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, 2005
   4    Free Software Foundation, Inc.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 2, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING.  If not, write to the Free
  20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  21 02111-1307, USA.  */
  22
  23 #ifndef GCC_EXPR_H
  24 #define GCC_EXPR_H
  25
  26 /* For inhibit_defer_pop */
  27 #include "function.h"
  28 /* For XEXP, GEN_INT, rtx_code */
  29 #include "rtl.h"
  30 /* For optimize_size */
  31 #include "flags.h"
  32 /* For host_integerp, tree_low_cst, convert, size_binop, ssize_int, TREE_CODE,
  33    TYPE_SIZE, int_size_in_bytes,    */
  34 #include "tree.h"
  35 /* For GET_MODE_BITSIZE, word_mode */
  36 #include "machmode.h"
  37
  38 /* The default branch cost is 1.  */
  39 #ifndef BRANCH_COST
  40 #define BRANCH_COST 1
  41 #endif
  42
  43 /* This is the 4th arg to `expand_expr'.
  44    EXPAND_STACK_PARM means we are possibly expanding a call param onto
  45    the stack.
  46    EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
  47    EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
  48    EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
  49     is a constant that is not a legitimate address.
  50    EXPAND_WRITE means we are only going to write to the resulting rtx.
  51    EXPAND_MEMORY means we are interested in a memory result, even if
  52     the memory is constant and we could have propagated a constant value.  */
  53 enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
  54                       EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
  55                       EXPAND_MEMORY};
  56
  57 /* Prevent the compiler from deferring stack pops.  See
  58    inhibit_defer_pop for more information.  */
  59 #define NO_DEFER_POP (inhibit_defer_pop += 1)
  60
  61 /* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
  62    more information.  */
  63 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
  64 \f
  65 /* If a memory-to-memory move would take MOVE_RATIO or more simple
  66    move-instruction sequences, we will do a movmem or libcall instead.  */
  67
  68 #ifndef MOVE_RATIO
  69 #if defined (HAVE_movmemqi) || defined (HAVE_movmemhi) || defined (HAVE_movmemsi) || defined (HAVE_movmemdi) || defined (HAVE_movmemti)
  70 #define MOVE_RATIO 2
  71 #else
  72 /* If we are optimizing for space (-Os), cut down the default move ratio.  */
  73 #define MOVE_RATIO (optimize_size ? 3 : 15)
  74 #endif
  75 #endif
  76
  77 /* If a clear memory operation would take CLEAR_RATIO or more simple
  78    move-instruction sequences, we will do a clrmem or libcall instead.  */
  79
  80 #ifndef CLEAR_RATIO
  81 #if defined (HAVE_clrmemqi) || defined (HAVE_clrmemhi) || defined (HAVE_clrmemsi) || defined (HAVE_clrmemdi) || defined (HAVE_clrmemti)
  82 #define CLEAR_RATIO 2
  83 #else
  84 /* If we are optimizing for space, cut down the default clear ratio.  */
  85 #define CLEAR_RATIO (optimize_size ? 3 : 15)
  86 #endif
  87 #endif
  88 \f
  89 enum direction {none, upward, downward};
  90
  91 /* Structure to record the size of a sequence of arguments
  92    as the sum of a tree-expression and a constant.  This structure is
  93    also used to store offsets from the stack, which might be negative,
  94    so the variable part must be ssizetype, not sizetype.  */
  95
  96 struct args_size
  97 {
  98   HOST_WIDE_INT constant;
  99   tree var;
 100 };
 101
 102 /* Package up various arg related fields of struct args for
 103    locate_and_pad_parm.  */
 104 struct locate_and_pad_arg_data
 105 {
 106   /* Size of this argument on the stack, rounded up for any padding it
 107      gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
 108      counted here, otherwise they aren't.  */
 109   struct args_size size;
 110   /* Offset of this argument from beginning of stack-args.  */
 111   struct args_size offset;
 112   /* Offset to the start of the stack slot.  Different from OFFSET
 113      if this arg pads downward.  */
 114   struct args_size slot_offset;
 115   /* The amount that the stack pointer needs to be adjusted to
 116      force alignment for the next argument.  */
 117   struct args_size alignment_pad;
 118   /* Which way we should pad this arg.  */
 119   enum direction where_pad;
 120   /* slot_offset is at least this aligned.  */
 121   unsigned int boundary;
 122 };
 123
 124 /* Add the value of the tree INC to the `struct args_size' TO.  */
 125
 126 #define ADD_PARM_SIZE(TO, INC)                          \
 127 do {                                                    \
 128   tree inc = (INC);                                     \
 129   if (host_integerp (inc, 0))                           \
 130     (TO).constant += tree_low_cst (inc, 0);             \
 131   else if ((TO).var == 0)                               \
 132     (TO).var = convert (ssizetype, inc);                \
 133   else                                                  \
 134     (TO).var = size_binop (PLUS_EXPR, (TO).var,         \
 135                            convert (ssizetype, inc));   \
 136 } while (0)
 137
 138 #define SUB_PARM_SIZE(TO, DEC)                          \
 139 do {                                                    \
 140   tree dec = (DEC);                                     \
 141   if (host_integerp (dec, 0))                           \
 142     (TO).constant -= tree_low_cst (dec, 0);             \
 143   else if ((TO).var == 0)                               \
 144     (TO).var = size_binop (MINUS_EXPR, ssize_int (0),   \
 145                            convert (ssizetype, dec));   \
 146   else                                                  \
 147     (TO).var = size_binop (MINUS_EXPR, (TO).var,        \
 148                            convert (ssizetype, dec));   \
 149 } while (0)
 150
 151 /* Convert the implicit sum in a `struct args_size' into a tree
 152    of type ssizetype.  */
 153 #define ARGS_SIZE_TREE(SIZE)                                    \
 154 ((SIZE).var == 0 ? ssize_int ((SIZE).constant)                  \
 155  : size_binop (PLUS_EXPR, convert (ssizetype, (SIZE).var),      \
 156                ssize_int ((SIZE).constant)))
 157
 158 /* Convert the implicit sum in a `struct args_size' into an rtx.  */
 159 #define ARGS_SIZE_RTX(SIZE)                                     \
 160 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant)                    \
 161  : expand_expr (ARGS_SIZE_TREE (SIZE), NULL_RTX, VOIDmode, 0))
 162
 163 /* Supply a default definition for FUNCTION_ARG_PADDING:
 164    usually pad upward, but pad short args downward on
 165    big-endian machines.  */
 166
 167 #define DEFAULT_FUNCTION_ARG_PADDING(MODE, TYPE)                        \
 168   (! BYTES_BIG_ENDIAN                                                   \
 169    ? upward                                                             \
 170    : (((MODE) == BLKmode                                                \
 171        ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST         \
 172           && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
 173        : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)                       \
 174       ? downward : upward))
 175
 176 #ifndef FUNCTION_ARG_PADDING
 177 #define FUNCTION_ARG_PADDING(MODE, TYPE)        \
 178   DEFAULT_FUNCTION_ARG_PADDING ((MODE), (TYPE))
 179 #endif
 180
 181 /* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
 182    FUNCTION_ARG_PADDING, which also pads the length, handle any needed
 183    alignment.  */
 184
 185 #ifndef FUNCTION_ARG_BOUNDARY
 186 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE)       PARM_BOUNDARY
 187 #endif
 188
 189 /* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
 190    Normally move_insn, so Pmode stack pointer.  */
 191
 192 #ifndef STACK_SAVEAREA_MODE
 193 #define STACK_SAVEAREA_MODE(LEVEL) Pmode
 194 #endif
 195
 196 /* Supply a default definition of STACK_SIZE_MODE for
 197    allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
 198
 199 #ifndef STACK_SIZE_MODE
 200 #define STACK_SIZE_MODE word_mode
 201 #endif
 202
 203 /* Provide default values for the macros controlling stack checking.  */
 204
 205 #ifndef STACK_CHECK_BUILTIN
 206 #define STACK_CHECK_BUILTIN 0
 207 #endif
 208
 209 /* The default interval is one page.  */
 210 #ifndef STACK_CHECK_PROBE_INTERVAL
 211 #define STACK_CHECK_PROBE_INTERVAL 4096
 212 #endif
 213
 214 /* The default is to do a store into the stack.  */
 215 #ifndef STACK_CHECK_PROBE_LOAD
 216 #define STACK_CHECK_PROBE_LOAD 0
 217 #endif
 218
 219 /* This value is arbitrary, but should be sufficient for most machines.  */
 220 #ifndef STACK_CHECK_PROTECT
 221 #define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
 222 #endif
 223
 224 /* Make the maximum frame size be the largest we can and still only need
 225    one probe per function.  */
 226 #ifndef STACK_CHECK_MAX_FRAME_SIZE
 227 #define STACK_CHECK_MAX_FRAME_SIZE \
 228   (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
 229 #endif
 230
 231 /* This is arbitrary, but should be large enough everywhere.  */
 232 #ifndef STACK_CHECK_FIXED_FRAME_SIZE
 233 #define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
 234 #endif
 235
 236 /* Provide a reasonable default for the maximum size of an object to
 237    allocate in the fixed frame.  We may need to be able to make this
 238    controllable by the user at some point.  */
 239 #ifndef STACK_CHECK_MAX_VAR_SIZE
 240 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
 241 #endif
 242 \f
 243 /* Functions from optabs.c, commonly used, and without need for the optabs
 244    tables:  */
 245
 246 /* Passed to expand_simple_binop and expand_binop to say which options
 247    to try to use if the requested operation can't be open-coded on the
 248    requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
 249    a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
 250    using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
 251    try anything else.  */
 252
 253 enum optab_methods
 254 {
 255   OPTAB_DIRECT,
 256   OPTAB_LIB,
 257   OPTAB_WIDEN,
 258   OPTAB_LIB_WIDEN,
 259   OPTAB_MUST_WIDEN
 260 };
 261
 262 /* Generate code for a simple binary or unary operation.  "Simple" in
 263    this case means "can be unambiguously described by a (mode, code)
 264    pair and mapped to a single optab."  */
 265 extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
 266                                 rtx, rtx, int, enum optab_methods);
 267 extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
 268                                int);
 269
 270 /* Report whether the machine description contains an insn which can
 271    perform the operation described by CODE and MODE.  */
 272 extern int have_insn_for (enum rtx_code, enum machine_mode);
 273
 274 /* Emit code to make a call to a constant function or a library call.  */
 275 extern void emit_libcall_block (rtx, rtx, rtx, rtx);
 276
 277 /* Create but don't emit one rtl instruction to perform certain operations.
 278    Modes must match; operands must meet the operation's predicates.
 279    Likewise for subtraction and for just copying.  */
 280 extern rtx gen_add2_insn (rtx, rtx);
 281 extern rtx gen_add3_insn (rtx, rtx, rtx);
 282 extern rtx gen_sub2_insn (rtx, rtx);
 283 extern rtx gen_sub3_insn (rtx, rtx, rtx);
 284 extern rtx gen_move_insn (rtx, rtx);
 285 extern int have_add2_insn (rtx, rtx);
 286 extern int have_sub2_insn (rtx, rtx);
 287
 288 /* Emit a pair of rtl insns to compare two rtx's and to jump
 289    to a label if the comparison is true.  */
 290 extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
 291                                      enum machine_mode, int, rtx);
 292
 293 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 294 extern void emit_indirect_jump (rtx);
 295
 296 /* Generate a conditional trap instruction.  */
 297 extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
 298
 299 #include "insn-config.h"
 300
 301 #ifdef HAVE_conditional_move
 302 /* Emit a conditional move operation.  */
 303 rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 304                            rtx, rtx, enum machine_mode, int);
 305
 306 /* Return nonzero if the conditional move is supported.  */
 307 int can_conditionally_move_p (enum machine_mode mode);
 308
 309 #endif
 310 rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 311                           rtx, rtx, enum machine_mode, int);
 312
 313 \f
 314 /* Functions from expmed.c:  */
 315
 316 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 317    May emit insns.  */
 318 extern rtx negate_rtx (enum machine_mode, rtx);
 319
 320 /* Expand a logical AND operation.  */
 321 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
 322
 323 /* Emit a store-flag operation.  */
 324 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 325                             int, int);
 326
 327 /* Like emit_store_flag, but always succeeds.  */
 328 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 329                                   enum machine_mode, int, int);
 330 \f
 331 /* Functions from builtins.c:  */
 332 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 333 extern tree std_build_builtin_va_list (void);
 334 extern void std_expand_builtin_va_start (tree, rtx);
 335 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 336 extern void expand_builtin_setjmp_setup (rtx, rtx);
 337 extern void expand_builtin_setjmp_receiver (rtx);
 338 extern rtx expand_builtin_saveregs (void);
 339 \f
 340 /* Functions from expr.c:  */
 341
 342 /* This is run once per compilation to set up which modes can be used
 343    directly in memory and to initialize the block move optab.  */
 344 extern void init_expr_once (void);
 345
 346 /* This is run at the start of compiling a function.  */
 347 extern void init_expr (void);
 348
 349 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 350    Both modes must be floating or both fixed.  */
 351 extern void convert_move (rtx, rtx, int);
 352
 353 /* Convert an rtx to specified machine mode and return the result.  */
 354 extern rtx convert_to_mode (enum machine_mode, rtx, int);
 355
 356 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 357 extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
 358
 359 /* Emit code to move a block Y to a block X.  */
 360
 361 enum block_op_methods
 362 {
 363   BLOCK_OP_NORMAL,
 364   BLOCK_OP_NO_LIBCALL,
 365   BLOCK_OP_CALL_PARM
 366 };
 367
 368 extern void init_block_move_fn (const char *);
 369 extern void init_block_clear_fn (const char *);
 370
 371 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 372
 373 /* Copy all or part of a value X into registers starting at REGNO.
 374    The number of registers to be filled is NREGS.  */
 375 extern void move_block_to_reg (int, rtx, int, enum machine_mode);
 376
 377 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 378    The number of registers to be filled is NREGS.  */
 379 extern void move_block_from_reg (int, rtx, int);
 380
 381 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 382 extern rtx gen_group_rtx (rtx);
 383
 384 /* Load a BLKmode value into non-consecutive registers represented by a
 385    PARALLEL.  */
 386 extern void emit_group_load (rtx, rtx, tree, int);
 387
 388 /* Similarly, but load into new temporaries.  */
 389 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
 390
 391 /* Move a non-consecutive group of registers represented by a PARALLEL into
 392    a non-consecutive group of registers represented by a PARALLEL.  */
 393 extern void emit_group_move (rtx, rtx);
 394
 395 /* Move a group of registers represented by a PARALLEL into pseudos.  */
 396 extern rtx emit_group_move_into_temps (rtx);
 397
 398 /* Store a BLKmode value from non-consecutive registers represented by a
 399    PARALLEL.  */
 400 extern void emit_group_store (rtx, rtx, tree, int);
 401
 402 /* Copy BLKmode object from a set of registers.  */
 403 extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
 404
 405 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 406 extern void use_reg (rtx *, rtx);
 407
 408 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 409    for the next CALL_INSN.  */
 410 extern void use_regs (rtx *, int, int);
 411
 412 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 413 extern void use_group_regs (rtx *, rtx);
 414
 415 /* Write zeros through the storage of OBJECT.
 416    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 417 extern rtx clear_storage (rtx, rtx);
 418
 419 /* Determine whether the LEN bytes can be moved by using several move
 420    instructions.  Return nonzero if a call to move_by_pieces should
 421    succeed.  */
 422 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 423
 424 /* Return nonzero if it is desirable to store LEN bytes generated by
 425    CONSTFUN with several move instructions by store_by_pieces
 426    function.  CONSTFUNDATA is a pointer which will be passed as argument
 427    in every CONSTFUN call.
 428    ALIGN is maximum alignment we can assume.  */
 429 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 430                                 rtx (*) (void *, HOST_WIDE_INT,
 431                                          enum machine_mode),
 432                                 void *, unsigned int);
 433
 434 /* Generate several move instructions to store LEN bytes generated by
 435    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 436    pointer which will be passed as argument in every CONSTFUN call.
 437    ALIGN is maximum alignment we can assume.
 438    Returns TO + LEN.  */
 439 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 440                             rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
 441                             void *, unsigned int, int);
 442
 443 /* Emit insns to set X from Y.  */
 444 extern rtx emit_move_insn (rtx, rtx);
 445
 446 /* Emit insns to set X from Y, with no frills.  */
 447 extern rtx emit_move_insn_1 (rtx, rtx);
 448
 449 /* Push a block of length SIZE (perhaps variable)
 450    and return an rtx to address the beginning of the block.  */
 451 extern rtx push_block (rtx, int, int);
 452
 453 /* Generate code to push something onto the stack, given its mode and type.  */
 454 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
 455                             int, rtx, int, rtx, rtx, int, rtx);
 456
 457 /* Expand an assignment that stores the value of FROM into TO.  */
 458 extern void expand_assignment (tree, tree);
 459
 460 /* Generate code for computing expression EXP,
 461    and storing the value into TARGET.
 462    If SUGGEST_REG is nonzero, copy the value through a register
 463    and return that register, if that is possible.  */
 464 extern rtx store_expr (tree, rtx, int);
 465
 466 /* Given an rtx that may include add and multiply operations,
 467    generate them as insns and return a pseudo-reg containing the value.
 468    Useful after calling expand_expr with 1 as sum_ok.  */
 469 extern rtx force_operand (rtx, rtx);
 470
 471 /* Work horse for expand_expr.  */
 472 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
 473                              enum expand_modifier, rtx *);
 474
 475 /* Generate code for computing expression EXP.
 476    An rtx for the computed value is returned.  The value is never null.
 477    In the case of a void EXP, const0_rtx is returned.  */
 478 static inline rtx
 479 expand_expr (tree exp, rtx target, enum machine_mode mode,
 480              enum expand_modifier modifier)
 481 {
 482   return expand_expr_real (exp, target, mode, modifier, NULL);
 483 }
 484
 485 extern void expand_var (tree);
 486
 487 /* At the start of a function, record that we have no previously-pushed
 488    arguments waiting to be popped.  */
 489 extern void init_pending_stack_adjust (void);
 490
 491 /* Discard any pending stack adjustment.  */
 492 extern void discard_pending_stack_adjust (void);
 493
 494 /* When exiting from function, if safe, clear out any pending stack adjust
 495    so the adjustment won't get done.  */
 496 extern void clear_pending_stack_adjust (void);
 497
 498 /* Pop any previously-pushed arguments that have not been popped yet.  */
 499 extern void do_pending_stack_adjust (void);
 500
 501 /* Return the tree node and offset if a given argument corresponds to
 502    a string constant.  */
 503 extern tree string_constant (tree, tree *);
 504
 505 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 506 extern void jumpifnot (tree, rtx);
 507
 508 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 509 extern void jumpif (tree, rtx);
 510
 511 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 512    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 513 extern void do_jump (tree, rtx, rtx);
 514
 515 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 516 extern rtx compare_from_rtx (rtx, rtx, enum rtx_code, int, enum machine_mode,
 517                              rtx);
 518 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 519                                      enum machine_mode, rtx, rtx, rtx);
 520
 521 /* Two different ways of generating switch statements.  */
 522 extern int try_casesi (tree, tree, tree, tree, rtx, rtx);
 523 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
 524
 525 /* Smallest number of adjacent cases before we use a jump table.
 526    XXX Should be a target hook.  */
 527 extern unsigned int case_values_threshold (void);
 528
 529 /* Functions from alias.c */
 530 #include "alias.h"
 531
 532 \f
 533 /* rtl.h and tree.h were included.  */
 534 /* Return an rtx for the size in bytes of the value of an expr.  */
 535 extern rtx expr_size (tree);
 536
 537 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 538    if the size can vary or is larger than an integer.  */
 539 extern HOST_WIDE_INT int_expr_size (tree);
 540
 541 /* Return an rtx that refers to the value returned by a function
 542    in its original home.  This becomes invalid if any more code is emitted.  */
 543 extern rtx hard_function_value (tree, tree, int);
 544
 545 extern rtx prepare_call_address (rtx, rtx, rtx *, int, int);
 546
 547 extern bool shift_return_value (enum machine_mode, bool, rtx);
 548
 549 extern rtx expand_call (tree, rtx, int);
 550
 551 extern void fixup_tail_calls (void);
 552
 553 #ifdef TREE_CODE
 554 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
 555                          int);
 556 extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
 557                           rtx, int);
 558 #endif
 559
 560 extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
 561                                  struct args_size *,
 562                                  struct locate_and_pad_arg_data *);
 563
 564 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 565 extern rtx label_rtx (tree);
 566
 567 /* As label_rtx, but additionally the label is placed on the forced label
 568    list of its containing function (i.e. it is treated as reachable even
 569    if how is not obvious).  */
 570 extern rtx force_label_rtx (tree);
 571
 572 /* Indicate how an input argument register was promoted.  */
 573 extern rtx promoted_input_arg (unsigned int, enum machine_mode *, int *);
 574
 575 /* Return an rtx like arg but sans any constant terms.
 576    Returns the original rtx if it has no constant terms.
 577    The constant terms are added and stored via a second arg.  */
 578 extern rtx eliminate_constant_term (rtx, rtx *);
 579
 580 /* Convert arg to a valid memory address for specified machine mode,
 581    by emitting insns to perform arithmetic if nec.  */
 582 extern rtx memory_address (enum machine_mode, rtx);
 583
 584 /* Like `memory_address' but pretent `flag_force_addr' is 0.  */
 585 extern rtx memory_address_noforce (enum machine_mode, rtx);
 586
 587 /* Return a memory reference like MEMREF, but with its mode changed
 588    to MODE and its address changed to ADDR.
 589    (VOIDmode means don't change the mode.
 590    NULL for ADDR means don't change the address.)  */
 591 extern rtx change_address (rtx, enum machine_mode, rtx);
 592
 593 /* Return a memory reference like MEMREF, but with its mode changed
 594    to MODE and its address offset by OFFSET bytes.  */
 595 #define adjust_address(MEMREF, MODE, OFFSET) \
 596   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
 597
 598 /* Likewise, but the reference is not required to be valid.  */
 599 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 600   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
 601
 602 /* Return a memory reference like MEMREF, but with its mode changed
 603    to MODE and its address changed to ADDR, which is assumed to be
 604    increased by OFFSET bytes from MEMREF.  */
 605 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 606   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 607
 608 /* Likewise, but the reference is not required to be valid.  */
 609 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 610   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 611
 612 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
 613 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
 614                                         HOST_WIDE_INT, int);
 615
 616 /* Return a memory reference like MEMREF, but whose address is changed by
 617    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 618    known to be in OFFSET (possibly 1).  */
 619 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 620
 621 /* Definitions from emit-rtl.c */
 622 #include "emit-rtl.h"
 623
 624 /* Return a memory reference like MEMREF, but with its mode widened to
 625    MODE and adjusted by OFFSET.  */
 626 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
 627
 628 /* Return a memory reference like MEMREF, but which is known to have a
 629    valid address.  */
 630 extern rtx validize_mem (rtx);
 631
 632 /* Given REF, a MEM, and T, either the type of X or the expression
 633    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 634    if we are making a new object of this type.  */
 635 extern void set_mem_attributes (rtx, tree, int);
 636
 637 /* Similar, except that BITPOS has not yet been applied to REF, so if
 638    we alter MEM_OFFSET according to T then we should subtract BITPOS
 639    expecting that it'll be added back in later.  */
 640 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 641
 642 /* Assemble the static constant template for function entry trampolines.  */
 643 extern rtx assemble_trampoline_template (void);
 644
 645 /* Copy given rtx to a new temp reg and return that.  */
 646 extern rtx copy_to_reg (rtx);
 647
 648 /* Like copy_to_reg but always make the reg Pmode.  */
 649 extern rtx copy_addr_to_reg (rtx);
 650
 651 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 652 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
 653
 654 /* Copy given rtx to given temp reg and return that.  */
 655 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
 656
 657 /* Copy a value to a register if it isn't already a register.
 658    Args are mode (in case value is a constant) and the value.  */
 659 extern rtx force_reg (enum machine_mode, rtx);
 660
 661 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 662 extern rtx force_not_mem (rtx);
 663
 664 /* Return mode and signedness to use when object is promoted.  */
 665 extern enum machine_mode promote_mode (tree, enum machine_mode, int *, int);
 666
 667 /* Remove some bytes from the stack.  An rtx says how many.  */
 668 extern void adjust_stack (rtx);
 669
 670 /* Add some bytes to the stack.  An rtx says how many.  */
 671 extern void anti_adjust_stack (rtx);
 672
 673 /* This enum is used for the following two functions.  */
 674 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 675
 676 /* Save the stack pointer at the specified level.  */
 677 extern void emit_stack_save (enum save_level, rtx *, rtx);
 678
 679 /* Restore the stack pointer from a save area of the specified level.  */
 680 extern void emit_stack_restore (enum save_level, rtx, rtx);
 681
 682 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 683 extern void update_nonlocal_goto_save_area (void);
 684
 685 /* Allocate some space on the stack dynamically and return its address.  An rtx
 686    says how many bytes.  */
 687 extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
 688
 689 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 690    FIRST is a constant and size is a Pmode RTX.  These are offsets from the
 691    current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
 692    subtract from the stack.  If SIZE is constant, this is done
 693    with a fixed number of probes.  Otherwise, we must make a loop.  */
 694 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 695
 696 /* Return an rtx that refers to the value returned by a library call
 697    in its original home.  This becomes invalid if any more code is emitted.  */
 698 extern rtx hard_libcall_value (enum machine_mode);
 699
 700 /* Return the mode desired by operand N of a particular bitfield
 701    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
 702    available.  */
 703
 704 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
 705 extern enum machine_mode
 706 mode_for_extraction (enum extraction_pattern, int);
 707
 708 extern rtx store_bit_field (rtx, unsigned HOST_WIDE_INT,
 709                             unsigned HOST_WIDE_INT, enum machine_mode, rtx);
 710 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 711                               unsigned HOST_WIDE_INT, int, rtx,
 712                               enum machine_mode, enum machine_mode);
 713 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
 714 extern bool const_mult_add_overflow_p (rtx, rtx, rtx, enum machine_mode, int);
 715 extern rtx expand_mult_add (rtx, rtx, rtx, rtx,enum machine_mode, int);
 716 extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
 717
 718 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
 719 extern int safe_from_p (rtx, tree, int);
 720
 721 /* Call this once to initialize the contents of the optabs
 722    appropriately for the current target machine.  */
 723 extern void init_optabs (void);
 724 extern void init_all_optabs (void);
 725
 726 /* Call this to initialize an optab function entry.  */
 727 extern rtx init_one_libfunc (const char *);
 728
 729 extern void do_jump_by_parts_equality_rtx (rtx, rtx, rtx);
 730 extern void do_jump_by_parts_greater_rtx (enum machine_mode, int, rtx, rtx,
 731                                           rtx, rtx);
 732
 733 extern int vector_mode_valid_p (enum machine_mode);
 734
 735 #endif /* GCC_EXPR_H */