[mlir][Vector] Update lowering of vector ops to llvm intrinsics to use row-major.

Summary:
LLVM matrix intrinsics recently introduced an option to support row-major mode.
This matches the MLIR vector model, this revision switches to row-major.

A corner case related to degenerate sizes was also fixed upstream.
This revision removes the guard against this corner case.

A bug was uncovered on the output vector construction which this revision also fixes.

Lastly, this has been tested on a small size and benchmarked independently: no visible performance regression is observed.

In the future, when matrix intrinsics support per op attribute, we can more aggressively translate to that and avoid inserting MLIR-level transposes.

This has been tested independently to work on small matrices.

Differential Revision: https://reviews.llvm.org/D77761
This commit is contained in:
Nicolas Vasilache
2020-04-09 16:36:45 -04:00
parent 00a1032412
commit 2d32ee0d7a
3 changed files with 52 additions and 72 deletions

View File

@@ -1446,7 +1446,7 @@ def Vector_MatmulOp : Vector_Op<"matrix_multiply", [NoSideEffect,
result.addAttribute("lhs_rows", builder->getI32IntegerAttr(lhsRows));
result.addAttribute("lhs_columns", builder->getI32IntegerAttr(lhsColumns));
result.addAttribute("rhs_columns", builder->getI32IntegerAttr(rhsColumns));
result.addTypes(VectorType::get(lhsRows * lhsColumns,
result.addTypes(VectorType::get(lhsRows * rhsColumns,
lhs.getType().cast<VectorType>().getElementType()));
}]>,
];

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@@ -1125,43 +1125,34 @@ public:
// TODO(ntv, ajcbik): implement benefits, cost models, separate this out in
// a new pattern.
// TODO(ntv, fhahn): once row-major mode is available in LLVM's matrix
// intrinsics, use that.
if (vectorTransformsOptions.lowerToLLVMMatrixIntrinsics &&
isColumnMajorMatmul(op.indexing_maps())) {
isRowMajorMatmul(op.indexing_maps())) {
VectorType lhsType = op.getLhsType();
VectorType rhsType = op.getRhsType();
unsigned lhsRows = op.getLhsType().getShape()[0];
unsigned lhsColumns = op.getLhsType().getShape()[1];
unsigned rhsColumns = op.getRhsType().getShape()[1];
// In cases where matrices are degenerate, scalarization issues occur in
// the backend. Avoid all LLVM scalarization issues for now.
// For more details, see: https://bugs.llvm.org/show_bug.cgi?id=45227 and
// https://bugs.llvm.org/show_bug.cgi?id=45229
// TODO(ntv, fhahn): Relax once above bugs are fixed.
if (lhsRows != 1 && lhsColumns != 1 && rhsColumns != 1) {
Type flattenedLHSType =
VectorType::get(lhsType.getNumElements(), lhsType.getElementType());
Type flattenedRHSType =
VectorType::get(rhsType.getNumElements(), rhsType.getElementType());
auto lhs = rewriter.create<vector::ShapeCastOp>(
op.getLoc(), flattenedLHSType, op.lhs());
auto rhs = rewriter.create<vector::ShapeCastOp>(
op.getLoc(), flattenedRHSType, op.rhs());
Type flattenedLHSType =
VectorType::get(lhsType.getNumElements(), lhsType.getElementType());
Type flattenedRHSType =
VectorType::get(rhsType.getNumElements(), rhsType.getElementType());
auto lhs = rewriter.create<vector::ShapeCastOp>(
op.getLoc(), flattenedLHSType, op.lhs());
auto rhs = rewriter.create<vector::ShapeCastOp>(
op.getLoc(), flattenedRHSType, op.rhs());
Value mul = rewriter.create<vector::MatmulOp>(
op.getLoc(), lhs, rhs, lhsRows, lhsColumns, rhsColumns);
mul = rewriter.create<vector::ShapeCastOp>(op.getLoc(),
op.acc().getType(), mul);
Type elementType = op.getLhsType().getElementType();
assert(elementType.isIntOrFloat());
if (elementType.isa<IntegerType>())
rewriter.replaceOpWithNewOp<AddIOp>(op, op.acc(), mul);
else
rewriter.replaceOpWithNewOp<AddFOp>(op, op.acc(), mul);
return success();
}
Value mul = rewriter.create<vector::MatmulOp>(
op.getLoc(), lhs, rhs, lhsRows, lhsColumns, rhsColumns);
mul = rewriter.create<vector::ShapeCastOp>(op.getLoc(),
op.acc().getType(), mul);
Type elementType = op.getLhsType().getElementType();
assert(elementType.isIntOrFloat());
if (elementType.isa<IntegerType>())
rewriter.replaceOpWithNewOp<AddIOp>(op, op.acc(), mul);
else
rewriter.replaceOpWithNewOp<AddFOp>(op, op.acc(), mul);
return success();
}
// Find first batch dimension in LHS/RHS, and lower when found.

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@@ -357,46 +357,35 @@ func @shape_casts(%a: vector<2x2xf32>) -> (vector<4xf32>, vector<2x2xf32>) {
return %r0, %1 : vector<4xf32>, vector<2x2xf32>
}
// MATRIX-LABEL: func @column_major_matmul
// MATRIX-SAME: %[[A:[a-zA-Z0-9]*]]: vector<4x3xf32>,
// MATRIX-SAME: %[[B:[a-zA-Z0-9]*]]: vector<2x4xf32>,
// MATRIX-SAME: %[[C:[a-zA-Z0-9]*]]: vector<3x2xf32>
// MATRIX: %[[vcst:.*]] = constant dense<0.000000e+00> : vector<12xf32>
// MATRIX: %[[vcst_0:.*]] = constant dense<0.000000e+00> : vector<8xf32>
// MATRIX: %[[vcst_1:.*]] = constant dense<0.000000e+00> : vector<3x2xf32>
// MATRIX: %[[a0:.*]] = vector.extract %[[A]][0] : vector<4x3xf32>
// MATRIX: %[[a1:.*]] = vector.insert_strided_slice %[[a0]], %[[vcst]] {offsets = [0], strides = [1]} : vector<3xf32> into vector<12xf32>
// MATRIX: %[[a2:.*]] = vector.extract %[[A]][1] : vector<4x3xf32>
// MATRIX: %[[a3:.*]] = vector.insert_strided_slice %[[a2]], %[[a1]] {offsets = [3], strides = [1]} : vector<3xf32> into vector<12xf32>
// MATRIX: %[[a4:.*]] = vector.extract %[[A]][2] : vector<4x3xf32>
// MATRIX: %[[a5:.*]] = vector.insert_strided_slice %[[a4]], %[[a3]] {offsets = [6], strides = [1]} : vector<3xf32> into vector<12xf32>
// MATRIX: %[[a6:.*]] = vector.extract %[[A]][3] : vector<4x3xf32>
// MATRIX: %[[a7:.*]] = vector.insert_strided_slice %[[a6]], %[[a5]] {offsets = [9], strides = [1]} : vector<3xf32> into vector<12xf32>
// MATRIX: %[[b8:.*]] = vector.extract %[[B]][0] : vector<2x4xf32>
// MATRIX: %[[b9:.*]] = vector.insert_strided_slice %[[b8]], %[[vcst_0]] {offsets = [0], strides = [1]} : vector<4xf32> into vector<8xf32>
// MATRIX: %[[b10:.*]] = vector.extract %[[B]][1] : vector<2x4xf32>
// MATRIX: %[[b11:.*]] = vector.insert_strided_slice %[[b10]], %[[b9]] {offsets = [4], strides = [1]} : vector<4xf32> into vector<8xf32>
// MATRIX: %[[mm12:.*]] = vector.matrix_multiply %[[a7]], %[[b11]] {lhs_columns = 3 : i32, lhs_rows = 4 : i32, rhs_columns = 4 : i32} : (vector<12xf32>, vector<8xf32>) -> vector<12xf32>
// MATRIX: %[[mm13:.*]] = vector.strided_slice %[[mm12]] {offsets = [0], sizes = [2], strides = [1]} : vector<12xf32> to vector<2xf32>
// MATRIX: %[[mm14:.*]] = vector.insert %[[mm13]], %[[vcst_1]] [0] : vector<2xf32> into vector<3x2xf32>
// MATRIX: %[[mm15:.*]] = vector.strided_slice %[[mm12]] {offsets = [2], sizes = [2], strides = [1]} : vector<12xf32> to vector<2xf32>
// MATRIX: %[[mm16:.*]] = vector.insert %[[mm15]], %[[mm14]] [1] : vector<2xf32> into vector<3x2xf32>
// MATRIX: %[[mm17:.*]] = vector.strided_slice %[[mm12]] {offsets = [4], sizes = [2], strides = [1]} : vector<12xf32> to vector<2xf32>
// MATRIX: %[[mm18:.*]] = vector.insert %[[mm17]], %[[mm16]] [2] : vector<2xf32> into vector<3x2xf32>
// MATRIX: %[[mm19:.*]] = addf %[[C]], %[[mm18]] : vector<3x2xf32>
#column_major_matmat_accesses = [
affine_map<(i, j, k) -> (k, j)>,
affine_map<(i, j, k) -> (i, k)>,
affine_map<(i, j, k) -> (j, i)>
]
#column_major_matmat_trait = {
indexing_maps = #column_major_matmat_accesses,
iterator_types = ["parallel", "parallel", "reduction"]
}
func @column_major_matmul(%arg0: vector<4x3xf32>,
%arg1: vector<2x4xf32>,
%arg2: vector<3x2xf32>) -> vector<3x2xf32> {
%0 = vector.contract #column_major_matmat_trait %arg0, %arg1, %arg2
: vector<4x3xf32>, vector<2x4xf32> into vector<3x2xf32>
return %0 : vector<3x2xf32>
// MATRIX-LABEL: func @matmul
// MATRIX-SAME: %[[A:[a-zA-Z0-9]*]]: vector<2x4xf32>,
// MATRIX-SAME: %[[B:[a-zA-Z0-9]*]]: vector<4x3xf32>,
// MATRIX-SAME: %[[C:[a-zA-Z0-9]*]]: vector<2x3xf32>
// MATRIX: %[[vcst:.*]] = constant dense<0.000000e+00> : vector<8xf32>
// MATRIX: %[[vcst_0:.*]] = constant dense<0.000000e+00> : vector<12xf32>
// MATRIX: %[[vcst_1:.*]] = constant dense<0.000000e+00> : vector<2x3xf32>
// MATRIX: %[[a0:.*]] = vector.extract %[[A]][0] : vector<2x4xf32>
// MATRIX: %[[a1:.*]] = vector.insert_strided_slice %[[a0]], %[[vcst]] {offsets = [0], strides = [1]} : vector<4xf32> into vector<8xf32>
// MATRIX: %[[a2:.*]] = vector.extract %[[A]][1] : vector<2x4xf32>
// MATRIX: %[[a3:.*]] = vector.insert_strided_slice %[[a2]], %[[a1]] {offsets = [4], strides = [1]} : vector<4xf32> into vector<8xf32>
// MATRIX: %[[b0:.*]] = vector.extract %[[B]][0] : vector<4x3xf32>
// MATRIX: %[[b1:.*]] = vector.insert_strided_slice %[[b0]], %[[vcst_0]] {offsets = [0], strides = [1]} : vector<3xf32> into vector<12xf32>
// MATRIX: %[[b2:.*]] = vector.extract %[[B]][1] : vector<4x3xf32>
// MATRIX: %[[b3:.*]] = vector.insert_strided_slice %[[b2]], %[[b1]] {offsets = [3], strides = [1]} : vector<3xf32> into vector<12xf32>
// MATRIX: %[[b4:.*]] = vector.extract %[[B]][2] : vector<4x3xf32>
// MATRIX: %[[b5:.*]] = vector.insert_strided_slice %[[b4]], %[[b3]] {offsets = [6], strides = [1]} : vector<3xf32> into vector<12xf32>
// MATRIX: %[[b6:.*]] = vector.extract %[[B]][3] : vector<4x3xf32>
// MATRIX: %[[b7:.*]] = vector.insert_strided_slice %[[b6]], %[[b5]] {offsets = [9], strides = [1]} : vector<3xf32> into vector<12xf32>
// MATRIX: %[[mm1:.*]] = vector.matrix_multiply %[[a3]], %[[b7]] {lhs_columns = 4 : i32, lhs_rows = 2 : i32, rhs_columns = 3 : i32} : (vector<8xf32>, vector<12xf32>) -> vector<6xf32>
// MATRIX: %[[mm2:.*]] = vector.strided_slice %[[mm1]] {offsets = [0], sizes = [3], strides = [1]} : vector<6xf32> to vector<3xf32>
// MATRIX: %[[mm3:.*]] = vector.insert %[[mm2]], %[[vcst_1]] [0] : vector<3xf32> into vector<2x3xf32>
// MATRIX: %[[mm4:.*]] = vector.strided_slice %[[mm1]] {offsets = [3], sizes = [3], strides = [1]} : vector<6xf32> to vector<3xf32>
// MATRIX: %[[mm5:.*]] = vector.insert %[[mm4]], %[[mm3]] [1] : vector<3xf32> into vector<2x3xf32>
// MATRIX: %[[mm6:.*]] = addf %[[C]], %[[mm5]] : vector<2x3xf32>
func @matmul(%arg0: vector<2x4xf32>,
%arg1: vector<4x3xf32>,
%arg2: vector<2x3xf32>) -> vector<2x3xf32> {
%0 = vector.contract #matmat_trait %arg0, %arg1, %arg2
: vector<2x4xf32>, vector<4x3xf32> into vector<2x3xf32>
return %0 : vector<2x3xf32>
}