[tosa]: canonicalize dynamic size of tosa.slice to static output shape (#135429)

Addresses https://github.com/llvm/llvm-project/issues/135389
This commit is contained in:
Sayan Saha 2025-04-12 18:24:07 -04:00 committed by GitHub
parent b0fede358f
commit 60b1d44d70
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2 changed files with 69 additions and 1 deletions

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@ -731,9 +731,62 @@ struct ConcatSliceOptimization : public OpRewritePattern<tosa::SliceOp> {
}
};
// Update size operand of tosa.slice if size has dynamic dims but corresponding
// output dim is static
struct SliceDynamicSizeCanonicalization
: public OpRewritePattern<tosa::SliceOp> {
using OpRewritePattern<tosa::SliceOp>::OpRewritePattern;
LogicalResult matchAndRewrite(tosa::SliceOp sliceOp,
PatternRewriter &rewriter) const override {
ShapedType resultType = cast<ShapedType>(sliceOp.getType());
ElementsAttr sizeElems;
if (!matchPattern(sliceOp.getSize(), m_Constant(&sizeElems))) {
return rewriter.notifyMatchFailure(
sliceOp, "size of slice must be a static ranked shape");
}
llvm::SmallVector<int64_t> sliceSizes =
llvm::to_vector(sizeElems.getValues<int64_t>());
bool replaceSliceSize{false};
// if size op has -1 indicating dynamic shape but corresponding dim on the
// output is statically known, update size to match with known output dim
// shape
for (const auto &[index, size] : llvm::enumerate(sliceSizes)) {
if (size == -1 && !resultType.isDynamicDim(index)) {
sliceSizes[index] = resultType.getDimSize(index);
replaceSliceSize = true;
}
}
if (!replaceSliceSize) {
return rewriter.notifyMatchFailure(
sliceOp, "no dimension of size of slice is dynamic that resolves "
"to static output shape");
}
auto size_op = getTosaConstShape(rewriter, sliceOp.getLoc(), sliceSizes);
auto newSliceOp = rewriter.create<tosa::SliceOp>(
sliceOp.getLoc(), sliceOp.getType(), sliceOp.getInput1(),
sliceOp.getStart(), size_op);
rewriter.replaceOp(sliceOp, newSliceOp.getResult());
// Remove const_shape size op when it no longer has use point.
Operation *sizeConstShape = sliceOp.getSize().getDefiningOp();
if (sizeConstShape->getResult(0).hasOneUse())
rewriter.eraseOp(sizeConstShape);
return success();
}
};
void SliceOp::getCanonicalizationPatterns(RewritePatternSet &results,
MLIRContext *context) {
results.add<ConcatSliceOptimization>(context);
results.add<ConcatSliceOptimization, SliceDynamicSizeCanonicalization>(
context);
}
//===----------------------------------------------------------------------===//

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@ -1212,3 +1212,18 @@ func.func @do_not_fold_intdiv_division_by_0() -> tensor<1x24x2xi32> {
%16 = tosa.intdiv %4, %1 : (tensor<1x24x2xi32>, tensor<1x24x2xi32>) -> tensor<1x24x2xi32>
return %16 : tensor<1x24x2xi32>
}
// ----
// CHECK-LABEL: func.func @slice_dynamic_size_static_output_canonicalize(
// CHECK-SAME: %[[ARG0:.*]]: tensor<2x60x59x?xf32>) -> tensor<2x60x58x?xf32> {
// CHECK: %[[START:.*]] = tosa.const_shape {values = dense<0> : tensor<4xindex>} : () -> !tosa.shape<4>
// CHECK: %[[SIZE:.*]] = tosa.const_shape {values = dense<[2, 60, 58, -1]> : tensor<4xindex>} : () -> !tosa.shape<4>
// CHECK: %[[SLICE:.*]] = tosa.slice %[[ARG0]], %[[START]], %[[SIZE]] : (tensor<2x60x59x?xf32>, !tosa.shape<4>, !tosa.shape<4>) -> tensor<2x60x58x?xf32>
// CHECK: return %[[SLICE]]
func.func @slice_dynamic_size_static_output_canonicalize(%arg0: tensor<2x60x59x?xf32>) -> tensor<2x60x58x?xf32> {
%0 = tosa.const_shape {values = dense<0> : tensor<4xindex>} : () -> !tosa.shape<4>
%1 = tosa.const_shape {values = dense<[-1, 60, 58, -1]> : tensor<4xindex>} : () -> !tosa.shape<4>
%2 = tosa.slice %arg0, %0, %1 : (tensor<2x60x59x?xf32>, !tosa.shape<4>, !tosa.shape<4>) -> tensor<2x60x58x?xf32>
return %2 : tensor<2x60x58x?xf32>
}