| ///===- FastISelEmitter.cpp - Generate an instruction selector ------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // 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 "Common/CodeGenDAGPatterns.h" |
| #include "Common/CodeGenInstruction.h" |
| #include "Common/CodeGenRegisters.h" |
| #include "Common/CodeGenTarget.h" |
| #include "Common/InfoByHwMode.h" |
| #include "llvm/ADT/StringSwitch.h" |
| #include "llvm/Support/ErrorHandling.h" |
| #include "llvm/TableGen/Error.h" |
| #include "llvm/TableGen/Record.h" |
| #include "llvm/TableGen/TableGenBackend.h" |
| #include <set> |
| #include <utility> |
| using namespace llvm; |
| |
| /// InstructionMemo - This class holds additional information about an |
| /// instruction needed to emit code for it. |
| /// |
| namespace { |
| struct InstructionMemo { |
| std::string Name; |
| const CodeGenRegisterClass *RC; |
| std::string SubRegNo; |
| std::vector<std::string> PhysRegs; |
| std::string PredicateCheck; |
| |
| InstructionMemo(StringRef Name, const CodeGenRegisterClass *RC, |
| std::string SubRegNo, std::vector<std::string> PhysRegs, |
| std::string PredicateCheck) |
| : Name(Name), RC(RC), SubRegNo(std::move(SubRegNo)), |
| PhysRegs(std::move(PhysRegs)), |
| PredicateCheck(std::move(PredicateCheck)) {} |
| |
| // Make sure we do not copy InstructionMemo. |
| InstructionMemo(const InstructionMemo &Other) = delete; |
| InstructionMemo(InstructionMemo &&Other) = default; |
| }; |
| } // End anonymous namespace |
| |
| /// ImmPredicateSet - This uniques predicates (represented as a string) and |
| /// gives them unique (small) integer ID's that start at 0. |
| namespace { |
| class ImmPredicateSet { |
| DenseMap<TreePattern *, unsigned> ImmIDs; |
| std::vector<TreePredicateFn> PredsByName; |
| |
| public: |
| unsigned getIDFor(TreePredicateFn Pred) { |
| unsigned &Entry = ImmIDs[Pred.getOrigPatFragRecord()]; |
| if (Entry == 0) { |
| PredsByName.push_back(Pred); |
| Entry = PredsByName.size(); |
| } |
| return Entry - 1; |
| } |
| |
| const TreePredicateFn &getPredicate(unsigned i) { |
| assert(i < PredsByName.size()); |
| return PredsByName[i]; |
| } |
| |
| typedef std::vector<TreePredicateFn>::const_iterator iterator; |
| iterator begin() const { return PredsByName.begin(); } |
| iterator end() const { return PredsByName.end(); } |
| }; |
| } // End anonymous namespace |
| |
| /// OperandsSignature - This class holds a description of a list of operand |
| /// types. It has utility methods for emitting text based on the operands. |
| /// |
| namespace { |
| struct OperandsSignature { |
| class OpKind { |
| enum { OK_Reg, OK_FP, OK_Imm, OK_Invalid = -1 }; |
| char Repr; |
| |
| public: |
| OpKind() : Repr(OK_Invalid) {} |
| |
| bool operator<(OpKind RHS) const { return Repr < RHS.Repr; } |
| bool operator==(OpKind RHS) const { return Repr == RHS.Repr; } |
| |
| static OpKind getReg() { |
| OpKind K; |
| K.Repr = OK_Reg; |
| return K; |
| } |
| static OpKind getFP() { |
| OpKind K; |
| K.Repr = OK_FP; |
| return K; |
| } |
| static OpKind getImm(unsigned V) { |
| assert((unsigned)OK_Imm + V < 128 && |
| "Too many integer predicates for the 'Repr' char"); |
| OpKind K; |
| K.Repr = OK_Imm + V; |
| return K; |
| } |
| |
| bool isReg() const { return Repr == OK_Reg; } |
| bool isFP() const { return Repr == OK_FP; } |
| bool isImm() const { return Repr >= OK_Imm; } |
| |
| unsigned getImmCode() const { |
| assert(isImm()); |
| return Repr - OK_Imm; |
| } |
| |
| void printManglingSuffix(raw_ostream &OS, ImmPredicateSet &ImmPredicates, |
| bool StripImmCodes) const { |
| if (isReg()) |
| OS << 'r'; |
| else if (isFP()) |
| OS << 'f'; |
| else { |
| OS << 'i'; |
| if (!StripImmCodes) |
| if (unsigned Code = getImmCode()) |
| OS << "_" << ImmPredicates.getPredicate(Code - 1).getFnName(); |
| } |
| } |
| }; |
| |
| SmallVector<OpKind, 3> Operands; |
| |
| bool operator<(const OperandsSignature &O) const { |
| return Operands < O.Operands; |
| } |
| bool operator==(const OperandsSignature &O) const { |
| return Operands == O.Operands; |
| } |
| |
| bool empty() const { return Operands.empty(); } |
| |
| bool hasAnyImmediateCodes() const { |
| for (unsigned i = 0, e = Operands.size(); i != e; ++i) |
| if (Operands[i].isImm() && Operands[i].getImmCode() != 0) |
| return true; |
| return false; |
| } |
| |
| /// getWithoutImmCodes - Return a copy of this with any immediate codes forced |
| /// to zero. |
| OperandsSignature getWithoutImmCodes() const { |
| OperandsSignature Result; |
| for (unsigned i = 0, e = Operands.size(); i != e; ++i) |
| if (!Operands[i].isImm()) |
| Result.Operands.push_back(Operands[i]); |
| else |
| Result.Operands.push_back(OpKind::getImm(0)); |
| return Result; |
| } |
| |
| void emitImmediatePredicate(raw_ostream &OS, ImmPredicateSet &ImmPredicates) { |
| bool EmittedAnything = false; |
| for (unsigned i = 0, e = Operands.size(); i != e; ++i) { |
| if (!Operands[i].isImm()) |
| continue; |
| |
| unsigned Code = Operands[i].getImmCode(); |
| if (Code == 0) |
| continue; |
| |
| if (EmittedAnything) |
| OS << " &&\n "; |
| |
| TreePredicateFn PredFn = ImmPredicates.getPredicate(Code - 1); |
| |
| // Emit the type check. |
| TreePattern *TP = PredFn.getOrigPatFragRecord(); |
| ValueTypeByHwMode VVT = TP->getTree(0)->getType(0); |
| assert(VVT.isSimple() && |
| "Cannot use variable value types with fast isel"); |
| OS << "VT == " << getEnumName(VVT.getSimple().SimpleTy) << " && "; |
| |
| OS << PredFn.getFnName() << "(imm" << i << ')'; |
| EmittedAnything = true; |
| } |
| } |
| |
| /// 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, ImmPredicateSet &ImmediatePredicates, |
| const CodeGenRegisterClass *OrigDstRC) { |
| if (InstPatNode.isLeaf()) |
| return false; |
| |
| if (InstPatNode.getOperator()->getName() == "imm") { |
| Operands.push_back(OpKind::getImm(0)); |
| return true; |
| } |
| |
| if (InstPatNode.getOperator()->getName() == "fpimm") { |
| Operands.push_back(OpKind::getFP()); |
| return true; |
| } |
| |
| const CodeGenRegisterClass *DstRC = nullptr; |
| |
| for (unsigned i = 0, e = InstPatNode.getNumChildren(); i != e; ++i) { |
| TreePatternNode &Op = InstPatNode.getChild(i); |
| |
| // Handle imm operands specially. |
| if (!Op.isLeaf() && Op.getOperator()->getName() == "imm") { |
| unsigned PredNo = 0; |
| if (!Op.getPredicateCalls().empty()) { |
| TreePredicateFn PredFn = Op.getPredicateCalls()[0].Fn; |
| // If there is more than one predicate weighing in on this operand |
| // then we don't handle it. This doesn't typically happen for |
| // immediates anyway. |
| if (Op.getPredicateCalls().size() > 1 || |
| !PredFn.isImmediatePattern() || PredFn.usesOperands()) |
| return false; |
| // Ignore any instruction with 'FastIselShouldIgnore', these are |
| // not needed and just bloat the fast instruction selector. For |
| // example, X86 doesn't need to generate code to match ADD16ri8 since |
| // ADD16ri will do just fine. |
| const Record *Rec = PredFn.getOrigPatFragRecord()->getRecord(); |
| if (Rec->getValueAsBit("FastIselShouldIgnore")) |
| return false; |
| |
| PredNo = ImmediatePredicates.getIDFor(PredFn) + 1; |
| } |
| |
| Operands.push_back(OpKind::getImm(PredNo)); |
| continue; |
| } |
| |
| // For now, filter out any operand with a predicate. |
| // For now, filter out any operand with multiple values. |
| if (!Op.getPredicateCalls().empty() || Op.getNumTypes() != 1) |
| return false; |
| |
| if (!Op.isLeaf()) { |
| if (Op.getOperator()->getName() == "fpimm") { |
| Operands.push_back(OpKind::getFP()); |
| continue; |
| } |
| // For now, ignore other non-leaf nodes. |
| return false; |
| } |
| |
| assert(Op.hasConcreteType(0) && "Type infererence not done?"); |
| |
| // For now, all the operands must have the same type (if they aren't |
| // immediates). Note that this causes us to reject variable sized shifts |
| // on X86. |
| if (Op.getSimpleType(0) != VT) |
| return false; |
| |
| const DefInit *OpDI = dyn_cast<DefInit>(Op.getLeafValue()); |
| if (!OpDI) |
| return false; |
| const Record *OpLeafRec = OpDI->getDef(); |
| |
| // For now, the only other thing we accept is register operands. |
| const CodeGenRegisterClass *RC = nullptr; |
| if (OpLeafRec->isSubClassOf("RegisterOperand")) |
| OpLeafRec = OpLeafRec->getValueAsDef("RegClass"); |
| if (OpLeafRec->isSubClassOf("RegisterClass")) |
| RC = &Target.getRegisterClass(OpLeafRec); |
| else if (OpLeafRec->isSubClassOf("Register")) |
| RC = Target.getRegBank().getRegClassForRegister(OpLeafRec); |
| else if (OpLeafRec->isSubClassOf("ValueType")) { |
| RC = OrigDstRC; |
| } 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(OpKind::getReg()); |
| } |
| return true; |
| } |
| |
| void PrintParameters(raw_ostream &OS) const { |
| ListSeparator LS; |
| for (unsigned i = 0, e = Operands.size(); i != e; ++i) { |
| OS << LS; |
| if (Operands[i].isReg()) { |
| OS << "unsigned Op" << i; |
| } else if (Operands[i].isImm()) { |
| OS << "uint64_t imm" << i; |
| } else if (Operands[i].isFP()) { |
| OS << "const ConstantFP *f" << i; |
| } else { |
| llvm_unreachable("Unknown operand kind!"); |
| } |
| } |
| } |
| |
| void PrintArguments(raw_ostream &OS, |
| const std::vector<std::string> &PR) const { |
| assert(PR.size() == Operands.size()); |
| ListSeparator LS; |
| for (unsigned i = 0, e = Operands.size(); i != e; ++i) { |
| if (PR[i] != "") |
| // Implicit physical register operand. |
| continue; |
| |
| OS << LS; |
| if (Operands[i].isReg()) { |
| OS << "Op" << i; |
| } else if (Operands[i].isImm()) { |
| OS << "imm" << i; |
| } else if (Operands[i].isFP()) { |
| OS << "f" << i; |
| } else { |
| llvm_unreachable("Unknown operand kind!"); |
| } |
| } |
| } |
| |
| void PrintArguments(raw_ostream &OS) const { |
| ListSeparator LS; |
| for (unsigned i = 0, e = Operands.size(); i != e; ++i) { |
| OS << LS; |
| if (Operands[i].isReg()) { |
| OS << "Op" << i; |
| } else if (Operands[i].isImm()) { |
| OS << "imm" << i; |
| } else if (Operands[i].isFP()) { |
| OS << "f" << i; |
| } else { |
| llvm_unreachable("Unknown operand kind!"); |
| } |
| } |
| } |
| |
| void PrintManglingSuffix(raw_ostream &OS, const std::vector<std::string> &PR, |
| ImmPredicateSet &ImmPredicates, |
| bool StripImmCodes = false) 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; |
| Operands[i].printManglingSuffix(OS, ImmPredicates, StripImmCodes); |
| } |
| } |
| |
| void PrintManglingSuffix(raw_ostream &OS, ImmPredicateSet &ImmPredicates, |
| bool StripImmCodes = false) const { |
| for (unsigned i = 0, e = Operands.size(); i != e; ++i) |
| Operands[i].printManglingSuffix(OS, ImmPredicates, StripImmCodes); |
| } |
| }; |
| } // End anonymous namespace |
| |
| namespace { |
| class FastISelMap { |
| // A multimap is needed instead of a "plain" map because the key is |
| // the instruction's complexity (an int) and they are not unique. |
| typedef std::multimap<int, 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; |
| |
| // This is used to check that there are no duplicate predicates |
| std::set<std::tuple<OperandsSignature, std::string, MVT::SimpleValueType, |
| MVT::SimpleValueType, std::string>> |
| SimplePatternsCheck; |
| |
| std::map<OperandsSignature, std::vector<OperandsSignature>> |
| SignaturesWithConstantForms; |
| |
| StringRef InstNS; |
| ImmPredicateSet ImmediatePredicates; |
| |
| public: |
| explicit FastISelMap(StringRef InstNS); |
| |
| void collectPatterns(const CodeGenDAGPatterns &CGP); |
| void printImmediatePredicates(raw_ostream &OS); |
| void printFunctionDefinitions(raw_ostream &OS); |
| |
| private: |
| void emitInstructionCode(raw_ostream &OS, const OperandsSignature &Operands, |
| const PredMap &PM, const std::string &RetVTName); |
| }; |
| } // End anonymous namespace |
| |
| static std::string getOpcodeName(const Record *Op, |
| const CodeGenDAGPatterns &CGP) { |
| return std::string(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(StringRef instns) : InstNS(instns) {} |
| |
| static std::string PhyRegForNode(TreePatternNode &Op, |
| const CodeGenTarget &Target) { |
| std::string PhysReg; |
| |
| if (!Op.isLeaf()) |
| return PhysReg; |
| |
| const Record *OpLeafRec = cast<DefInit>(Op.getLeafValue())->getDef(); |
| if (!OpLeafRec->isSubClassOf("Register")) |
| return PhysReg; |
| |
| PhysReg += cast<StringInit>(OpLeafRec->getValue("Namespace")->getValue()) |
| ->getValue(); |
| PhysReg += "::"; |
| PhysReg += Target.getRegBank().getReg(OpLeafRec)->getName(); |
| return PhysReg; |
| } |
| |
| void FastISelMap::collectPatterns(const CodeGenDAGPatterns &CGP) { |
| const CodeGenTarget &Target = CGP.getTargetInfo(); |
| |
| // 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; |
| const Record *Op = Dst.getOperator(); |
| if (!Op->isSubClassOf("Instruction")) |
| continue; |
| CodeGenInstruction &II = CGP.getTargetInfo().getInstruction(Op); |
| if (II.Operands.empty()) |
| continue; |
| |
| // Allow instructions to be marked as unavailable for FastISel for |
| // certain cases, i.e. an ISA has two 'and' instruction which differ |
| // by what registers they can use but are otherwise identical for |
| // codegen purposes. |
| if (II.FastISelShouldIgnore) |
| 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 = nullptr; |
| std::string SubRegNo; |
| if (Op->getName() != "EXTRACT_SUBREG") { |
| const Record *Op0Rec = II.Operands[0].Rec; |
| if (Op0Rec->isSubClassOf("RegisterOperand")) |
| Op0Rec = Op0Rec->getValueAsDef("RegClass"); |
| 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; |
| |
| const DefInit *SR = dyn_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.isLeaf()) |
| continue; |
| |
| // Ignore multiple result nodes for now. |
| if (InstPatNode.getNumTypes() > 1) |
| continue; |
| |
| const Record *InstPatOp = InstPatNode.getOperator(); |
| std::string OpcodeName = getOpcodeName(InstPatOp, CGP); |
| MVT::SimpleValueType RetVT = MVT::isVoid; |
| if (InstPatNode.getNumTypes()) |
| RetVT = InstPatNode.getSimpleType(0); |
| MVT::SimpleValueType VT = RetVT; |
| if (InstPatNode.getNumChildren()) { |
| assert(InstPatNode.getChild(0).getNumTypes() == 1); |
| VT = InstPatNode.getChild(0).getSimpleType(0); |
| } |
| |
| // For now, filter out any instructions with predicates. |
| if (!InstPatNode.getPredicateCalls().empty()) |
| continue; |
| |
| // Check all the operands. |
| OperandsSignature Operands; |
| if (!Operands.initialize(InstPatNode, Target, VT, ImmediatePredicates, |
| DstRC)) |
| continue; |
| |
| std::vector<std::string> PhysRegInputs; |
| if (InstPatNode.getOperator()->getName() == "imm" || |
| InstPatNode.getOperator()->getName() == "fpimm") |
| PhysRegInputs.push_back(""); |
| else { |
| // Compute the PhysRegs used by the given pattern, and check that |
| // the mapping from the src to dst patterns is simple. |
| bool FoundNonSimplePattern = false; |
| unsigned DstIndex = 0; |
| for (unsigned i = 0, e = InstPatNode.getNumChildren(); i != e; ++i) { |
| std::string PhysReg = PhyRegForNode(InstPatNode.getChild(i), Target); |
| if (PhysReg.empty()) { |
| if (DstIndex >= Dst.getNumChildren() || |
| Dst.getChild(DstIndex).getName() != |
| InstPatNode.getChild(i).getName()) { |
| FoundNonSimplePattern = true; |
| break; |
| } |
| ++DstIndex; |
| } |
| |
| PhysRegInputs.push_back(PhysReg); |
| } |
| |
| if (Op->getName() != "EXTRACT_SUBREG" && DstIndex < Dst.getNumChildren()) |
| FoundNonSimplePattern = true; |
| |
| if (FoundNonSimplePattern) |
| continue; |
| } |
| |
| // Check if the operands match one of the patterns handled by FastISel. |
| std::string ManglingSuffix; |
| raw_string_ostream SuffixOS(ManglingSuffix); |
| Operands.PrintManglingSuffix(SuffixOS, ImmediatePredicates, true); |
| if (!StringSwitch<bool>(ManglingSuffix) |
| .Cases("", "r", "rr", "ri", "i", "f", true) |
| .Default(false)) |
| continue; |
| |
| // 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, PredicateCheck); |
| |
| int complexity = Pattern.getPatternComplexity(CGP); |
| |
| auto inserted_simple_pattern = SimplePatternsCheck.insert( |
| std::tuple(Operands, OpcodeName, VT, RetVT, PredicateCheck)); |
| if (!inserted_simple_pattern.second) { |
| PrintFatalError(Pattern.getSrcRecord()->getLoc(), |
| "Duplicate predicate in FastISel table!"); |
| } |
| |
| // Note: Instructions with the same complexity will appear in the order |
| // that they are encountered. |
| SimplePatterns[Operands][OpcodeName][VT][RetVT].emplace(complexity, |
| std::move(Memo)); |
| |
| // If any of the operands were immediates with predicates on them, strip |
| // them down to a signature that doesn't have predicates so that we can |
| // associate them with the stripped predicate version. |
| if (Operands.hasAnyImmediateCodes()) { |
| SignaturesWithConstantForms[Operands.getWithoutImmCodes()].push_back( |
| Operands); |
| } |
| } |
| } |
| |
| void FastISelMap::printImmediatePredicates(raw_ostream &OS) { |
| if (ImmediatePredicates.begin() == ImmediatePredicates.end()) |
| return; |
| |
| OS << "\n// FastEmit Immediate Predicate functions.\n"; |
| for (auto ImmediatePredicate : ImmediatePredicates) { |
| OS << "static bool " << ImmediatePredicate.getFnName() |
| << "(int64_t Imm) {\n"; |
| OS << ImmediatePredicate.getImmediatePredicateCode() << "\n}\n"; |
| } |
| |
| OS << "\n\n"; |
| } |
| |
| void FastISelMap::emitInstructionCode(raw_ostream &OS, |
| const OperandsSignature &Operands, |
| const PredMap &PM, |
| const std::string &RetVTName) { |
| // Emit code for each possible instruction. There may be |
| // multiple if there are subtarget concerns. A reverse iterator |
| // is used to produce the ones with highest complexity first. |
| |
| bool OneHadNoPredicate = false; |
| for (PredMap::const_reverse_iterator PI = PM.rbegin(), PE = PM.rend(); |
| PI != PE; ++PI) { |
| const InstructionMemo &Memo = PI->second; |
| std::string PredicateCheck = Memo.PredicateCheck; |
| |
| if (PredicateCheck.empty()) { |
| assert(!OneHadNoPredicate && |
| "Multiple instructions match and more than one had " |
| "no predicate!"); |
| OneHadNoPredicate = true; |
| } else { |
| if (OneHadNoPredicate) { |
| PrintFatalError("Multiple instructions match and one with no " |
| "predicate came before one with a predicate! " |
| "name:" + |
| Memo.Name + " predicate: " + PredicateCheck); |
| } |
| OS << " if (" + PredicateCheck + ") {\n"; |
| OS << " "; |
| } |
| |
| for (unsigned i = 0; i < Memo.PhysRegs.size(); ++i) { |
| if (Memo.PhysRegs[i] != "") |
| OS << " BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, MIMD, " |
| << "TII.get(TargetOpcode::COPY), " << Memo.PhysRegs[i] |
| << ").addReg(Op" << i << ");\n"; |
| } |
| |
| OS << " return fastEmitInst_"; |
| if (Memo.SubRegNo.empty()) { |
| Operands.PrintManglingSuffix(OS, Memo.PhysRegs, ImmediatePredicates, |
| true); |
| OS << "(" << InstNS << "::" << Memo.Name << ", "; |
| OS << "&" << InstNS << "::" << Memo.RC->getName() << "RegClass"; |
| if (!Operands.empty()) |
| OS << ", "; |
| Operands.PrintArguments(OS, Memo.PhysRegs); |
| OS << ");\n"; |
| } else { |
| OS << "extractsubreg(" << RetVTName << ", Op0, " << Memo.SubRegNo |
| << ");\n"; |
| } |
| |
| if (!PredicateCheck.empty()) { |
| OS << " }\n"; |
| } |
| } |
| // Return 0 if all of the possibilities had predicates but none |
| // were satisfied. |
| if (!OneHadNoPredicate) |
| OS << " return 0;\n"; |
| OS << "}\n"; |
| OS << "\n"; |
| } |
| |
| void FastISelMap::printFunctionDefinitions(raw_ostream &OS) { |
| // Now emit code for all the patterns that we collected. |
| for (const auto &SimplePattern : SimplePatterns) { |
| const OperandsSignature &Operands = SimplePattern.first; |
| const OpcodeTypeRetPredMap &OTM = SimplePattern.second; |
| |
| for (const auto &I : OTM) { |
| 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 (const auto &TI : TM) { |
| MVT::SimpleValueType VT = TI.first; |
| const RetPredMap &RM = TI.second; |
| if (RM.size() != 1) { |
| for (const auto &RI : RM) { |
| MVT::SimpleValueType RetVT = RI.first; |
| const PredMap &PM = RI.second; |
| |
| OS << "unsigned fastEmit_" << getLegalCName(Opcode) << "_" |
| << getLegalCName(std::string(getEnumName(VT))) << "_" |
| << getLegalCName(std::string(getEnumName(RetVT))) << "_"; |
| Operands.PrintManglingSuffix(OS, ImmediatePredicates); |
| OS << "("; |
| Operands.PrintParameters(OS); |
| OS << ") {\n"; |
| |
| emitInstructionCode(OS, Operands, PM, |
| std::string(getEnumName(RetVT))); |
| } |
| |
| // Emit one function for the type that demultiplexes on return type. |
| OS << "unsigned fastEmit_" << getLegalCName(Opcode) << "_" |
| << getLegalCName(std::string(getEnumName(VT))) << "_"; |
| Operands.PrintManglingSuffix(OS, ImmediatePredicates); |
| OS << "(MVT RetVT"; |
| if (!Operands.empty()) |
| OS << ", "; |
| Operands.PrintParameters(OS); |
| OS << ") {\nswitch (RetVT.SimpleTy) {\n"; |
| for (const auto &RI : RM) { |
| MVT::SimpleValueType RetVT = RI.first; |
| OS << " case " << getEnumName(RetVT) << ": return fastEmit_" |
| << getLegalCName(Opcode) << "_" |
| << getLegalCName(std::string(getEnumName(VT))) << "_" |
| << getLegalCName(std::string(getEnumName(RetVT))) << "_"; |
| Operands.PrintManglingSuffix(OS, ImmediatePredicates); |
| 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(std::string(getEnumName(VT))) << "_"; |
| Operands.PrintManglingSuffix(OS, ImmediatePredicates); |
| OS << "(MVT RetVT"; |
| if (!Operands.empty()) |
| OS << ", "; |
| Operands.PrintParameters(OS); |
| OS << ") {\n"; |
| |
| OS << " if (RetVT.SimpleTy != " << getEnumName(RM.begin()->first) |
| << ")\n return 0;\n"; |
| |
| const PredMap &PM = RM.begin()->second; |
| |
| emitInstructionCode(OS, Operands, PM, "RetVT"); |
| } |
| } |
| |
| // Emit one function for the opcode that demultiplexes based on the type. |
| OS << "unsigned fastEmit_" << getLegalCName(Opcode) << "_"; |
| Operands.PrintManglingSuffix(OS, ImmediatePredicates); |
| OS << "(MVT VT, MVT RetVT"; |
| if (!Operands.empty()) |
| OS << ", "; |
| Operands.PrintParameters(OS); |
| OS << ") {\n"; |
| OS << " switch (VT.SimpleTy) {\n"; |
| for (const auto &TI : TM) { |
| MVT::SimpleValueType VT = TI.first; |
| std::string TypeName = std::string(getEnumName(VT)); |
| OS << " case " << TypeName << ": return fastEmit_" |
| << getLegalCName(Opcode) << "_" << getLegalCName(TypeName) << "_"; |
| Operands.PrintManglingSuffix(OS, ImmediatePredicates); |
| 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, ImmediatePredicates); |
| OS << "(MVT VT, MVT RetVT, unsigned Opcode"; |
| if (!Operands.empty()) |
| OS << ", "; |
| Operands.PrintParameters(OS); |
| OS << ") "; |
| if (!Operands.hasAnyImmediateCodes()) |
| OS << "override "; |
| OS << "{\n"; |
| |
| // If there are any forms of this signature available that operate on |
| // constrained forms of the immediate (e.g., 32-bit sext immediate in a |
| // 64-bit operand), check them first. |
| |
| std::map<OperandsSignature, std::vector<OperandsSignature>>::iterator MI = |
| SignaturesWithConstantForms.find(Operands); |
| if (MI != SignaturesWithConstantForms.end()) { |
| // Unique any duplicates out of the list. |
| llvm::sort(MI->second); |
| MI->second.erase(llvm::unique(MI->second), MI->second.end()); |
| |
| // Check each in order it was seen. It would be nice to have a good |
| // relative ordering between them, but we're not going for optimality |
| // here. |
| for (unsigned i = 0, e = MI->second.size(); i != e; ++i) { |
| OS << " if ("; |
| MI->second[i].emitImmediatePredicate(OS, ImmediatePredicates); |
| OS << ")\n if (unsigned Reg = fastEmit_"; |
| MI->second[i].PrintManglingSuffix(OS, ImmediatePredicates); |
| OS << "(VT, RetVT, Opcode"; |
| if (!MI->second[i].empty()) |
| OS << ", "; |
| MI->second[i].PrintArguments(OS); |
| OS << "))\n return Reg;\n\n"; |
| } |
| |
| // Done with this, remove it. |
| SignaturesWithConstantForms.erase(MI); |
| } |
| |
| OS << " switch (Opcode) {\n"; |
| for (const auto &I : OTM) { |
| const std::string &Opcode = I.first; |
| |
| OS << " case " << Opcode << ": return fastEmit_" << getLegalCName(Opcode) |
| << "_"; |
| Operands.PrintManglingSuffix(OS, ImmediatePredicates); |
| OS << "(VT, RetVT"; |
| if (!Operands.empty()) |
| OS << ", "; |
| Operands.PrintArguments(OS); |
| OS << ");\n"; |
| } |
| OS << " default: return 0;\n"; |
| OS << " }\n"; |
| OS << "}\n"; |
| OS << "\n"; |
| } |
| |
| // TODO: SignaturesWithConstantForms should be empty here. |
| } |
| |
| static void EmitFastISel(const RecordKeeper &RK, raw_ostream &OS) { |
| const CodeGenDAGPatterns CGP(RK); |
| const CodeGenTarget &Target = CGP.getTargetInfo(); |
| emitSourceFileHeader("\"Fast\" Instruction Selector for the " + |
| Target.getName().str() + " target", |
| OS); |
| |
| // Determine the target's namespace name. |
| StringRef InstNS = Target.getInstNamespace(); |
| assert(!InstNS.empty() && "Can't determine target-specific namespace!"); |
| |
| FastISelMap F(InstNS); |
| F.collectPatterns(CGP); |
| F.printImmediatePredicates(OS); |
| F.printFunctionDefinitions(OS); |
| } |
| |
| static TableGen::Emitter::Opt X("gen-fast-isel", EmitFastISel, |
| "Generate a \"fast\" instruction selector"); |