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Diffstat (limited to 'contrib/llvm/utils/TableGen/FastISelEmitter.cpp')
| -rw-r--r-- | contrib/llvm/utils/TableGen/FastISelEmitter.cpp | 653 |
1 files changed, 653 insertions, 0 deletions
diff --git a/contrib/llvm/utils/TableGen/FastISelEmitter.cpp b/contrib/llvm/utils/TableGen/FastISelEmitter.cpp new file mode 100644 index 0000000..f01de1d --- /dev/null +++ b/contrib/llvm/utils/TableGen/FastISelEmitter.cpp @@ -0,0 +1,653 @@ +//===- FastISelEmitter.cpp - Generate an instruction selector -------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This tablegen backend emits code for use by the "fast" instruction +// selection algorithm. See the comments at the top of +// lib/CodeGen/SelectionDAG/FastISel.cpp for background. +// +// This file scans through the target's tablegen instruction-info files +// and extracts instructions with obvious-looking patterns, and it emits +// code to look up these instructions by type and operator. +// +//===----------------------------------------------------------------------===// + +#include "FastISelEmitter.h" +#include "Record.h" +#include "llvm/Support/Debug.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/VectorExtras.h" +using namespace llvm; + +namespace { + +/// InstructionMemo - This class holds additional information about an +/// instruction needed to emit code for it. +/// +struct InstructionMemo { + std::string Name; + const CodeGenRegisterClass *RC; + std::string SubRegNo; + std::vector<std::string>* PhysRegs; +}; + +/// OperandsSignature - This class holds a description of a list of operand +/// types. It has utility methods for emitting text based on the operands. +/// +struct OperandsSignature { + std::vector<std::string> Operands; + + bool operator<(const OperandsSignature &O) const { + return Operands < O.Operands; + } + + bool empty() const { return Operands.empty(); } + + /// initialize - Examine the given pattern and initialize the contents + /// of the Operands array accordingly. Return true if all the operands + /// are supported, false otherwise. + /// + bool initialize(TreePatternNode *InstPatNode, + const CodeGenTarget &Target, + MVT::SimpleValueType VT) { + + if (!InstPatNode->isLeaf()) { + if (InstPatNode->getOperator()->getName() == "imm") { + Operands.push_back("i"); + return true; + } + if (InstPatNode->getOperator()->getName() == "fpimm") { + Operands.push_back("f"); + return true; + } + } + + const CodeGenRegisterClass *DstRC = 0; + + for (unsigned i = 0, e = InstPatNode->getNumChildren(); i != e; ++i) { + TreePatternNode *Op = InstPatNode->getChild(i); + + // For now, filter out any operand with a predicate. + // For now, filter out any operand with multiple values. + if (!Op->getPredicateFns().empty() || + Op->getNumTypes() != 1) + return false; + + assert(Op->hasTypeSet(0) && "Type infererence not done?"); + // For now, all the operands must have the same type. + if (Op->getType(0) != VT) + return false; + + if (!Op->isLeaf()) { + if (Op->getOperator()->getName() == "imm") { + Operands.push_back("i"); + continue; + } + if (Op->getOperator()->getName() == "fpimm") { + Operands.push_back("f"); + continue; + } + // For now, ignore other non-leaf nodes. + return false; + } + DefInit *OpDI = dynamic_cast<DefInit*>(Op->getLeafValue()); + if (!OpDI) + return false; + Record *OpLeafRec = OpDI->getDef(); + // For now, the only other thing we accept is register operands. + + const CodeGenRegisterClass *RC = 0; + if (OpLeafRec->isSubClassOf("RegisterClass")) + RC = &Target.getRegisterClass(OpLeafRec); + else if (OpLeafRec->isSubClassOf("Register")) + RC = Target.getRegisterClassForRegister(OpLeafRec); + else + return false; + + // For now, this needs to be a register class of some sort. + if (!RC) + return false; + + // For now, all the operands must have the same register class or be + // a strict subclass of the destination. + if (DstRC) { + if (DstRC != RC && !DstRC->hasSubClass(RC)) + return false; + } else + DstRC = RC; + Operands.push_back("r"); + } + return true; + } + + void PrintParameters(raw_ostream &OS) const { + for (unsigned i = 0, e = Operands.size(); i != e; ++i) { + if (Operands[i] == "r") { + OS << "unsigned Op" << i << ", bool Op" << i << "IsKill"; + } else if (Operands[i] == "i") { + OS << "uint64_t imm" << i; + } else if (Operands[i] == "f") { + OS << "ConstantFP *f" << i; + } else { + assert("Unknown operand kind!"); + abort(); + } + if (i + 1 != e) + OS << ", "; + } + } + + void PrintArguments(raw_ostream &OS, + const std::vector<std::string>& PR) const { + assert(PR.size() == Operands.size()); + bool PrintedArg = false; + for (unsigned i = 0, e = Operands.size(); i != e; ++i) { + if (PR[i] != "") + // Implicit physical register operand. + continue; + + if (PrintedArg) + OS << ", "; + if (Operands[i] == "r") { + OS << "Op" << i << ", Op" << i << "IsKill"; + PrintedArg = true; + } else if (Operands[i] == "i") { + OS << "imm" << i; + PrintedArg = true; + } else if (Operands[i] == "f") { + OS << "f" << i; + PrintedArg = true; + } else { + assert("Unknown operand kind!"); + abort(); + } + } + } + + void PrintArguments(raw_ostream &OS) const { + for (unsigned i = 0, e = Operands.size(); i != e; ++i) { + if (Operands[i] == "r") { + OS << "Op" << i << ", Op" << i << "IsKill"; + } else if (Operands[i] == "i") { + OS << "imm" << i; + } else if (Operands[i] == "f") { + OS << "f" << i; + } else { + assert("Unknown operand kind!"); + abort(); + } + if (i + 1 != e) + OS << ", "; + } + } + + + void PrintManglingSuffix(raw_ostream &OS, + const std::vector<std::string>& PR) const { + for (unsigned i = 0, e = Operands.size(); i != e; ++i) { + if (PR[i] != "") + // Implicit physical register operand. e.g. Instruction::Mul expect to + // select to a binary op. On x86, mul may take a single operand with + // the other operand being implicit. We must emit something that looks + // like a binary instruction except for the very inner FastEmitInst_* + // call. + continue; + OS << Operands[i]; + } + } + + void PrintManglingSuffix(raw_ostream &OS) const { + for (unsigned i = 0, e = Operands.size(); i != e; ++i) { + OS << Operands[i]; + } + } +}; + +class FastISelMap { + typedef std::map<std::string, InstructionMemo> PredMap; + typedef std::map<MVT::SimpleValueType, PredMap> RetPredMap; + typedef std::map<MVT::SimpleValueType, RetPredMap> TypeRetPredMap; + typedef std::map<std::string, TypeRetPredMap> OpcodeTypeRetPredMap; + typedef std::map<OperandsSignature, OpcodeTypeRetPredMap> + OperandsOpcodeTypeRetPredMap; + + OperandsOpcodeTypeRetPredMap SimplePatterns; + + std::string InstNS; + +public: + explicit FastISelMap(std::string InstNS); + + void CollectPatterns(CodeGenDAGPatterns &CGP); + void PrintFunctionDefinitions(raw_ostream &OS); +}; + +} + +static std::string getOpcodeName(Record *Op, CodeGenDAGPatterns &CGP) { + return CGP.getSDNodeInfo(Op).getEnumName(); +} + +static std::string getLegalCName(std::string OpName) { + std::string::size_type pos = OpName.find("::"); + if (pos != std::string::npos) + OpName.replace(pos, 2, "_"); + return OpName; +} + +FastISelMap::FastISelMap(std::string instns) + : InstNS(instns) { +} + +void FastISelMap::CollectPatterns(CodeGenDAGPatterns &CGP) { + const CodeGenTarget &Target = CGP.getTargetInfo(); + + // Determine the target's namespace name. + InstNS = Target.getInstNamespace() + "::"; + assert(InstNS.size() > 2 && "Can't determine target-specific namespace!"); + + // Scan through all the patterns and record the simple ones. + for (CodeGenDAGPatterns::ptm_iterator I = CGP.ptm_begin(), + E = CGP.ptm_end(); I != E; ++I) { + const PatternToMatch &Pattern = *I; + + // For now, just look at Instructions, so that we don't have to worry + // about emitting multiple instructions for a pattern. + TreePatternNode *Dst = Pattern.getDstPattern(); + if (Dst->isLeaf()) continue; + Record *Op = Dst->getOperator(); + if (!Op->isSubClassOf("Instruction")) + continue; + CodeGenInstruction &II = CGP.getTargetInfo().getInstruction(Op); + if (II.Operands.size() == 0) + continue; + + // For now, ignore multi-instruction patterns. + bool MultiInsts = false; + for (unsigned i = 0, e = Dst->getNumChildren(); i != e; ++i) { + TreePatternNode *ChildOp = Dst->getChild(i); + if (ChildOp->isLeaf()) + continue; + if (ChildOp->getOperator()->isSubClassOf("Instruction")) { + MultiInsts = true; + break; + } + } + if (MultiInsts) + continue; + + // For now, ignore instructions where the first operand is not an + // output register. + const CodeGenRegisterClass *DstRC = 0; + std::string SubRegNo; + if (Op->getName() != "EXTRACT_SUBREG") { + Record *Op0Rec = II.Operands[0].Rec; + if (!Op0Rec->isSubClassOf("RegisterClass")) + continue; + DstRC = &Target.getRegisterClass(Op0Rec); + if (!DstRC) + continue; + } else { + // If this isn't a leaf, then continue since the register classes are + // a bit too complicated for now. + if (!Dst->getChild(1)->isLeaf()) continue; + + DefInit *SR = dynamic_cast<DefInit*>(Dst->getChild(1)->getLeafValue()); + if (SR) + SubRegNo = getQualifiedName(SR->getDef()); + else + SubRegNo = Dst->getChild(1)->getLeafValue()->getAsString(); + } + + // Inspect the pattern. + TreePatternNode *InstPatNode = Pattern.getSrcPattern(); + if (!InstPatNode) continue; + if (InstPatNode->isLeaf()) continue; + + // Ignore multiple result nodes for now. + if (InstPatNode->getNumTypes() > 1) continue; + + Record *InstPatOp = InstPatNode->getOperator(); + std::string OpcodeName = getOpcodeName(InstPatOp, CGP); + MVT::SimpleValueType RetVT = MVT::isVoid; + if (InstPatNode->getNumTypes()) RetVT = InstPatNode->getType(0); + MVT::SimpleValueType VT = RetVT; + if (InstPatNode->getNumChildren()) { + assert(InstPatNode->getChild(0)->getNumTypes() == 1); + VT = InstPatNode->getChild(0)->getType(0); + } + + // For now, filter out instructions which just set a register to + // an Operand or an immediate, like MOV32ri. + if (InstPatOp->isSubClassOf("Operand")) + continue; + + // For now, filter out any instructions with predicates. + if (!InstPatNode->getPredicateFns().empty()) + continue; + + // Check all the operands. + OperandsSignature Operands; + if (!Operands.initialize(InstPatNode, Target, VT)) + continue; + + std::vector<std::string>* PhysRegInputs = new std::vector<std::string>(); + if (!InstPatNode->isLeaf() && + (InstPatNode->getOperator()->getName() == "imm" || + InstPatNode->getOperator()->getName() == "fpimmm")) + PhysRegInputs->push_back(""); + else if (!InstPatNode->isLeaf()) { + for (unsigned i = 0, e = InstPatNode->getNumChildren(); i != e; ++i) { + TreePatternNode *Op = InstPatNode->getChild(i); + if (!Op->isLeaf()) { + PhysRegInputs->push_back(""); + continue; + } + + DefInit *OpDI = dynamic_cast<DefInit*>(Op->getLeafValue()); + Record *OpLeafRec = OpDI->getDef(); + std::string PhysReg; + if (OpLeafRec->isSubClassOf("Register")) { + PhysReg += static_cast<StringInit*>(OpLeafRec->getValue( \ + "Namespace")->getValue())->getValue(); + PhysReg += "::"; + + std::vector<CodeGenRegister> Regs = Target.getRegisters(); + for (unsigned i = 0; i < Regs.size(); ++i) { + if (Regs[i].TheDef == OpLeafRec) { + PhysReg += Regs[i].getName(); + break; + } + } + } + + PhysRegInputs->push_back(PhysReg); + } + } else + PhysRegInputs->push_back(""); + + // Get the predicate that guards this pattern. + std::string PredicateCheck = Pattern.getPredicateCheck(); + + // Ok, we found a pattern that we can handle. Remember it. + InstructionMemo Memo = { + Pattern.getDstPattern()->getOperator()->getName(), + DstRC, + SubRegNo, + PhysRegInputs + }; + if (SimplePatterns[Operands][OpcodeName][VT][RetVT] + .count(PredicateCheck)) + throw TGError(Pattern.getSrcRecord()->getLoc(), "Duplicate record!"); + + SimplePatterns[Operands][OpcodeName][VT][RetVT][PredicateCheck] = Memo; + } +} + +void FastISelMap::PrintFunctionDefinitions(raw_ostream &OS) { + // Now emit code for all the patterns that we collected. + for (OperandsOpcodeTypeRetPredMap::const_iterator OI = SimplePatterns.begin(), + OE = SimplePatterns.end(); OI != OE; ++OI) { + const OperandsSignature &Operands = OI->first; + const OpcodeTypeRetPredMap &OTM = OI->second; + + for (OpcodeTypeRetPredMap::const_iterator I = OTM.begin(), E = OTM.end(); + I != E; ++I) { + const std::string &Opcode = I->first; + const TypeRetPredMap &TM = I->second; + + OS << "// FastEmit functions for " << Opcode << ".\n"; + OS << "\n"; + + // Emit one function for each opcode,type pair. + for (TypeRetPredMap::const_iterator TI = TM.begin(), TE = TM.end(); + TI != TE; ++TI) { + MVT::SimpleValueType VT = TI->first; + const RetPredMap &RM = TI->second; + if (RM.size() != 1) { + for (RetPredMap::const_iterator RI = RM.begin(), RE = RM.end(); + RI != RE; ++RI) { + MVT::SimpleValueType RetVT = RI->first; + const PredMap &PM = RI->second; + bool HasPred = false; + + OS << "unsigned FastEmit_" + << getLegalCName(Opcode) + << "_" << getLegalCName(getName(VT)) + << "_" << getLegalCName(getName(RetVT)) << "_"; + Operands.PrintManglingSuffix(OS); + OS << "("; + Operands.PrintParameters(OS); + OS << ") {\n"; + + // Emit code for each possible instruction. There may be + // multiple if there are subtarget concerns. + for (PredMap::const_iterator PI = PM.begin(), PE = PM.end(); + PI != PE; ++PI) { + std::string PredicateCheck = PI->first; + const InstructionMemo &Memo = PI->second; + + if (PredicateCheck.empty()) { + assert(!HasPred && + "Multiple instructions match, at least one has " + "a predicate and at least one doesn't!"); + } else { + OS << " if (" + PredicateCheck + ") {\n"; + OS << " "; + HasPred = true; + } + + for (unsigned i = 0; i < Memo.PhysRegs->size(); ++i) { + if ((*Memo.PhysRegs)[i] != "") + OS << " BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, " + << "TII.get(TargetOpcode::COPY), " + << (*Memo.PhysRegs)[i] << ").addReg(Op" << i << ");\n"; + } + + OS << " return FastEmitInst_"; + if (Memo.SubRegNo.empty()) { + Operands.PrintManglingSuffix(OS, *Memo.PhysRegs); + OS << "(" << InstNS << Memo.Name << ", "; + OS << InstNS << Memo.RC->getName() << "RegisterClass"; + if (!Operands.empty()) + OS << ", "; + Operands.PrintArguments(OS, *Memo.PhysRegs); + OS << ");\n"; + } else { + OS << "extractsubreg(" << getName(RetVT); + OS << ", Op0, Op0IsKill, "; + OS << Memo.SubRegNo; + OS << ");\n"; + } + + if (HasPred) + OS << " }\n"; + + } + // Return 0 if none of the predicates were satisfied. + if (HasPred) + OS << " return 0;\n"; + OS << "}\n"; + OS << "\n"; + } + + // Emit one function for the type that demultiplexes on return type. + OS << "unsigned FastEmit_" + << getLegalCName(Opcode) << "_" + << getLegalCName(getName(VT)) << "_"; + Operands.PrintManglingSuffix(OS); + OS << "(MVT RetVT"; + if (!Operands.empty()) + OS << ", "; + Operands.PrintParameters(OS); + OS << ") {\nswitch (RetVT.SimpleTy) {\n"; + for (RetPredMap::const_iterator RI = RM.begin(), RE = RM.end(); + RI != RE; ++RI) { + MVT::SimpleValueType RetVT = RI->first; + OS << " case " << getName(RetVT) << ": return FastEmit_" + << getLegalCName(Opcode) << "_" << getLegalCName(getName(VT)) + << "_" << getLegalCName(getName(RetVT)) << "_"; + Operands.PrintManglingSuffix(OS); + OS << "("; + Operands.PrintArguments(OS); + OS << ");\n"; + } + OS << " default: return 0;\n}\n}\n\n"; + + } else { + // Non-variadic return type. + OS << "unsigned FastEmit_" + << getLegalCName(Opcode) << "_" + << getLegalCName(getName(VT)) << "_"; + Operands.PrintManglingSuffix(OS); + OS << "(MVT RetVT"; + if (!Operands.empty()) + OS << ", "; + Operands.PrintParameters(OS); + OS << ") {\n"; + + OS << " if (RetVT.SimpleTy != " << getName(RM.begin()->first) + << ")\n return 0;\n"; + + const PredMap &PM = RM.begin()->second; + bool HasPred = false; + + // Emit code for each possible instruction. There may be + // multiple if there are subtarget concerns. + for (PredMap::const_iterator PI = PM.begin(), PE = PM.end(); PI != PE; + ++PI) { + std::string PredicateCheck = PI->first; + const InstructionMemo &Memo = PI->second; + + if (PredicateCheck.empty()) { + assert(!HasPred && + "Multiple instructions match, at least one has " + "a predicate and at least one doesn't!"); + } else { + OS << " if (" + PredicateCheck + ") {\n"; + OS << " "; + HasPred = true; + } + + for (unsigned i = 0; i < Memo.PhysRegs->size(); ++i) { + if ((*Memo.PhysRegs)[i] != "") + OS << " BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, " + << "TII.get(TargetOpcode::COPY), " + << (*Memo.PhysRegs)[i] << ").addReg(Op" << i << ");\n"; + } + + OS << " return FastEmitInst_"; + + if (Memo.SubRegNo.empty()) { + Operands.PrintManglingSuffix(OS, *Memo.PhysRegs); + OS << "(" << InstNS << Memo.Name << ", "; + OS << InstNS << Memo.RC->getName() << "RegisterClass"; + if (!Operands.empty()) + OS << ", "; + Operands.PrintArguments(OS, *Memo.PhysRegs); + OS << ");\n"; + } else { + OS << "extractsubreg(RetVT, Op0, Op0IsKill, "; + OS << Memo.SubRegNo; + OS << ");\n"; + } + + if (HasPred) + OS << " }\n"; + } + + // Return 0 if none of the predicates were satisfied. + if (HasPred) + OS << " return 0;\n"; + OS << "}\n"; + OS << "\n"; + } + } + + // Emit one function for the opcode that demultiplexes based on the type. + OS << "unsigned FastEmit_" + << getLegalCName(Opcode) << "_"; + Operands.PrintManglingSuffix(OS); + OS << "(MVT VT, MVT RetVT"; + if (!Operands.empty()) + OS << ", "; + Operands.PrintParameters(OS); + OS << ") {\n"; + OS << " switch (VT.SimpleTy) {\n"; + for (TypeRetPredMap::const_iterator TI = TM.begin(), TE = TM.end(); + TI != TE; ++TI) { + MVT::SimpleValueType VT = TI->first; + std::string TypeName = getName(VT); + OS << " case " << TypeName << ": return FastEmit_" + << getLegalCName(Opcode) << "_" << getLegalCName(TypeName) << "_"; + Operands.PrintManglingSuffix(OS); + OS << "(RetVT"; + if (!Operands.empty()) + OS << ", "; + Operands.PrintArguments(OS); + OS << ");\n"; + } + OS << " default: return 0;\n"; + OS << " }\n"; + OS << "}\n"; + OS << "\n"; + } + + OS << "// Top-level FastEmit function.\n"; + OS << "\n"; + + // Emit one function for the operand signature that demultiplexes based + // on opcode and type. + OS << "unsigned FastEmit_"; + Operands.PrintManglingSuffix(OS); + OS << "(MVT VT, MVT RetVT, unsigned Opcode"; + if (!Operands.empty()) + OS << ", "; + Operands.PrintParameters(OS); + OS << ") {\n"; + OS << " switch (Opcode) {\n"; + for (OpcodeTypeRetPredMap::const_iterator I = OTM.begin(), E = OTM.end(); + I != E; ++I) { + const std::string &Opcode = I->first; + + OS << " case " << Opcode << ": return FastEmit_" + << getLegalCName(Opcode) << "_"; + Operands.PrintManglingSuffix(OS); + OS << "(VT, RetVT"; + if (!Operands.empty()) + OS << ", "; + Operands.PrintArguments(OS); + OS << ");\n"; + } + OS << " default: return 0;\n"; + OS << " }\n"; + OS << "}\n"; + OS << "\n"; + } +} + +void FastISelEmitter::run(raw_ostream &OS) { + const CodeGenTarget &Target = CGP.getTargetInfo(); + + // Determine the target's namespace name. + std::string InstNS = Target.getInstNamespace() + "::"; + assert(InstNS.size() > 2 && "Can't determine target-specific namespace!"); + + EmitSourceFileHeader("\"Fast\" Instruction Selector for the " + + Target.getName() + " target", OS); + + FastISelMap F(InstNS); + F.CollectPatterns(CGP); + F.PrintFunctionDefinitions(OS); +} + +FastISelEmitter::FastISelEmitter(RecordKeeper &R) + : Records(R), + CGP(R) { +} + |
