From 1620117f76b99560406ed90197173b72a9b8b66e Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Mon, 15 Nov 2010 06:59:17 +0000 Subject: [PATCH] split the giant encoder loop into two new helper functions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119129 91177308-0d34-0410-b5e6-96231b3b80d8 --- utils/TableGen/CodeEmitterGen.cpp | 234 ++++++++++++++++-------------- utils/TableGen/CodeEmitterGen.h | 7 + 2 files changed, 129 insertions(+), 112 deletions(-) diff --git a/utils/TableGen/CodeEmitterGen.cpp b/utils/TableGen/CodeEmitterGen.cpp index 0f0c4a31d52..f3c9de96bdb 100644 --- a/utils/TableGen/CodeEmitterGen.cpp +++ b/utils/TableGen/CodeEmitterGen.cpp @@ -61,7 +61,7 @@ void CodeEmitterGen::reverseBits(std::vector &Insts) { // If the VarBitInit at position 'bit' matches the specified variable then // return the variable bit position. Otherwise return -1. int CodeEmitterGen::getVariableBit(const std::string &VarName, - BitsInit *BI, int bit) { + BitsInit *BI, int bit) { if (VarBitInit *VBI = dynamic_cast(BI->getBit(bit))) if (VarInit *VI = dynamic_cast(VBI->getVariable())) if (VI->getName() == VarName) @@ -70,6 +70,123 @@ int CodeEmitterGen::getVariableBit(const std::string &VarName, return -1; } +void CodeEmitterGen:: +AddCodeToMergeInOperand(Record *R, BitsInit *BI, const std::string &VarName, + unsigned &NumberedOp, + std::string &Case, CodeGenTarget &Target) { + bool gotOp = false; + CodeGenInstruction &CGI = Target.getInstruction(R); + + for (int bit = BI->getNumBits()-1; bit >= 0; ) { + int varBit = getVariableBit(VarName, BI, bit); + + // If this bit isn't from a variable, skip it. + if (varBit == -1) { + --bit; + continue; + } + + // Figure out the consequtive range of bits covered by this operand, in + // order to generate better encoding code. + int beginInstBit = bit; + int beginVarBit = varBit; + int N = 1; + for (--bit; bit >= 0;) { + varBit = getVariableBit(VarName, BI, bit); + if (varBit == -1 || varBit != (beginVarBit - N)) break; + ++N; + --bit; + } + + if (!gotOp) { + // If the operand matches by name, reference according to that + // operand number. Non-matching operands are assumed to be in + // order. + unsigned OpIdx; + if (CGI.Operands.hasOperandNamed(VarName, OpIdx)) { + // Get the machine operand number for the indicated operand. + OpIdx = CGI.Operands[OpIdx].MIOperandNo; + assert(!CGI.Operands.isFlatOperandNotEmitted(OpIdx) && + "Explicitly used operand also marked as not emitted!"); + } else { + /// If this operand is not supposed to be emitted by the + /// generated emitter, skip it. + while (CGI.Operands.isFlatOperandNotEmitted(NumberedOp)) + ++NumberedOp; + OpIdx = NumberedOp++; + } + std::pair SO =CGI.Operands.getSubOperandNumber(OpIdx); + std::string &EncoderMethodName = CGI.Operands[SO.first].EncoderMethodName; + + // If the source operand has a custom encoder, use it. This will + // get the encoding for all of the suboperands. + if (!EncoderMethodName.empty()) { + // A custom encoder has all of the information for the + // sub-operands, if there are more than one, so only + // query the encoder once per source operand. + if (SO.second == 0) { + Case += " // op: " + VarName + "\n" + + " op = " + EncoderMethodName + "(MI, " + + utostr(OpIdx); + if (MCEmitter) + Case += ", Fixups"; + Case += ");\n"; + } + } else { + Case += " // op: " + VarName + "\n" + + " op = getMachineOpValue(MI, MI.getOperand(" + + utostr(OpIdx) + ")"; + if (MCEmitter) + Case += ", Fixups"; + Case += ");\n"; + } + gotOp = true; + } + + unsigned opMask = ~0U >> (32-N); + int opShift = beginVarBit - N + 1; + opMask <<= opShift; + opShift = beginInstBit - beginVarBit; + + if (opShift > 0) { + Case += " Value |= (op & " + utostr(opMask) + "U) << " + + itostr(opShift) + ";\n"; + } else if (opShift < 0) { + Case += " Value |= (op & " + utostr(opMask) + "U) >> " + + itostr(-opShift) + ";\n"; + } else { + Case += " Value |= op & " + utostr(opMask) + "U;\n"; + } + } +} + + +std::string CodeEmitterGen::getInstructionCase(Record *R, + CodeGenTarget &Target) { + std::string Case; + + BitsInit *BI = R->getValueAsBitsInit("Inst"); + const std::vector &Vals = R->getValues(); + unsigned NumberedOp = 0; + + // Loop over all of the fields in the instruction, determining which are the + // operands to the instruction. + for (unsigned i = 0, e = Vals.size(); i != e; ++i) { + // Ignore fixed fields in the record, we're looking for values like: + // bits<5> RST = { ?, ?, ?, ?, ? }; + if (Vals[i].getPrefix() || Vals[i].getValue()->isComplete()) + continue; + + AddCodeToMergeInOperand(R, BI, Vals[i].getName(), NumberedOp, Case, Target); + } + + std::string PostEmitter = R->getValueAsString("PostEncoderMethod"); + if (!PostEmitter.empty()) + Case += " Value = " + PostEmitter + "(MI, Value);\n"; + + return Case; +} + void CodeEmitterGen::run(raw_ostream &o) { CodeGenTarget Target; std::vector Insts = Records.getAllDerivedDefinitions("Instruction"); @@ -107,12 +224,11 @@ void CodeEmitterGen::run(raw_ostream &o) { BitsInit *BI = R->getValueAsBitsInit("Inst"); - // Start by filling in fixed values... + // Start by filling in fixed values. unsigned Value = 0; for (unsigned i = 0, e = BI->getNumBits(); i != e; ++i) { - if (BitInit *B = dynamic_cast(BI->getBit(e-i-1))) { + if (BitInit *B = dynamic_cast(BI->getBit(e-i-1))) Value |= B->getValue() << (e-i-1); - } } o << " " << Value << "U," << '\t' << "// " << R->getName() << "\n"; } @@ -128,115 +244,9 @@ void CodeEmitterGen::run(raw_ostream &o) { if (R->getValueAsString("Namespace") == "TargetOpcode") continue; const std::string &InstName = R->getName(); - std::string Case(""); + std::string Case = getInstructionCase(R, Target); - BitsInit *BI = R->getValueAsBitsInit("Inst"); - const std::vector &Vals = R->getValues(); - CodeGenInstruction &CGI = Target.getInstruction(R); - - // Loop over all of the fields in the instruction, determining which are the - // operands to the instruction. - unsigned NumberedOp = 0; - for (unsigned i = 0, e = Vals.size(); i != e; ++i) { - // Ignore fixed fields. - if (Vals[i].getPrefix() || Vals[i].getValue()->isComplete()) - continue; - - // Is the operand continuous? If so, we can just mask and OR it in - // instead of doing it bit-by-bit, saving a lot in runtime cost. - const std::string &VarName = Vals[i].getName(); - bool gotOp = false; - - for (int bit = BI->getNumBits()-1; bit >= 0; ) { - int varBit = getVariableBit(VarName, BI, bit); - - // If this bit isn't from a variable, skip it. - if (varBit == -1) { - --bit; - continue; - } - - int beginInstBit = bit; - int beginVarBit = varBit; - int N = 1; - - for (--bit; bit >= 0;) { - varBit = getVariableBit(VarName, BI, bit); - if (varBit == -1 || varBit != (beginVarBit - N)) break; - ++N; - --bit; - } - - if (!gotOp) { - // If the operand matches by name, reference according to that - // operand number. Non-matching operands are assumed to be in - // order. - unsigned OpIdx; - if (CGI.Operands.hasOperandNamed(VarName, OpIdx)) { - // Get the machine operand number for the indicated operand. - OpIdx = CGI.Operands[OpIdx].MIOperandNo; - assert (!CGI.Operands.isFlatOperandNotEmitted(OpIdx) && - "Explicitly used operand also marked as not emitted!"); - } else { - /// If this operand is not supposed to be emitted by the - /// generated emitter, skip it. - while (CGI.Operands.isFlatOperandNotEmitted(NumberedOp)) - ++NumberedOp; - OpIdx = NumberedOp++; - } - std::pair SO = - CGI.Operands.getSubOperandNumber(OpIdx); - std::string &EncoderMethodName = - CGI.Operands[SO.first].EncoderMethodName; - - // If the source operand has a custom encoder, use it. This will - // get the encoding for all of the suboperands. - if (!EncoderMethodName.empty()) { - // A custom encoder has all of the information for the - // sub-operands, if there are more than one, so only - // query the encoder once per source operand. - if (SO.second == 0) { - Case += " // op: " + VarName + "\n" - + " op = " + EncoderMethodName + "(MI, " - + utostr(OpIdx); - if (MCEmitter) - Case += ", Fixups"; - Case += ");\n"; - } - } else { - Case += " // op: " + VarName + "\n" - + " op = getMachineOpValue(MI, MI.getOperand(" - + utostr(OpIdx) + ")"; - if (MCEmitter) - Case += ", Fixups"; - Case += ");\n"; - } - gotOp = true; - } - - unsigned opMask = ~0U >> (32-N); - int opShift = beginVarBit - N + 1; - opMask <<= opShift; - opShift = beginInstBit - beginVarBit; - - if (opShift > 0) { - Case += " Value |= (op & " + utostr(opMask) + "U) << " - + itostr(opShift) + ";\n"; - } else if (opShift < 0) { - Case += " Value |= (op & " + utostr(opMask) + "U) >> " - + itostr(-opShift) + ";\n"; - } else { - Case += " Value |= op & " + utostr(opMask) + "U;\n"; - } - } - } - - std::string PostEmitter = R->getValueAsString("PostEncoderMethod"); - if (!PostEmitter.empty()) - Case += " Value = " + PostEmitter + "(MI, Value);\n"; - - std::vector &InstList = CaseMap[Case]; - InstList.push_back(InstName); + CaseMap[Case].push_back(InstName); } // Emit initial function code diff --git a/utils/TableGen/CodeEmitterGen.h b/utils/TableGen/CodeEmitterGen.h index f0b3229c041..2b877954d4c 100644 --- a/utils/TableGen/CodeEmitterGen.h +++ b/utils/TableGen/CodeEmitterGen.h @@ -23,6 +23,7 @@ namespace llvm { class RecordVal; class BitsInit; +class CodeGenTarget; class CodeEmitterGen : public TableGenBackend { RecordKeeper &Records; @@ -36,6 +37,12 @@ private: void emitGetValueBit(raw_ostream &o, const std::string &Namespace); void reverseBits(std::vector &Insts); int getVariableBit(const std::string &VarName, BitsInit *BI, int bit); + std::string getInstructionCase(Record *R, CodeGenTarget &Target); + void + AddCodeToMergeInOperand(Record *R, BitsInit *BI, const std::string &VarName, + unsigned &NumberedOp, + std::string &Case, CodeGenTarget &Target); + }; } // End llvm namespace