gcc/expr.h

   1 /* Definitions for code generation pass of GNU compiler.
   2    Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   3    1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #ifndef GCC_EXPR_H
  23 #define GCC_EXPR_H
  24
  25 /* For inhibit_defer_pop */
  26 #include "function.h"
  27 /* For XEXP, GEN_INT, rtx_code */
  28 #include "rtl.h"
  29 /* For optimize_size */
  30 #include "flags.h"
  31 /* For host_integerp, tree_low_cst, convert, size_binop, ssize_int, TREE_CODE,
  32    TYPE_SIZE, int_size_in_bytes,    */
  33 #include "tree.h"
  34 /* For GET_MODE_BITSIZE, word_mode */
  35 #include "machmode.h"
  36
  37 /* The default branch cost is 1.  */
  38 #ifndef BRANCH_COST
  39 #define BRANCH_COST 1
  40 #endif
  41
  42 /* This is the 4th arg to `expand_expr'.
  43    EXPAND_STACK_PARM means we are possibly expanding a call param onto
  44    the stack.  Choosing a value of 2 isn't special;  It just allows
  45    some code optimization in store_expr.
  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 = 2, 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 };
 121
 122 /* Add the value of the tree INC to the `struct args_size' TO.  */
 123
 124 #define ADD_PARM_SIZE(TO, INC)                          \
 125 do {                                                    \
 126   tree inc = (INC);                                     \
 127   if (host_integerp (inc, 0))                           \
 128     (TO).constant += tree_low_cst (inc, 0);             \
 129   else if ((TO).var == 0)                               \
 130     (TO).var = convert (ssizetype, inc);                \
 131   else                                                  \
 132     (TO).var = size_binop (PLUS_EXPR, (TO).var,         \
 133                            convert (ssizetype, inc));   \
 134 } while (0)
 135
 136 #define SUB_PARM_SIZE(TO, DEC)                          \
 137 do {                                                    \
 138   tree dec = (DEC);                                     \
 139   if (host_integerp (dec, 0))                           \
 140     (TO).constant -= tree_low_cst (dec, 0);             \
 141   else if ((TO).var == 0)                               \
 142     (TO).var = size_binop (MINUS_EXPR, ssize_int (0),   \
 143                            convert (ssizetype, dec));   \
 144   else                                                  \
 145     (TO).var = size_binop (MINUS_EXPR, (TO).var,        \
 146                            convert (ssizetype, dec));   \
 147 } while (0)
 148
 149 /* Convert the implicit sum in a `struct args_size' into a tree
 150    of type ssizetype.  */
 151 #define ARGS_SIZE_TREE(SIZE)                                    \
 152 ((SIZE).var == 0 ? ssize_int ((SIZE).constant)                  \
 153  : size_binop (PLUS_EXPR, convert (ssizetype, (SIZE).var),      \
 154                ssize_int ((SIZE).constant)))
 155
 156 /* Convert the implicit sum in a `struct args_size' into an rtx.  */
 157 #define ARGS_SIZE_RTX(SIZE)                                     \
 158 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant)                    \
 159  : expand_expr (ARGS_SIZE_TREE (SIZE), NULL_RTX, VOIDmode, 0))
 160
 161 /* Supply a default definition for FUNCTION_ARG_PADDING:
 162    usually pad upward, but pad short args downward on
 163    big-endian machines.  */
 164
 165 #define DEFAULT_FUNCTION_ARG_PADDING(MODE, TYPE)                        \
 166   (! BYTES_BIG_ENDIAN                                                   \
 167    ? upward                                                             \
 168    : (((MODE) == BLKmode                                                \
 169        ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST         \
 170           && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
 171        : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)                       \
 172       ? downward : upward))
 173
 174 #ifndef FUNCTION_ARG_PADDING
 175 #define FUNCTION_ARG_PADDING(MODE, TYPE)        \
 176   DEFAULT_FUNCTION_ARG_PADDING ((MODE), (TYPE))
 177 #endif
 178
 179 /* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
 180    FUNCTION_ARG_PADDING, which also pads the length, handle any needed
 181    alignment.  */
 182
 183 #ifndef FUNCTION_ARG_BOUNDARY
 184 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE)       PARM_BOUNDARY
 185 #endif
 186
 187 #ifndef FUNCTION_ARG_PARTIAL_NREGS
 188 #define FUNCTION_ARG_PARTIAL_NREGS(CUM, MODE, TYPE, NAMED) 0
 189 #endif
 190
 191 #ifndef FUNCTION_ARG_CALLEE_COPIES
 192 #define FUNCTION_ARG_CALLEE_COPIES(CUM, MODE, TYPE, NAMED) 0
 193 #endif
 194
 195 tree split_complex_types (tree);
 196 tree split_complex_values (tree);
 197
 198 /* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
 199    Normally move_insn, so Pmode stack pointer.  */
 200
 201 #ifndef STACK_SAVEAREA_MODE
 202 #define STACK_SAVEAREA_MODE(LEVEL) Pmode
 203 #endif
 204
 205 /* Supply a default definition of STACK_SIZE_MODE for
 206    allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
 207
 208 #ifndef STACK_SIZE_MODE
 209 #define STACK_SIZE_MODE word_mode
 210 #endif
 211
 212 /* Provide default values for the macros controlling stack checking.  */
 213
 214 #ifndef STACK_CHECK_BUILTIN
 215 #define STACK_CHECK_BUILTIN 0
 216 #endif
 217
 218 /* The default interval is one page.  */
 219 #ifndef STACK_CHECK_PROBE_INTERVAL
 220 #define STACK_CHECK_PROBE_INTERVAL 4096
 221 #endif
 222
 223 /* The default is to do a store into the stack.  */
 224 #ifndef STACK_CHECK_PROBE_LOAD
 225 #define STACK_CHECK_PROBE_LOAD 0
 226 #endif
 227
 228 /* This value is arbitrary, but should be sufficient for most machines.  */
 229 #ifndef STACK_CHECK_PROTECT
 230 #define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
 231 #endif
 232
 233 /* Make the maximum frame size be the largest we can and still only need
 234    one probe per function.  */
 235 #ifndef STACK_CHECK_MAX_FRAME_SIZE
 236 #define STACK_CHECK_MAX_FRAME_SIZE \
 237   (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
 238 #endif
 239
 240 /* This is arbitrary, but should be large enough everywhere.  */
 241 #ifndef STACK_CHECK_FIXED_FRAME_SIZE
 242 #define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
 243 #endif
 244
 245 /* Provide a reasonable default for the maximum size of an object to
 246    allocate in the fixed frame.  We may need to be able to make this
 247    controllable by the user at some point.  */
 248 #ifndef STACK_CHECK_MAX_VAR_SIZE
 249 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
 250 #endif
 251 \f
 252 /* Functions from optabs.c, commonly used, and without need for the optabs
 253    tables:  */
 254
 255 /* Passed to expand_simple_binop and expand_binop to say which options
 256    to try to use if the requested operation can't be open-coded on the
 257    requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
 258    a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
 259    using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
 260    try anything else.  */
 261
 262 enum optab_methods
 263 {
 264   OPTAB_DIRECT,
 265   OPTAB_LIB,
 266   OPTAB_WIDEN,
 267   OPTAB_LIB_WIDEN,
 268   OPTAB_MUST_WIDEN
 269 };
 270
 271 /* Generate code for a simple binary or unary operation.  "Simple" in
 272    this case means "can be unambiguously described by a (mode, code)
 273    pair and mapped to a single optab."  */
 274 extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
 275                                 rtx, rtx, int, enum optab_methods);
 276 extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
 277                                int);
 278
 279 /* Report whether the machine description contains an insn which can
 280    perform the operation described by CODE and MODE.  */
 281 extern int have_insn_for (enum rtx_code, enum machine_mode);
 282
 283 /* Emit code to make a call to a constant function or a library call.  */
 284 extern void emit_libcall_block (rtx, rtx, rtx, rtx);
 285
 286 /* Create but don't emit one rtl instruction to perform certain operations.
 287    Modes must match; operands must meet the operation's predicates.
 288    Likewise for subtraction and for just copying.  */
 289 extern rtx gen_add2_insn (rtx, rtx);
 290 extern rtx gen_add3_insn (rtx, rtx, rtx);
 291 extern rtx gen_sub2_insn (rtx, rtx);
 292 extern rtx gen_sub3_insn (rtx, rtx, rtx);
 293 extern rtx gen_move_insn (rtx, rtx);
 294 extern int have_add2_insn (rtx, rtx);
 295 extern int have_sub2_insn (rtx, rtx);
 296
 297 /* Emit a pair of rtl insns to compare two rtx's and to jump
 298    to a label if the comparison is true.  */
 299 extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
 300                                      enum machine_mode, int, rtx);
 301
 302 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 303 extern void emit_indirect_jump (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 \f
 320 /* Functions from expmed.c:  */
 321
 322 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 323    May emit insns.  */
 324 extern rtx negate_rtx (enum machine_mode, rtx);
 325
 326 /* Expand a logical AND operation.  */
 327 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
 328
 329 /* Emit a store-flag operation.  */
 330 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 331                             int, int);
 332
 333 /* Like emit_store_flag, but always succeeds.  */
 334 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 335                                   enum machine_mode, int, int);
 336
 337 /* Functions from loop.c:  */
 338
 339 /* Given an insn and condition, return a canonical description of
 340    the test being made.  */
 341 extern rtx canonicalize_condition (rtx, rtx, int, rtx *, rtx, int, int);
 342
 343 /* Given a JUMP_INSN, return a canonical description of the test
 344    being made.  */
 345 extern rtx get_condition (rtx, rtx *, int, int);
 346
 347 /* Generate a conditional trap instruction.  */
 348 extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
 349 \f
 350 /* Functions from builtins.c:  */
 351 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 352 extern tree std_build_builtin_va_list (void);
 353 extern void std_expand_builtin_va_start (tree, rtx);
 354 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 355 extern void expand_builtin_setjmp_setup (rtx, rtx);
 356 extern void expand_builtin_setjmp_receiver (rtx);
 357 extern void expand_builtin_longjmp (rtx, rtx);
 358 extern rtx expand_builtin_saveregs (void);
 359 extern void expand_builtin_trap (void);
 360 \f
 361 /* Functions from expr.c:  */
 362
 363 /* This is run once per compilation to set up which modes can be used
 364    directly in memory and to initialize the block move optab.  */
 365 extern void init_expr_once (void);
 366
 367 /* This is run at the start of compiling a function.  */
 368 extern void init_expr (void);
 369
 370 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 371    Both modes must be floating or both fixed.  */
 372 extern void convert_move (rtx, rtx, int);
 373
 374 /* Convert an rtx to specified machine mode and return the result.  */
 375 extern rtx convert_to_mode (enum machine_mode, rtx, int);
 376
 377 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 378 extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
 379
 380 /* Emit code to move a block Y to a block X.  */
 381
 382 enum block_op_methods
 383 {
 384   BLOCK_OP_NORMAL,
 385   BLOCK_OP_NO_LIBCALL,
 386   BLOCK_OP_CALL_PARM
 387 };
 388
 389 extern void init_block_move_fn (const char *);
 390 extern void init_block_clear_fn (const char *);
 391
 392 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 393
 394 /* Copy all or part of a value X into registers starting at REGNO.
 395    The number of registers to be filled is NREGS.  */
 396 extern void move_block_to_reg (int, rtx, int, enum machine_mode);
 397
 398 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 399    The number of registers to be filled is NREGS.  */
 400 extern void move_block_from_reg (int, rtx, int);
 401
 402 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 403 extern rtx gen_group_rtx (rtx);
 404
 405 /* Load a BLKmode value into non-consecutive registers represented by a
 406    PARALLEL.  */
 407 extern void emit_group_load (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 /* Store a BLKmode value from non-consecutive registers represented by a
 414    PARALLEL.  */
 415 extern void emit_group_store (rtx, rtx, tree, int);
 416
 417 /* Copy BLKmode object from a set of registers.  */
 418 extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
 419
 420 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 421 extern void use_reg (rtx *, rtx);
 422
 423 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 424    for the next CALL_INSN.  */
 425 extern void use_regs (rtx *, int, int);
 426
 427 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 428 extern void use_group_regs (rtx *, rtx);
 429
 430 /* Write zeros through the storage of OBJECT.
 431    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 432 extern rtx clear_storage (rtx, rtx);
 433
 434 /* Determine whether the LEN bytes can be moved by using several move
 435    instructions.  Return nonzero if a call to move_by_pieces should
 436    succeed.  */
 437 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 438
 439 /* Return nonzero if it is desirable to store LEN bytes generated by
 440    CONSTFUN with several move instructions by store_by_pieces
 441    function.  CONSTFUNDATA is a pointer which will be passed as argument
 442    in every CONSTFUN call.
 443    ALIGN is maximum alignment we can assume.  */
 444 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 445                                 rtx (*) (void *, HOST_WIDE_INT,
 446                                          enum machine_mode),
 447                                 void *, unsigned int);
 448
 449 /* Generate several move instructions to store LEN bytes generated by
 450    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 451    pointer which will be passed as argument in every CONSTFUN call.
 452    ALIGN is maximum alignment we can assume.
 453    Returns TO + LEN.  */
 454 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 455                             rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
 456                             void *, unsigned int, int);
 457
 458 /* Emit insns to set X from Y.  */
 459 extern rtx emit_move_insn (rtx, rtx);
 460
 461 /* Emit insns to set X from Y, with no frills.  */
 462 extern rtx emit_move_insn_1 (rtx, rtx);
 463
 464 /* Push a block of length SIZE (perhaps variable)
 465    and return an rtx to address the beginning of the block.  */
 466 extern rtx push_block (rtx, int, int);
 467
 468 /* Generate code to push something onto the stack, given its mode and type.  */
 469 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
 470                             int, rtx, int, rtx, rtx, int, rtx);
 471
 472 /* Expand an assignment that stores the value of FROM into TO.  */
 473 extern rtx expand_assignment (tree, tree, int);
 474
 475 /* Generate code for computing expression EXP,
 476    and storing the value into TARGET.
 477    If SUGGEST_REG is nonzero, copy the value through a register
 478    and return that register, if that is possible.  */
 479 extern rtx store_expr (tree, rtx, int);
 480
 481 /* Given an rtx that may include add and multiply operations,
 482    generate them as insns and return a pseudo-reg containing the value.
 483    Useful after calling expand_expr with 1 as sum_ok.  */
 484 extern rtx force_operand (rtx, rtx);
 485
 486 /* Work horse for expand_expr.  */
 487 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
 488                              enum expand_modifier, rtx *);
 489
 490 /* Generate code for computing expression EXP.
 491    An rtx for the computed value is returned.  The value is never null.
 492    In the case of a void EXP, const0_rtx is returned.  */
 493 static inline rtx
 494 expand_expr (tree exp, rtx target, enum machine_mode mode,
 495              enum expand_modifier modifier)
 496 {
 497   return expand_expr_real (exp, target, mode, modifier, NULL);
 498 }
 499
 500 extern void expand_var (tree);
 501
 502 /* At the start of a function, record that we have no previously-pushed
 503    arguments waiting to be popped.  */
 504 extern void init_pending_stack_adjust (void);
 505
 506 /* When exiting from function, if safe, clear out any pending stack adjust
 507    so the adjustment won't get done.  */
 508 extern void clear_pending_stack_adjust (void);
 509
 510 /* Pop any previously-pushed arguments that have not been popped yet.  */
 511 extern void do_pending_stack_adjust (void);
 512
 513 /* Return the tree node and offset if a given argument corresponds to
 514    a string constant.  */
 515 extern tree string_constant (tree, tree *);
 516
 517 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 518 extern void jumpifnot (tree, rtx);
 519
 520 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 521 extern void jumpif (tree, rtx);
 522
 523 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 524    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 525 extern void do_jump (tree, rtx, rtx);
 526
 527 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 528 extern rtx compare_from_rtx (rtx, rtx, enum rtx_code, int, enum machine_mode,
 529                              rtx);
 530 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 531                                      enum machine_mode, rtx, rtx, rtx);
 532
 533 /* Two different ways of generating switch statements.  */
 534 extern int try_casesi (tree, tree, tree, tree, rtx, rtx);
 535 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
 536
 537 /* Smallest number of adjacent cases before we use a jump table.
 538    XXX Should be a target hook.  */
 539 extern unsigned int case_values_threshold (void);
 540
 541 /* Functions from alias.c */
 542 #include "alias.h"
 543 /* extern HOST_WIDE_INT get_varargs_alias_set (void); */
 544 /* extern HOST_WIDE_INT get_frame_alias_set (void); */
 545 /* extern void record_base_value (unsigned int, rtx, int); */
 546 /* extern void record_alias_subset (HOST_WIDE_INT, HOST_WIDE_INT); */
 547 /* extern HOST_WIDE_INT new_alias_set (void); */
 548 /* extern int can_address_p (tree); */
 549
 550 \f
 551 /* rtl.h and tree.h were included.  */
 552 /* Return an rtx for the size in bytes of the value of an expr.  */
 553 extern rtx expr_size (tree);
 554
 555 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 556    if the size can vary or is larger than an integer.  */
 557 extern HOST_WIDE_INT int_expr_size (tree);
 558
 559 /* Return the address of the trampoline for entering nested fn FUNCTION.  */
 560 extern rtx trampoline_address (tree);
 561
 562 /* Return an rtx that refers to the value returned by a function
 563    in its original home.  This becomes invalid if any more code is emitted.  */
 564 extern rtx hard_function_value (tree, tree, int);
 565
 566 extern rtx prepare_call_address (rtx, rtx, rtx *, int, int);
 567
 568 extern rtx expand_call (tree, rtx, int);
 569
 570 extern void fixup_tail_calls (void);
 571
 572 #ifdef TREE_CODE
 573 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
 574                          int);
 575 extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
 576                           rtx, int);
 577 #endif
 578
 579 extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
 580                                  struct args_size *,
 581                                  struct locate_and_pad_arg_data *);
 582
 583 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 584 extern rtx label_rtx (tree);
 585
 586 /* As label_rtx, but additionally the label is placed on the forced label
 587    list of its containing function (i.e. it is treated as reachable even
 588    if how is not obvious).  */
 589 extern rtx force_label_rtx (tree);
 590
 591 /* Indicate how an input argument register was promoted.  */
 592 extern rtx promoted_input_arg (unsigned int, enum machine_mode *, int *);
 593
 594 /* Return an rtx like arg but sans any constant terms.
 595    Returns the original rtx if it has no constant terms.
 596    The constant terms are added and stored via a second arg.  */
 597 extern rtx eliminate_constant_term (rtx, rtx *);
 598
 599 /* Convert arg to a valid memory address for specified machine mode,
 600    by emitting insns to perform arithmetic if nec.  */
 601 extern rtx memory_address (enum machine_mode, rtx);
 602
 603 /* Like `memory_address' but pretent `flag_force_addr' is 0.  */
 604 extern rtx memory_address_noforce (enum machine_mode, rtx);
 605
 606 /* Return a memory reference like MEMREF, but with its mode changed
 607    to MODE and its address changed to ADDR.
 608    (VOIDmode means don't change the mode.
 609    NULL for ADDR means don't change the address.)  */
 610 extern rtx change_address (rtx, enum machine_mode, rtx);
 611
 612 /* Return a memory reference like MEMREF, but with its mode changed
 613    to MODE and its address offset by OFFSET bytes.  */
 614 #define adjust_address(MEMREF, MODE, OFFSET) \
 615   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
 616
 617 /* Likewise, but the reference is not required to be valid.  */
 618 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 619   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
 620
 621 /* Return a memory reference like MEMREF, but with its mode changed
 622    to MODE and its address changed to ADDR, which is assumed to be
 623    increased by OFFSET bytes from MEMREF.  */
 624 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 625   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 626
 627 /* Likewise, but the reference is not required to be valid.  */
 628 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 629   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 630
 631 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
 632 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
 633                                         HOST_WIDE_INT, int);
 634
 635 /* Return a memory reference like MEMREF, but whose address is changed by
 636    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 637    known to be in OFFSET (possibly 1).  */
 638 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 639
 640 /* Definitions from emit-rtl.c */
 641 #include "emit-rtl.h"
 642
 643 /* Return a memory reference like MEMREF, but with its mode widened to
 644    MODE and adjusted by OFFSET.  */
 645 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
 646
 647 /* Return a memory reference like MEMREF, but which is known to have a
 648    valid address.  */
 649 extern rtx validize_mem (rtx);
 650
 651 /* Given REF, a MEM, and T, either the type of X or the expression
 652    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 653    if we are making a new object of this type.  */
 654 extern void set_mem_attributes (rtx, tree, int);
 655
 656 /* Similar, except that BITPOS has not yet been applied to REF, so if
 657    we alter MEM_OFFSET according to T then we should subtract BITPOS
 658    expecting that it'll be added back in later.  */
 659 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 660
 661 /* Assemble the static constant template for function entry trampolines.  */
 662 extern rtx assemble_trampoline_template (void);
 663
 664 /* Given rtx, return new rtx whose address won't be affected by
 665    any side effects.  It has been copied to a new temporary reg.  */
 666 extern rtx stabilize (rtx);
 667
 668 /* Given an rtx, copy all regs it refers to into new temps
 669    and return a modified copy that refers to the new temps.  */
 670 extern rtx copy_all_regs (rtx);
 671
 672 /* Copy given rtx to a new temp reg and return that.  */
 673 extern rtx copy_to_reg (rtx);
 674
 675 /* Like copy_to_reg but always make the reg Pmode.  */
 676 extern rtx copy_addr_to_reg (rtx);
 677
 678 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 679 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
 680
 681 /* Copy given rtx to given temp reg and return that.  */
 682 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
 683
 684 /* Copy a value to a register if it isn't already a register.
 685    Args are mode (in case value is a constant) and the value.  */
 686 extern rtx force_reg (enum machine_mode, rtx);
 687
 688 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 689 extern rtx force_not_mem (rtx);
 690
 691 /* Return mode and signedness to use when object is promoted.  */
 692 extern enum machine_mode promote_mode (tree, enum machine_mode, int *, int);
 693
 694 /* Remove some bytes from the stack.  An rtx says how many.  */
 695 extern void adjust_stack (rtx);
 696
 697 /* Add some bytes to the stack.  An rtx says how many.  */
 698 extern void anti_adjust_stack (rtx);
 699
 700 /* This enum is used for the following two functions.  */
 701 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 702
 703 /* Save the stack pointer at the specified level.  */
 704 extern void emit_stack_save (enum save_level, rtx *, rtx);
 705
 706 /* Restore the stack pointer from a save area of the specified level.  */
 707 extern void emit_stack_restore (enum save_level, rtx, rtx);
 708
 709 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 710 extern void update_nonlocal_goto_save_area (void);
 711
 712 /* Allocate some space on the stack dynamically and return its address.  An rtx
 713    says how many bytes.  */
 714 extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
 715
 716 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 717    FIRST is a constant and size is a Pmode RTX.  These are offsets from the
 718    current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
 719    subtract from the stack.  If SIZE is constant, this is done
 720    with a fixed number of probes.  Otherwise, we must make a loop.  */
 721 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 722
 723 /* Return an rtx that refers to the value returned by a library call
 724    in its original home.  This becomes invalid if any more code is emitted.  */
 725 extern rtx hard_libcall_value (enum machine_mode);
 726
 727 /* Given an rtx, return an rtx for a value rounded up to a multiple
 728    of STACK_BOUNDARY / BITS_PER_UNIT.  */
 729 extern rtx round_push (rtx);
 730
 731 /* Return the mode desired by operand N of a particular bitfield
 732    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
 733    available.  */
 734
 735 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
 736 extern enum machine_mode
 737 mode_for_extraction (enum extraction_pattern, int);
 738
 739 extern rtx store_bit_field (rtx, unsigned HOST_WIDE_INT,
 740                             unsigned HOST_WIDE_INT, enum machine_mode, rtx);
 741 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 742                               unsigned HOST_WIDE_INT, int, rtx,
 743                               enum machine_mode, enum machine_mode);
 744 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
 745 extern bool const_mult_add_overflow_p (rtx, rtx, rtx, enum machine_mode, int);
 746 extern rtx expand_mult_add (rtx, rtx, rtx, rtx,enum machine_mode, 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 (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 void do_jump_by_parts_equality_rtx (rtx, rtx, rtx);
 761 extern void do_jump_by_parts_greater_rtx (enum machine_mode, int, rtx, rtx,
 762                                           rtx, rtx);
 763
 764 extern int vector_mode_valid_p (enum machine_mode);
 765
 766 #endif /* GCC_EXPR_H */