[MLIR][HLO] Move broadcasts over n-ary shape-preserving ops

This will open up more fusion opportunities.

PiperOrigin-RevId: 364577231
This commit is contained in:
A. Unique TensorFlower 2021-03-23 09:38:00 -07:00 committed by TensorFlow MLIR Team
parent 5bc4bf0834
commit 8987dfd1d6
3 changed files with 25 additions and 12 deletions

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@ -270,9 +270,8 @@ def HLO_TanhOp: HLO_UnaryElementwiseOp<"tanh",
// See https://www.tensorflow.org/xla/operation_semantics#element-wise_binary_arithmetic_operations
class HLO_BinaryElementwiseOp<string mnemonic, list<OpTrait> traits> :
HLO_Op<mnemonic, !listconcat(traits,
[InferShapedTypeOpInterface, InferFusibilityOpInterface,
SameOperandsAndResultShape])> {
HLO_Op<mnemonic, traits # [InferShapedTypeOpInterface,
InferFusibilityOpInterface, SameOperandsAndResultShape, Elementwise]> {
let arguments = (ins
HLO_Tensor:$lhs,
HLO_Tensor:$rhs

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@ -77,14 +77,12 @@ struct ShapeOfOpConversion : public OpConversionPattern<shape::ShapeOfOp> {
};
// We can only move up broadcasting ops that apply to the result of a
// shape-preserving operation. For now, we restrict this to unary operations.
// TODO(frgossen): Generalize this to n-ary operations.
// shape-preserving operation.
bool isDynamicBroadcastInDimOpMovable(Value operand) {
Operation *producer_op = operand.getDefiningOp();
return producer_op != nullptr &&
producer_op->hasTrait<OpTrait::SameOperandsAndResultShape>() &&
producer_op->hasTrait<OpTrait::Elementwise>() &&
producer_op->getNumOperands() == 1;
producer_op->hasTrait<OpTrait::Elementwise>();
}
// TODO(frgossen): Only move up broadcasting operations if there is a consumer.
@ -96,8 +94,6 @@ struct MoveUpBroadcastInDimOpConversion
LogicalResult matchAndRewrite(
DynamicBroadcastInDimOp bcast_op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
// We can only move up broadcasting ops that apply to the result of a
// shape-preserving operation.
DynamicBroadcastInDimOp::Adaptor transformed(operands);
if (!isDynamicBroadcastInDimOpMovable(transformed.operand()))
return failure();

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@ -29,10 +29,10 @@ func @shape_of_nary(%arg0 : tensor<?x32xf16>, %arg1 : tensor<?x32xf16>) {
// -----
// Broadcasts can be moved up over shape-preserving operations.
// CHECK-LABEL: @bcast
// Broadcasts can be moved up over unary shape-preserving operations.
// CHECK-LABEL: @bcast_unary
// CHECK-SAME: (%[[ARG:.*]]: tensor<?x32xi16>, %[[OUT_DIMS:.*]]: tensor<3xindex>)
func @bcast(%arg : tensor<?x32xi16>, %out_dims : tensor<3xindex>)
func @bcast_unary(%arg : tensor<?x32xi16>, %out_dims : tensor<3xindex>)
-> tensor<?x?x32xf16> {
// CHECK: %[[BCASTED_OPERAND:.*]] = "mhlo.dynamic_broadcast_in_dim"(%[[ARG]], %[[OUT_DIMS]])
// CHECK-SAME: broadcast_dimensions = dense<[0, 1]> : tensor<2xi64>} : (tensor<?x32xi16>, tensor<3xindex>) -> tensor<?x?x32xi16>
@ -46,6 +46,24 @@ func @bcast(%arg : tensor<?x32xi16>, %out_dims : tensor<3xindex>)
// -----
// Broadcasts can be moved up over n-ary shape-preserving operations.
// CHECK-LABEL: @bcast_nary
// CHECK-SAME: (%[[ARG0:.*]]: tensor<?x32xf32>, %[[ARG1:.*]]: tensor<?x32xf32>, %[[OUT_DIMS:.*]]: tensor<3xindex>)
func @bcast_nary(%arg0 : tensor<?x32xf32>, %arg1 : tensor<?x32xf32>,
%out_dims : tensor<3xindex>) -> tensor<?x?x32xf32> {
// CHECK-NOT: subtract
// CHECK: %[[BCASTED_ARG0:.*]] = "mhlo.dynamic_broadcast_in_dim"(%[[ARG0]], %[[OUT_DIMS]])
// CHECK: %[[BCASTED_ARG1:.*]] = "mhlo.dynamic_broadcast_in_dim"(%[[ARG1]], %[[OUT_DIMS]])
// CHECK: %{{.*}} = mhlo.subtract %[[BCASTED_ARG0]], %[[BCASTED_ARG1]] : tensor<?x?x32xf32>
%0 = mhlo.subtract %arg0, %arg1 : tensor<?x32xf32>
%1 = "mhlo.dynamic_broadcast_in_dim"(%0, %out_dims) {
broadcast_dimensions = dense<[0, 1]> : tensor<2xi64> } :
(tensor<?x32xf32>, tensor<3xindex>) -> tensor<?x?x32xf32>
return %1 : tensor<?x?x32xf32>
}
// -----
// Exemplary IR as it appears in the lowering with `tf.Sub` and `tf.Cast`.
// CHECK-LABEL: @cast_sub
// CHECK-SAME: (%[[ARG0:.*]]: tensor<?x32xi16>, %[[ARG1:.*]]: tensor<?x?x32xf16>) -> tensor<?x?x32xf16>