[MLIR][DataLayout] Add support for scalable vectors (#89349)

This commit extends the data layout to support scalable vectors. For
scalable vectors, the `TypeSize`'s scalable field is set accordingly,
and the alignment information remains the same as for normal vectors.
This behavior is in sync with what LLVM's data layout queries are
producing.

Before this change, scalable vectors incorrectly returned the same size
as "normal" vectors.
This commit is contained in:
Christian Ulmann 2024-04-19 13:46:10 +02:00 committed by GitHub
parent 4d7f3d9e0f
commit df411fbac6
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3 changed files with 36 additions and 8 deletions

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@ -75,10 +75,12 @@ mlir::detail::getDefaultTypeSizeInBits(Type type, const DataLayout &dataLayout,
// there is no bit-packing at the moment element sizes are taken in bytes and
// multiplied with 8 bits.
// TODO: make this extensible.
if (auto vecType = dyn_cast<VectorType>(type))
return vecType.getNumElements() / vecType.getShape().back() *
llvm::PowerOf2Ceil(vecType.getShape().back()) *
dataLayout.getTypeSize(vecType.getElementType()) * 8;
if (auto vecType = dyn_cast<VectorType>(type)) {
uint64_t baseSize = vecType.getNumElements() / vecType.getShape().back() *
llvm::PowerOf2Ceil(vecType.getShape().back()) *
dataLayout.getTypeSize(vecType.getElementType()) * 8;
return llvm::TypeSize::get(baseSize, vecType.isScalable());
}
if (auto typeInterface = dyn_cast<DataLayoutTypeInterface>(type))
return typeInterface.getTypeSizeInBits(dataLayout, params);
@ -138,9 +140,10 @@ getFloatTypeABIAlignment(FloatType fltType, const DataLayout &dataLayout,
uint64_t mlir::detail::getDefaultABIAlignment(
Type type, const DataLayout &dataLayout,
ArrayRef<DataLayoutEntryInterface> params) {
// Natural alignment is the closest power-of-two number above.
// Natural alignment is the closest power-of-two number above. For scalable
// vectors, aligning them to the same as the base vector is sufficient.
if (isa<VectorType>(type))
return llvm::PowerOf2Ceil(dataLayout.getTypeSize(type));
return llvm::PowerOf2Ceil(dataLayout.getTypeSize(type).getKnownMinValue());
if (auto fltType = dyn_cast<FloatType>(type))
return getFloatTypeABIAlignment(fltType, dataLayout, params);

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@ -32,6 +32,18 @@ func.func @no_layout_builtin() {
// CHECK: preferred = 8
// CHECK: size = 8
"test.data_layout_query"() : () -> index
// CHECK: alignment = 16
// CHECK: bitsize = 128
// CHECK: index = 0
// CHECK: preferred = 16
// CHECK: size = 16
"test.data_layout_query"() : () -> vector<4xi32>
// CHECK: alignment = 16
// CHECK: bitsize = {minimal_size = 128 : index, scalable}
// CHECK: index = 0
// CHECK: preferred = 16
// CHECK: size = {minimal_size = 16 : index, scalable}
"test.data_layout_query"() : () -> vector<[4]xi32>
return
}

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@ -46,9 +46,22 @@ struct TestDataLayoutQuery
Attribute programMemorySpace = layout.getProgramMemorySpace();
Attribute globalMemorySpace = layout.getGlobalMemorySpace();
uint64_t stackAlignment = layout.getStackAlignment();
auto convertTypeSizeToAttr = [&](llvm::TypeSize typeSize) -> Attribute {
if (!typeSize.isScalable())
return builder.getIndexAttr(typeSize);
return builder.getDictionaryAttr({
builder.getNamedAttr("scalable", builder.getUnitAttr()),
builder.getNamedAttr(
"minimal_size",
builder.getIndexAttr(typeSize.getKnownMinValue())),
});
};
op->setAttrs(
{builder.getNamedAttr("size", builder.getIndexAttr(size)),
builder.getNamedAttr("bitsize", builder.getIndexAttr(bitsize)),
{builder.getNamedAttr("size", convertTypeSizeToAttr(size)),
builder.getNamedAttr("bitsize", convertTypeSizeToAttr(bitsize)),
builder.getNamedAttr("alignment", builder.getIndexAttr(alignment)),
builder.getNamedAttr("preferred", builder.getIndexAttr(preferred)),
builder.getNamedAttr("index", builder.getIndexAttr(index)),