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[mlir][vector] Allow lowering multi-dim scatters to LLVM #132227

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[mlir][vector] Allow lowering multi-dim scatters to LLVM #132227

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8 changes: 6 additions & 2 deletions mlir/include/mlir/Dialect/Vector/Transforms/LoweringPatterns.h
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Original file line number Diff line number Diff line change
Expand Up @@ -244,8 +244,12 @@ void populateVectorStepLoweringPatterns(RewritePatternSet &patterns,
/// [UnrollGather]
/// Unrolls 2 or more dimensional `vector.gather` ops by unrolling the
/// outermost dimension.
void populateVectorGatherLoweringPatterns(RewritePatternSet &patterns,
PatternBenefit benefit = 1);
///
/// [UnrollScatter]
/// Unrolls 2 or more dimensional `vector.scatter` ops by unrolling the
/// outermost dimension.
void populateVectorGatherScatterLoweringPatterns(RewritePatternSet &patterns,
PatternBenefit benefit = 1);

/// Populate the pattern set with the following patterns:
///
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5 changes: 2 additions & 3 deletions mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
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Expand Up @@ -286,10 +286,9 @@ class VectorGatherOpConversion
// Resolve address.
Value ptr = getStridedElementPtr(loc, memRefType, adaptor.getBase(),
adaptor.getIndices(), rewriter);
Value base = adaptor.getBase();
Value ptrs =
getIndexedPtrs(rewriter, loc, *this->getTypeConverter(), memRefType,
base, ptr, adaptor.getIndexVec(), vType);
adaptor.getBase(), ptr, adaptor.getIndexVec(), vType);

// Replace with the gather intrinsic.
rewriter.replaceOpWithNewOp<LLVM::masked_gather>(
Expand All @@ -308,7 +307,7 @@ class VectorScatterOpConversion
LogicalResult
matchAndRewrite(vector::ScatterOp scatter, OpAdaptor adaptor,
ConversionPatternRewriter &rewriter) const override {
auto loc = scatter->getLoc();
Location loc = scatter->getLoc();
MemRefType memRefType = scatter.getMemRefType();

if (failed(isMemRefTypeSupported(memRefType, *this->getTypeConverter())))
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2 changes: 1 addition & 1 deletion mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVMPass.cpp
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Expand Up @@ -81,7 +81,7 @@ void ConvertVectorToLLVMPass::runOnOperation() {
populateVectorInsertExtractStridedSliceTransforms(patterns);
populateVectorStepLoweringPatterns(patterns);
populateVectorRankReducingFMAPattern(patterns);
populateVectorGatherLoweringPatterns(patterns);
populateVectorGatherScatterLoweringPatterns(patterns);
(void)applyPatternsGreedily(getOperation(), std::move(patterns));
}

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2 changes: 1 addition & 1 deletion mlir/lib/Dialect/Vector/TransformOps/VectorTransformOps.cpp
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Expand Up @@ -138,7 +138,7 @@ void transform::ApplyLowerOuterProductPatternsOp::populatePatterns(

void transform::ApplyLowerGatherPatternsOp::populatePatterns(
RewritePatternSet &patterns) {
vector::populateVectorGatherLoweringPatterns(patterns);
vector::populateVectorGatherScatterLoweringPatterns(patterns);
}

void transform::ApplyLowerScanPatternsOp::populatePatterns(
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2 changes: 1 addition & 1 deletion mlir/lib/Dialect/Vector/Transforms/CMakeLists.txt
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Expand Up @@ -3,7 +3,7 @@ add_mlir_dialect_library(MLIRVectorTransforms
LowerVectorBitCast.cpp
LowerVectorBroadcast.cpp
LowerVectorContract.cpp
LowerVectorGather.cpp
LowerVectorGatherScatter.cpp
LowerVectorInterleave.cpp
LowerVectorMask.cpp
LowerVectorMultiReduction.cpp
Expand Down
69 changes: 58 additions & 11 deletions ...t/Vector/Transforms/LowerVectorGather.cpp → ...r/Transforms/LowerVectorGatherScatter.cpp
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Expand Up @@ -38,6 +38,7 @@ using namespace mlir;
using namespace mlir::vector;

namespace {

/// Unrolls 2 or more dimensional `vector.gather` ops by unrolling the
/// outermost dimension. For example:
/// ```
Expand Down Expand Up @@ -81,26 +82,72 @@ struct UnrollGather : OpRewritePattern<vector::GatherOp> {
VectorType subTy = VectorType::Builder(resultTy).dropDim(0);

for (int64_t i = 0, e = resultTy.getShape().front(); i < e; ++i) {
int64_t thisIdx[1] = {i};

Value indexSubVec =
rewriter.create<vector::ExtractOp>(loc, indexVec, thisIdx);
Value maskSubVec =
rewriter.create<vector::ExtractOp>(loc, maskVec, thisIdx);
Value indexSubVec = rewriter.create<vector::ExtractOp>(loc, indexVec, i);
Value maskSubVec = rewriter.create<vector::ExtractOp>(loc, maskVec, i);
Value passThruSubVec =
rewriter.create<vector::ExtractOp>(loc, passThruVec, thisIdx);
rewriter.create<vector::ExtractOp>(loc, passThruVec, i);
Value subGather = rewriter.create<vector::GatherOp>(
loc, subTy, op.getBase(), op.getIndices(), indexSubVec, maskSubVec,
passThruSubVec);
result =
rewriter.create<vector::InsertOp>(loc, subGather, result, thisIdx);
result = rewriter.create<vector::InsertOp>(loc, subGather, result, i);
}
Comment on lines 84 to 93
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Wonder if we could have a generic utility for this?


rewriter.replaceOp(op, result);
return success();
}
};

/// Unrolls 2 or more dimensional `vector.scatter` ops by unrolling the
/// outermost dimension. For example:
/// ```
/// %g = vector.scatter %base[%c0][%v], %mask, %valueToStore : ...
/// vector<2x3xf32>
///
/// ==>
///
/// %g0 = vector.extract %valueToStore[0] : vector<3xf32> from vector<2x3xf32>
/// vector.scatter %base[%c0][%v0], %mask0, %g0
/// %g1 = vector.extract %valueToStore[1] : vector<3xf32> from vector<2x3xf32>
/// vector.scatter %base[%c0][%v0], %mask0, %g1
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%c0 -> %c1?

/// ```
///
/// When applied exhaustively, this will produce a sequence of 1-d scatter ops.
///
/// Supports vector types with a fixed leading dimension.
struct UnrollScatter : OpRewritePattern<vector::ScatterOp> {
using OpRewritePattern::OpRewritePattern;

LogicalResult matchAndRewrite(vector::ScatterOp op,
PatternRewriter &rewriter) const override {
VectorType vectorTy = op.getVectorType();
if (vectorTy.getRank() < 2)
return rewriter.notifyMatchFailure(op, "already 1-D");

// Unrolling doesn't take vscale into account. Pattern is disabled for
// vectors with leading scalable dim(s).
if (vectorTy.getScalableDims().front())
return rewriter.notifyMatchFailure(op, "cannot unroll scalable dim");

Location loc = op.getLoc();
Value indexVec = op.getIndexVec();
Value maskVec = op.getMask();
Value valueToStoreVec = op.getValueToStore();

for (int64_t i = 0, e = vectorTy.getShape().front(); i < e; ++i) {
Value indexSubVec = rewriter.create<vector::ExtractOp>(loc, indexVec, i);
Value maskSubVec = rewriter.create<vector::ExtractOp>(loc, maskVec, i);
Value valueToStoreSubVec =
rewriter.create<vector::ExtractOp>(loc, valueToStoreVec, i);
rewriter.create<vector::ScatterOp>(loc, op.getBase(), op.getIndices(),
indexSubVec, maskSubVec,
valueToStoreSubVec);
}

rewriter.eraseOp(op);
return success();
}
};

/// Rewrites a vector.gather of a strided MemRef as a gather of a non-strided
/// MemRef with updated indices that model the strided access.
///
Expand Down Expand Up @@ -268,9 +315,9 @@ struct Gather1DToConditionalLoads : OpRewritePattern<vector::GatherOp> {
};
} // namespace

void mlir::vector::populateVectorGatherLoweringPatterns(
void mlir::vector::populateVectorGatherScatterLoweringPatterns(
RewritePatternSet &patterns, PatternBenefit benefit) {
patterns.add<UnrollGather>(patterns.getContext(), benefit);
patterns.add<UnrollGather, UnrollScatter>(patterns.getContext(), benefit);
}

void mlir::vector::populateVectorGatherToConditionalLoadPatterns(
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6 changes: 4 additions & 2 deletions mlir/test/Conversion/VectorToLLVM/vector-to-llvm.mlir
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Expand Up @@ -1734,7 +1734,8 @@ func.func @scatter_with_mask(%arg0: memref<?xf32>, %arg1: vector<2x3xi32>, %arg2
}

// CHECK-LABEL: func @scatter_with_mask
// CHECK: vector.scatter
// CHECK: llvm.intr.masked.scatter %{{.*}}, %{{.*}}, %{{.*}} {alignment = 4 : i32} : vector<3xf32>, vector<3xi1> into !llvm.vec<3 x ptr>
// CHECK: llvm.intr.masked.scatter %{{.*}}, %{{.*}}, %{{.*}} {alignment = 4 : i32} : vector<3xf32>, vector<3xi1> into !llvm.vec<3 x ptr>

// -----

Expand All @@ -1749,7 +1750,8 @@ func.func @scatter_with_mask_scalable(%arg0: memref<?xf32>, %arg1: vector<2x[3]x
}

// CHECK-LABEL: func @scatter_with_mask_scalable
// CHECK: vector.scatter
// CHECK: llvm.intr.masked.scatter %{{.*}}, %{{.*}}, %{{.*}} {alignment = 4 : i32} : vector<[3]xf32>, vector<[3]xi1> into !llvm.vec<? x 3 x ptr>
// CHECK: llvm.intr.masked.scatter %{{.*}}, %{{.*}}, %{{.*}} {alignment = 4 : i32} : vector<[3]xf32>, vector<[3]xi1> into !llvm.vec<? x 3 x ptr>

// -----

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2 changes: 1 addition & 1 deletion mlir/test/lib/Dialect/Vector/TestVectorTransforms.cpp
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Expand Up @@ -781,7 +781,7 @@ struct TestVectorGatherLowering

void runOnOperation() override {
RewritePatternSet patterns(&getContext());
populateVectorGatherLoweringPatterns(patterns);
populateVectorGatherScatterLoweringPatterns(patterns);
populateVectorGatherToConditionalLoadPatterns(patterns);
(void)applyPatternsGreedily(getOperation(), std::move(patterns));
}
Expand Down