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, 2008, 2009, 2010
   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 /* This is the 4th arg to `expand_expr'.
  38    EXPAND_STACK_PARM means we are possibly expanding a call param onto
  39    the stack.
  40    EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
  41    EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
  42    EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
  43     is a constant that is not a legitimate address.
  44    EXPAND_WRITE means we are only going to write to the resulting rtx.
  45    EXPAND_MEMORY means we are interested in a memory result, even if
  46     the memory is constant and we could have propagated a constant value.  */
  47 enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM, EXPAND_SUM,
  48                       EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
  49                       EXPAND_MEMORY};
  50
  51 /* Prevent the compiler from deferring stack pops.  See
  52    inhibit_defer_pop for more information.  */
  53 #define NO_DEFER_POP (inhibit_defer_pop += 1)
  54
  55 /* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
  56    more information.  */
  57 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
  58 \f
  59 enum direction {none, upward, downward};
  60
  61 /* Structure to record the size of a sequence of arguments
  62    as the sum of a tree-expression and a constant.  This structure is
  63    also used to store offsets from the stack, which might be negative,
  64    so the variable part must be ssizetype, not sizetype.  */
  65
  66 struct args_size
  67 {
  68   HOST_WIDE_INT constant;
  69   tree var;
  70 };
  71
  72 /* Package up various arg related fields of struct args for
  73    locate_and_pad_parm.  */
  74 struct locate_and_pad_arg_data
  75 {
  76   /* Size of this argument on the stack, rounded up for any padding it
  77      gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
  78      counted here, otherwise they aren't.  */
  79   struct args_size size;
  80   /* Offset of this argument from beginning of stack-args.  */
  81   struct args_size offset;
  82   /* Offset to the start of the stack slot.  Different from OFFSET
  83      if this arg pads downward.  */
  84   struct args_size slot_offset;
  85   /* The amount that the stack pointer needs to be adjusted to
  86      force alignment for the next argument.  */
  87   struct args_size alignment_pad;
  88   /* Which way we should pad this arg.  */
  89   enum direction where_pad;
  90   /* slot_offset is at least this aligned.  */
  91   unsigned int boundary;
  92 };
  93
  94 /* Add the value of the tree INC to the `struct args_size' TO.  */
  95
  96 #define ADD_PARM_SIZE(TO, INC)                                  \
  97 do {                                                            \
  98   tree inc = (INC);                                             \
  99   if (host_integerp (inc, 0))                                   \
 100     (TO).constant += tree_low_cst (inc, 0);                     \
 101   else if ((TO).var == 0)                                       \
 102     (TO).var = fold_convert (ssizetype, inc);                   \
 103   else                                                          \
 104     (TO).var = size_binop (PLUS_EXPR, (TO).var,                 \
 105                            fold_convert (ssizetype, inc));      \
 106 } while (0)
 107
 108 #define SUB_PARM_SIZE(TO, DEC)                                  \
 109 do {                                                            \
 110   tree dec = (DEC);                                             \
 111   if (host_integerp (dec, 0))                                   \
 112     (TO).constant -= tree_low_cst (dec, 0);                     \
 113   else if ((TO).var == 0)                                       \
 114     (TO).var = size_binop (MINUS_EXPR, ssize_int (0),           \
 115                            fold_convert (ssizetype, dec));      \
 116   else                                                          \
 117     (TO).var = size_binop (MINUS_EXPR, (TO).var,                \
 118                            fold_convert (ssizetype, dec));      \
 119 } while (0)
 120
 121 /* Convert the implicit sum in a `struct args_size' into a tree
 122    of type ssizetype.  */
 123 #define ARGS_SIZE_TREE(SIZE)                                    \
 124 ((SIZE).var == 0 ? ssize_int ((SIZE).constant)                  \
 125  : size_binop (PLUS_EXPR, fold_convert (ssizetype, (SIZE).var), \
 126                ssize_int ((SIZE).constant)))
 127
 128 /* Convert the implicit sum in a `struct args_size' into an rtx.  */
 129 #define ARGS_SIZE_RTX(SIZE)                                     \
 130 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant)                    \
 131  : expand_normal (ARGS_SIZE_TREE (SIZE)))
 132
 133 \f
 134 /* This structure is used to pass around information about exploded
 135    unary, binary and trinary expressions between expand_expr_real_1 and
 136    friends.  */
 137 typedef struct separate_ops
 138 {
 139   enum tree_code code;
 140   location_t location;
 141   tree type;
 142   tree op0, op1, op2;
 143 } *sepops;
 144 \f
 145 /* Functions from optabs.c, commonly used, and without need for the optabs
 146    tables:  */
 147
 148 /* Passed to expand_simple_binop and expand_binop to say which options
 149    to try to use if the requested operation can't be open-coded on the
 150    requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
 151    a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
 152    using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
 153    try anything else.  */
 154
 155 enum optab_methods
 156 {
 157   OPTAB_DIRECT,
 158   OPTAB_LIB,
 159   OPTAB_WIDEN,
 160   OPTAB_LIB_WIDEN,
 161   OPTAB_MUST_WIDEN
 162 };
 163
 164 /* Generate code for a simple binary or unary operation.  "Simple" in
 165    this case means "can be unambiguously described by a (mode, code)
 166    pair and mapped to a single optab."  */
 167 extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
 168                                 rtx, rtx, int, enum optab_methods);
 169 extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
 170                                int);
 171
 172 /* Report whether the machine description contains an insn which can
 173    perform the operation described by CODE and MODE.  */
 174 extern int have_insn_for (enum rtx_code, enum machine_mode);
 175
 176 /* Emit code to make a call to a constant function or a library call.  */
 177 extern void emit_libcall_block (rtx, rtx, rtx, rtx);
 178
 179 /* Create but don't emit one rtl instruction to perform certain operations.
 180    Modes must match; operands must meet the operation's predicates.
 181    Likewise for subtraction and for just copying.  */
 182 extern rtx gen_add2_insn (rtx, rtx);
 183 extern rtx gen_add3_insn (rtx, rtx, rtx);
 184 extern rtx gen_sub2_insn (rtx, rtx);
 185 extern rtx gen_sub3_insn (rtx, rtx, rtx);
 186 extern rtx gen_move_insn (rtx, rtx);
 187 extern int have_add2_insn (rtx, rtx);
 188 extern int have_sub2_insn (rtx, rtx);
 189
 190 /* Emit a pair of rtl insns to compare two rtx's and to jump
 191    to a label if the comparison is true.  */
 192 extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
 193                                      enum machine_mode, int, rtx);
 194
 195 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 196 extern void emit_indirect_jump (rtx);
 197
 198 /* Generate a conditional trap instruction.  */
 199 extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
 200
 201 #include "insn-config.h"
 202
 203 #ifdef HAVE_conditional_move
 204 /* Emit a conditional move operation.  */
 205 rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 206                            rtx, rtx, enum machine_mode, int);
 207
 208 /* Return nonzero if the conditional move is supported.  */
 209 int can_conditionally_move_p (enum machine_mode mode);
 210
 211 #endif
 212 rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 213                           rtx, rtx, enum machine_mode, int);
 214
 215 rtx expand_sync_operation (rtx, rtx, enum rtx_code);
 216 rtx expand_sync_fetch_operation (rtx, rtx, enum rtx_code, bool, rtx);
 217
 218 rtx expand_atomic_exchange (rtx, rtx, rtx, enum memmodel, bool);
 219 rtx expand_atomic_load (rtx, rtx, enum memmodel);
 220 rtx expand_atomic_store (rtx, rtx, enum memmodel, bool);
 221 rtx expand_atomic_fetch_op (rtx, rtx, rtx, enum rtx_code, enum memmodel,
 222                               bool);
 223 void expand_atomic_thread_fence (enum memmodel);
 224 void expand_atomic_signal_fence (enum memmodel);
 225
 226 \f
 227 /* Functions from expmed.c:  */
 228
 229 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 230    May emit insns.  */
 231 extern rtx negate_rtx (enum machine_mode, rtx);
 232
 233 /* Expand a logical AND operation.  */
 234 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
 235
 236 /* Emit a store-flag operation.  */
 237 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 238                             int, int);
 239
 240 /* Like emit_store_flag, but always succeeds.  */
 241 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 242                                   enum machine_mode, int, int);
 243 \f
 244 /* Functions from builtins.c:  */
 245 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 246 extern tree std_build_builtin_va_list (void);
 247 extern tree std_fn_abi_va_list (tree);
 248 extern tree std_canonical_va_list_type (tree);
 249
 250 extern void std_expand_builtin_va_start (tree, rtx);
 251 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 252 extern void expand_builtin_setjmp_setup (rtx, rtx);
 253 extern void expand_builtin_setjmp_receiver (rtx);
 254 extern rtx expand_builtin_saveregs (void);
 255 extern void expand_builtin_trap (void);
 256 extern rtx builtin_strncpy_read_str (void *, HOST_WIDE_INT, enum machine_mode);
 257 \f
 258 /* Functions from expr.c:  */
 259
 260 /* This is run during target initialization to set up which modes can be
 261    used directly in memory and to initialize the block move optab.  */
 262 extern void init_expr_target (void);
 263
 264 /* This is run at the start of compiling a function.  */
 265 extern void init_expr (void);
 266
 267 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 268    Both modes must be floating or both fixed.  */
 269 extern void convert_move (rtx, rtx, int);
 270
 271 /* Convert an rtx to specified machine mode and return the result.  */
 272 extern rtx convert_to_mode (enum machine_mode, rtx, int);
 273
 274 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 275 extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
 276
 277 /* Emit code to move a block Y to a block X.  */
 278
 279 enum block_op_methods
 280 {
 281   BLOCK_OP_NORMAL,
 282   BLOCK_OP_NO_LIBCALL,
 283   BLOCK_OP_CALL_PARM,
 284   /* Like BLOCK_OP_NORMAL, but the libcall can be tail call optimized.  */
 285   BLOCK_OP_TAILCALL
 286 };
 287
 288 extern GTY(()) tree block_clear_fn;
 289 extern void init_block_move_fn (const char *);
 290 extern void init_block_clear_fn (const char *);
 291
 292 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 293 extern rtx emit_block_move_via_libcall (rtx, rtx, rtx, bool);
 294 extern rtx emit_block_move_hints (rtx, rtx, rtx, enum block_op_methods,
 295                                   unsigned int, HOST_WIDE_INT);
 296 extern bool emit_storent_insn (rtx to, rtx from);
 297
 298 /* Copy all or part of a value X into registers starting at REGNO.
 299    The number of registers to be filled is NREGS.  */
 300 extern void move_block_to_reg (int, rtx, int, enum machine_mode);
 301
 302 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 303    The number of registers to be filled is NREGS.  */
 304 extern void move_block_from_reg (int, rtx, int);
 305
 306 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 307 extern rtx gen_group_rtx (rtx);
 308
 309 /* Load a BLKmode value into non-consecutive registers represented by a
 310    PARALLEL.  */
 311 extern void emit_group_load (rtx, rtx, tree, int);
 312
 313 /* Similarly, but load into new temporaries.  */
 314 extern rtx emit_group_load_into_temps (rtx, rtx, tree, int);
 315
 316 /* Move a non-consecutive group of registers represented by a PARALLEL into
 317    a non-consecutive group of registers represented by a PARALLEL.  */
 318 extern void emit_group_move (rtx, rtx);
 319
 320 /* Move a group of registers represented by a PARALLEL into pseudos.  */
 321 extern rtx emit_group_move_into_temps (rtx);
 322
 323 /* Store a BLKmode value from non-consecutive registers represented by a
 324    PARALLEL.  */
 325 extern void emit_group_store (rtx, rtx, tree, int);
 326
 327 /* Copy BLKmode object from a set of registers.  */
 328 extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
 329
 330 /* Mark REG as holding a parameter for the next CALL_INSN.
 331    Mode is TYPE_MODE of the non-promoted parameter, or VOIDmode.  */
 332 extern void use_reg_mode (rtx *, rtx, enum machine_mode);
 333
 334 extern rtx copy_blkmode_to_reg (enum machine_mode, tree);
 335
 336 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 337 static inline void
 338 use_reg (rtx *fusage, rtx reg)
 339 {
 340   use_reg_mode (fusage, reg, VOIDmode);
 341 }
 342
 343 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 344    for the next CALL_INSN.  */
 345 extern void use_regs (rtx *, int, int);
 346
 347 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 348 extern void use_group_regs (rtx *, rtx);
 349
 350 /* Write zeros through the storage of OBJECT.
 351    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 352 extern rtx clear_storage (rtx, rtx, enum block_op_methods);
 353 extern rtx clear_storage_hints (rtx, rtx, enum block_op_methods,
 354                                 unsigned int, HOST_WIDE_INT);
 355 /* The same, but always output an library call.  */
 356 rtx set_storage_via_libcall (rtx, rtx, rtx, bool);
 357
 358 /* Expand a setmem pattern; return true if successful.  */
 359 extern bool set_storage_via_setmem (rtx, rtx, rtx, unsigned int,
 360                                     unsigned int, HOST_WIDE_INT);
 361
 362 /* Determine whether the LEN bytes can be moved by using several move
 363    instructions.  Return nonzero if a call to move_by_pieces should
 364    succeed.  */
 365 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 366
 367 /* Return nonzero if it is desirable to store LEN bytes generated by
 368    CONSTFUN with several move instructions by store_by_pieces
 369    function.  CONSTFUNDATA is a pointer which will be passed as argument
 370    in every CONSTFUN call.
 371    ALIGN is maximum alignment we can assume.
 372    MEMSETP is true if this is a real memset/bzero, not a copy
 373    of a const string.  */
 374 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 375                                 rtx (*) (void *, HOST_WIDE_INT,
 376                                          enum machine_mode),
 377                                 void *, unsigned int, bool);
 378
 379 /* Generate several move instructions to store LEN bytes generated by
 380    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 381    pointer which will be passed as argument in every CONSTFUN call.
 382    ALIGN is maximum alignment we can assume.
 383    MEMSETP is true if this is a real memset/bzero, not a copy.
 384    Returns TO + LEN.  */
 385 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 386                             rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
 387                             void *, unsigned int, bool, int);
 388
 389 /* Emit insns to set X from Y.  */
 390 extern rtx emit_move_insn (rtx, rtx);
 391
 392 /* Emit insns to set X from Y, with no frills.  */
 393 extern rtx emit_move_insn_1 (rtx, rtx);
 394
 395 extern rtx emit_move_complex_push (enum machine_mode, rtx, rtx);
 396 extern rtx emit_move_complex_parts (rtx, rtx);
 397
 398 /* Push a block of length SIZE (perhaps variable)
 399    and return an rtx to address the beginning of the block.  */
 400 extern rtx push_block (rtx, int, int);
 401
 402 /* Generate code to push something onto the stack, given its mode and type.  */
 403 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
 404                             int, rtx, int, rtx, rtx, int, rtx);
 405
 406 /* Expand an assignment that stores the value of FROM into TO.  */
 407 extern void expand_assignment (tree, tree, bool);
 408
 409 /* Generate code for computing expression EXP,
 410    and storing the value into TARGET.
 411    If SUGGEST_REG is nonzero, copy the value through a register
 412    and return that register, if that is possible.  */
 413 extern rtx store_expr (tree, rtx, int, bool);
 414
 415 /* Given an rtx that may include add and multiply operations,
 416    generate them as insns and return a pseudo-reg containing the value.
 417    Useful after calling expand_expr with 1 as sum_ok.  */
 418 extern rtx force_operand (rtx, rtx);
 419
 420 /* Work horses for expand_expr.  */
 421 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
 422                              enum expand_modifier, rtx *);
 423 extern rtx expand_expr_real_1 (tree, rtx, enum machine_mode,
 424                                enum expand_modifier, rtx *);
 425 extern rtx expand_expr_real_2 (sepops, rtx, enum machine_mode,
 426                                enum expand_modifier);
 427
 428 /* Generate code for computing expression EXP.
 429    An rtx for the computed value is returned.  The value is never null.
 430    In the case of a void EXP, const0_rtx is returned.  */
 431 static inline rtx
 432 expand_expr (tree exp, rtx target, enum machine_mode mode,
 433              enum expand_modifier modifier)
 434 {
 435   return expand_expr_real (exp, target, mode, modifier, NULL);
 436 }
 437
 438 static inline rtx
 439 expand_normal (tree exp)
 440 {
 441   return expand_expr_real (exp, NULL_RTX, VOIDmode, EXPAND_NORMAL, NULL);
 442 }
 443
 444 /* At the start of a function, record that we have no previously-pushed
 445    arguments waiting to be popped.  */
 446 extern void init_pending_stack_adjust (void);
 447
 448 /* Discard any pending stack adjustment.  */
 449 extern void discard_pending_stack_adjust (void);
 450
 451 /* When exiting from function, if safe, clear out any pending stack adjust
 452    so the adjustment won't get done.  */
 453 extern void clear_pending_stack_adjust (void);
 454
 455 /* Pop any previously-pushed arguments that have not been popped yet.  */
 456 extern void do_pending_stack_adjust (void);
 457
 458 /* Return the tree node and offset if a given argument corresponds to
 459    a string constant.  */
 460 extern tree string_constant (tree, tree *);
 461
 462 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 463 extern void jumpifnot (tree, rtx, int);
 464 extern void jumpifnot_1 (enum tree_code, tree, tree, rtx, int);
 465
 466 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 467 extern void jumpif (tree, rtx, int);
 468 extern void jumpif_1 (enum tree_code, tree, tree, rtx, int);
 469
 470 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 471    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 472 extern void do_jump (tree, rtx, rtx, int);
 473 extern void do_jump_1 (enum tree_code, tree, tree, rtx, rtx, int);
 474
 475 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 476                                      enum machine_mode, rtx, rtx, rtx, int);
 477
 478 /* Two different ways of generating switch statements.  */
 479 extern int try_casesi (tree, tree, tree, tree, rtx, rtx, rtx);
 480 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
 481
 482 /* Functions from alias.c */
 483 #include "alias.h"
 484
 485 \f
 486 /* rtl.h and tree.h were included.  */
 487 /* Return an rtx for the size in bytes of the value of an expr.  */
 488 extern rtx expr_size (tree);
 489
 490 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 491    if the size can vary or is larger than an integer.  */
 492 extern HOST_WIDE_INT int_expr_size (tree);
 493
 494 /* Return an rtx that refers to the value returned by a function
 495    in its original home.  This becomes invalid if any more code is emitted.  */
 496 extern rtx hard_function_value (const_tree, const_tree, const_tree, int);
 497
 498 extern rtx prepare_call_address (tree, rtx, rtx, rtx *, int, int);
 499
 500 extern bool shift_return_value (enum machine_mode, bool, rtx);
 501
 502 extern rtx expand_call (tree, rtx, int);
 503
 504 extern void fixup_tail_calls (void);
 505
 506 #ifdef TREE_CODE
 507 extern rtx expand_variable_shift (enum tree_code, enum machine_mode,
 508                                   rtx, tree, rtx, int);
 509 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, int, rtx,
 510                              int);
 511 extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
 512                           rtx, int);
 513 #endif
 514
 515 extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
 516                                  struct args_size *,
 517                                  struct locate_and_pad_arg_data *);
 518
 519 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 520 extern rtx label_rtx (tree);
 521
 522 /* As label_rtx, but additionally the label is placed on the forced label
 523    list of its containing function (i.e. it is treated as reachable even
 524    if how is not obvious).  */
 525 extern rtx force_label_rtx (tree);
 526
 527 /* Return an rtx like arg but sans any constant terms.
 528    Returns the original rtx if it has no constant terms.
 529    The constant terms are added and stored via a second arg.  */
 530 extern rtx eliminate_constant_term (rtx, rtx *);
 531
 532 /* Convert arg to a valid memory address for specified machine mode that points
 533    to a specific named address space, by emitting insns to perform arithmetic
 534    if necessary.  */
 535 extern rtx memory_address_addr_space (enum machine_mode, rtx, addr_space_t);
 536
 537 /* Like memory_address_addr_space, except assume the memory address points to
 538    the generic named address space.  */
 539 #define memory_address(MODE,RTX) \
 540         memory_address_addr_space ((MODE), (RTX), ADDR_SPACE_GENERIC)
 541
 542 /* Return a memory reference like MEMREF, but with its mode changed
 543    to MODE and its address changed to ADDR.
 544    (VOIDmode means don't change the mode.
 545    NULL for ADDR means don't change the address.)  */
 546 extern rtx change_address (rtx, enum machine_mode, rtx);
 547
 548 /* Return a memory reference like MEMREF, but with its mode changed
 549    to MODE and its address offset by OFFSET bytes.  */
 550 #define adjust_address(MEMREF, MODE, OFFSET) \
 551   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
 552
 553 /* Likewise, but the reference is not required to be valid.  */
 554 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 555   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
 556
 557 /* Return a memory reference like MEMREF, but with its mode changed
 558    to MODE and its address changed to ADDR, which is assumed to be
 559    increased by OFFSET bytes from MEMREF.  */
 560 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 561   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 562
 563 /* Likewise, but the reference is not required to be valid.  */
 564 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 565   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 566
 567 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
 568 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
 569                                         HOST_WIDE_INT, int);
 570
 571 /* Return a memory reference like MEMREF, but whose address is changed by
 572    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 573    known to be in OFFSET (possibly 1).  */
 574 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 575
 576 /* Definitions from emit-rtl.c */
 577 #include "emit-rtl.h"
 578
 579 /* Return a memory reference like MEMREF, but with its mode widened to
 580    MODE and adjusted by OFFSET.  */
 581 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
 582
 583 /* Return a memory reference like MEMREF, but which is known to have a
 584    valid address.  */
 585 extern rtx validize_mem (rtx);
 586
 587 extern rtx use_anchored_address (rtx);
 588
 589 /* Given REF, a MEM, and T, either the type of X or the expression
 590    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 591    if we are making a new object of this type.  */
 592 extern void set_mem_attributes (rtx, tree, int);
 593
 594 /* Similar, except that BITPOS has not yet been applied to REF, so if
 595    we alter MEM_OFFSET according to T then we should subtract BITPOS
 596    expecting that it'll be added back in later.  */
 597 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 598
 599 /* Return OFFSET if XEXP (MEM, 0) - OFFSET is known to be ALIGN
 600    bits aligned for 0 <= OFFSET < ALIGN / BITS_PER_UNIT, or
 601    -1 if not known.  */
 602 extern int get_mem_align_offset (rtx, unsigned int);
 603
 604 /* Assemble the static constant template for function entry trampolines.  */
 605 extern rtx assemble_trampoline_template (void);
 606
 607 /* Copy given rtx to a new temp reg and return that.  */
 608 extern rtx copy_to_reg (rtx);
 609
 610 /* Like copy_to_reg but always make the reg Pmode.  */
 611 extern rtx copy_addr_to_reg (rtx);
 612
 613 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 614 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
 615
 616 /* Copy given rtx to given temp reg and return that.  */
 617 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
 618
 619 /* Copy a value to a register if it isn't already a register.
 620    Args are mode (in case value is a constant) and the value.  */
 621 extern rtx force_reg (enum machine_mode, rtx);
 622
 623 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 624 extern rtx force_not_mem (rtx);
 625
 626 /* Return mode and signedness to use when an argument or result in the
 627    given mode is promoted.  */
 628 extern enum machine_mode promote_function_mode (const_tree, enum machine_mode, int *,
 629                                                 const_tree, int);
 630
 631 /* Return mode and signedness to use when an object in the given mode
 632    is promoted.  */
 633 extern enum machine_mode promote_mode (const_tree, enum machine_mode, int *);
 634
 635 /* Return mode and signedness to use when object is promoted.  */
 636 enum machine_mode promote_decl_mode (const_tree, int *);
 637
 638 /* Remove some bytes from the stack.  An rtx says how many.  */
 639 extern void adjust_stack (rtx);
 640
 641 /* Add some bytes to the stack.  An rtx says how many.  */
 642 extern void anti_adjust_stack (rtx);
 643
 644 /* Add some bytes to the stack while probing it.  An rtx says how many. */
 645 extern void anti_adjust_stack_and_probe (rtx, bool);
 646
 647 /* This enum is used for the following two functions.  */
 648 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 649
 650 /* Save the stack pointer at the specified level.  */
 651 extern void emit_stack_save (enum save_level, rtx *);
 652
 653 /* Restore the stack pointer from a save area of the specified level.  */
 654 extern void emit_stack_restore (enum save_level, rtx);
 655
 656 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 657 extern void update_nonlocal_goto_save_area (void);
 658
 659 /* Allocate some space on the stack dynamically and return its address.  */
 660 extern rtx allocate_dynamic_stack_space (rtx, unsigned, unsigned, bool);
 661
 662 /* Emit one stack probe at ADDRESS, an address within the stack.  */
 663 extern void emit_stack_probe (rtx);
 664
 665 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 666    FIRST is a constant and size is a Pmode RTX.  These are offsets from
 667    the current stack pointer.  STACK_GROWS_DOWNWARD says whether to add
 668    or subtract them from the stack pointer.  */
 669 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 670
 671 /* Return an rtx that refers to the value returned by a library call
 672    in its original home.  This becomes invalid if any more code is emitted.  */
 673 extern rtx hard_libcall_value (enum machine_mode, rtx);
 674
 675 /* Return the mode desired by operand N of a particular bitfield
 676    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
 677    available.  */
 678
 679 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
 680 extern enum machine_mode
 681 mode_for_extraction (enum extraction_pattern, int);
 682
 683 extern void store_bit_field (rtx, unsigned HOST_WIDE_INT,
 684                              unsigned HOST_WIDE_INT,
 685                              unsigned HOST_WIDE_INT,
 686                              unsigned HOST_WIDE_INT,
 687                              enum machine_mode, rtx);
 688 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 689                               unsigned HOST_WIDE_INT, int, bool, rtx,
 690                               enum machine_mode, enum machine_mode);
 691 extern rtx extract_low_bits (enum machine_mode, enum machine_mode, rtx);
 692 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
 693 extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
 694
 695 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
 696 extern int safe_from_p (const_rtx, tree, int);
 697 extern bool split_comparison (enum rtx_code, enum machine_mode,
 698                               enum rtx_code *, enum rtx_code *);
 699
 700 /* Call this once to initialize the contents of the optabs
 701    appropriately for the current target machine.  */
 702 extern void init_optabs (void);
 703 extern void init_all_optabs (void);
 704
 705 /* Call this to initialize an optab function entry.  */
 706 extern rtx init_one_libfunc (const char *);
 707 extern rtx set_user_assembler_libfunc (const char *, const char *);
 708
 709 /* Build a decl for a libfunc named NAME. */
 710 extern tree build_libfunc_function (const char *);
 711
 712 /* Get the personality libfunc for a function decl.  */
 713 rtx get_personality_function (tree);
 714
 715 #endif /* GCC_EXPR_H */