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[TableGen] Fixes for per-HwMode decoding problem. #82201

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Merged
merged 1 commit into from
Feb 19, 2024
Merged

[TableGen] Fixes for per-HwMode decoding problem. #82201

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5 changes: 2 additions & 3 deletions llvm/test/TableGen/HwModeEncodeDecode.td
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Original file line number Diff line number Diff line change
Expand Up @@ -74,9 +74,8 @@ def baz : Instruction {
// DECODER-DAG: Opcode: fooTypeEncA:foo
// DECODER-DAG: Opcode: bar
// DECODER-LABEL: DecoderTable_ModeB32[] =
// Note that the comment says fooTypeEncA but this is actually fooTypeEncB; plumbing
// the correct comment text through the decoder is nontrivial.
// DECODER-DAG: Opcode: fooTypeEncA:foo
// DECODER-DAG: Opcode: fooTypeEncB:foo
// DECODER-DAG: Opcode: fooTypeEncA:baz
// DECODER-DAG: Opcode: bar

// ENCODER-LABEL: static const uint64_t InstBits_ModeA[] = {
Expand Down
35 changes: 23 additions & 12 deletions llvm/utils/TableGen/DecoderEmitter.cpp
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Expand Up @@ -118,6 +118,8 @@ struct EncodingIDAndOpcode {
: EncodingID(EncodingID), Opcode(Opcode) {}
};

using EncodingIDsVec = std::vector<EncodingIDAndOpcode>;

raw_ostream &operator<<(raw_ostream &OS, const EncodingAndInst &Value) {
if (Value.EncodingDef != Value.Inst->TheDef)
OS << Value.EncodingDef->getName() << ":";
Expand All @@ -135,8 +137,8 @@ class DecoderEmitter {

// Emit the decoder state machine table.
void emitTable(formatted_raw_ostream &o, DecoderTable &Table,
unsigned Indentation, unsigned BitWidth,
StringRef Namespace) const;
unsigned Indentation, unsigned BitWidth, StringRef Namespace,
const EncodingIDsVec &EncodingIDs) const;
void emitInstrLenTable(formatted_raw_ostream &OS,
std::vector<unsigned> &InstrLen) const;
void emitPredicateFunction(formatted_raw_ostream &OS,
Expand Down Expand Up @@ -766,7 +768,16 @@ unsigned Filter::usefulness() const {
// Emit the decoder state machine table.
void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
unsigned Indentation, unsigned BitWidth,
StringRef Namespace) const {
StringRef Namespace,
const EncodingIDsVec &EncodingIDs) const {
// We'll need to be able to map from a decoded opcode into the corresponding
// EncodingID for this specific combination of BitWidth and Namespace. This
// is used below to index into NumberedEncodings.
DenseMap<unsigned, unsigned> OpcodeToEncodingID;
OpcodeToEncodingID.reserve(EncodingIDs.size());
for (auto &EI : EncodingIDs)
OpcodeToEncodingID[EI.Opcode] = EI.EncodingID;

OS.indent(Indentation) << "static const uint8_t DecoderTable" << Namespace
<< BitWidth << "[] = {\n";

Expand Down Expand Up @@ -888,8 +899,12 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
// Decoder index.
I += emitULEB128(I, OS);

auto EncI = OpcodeToEncodingID.find(Opc);
assert(EncI != OpcodeToEncodingID.end() && "no encoding entry");
auto EncodingID = EncI->second;

if (!IsTry) {
OS << "// Opcode: " << NumberedEncodings[Opc] << "\n";
OS << "// Opcode: " << NumberedEncodings[EncodingID] << "\n";
break;
}

Expand All @@ -899,7 +914,7 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
uint32_t NumToSkip = emitNumToSkip(I, OS);
I += 3;

OS << "// Opcode: " << NumberedEncodings[Opc]
OS << "// Opcode: " << NumberedEncodings[EncodingID]
<< ", skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
break;
}
Expand Down Expand Up @@ -2449,11 +2464,8 @@ void DecoderEmitter::run(raw_ostream &o) {
std::set<StringRef> HwModeNames;
const auto &NumberedInstructions = Target.getInstructionsByEnumValue();
NumberedEncodings.reserve(NumberedInstructions.size());
DenseMap<Record *, unsigned> IndexOfInstruction;
// First, collect all HwModes referenced by the target.
for (const auto &NumberedInstruction : NumberedInstructions) {
IndexOfInstruction[NumberedInstruction->TheDef] = NumberedEncodings.size();

if (const RecordVal *RV =
NumberedInstruction->TheDef->getValue("EncodingInfos")) {
if (auto *DI = dyn_cast_or_null<DefInit>(RV->getValue())) {
Expand All @@ -2470,8 +2482,6 @@ void DecoderEmitter::run(raw_ostream &o) {
HwModeNames.insert("");

for (const auto &NumberedInstruction : NumberedInstructions) {
IndexOfInstruction[NumberedInstruction->TheDef] = NumberedEncodings.size();

if (const RecordVal *RV =
NumberedInstruction->TheDef->getValue("EncodingInfos")) {
if (DefInit *DI = dyn_cast_or_null<DefInit>(RV->getValue())) {
Expand Down Expand Up @@ -2544,7 +2554,7 @@ void DecoderEmitter::run(raw_ostream &o) {
DecoderNamespace +=
std::string("_") + NumberedEncodings[i].HwModeName.str();
OpcMap[std::pair(DecoderNamespace, Size)].emplace_back(
i, IndexOfInstruction.find(Def)->second);
i, Target.getInstrIntValue(Def));
} else {
NumEncodingsOmitted++;
}
Expand Down Expand Up @@ -2577,7 +2587,8 @@ void DecoderEmitter::run(raw_ostream &o) {
TableInfo.Table.push_back(MCD::OPC_Fail);

// Print the table to the output stream.
emitTable(OS, TableInfo.Table, 0, FC.getBitWidth(), Opc.first.first);
emitTable(OS, TableInfo.Table, 0, FC.getBitWidth(), Opc.first.first,
Opc.second);
}

// For variable instruction, we emit a instruction length table
Expand Down