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 /* Macros to access the slots of a QUEUED rtx.
  43    Here rather than in rtl.h because only the expansion pass
  44    should ever encounter a QUEUED.  */
  45
  46 /* The variable for which an increment is queued.  */
  47 #define QUEUED_VAR(P) XEXP (P, 0)
  48 /* If the increment has been emitted, this is the insn
  49    that does the increment.  It is zero before the increment is emitted.
  50    If more than one insn is emitted, this is the first insn.  */
  51 #define QUEUED_INSN(P) XEXP (P, 1)
  52 /* If a pre-increment copy has been generated, this is the copy
  53    (it is a temporary reg).  Zero if no copy made yet.  */
  54 #define QUEUED_COPY(P) XEXP (P, 2)
  55 /* This is the body to use for the insn to do the increment.
  56    It is used to emit the increment.  */
  57 #define QUEUED_BODY(P) XEXP (P, 3)
  58 /* Next QUEUED in the queue.  */
  59 #define QUEUED_NEXT(P) XEXP (P, 4)
  60
  61 /* This is the 4th arg to `expand_expr'.
  62    EXPAND_STACK_PARM means we are possibly expanding a call param onto
  63    the stack.  Choosing a value of 2 isn't special;  It just allows
  64    some code optimization in store_expr.
  65    EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
  66    EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
  67    EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
  68     is a constant that is not a legitimate address.
  69    EXPAND_WRITE means we are only going to write to the resulting rtx.
  70    EXPAND_MEMORY means we are interested in a memory result, even if
  71     the memory is constant and we could have propagated a constant value.  */
  72 enum expand_modifier {EXPAND_NORMAL = 0, EXPAND_STACK_PARM = 2, EXPAND_SUM,
  73                       EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER, EXPAND_WRITE,
  74                       EXPAND_MEMORY};
  75
  76 /* Prevent the compiler from deferring stack pops.  See
  77    inhibit_defer_pop for more information.  */
  78 #define NO_DEFER_POP (inhibit_defer_pop += 1)
  79
  80 /* Allow the compiler to defer stack pops.  See inhibit_defer_pop for
  81    more information.  */
  82 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
  83 \f
  84 /* If a memory-to-memory move would take MOVE_RATIO or more simple
  85    move-instruction sequences, we will do a movstr or libcall instead.  */
  86
  87 #ifndef MOVE_RATIO
  88 #if defined (HAVE_movstrqi) || defined (HAVE_movstrhi) || defined (HAVE_movstrsi) || defined (HAVE_movstrdi) || defined (HAVE_movstrti)
  89 #define MOVE_RATIO 2
  90 #else
  91 /* If we are optimizing for space (-Os), cut down the default move ratio.  */
  92 #define MOVE_RATIO (optimize_size ? 3 : 15)
  93 #endif
  94 #endif
  95
  96 /* If a clear memory operation would take CLEAR_RATIO or more simple
  97    move-instruction sequences, we will do a clrstr or libcall instead.  */
  98
  99 #ifndef CLEAR_RATIO
 100 #if defined (HAVE_clrstrqi) || defined (HAVE_clrstrhi) || defined (HAVE_clrstrsi) || defined (HAVE_clrstrdi) || defined (HAVE_clrstrti)
 101 #define CLEAR_RATIO 2
 102 #else
 103 /* If we are optimizing for space, cut down the default clear ratio.  */
 104 #define CLEAR_RATIO (optimize_size ? 3 : 15)
 105 #endif
 106 #endif
 107 \f
 108 enum direction {none, upward, downward};
 109
 110 /* Structure to record the size of a sequence of arguments
 111    as the sum of a tree-expression and a constant.  This structure is
 112    also used to store offsets from the stack, which might be negative,
 113    so the variable part must be ssizetype, not sizetype.  */
 114
 115 struct args_size
 116 {
 117   HOST_WIDE_INT constant;
 118   tree var;
 119 };
 120
 121 /* Package up various arg related fields of struct args for
 122    locate_and_pad_parm.  */
 123 struct locate_and_pad_arg_data
 124 {
 125   /* Size of this argument on the stack, rounded up for any padding it
 126      gets.  If REG_PARM_STACK_SPACE is defined, then register parms are
 127      counted here, otherwise they aren't.  */
 128   struct args_size size;
 129   /* Offset of this argument from beginning of stack-args.  */
 130   struct args_size offset;
 131   /* Offset to the start of the stack slot.  Different from OFFSET
 132      if this arg pads downward.  */
 133   struct args_size slot_offset;
 134   /* The amount that the stack pointer needs to be adjusted to
 135      force alignment for the next argument.  */
 136   struct args_size alignment_pad;
 137   /* Which way we should pad this arg.  */
 138   enum direction where_pad;
 139 };
 140
 141 /* Add the value of the tree INC to the `struct args_size' TO.  */
 142
 143 #define ADD_PARM_SIZE(TO, INC)                          \
 144 do {                                                    \
 145   tree inc = (INC);                                     \
 146   if (host_integerp (inc, 0))                           \
 147     (TO).constant += tree_low_cst (inc, 0);             \
 148   else if ((TO).var == 0)                               \
 149     (TO).var = convert (ssizetype, inc);                \
 150   else                                                  \
 151     (TO).var = size_binop (PLUS_EXPR, (TO).var,         \
 152                            convert (ssizetype, inc));   \
 153 } while (0)
 154
 155 #define SUB_PARM_SIZE(TO, DEC)                          \
 156 do {                                                    \
 157   tree dec = (DEC);                                     \
 158   if (host_integerp (dec, 0))                           \
 159     (TO).constant -= tree_low_cst (dec, 0);             \
 160   else if ((TO).var == 0)                               \
 161     (TO).var = size_binop (MINUS_EXPR, ssize_int (0),   \
 162                            convert (ssizetype, dec));   \
 163   else                                                  \
 164     (TO).var = size_binop (MINUS_EXPR, (TO).var,        \
 165                            convert (ssizetype, dec));   \
 166 } while (0)
 167
 168 /* Convert the implicit sum in a `struct args_size' into a tree
 169    of type ssizetype.  */
 170 #define ARGS_SIZE_TREE(SIZE)                                    \
 171 ((SIZE).var == 0 ? ssize_int ((SIZE).constant)                  \
 172  : size_binop (PLUS_EXPR, convert (ssizetype, (SIZE).var),      \
 173                ssize_int ((SIZE).constant)))
 174
 175 /* Convert the implicit sum in a `struct args_size' into an rtx.  */
 176 #define ARGS_SIZE_RTX(SIZE)                                     \
 177 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant)                    \
 178  : expand_expr (ARGS_SIZE_TREE (SIZE), NULL_RTX, VOIDmode, 0))
 179
 180 /* Supply a default definition for FUNCTION_ARG_PADDING:
 181    usually pad upward, but pad short args downward on
 182    big-endian machines.  */
 183
 184 #define DEFAULT_FUNCTION_ARG_PADDING(MODE, TYPE)                        \
 185   (! BYTES_BIG_ENDIAN                                                   \
 186    ? upward                                                             \
 187    : (((MODE) == BLKmode                                                \
 188        ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST         \
 189           && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
 190        : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)                       \
 191       ? downward : upward))
 192
 193 #ifndef FUNCTION_ARG_PADDING
 194 #define FUNCTION_ARG_PADDING(MODE, TYPE)        \
 195   DEFAULT_FUNCTION_ARG_PADDING ((MODE), (TYPE))
 196 #endif
 197
 198 /* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
 199    FUNCTION_ARG_PADDING, which also pads the length, handle any needed
 200    alignment.  */
 201
 202 #ifndef FUNCTION_ARG_BOUNDARY
 203 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE)       PARM_BOUNDARY
 204 #endif
 205
 206 tree split_complex_types (tree);
 207 tree split_complex_values (tree);
 208
 209 /* Nonzero if we do not know how to pass TYPE solely in registers.  */
 210 extern bool default_must_pass_in_stack (enum machine_mode, tree);
 211 #ifndef MUST_PASS_IN_STACK
 212 #define MUST_PASS_IN_STACK(MODE,TYPE) default_must_pass_in_stack(MODE, TYPE)
 213 #endif
 214
 215 /* Supply a default definition of STACK_SAVEAREA_MODE for emit_stack_save.
 216    Normally move_insn, so Pmode stack pointer.  */
 217
 218 #ifndef STACK_SAVEAREA_MODE
 219 #define STACK_SAVEAREA_MODE(LEVEL) Pmode
 220 #endif
 221
 222 /* Supply a default definition of STACK_SIZE_MODE for
 223    allocate_dynamic_stack_space.  Normally PLUS/MINUS, so word_mode.  */
 224
 225 #ifndef STACK_SIZE_MODE
 226 #define STACK_SIZE_MODE word_mode
 227 #endif
 228
 229 /* Provide default values for the macros controlling stack checking.  */
 230
 231 #ifndef STACK_CHECK_BUILTIN
 232 #define STACK_CHECK_BUILTIN 0
 233 #endif
 234
 235 /* The default interval is one page.  */
 236 #ifndef STACK_CHECK_PROBE_INTERVAL
 237 #define STACK_CHECK_PROBE_INTERVAL 4096
 238 #endif
 239
 240 /* The default is to do a store into the stack.  */
 241 #ifndef STACK_CHECK_PROBE_LOAD
 242 #define STACK_CHECK_PROBE_LOAD 0
 243 #endif
 244
 245 /* This value is arbitrary, but should be sufficient for most machines.  */
 246 #ifndef STACK_CHECK_PROTECT
 247 #define STACK_CHECK_PROTECT (75 * UNITS_PER_WORD)
 248 #endif
 249
 250 /* Make the maximum frame size be the largest we can and still only need
 251    one probe per function.  */
 252 #ifndef STACK_CHECK_MAX_FRAME_SIZE
 253 #define STACK_CHECK_MAX_FRAME_SIZE \
 254   (STACK_CHECK_PROBE_INTERVAL - UNITS_PER_WORD)
 255 #endif
 256
 257 /* This is arbitrary, but should be large enough everywhere.  */
 258 #ifndef STACK_CHECK_FIXED_FRAME_SIZE
 259 #define STACK_CHECK_FIXED_FRAME_SIZE (4 * UNITS_PER_WORD)
 260 #endif
 261
 262 /* Provide a reasonable default for the maximum size of an object to
 263    allocate in the fixed frame.  We may need to be able to make this
 264    controllable by the user at some point.  */
 265 #ifndef STACK_CHECK_MAX_VAR_SIZE
 266 #define STACK_CHECK_MAX_VAR_SIZE (STACK_CHECK_MAX_FRAME_SIZE / 100)
 267 #endif
 268 \f
 269 /* Functions from optabs.c, commonly used, and without need for the optabs
 270    tables:  */
 271
 272 /* Passed to expand_simple_binop and expand_binop to say which options
 273    to try to use if the requested operation can't be open-coded on the
 274    requisite mode.  Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using
 275    a library call.  Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try
 276    using a wider mode.  OPTAB_MUST_WIDEN says try widening and don't
 277    try anything else.  */
 278
 279 enum optab_methods
 280 {
 281   OPTAB_DIRECT,
 282   OPTAB_LIB,
 283   OPTAB_WIDEN,
 284   OPTAB_LIB_WIDEN,
 285   OPTAB_MUST_WIDEN
 286 };
 287
 288 /* Generate code for a simple binary or unary operation.  "Simple" in
 289    this case means "can be unambiguously described by a (mode, code)
 290    pair and mapped to a single optab."  */
 291 extern rtx expand_simple_binop (enum machine_mode, enum rtx_code, rtx,
 292                                 rtx, rtx, int, enum optab_methods);
 293 extern rtx expand_simple_unop (enum machine_mode, enum rtx_code, rtx, rtx,
 294                                int);
 295
 296 /* Report whether the machine description contains an insn which can
 297    perform the operation described by CODE and MODE.  */
 298 extern int have_insn_for (enum rtx_code, enum machine_mode);
 299
 300 /* Emit code to make a call to a constant function or a library call.  */
 301 extern void emit_libcall_block (rtx, rtx, rtx, rtx);
 302
 303 /* Create but don't emit one rtl instruction to perform certain operations.
 304    Modes must match; operands must meet the operation's predicates.
 305    Likewise for subtraction and for just copying.
 306    These do not call protect_from_queue; caller must do so.  */
 307 extern rtx gen_add2_insn (rtx, rtx);
 308 extern rtx gen_add3_insn (rtx, rtx, rtx);
 309 extern rtx gen_sub2_insn (rtx, rtx);
 310 extern rtx gen_sub3_insn (rtx, rtx, rtx);
 311 extern rtx gen_move_insn (rtx, rtx);
 312 extern int have_add2_insn (rtx, rtx);
 313 extern int have_sub2_insn (rtx, rtx);
 314
 315 /* Emit a pair of rtl insns to compare two rtx's and to jump
 316    to a label if the comparison is true.  */
 317 extern void emit_cmp_and_jump_insns (rtx, rtx, enum rtx_code, rtx,
 318                                      enum machine_mode, int, rtx);
 319
 320 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 321 extern void emit_indirect_jump (rtx);
 322
 323 #include "insn-config.h"
 324
 325 #ifdef HAVE_conditional_move
 326 /* Emit a conditional move operation.  */
 327 rtx emit_conditional_move (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 328                            rtx, rtx, enum machine_mode, int);
 329
 330 /* Return nonzero if the conditional move is supported.  */
 331 int can_conditionally_move_p (enum machine_mode mode);
 332
 333 #endif
 334 rtx emit_conditional_add (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 335                           rtx, rtx, enum machine_mode, int);
 336
 337 \f
 338 /* Functions from expmed.c:  */
 339
 340 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 341    May emit insns.  */
 342 extern rtx negate_rtx (enum machine_mode, rtx);
 343
 344 /* Expand a logical AND operation.  */
 345 extern rtx expand_and (enum machine_mode, rtx, rtx, rtx);
 346
 347 /* Emit a store-flag operation.  */
 348 extern rtx emit_store_flag (rtx, enum rtx_code, rtx, rtx, enum machine_mode,
 349                             int, int);
 350
 351 /* Like emit_store_flag, but always succeeds.  */
 352 extern rtx emit_store_flag_force (rtx, enum rtx_code, rtx, rtx,
 353                                   enum machine_mode, int, int);
 354
 355 /* Functions from loop.c:  */
 356
 357 /* Given an insn and condition, return a canonical description of
 358    the test being made.  */
 359 extern rtx canonicalize_condition (rtx, rtx, int, rtx *, rtx, int);
 360
 361 /* Given a JUMP_INSN, return a canonical description of the test
 362    being made.  */
 363 extern rtx get_condition (rtx, rtx *, int);
 364
 365 /* Generate a conditional trap instruction.  */
 366 extern rtx gen_cond_trap (enum rtx_code, rtx, rtx, rtx);
 367 \f
 368 /* Functions from builtins.c:  */
 369 extern rtx expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 370 extern tree std_build_builtin_va_list (void);
 371 extern void std_expand_builtin_va_start (tree, rtx);
 372 extern rtx std_expand_builtin_va_arg (tree, tree);
 373 extern rtx expand_builtin_va_arg (tree, tree);
 374 extern rtx default_expand_builtin (tree, rtx, rtx, enum machine_mode, int);
 375 extern void expand_builtin_setjmp_setup (rtx, rtx);
 376 extern void expand_builtin_setjmp_receiver (rtx);
 377 extern void expand_builtin_longjmp (rtx, rtx);
 378 extern rtx expand_builtin_saveregs (void);
 379 extern void expand_builtin_trap (void);
 380 extern tree simplify_builtin_fputs (tree, int, int, tree);
 381 extern tree simplify_builtin_strcpy (tree, tree);
 382 extern tree simplify_builtin_strncpy (tree, tree);
 383 \f
 384 /* Functions from expr.c:  */
 385
 386 /* This is run once per compilation to set up which modes can be used
 387    directly in memory and to initialize the block move optab.  */
 388 extern void init_expr_once (void);
 389
 390 /* This is run at the start of compiling a function.  */
 391 extern void init_expr (void);
 392
 393 /* This is run at the end of compiling a function.  */
 394 extern void finish_expr_for_function (void);
 395
 396 /* Use protect_from_queue to convert a QUEUED expression
 397    into something that you can put immediately into an instruction.  */
 398 extern rtx protect_from_queue (rtx, int);
 399
 400 /* Perform all the pending incrementations.  */
 401 extern void emit_queue (void);
 402
 403 /* Tell if something has a queued subexpression.  */
 404 extern int queued_subexp_p (rtx);
 405
 406 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 407    Both modes must be floating or both fixed.  */
 408 extern void convert_move (rtx, rtx, int);
 409
 410 /* Convert an rtx to specified machine mode and return the result.  */
 411 extern rtx convert_to_mode (enum machine_mode, rtx, int);
 412
 413 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 414 extern rtx convert_modes (enum machine_mode, enum machine_mode, rtx, int);
 415
 416 /* Emit code to move a block Y to a block X.  */
 417
 418 enum block_op_methods
 419 {
 420   BLOCK_OP_NORMAL,
 421   BLOCK_OP_NO_LIBCALL,
 422   BLOCK_OP_CALL_PARM
 423 };
 424
 425 extern void init_block_move_fn (const char *);
 426 extern void init_block_clear_fn (const char *);
 427
 428 extern rtx emit_block_move (rtx, rtx, rtx, enum block_op_methods);
 429
 430 /* Copy all or part of a value X into registers starting at REGNO.
 431    The number of registers to be filled is NREGS.  */
 432 extern void move_block_to_reg (int, rtx, int, enum machine_mode);
 433
 434 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 435    The number of registers to be filled is NREGS.  */
 436 extern void move_block_from_reg (int, rtx, int);
 437
 438 /* Generate a non-consecutive group of registers represented by a PARALLEL.  */
 439 extern rtx gen_group_rtx (rtx);
 440
 441 /* Load a BLKmode value into non-consecutive registers represented by a
 442    PARALLEL.  */
 443 extern void emit_group_load (rtx, rtx, tree, int);
 444
 445 /* Move a non-consecutive group of registers represented by a PARALLEL into
 446    a non-consecutive group of registers represented by a PARALLEL.  */
 447 extern void emit_group_move (rtx, rtx);
 448
 449 /* Store a BLKmode value from non-consecutive registers represented by a
 450    PARALLEL.  */
 451 extern void emit_group_store (rtx, rtx, tree, int);
 452
 453 /* Copy BLKmode object from a set of registers.  */
 454 extern rtx copy_blkmode_from_reg (rtx, rtx, tree);
 455
 456 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 457 extern void use_reg (rtx *, rtx);
 458
 459 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 460    for the next CALL_INSN.  */
 461 extern void use_regs (rtx *, int, int);
 462
 463 /* Mark a PARALLEL as holding a parameter for the next CALL_INSN.  */
 464 extern void use_group_regs (rtx *, rtx);
 465
 466 /* Write zeros through the storage of OBJECT.
 467    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 468 extern rtx clear_storage (rtx, rtx);
 469
 470 /* Determine whether the LEN bytes can be moved by using several move
 471    instructions.  Return nonzero if a call to move_by_pieces should
 472    succeed.  */
 473 extern int can_move_by_pieces (unsigned HOST_WIDE_INT, unsigned int);
 474
 475 /* Return nonzero if it is desirable to store LEN bytes generated by
 476    CONSTFUN with several move instructions by store_by_pieces
 477    function.  CONSTFUNDATA is a pointer which will be passed as argument
 478    in every CONSTFUN call.
 479    ALIGN is maximum alignment we can assume.  */
 480 extern int can_store_by_pieces (unsigned HOST_WIDE_INT,
 481                                 rtx (*) (void *, HOST_WIDE_INT,
 482                                          enum machine_mode),
 483                                 void *, unsigned int);
 484
 485 /* Generate several move instructions to store LEN bytes generated by
 486    CONSTFUN to block TO.  (A MEM rtx with BLKmode).  CONSTFUNDATA is a
 487    pointer which will be passed as argument in every CONSTFUN call.
 488    ALIGN is maximum alignment we can assume.
 489    Returns TO + LEN.  */
 490 extern rtx store_by_pieces (rtx, unsigned HOST_WIDE_INT,
 491                             rtx (*) (void *, HOST_WIDE_INT, enum machine_mode),
 492                             void *, unsigned int, int);
 493
 494 /* Emit insns to set X from Y.  */
 495 extern rtx emit_move_insn (rtx, rtx);
 496
 497 /* Emit insns to set X from Y, with no frills.  */
 498 extern rtx emit_move_insn_1 (rtx, rtx);
 499
 500 /* Push a block of length SIZE (perhaps variable)
 501    and return an rtx to address the beginning of the block.  */
 502 extern rtx push_block (rtx, int, int);
 503
 504 /* Generate code to push something onto the stack, given its mode and type.  */
 505 extern void emit_push_insn (rtx, enum machine_mode, tree, rtx, unsigned int,
 506                             int, rtx, int, rtx, rtx, int, rtx);
 507
 508 /* Expand an assignment that stores the value of FROM into TO.  */
 509 extern rtx expand_assignment (tree, tree, int);
 510
 511 /* Generate code for computing expression EXP,
 512    and storing the value into TARGET.
 513    If SUGGEST_REG is nonzero, copy the value through a register
 514    and return that register, if that is possible.  */
 515 extern rtx store_expr (tree, rtx, int);
 516
 517 /* Given an rtx that may include add and multiply operations,
 518    generate them as insns and return a pseudo-reg containing the value.
 519    Useful after calling expand_expr with 1 as sum_ok.  */
 520 extern rtx force_operand (rtx, rtx);
 521
 522 /* Work horse for expand_expr.  */
 523 extern rtx expand_expr_real (tree, rtx, enum machine_mode,
 524                              enum expand_modifier, rtx *);
 525
 526 /* Generate code for computing expression EXP.
 527    An rtx for the computed value is returned.  The value is never null.
 528    In the case of a void EXP, const0_rtx is returned.  */
 529 static inline rtx
 530 expand_expr (tree exp, rtx target, enum machine_mode mode,
 531              enum expand_modifier modifier)
 532 {
 533   return expand_expr_real(exp, target, mode, modifier, NULL);
 534 }
 535
 536 extern void expand_var (tree);
 537
 538 /* At the start of a function, record that we have no previously-pushed
 539    arguments waiting to be popped.  */
 540 extern void init_pending_stack_adjust (void);
 541
 542 /* When exiting from function, if safe, clear out any pending stack adjust
 543    so the adjustment won't get done.  */
 544 extern void clear_pending_stack_adjust (void);
 545
 546 /* Pop any previously-pushed arguments that have not been popped yet.  */
 547 extern void do_pending_stack_adjust (void);
 548
 549 /* Return the tree node and offset if a given argument corresponds to
 550    a string constant.  */
 551 extern tree string_constant (tree, tree *);
 552
 553 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 554 extern void jumpifnot (tree, rtx);
 555
 556 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 557 extern void jumpif (tree, rtx);
 558
 559 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 560    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 561 extern void do_jump (tree, rtx, rtx);
 562
 563 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 564 extern rtx compare_from_rtx (rtx, rtx, enum rtx_code, int, enum machine_mode,
 565                              rtx);
 566 extern void do_compare_rtx_and_jump (rtx, rtx, enum rtx_code, int,
 567                                      enum machine_mode, rtx, rtx, rtx);
 568
 569 /* Two different ways of generating switch statements.  */
 570 extern int try_casesi (tree, tree, tree, tree, rtx, rtx);
 571 extern int try_tablejump (tree, tree, tree, tree, rtx, rtx);
 572
 573 /* Smallest number of adjacent cases before we use a jump table.
 574    XXX Should be a target hook.  */
 575 extern unsigned int case_values_threshold (void);
 576
 577 /* Functions from alias.c */
 578 #include "alias.h"
 579 /* extern HOST_WIDE_INT get_varargs_alias_set (void); */
 580 /* extern HOST_WIDE_INT get_frame_alias_set (void); */
 581 /* extern void record_base_value (unsigned int, rtx, int); */
 582 /* extern void record_alias_subset (HOST_WIDE_INT, HOST_WIDE_INT); */
 583 /* extern HOST_WIDE_INT new_alias_set (void); */
 584 /* extern int can_address_p (tree); */
 585
 586 \f
 587 /* rtl.h and tree.h were included.  */
 588 /* Return an rtx for the size in bytes of the value of an expr.  */
 589 extern rtx expr_size (tree);
 590
 591 /* Return a wide integer for the size in bytes of the value of EXP, or -1
 592    if the size can vary or is larger than an integer.  */
 593 extern HOST_WIDE_INT int_expr_size (tree);
 594
 595 /* Convert a stack slot address ADDR valid in function FNDECL
 596    into an address valid in this function (using a static chain).  */
 597 extern rtx fix_lexical_addr (rtx, tree);
 598
 599 /* Return the address of the trampoline for entering nested fn FUNCTION.  */
 600 extern rtx trampoline_address (tree);
 601
 602 /* Return an rtx that refers to the value returned by a function
 603    in its original home.  This becomes invalid if any more code is emitted.  */
 604 extern rtx hard_function_value (tree, tree, int);
 605
 606 extern rtx prepare_call_address (rtx, rtx, rtx *, int, int);
 607
 608 extern rtx expand_call (tree, rtx, int);
 609
 610 extern void fixup_tail_calls (void);
 611
 612 #ifdef TREE_CODE
 613 extern rtx expand_shift (enum tree_code, enum machine_mode, rtx, tree, rtx,
 614                          int);
 615 extern rtx expand_divmod (int, enum tree_code, enum machine_mode, rtx, rtx,
 616                           rtx, int);
 617 #endif
 618
 619 extern void locate_and_pad_parm (enum machine_mode, tree, int, int, tree,
 620                                  struct args_size *,
 621                                  struct locate_and_pad_arg_data *);
 622
 623 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 624 extern rtx label_rtx (tree);
 625
 626 /* As label_rtx, but additionally the label is placed on the forced label
 627    list of its containing function (i.e. it is treated as reachable even
 628    if how is not obvious).  */
 629 extern rtx force_label_rtx (tree);
 630
 631 /* Indicate how an input argument register was promoted.  */
 632 extern rtx promoted_input_arg (unsigned int, enum machine_mode *, int *);
 633
 634 /* Return an rtx like arg but sans any constant terms.
 635    Returns the original rtx if it has no constant terms.
 636    The constant terms are added and stored via a second arg.  */
 637 extern rtx eliminate_constant_term (rtx, rtx *);
 638
 639 /* Convert arg to a valid memory address for specified machine mode,
 640    by emitting insns to perform arithmetic if nec.  */
 641 extern rtx memory_address (enum machine_mode, rtx);
 642
 643 /* Like `memory_address' but pretent `flag_force_addr' is 0.  */
 644 extern rtx memory_address_noforce (enum machine_mode, rtx);
 645
 646 /* Return a memory reference like MEMREF, but with its mode changed
 647    to MODE and its address changed to ADDR.
 648    (VOIDmode means don't change the mode.
 649    NULL for ADDR means don't change the address.)  */
 650 extern rtx change_address (rtx, enum machine_mode, rtx);
 651
 652 /* Return a memory reference like MEMREF, but with its mode changed
 653    to MODE and its address offset by OFFSET bytes.  */
 654 #define adjust_address(MEMREF, MODE, OFFSET) \
 655   adjust_address_1 (MEMREF, MODE, OFFSET, 1, 1)
 656
 657 /* Likewise, but the reference is not required to be valid.  */
 658 #define adjust_address_nv(MEMREF, MODE, OFFSET) \
 659   adjust_address_1 (MEMREF, MODE, OFFSET, 0, 1)
 660
 661 /* Return a memory reference like MEMREF, but with its mode changed
 662    to MODE and its address changed to ADDR, which is assumed to be
 663    increased by OFFSET bytes from MEMREF.  */
 664 #define adjust_automodify_address(MEMREF, MODE, ADDR, OFFSET) \
 665   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 1)
 666
 667 /* Likewise, but the reference is not required to be valid.  */
 668 #define adjust_automodify_address_nv(MEMREF, MODE, ADDR, OFFSET) \
 669   adjust_automodify_address_1 (MEMREF, MODE, ADDR, OFFSET, 0)
 670
 671 extern rtx adjust_address_1 (rtx, enum machine_mode, HOST_WIDE_INT, int, int);
 672 extern rtx adjust_automodify_address_1 (rtx, enum machine_mode, rtx,
 673                                         HOST_WIDE_INT, int);
 674
 675 /* Return a memory reference like MEMREF, but whose address is changed by
 676    adding OFFSET, an RTX, to it.  POW2 is the highest power of two factor
 677    known to be in OFFSET (possibly 1).  */
 678 extern rtx offset_address (rtx, rtx, unsigned HOST_WIDE_INT);
 679
 680 /* Definitions from emit-rtl.c */
 681 #include "emit-rtl.h"
 682
 683 /* Return a memory reference like MEMREF, but with its mode widened to
 684    MODE and adjusted by OFFSET.  */
 685 extern rtx widen_memory_access (rtx, enum machine_mode, HOST_WIDE_INT);
 686
 687 /* Return a memory reference like MEMREF, but which is known to have a
 688    valid address.  */
 689 extern rtx validize_mem (rtx);
 690
 691 /* Given REF, either a MEM or a REG, and T, either the type of X or
 692    the expression corresponding to REF, set RTX_UNCHANGING_P if
 693    appropriate.  */
 694 extern void maybe_set_unchanging (rtx, tree);
 695
 696 /* Given REF, a MEM, and T, either the type of X or the expression
 697    corresponding to REF, set the memory attributes.  OBJECTP is nonzero
 698    if we are making a new object of this type.  */
 699 extern void set_mem_attributes (rtx, tree, int);
 700
 701 /* Similar, except that BITPOS has not yet been applied to REF, so if
 702    we alter MEM_OFFSET according to T then we should subtract BITPOS
 703    expecting that it'll be added back in later.  */
 704 extern void set_mem_attributes_minus_bitpos (rtx, tree, int, HOST_WIDE_INT);
 705
 706 /* Assemble the static constant template for function entry trampolines.  */
 707 extern rtx assemble_trampoline_template (void);
 708
 709 /* Given rtx, return new rtx whose address won't be affected by
 710    any side effects.  It has been copied to a new temporary reg.  */
 711 extern rtx stabilize (rtx);
 712
 713 /* Given an rtx, copy all regs it refers to into new temps
 714    and return a modified copy that refers to the new temps.  */
 715 extern rtx copy_all_regs (rtx);
 716
 717 /* Copy given rtx to a new temp reg and return that.  */
 718 extern rtx copy_to_reg (rtx);
 719
 720 /* Like copy_to_reg but always make the reg Pmode.  */
 721 extern rtx copy_addr_to_reg (rtx);
 722
 723 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 724 extern rtx copy_to_mode_reg (enum machine_mode, rtx);
 725
 726 /* Copy given rtx to given temp reg and return that.  */
 727 extern rtx copy_to_suggested_reg (rtx, rtx, enum machine_mode);
 728
 729 /* Copy a value to a register if it isn't already a register.
 730    Args are mode (in case value is a constant) and the value.  */
 731 extern rtx force_reg (enum machine_mode, rtx);
 732
 733 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 734 extern rtx force_not_mem (rtx);
 735
 736 /* Return mode and signedness to use when object is promoted.  */
 737 extern enum machine_mode promote_mode (tree, enum machine_mode, int *, int);
 738
 739 /* Remove some bytes from the stack.  An rtx says how many.  */
 740 extern void adjust_stack (rtx);
 741
 742 /* Add some bytes to the stack.  An rtx says how many.  */
 743 extern void anti_adjust_stack (rtx);
 744
 745 /* This enum is used for the following two functions.  */
 746 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 747
 748 /* Save the stack pointer at the specified level.  */
 749 extern void emit_stack_save (enum save_level, rtx *, rtx);
 750
 751 /* Restore the stack pointer from a save area of the specified level.  */
 752 extern void emit_stack_restore (enum save_level, rtx, rtx);
 753
 754 /* Invoke emit_stack_save for the nonlocal_goto_save_area.  */
 755 extern void update_nonlocal_goto_save_area (void);
 756
 757 /* Allocate some space on the stack dynamically and return its address.  An rtx
 758    says how many bytes.  */
 759 extern rtx allocate_dynamic_stack_space (rtx, rtx, int);
 760
 761 /* Probe a range of stack addresses from FIRST to FIRST+SIZE, inclusive.
 762    FIRST is a constant and size is a Pmode RTX.  These are offsets from the
 763    current stack pointer.  STACK_GROWS_DOWNWARD says whether to add or
 764    subtract from the stack.  If SIZE is constant, this is done
 765    with a fixed number of probes.  Otherwise, we must make a loop.  */
 766 extern void probe_stack_range (HOST_WIDE_INT, rtx);
 767
 768 /* Return an rtx that refers to the value returned by a library call
 769    in its original home.  This becomes invalid if any more code is emitted.  */
 770 extern rtx hard_libcall_value (enum machine_mode);
 771
 772 /* Given an rtx, return an rtx for a value rounded up to a multiple
 773    of STACK_BOUNDARY / BITS_PER_UNIT.  */
 774 extern rtx round_push (rtx);
 775
 776 /* Return the mode desired by operand N of a particular bitfield
 777    insert/extract insn, or MAX_MACHINE_MODE if no such insn is
 778    available.  */
 779
 780 enum extraction_pattern { EP_insv, EP_extv, EP_extzv };
 781 extern enum machine_mode
 782 mode_for_extraction (enum extraction_pattern, int);
 783
 784 extern rtx store_bit_field (rtx, unsigned HOST_WIDE_INT,
 785                             unsigned HOST_WIDE_INT, enum machine_mode, rtx,
 786                             HOST_WIDE_INT);
 787 extern rtx extract_bit_field (rtx, unsigned HOST_WIDE_INT,
 788                               unsigned HOST_WIDE_INT, int, rtx,
 789                               enum machine_mode, enum machine_mode,
 790                               HOST_WIDE_INT);
 791 extern rtx expand_mult (enum machine_mode, rtx, rtx, rtx, int);
 792 extern bool const_mult_add_overflow_p (rtx, rtx, rtx, enum machine_mode, int);
 793 extern rtx expand_mult_add (rtx, rtx, rtx, rtx,enum machine_mode, int);
 794 extern rtx expand_mult_highpart_adjust (enum machine_mode, rtx, rtx, rtx, rtx, int);
 795
 796 extern rtx assemble_static_space (unsigned HOST_WIDE_INT);
 797 extern int safe_from_p (rtx, tree, int);
 798
 799 /* Call this once to initialize the contents of the optabs
 800    appropriately for the current target machine.  */
 801 extern void init_optabs (void);
 802 extern void init_all_optabs (void);
 803
 804 /* Call this to initialize an optab function entry.  */
 805 extern rtx init_one_libfunc (const char *);
 806
 807 extern void do_jump_by_parts_equality_rtx (rtx, rtx, rtx);
 808 extern void do_jump_by_parts_greater_rtx (enum machine_mode, int, rtx, rtx,
 809                                           rtx, rtx);
 810
 811 extern int vector_mode_valid_p (enum machine_mode);
 812
 813 #endif /* GCC_EXPR_H */