[llvm][Codegen] Make `getVectorTypeBreakdownMVT` work with scalable types.

Reviewers: efriedma, andwar, sdesmalen

Reviewed By: efriedma

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77434
This commit is contained in:
Francesco Petrogalli 2020-04-10 00:10:52 +01:00
parent 9f87d951fc
commit c846d2682b
2 changed files with 19 additions and 15 deletions

View File

@ -37,6 +37,7 @@ public:
return { Min * RHS, Scalable };
}
ElementCount operator/(unsigned RHS) {
assert(Min % RHS == 0 && "Min is not a multiple of RHS.");
return { Min / RHS, Scalable };
}

View File

@ -944,42 +944,45 @@ static unsigned getVectorTypeBreakdownMVT(MVT VT, MVT &IntermediateVT,
MVT &RegisterVT,
TargetLoweringBase *TLI) {
// Figure out the right, legal destination reg to copy into.
unsigned NumElts = VT.getVectorNumElements();
ElementCount EC = VT.getVectorElementCount();
MVT EltTy = VT.getVectorElementType();
unsigned NumVectorRegs = 1;
// FIXME: We don't support non-power-of-2-sized vectors for now. Ideally we
// could break down into LHS/RHS like LegalizeDAG does.
if (!isPowerOf2_32(NumElts)) {
NumVectorRegs = NumElts;
NumElts = 1;
// FIXME: We don't support non-power-of-2-sized vectors for now.
// Ideally we could break down into LHS/RHS like LegalizeDAG does.
if (!isPowerOf2_32(EC.Min)) {
// Split EC to unit size (scalable property is preserved).
NumVectorRegs = EC.Min;
EC = EC / NumVectorRegs;
}
// Divide the input until we get to a supported size. This will always
// end with a scalar if the target doesn't support vectors.
while (NumElts > 1 && !TLI->isTypeLegal(MVT::getVectorVT(EltTy, NumElts))) {
NumElts >>= 1;
// Divide the input until we get to a supported size. This will
// always end up with an EC that represent a scalar or a scalable
// scalar.
while (EC.Min > 1 && !TLI->isTypeLegal(MVT::getVectorVT(EltTy, EC))) {
EC.Min >>= 1;
NumVectorRegs <<= 1;
}
NumIntermediates = NumVectorRegs;
MVT NewVT = MVT::getVectorVT(EltTy, NumElts);
MVT NewVT = MVT::getVectorVT(EltTy, EC);
if (!TLI->isTypeLegal(NewVT))
NewVT = EltTy;
IntermediateVT = NewVT;
unsigned NewVTSize = NewVT.getSizeInBits();
unsigned LaneSizeInBits = NewVT.getScalarSizeInBits().getFixedSize();
// Convert sizes such as i33 to i64.
if (!isPowerOf2_32(NewVTSize))
NewVTSize = NextPowerOf2(NewVTSize);
if (!isPowerOf2_32(LaneSizeInBits))
LaneSizeInBits = NextPowerOf2(LaneSizeInBits);
MVT DestVT = TLI->getRegisterType(NewVT);
RegisterVT = DestVT;
if (EVT(DestVT).bitsLT(NewVT)) // Value is expanded, e.g. i64 -> i16.
return NumVectorRegs*(NewVTSize/DestVT.getSizeInBits());
return NumVectorRegs *
(LaneSizeInBits / DestVT.getScalarSizeInBits().getFixedSize());
// Otherwise, promotion or legal types use the same number of registers as
// the vector decimated to the appropriate level.