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[TableGen] Combine the two separate OperandMapping loops in PseudoLoweringEmitter. #136007

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Merged
merged 3 commits into from
Apr 16, 2025
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[TableGen] Combine the two separate OperandMapping loops in PseudoLoweringEmitter. #136007

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efb9f4e
[TableGen] Combine the two separate OperandMapping loops in PseudoLow…
topperc Apr 16, 2025
32525f2
fixup! address review comments
topperc Apr 16, 2025
3a9db6e
fixup! address review comment
topperc Apr 16, 2025
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194 changes: 98 additions & 96 deletions llvm/utils/TableGen/PseudoLoweringEmitter.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -51,10 +51,11 @@ class PseudoLoweringEmitter {

SmallVector<PseudoExpansion, 64> Expansions;

unsigned addDagOperandMapping(const Record *Rec, const DagInit *Dag,
const CodeGenInstruction &Insn,
IndexedMap<OpData> &OperandMap,
unsigned BaseIdx);
void addOperandMapping(unsigned MIOpNo, unsigned NumOps, const Record *Rec,
const DagInit *Dag, unsigned DagIdx,
const Record *OpRec, IndexedMap<OpData> &OperandMap,
const StringMap<unsigned> &SourceOperands,
const CodeGenInstruction &SourceInsn);
void evaluateExpansion(const Record *Pseudo);
void emitLoweringEmitter(raw_ostream &o);

Expand All @@ -66,64 +67,67 @@ class PseudoLoweringEmitter {
};
} // End anonymous namespace

// FIXME: This pass currently can only expand a pseudo to a single instruction.
// The pseudo expansion really should take a list of dags, not just
// a single dag, so we can do fancier things.
unsigned PseudoLoweringEmitter::addDagOperandMapping(
const Record *Rec, const DagInit *Dag, const CodeGenInstruction &Insn,
IndexedMap<OpData> &OperandMap, unsigned BaseIdx) {
unsigned OpsAdded = 0;
for (unsigned i = 0, e = Dag->getNumArgs(); i != e; ++i) {
if (const DefInit *DI = dyn_cast<DefInit>(Dag->getArg(i))) {
// Physical register reference. Explicit check for the special case
// "zero_reg" definition.
if (DI->getDef()->isSubClassOf("Register") ||
DI->getDef()->getName() == "zero_reg") {
auto &Entry = OperandMap[BaseIdx + i];
Entry.Kind = OpData::Reg;
Entry.Data.Reg = DI->getDef();
++OpsAdded;
continue;
}
void PseudoLoweringEmitter::addOperandMapping(
unsigned MIOpNo, unsigned NumOps, const Record *Rec, const DagInit *Dag,
unsigned DagIdx, const Record *OpRec, IndexedMap<OpData> &OperandMap,
const StringMap<unsigned> &SourceOperands,
const CodeGenInstruction &SourceInsn) {
const Init *DagArg = Dag->getArg(DagIdx);
if (const DefInit *DI = dyn_cast<DefInit>(DagArg)) {
// Physical register reference. Explicit check for the special case
// "zero_reg" definition.
if (DI->getDef()->isSubClassOf("Register") ||
DI->getDef()->getName() == "zero_reg") {
auto &Entry = OperandMap[MIOpNo];
Entry.Kind = OpData::Reg;
Entry.Data.Reg = DI->getDef();
return;
}

// Normal operands should always have the same type, or we have a
// problem.
// FIXME: We probably shouldn't ever get a non-zero BaseIdx here.
assert(BaseIdx == 0 && "Named subargument in pseudo expansion?!");
if (DI->getDef() != Insn.Operands[BaseIdx + i].Rec)
PrintFatalError(Rec, "In pseudo instruction '" + Rec->getName() +
"', operand type '" + DI->getDef()->getName() +
"' does not match expansion operand type '" +
Insn.Operands[BaseIdx + i].Rec->getName() +
"'");
// Source operand maps to destination operand. The Data element
// will be filled in later, just set the Kind for now. Do it
// for each corresponding MachineInstr operand, not just the first.
for (unsigned I = 0, E = Insn.Operands[i].MINumOperands; I != E; ++I)
OperandMap[BaseIdx + i + I].Kind = OpData::Operand;
OpsAdded += Insn.Operands[i].MINumOperands;
} else if (const IntInit *II = dyn_cast<IntInit>(Dag->getArg(i))) {
auto &Entry = OperandMap[BaseIdx + i];
Entry.Kind = OpData::Imm;
Entry.Data.Imm = II->getValue();
++OpsAdded;
} else if (const auto *BI = dyn_cast<BitsInit>(Dag->getArg(i))) {
auto &Entry = OperandMap[BaseIdx + i];
Entry.Kind = OpData::Imm;
Entry.Data.Imm = *BI->convertInitializerToInt();
++OpsAdded;
} else if (const DagInit *SubDag = dyn_cast<DagInit>(Dag->getArg(i))) {
// Just add the operands recursively. This is almost certainly
// a constant value for a complex operand (> 1 MI operand).
unsigned NewOps =
addDagOperandMapping(Rec, SubDag, Insn, OperandMap, BaseIdx + i);
OpsAdded += NewOps;
// Since we added more than one, we also need to adjust the base.
BaseIdx += NewOps - 1;
} else
llvm_unreachable("Unhandled pseudo-expansion argument type!");
}
return OpsAdded;
if (DI->getDef() != OpRec)
PrintFatalError(Rec, "In pseudo instruction '" + Rec->getName() +
"', operand type '" + DI->getDef()->getName() +
"' does not match expansion operand type '" +
OpRec->getName() + "'");

StringMap<unsigned>::const_iterator SourceOp =
SourceOperands.find(Dag->getArgNameStr(DagIdx));
if (SourceOp == SourceOperands.end())
PrintFatalError(Rec, "In pseudo instruction '" + Rec->getName() +
"', output operand '" +
Dag->getArgNameStr(DagIdx) +
"' has no matching source operand");
const auto &SrcOpnd = SourceInsn.Operands[SourceOp->getValue()];
if (NumOps != SrcOpnd.MINumOperands)
PrintFatalError(
Rec,
"In pseudo instruction '" + Rec->getName() + "', output operand '" +
OpRec->getName() +
"' has a different number of sub operands than source operand '" +
SrcOpnd.Rec->getName() + "'");

// Source operand maps to destination operand. Do it for each corresponding
// MachineInstr operand, not just the first.
for (unsigned I = 0, E = NumOps; I != E; ++I) {
auto &Entry = OperandMap[MIOpNo + I];
Entry.Kind = OpData::Operand;
Entry.Data.Operand = SrcOpnd.MIOperandNo + I;
}

LLVM_DEBUG(dbgs() << " " << SourceOp->getValue() << " ==> " << DagIdx
<< "\n");
} else if (const auto *II = dyn_cast<IntInit>(DagArg)) {
assert(NumOps == 1);
auto &Entry = OperandMap[MIOpNo];
Entry.Kind = OpData::Imm;
Entry.Data.Imm = II->getValue();
} else if (const auto *BI = dyn_cast<BitsInit>(DagArg)) {
assert(NumOps == 1);
auto &Entry = OperandMap[MIOpNo];
Entry.Kind = OpData::Imm;
Entry.Data.Imm = *BI->convertInitializerToInt();
} else
llvm_unreachable("Unhandled pseudo-expansion argument type!");
}

void PseudoLoweringEmitter::evaluateExpansion(const Record *Rec) {
Expand Down Expand Up @@ -157,14 +161,6 @@ void PseudoLoweringEmitter::evaluateExpansion(const Record *Rec) {
"', result operator '" + Operator->getName() +
"' has the wrong number of operands");

unsigned NumMIOperands = 0;
for (const auto &Op : Insn.Operands)
NumMIOperands += Op.MINumOperands;
IndexedMap<OpData> OperandMap;
OperandMap.grow(NumMIOperands);

addDagOperandMapping(Rec, Dag, Insn, OperandMap, 0);

// If there are more operands that weren't in the DAG, they have to
// be operands that have default values, or we have an error. Currently,
// Operands that are a subclass of OperandWithDefaultOp have default values.
Expand All @@ -180,37 +176,43 @@ void PseudoLoweringEmitter::evaluateExpansion(const Record *Rec) {
for (const auto &[Idx, SrcOp] : enumerate(SourceInsn.Operands))
SourceOperands[SrcOp.Name] = Idx;

LLVM_DEBUG(dbgs() << " Operand mapping:\n");
for (const auto &[Idx, Opnd] : enumerate(Insn.Operands)) {
// We've already handled constant values. Just map instruction operands
// here.
if (OperandMap[Opnd.MIOperandNo].Kind != OpData::Operand)
continue;
StringMap<unsigned>::iterator SourceOp =
SourceOperands.find(Dag->getArgNameStr(Idx));
if (SourceOp == SourceOperands.end())
PrintFatalError(Rec, "In pseudo instruction '" + Rec->getName() +
"', output operand '" + Dag->getArgNameStr(Idx) +
"' has no matching source operand");
const auto &SrcOpnd = SourceInsn.Operands[SourceOp->getValue()];
if (Opnd.MINumOperands != SrcOpnd.MINumOperands)
PrintFatalError(
Rec,
"In pseudo instruction '" + Rec->getName() + "', output operand '" +
Opnd.Rec->getName() +
"' has a different number of sub operands than source operand '" +
SrcOpnd.Rec->getName() + "'");
unsigned NumMIOperands = 0;
for (const auto &Op : Insn.Operands)
NumMIOperands += Op.MINumOperands;
IndexedMap<OpData> OperandMap;
OperandMap.grow(NumMIOperands);

// Map the source operand to the destination operand index for each
// MachineInstr operand.
for (unsigned I = 0, E = Opnd.MINumOperands; I != E; ++I)
OperandMap[Opnd.MIOperandNo + I].Data.Operand = SrcOpnd.MIOperandNo + I;
// FIXME: This pass currently can only expand a pseudo to a single
// instruction. The pseudo expansion really should take a list of dags, not
// just a single dag, so we can do fancier things.
LLVM_DEBUG(dbgs() << " Operand mapping:\n");
for (const auto &[Idx, DstOp] : enumerate(Insn.Operands)) {
unsigned MIOpNo = DstOp.MIOperandNo;

LLVM_DEBUG(dbgs() << " " << SourceOp->getValue() << " ==> " << Idx
<< "\n");
if (const auto *SubDag = dyn_cast<DagInit>(Dag->getArg(Idx))) {
if (!DstOp.MIOperandInfo || DstOp.MIOperandInfo->getNumArgs() == 0)
PrintFatalError(Rec, "In pseudo instruction '" + Rec->getName() +
"', operand '" + DstOp.Rec->getName() +
"' does not have suboperands");
if (DstOp.MINumOperands != SubDag->getNumArgs()) {
PrintFatalError(
Rec, "In pseudo instruction '" + Rec->getName() + "', '" +
SubDag->getAsString() +
"' has wrong number of operands for operand type '" +
DstOp.Rec->getName() + "'");
}
for (unsigned I = 0, E = DstOp.MINumOperands; I != E; ++I) {
auto *OpndRec = cast<DefInit>(DstOp.MIOperandInfo->getArg(I))->getDef();
addOperandMapping(MIOpNo + I, 1, Rec, SubDag, I, OpndRec, OperandMap,
SourceOperands, SourceInsn);
}
} else {
addOperandMapping(MIOpNo, DstOp.MINumOperands, Rec, Dag, Idx, DstOp.Rec,
OperandMap, SourceOperands, SourceInsn);
}
}

Expansions.push_back(PseudoExpansion(SourceInsn, Insn, OperandMap));
Expansions.emplace_back(SourceInsn, Insn, OperandMap);
}

void PseudoLoweringEmitter::emitLoweringEmitter(raw_ostream &o) {
Expand Down
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