GlobalISel: Partially implement fewerElementsVector G_UNMERGE_VALUES
Odd sized vectors aren't handled yet.
llvm-svn: 368713
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index a96d748..db796e9 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -171,6 +171,26 @@
return true;
}
+static LLT getGCDType(LLT OrigTy, LLT TargetTy) {
+ if (OrigTy.isVector() && TargetTy.isVector()) {
+ assert(OrigTy.getElementType() == TargetTy.getElementType());
+ int GCD = greatestCommonDivisor(OrigTy.getNumElements(),
+ TargetTy.getNumElements());
+ return LLT::scalarOrVector(GCD, OrigTy.getElementType());
+ }
+
+ if (OrigTy.isVector() && !TargetTy.isVector()) {
+ assert(OrigTy.getElementType() == TargetTy);
+ return TargetTy;
+ }
+
+ assert(!OrigTy.isVector() && !TargetTy.isVector());
+
+ int GCD = greatestCommonDivisor(OrigTy.getSizeInBits(),
+ TargetTy.getSizeInBits());
+ return LLT::scalar(GCD);
+}
+
void LegalizerHelper::insertParts(Register DstReg,
LLT ResultTy, LLT PartTy,
ArrayRef<Register> PartRegs,
@@ -2574,6 +2594,46 @@
}
LegalizerHelper::LegalizeResult
+LegalizerHelper::fewerElementsVectorUnmergeValues(MachineInstr &MI,
+ unsigned TypeIdx,
+ LLT NarrowTy) {
+ if (TypeIdx != 1)
+ return UnableToLegalize;
+
+ const int NumDst = MI.getNumOperands() - 1;
+ const Register SrcReg = MI.getOperand(NumDst).getReg();
+ LLT SrcTy = MRI.getType(SrcReg);
+
+ LLT DstTy = MRI.getType(MI.getOperand(0).getReg());
+
+ // TODO: Create sequence of extracts.
+ if (DstTy == NarrowTy)
+ return UnableToLegalize;
+
+ LLT GCDTy = getGCDType(SrcTy, NarrowTy);
+ if (DstTy == GCDTy) {
+ // This would just be a copy of the same unmerge.
+ // TODO: Create extracts, pad with undef and create intermediate merges.
+ return UnableToLegalize;
+ }
+
+ auto Unmerge = MIRBuilder.buildUnmerge(GCDTy, SrcReg);
+ const int NumUnmerge = Unmerge->getNumOperands() - 1;
+ const int PartsPerUnmerge = NumDst / NumUnmerge;
+
+ for (int I = 0; I != NumUnmerge; ++I) {
+ auto MIB = MIRBuilder.buildInstr(TargetOpcode::G_UNMERGE_VALUES);
+
+ for (int J = 0; J != PartsPerUnmerge; ++J)
+ MIB.addDef(MI.getOperand(I * PartsPerUnmerge + J).getReg());
+ MIB.addUse(Unmerge.getReg(I));
+ }
+
+ MI.eraseFromParent();
+ return Legalized;
+}
+
+LegalizerHelper::LegalizeResult
LegalizerHelper::reduceLoadStoreWidth(MachineInstr &MI, unsigned TypeIdx,
LLT NarrowTy) {
// FIXME: Don't know how to handle secondary types yet.
@@ -2744,6 +2804,8 @@
return fewerElementsVectorSelect(MI, TypeIdx, NarrowTy);
case G_PHI:
return fewerElementsVectorPhi(MI, TypeIdx, NarrowTy);
+ case G_UNMERGE_VALUES:
+ return fewerElementsVectorUnmergeValues(MI, TypeIdx, NarrowTy);
case G_LOAD:
case G_STORE:
return reduceLoadStoreWidth(MI, TypeIdx, NarrowTy);
