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 #ifndef FUNCTION_ARG_PARTIAL_NREGS
 187 #define FUNCTION_ARG_PARTIAL_NREGS(CUM, MODE, TYPE, NAMED) 0
 188 #endif
 189
 190 /* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
 191    Normally move_insn, so Pmode stack pointer.  */
 192
 193 #ifndef STACK_SAVEAREA_MODE
 194 #define STACK_SAVEAREA_MODE(LEVEL) Pmode
 195 #endif
 196
 197 /* Supply a default definition of STACK_SIZE_MODE for
 198    allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
 199
 200 #ifndef STACK_SIZE_MODE
 201 #define STACK_SIZE_MODE word_mode
 202 #endif
 203
 204 /* Provide default values for the macros controlling stack checking.  */
 205
 206 #ifndef STACK_CHECK_BUILTIN
 207 #define STACK_CHECK_BUILTIN 0
 208 #endif
 209
 210 /* The default interval is one page.  */
 211 #ifndef STACK_CHECK_PROBE_INTERVAL
 212 #define STACK_CHECK_PROBE_INTERVAL 4096
 213 #endif
 214
 215 /* The default is to do a store into the stack.  */
 216 #ifndef STACK_CHECK_PROBE_LOAD
 217 #define STACK_CHECK_PROBE_LOAD 0
 218 #endif
 219
 220 /* This value is arbitrary, but should be sufficient for most machines.  */
 221 #ifndef STACK_CHECK_PROTECT
 222 #define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
 223 #endif
 224
 225 /* Make the maximum frame size be the largest we can and still only need
 226    one probe per function.  */
 227 #ifndef STACK_CHECK_MAX_FRAME_SIZE
 228 #define STACK_CHECK_MAX_FRAME_SIZE \
 229   (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
 230 #endif
 231
 232 /* This is arbitrary, but should be large enough everywhere.  */
 233 #ifndef STACK_CHECK_FIXED_FRAME_SIZE
 234 #define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
 235 #endif
 236
 237 /* Provide a reasonable default for the maximum size of an object to
 238    allocate in the fixed frame.  We may need to be able to make this
 239    controllable by the user at some point.  */
 240 #ifndef STACK_CHECK_MAX_VAR_SIZE
 241 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
 242 #endif
 243 \f
 244 /* Functions from optabs.c, commonly used, and without need for the optabs
 245    tables:  */
 246
 247 /* Passed to expand_simple_binop and expand_binop to say which options
 248    to try to use if the requested operation can't be open-coded on the
 249    requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
 250    a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
 251    using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
 252    try anything else.  */
 253
 254 enum optab_methods
 255 {
 256   OPTAB_DIRECT,
 257   OPTAB_LIB,
 258   OPTAB_WIDEN,
 259   OPTAB_LIB_WIDEN,
 260   OPTAB_MUST_WIDEN
 261 };
 262
 263 /* Generate code for a simple binary or unary operation.  "Simple" in
 264    this case means "can be unambiguously described by a (mode, code)
 265    pair and mapped to a single optab."  */
 266 extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
 267                                 rtx, rtx, int, enum optab_methods);
 268 extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
 269                                int);
 270
 271 /* Report whether the machine description contains an insn which can
 272    perform the operation described by CODE and MODE.  */
 273 extern int have_insn_for (enum rtx_code, enum machine_mode);
 274
 275 /* Emit code to make a call to a constant function or a library call.  */
 276 extern void emit_libcall_block (rtx, rtx, rtx, rtx);
 277
 278 /* Create but don't emit one rtl instruction to perform certain operations.
 279    Modes must match; operands must meet the operation's predicates.
 280    Likewise for subtraction and for just copying.  */
 281 extern rtx gen_add2_insn (rtx, rtx);
 282 extern rtx gen_add3_insn (rtx, rtx, rtx);
 283 extern rtx gen_sub2_insn (rtx, rtx);
 284 extern rtx gen_sub3_insn (rtx, rtx, rtx);
 285 extern rtx gen_move_insn (rtx, rtx);
 286 extern int have_add2_insn (rtx, rtx);
 287 extern int have_sub2_insn (rtx, rtx);
 288
 289 /* Emit a pair of rtl insns to compare two rtx's and to jump
 290    to a label if the comparison is true.  */
 291 extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
 292                                      enum machine_mode, int, rtx);
 293
 294 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 295 extern void emit_indirect_jump (rtx);
 296
 297 /* Generate a conditional trap instruction.  */
 298 extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
 299
 300 #include "insn-config.h"
 301
 302 #ifdef HAVE_conditional_move
 303 /* Emit a conditional move operation.  */
 304 rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 305                            rtx, rtx, enum machine_mode, int);
 306
 307 /* Return nonzero if the conditional move is supported.  */
 308 int can_conditionally_move_p (enum machine_mode mode);
 309
 310 #endif
 311 rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 312                           rtx, rtx, enum machine_mode, int);
 313
 314 \f
 315 /* Functions from expmed.c:  */
 316
 317 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 318    May emit insns.  */
 319 extern rtx negate_rtx (enum machine_mode, rtx);
 320
 321 /* Expand a logical AND operation.  */
 322 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
 323
 324 /* Emit a store-flag operation.  */
 325 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 326                             int, int);
 327
 328 /* Like emit_store_flag, but always succeeds.  */
 329 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 330                                   enum machine_mode, int, int);
 331 \f
 332 /* Functions from builtins.c:  */
 333 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 334 extern tree std_build_builtin_va_list (void);
 335 extern void std_expand_builtin_va_start (tree, rtx);
 336 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 337 extern void expand_builtin_setjmp_setup (rtx, rtx);
 338 extern void expand_builtin_setjmp_receiver (rtx);
 339 extern rtx expand_builtin_saveregs (void);
 340 \f
 341 /* Functions from expr.c:  */
 342
 343 /* This is run once per compilation to set up which modes can be used
 344    directly in memory and to initialize the block move optab.  */
 345 extern void init_expr_once (void);
 346
 347 /* This is run at the start of compiling a function.  */
 348 extern void init_expr (void);
 349
 350 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 351    Both modes must be floating or both fixed.  */
 352 extern void convert_move (rtx, rtx, int);
 353
 354 /* Convert an rtx to specified machine mode and return the result.  */
 355 extern rtx convert_to_mode (enum machine_mode, rtx, int);
 356
 357 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 358 extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
 359
 360 /* Emit code to move a block Y to a block X.  */
 361
 362 enum block_op_methods
 363 {
 364   BLOCK_OP_NORMAL,
 365   BLOCK_OP_NO_LIBCALL,
 366   BLOCK_OP_CALL_PARM
 367 };
 368
 369 extern void init_block_move_fn (const char *);
 370 extern void init_block_clear_fn (const char *);
 371
 372 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 373
 374 /* Copy all or part of a value X into registers starting at REGNO.
 375    The number of registers to be filled is NREGS.  */
 376 extern void move_block_to_reg (int, rtx, int, enum machine_mode);
 377
 378 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 379    The number of registers to be filled is NREGS.  */
 380 extern void move_block_from_reg (int, rtx, int);
 381
 382 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 383 extern rtx gen_group_rtx (rtx);
 384
 385 /* Load a BLKmode value into non-consecutive registers represented by a
 386    PARALLEL.  */
 387 extern void emit_group_load (rtx, rtx, tree, int);
 388
 389 /* Similarly, but load into new temporaries.  */
 390 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
 391
 392 /* Move a non-consecutive group of registers represented by a PARALLEL into
 393    a non-consecutive group of registers represented by a PARALLEL.  */
 394 extern void emit_group_move (rtx, rtx);
 395
 396 /* Move a group of registers represented by a PARALLEL into pseudos.  */
 397 extern rtx emit_group_move_into_temps (rtx);
 398
 399 /* Store a BLKmode value from non-consecutive registers represented by a
 400    PARALLEL.  */
 401 extern void emit_group_store (rtx, rtx, tree, int);
 402
 403 /* Copy BLKmode object from a set of registers.  */
 404 extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
 405
 406 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 407 extern void use_reg (rtx *, rtx);
 408
 409 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 410    for the next CALL_INSN.  */
 411 extern void use_regs (rtx *, int, int);
 412
 413 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 414 extern void use_group_regs (rtx *, rtx);
 415
 416 /* Write zeros through the storage of OBJECT.
 417    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 418 extern rtx clear_storage (rtx, rtx);
 419
 420 /* Determine whether the LEN bytes can be moved by using several move
 421    instructions.  Return nonzero if a call to move_by_pieces should
 422    succeed.  */
 423 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 424
 425 /* Return nonzero if it is desirable to store LEN bytes generated by
 426    CONSTFUN with several move instructions by store_by_pieces
 427    function.  CONSTFUNDATA is a pointer which will be passed as argument
 428    in every CONSTFUN call.
 429    ALIGN is maximum alignment we can assume.  */
 430 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 431                                 rtx (*) (void *, HOST_WIDE_INT,
 432                                          enum machine_mode),
 433                                 void *, unsigned int);
 434
 435 /* Generate several move instructions to store LEN bytes generated by
 436    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 437    pointer which will be passed as argument in every CONSTFUN call.
 438    ALIGN is maximum alignment we can assume.
 439    Returns TO + LEN.  */
 440 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 441                             rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
 442                             void *, unsigned int, int);
 443
 444 /* Emit insns to set X from Y.  */
 445 extern rtx emit_move_insn (rtx, rtx);
 446
 447 /* Emit insns to set X from Y, with no frills.  */
 448 extern rtx emit_move_insn_1 (rtx, rtx);
 449
 450 /* Push a block of length SIZE (perhaps variable)
 451    and return an rtx to address the beginning of the block.  */
 452 extern rtx push_block (rtx, int, int);
 453
 454 /* Generate code to push something onto the stack, given its mode and type.  */
 455 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
 456                             int, rtx, int, rtx, rtx, int, rtx);
 457
 458 /* Expand an assignment that stores the value of FROM into TO.  */
 459 extern void expand_assignment (tree, tree);
 460
 461 /* Generate code for computing expression EXP,
 462    and storing the value into TARGET.
 463    If SUGGEST_REG is nonzero, copy the value through a register
 464    and return that register, if that is possible.  */
 465 extern rtx store_expr (tree, rtx, int);
 466
 467 /* Given an rtx that may include add and multiply operations,
 468    generate them as insns and return a pseudo-reg containing the value.
 469    Useful after calling expand_expr with 1 as sum_ok.  */
 470 extern rtx force_operand (rtx, rtx);
 471
 472 /* Work horse for expand_expr.  */
 473 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
 474                              enum expand_modifier, rtx *);
 475
 476 /* Generate code for computing expression EXP.
 477    An rtx for the computed value is returned.  The value is never null.
 478    In the case of a void EXP, const0_rtx is returned.  */
 479 static inline rtx
 480 expand_expr (tree exp, rtx target, enum machine_mode mode,
 481              enum expand_modifier modifier)
 482 {
 483   return expand_expr_real (exp, target, mode, modifier, NULL);
 484 }
 485
 486 extern void expand_var (tree);
 487
 488 /* At the start of a function, record that we have no previously-pushed
 489    arguments waiting to be popped.  */
 490 extern void init_pending_stack_adjust (void);
 491
 492 /* Discard any pending stack adjustment.  */
 493 extern void discard_pending_stack_adjust (void);
 494
 495 /* When exiting from function, if safe, clear out any pending stack adjust
 496    so the adjustment won't get done.  */
 497 extern void clear_pending_stack_adjust (void);
 498
 499 /* Pop any previously-pushed arguments that have not been popped yet.  */
 500 extern void do_pending_stack_adjust (void);
 501
 502 /* Return the tree node and offset if a given argument corresponds to
 503    a string constant.  */
 504 extern tree string_constant (tree, tree *);
 505
 506 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 507 extern void jumpifnot (tree, rtx);
 508
 509 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 510 extern void jumpif (tree, rtx);
 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);
 515
 516 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 517 extern rtx compare_from_rtx (rtx, rtx, enum rtx_code, int, enum machine_mode,
 518                              rtx);
 519 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 520                                      enum machine_mode, rtx, rtx, rtx);
 521
 522 /* Two different ways of generating switch statements.  */
 523 extern int try_casesi (tree, tree, tree, tree, rtx, rtx);
 524 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
 525
 526 /* Smallest number of adjacent cases before we use a jump table.
 527    XXX Should be a target hook.  */
 528 extern unsigned int case_values_threshold (void);
 529
 530 /* Functions from alias.c */
 531 #include "alias.h"
 532
 533 \f
 534 /* rtl.h and tree.h were included.  */
 535 /* Return an rtx for the size in bytes of the value of an expr.  */
 536 extern rtx expr_size (tree);
 537
 538 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 539    if the size can vary or is larger than an integer.  */
 540 extern HOST_WIDE_INT int_expr_size (tree);
 541
 542 /* Return an rtx that refers to the value returned by a function
 543    in its original home.  This becomes invalid if any more code is emitted.  */
 544 extern rtx hard_function_value (tree, tree, int);
 545
 546 extern rtx prepare_call_address (rtx, rtx, rtx *, int, int);
 547
 548 extern bool shift_return_value (enum machine_mode, bool, rtx);
 549
 550 extern rtx expand_call (tree, rtx, int);
 551
 552 extern void fixup_tail_calls (void);
 553
 554 #ifdef TREE_CODE
 555 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
 556                          int);
 557 extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
 558                           rtx, int);
 559 #endif
 560
 561 extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
 562                                  struct args_size *,
 563                                  struct locate_and_pad_arg_data *);
 564
 565 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 566 extern rtx label_rtx (tree);
 567
 568 /* As label_rtx, but additionally the label is placed on the forced label
 569    list of its containing function (i.e. it is treated as reachable even
 570    if how is not obvious).  */
 571 extern rtx force_label_rtx (tree);
 572
 573 /* Indicate how an input argument register was promoted.  */
 574 extern rtx promoted_input_arg (unsigned int, enum machine_mode *, int *);
 575
 576 /* Return an rtx like arg but sans any constant terms.
 577    Returns the original rtx if it has no constant terms.
 578    The constant terms are added and stored via a second arg.  */
 579 extern rtx eliminate_constant_term (rtx, rtx *);
 580
 581 /* Convert arg to a valid memory address for specified machine mode,
 582    by emitting insns to perform arithmetic if nec.  */
 583 extern rtx memory_address (enum machine_mode, rtx);
 584
 585 /* Like `memory_address' but pretent `flag_force_addr' is 0.  */
 586 extern rtx memory_address_noforce (enum machine_mode, rtx);
 587
 588 /* Return a memory reference like MEMREF, but with its mode changed
 589    to MODE and its address changed to ADDR.
 590    (VOIDmode means don't change the mode.
 591    NULL for ADDR means don't change the address.)  */
 592 extern rtx change_address (rtx, enum machine_mode, rtx);
 593
 594 /* Return a memory reference like MEMREF, but with its mode changed
 595    to MODE and its address offset by OFFSET bytes.  */
 596 #define adjust_address(MEMREF, MODE, OFFSET) \
 597   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
 598
 599 /* Likewise, but the reference is not required to be valid.  */
 600 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 601   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
 602
 603 /* Return a memory reference like MEMREF, but with its mode changed
 604    to MODE and its address changed to ADDR, which is assumed to be
 605    increased by OFFSET bytes from MEMREF.  */
 606 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 607   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 608
 609 /* Likewise, but the reference is not required to be valid.  */
 610 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 611   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 612
 613 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
 614 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
 615                                         HOST_WIDE_INT, int);
 616
 617 /* Return a memory reference like MEMREF, but whose address is changed by
 618    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 619    known to be in OFFSET (possibly 1).  */
 620 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 621
 622 /* Definitions from emit-rtl.c */
 623 #include "emit-rtl.h"
 624
 625 /* Return a memory reference like MEMREF, but with its mode widened to
 626    MODE and adjusted by OFFSET.  */
 627 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
 628
 629 /* Return a memory reference like MEMREF, but which is known to have a
 630    valid address.  */
 631 extern rtx validize_mem (rtx);
 632
 633 /* Given REF, a MEM, and T, either the type of X or the expression
 634    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 635    if we are making a new object of this type.  */
 636 extern void set_mem_attributes (rtx, tree, int);
 637
 638 /* Similar, except that BITPOS has not yet been applied to REF, so if
 639    we alter MEM_OFFSET according to T then we should subtract BITPOS
 640    expecting that it'll be added back in later.  */
 641 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 642
 643 /* Assemble the static constant template for function entry trampolines.  */
 644 extern rtx assemble_trampoline_template (void);
 645
 646 /* Given rtx, return new rtx whose address won't be affected by
 647    any side effects.  It has been copied to a new temporary reg.  */
 648 extern rtx stabilize (rtx);
 649
 650 /* Given an rtx, copy all regs it refers to into new temps
 651    and return a modified copy that refers to the new temps.  */
 652 extern rtx copy_all_regs (rtx);
 653
 654 /* Copy given rtx to a new temp reg and return that.  */
 655 extern rtx copy_to_reg (rtx);
 656
 657 /* Like copy_to_reg but always make the reg Pmode.  */
 658 extern rtx copy_addr_to_reg (rtx);
 659
 660 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 661 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
 662
 663 /* Copy given rtx to given temp reg and return that.  */
 664 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
 665
 666 /* Copy a value to a register if it isn't already a register.
 667    Args are mode (in case value is a constant) and the value.  */
 668 extern rtx force_reg (enum machine_mode, rtx);
 669
 670 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 671 extern rtx force_not_mem (rtx);
 672
 673 /* Return mode and signedness to use when object is promoted.  */
 674 extern enum machine_mode promote_mode (tree, enum machine_mode, int *, int);
 675
 676 /* Remove some bytes from the stack.  An rtx says how many.  */
 677 extern void adjust_stack (rtx);
 678
 679 /* Add some bytes to the stack.  An rtx says how many.  */
 680 extern void anti_adjust_stack (rtx);
 681
 682 /* This enum is used for the following two functions.  */
 683 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 684
 685 /* Save the stack pointer at the specified level.  */
 686 extern void emit_stack_save (enum save_level, rtx *, rtx);
 687
 688 /* Restore the stack pointer from a save area of the specified level.  */
 689 extern void emit_stack_restore (enum save_level, rtx, rtx);
 690
 691 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 692 extern void update_nonlocal_goto_save_area (void);
 693
 694 /* Allocate some space on the stack dynamically and return its address.  An rtx
 695    says how many bytes.  */
 696 extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
 697
 698 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 699    FIRST is a constant and size is a Pmode RTX.  These are offsets from the
 700    current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
 701    subtract from the stack.  If SIZE is constant, this is done
 702    with a fixed number of probes.  Otherwise, we must make a loop.  */
 703 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 704
 705 /* Return an rtx that refers to the value returned by a library call
 706    in its original home.  This becomes invalid if any more code is emitted.  */
 707 extern rtx hard_libcall_value (enum machine_mode);
 708
 709 /* Return the mode desired by operand N of a particular bitfield
 710    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
 711    available.  */
 712
 713 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
 714 extern enum machine_mode
 715 mode_for_extraction (enum extraction_pattern, int);
 716
 717 extern rtx store_bit_field (rtx, unsigned HOST_WIDE_INT,
 718                             unsigned HOST_WIDE_INT, enum machine_mode, rtx);
 719 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 720                               unsigned HOST_WIDE_INT, int, rtx,
 721                               enum machine_mode, enum machine_mode);
 722 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
 723 extern bool const_mult_add_overflow_p (rtx, rtx, rtx, enum machine_mode, int);
 724 extern rtx expand_mult_add (rtx, rtx, rtx, rtx,enum machine_mode, int);
 725 extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
 726
 727 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
 728 extern int safe_from_p (rtx, tree, int);
 729
 730 /* Call this once to initialize the contents of the optabs
 731    appropriately for the current target machine.  */
 732 extern void init_optabs (void);
 733 extern void init_all_optabs (void);
 734
 735 /* Call this to initialize an optab function entry.  */
 736 extern rtx init_one_libfunc (const char *);
 737
 738 extern void do_jump_by_parts_equality_rtx (rtx, rtx, rtx);
 739 extern void do_jump_by_parts_greater_rtx (enum machine_mode, int, rtx, rtx,
 740                                           rtx, rtx);
 741
 742 extern int vector_mode_valid_p (enum machine_mode);
 743
 744 #endif /* GCC_EXPR_H */