diff options
Diffstat (limited to 'contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp')
| -rw-r--r-- | contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp | 492 |
1 files changed, 300 insertions, 192 deletions
diff --git a/contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp b/contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp index c9dcb01..02b966a 100644 --- a/contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp +++ b/contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp @@ -16,7 +16,7 @@ #include "FixedLenDecoderEmitter.h" #include "CodeGenTarget.h" -#include "Record.h" +#include "llvm/TableGen/Record.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Support/Debug.h" #include "llvm/Support/raw_ostream.h" @@ -84,11 +84,8 @@ static BitsInit &getBitsField(const Record &def, const char *str) { // Forward declaration. class FilterChooser; -// FIXME: Possibly auto-detected? -#define BIT_WIDTH 32 - // Representation of the instruction to work on. -typedef bit_value_t insn_t[BIT_WIDTH]; +typedef std::vector<bit_value_t> insn_t; /// Filter - Filter works with FilterChooser to produce the decoding tree for /// the ISA. @@ -230,7 +227,7 @@ protected: // Array of bit values passed down from our parent. // Set to all BIT_UNFILTERED's for Parent == NULL. - bit_value_t FilterBitValues[BIT_WIDTH]; + std::vector<bit_value_t> FilterBitValues; // Links to the FilterChooser above us in the decoding tree. FilterChooser *Parent; @@ -238,21 +235,29 @@ protected: // Index of the best filter from Filters. int BestIndex; + // Width of instructions + unsigned BitWidth; + + // Parent emitter + const FixedLenDecoderEmitter *Emitter; + public: FilterChooser(const FilterChooser &FC) : AllInstructions(FC.AllInstructions), Opcodes(FC.Opcodes), - Operands(FC.Operands), Filters(FC.Filters), Parent(FC.Parent), - BestIndex(FC.BestIndex) { - memcpy(FilterBitValues, FC.FilterBitValues, sizeof(FilterBitValues)); - } + Operands(FC.Operands), Filters(FC.Filters), + FilterBitValues(FC.FilterBitValues), Parent(FC.Parent), + BestIndex(FC.BestIndex), BitWidth(FC.BitWidth), + Emitter(FC.Emitter) { } FilterChooser(const std::vector<const CodeGenInstruction*> &Insts, const std::vector<unsigned> &IDs, - std::map<unsigned, std::vector<OperandInfo> > &Ops) : + std::map<unsigned, std::vector<OperandInfo> > &Ops, + unsigned BW, + const FixedLenDecoderEmitter *E) : AllInstructions(Insts), Opcodes(IDs), Operands(Ops), Filters(), - Parent(NULL), BestIndex(-1) { - for (unsigned i = 0; i < BIT_WIDTH; ++i) - FilterBitValues[i] = BIT_UNFILTERED; + Parent(NULL), BestIndex(-1), BitWidth(BW), Emitter(E) { + for (unsigned i = 0; i < BitWidth; ++i) + FilterBitValues.push_back(BIT_UNFILTERED); doFilter(); } @@ -260,13 +265,12 @@ public: FilterChooser(const std::vector<const CodeGenInstruction*> &Insts, const std::vector<unsigned> &IDs, std::map<unsigned, std::vector<OperandInfo> > &Ops, - bit_value_t (&ParentFilterBitValues)[BIT_WIDTH], + std::vector<bit_value_t> &ParentFilterBitValues, FilterChooser &parent) : AllInstructions(Insts), Opcodes(IDs), Operands(Ops), - Filters(), Parent(&parent), BestIndex(-1) { - for (unsigned i = 0; i < BIT_WIDTH; ++i) - FilterBitValues[i] = ParentFilterBitValues[i]; - + Filters(), FilterBitValues(ParentFilterBitValues), + Parent(&parent), BestIndex(-1), BitWidth(parent.BitWidth), + Emitter(parent.Emitter) { doFilter(); } @@ -274,15 +278,15 @@ public: bool isTopLevel() { return Parent == NULL; } // Emit the top level typedef and decodeInstruction() function. - void emitTop(raw_ostream &o, unsigned Indentation); + void emitTop(raw_ostream &o, unsigned Indentation, std::string Namespace); protected: // Populates the insn given the uid. void insnWithID(insn_t &Insn, unsigned Opcode) const { BitsInit &Bits = getBitsField(*AllInstructions[Opcode]->TheDef, "Inst"); - for (unsigned i = 0; i < BIT_WIDTH; ++i) - Insn[i] = bitFromBits(Bits, i); + for (unsigned i = 0; i < BitWidth; ++i) + Insn.push_back(bitFromBits(Bits, i)); } // Returns the record name. @@ -300,7 +304,7 @@ protected: /// dumpFilterArray - dumpFilterArray prints out debugging info for the given /// filter array as a series of chars. - void dumpFilterArray(raw_ostream &o, bit_value_t (&filter)[BIT_WIDTH]); + void dumpFilterArray(raw_ostream &o, std::vector<bit_value_t> & filter); /// dumpStack - dumpStack traverses the filter chooser chain and calls /// dumpFilterArray on each filter chooser up to the top level one. @@ -326,6 +330,10 @@ protected: std::vector<unsigned> &EndBits, std::vector<uint64_t> &FieldVals, insn_t &Insn); + // Emits code to check the Predicates member of an instruction are true. + // Returns true if predicate matches were emitted, false otherwise. + bool emitPredicateMatch(raw_ostream &o, unsigned &Indentation,unsigned Opc); + // Emits code to decode the singleton. Return true if we have matched all the // well-known bits. bool emitSingletonDecoder(raw_ostream &o, unsigned &Indentation,unsigned Opc); @@ -333,6 +341,9 @@ 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); @@ -375,7 +386,7 @@ Filter::Filter(const Filter &f) : Filter::Filter(FilterChooser &owner, unsigned startBit, unsigned numBits, bool mixed) : Owner(&owner), StartBit(startBit), NumBits(numBits), Mixed(mixed) { - assert(StartBit + NumBits - 1 < BIT_WIDTH); + assert(StartBit + NumBits - 1 < Owner->BitWidth); NumFiltered = 0; LastOpcFiltered = 0; @@ -427,9 +438,8 @@ Filter::~Filter() { void Filter::recurse() { std::map<uint64_t, std::vector<unsigned> >::const_iterator mapIterator; - bit_value_t BitValueArray[BIT_WIDTH]; // Starts by inheriting our parent filter chooser's filter bit values. - memcpy(BitValueArray, Owner->FilterBitValues, sizeof(BitValueArray)); + std::vector<bit_value_t> BitValueArray(Owner->FilterBitValues); unsigned bitIndex; @@ -493,8 +503,9 @@ void Filter::emit(raw_ostream &o, unsigned &Indentation) { o << StartBit << "} ...\n"; - o.indent(Indentation) << "switch (fieldFromInstruction(insn, " - << StartBit << ", " << NumBits << ")) {\n"; + o.indent(Indentation) << "switch (fieldFromInstruction" << Owner->BitWidth + << "(insn, " << StartBit << ", " + << NumBits << ")) {\n"; std::map<unsigned, FilterChooser*>::iterator filterIterator; @@ -559,68 +570,21 @@ unsigned Filter::usefulness() const { ////////////////////////////////// // Emit the top level typedef and decodeInstruction() function. -void FilterChooser::emitTop(raw_ostream &o, unsigned Indentation) { - switch (BIT_WIDTH) { - case 8: - o.indent(Indentation) << "typedef uint8_t field_t;\n"; - break; - case 16: - o.indent(Indentation) << "typedef uint16_t field_t;\n"; - break; - case 32: - o.indent(Indentation) << "typedef uint32_t field_t;\n"; - break; - case 64: - o.indent(Indentation) << "typedef uint64_t field_t;\n"; - break; - default: - assert(0 && "Unexpected instruction size!"); - } - - o << '\n'; - - o.indent(Indentation) << "static field_t " << - "fieldFromInstruction(field_t insn, unsigned startBit, unsigned numBits)\n"; - - o.indent(Indentation) << "{\n"; - - ++Indentation; ++Indentation; - o.indent(Indentation) << "assert(startBit + numBits <= " << BIT_WIDTH - << " && \"Instruction field out of bounds!\");\n"; - o << '\n'; - o.indent(Indentation) << "field_t fieldMask;\n"; - o << '\n'; - o.indent(Indentation) << "if (numBits == " << BIT_WIDTH << ")\n"; - - ++Indentation; ++Indentation; - o.indent(Indentation) << "fieldMask = (field_t)-1;\n"; - --Indentation; --Indentation; - - o.indent(Indentation) << "else\n"; - - ++Indentation; ++Indentation; - o.indent(Indentation) << "fieldMask = ((1 << numBits) - 1) << startBit;\n"; - --Indentation; --Indentation; - - o << '\n'; - o.indent(Indentation) << "return (insn & fieldMask) >> startBit;\n"; - --Indentation; --Indentation; - - o.indent(Indentation) << "}\n"; - - o << '\n'; - +void FilterChooser::emitTop(raw_ostream &o, unsigned Indentation, + std::string Namespace) { o.indent(Indentation) << - "static bool decodeInstruction(MCInst &MI, field_t insn, " - "uint64_t Address, const void *Decoder) {\n"; - o.indent(Indentation) << " unsigned tmp = 0;\n"; + "static MCDisassembler::DecodeStatus decode" << Namespace << "Instruction" << BitWidth + << "(MCInst &MI, uint" << BitWidth << "_t insn, uint64_t Address, " + << "const void *Decoder, const MCSubtargetInfo &STI) {\n"; + o.indent(Indentation) << " unsigned tmp = 0;\n (void)tmp;\n" << Emitter->Locals << "\n"; + o.indent(Indentation) << " uint64_t Bits = STI.getFeatureBits();\n"; ++Indentation; ++Indentation; // Emits code to decode the instructions. emit(o, Indentation); o << '\n'; - o.indent(Indentation) << "return false;\n"; + o.indent(Indentation) << "return " << Emitter->ReturnFail << ";\n"; --Indentation; --Indentation; o.indent(Indentation) << "}\n"; @@ -651,10 +615,10 @@ bool FilterChooser::fieldFromInsn(uint64_t &Field, insn_t &Insn, /// dumpFilterArray - dumpFilterArray prints out debugging info for the given /// filter array as a series of chars. void FilterChooser::dumpFilterArray(raw_ostream &o, - bit_value_t (&filter)[BIT_WIDTH]) { + std::vector<bit_value_t> &filter) { unsigned bitIndex; - for (bitIndex = BIT_WIDTH; bitIndex > 0; bitIndex--) { + for (bitIndex = BitWidth; bitIndex > 0; bitIndex--) { switch (filter[bitIndex - 1]) { case BIT_UNFILTERED: o << "."; @@ -727,7 +691,7 @@ unsigned FilterChooser::getIslands(std::vector<unsigned> &StartBits, int State = 0; int Val = -1; - for (unsigned i = 0; i < BIT_WIDTH; ++i) { + for (unsigned i = 0; i < BitWidth; ++i) { Val = Value(Insn[i]); bool Filtered = PositionFiltered(i); switch (State) { @@ -761,7 +725,7 @@ unsigned FilterChooser::getIslands(std::vector<unsigned> &StartBits, } // If we are still in Island after the loop, do some housekeeping. if (State == 2) { - EndBits.push_back(BIT_WIDTH - 1); + EndBits.push_back(BitWidth - 1); FieldVals.push_back(FieldVal); ++Num; } @@ -771,6 +735,70 @@ unsigned FilterChooser::getIslands(std::vector<unsigned> &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) << " " << Emitter->GuardPrefix << Decoder + << "(MI, tmp, Address, Decoder)" << Emitter->GuardPostfix << "\n"; + else + o.indent(Indentation) << " MI.addOperand(MCOperand::CreateImm(tmp));\n"; + +} + +static void emitSinglePredicateMatch(raw_ostream &o, StringRef str, + std::string PredicateNamespace) { + if (str[0] == '!') + o << "!(Bits & " << PredicateNamespace << "::" + << str.slice(1,str.size()) << ")"; + else + o << "(Bits & " << PredicateNamespace << "::" << str << ")"; +} + +bool FilterChooser::emitPredicateMatch(raw_ostream &o, unsigned &Indentation, + unsigned Opc) { + ListInit *Predicates = AllInstructions[Opc]->TheDef->getValueAsListInit("Predicates"); + for (unsigned i = 0; i < Predicates->getSize(); ++i) { + Record *Pred = Predicates->getElementAsRecord(i); + if (!Pred->getValue("AssemblerMatcherPredicate")) + continue; + + std::string P = Pred->getValueAsString("AssemblerCondString"); + + if (!P.length()) + continue; + + if (i != 0) + o << " && "; + + StringRef SR(P); + std::pair<StringRef, StringRef> pairs = SR.split(','); + while (pairs.second.size()) { + emitSinglePredicateMatch(o, pairs.first, Emitter->PredicateNamespace); + o << " && "; + pairs = pairs.second.split(','); + } + emitSinglePredicateMatch(o, pairs.first, Emitter->PredicateNamespace); + } + return Predicates->getSize() > 0; +} + // 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, @@ -789,33 +817,27 @@ bool FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation, // If we have matched all the well-known bits, just issue a return. if (Size == 0) { - o.indent(Indentation) << "{\n"; + o.indent(Indentation) << "if ("; + if (!emitPredicateMatch(o, Indentation, Opc)) + o << "1"; + o << ") {\n"; o.indent(Indentation) << " MI.setOpcode(" << Opc << ");\n"; std::vector<OperandInfo>& InsnOperands = Operands[Opc]; for (std::vector<OperandInfo>::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) { - o.indent(Indentation) << " " << I->Decoder - << "(MI, insn, Address, Decoder);\n"; + if (I->numFields() == 0 && I->Decoder.size()) { + o.indent(Indentation) << " " << Emitter->GuardPrefix << I->Decoder + << "(MI, insn, Address, Decoder)" << Emitter->GuardPostfix << "\n"; break; } - o.indent(Indentation) - << " tmp = fieldFromInstruction(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) + o.indent(Indentation) << " return " << Emitter->ReturnOK << "; // " << nameWithID(Opc) << '\n'; - o.indent(Indentation) << "}\n"; + o.indent(Indentation) << "}\n"; // Closing predicate block. return true; } @@ -827,16 +849,21 @@ bool FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation, for (I = Size; I != 0; --I) { o << "Inst{" << EndBits[I-1] << '-' << StartBits[I-1] << "} "; if (I > 1) - o << "&& "; + o << " && "; else o << "for singleton decoding...\n"; } o.indent(Indentation) << "if ("; + if (emitPredicateMatch(o, Indentation, Opc)) { + o << " &&\n"; + o.indent(Indentation+4); + } for (I = Size; I != 0; --I) { NumBits = EndBits[I-1] - StartBits[I-1] + 1; - o << "fieldFromInstruction(insn, " << StartBits[I-1] << ", " << NumBits + o << "fieldFromInstruction" << BitWidth << "(insn, " + << StartBits[I-1] << ", " << NumBits << ") == " << FieldVals[I-1]; if (I > 1) o << " && "; @@ -848,24 +875,15 @@ bool FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation, for (std::vector<OperandInfo>::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) { - o.indent(Indentation) << " " << I->Decoder - << "(MI, insn, Address, Decoder);\n"; + if (I->numFields() == 0 && I->Decoder.size()) { + o.indent(Indentation) << " " << Emitter->GuardPrefix << I->Decoder + << "(MI, insn, Address, Decoder)" << Emitter->GuardPostfix << "\n"; break; } - o.indent(Indentation) - << " tmp = fieldFromInstruction(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) + o.indent(Indentation) << " return " << Emitter->ReturnOK << "; // " << nameWithID(Opc) << '\n'; o.indent(Indentation) << "}\n"; @@ -965,23 +983,23 @@ bool FilterChooser::filterProcessor(bool AllowMixed, bool Greedy) { // (MIXED) ------ . ----> (MIXED) // (FILTERED)---- . ----> (FILTERED) - bitAttr_t bitAttrs[BIT_WIDTH]; + std::vector<bitAttr_t> bitAttrs; // FILTERED bit positions provide no entropy and are not worthy of pursuing. // Filter::recurse() set either BIT_TRUE or BIT_FALSE for each position. - for (BitIndex = 0; BitIndex < BIT_WIDTH; ++BitIndex) + for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex) if (FilterBitValues[BitIndex] == BIT_TRUE || FilterBitValues[BitIndex] == BIT_FALSE) - bitAttrs[BitIndex] = ATTR_FILTERED; + bitAttrs.push_back(ATTR_FILTERED); else - bitAttrs[BitIndex] = ATTR_NONE; + bitAttrs.push_back(ATTR_NONE); for (InsnIndex = 0; InsnIndex < numInstructions; ++InsnIndex) { insn_t insn; insnWithID(insn, Opcodes[InsnIndex]); - for (BitIndex = 0; BitIndex < BIT_WIDTH; ++BitIndex) { + for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex) { switch (bitAttrs[BitIndex]) { case ATTR_NONE: if (insn[BitIndex] == BIT_UNSET) @@ -1027,7 +1045,7 @@ bool FilterChooser::filterProcessor(bool AllowMixed, bool Greedy) { bitAttr_t RA = ATTR_NONE; unsigned StartBit = 0; - for (BitIndex = 0; BitIndex < BIT_WIDTH; BitIndex++) { + for (BitIndex = 0; BitIndex < BitWidth; BitIndex++) { bitAttr_t bitAttr = bitAttrs[BitIndex]; assert(bitAttr != ATTR_NONE && "Bit without attributes"); @@ -1216,8 +1234,9 @@ bool FilterChooser::emit(raw_ostream &o, unsigned &Indentation) { return true; } -bool FixedLenDecoderEmitter::populateInstruction(const CodeGenInstruction &CGI, - unsigned Opc){ +static bool populateInstruction(const CodeGenInstruction &CGI, + unsigned Opc, + std::map<unsigned, std::vector<OperandInfo> >& Operands){ const Record &Def = *CGI.TheDef; // If all the bit positions are not specified; do not decode this instruction. // We are bound to fail! For proper disassembly, the well-known encoding bits @@ -1239,7 +1258,7 @@ bool FixedLenDecoderEmitter::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; } @@ -1259,72 +1278,97 @@ bool FixedLenDecoderEmitter::populateInstruction(const CodeGenInstruction &CGI, for (unsigned i = 0; i < In->getNumArgs(); ++i) InOutOperands.push_back(std::make_pair(In->getArg(i), In->getArgName(i))); + // Search for tied operands, so that we can correctly instantiate + // operands that are not explicitly represented in the encoding. + std::map<std::string, std::string> TiedNames; + for (unsigned i = 0; i < CGI.Operands.size(); ++i) { + int tiedTo = CGI.Operands[i].getTiedRegister(); + if (tiedTo != -1) { + TiedNames[InOutOperands[i].second] = InOutOperands[tiedTo].second; + TiedNames[InOutOperands[tiedTo].second] = InOutOperands[i].second; + } + } + // For each operand, see if we can figure out where it is encoded. for (std::vector<std::pair<Init*, std::string> >::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<TypedInit*>(NI->first); + RecordRecTy *Type = dynamic_cast<RecordRecTy*>(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<StringInit*>(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) { + VarInit *Var = 0; VarBitInit *BI = dynamic_cast<VarBitInit*>(Bits.getBit(bi)); - if (!BI) continue; - - VarInit *Var = dynamic_cast<VarInit*>(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 (BI) + Var = dynamic_cast<VarInit*>(BI->getVariable()); + else + Var = dynamic_cast<VarInit*>(Bits.getBit(bi)); + + if (!Var) { + 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 (Var->getName() != NI->second && + Var->getName() != TiedNames[NI->second]) { + if (Base != ~0U) { + OpInfo.addField(Base, Width, Offset); + Base = ~0U; + Width = 0; + Offset = 0; + } + continue; } - 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<TypedInit*>(NI->first); - RecordRecTy *Type = dynamic_cast<RecordRecTy*>(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; + if (Base == ~0U) { + Base = bi; + Width = 1; + Offset = BI ? BI->getBitNum() : 0; + } else if (BI && BI->getBitNum() != Offset + Width) { + OpInfo.addField(Base, Width, Offset); + Base = bi; + Width = 1; + Offset = BI->getBitNum(); + } else { + ++Width; } - - RecordVal *DecoderString = TypeRecord->getValue("DecoderMethod"); - StringInit *String = DecoderString ? - dynamic_cast<StringInit*>(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; @@ -1351,16 +1395,43 @@ bool FixedLenDecoderEmitter::populateInstruction(const CodeGenInstruction &CGI, return true; } -void FixedLenDecoderEmitter::populateInstructions() { - for (unsigned i = 0, e = NumberedInstructions.size(); i < e; ++i) { - Record *R = NumberedInstructions[i]->TheDef; - if (R->getValueAsString("Namespace") == "TargetOpcode" || - R->getValueAsBit("isPseudo")) - continue; +static void emitHelper(llvm::raw_ostream &o, unsigned BitWidth) { + unsigned Indentation = 0; + std::string WidthStr = "uint" + utostr(BitWidth) + "_t"; - if (populateInstruction(*NumberedInstructions[i], i)) - Opcodes.push_back(i); - } + o << '\n'; + + o.indent(Indentation) << "static " << WidthStr << + " fieldFromInstruction" << BitWidth << + "(" << WidthStr <<" insn, unsigned startBit, unsigned numBits)\n"; + + o.indent(Indentation) << "{\n"; + + ++Indentation; ++Indentation; + o.indent(Indentation) << "assert(startBit + numBits <= " << BitWidth + << " && \"Instruction field out of bounds!\");\n"; + o << '\n'; + o.indent(Indentation) << WidthStr << " fieldMask;\n"; + o << '\n'; + o.indent(Indentation) << "if (numBits == " << BitWidth << ")\n"; + + ++Indentation; ++Indentation; + o.indent(Indentation) << "fieldMask = (" << WidthStr << ")-1;\n"; + --Indentation; --Indentation; + + o.indent(Indentation) << "else\n"; + + ++Indentation; ++Indentation; + o.indent(Indentation) << "fieldMask = ((1 << numBits) - 1) << startBit;\n"; + --Indentation; --Indentation; + + o << '\n'; + o.indent(Indentation) << "return (insn & fieldMask) >> startBit;\n"; + --Indentation; --Indentation; + + o.indent(Indentation) << "}\n"; + + o << '\n'; } // Emits disassembler code for instruction decoding. @@ -1372,10 +1443,47 @@ void FixedLenDecoderEmitter::run(raw_ostream &o) o << '\n'; o << "namespace llvm {\n\n"; + // Parameterize the decoders based on namespace and instruction width. NumberedInstructions = Target.getInstructionsByEnumValue(); - populateInstructions(); - FilterChooser FC(NumberedInstructions, Opcodes, Operands); - FC.emitTop(o, 0); + std::map<std::pair<std::string, unsigned>, + std::vector<unsigned> > OpcMap; + std::map<unsigned, std::vector<OperandInfo> > Operands; + + for (unsigned i = 0; i < NumberedInstructions.size(); ++i) { + const CodeGenInstruction *Inst = NumberedInstructions[i]; + Record *Def = Inst->TheDef; + unsigned Size = Def->getValueAsInt("Size"); + if (Def->getValueAsString("Namespace") == "TargetOpcode" || + Def->getValueAsBit("isPseudo") || + Def->getValueAsBit("isAsmParserOnly") || + Def->getValueAsBit("isCodeGenOnly")) + continue; + + std::string DecoderNamespace = Def->getValueAsString("DecoderNamespace"); + + if (Size) { + if (populateInstruction(*Inst, i, Operands)) { + OpcMap[std::make_pair(DecoderNamespace, Size)].push_back(i); + } + } + } + + std::set<unsigned> Sizes; + for (std::map<std::pair<std::string, unsigned>, + std::vector<unsigned> >::iterator + I = OpcMap.begin(), E = OpcMap.end(); I != E; ++I) { + // If we haven't visited this instruction width before, emit the + // helper method to extract fields. + if (!Sizes.count(I->first.second)) { + emitHelper(o, 8*I->first.second); + Sizes.insert(I->first.second); + } + + // Emit the decoder for this namespace+width combination. + FilterChooser FC(NumberedInstructions, I->second, Operands, + 8*I->first.second, this); + FC.emitTop(o, 0, I->first.first); + } o << "\n} // End llvm namespace \n"; } |
