diff --git a/mlir/lib/Conversion/ShapeToStandard/ShapeToStandardPatterns.td b/mlir/lib/Conversion/ShapeToStandard/ShapeToStandardPatterns.td --- a/mlir/lib/Conversion/ShapeToStandard/ShapeToStandardPatterns.td +++ b/mlir/lib/Conversion/ShapeToStandard/ShapeToStandardPatterns.td @@ -19,3 +19,10 @@ (Shape_SizeToIndexOp $arg), (replaceWithValue $arg)>; +// Derive shape extent directly from shape origin if possible. +// This circumvents the necessity to materialize the shape in memory. +def GetExtentShapeOfConversion : Pat< + (Shape_GetExtentOp (Shape_ShapeOfOp $arg), $idx), + (Shape_IndexToSizeOp (DimOp $arg, (Shape_SizeToIndexOp $idx))), + [], + (addBenefit 10)>; diff --git a/mlir/test/Conversion/ShapeToStandard/shape-to-standard.mlir b/mlir/test/Conversion/ShapeToStandard/shape-to-standard.mlir --- a/mlir/test/Conversion/ShapeToStandard/shape-to-standard.mlir +++ b/mlir/test/Conversion/ShapeToStandard/shape-to-standard.mlir @@ -127,3 +127,19 @@ %rank = shape.rank %shape return %rank : !shape.size } + +// ----- + +// Express `get_extent` as `std.dim` when it relies directly on the outcome of a +// `shape_of` operation. +// CHECK-LABEL: @get_extent_shape_of +// CHECK-SAME: (%[[ARG:.*]]: tensor<2x3xf32>, %[[IDX:.*]]: index) -> index +func @get_extent_shape_of(%arg : tensor<2x3xf32>, %idx : !shape.size) + -> !shape.size { + // CHECK: %[[RESULT:.*]] = dim %[[ARG]], %[[IDX]] : tensor<2x3xf32> + // CHECK: return %[[RESULT]] : index + %shape = shape.shape_of %arg : tensor<2x3xf32> + %result = shape.get_extent %shape, %idx + return %result : !shape.size +} +