llvm-6502/include/llvm/CodeGen/SelectionDAG.h
2005-01-07 21:08:55 +00:00

167 lines
6.1 KiB
C++

//===-- llvm/CodeGen/SelectionDAG.h - InstSelection DAG ---------*- 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 SelectionDAG class, and transitively defines the
// SDNode class and subclasses.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SELECTIONDAG_H
#define LLVM_CODEGEN_SELECTIONDAG_H
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include <map>
#include <string> // FIXME remove eventually, turning map into const char* map.
namespace llvm {
class TargetLowering;
class TargetMachine;
class MachineFunction;
/// SelectionDAG class - This is used to represent a portion of an LLVM function
/// in a low-level Data Dependence DAG representation suitable for instruction
/// selection. This DAG is constructed as the first step of instruction
/// selection in order to allow implementation of machine specific optimizations
/// and code simplifications.
///
/// The representation used by the SelectionDAG is a target-independent
/// representation, which has some similarities to the GCC RTL representation,
/// but is significantly more simple, powerful, and is a graph form instead of a
/// linear form.
///
class SelectionDAG {
const TargetMachine &TM;
MachineFunction &MF;
// Root - The root of the entire DAG. EntryNode - The starting token.
SDOperand Root, EntryNode;
// AllNodes - All of the nodes in the DAG
std::vector<SDNode*> AllNodes;
// Maps to auto-CSE operations.
std::map<std::pair<unsigned, std::pair<SDOperand, MVT::ValueType> >,
SDNode *> UnaryOps;
std::map<std::pair<unsigned, std::pair<SDOperand, SDOperand> >,
SDNode *> BinaryOps;
std::map<std::pair<std::pair<SDOperand, SDOperand>, ISD::CondCode>,
SetCCSDNode*> SetCCs;
std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >,
SDNode *> Loads;
std::map<const GlobalValue*, SDNode*> GlobalValues;
std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants;
std::map<std::pair<double, MVT::ValueType>, SDNode*> ConstantFPs;
std::map<int, SDNode*> FrameIndices;
std::map<unsigned, SDNode*> ConstantPoolIndices;
std::map<MachineBasicBlock *, SDNode*> BBNodes;
std::map<std::string, SDNode*> ExternalSymbols;
public:
SelectionDAG(const TargetMachine &tm, MachineFunction &mf) : TM(tm), MF(mf) {
EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
}
~SelectionDAG();
MachineFunction &getMachineFunction() const { return MF; }
const TargetMachine &getTarget() { return TM; }
/// getRoot - Return the root tag of the SelectionDAG.
///
const SDOperand &getRoot() const { return Root; }
/// getEntryNode - Return the token chain corresponding to the entry of the
/// function.
const SDOperand &getEntryNode() const { return EntryNode; }
/// setRoot - Set the current root tag of the SelectionDAG.
///
const SDOperand &setRoot(SDOperand N) { return Root = N; }
/// Legalize - This transforms the SelectionDAG into a SelectionDAG that is
/// compatible with the target instruction selector, as indicated by the
/// TargetLowering object.
///
/// Note that this is an involved process that may invalidate pointers into
/// the graph.
void Legalize(TargetLowering &TLI);
/// RemoveDeadNodes - This method deletes all unreachable nodes in the
/// SelectionDAG, including nodes (like loads) that have uses of their token
/// chain but no other uses and no side effect. If a node is passed in as an
/// argument, it is used as the seed for node deletion.
void RemoveDeadNodes(SDNode *N = 0);
SDOperand getConstant(uint64_t Val, MVT::ValueType VT);
SDOperand getConstantFP(double Val, MVT::ValueType VT);
SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT);
SDOperand getFrameIndex(int FI, MVT::ValueType VT);
SDOperand getConstantPool(unsigned CPIdx, MVT::ValueType VT);
SDOperand getBasicBlock(MachineBasicBlock *MBB);
SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
SDOperand getCopyToReg(SDOperand Chain, SDOperand N, unsigned VReg) {
// Note: these are auto-CSE'd because the caller doesn't make requests that
// could cause duplicates to occur.
SDNode *NN = new CopyRegSDNode(Chain, N, VReg);
AllNodes.push_back(NN);
return SDOperand(NN, 0);
}
SDOperand getCopyFromReg(unsigned VReg, MVT::ValueType VT) {
// Note: These nodes are auto-CSE'd by the caller of this method.
SDNode *NN = new CopyRegSDNode(VReg, VT);
AllNodes.push_back(NN);
return SDOperand(NN, 0);
}
/// getCall - Note that this destroys the vector of RetVals passed in.
///
SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
SDOperand Callee) {
SDNode *NN = new SDNode(ISD::CALL, Chain, Callee);
NN->setValueTypes(RetVals);
AllNodes.push_back(NN);
return NN;
}
SDOperand getSetCC(ISD::CondCode, SDOperand LHS, SDOperand RHS);
/// getNode - Gets or creates the specified node.
///
SDOperand getNode(unsigned Opcode, MVT::ValueType VT);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2, SDOperand N3);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
std::vector<SDOperand> &Children);
/// getLoad - Loads are not normal binary operators: their result type is not
/// determined by their operands, and they produce a value AND a token chain.
///
SDOperand getLoad(MVT::ValueType VT, SDOperand Chain, SDOperand Ptr);
void replaceAllUsesWith(SDOperand Old, SDOperand New) {
assert(Old != New && "RAUW self!");
assert(0 && "Unimplemented!");
}
void dump() const;
private:
void DeleteNodeIfDead(SDNode *N, void *NodeSet);
};
}
#endif