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Jul 30, 2025
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[mlir][Vector] Allow elementwise/broadcast swap to handle mixed types #151274

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15d432f
[mlir][Vector] Allow elementwise/broadcast swap to handle mixed types
krzysz00 Jul 30, 2025
d1e4983
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krzysz00 Jul 30, 2025
99c5d23
Reorder tests
krzysz00 Jul 30, 2025
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70 changes: 45 additions & 25 deletions mlir/lib/Dialect/Vector/Transforms/VectorTransforms.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -965,6 +965,28 @@ struct BreakDownVectorBitCast : public OpRewritePattern<vector::BitCastOp> {
std::function<bool(BitCastOp)> controlFn;
};

static bool haveSameShapeAndScaling(Type t, Type u) {
auto tVec = dyn_cast<VectorType>(t);
auto uVec = dyn_cast<VectorType>(u);
if (!tVec) {
return !uVec;
}
if (!uVec) {
return false;
}
return tVec.getShape() == uVec.getShape() &&
tVec.getScalableDims() == uVec.getScalableDims();
}

/// If `type` is shaped, clone it with `newElementType`. Otherwise,
/// return `newElementType`.
static Type cloneOrReplace(Type type, Type newElementType) {
if (auto shapedType = dyn_cast<ShapedType>(type)) {
return shapedType.clone(newElementType);
}
return newElementType;
}

/// Reorders elementwise(broadcast/splat) to broadcast(elementwise). Ex:
///
/// Example:
Expand All @@ -988,23 +1010,22 @@ struct ReorderElementwiseOpsOnBroadcast final
PatternRewriter &rewriter) const override {
if (op->getNumResults() != 1)
return failure();
if (!llvm::isa<ShapedType>(op->getResults()[0].getType()))
auto resultType = dyn_cast<VectorType>(op->getResult(0).getType());
if (!resultType)
return failure();
if (!OpTrait::hasElementwiseMappableTraits(op))
return rewriter.notifyMatchFailure(
op, "Op doesn't have ElementwiseMappableTraits");
if (op->getNumOperands() == 0)
return failure();
if (op->getResults()[0].getType() != op->getOperand(0).getType())
return rewriter.notifyMatchFailure(op,
"result and operand type mismatch");
if (isa<vector::FMAOp>(op)) {
return rewriter.notifyMatchFailure(
op,
"Op only accepts vector types - not supported as broadcast source "
"might be a scalar");
}

Type resultElemType = resultType.getElementType();
// Get the type of the first non-constant operand
Operation *firstBroadcastOrSplat = nullptr;
for (Value operand : op->getOperands()) {
Expand All @@ -1020,24 +1041,23 @@ struct ReorderElementwiseOpsOnBroadcast final
}
if (!firstBroadcastOrSplat)
return failure();
Type firstBroadcastOrSplatType =
firstBroadcastOrSplat->getOperand(0).getType();
Type unbroadcastResultType = cloneOrReplace(
firstBroadcastOrSplat->getOperand(0).getType(), resultElemType);

// Make sure that all operands are broadcast from identical types:
// Make sure that all operands are broadcast from identically-shaped types:
// * scalar (`vector.broadcast` + `vector.splat`), or
// * vector (`vector.broadcast`).
// Otherwise the re-ordering wouldn't be safe.
if (!llvm::all_of(
op->getOperands(), [&firstBroadcastOrSplatType](Value val) {
if (auto bcastOp = val.getDefiningOp<vector::BroadcastOp>())
return (bcastOp.getOperand().getType() ==
firstBroadcastOrSplatType);
if (auto splatOp = val.getDefiningOp<vector::SplatOp>())
return (splatOp.getOperand().getType() ==
firstBroadcastOrSplatType);
SplatElementsAttr splatConst;
return matchPattern(val, m_Constant(&splatConst));
})) {
if (!llvm::all_of(op->getOperands(), [&unbroadcastResultType](Value val) {
if (auto bcastOp = val.getDefiningOp<vector::BroadcastOp>())
return haveSameShapeAndScaling(bcastOp.getOperand().getType(),
unbroadcastResultType);
if (auto splatOp = val.getDefiningOp<vector::SplatOp>())
return haveSameShapeAndScaling(splatOp.getOperand().getType(),
unbroadcastResultType);
SplatElementsAttr splatConst;
return matchPattern(val, m_Constant(&splatConst));
})) {
return failure();
}

Expand All @@ -1048,15 +1068,16 @@ struct ReorderElementwiseOpsOnBroadcast final
SplatElementsAttr splatConst;
if (matchPattern(operand, m_Constant(&splatConst))) {
Attribute newConst;
if (auto shapedTy = dyn_cast<ShapedType>(firstBroadcastOrSplatType)) {
newConst = splatConst.resizeSplat(shapedTy);
Type elementType = getElementTypeOrSelf(operand.getType());
Type newType = cloneOrReplace(unbroadcastResultType, elementType);
if (auto shapedTy = dyn_cast<ShapedType>(unbroadcastResultType)) {
newConst = splatConst.resizeSplat(cast<ShapedType>(newType));
} else {
newConst = splatConst.getSplatValue<Attribute>();
}
Operation *newConstOp =
operand.getDefiningOp()->getDialect()->materializeConstant(
rewriter, newConst, firstBroadcastOrSplatType,
operand.getLoc());
rewriter, newConst, newType, operand.getLoc());
srcValues.push_back(newConstOp->getResult(0));
} else {
srcValues.push_back(operand.getDefiningOp()->getOperand(0));
Expand All @@ -1066,12 +1087,11 @@ struct ReorderElementwiseOpsOnBroadcast final
// Create the "elementwise" Op
Operation *elementwiseOp =
rewriter.create(op->getLoc(), op->getName().getIdentifier(), srcValues,
firstBroadcastOrSplatType, op->getAttrs());
unbroadcastResultType, op->getAttrs());

// Replace the original Op with the elementwise Op
auto vectorType = op->getResultTypes()[0];
rewriter.replaceOpWithNewOp<vector::BroadcastOp>(
op, vectorType, elementwiseOp->getResults());
op, resultType, elementwiseOp->getResults());

return success();
}
Expand Down
75 changes: 68 additions & 7 deletions mlir/test/Dialect/Vector/vector-sink.mlir
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Original file line number Diff line number Diff line change
Expand Up @@ -180,13 +180,14 @@ func.func @negative_not_elementwise() -> vector<2x2xf32> {

// -----

// The source and the result for arith.cmp have different types - not supported

// CHECK-LABEL: func.func @negative_source_and_result_mismatch
// CHECK: %[[BROADCAST:.+]] = vector.broadcast
// CHECK: %[[RETURN:.+]] = arith.cmpf uno, %[[BROADCAST]], %[[BROADCAST]]
// CHECK: return %[[RETURN]]
func.func @negative_source_and_result_mismatch(%arg0 : f32, %arg1 : vector<1xf32>) -> vector<1xi1> {
// The source and the result for arith.cmp have different types

// CHECK-LABEL: func.func @source_and_result_mismatch(
// CHECK-SAME: %[[ARG0:.+]]: f32)
// CHECK: %[[COMPARE:.+]] = arith.cmpf uno, %[[ARG0]], %[[ARG0]]
// CHECK: %[[BROADCAST:.+]] = vector.broadcast %[[COMPARE]] : i1 to vector<1xi1>
// CHECK: return %[[BROADCAST]]
func.func @source_and_result_mismatch(%arg0 : f32) -> vector<1xi1> {
%0 = vector.broadcast %arg0 : f32 to vector<1xf32>
%1 = arith.cmpf uno, %0, %0 : vector<1xf32>
return %1 : vector<1xi1>
Expand Down Expand Up @@ -321,6 +322,66 @@ func.func @negative_broadcast_with_non_splat_const(%arg0: index) -> vector<1x4xi
return %2 : vector<1x4xindex>
}

// -----

// CHECK-LABEL: func.func @broadcast_scalar_mixed_type(
// CHECK-SAME: %[[ARG_0:.*]]: f16) -> vector<1x4xf32> {
// CHECK: %[[EXTF:.*]] = arith.extf %[[ARG_0]] : f16 to f32
// CHECK: %[[BCAST:.*]] = vector.broadcast %[[EXTF]] : f32 to vector<1x4xf32>
// CHECK: return %[[BCAST]] : vector<1x4xf32>

func.func @broadcast_scalar_mixed_type(%arg0: f16) -> vector<1x4xf32> {
%0 = vector.broadcast %arg0 : f16 to vector<1x4xf16>
%1 = arith.extf %0 : vector<1x4xf16> to vector<1x4xf32>
return %1 : vector<1x4xf32>
}

// -----

// CHECK-LABEL: func.func @broadcast_vector_mixed_type(
// CHECK-SAME: %[[ARG_0:.*]]: vector<4xf16>) -> vector<3x4xf32> {
// CHECK: %[[EXTF:.*]] = arith.extf %[[ARG_0]] : vector<4xf16> to vector<4xf32>
// CHECK: %[[BCAST:.*]] = vector.broadcast %[[EXTF]] : vector<4xf32> to vector<3x4xf32>
// CHECK: return %[[BCAST]] : vector<3x4xf32>

func.func @broadcast_vector_mixed_type(%arg0: vector<4xf16>) -> vector<3x4xf32> {
%0 = vector.broadcast %arg0 : vector<4xf16> to vector<3x4xf16>
%1 = arith.extf %0 : vector<3x4xf16> to vector<3x4xf32>
return %1 : vector<3x4xf32>
}

// -----

// CHECK-LABEL: func.func @broadcast_scalar_and_splat_const_mixed_type(
// CHECK-SAME: %[[ARG_0:.*]]: f32) -> vector<1x4xf32> {
// CHECK: %[[NEW_CST:.*]] = arith.constant 3 : i32
// CHECK: %[[POW:.*]] = math.fpowi %[[ARG_0]], %[[NEW_CST]] : f32, i32
// CHECK: %[[BCAST:.*]] = vector.broadcast %[[POW]] : f32 to vector<1x4xf32>
// CHECK: return %[[BCAST]] : vector<1x4xf32>

func.func @broadcast_scalar_and_splat_const_mixed_type(%arg0: f32) -> vector<1x4xf32> {
%0 = vector.broadcast %arg0 : f32 to vector<1x4xf32>
%cst = arith.constant dense<3> : vector<1x4xi32>
%2 = math.fpowi %0, %cst : vector<1x4xf32>, vector<1x4xi32>
return %2 : vector<1x4xf32>
}

// -----

// CHECK-LABEL: func.func @broadcast_vector_and_splat_const_mixed_type(
// CHECK-SAME: %[[ARG_0:.*]]: vector<4xf32>) -> vector<3x4xf32> {
// CHECK: %[[NEW_CST:.*]] = arith.constant dense<3> : vector<4xi32>
// CHECK: %[[POW:.*]] = math.fpowi %[[ARG_0]], %[[NEW_CST]] : vector<4xf32>, vector<4xi32>
// CHECK: %[[BCAST:.*]] = vector.broadcast %[[POW]] : vector<4xf32> to vector<3x4xf32>
// CHECK: return %[[BCAST]] : vector<3x4xf32>

func.func @broadcast_vector_and_splat_const_mixed_type(%arg0: vector<4xf32>) -> vector<3x4xf32> {
%0 = vector.broadcast %arg0 : vector<4xf32> to vector<3x4xf32>
%cst = arith.constant dense<3> : vector<3x4xi32>
%2 = math.fpowi %0, %cst : vector<3x4xf32>, vector<3x4xi32>
return %2 : vector<3x4xf32>
}

//===----------------------------------------------------------------------===//
// [Pattern: ReorderElementwiseOpsOnTranspose]
//===----------------------------------------------------------------------===//
Expand Down