gcc/expr.h

   1 /* Definitions for code generation pass of GNU compiler.
   2    Copyright (C) 1987, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20
  21 #ifndef __STDC__
  22 #ifndef const
  23 #define const
  24 #endif
  25 #endif
  26
  27 /* The default branch cost is 1.  */
  28 #ifndef BRANCH_COST
  29 #define BRANCH_COST 1
  30 #endif
  31
  32 /* Macros to access the slots of a QUEUED rtx.
  33    Here rather than in rtl.h because only the expansion pass
  34    should ever encounter a QUEUED.  */
  35
  36 /* The variable for which an increment is queued.  */
  37 #define QUEUED_VAR(P) XEXP (P, 0)
  38 /* If the increment has been emitted, this is the insn
  39    that does the increment.  It is zero before the increment is emitted.  */
  40 #define QUEUED_INSN(P) XEXP (P, 1)
  41 /* If a pre-increment copy has been generated, this is the copy
  42    (it is a temporary reg).  Zero if no copy made yet.  */
  43 #define QUEUED_COPY(P) XEXP (P, 2)
  44 /* This is the body to use for the insn to do the increment.
  45    It is used to emit the increment.  */
  46 #define QUEUED_BODY(P) XEXP (P, 3)
  47 /* Next QUEUED in the queue.  */
  48 #define QUEUED_NEXT(P) XEXP (P, 4)
  49
  50 /* This is the 4th arg to `expand_expr'.
  51    EXPAND_SUM means it is ok to return a PLUS rtx or MULT rtx.
  52    EXPAND_INITIALIZER is similar but also record any labels on forced_labels.
  53    EXPAND_CONST_ADDRESS means it is ok to return a MEM whose address
  54     is a constant that is not a legitimate address.  */
  55 enum expand_modifier {EXPAND_NORMAL, EXPAND_SUM,
  56                       EXPAND_CONST_ADDRESS, EXPAND_INITIALIZER};
  57
  58 /* List of labels that must never be deleted.  */
  59 extern rtx forced_labels;
  60
  61 /* List (chain of EXPR_LISTs) of pseudo-regs of SAVE_EXPRs.
  62    So we can mark them all live at the end of the function, if stupid.  */
  63 extern rtx save_expr_regs;
  64
  65 extern int current_function_calls_alloca;
  66 extern int current_function_outgoing_args_size;
  67
  68 /* This is the offset from the arg pointer to the place where the first
  69    anonymous arg can be found, if there is one.  */
  70 extern rtx current_function_arg_offset_rtx;
  71
  72 /* This is nonzero if the current function uses the constant pool.  */
  73 extern int current_function_uses_const_pool;
  74
  75 /* This is nonzero if the current function uses pic_offset_table_rtx.  */
  76 extern int current_function_uses_pic_offset_table;
  77
  78 /* The arg pointer hard register, or the pseudo into which it was copied.  */
  79 extern rtx current_function_internal_arg_pointer;
  80
  81 /* Nonzero means stack pops must not be deferred, and deferred stack
  82    pops must not be output.  It is nonzero inside a function call,
  83    inside a conditional expression, inside a statement expression,
  84    and in other cases as well.  */
  85 extern int inhibit_defer_pop;
  86
  87 /* Number of function calls seen so far in current function.  */
  88
  89 extern int function_call_count;
  90
  91 /* RTX for stack slot that holds the current handler for nonlocal gotos.
  92    Zero when function does not have nonlocal labels.  */
  93
  94 extern rtx nonlocal_goto_handler_slot;
  95
  96 /* RTX for stack slot that holds the stack pointer value to restore
  97    for a nonlocal goto.
  98    Zero when function does not have nonlocal labels.  */
  99
 100 extern rtx nonlocal_goto_stack_level;
 101
 102 /* List (chain of TREE_LIST) of LABEL_DECLs for all nonlocal labels
 103    (labels to which there can be nonlocal gotos from nested functions)
 104    in this function.  */
 105
 106 #ifdef TREE_CODE   /* Don't lose if tree.h not included.  */
 107 extern tree nonlocal_labels;
 108 #endif
 109
 110 #define NO_DEFER_POP (inhibit_defer_pop += 1)
 111 #define OK_DEFER_POP (inhibit_defer_pop -= 1)
 112
 113 /* Number of units that we should eventually pop off the stack.
 114    These are the arguments to function calls that have already returned.  */
 115 extern int pending_stack_adjust;
 116
 117 /* A list of all cleanups which belong to the arguments of
 118    function calls being expanded by expand_call.  */
 119 #ifdef TREE_CODE   /* Don't lose if tree.h not included.  */
 120 extern tree cleanups_this_call;
 121 #endif
 122
 123 /* When temporaries are created by TARGET_EXPRs, they are created at
 124    this level of temp_slot_level, so that they can remain allocated
 125    until no longer needed.  CLEANUP_POINT_EXPRs define the lifetime
 126    of TARGET_EXPRs.  */
 127 extern int target_temp_slot_level;
 128 \f
 129 #ifdef TREE_CODE /* Don't lose if tree.h not included.  */
 130 /* Structure to record the size of a sequence of arguments
 131    as the sum of a tree-expression and a constant.  */
 132
 133 struct args_size
 134 {
 135   int constant;
 136   tree var;
 137 };
 138 #endif
 139
 140 /* Add the value of the tree INC to the `struct args_size' TO.  */
 141
 142 #define ADD_PARM_SIZE(TO, INC)  \
 143 { tree inc = (INC);                             \
 144   if (TREE_CODE (inc) == INTEGER_CST)           \
 145     (TO).constant += TREE_INT_CST_LOW (inc);    \
 146   else if ((TO).var == 0)                       \
 147     (TO).var = inc;                             \
 148   else                                          \
 149     (TO).var = size_binop (PLUS_EXPR, (TO).var, inc); }
 150
 151 #define SUB_PARM_SIZE(TO, DEC)  \
 152 { tree dec = (DEC);                             \
 153   if (TREE_CODE (dec) == INTEGER_CST)           \
 154     (TO).constant -= TREE_INT_CST_LOW (dec);    \
 155   else if ((TO).var == 0)                       \
 156     (TO).var = size_binop (MINUS_EXPR, integer_zero_node, dec); \
 157   else                                          \
 158     (TO).var = size_binop (MINUS_EXPR, (TO).var, dec); }
 159
 160 /* Convert the implicit sum in a `struct args_size' into an rtx.  */
 161 #define ARGS_SIZE_RTX(SIZE)                                             \
 162 ((SIZE).var == 0 ? GEN_INT ((SIZE).constant)    \
 163  : expand_expr (size_binop (PLUS_EXPR, (SIZE).var,                      \
 164                             size_int ((SIZE).constant)),                \
 165                 NULL_RTX, VOIDmode, 0))
 166
 167 /* Convert the implicit sum in a `struct args_size' into a tree.  */
 168 #define ARGS_SIZE_TREE(SIZE)                                            \
 169 ((SIZE).var == 0 ? size_int ((SIZE).constant)                           \
 170  : size_binop (PLUS_EXPR, (SIZE).var, size_int ((SIZE).constant)))
 171
 172 /* Supply a default definition for FUNCTION_ARG_PADDING:
 173    usually pad upward, but pad short args downward on
 174    big-endian machines.  */
 175
 176 enum direction {none, upward, downward};  /* Value has this type.  */
 177
 178 #ifndef FUNCTION_ARG_PADDING
 179 #if BYTES_BIG_ENDIAN
 180 #define FUNCTION_ARG_PADDING(MODE, TYPE)                                \
 181   (((MODE) == BLKmode                                                   \
 182     ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST            \
 183        && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT))   \
 184     : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)                          \
 185    ? downward : upward)
 186 #else
 187 #define FUNCTION_ARG_PADDING(MODE, TYPE) upward
 188 #endif
 189 #endif
 190
 191 /* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
 192    FUNCTION_ARG_PADDING, which also pads the length, handle any needed
 193    alignment.  */
 194
 195 #ifndef FUNCTION_ARG_BOUNDARY
 196 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE)       PARM_BOUNDARY
 197 #endif
 198
 199 /* Nonzero if we do not know how to pass TYPE solely in registers.
 200    We cannot do so in the following cases:
 201
 202    - if the type has variable size
 203    - if the type is marked as addressable (it is required to be constructed
 204      into the stack)
 205    - if the padding and mode of the type is such that a copy into a register
 206      would put it into the wrong part of the register.
 207
 208    Which padding can't be supported depends on the byte endianness.
 209
 210    A value in a register is implicitly padded at the most significant end.
 211    On a big-endian machine, that is the lower end in memory.
 212    So a value padded in memory at the upper end can't go in a register.
 213    For a little-endian machine, the reverse is true.  */
 214
 215 #if BYTES_BIG_ENDIAN
 216 #define MUST_PASS_IN_STACK_BAD_PADDING  upward
 217 #else
 218 #define MUST_PASS_IN_STACK_BAD_PADDING  downward
 219 #endif
 220
 221 #define MUST_PASS_IN_STACK(MODE,TYPE)                   \
 222   ((TYPE) != 0                                          \
 223    && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST      \
 224        || TREE_ADDRESSABLE (TYPE)                       \
 225        || ((MODE) == BLKmode                            \
 226            && ! ((TYPE) != 0 && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST \
 227                  && 0 == (int_size_in_bytes (TYPE)      \
 228                           % (PARM_BOUNDARY / BITS_PER_UNIT))) \
 229            && (FUNCTION_ARG_PADDING (MODE, TYPE)        \
 230                == MUST_PASS_IN_STACK_BAD_PADDING))))
 231
 232 /* Nonzero if type TYPE should be returned in memory.
 233    Most machines can use the following default definition.  */
 234
 235 #ifndef RETURN_IN_MEMORY
 236 #define RETURN_IN_MEMORY(TYPE) (TYPE_MODE (TYPE) == BLKmode)
 237 #endif
 238 \f
 239 /* Optabs are tables saying how to generate insn bodies
 240    for various machine modes and numbers of operands.
 241    Each optab applies to one operation.
 242    For example, add_optab applies to addition.
 243
 244    The insn_code slot is the enum insn_code that says how to
 245    generate an insn for this operation on a particular machine mode.
 246    It is CODE_FOR_nothing if there is no such insn on the target machine.
 247
 248    The `lib_call' slot is the name of the library function that
 249    can be used to perform the operation.
 250
 251    A few optabs, such as move_optab and cmp_optab, are used
 252    by special code.  */
 253
 254 /* Everything that uses expr.h needs to define enum insn_code
 255    but we don't list it in the Makefile dependencies just for that.  */
 256 #include "insn-codes.h"
 257
 258 typedef struct optab
 259 {
 260   enum rtx_code code;
 261   struct {
 262     enum insn_code insn_code;
 263     rtx libfunc;
 264   } handlers [NUM_MACHINE_MODES];
 265 } * optab;
 266
 267 /* Given an enum insn_code, access the function to construct
 268    the body of that kind of insn.  */
 269 #ifdef FUNCTION_CONVERSION_BUG
 270 /* Some compilers fail to convert a function properly to a
 271    pointer-to-function when used as an argument.
 272    So produce the pointer-to-function directly.
 273    Luckily, these compilers seem to work properly when you
 274    call the pointer-to-function.  */
 275 #define GEN_FCN(CODE) (insn_gen_function[(int) (CODE)])
 276 #else
 277 #define GEN_FCN(CODE) (*insn_gen_function[(int) (CODE)])
 278 #endif
 279
 280 extern rtx (*const insn_gen_function[]) ();
 281
 282 extern optab add_optab;
 283 extern optab sub_optab;
 284 extern optab smul_optab;        /* Signed and floating-point multiply */
 285 extern optab smul_highpart_optab; /* Signed multiply, return high word */
 286 extern optab umul_highpart_optab;
 287 extern optab smul_widen_optab;  /* Signed multiply with result
 288                                    one machine mode wider than args */
 289 extern optab umul_widen_optab;
 290 extern optab sdiv_optab;        /* Signed divide */
 291 extern optab sdivmod_optab;     /* Signed divide-and-remainder in one */
 292 extern optab udiv_optab;
 293 extern optab udivmod_optab;
 294 extern optab smod_optab;        /* Signed remainder */
 295 extern optab umod_optab;
 296 extern optab flodiv_optab;      /* Optab for floating divide. */
 297 extern optab ftrunc_optab;      /* Convert float to integer in float fmt */
 298 extern optab and_optab;         /* Logical and */
 299 extern optab ior_optab;         /* Logical or */
 300 extern optab xor_optab;         /* Logical xor */
 301 extern optab ashl_optab;        /* Arithmetic shift left */
 302 extern optab ashr_optab;        /* Arithmetic shift right */
 303 extern optab lshr_optab;        /* Logical shift right */
 304 extern optab rotl_optab;        /* Rotate left */
 305 extern optab rotr_optab;        /* Rotate right */
 306 extern optab smin_optab;        /* Signed and floating-point minimum value */
 307 extern optab smax_optab;        /* Signed and floating-point maximum value */
 308 extern optab umin_optab;        /* Unsigned minimum value */
 309 extern optab umax_optab;        /* Unsigned maximum value */
 310
 311 extern optab mov_optab;         /* Move instruction.  */
 312 extern optab movstrict_optab;   /* Move, preserving high part of register.  */
 313
 314 extern optab cmp_optab;         /* Compare insn; two operands.  */
 315 extern optab tst_optab;         /* tst insn; compare one operand against 0 */
 316
 317 /* Unary operations */
 318 extern optab neg_optab;         /* Negation */
 319 extern optab abs_optab;         /* Abs value */
 320 extern optab one_cmpl_optab;    /* Bitwise not */
 321 extern optab ffs_optab;         /* Find first bit set */
 322 extern optab sqrt_optab;        /* Square root */
 323 extern optab sin_optab;         /* Sine */
 324 extern optab cos_optab;         /* Cosine */
 325 extern optab strlen_optab;      /* String length */
 326
 327 /* Tables of patterns for extending one integer mode to another.  */
 328 extern enum insn_code extendtab[MAX_MACHINE_MODE][MAX_MACHINE_MODE][2];
 329
 330 /* Tables of patterns for converting between fixed and floating point. */
 331 extern enum insn_code fixtab[NUM_MACHINE_MODES][NUM_MACHINE_MODES][2];
 332 extern enum insn_code fixtrunctab[NUM_MACHINE_MODES][NUM_MACHINE_MODES][2];
 333 extern enum insn_code floattab[NUM_MACHINE_MODES][NUM_MACHINE_MODES][2];
 334
 335 /* Contains the optab used for each rtx code.  */
 336 extern optab code_to_optab[NUM_RTX_CODE + 1];
 337
 338 /* Passed to expand_binop and expand_unop to say which options to try to use
 339    if the requested operation can't be open-coded on the requisite mode.
 340    Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using a library call.
 341    Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try using a wider mode.
 342    OPTAB_MUST_WIDEN says try widening and don't try anything else.  */
 343
 344 enum optab_methods
 345 {
 346   OPTAB_DIRECT,
 347   OPTAB_LIB,
 348   OPTAB_WIDEN,
 349   OPTAB_LIB_WIDEN,
 350   OPTAB_MUST_WIDEN
 351 };
 352
 353 /* SYMBOL_REF rtx's for the library functions that are called
 354    implicitly and not via optabs.  */
 355
 356 extern rtx extendsfdf2_libfunc;
 357 extern rtx extendsfxf2_libfunc;
 358 extern rtx extendsftf2_libfunc;
 359 extern rtx extenddfxf2_libfunc;
 360 extern rtx extenddftf2_libfunc;
 361
 362 extern rtx truncdfsf2_libfunc;
 363 extern rtx truncxfsf2_libfunc;
 364 extern rtx trunctfsf2_libfunc;
 365 extern rtx truncxfdf2_libfunc;
 366 extern rtx trunctfdf2_libfunc;
 367
 368 extern rtx memcpy_libfunc;
 369 extern rtx bcopy_libfunc;
 370 extern rtx memcmp_libfunc;
 371 extern rtx bcmp_libfunc;
 372 extern rtx memset_libfunc;
 373 extern rtx bzero_libfunc;
 374
 375 extern rtx eqhf2_libfunc;
 376 extern rtx nehf2_libfunc;
 377 extern rtx gthf2_libfunc;
 378 extern rtx gehf2_libfunc;
 379 extern rtx lthf2_libfunc;
 380 extern rtx lehf2_libfunc;
 381
 382 extern rtx eqsf2_libfunc;
 383 extern rtx nesf2_libfunc;
 384 extern rtx gtsf2_libfunc;
 385 extern rtx gesf2_libfunc;
 386 extern rtx ltsf2_libfunc;
 387 extern rtx lesf2_libfunc;
 388
 389 extern rtx eqdf2_libfunc;
 390 extern rtx nedf2_libfunc;
 391 extern rtx gtdf2_libfunc;
 392 extern rtx gedf2_libfunc;
 393 extern rtx ltdf2_libfunc;
 394 extern rtx ledf2_libfunc;
 395
 396 extern rtx eqxf2_libfunc;
 397 extern rtx nexf2_libfunc;
 398 extern rtx gtxf2_libfunc;
 399 extern rtx gexf2_libfunc;
 400 extern rtx ltxf2_libfunc;
 401 extern rtx lexf2_libfunc;
 402
 403 extern rtx eqtf2_libfunc;
 404 extern rtx netf2_libfunc;
 405 extern rtx gttf2_libfunc;
 406 extern rtx getf2_libfunc;
 407 extern rtx lttf2_libfunc;
 408 extern rtx letf2_libfunc;
 409
 410 extern rtx floatsisf_libfunc;
 411 extern rtx floatdisf_libfunc;
 412 extern rtx floattisf_libfunc;
 413
 414 extern rtx floatsidf_libfunc;
 415 extern rtx floatdidf_libfunc;
 416 extern rtx floattidf_libfunc;
 417
 418 extern rtx floatsixf_libfunc;
 419 extern rtx floatdixf_libfunc;
 420 extern rtx floattixf_libfunc;
 421
 422 extern rtx floatsitf_libfunc;
 423 extern rtx floatditf_libfunc;
 424 extern rtx floattitf_libfunc;
 425
 426 extern rtx fixsfsi_libfunc;
 427 extern rtx fixsfdi_libfunc;
 428 extern rtx fixsfti_libfunc;
 429
 430 extern rtx fixdfsi_libfunc;
 431 extern rtx fixdfdi_libfunc;
 432 extern rtx fixdfti_libfunc;
 433
 434 extern rtx fixxfsi_libfunc;
 435 extern rtx fixxfdi_libfunc;
 436 extern rtx fixxfti_libfunc;
 437
 438 extern rtx fixtfsi_libfunc;
 439 extern rtx fixtfdi_libfunc;
 440 extern rtx fixtfti_libfunc;
 441
 442 extern rtx fixunssfsi_libfunc;
 443 extern rtx fixunssfdi_libfunc;
 444 extern rtx fixunssfti_libfunc;
 445
 446 extern rtx fixunsdfsi_libfunc;
 447 extern rtx fixunsdfdi_libfunc;
 448 extern rtx fixunsdfti_libfunc;
 449
 450 extern rtx fixunsxfsi_libfunc;
 451 extern rtx fixunsxfdi_libfunc;
 452 extern rtx fixunsxfti_libfunc;
 453
 454 extern rtx fixunstfsi_libfunc;
 455 extern rtx fixunstfdi_libfunc;
 456 extern rtx fixunstfti_libfunc;
 457 \f
 458 typedef rtx (*rtxfun) ();
 459
 460 /* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
 461    gives the gen_function to make a branch to test that condition.  */
 462
 463 extern rtxfun bcc_gen_fctn[NUM_RTX_CODE];
 464
 465 /* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
 466    gives the insn code to make a store-condition insn
 467    to test that condition.  */
 468
 469 extern enum insn_code setcc_gen_code[NUM_RTX_CODE];
 470
 471 /* This array records the insn_code of insns to perform block moves.  */
 472 extern enum insn_code movstr_optab[NUM_MACHINE_MODES];
 473
 474 /* Define functions given in optabs.c.  */
 475
 476 /* Expand a binary operation given optab and rtx operands.  */
 477 extern rtx expand_binop PROTO((enum machine_mode, optab, rtx, rtx, rtx,
 478                                int, enum optab_methods));
 479
 480 /* Expand a binary operation with both signed and unsigned forms.  */
 481 extern rtx sign_expand_binop PROTO((enum machine_mode, optab, optab, rtx,
 482                                     rtx, rtx, int, enum optab_methods));
 483
 484 /* Generate code to perform an operation on two operands with two results.  */
 485 extern int expand_twoval_binop PROTO((optab, rtx, rtx, rtx, rtx, int));
 486
 487 /* Expand a unary arithmetic operation given optab rtx operand.  */
 488 extern rtx expand_unop PROTO((enum machine_mode, optab, rtx, rtx, int));
 489
 490 /* Expand the complex absolute value operation.  */
 491 extern rtx expand_complex_abs PROTO((enum machine_mode, rtx, rtx, int));
 492
 493 /* Generate an instruction with a given INSN_CODE with an output and
 494    an input.  */
 495 extern void emit_unop_insn PROTO((int, rtx, rtx, enum rtx_code));
 496
 497 /* Emit code to perform a series of operations on a multi-word quantity, one
 498    word at a time.  */
 499 extern rtx emit_no_conflict_block PROTO((rtx, rtx, rtx, rtx, rtx));
 500
 501 /* Emit code to make a call to a constant function or a library call. */
 502 extern void emit_libcall_block PROTO((rtx, rtx, rtx, rtx));
 503
 504 /* Emit one rtl instruction to store zero in specified rtx.  */
 505 extern void emit_clr_insn PROTO((rtx));
 506
 507 /* Emit one rtl insn to store 1 in specified rtx assuming it contains 0.  */
 508 extern void emit_0_to_1_insn PROTO((rtx));
 509
 510 /* Emit one rtl insn to compare two rtx's.  */
 511 extern void emit_cmp_insn PROTO((rtx, rtx, enum rtx_code, rtx,
 512                                  enum machine_mode, int, int));
 513
 514 /* Nonzero if a compare of mode MODE can be done straightforwardly
 515    (without splitting it into pieces).  */
 516 extern int can_compare_p PROTO((enum machine_mode));
 517
 518 /* Emit a library call comparison between floating point X and Y.
 519    COMPARISON is the rtl operator to compare with (EQ, NE, GT, etc.).  */
 520 extern void emit_float_lib_cmp PROTO((rtx, rtx, enum rtx_code));
 521
 522 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 523 extern void emit_indirect_jump PROTO((rtx));
 524
 525 /* Create but don't emit one rtl instruction to add one rtx into another.
 526    Modes must match; operands must meet the operation's predicates.
 527    Likewise for subtraction and for just copying.
 528    These do not call protect_from_queue; caller must do so.  */
 529 extern rtx gen_add2_insn PROTO((rtx, rtx));
 530 extern rtx gen_sub2_insn PROTO((rtx, rtx));
 531 extern rtx gen_move_insn PROTO((rtx, rtx));
 532 extern int have_add2_insn PROTO((enum machine_mode));
 533 extern int have_sub2_insn PROTO((enum machine_mode));
 534
 535 /* Return the INSN_CODE to use for an extend operation.  */
 536 extern enum insn_code can_extend_p PROTO((enum machine_mode,
 537                                           enum machine_mode, int));
 538
 539 /* Generate the body of an insn to extend Y (with mode MFROM)
 540    into X (with mode MTO).  Do zero-extension if UNSIGNEDP is nonzero.  */
 541 extern rtx gen_extend_insn PROTO((rtx, rtx, enum machine_mode,
 542                                   enum machine_mode, int));
 543
 544 /* Initialize the tables that control conversion between fixed and
 545    floating values.  */
 546 extern void init_fixtab PROTO((void));
 547 extern void init_floattab PROTO((void));
 548
 549 /* Generate code for a FLOAT_EXPR.  */
 550 extern void expand_float PROTO((rtx, rtx, int));
 551
 552 /* Generate code for a FIX_EXPR.  */
 553 extern void expand_fix PROTO((rtx, rtx, int));
 554
 555 /* Call this once to initialize the contents of the optabs
 556    appropriately for the current target machine.  */
 557 extern void init_optabs PROTO((void));
 558 \f
 559 /* Functions from expmed.c:  */
 560
 561 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 562    May emit insns.  */
 563 extern rtx negate_rtx PROTO((enum machine_mode, rtx));
 564
 565 /* Expand a logical AND operation.  */
 566 extern rtx expand_and PROTO((rtx, rtx, rtx));
 567
 568 /* Emit a store-flag operation.  */
 569 extern rtx emit_store_flag PROTO((rtx, enum rtx_code, rtx, rtx,
 570                                   enum machine_mode, int, int));
 571
 572 /* Functions from loop.c:  */
 573
 574 /* Given a JUMP_INSN, return a description of the test being made.  */
 575 extern rtx get_condition PROTO((rtx, rtx *));
 576 \f
 577 /* Functions from expr.c:  */
 578
 579 /* This is run once per compilation to set up which modes can be used
 580    directly in memory and to initialize the block move optab.  */
 581 extern void init_expr_once PROTO((void));
 582
 583 /* This is run at the start of compiling a function.  */
 584 extern void init_expr PROTO((void));
 585
 586 /* Use protect_from_queue to convert a QUEUED expression
 587    into something that you can put immediately into an instruction.  */
 588 extern rtx protect_from_queue PROTO((rtx, int));
 589
 590 /* Perform all the pending incrementations.  */
 591 extern void emit_queue PROTO((void));
 592
 593 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 594    Both modes must be floating or both fixed.  */
 595 extern void convert_move PROTO((rtx, rtx, int));
 596
 597 /* Convert an rtx to specified machine mode and return the result.  */
 598 extern rtx convert_to_mode PROTO((enum machine_mode, rtx, int));
 599
 600 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 601 extern rtx convert_modes PROTO((enum machine_mode, enum machine_mode, rtx, int));
 602
 603 /* Emit code to move a block Y to a block X.  */
 604 extern void emit_block_move PROTO((rtx, rtx, rtx, int));
 605
 606 /* Copy all or part of a value X into registers starting at REGNO.
 607    The number of registers to be filled is NREGS.  */
 608 extern void move_block_to_reg PROTO((int, rtx, int, enum machine_mode));
 609
 610 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 611    The number of registers to be filled is NREGS.  */
 612 extern void move_block_from_reg PROTO((int, rtx, int, int));
 613
 614 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 615 extern void use_reg PROTO((rtx*, rtx));
 616 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 617    for the next CALL_INSN.  */
 618 extern void use_regs PROTO((rtx*, int, int));
 619
 620 /* Write zeros through the storage of OBJECT.
 621    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 622 extern void clear_storage PROTO((rtx, int));
 623
 624 /* Emit insns to set X from Y.  */
 625 extern rtx emit_move_insn PROTO((rtx, rtx));
 626
 627 /* Emit insns to set X from Y, with no frills.  */
 628 extern rtx emit_move_insn_1 PROTO ((rtx, rtx));
 629
 630 /* Push a block of length SIZE (perhaps variable)
 631    and return an rtx to address the beginning of the block.  */
 632 extern rtx push_block PROTO((rtx, int, int));
 633
 634 /* Make an operand to push someting on the stack.  */
 635 extern rtx gen_push_operand PROTO((void));
 636
 637 #ifdef TREE_CODE
 638 /* Generate code to push something onto the stack, given its mode and type.  */
 639 extern void emit_push_insn PROTO((rtx, enum machine_mode, tree, rtx, int,
 640                                   int, rtx, int, rtx, rtx));
 641
 642 /* Emit library call.  */
 643 extern void emit_library_call PVPROTO((rtx orgfun, int no_queue,
 644   enum machine_mode outmode, int nargs, ...));
 645 extern rtx emit_library_call_value PVPROTO((rtx orgfun, rtx value, int no_queue,
 646   enum machine_mode outmode, int nargs, ...));
 647
 648 /* Expand an assignment that stores the value of FROM into TO. */
 649 extern rtx expand_assignment PROTO((tree, tree, int, int));
 650
 651 /* Generate code for computing expression EXP,
 652    and storing the value into TARGET.
 653    If SUGGEST_REG is nonzero, copy the value through a register
 654    and return that register, if that is possible.  */
 655 extern rtx store_expr PROTO((tree, rtx, int));
 656 #endif
 657
 658 /* Given an rtx that may include add and multiply operations,
 659    generate them as insns and return a pseudo-reg containing the value.
 660    Useful after calling expand_expr with 1 as sum_ok.  */
 661 extern rtx force_operand PROTO((rtx, rtx));
 662
 663 #ifdef TREE_CODE
 664 /* Generate code for computing expression EXP.
 665    An rtx for the computed value is returned.  The value is never null.
 666    In the case of a void EXP, const0_rtx is returned.  */
 667 extern rtx expand_expr PROTO((tree, rtx, enum machine_mode,
 668                               enum expand_modifier));
 669 #endif
 670
 671 /* At the start of a function, record that we have no previously-pushed
 672    arguments waiting to be popped.  */
 673 extern void init_pending_stack_adjust PROTO((void));
 674
 675 /* When exiting from function, if safe, clear out any pending stack adjust
 676    so the adjustment won't get done.  */
 677 extern void clear_pending_stack_adjust PROTO((void));
 678
 679 /* Pop any previously-pushed arguments that have not been popped yet.  */
 680 extern void do_pending_stack_adjust PROTO((void));
 681
 682 #ifdef TREE_CODE
 683 /* Expand all cleanups up to OLD_CLEANUPS.  */
 684 extern void expand_cleanups_to PROTO((tree));
 685
 686 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 687 extern void jumpifnot PROTO((tree, rtx));
 688
 689 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 690 extern void jumpif PROTO((tree, rtx));
 691
 692 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 693    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 694 extern void do_jump PROTO((tree, rtx, rtx));
 695 #endif
 696
 697 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 698 extern rtx compare_from_rtx PROTO((rtx, rtx, enum rtx_code, int,
 699                                    enum machine_mode, rtx, int));
 700
 701 /* Generate a tablejump instruction (used for switch statements).  */
 702 extern void do_tablejump PROTO((rtx, enum machine_mode, rtx, rtx, rtx));
 703 \f
 704 #ifdef TREE_CODE
 705 /* rtl.h and tree.h were included.  */
 706 /* Return an rtx for the size in bytes of the value of an expr.  */
 707 extern rtx expr_size PROTO((tree));
 708
 709 extern rtx lookup_static_chain PROTO((tree));
 710
 711 /* Convert a stack slot address ADDR valid in function FNDECL
 712    into an address valid in this function (using a static chain).  */
 713 extern rtx fix_lexical_addr PROTO((rtx, tree));
 714
 715 /* Return the address of the trampoline for entering nested fn FUNCTION.  */
 716 extern rtx trampoline_address PROTO((tree));
 717
 718 /* Return an rtx that refers to the value returned by a function
 719    in its original home.  This becomes invalid if any more code is emitted.  */
 720 extern rtx hard_function_value PROTO((tree, tree));
 721
 722 extern rtx prepare_call_address PROTO((rtx, tree, rtx *, int));
 723
 724 extern rtx expand_call PROTO((tree, rtx, int));
 725
 726 extern rtx expand_shift PROTO((enum tree_code, enum machine_mode, rtx, tree, rtx, int));
 727 extern rtx expand_divmod PROTO((int, enum tree_code, enum machine_mode, rtx, rtx, rtx, int));
 728 extern void locate_and_pad_parm PROTO((enum machine_mode, tree, int, tree, struct args_size *, struct args_size *, struct args_size *));
 729 extern rtx expand_inline_function PROTO((tree, tree, rtx, int, tree, rtx));
 730 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 731 extern rtx label_rtx PROTO((tree));
 732 #endif
 733
 734 /* Indicate how an input argument register was promoted.  */
 735 extern rtx promoted_input_arg PROTO((int, enum machine_mode *, int *));
 736
 737 /* Return an rtx like arg but sans any constant terms.
 738    Returns the original rtx if it has no constant terms.
 739    The constant terms are added and stored via a second arg.  */
 740 extern rtx eliminate_constant_term PROTO((rtx, rtx *));
 741
 742 /* Convert arg to a valid memory address for specified machine mode,
 743    by emitting insns to perform arithmetic if nec.  */
 744 extern rtx memory_address PROTO((enum machine_mode, rtx));
 745
 746 /* Like `memory_address' but pretent `flag_force_addr' is 0.  */
 747 extern rtx memory_address_noforce PROTO((enum machine_mode, rtx));
 748
 749 /* Return a memory reference like MEMREF, but with its mode changed
 750    to MODE and its address changed to ADDR.
 751    (VOIDmode means don't change the mode.
 752    NULL for ADDR means don't change the address.)  */
 753 extern rtx change_address PROTO((rtx, enum machine_mode, rtx));
 754
 755 /* Return a memory reference like MEMREF, but which is known to have a
 756    valid address.  */
 757
 758 extern rtx validize_mem PROTO((rtx));
 759
 760 /* Assemble the static constant template for function entry trampolines.  */
 761 extern rtx assemble_trampoline_template PROTO((void));
 762
 763 /* Return 1 if two rtx's are equivalent in structure and elements.  */
 764 extern int rtx_equal_p PROTO((rtx, rtx));
 765
 766 /* Given rtx, return new rtx whose address won't be affected by
 767    any side effects.  It has been copied to a new temporary reg.  */
 768 extern rtx stabilize PROTO((rtx));
 769
 770 /* Given an rtx, copy all regs it refers to into new temps
 771    and return a modified copy that refers to the new temps.  */
 772 extern rtx copy_all_regs PROTO((rtx));
 773
 774 /* Copy given rtx to a new temp reg and return that.  */
 775 extern rtx copy_to_reg PROTO((rtx));
 776
 777 /* Like copy_to_reg but always make the reg Pmode.  */
 778 extern rtx copy_addr_to_reg PROTO((rtx));
 779
 780 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 781 extern rtx copy_to_mode_reg PROTO((enum machine_mode, rtx));
 782
 783 /* Copy given rtx to given temp reg and return that.  */
 784 extern rtx copy_to_suggested_reg PROTO((rtx, rtx, enum machine_mode));
 785
 786 /* Copy a value to a register if it isn't already a register.
 787    Args are mode (in case value is a constant) and the value.  */
 788 extern rtx force_reg PROTO((enum machine_mode, rtx));
 789
 790 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 791 extern rtx force_not_mem PROTO((rtx));
 792
 793 #ifdef TREE_CODE
 794 /* Return mode and signedness to use when object is promoted.  */
 795 extern enum machine_mode promote_mode PROTO((tree, enum machine_mode,
 796                                              int *, int));
 797 #endif
 798
 799 /* Remove some bytes from the stack.  An rtx says how many.  */
 800 extern void adjust_stack PROTO((rtx));
 801
 802 /* Add some bytes to the stack.  An rtx says how many.  */
 803 extern void anti_adjust_stack PROTO((rtx));
 804
 805 /* This enum is used for the following two functions.  */
 806 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 807
 808 /* Save the stack pointer at the specified level.  */
 809 extern void emit_stack_save PROTO((enum save_level, rtx *, rtx));
 810
 811 /* Restore the stack pointer from a save area of the specified level.  */
 812 extern void emit_stack_restore PROTO((enum save_level, rtx, rtx));
 813
 814 /* Allocate some space on the stack dynamically and return its address.  An rtx
 815    says how many bytes.  */
 816 extern rtx allocate_dynamic_stack_space PROTO((rtx, rtx, int));
 817
 818 /* Emit code to copy function value to a new temp reg and return that reg.  */
 819 extern rtx function_value ();
 820
 821 /* Return an rtx that refers to the value returned by a library call
 822    in its original home.  This becomes invalid if any more code is emitted.  */
 823 extern rtx hard_libcall_value PROTO((enum machine_mode));
 824
 825 /* Given an rtx, return an rtx for a value rounded up to a multiple
 826    of STACK_BOUNDARY / BITS_PER_UNIT.  */
 827 extern rtx round_push PROTO((rtx));
 828
 829 extern void emit_block_move PROTO((rtx, rtx, rtx, int));
 830
 831 extern rtx store_bit_field PROTO((rtx, int, int, enum machine_mode, rtx, int, int));
 832 extern rtx extract_bit_field PROTO((rtx, int, int, int, rtx, enum machine_mode, enum machine_mode, int, int));
 833 extern rtx expand_mult PROTO((enum machine_mode, rtx, rtx, rtx, int));
 834 extern rtx expand_mult_add PROTO((rtx, rtx, rtx, rtx,enum machine_mode, int));
 835
 836 extern rtx assemble_static_space PROTO((int));
 837
 838 /* Hook called by expand_expr for language-specific tree codes.
 839    It is up to the language front end to install a hook
 840    if it has any such codes that expand_expr needs to know about.  */
 841 extern rtx (*lang_expand_expr) ();