llvm-6502/include/llvm/CodeGen/SelectionDAG.h
Andrew Lenharth 691ef2ba06 Implement count leading zeros (ctlz), count trailing zeros (cttz), and count
population (ctpop).  Generic lowering is implemented, however only promotion
is implemented for SelectionDAG at the moment.

More coming soon.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21676 91177308-0d34-0410-b5e6-96231b3b80d8
2005-05-03 17:19:30 +00:00

252 lines
9.5 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(); }
/// 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();
/// 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 Reg) {
// Note: these are auto-CSE'd because the caller doesn't make requests that
// could cause duplicates to occur.
SDNode *NN = new RegSDNode(ISD::CopyToReg, Chain, N, Reg);
NN->setValueTypes(MVT::Other);
AllNodes.push_back(NN);
return SDOperand(NN, 0);
}
SDOperand getCopyFromReg(unsigned Reg, MVT::ValueType VT, SDOperand Chain) {
// Note: These nodes are auto-CSE'd by the caller of this method.
SDNode *NN = new RegSDNode(ISD::CopyFromReg, Chain, Reg);
NN->setValueTypes(VT, MVT::Other);
AllNodes.push_back(NN);
return SDOperand(NN, 0);
}
SDOperand getImplicitDef(SDOperand Chain, unsigned Reg) {
// Note: These nodes are auto-CSE'd by the caller of this method.
SDNode *NN = new RegSDNode(ISD::ImplicitDef, Chain, Reg);
NN->setValueTypes(MVT::Other);
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;
}
/// 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) {
ArgsInRegs.insert(ArgsInRegs.begin(), Callee);
ArgsInRegs.insert(ArgsInRegs.begin(), Chain);
SDNode *NN = new SDNode(ISD::CALL, ArgsInRegs);
NN->setValueTypes(RetVals);
AllNodes.push_back(NN);
return NN;
}
SDOperand getSetCC(ISD::CondCode, MVT::ValueType VT,
SDOperand LHS, SDOperand RHS);
/// 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,
std::vector<SDOperand> &Children);
// getNode - These versions take an extra value type for extending and
// truncating loads, stores, rounds, extends etc.
SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N1,
SDOperand N2, MVT::ValueType EVT);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT,
SDOperand N, MVT::ValueType EVT);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N1,
SDOperand N2, SDOperand N3, MVT::ValueType EVT);
SDOperand getNode(unsigned Opcode, MVT::ValueType VT, SDOperand N1,
SDOperand N2, SDOperand N3, SDOperand N4, MVT::ValueType EVT);
/// 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);
// getSrcValue - construct a node to track a Value* through the backend
SDOperand getSrcValue(const Value* I, int offset = 0);
void replaceAllUsesWith(SDOperand Old, SDOperand New) {
assert(Old != New && "RAUW self!");
assert(0 && "Unimplemented!");
}
void dump() const;
private:
void DeleteNodeIfDead(SDNode *N, void *NodeSet);
// 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>,
std::pair<ISD::CondCode, MVT::ValueType> >,
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<uint64_t, 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;
struct EVTStruct {
unsigned Opcode;
MVT::ValueType VT, EVT;
std::vector<SDOperand> Ops;
bool operator<(const EVTStruct &RHS) const {
if (Opcode < RHS.Opcode) return true;
if (Opcode > RHS.Opcode) return false;
if (VT < RHS.VT) return true;
if (VT > RHS.VT) return false;
if (EVT < RHS.EVT) return true;
if (EVT > RHS.EVT) return false;
return Ops < RHS.Ops;
}
};
std::map<EVTStruct, SDNode*> MVTSDNodes;
};
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