment we can assume.
 391    MEMSETP is true if this is a real memset/bzero, not a copy
 392    of a const string.  */
 393 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 394                                 rtx (*) (void *, HOST_WIDE_INT,
 395                                          enum machine_mode),
 396                                 void *, unsigned int, bool);
 397
 398 /* Generate several move instructions to store LEN bytes generated by
 399    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 400    pointer which will be passed as argument in every CONSTFUN call.
 401    ALIGN is maximum alignment we can assume.
 402    MEMSETP is true if this is a real memset/bzero, not a copy.
 403    Returns TO + LEN.  */
 404 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 405                             rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
 406                             void *, unsigned int, bool, int);
 407
 408 /* Emit insns to set X from Y.  */
 409 extern rtx emit_move_insn (rtx, rtx);
 410
 411 /* Emit insns to set X from Y, with no frills.  */
 412 extern rtx emit_move_insn_1 (rtx, rtx);
 413
 414 extern rtx emit_move_complex_push (enum machine_mode, rtx, rtx);
 415 extern rtx emit_move_complex_parts (rtx, rtx);
 416 extern rtx emit_move_resolve_push (enum machine_mode, rtx);
 417
 418 /* Push a block of length SIZE (perhaps variable)
 419    and return an rtx to address the beginning of the block.  */
 420 extern rtx push_block (rtx, int, int);
 421
 422 /* Generate code to push something onto the stack, given its mode and type.  */
 423 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
 424                             int, rtx, int, rtx, rtx, int, rtx);
 425
 426 /* Expand an assignment that stores the value of FROM into TO.  */
 427 extern void expand_assignment (tree, tree, bool);
 428
 429 /* Generate code for computing expression EXP,
 430    and storing the value into TARGET.
 431    If SUGGEST_REG is nonzero, copy the value through a register
 432    and return that register, if that is possible.  */
 433 extern rtx store_expr (tree, rtx, int, bool);
 434
 435 /* Given an rtx that may include add and multiply operations,
 436    generate them as insns and return a pseudo-reg containing the value.
 437    Useful after calling expand_expr with 1 as sum_ok.  */
 438 extern rtx force_operand (rtx, rtx);
 439
 440 /* Work horses for expand_expr.  */
 441 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
 442                              enum expand_modifier, rtx *, bool);
 443 extern rtx expand_expr_real_1 (tree, rtx, enum machine_mode,
 444                                enum expand_modifier, rtx *, bool);
 445 extern rtx expand_expr_real_2 (sepops, rtx, enum machine_mode,
 446                                enum expand_modifier);
 447
 448 /* Generate code for computing expression EXP.
 449    An rtx for the computed value is returned.  The value is never null.
 450    In the case of a void EXP, const0_rtx is returned.  */
 451 static inline rtx
 452 expand_expr (tree exp, rtx target, enum machine_mode mode,
 453              enum expand_modifier modifier)
 454 {
 455   return expand_expr_real (exp, target, mode, modifier, NULL, false);
 456 }
 457
 458 static inline rtx
 459 expand_normal (tree exp)
 460 {
 461   return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL, false);
 462 }
 463
 464 /* At the start of a function, record that we have no previously-pushed
 465    arguments waiting to be popped.  */
 466 extern void init_pending_stack_adjust (void);
 467
 468 /* Discard any pending stack adjustment.  */
 469 extern void discard_pending_stack_adjust (void);
 470
 471 /* When exiting from function, if safe, clear out any pending stack adjust
 472    so the adjustment won't get done.  */
 473 extern void clear_pending_stack_adjust (void);
 474
 475 /* Pop any previously-pushed arguments that have not been popped yet.  */
 476 extern void do_pending_stack_adjust (void);
 477
 478 /* Struct for saving/restoring of pending_stack_adjust/stack_pointer_delta
 479    values.  */
 480
 481 struct saved_pending_stack_adjust
 482 {
 483   /* Saved value of pending_stack_adjust.  */
 484   int x_pending_stack_adjust;
 485
 486   /* Saved value of stack_pointer_delta.  */
 487   int x_stack_pointer_delta;
 488 };
 489
 490 /* Remember pending_stack_adjust/stack_pointer_delta.
 491    To be used around code that may call do_pending_stack_adjust (),
 492    but the generated code could be discarded e.g. using delete_insns_since.  */
 493
 494 extern void save_pending_stack_adjust (saved_pending_stack_adjust *);
 495
 496 /* Restore the saved pending_stack_adjust/stack_pointer_delta.  */
 497
 498 extern void restore_pending_stack_adjust (saved_pending_stack_adjust *);
 499
 500 /* Return the tree node and offset if a given argument corresponds to
 501    a string constant.  */
 502 extern tree string_constant (tree, tree *);
 503
 504 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 505 extern void jumpifnot (tree, rtx, int);
 506 extern void jumpifnot_1 (enum tree_code, tree, tree, rtx, int);
 507
 508 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 509 extern void jumpif (tree, rtx, int);
 510 extern void jumpif_1 (enum tree_code, tree, tree, rtx, int);
 511
 512 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 513    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 514 extern void do_jump (tree, rtx, rtx, int);
 515 extern void do_jump_1 (enum tree_code, tree, tree, rtx, rtx, int);
 516
 517 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 518                                      enum machine_mode, rtx, rtx, rtx, int);
 519
 520 /* Two different ways of generating switch statements.  */
 521 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx, int);
 522 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx, int);
 523
 524 /* Functions from alias.c */
 525 #include "alias.h"
 526
 527 \f
 528 /* rtl.h and tree.h were included.  */
 529 /* Return an rtx for the size in bytes of the value of an expr.  */
 530 extern rtx expr_size (tree);
 531
 532 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 533    if the size can vary or is larger than an integer.  */
 534 extern HOST_WIDE_INT int_expr_size (tree);
 535
 536 /* Return an rtx that refers to the value returned by a function
 537    in its original home.  This becomes invalid if any more code is emitted.  */
 538 extern rtx hard_function_value (const_tree, const_tree, const_tree, int);
 539
 540 extern rtx prepare_call_address (tree, rtx, rtx, rtx *, int, int);
 541
 542 extern bool shift_return_value (enum machine_mode, bool, rtx);
 543
 544 extern rtx expand_call (tree, rtx, int);
 545
 546 extern void fixup_tail_calls (void);
 547
 548 #ifdef TREE_CODE
 549 extern rtx expand_variable_shift (enum tree_code, enum machine_mode,
 550                                   rtx, tree, rtx, int);
 551 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, int, rtx,
 552                              int);
 553 extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
 554                           rtx, int);
 555 #endif
 556
 557 extern void locate_and_pad_parm (enum machine_mode, tree, int, int, int,
 558                                  tree, struct args_size *,
 559                                  struct locate_and_pad_arg_data *);
 560
 561 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 562 extern rtx label_rtx (tree);
 563
 564 /* As label_rtx, but additionally the label is placed on the forced label
 565    list of its containing function (i.e. it is treated as reachable even
 566    if how is not obvious).  */
 567 extern rtx force_label_rtx (tree);
 568
 569 /* Return an rtx like arg but sans any constant terms.
 570    Returns the original rtx if it has no constant terms.
 571    The constant terms are added and stored via a second arg.  */
 572 extern rtx eliminate_constant_term (rtx, rtx *);
 573
 574 /* Convert arg to a valid memory address for specified machine mode that points
 575    to a specific named address space, by emitting insns to perform arithmetic
 576    if necessary.  */
 577 extern rtx memory_address_addr_space (enum machine_mode, rtx, addr_space_t);
 578
 579 /* Like memory_address_addr_space, except assume the memory address points to
 580    the generic named address space.  */
 581 #define memory_address(MODE,RTX) \
 582         memory_address_addr_space ((MODE), (RTX), ADDR_SPACE_GENERIC)
 583
 584 /* Return a memory reference like MEMREF, but with its mode changed
 585    to MODE and its address changed to ADDR.
 586    (VOIDmode means don't change the mode.
 587    NULL for ADDR means don't change the address.)  */
 588 extern rtx change_address (rtx, enum machine_mode, rtx);
 589
 590 /* Return a memory reference like MEMREF, but with its mode changed
 591    to MODE and its address offset by OFFSET bytes.  */
 592 #define adjust_address(MEMREF, MODE, OFFSET) \
 593   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 0, 0)
 594
 595 /* Likewise, but the reference is not required to be valid.  */
 596 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 597   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1, 0, 0)
 598
 599 /* Return a memory reference like MEMREF, but with its mode changed
 600    to MODE and its address offset by OFFSET bytes.  Assume that it's
 601    for a bitfield and conservatively drop the underlying object if we
 602    cannot be sure to stay within its bounds.  */
 603 #define adjust_bitfield_address(MEMREF, MODE, OFFSET) \
 604   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 1, 0)
 605
 606 /* As for adjust_bitfield_address, but specify that the width of
 607    BLKmode accesses is SIZE bytes.  */
 608 #define adjust_bitfield_address_size(MEMREF, MODE, OFFSET, SIZE) \
 609   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1, 1, SIZE)
 610
 611 /* Likewise, but the reference is not required to be valid.  */
 612 #define adjust_bitfield_address_nv(MEMREF, MODE, OFFSET) \
 613   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1, 1, 0)
 614
 615 /* Return a memory reference like MEMREF, but with its mode changed
 616    to MODE and its address changed to ADDR, which is assumed to be
 617    increased by OFFSET bytes from MEMREF.  */
 618 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 619   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 620
 621 /* Likewise, but the reference is not required to be valid.  */
 622 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 623   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 624
 625 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int,
 626                              int, HOST_WIDE_INT);
 627 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
 628                                         HOST_WIDE_INT, int);
 629
 630 /* Return a memory reference like MEMREF, but whose address is changed by
 631    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 632    known to be in OFFSET (possibly 1).  */
 633 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 634
 635 /* Definitions from emit-rtl.c */
 636 #include "emit-rtl.h"
 637
 638 /* Return a memory reference like MEMREF, but with its mode widened to
 639    MODE and adjusted by OFFSET.  */
 640 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
 641
 642 /* Return a memory reference like MEMREF, but which is known to have a
 643    valid address.  */
 644 extern rtx validize_mem (rtx);
 645
 646 extern rtx use_anchored_address (rtx);
 647
 648 /* Given REF, a MEM, and T, either the type of X or the expression
 649    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 650    if we are making a new object of this type.  */
 651 extern void set_mem_attributes (rtx, tree, int);
 652
 653 /* Similar, except that BITPOS has not yet been applied to REF, so if
 654    we alter MEM_OFFSET according to T then we should subtract BITPOS
 655    expecting that it'll be added back in later.  */
 656 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 657
 658 /* Return OFFSET if XEXP (MEM, 0) - OFFSET is known to be ALIGN
 659    bits aligned for 0 <= OFFSET < ALIGN / BITS_PER_UNIT, or
 660    -1 if not known.  */
 661 extern int get_mem_align_offset (rtx, unsigned int);
 662
 663 /* Assemble the static constant template for function entry trampolines.  */
 664 extern rtx assemble_trampoline_template (void);
 665
 666 /* Copy given rtx to a new temp reg and return that.  */
 667 extern rtx copy_to_reg (rtx);
 668
 669 /* Like copy_to_reg but always make the reg Pmode.  */
 670 extern rtx copy_addr_to_reg (rtx);
 671
 672 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 673 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
 674
 675 /* Copy given rtx to given temp reg and return that.  */
 676 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
 677
 678 /* Copy a value to a register if it isn't already a register.
 679    Args are mode (in case value is a constant) and the value.  */
 680 extern rtx force_reg (enum machine_mode, rtx);
 681
 682 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 683 extern rtx force_not_mem (rtx);
 684
 685 /* Return mode and signedness to use when an argument or result in the
 686    given mode is promoted.  */
 687 extern enum machine_mode promote_function_mode (const_tree, enum machine_mode, int *,
 688                                                 const_tree, int);
 689
 690 /* Return mode and signedness to use when an object in the given mode
 691    is promoted.  */
 692 extern enum machine_mode promote_mode (const_tree, enum machine_mode, int *);
 693
 694 /* Return mode and signedness to use when object is promoted.  */
 695 enum machine_mode promote_decl_mode (const_tree, int *);
 696
 697 /* Remove some bytes from the stack.  An rtx says how many.  */
 698 extern void adjust_stack (rtx);
 699
 700 /* Add some bytes to the stack.  An rtx says how many.  */
 701 extern void anti_adjust_stack (rtx);
 702
 703 /* Add some bytes to the stack while probing it.  An rtx says how many. */
 704 extern void anti_adjust_stack_and_probe (rtx, bool);
 705
 706 /* This enum is used for the following two functions.  */
 707 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 708
 709 /* Save the stack pointer at the specified level.  */
 710 extern void emit_stack_save (enum save_level, rtx *);
 711
 712 /* Restore the stack pointer from a save area of the specified level.  */
 713 extern void emit_stack_restore (enum save_level, rtx);
 714
 715 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 716 extern void update_nonlocal_goto_save_area (void);
 717
 718 /* Allocate some space on the stack dynamically and return its address.  */
 719 extern rtx allocate_dynamic_stack_space (rtx, unsigned, unsigned, bool);
 720
 721 /* Emit one stack probe at ADDRESS, an address within the stack.  */
 722 extern void emit_stack_probe (rtx);
 723
 724 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 725    FIRST is a constant and size is a Pmode RTX.  These are offsets from
 726    the current stack pointer.  STACK_GROWS_DOWNWARD says whether to add
 727    or subtract them from the stack pointer.  */
 728 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 729
 730 /* Return an rtx that refers to the value returned by a library call
 731    in its original home.  This becomes invalid if any more code is emitted.  */
 732 extern rtx hard_libcall_value (enum machine_mode, rtx);
 733
 734 extern void store_bit_field (rtx, unsigned HOST_WIDE_INT,
 735                              unsigned HOST_WIDE_INT,
 736                              unsigned HOST_WIDE_INT,
 737                              unsigned HOST_WIDE_INT,
 738                              enum machine_mode, rtx);
 739 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 740                               unsigned HOST_WIDE_INT, int, rtx,
 741                               enum machine_mode, enum machine_mode);
 742 extern rtx extract_low_bits (enum machine_mode, enum machine_mode, rtx);
 743 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
 744 extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
 745
 746 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
 747 extern int safe_from_p (const_rtx, tree, int);
 748 extern bool split_comparison (enum rtx_code, enum machine_mode,
 749                               enum rtx_code *, enum rtx_code *);
 750
 751 /* Call this once to initialize the contents of the optabs
 752    appropriately for the current target machine.  */
 753 extern void init_optabs (void);
 754 extern void init_all_optabs (struct target_optabs *);
 755
 756 /* Call this to initialize an optab function entry.  */
 757 extern rtx init_one_libfunc (const char *);
 758 extern rtx set_user_assembler_libfunc (const char *, const char *);
 759
 760 /* Build a decl for a libfunc named NAME. */
 761 extern tree build_libfunc_function (const char *);
 762
 763 /* Get the personality libfunc for a function decl.  */
 764 rtx get_personality_function (tree);
 765
 766
 767 /* In stmt.c */
 768
 769 /* Expand a GIMPLE_SWITCH statement.  */
 770 extern void expand_case (gimple);
 771
 772 /* Like expand_case but special-case for SJLJ exception dispatching.  */
 773 extern void expand_sjlj_dispatch_table (rtx, vec<tree> );
 774
 775 /* Determine whether the LEN bytes can be moved by using several move
 776    instructions.  Return nonzero if a call to move_by_pieces should
 777    succeed.  */
 778 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 779
 780 extern unsigned HOST_WIDE_INT highest_pow2_factor (const_tree);
 781 bool array_at_struct_end_p (tree);
 782
 783 /* Return a tree of sizetype representing the size, in bytes, of the element
 784    of EXP, an ARRAY_REF or an ARRAY_RANGE_REF.  */
 785 extern tree array_ref_element_size (tree);
 786
 787 extern bool categorize_ctor_elements (const_tree, HOST_WIDE_INT *,
 788                                       HOST_WIDE_INT *, bool *);
 789
 790 /* Return a tree representing the offset, in bytes, of the field referenced
 791    by EXP.  This does not include any offset in DECL_FIELD_BIT_OFFSET.  */
 792 extern tree component_ref_field_offset (tree);
 793
 794 #endif /* GCC_EXPR_H */