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, 51 Franklin Street, Fifth Floor, Boston, MA
  21 02110-1301, 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 setmem or libcall instead.  */
  79
  80 #ifndef CLEAR_RATIO
  81 #if defined (HAVE_setmemqi) || defined (HAVE_setmemhi) || defined (HAVE_setmemsi) || defined (HAVE_setmemdi) || defined (HAVE_setmemti)
  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 rtx expand_val_compare_and_swap (rtx, rtx, rtx, rtx);
 314 rtx expand_bool_compare_and_swap (rtx, rtx, rtx, rtx);
 315 rtx expand_sync_operation (rtx, rtx, enum rtx_code);
 316 rtx expand_sync_fetch_operation (rtx, rtx, enum rtx_code, bool, rtx);
 317 rtx expand_sync_lock_test_and_set (rtx, rtx, rtx);
 318 \f
 319 /* Functions from expmed.c:  */
 320
 321 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 322    May emit insns.  */
 323 extern rtx negate_rtx (enum machine_mode, rtx);
 324
 325 /* Expand a logical AND operation.  */
 326 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
 327
 328 /* Emit a store-flag operation.  */
 329 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 330                             int, int);
 331
 332 /* Like emit_store_flag, but always succeeds.  */
 333 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 334                                   enum machine_mode, int, int);
 335 \f
 336 /* Functions from builtins.c:  */
 337 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 338 extern tree std_build_builtin_va_list (void);
 339 extern void std_expand_builtin_va_start (tree, rtx);
 340 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 341 extern void expand_builtin_setjmp_setup (rtx, rtx);
 342 extern void expand_builtin_setjmp_receiver (rtx);
 343 extern rtx expand_builtin_saveregs (void);
 344 extern void expand_builtin_trap (void);
 345 \f
 346 /* Functions from expr.c:  */
 347
 348 /* This is run once per compilation to set up which modes can be used
 349    directly in memory and to initialize the block move optab.  */
 350 extern void init_expr_once (void);
 351
 352 /* This is run at the start of compiling a function.  */
 353 extern void init_expr (void);
 354
 355 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 356    Both modes must be floating or both fixed.  */
 357 extern void convert_move (rtx, rtx, int);
 358
 359 /* Convert an rtx to specified machine mode and return the result.  */
 360 extern rtx convert_to_mode (enum machine_mode, rtx, int);
 361
 362 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 363 extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
 364
 365 /* Emit code to move a block Y to a block X.  */
 366
 367 enum block_op_methods
 368 {
 369   BLOCK_OP_NORMAL,
 370   BLOCK_OP_NO_LIBCALL,
 371   BLOCK_OP_CALL_PARM,
 372   /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized.  */
 373   BLOCK_OP_TAILCALL
 374 };
 375
 376 extern void init_block_move_fn (const char *);
 377 extern void init_block_clear_fn (const char *);
 378
 379 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 380
 381 /* Copy all or part of a value X into registers starting at REGNO.
 382    The number of registers to be filled is NREGS.  */
 383 extern void move_block_to_reg (int, rtx, int, enum machine_mode);
 384
 385 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 386    The number of registers to be filled is NREGS.  */
 387 extern void move_block_from_reg (int, rtx, int);
 388
 389 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 390 extern rtx gen_group_rtx (rtx);
 391
 392 /* Load a BLKmode value into non-consecutive registers represented by a
 393    PARALLEL.  */
 394 extern void emit_group_load (rtx, rtx, tree, int);
 395
 396 /* Similarly, but load into new temporaries.  */
 397 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
 398
 399 /* Move a non-consecutive group of registers represented by a PARALLEL into
 400    a non-consecutive group of registers represented by a PARALLEL.  */
 401 extern void emit_group_move (rtx, rtx);
 402
 403 /* Move a group of registers represented by a PARALLEL into pseudos.  */
 404 extern rtx emit_group_move_into_temps (rtx);
 405
 406 /* Store a BLKmode value from non-consecutive registers represented by a
 407    PARALLEL.  */
 408 extern void emit_group_store (rtx, rtx, tree, int);
 409
 410 /* Copy BLKmode object from a set of registers.  */
 411 extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
 412
 413 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 414 extern void use_reg (rtx *, rtx);
 415
 416 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 417    for the next CALL_INSN.  */
 418 extern void use_regs (rtx *, int, int);
 419
 420 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 421 extern void use_group_regs (rtx *, rtx);
 422
 423 /* Write zeros through the storage of OBJECT.
 424    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 425 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
 426
 427 /* Expand a setmem pattern; return true if successful.  */
 428 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int);
 429
 430 /* Determine whether the LEN bytes can be moved by using several move
 431    instructions.  Return nonzero if a call to move_by_pieces should
 432    succeed.  */
 433 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 434
 435 /* Return nonzero if it is desirable to store LEN bytes generated by
 436    CONSTFUN with several move instructions by store_by_pieces
 437    function.  CONSTFUNDATA is a pointer which will be passed as argument
 438    in every CONSTFUN call.
 439    ALIGN is maximum alignment we can assume.  */
 440 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 441                                 rtx (*) (void *, HOST_WIDE_INT,
 442                                          enum machine_mode),
 443                                 void *, unsigned int);
 444
 445 /* Generate several move instructions to store LEN bytes generated by
 446    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 447    pointer which will be passed as argument in every CONSTFUN call.
 448    ALIGN is maximum alignment we can assume.
 449    Returns TO + LEN.  */
 450 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 451                             rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
 452                             void *, unsigned int, int);
 453
 454 /* Emit insns to set X from Y.  */
 455 extern rtx emit_move_insn (rtx, rtx);
 456
 457 /* Emit insns to set X from Y, with no frills.  */
 458 extern rtx emit_move_insn_1 (rtx, rtx);
 459
 460 /* Push a block of length SIZE (perhaps variable)
 461    and return an rtx to address the beginning of the block.  */
 462 extern rtx push_block (rtx, int, int);
 463
 464 /* Generate code to push something onto the stack, given its mode and type.  */
 465 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
 466                             int, rtx, int, rtx, rtx, int, rtx);
 467
 468 /* Expand an assignment that stores the value of FROM into TO.  */
 469 extern void expand_assignment (tree, tree);
 470
 471 /* Generate code for computing expression EXP,
 472    and storing the value into TARGET.
 473    If SUGGEST_REG is nonzero, copy the value through a register
 474    and return that register, if that is possible.  */
 475 extern rtx store_expr (tree, rtx, int);
 476
 477 /* Given an rtx that may include add and multiply operations,
 478    generate them as insns and return a pseudo-reg containing the value.
 479    Useful after calling expand_expr with 1 as sum_ok.  */
 480 extern rtx force_operand (rtx, rtx);
 481
 482 /* Work horse for expand_expr.  */
 483 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
 484                              enum expand_modifier, rtx *);
 485
 486 /* Generate code for computing expression EXP.
 487    An rtx for the computed value is returned.  The value is never null.
 488    In the case of a void EXP, const0_rtx is returned.  */
 489 static inline rtx
 490 expand_expr (tree exp, rtx target, enum machine_mode mode,
 491              enum expand_modifier modifier)
 492 {
 493   return expand_expr_real (exp, target, mode, modifier, NULL);
 494 }
 495
 496 extern void expand_var (tree);
 497
 498 /* At the start of a function, record that we have no previously-pushed
 499    arguments waiting to be popped.  */
 500 extern void init_pending_stack_adjust (void);
 501
 502 /* Discard any pending stack adjustment.  */
 503 extern void discard_pending_stack_adjust (void);
 504
 505 /* When exiting from function, if safe, clear out any pending stack adjust
 506    so the adjustment won't get done.  */
 507 extern void clear_pending_stack_adjust (void);
 508
 509 /* Pop any previously-pushed arguments that have not been popped yet.  */
 510 extern void do_pending_stack_adjust (void);
 511
 512 /* Return the tree node and offset if a given argument corresponds to
 513    a string constant.  */
 514 extern tree string_constant (tree, tree *);
 515
 516 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 517 extern void jumpifnot (tree, rtx);
 518
 519 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 520 extern void jumpif (tree, rtx);
 521
 522 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 523    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 524 extern void do_jump (tree, rtx, rtx);
 525
 526 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 527 extern rtx compare_from_rtx (rtx, rtx, enum rtx_code, int, enum machine_mode,
 528                              rtx);
 529 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 530                                      enum machine_mode, rtx, rtx, rtx);
 531
 532 /* Two different ways of generating switch statements.  */
 533 extern int try_casesi (tree, tree, tree, tree, rtx, rtx);
 534 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
 535
 536 /* Smallest number of adjacent cases before we use a jump table.
 537    XXX Should be a target hook.  */
 538 extern unsigned int case_values_threshold (void);
 539
 540 /* Functions from alias.c */
 541 #include "alias.h"
 542
 543 \f
 544 /* rtl.h and tree.h were included.  */
 545 /* Return an rtx for the size in bytes of the value of an expr.  */
 546 extern rtx expr_size (tree);
 547
 548 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 549    if the size can vary or is larger than an integer.  */
 550 extern HOST_WIDE_INT int_expr_size (tree);
 551
 552 /* Return an rtx that refers to the value returned by a function
 553    in its original home.  This becomes invalid if any more code is emitted.  */
 554 extern rtx hard_function_value (tree, tree, tree, int);
 555
 556 extern rtx prepare_call_address (rtx, rtx, rtx *, int, int);
 557
 558 extern bool shift_return_value (enum machine_mode, bool, rtx);
 559
 560 extern rtx expand_call (tree, rtx, int);
 561
 562 extern void fixup_tail_calls (void);
 563
 564 #ifdef TREE_CODE
 565 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
 566                          int);
 567 extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
 568                           rtx, int);
 569 #endif
 570
 571 extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
 572                                  struct args_size *,
 573                                  struct locate_and_pad_arg_data *);
 574
 575 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 576 extern rtx label_rtx (tree);
 577
 578 /* As label_rtx, but additionally the label is placed on the forced label
 579    list of its containing function (i.e. it is treated as reachable even
 580    if how is not obvious).  */
 581 extern rtx force_label_rtx (tree);
 582
 583 /* Indicate how an input argument register was promoted.  */
 584 extern rtx promoted_input_arg (unsigned int, enum machine_mode *, int *);
 585
 586 /* Return an rtx like arg but sans any constant terms.
 587    Returns the original rtx if it has no constant terms.
 588    The constant terms are added and stored via a second arg.  */
 589 extern rtx eliminate_constant_term (rtx, rtx *);
 590
 591 /* Convert arg to a valid memory address for specified machine mode,
 592    by emitting insns to perform arithmetic if nec.  */
 593 extern rtx memory_address (enum machine_mode, rtx);
 594
 595 /* Like `memory_address' but pretend `flag_force_addr' is 0.  */
 596 extern rtx memory_address_noforce (enum machine_mode, rtx);
 597
 598 /* Return a memory reference like MEMREF, but with its mode changed
 599    to MODE and its address changed to ADDR.
 600    (VOIDmode means don't change the mode.
 601    NULL for ADDR means don't change the address.)  */
 602 extern rtx change_address (rtx, enum machine_mode, rtx);
 603
 604 /* Return a memory reference like MEMREF, but with its mode changed
 605    to MODE and its address offset by OFFSET bytes.  */
 606 #define adjust_address(MEMREF, MODE, OFFSET) \
 607   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
 608
 609 /* Likewise, but the reference is not required to be valid.  */
 610 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 611   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
 612
 613 /* Return a memory reference like MEMREF, but with its mode changed
 614    to MODE and its address changed to ADDR, which is assumed to be
 615    increased by OFFSET bytes from MEMREF.  */
 616 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 617   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 618
 619 /* Likewise, but the reference is not required to be valid.  */
 620 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 621   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 622
 623 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
 624 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
 625                                         HOST_WIDE_INT, int);
 626
 627 /* Return a memory reference like MEMREF, but whose address is changed by
 628    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 629    known to be in OFFSET (possibly 1).  */
 630 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 631
 632 /* Definitions from emit-rtl.c */
 633 #include "emit-rtl.h"
 634
 635 /* Return a memory reference like MEMREF, but with its mode widened to
 636    MODE and adjusted by OFFSET.  */
 637 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
 638
 639 /* Return a memory reference like MEMREF, but which is known to have a
 640    valid address.  */
 641 extern rtx validize_mem (rtx);
 642
 643 /* Given REF, a MEM, and T, either the type of X or the expression
 644    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 645    if we are making a new object of this type.  */
 646 extern void set_mem_attributes (rtx, tree, int);
 647
 648 /* Similar, except that BITPOS has not yet been applied to REF, so if
 649    we alter MEM_OFFSET according to T then we should subtract BITPOS
 650    expecting that it'll be added back in later.  */
 651 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 652
 653 /* Assemble the static constant template for function entry trampolines.  */
 654 extern rtx assemble_trampoline_template (void);
 655
 656 /* Copy given rtx to a new temp reg and return that.  */
 657 extern rtx copy_to_reg (rtx);
 658
 659 /* Like copy_to_reg but always make the reg Pmode.  */
 660 extern rtx copy_addr_to_reg (rtx);
 661
 662 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 663 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
 664
 665 /* Copy given rtx to given temp reg and return that.  */
 666 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
 667
 668 /* Copy a value to a register if it isn't already a register.
 669    Args are mode (in case value is a constant) and the value.  */
 670 extern rtx force_reg (enum machine_mode, rtx);
 671
 672 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 673 extern rtx force_not_mem (rtx);
 674
 675 /* Return mode and signedness to use when object is promoted.  */
 676 extern enum machine_mode promote_mode (tree, enum machine_mode, int *, int);
 677
 678 /* Remove some bytes from the stack.  An rtx says how many.  */
 679 extern void adjust_stack (rtx);
 680
 681 /* Add some bytes to the stack.  An rtx says how many.  */
 682 extern void anti_adjust_stack (rtx);
 683
 684 /* This enum is used for the following two functions.  */
 685 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 686
 687 /* Save the stack pointer at the specified level.  */
 688 extern void emit_stack_save (enum save_level, rtx *, rtx);
 689
 690 /* Restore the stack pointer from a save area of the specified level.  */
 691 extern void emit_stack_restore (enum save_level, rtx, rtx);
 692
 693 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 694 extern void update_nonlocal_goto_save_area (void);
 695
 696 /* Allocate some space on the stack dynamically and return its address.  An rtx
 697    says how many bytes.  */
 698 extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
 699
 700 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 701    FIRST is a constant and size is a Pmode RTX.  These are offsets from the
 702    current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
 703    subtract from the stack.  If SIZE is constant, this is done
 704    with a fixed number of probes.  Otherwise, we must make a loop.  */
 705 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 706
 707 /* Return an rtx that refers to the value returned by a library call
 708    in its original home.  This becomes invalid if any more code is emitted.  */
 709 extern rtx hard_libcall_value (enum machine_mode);
 710
 711 /* Return the mode desired by operand N of a particular bitfield
 712    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
 713    available.  */
 714
 715 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
 716 extern enum machine_mode
 717 mode_for_extraction (enum extraction_pattern, int);
 718
 719 extern rtx store_bit_field (rtx, unsigned HOST_WIDE_INT,
 720                             unsigned HOST_WIDE_INT, enum machine_mode, rtx);
 721 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 722                               unsigned HOST_WIDE_INT, int, rtx,
 723                               enum machine_mode, enum machine_mode);
 724 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
 725 extern bool const_mult_add_overflow_p (rtx, rtx, rtx, enum machine_mode, int);
 726 extern rtx expand_mult_add (rtx, rtx, rtx, rtx,enum machine_mode, int);
 727 extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
 728
 729 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
 730 extern int safe_from_p (rtx, tree, int);
 731
 732 /* Call this once to initialize the contents of the optabs
 733    appropriately for the current target machine.  */
 734 extern void init_optabs (void);
 735 extern void init_all_optabs (void);
 736
 737 /* Call this to initialize an optab function entry.  */
 738 extern rtx init_one_libfunc (const char *);
 739
 740 extern void do_jump_by_parts_equality_rtx (rtx, rtx, rtx);
 741 extern void do_jump_by_parts_greater_rtx (enum machine_mode, int, rtx, rtx,
 742                                           rtx, rtx);
 743
 744 extern int vector_mode_valid_p (enum machine_mode);
 745
 746 #endif /* GCC_EXPR_H */