From d1e38dfb8d53df048b15e5f2ae70d4e1c9ce61bf Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Thu, 28 Jul 2011 21:54:31 +0000 Subject: [PATCH] Enhance the fixed-length decoder emitter to support parsing scattered fields. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136405 91177308-0d34-0410-b5e6-96231b3b80d8 --- utils/TableGen/FixedLenDecoderEmitter.cpp | 167 ++++++++++++---------- utils/TableGen/FixedLenDecoderEmitter.h | 24 +++- 2 files changed, 111 insertions(+), 80 deletions(-) diff --git a/utils/TableGen/FixedLenDecoderEmitter.cpp b/utils/TableGen/FixedLenDecoderEmitter.cpp index 95372ade59c..b062b403a16 100644 --- a/utils/TableGen/FixedLenDecoderEmitter.cpp +++ b/utils/TableGen/FixedLenDecoderEmitter.cpp @@ -331,6 +331,9 @@ protected: // Emits code to decode the singleton, and then to decode the rest. void emitSingletonDecoder(raw_ostream &o, unsigned &Indentation,Filter &Best); + void emitBinaryParser(raw_ostream &o , unsigned &Indentation, + OperandInfo &OpInfo); + // Assign a single filter and run with it. void runSingleFilter(FilterChooser &owner, unsigned startBit, unsigned numBit, bool mixed); @@ -563,7 +566,7 @@ void FilterChooser::emitTop(raw_ostream &o, unsigned Indentation, "static bool decode" << Namespace << "Instruction" << BitWidth << "(MCInst &MI, uint" << BitWidth << "_t insn, uint64_t Address, " << "const void *Decoder) {\n"; - o.indent(Indentation) << " unsigned tmp = 0;\n"; + o.indent(Indentation) << " unsigned tmp = 0;\n(void)tmp;\n"; ++Indentation; ++Indentation; // Emits code to decode the instructions. @@ -721,6 +724,33 @@ unsigned FilterChooser::getIslands(std::vector &StartBits, return Num; } +void FilterChooser::emitBinaryParser(raw_ostream &o, unsigned &Indentation, + OperandInfo &OpInfo) { + std::string &Decoder = OpInfo.Decoder; + + if (OpInfo.numFields() == 1) { + OperandInfo::iterator OI = OpInfo.begin(); + o.indent(Indentation) << " tmp = fieldFromInstruction" << BitWidth + << "(insn, " << OI->Base << ", " << OI->Width + << ");\n"; + } else { + o.indent(Indentation) << " tmp = 0;\n"; + for (OperandInfo::iterator OI = OpInfo.begin(), OE = OpInfo.end(); + OI != OE; ++OI) { + o.indent(Indentation) << " tmp |= (fieldFromInstruction" << BitWidth + << "(insn, " << OI->Base << ", " << OI->Width + << ") << " << OI->Offset << ");\n"; + } + } + + if (Decoder != "") + o.indent(Indentation) << " " << Decoder + << "(MI, tmp, Address, Decoder);\n"; + else + o.indent(Indentation) << " MI.addOperand(MCOperand::CreateImm(tmp));\n"; + +} + // Emits code to decode the singleton. Return true if we have matched all the // well-known bits. bool FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation, @@ -745,22 +775,13 @@ bool FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation, for (std::vector::iterator I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) { // If a custom instruction decoder was specified, use that. - if (I->FieldBase == ~0U && I->FieldLength == ~0U) { + if (I->numFields() == 0 && I->Decoder.size()) { o.indent(Indentation) << " " << I->Decoder << "(MI, insn, Address, Decoder);\n"; break; } - o.indent(Indentation) - << " tmp = fieldFromInstruction" << BitWidth - << "(insn, " << I->FieldBase << ", " << I->FieldLength << ");\n"; - if (I->Decoder != "") { - o.indent(Indentation) << " " << I->Decoder - << "(MI, tmp, Address, Decoder);\n"; - } else { - o.indent(Indentation) - << " MI.addOperand(MCOperand::CreateImm(tmp));\n"; - } + emitBinaryParser(o, Indentation, *I); } o.indent(Indentation) << " return true; // " << nameWithID(Opc) @@ -799,23 +820,13 @@ bool FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation, for (std::vector::iterator I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) { // If a custom instruction decoder was specified, use that. - if (I->FieldBase == ~0U && I->FieldLength == ~0U) { + if (I->numFields() == 0 && I->Decoder.size()) { o.indent(Indentation) << " " << I->Decoder << "(MI, insn, Address, Decoder);\n"; break; } - o.indent(Indentation) - << " tmp = fieldFromInstruction" << BitWidth - << "(insn, " << I->FieldBase - << ", " << I->FieldLength << ");\n"; - if (I->Decoder != "") { - o.indent(Indentation) << " " << I->Decoder - << "(MI, tmp, Address, Decoder);\n"; - } else { - o.indent(Indentation) - << " MI.addOperand(MCOperand::CreateImm(tmp));\n"; - } + emitBinaryParser(o, Indentation, *I); } o.indent(Indentation) << " return true; // " << nameWithID(Opc) << '\n'; @@ -1192,7 +1203,7 @@ static bool populateInstruction(const CodeGenInstruction &CGI, // of trying to auto-generate the decoder. std::string InstDecoder = Def.getValueAsString("DecoderMethod"); if (InstDecoder != "") { - InsnOperands.push_back(OperandInfo(~0U, ~0U, InstDecoder)); + InsnOperands.push_back(OperandInfo(InstDecoder)); Operands[Opc] = InsnOperands; return true; } @@ -1215,69 +1226,73 @@ static bool populateInstruction(const CodeGenInstruction &CGI, // For each operand, see if we can figure out where it is encoded. for (std::vector >::iterator NI = InOutOperands.begin(), NE = InOutOperands.end(); NI != NE; ++NI) { - unsigned PrevBit = ~0; - unsigned Base = ~0; - unsigned PrevPos = ~0; std::string Decoder = ""; + // At this point, we can locate the field, but we need to know how to + // interpret it. As a first step, require the target to provide callbacks + // for decoding register classes. + // FIXME: This need to be extended to handle instructions with custom + // decoder methods, and operands with (simple) MIOperandInfo's. + TypedInit *TI = dynamic_cast(NI->first); + RecordRecTy *Type = dynamic_cast(TI->getType()); + Record *TypeRecord = Type->getRecord(); + bool isReg = false; + if (TypeRecord->isSubClassOf("RegisterOperand")) + TypeRecord = TypeRecord->getValueAsDef("RegClass"); + if (TypeRecord->isSubClassOf("RegisterClass")) { + Decoder = "Decode" + TypeRecord->getName() + "RegisterClass"; + isReg = true; + } + + RecordVal *DecoderString = TypeRecord->getValue("DecoderMethod"); + StringInit *String = DecoderString ? + dynamic_cast(DecoderString->getValue()) : 0; + if (!isReg && String && String->getValue() != "") + Decoder = String->getValue(); + + OperandInfo OpInfo(Decoder); + unsigned Base = ~0U; + unsigned Width = 0; + unsigned Offset = 0; + for (unsigned bi = 0; bi < Bits.getNumBits(); ++bi) { VarBitInit *BI = dynamic_cast(Bits.getBit(bi)); - if (!BI) continue; + if (!BI) { + if (Base != ~0U) { + OpInfo.addField(Base, Width, Offset); + Base = ~0U; + Width = 0; + Offset = 0; + } + continue; + } VarInit *Var = dynamic_cast(BI->getVariable()); assert(Var); - unsigned CurrBit = BI->getBitNum(); - if (Var->getName() != NI->second) continue; - - // Figure out the lowest bit of the value, and the width of the field. - // Deliberately don't try to handle cases where the field is scattered, - // or where not all bits of the the field are explicit. - if (Base == ~0U && PrevBit == ~0U && PrevPos == ~0U) { - if (CurrBit == 0) - Base = bi; - else - continue; + if (Var->getName() != NI->second) { + if (Base != ~0U) { + OpInfo.addField(Base, Width, Offset); + Base = ~0U; + Width = 0; + Offset = 0; + } + continue; } - if ((PrevPos != ~0U && bi-1 != PrevPos) || - (CurrBit != ~0U && CurrBit-1 != PrevBit)) { - PrevBit = ~0; - Base = ~0; - PrevPos = ~0; + if (Base == ~0U) { + Base = bi; + Width = 1; + Offset = BI->getBitNum(); + } else { + ++Width; } - - PrevPos = bi; - PrevBit = CurrBit; - - // At this point, we can locate the field, but we need to know how to - // interpret it. As a first step, require the target to provide callbacks - // for decoding register classes. - // FIXME: This need to be extended to handle instructions with custom - // decoder methods, and operands with (simple) MIOperandInfo's. - TypedInit *TI = dynamic_cast(NI->first); - RecordRecTy *Type = dynamic_cast(TI->getType()); - Record *TypeRecord = Type->getRecord(); - bool isReg = false; - if (TypeRecord->isSubClassOf("RegisterOperand")) - TypeRecord = TypeRecord->getValueAsDef("RegClass"); - if (TypeRecord->isSubClassOf("RegisterClass")) { - Decoder = "Decode" + TypeRecord->getName() + "RegisterClass"; - isReg = true; - } - - RecordVal *DecoderString = TypeRecord->getValue("DecoderMethod"); - StringInit *String = DecoderString ? - dynamic_cast(DecoderString->getValue()) : - 0; - if (!isReg && String && String->getValue() != "") - Decoder = String->getValue(); } - if (Base != ~0U) { - InsnOperands.push_back(OperandInfo(Base, PrevBit+1, Decoder)); - DEBUG(errs() << "ENCODED OPERAND: $" << NI->second << " @ (" - << utostr(Base+PrevBit) << ", " << utostr(Base) << ")\n"); - } + if (Base != ~0U) + OpInfo.addField(Base, Width, Offset); + + if (OpInfo.numFields() > 0) + InsnOperands.push_back(OpInfo); } Operands[Opc] = InsnOperands; diff --git a/utils/TableGen/FixedLenDecoderEmitter.h b/utils/TableGen/FixedLenDecoderEmitter.h index fc3710e6904..300a2f49f80 100644 --- a/utils/TableGen/FixedLenDecoderEmitter.h +++ b/utils/TableGen/FixedLenDecoderEmitter.h @@ -22,13 +22,29 @@ namespace llvm { +struct EncodingField { + unsigned Base, Width, Offset; + EncodingField(unsigned B, unsigned W, unsigned O) + : Base(B), Width(W), Offset(O) { } +}; + struct OperandInfo { - unsigned FieldBase; - unsigned FieldLength; + std::vector Fields; std::string Decoder; - OperandInfo(unsigned FB, unsigned FL, std::string D) - : FieldBase(FB), FieldLength(FL), Decoder(D) { } + OperandInfo(std::string D) + : Decoder(D) { } + + void addField(unsigned Base, unsigned Width, unsigned Offset) { + Fields.push_back(EncodingField(Base, Width, Offset)); + } + + unsigned numFields() { return Fields.size(); } + + typedef std::vector::iterator iterator; + + iterator begin() { return Fields.begin(); } + iterator end() { return Fields.end(); } }; class FixedLenDecoderEmitter : public TableGenBackend {