diff options
Diffstat (limited to 'utils/TableGen/FixedLenDecoderEmitter.cpp')
| -rw-r--r-- | utils/TableGen/FixedLenDecoderEmitter.cpp | 1036 |
1 files changed, 735 insertions, 301 deletions
diff --git a/utils/TableGen/FixedLenDecoderEmitter.cpp b/utils/TableGen/FixedLenDecoderEmitter.cpp index 2cdde55009..e89c393b6a 100644 --- a/utils/TableGen/FixedLenDecoderEmitter.cpp +++ b/utils/TableGen/FixedLenDecoderEmitter.cpp @@ -17,9 +17,15 @@ #include "CodeGenTarget.h" #include "llvm/TableGen/Record.h" #include "llvm/ADT/APInt.h" +#include "llvm/ADT/SmallString.h" #include "llvm/ADT/StringExtras.h" +#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/Twine.h" +#include "llvm/MC/MCFixedLenDisassembler.h" #include "llvm/Support/DataTypes.h" #include "llvm/Support/Debug.h" +#include "llvm/Support/FormattedStream.h" +#include "llvm/Support/LEB128.h" #include "llvm/Support/raw_ostream.h" #include "llvm/TableGen/TableGenBackend.h" @@ -35,9 +41,7 @@ struct EncodingField { EncodingField(unsigned B, unsigned W, unsigned O) : Base(B), Width(W), Offset(O) { } }; -} // End anonymous namespace -namespace { struct OperandInfo { std::vector<EncodingField> Fields; std::string Decoder; @@ -56,10 +60,25 @@ struct OperandInfo { const_iterator begin() const { return Fields.begin(); } const_iterator end() const { return Fields.end(); } }; + +typedef std::vector<uint8_t> DecoderTable; +typedef uint32_t DecoderFixup; +typedef std::vector<DecoderFixup> FixupList; +typedef std::vector<FixupList> FixupScopeList; +typedef SetVector<std::string> PredicateSet; +typedef SetVector<std::string> DecoderSet; +struct DecoderTableInfo { + DecoderTable Table; + FixupScopeList FixupStack; + PredicateSet Predicates; + DecoderSet Decoders; +}; + } // End anonymous namespace namespace { class FixedLenDecoderEmitter { + const std::vector<const CodeGenInstruction*> *NumberedInstructions; public: // Defaults preserved here for documentation, even though they aren't @@ -77,6 +96,17 @@ public: GuardPrefix(GPrefix), GuardPostfix(GPostfix), ReturnOK(ROK), ReturnFail(RFail), Locals(L) {} + // Emit the decoder state machine table. + void emitTable(formatted_raw_ostream &o, DecoderTable &Table, + unsigned Indentation, unsigned BitWidth, + StringRef Namespace) const; + void emitPredicateFunction(formatted_raw_ostream &OS, + PredicateSet &Predicates, + unsigned Indentation) const; + void emitDecoderFunction(formatted_raw_ostream &OS, + DecoderSet &Decoders, + unsigned Indentation) const; + // run - Output the code emitter void run(raw_ostream &o); @@ -120,9 +150,7 @@ static bit_value_t bitFromBits(const BitsInit &bits, unsigned index) { } // Prints the bit value for each position. static void dumpBits(raw_ostream &o, const BitsInit &bits) { - unsigned index; - - for (index = bits.getNumBits(); index > 0; index--) { + for (unsigned index = bits.getNumBits(); index > 0; --index) { switch (bitFromBits(bits, index - 1)) { case BIT_TRUE: o << "1"; @@ -238,8 +266,9 @@ public: // match the remaining undecoded encoding bits against the singleton. void recurse(); - // Emit code to decode instructions given a segment or segments of bits. - void emit(raw_ostream &o, unsigned &Indentation) const; + // Emit table entries to decode instructions given a segment or segments of + // bits. + void emitTableEntry(DecoderTableInfo &TableInfo) const; // Returns the number of fanout produced by the filter. More fanout implies // the filter distinguishes more categories of instructions. @@ -338,12 +367,7 @@ public: doFilter(); } - // The top level filter chooser has NULL as its parent. - bool isTopLevel() const { return Parent == NULL; } - - // Emit the top level typedef and decodeInstruction() function. - void emitTop(raw_ostream &o, unsigned Indentation, - const std::string &Namespace) const; + unsigned getBitWidth() const { return BitWidth; } protected: // Populates the insn given the uid. @@ -414,21 +438,28 @@ protected: bool emitPredicateMatch(raw_ostream &o, unsigned &Indentation, unsigned Opc) const; - void emitSoftFailCheck(raw_ostream &o, unsigned Indentation, - unsigned Opc) const; + bool doesOpcodeNeedPredicate(unsigned Opc) const; + unsigned getPredicateIndex(DecoderTableInfo &TableInfo, StringRef P) const; + void emitPredicateTableEntry(DecoderTableInfo &TableInfo, + unsigned Opc) const; + + void emitSoftFailTableEntry(DecoderTableInfo &TableInfo, + unsigned Opc) const; - // 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) const; + // Emits table entries to decode the singleton. + void emitSingletonTableEntry(DecoderTableInfo &TableInfo, + unsigned Opc) const; // Emits code to decode the singleton, and then to decode the rest. - void emitSingletonDecoder(raw_ostream &o, unsigned &Indentation, - const Filter &Best) const; + void emitSingletonTableEntry(DecoderTableInfo &TableInfo, + const Filter &Best) const; - void emitBinaryParser(raw_ostream &o , unsigned &Indentation, + void emitBinaryParser(raw_ostream &o, unsigned &Indentation, const OperandInfo &OpInfo) const; + void emitDecoder(raw_ostream &OS, unsigned Indentation, unsigned Opc) const; + unsigned getDecoderIndex(DecoderSet &Decoders, unsigned Opc) const; + // Assign a single filter and run with it. void runSingleFilter(unsigned startBit, unsigned numBit, bool mixed); @@ -447,10 +478,10 @@ protected: // dump the conflict set to the standard error. void doFilter(); - // Emits code to decode our share of instructions. Returns true if the - // emitted code causes a return, which occurs if we know how to decode - // the instruction at this level or the instruction is not decodeable. - bool emit(raw_ostream &o, unsigned &Indentation) const; +public: + // emitTableEntries - Emit state machine entries to decode our share of + // instructions. + void emitTableEntries(DecoderTableInfo &TableInfo) const; }; } // End anonymous namespace @@ -524,11 +555,9 @@ void Filter::recurse() { // Starts by inheriting our parent filter chooser's filter bit values. std::vector<bit_value_t> BitValueArray(Owner->FilterBitValues); - unsigned bitIndex; - if (VariableInstructions.size()) { // Conservatively marks each segment position as BIT_UNSET. - for (bitIndex = 0; bitIndex < NumBits; bitIndex++) + for (unsigned bitIndex = 0; bitIndex < NumBits; ++bitIndex) BitValueArray[StartBit + bitIndex] = BIT_UNSET; // Delegates to an inferior filter chooser for further processing on this @@ -544,7 +573,7 @@ void Filter::recurse() { } // No need to recurse for a singleton filtered instruction. - // See also Filter::emit(). + // See also Filter::emit*(). if (getNumFiltered() == 1) { //Owner->SingletonExists(LastOpcFiltered); assert(FilterChooserMap.size() == 1); @@ -557,7 +586,7 @@ void Filter::recurse() { mapIterator++) { // Marks all the segment positions with either BIT_TRUE or BIT_FALSE. - for (bitIndex = 0; bitIndex < NumBits; bitIndex++) { + for (unsigned bitIndex = 0; bitIndex < NumBits; ++bitIndex) { if (mapIterator->first & (1ULL << bitIndex)) BitValueArray[StartBit + bitIndex] = BIT_TRUE; else @@ -577,64 +606,100 @@ void Filter::recurse() { } } -// Emit code to decode instructions given a segment or segments of bits. -void Filter::emit(raw_ostream &o, unsigned &Indentation) const { - o.indent(Indentation) << "// Check Inst{"; - - if (NumBits > 1) - o << (StartBit + NumBits - 1) << '-'; +static void resolveTableFixups(DecoderTable &Table, const FixupList &Fixups, + uint32_t DestIdx) { + // Any NumToSkip fixups in the current scope can resolve to the + // current location. + for (FixupList::const_reverse_iterator I = Fixups.rbegin(), + E = Fixups.rend(); + I != E; ++I) { + // Calculate the distance from the byte following the fixup entry byte + // to the destination. The Target is calculated from after the 16-bit + // NumToSkip entry itself, so subtract two from the displacement here + // to account for that. + uint32_t FixupIdx = *I; + uint32_t Delta = DestIdx - FixupIdx - 2; + // Our NumToSkip entries are 16-bits. Make sure our table isn't too + // big. + assert(Delta < 65536U && "disassembler decoding table too large!"); + Table[FixupIdx] = (uint8_t)Delta; + Table[FixupIdx + 1] = (uint8_t)(Delta >> 8); + } +} - o << StartBit << "} ...\n"; +// Emit table entries to decode instructions given a segment or segments +// of bits. +void Filter::emitTableEntry(DecoderTableInfo &TableInfo) const { + TableInfo.Table.push_back(MCD::OPC_ExtractField); + TableInfo.Table.push_back(StartBit); + TableInfo.Table.push_back(NumBits); - o.indent(Indentation) << "switch (fieldFromInstruction" << Owner->BitWidth - << "(insn, " << StartBit << ", " - << NumBits << ")) {\n"; + // A new filter entry begins a new scope for fixup resolution. + TableInfo.FixupStack.push_back(FixupList()); std::map<unsigned, const FilterChooser*>::const_iterator filterIterator; - bool DefaultCase = false; + DecoderTable &Table = TableInfo.Table; + + size_t PrevFilter = 0; + bool HasFallthrough = false; for (filterIterator = FilterChooserMap.begin(); filterIterator != FilterChooserMap.end(); filterIterator++) { - // Field value -1 implies a non-empty set of variable instructions. // See also recurse(). if (filterIterator->first == (unsigned)-1) { - DefaultCase = true; - - o.indent(Indentation) << "default:\n"; - o.indent(Indentation) << " break; // fallthrough\n"; - - // Closing curly brace for the switch statement. - // This is unconventional because we want the default processing to be - // performed for the fallthrough cases as well, i.e., when the "cases" - // did not prove a decoded instruction. - o.indent(Indentation) << "}\n"; - - } else - o.indent(Indentation) << "case " << filterIterator->first << ":\n"; + HasFallthrough = true; + + // Each scope should always have at least one filter value to check + // for. + assert(PrevFilter != 0 && "empty filter set!"); + FixupList &CurScope = TableInfo.FixupStack.back(); + // Resolve any NumToSkip fixups in the current scope. + resolveTableFixups(Table, CurScope, Table.size()); + CurScope.clear(); + PrevFilter = 0; // Don't re-process the filter's fallthrough. + } else { + Table.push_back(MCD::OPC_FilterValue); + // Encode and emit the value to filter against. + uint8_t Buffer[8]; + unsigned Len = encodeULEB128(filterIterator->first, Buffer); + Table.insert(Table.end(), Buffer, Buffer + Len); + // Reserve space for the NumToSkip entry. We'll backpatch the value + // later. + PrevFilter = Table.size(); + Table.push_back(0); + Table.push_back(0); + } // We arrive at a category of instructions with the same segment value. // Now delegate to the sub filter chooser for further decodings. // The case may fallthrough, which happens if the remaining well-known // encoding bits do not match exactly. - if (!DefaultCase) { ++Indentation; ++Indentation; } - - filterIterator->second->emit(o, Indentation); - // For top level default case, there's no need for a break statement. - if (Owner->isTopLevel() && DefaultCase) - break; - - o.indent(Indentation) << "break;\n"; - - if (!DefaultCase) { --Indentation; --Indentation; } + filterIterator->second->emitTableEntries(TableInfo); + + // Now that we've emitted the body of the handler, update the NumToSkip + // of the filter itself to be able to skip forward when false. Subtract + // two as to account for the width of the NumToSkip field itself. + if (PrevFilter) { + uint32_t NumToSkip = Table.size() - PrevFilter - 2; + assert(NumToSkip < 65536U && "disassembler decoding table too large!"); + Table[PrevFilter] = (uint8_t)NumToSkip; + Table[PrevFilter + 1] = (uint8_t)(NumToSkip >> 8); + } } - // If there is no default case, we still need to supply a closing brace. - if (!DefaultCase) { - // Closing curly brace for the switch statement. - o.indent(Indentation) << "}\n"; - } + // Any remaining unresolved fixups bubble up to the parent fixup scope. + assert(TableInfo.FixupStack.size() > 1 && "fixup stack underflow!"); + FixupScopeList::iterator Source = TableInfo.FixupStack.end() - 1; + FixupScopeList::iterator Dest = Source - 1; + Dest->insert(Dest->end(), Source->begin(), Source->end()); + TableInfo.FixupStack.pop_back(); + + // If there is no fallthrough, then the final filter should get fixed + // up according to the enclosing scope rather than the current position. + if (!HasFallthrough) + TableInfo.FixupStack.back().push_back(PrevFilter); } // Returns the number of fanout produced by the filter. More fanout implies @@ -652,31 +717,205 @@ unsigned Filter::usefulness() const { // // ////////////////////////////////// -// Emit the top level typedef and decodeInstruction() function. -void FilterChooser::emitTop(raw_ostream &o, unsigned Indentation, - const std::string &Namespace) const { - o.indent(Indentation) << - "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"; - o.indent(Indentation) << " (void)tmp;\n"; - o.indent(Indentation) << Emitter->Locals << "\n"; - o.indent(Indentation) << " uint64_t Bits = STI.getFeatureBits();\n"; - o.indent(Indentation) << " (void)Bits;\n"; - - ++Indentation; ++Indentation; - // Emits code to decode the instructions. - emit(o, Indentation); - - o << '\n'; - o.indent(Indentation) << "return " << Emitter->ReturnFail << ";\n"; - --Indentation; --Indentation; - - o.indent(Indentation) << "}\n"; - - o << '\n'; +// Emit the decoder state machine table. +void FixedLenDecoderEmitter::emitTable(formatted_raw_ostream &OS, + DecoderTable &Table, + unsigned Indentation, + unsigned BitWidth, + StringRef Namespace) const { + OS.indent(Indentation) << "static const uint8_t DecoderTable" << Namespace + << BitWidth << "[] = {\n"; + + Indentation += 2; + + // FIXME: We may be able to use the NumToSkip values to recover + // appropriate indentation levels. + DecoderTable::const_iterator I = Table.begin(); + DecoderTable::const_iterator E = Table.end(); + while (I != E) { + assert (I < E && "incomplete decode table entry!"); + + uint64_t Pos = I - Table.begin(); + OS << "/* " << Pos << " */"; + OS.PadToColumn(12); + + switch (*I) { + default: + throw "invalid decode table opcode"; + case MCD::OPC_ExtractField: { + ++I; + unsigned Start = *I++; + unsigned Len = *I++; + OS.indent(Indentation) << "MCD::OPC_ExtractField, " << Start << ", " + << Len << ", // Inst{"; + if (Len > 1) + OS << (Start + Len - 1) << "-"; + OS << Start << "} ...\n"; + break; + } + case MCD::OPC_FilterValue: { + ++I; + OS.indent(Indentation) << "MCD::OPC_FilterValue, "; + // The filter value is ULEB128 encoded. + while (*I >= 128) + OS << utostr(*I++) << ", "; + OS << utostr(*I++) << ", "; + + // 16-bit numtoskip value. + uint8_t Byte = *I++; + uint32_t NumToSkip = Byte; + OS << utostr(Byte) << ", "; + Byte = *I++; + OS << utostr(Byte) << ", "; + NumToSkip |= Byte << 8; + OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n"; + break; + } + case MCD::OPC_CheckField: { + ++I; + unsigned Start = *I++; + unsigned Len = *I++; + OS.indent(Indentation) << "MCD::OPC_CheckField, " << Start << ", " + << Len << ", ";// << Val << ", " << NumToSkip << ",\n"; + // ULEB128 encoded field value. + for (; *I >= 128; ++I) + OS << utostr(*I) << ", "; + OS << utostr(*I++) << ", "; + // 16-bit numtoskip value. + uint8_t Byte = *I++; + uint32_t NumToSkip = Byte; + OS << utostr(Byte) << ", "; + Byte = *I++; + OS << utostr(Byte) << ", "; + NumToSkip |= Byte << 8; + OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n"; + break; + } + case MCD::OPC_CheckPredicate: { + ++I; + OS.indent(Indentation) << "MCD::OPC_CheckPredicate, "; + for (; *I >= 128; ++I) + OS << utostr(*I) << ", "; + OS << utostr(*I++) << ", "; + + // 16-bit numtoskip value. + uint8_t Byte = *I++; + uint32_t NumToSkip = Byte; + OS << utostr(Byte) << ", "; + Byte = *I++; + OS << utostr(Byte) << ", "; + NumToSkip |= Byte << 8; + OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n"; + break; + } + case MCD::OPC_Decode: { + ++I; + // Extract the ULEB128 encoded Opcode to a buffer. + uint8_t Buffer[8], *p = Buffer; + while ((*p++ = *I++) >= 128) + assert((p - Buffer) <= (ptrdiff_t)sizeof(Buffer) + && "ULEB128 value too large!"); + // Decode the Opcode value. + unsigned Opc = decodeULEB128(Buffer); + OS.indent(Indentation) << "MCD::OPC_Decode, "; + for (p = Buffer; *p >= 128; ++p) + OS << utostr(*p) << ", "; + OS << utostr(*p) << ", "; + + // Decoder index. + for (; *I >= 128; ++I) + OS << utostr(*I) << ", "; + OS << utostr(*I++) << ", "; + + OS << "// Opcode: " + << NumberedInstructions->at(Opc)->TheDef->getName() << "\n"; + break; + } + case MCD::OPC_SoftFail: { + ++I; + OS.indent(Indentation) << "MCD::OPC_SoftFail"; + // Positive mask + uint64_t Value = 0; + unsigned Shift = 0; + do { + OS << ", " << utostr(*I); + Value += (*I & 0x7f) << Shift; + Shift += 7; + } while (*I++ >= 128); + if (Value > 127) + OS << " /* 0x" << utohexstr(Value) << " */"; + // Negative mask + Value = 0; + Shift = 0; + do { + OS << ", " << utostr(*I); + Value += (*I & 0x7f) << Shift; + Shift += 7; + } while (*I++ >= 128); + if (Value > 127) + OS << " /* 0x" << utohexstr(Value) << " */"; + OS << ",\n"; + break; + } + case MCD::OPC_Fail: { + ++I; + OS.indent(Indentation) << "MCD::OPC_Fail,\n"; + break; + } + } + } + OS.indent(Indentation) << "0\n"; + + Indentation -= 2; + + OS.indent(Indentation) << "};\n\n"; +} + +void FixedLenDecoderEmitter:: +emitPredicateFunction(formatted_raw_ostream &OS, PredicateSet &Predicates, + unsigned Indentation) const { + // The predicate function is just a big switch statement based on the + // input predicate index. + OS.indent(Indentation) << "static bool checkDecoderPredicate(unsigned Idx, " + << "uint64_t Bits) {\n"; + Indentation += 2; + OS.indent(Indentation) << "switch (Idx) {\n"; + OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n"; + unsigned Index = 0; + for (PredicateSet::const_iterator I = Predicates.begin(), E = Predicates.end(); + I != E; ++I, ++Index) { + OS.indent(Indentation) << "case " << Index << ":\n"; + OS.indent(Indentation+2) << "return (" << *I << ");\n"; + } + OS.indent(Indentation) << "}\n"; + Indentation -= 2; + OS.indent(Indentation) << "}\n\n"; +} + +void FixedLenDecoderEmitter:: +emitDecoderFunction(formatted_raw_ostream &OS, DecoderSet &Decoders, + unsigned Indentation) const { + // The decoder function is just a big switch statement based on the + // input decoder index. + OS.indent(Indentation) << "template<typename InsnType>\n"; + OS.indent(Indentation) << "static DecodeStatus decodeToMCInst(DecodeStatus S," + << " unsigned Idx, InsnType insn, MCInst &MI,\n"; + OS.indent(Indentation) << " uint64_t " + << "Address, const void *Decoder) {\n"; + Indentation += 2; + OS.indent(Indentation) << "InsnType tmp;\n"; + OS.indent(Indentation) << "switch (Idx) {\n"; + OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n"; + unsigned Index = 0; + for (DecoderSet::const_iterator I = Decoders.begin(), E = Decoders.end(); + I != E; ++I, ++Index) { + OS.indent(Indentation) << "case " << Index << ":\n"; + OS << *I; + OS.indent(Indentation+2) << "return S;\n"; + } + OS.indent(Indentation) << "}\n"; + Indentation -= 2; + OS.indent(Indentation) << "}\n\n"; } // Populates the field of the insn given the start position and the number of @@ -703,9 +942,7 @@ bool FilterChooser::fieldFromInsn(uint64_t &Field, insn_t &Insn, /// filter array as a series of chars. void FilterChooser::dumpFilterArray(raw_ostream &o, const std::vector<bit_value_t> &filter) const { - unsigned bitIndex; - - for (bitIndex = BitWidth; bitIndex > 0; bitIndex--) { + for (unsigned bitIndex = BitWidth; bitIndex > 0; bitIndex--) { switch (filter[bitIndex - 1]) { case BIT_UNFILTERED: o << "."; @@ -827,26 +1064,71 @@ void FilterChooser::emitBinaryParser(raw_ostream &o, unsigned &Indentation, if (OpInfo.numFields() == 1) { OperandInfo::const_iterator OI = OpInfo.begin(); - o.indent(Indentation) << " tmp = fieldFromInstruction" << BitWidth - << "(insn, " << OI->Base << ", " << OI->Width - << ");\n"; + o.indent(Indentation) << "tmp = fieldFromInstruction" + << "(insn, " << OI->Base << ", " << OI->Width + << ");\n"; } else { - o.indent(Indentation) << " tmp = 0;\n"; + o.indent(Indentation) << "tmp = 0;\n"; for (OperandInfo::const_iterator OI = OpInfo.begin(), OE = OpInfo.end(); OI != OE; ++OI) { - o.indent(Indentation) << " tmp |= (fieldFromInstruction" << BitWidth + o.indent(Indentation) << "tmp |= (fieldFromInstruction" << "(insn, " << OI->Base << ", " << OI->Width << ") << " << OI->Offset << ");\n"; } } if (Decoder != "") - o.indent(Indentation) << " " << Emitter->GuardPrefix << Decoder + o.indent(Indentation) << Emitter->GuardPrefix << Decoder << "(MI, tmp, Address, Decoder)" << Emitter->GuardPostfix << "\n"; else - o.indent(Indentation) << " MI.addOperand(MCOperand::CreateImm(tmp));\n"; + o.indent(Indentation) << "MI.addOperand(MCOperand::CreateImm(tmp));\n"; + +} + +void FilterChooser::emitDecoder(raw_ostream &OS, unsigned Indentation, + unsigned Opc) const { + std::map<unsigned, std::vector<OperandInfo> >::const_iterator OpIter = + Operands.find(Opc); + const std::vector<OperandInfo>& InsnOperands = OpIter->second; + for (std::vector<OperandInfo>::const_iterator + I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) { + // If a custom instruction decoder was specified, use that. + if (I->numFields() == 0 && I->Decoder.size()) { + OS.indent(Indentation) << Emitter->GuardPrefix << I->Decoder + << "(MI, insn, Address, Decoder)" + << Emitter->GuardPostfix << "\n"; + break; + } + emitBinaryParser(OS, Indentation, *I); + } +} + +unsigned FilterChooser::getDecoderIndex(DecoderSet &Decoders, + unsigned Opc) const { + // Build up the predicate string. + SmallString<256> Decoder; + // FIXME: emitDecoder() function can take a buffer directly rather than + // a stream. + raw_svector_ostream S(Decoder); + unsigned I = 4; + emitDecoder(S, I, Opc); + S.flush(); + + // Using the full decoder string as the key value here is a bit + // heavyweight, but is effective. If the string comparisons become a + // performance concern, we can implement a mangling of the predicate + // data easilly enough with a map back to the actual string. That's + // overkill for now, though. + + // Make sure the predicate is in the table. + Decoders.insert(Decoder.str()); + // Now figure out the index for when we write out the table. + DecoderSet::const_iterator P = std::find(Decoders.begin(), + Decoders.end(), + Decoder.str()); + return (unsigned)(P - Decoders.begin()); } static void emitSinglePredicateMatch(raw_ostream &o, StringRef str, @@ -887,8 +1169,74 @@ bool FilterChooser::emitPredicateMatch(raw_ostream &o, unsigned &Indentation, return Predicates->getSize() > 0; } -void FilterChooser::emitSoftFailCheck(raw_ostream &o, unsigned Indentation, - unsigned Opc) const { +bool FilterChooser::doesOpcodeNeedPredicate(unsigned Opc) const { + 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; + + return true; + } + return false; +} + +unsigned FilterChooser::getPredicateIndex(DecoderTableInfo &TableInfo, + StringRef Predicate) const { + // Using the full predicate string as the key value here is a bit + // heavyweight, but is effective. If the string comparisons become a + // performance concern, we can implement a mangling of the predicate + // data easilly enough with a map back to the actual string. That's + // overkill for now, though. + + // Make sure the predicate is in the table. + TableInfo.Predicates.insert(Predicate.str()); + // Now figure out the index for when we write out the table. + PredicateSet::const_iterator P = std::find(TableInfo.Predicates.begin(), + TableInfo.Predicates.end(), + Predicate.str()); + return (unsigned)(P - TableInfo.Predicates.begin()); +} + +void FilterChooser::emitPredicateTableEntry(DecoderTableInfo &TableInfo, + unsigned Opc) const { + if (!doesOpcodeNeedPredicate(Opc)) + return; + + // Build up the predicate string. + SmallString<256> Predicate; + // FIXME: emitPredicateMatch() functions can take a buffer directly rather + // than a stream. + raw_svector_ostream PS(Predicate); + unsigned I = 0; + emitPredicateMatch(PS, I, Opc); + + // Figure out the index into the predicate table for the predicate just + // computed. + unsigned PIdx = getPredicateIndex(TableInfo, PS.str()); + SmallString<16> PBytes; + raw_svector_ostream S(PBytes); + encodeULEB128(PIdx, S); + S.flush(); + + TableInfo.Table.push_back(MCD::OPC_CheckPredicate); + // Predicate index + for (unsigned i = 0, e = PBytes.size(); i != e; ++i) + TableInfo.Table.push_back(PBytes[i]); + // Push location for NumToSkip backpatching. + TableInfo.FixupStack.back().push_back(TableInfo.Table.size()); + TableInfo.Table.push_back(0); + TableInfo.Table.push_back(0); +} + +void FilterChooser::emitSoftFailTableEntry(DecoderTableInfo &TableInfo, + unsigned Opc) const { BitsInit *SFBits = AllInstructions[Opc]->TheDef->getValueAsBitsInit("SoftFail"); if (!SFBits) return; @@ -914,13 +1262,11 @@ void FilterChooser::emitSoftFailCheck(raw_ostream &o, unsigned Indentation, default: // The bit is not set; this must be an error! StringRef Name = AllInstructions[Opc]->TheDef->getName(); - errs() << "SoftFail Conflict: bit SoftFail{" << i << "} in " - << Name - << " is set but Inst{" << i <<"} is unset!\n" + errs() << "SoftFail Conflict: bit SoftFail{" << i << "} in " << Name + << " is set but Inst{" << i << "} is unset!\n" << " - You can only mark a bit as SoftFail if it is fully defined" << " (1/0 - not '?') in Inst\n"; - o << "#error SoftFail Conflict, " << Name << "::SoftFail{" << i - << "} set but Inst{" << i << "} undefined!\n"; + return; } } @@ -930,27 +1276,31 @@ void FilterChooser::emitSoftFailCheck(raw_ostream &o, unsigned Indentation, if (!NeedPositiveMask && !NeedNegativeMask) return; - std::string PositiveMaskStr = PositiveMask.toString(16, /*signed=*/false); - std::string NegativeMaskStr = NegativeMask.toString(16, /*signed=*/false); - StringRef BitExt = ""; - if (BitWidth > 32) - BitExt = "ULL"; - - o.indent(Indentation) << "if ("; - if (NeedPositiveMask) - o << "insn & 0x" << PositiveMaskStr << BitExt; - if (NeedPositiveMask && NeedNegativeMask) - o << " || "; - if (NeedNegativeMask) - o << "~insn & 0x" << NegativeMaskStr << BitExt; - o << ")\n"; - o.indent(Indentation+2) << "S = MCDisassembler::SoftFail;\n"; + TableInfo.Table.push_back(MCD::OPC_SoftFail); + + SmallString<16> MaskBytes; + raw_svector_ostream S(MaskBytes); + if (NeedPositiveMask) { + encodeULEB128(PositiveMask.getZExtValue(), S); + S.flush(); + for (unsigned i = 0, e = MaskBytes.size(); i != e; ++i) + TableInfo.Table.push_back(MaskBytes[i]); + } else + TableInfo.Table.push_back(0); + if (NeedNegativeMask) { + MaskBytes.clear(); + S.resync(); + encodeULEB128(NegativeMask.getZExtValue(), S); + S.flush(); + for (unsigned i = 0, e = MaskBytes.size(); i != e; ++i) + TableInfo.Table.push_back(MaskBytes[i]); + } else + TableInfo.Table.push_back(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, - unsigned Opc) const { +// Emits table entries to decode the singleton. +void FilterChooser::emitSingletonTableEntry(DecoderTableInfo &TableInfo, + unsigned Opc) const { std::vector<unsigned> StartBits; std::vector<unsigned> EndBits; std::vector<uint64_t> FieldVals; @@ -961,107 +1311,70 @@ bool FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation, getIslands(StartBits, EndBits, FieldVals, Insn); unsigned Size = StartBits.size(); - unsigned I, NumBits; - // If we have matched all the well-known bits, just issue a return. - if (Size == 0) { - o.indent(Indentation) << "if ("; - if (!emitPredicateMatch(o, Indentation, Opc)) - o << "1"; - o << ") {\n"; - emitSoftFailCheck(o, Indentation+2, Opc); - o.indent(Indentation) << " MI.setOpcode(" << Opc << ");\n"; - std::map<unsigned, std::vector<OperandInfo> >::const_iterator OpIter = - Operands.find(Opc); - const std::vector<OperandInfo>& InsnOperands = OpIter->second; - for (std::vector<OperandInfo>::const_iterator - I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) { - // If a custom instruction decoder was specified, use that. - if (I->numFields() == 0 && I->Decoder.size()) { - o.indent(Indentation) << " " << Emitter->GuardPrefix << I->Decoder - << "(MI, insn, Address, Decoder)" - << Emitter->GuardPostfix << "\n"; - break; - } - - emitBinaryParser(o, Indentation, *I); - } - - o.indent(Indentation) << " return " << Emitter->ReturnOK << "; // " - << nameWithID(Opc) << '\n'; - o.indent(Indentation) << "}\n"; // Closing predicate block. - return true; - } - - // Otherwise, there are more decodings to be done! - - // Emit code to match the island(s) for the singleton. - o.indent(Indentation) << "// Check "; - - for (I = Size; I != 0; --I) { - o << "Inst{" << EndBits[I-1] << '-' << StartBits[I-1] << "} "; - if (I > 1) - o << " && "; - else - o << "for singleton decoding...\n"; - } - - o.indent(Indentation) << "if ("; - if (emitPredicateMatch(o, Indentation, Opc)) { - o << " &&\n"; - o.indent(Indentation+4); + // Emit the predicate table entry if one is needed. + emitPredicateTableEntry(TableInfo, Opc); + + // Check any additional encoding fields needed. + for (unsigned I = Size; I != 0; --I) { + unsigned NumBits = EndBits[I-1] - StartBits[I-1] + 1; + TableInfo.Table.push_back(MCD::OPC_CheckField); + TableInfo.Table.push_back(StartBits[I-1]); + TableInfo.Table.push_back(NumBits); + uint8_t Buffer[8], *p; + encodeULEB128(FieldVals[I-1], Buffer); + for (p = Buffer; *p >= 128 ; ++p) + TableInfo.Table.push_back(*p); + TableInfo.Table.push_back(*p); + // Push location for NumToSkip backpatching. + TableInfo.FixupStack.back().push_back(TableInfo.Table.size()); + // The fixup is always 16-bits, so go ahead and allocate the space + // in the table so all our relative position calculations work OK even + // before we fully resolve the real value here. + TableInfo.Table.push_back(0); + TableInfo.Table.push_back(0); } - for (I = Size; I != 0; --I) { - NumBits = EndBits[I-1] - StartBits[I-1] + 1; - o << "fieldFromInstruction" << BitWidth << "(insn, " - << StartBits[I-1] << ", " << NumBits - << ") == " << FieldVals[I-1]; - if (I > 1) - o << " && "; - else - o << ") {\n"; - } - emitSoftFailCheck(o, Indentation+2, Opc); - o.indent(Indentation) << " MI.setOpcode(" << Opc << ");\n"; - std::map<unsigned, std::vector<OperandInfo> >::const_iterator OpIter = - Operands.find(Opc); - const std::vector<OperandInfo>& InsnOperands = OpIter->second; - for (std::vector<OperandInfo>::const_iterator - I = InsnOperands.begin(), E = InsnOperands.end(); I != E; ++I) { - // If a custom instruction decoder was specified, use that. - if (I->numFields() == 0 && I->Decoder.size()) { - o.indent(Indentation) << " " << Emitter->GuardPrefix << I->Decoder - << "(MI, insn, Address, Decoder)" - << Emitter->GuardPostfix << "\n"; - break; - } - - emitBinaryParser(o, Indentation, *I); - } - o.indent(Indentation) << " return " << Emitter->ReturnOK << "; // " - << nameWithID(Opc) << '\n'; - o.indent(Indentation) << "}\n"; - - return false; + // Check for soft failure of the match. + emitSoftFailTableEntry(TableInfo, Opc); + + TableInfo.Table.push_back(MCD::OPC_Decode); + uint8_t Buffer[8], *p; + encodeULEB128(Opc, Buffer); + for (p = Buffer; *p >= 128 ; ++p) + TableInfo.Table.push_back(*p); + TableInfo.Table.push_back(*p); + + unsigned DIdx = getDecoderIndex(TableInfo.Decoders, Opc); + SmallString<16> Bytes; + raw_svector_ostream S(Bytes); + encodeULEB128(DIdx, S); + S.flush(); + + // Decoder index + for (unsigned i = 0, e = Bytes.size(); i != e; ++i) + TableInfo.Table.push_back(Bytes[i]); } -// Emits code to decode the singleton, and then to decode the rest. -void FilterChooser::emitSingletonDecoder(raw_ostream &o, unsigned &Indentation, - const Filter &Best) const { - +// Emits table entries to decode the singleton, and then to decode the rest. +void FilterChooser::emitSingletonTableEntry(DecoderTableInfo &TableInfo, + const Filter &Best) const { unsigned Opc = Best.getSingletonOpc(); - emitSingletonDecoder(o, Indentation, Opc); + // complex singletons need predicate checks from the first singleton + // to refer forward to the variable filterchooser that follows. + TableInfo.FixupStack.push_back(FixupList()); - // Emit code for the rest. - o.indent(Indentation) << "else\n"; + emitSingletonTableEntry(TableInfo, Opc); - Indentation += 2; - Best.getVariableFC().emit(o, Indentation); - Indentation -= 2; + resolveTableFixups(TableInfo.Table, TableInfo.FixupStack.back(), + TableInfo.Table.size()); + TableInfo.FixupStack.pop_back(); + + Best.getVariableFC().emitTableEntries(TableInfo); } + // Assign a single filter and run with it. Top level API client can initialize // with a single filter to start the filtering process. void FilterChooser::runSingleFilter(unsigned startBit, unsigned numBit, @@ -1119,7 +1432,7 @@ bool FilterChooser::filterProcessor(bool AllowMixed, bool Greedy) { } } - unsigned BitIndex, InsnIndex; + unsigned BitIndex; // We maintain BIT_WIDTH copies of the bitAttrs automaton. // The automaton consumes the corresponding bit from each @@ -1149,7 +1462,7 @@ bool FilterChooser::filterProcessor(bool AllowMixed, bool Greedy) { else bitAttrs.push_back(ATTR_NONE); - for (InsnIndex = 0; InsnIndex < numInstructions; ++InsnIndex) { + for (unsigned InsnIndex = 0; InsnIndex < numInstructions; ++InsnIndex) { insn_t insn; insnWithID(insn, Opcodes[InsnIndex]); @@ -1200,7 +1513,7 @@ bool FilterChooser::filterProcessor(bool AllowMixed, bool Greedy) { bitAttr_t RA = ATTR_NONE; unsigned StartBit = 0; - for (BitIndex = 0; BitIndex < BitWidth; BitIndex++) { + for (BitIndex = 0; BitIndex < BitWidth; ++BitIndex) { bitAttr_t bitAttr = bitAttrs[BitIndex]; assert(bitAttr != ATTR_NONE && "Bit without attributes"); @@ -1341,36 +1654,29 @@ void FilterChooser::doFilter() { BestIndex = -1; } -// Emits code to decode our share of instructions. Returns true if the -// emitted code causes a return, which occurs if we know how to decode -// the instruction at this level or the instruction is not decodeable. -bool FilterChooser::emit(raw_ostream &o, unsigned &Indentation) const { - if (Opcodes.size() == 1) +// emitTableEntries - Emit state machine entries to decode our share of +// instructions. +void FilterChooser::emitTableEntries(DecoderTableInfo &TableInfo) const { + if (Opcodes.size() == 1) { // There is only one instruction in the set, which is great! // Call emitSingletonDecoder() to see whether there are any remaining // encodings bits. - return emitSingletonDecoder(o, Indentation, Opcodes[0]); + emitSingletonTableEntry(TableInfo, Opcodes[0]); + return; + } // Choose the best filter to do the decodings! if (BestIndex != -1) { const Filter &Best = Filters[BestIndex]; if (Best.getNumFiltered() == 1) - emitSingletonDecoder(o, Indentation, Best); + emitSingletonTableEntry(TableInfo, Best); else - Best.emit(o, Indentation); - return false; + Best.emitTableEntry(TableInfo); + return; } - // We don't know how to decode these instructions! Return 0 and dump the - // conflict set! - o.indent(Indentation) << "return 0;" << " // Conflict set: "; - for (int i = 0, N = Opcodes.size(); i < N; ++i) { - o << nameWithID(Opcodes[i]); - if (i < (N - 1)) - o << ", "; - else - o << '\n'; - } + // We don't know how to decode these instructions! Dump the + // conflict set and bail. // Print out useful conflict information for postmortem analysis. errs() << "Decoding Conflict:\n"; @@ -1385,8 +1691,6 @@ bool FilterChooser::emit(raw_ostream &o, unsigned &Indentation) const { getBitsField(*AllInstructions[Opcodes[i]]->TheDef, "Inst")); errs() << '\n'; } - - return true; } static bool populateInstruction(const CodeGenInstruction &CGI, unsigned Opc, @@ -1549,62 +1853,168 @@ static bool populateInstruction(const CodeGenInstruction &CGI, unsigned Opc, return true; } -static void emitHelper(llvm::raw_ostream &o, unsigned BitWidth) { - unsigned Indentation = 0; - std::string WidthStr = "uint" + utostr(BitWidth) + "_t"; - - 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"; +// emitFieldFromInstruction - Emit the templated helper function +// fieldFromInstruction(). +static void emitFieldFromInstruction(formatted_raw_ostream &OS) { + OS << "// Helper function for extracting fields from encoded instructions.\n" + << "template<typename InsnType>\n" + << "static InsnType fieldFromInstruction(InsnType insn, unsigned startBit,\n" + << " unsigned numBits) {\n" + << " assert(startBit + numBits <= (sizeof(InsnType)*8) &&\n" + << " \"Instruction field out of bounds!\");\n" + << " InsnType fieldMask;\n" + << " if (numBits == sizeof(InsnType)*8)\n" + << " fieldMask = (InsnType)(-1LL);\n" + << " else\n" + << " fieldMask = ((1 << numBits) - 1) << startBit;\n" + << " return (insn & fieldMask) >> startBit;\n" + << "}\n\n"; +} - o << '\n'; +// emitDecodeInstruction - Emit the templated helper function +// decodeInstruction(). +static void emitDecodeInstruction(formatted_raw_ostream &OS) { + OS << "template<typename InsnType>\n" + << "static DecodeStatus decodeInstruction(const uint8_t DecodeTable[], MCInst &MI,\n" + << " InsnType insn, uint64_t Address,\n" + << " const void *DisAsm,\n" + << " const MCSubtargetInfo &STI) {\n" + << " uint64_t Bits = STI.getFeatureBits();\n" + << "\n" + << " const uint8_t *Ptr = DecodeTable;\n" + << " uint32_t CurFieldValue;\n" + << " DecodeStatus S = MCDisassembler::Success;\n" + << " for (;;) {\n" + << " ptrdiff_t Loc = Ptr - DecodeTable;\n" + << " switch (*Ptr) {\n" + << " default:\n" + << " errs() << Loc << \": Unexpected decode table opcode!\\n\";\n" + << " return MCDisassembler::Fail;\n" + << " case MCD::OPC_ExtractField: {\n" + << " unsigned Start = *++Ptr;\n" + << " unsigned Len = *++Ptr;\n" + << " ++Ptr;\n" + << " CurFieldValue = fieldFromInstruction(insn, Start, Len);\n" + << " DEBUG(dbgs() << Loc << \": OPC_ExtractField(\" << Start << \", \"\n" + << " << Len << \"): \" << CurFieldValue << \"\\n\");\n" + << " break;\n" + << " }\n" + << " case MCD::OPC_FilterValue: {\n" + << " // Decode the field value.\n" + << " unsigned Len;\n" + << " InsnType Val = decodeULEB128(++Ptr, &Len);\n" + << " Ptr += Len;\n" + << " // NumToSkip is a plain 16-bit integer.\n" + << " unsigned NumToSkip = *Ptr++;\n" + << " NumToSkip |= (*Ptr++) << 8;\n" + << "\n" + << " // Perform the filter operation.\n" + << " if (Val != CurFieldValue)\n" + << " Ptr += NumToSkip;\n" + << " DEBUG(dbgs() << Loc << \": OPC_FilterValue(\" << Val << \", \" << NumToSkip\n" + << " << \"): \" << ((Val != CurFieldValue) ? \"FAIL:\" : \"PASS:\")\n" + << " << \" continuing at \" << (Ptr - DecodeTable) << \"\\n\");\n" + << "\n" + << " break;\n" + << " }\n" + << " case MCD::OPC_CheckField: {\n" + << " unsigned Start = *++Ptr;\n" + << " unsigned Len = *++Ptr;\n" + << " InsnType FieldValue = fieldFromInstruction(insn, Start, Len);\n" + << " // Decode the field value.\n" + << " uint32_t ExpectedValue = decodeULEB128(++Ptr, &Len);\n" + << " Ptr += Len;\n" + << " // NumToSkip is a plain 16-bit integer.\n" + << " unsigned NumToSkip = *Ptr++;\n" + << " NumToSkip |= (*Ptr++) << 8;\n" + << "\n" + << " // If the actual and expected values don't match, skip.\n" + << " if (ExpectedValue != FieldValue)\n" + << " Ptr += NumToSkip;\n" + << " DEBUG(dbgs() << Loc << \": OPC_CheckField(\" << Start << \", \"\n" + << " << Len << \", \" << ExpectedValue << \", \" << NumToSkip\n" + << " << \"): FieldValue = \" << FieldValue << \", ExpectedValue = \"\n" + << " << ExpectedValue << \": \"\n" + << " << ((ExpectedValue == FieldValue) ? \"PASS\\n\" : \"FAIL\\n\"));\n" + << " break;\n" + << " }\n" + << " case MCD::OPC_CheckPredicate: {\n" + << " unsigned Len;\n" + << " // Decode the Predicate Index value.\n" + << " unsigned PIdx = decodeULEB128(++Ptr, &Len);\n" + << " Ptr += Len;\n" + << " // NumToSkip is a plain 16-bit integer.\n" + << " unsigned NumToSkip = *Ptr++;\n" + << " NumToSkip |= (*Ptr++) << 8;\n" + << " // Check the predicate.\n" + << " bool Pred;\n" + << " if (!(Pred = checkDecoderPredicate(PIdx, Bits)))\n" + << " Ptr += NumToSkip;\n" + << " (void)Pred;\n" + << " DEBUG(dbgs() << Loc << \": OPC_CheckPredicate(\" << PIdx << \"): \"\n" + << " << (Pred ? \"PASS\\n\" : \"FAIL\\n\"));\n" + << "\n" + << " break;\n" + << " }\n" + << " case MCD::OPC_Decode: {\n" + << " unsigned Len;\n" + << " // Decode the Opcode value.\n" + << " unsigned Opc = decodeULEB128(++Ptr, &Len);\n" + << " Ptr += Len;\n" + << " unsigned DecodeIdx = decodeULEB128(Ptr, &Len);\n" + << " Ptr += Len;\n" + << " DEBUG(dbgs() << Loc << \": OPC_Decode: opcode \" << Opc\n" + << " << \", using decoder \" << DecodeIdx << \"\\n\" );\n" + << " DEBUG(dbgs() << \"----- DECODE SUCCESSFUL -----\\n\");\n" + << "\n" + << " MI.setOpcode(Opc);\n" + << " return decodeToMCInst(S, DecodeIdx, insn, MI, Address, DisAsm);\n" + << " }\n" + << " case MCD::OPC_SoftFail: {\n" + << " // Decode the mask values.\n" + << " unsigned Len;\n" + << " InsnType PositiveMask = decodeULEB128(++Ptr, &Len);\n" + << " Ptr += Len;\n" + << " InsnType NegativeMask = decodeULEB128(Ptr, &Len);\n" + << " Ptr += Len;\n" + << " bool Fail = (insn & PositiveMask) || (~insn & NegativeMask);\n" + << " if (Fail)\n" + << " S = MCDisassembler::SoftFail;\n" + << " DEBUG(dbgs() << Loc << \": OPC_SoftFail: \" << (Fail ? \"FAIL\\n\":\"PASS\\n\"));\n" + << " break;\n" + << " }\n" + << " case MCD::OPC_Fail: {\n" + << " DEBUG(dbgs() << Loc << \": OPC_Fail\\n\");\n" + << " return MCDisassembler::Fail;\n" + << " }\n" + << " }\n" + << " }\n" + << " llvm_unreachable(\"bogosity detected in disassembler state machine!\");\n" + << "}\n\n"; } // Emits disassembler code for instruction decoding. void FixedLenDecoderEmitter::run(raw_ostream &o) { - o << "#include \"llvm/MC/MCInst.h\"\n"; - o << "#include \"llvm/Support/DataTypes.h\"\n"; - o << "#include <assert.h>\n"; - o << '\n'; - o << "namespace llvm {\n\n"; + formatted_raw_ostream OS(o); + OS << "#include \"llvm/MC/MCInst.h\"\n"; + OS << "#include \"llvm/Support/Debug.h\"\n"; + OS << "#include \"llvm/Support/DataTypes.h\"\n"; + OS << "#include \"llvm/Support/LEB128.h\"\n"; + OS << "#include \"llvm/Support/raw_ostream.h\"\n"; + OS << "#include <assert.h>\n"; + OS << '\n'; + OS << "namespace llvm {\n\n"; + + emitFieldFromInstruction(OS); // Parameterize the decoders based on namespace and instruction width. - const std::vector<const CodeGenInstruction*> &NumberedInstructions = - Target.getInstructionsByEnumValue(); + NumberedInstructions = &Target.getInstructionsByEnumValue(); 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]; + for (unsigned i = 0; i < NumberedInstructions->size(); ++i) { + const CodeGenInstruction *Inst = NumberedInstructions->at(i); const Record *Def = Inst->TheDef; unsigned Size = Def->getValueAsInt("Size"); if (Def->getValueAsString("Namespace") == "TargetOpcode" || @@ -1622,24 +2032,48 @@ void FixedLenDecoderEmitter::run(raw_ostream &o) { } } + DecoderTableInfo TableInfo; std::set<unsigned> Sizes; for (std::map<std::pair<std::string, unsigned>, std::vector<unsigned> >::const_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, + FilterChooser FC(*NumberedInstructions, I->second, Operands, 8*I->first.second, this); - FC.emitTop(o, 0, I->first.first); + + // The decode table is cleared for each top level decoder function. The + // predicates and decoders themselves, however, are shared across all + // decoders to give more opportunities for uniqueing. + TableInfo.Table.clear(); + TableInfo.FixupStack.clear(); + TableInfo.Table.reserve(16384); + TableInfo.FixupStack.push_back(FixupList()); + FC.emitTableEntries(TableInfo); + // Any NumToSkip fixups in the top level scope can resolve to the + // OPC_Fail at the end of the table. + assert(TableInfo.FixupStack.size() == 1 && "fixup stack phasing error!"); + // Resolve any NumToSkip fixups in the current scope. + resolveTableFixups(TableInfo.Table, TableInfo.FixupStack.back(), + TableInfo.Table.size()); + TableInfo.FixupStack.clear(); + + TableInfo.Table.push_back(MCD::OPC_Fail); + + // Print the table to the output stream. + emitTable(OS, TableInfo.Table, 0, FC.getBitWidth(), I->first.first); + OS.flush(); } - o << "\n} // End llvm namespace \n"; + // Emit the predicate function. + emitPredicateFunction(OS, TableInfo.Predicates, 0); + + // Emit the decoder function. + emitDecoderFunction(OS, TableInfo.Decoders, 0); + + // Emit the main entry point for the decoder, decodeInstruction(). + emitDecodeInstruction(OS); + + OS << "\n} // End llvm namespace\n"; } namespace llvm { |