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-rw-r--r--contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp189
1 files changed, 148 insertions, 41 deletions
diff --git a/contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp b/contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp
index c4df283..8ca4a1b 100644
--- a/contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp
+++ b/contrib/llvm/utils/TableGen/FixedLenDecoderEmitter.cpp
@@ -44,9 +44,10 @@ struct EncodingField {
struct OperandInfo {
std::vector<EncodingField> Fields;
std::string Decoder;
+ bool HasCompleteDecoder;
- OperandInfo(std::string D)
- : Decoder(D) { }
+ OperandInfo(std::string D, bool HCD)
+ : Decoder(D), HasCompleteDecoder(HCD) { }
void addField(unsigned Base, unsigned Width, unsigned Offset) {
Fields.push_back(EncodingField(Base, Width, Offset));
@@ -64,8 +65,8 @@ 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;
+typedef SmallSetVector<std::string, 16> PredicateSet;
+typedef SmallSetVector<std::string, 16> DecoderSet;
struct DecoderTableInfo {
DecoderTable Table;
FixupScopeList FixupStack;
@@ -85,8 +86,7 @@ public:
FixedLenDecoderEmitter(RecordKeeper &R,
std::string PredicateNamespace,
std::string GPrefix = "if (",
- std::string GPostfix = " == MCDisassembler::Fail)"
- " return MCDisassembler::Fail;",
+ std::string GPostfix = " == MCDisassembler::Fail)",
std::string ROK = "MCDisassembler::Success",
std::string RFail = "MCDisassembler::Fail",
std::string L = "") :
@@ -448,10 +448,13 @@ protected:
const Filter &Best) const;
void emitBinaryParser(raw_ostream &o, unsigned &Indentation,
- const OperandInfo &OpInfo) const;
+ const OperandInfo &OpInfo,
+ bool &OpHasCompleteDecoder) const;
- void emitDecoder(raw_ostream &OS, unsigned Indentation, unsigned Opc) const;
- unsigned getDecoderIndex(DecoderSet &Decoders, unsigned Opc) const;
+ void emitDecoder(raw_ostream &OS, unsigned Indentation, unsigned Opc,
+ bool &HasCompleteDecoder) const;
+ unsigned getDecoderIndex(DecoderSet &Decoders, unsigned Opc,
+ bool &HasCompleteDecoder) const;
// Assign a single filter and run with it.
void runSingleFilter(unsigned startBit, unsigned numBit, bool mixed);
@@ -779,7 +782,9 @@ void FixedLenDecoderEmitter::emitTable(formatted_raw_ostream &OS,
OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
break;
}
- case MCD::OPC_Decode: {
+ case MCD::OPC_Decode:
+ case MCD::OPC_TryDecode: {
+ bool IsTry = *I == MCD::OPC_TryDecode;
++I;
// Extract the ULEB128 encoded Opcode to a buffer.
uint8_t Buffer[8], *p = Buffer;
@@ -788,7 +793,8 @@ void FixedLenDecoderEmitter::emitTable(formatted_raw_ostream &OS,
&& "ULEB128 value too large!");
// Decode the Opcode value.
unsigned Opc = decodeULEB128(Buffer);
- OS.indent(Indentation) << "MCD::OPC_Decode, ";
+ OS.indent(Indentation) << "MCD::OPC_" << (IsTry ? "Try" : "")
+ << "Decode, ";
for (p = Buffer; *p >= 128; ++p)
OS << utostr(*p) << ", ";
OS << utostr(*p) << ", ";
@@ -798,8 +804,25 @@ void FixedLenDecoderEmitter::emitTable(formatted_raw_ostream &OS,
OS << utostr(*I) << ", ";
OS << utostr(*I++) << ", ";
+ if (!IsTry) {
+ OS << "// Opcode: "
+ << NumberedInstructions->at(Opc)->TheDef->getName() << "\n";
+ break;
+ }
+
+ // Fallthrough for OPC_TryDecode.
+
+ // 16-bit numtoskip value.
+ uint8_t Byte = *I++;
+ uint32_t NumToSkip = Byte;
+ OS << utostr(Byte) << ", ";
+ Byte = *I++;
+ OS << utostr(Byte) << ", ";
+ NumToSkip |= Byte << 8;
+
OS << "// Opcode: "
- << NumberedInstructions->at(Opc)->TheDef->getName() << "\n";
+ << NumberedInstructions->at(Opc)->TheDef->getName()
+ << ", skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
break;
}
case MCD::OPC_SoftFail: {
@@ -876,8 +899,9 @@ emitDecoderFunction(formatted_raw_ostream &OS, DecoderSet &Decoders,
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";
+ << "Address, const void *Decoder, bool &DecodeComplete) {\n";
Indentation += 2;
+ OS.indent(Indentation) << "DecodeComplete = true;\n";
OS.indent(Indentation) << "InsnType tmp;\n";
OS.indent(Indentation) << "switch (Idx) {\n";
OS.indent(Indentation) << "default: llvm_unreachable(\"Invalid index!\");\n";
@@ -1033,7 +1057,8 @@ unsigned FilterChooser::getIslands(std::vector<unsigned> &StartBits,
}
void FilterChooser::emitBinaryParser(raw_ostream &o, unsigned &Indentation,
- const OperandInfo &OpInfo) const {
+ const OperandInfo &OpInfo,
+ bool &OpHasCompleteDecoder) const {
const std::string &Decoder = OpInfo.Decoder;
if (OpInfo.numFields() != 1)
@@ -1049,45 +1074,57 @@ void FilterChooser::emitBinaryParser(raw_ostream &o, unsigned &Indentation,
o << ";\n";
}
- if (Decoder != "")
+ if (Decoder != "") {
+ OpHasCompleteDecoder = OpInfo.HasCompleteDecoder;
o.indent(Indentation) << Emitter->GuardPrefix << Decoder
- << "(MI, tmp, Address, Decoder)"
- << Emitter->GuardPostfix << "\n";
- else
+ << "(MI, tmp, Address, Decoder)"
+ << Emitter->GuardPostfix
+ << " { " << (OpHasCompleteDecoder ? "" : "DecodeComplete = false; ")
+ << "return MCDisassembler::Fail; }\n";
+ } else {
+ OpHasCompleteDecoder = true;
o.indent(Indentation) << "MI.addOperand(MCOperand::createImm(tmp));\n";
-
+ }
}
void FilterChooser::emitDecoder(raw_ostream &OS, unsigned Indentation,
- unsigned Opc) const {
+ unsigned Opc, bool &HasCompleteDecoder) const {
+ HasCompleteDecoder = true;
+
for (const auto &Op : Operands.find(Opc)->second) {
// If a custom instruction decoder was specified, use that.
if (Op.numFields() == 0 && Op.Decoder.size()) {
+ HasCompleteDecoder = Op.HasCompleteDecoder;
OS.indent(Indentation) << Emitter->GuardPrefix << Op.Decoder
<< "(MI, insn, Address, Decoder)"
- << Emitter->GuardPostfix << "\n";
+ << Emitter->GuardPostfix
+ << " { " << (HasCompleteDecoder ? "" : "DecodeComplete = false; ")
+ << "return MCDisassembler::Fail; }\n";
break;
}
- emitBinaryParser(OS, Indentation, Op);
+ bool OpHasCompleteDecoder;
+ emitBinaryParser(OS, Indentation, Op, OpHasCompleteDecoder);
+ if (!OpHasCompleteDecoder)
+ HasCompleteDecoder = false;
}
}
unsigned FilterChooser::getDecoderIndex(DecoderSet &Decoders,
- unsigned Opc) const {
+ unsigned Opc,
+ bool &HasCompleteDecoder) 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();
+ emitDecoder(S, I, Opc, HasCompleteDecoder);
// 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
+ // data easily enough with a map back to the actual string. That's
// overkill for now, though.
// Make sure the predicate is in the table.
@@ -1162,7 +1199,7 @@ unsigned FilterChooser::getPredicateIndex(DecoderTableInfo &TableInfo,
// 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
+ // data easily enough with a map back to the actual string. That's
// overkill for now, though.
// Make sure the predicate is in the table.
@@ -1193,7 +1230,6 @@ void FilterChooser::emitPredicateTableEntry(DecoderTableInfo &TableInfo,
SmallString<16> PBytes;
raw_svector_ostream S(PBytes);
encodeULEB128(PIdx, S);
- S.flush();
TableInfo.Table.push_back(MCD::OPC_CheckPredicate);
// Predicate index
@@ -1252,16 +1288,13 @@ void FilterChooser::emitSoftFailTableEntry(DecoderTableInfo &TableInfo,
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
@@ -1308,22 +1341,41 @@ void FilterChooser::emitSingletonTableEntry(DecoderTableInfo &TableInfo,
// Check for soft failure of the match.
emitSoftFailTableEntry(TableInfo, Opc);
- TableInfo.Table.push_back(MCD::OPC_Decode);
+ bool HasCompleteDecoder;
+ unsigned DIdx = getDecoderIndex(TableInfo.Decoders, Opc, HasCompleteDecoder);
+
+ // Produce OPC_Decode or OPC_TryDecode opcode based on the information
+ // whether the instruction decoder is complete or not. If it is complete
+ // then it handles all possible values of remaining variable/unfiltered bits
+ // and for any value can determine if the bitpattern is a valid instruction
+ // or not. This means OPC_Decode will be the final step in the decoding
+ // process. If it is not complete, then the Fail return code from the
+ // decoder method indicates that additional processing should be done to see
+ // if there is any other instruction that also matches the bitpattern and
+ // can decode it.
+ TableInfo.Table.push_back(HasCompleteDecoder ? MCD::OPC_Decode :
+ MCD::OPC_TryDecode);
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]);
+
+ if (!HasCompleteDecoder) {
+ // Push location for NumToSkip backpatching.
+ TableInfo.FixupStack.back().push_back(TableInfo.Table.size());
+ // Allocate the space for the fixup.
+ TableInfo.Table.push_back(0);
+ TableInfo.Table.push_back(0);
+ }
}
// Emits table entries to decode the singleton, and then to decode the rest.
@@ -1679,7 +1731,8 @@ static bool populateInstruction(CodeGenTarget &Target,
// of trying to auto-generate the decoder.
std::string InstDecoder = Def.getValueAsString("DecoderMethod");
if (InstDecoder != "") {
- InsnOperands.push_back(OperandInfo(InstDecoder));
+ bool HasCompleteInstDecoder = Def.getValueAsBit("hasCompleteDecoder");
+ InsnOperands.push_back(OperandInfo(InstDecoder, HasCompleteInstDecoder));
Operands[Opc] = InsnOperands;
return true;
}
@@ -1835,7 +1888,14 @@ static bool populateInstruction(CodeGenTarget &Target,
if (!isReg && String && String->getValue() != "")
Decoder = String->getValue();
- OperandInfo OpInfo(Decoder);
+ RecordVal *HasCompleteDecoderVal =
+ TypeRecord->getValue("hasCompleteDecoder");
+ BitInit *HasCompleteDecoderBit = HasCompleteDecoderVal ?
+ dyn_cast<BitInit>(HasCompleteDecoderVal->getValue()) : nullptr;
+ bool HasCompleteDecoder = HasCompleteDecoderBit ?
+ HasCompleteDecoderBit->getValue() : true;
+
+ OperandInfo OpInfo(Decoder, HasCompleteDecoder);
OpInfo.addField(bitStart, bitWidth, 0);
NumberedInsnOperands[Name].push_back(OpInfo);
@@ -1907,7 +1967,14 @@ static bool populateInstruction(CodeGenTarget &Target,
if (!isReg && String && String->getValue() != "")
Decoder = String->getValue();
- OperandInfo OpInfo(Decoder);
+ RecordVal *HasCompleteDecoderVal =
+ TypeRecord->getValue("hasCompleteDecoder");
+ BitInit *HasCompleteDecoderBit = HasCompleteDecoderVal ?
+ dyn_cast<BitInit>(HasCompleteDecoderVal->getValue()) : nullptr;
+ bool HasCompleteDecoder = HasCompleteDecoderBit ?
+ HasCompleteDecoderBit->getValue() : true;
+
+ OperandInfo OpInfo(Decoder, HasCompleteDecoder);
unsigned Base = ~0U;
unsigned Width = 0;
unsigned Offset = 0;
@@ -2096,12 +2163,52 @@ static void emitDecodeInstruction(formatted_raw_ostream &OS) {
<< " 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.clear();\n"
<< " MI.setOpcode(Opc);\n"
- << " return decodeToMCInst(S, DecodeIdx, insn, MI, Address, DisAsm);\n"
+ << " bool DecodeComplete;\n"
+ << " S = decodeToMCInst(S, DecodeIdx, insn, MI, Address, DisAsm, DecodeComplete);\n"
+ << " assert(DecodeComplete);\n"
+ << "\n"
+ << " DEBUG(dbgs() << Loc << \": OPC_Decode: opcode \" << Opc\n"
+ << " << \", using decoder \" << DecodeIdx << \": \"\n"
+ << " << (S != MCDisassembler::Fail ? \"PASS\" : \"FAIL\") << \"\\n\");\n"
+ << " return S;\n"
+ << " }\n"
+ << " case MCD::OPC_TryDecode: {\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"
+ << " // NumToSkip is a plain 16-bit integer.\n"
+ << " unsigned NumToSkip = *Ptr++;\n"
+ << " NumToSkip |= (*Ptr++) << 8;\n"
+ << "\n"
+ << " // Perform the decode operation.\n"
+ << " MCInst TmpMI;\n"
+ << " TmpMI.setOpcode(Opc);\n"
+ << " bool DecodeComplete;\n"
+ << " S = decodeToMCInst(S, DecodeIdx, insn, TmpMI, Address, DisAsm, DecodeComplete);\n"
+ << " DEBUG(dbgs() << Loc << \": OPC_TryDecode: opcode \" << Opc\n"
+ << " << \", using decoder \" << DecodeIdx << \": \");\n"
+ << "\n"
+ << " if (DecodeComplete) {\n"
+ << " // Decoding complete.\n"
+ << " DEBUG(dbgs() << (S != MCDisassembler::Fail ? \"PASS\" : \"FAIL\") << \"\\n\");\n"
+ << " MI = TmpMI;\n"
+ << " return S;\n"
+ << " } else {\n"
+ << " assert(S == MCDisassembler::Fail);\n"
+ << " // If the decoding was incomplete, skip.\n"
+ << " Ptr += NumToSkip;\n"
+ << " DEBUG(dbgs() << \"FAIL: continuing at \" << (Ptr - DecodeTable) << \"\\n\");\n"
+ << " // Reset decode status. This also drops a SoftFail status that could be\n"
+ << " // set before the decode attempt.\n"
+ << " S = MCDisassembler::Success;\n"
+ << " }\n"
+ << " break;\n"
<< " }\n"
<< " case MCD::OPC_SoftFail: {\n"
<< " // Decode the mask values.\n"
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