path: root/include/llvm/CodeGen/SelectionDAGNodes.h

//===-- llvm/CodeGen/SelectionDAGNodes.h - SelectionDAG Nodes ---*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the SDNode class and derived classes, which are used to
// represent the nodes and operations present in a SelectionDAG.  These nodes
// and operations are machine code level operations, with some similarities to
// the GCC RTL representation.
//
// Clients should include the SelectionDAG.h file instead of this file directly.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_SELECTIONDAGNODES_H
#define LLVM_CODEGEN_SELECTIONDAGNODES_H

#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/Value.h"
#include "llvm/ADT/GraphTraits.h"
#include "llvm/ADT/iterator"
#include "llvm/Support/DataTypes.h"
#include <cassert>
#include <vector>

namespace llvm {

class SelectionDAG;
class GlobalValue;
class MachineBasicBlock;
class SDNode;
template <typename T> struct simplify_type;
template <typename T> struct ilist_traits;
template<typename NodeTy, typename Traits> class iplist;
template<typename NodeTy> class ilist_iterator;

/// ISD namespace - This namespace contains an enum which represents all of the
/// SelectionDAG node types and value types.
///
namespace ISD {
  //===--------------------------------------------------------------------===//
  /// ISD::NodeType enum - This enum defines all of the operators valid in a
  /// SelectionDAG.
  ///
  enum NodeType {
    // EntryToken - This is the marker used to indicate the start of the region.
    EntryToken,

    // Token factor - This node takes multiple tokens as input and produces a
    // single token result.  This is used to represent the fact that the operand
    // operators are independent of each other.
    TokenFactor,
    
    // AssertSext, AssertZext - These nodes record if a register contains a 
    // value that has already been zero or sign extended from a narrower type.  
    // These nodes take two operands.  The first is the node that has already 
    // been extended, and the second is a value type node indicating the width
    // of the extension
    AssertSext, AssertZext,

    // Various leaf nodes.
    Constant, ConstantFP, STRING,
    GlobalAddress, FrameIndex, ConstantPool,
    BasicBlock, ExternalSymbol, VALUETYPE, CONDCODE, Register,
    
    // ConstantVec works like Constant or ConstantFP, except that it is not a
    // leaf node.  All operands are either Constant or ConstantFP nodes.
    ConstantVec,
    
    // TargetConstant - Like Constant, but the DAG does not do any folding or
    // simplification of the constant.  This is used by the DAG->DAG selector.
    TargetConstant,
    
    // TargetGlobalAddress - Like GlobalAddress, but the DAG does no folding or
    // anything else with this node, and this is valid in the target-specific
    // dag, turning into a GlobalAddress operand.
    TargetGlobalAddress,
    TargetFrameIndex,
    TargetConstantPool,
    TargetExternalSymbol,

    // CopyToReg - This node has three operands: a chain, a register number to
    // set to this value, and a value.  
    CopyToReg,

    // CopyFromReg - This node indicates that the input value is a virtual or
    // physical register that is defined outside of the scope of this
    // SelectionDAG.  The register is available from the RegSDNode object.
    CopyFromReg,

    // UNDEF - An undefined node
    UNDEF,

    // EXTRACT_ELEMENT - This is used to get the first or second (determined by
    // a Constant, which is required to be operand #1), element of the aggregate
    // value specified as operand #0.  This is only for use before legalization,
    // for values that will be broken into multiple registers.
    EXTRACT_ELEMENT,

    // BUILD_PAIR - This is the opposite of EXTRACT_ELEMENT in some ways.  Given
    // two values of the same integer value type, this produces a value twice as
    // big.  Like EXTRACT_ELEMENT, this can only be used before legalization.
    BUILD_PAIR,
    
    // MERGE_VALUES - This node takes multiple discrete operands and returns
    // them all as its individual results.  This nodes has exactly the same
    // number of inputs and outputs, and is only valid before legalization.
    // This node is useful for some pieces of the code generator that want to
    // think about a single node with multiple results, not multiple nodes.
    MERGE_VALUES,

    // Simple integer binary arithmetic operators.
    ADD, SUB, MUL, SDIV, UDIV, SREM, UREM,
    
    // Simple binary floating point operators.
    FADD, FSUB, FMUL, FDIV, FREM,
    
    // Simple abstract vector operators.  Unlike the integer and floating point
    // binary operators, these nodes also take two additional operands:
    // a constant element count, and a value type node indicating the type of
    // the elements.  The order is op0, op1, count, type.  All vector opcodes,
    // including VLOAD, must currently have count and type as their 3rd and 4th
    // arguments.
    VADD, VSUB, VMUL,

    // MULHU/MULHS - Multiply high - Multiply two integers of type iN, producing
    // an unsigned/signed value of type i[2*n], then return the top part.
    MULHU, MULHS,

    // Bitwise operators - logical and, logical or, logical xor, shift left,
    // shift right algebraic (shift in sign bits), shift right logical (shift in
    // zeroes), rotate left, rotate right, and byteswap.
    AND, OR, XOR, SHL, SRA, SRL, ROTL, ROTR, BSWAP,

    // Counting operators
    CTTZ, CTLZ