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      1 //===-- llvm/CodeGen/ISDOpcodes.h - CodeGen opcodes -------------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file declares codegen opcodes and related utilities.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef LLVM_CODEGEN_ISDOPCODES_H
     15 #define LLVM_CODEGEN_ISDOPCODES_H
     16 
     17 namespace llvm {
     18 
     19 /// ISD namespace - This namespace contains an enum which represents all of the
     20 /// SelectionDAG node types and value types.
     21 ///
     22 namespace ISD {
     23 
     24   //===--------------------------------------------------------------------===//
     25   /// ISD::NodeType enum - This enum defines the target-independent operators
     26   /// for a SelectionDAG.
     27   ///
     28   /// Targets may also define target-dependent operator codes for SDNodes. For
     29   /// example, on x86, these are the enum values in the X86ISD namespace.
     30   /// Targets should aim to use target-independent operators to model their
     31   /// instruction sets as much as possible, and only use target-dependent
     32   /// operators when they have special requirements.
     33   ///
     34   /// Finally, during and after selection proper, SNodes may use special
     35   /// operator codes that correspond directly with MachineInstr opcodes. These
     36   /// are used to represent selected instructions. See the isMachineOpcode()
     37   /// and getMachineOpcode() member functions of SDNode.
     38   ///
     39   enum NodeType {
     40     // DELETED_NODE - This is an illegal value that is used to catch
     41     // errors.  This opcode is not a legal opcode for any node.
     42     DELETED_NODE,
     43 
     44     // EntryToken - This is the marker used to indicate the start of the region.
     45     EntryToken,
     46 
     47     // TokenFactor - This node takes multiple tokens as input and produces a
     48     // single token result.  This is used to represent the fact that the operand
     49     // operators are independent of each other.
     50     TokenFactor,
     51 
     52     // AssertSext, AssertZext - These nodes record if a register contains a
     53     // value that has already been zero or sign extended from a narrower type.
     54     // These nodes take two operands.  The first is the node that has already
     55     // been extended, and the second is a value type node indicating the width
     56     // of the extension
     57     AssertSext, AssertZext,
     58 
     59     // Various leaf nodes.
     60     BasicBlock, VALUETYPE, CONDCODE, Register,
     61     Constant, ConstantFP,
     62     GlobalAddress, GlobalTLSAddress, FrameIndex,
     63     JumpTable, ConstantPool, ExternalSymbol, BlockAddress,
     64 
     65     // The address of the GOT
     66     GLOBAL_OFFSET_TABLE,
     67 
     68     // FRAMEADDR, RETURNADDR - These nodes represent llvm.frameaddress and
     69     // llvm.returnaddress on the DAG.  These nodes take one operand, the index
     70     // of the frame or return address to return.  An index of zero corresponds
     71     // to the current function's frame or return address, an index of one to the
     72     // parent's frame or return address, and so on.
     73     FRAMEADDR, RETURNADDR,
     74 
     75     // FRAME_TO_ARGS_OFFSET - This node represents offset from frame pointer to
     76     // first (possible) on-stack argument. This is needed for correct stack
     77     // adjustment during unwind.
     78     FRAME_TO_ARGS_OFFSET,
     79 
     80     // RESULT, OUTCHAIN = EXCEPTIONADDR(INCHAIN) - This node represents the
     81     // address of the exception block on entry to an landing pad block.
     82     EXCEPTIONADDR,
     83 
     84     // RESULT, OUTCHAIN = LSDAADDR(INCHAIN) - This node represents the
     85     // address of the Language Specific Data Area for the enclosing function.
     86     LSDAADDR,
     87 
     88     // RESULT, OUTCHAIN = EHSELECTION(INCHAIN, EXCEPTION) - This node represents
     89     // the selection index of the exception thrown.
     90     EHSELECTION,
     91 
     92     // OUTCHAIN = EH_RETURN(INCHAIN, OFFSET, HANDLER) - This node represents
     93     // 'eh_return' gcc dwarf builtin, which is used to return from
     94     // exception. The general meaning is: adjust stack by OFFSET and pass
     95     // execution to HANDLER. Many platform-related details also :)
     96     EH_RETURN,
     97 
     98     // RESULT, OUTCHAIN = EH_SJLJ_SETJMP(INCHAIN, buffer)
     99     // This corresponds to the eh.sjlj.setjmp intrinsic.
    100     // It takes an input chain and a pointer to the jump buffer as inputs
    101     // and returns an outchain.
    102     EH_SJLJ_SETJMP,
    103 
    104     // OUTCHAIN = EH_SJLJ_LONGJMP(INCHAIN, buffer)
    105     // This corresponds to the eh.sjlj.longjmp intrinsic.
    106     // It takes an input chain and a pointer to the jump buffer as inputs
    107     // and returns an outchain.
    108     EH_SJLJ_LONGJMP,
    109 
    110     // OUTCHAIN = EH_SJLJ_DISPATCHSETUP(INCHAIN, setjmpval)
    111     // This corresponds to the eh.sjlj.dispatchsetup intrinsic. It takes an
    112     // input chain and the value returning from setjmp as inputs and returns an
    113     // outchain. By default, this does nothing. Targets can lower this to unwind
    114     // setup code if needed.
    115     EH_SJLJ_DISPATCHSETUP,
    116 
    117     // TargetConstant* - Like Constant*, but the DAG does not do any folding,
    118     // simplification, or lowering of the constant. They are used for constants
    119     // which are known to fit in the immediate fields of their users, or for
    120     // carrying magic numbers which are not values which need to be materialized
    121     // in registers.
    122     TargetConstant,
    123     TargetConstantFP,
    124 
    125     // TargetGlobalAddress - Like GlobalAddress, but the DAG does no folding or
    126     // anything else with this node, and this is valid in the target-specific
    127     // dag, turning into a GlobalAddress operand.
    128     TargetGlobalAddress,
    129     TargetGlobalTLSAddress,
    130     TargetFrameIndex,
    131     TargetJumpTable,
    132     TargetConstantPool,
    133     TargetExternalSymbol,
    134     TargetBlockAddress,
    135 
    136     /// RESULT = INTRINSIC_WO_CHAIN(INTRINSICID, arg1, arg2, ...)
    137     /// This node represents a target intrinsic function with no side effects.
    138     /// The first operand is the ID number of the intrinsic from the
    139     /// llvm::Intrinsic namespace.  The operands to the intrinsic follow.  The
    140     /// node returns the result of the intrinsic.
    141     INTRINSIC_WO_CHAIN,
    142 
    143     /// RESULT,OUTCHAIN = INTRINSIC_W_CHAIN(INCHAIN, INTRINSICID, arg1, ...)
    144     /// This node represents a target intrinsic function with side effects that
    145     /// returns a result.  The first operand is a chain pointer.  The second is
    146     /// the ID number of the intrinsic from the llvm::Intrinsic namespace.  The
    147     /// operands to the intrinsic follow.  The node has two results, the result
    148     /// of the intrinsic and an output chain.
    149     INTRINSIC_W_CHAIN,
    150 
    151     /// OUTCHAIN = INTRINSIC_VOID(INCHAIN, INTRINSICID, arg1, arg2, ...)
    152     /// This node represents a target intrinsic function with side effects that
    153     /// does not return a result.  The first operand is a chain pointer.  The
    154     /// second is the ID number of the intrinsic from the llvm::Intrinsic
    155     /// namespace.  The operands to the intrinsic follow.
    156     INTRINSIC_VOID,
    157 
    158     // CopyToReg - This node has three operands: a chain, a register number to
    159     // set to this value, and a value.
    160     CopyToReg,
    161 
    162     // CopyFromReg - This node indicates that the input value is a virtual or
    163     // physical register that is defined outside of the scope of this
    164     // SelectionDAG.  The register is available from the RegisterSDNode object.
    165     CopyFromReg,
    166 
    167     // UNDEF - An undefined node
    168     UNDEF,
    169 
    170     // EXTRACT_ELEMENT - This is used to get the lower or upper (determined by
    171     // a Constant, which is required to be operand #1) half of the integer or
    172     // float value specified as operand #0.  This is only for use before
    173     // legalization, for values that will be broken into multiple registers.
    174     EXTRACT_ELEMENT,
    175 
    176     // BUILD_PAIR - This is the opposite of EXTRACT_ELEMENT in some ways.  Given
    177     // two values of the same integer value type, this produces a value twice as
    178     // big.  Like EXTRACT_ELEMENT, this can only be used before legalization.
    179     BUILD_PAIR,
    180 
    181     // MERGE_VALUES - This node takes multiple discrete operands and returns
    182     // them all as its individual results.  This nodes has exactly the same
    183     // number of inputs and outputs. This node is useful for some pieces of the
    184     // code generator that want to think about a single node with multiple
    185     // results, not multiple nodes.
    186     MERGE_VALUES,
    187 
    188     // Simple integer binary arithmetic operators.
    189     ADD, SUB, MUL, SDIV, UDIV, SREM, UREM,
    190 
    191     // SMUL_LOHI/UMUL_LOHI - Multiply two integers of type iN, producing
    192     // a signed/unsigned value of type i[2*N], and return the full value as
    193     // two results, each of type iN.
    194     SMUL_LOHI, UMUL_LOHI,
    195 
    196     // SDIVREM/UDIVREM - Divide two integers and produce both a quotient and
    197     // remainder result.
    198     SDIVREM, UDIVREM,
    199 
    200     // CARRY_FALSE - This node is used when folding other nodes,
    201     // like ADDC/SUBC, which indicate the carry result is always false.
    202     CARRY_FALSE,
    203 
    204     // Carry-setting nodes for multiple precision addition and subtraction.
    205     // These nodes take two operands of the same value type, and produce two
    206     // results.  The first result is the normal add or sub result, the second
    207     // result is the carry flag result.
    208     ADDC, SUBC,
    209 
    210     // Carry-using nodes for multiple precision addition and subtraction.  These
    211     // nodes take three operands: The first two are the normal lhs and rhs to
    212     // the add or sub, and the third is the input carry flag.  These nodes
    213     // produce two results; the normal result of the add or sub, and the output
    214     // carry flag.  These nodes both read and write a carry flag to allow them
    215     // to them to be chained together for add and sub of arbitrarily large
    216     // values.
    217     ADDE, SUBE,
    218 
    219     // RESULT, BOOL = [SU]ADDO(LHS, RHS) - Overflow-aware nodes for addition.
    220     // These nodes take two operands: the normal LHS and RHS to the add. They
    221     // produce two results: the normal result of the add, and a boolean that
    222     // indicates if an overflow occurred (*not* a flag, because it may be stored
    223     // to memory, etc.).  If the type of the boolean is not i1 then the high
    224     // bits conform to getBooleanContents.
    225     // These nodes are generated from the llvm.[su]add.with.overflow intrinsics.
    226     SADDO, UADDO,
    227 
    228     // Same for subtraction
    229     SSUBO, USUBO,
    230 
    231     // Same for multiplication
    232     SMULO, UMULO,
    233 
    234     // Simple binary floating point operators.
    235     FADD, FSUB, FMUL, FMA, FDIV, FREM,
    236 
    237     // FCOPYSIGN(X, Y) - Return the value of X with the sign of Y.  NOTE: This
    238     // DAG node does not require that X and Y have the same type, just that they
    239     // are both floating point.  X and the result must have the same type.
    240     // FCOPYSIGN(f32, f64) is allowed.
    241     FCOPYSIGN,
    242 
    243     // INT = FGETSIGN(FP) - Return the sign bit of the specified floating point
    244     // value as an integer 0/1 value.
    245     FGETSIGN,
    246 
    247     /// BUILD_VECTOR(ELT0, ELT1, ELT2, ELT3,...) - Return a vector with the
    248     /// specified, possibly variable, elements.  The number of elements is
    249     /// required to be a power of two.  The types of the operands must all be
    250     /// the same and must match the vector element type, except that integer
    251     /// types are allowed to be larger than the element type, in which case
    252     /// the operands are implicitly truncated.
    253     BUILD_VECTOR,
    254 
    255     /// INSERT_VECTOR_ELT(VECTOR, VAL, IDX) - Returns VECTOR with the element
    256     /// at IDX replaced with VAL.  If the type of VAL is larger than the vector
    257     /// element type then VAL is truncated before replacement.
    258     INSERT_VECTOR_ELT,
    259 
    260     /// EXTRACT_VECTOR_ELT(VECTOR, IDX) - Returns a single element from VECTOR
    261     /// identified by the (potentially variable) element number IDX.  If the
    262     /// return type is an integer type larger than the element type of the
    263     /// vector, the result is extended to the width of the return type.
    264     EXTRACT_VECTOR_ELT,
    265 
    266     /// CONCAT_VECTORS(VECTOR0, VECTOR1, ...) - Given a number of values of
    267     /// vector type with the same length and element type, this produces a
    268     /// concatenated vector result value, with length equal to the sum of the
    269     /// lengths of the input vectors.
    270     CONCAT_VECTORS,
    271 
    272     /// INSERT_SUBVECTOR(VECTOR1, VECTOR2, IDX) - Returns a vector
    273     /// with VECTOR2 inserted into VECTOR1 at the (potentially
    274     /// variable) element number IDX, which must be a multiple of the
    275     /// VECTOR2 vector length.  The elements of VECTOR1 starting at
    276     /// IDX are overwritten with VECTOR2.  Elements IDX through
    277     /// vector_length(VECTOR2) must be valid VECTOR1 indices.
    278     INSERT_SUBVECTOR,
    279 
    280     /// EXTRACT_SUBVECTOR(VECTOR, IDX) - Returns a subvector from VECTOR (an
    281     /// vector value) starting with the element number IDX, which must be a
    282     /// constant multiple of the result vector length.
    283     EXTRACT_SUBVECTOR,
    284 
    285     /// VECTOR_SHUFFLE(VEC1, VEC2) - Returns a vector, of the same type as
    286     /// VEC1/VEC2.  A VECTOR_SHUFFLE node also contains an array of constant int
    287     /// values that indicate which value (or undef) each result element will
    288     /// get.  These constant ints are accessible through the
    289     /// ShuffleVectorSDNode class.  This is quite similar to the Altivec
    290     /// 'vperm' instruction, except that the indices must be constants and are
    291     /// in terms of the element size of VEC1/VEC2, not in terms of bytes.
    292     VECTOR_SHUFFLE,
    293 
    294     /// SCALAR_TO_VECTOR(VAL) - This represents the operation of loading a
    295     /// scalar value into element 0 of the resultant vector type.  The top
    296     /// elements 1 to N-1 of the N-element vector are undefined.  The type
    297     /// of the operand must match the vector element type, except when they
    298     /// are integer types.  In this case the operand is allowed to be wider
    299     /// than the vector element type, and is implicitly truncated to it.
    300     SCALAR_TO_VECTOR,
    301 
    302     // MULHU/MULHS - Multiply high - Multiply two integers of type iN, producing
    303     // an unsigned/signed value of type i[2*N], then return the top part.
    304     MULHU, MULHS,
    305 
    306     /// Bitwise operators - logical and, logical or, logical xor.
    307     AND, OR, XOR,
    308 
    309     /// Shift and rotation operations.  After legalization, the type of the
    310     /// shift amount is known to be TLI.getShiftAmountTy().  Before legalization
    311     /// the shift amount can be any type, but care must be taken to ensure it is
    312     /// large enough.  TLI.getShiftAmountTy() is i8 on some targets, but before
    313     /// legalization, types like i1024 can occur and i8 doesn't have enough bits
    314     /// to represent the shift amount.  By convention, DAGCombine and
    315     /// SelectionDAGBuilder forces these shift amounts to i32 for simplicity.
    316     ///
    317     SHL, SRA, SRL, ROTL, ROTR,
    318 
    319     /// Byte Swap and Counting operators.
    320     BSWAP, CTTZ, CTLZ, CTPOP,
    321 
    322     // Select(COND, TRUEVAL, FALSEVAL).  If the type of the boolean COND is not
    323     // i1 then the high bits must conform to getBooleanContents.
    324     SELECT,
    325 
    326     // Select with a vector condition (op #0) and two vector operands (ops #1
    327     // and #2), returning a vector result.  All vectors have the same length.
    328     // Much like the scalar select and setcc, each bit in the condition selects
    329     // whether the corresponding result element is taken from op #1 or op #2.
    330     VSELECT,
    331 
    332     // Select with condition operator - This selects between a true value and
    333     // a false value (ops #2 and #3) based on the boolean result of comparing
    334     // the lhs and rhs (ops #0 and #1) of a conditional expression with the
    335     // condition code in op #4, a CondCodeSDNode.
    336     SELECT_CC,
    337 
    338     // SetCC operator - This evaluates to a true value iff the condition is
    339     // true.  If the result value type is not i1 then the high bits conform
    340     // to getBooleanContents.  The operands to this are the left and right
    341     // operands to compare (ops #0, and #1) and the condition code to compare
    342     // them with (op #2) as a CondCodeSDNode. If the operands are vector types
    343     // then the result type must also be a vector type.
    344     SETCC,
    345 
    346     // SHL_PARTS/SRA_PARTS/SRL_PARTS - These operators are used for expanded
    347     // integer shift operations, just like ADD/SUB_PARTS.  The operation
    348     // ordering is:
    349     //       [Lo,Hi] = op [LoLHS,HiLHS], Amt
    350     SHL_PARTS, SRA_PARTS, SRL_PARTS,
    351 
    352     // Conversion operators.  These are all single input single output
    353     // operations.  For all of these, the result type must be strictly
    354     // wider or narrower (depending on the operation) than the source
    355     // type.
    356 
    357     // SIGN_EXTEND - Used for integer types, replicating the sign bit
    358     // into new bits.
    359     SIGN_EXTEND,
    360 
    361     // ZERO_EXTEND - Used for integer types, zeroing the new bits.
    362     ZERO_EXTEND,
    363 
    364     // ANY_EXTEND - Used for integer types.  The high bits are undefined.
    365     ANY_EXTEND,
    366 
    367     // TRUNCATE - Completely drop the high bits.
    368     TRUNCATE,
    369 
    370     // [SU]INT_TO_FP - These operators convert integers (whose interpreted sign
    371     // depends on the first letter) to floating point.
    372     SINT_TO_FP,
    373     UINT_TO_FP,
    374 
    375     // SIGN_EXTEND_INREG - This operator atomically performs a SHL/SRA pair to
    376     // sign extend a small value in a large integer register (e.g. sign
    377     // extending the low 8 bits of a 32-bit register to fill the top 24 bits
    378     // with the 7th bit).  The size of the smaller type is indicated by the 1th
    379     // operand, a ValueType node.
    380     SIGN_EXTEND_INREG,
    381 
    382     /// FP_TO_[US]INT - Convert a floating point value to a signed or unsigned
    383     /// integer.
    384     FP_TO_SINT,
    385     FP_TO_UINT,
    386 
    387     /// X = FP_ROUND(Y, TRUNC) - Rounding 'Y' from a larger floating point type
    388     /// down to the precision of the destination VT.  TRUNC is a flag, which is
    389     /// always an integer that is zero or one.  If TRUNC is 0, this is a
    390     /// normal rounding, if it is 1, this FP_ROUND is known to not change the
    391     /// value of Y.
    392     ///
    393     /// The TRUNC = 1 case is used in cases where we know that the value will
    394     /// not be modified by the node, because Y is not using any of the extra
    395     /// precision of source type.  This allows certain transformations like
    396     /// FP_EXTEND(FP_ROUND(X,1)) -> X which are not safe for
    397     /// FP_EXTEND(FP_ROUND(X,0)) because the extra bits aren't removed.
    398     FP_ROUND,
    399 
    400     // FLT_ROUNDS_ - Returns current rounding mode:
    401     // -1 Undefined
    402     //  0 Round to 0
    403     //  1 Round to nearest
    404     //  2 Round to +inf
    405     //  3 Round to -inf
    406     FLT_ROUNDS_,
    407 
    408     /// X = FP_ROUND_INREG(Y, VT) - This operator takes an FP register, and
    409     /// rounds it to a floating point value.  It then promotes it and returns it
    410     /// in a register of the same size.  This operation effectively just
    411     /// discards excess precision.  The type to round down to is specified by
    412     /// the VT operand, a VTSDNode.
    413     FP_ROUND_INREG,
    414 
    415     /// X = FP_EXTEND(Y) - Extend a smaller FP type into a larger FP type.
    416     FP_EXTEND,
    417 
    418     // BITCAST - This operator converts between integer, vector and FP
    419     // values, as if the value was stored to memory with one type and loaded
    420     // from the same address with the other type (or equivalently for vector
    421     // format conversions, etc).  The source and result are required to have
    422     // the same bit size (e.g.  f32 <-> i32).  This can also be used for
    423     // int-to-int or fp-to-fp conversions, but that is a noop, deleted by
    424     // getNode().
    425     BITCAST,
    426 
    427     // CONVERT_RNDSAT - This operator is used to support various conversions
    428     // between various types (float, signed, unsigned and vectors of those
    429     // types) with rounding and saturation. NOTE: Avoid using this operator as
    430     // most target don't support it and the operator might be removed in the
    431     // future. It takes the following arguments:
    432     //   0) value
    433     //   1) dest type (type to convert to)
    434     //   2) src type (type to convert from)
    435     //   3) rounding imm
    436     //   4) saturation imm
    437     //   5) ISD::CvtCode indicating the type of conversion to do
    438     CONVERT_RNDSAT,
    439 
    440     // FP16_TO_FP32, FP32_TO_FP16 - These operators are used to perform
    441     // promotions and truncation for half-precision (16 bit) floating
    442     // numbers. We need special nodes since FP16 is a storage-only type with
    443     // special semantics of operations.
    444     FP16_TO_FP32, FP32_TO_FP16,
    445 
    446     // FNEG, FABS, FSQRT, FSIN, FCOS, FPOWI, FPOW,
    447     // FLOG, FLOG2, FLOG10, FEXP, FEXP2,
    448     // FCEIL, FTRUNC, FRINT, FNEARBYINT, FFLOOR - Perform various unary floating
    449     // point operations. These are inspired by libm.
    450     FNEG, FABS, FSQRT, FSIN, FCOS, FPOWI, FPOW,
    451     FLOG, FLOG2, FLOG10, FEXP, FEXP2,
    452     FCEIL, FTRUNC, FRINT, FNEARBYINT, FFLOOR,
    453 
    454     // LOAD and STORE have token chains as their first operand, then the same
    455     // operands as an LLVM load/store instruction, then an offset node that
    456     // is added / subtracted from the base pointer to form the address (for
    457     // indexed memory ops).
    458     LOAD, STORE,
    459 
    460     // DYNAMIC_STACKALLOC - Allocate some number of bytes on the stack aligned
    461     // to a specified boundary.  This node always has two return values: a new
    462     // stack pointer value and a chain. The first operand is the token chain,
    463     // the second is the number of bytes to allocate, and the third is the
    464     // alignment boundary.  The size is guaranteed to be a multiple of the stack
    465     // alignment, and the alignment is guaranteed to be bigger than the stack
    466     // alignment (if required) or 0 to get standard stack alignment.
    467     DYNAMIC_STACKALLOC,
    468 
    469     // Control flow instructions.  These all have token chains.
    470 
    471     // BR - Unconditional branch.  The first operand is the chain
    472     // operand, the second is the MBB to branch to.
    473     BR,
    474 
    475     // BRIND - Indirect branch.  The first operand is the chain, the second
    476     // is the value to branch to, which must be of the same type as the target's
    477     // pointer type.
    478     BRIND,
    479 
    480     // BR_JT - Jumptable branch. The first operand is the chain, the second
    481     // is the jumptable index, the last one is the jumptable entry index.
    482     BR_JT,
    483 
    484     // BRCOND - Conditional branch.  The first operand is the chain, the
    485     // second is the condition, the third is the block to branch to if the
    486     // condition is true.  If the type of the condition is not i1, then the
    487     // high bits must conform to getBooleanContents.
    488     BRCOND,
    489 
    490     // BR_CC - Conditional branch.  The behavior is like that of SELECT_CC, in
    491     // that the condition is represented as condition code, and two nodes to
    492     // compare, rather than as a combined SetCC node.  The operands in order are
    493     // chain, cc, lhs, rhs, block to branch to if condition is true.
    494     BR_CC,
    495 
    496     // INLINEASM - Represents an inline asm block.  This node always has two
    497     // return values: a chain and a flag result.  The inputs are as follows:
    498     //   Operand #0   : Input chain.
    499     //   Operand #1   : a ExternalSymbolSDNode with a pointer to the asm string.
    500     //   Operand #2   : a MDNodeSDNode with the !srcloc metadata.
    501     //   Operand #3   : HasSideEffect, IsAlignStack bits.
    502     //   After this, it is followed by a list of operands with this format:
    503     //     ConstantSDNode: Flags that encode whether it is a mem or not, the
    504     //                     of operands that follow, etc.  See InlineAsm.h.
    505     //     ... however many operands ...
    506     //   Operand #last: Optional, an incoming flag.
    507     //
    508     // The variable width operands are required to represent target addressing
    509     // modes as a single "operand", even though they may have multiple
    510     // SDOperands.
    511     INLINEASM,
    512 
    513     // EH_LABEL - Represents a label in mid basic block used to track
    514     // locations needed for debug and exception handling tables.  These nodes
    515     // take a chain as input and return a chain.
    516     EH_LABEL,
    517 
    518     // STACKSAVE - STACKSAVE has one operand, an input chain.  It produces a
    519     // value, the same type as the pointer type for the system, and an output
    520     // chain.
    521     STACKSAVE,
    522 
    523     // STACKRESTORE has two operands, an input chain and a pointer to restore to
    524     // it returns an output chain.
    525     STACKRESTORE,
    526 
    527     // CALLSEQ_START/CALLSEQ_END - These operators mark the beginning and end of
    528     // a call sequence, and carry arbitrary information that target might want
    529     // to know.  The first operand is a chain, the rest are specified by the
    530     // target and not touched by the DAG optimizers.
    531     // CALLSEQ_START..CALLSEQ_END pairs may not be nested.
    532     CALLSEQ_START,  // Beginning of a call sequence
    533     CALLSEQ_END,    // End of a call sequence
    534 
    535     // VAARG - VAARG has four operands: an input chain, a pointer, a SRCVALUE,
    536     // and the alignment. It returns a pair of values: the vaarg value and a
    537     // new chain.
    538     VAARG,
    539 
    540     // VACOPY - VACOPY has five operands: an input chain, a destination pointer,
    541     // a source pointer, a SRCVALUE for the destination, and a SRCVALUE for the
    542     // source.
    543     VACOPY,
    544 
    545     // VAEND, VASTART - VAEND and VASTART have three operands: an input chain, a
    546     // pointer, and a SRCVALUE.
    547     VAEND, VASTART,
    548 
    549     // SRCVALUE - This is a node type that holds a Value* that is used to
    550     // make reference to a value in the LLVM IR.
    551     SRCVALUE,
    552 
    553     // MDNODE_SDNODE - This is a node that holdes an MDNode*, which is used to
    554     // reference metadata in the IR.
    555     MDNODE_SDNODE,
    556 
    557     // PCMARKER - This corresponds to the pcmarker intrinsic.
    558     PCMARKER,
    559 
    560     // READCYCLECOUNTER - This corresponds to the readcyclecounter intrinsic.
    561     // The only operand is a chain and a value and a chain are produced.  The
    562     // value is the contents of the architecture specific cycle counter like
    563     // register (or other high accuracy low latency clock source)
    564     READCYCLECOUNTER,
    565 
    566     // HANDLENODE node - Used as a handle for various purposes.
    567     HANDLENODE,
    568 
    569     // INIT_TRAMPOLINE - This corresponds to the init_trampoline intrinsic.  It
    570     // takes as input a token chain, the pointer to the trampoline, the pointer
    571     // to the nested function, the pointer to pass for the 'nest' parameter, a
    572     // SRCVALUE for the trampoline and another for the nested function (allowing
    573     // targets to access the original Function*).  It produces a token chain as
    574     // output.
    575     INIT_TRAMPOLINE,
    576 
    577     // ADJUST_TRAMPOLINE - This corresponds to the adjust_trampoline intrinsic.
    578     // It takes a pointer to the trampoline and produces a (possibly) new
    579     // pointer to the same trampoline with platform-specific adjustments
    580     // applied.  The pointer it returns points to an executable block of code.
    581     ADJUST_TRAMPOLINE,
    582 
    583     // TRAP - Trapping instruction
    584     TRAP,
    585 
    586     // PREFETCH - This corresponds to a prefetch intrinsic. It takes chains are
    587     // their first operand. The other operands are the address to prefetch,
    588     // read / write specifier, locality specifier and instruction / data cache
    589     // specifier.
    590     PREFETCH,
    591 
    592     // OUTCHAIN = MEMBARRIER(INCHAIN, load-load, load-store, store-load,
    593     //                       store-store, device)
    594     // This corresponds to the memory.barrier intrinsic.
    595     // it takes an input chain, 4 operands to specify the type of barrier, an
    596     // operand specifying if the barrier applies to device and uncached memory
    597     // and produces an output chain.
    598     MEMBARRIER,
    599 
    600     // OUTCHAIN = ATOMIC_FENCE(INCHAIN, ordering, scope)
    601     // This corresponds to the fence instruction. It takes an input chain, and
    602     // two integer constants: an AtomicOrdering and a SynchronizationScope.
    603     ATOMIC_FENCE,
    604 
    605     // Val, OUTCHAIN = ATOMIC_LOAD(INCHAIN, ptr)
    606     // This corresponds to "load atomic" instruction.
    607     ATOMIC_LOAD,
    608 
    609     // OUTCHAIN = ATOMIC_LOAD(INCHAIN, ptr, val)
    610     // This corresponds to "store atomic" instruction.
    611     ATOMIC_STORE,
    612 
    613     // Val, OUTCHAIN = ATOMIC_CMP_SWAP(INCHAIN, ptr, cmp, swap)
    614     // This corresponds to the cmpxchg instruction.
    615     ATOMIC_CMP_SWAP,
    616 
    617     // Val, OUTCHAIN = ATOMIC_SWAP(INCHAIN, ptr, amt)
    618     // Val, OUTCHAIN = ATOMIC_LOAD_[OpName](INCHAIN, ptr, amt)
    619     // These correspond to the atomicrmw instruction.
    620     ATOMIC_SWAP,
    621     ATOMIC_LOAD_ADD,
    622     ATOMIC_LOAD_SUB,
    623     ATOMIC_LOAD_AND,
    624     ATOMIC_LOAD_OR,
    625     ATOMIC_LOAD_XOR,
    626     ATOMIC_LOAD_NAND,
    627     ATOMIC_LOAD_MIN,
    628     ATOMIC_LOAD_MAX,
    629     ATOMIC_LOAD_UMIN,
    630     ATOMIC_LOAD_UMAX,
    631 
    632     /// BUILTIN_OP_END - This must be the last enum value in this list.
    633     /// The target-specific pre-isel opcode values start here.
    634     BUILTIN_OP_END
    635   };
    636 
    637   /// FIRST_TARGET_MEMORY_OPCODE - Target-specific pre-isel operations
    638   /// which do not reference a specific memory location should be less than
    639   /// this value. Those that do must not be less than this value, and can
    640   /// be used with SelectionDAG::getMemIntrinsicNode.
    641   static const int FIRST_TARGET_MEMORY_OPCODE = BUILTIN_OP_END+150;
    642 
    643   //===--------------------------------------------------------------------===//
    644   /// MemIndexedMode enum - This enum defines the load / store indexed
    645   /// addressing modes.
    646   ///
    647   /// UNINDEXED    "Normal" load / store. The effective address is already
    648   ///              computed and is available in the base pointer. The offset
    649   ///              operand is always undefined. In addition to producing a
    650   ///              chain, an unindexed load produces one value (result of the
    651   ///              load); an unindexed store does not produce a value.
    652   ///
    653   /// PRE_INC      Similar to the unindexed mode where the effective address is
    654   /// PRE_DEC      the value of the base pointer add / subtract the offset.
    655   ///              It considers the computation as being folded into the load /
    656   ///              store operation (i.e. the load / store does the address
    657   ///              computation as well as performing the memory transaction).
    658   ///              The base operand is always undefined. In addition to
    659   ///              producing a chain, pre-indexed load produces two values
    660   ///              (result of the load and the result of the address
    661   ///              computation); a pre-indexed store produces one value (result
    662   ///              of the address computation).
    663   ///
    664   /// POST_INC     The effective address is the value of the base pointer. The
    665   /// POST_DEC     value of the offset operand is then added to / subtracted
    666   ///              from the base after memory transaction. In addition to
    667   ///              producing a chain, post-indexed load produces two values
    668   ///              (the result of the load and the result of the base +/- offset
    669   ///              computation); a post-indexed store produces one value (the
    670   ///              the result of the base +/- offset computation).
    671   enum MemIndexedMode {
    672     UNINDEXED = 0,
    673     PRE_INC,
    674     PRE_DEC,
    675     POST_INC,
    676     POST_DEC,
    677     LAST_INDEXED_MODE
    678   };
    679 
    680   //===--------------------------------------------------------------------===//
    681   /// LoadExtType enum - This enum defines the three variants of LOADEXT
    682   /// (load with extension).
    683   ///
    684   /// SEXTLOAD loads the integer operand and sign extends it to a larger
    685   ///          integer result type.
    686   /// ZEXTLOAD loads the integer operand and zero extends it to a larger
    687   ///          integer result type.
    688   /// EXTLOAD  is used for two things: floating point extending loads and
    689   ///          integer extending loads [the top bits are undefined].
    690   enum LoadExtType {
    691     NON_EXTLOAD = 0,
    692     EXTLOAD,
    693     SEXTLOAD,
    694     ZEXTLOAD,
    695     LAST_LOADEXT_TYPE
    696   };
    697 
    698   //===--------------------------------------------------------------------===//
    699   /// ISD::CondCode enum - These are ordered carefully to make the bitfields
    700   /// below work out, when considering SETFALSE (something that never exists
    701   /// dynamically) as 0.  "U" -> Unsigned (for integer operands) or Unordered
    702   /// (for floating point), "L" -> Less than, "G" -> Greater than, "E" -> Equal
    703   /// to.  If the "N" column is 1, the result of the comparison is undefined if
    704   /// the input is a NAN.
    705   ///
    706   /// All of these (except for the 'always folded ops') should be handled for
    707   /// floating point.  For integer, only the SETEQ,SETNE,SETLT,SETLE,SETGT,
    708   /// SETGE,SETULT,SETULE,SETUGT, and SETUGE opcodes are used.
    709   ///
    710   /// Note that these are laid out in a specific order to allow bit-twiddling
    711   /// to transform conditions.
    712   enum CondCode {
    713     // Opcode          N U L G E       Intuitive operation
    714     SETFALSE,      //    0 0 0 0       Always false (always folded)
    715     SETOEQ,        //    0 0 0 1       True if ordered and equal
    716     SETOGT,        //    0 0 1 0       True if ordered and greater than
    717     SETOGE,        //    0 0 1 1       True if ordered and greater than or equal
    718     SETOLT,        //    0 1 0 0       True if ordered and less than
    719     SETOLE,        //    0 1 0 1       True if ordered and less than or equal
    720     SETONE,        //    0 1 1 0       True if ordered and operands are unequal
    721     SETO,          //    0 1 1 1       True if ordered (no nans)
    722     SETUO,         //    1 0 0 0       True if unordered: isnan(X) | isnan(Y)
    723     SETUEQ,        //    1 0 0 1       True if unordered or equal
    724     SETUGT,        //    1 0 1 0       True if unordered or greater than
    725     SETUGE,        //    1 0 1 1       True if unordered, greater than, or equal
    726     SETULT,        //    1 1 0 0       True if unordered or less than
    727     SETULE,        //    1 1 0 1       True if unordered, less than, or equal
    728     SETUNE,        //    1 1 1 0       True if unordered or not equal
    729     SETTRUE,       //    1 1 1 1       Always true (always folded)
    730     // Don't care operations: undefined if the input is a nan.
    731     SETFALSE2,     //  1 X 0 0 0       Always false (always folded)
    732     SETEQ,         //  1 X 0 0 1       True if equal
    733     SETGT,         //  1 X 0 1 0       True if greater than
    734     SETGE,         //  1 X 0 1 1       True if greater than or equal
    735     SETLT,         //  1 X 1 0 0       True if less than
    736     SETLE,         //  1 X 1 0 1       True if less than or equal
    737     SETNE,         //  1 X 1 1 0       True if not equal
    738     SETTRUE2,      //  1 X 1 1 1       Always true (always folded)
    739 
    740     SETCC_INVALID       // Marker value.
    741   };
    742 
    743   /// isSignedIntSetCC - Return true if this is a setcc instruction that
    744   /// performs a signed comparison when used with integer operands.
    745   inline bool isSignedIntSetCC(CondCode Code) {
    746     return Code == SETGT || Code == SETGE || Code == SETLT || Code == SETLE;
    747   }
    748 
    749   /// isUnsignedIntSetCC - Return true if this is a setcc instruction that
    750   /// performs an unsigned comparison when used with integer operands.
    751   inline bool isUnsignedIntSetCC(CondCode Code) {
    752     return Code == SETUGT || Code == SETUGE || Code == SETULT || Code == SETULE;
    753   }
    754 
    755   /// isTrueWhenEqual - Return true if the specified condition returns true if
    756   /// the two operands to the condition are equal.  Note that if one of the two
    757   /// operands is a NaN, this value is meaningless.
    758   inline bool isTrueWhenEqual(CondCode Cond) {
    759     return ((int)Cond & 1) != 0;
    760   }
    761 
    762   /// getUnorderedFlavor - This function returns 0 if the condition is always
    763   /// false if an operand is a NaN, 1 if the condition is always true if the
    764   /// operand is a NaN, and 2 if the condition is undefined if the operand is a
    765   /// NaN.
    766   inline unsigned getUnorderedFlavor(CondCode Cond) {
    767     return ((int)Cond >> 3) & 3;
    768   }
    769 
    770   /// getSetCCInverse - Return the operation corresponding to !(X op Y), where
    771   /// 'op' is a valid SetCC operation.
    772   CondCode getSetCCInverse(CondCode Operation, bool isInteger);
    773 
    774   /// getSetCCSwappedOperands - Return the operation corresponding to (Y op X)
    775   /// when given the operation for (X op Y).
    776   CondCode getSetCCSwappedOperands(CondCode Operation);
    777 
    778   /// getSetCCOrOperation - Return the result of a logical OR between different
    779   /// comparisons of identical values: ((X op1 Y) | (X op2 Y)).  This
    780   /// function returns SETCC_INVALID if it is not possible to represent the
    781   /// resultant comparison.
    782   CondCode getSetCCOrOperation(CondCode Op1, CondCode Op2, bool isInteger);
    783 
    784   /// getSetCCAndOperation - Return the result of a logical AND between
    785   /// different comparisons of identical values: ((X op1 Y) & (X op2 Y)).  This
    786   /// function returns SETCC_INVALID if it is not possible to represent the
    787   /// resultant comparison.
    788   CondCode getSetCCAndOperation(CondCode Op1, CondCode Op2, bool isInteger);
    789 
    790   //===--------------------------------------------------------------------===//
    791   /// CvtCode enum - This enum defines the various converts CONVERT_RNDSAT
    792   /// supports.
    793   enum CvtCode {
    794     CVT_FF,     // Float from Float
    795     CVT_FS,     // Float from Signed
    796     CVT_FU,     // Float from Unsigned
    797     CVT_SF,     // Signed from Float
    798     CVT_UF,     // Unsigned from Float
    799     CVT_SS,     // Signed from Signed
    800     CVT_SU,     // Signed from Unsigned
    801     CVT_US,     // Unsigned from Signed
    802     CVT_UU,     // Unsigned from Unsigned
    803     CVT_INVALID // Marker - Invalid opcode
    804   };
    805 
    806 } // end llvm::ISD namespace
    807 
    808 } // end llvm namespace
    809 
    810 #endif
    811