llvm-6502/include/llvm/CodeGen/SelectionDAG.h
2005-09-30 19:27:01 +00:00

413 lines
17 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 {
TargetLowering &TLI;
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;
// ValueNodes - track SrcValue nodes
std::map<std::pair<const Value*, int>, SDNode*> ValueNodes;
public:
SelectionDAG(TargetLowering &tli, MachineFunction &mf) : TLI(tli), MF(mf) {
EntryNode = Root = getNode(ISD::EntryToken, MVT::Other);
}
~SelectionDAG();
MachineFunction &getMachineFunction() const { return MF; }
const TargetMachine &getTarget() const;
TargetLowering &getTargetLoweringInfo() const { return TLI; }
/// viewGraph - Pop up a ghostview window with the DAG rendered using 'dot'.
///
void viewGraph();
typedef std::vector<SDNode*>::const_iterator allnodes_iterator;
allnodes_iterator allnodes_begin() const { return AllNodes.begin(); }
allnodes_iterator allnodes_end() const { return AllNodes.end(); }
unsigned allnodes_size() const { return AllNodes.size(); }
/// 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; }
/// Combine - This iterates over the nodes in the SelectionDAG, folding
/// certain types of nodes together, or eliminating superfluous nodes. When
/// the AfterLegalize argument is set to 'true', Combine takes care not to
/// generate any nodes that will be illegal on the target.
void Combine(bool AfterLegalize);
/// 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();
/// 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 getTargetConstant(uint64_t Val, MVT::ValueType VT);
SDOperand getConstantFP(double Val, MVT::ValueType VT);
SDOperand getGlobalAddress(const GlobalValue *GV, MVT::ValueType VT);
SDOperand getTargetGlobalAddress(const GlobalValue *GV, MVT::ValueType VT);
SDOperand getFrameIndex(int FI, MVT::ValueType VT);
SDOperand getTargetFrameIndex(int FI, MVT::ValueType VT);
SDOperand getConstantPool(Constant *C, MVT::ValueType VT);
SDOperand getTargetConstantPool(Constant *C, MVT::ValueType VT);
SDOperand getBasicBlock(MachineBasicBlock *MBB);
SDOperand getExternalSymbol(const char *Sym, MVT::ValueType VT);
SDOperand getValueType(MVT::ValueType);
SDOperand getRegister(unsigned Reg, MVT::ValueType VT);
SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N) {
return getNode(ISD::CopyToReg, MVT::Other, Chain,
getRegister(Reg, N.getValueType()), N);
}
// This version of the getCopyToReg method takes an extra operand, which
// indicates that there is potentially an incoming flag value (if Flag is not
// null) and that there should be a flag result.
SDOperand getCopyToReg(SDOperand Chain, unsigned Reg, SDOperand N,
SDOperand Flag) {
std::vector<MVT::ValueType> VTs;
VTs.push_back(MVT::Other);
VTs.push_back(MVT::Flag);
std::vector<SDOperand> Ops;
Ops.push_back(Chain);
Ops.push_back(getRegister(Reg, N.getValueType()));
Ops.push_back(N);
if (Flag.Val) Ops.push_back(Flag);
return getNode(ISD::CopyToReg, VTs, Ops);
}
SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
std::vector<MVT::ValueType> ResultTys;
ResultTys.push_back(VT);
ResultTys.push_back(MVT::Other);
std::vector<SDOperand> Ops;
Ops.push_back(Chain);
Ops.push_back(getRegister(Reg, VT));
return getNode(ISD::CopyFromReg, ResultTys, Ops);
}
// This version of the getCopyFromReg method takes an extra operand, which
// indicates that there is potentially an incoming flag value (if Flag is not
// null) and that there should be a flag result.
SDOperand getCopyFromReg(SDOperand Chain, unsigned Reg, MVT::ValueType VT,
SDOperand Flag) {
std::vector<MVT::ValueType> ResultTys;
ResultTys.push_back(VT);
ResultTys.push_back(MVT::Other);
ResultTys.push_back(MVT::Flag);
std::vector<SDOperand> Ops;
Ops.push_back(Chain);
Ops.push_back(getRegister(Reg, VT));
if (Flag.Val) Ops.push_back(Flag);
return getNode(ISD::CopyFromReg, ResultTys, Ops);
}
SDOperand getImplicitDef(SDOperand Chain, unsigned Reg, MVT::ValueType VT) {
return getNode(ISD::ImplicitDef, MVT::Other, Chain, getRegister(Reg, VT));
}
/// getCall - Note that this destroys the vector of RetVals passed in.
///
SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
SDOperand Callee, bool isTailCall = false) {
SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, Chain,
Callee);
NN->setValueTypes(RetVals);
AllNodes.push_back(NN);
return NN;
}
/// getCall - This is identical to the one above, and should be used for calls
/// where arguments are passed in physical registers. This destroys the
/// RetVals and ArgsInRegs vectors.
SDNode *getCall(std::vector<MVT::ValueType> &RetVals, SDOperand Chain,
SDOperand Callee, std::vector<SDOperand> &ArgsInRegs,
bool isTailCall = false) {
ArgsInRegs.insert(ArgsInRegs.begin(), Callee);
ArgsInRegs.insert(ArgsInRegs.begin(), Chain);
SDNode *NN = new SDNode(isTailCall ? ISD::TAILCALL : ISD::CALL, ArgsInRegs);
NN->setValueTypes(RetVals);
AllNodes.push_back(NN);
return NN;
}
SDOperand getCondCode(ISD::CondCode Cond);
/// getZeroExtendInReg - Return the expression required to zero extend the Op
/// value assuming it was the smaller SrcTy value.
SDOperand getZeroExtendInReg(SDOperand Op, MVT::ValueType SrcTy);
/// 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,
SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N1, SDOperand N2, SDOperand N3, SDOperand N4,
SDOperand N5);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
std::vector<SDOperand> &Children);
SDOperand getNode(unsigned Opcode, std::vector<MVT::ValueType> &ResultTys,
std::vector<SDOperand> &Ops);
/// getSetCC - Helper function to make it easier to build SetCC's if you just
/// have an ISD::CondCode instead of an SDOperand.
///
SDOperand getSetCC(MVT::ValueType VT, SDOperand LHS, SDOperand RHS,
ISD::CondCode Cond) {
return getNode(ISD::SETCC, VT, LHS, RHS, getCondCode(Cond));
}
/// getSelectCC - Helper function to make it easier to build SelectCC's if you
/// just have an ISD::CondCode instead of an SDOperand.
///
SDOperand getSelectCC(SDOperand LHS, SDOperand RHS,
SDOperand True, SDOperand False, ISD::CondCode Cond) {
MVT::ValueType VT = True.getValueType();
return getNode(ISD::SELECT_CC, VT, LHS, RHS, True, False,getCondCode(Cond));
}
/// getBR2Way_CC - Helper function to make it easier to build BRTWOWAY_CC
/// nodes.
///
SDOperand getBR2Way_CC(SDOperand Chain, SDOperand CCNode, SDOperand LHS,
SDOperand RHS, SDOperand True, SDOperand False) {
std::vector<SDOperand> Ops;
Ops.push_back(Chain);
Ops.push_back(CCNode);
Ops.push_back(LHS);
Ops.push_back(RHS);
Ops.push_back(True);
Ops.push_back(False);
return getNode(ISD::BRTWOWAY_CC, MVT::Other, Ops);
}
/// 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,
SDOperand SV);
SDOperand getExtLoad(unsigned Opcode, MVT::ValueType VT, SDOperand Chain,
SDOperand Ptr, SDOperand SV, MVT::ValueType EVT);
// getSrcValue - construct a node to track a Value* through the backend
SDOperand getSrcValue(const Value* I, int offset = 0);
/// SelectNodeTo - These are used for target selectors to *mutate* the
/// specified node to have the specified return type, Target opcode, and
/// operands. Note that target opcodes are stored as
/// ISD::BUILTIN_OP_END+TargetOpcode in the node opcode field.
void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT);
void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
SDOperand Op1);
void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2);
void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2, SDOperand Op3);
void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2, SDOperand Op3, SDOperand Op4);
void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2, SDOperand Op3, SDOperand Op4,
SDOperand Op5);
void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
MVT::ValueType VT2, SDOperand Op1, SDOperand Op2);
void SelectNodeTo(SDNode *N, unsigned TargetOpc, MVT::ValueType VT1,
MVT::ValueType VT2, SDOperand Op1, SDOperand Op2,
SDOperand Op3);
SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
SDOperand Op1) {
return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1);
}
SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2) {
return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2);
}
SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
MVT::ValueType VT2, SDOperand Op1, SDOperand Op2) {
std::vector<MVT::ValueType> ResultTys;
ResultTys.push_back(VT1);
ResultTys.push_back(VT2);
std::vector<SDOperand> Ops;
Ops.push_back(Op1);
Ops.push_back(Op2);
return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
}
SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2, SDOperand Op3) {
return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3);
}
SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2, SDOperand Op3,
SDOperand Op4) {
return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4);
}
SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
SDOperand Op1, SDOperand Op2, SDOperand Op3,
SDOperand Op4, SDOperand Op5) {
return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Op1, Op2, Op3, Op4, Op5);
}
SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT,
std::vector<SDOperand> &Ops) {
return getNode(ISD::BUILTIN_OP_END+Opcode, VT, Ops);
}
SDOperand getTargetNode(unsigned Opcode, MVT::ValueType VT1,
MVT::ValueType VT2, std::vector<SDOperand> &Ops) {
std::vector<MVT::ValueType> ResultTys;
ResultTys.push_back(VT1);
ResultTys.push_back(VT2);
return getNode(ISD::BUILTIN_OP_END+Opcode, ResultTys, Ops);
}
/// ReplaceAllUsesWith - Modify anything using 'From' to use 'To' instead.
/// This can cause recursive merging of nodes in the DAG. Use the first
/// version if 'From' is known to have a single result, use the second
/// if you have two nodes with identical results, use the third otherwise.
///
/// These methods all take an optional vector, which (if not null) is
/// populated with any nodes that are deleted from the SelectionDAG, due to
/// new equivalences that are discovered.
///
void ReplaceAllUsesWith(SDOperand From, SDOperand Op,
std::vector<SDNode*> *Deleted = 0);
void ReplaceAllUsesWith(SDNode *From, SDNode *To,
std::vector<SDNode*> *Deleted = 0);
void ReplaceAllUsesWith(SDNode *From, const std::vector<SDOperand> &To,
std::vector<SDNode*> *Deleted = 0);
/// DeleteNode - Remove the specified node from the system. This node must
/// have no referrers.
void DeleteNode(SDNode *N);
void dump() const;
private:
void RemoveNodeFromCSEMaps(SDNode *N);
SDNode *AddNonLeafNodeToCSEMaps(SDNode *N);
void DeleteNodeIfDead(SDNode *N, void *NodeSet);
void DeleteNodeNotInCSEMaps(SDNode *N);
/// SimplifySetCC - Try to simplify a setcc built with the specified operands
/// and cc. If unable to simplify it, return a null SDOperand.
SDOperand SimplifySetCC(MVT::ValueType VT, SDOperand N1,
SDOperand N2, ISD::CondCode Cond);
/// SimplifySelectCC - Try to simplify a select_cc built with the specified
/// operands and cc. This can be used to simplify both the select_cc node,
/// and a select node whose first operand is a setcc.
SDOperand SimplifySelectCC(SDOperand N1, SDOperand N2, SDOperand N3,
SDOperand N4, ISD::CondCode CC);
// Maps to auto-CSE operations.
std::map<std::pair<unsigned, MVT::ValueType>, SDNode *> NullaryOps;
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<unsigned, MVT::ValueType>, RegisterSDNode*> RegNodes;
std::vector<CondCodeSDNode*> CondCodeNodes;
std::map<std::pair<SDOperand, std::pair<SDOperand, MVT::ValueType> >,
SDNode *> Loads;
std::map<const GlobalValue*, SDNode*> GlobalValues;
std::map<const GlobalValue*, SDNode*> TargetGlobalValues;
std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> Constants;
std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> TargetConstants;
std::map<std::pair<uint64_t, MVT::ValueType>, SDNode*> ConstantFPs;
std::map<int, SDNode*> FrameIndices, TargetFrameIndices;
std::map<Constant *, SDNode*> ConstantPoolIndices;
std::map<Constant *, SDNode*> TargetConstantPoolIndices;
std::map<MachineBasicBlock *, SDNode*> BBNodes;
std::vector<SDNode*> ValueTypeNodes;
std::map<std::string, SDNode*> ExternalSymbols;
std::map<std::pair<unsigned,
std::pair<MVT::ValueType, std::vector<SDOperand> > >,
SDNode*> OneResultNodes;
std::map<std::pair<unsigned,
std::pair<std::vector<MVT::ValueType>,
std::vector<SDOperand> > >,
SDNode*> ArbitraryNodes;
};
template <> struct GraphTraits<SelectionDAG*> : public GraphTraits<SDNode*> {
typedef SelectionDAG::allnodes_iterator nodes_iterator;
static nodes_iterator nodes_begin(SelectionDAG *G) {
return G->allnodes_begin();
}
static nodes_iterator nodes_end(SelectionDAG *G) {
return G->allnodes_end();
}
};
}
#endif