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[TableGen] Simplify emitULEB128 in DecoderEmitter.cpp. NFC #130214

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Merged
merged 1 commit into from
Mar 7, 2025
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[TableGen] Simplify emitULEB128 in DecoderEmitter.cpp. NFC #130214

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28 changes: 10 additions & 18 deletions llvm/utils/TableGen/DecoderEmitter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -808,19 +808,15 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
Indent += 2;

// Emit ULEB128 encoded value to OS, returning the number of bytes emitted.
auto emitULEB128 = [](DecoderTable::const_iterator I,
auto emitULEB128 = [](DecoderTable::const_iterator &I,
formatted_raw_ostream &OS) {
unsigned Len = 0;
while (*I >= 128) {
while (*I >= 128)
OS << (unsigned)*I++ << ", ";
Len++;
}
OS << (unsigned)*I++ << ", ";
return Len + 1;
};

// Emit 24-bit numtoskip value to OS, returning the NumToSkip value.
auto emitNumToSkip = [](DecoderTable::const_iterator I,
auto emitNumToSkip = [](DecoderTable::const_iterator &I,
formatted_raw_ostream &OS) {
uint8_t Byte = *I++;
uint32_t NumToSkip = Byte;
Expand Down Expand Up @@ -857,7 +853,7 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
unsigned Start = decodeULEB128(Table.data() + Pos + 1, nullptr,
Table.data() + Table.size(), &ErrMsg);
assert(ErrMsg == nullptr && "ULEB128 value too large!");
I += emitULEB128(I, OS);
emitULEB128(I, OS);

unsigned Len = *I++;
OS << Len << ", // Inst{";
Expand All @@ -870,39 +866,36 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
++I;
OS << Indent << "MCD::OPC_FilterValue, ";
// The filter value is ULEB128 encoded.
I += emitULEB128(I, OS);
emitULEB128(I, OS);

// 24-bit numtoskip value.
uint32_t NumToSkip = emitNumToSkip(I, OS);
I += 3;
OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
break;
}
case MCD::OPC_CheckField: {
++I;
OS << Indent << "MCD::OPC_CheckField, ";
// ULEB128 encoded start value.
I += emitULEB128(I, OS);
emitULEB128(I, OS);
// 8-bit length.
unsigned Len = *I++;
OS << Len << ", ";
// ULEB128 encoded field value.
I += emitULEB128(I, OS);
emitULEB128(I, OS);

// 24-bit numtoskip value.
uint32_t NumToSkip = emitNumToSkip(I, OS);
I += 3;
OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
break;
}
case MCD::OPC_CheckPredicate: {
++I;
OS << Indent << "MCD::OPC_CheckPredicate, ";
I += emitULEB128(I, OS);
emitULEB128(I, OS);

// 24-bit numtoskip value.
uint32_t NumToSkip = emitNumToSkip(I, OS);
I += 3;
OS << "// Skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
break;
}
Expand All @@ -917,10 +910,10 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,
assert(ErrMsg == nullptr && "ULEB128 value too large!");

OS << Indent << "MCD::OPC_" << (IsTry ? "Try" : "") << "Decode, ";
I += emitULEB128(I, OS);
emitULEB128(I, OS);

// Decoder index.
I += emitULEB128(I, OS);
emitULEB128(I, OS);

auto EncI = OpcodeToEncodingID.find(Opc);
assert(EncI != OpcodeToEncodingID.end() && "no encoding entry");
Expand All @@ -935,7 +928,6 @@ void DecoderEmitter::emitTable(formatted_raw_ostream &OS, DecoderTable &Table,

// 24-bit numtoskip value.
uint32_t NumToSkip = emitNumToSkip(I, OS);
I += 3;

OS << "// Opcode: " << NumberedEncodings[EncodingID]
<< ", skip to: " << ((I - Table.begin()) + NumToSkip) << "\n";
Expand Down