Skip to content

[mlir][Vector] Support scalar vector.extract in VectorLinearize #147440

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
Open

[mlir][Vector] Support scalar vector.extract in VectorLinearize #147440

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
49 changes: 36 additions & 13 deletions mlir/lib/Dialect/Vector/Transforms/VectorLinearize.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -395,15 +395,32 @@ struct LinearizeVectorShuffle final
}
};

/// This pattern converts the ExtractOp to a ShuffleOp that works on a
/// linearized vector.
/// Following,
/// vector.extract %source [ position ]
/// is converted to :
/// %source_1d = vector.shape_cast %source
/// %out_1d = vector.shuffle %source_1d, %source_1d [ shuffle_indices_1d ]
/// %out_nd = vector.shape_cast %out_1d
/// `shuffle_indices_1d` is computed using the position of the original extract.
/// This pattern linearizes `vector.extract` operations. It generates a 1-D
/// version of the `vector.extract` operation when extracting a scalar from a
/// vector. It generates a 1-D `vector.shuffle` operation when extracting a
/// subvector from a larger vector.
///
/// Example #1:
///
/// %0 = vector.extract %arg0[1]: vector<8x2xf32> from vector<2x8x2xf32>
///
/// is converted to:
///
/// %0 = vector.shape_cast %arg0 : vector<2x8x2xf32> to vector<32xf32>
/// %1 = vector.shuffle %0, %0 [16, 17, 18, 19, 20, 21, 22, 23,
/// 24, 25, 26, 27, 28, 29, 30, 31] :
/// vector<32xf32>, vector<32xf32>
/// %2 = vector.shape_cast %1 : vector<16xf32> to vector<8x2xf32>
///
/// Example #2:
///
/// %0 = vector.extract %arg0[1, 2] : i32 from vector<2x4xi32>
///
/// is converted to:
///
/// %0 = vector.shape_cast %arg0 : vector<2x4xi32> to vector<8xi32>
/// %1 = vector.extract %0[6] : i32 from vector<8xi32>
///
struct LinearizeVectorExtract final
: public OpConversionPattern<vector::ExtractOp> {
using OpConversionPattern::OpConversionPattern;
Expand All @@ -413,10 +430,6 @@ struct LinearizeVectorExtract final
LogicalResult
matchAndRewrite(vector::ExtractOp extractOp, OpAdaptor adaptor,
ConversionPatternRewriter &rewriter) const override {
// Skip if result is not a vector type
if (!isa<VectorType>(extractOp.getType()))
return rewriter.notifyMatchFailure(extractOp,
"scalar extract not supported");
Type dstTy = getTypeConverter()->convertType(extractOp.getType());
assert(dstTy && "expected 1-D vector type");

Expand All @@ -436,6 +449,16 @@ struct LinearizeVectorExtract final
linearizedOffset += offsets[i] * size;
}

if (!isa<VectorType>(extractOp.getType())) {
// Scalar case: generate a 1-D extract.
Value result = rewriter.createOrFold<vector::ExtractOp>(
extractOp.getLoc(), adaptor.getVector(), linearizedOffset);
rewriter.replaceOp(extractOp, result);
return success();
}

// Vector case: generate a shuffle.

llvm::SmallVector<int64_t, 2> indices(size);
std::iota(indices.begin(), indices.end(), linearizedOffset);
rewriter.replaceOpWithNewOp<vector::ShuffleOp>(
Expand Down
26 changes: 13 additions & 13 deletions mlir/test/Dialect/Vector/linearize.mlir
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -264,6 +264,19 @@ func.func @test_vector_shuffle(%arg0: vector<4x2xf32>, %arg1: vector<4x2xf32>) -

// -----

// CHECK-LABEL: test_vector_extract_scalar
// CHECK-SAME: (%[[ARG:.*]]: vector<2x4xi32>) -> i32 {
func.func @test_vector_extract_scalar(%arg0 : vector<2x4xi32>) -> i32 {

// CHECK: %[[SRC_1D:.*]] = vector.shape_cast %[[ARG]] : vector<2x4xi32> to vector<8xi32>
// CHECK: %[[EXTRACT_1D:.*]] = vector.extract %[[SRC_1D]][6] : i32 from vector<8xi32>
// CHECK: return %[[EXTRACT_1D]] : i32
%0 = vector.extract %arg0[1, 2] : i32 from vector<2x4xi32>
return %0 : i32
}

// -----

// CHECK-LABEL: test_vector_extract
// CHECK-SAME: (%[[ORIG_ARG:.*]]: vector<2x8x2xf32>) -> vector<8x2xf32> {
func.func @test_vector_extract(%arg0: vector<2x8x2xf32>) -> vector<8x2xf32> {
Expand Down Expand Up @@ -341,19 +354,6 @@ func.func @test_vector_insert_scalable(%arg0: vector<2x8x[4]xf32>, %arg1: vector

// -----

// CHECK-LABEL: test_vector_extract_scalar
func.func @test_vector_extract_scalar(%idx : index) {
%cst = arith.constant dense<[1, 2, 3, 4]> : vector<4xi32>

// CHECK-NOT: vector.shuffle
// CHECK: vector.extract
// CHECK-NOT: vector.shuffle
%0 = vector.extract %cst[%idx] : i32 from vector<4xi32>
return
}

// -----

// CHECK-LABEL: test_vector_bitcast
// CHECK-SAME: %[[ARG_0:.*]]: vector<4x4xf32>
func.func @test_vector_bitcast(%arg0: vector<4x4xf32>) -> vector<4x8xf16> {
Expand Down
Loading