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      1 /* This file contains the definitions and documentation for the
      2    Register Transfer Expressions (rtx's) that make up the
      3    Register Transfer Language (rtl) used in the Back End of the GNU compiler.
      4    Copyright (C) 1987-2013 Free Software Foundation, Inc.
      5 
      6 This file is part of GCC.
      7 
      8 GCC is free software; you can redistribute it and/or modify it under
      9 the terms of the GNU General Public License as published by the Free
     10 Software Foundation; either version 3, or (at your option) any later
     11 version.
     12 
     13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
     14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
     15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
     16 for more details.
     17 
     18 You should have received a copy of the GNU General Public License
     19 along with GCC; see the file COPYING3.  If not see
     20 <http://www.gnu.org/licenses/>.  */
     21 
     22 
     23 /* Expression definitions and descriptions for all targets are in this file.
     24    Some will not be used for some targets.
     25 
     26    The fields in the cpp macro call "DEF_RTL_EXPR()"
     27    are used to create declarations in the C source of the compiler.
     28 
     29    The fields are:
     30 
     31    1.  The internal name of the rtx used in the C source.
     32    It is a tag in the enumeration "enum rtx_code" defined in "rtl.h".
     33    By convention these are in UPPER_CASE.
     34 
     35    2.  The name of the rtx in the external ASCII format read by
     36    read_rtx(), and printed by print_rtx().
     37    These names are stored in rtx_name[].
     38    By convention these are the internal (field 1) names in lower_case.
     39 
     40    3.  The print format, and type of each rtx->u.fld[] (field) in this rtx.
     41    These formats are stored in rtx_format[].
     42    The meaning of the formats is documented in front of this array in rtl.c
     43 
     44    4.  The class of the rtx.  These are stored in rtx_class and are accessed
     45    via the GET_RTX_CLASS macro.  They are defined as follows:
     46 
     47      RTX_CONST_OBJ
     48          an rtx code that can be used to represent a constant object
     49          (e.g, CONST_INT)
     50      RTX_OBJ
     51          an rtx code that can be used to represent an object (e.g, REG, MEM)
     52      RTX_COMPARE
     53          an rtx code for a comparison (e.g, LT, GT)
     54      RTX_COMM_COMPARE
     55          an rtx code for a commutative comparison (e.g, EQ, NE, ORDERED)
     56      RTX_UNARY
     57          an rtx code for a unary arithmetic expression (e.g, NEG, NOT)
     58      RTX_COMM_ARITH
     59          an rtx code for a commutative binary operation (e.g,, PLUS, MULT)
     60      RTX_TERNARY
     61          an rtx code for a non-bitfield three input operation (IF_THEN_ELSE)
     62      RTX_BIN_ARITH
     63          an rtx code for a non-commutative binary operation (e.g., MINUS, DIV)
     64      RTX_BITFIELD_OPS
     65          an rtx code for a bit-field operation (ZERO_EXTRACT, SIGN_EXTRACT)
     66      RTX_INSN
     67          an rtx code for a machine insn (INSN, JUMP_INSN, CALL_INSN)
     68      RTX_MATCH
     69          an rtx code for something that matches in insns (e.g, MATCH_DUP)
     70      RTX_AUTOINC
     71          an rtx code for autoincrement addressing modes (e.g. POST_DEC)
     72      RTX_EXTRA
     73          everything else
     74 
     75    All of the expressions that appear only in machine descriptions,
     76    not in RTL used by the compiler itself, are at the end of the file.  */
     77 
     78 /* Unknown, or no such operation; the enumeration constant should have
     79    value zero.  */
     80 DEF_RTL_EXPR(UNKNOWN, "UnKnown", "*", RTX_EXTRA)
     81 
     82 /* Used in the cselib routines to describe a value.  Objects of this
     83    kind are only allocated in cselib.c, in an alloc pool instead of in
     84    GC memory.  The only operand of a VALUE is a cselib_val_struct.
     85    var-tracking requires this to have a distinct integral value from
     86    DECL codes in trees.  */
     87 DEF_RTL_EXPR(VALUE, "value", "0", RTX_OBJ)
     88 
     89 /* The RTL generated for a DEBUG_EXPR_DECL.  It links back to the
     90    DEBUG_EXPR_DECL in the first operand.  */
     91 DEF_RTL_EXPR(DEBUG_EXPR, "debug_expr", "0", RTX_OBJ)
     92 
     93 /* ---------------------------------------------------------------------
     94    Expressions used in constructing lists.
     95    --------------------------------------------------------------------- */
     96 
     97 /* a linked list of expressions */
     98 DEF_RTL_EXPR(EXPR_LIST, "expr_list", "ee", RTX_EXTRA)
     99 
    100 /* a linked list of instructions.
    101    The insns are represented in print by their uids.  */
    102 DEF_RTL_EXPR(INSN_LIST, "insn_list", "ue", RTX_EXTRA)
    103 
    104 /* SEQUENCE appears in the result of a `gen_...' function
    105    for a DEFINE_EXPAND that wants to make several insns.
    106    Its elements are the bodies of the insns that should be made.
    107    `emit_insn' takes the SEQUENCE apart and makes separate insns.  */
    108 DEF_RTL_EXPR(SEQUENCE, "sequence", "E", RTX_EXTRA)
    109 
    110 /* Represents a non-global base address.  This is only used in alias.c.  */
    111 DEF_RTL_EXPR(ADDRESS, "address", "i", RTX_EXTRA)
    112 
    113 /* ----------------------------------------------------------------------
    114    Expression types used for things in the instruction chain.
    115 
    116    All formats must start with "iuu" to handle the chain.
    117    Each insn expression holds an rtl instruction and its semantics
    118    during back-end processing.
    119    See macros's in "rtl.h" for the meaning of each rtx->u.fld[].
    120 
    121    ---------------------------------------------------------------------- */
    122 
    123 /* An annotation for variable assignment tracking.  */
    124 DEF_RTL_EXPR(DEBUG_INSN, "debug_insn", "iuuBeiie", RTX_INSN)
    125 
    126 /* An instruction that cannot jump.  */
    127 DEF_RTL_EXPR(INSN, "insn", "iuuBeiie", RTX_INSN)
    128 
    129 /* An instruction that can possibly jump.
    130    Fields ( rtx->u.fld[] ) have exact same meaning as INSN's.  */
    131 DEF_RTL_EXPR(JUMP_INSN, "jump_insn", "iuuBeiie0", RTX_INSN)
    132 
    133 /* An instruction that can possibly call a subroutine
    134    but which will not change which instruction comes next
    135    in the current function.
    136    Field ( rtx->u.fld[8] ) is CALL_INSN_FUNCTION_USAGE.
    137    All other fields ( rtx->u.fld[] ) have exact same meaning as INSN's.  */
    138 DEF_RTL_EXPR(CALL_INSN, "call_insn", "iuuBeiiee", RTX_INSN)
    139 
    140 /* A marker that indicates that control will not flow through.  */
    141 DEF_RTL_EXPR(BARRIER, "barrier", "iuu00000", RTX_EXTRA)
    142 
    143 /* Holds a label that is followed by instructions.
    144    Operand:
    145    4: is used in jump.c for the use-count of the label.
    146    5: is used in the sh backend.
    147    6: is a number that is unique in the entire compilation.
    148    7: is the user-given name of the label, if any.  */
    149 DEF_RTL_EXPR(CODE_LABEL, "code_label", "iuuB00is", RTX_EXTRA)
    150 
    151 /* Say where in the code a source line starts, for symbol table's sake.
    152    Operand:
    153    4: note-specific data
    154    5: enum insn_note
    155    6: unique number if insn_note == note_insn_deleted_label.  */
    156 DEF_RTL_EXPR(NOTE, "note", "iuuB0ni", RTX_EXTRA)
    157 
    158 /* ----------------------------------------------------------------------
    159    Top level constituents of INSN, JUMP_INSN and CALL_INSN.
    160    ---------------------------------------------------------------------- */
    161 
    162 /* Conditionally execute code.
    163    Operand 0 is the condition that if true, the code is executed.
    164    Operand 1 is the code to be executed (typically a SET).
    165 
    166    Semantics are that there are no side effects if the condition
    167    is false.  This pattern is created automatically by the if_convert
    168    pass run after reload or by target-specific splitters.  */
    169 DEF_RTL_EXPR(COND_EXEC, "cond_exec", "ee", RTX_EXTRA)
    170 
    171 /* Several operations to be done in parallel (perhaps under COND_EXEC).  */
    172 DEF_RTL_EXPR(PARALLEL, "parallel", "E", RTX_EXTRA)
    173 
    174 /* A string that is passed through to the assembler as input.
    175      One can obviously pass comments through by using the
    176      assembler comment syntax.
    177      These occur in an insn all by themselves as the PATTERN.
    178      They also appear inside an ASM_OPERANDS
    179      as a convenient way to hold a string.  */
    180 DEF_RTL_EXPR(ASM_INPUT, "asm_input", "si", RTX_EXTRA)
    181 
    182 /* An assembler instruction with operands.
    183    1st operand is the instruction template.
    184    2nd operand is the constraint for the output.
    185    3rd operand is the number of the output this expression refers to.
    186      When an insn stores more than one value, a separate ASM_OPERANDS
    187      is made for each output; this integer distinguishes them.
    188    4th is a vector of values of input operands.
    189    5th is a vector of modes and constraints for the input operands.
    190      Each element is an ASM_INPUT containing a constraint string
    191      and whose mode indicates the mode of the input operand.
    192    6th is a vector of labels that may be branched to by the asm.
    193    7th is the source line number.  */
    194 DEF_RTL_EXPR(ASM_OPERANDS, "asm_operands", "ssiEEEi", RTX_EXTRA)
    195 
    196 /* A machine-specific operation.
    197    1st operand is a vector of operands being used by the operation so that
    198      any needed reloads can be done.
    199    2nd operand is a unique value saying which of a number of machine-specific
    200      operations is to be performed.
    201    (Note that the vector must be the first operand because of the way that
    202    genrecog.c record positions within an insn.)
    203 
    204    UNSPEC can occur all by itself in a PATTERN, as a component of a PARALLEL,
    205    or inside an expression.
    206    UNSPEC by itself or as a component of a PARALLEL
    207    is currently considered not deletable.
    208 
    209    FIXME: Replace all uses of UNSPEC that appears by itself or as a component
    210    of a PARALLEL with USE.
    211    */
    212 DEF_RTL_EXPR(UNSPEC, "unspec", "Ei", RTX_EXTRA)
    213 
    214 /* Similar, but a volatile operation and one which may trap.  */
    215 DEF_RTL_EXPR(UNSPEC_VOLATILE, "unspec_volatile", "Ei", RTX_EXTRA)
    216 
    217 /* Vector of addresses, stored as full words.  */
    218 /* Each element is a LABEL_REF to a CODE_LABEL whose address we want.  */
    219 DEF_RTL_EXPR(ADDR_VEC, "addr_vec", "E", RTX_EXTRA)
    220 
    221 /* Vector of address differences X0 - BASE, X1 - BASE, ...
    222    First operand is BASE; the vector contains the X's.
    223    The machine mode of this rtx says how much space to leave
    224    for each difference and is adjusted by branch shortening if
    225    CASE_VECTOR_SHORTEN_MODE is defined.
    226    The third and fourth operands store the target labels with the
    227    minimum and maximum addresses respectively.
    228    The fifth operand stores flags for use by branch shortening.
    229   Set at the start of shorten_branches:
    230    min_align: the minimum alignment for any of the target labels.
    231    base_after_vec: true iff BASE is after the ADDR_DIFF_VEC.
    232    min_after_vec: true iff minimum addr target label is after the ADDR_DIFF_VEC.
    233    max_after_vec: true iff maximum addr target label is after the ADDR_DIFF_VEC.
    234    min_after_base: true iff minimum address target label is after BASE.
    235    max_after_base: true iff maximum address target label is after BASE.
    236   Set by the actual branch shortening process:
    237    offset_unsigned: true iff offsets have to be treated as unsigned.
    238    scale: scaling that is necessary to make offsets fit into the mode.
    239 
    240    The third, fourth and fifth operands are only valid when
    241    CASE_VECTOR_SHORTEN_MODE is defined, and only in an optimizing
    242    compilation.  */
    243 
    244 DEF_RTL_EXPR(ADDR_DIFF_VEC, "addr_diff_vec", "eEee0", RTX_EXTRA)
    245 
    246 /* Memory prefetch, with attributes supported on some targets.
    247    Operand 1 is the address of the memory to fetch.
    248    Operand 2 is 1 for a write access, 0 otherwise.
    249    Operand 3 is the level of temporal locality; 0 means there is no
    250    temporal locality and 1, 2, and 3 are for increasing levels of temporal
    251    locality.
    252 
    253    The attributes specified by operands 2 and 3 are ignored for targets
    254    whose prefetch instructions do not support them.  */
    255 DEF_RTL_EXPR(PREFETCH, "prefetch", "eee", RTX_EXTRA)
    256 
    257 /* ----------------------------------------------------------------------
    258    At the top level of an instruction (perhaps under PARALLEL).
    259    ---------------------------------------------------------------------- */
    260 
    261 /* Assignment.
    262    Operand 1 is the location (REG, MEM, PC, CC0 or whatever) assigned to.
    263    Operand 2 is the value stored there.
    264    ALL assignment must use SET.
    265    Instructions that do multiple assignments must use multiple SET,
    266    under PARALLEL.  */
    267 DEF_RTL_EXPR(SET, "set", "ee", RTX_EXTRA)
    268 
    269 /* Indicate something is used in a way that we don't want to explain.
    270    For example, subroutine calls will use the register
    271    in which the static chain is passed.
    272 
    273    USE can not appear as an operand of other rtx except for PARALLEL.
    274    USE is not deletable, as it indicates that the operand
    275    is used in some unknown way.  */
    276 DEF_RTL_EXPR(USE, "use", "e", RTX_EXTRA)
    277 
    278 /* Indicate something is clobbered in a way that we don't want to explain.
    279    For example, subroutine calls will clobber some physical registers
    280    (the ones that are by convention not saved).
    281 
    282    CLOBBER can not appear as an operand of other rtx except for PARALLEL.
    283    CLOBBER of a hard register appearing by itself (not within PARALLEL)
    284    is considered undeletable before reload.  */
    285 DEF_RTL_EXPR(CLOBBER, "clobber", "e", RTX_EXTRA)
    286 
    287 /* Call a subroutine.
    288    Operand 1 is the address to call.
    289    Operand 2 is the number of arguments.  */
    290 
    291 DEF_RTL_EXPR(CALL, "call", "ee", RTX_EXTRA)
    292 
    293 /* Return from a subroutine.  */
    294 
    295 DEF_RTL_EXPR(RETURN, "return", "", RTX_EXTRA)
    296 
    297 /* Like RETURN, but truly represents only a function return, while
    298    RETURN may represent an insn that also performs other functions
    299    of the function epilogue.  Like RETURN, this may also occur in
    300    conditional jumps.  */
    301 DEF_RTL_EXPR(SIMPLE_RETURN, "simple_return", "", RTX_EXTRA)
    302 
    303 /* Special for EH return from subroutine.  */
    304 
    305 DEF_RTL_EXPR(EH_RETURN, "eh_return", "", RTX_EXTRA)
    306 
    307 /* Conditional trap.
    308    Operand 1 is the condition.
    309    Operand 2 is the trap code.
    310    For an unconditional trap, make the condition (const_int 1).  */
    311 DEF_RTL_EXPR(TRAP_IF, "trap_if", "ee", RTX_EXTRA)
    312 
    313 /* ----------------------------------------------------------------------
    314    Primitive values for use in expressions.
    315    ---------------------------------------------------------------------- */
    316 
    317 /* numeric integer constant */
    318 DEF_RTL_EXPR(CONST_INT, "const_int", "w", RTX_CONST_OBJ)
    319 
    320 /* fixed-point constant */
    321 DEF_RTL_EXPR(CONST_FIXED, "const_fixed", "www", RTX_CONST_OBJ)
    322 
    323 /* numeric floating point or integer constant.  If the mode is
    324    VOIDmode it is an int otherwise it has a floating point mode and a
    325    floating point value.  Operands hold the value.  They are all 'w'
    326    and there may be from 2 to 6; see real.h.  */
    327 DEF_RTL_EXPR(CONST_DOUBLE, "const_double", CONST_DOUBLE_FORMAT, RTX_CONST_OBJ)
    328 
    329 /* Describes a vector constant.  */
    330 DEF_RTL_EXPR(CONST_VECTOR, "const_vector", "E", RTX_CONST_OBJ)
    331 
    332 /* String constant.  Used for attributes in machine descriptions and
    333    for special cases in DWARF2 debug output.  NOT used for source-
    334    language string constants.  */
    335 DEF_RTL_EXPR(CONST_STRING, "const_string", "s", RTX_OBJ)
    336 
    337 /* This is used to encapsulate an expression whose value is constant
    338    (such as the sum of a SYMBOL_REF and a CONST_INT) so that it will be
    339    recognized as a constant operand rather than by arithmetic instructions.  */
    340 
    341 DEF_RTL_EXPR(CONST, "const", "e", RTX_CONST_OBJ)
    342 
    343 /* program counter.  Ordinary jumps are represented
    344    by a SET whose first operand is (PC).  */
    345 DEF_RTL_EXPR(PC, "pc", "", RTX_OBJ)
    346 
    347 /* A register.  The "operand" is the register number, accessed with
    348    the REGNO macro.  If this number is less than FIRST_PSEUDO_REGISTER
    349    than a hardware register is being referred to.  The second operand
    350    holds the original register number - this will be different for a
    351    pseudo register that got turned into a hard register.  The third
    352    operand points to a reg_attrs structure.
    353    This rtx needs to have as many (or more) fields as a MEM, since we
    354    can change REG rtx's into MEMs during reload.  */
    355 DEF_RTL_EXPR(REG, "reg", "i00", RTX_OBJ)
    356 
    357 /* A scratch register.  This represents a register used only within a
    358    single insn.  It will be turned into a REG during register allocation
    359    or reload unless the constraint indicates that the register won't be
    360    needed, in which case it can remain a SCRATCH.  This code is
    361    marked as having one operand so it can be turned into a REG.  */
    362 DEF_RTL_EXPR(SCRATCH, "scratch", "0", RTX_OBJ)
    363 
    364 /* A reference to a part of another value.  The first operand is the
    365    complete value and the second is the byte offset of the selected part.   */
    366 DEF_RTL_EXPR(SUBREG, "subreg", "ei", RTX_EXTRA)
    367 
    368 /* This one-argument rtx is used for move instructions
    369    that are guaranteed to alter only the low part of a destination.
    370    Thus, (SET (SUBREG:HI (REG...)) (MEM:HI ...))
    371    has an unspecified effect on the high part of REG,
    372    but (SET (STRICT_LOW_PART (SUBREG:HI (REG...))) (MEM:HI ...))
    373    is guaranteed to alter only the bits of REG that are in HImode.
    374 
    375    The actual instruction used is probably the same in both cases,
    376    but the register constraints may be tighter when STRICT_LOW_PART
    377    is in use.  */
    378 
    379 DEF_RTL_EXPR(STRICT_LOW_PART, "strict_low_part", "e", RTX_EXTRA)
    380 
    381 /* (CONCAT a b) represents the virtual concatenation of a and b
    382    to make a value that has as many bits as a and b put together.
    383    This is used for complex values.  Normally it appears only
    384    in DECL_RTLs and during RTL generation, but not in the insn chain.  */
    385 DEF_RTL_EXPR(CONCAT, "concat", "ee", RTX_OBJ)
    386 
    387 /* (CONCATN [a1 a2 ... an]) represents the virtual concatenation of
    388    all An to make a value.  This is an extension of CONCAT to larger
    389    number of components.  Like CONCAT, it should not appear in the
    390    insn chain.  Every element of the CONCATN is the same size.  */
    391 DEF_RTL_EXPR(CONCATN, "concatn", "E", RTX_OBJ)
    392 
    393 /* A memory location; operand is the address.  The second operand is the
    394    alias set to which this MEM belongs.  We use `0' instead of `w' for this
    395    field so that the field need not be specified in machine descriptions.  */
    396 DEF_RTL_EXPR(MEM, "mem", "e0", RTX_OBJ)
    397 
    398 /* Reference to an assembler label in the code for this function.
    399    The operand is a CODE_LABEL found in the insn chain.  */
    400 DEF_RTL_EXPR(LABEL_REF, "label_ref", "u", RTX_CONST_OBJ)
    401 
    402 /* Reference to a named label:
    403    Operand 0: label name
    404    Operand 1: flags (see SYMBOL_FLAG_* in rtl.h)
    405    Operand 2: tree from which this symbol is derived, or null.
    406    This is either a DECL node, or some kind of constant.  */
    407 DEF_RTL_EXPR(SYMBOL_REF, "symbol_ref", "s00", RTX_CONST_OBJ)
    408 
    409 /* The condition code register is represented, in our imagination,
    410    as a register holding a value that can be compared to zero.
    411    In fact, the machine has already compared them and recorded the
    412    results; but instructions that look at the condition code
    413    pretend to be looking at the entire value and comparing it.  */
    414 DEF_RTL_EXPR(CC0, "cc0", "", RTX_OBJ)
    415 
    416 /* ----------------------------------------------------------------------
    417    Expressions for operators in an rtl pattern
    418    ---------------------------------------------------------------------- */
    419 
    420 /* if_then_else.  This is used in representing ordinary
    421    conditional jump instructions.
    422      Operand:
    423      0:  condition
    424      1:  then expr
    425      2:  else expr */
    426 DEF_RTL_EXPR(IF_THEN_ELSE, "if_then_else", "eee", RTX_TERNARY)
    427 
    428 /* Comparison, produces a condition code result.  */
    429 DEF_RTL_EXPR(COMPARE, "compare", "ee", RTX_BIN_ARITH)
    430 
    431 /* plus */
    432 DEF_RTL_EXPR(PLUS, "plus", "ee", RTX_COMM_ARITH)
    433 
    434 /* Operand 0 minus operand 1.  */
    435 DEF_RTL_EXPR(MINUS, "minus", "ee", RTX_BIN_ARITH)
    436 
    437 /* Minus operand 0.  */
    438 DEF_RTL_EXPR(NEG, "neg", "e", RTX_UNARY)
    439 
    440 DEF_RTL_EXPR(MULT, "mult", "ee", RTX_COMM_ARITH)
    441 
    442 /* Multiplication with signed saturation */
    443 DEF_RTL_EXPR(SS_MULT, "ss_mult", "ee", RTX_COMM_ARITH)
    444 /* Multiplication with unsigned saturation */
    445 DEF_RTL_EXPR(US_MULT, "us_mult", "ee", RTX_COMM_ARITH)
    446 
    447 /* Operand 0 divided by operand 1.  */
    448 DEF_RTL_EXPR(DIV, "div", "ee", RTX_BIN_ARITH)
    449 /* Division with signed saturation */
    450 DEF_RTL_EXPR(SS_DIV, "ss_div", "ee", RTX_BIN_ARITH)
    451 /* Division with unsigned saturation */
    452 DEF_RTL_EXPR(US_DIV, "us_div", "ee", RTX_BIN_ARITH)
    453 
    454 /* Remainder of operand 0 divided by operand 1.  */
    455 DEF_RTL_EXPR(MOD, "mod", "ee", RTX_BIN_ARITH)
    456 
    457 /* Unsigned divide and remainder.  */
    458 DEF_RTL_EXPR(UDIV, "udiv", "ee", RTX_BIN_ARITH)
    459 DEF_RTL_EXPR(UMOD, "umod", "ee", RTX_BIN_ARITH)
    460 
    461 /* Bitwise operations.  */
    462 DEF_RTL_EXPR(AND, "and", "ee", RTX_COMM_ARITH)
    463 DEF_RTL_EXPR(IOR, "ior", "ee", RTX_COMM_ARITH)
    464 DEF_RTL_EXPR(XOR, "xor", "ee", RTX_COMM_ARITH)
    465 DEF_RTL_EXPR(NOT, "not", "e", RTX_UNARY)
    466 
    467 /* Operand:
    468      0:  value to be shifted.
    469      1:  number of bits.  */
    470 DEF_RTL_EXPR(ASHIFT, "ashift", "ee", RTX_BIN_ARITH) /* shift left */
    471 DEF_RTL_EXPR(ROTATE, "rotate", "ee", RTX_BIN_ARITH) /* rotate left */
    472 DEF_RTL_EXPR(ASHIFTRT, "ashiftrt", "ee", RTX_BIN_ARITH) /* arithmetic shift right */
    473 DEF_RTL_EXPR(LSHIFTRT, "lshiftrt", "ee", RTX_BIN_ARITH) /* logical shift right */
    474 DEF_RTL_EXPR(ROTATERT, "rotatert", "ee", RTX_BIN_ARITH) /* rotate right */
    475 
    476 /* Minimum and maximum values of two operands.  We need both signed and
    477    unsigned forms.  (We cannot use MIN for SMIN because it conflicts
    478    with a macro of the same name.)   The signed variants should be used
    479    with floating point.  Further, if both operands are zeros, or if either
    480    operand is NaN, then it is unspecified which of the two operands is
    481    returned as the result.  */
    482 
    483 DEF_RTL_EXPR(SMIN, "smin", "ee", RTX_COMM_ARITH)
    484 DEF_RTL_EXPR(SMAX, "smax", "ee", RTX_COMM_ARITH)
    485 DEF_RTL_EXPR(UMIN, "umin", "ee", RTX_COMM_ARITH)
    486 DEF_RTL_EXPR(UMAX, "umax", "ee", RTX_COMM_ARITH)
    487 
    488 /* These unary operations are used to represent incrementation
    489    and decrementation as they occur in memory addresses.
    490    The amount of increment or decrement are not represented
    491    because they can be understood from the machine-mode of the
    492    containing MEM.  These operations exist in only two cases:
    493    1. pushes onto the stack.
    494    2. created automatically by the auto-inc-dec pass.  */
    495 DEF_RTL_EXPR(PRE_DEC, "pre_dec", "e", RTX_AUTOINC)
    496 DEF_RTL_EXPR(PRE_INC, "pre_inc", "e", RTX_AUTOINC)
    497 DEF_RTL_EXPR(POST_DEC, "post_dec", "e", RTX_AUTOINC)
    498 DEF_RTL_EXPR(POST_INC, "post_inc", "e", RTX_AUTOINC)
    499 
    500 /* These binary operations are used to represent generic address
    501    side-effects in memory addresses, except for simple incrementation
    502    or decrementation which use the above operations.  They are
    503    created automatically by the life_analysis pass in flow.c.
    504    The first operand is a REG which is used as the address.
    505    The second operand is an expression that is assigned to the
    506    register, either before (PRE_MODIFY) or after (POST_MODIFY)
    507    evaluating the address.
    508    Currently, the compiler can only handle second operands of the
    509    form (plus (reg) (reg)) and (plus (reg) (const_int)), where
    510    the first operand of the PLUS has to be the same register as
    511    the first operand of the *_MODIFY.  */
    512 DEF_RTL_EXPR(PRE_MODIFY, "pre_modify", "ee", RTX_AUTOINC)
    513 DEF_RTL_EXPR(POST_MODIFY, "post_modify", "ee", RTX_AUTOINC)
    514 
    515 /* Comparison operations.  The ordered comparisons exist in two
    516    flavors, signed and unsigned.  */
    517 DEF_RTL_EXPR(NE, "ne", "ee", RTX_COMM_COMPARE)
    518 DEF_RTL_EXPR(EQ, "eq", "ee", RTX_COMM_COMPARE)
    519 DEF_RTL_EXPR(GE, "ge", "ee", RTX_COMPARE)
    520 DEF_RTL_EXPR(GT, "gt", "ee", RTX_COMPARE)
    521 DEF_RTL_EXPR(LE, "le", "ee", RTX_COMPARE)
    522 DEF_RTL_EXPR(LT, "lt", "ee", RTX_COMPARE)
    523 DEF_RTL_EXPR(GEU, "geu", "ee", RTX_COMPARE)
    524 DEF_RTL_EXPR(GTU, "gtu", "ee", RTX_COMPARE)
    525 DEF_RTL_EXPR(LEU, "leu", "ee", RTX_COMPARE)
    526 DEF_RTL_EXPR(LTU, "ltu", "ee", RTX_COMPARE)
    527 
    528 /* Additional floating point unordered comparison flavors.  */
    529 DEF_RTL_EXPR(UNORDERED, "unordered", "ee", RTX_COMM_COMPARE)
    530 DEF_RTL_EXPR(ORDERED, "ordered", "ee", RTX_COMM_COMPARE)
    531 
    532 /* These are equivalent to unordered or ...  */
    533 DEF_RTL_EXPR(UNEQ, "uneq", "ee", RTX_COMM_COMPARE)
    534 DEF_RTL_EXPR(UNGE, "unge", "ee", RTX_COMPARE)
    535 DEF_RTL_EXPR(UNGT, "ungt", "ee", RTX_COMPARE)
    536 DEF_RTL_EXPR(UNLE, "unle", "ee", RTX_COMPARE)
    537 DEF_RTL_EXPR(UNLT, "unlt", "ee", RTX_COMPARE)
    538 
    539 /* This is an ordered NE, ie !UNEQ, ie false for NaN.  */
    540 DEF_RTL_EXPR(LTGT, "ltgt", "ee", RTX_COMM_COMPARE)
    541 
    542 /* Represents the result of sign-extending the sole operand.
    543    The machine modes of the operand and of the SIGN_EXTEND expression
    544    determine how much sign-extension is going on.  */
    545 DEF_RTL_EXPR(SIGN_EXTEND, "sign_extend", "e", RTX_UNARY)
    546 
    547 /* Similar for zero-extension (such as unsigned short to int).  */
    548 DEF_RTL_EXPR(ZERO_EXTEND, "zero_extend", "e", RTX_UNARY)
    549 
    550 /* Similar but here the operand has a wider mode.  */
    551 DEF_RTL_EXPR(TRUNCATE, "truncate", "e", RTX_UNARY)
    552 
    553 /* Similar for extending floating-point values (such as SFmode to DFmode).  */
    554 DEF_RTL_EXPR(FLOAT_EXTEND, "float_extend", "e", RTX_UNARY)
    555 DEF_RTL_EXPR(FLOAT_TRUNCATE, "float_truncate", "e", RTX_UNARY)
    556 
    557 /* Conversion of fixed point operand to floating point value.  */
    558 DEF_RTL_EXPR(FLOAT, "float", "e", RTX_UNARY)
    559 
    560 /* With fixed-point machine mode:
    561    Conversion of floating point operand to fixed point value.
    562    Value is defined only when the operand's value is an integer.
    563    With floating-point machine mode (and operand with same mode):
    564    Operand is rounded toward zero to produce an integer value
    565    represented in floating point.  */
    566 DEF_RTL_EXPR(FIX, "fix", "e", RTX_UNARY)
    567 
    568 /* Conversion of unsigned fixed point operand to floating point value.  */
    569 DEF_RTL_EXPR(UNSIGNED_FLOAT, "unsigned_float", "e", RTX_UNARY)
    570 
    571 /* With fixed-point machine mode:
    572    Conversion of floating point operand to *unsigned* fixed point value.
    573    Value is defined only when the operand's value is an integer.  */
    574 DEF_RTL_EXPR(UNSIGNED_FIX, "unsigned_fix", "e", RTX_UNARY)
    575 
    576 /* Conversions involving fractional fixed-point types without saturation,
    577    including:
    578      fractional to fractional (of different precision),
    579      signed integer to fractional,
    580      fractional to signed integer,
    581      floating point to fractional,
    582      fractional to floating point.
    583    NOTE: fractional can be either signed or unsigned for conversions.  */
    584 DEF_RTL_EXPR(FRACT_CONVERT, "fract_convert", "e", RTX_UNARY)
    585 
    586 /* Conversions involving fractional fixed-point types and unsigned integer
    587    without saturation, including:
    588      unsigned integer to fractional,
    589      fractional to unsigned integer.
    590    NOTE: fractional can be either signed or unsigned for conversions.  */
    591 DEF_RTL_EXPR(UNSIGNED_FRACT_CONVERT, "unsigned_fract_convert", "e", RTX_UNARY)
    592 
    593 /* Conversions involving fractional fixed-point types with saturation,
    594    including:
    595      fractional to fractional (of different precision),
    596      signed integer to fractional,
    597      floating point to fractional.
    598    NOTE: fractional can be either signed or unsigned for conversions.  */
    599 DEF_RTL_EXPR(SAT_FRACT, "sat_fract", "e", RTX_UNARY)
    600 
    601 /* Conversions involving fractional fixed-point types and unsigned integer
    602    with saturation, including:
    603      unsigned integer to fractional.
    604    NOTE: fractional can be either signed or unsigned for conversions.  */
    605 DEF_RTL_EXPR(UNSIGNED_SAT_FRACT, "unsigned_sat_fract", "e", RTX_UNARY)
    606 
    607 /* Absolute value */
    608 DEF_RTL_EXPR(ABS, "abs", "e", RTX_UNARY)
    609 
    610 /* Square root */
    611 DEF_RTL_EXPR(SQRT, "sqrt", "e", RTX_UNARY)
    612 
    613 /* Swap bytes.  */
    614 DEF_RTL_EXPR(BSWAP, "bswap", "e", RTX_UNARY)
    615 
    616 /* Find first bit that is set.
    617    Value is 1 + number of trailing zeros in the arg.,
    618    or 0 if arg is 0.  */
    619 DEF_RTL_EXPR(FFS, "ffs", "e", RTX_UNARY)
    620 
    621 /* Count number of leading redundant sign bits (number of leading
    622    sign bits minus one).  */
    623 DEF_RTL_EXPR(CLRSB, "clrsb", "e", RTX_UNARY)
    624 
    625 /* Count leading zeros.  */
    626 DEF_RTL_EXPR(CLZ, "clz", "e", RTX_UNARY)
    627 
    628 /* Count trailing zeros.  */
    629 DEF_RTL_EXPR(CTZ, "ctz", "e", RTX_UNARY)
    630 
    631 /* Population count (number of 1 bits).  */
    632 DEF_RTL_EXPR(POPCOUNT, "popcount", "e", RTX_UNARY)
    633 
    634 /* Population parity (number of 1 bits modulo 2).  */
    635 DEF_RTL_EXPR(PARITY, "parity", "e", RTX_UNARY)
    636 
    637 /* Reference to a signed bit-field of specified size and position.
    638    Operand 0 is the memory unit (usually SImode or QImode) which
    639    contains the field's first bit.  Operand 1 is the width, in bits.
    640    Operand 2 is the number of bits in the memory unit before the
    641    first bit of this field.
    642    If BITS_BIG_ENDIAN is defined, the first bit is the msb and
    643    operand 2 counts from the msb of the memory unit.
    644    Otherwise, the first bit is the lsb and operand 2 counts from
    645    the lsb of the memory unit.
    646    This kind of expression can not appear as an lvalue in RTL.  */
    647 DEF_RTL_EXPR(SIGN_EXTRACT, "sign_extract", "eee", RTX_BITFIELD_OPS)
    648 
    649 /* Similar for unsigned bit-field.
    650    But note!  This kind of expression _can_ appear as an lvalue.  */
    651 DEF_RTL_EXPR(ZERO_EXTRACT, "zero_extract", "eee", RTX_BITFIELD_OPS)
    652 
    653 /* For RISC machines.  These save memory when splitting insns.  */
    654 
    655 /* HIGH are the high-order bits of a constant expression.  */
    656 DEF_RTL_EXPR(HIGH, "high", "e", RTX_CONST_OBJ)
    657 
    658 /* LO_SUM is the sum of a register and the low-order bits
    659    of a constant expression.  */
    660 DEF_RTL_EXPR(LO_SUM, "lo_sum", "ee", RTX_OBJ)
    661 
    662 /* Describes a merge operation between two vector values.
    663    Operands 0 and 1 are the vectors to be merged, operand 2 is a bitmask
    664    that specifies where the parts of the result are taken from.  Set bits
    665    indicate operand 0, clear bits indicate operand 1.  The parts are defined
    666    by the mode of the vectors.  */
    667 DEF_RTL_EXPR(VEC_MERGE, "vec_merge", "eee", RTX_TERNARY)
    668 
    669 /* Describes an operation that selects parts of a vector.
    670    Operands 0 is the source vector, operand 1 is a PARALLEL that contains
    671    a CONST_INT for each of the subparts of the result vector, giving the
    672    number of the source subpart that should be stored into it.  */
    673 DEF_RTL_EXPR(VEC_SELECT, "vec_select", "ee", RTX_BIN_ARITH)
    674 
    675 /* Describes a vector concat operation.  Operands 0 and 1 are the source
    676    vectors, the result is a vector that is as long as operands 0 and 1
    677    combined and is the concatenation of the two source vectors.  */
    678 DEF_RTL_EXPR(VEC_CONCAT, "vec_concat", "ee", RTX_BIN_ARITH)
    679 
    680 /* Describes an operation that converts a small vector into a larger one by
    681    duplicating the input values.  The output vector mode must have the same
    682    submodes as the input vector mode, and the number of output parts must be
    683    an integer multiple of the number of input parts.  */
    684 DEF_RTL_EXPR(VEC_DUPLICATE, "vec_duplicate", "e", RTX_UNARY)
    685 
    686 /* Addition with signed saturation */
    687 DEF_RTL_EXPR(SS_PLUS, "ss_plus", "ee", RTX_COMM_ARITH)
    688 
    689 /* Addition with unsigned saturation */
    690 DEF_RTL_EXPR(US_PLUS, "us_plus", "ee", RTX_COMM_ARITH)
    691 
    692 /* Operand 0 minus operand 1, with signed saturation.  */
    693 DEF_RTL_EXPR(SS_MINUS, "ss_minus", "ee", RTX_BIN_ARITH)
    694 
    695 /* Negation with signed saturation.  */
    696 DEF_RTL_EXPR(SS_NEG, "ss_neg", "e", RTX_UNARY)
    697 /* Negation with unsigned saturation.  */
    698 DEF_RTL_EXPR(US_NEG, "us_neg", "e", RTX_UNARY)
    699 
    700 /* Absolute value with signed saturation.  */
    701 DEF_RTL_EXPR(SS_ABS, "ss_abs", "e", RTX_UNARY)
    702 
    703 /* Shift left with signed saturation.  */
    704 DEF_RTL_EXPR(SS_ASHIFT, "ss_ashift", "ee", RTX_BIN_ARITH)
    705 
    706 /* Shift left with unsigned saturation.  */
    707 DEF_RTL_EXPR(US_ASHIFT, "us_ashift", "ee", RTX_BIN_ARITH)
    708 
    709 /* Operand 0 minus operand 1, with unsigned saturation.  */
    710 DEF_RTL_EXPR(US_MINUS, "us_minus", "ee", RTX_BIN_ARITH)
    711 
    712 /* Signed saturating truncate.  */
    713 DEF_RTL_EXPR(SS_TRUNCATE, "ss_truncate", "e", RTX_UNARY)
    714 
    715 /* Unsigned saturating truncate.  */
    716 DEF_RTL_EXPR(US_TRUNCATE, "us_truncate", "e", RTX_UNARY)
    717 
    718 /* Floating point multiply/add combined instruction.  */
    719 DEF_RTL_EXPR(FMA, "fma", "eee", RTX_TERNARY)
    720 
    721 /* Information about the variable and its location.  */
    722 /* Changed 'te' to 'tei'; the 'i' field is for recording
    723    initialization status of variables.  */
    724 DEF_RTL_EXPR(VAR_LOCATION, "var_location", "tei", RTX_EXTRA)
    725 
    726 /* Used in VAR_LOCATION for a pointer to a decl that is no longer
    727    addressable.  */
    728 DEF_RTL_EXPR(DEBUG_IMPLICIT_PTR, "debug_implicit_ptr", "t", RTX_OBJ)
    729 
    730 /* Represents value that argument had on function entry.  The
    731    single argument is the DECL_INCOMING_RTL of the corresponding
    732    parameter.  */
    733 DEF_RTL_EXPR(ENTRY_VALUE, "entry_value", "0", RTX_OBJ)
    734 
    735 /* Used in VAR_LOCATION for a reference to a parameter that has
    736    been optimized away completely.  */
    737 DEF_RTL_EXPR(DEBUG_PARAMETER_REF, "debug_parameter_ref", "t", RTX_OBJ)
    738 
    739 /* All expressions from this point forward appear only in machine
    740    descriptions.  */
    741 #ifdef GENERATOR_FILE
    742 
    743 /* Pattern-matching operators:  */
    744 
    745 /* Use the function named by the second arg (the string)
    746    as a predicate; if matched, store the structure that was matched
    747    in the operand table at index specified by the first arg (the integer).
    748    If the second arg is the null string, the structure is just stored.
    749 
    750    A third string argument indicates to the register allocator restrictions
    751    on where the operand can be allocated.
    752 
    753    If the target needs no restriction on any instruction this field should
    754    be the null string.
    755 
    756    The string is prepended by:
    757    '=' to indicate the operand is only written to.
    758    '+' to indicate the operand is both read and written to.
    759 
    760    Each character in the string represents an allocable class for an operand.
    761    'g' indicates the operand can be any valid class.
    762    'i' indicates the operand can be immediate (in the instruction) data.
    763    'r' indicates the operand can be in a register.
    764    'm' indicates the operand can be in memory.
    765    'o' a subset of the 'm' class.  Those memory addressing modes that
    766        can be offset at compile time (have a constant added to them).
    767 
    768    Other characters indicate target dependent operand classes and
    769    are described in each target's machine description.
    770 
    771    For instructions with more than one operand, sets of classes can be
    772    separated by a comma to indicate the appropriate multi-operand constraints.
    773    There must be a 1 to 1 correspondence between these sets of classes in
    774    all operands for an instruction.
    775    */
    776 DEF_RTL_EXPR(MATCH_OPERAND, "match_operand", "iss", RTX_MATCH)
    777 
    778 /* Match a SCRATCH or a register.  When used to generate rtl, a
    779    SCRATCH is generated.  As for MATCH_OPERAND, the mode specifies
    780    the desired mode and the first argument is the operand number.
    781    The second argument is the constraint.  */
    782 DEF_RTL_EXPR(MATCH_SCRATCH, "match_scratch", "is", RTX_MATCH)
    783 
    784 /* Apply a predicate, AND match recursively the operands of the rtx.
    785    Operand 0 is the operand-number, as in match_operand.
    786    Operand 1 is a predicate to apply (as a string, a function name).
    787    Operand 2 is a vector of expressions, each of which must match
    788    one subexpression of the rtx this construct is matching.  */
    789 DEF_RTL_EXPR(MATCH_OPERATOR, "match_operator", "isE", RTX_MATCH)
    790 
    791 /* Match a PARALLEL of arbitrary length.  The predicate is applied
    792    to the PARALLEL and the initial expressions in the PARALLEL are matched.
    793    Operand 0 is the operand-number, as in match_operand.
    794    Operand 1 is a predicate to apply to the PARALLEL.
    795    Operand 2 is a vector of expressions, each of which must match the
    796    corresponding element in the PARALLEL.  */
    797 DEF_RTL_EXPR(MATCH_PARALLEL, "match_parallel", "isE", RTX_MATCH)
    798 
    799 /* Match only something equal to what is stored in the operand table
    800    at the index specified by the argument.  Use with MATCH_OPERAND.  */
    801 DEF_RTL_EXPR(MATCH_DUP, "match_dup", "i", RTX_MATCH)
    802 
    803 /* Match only something equal to what is stored in the operand table
    804    at the index specified by the argument.  Use with MATCH_OPERATOR.  */
    805 DEF_RTL_EXPR(MATCH_OP_DUP, "match_op_dup", "iE", RTX_MATCH)
    806 
    807 /* Match only something equal to what is stored in the operand table
    808    at the index specified by the argument.  Use with MATCH_PARALLEL.  */
    809 DEF_RTL_EXPR(MATCH_PAR_DUP, "match_par_dup", "iE", RTX_MATCH)
    810 
    811 /* Appears only in define_predicate/define_special_predicate
    812    expressions.  Evaluates true only if the operand has an RTX code
    813    from the set given by the argument (a comma-separated list).  If the
    814    second argument is present and nonempty, it is a sequence of digits
    815    and/or letters which indicates the subexpression to test, using the
    816    same syntax as genextract/genrecog's location strings: 0-9 for
    817    XEXP (op, n), a-z for XVECEXP (op, 0, n); each character applies to
    818    the result of the one before it.  */
    819 DEF_RTL_EXPR(MATCH_CODE, "match_code", "ss", RTX_MATCH)
    820 
    821 /* Used to inject a C conditional expression into an .md file.  It can
    822    appear in a predicate definition or an attribute expression.  */
    823 DEF_RTL_EXPR(MATCH_TEST, "match_test", "s", RTX_MATCH)
    824 
    825 /* Insn (and related) definitions.  */
    826 
    827 /* Definition of the pattern for one kind of instruction.
    828    Operand:
    829    0: names this instruction.
    830       If the name is the null string, the instruction is in the
    831       machine description just to be recognized, and will never be emitted by
    832       the tree to rtl expander.
    833    1: is the pattern.
    834    2: is a string which is a C expression
    835       giving an additional condition for recognizing this pattern.
    836       A null string means no extra condition.
    837    3: is the action to execute if this pattern is matched.
    838       If this assembler code template starts with a * then it is a fragment of
    839       C code to run to decide on a template to use.  Otherwise, it is the
    840       template to use.
    841    4: optionally, a vector of attributes for this insn.
    842      */
    843 DEF_RTL_EXPR(DEFINE_INSN, "define_insn", "sEsTV", RTX_EXTRA)
    844 
    845 /* Definition of a peephole optimization.
    846    1st operand: vector of insn patterns to match
    847    2nd operand: C expression that must be true
    848    3rd operand: template or C code to produce assembler output.
    849    4: optionally, a vector of attributes for this insn.
    850 
    851    This form is deprecated; use define_peephole2 instead.  */
    852 DEF_RTL_EXPR(DEFINE_PEEPHOLE, "define_peephole", "EsTV", RTX_EXTRA)
    853 
    854 /* Definition of a split operation.
    855    1st operand: insn pattern to match
    856    2nd operand: C expression that must be true
    857    3rd operand: vector of insn patterns to place into a SEQUENCE
    858    4th operand: optionally, some C code to execute before generating the
    859 	insns.  This might, for example, create some RTX's and store them in
    860 	elements of `recog_data.operand' for use by the vector of
    861 	insn-patterns.
    862 	(`operands' is an alias here for `recog_data.operand').  */
    863 DEF_RTL_EXPR(DEFINE_SPLIT, "define_split", "EsES", RTX_EXTRA)
    864 
    865 /* Definition of an insn and associated split.
    866    This is the concatenation, with a few modifications, of a define_insn
    867    and a define_split which share the same pattern.
    868    Operand:
    869    0: names this instruction.
    870       If the name is the null string, the instruction is in the
    871       machine description just to be recognized, and will never be emitted by
    872       the tree to rtl expander.
    873    1: is the pattern.
    874    2: is a string which is a C expression
    875       giving an additional condition for recognizing this pattern.
    876       A null string means no extra condition.
    877    3: is the action to execute if this pattern is matched.
    878       If this assembler code template starts with a * then it is a fragment of
    879       C code to run to decide on a template to use.  Otherwise, it is the
    880       template to use.
    881    4: C expression that must be true for split.  This may start with "&&"
    882       in which case the split condition is the logical and of the insn
    883       condition and what follows the "&&" of this operand.
    884    5: vector of insn patterns to place into a SEQUENCE
    885    6: optionally, some C code to execute before generating the
    886 	insns.  This might, for example, create some RTX's and store them in
    887 	elements of `recog_data.operand' for use by the vector of
    888 	insn-patterns.
    889 	(`operands' is an alias here for `recog_data.operand').
    890    7: optionally, a vector of attributes for this insn.  */
    891 DEF_RTL_EXPR(DEFINE_INSN_AND_SPLIT, "define_insn_and_split", "sEsTsESV", RTX_EXTRA)
    892 
    893 /* Definition of an RTL peephole operation.
    894    Follows the same arguments as define_split.  */
    895 DEF_RTL_EXPR(DEFINE_PEEPHOLE2, "define_peephole2", "EsES", RTX_EXTRA)
    896 
    897 /* Define how to generate multiple insns for a standard insn name.
    898    1st operand: the insn name.
    899    2nd operand: vector of insn-patterns.
    900 	Use match_operand to substitute an element of `recog_data.operand'.
    901    3rd operand: C expression that must be true for this to be available.
    902 	This may not test any operands.
    903    4th operand: Extra C code to execute before generating the insns.
    904 	This might, for example, create some RTX's and store them in
    905 	elements of `recog_data.operand' for use by the vector of
    906 	insn-patterns.
    907 	(`operands' is an alias here for `recog_data.operand').
    908    5th: optionally, a vector of attributes for this expand.  */
    909 DEF_RTL_EXPR(DEFINE_EXPAND, "define_expand", "sEssV", RTX_EXTRA)
    910 
    911 /* Define a requirement for delay slots.
    912    1st operand: Condition involving insn attributes that, if true,
    913 	        indicates that the insn requires the number of delay slots
    914 		shown.
    915    2nd operand: Vector whose length is the three times the number of delay
    916 		slots required.
    917 	        Each entry gives three conditions, each involving attributes.
    918 		The first must be true for an insn to occupy that delay slot
    919 		location.  The second is true for all insns that can be
    920 		annulled if the branch is true and the third is true for all
    921 		insns that can be annulled if the branch is false.
    922 
    923    Multiple DEFINE_DELAYs may be present.  They indicate differing
    924    requirements for delay slots.  */
    925 DEF_RTL_EXPR(DEFINE_DELAY, "define_delay", "eE", RTX_EXTRA)
    926 
    927 /* Define attribute computation for `asm' instructions.  */
    928 DEF_RTL_EXPR(DEFINE_ASM_ATTRIBUTES, "define_asm_attributes", "V", RTX_EXTRA)
    929 
    930 /* Definition of a conditional execution meta operation.  Automatically
    931    generates new instances of DEFINE_INSN, selected by having attribute
    932    "predicable" true.  The new pattern will contain a COND_EXEC and the
    933    predicate at top-level.
    934 
    935    Operand:
    936    0: The predicate pattern.  The top-level form should match a
    937       relational operator.  Operands should have only one alternative.
    938    1: A C expression giving an additional condition for recognizing
    939       the generated pattern.
    940    2: A template or C code to produce assembler output.  */
    941 DEF_RTL_EXPR(DEFINE_COND_EXEC, "define_cond_exec", "Ess", RTX_EXTRA)
    942 
    943 /* Definition of an operand predicate.  The difference between
    944    DEFINE_PREDICATE and DEFINE_SPECIAL_PREDICATE is that genrecog will
    945    not warn about a match_operand with no mode if it has a predicate
    946    defined with DEFINE_SPECIAL_PREDICATE.
    947 
    948    Operand:
    949    0: The name of the predicate.
    950    1: A boolean expression which computes whether or not the predicate
    951       matches.  This expression can use IOR, AND, NOT, MATCH_OPERAND,
    952       MATCH_CODE, and MATCH_TEST.  It must be specific enough that genrecog
    953       can calculate the set of RTX codes that can possibly match.
    954    2: A C function body which must return true for the predicate to match.
    955       Optional.  Use this when the test is too complicated to fit into a
    956       match_test expression.  */
    957 DEF_RTL_EXPR(DEFINE_PREDICATE, "define_predicate", "ses", RTX_EXTRA)
    958 DEF_RTL_EXPR(DEFINE_SPECIAL_PREDICATE, "define_special_predicate", "ses", RTX_EXTRA)
    959 
    960 /* Definition of a register operand constraint.  This simply maps the
    961    constraint string to a register class.
    962 
    963    Operand:
    964    0: The name of the constraint (often, but not always, a single letter).
    965    1: A C expression which evaluates to the appropriate register class for
    966       this constraint.  If this is not just a constant, it should look only
    967       at -m switches and the like.
    968    2: A docstring for this constraint, in Texinfo syntax; not currently
    969       used, in future will be incorporated into the manual's list of
    970       machine-specific operand constraints.  */
    971 DEF_RTL_EXPR(DEFINE_REGISTER_CONSTRAINT, "define_register_constraint", "sss", RTX_EXTRA)
    972 
    973 /* Definition of a non-register operand constraint.  These look at the
    974    operand and decide whether it fits the constraint.
    975 
    976    DEFINE_CONSTRAINT gets no special treatment if it fails to match.
    977    It is appropriate for constant-only constraints, and most others.
    978 
    979    DEFINE_MEMORY_CONSTRAINT tells reload that this constraint can be made
    980    to match, if it doesn't already, by converting the operand to the form
    981    (mem (reg X)) where X is a base register.  It is suitable for constraints
    982    that describe a subset of all memory references.
    983 
    984    DEFINE_ADDRESS_CONSTRAINT tells reload that this constraint can be made
    985    to match, if it doesn't already, by converting the operand to the form
    986    (reg X) where X is a base register.  It is suitable for constraints that
    987    describe a subset of all address references.
    988 
    989    When in doubt, use plain DEFINE_CONSTRAINT.
    990 
    991    Operand:
    992    0: The name of the constraint (often, but not always, a single letter).
    993    1: A docstring for this constraint, in Texinfo syntax; not currently
    994       used, in future will be incorporated into the manual's list of
    995       machine-specific operand constraints.
    996    2: A boolean expression which computes whether or not the constraint
    997       matches.  It should follow the same rules as a define_predicate
    998       expression, including the bit about specifying the set of RTX codes
    999       that could possibly match.  MATCH_TEST subexpressions may make use of
   1000       these variables:
   1001         `op'    - the RTL object defining the operand.
   1002         `mode'  - the mode of `op'.
   1003 	`ival'  - INTVAL(op), if op is a CONST_INT.
   1004         `hval'  - CONST_DOUBLE_HIGH(op), if op is an integer CONST_DOUBLE.
   1005         `lval'  - CONST_DOUBLE_LOW(op), if op is an integer CONST_DOUBLE.
   1006         `rval'  - CONST_DOUBLE_REAL_VALUE(op), if op is a floating-point
   1007                   CONST_DOUBLE.
   1008       Do not use ival/hval/lval/rval if op is not the appropriate kind of
   1009       RTL object.  */
   1010 DEF_RTL_EXPR(DEFINE_CONSTRAINT, "define_constraint", "sse", RTX_EXTRA)
   1011 DEF_RTL_EXPR(DEFINE_MEMORY_CONSTRAINT, "define_memory_constraint", "sse", RTX_EXTRA)
   1012 DEF_RTL_EXPR(DEFINE_ADDRESS_CONSTRAINT, "define_address_constraint", "sse", RTX_EXTRA)
   1013 
   1014 
   1015 /* Constructions for CPU pipeline description described by NDFAs.  */
   1016 
   1017 /* (define_cpu_unit string [string]) describes cpu functional
   1018    units (separated by comma).
   1019 
   1020    1st operand: Names of cpu functional units.
   1021    2nd operand: Name of automaton (see comments for DEFINE_AUTOMATON).
   1022 
   1023    All define_reservations, define_cpu_units, and
   1024    define_query_cpu_units should have unique names which may not be
   1025    "nothing".  */
   1026 DEF_RTL_EXPR(DEFINE_CPU_UNIT, "define_cpu_unit", "sS", RTX_EXTRA)
   1027 
   1028 /* (define_query_cpu_unit string [string]) describes cpu functional
   1029    units analogously to define_cpu_unit.  The reservation of such
   1030    units can be queried for automaton state.  */
   1031 DEF_RTL_EXPR(DEFINE_QUERY_CPU_UNIT, "define_query_cpu_unit", "sS", RTX_EXTRA)
   1032 
   1033 /* (exclusion_set string string) means that each CPU functional unit
   1034    in the first string can not be reserved simultaneously with any
   1035    unit whose name is in the second string and vise versa.  CPU units
   1036    in the string are separated by commas.  For example, it is useful
   1037    for description CPU with fully pipelined floating point functional
   1038    unit which can execute simultaneously only single floating point
   1039    insns or only double floating point insns.  All CPU functional
   1040    units in a set should belong to the same automaton.  */
   1041 DEF_RTL_EXPR(EXCLUSION_SET, "exclusion_set", "ss", RTX_EXTRA)
   1042 
   1043 /* (presence_set string string) means that each CPU functional unit in
   1044    the first string can not be reserved unless at least one of pattern
   1045    of units whose names are in the second string is reserved.  This is
   1046    an asymmetric relation.  CPU units or unit patterns in the strings
   1047    are separated by commas.  Pattern is one unit name or unit names
   1048    separated by white-spaces.
   1049 
   1050    For example, it is useful for description that slot1 is reserved
   1051    after slot0 reservation for a VLIW processor.  We could describe it
   1052    by the following construction
   1053 
   1054       (presence_set "slot1" "slot0")
   1055 
   1056    Or slot1 is reserved only after slot0 and unit b0 reservation.  In
   1057    this case we could write
   1058 
   1059       (presence_set "slot1" "slot0 b0")
   1060 
   1061    All CPU functional units in a set should belong to the same
   1062    automaton.  */
   1063 DEF_RTL_EXPR(PRESENCE_SET, "presence_set", "ss", RTX_EXTRA)
   1064 
   1065 /* (final_presence_set string string) is analogous to `presence_set'.
   1066    The difference between them is when checking is done.  When an
   1067    instruction is issued in given automaton state reflecting all
   1068    current and planned unit reservations, the automaton state is
   1069    changed.  The first state is a source state, the second one is a
   1070    result state.  Checking for `presence_set' is done on the source
   1071    state reservation, checking for `final_presence_set' is done on the
   1072    result reservation.  This construction is useful to describe a
   1073    reservation which is actually two subsequent reservations.  For
   1074    example, if we use
   1075 
   1076       (presence_set "slot1" "slot0")
   1077 
   1078    the following insn will be never issued (because slot1 requires
   1079    slot0 which is absent in the source state).
   1080 
   1081       (define_reservation "insn_and_nop" "slot0 + slot1")
   1082 
   1083    but it can be issued if we use analogous `final_presence_set'.  */
   1084 DEF_RTL_EXPR(FINAL_PRESENCE_SET, "final_presence_set", "ss", RTX_EXTRA)
   1085 
   1086 /* (absence_set string string) means that each CPU functional unit in
   1087    the first string can be reserved only if each pattern of units
   1088    whose names are in the second string is not reserved.  This is an
   1089    asymmetric relation (actually exclusion set is analogous to this
   1090    one but it is symmetric).  CPU units or unit patterns in the string
   1091    are separated by commas.  Pattern is one unit name or unit names
   1092    separated by white-spaces.
   1093 
   1094    For example, it is useful for description that slot0 can not be
   1095    reserved after slot1 or slot2 reservation for a VLIW processor.  We
   1096    could describe it by the following construction
   1097 
   1098       (absence_set "slot2" "slot0, slot1")
   1099 
   1100    Or slot2 can not be reserved if slot0 and unit b0 are reserved or
   1101    slot1 and unit b1 are reserved .  In this case we could write
   1102 
   1103       (absence_set "slot2" "slot0 b0, slot1 b1")
   1104 
   1105    All CPU functional units in a set should to belong the same
   1106    automaton.  */
   1107 DEF_RTL_EXPR(ABSENCE_SET, "absence_set", "ss", RTX_EXTRA)
   1108 
   1109 /* (final_absence_set string string) is analogous to `absence_set' but
   1110    checking is done on the result (state) reservation.  See comments
   1111    for `final_presence_set'.  */
   1112 DEF_RTL_EXPR(FINAL_ABSENCE_SET, "final_absence_set", "ss", RTX_EXTRA)
   1113 
   1114 /* (define_bypass number out_insn_names in_insn_names) names bypass
   1115    with given latency (the first number) from insns given by the first
   1116    string (see define_insn_reservation) into insns given by the second
   1117    string.  Insn names in the strings are separated by commas.  The
   1118    third operand is optional name of function which is additional
   1119    guard for the bypass.  The function will get the two insns as
   1120    parameters.  If the function returns zero the bypass will be
   1121    ignored for this case.  Additional guard is necessary to recognize
   1122    complicated bypasses, e.g. when consumer is load address.  If there
   1123    are more one bypass with the same output and input insns, the
   1124    chosen bypass is the first bypass with a guard in description whose
   1125    guard function returns nonzero.  If there is no such bypass, then
   1126    bypass without the guard function is chosen.  */
   1127 DEF_RTL_EXPR(DEFINE_BYPASS, "define_bypass", "issS", RTX_EXTRA)
   1128 
   1129 /* (define_automaton string) describes names of automata generated and
   1130    used for pipeline hazards recognition.  The names are separated by
   1131    comma.  Actually it is possibly to generate the single automaton
   1132    but unfortunately it can be very large.  If we use more one
   1133    automata, the summary size of the automata usually is less than the
   1134    single one.  The automaton name is used in define_cpu_unit and
   1135    define_query_cpu_unit.  All automata should have unique names.  */
   1136 DEF_RTL_EXPR(DEFINE_AUTOMATON, "define_automaton", "s", RTX_EXTRA)
   1137 
   1138 /* (automata_option string) describes option for generation of
   1139    automata.  Currently there are the following options:
   1140 
   1141    o "no-minimization" which makes no minimization of automata.  This
   1142      is only worth to do when we are debugging the description and
   1143      need to look more accurately at reservations of states.
   1144 
   1145    o "time" which means printing additional time statistics about
   1146       generation of automata.
   1147 
   1148    o "v" which means generation of file describing the result
   1149      automata.  The file has suffix `.dfa' and can be used for the
   1150      description verification and debugging.
   1151 
   1152    o "w" which means generation of warning instead of error for
   1153      non-critical errors.
   1154 
   1155    o "ndfa" which makes nondeterministic finite state automata.
   1156 
   1157    o "progress" which means output of a progress bar showing how many
   1158      states were generated so far for automaton being processed.  */
   1159 DEF_RTL_EXPR(AUTOMATA_OPTION, "automata_option", "s", RTX_EXTRA)
   1160 
   1161 /* (define_reservation string string) names reservation (the first
   1162    string) of cpu functional units (the 2nd string).  Sometimes unit
   1163    reservations for different insns contain common parts.  In such
   1164    case, you can describe common part and use its name (the 1st
   1165    parameter) in regular expression in define_insn_reservation.  All
   1166    define_reservations, define_cpu_units, and define_query_cpu_units
   1167    should have unique names which may not be "nothing".  */
   1168 DEF_RTL_EXPR(DEFINE_RESERVATION, "define_reservation", "ss", RTX_EXTRA)
   1169 
   1170 /* (define_insn_reservation name default_latency condition regexpr)
   1171    describes reservation of cpu functional units (the 3nd operand) for
   1172    instruction which is selected by the condition (the 2nd parameter).
   1173    The first parameter is used for output of debugging information.
   1174    The reservations are described by a regular expression according
   1175    the following syntax:
   1176 
   1177        regexp = regexp "," oneof
   1178               | oneof
   1179 
   1180        oneof = oneof "|" allof
   1181              | allof
   1182 
   1183        allof = allof "+" repeat
   1184              | repeat
   1185 
   1186        repeat = element "*" number
   1187               | element
   1188 
   1189        element = cpu_function_unit_name
   1190                | reservation_name
   1191                | result_name
   1192                | "nothing"
   1193                | "(" regexp ")"
   1194 
   1195        1. "," is used for describing start of the next cycle in
   1196        reservation.
   1197 
   1198        2. "|" is used for describing the reservation described by the
   1199        first regular expression *or* the reservation described by the
   1200        second regular expression *or* etc.
   1201 
   1202        3. "+" is used for describing the reservation described by the
   1203        first regular expression *and* the reservation described by the
   1204        second regular expression *and* etc.
   1205 
   1206        4. "*" is used for convenience and simply means sequence in
   1207        which the regular expression are repeated NUMBER times with
   1208        cycle advancing (see ",").
   1209 
   1210        5. cpu functional unit name which means its reservation.
   1211 
   1212        6. reservation name -- see define_reservation.
   1213 
   1214        7. string "nothing" means no units reservation.  */
   1215 
   1216 DEF_RTL_EXPR(DEFINE_INSN_RESERVATION, "define_insn_reservation", "sies", RTX_EXTRA)
   1217 
   1218 /* Expressions used for insn attributes.  */
   1219 
   1220 /* Definition of an insn attribute.
   1221    1st operand: name of the attribute
   1222    2nd operand: comma-separated list of possible attribute values
   1223    3rd operand: expression for the default value of the attribute.  */
   1224 DEF_RTL_EXPR(DEFINE_ATTR, "define_attr", "sse", RTX_EXTRA)
   1225 
   1226 /* Definition of an insn attribute that uses an existing enumerated type.
   1227    1st operand: name of the attribute
   1228    2nd operand: the name of the enumerated type
   1229    3rd operand: expression for the default value of the attribute.  */
   1230 DEF_RTL_EXPR(DEFINE_ENUM_ATTR, "define_enum_attr", "sse", RTX_EXTRA)
   1231 
   1232 /* Marker for the name of an attribute.  */
   1233 DEF_RTL_EXPR(ATTR, "attr", "s", RTX_EXTRA)
   1234 
   1235 /* For use in the last (optional) operand of DEFINE_INSN or DEFINE_PEEPHOLE and
   1236    in DEFINE_ASM_INSN to specify an attribute to assign to insns matching that
   1237    pattern.
   1238 
   1239    (set_attr "name" "value") is equivalent to
   1240    (set (attr "name") (const_string "value"))  */
   1241 DEF_RTL_EXPR(SET_ATTR, "set_attr", "ss", RTX_EXTRA)
   1242 
   1243 /* In the last operand of DEFINE_INSN and DEFINE_PEEPHOLE, this can be used to
   1244    specify that attribute values are to be assigned according to the
   1245    alternative matched.
   1246 
   1247    The following three expressions are equivalent:
   1248 
   1249    (set (attr "att") (cond [(eq_attrq "alternative" "1") (const_string "a1")
   1250 			    (eq_attrq "alternative" "2") (const_string "a2")]
   1251 			   (const_string "a3")))
   1252    (set_attr_alternative "att" [(const_string "a1") (const_string "a2")
   1253 				 (const_string "a3")])
   1254    (set_attr "att" "a1,a2,a3")
   1255  */
   1256 DEF_RTL_EXPR(SET_ATTR_ALTERNATIVE, "set_attr_alternative", "sE", RTX_EXTRA)
   1257 
   1258 /* A conditional expression true if the value of the specified attribute of
   1259    the current insn equals the specified value.  The first operand is the
   1260    attribute name and the second is the comparison value.  */
   1261 DEF_RTL_EXPR(EQ_ATTR, "eq_attr", "ss", RTX_EXTRA)
   1262 
   1263 /* A special case of the above representing a set of alternatives.  The first
   1264    operand is bitmap of the set, the second one is the default value.  */
   1265 DEF_RTL_EXPR(EQ_ATTR_ALT, "eq_attr_alt", "ii", RTX_EXTRA)
   1266 
   1267 /* A conditional expression which is true if the specified flag is
   1268    true for the insn being scheduled in reorg.
   1269 
   1270    genattr.c defines the following flags which can be tested by
   1271    (attr_flag "foo") expressions in eligible_for_delay: forward, backward.  */
   1272 
   1273 DEF_RTL_EXPR (ATTR_FLAG, "attr_flag", "s", RTX_EXTRA)
   1274 
   1275 /* General conditional. The first operand is a vector composed of pairs of
   1276    expressions.  The first element of each pair is evaluated, in turn.
   1277    The value of the conditional is the second expression of the first pair
   1278    whose first expression evaluates nonzero.  If none of the expressions is
   1279    true, the second operand will be used as the value of the conditional.  */
   1280 DEF_RTL_EXPR(COND, "cond", "Ee", RTX_EXTRA)
   1281 
   1282 DEF_RTL_EXPR(DEFINE_SUBST, "define_subst", "sEsE", RTX_EXTRA)
   1283 DEF_RTL_EXPR(DEFINE_SUBST_ATTR, "define_subst_attr", "ssss", RTX_EXTRA)
   1284 #endif /* GENERATOR_FILE */
   1285 
   1286 /*
   1287 Local variables:
   1288 mode:c
   1289 End:
   1290 */
   1291