gcc/expr.h

   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 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  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, convert, size_binop, ssize_int, TREE_CODE,
  32    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 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 \f
  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 2
  70 #else
  71 /* If we are optimizing for space (-Os), cut down the default move ratio.  */
  72 #define MOVE_RATIO (optimize_size ? 3 : 15)
  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 clrmem or libcall instead.  */
  78
  79 #ifndef CLEAR_RATIO
  80 #if defined (HAVE_clrmemqi) || defined (HAVE_clrmemhi) || defined (HAVE_clrmemsi) || defined (HAVE_clrmemdi) || defined (HAVE_clrmemti)
  81 #define CLEAR_RATIO 2
  82 #else
  83 /* If we are optimizing for space, cut down the default clear ratio.  */
  84 #define CLEAR_RATIO (optimize_size ? 3 : 15)
  85 #endif
  86 #endif
  87 \f
  88 enum direction {none, upward, downward};
  89
  90 /* Structure to record the size of a sequence of arguments
  91    as the sum of a tree-expression and a constant.  This structure is
  92    also used to store offsets from the stack, which might be negative,
  93    so the variable part must be ssizetype, not sizetype.  */
  94
  95 struct args_size
  96 {
  97   HOST_WIDE_INT constant;
  98   tree var;
  99 };
 100
 101 /* Package up various arg related fields of struct args for
 102    locate_and_pad_parm.  */
 103 struct locate_and_pad_arg_data
 104 {
 105   /* Size of this argument on the stack, rounded up for any padding it
 106      gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
 107      counted here, otherwise they aren't.  */
 108   struct args_size size;
 109   /* Offset of this argument from beginning of stack-args.  */
 110   struct args_size offset;
 111   /* Offset to the start of the stack slot.  Different from OFFSET
 112      if this arg pads downward.  */
 113   struct args_size slot_offset;
 114   /* The amount that the stack pointer needs to be adjusted to
 115      force alignment for the next argument.  */
 116   struct args_size alignment_pad;
 117   /* Which way we should pad this arg.  */
 118   enum direction where_pad;
 119 };
 120
 121 /* Add the value of the tree INC to the `struct args_size' TO.  */
 122
 123 #define ADD_PARM_SIZE(TO, INC)                          \
 124 do {                                                    \
 125   tree inc = (INC);                                     \
 126   if (host_integerp (inc, 0))                           \
 127     (TO).constant += tree_low_cst (inc, 0);             \
 128   else if ((TO).var == 0)                               \
 129     (TO).var = convert (ssizetype, inc);                \
 130   else                                                  \
 131     (TO).var = size_binop (PLUS_EXPR, (TO).var,         \
 132                            convert (ssizetype, inc));   \
 133 } while (0)
 134
 135 #define SUB_PARM_SIZE(TO, DEC)                          \
 136 do {                                                    \
 137   tree dec = (DEC);                                     \
 138   if (host_integerp (dec, 0))                           \
 139     (TO).constant -= tree_low_cst (dec, 0);             \
 140   else if ((TO).var == 0)                               \
 141     (TO).var = size_binop (MINUS_EXPR, ssize_int (0),   \
 142                            convert (ssizetype, dec));   \
 143   else                                                  \
 144     (TO).var = size_binop (MINUS_EXPR, (TO).var,        \
 145                            convert (ssizetype, dec));   \
 146 } while (0)
 147
 148 /* Convert the implicit sum in a `struct args_size' into a tree
 149    of type ssizetype.  */
 150 #define ARGS_SIZE_TREE(SIZE)                                    \
 151 ((SIZE).var == 0 ? ssize_int ((SIZE).constant)                  \
 152  : size_binop (PLUS_EXPR, convert (ssizetype, (SIZE).var),      \
 153                ssize_int ((SIZE).constant)))
 154
 155 /* Convert the implicit sum in a `struct args_size' into an rtx.  */
 156 #define ARGS_SIZE_RTX(SIZE)                                     \
 157 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant)                    \
 158  : expand_expr (ARGS_SIZE_TREE (SIZE), NULL_RTX, VOIDmode, 0))
 159
 160 /* Supply a default definition for FUNCTION_ARG_PADDING:
 161    usually pad upward, but pad short args downward on
 162    big-endian machines.  */
 163
 164 #define DEFAULT_FUNCTION_ARG_PADDING(MODE, TYPE)                        \
 165   (! BYTES_BIG_ENDIAN                                                   \
 166    ? upward                                                             \
 167    : (((MODE) == BLKmode                                                \
 168        ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST         \
 169           && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
 170        : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)                       \
 171       ? downward : upward))
 172
 173 #ifndef FUNCTION_ARG_PADDING
 174 #define FUNCTION_ARG_PADDING(MODE, TYPE)        \
 175   DEFAULT_FUNCTION_ARG_PADDING ((MODE), (TYPE))
 176 #endif
 177
 178 /* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
 179    FUNCTION_ARG_PADDING, which also pads the length, handle any needed
 180    alignment.  */
 181
 182 #ifndef FUNCTION_ARG_BOUNDARY
 183 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE)       PARM_BOUNDARY
 184 #endif
 185
 186 /* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
 187    Normally move_insn, so Pmode stack pointer.  */
 188
 189 #ifndef STACK_SAVEAREA_MODE
 190 #define STACK_SAVEAREA_MODE(LEVEL) Pmode
 191 #endif
 192
 193 /* Supply a default definition of STACK_SIZE_MODE for
 194    allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
 195
 196 #ifndef STACK_SIZE_MODE
 197 #define STACK_SIZE_MODE word_mode
 198 #endif
 199
 200 /* Provide default values for the macros controlling stack checking.  */
 201
 202 #ifndef STACK_CHECK_BUILTIN
 203 #define STACK_CHECK_BUILTIN 0
 204 #endif
 205
 206 /* The default interval is one page.  */
 207 #ifndef STACK_CHECK_PROBE_INTERVAL
 208 #define STACK_CHECK_PROBE_INTERVAL 4096
 209 #endif
 210
 211 /* The default is to do a store into the stack.  */
 212 #ifndef STACK_CHECK_PROBE_LOAD
 213 #define STACK_CHECK_PROBE_LOAD 0
 214 #endif
 215
 216 /* This value is arbitrary, but should be sufficient for most machines.  */
 217 #ifndef STACK_CHECK_PROTECT
 218 #define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
 219 #endif
 220
 221 /* Make the maximum frame size be the largest we can and still only need
 222    one probe per function.  */
 223 #ifndef STACK_CHECK_MAX_FRAME_SIZE
 224 #define STACK_CHECK_MAX_FRAME_SIZE \
 225   (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
 226 #endif
 227
 228 /* This is arbitrary, but should be large enough everywhere.  */
 229 #ifndef STACK_CHECK_FIXED_FRAME_SIZE
 230 #define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
 231 #endif
 232
 233 /* Provide a reasonable default for the maximum size of an object to
 234    allocate in the fixed frame.  We may need to be able to make this
 235    controllable by the user at some point.  */
 236 #ifndef STACK_CHECK_MAX_VAR_SIZE
 237 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
 238 #endif
 239 \f
 240 /* Functions from optabs.c, commonly used, and without need for the optabs
 241    tables:  */
 242
 243 /* Passed to expand_simple_binop and expand_binop to say which options
 244    to try to use if the requested operation can't be open-coded on the
 245    requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
 246    a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
 247    using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
 248    try anything else.  */
 249
 250 enum optab_methods
 251 {
 252   OPTAB_DIRECT,
 253   OPTAB_LIB,
 254   OPTAB_WIDEN,
 255   OPTAB_LIB_WIDEN,
 256   OPTAB_MUST_WIDEN
 257 };
 258
 259 /* Generate code for a simple binary or unary operation.  "Simple" in
 260    this case means "can be unambiguously described by a (mode, code)
 261    pair and mapped to a single optab."  */
 262 extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
 263                                 rtx, rtx, int, enum optab_methods);
 264 extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
 265                                int);
 266
 267 /* Report whether the machine description contains an insn which can
 268    perform the operation described by CODE and MODE.  */
 269 extern int have_insn_for (enum rtx_code, enum machine_mode);
 270
 271 /* Emit code to make a call to a constant function or a library call.  */
 272 extern void emit_libcall_block (rtx, rtx, rtx, rtx);
 273
 274 /* Create but don't emit one rtl instruction to perform certain operations.
 275    Modes must match; operands must meet the operation's predicates.
 276    Likewise for subtraction and for just copying.  */
 277 extern rtx gen_add2_insn (rtx, rtx);
 278 extern rtx gen_add3_insn (rtx, rtx, rtx);
 279 extern rtx gen_sub2_insn (rtx, rtx);
 280 extern rtx gen_sub3_insn (rtx, rtx, rtx);
 281 extern rtx gen_move_insn (rtx, rtx);
 282 extern int have_add2_insn (rtx, rtx);
 283 extern int have_sub2_insn (rtx, rtx);
 284
 285 /* Emit a pair of rtl insns to compare two rtx's and to jump
 286    to a label if the comparison is true.  */
 287 extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
 288                                      enum machine_mode, int, rtx);
 289
 290 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 291 extern void emit_indirect_jump (rtx);
 292
 293 /* Generate a conditional trap instruction.  */
 294 extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
 295
 296 #include "insn-config.h"
 297
 298 #ifdef HAVE_conditional_move
 299 /* Emit a conditional move operation.  */
 300 rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 301                            rtx, rtx, enum machine_mode, int);
 302
 303 /* Return nonzero if the conditional move is supported.  */
 304 int can_conditionally_move_p (enum machine_mode mode);
 305
 306 #endif
 307 rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 308                           rtx, rtx, enum machine_mode, int);
 309
 310 \f
 311 /* Functions from expmed.c:  */
 312
 313 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 314    May emit insns.  */
 315 extern rtx negate_rtx (enum machine_mode, rtx);
 316
 317 /* Expand a logical AND operation.  */
 318 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
 319
 320 /* Emit a store-flag operation.  */
 321 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 322                             int, int);
 323
 324 /* Like emit_store_flag, but always succeeds.  */
 325 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 326                                   enum machine_mode, int, int);
 327 \f
 328 /* Functions from builtins.c:  */
 329 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 330 extern tree std_build_builtin_va_list (void);
 331 extern void std_expand_builtin_va_start (tree, rtx);
 332 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 333 extern void expand_builtin_setjmp_setup (rtx, rtx);
 334 extern void expand_builtin_setjmp_receiver (rtx);
 335 extern rtx expand_builtin_saveregs (void);
 336 \f
 337 /* Functions from expr.c:  */
 338
 339 /* This is run once per compilation to set up which modes can be used
 340    directly in memory and to initialize the block move optab.  */
 341 extern void init_expr_once (void);
 342
 343 /* This is run at the start of compiling a function.  */
 344 extern void init_expr (void);
 345
 346 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 347    Both modes must be floating or both fixed.  */
 348 extern void convert_move (rtx, rtx, int);
 349
 350 /* Convert an rtx to specified machine mode and return the result.  */
 351 extern rtx convert_to_mode (enum machine_mode, rtx, int);
 352
 353 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 354 extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
 355
 356 /* Emit code to move a block Y to a block X.  */
 357
 358 enum block_op_methods
 359 {
 360   BLOCK_OP_NORMAL,
 361   BLOCK_OP_NO_LIBCALL,
 362   BLOCK_OP_CALL_PARM
 363 };
 364
 365 extern void init_block_move_fn (const char *);
 366 extern void init_block_clear_fn (const char *);
 367
 368 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 369
 370 /* Copy all or part of a value X into registers starting at REGNO.
 371    The number of registers to be filled is NREGS.  */
 372 extern void move_block_to_reg (int, rtx, int, enum machine_mode);
 373
 374 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 375    The number of registers to be filled is NREGS.  */
 376 extern void move_block_from_reg (int, rtx, int);
 377
 378 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 379 extern rtx gen_group_rtx (rtx);
 380
 381 /* Load a BLKmode value into non-consecutive registers represented by a
 382    PARALLEL.  */
 383 extern void emit_group_load (rtx, rtx, tree, int);
 384
 385 /* Similarly, but load into new temporaries.  */
 386 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
 387
 388 /* Move a non-consecutive group of registers represented by a PARALLEL into
 389    a non-consecutive group of registers represented by a PARALLEL.  */
 390 extern void emit_group_move (rtx, rtx);
 391
 392 /* Move a group of registers represented by a PARALLEL into pseudos.  */
 393 extern rtx emit_group_move_into_temps (rtx);
 394
 395 /* Store a BLKmode value from non-consecutive registers represented by a
 396    PARALLEL.  */
 397 extern void emit_group_store (rtx, rtx, tree, int);
 398
 399 /* Copy BLKmode object from a set of registers.  */
 400 extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
 401
 402 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 403 extern void use_reg (rtx *, rtx);
 404
 405 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 406    for the next CALL_INSN.  */
 407 extern void use_regs (rtx *, int, int);
 408
 409 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 410 extern void use_group_regs (rtx *, rtx);
 411
 412 /* Write zeros through the storage of OBJECT.
 413    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 414 extern rtx clear_storage (rtx, rtx);
 415
 416 /* Determine whether the LEN bytes can be moved by using several move
 417    instructions.  Return nonzero if a call to move_by_pieces should
 418    succeed.  */
 419 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 420
 421 /* Return nonzero if it is desirable to store LEN bytes generated by
 422    CONSTFUN with several move instructions by store_by_pieces
 423    function.  CONSTFUNDATA is a pointer which will be passed as argument
 424    in every CONSTFUN call.
 425    ALIGN is maximum alignment we can assume.  */
 426 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 427                                 rtx (*) (void *, HOST_WIDE_INT,
 428                                          enum machine_mode),
 429                                 void *, unsigned int);
 430
 431 /* Generate several move instructions to store LEN bytes generated by
 432    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 433    pointer which will be passed as argument in every CONSTFUN call.
 434    ALIGN is maximum alignment we can assume.
 435    Returns TO + LEN.  */
 436 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 437                             rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
 438                             void *, unsigned int, int);
 439
 440 /* Emit insns to set X from Y.  */
 441 extern rtx emit_move_insn (rtx, rtx);
 442
 443 /* Emit insns to set X from Y, with no frills.  */
 444 extern rtx emit_move_insn_1 (rtx, rtx);
 445
 446 /* Push a block of length SIZE (perhaps variable)
 447    and return an rtx to address the beginning of the block.  */
 448 extern rtx push_block (rtx, int, int);
 449
 450 /* Generate code to push something onto the stack, given its mode and type.  */
 451 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
 452                             int, rtx, int, rtx, rtx, int, rtx);
 453
 454 /* Expand an assignment that stores the value of FROM into TO.  */
 455 extern void expand_assignment (tree, tree);
 456
 457 /* Generate code for computing expression EXP,
 458    and storing the value into TARGET.
 459    If SUGGEST_REG is nonzero, copy the value through a register
 460    and return that register, if that is possible.  */
 461 extern rtx store_expr (tree, rtx, int);
 462
 463 /* Given an rtx that may include add and multiply operations,
 464    generate them as insns and return a pseudo-reg containing the value.
 465    Useful after calling expand_expr with 1 as sum_ok.  */
 466 extern rtx force_operand (rtx, rtx);
 467
 468 /* Work horse for expand_expr.  */
 469 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
 470                              enum expand_modifier, rtx *);
 471
 472 /* Generate code for computing expression EXP.
 473    An rtx for the computed value is returned.  The value is never null.
 474    In the case of a void EXP, const0_rtx is returned.  */
 475 static inline rtx
 476 expand_expr (tree exp, rtx target, enum machine_mode mode,
 477              enum expand_modifier modifier)
 478 {
 479   return expand_expr_real (exp, target, mode, modifier, NULL);
 480 }
 481
 482 extern void expand_var (tree);
 483
 484 /* At the start of a function, record that we have no previously-pushed
 485    arguments waiting to be popped.  */
 486 extern void init_pending_stack_adjust (void);
 487
 488 /* Discard any pending stack adjustment.  */
 489 extern void discard_pending_stack_adjust (void);
 490
 491 /* When exiting from function, if safe, clear out any pending stack adjust
 492    so the adjustment won't get done.  */
 493 extern void clear_pending_stack_adjust (void);
 494
 495 /* Pop any previously-pushed arguments that have not been popped yet.  */
 496 extern void do_pending_stack_adjust (void);
 497
 498 /* Return the tree node and offset if a given argument corresponds to
 499    a string constant.  */
 500 extern tree string_constant (tree, tree *);
 501
 502 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 503 extern void jumpifnot (tree, rtx);
 504
 505 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 506 extern void jumpif (tree, rtx);
 507
 508 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 509    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 510 extern void do_jump (tree, rtx, rtx);
 511
 512 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 513 extern rtx compare_from_rtx (rtx, rtx, enum rtx_code, int, enum machine_mode,
 514                              rtx);
 515 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 516                                      enum machine_mode, rtx, rtx, rtx);
 517
 518 /* Two different ways of generating switch statements.  */
 519 extern int try_casesi (tree, tree, tree, tree, rtx, rtx);
 520 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
 521
 522 /* Smallest number of adjacent cases before we use a jump table.
 523    XXX Should be a target hook.  */
 524 extern unsigned int case_values_threshold (void);
 525
 526 /* Functions from alias.c */
 527 #include "alias.h"
 528
 529 \f
 530 /* rtl.h and tree.h were included.  */
 531 /* Return an rtx for the size in bytes of the value of an expr.  */
 532 extern rtx expr_size (tree);
 533
 534 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 535    if the size can vary or is larger than an integer.  */
 536 extern HOST_WIDE_INT int_expr_size (tree);
 537
 538 /* Return an rtx that refers to the value returned by a function
 539    in its original home.  This becomes invalid if any more code is emitted.  */
 540 extern rtx hard_function_value (tree, tree, int);
 541
 542 extern rtx prepare_call_address (rtx, rtx, rtx *, int, int);
 543
 544 extern bool shift_return_value (enum machine_mode, bool, rtx);
 545
 546 extern rtx expand_call (tree, rtx, int);
 547
 548 extern void fixup_tail_calls (void);
 549
 550 #ifdef TREE_CODE
 551 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, 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, tree,
 558                                  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 /* Indicate how an input argument register was promoted.  */
 570 extern rtx promoted_input_arg (unsigned int, enum machine_mode *, int *);
 571
 572 /* Return an rtx like arg but sans any constant terms.
 573    Returns the original rtx if it has no constant terms.
 574    The constant terms are added and stored via a second arg.  */
 575 extern rtx eliminate_constant_term (rtx, rtx *);
 576
 577 /* Convert arg to a valid memory address for specified machine mode,
 578    by emitting insns to perform arithmetic if nec.  */
 579 extern rtx memory_address (enum machine_mode, rtx);
 580
 581 /* Like `memory_address' but pretent `flag_force_addr' is 0.  */
 582 extern rtx memory_address_noforce (enum machine_mode, rtx);
 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)
 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)
 598
 599 /* Return a memory reference like MEMREF, but with its mode changed
 600    to MODE and its address changed to ADDR, which is assumed to be
 601    increased by OFFSET bytes from MEMREF.  */
 602 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 603   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 604
 605 /* Likewise, but the reference is not required to be valid.  */
 606 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 607   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 608
 609 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
 610 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
 611                                         HOST_WIDE_INT, int);
 612
 613 /* Return a memory reference like MEMREF, but whose address is changed by
 614    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 615    known to be in OFFSET (possibly 1).  */
 616 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 617
 618 /* Definitions from emit-rtl.c */
 619 #include "emit-rtl.h"
 620
 621 /* Return a memory reference like MEMREF, but with its mode widened to
 622    MODE and adjusted by OFFSET.  */
 623 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
 624
 625 /* Return a memory reference like MEMREF, but which is known to have a
 626    valid address.  */
 627 extern rtx validize_mem (rtx);
 628
 629 /* Given REF, a MEM, and T, either the type of X or the expression
 630    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 631    if we are making a new object of this type.  */
 632 extern void set_mem_attributes (rtx, tree, int);
 633
 634 /* Similar, except that BITPOS has not yet been applied to REF, so if
 635    we alter MEM_OFFSET according to T then we should subtract BITPOS
 636    expecting that it'll be added back in later.  */
 637 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 638
 639 /* Assemble the static constant template for function entry trampolines.  */
 640 extern rtx assemble_trampoline_template (void);
 641
 642 /* Given rtx, return new rtx whose address won't be affected by
 643    any side effects.  It has been copied to a new temporary reg.  */
 644 extern rtx stabilize (rtx);
 645
 646 /* Given an rtx, copy all regs it refers to into new temps
 647    and return a modified copy that refers to the new temps.  */
 648 extern rtx copy_all_regs (rtx);
 649
 650 /* Copy given rtx to a new temp reg and return that.  */
 651 extern rtx copy_to_reg (rtx);
 652
 653 /* Like copy_to_reg but always make the reg Pmode.  */
 654 extern rtx copy_addr_to_reg (rtx);
 655
 656 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 657 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
 658
 659 /* Copy given rtx to given temp reg and return that.  */
 660 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
 661
 662 /* Copy a value to a register if it isn't already a register.
 663    Args are mode (in case value is a constant) and the value.  */
 664 extern rtx force_reg (enum machine_mode, rtx);
 665
 666 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 667 extern rtx force_not_mem (rtx);
 668
 669 /* Return mode and signedness to use when object is promoted.  */
 670 extern enum machine_mode promote_mode (tree, enum machine_mode, int *, int);
 671
 672 /* Remove some bytes from the stack.  An rtx says how many.  */
 673 extern void adjust_stack (rtx);
 674
 675 /* Add some bytes to the stack.  An rtx says how many.  */
 676 extern void anti_adjust_stack (rtx);
 677
 678 /* This enum is used for the following two functions.  */
 679 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 680
 681 /* Save the stack pointer at the specified level.  */
 682 extern void emit_stack_save (enum save_level, rtx *, rtx);
 683
 684 /* Restore the stack pointer from a save area of the specified level.  */
 685 extern void emit_stack_restore (enum save_level, rtx, rtx);
 686
 687 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 688 extern void update_nonlocal_goto_save_area (void);
 689
 690 /* Allocate some space on the stack dynamically and return its address.  An rtx
 691    says how many bytes.  */
 692 extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
 693
 694 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 695    FIRST is a constant and size is a Pmode RTX.  These are offsets from the
 696    current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
 697    subtract from the stack.  If SIZE is constant, this is done
 698    with a fixed number of probes.  Otherwise, we must make a loop.  */
 699 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 700
 701 /* Return an rtx that refers to the value returned by a library call
 702    in its original home.  This becomes invalid if any more code is emitted.  */
 703 extern rtx hard_libcall_value (enum machine_mode);
 704
 705 /* Return the mode desired by operand N of a particular bitfield
 706    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
 707    available.  */
 708
 709 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
 710 extern enum machine_mode
 711 mode_for_extraction (enum extraction_pattern, int);
 712
 713 extern rtx store_bit_field (rtx, unsigned HOST_WIDE_INT,
 714                             unsigned HOST_WIDE_INT, enum machine_mode, rtx);
 715 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 716                               unsigned HOST_WIDE_INT, int, rtx,
 717                               enum machine_mode, enum machine_mode);
 718 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
 719 extern bool const_mult_add_overflow_p (rtx, rtx, rtx, enum machine_mode, int);
 720 extern rtx expand_mult_add (rtx, rtx, rtx, rtx,enum machine_mode, int);
 721 extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
 722
 723 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
 724 extern int safe_from_p (rtx, tree, int);
 725
 726 /* Call this once to initialize the contents of the optabs
 727    appropriately for the current target machine.  */
 728 extern void init_optabs (void);
 729 extern void init_all_optabs (void);
 730
 731 /* Call this to initialize an optab function entry.  */
 732 extern rtx init_one_libfunc (const char *);
 733
 734 extern void do_jump_by_parts_equality_rtx (rtx, rtx, rtx);
 735 extern void do_jump_by_parts_greater_rtx (enum machine_mode, int, rtx, rtx,
 736                                           rtx, rtx);
 737
 738 extern int vector_mode_valid_p (enum machine_mode);
 739
 740 #endif /* GCC_EXPR_H */