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, 2006, 2007
   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 3, 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 COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  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, fold_convert, size_binop, ssize_int,
  32    TREE_CODE, 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 setmem or libcall instead.  */
  78
  79 #ifndef CLEAR_RATIO
  80 #if defined (HAVE_setmemqi) || defined (HAVE_setmemhi) || defined (HAVE_setmemsi) || defined (HAVE_setmemdi) || defined (HAVE_setmemti)
  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
  88 /* If a memory set (to value other than zero) operation would take
  89    SET_RATIO or more simple move-instruction sequences, we will do a movmem
  90    or libcall instead.  */
  91 #ifndef SET_RATIO
  92 #define SET_RATIO MOVE_RATIO
  93 #endif
  94 \f
  95 enum direction {none, upward, downward};
  96
  97 /* Structure to record the size of a sequence of arguments
  98    as the sum of a tree-expression and a constant.  This structure is
  99    also used to store offsets from the stack, which might be negative,
 100    so the variable part must be ssizetype, not sizetype.  */
 101
 102 struct args_size
 103 {
 104   HOST_WIDE_INT constant;
 105   tree var;
 106 };
 107
 108 /* Package up various arg related fields of struct args for
 109    locate_and_pad_parm.  */
 110 struct locate_and_pad_arg_data
 111 {
 112   /* Size of this argument on the stack, rounded up for any padding it
 113      gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
 114      counted here, otherwise they aren't.  */
 115   struct args_size size;
 116   /* Offset of this argument from beginning of stack-args.  */
 117   struct args_size offset;
 118   /* Offset to the start of the stack slot.  Different from OFFSET
 119      if this arg pads downward.  */
 120   struct args_size slot_offset;
 121   /* The amount that the stack pointer needs to be adjusted to
 122      force alignment for the next argument.  */
 123   struct args_size alignment_pad;
 124   /* Which way we should pad this arg.  */
 125   enum direction where_pad;
 126   /* slot_offset is at least this aligned.  */
 127   unsigned int boundary;
 128 };
 129
 130 /* Add the value of the tree INC to the `struct args_size' TO.  */
 131
 132 #define ADD_PARM_SIZE(TO, INC)                                  \
 133 do {                                                            \
 134   tree inc = (INC);                                             \
 135   if (host_integerp (inc, 0))                                   \
 136     (TO).constant += tree_low_cst (inc, 0);                     \
 137   else if ((TO).var == 0)                                       \
 138     (TO).var = fold_convert (ssizetype, inc);                   \
 139   else                                                          \
 140     (TO).var = size_binop (PLUS_EXPR, (TO).var,                 \
 141                            fold_convert (ssizetype, inc));      \
 142 } while (0)
 143
 144 #define SUB_PARM_SIZE(TO, DEC)                                  \
 145 do {                                                            \
 146   tree dec = (DEC);                                             \
 147   if (host_integerp (dec, 0))                                   \
 148     (TO).constant -= tree_low_cst (dec, 0);                     \
 149   else if ((TO).var == 0)                                       \
 150     (TO).var = size_binop (MINUS_EXPR, ssize_int (0),           \
 151                            fold_convert (ssizetype, dec));      \
 152   else                                                          \
 153     (TO).var = size_binop (MINUS_EXPR, (TO).var,                \
 154                            fold_convert (ssizetype, dec));      \
 155 } while (0)
 156
 157 /* Convert the implicit sum in a `struct args_size' into a tree
 158    of type ssizetype.  */
 159 #define ARGS_SIZE_TREE(SIZE)                                    \
 160 ((SIZE).var == 0 ? ssize_int ((SIZE).constant)                  \
 161  : size_binop (PLUS_EXPR, fold_convert (ssizetype, (SIZE).var), \
 162                ssize_int ((SIZE).constant)))
 163
 164 /* Convert the implicit sum in a `struct args_size' into an rtx.  */
 165 #define ARGS_SIZE_RTX(SIZE)                                     \
 166 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant)                    \
 167  : expand_normal (ARGS_SIZE_TREE (SIZE)))
 168
 169 /* Supply a default definition for FUNCTION_ARG_PADDING:
 170    usually pad upward, but pad short args downward on
 171    big-endian machines.  */
 172
 173 #define DEFAULT_FUNCTION_ARG_PADDING(MODE, TYPE)                        \
 174   (! BYTES_BIG_ENDIAN                                                   \
 175    ? upward                                                             \
 176    : (((MODE) == BLKmode                                                \
 177        ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST         \
 178           && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
 179        : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)                       \
 180       ? downward : upward))
 181
 182 #ifndef FUNCTION_ARG_PADDING
 183 #define FUNCTION_ARG_PADDING(MODE, TYPE)        \
 184   DEFAULT_FUNCTION_ARG_PADDING ((MODE), (TYPE))
 185 #endif
 186
 187 /* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
 188    FUNCTION_ARG_PADDING, which also pads the length, handle any needed
 189    alignment.  */
 190
 191 #ifndef FUNCTION_ARG_BOUNDARY
 192 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE)       PARM_BOUNDARY
 193 #endif
 194
 195 /* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
 196    Normally move_insn, so Pmode stack pointer.  */
 197
 198 #ifndef STACK_SAVEAREA_MODE
 199 #define STACK_SAVEAREA_MODE(LEVEL) Pmode
 200 #endif
 201
 202 /* Supply a default definition of STACK_SIZE_MODE for
 203    allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
 204
 205 #ifndef STACK_SIZE_MODE
 206 #define STACK_SIZE_MODE word_mode
 207 #endif
 208
 209 /* Provide default values for the macros controlling stack checking.  */
 210
 211 #ifndef STACK_CHECK_BUILTIN
 212 #define STACK_CHECK_BUILTIN 0
 213 #endif
 214
 215 /* The default interval is one page.  */
 216 #ifndef STACK_CHECK_PROBE_INTERVAL
 217 #define STACK_CHECK_PROBE_INTERVAL 4096
 218 #endif
 219
 220 /* The default is to do a store into the stack.  */
 221 #ifndef STACK_CHECK_PROBE_LOAD
 222 #define STACK_CHECK_PROBE_LOAD 0
 223 #endif
 224
 225 /* This value is arbitrary, but should be sufficient for most machines.  */
 226 #ifndef STACK_CHECK_PROTECT
 227 #define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
 228 #endif
 229
 230 /* Make the maximum frame size be the largest we can and still only need
 231    one probe per function.  */
 232 #ifndef STACK_CHECK_MAX_FRAME_SIZE
 233 #define STACK_CHECK_MAX_FRAME_SIZE \
 234   (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
 235 #endif
 236
 237 /* This is arbitrary, but should be large enough everywhere.  */
 238 #ifndef STACK_CHECK_FIXED_FRAME_SIZE
 239 #define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
 240 #endif
 241
 242 /* Provide a reasonable default for the maximum size of an object to
 243    allocate in the fixed frame.  We may need to be able to make this
 244    controllable by the user at some point.  */
 245 #ifndef STACK_CHECK_MAX_VAR_SIZE
 246 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
 247 #endif
 248 \f
 249 /* Functions from optabs.c, commonly used, and without need for the optabs
 250    tables:  */
 251
 252 /* Passed to expand_simple_binop and expand_binop to say which options
 253    to try to use if the requested operation can't be open-coded on the
 254    requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
 255    a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
 256    using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
 257    try anything else.  */
 258
 259 enum optab_methods
 260 {
 261   OPTAB_DIRECT,
 262   OPTAB_LIB,
 263   OPTAB_WIDEN,
 264   OPTAB_LIB_WIDEN,
 265   OPTAB_MUST_WIDEN
 266 };
 267
 268 /* Generate code for a simple binary or unary operation.  "Simple" in
 269    this case means "can be unambiguously described by a (mode, code)
 270    pair and mapped to a single optab."  */
 271 extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
 272                                 rtx, rtx, int, enum optab_methods);
 273 extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
 274                                int);
 275
 276 /* Report whether the machine description contains an insn which can
 277    perform the operation described by CODE and MODE.  */
 278 extern int have_insn_for (enum rtx_code, enum machine_mode);
 279
 280 /* Emit code to make a call to a constant function or a library call.  */
 281 extern void emit_libcall_block (rtx, rtx, rtx, rtx);
 282
 283 /* Create but don't emit one rtl instruction to perform certain operations.
 284    Modes must match; operands must meet the operation's predicates.
 285    Likewise for subtraction and for just copying.  */
 286 extern rtx gen_add2_insn (rtx, rtx);
 287 extern rtx gen_add3_insn (rtx, rtx, rtx);
 288 extern rtx gen_sub2_insn (rtx, rtx);
 289 extern rtx gen_sub3_insn (rtx, rtx, rtx);
 290 extern rtx gen_move_insn (rtx, rtx);
 291 extern int have_add2_insn (rtx, rtx);
 292 extern int have_sub2_insn (rtx, rtx);
 293
 294 /* Emit a pair of rtl insns to compare two rtx's and to jump
 295    to a label if the comparison is true.  */
 296 extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
 297                                      enum machine_mode, int, rtx);
 298
 299 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 300 extern void emit_indirect_jump (rtx);
 301
 302 /* Generate a conditional trap instruction.  */
 303 extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
 304
 305 #include "insn-config.h"
 306
 307 #ifdef HAVE_conditional_move
 308 /* Emit a conditional move operation.  */
 309 rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 310                            rtx, rtx, enum machine_mode, int);
 311
 312 /* Return nonzero if the conditional move is supported.  */
 313 int can_conditionally_move_p (enum machine_mode mode);
 314
 315 #endif
 316 rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 317                           rtx, rtx, enum machine_mode, int);
 318
 319 rtx expand_val_compare_and_swap (rtx, rtx, rtx, rtx);
 320 rtx expand_bool_compare_and_swap (rtx, rtx, rtx, rtx);
 321 rtx expand_sync_operation (rtx, rtx, enum rtx_code);
 322 rtx expand_sync_fetch_operation (rtx, rtx, enum rtx_code, bool, rtx);
 323 rtx expand_sync_lock_test_and_set (rtx, rtx, rtx);
 324 \f
 325 /* Functions from expmed.c:  */
 326
 327 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 328    May emit insns.  */
 329 extern rtx negate_rtx (enum machine_mode, rtx);
 330
 331 /* Expand a logical AND operation.  */
 332 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
 333
 334 /* Emit a store-flag operation.  */
 335 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 336                             int, int);
 337
 338 /* Like emit_store_flag, but always succeeds.  */
 339 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 340                                   enum machine_mode, int, int);
 341 \f
 342 /* Functions from builtins.c:  */
 343 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 344 extern tree std_build_builtin_va_list (void);
 345 extern void std_expand_builtin_va_start (tree, rtx);
 346 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 347 extern void expand_builtin_setjmp_setup (rtx, rtx);
 348 extern void expand_builtin_setjmp_receiver (rtx);
 349 extern rtx expand_builtin_saveregs (void);
 350 extern void expand_builtin_trap (void);
 351 extern rtx builtin_strncpy_read_str (void *, HOST_WIDE_INT, enum machine_mode);
 352 \f
 353 /* Functions from expr.c:  */
 354
 355 /* This is run during target initialization to set up which modes can be
 356    used directly in memory and to initialize the block move optab.  */
 357 extern void init_expr_target (void);
 358
 359 /* This is run at the start of compiling a function.  */
 360 extern void init_expr (void);
 361
 362 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 363    Both modes must be floating or both fixed.  */
 364 extern void convert_move (rtx, rtx, int);
 365
 366 /* Convert an rtx to specified machine mode and return the result.  */
 367 extern rtx convert_to_mode (enum machine_mode, rtx, int);
 368
 369 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 370 extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
 371
 372 /* Emit code to move a block Y to a block X.  */
 373
 374 enum block_op_methods
 375 {
 376   BLOCK_OP_NORMAL,
 377   BLOCK_OP_NO_LIBCALL,
 378   BLOCK_OP_CALL_PARM,
 379   /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized.  */
 380   BLOCK_OP_TAILCALL
 381 };
 382
 383 extern void init_block_move_fn (const char *);
 384 extern void init_block_clear_fn (const char *);
 385
 386 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 387 extern rtx emit_block_move_via_libcall (rtx, rtx, rtx, bool);
 388 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
 389                                   unsigned int, HOST_WIDE_INT);
 390
 391 /* Copy all or part of a value X into registers starting at REGNO.
 392    The number of registers to be filled is NREGS.  */
 393 extern void move_block_to_reg (int, rtx, int, enum machine_mode);
 394
 395 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 396    The number of registers to be filled is NREGS.  */
 397 extern void move_block_from_reg (int, rtx, int);
 398
 399 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 400 extern rtx gen_group_rtx (rtx);
 401
 402 /* Load a BLKmode value into non-consecutive registers represented by a
 403    PARALLEL.  */
 404 extern void emit_group_load (rtx, rtx, tree, int);
 405
 406 /* Similarly, but load into new temporaries.  */
 407 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
 408
 409 /* Move a non-consecutive group of registers represented by a PARALLEL into
 410    a non-consecutive group of registers represented by a PARALLEL.  */
 411 extern void emit_group_move (rtx, rtx);
 412
 413 /* Move a group of registers represented by a PARALLEL into pseudos.  */
 414 extern rtx emit_group_move_into_temps (rtx);
 415
 416 /* Store a BLKmode value from non-consecutive registers represented by a
 417    PARALLEL.  */
 418 extern void emit_group_store (rtx, rtx, tree, int);
 419
 420 /* Copy BLKmode object from a set of registers.  */
 421 extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
 422
 423 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 424 extern void use_reg (rtx *, rtx);
 425
 426 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 427    for the next CALL_INSN.  */
 428 extern void use_regs (rtx *, int, int);
 429
 430 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 431 extern void use_group_regs (rtx *, rtx);
 432
 433 /* Write zeros through the storage of OBJECT.
 434    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 435 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
 436 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
 437                                 unsigned int, HOST_WIDE_INT);
 438 /* The same, but always output an library call.  */
 439 rtx set_storage_via_libcall (rtx, rtx, rtx, bool);
 440
 441 /* Expand a setmem pattern; return true if successful.  */
 442 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
 443                                     unsigned int, HOST_WIDE_INT);
 444
 445 /* Determine whether the LEN bytes can be moved by using several move
 446    instructions.  Return nonzero if a call to move_by_pieces should
 447    succeed.  */
 448 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 449
 450 /* Return nonzero if it is desirable to store LEN bytes generated by
 451    CONSTFUN with several move instructions by store_by_pieces
 452    function.  CONSTFUNDATA is a pointer which will be passed as argument
 453    in every CONSTFUN call.
 454    ALIGN is maximum alignment we can assume.
 455    MEMSETP is true if this is a real memset/bzero, not a copy
 456    of a const string.  */
 457 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 458                                 rtx (*) (void *, HOST_WIDE_INT,
 459                                          enum machine_mode),
 460                                 void *, unsigned int, bool);
 461
 462 /* Generate several move instructions to store LEN bytes generated by
 463    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 464    pointer which will be passed as argument in every CONSTFUN call.
 465    ALIGN is maximum alignment we can assume.
 466    MEMSETP is true if this is a real memset/bzero, not a copy.
 467    Returns TO + LEN.  */
 468 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 469                             rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
 470                             void *, unsigned int, bool, int);
 471
 472 /* Emit insns to set X from Y.  */
 473 extern rtx emit_move_insn (rtx, rtx);
 474
 475 /* Emit insns to set X from Y, with no frills.  */
 476 extern rtx emit_move_insn_1 (rtx, rtx);
 477
 478 extern rtx emit_move_complex_push (enum machine_mode, rtx, rtx);
 479 extern rtx emit_move_complex_parts (rtx, rtx);
 480
 481 /* Push a block of length SIZE (perhaps variable)
 482    and return an rtx to address the beginning of the block.  */
 483 extern rtx push_block (rtx, int, int);
 484
 485 /* Generate code to push something onto the stack, given its mode and type.  */
 486 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
 487                             int, rtx, int, rtx, rtx, int, rtx);
 488
 489 /* Expand an assignment that stores the value of FROM into TO.  */
 490 extern void expand_assignment (tree, tree, bool);
 491
 492 /* Generate code for computing expression EXP,
 493    and storing the value into TARGET.
 494    If SUGGEST_REG is nonzero, copy the value through a register
 495    and return that register, if that is possible.  */
 496 extern rtx store_expr (tree, rtx, int, bool);
 497
 498 /* Given an rtx that may include add and multiply operations,
 499    generate them as insns and return a pseudo-reg containing the value.
 500    Useful after calling expand_expr with 1 as sum_ok.  */
 501 extern rtx force_operand (rtx, rtx);
 502
 503 /* Work horse for expand_expr.  */
 504 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
 505                              enum expand_modifier, rtx *);
 506
 507 /* Generate code for computing expression EXP.
 508    An rtx for the computed value is returned.  The value is never null.
 509    In the case of a void EXP, const0_rtx is returned.  */
 510 static inline rtx
 511 expand_expr (tree exp, rtx target, enum machine_mode mode,
 512              enum expand_modifier modifier)
 513 {
 514   return expand_expr_real (exp, target, mode, modifier, NULL);
 515 }
 516
 517 static inline rtx
 518 expand_normal (tree exp)
 519 {
 520   return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL);
 521 }
 522
 523 /* At the start of a function, record that we have no previously-pushed
 524    arguments waiting to be popped.  */
 525 extern void init_pending_stack_adjust (void);
 526
 527 /* Discard any pending stack adjustment.  */
 528 extern void discard_pending_stack_adjust (void);
 529
 530 /* When exiting from function, if safe, clear out any pending stack adjust
 531    so the adjustment won't get done.  */
 532 extern void clear_pending_stack_adjust (void);
 533
 534 /* Pop any previously-pushed arguments that have not been popped yet.  */
 535 extern void do_pending_stack_adjust (void);
 536
 537 /* Return the tree node and offset if a given argument corresponds to
 538    a string constant.  */
 539 extern tree string_constant (tree, tree *);
 540
 541 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 542 extern void jumpifnot (tree, rtx);
 543
 544 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 545 extern void jumpif (tree, rtx);
 546
 547 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 548    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 549 extern void do_jump (tree, rtx, rtx);
 550
 551 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 552 extern rtx compare_from_rtx (rtx, rtx, enum rtx_code, int, enum machine_mode,
 553                              rtx);
 554 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 555                                      enum machine_mode, rtx, rtx, rtx);
 556
 557 /* Two different ways of generating switch statements.  */
 558 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx);
 559 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
 560
 561 /* Smallest number of adjacent cases before we use a jump table.
 562    XXX Should be a target hook.  */
 563 extern unsigned int case_values_threshold (void);
 564
 565 /* Functions from alias.c */
 566 #include "alias.h"
 567
 568 \f
 569 /* rtl.h and tree.h were included.  */
 570 /* Return an rtx for the size in bytes of the value of an expr.  */
 571 extern rtx expr_size (tree);
 572
 573 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 574    if the size can vary or is larger than an integer.  */
 575 extern HOST_WIDE_INT int_expr_size (tree);
 576
 577 /* Return an rtx that refers to the value returned by a function
 578    in its original home.  This becomes invalid if any more code is emitted.  */
 579 extern rtx hard_function_value (const_tree, const_tree, const_tree, int);
 580
 581 extern rtx prepare_call_address (rtx, rtx, rtx *, int, int);
 582
 583 extern bool shift_return_value (enum machine_mode, bool, rtx);
 584
 585 extern rtx expand_call (tree, rtx, int);
 586
 587 extern void fixup_tail_calls (void);
 588
 589 #ifdef TREE_CODE
 590 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
 591                          int);
 592 extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
 593                           rtx, int);
 594 #endif
 595
 596 extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
 597                                  struct args_size *,
 598                                  struct locate_and_pad_arg_data *);
 599
 600 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 601 extern rtx label_rtx (tree);
 602
 603 /* As label_rtx, but additionally the label is placed on the forced label
 604    list of its containing function (i.e. it is treated as reachable even
 605    if how is not obvious).  */
 606 extern rtx force_label_rtx (tree);
 607
 608 /* Return an rtx like arg but sans any constant terms.
 609    Returns the original rtx if it has no constant terms.
 610    The constant terms are added and stored via a second arg.  */
 611 extern rtx eliminate_constant_term (rtx, rtx *);
 612
 613 /* Convert arg to a valid memory address for specified machine mode,
 614    by emitting insns to perform arithmetic if nec.  */
 615 extern rtx memory_address (enum machine_mode, rtx);
 616
 617 /* Return a memory reference like MEMREF, but with its mode changed
 618    to MODE and its address changed to ADDR.
 619    (VOIDmode means don't change the mode.
 620    NULL for ADDR means don't change the address.)  */
 621 extern rtx change_address (rtx, enum machine_mode, rtx);
 622
 623 /* Return a memory reference like MEMREF, but with its mode changed
 624    to MODE and its address offset by OFFSET bytes.  */
 625 #define adjust_address(MEMREF, MODE, OFFSET) \
 626   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
 627
 628 /* Likewise, but the reference is not required to be valid.  */
 629 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 630   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
 631
 632 /* Return a memory reference like MEMREF, but with its mode changed
 633    to MODE and its address changed to ADDR, which is assumed to be
 634    increased by OFFSET bytes from MEMREF.  */
 635 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 636   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 637
 638 /* Likewise, but the reference is not required to be valid.  */
 639 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 640   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 641
 642 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
 643 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
 644                                         HOST_WIDE_INT, int);
 645
 646 /* Return a memory reference like MEMREF, but whose address is changed by
 647    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 648    known to be in OFFSET (possibly 1).  */
 649 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 650
 651 /* Definitions from emit-rtl.c */
 652 #include "emit-rtl.h"
 653
 654 /* Return a memory reference like MEMREF, but with its mode widened to
 655    MODE and adjusted by OFFSET.  */
 656 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
 657
 658 /* Return a memory reference like MEMREF, but which is known to have a
 659    valid address.  */
 660 extern rtx validize_mem (rtx);
 661
 662 extern rtx use_anchored_address (rtx);
 663
 664 /* Given REF, a MEM, and T, either the type of X or the expression
 665    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 666    if we are making a new object of this type.  */
 667 extern void set_mem_attributes (rtx, tree, int);
 668
 669 /* Similar, except that BITPOS has not yet been applied to REF, so if
 670    we alter MEM_OFFSET according to T then we should subtract BITPOS
 671    expecting that it'll be added back in later.  */
 672 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 673
 674 /* Assemble the static constant template for function entry trampolines.  */
 675 extern rtx assemble_trampoline_template (void);
 676
 677 /* Copy given rtx to a new temp reg and return that.  */
 678 extern rtx copy_to_reg (rtx);
 679
 680 /* Like copy_to_reg but always make the reg Pmode.  */
 681 extern rtx copy_addr_to_reg (rtx);
 682
 683 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 684 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
 685
 686 /* Copy given rtx to given temp reg and return that.  */
 687 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
 688
 689 /* Copy a value to a register if it isn't already a register.
 690    Args are mode (in case value is a constant) and the value.  */
 691 extern rtx force_reg (enum machine_mode, rtx);
 692
 693 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 694 extern rtx force_not_mem (rtx);
 695
 696 /* Return mode and signedness to use when object is promoted.  */
 697 extern enum machine_mode promote_mode (const_tree, enum machine_mode, int *, int);
 698
 699 /* Remove some bytes from the stack.  An rtx says how many.  */
 700 extern void adjust_stack (rtx);
 701
 702 /* Add some bytes to the stack.  An rtx says how many.  */
 703 extern void anti_adjust_stack (rtx);
 704
 705 /* This enum is used for the following two functions.  */
 706 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 707
 708 /* Save the stack pointer at the specified level.  */
 709 extern void emit_stack_save (enum save_level, rtx *, rtx);
 710
 711 /* Restore the stack pointer from a save area of the specified level.  */
 712 extern void emit_stack_restore (enum save_level, rtx, rtx);
 713
 714 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 715 extern void update_nonlocal_goto_save_area (void);
 716
 717 /* Allocate some space on the stack dynamically and return its address.  An rtx
 718    says how many bytes.  */
 719 extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
 720
 721 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 722    FIRST is a constant and size is a Pmode RTX.  These are offsets from the
 723    current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
 724    subtract from the stack.  If SIZE is constant, this is done
 725    with a fixed number of probes.  Otherwise, we must make a loop.  */
 726 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 727
 728 /* Return an rtx that refers to the value returned by a library call
 729    in its original home.  This becomes invalid if any more code is emitted.  */
 730 extern rtx hard_libcall_value (enum machine_mode);
 731
 732 /* Return the mode desired by operand N of a particular bitfield
 733    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
 734    available.  */
 735
 736 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
 737 extern enum machine_mode
 738 mode_for_extraction (enum extraction_pattern, int);
 739
 740 extern void store_bit_field (rtx, unsigned HOST_WIDE_INT,
 741                              unsigned HOST_WIDE_INT, enum machine_mode, rtx);
 742 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 743                               unsigned HOST_WIDE_INT, int, rtx,
 744                               enum machine_mode, enum machine_mode);
 745 extern rtx extract_low_bits (enum machine_mode, enum machine_mode, rtx);
 746 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
 747 extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
 748
 749 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
 750 extern int safe_from_p (const_rtx, tree, int);
 751
 752 /* Call this once to initialize the contents of the optabs
 753    appropriately for the current target machine.  */
 754 extern void init_optabs (void);
 755 extern void init_all_optabs (void);
 756
 757 /* Call this to initialize an optab function entry.  */
 758 extern rtx init_one_libfunc (const char *);
 759
 760 extern int vector_mode_valid_p (enum machine_mode);
 761
 762 #endif /* GCC_EXPR_H */