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 #define FUNCTION_ARG_PADDING(MODE, TYPE)                                \
 180   (! BYTES_BIG_ENDIAN                                                   \
 181    ? upward                                                             \
 182    : (((MODE) == BLKmode                                                \
 183        ? ((TYPE) && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST         \
 184           && int_size_in_bytes (TYPE) < (PARM_BOUNDARY / BITS_PER_UNIT)) \
 185        : GET_MODE_BITSIZE (MODE) < PARM_BOUNDARY)                       \
 186       ? downward : upward))
 187 #endif
 188
 189 /* Supply a default definition for FUNCTION_ARG_BOUNDARY.  Normally, we let
 190    FUNCTION_ARG_PADDING, which also pads the length, handle any needed
 191    alignment.  */
 192
 193 #ifndef FUNCTION_ARG_BOUNDARY
 194 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE)       PARM_BOUNDARY
 195 #endif
 196
 197 /* Nonzero if we do not know how to pass TYPE solely in registers.
 198    We cannot do so in the following cases:
 199
 200    - if the type has variable size
 201    - if the type is marked as addressable (it is required to be constructed
 202      into the stack)
 203    - if the padding and mode of the type is such that a copy into a register
 204      would put it into the wrong part of the register.
 205
 206    Which padding can't be supported depends on the byte endianness.
 207
 208    A value in a register is implicitly padded at the most significant end.
 209    On a big-endian machine, that is the lower end in memory.
 210    So a value padded in memory at the upper end can't go in a register.
 211    For a little-endian machine, the reverse is true.  */
 212
 213 #define MUST_PASS_IN_STACK(MODE,TYPE)                   \
 214   ((TYPE) != 0                                          \
 215    && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST      \
 216        || TREE_ADDRESSABLE (TYPE)                       \
 217        || ((MODE) == BLKmode                            \
 218            && ! ((TYPE) != 0 && TREE_CODE (TYPE_SIZE (TYPE)) == INTEGER_CST \
 219                  && 0 == (int_size_in_bytes (TYPE)      \
 220                           % (PARM_BOUNDARY / BITS_PER_UNIT))) \
 221            && (FUNCTION_ARG_PADDING (MODE, TYPE)        \
 222                == (BYTES_BIG_ENDIAN ? upward : downward)))))
 223
 224 /* Nonzero if type TYPE should be returned in memory.
 225    Most machines can use the following default definition.  */
 226
 227 #ifndef RETURN_IN_MEMORY
 228 #define RETURN_IN_MEMORY(TYPE) (TYPE_MODE (TYPE) == BLKmode)
 229 #endif
 230 \f
 231 /* Optabs are tables saying how to generate insn bodies
 232    for various machine modes and numbers of operands.
 233    Each optab applies to one operation.
 234    For example, add_optab applies to addition.
 235
 236    The insn_code slot is the enum insn_code that says how to
 237    generate an insn for this operation on a particular machine mode.
 238    It is CODE_FOR_nothing if there is no such insn on the target machine.
 239
 240    The `lib_call' slot is the name of the library function that
 241    can be used to perform the operation.
 242
 243    A few optabs, such as move_optab and cmp_optab, are used
 244    by special code.  */
 245
 246 /* Everything that uses expr.h needs to define enum insn_code
 247    but we don't list it in the Makefile dependencies just for that.  */
 248 #include "insn-codes.h"
 249
 250 typedef struct optab
 251 {
 252   enum rtx_code code;
 253   struct {
 254     enum insn_code insn_code;
 255     rtx libfunc;
 256   } handlers [NUM_MACHINE_MODES];
 257 } * optab;
 258
 259 /* Given an enum insn_code, access the function to construct
 260    the body of that kind of insn.  */
 261 #ifdef FUNCTION_CONVERSION_BUG
 262 /* Some compilers fail to convert a function properly to a
 263    pointer-to-function when used as an argument.
 264    So produce the pointer-to-function directly.
 265    Luckily, these compilers seem to work properly when you
 266    call the pointer-to-function.  */
 267 #define GEN_FCN(CODE) (insn_gen_function[(int) (CODE)])
 268 #else
 269 #define GEN_FCN(CODE) (*insn_gen_function[(int) (CODE)])
 270 #endif
 271
 272 extern rtx (*const insn_gen_function[]) ();
 273
 274 extern optab add_optab;
 275 extern optab sub_optab;
 276 extern optab smul_optab;        /* Signed and floating-point multiply */
 277 extern optab smul_highpart_optab; /* Signed multiply, return high word */
 278 extern optab umul_highpart_optab;
 279 extern optab smul_widen_optab;  /* Signed multiply with result
 280                                    one machine mode wider than args */
 281 extern optab umul_widen_optab;
 282 extern optab sdiv_optab;        /* Signed divide */
 283 extern optab sdivmod_optab;     /* Signed divide-and-remainder in one */
 284 extern optab udiv_optab;
 285 extern optab udivmod_optab;
 286 extern optab smod_optab;        /* Signed remainder */
 287 extern optab umod_optab;
 288 extern optab flodiv_optab;      /* Optab for floating divide. */
 289 extern optab ftrunc_optab;      /* Convert float to integer in float fmt */
 290 extern optab and_optab;         /* Logical and */
 291 extern optab ior_optab;         /* Logical or */
 292 extern optab xor_optab;         /* Logical xor */
 293 extern optab ashl_optab;        /* Arithmetic shift left */
 294 extern optab ashr_optab;        /* Arithmetic shift right */
 295 extern optab lshr_optab;        /* Logical shift right */
 296 extern optab rotl_optab;        /* Rotate left */
 297 extern optab rotr_optab;        /* Rotate right */
 298 extern optab smin_optab;        /* Signed and floating-point minimum value */
 299 extern optab smax_optab;        /* Signed and floating-point maximum value */
 300 extern optab umin_optab;        /* Unsigned minimum value */
 301 extern optab umax_optab;        /* Unsigned maximum value */
 302
 303 extern optab mov_optab;         /* Move instruction.  */
 304 extern optab movstrict_optab;   /* Move, preserving high part of register.  */
 305
 306 extern optab cmp_optab;         /* Compare insn; two operands.  */
 307 extern optab tst_optab;         /* tst insn; compare one operand against 0 */
 308
 309 /* Unary operations */
 310 extern optab neg_optab;         /* Negation */
 311 extern optab abs_optab;         /* Abs value */
 312 extern optab one_cmpl_optab;    /* Bitwise not */
 313 extern optab ffs_optab;         /* Find first bit set */
 314 extern optab sqrt_optab;        /* Square root */
 315 extern optab sin_optab;         /* Sine */
 316 extern optab cos_optab;         /* Cosine */
 317 extern optab strlen_optab;      /* String length */
 318
 319 /* Tables of patterns for extending one integer mode to another.  */
 320 extern enum insn_code extendtab[MAX_MACHINE_MODE][MAX_MACHINE_MODE][2];
 321
 322 /* Tables of patterns for converting between fixed and floating point. */
 323 extern enum insn_code fixtab[NUM_MACHINE_MODES][NUM_MACHINE_MODES][2];
 324 extern enum insn_code fixtrunctab[NUM_MACHINE_MODES][NUM_MACHINE_MODES][2];
 325 extern enum insn_code floattab[NUM_MACHINE_MODES][NUM_MACHINE_MODES][2];
 326
 327 /* Contains the optab used for each rtx code.  */
 328 extern optab code_to_optab[NUM_RTX_CODE + 1];
 329
 330 /* Passed to expand_binop and expand_unop to say which options to try to use
 331    if the requested operation can't be open-coded on the requisite mode.
 332    Either OPTAB_LIB or OPTAB_LIB_WIDEN says try using a library call.
 333    Either OPTAB_WIDEN or OPTAB_LIB_WIDEN says try using a wider mode.
 334    OPTAB_MUST_WIDEN says try widening and don't try anything else.  */
 335
 336 enum optab_methods
 337 {
 338   OPTAB_DIRECT,
 339   OPTAB_LIB,
 340   OPTAB_WIDEN,
 341   OPTAB_LIB_WIDEN,
 342   OPTAB_MUST_WIDEN
 343 };
 344
 345 /* SYMBOL_REF rtx's for the library functions that are called
 346    implicitly and not via optabs.  */
 347
 348 extern rtx extendsfdf2_libfunc;
 349 extern rtx extendsfxf2_libfunc;
 350 extern rtx extendsftf2_libfunc;
 351 extern rtx extenddfxf2_libfunc;
 352 extern rtx extenddftf2_libfunc;
 353
 354 extern rtx truncdfsf2_libfunc;
 355 extern rtx truncxfsf2_libfunc;
 356 extern rtx trunctfsf2_libfunc;
 357 extern rtx truncxfdf2_libfunc;
 358 extern rtx trunctfdf2_libfunc;
 359
 360 extern rtx memcpy_libfunc;
 361 extern rtx bcopy_libfunc;
 362 extern rtx memcmp_libfunc;
 363 extern rtx bcmp_libfunc;
 364 extern rtx memset_libfunc;
 365 extern rtx bzero_libfunc;
 366
 367 extern rtx eqhf2_libfunc;
 368 extern rtx nehf2_libfunc;
 369 extern rtx gthf2_libfunc;
 370 extern rtx gehf2_libfunc;
 371 extern rtx lthf2_libfunc;
 372 extern rtx lehf2_libfunc;
 373
 374 extern rtx eqsf2_libfunc;
 375 extern rtx nesf2_libfunc;
 376 extern rtx gtsf2_libfunc;
 377 extern rtx gesf2_libfunc;
 378 extern rtx ltsf2_libfunc;
 379 extern rtx lesf2_libfunc;
 380
 381 extern rtx eqdf2_libfunc;
 382 extern rtx nedf2_libfunc;
 383 extern rtx gtdf2_libfunc;
 384 extern rtx gedf2_libfunc;
 385 extern rtx ltdf2_libfunc;
 386 extern rtx ledf2_libfunc;
 387
 388 extern rtx eqxf2_libfunc;
 389 extern rtx nexf2_libfunc;
 390 extern rtx gtxf2_libfunc;
 391 extern rtx gexf2_libfunc;
 392 extern rtx ltxf2_libfunc;
 393 extern rtx lexf2_libfunc;
 394
 395 extern rtx eqtf2_libfunc;
 396 extern rtx netf2_libfunc;
 397 extern rtx gttf2_libfunc;
 398 extern rtx getf2_libfunc;
 399 extern rtx lttf2_libfunc;
 400 extern rtx letf2_libfunc;
 401
 402 extern rtx floatsisf_libfunc;
 403 extern rtx floatdisf_libfunc;
 404 extern rtx floattisf_libfunc;
 405
 406 extern rtx floatsidf_libfunc;
 407 extern rtx floatdidf_libfunc;
 408 extern rtx floattidf_libfunc;
 409
 410 extern rtx floatsixf_libfunc;
 411 extern rtx floatdixf_libfunc;
 412 extern rtx floattixf_libfunc;
 413
 414 extern rtx floatsitf_libfunc;
 415 extern rtx floatditf_libfunc;
 416 extern rtx floattitf_libfunc;
 417
 418 extern rtx fixsfsi_libfunc;
 419 extern rtx fixsfdi_libfunc;
 420 extern rtx fixsfti_libfunc;
 421
 422 extern rtx fixdfsi_libfunc;
 423 extern rtx fixdfdi_libfunc;
 424 extern rtx fixdfti_libfunc;
 425
 426 extern rtx fixxfsi_libfunc;
 427 extern rtx fixxfdi_libfunc;
 428 extern rtx fixxfti_libfunc;
 429
 430 extern rtx fixtfsi_libfunc;
 431 extern rtx fixtfdi_libfunc;
 432 extern rtx fixtfti_libfunc;
 433
 434 extern rtx fixunssfsi_libfunc;
 435 extern rtx fixunssfdi_libfunc;
 436 extern rtx fixunssfti_libfunc;
 437
 438 extern rtx fixunsdfsi_libfunc;
 439 extern rtx fixunsdfdi_libfunc;
 440 extern rtx fixunsdfti_libfunc;
 441
 442 extern rtx fixunsxfsi_libfunc;
 443 extern rtx fixunsxfdi_libfunc;
 444 extern rtx fixunsxfti_libfunc;
 445
 446 extern rtx fixunstfsi_libfunc;
 447 extern rtx fixunstfdi_libfunc;
 448 extern rtx fixunstfti_libfunc;
 449 \f
 450 typedef rtx (*rtxfun) ();
 451
 452 /* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
 453    gives the gen_function to make a branch to test that condition.  */
 454
 455 extern rtxfun bcc_gen_fctn[NUM_RTX_CODE];
 456
 457 /* Indexed by the rtx-code for a conditional (eg. EQ, LT,...)
 458    gives the insn code to make a store-condition insn
 459    to test that condition.  */
 460
 461 extern enum insn_code setcc_gen_code[NUM_RTX_CODE];
 462
 463 #ifdef HAVE_conditional_move
 464 /* Indexed by the the machine mode, gives the insn code to make a conditional
 465    move insn.  */
 466
 467 extern enum insn_code movcc_gen_code[NUM_MACHINE_MODES];
 468 #endif
 469
 470 /* This array records the insn_code of insns to perform block moves.  */
 471 extern enum insn_code movstr_optab[NUM_MACHINE_MODES];
 472
 473 /* Define functions given in optabs.c.  */
 474
 475 /* Expand a binary operation given optab and rtx operands.  */
 476 extern rtx expand_binop PROTO((enum machine_mode, optab, rtx, rtx, rtx,
 477                                int, enum optab_methods));
 478
 479 /* Expand a binary operation with both signed and unsigned forms.  */
 480 extern rtx sign_expand_binop PROTO((enum machine_mode, optab, optab, rtx,
 481                                     rtx, rtx, int, enum optab_methods));
 482
 483 /* Generate code to perform an operation on two operands with two results.  */
 484 extern int expand_twoval_binop PROTO((optab, rtx, rtx, rtx, rtx, int));
 485
 486 /* Expand a unary arithmetic operation given optab rtx operand.  */
 487 extern rtx expand_unop PROTO((enum machine_mode, optab, rtx, rtx, int));
 488
 489 /* Expand the absolute value operation.  */
 490 extern rtx expand_abs PROTO((enum machine_mode, rtx, rtx, int, int));
 491
 492 /* Expand the complex absolute value operation.  */
 493 extern rtx expand_complex_abs PROTO((enum machine_mode, rtx, rtx, int));
 494
 495 /* Generate an instruction with a given INSN_CODE with an output and
 496    an input.  */
 497 extern void emit_unop_insn PROTO((int, rtx, rtx, enum rtx_code));
 498
 499 /* Emit code to perform a series of operations on a multi-word quantity, one
 500    word at a time.  */
 501 extern rtx emit_no_conflict_block PROTO((rtx, rtx, rtx, rtx, rtx));
 502
 503 /* Emit code to make a call to a constant function or a library call. */
 504 extern void emit_libcall_block PROTO((rtx, rtx, rtx, rtx));
 505
 506 /* Emit one rtl instruction to store zero in specified rtx.  */
 507 extern void emit_clr_insn PROTO((rtx));
 508
 509 /* Emit one rtl insn to store 1 in specified rtx assuming it contains 0.  */
 510 extern void emit_0_to_1_insn PROTO((rtx));
 511
 512 /* Emit one rtl insn to compare two rtx's.  */
 513 extern void emit_cmp_insn PROTO((rtx, rtx, enum rtx_code, rtx,
 514                                  enum machine_mode, int, int));
 515
 516 /* Nonzero if a compare of mode MODE can be done straightforwardly
 517    (without splitting it into pieces).  */
 518 extern int can_compare_p PROTO((enum machine_mode));
 519
 520 /* Emit a library call comparison between floating point X and Y.
 521    COMPARISON is the rtl operator to compare with (EQ, NE, GT, etc.).  */
 522 extern void emit_float_lib_cmp PROTO((rtx, rtx, enum rtx_code));
 523
 524 /* Generate code to indirectly jump to a location given in the rtx LOC.  */
 525 extern void emit_indirect_jump PROTO((rtx));
 526
 527 #ifdef HAVE_conditional_move
 528 /* Emit a conditional move operation.  */
 529 rtx emit_conditional_move PROTO((rtx, enum rtx_code, rtx, rtx,
 530                                  enum machine_mode, rtx, rtx,
 531                                  enum machine_mode, int));
 532
 533 /* Return non-zero if the conditional move is supported.  */
 534 int can_conditionally_move_p PROTO((enum machine_mode mode));
 535 #endif
 536
 537 /* Create but don't emit one rtl instruction to add one rtx into another.
 538    Modes must match; operands must meet the operation's predicates.
 539    Likewise for subtraction and for just copying.
 540    These do not call protect_from_queue; caller must do so.  */
 541 extern rtx gen_add2_insn PROTO((rtx, rtx));
 542 extern rtx gen_sub2_insn PROTO((rtx, rtx));
 543 extern rtx gen_move_insn PROTO((rtx, rtx));
 544 extern int have_add2_insn PROTO((enum machine_mode));
 545 extern int have_sub2_insn PROTO((enum machine_mode));
 546
 547 /* Return the INSN_CODE to use for an extend operation.  */
 548 extern enum insn_code can_extend_p PROTO((enum machine_mode,
 549                                           enum machine_mode, int));
 550
 551 /* Generate the body of an insn to extend Y (with mode MFROM)
 552    into X (with mode MTO).  Do zero-extension if UNSIGNEDP is nonzero.  */
 553 extern rtx gen_extend_insn PROTO((rtx, rtx, enum machine_mode,
 554                                   enum machine_mode, int));
 555
 556 /* Initialize the tables that control conversion between fixed and
 557    floating values.  */
 558 extern void init_fixtab PROTO((void));
 559 extern void init_floattab PROTO((void));
 560
 561 /* Generate code for a FLOAT_EXPR.  */
 562 extern void expand_float PROTO((rtx, rtx, int));
 563
 564 /* Generate code for a FIX_EXPR.  */
 565 extern void expand_fix PROTO((rtx, rtx, int));
 566
 567 /* Call this once to initialize the contents of the optabs
 568    appropriately for the current target machine.  */
 569 extern void init_optabs PROTO((void));
 570 \f
 571 /* Functions from expmed.c:  */
 572
 573 /* Arguments MODE, RTX: return an rtx for the negation of that value.
 574    May emit insns.  */
 575 extern rtx negate_rtx PROTO((enum machine_mode, rtx));
 576
 577 /* Expand a logical AND operation.  */
 578 extern rtx expand_and PROTO((rtx, rtx, rtx));
 579
 580 /* Emit a store-flag operation.  */
 581 extern rtx emit_store_flag PROTO((rtx, enum rtx_code, rtx, rtx,
 582                                   enum machine_mode, int, int));
 583
 584 /* Functions from loop.c:  */
 585
 586 /* Given a JUMP_INSN, return a description of the test being made.  */
 587 extern rtx get_condition PROTO((rtx, rtx *));
 588 \f
 589 /* Functions from expr.c:  */
 590
 591 /* This is run once per compilation to set up which modes can be used
 592    directly in memory and to initialize the block move optab.  */
 593 extern void init_expr_once PROTO((void));
 594
 595 /* This is run at the start of compiling a function.  */
 596 extern void init_expr PROTO((void));
 597
 598 /* Use protect_from_queue to convert a QUEUED expression
 599    into something that you can put immediately into an instruction.  */
 600 extern rtx protect_from_queue PROTO((rtx, int));
 601
 602 /* Perform all the pending incrementations.  */
 603 extern void emit_queue PROTO((void));
 604
 605 /* Emit some rtl insns to move data between rtx's, converting machine modes.
 606    Both modes must be floating or both fixed.  */
 607 extern void convert_move PROTO((rtx, rtx, int));
 608
 609 /* Convert an rtx to specified machine mode and return the result.  */
 610 extern rtx convert_to_mode PROTO((enum machine_mode, rtx, int));
 611
 612 /* Convert an rtx to MODE from OLDMODE and return the result.  */
 613 extern rtx convert_modes PROTO((enum machine_mode, enum machine_mode, rtx, int));
 614
 615 /* Emit code to move a block Y to a block X.  */
 616 extern void emit_block_move PROTO((rtx, rtx, rtx, int));
 617
 618 /* Copy all or part of a value X into registers starting at REGNO.
 619    The number of registers to be filled is NREGS.  */
 620 extern void move_block_to_reg PROTO((int, rtx, int, enum machine_mode));
 621
 622 /* Copy all or part of a BLKmode value X out of registers starting at REGNO.
 623    The number of registers to be filled is NREGS.  */
 624 extern void move_block_from_reg PROTO((int, rtx, int, int));
 625
 626 /* Mark REG as holding a parameter for the next CALL_INSN.  */
 627 extern void use_reg PROTO((rtx*, rtx));
 628 /* Mark NREGS consecutive regs, starting at REGNO, as holding parameters
 629    for the next CALL_INSN.  */
 630 extern void use_regs PROTO((rtx*, int, int));
 631
 632 /* Write zeros through the storage of OBJECT.
 633    If OBJECT has BLKmode, SIZE is its length in bytes.  */
 634 extern void clear_storage PROTO((rtx, int));
 635
 636 /* Emit insns to set X from Y.  */
 637 extern rtx emit_move_insn PROTO((rtx, rtx));
 638
 639 /* Emit insns to set X from Y, with no frills.  */
 640 extern rtx emit_move_insn_1 PROTO ((rtx, rtx));
 641
 642 /* Push a block of length SIZE (perhaps variable)
 643    and return an rtx to address the beginning of the block.  */
 644 extern rtx push_block PROTO((rtx, int, int));
 645
 646 /* Make an operand to push someting on the stack.  */
 647 extern rtx gen_push_operand PROTO((void));
 648
 649 #ifdef TREE_CODE
 650 /* Generate code to push something onto the stack, given its mode and type.  */
 651 extern void emit_push_insn PROTO((rtx, enum machine_mode, tree, rtx, int,
 652                                   int, rtx, int, rtx, rtx));
 653
 654 /* Emit library call.  */
 655 extern void emit_library_call PVPROTO((rtx orgfun, int no_queue,
 656   enum machine_mode outmode, int nargs, ...));
 657 extern rtx emit_library_call_value PVPROTO((rtx orgfun, rtx value, int no_queue,
 658   enum machine_mode outmode, int nargs, ...));
 659
 660 /* Expand an assignment that stores the value of FROM into TO. */
 661 extern rtx expand_assignment PROTO((tree, tree, int, int));
 662
 663 /* Generate code for computing expression EXP,
 664    and storing the value into TARGET.
 665    If SUGGEST_REG is nonzero, copy the value through a register
 666    and return that register, if that is possible.  */
 667 extern rtx store_expr PROTO((tree, rtx, int));
 668 #endif
 669
 670 /* Given an rtx that may include add and multiply operations,
 671    generate them as insns and return a pseudo-reg containing the value.
 672    Useful after calling expand_expr with 1 as sum_ok.  */
 673 extern rtx force_operand PROTO((rtx, rtx));
 674
 675 #ifdef TREE_CODE
 676 /* Generate code for computing expression EXP.
 677    An rtx for the computed value is returned.  The value is never null.
 678    In the case of a void EXP, const0_rtx is returned.  */
 679 extern rtx expand_expr PROTO((tree, rtx, enum machine_mode,
 680                               enum expand_modifier));
 681 #endif
 682
 683 /* At the start of a function, record that we have no previously-pushed
 684    arguments waiting to be popped.  */
 685 extern void init_pending_stack_adjust PROTO((void));
 686
 687 /* When exiting from function, if safe, clear out any pending stack adjust
 688    so the adjustment won't get done.  */
 689 extern void clear_pending_stack_adjust PROTO((void));
 690
 691 /* Pop any previously-pushed arguments that have not been popped yet.  */
 692 extern void do_pending_stack_adjust PROTO((void));
 693
 694 #ifdef TREE_CODE
 695 /* Expand all cleanups up to OLD_CLEANUPS.  */
 696 extern void expand_cleanups_to PROTO((tree));
 697
 698 /* Generate code to evaluate EXP and jump to LABEL if the value is zero.  */
 699 extern void jumpifnot PROTO((tree, rtx));
 700
 701 /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero.  */
 702 extern void jumpif PROTO((tree, rtx));
 703
 704 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
 705    the result is zero, or IF_TRUE_LABEL if the result is one.  */
 706 extern void do_jump PROTO((tree, rtx, rtx));
 707 #endif
 708
 709 /* Generate rtl to compare two rtx's, will call emit_cmp_insn.  */
 710 extern rtx compare_from_rtx PROTO((rtx, rtx, enum rtx_code, int,
 711                                    enum machine_mode, rtx, int));
 712
 713 /* Generate a tablejump instruction (used for switch statements).  */
 714 extern void do_tablejump PROTO((rtx, enum machine_mode, rtx, rtx, rtx));
 715 \f
 716 #ifdef TREE_CODE
 717 /* rtl.h and tree.h were included.  */
 718 /* Return an rtx for the size in bytes of the value of an expr.  */
 719 extern rtx expr_size PROTO((tree));
 720
 721 extern rtx lookup_static_chain PROTO((tree));
 722
 723 /* Convert a stack slot address ADDR valid in function FNDECL
 724    into an address valid in this function (using a static chain).  */
 725 extern rtx fix_lexical_addr PROTO((rtx, tree));
 726
 727 /* Return the address of the trampoline for entering nested fn FUNCTION.  */
 728 extern rtx trampoline_address PROTO((tree));
 729
 730 /* Return an rtx that refers to the value returned by a function
 731    in its original home.  This becomes invalid if any more code is emitted.  */
 732 extern rtx hard_function_value PROTO((tree, tree));
 733
 734 extern rtx prepare_call_address PROTO((rtx, tree, rtx *, int));
 735
 736 extern rtx expand_call PROTO((tree, rtx, int));
 737
 738 extern rtx expand_shift PROTO((enum tree_code, enum machine_mode, rtx, tree, rtx, int));
 739 extern rtx expand_divmod PROTO((int, enum tree_code, enum machine_mode, rtx, rtx, rtx, int));
 740 extern void locate_and_pad_parm PROTO((enum machine_mode, tree, int, tree, struct args_size *, struct args_size *, struct args_size *));
 741 extern rtx expand_inline_function PROTO((tree, tree, rtx, int, tree, rtx));
 742 /* Return the CODE_LABEL rtx for a LABEL_DECL, creating it if necessary.  */
 743 extern rtx label_rtx PROTO((tree));
 744 #endif
 745
 746 /* Indicate how an input argument register was promoted.  */
 747 extern rtx promoted_input_arg PROTO((int, enum machine_mode *, int *));
 748
 749 /* Return an rtx like arg but sans any constant terms.
 750    Returns the original rtx if it has no constant terms.
 751    The constant terms are added and stored via a second arg.  */
 752 extern rtx eliminate_constant_term PROTO((rtx, rtx *));
 753
 754 /* Convert arg to a valid memory address for specified machine mode,
 755    by emitting insns to perform arithmetic if nec.  */
 756 extern rtx memory_address PROTO((enum machine_mode, rtx));
 757
 758 /* Like `memory_address' but pretent `flag_force_addr' is 0.  */
 759 extern rtx memory_address_noforce PROTO((enum machine_mode, rtx));
 760
 761 /* Return a memory reference like MEMREF, but with its mode changed
 762    to MODE and its address changed to ADDR.
 763    (VOIDmode means don't change the mode.
 764    NULL for ADDR means don't change the address.)  */
 765 extern rtx change_address PROTO((rtx, enum machine_mode, rtx));
 766
 767 /* Return a memory reference like MEMREF, but which is known to have a
 768    valid address.  */
 769
 770 extern rtx validize_mem PROTO((rtx));
 771
 772 /* Assemble the static constant template for function entry trampolines.  */
 773 extern rtx assemble_trampoline_template PROTO((void));
 774
 775 /* Return 1 if two rtx's are equivalent in structure and elements.  */
 776 extern int rtx_equal_p PROTO((rtx, rtx));
 777
 778 /* Given rtx, return new rtx whose address won't be affected by
 779    any side effects.  It has been copied to a new temporary reg.  */
 780 extern rtx stabilize PROTO((rtx));
 781
 782 /* Given an rtx, copy all regs it refers to into new temps
 783    and return a modified copy that refers to the new temps.  */
 784 extern rtx copy_all_regs PROTO((rtx));
 785
 786 /* Copy given rtx to a new temp reg and return that.  */
 787 extern rtx copy_to_reg PROTO((rtx));
 788
 789 /* Like copy_to_reg but always make the reg Pmode.  */
 790 extern rtx copy_addr_to_reg PROTO((rtx));
 791
 792 /* Like copy_to_reg but always make the reg the specified mode MODE.  */
 793 extern rtx copy_to_mode_reg PROTO((enum machine_mode, rtx));
 794
 795 /* Copy given rtx to given temp reg and return that.  */
 796 extern rtx copy_to_suggested_reg PROTO((rtx, rtx, enum machine_mode));
 797
 798 /* Copy a value to a register if it isn't already a register.
 799    Args are mode (in case value is a constant) and the value.  */
 800 extern rtx force_reg PROTO((enum machine_mode, rtx));
 801
 802 /* Return given rtx, copied into a new temp reg if it was in memory.  */
 803 extern rtx force_not_mem PROTO((rtx));
 804
 805 #ifdef TREE_CODE
 806 /* Return mode and signedness to use when object is promoted.  */
 807 extern enum machine_mode promote_mode PROTO((tree, enum machine_mode,
 808                                              int *, int));
 809 #endif
 810
 811 /* Remove some bytes from the stack.  An rtx says how many.  */
 812 extern void adjust_stack PROTO((rtx));
 813
 814 /* Add some bytes to the stack.  An rtx says how many.  */
 815 extern void anti_adjust_stack PROTO((rtx));
 816
 817 /* This enum is used for the following two functions.  */
 818 enum save_level {SAVE_BLOCK, SAVE_FUNCTION, SAVE_NONLOCAL};
 819
 820 /* Save the stack pointer at the specified level.  */
 821 extern void emit_stack_save PROTO((enum save_level, rtx *, rtx));
 822
 823 /* Restore the stack pointer from a save area of the specified level.  */
 824 extern void emit_stack_restore PROTO((enum save_level, rtx, rtx));
 825
 826 /* Allocate some space on the stack dynamically and return its address.  An rtx
 827    says how many bytes.  */
 828 extern rtx allocate_dynamic_stack_space PROTO((rtx, rtx, int));
 829
 830 /* Emit code to copy function value to a new temp reg and return that reg.  */
 831 extern rtx function_value ();
 832
 833 /* Return an rtx that refers to the value returned by a library call
 834    in its original home.  This becomes invalid if any more code is emitted.  */
 835 extern rtx hard_libcall_value PROTO((enum machine_mode));
 836
 837 /* Given an rtx, return an rtx for a value rounded up to a multiple
 838    of STACK_BOUNDARY / BITS_PER_UNIT.  */
 839 extern rtx round_push PROTO((rtx));
 840
 841 extern void emit_block_move PROTO((rtx, rtx, rtx, int));
 842
 843 extern rtx store_bit_field PROTO((rtx, int, int, enum machine_mode, rtx, int, int));
 844 extern rtx extract_bit_field PROTO((rtx, int, int, int, rtx, enum machine_mode, enum machine_mode, int, int));
 845 extern rtx expand_mult PROTO((enum machine_mode, rtx, rtx, rtx, int));
 846 extern rtx expand_mult_add PROTO((rtx, rtx, rtx, rtx,enum machine_mode, int));
 847
 848 extern rtx assemble_static_space PROTO((int));
 849
 850 /* Hook called by expand_expr for language-specific tree codes.
 851    It is up to the language front end to install a hook
 852    if it has any such codes that expand_expr needs to know about.  */
 853 extern rtx (*lang_expand_expr) ();