[mlir][tensor][memref] Enhance collapse(expand(src)) canonicalization pattern. (#145995)

This commit is contained in:
Han-Chung Wang
2025-06-26 19:39:50 -07:00
committed by GitHub
parent 30e519e1ad
commit 0515449f6d
3 changed files with 73 additions and 1 deletions

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@@ -14,6 +14,7 @@
#ifndef MLIR_DIALECT_UTILS_RESHAPEOPSUTILS_H
#define MLIR_DIALECT_UTILS_RESHAPEOPSUTILS_H
#include "mlir/Dialect/Arith/IR/Arith.h"
#include "mlir/Dialect/Utils/StaticValueUtils.h"
#include "mlir/IR/OpImplementation.h"
#include "mlir/IR/PatternMatch.h"
@@ -305,8 +306,43 @@ struct ComposeCollapseOfExpandOp : public OpRewritePattern<CollapseOpTy> {
rewriter.replaceOpWithNewOp<CollapseOpTy>(
collapseOp, resultType, expandOp.getSrc(), composedReassociation);
} else if (srcRank < resultRank) {
// Compute the dynamic output shape for the new expand_shape op.
Location loc = collapseOp.getLoc();
SmallVector<OpFoldResult> origOutputShape =
expandOp.getMixedOutputShape();
SmallVector<OpFoldResult> newOutputShape;
for (const ReassociationIndices &indices :
collapseOp.getReassociationIndices()) {
int64_t numStaticElems = 1;
SmallVector<Value> dynamicSizes;
for (int64_t idx : indices) {
OpFoldResult size = origOutputShape[idx];
if (std::optional<int64_t> maybeCst = getConstantIntValue(size)) {
numStaticElems *= maybeCst.value();
continue;
}
dynamicSizes.push_back(cast<Value>(size));
}
if (dynamicSizes.empty()) {
newOutputShape.push_back(rewriter.getIndexAttr(numStaticElems));
continue;
}
// There is at least one dynamic size, so we can initialize `result` to
// the first dynamic size.
Value result = dynamicSizes[0];
for (Value v : llvm::drop_begin(dynamicSizes))
result = rewriter.create<arith::MulIOp>(loc, result, v);
if (numStaticElems != 1) {
result = rewriter.create<arith::MulIOp>(
loc, result,
rewriter.create<arith::ConstantIndexOp>(loc, numStaticElems));
}
newOutputShape.push_back(result);
}
rewriter.replaceOpWithNewOp<ExpandOpTy>(
collapseOp, resultType, expandOp.getSrc(), composedReassociation);
collapseOp, resultType, expandOp.getSrc(), composedReassociation,
newOutputShape);
} else {
// Collapses/expansions that do not change the rank are not allowed. Use
// a cast instead.

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@@ -466,6 +466,24 @@ func.func @compose_collapse_of_collapse(%arg0 : memref<?x?x?x?x?xf32>)
// -----
func.func @compose_collapse_of_expand_partially_dynamic(%arg0: memref<?xf16>, %arg1: index, %arg2: index) -> memref<8x?x?xf16> {
%expanded = memref.expand_shape %arg0 [[0, 1, 2, 3, 4]] output_shape [4, 2, %arg1, %arg2, 32] : memref<?xf16> into memref<4x2x?x?x32xf16>
%collapsed = memref.collapse_shape %expanded [[0, 1], [2], [3, 4]] : memref<4x2x?x?x32xf16> into memref<8x?x?xf16>
return %collapsed : memref<8x?x?xf16>
}
// CHECK: func @compose_collapse_of_expand_partially_dynamic
// CHECK-SAME: %[[SRC:.[a-zA-Z0-9]+]]
// CHECK-SAME: %[[ORIG_D2:.[a-zA-Z0-9]+]]
// CHECK-SAME: %[[ORIG_D3:.[a-zA-Z0-9]+]]
// CHECK-DAG: %[[C32:.+]] = arith.constant 32
// CHECK: %[[COLLAPSED_D2:.+]] = arith.muli %[[ORIG_D3]], %[[C32]]
// CHECK: %[[RESULT:.+]] = memref.expand_shape %[[SRC]]
// CHECK-SAME: [0, 1, 2]
// CHECK-SAME: output_shape [8, %[[ORIG_D2]], %[[COLLAPSED_D2]]]
// CHECK: return %[[RESULT]]
// -----
func.func @do_not_compose_collapse_of_expand_non_identity_layout(
%arg0: memref<?x?xf32, strided<[?, 1], offset: 0>>, %sz0: index, %sz1: index)
-> memref<?xf32, strided<[?], offset: 0>> {

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@@ -1243,6 +1243,24 @@ func.func @compose_collapse_of_expand_1D(%arg0 : tensor<2048xf32>)
// -----
func.func @compose_collapse_of_expand_partially_dynamic(%arg0: tensor<?xf16>, %arg1: index, %arg2: index) -> tensor<8x?x?xf16> {
%expanded = tensor.expand_shape %arg0 [[0, 1, 2, 3, 4]] output_shape [4, 2, %arg1, %arg2, 32] : tensor<?xf16> into tensor<4x2x?x?x32xf16>
%collapsed = tensor.collapse_shape %expanded [[0, 1], [2], [3, 4]] : tensor<4x2x?x?x32xf16> into tensor<8x?x?xf16>
return %collapsed : tensor<8x?x?xf16>
}
// CHECK: func @compose_collapse_of_expand_partially_dynamic
// CHECK-SAME: %[[SRC:.[a-zA-Z0-9]+]]
// CHECK-SAME: %[[ORIG_D2:.[a-zA-Z0-9]+]]
// CHECK-SAME: %[[ORIG_D3:.[a-zA-Z0-9]+]]
// CHECK-DAG: %[[C32:.+]] = arith.constant 32
// CHECK: %[[COLLAPSED_D2:.+]] = arith.muli %[[ORIG_D3]], %[[C32]]
// CHECK: %[[RESULT:.+]] = tensor.expand_shape %[[SRC]]
// CHECK-SAME: [0, 1, 2]
// CHECK-SAME: output_shape [8, %[[ORIG_D2]], %[[COLLAPSED_D2]]]
// CHECK: return %[[RESULT]]
// -----
func.func @compose_expand_of_collapse_0_rank_to_expand(%arg0 : tensor<1x1x1xf32>)
-> tensor<1x1x1x1xf32> {
%0 = tensor.collapse_shape %arg0 []