[Mlir-commits] [mlir] a00b736 - [mlir][Vector] Support `vector.extract(xfer_read)` folding with dynamic indices (#143269)
llvmlistbot at llvm.org
llvmlistbot at llvm.org
Mon Jun 16 12:05:23 PDT 2025
Author: Diego Caballero
Date: 2025-06-16T12:05:20-07:00
New Revision: a00b736a797d252d9e26cc13fb45993d7b02ede2
URL: https://github.com/llvm/llvm-project/commit/a00b736a797d252d9e26cc13fb45993d7b02ede2
DIFF: https://github.com/llvm/llvm-project/commit/a00b736a797d252d9e26cc13fb45993d7b02ede2.diff
LOG: [mlir][Vector] Support `vector.extract(xfer_read)` folding with dynamic indices (#143269)
This PR is part of the last step to remove `vector.extractelement` and `vector.insertelement` ops.
RFC: https://discourse.llvm.org/t/rfc-psa-remove-vector-extractelement-and-vector-insertelement-ops-in-favor-of-vector-extract-and-vector-insert-ops
It adds support for folding `vector.transfer_read(vector.extract) ->
memref.load` with dynamic indices, which is currently supported by
`vector.extractelement`.
Added:
Modified:
mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp
mlir/test/Dialect/Vector/scalar-vector-transfer-to-memref.mlir
Removed:
################################################################################
diff --git a/mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp b/mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp
index 7dbb7a334fe62..384717aeca665 100644
--- a/mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp
+++ b/mlir/lib/Dialect/Vector/Transforms/VectorTransferOpTransforms.cpp
@@ -886,17 +886,31 @@ class RewriteScalarExtractOfTransferRead
SmallVector<Value> newIndices(xferOp.getIndices().begin(),
xferOp.getIndices().end());
for (auto [i, pos] : llvm::enumerate(extractOp.getMixedPosition())) {
- assert(isa<Attribute>(pos) && "Unexpected non-constant index");
- int64_t offset = cast<IntegerAttr>(cast<Attribute>(pos)).getInt();
int64_t idx = newIndices.size() - extractOp.getNumIndices() + i;
- OpFoldResult ofr = affine::makeComposedFoldedAffineApply(
- rewriter, extractOp.getLoc(),
- rewriter.getAffineSymbolExpr(0) + offset, {newIndices[idx]});
- if (auto value = dyn_cast<Value>(ofr)) {
+
+ // Compute affine expression `newIndices[idx] + pos` where `pos` can be
+ // either a constant or a value.
+ OpFoldResult composedIdx;
+ if (auto attr = dyn_cast<Attribute>(pos)) {
+ int64_t offset = cast<IntegerAttr>(attr).getInt();
+ composedIdx = affine::makeComposedFoldedAffineApply(
+ rewriter, extractOp.getLoc(),
+ rewriter.getAffineSymbolExpr(0) + offset, {newIndices[idx]});
+ } else {
+ Value dynamicOffset = cast<Value>(pos);
+ AffineExpr sym0, sym1;
+ bindSymbols(rewriter.getContext(), sym0, sym1);
+ composedIdx = affine::makeComposedFoldedAffineApply(
+ rewriter, extractOp.getLoc(), sym0 + sym1,
+ {newIndices[idx], dynamicOffset});
+ }
+
+ // Update the corresponding index with the folded result.
+ if (auto value = dyn_cast<Value>(composedIdx)) {
newIndices[idx] = value;
} else {
newIndices[idx] = rewriter.create<arith::ConstantIndexOp>(
- extractOp.getLoc(), *getConstantIntValue(ofr));
+ extractOp.getLoc(), *getConstantIntValue(composedIdx));
}
}
if (isa<MemRefType>(xferOp.getBase().getType())) {
diff --git a/mlir/test/Dialect/Vector/scalar-vector-transfer-to-memref.mlir b/mlir/test/Dialect/Vector/scalar-vector-transfer-to-memref.mlir
index 52b0fdee184f6..7a1d6b3a8344a 100644
--- a/mlir/test/Dialect/Vector/scalar-vector-transfer-to-memref.mlir
+++ b/mlir/test/Dialect/Vector/scalar-vector-transfer-to-memref.mlir
@@ -148,3 +148,33 @@ func.func @subvector_extract(%m: memref<?x?xf32>, %idx: index) -> vector<16xf32>
return %1 : vector<16xf32>
}
+// -----
+
+// CHECK: #[[$MAP:.*]] = affine_map<()[s0, s1] -> (s0 + s1)>
+// CHECK-LABEL: func @transfer_read_1d_extract_dynamic(
+// CHECK-SAME: %[[MEMREF:.*]]: memref<?xf32>, %[[M_IDX:.*]]: index, %[[E_IDX:.*]]: index
+// CHECK: %[[APPLY:.*]] = affine.apply #[[$MAP]]()[%[[M_IDX]], %[[E_IDX]]]
+// CHECK: %[[RES:.*]] = memref.load %[[MEMREF]][%[[APPLY]]]
+func.func @transfer_read_1d_extract_dynamic(%m: memref<?xf32>, %idx: index,
+ %offset: index) -> f32 {
+ %cst = arith.constant 0.0 : f32
+ %vec = vector.transfer_read %m[%idx], %cst {in_bounds = [true]} : memref<?xf32>, vector<5xf32>
+ %elem = vector.extract %vec[%offset] : f32 from vector<5xf32>
+ return %elem : f32
+}
+
+// -----
+
+// CHECK: #[[$MAP:.*]] = affine_map<()[s0, s1] -> (s0 + s1)>
+// CHECK-LABEL: func @transfer_read_2d_extract_dynamic(
+// CHECK-SAME: %[[MEMREF:.*]]: memref<?x?xf32>, %[[ROW_IDX:.*]]: index, %[[COL_IDX:.*]]: index, %[[ROW_OFFSET:.*]]: index, %[[COL_OFFSET:.*]]: index
+// CHECK: %[[ROW_APPLY:.*]] = affine.apply #[[$MAP]]()[%[[ROW_IDX]], %[[ROW_OFFSET]]]
+// CHECK: %[[COL_APPLY:.*]] = affine.apply #[[$MAP]]()[%[[COL_IDX]], %[[COL_OFFSET]]]
+// CHECK: %[[RES:.*]] = memref.load %[[MEMREF]][%[[ROW_APPLY]], %[[COL_APPLY]]]
+func.func @transfer_read_2d_extract_dynamic(%m: memref<?x?xf32>, %row_idx: index, %col_idx: index,
+ %row_offset: index, %col_offset: index) -> f32 {
+ %cst = arith.constant 0.0 : f32
+ %vec = vector.transfer_read %m[%row_idx, %col_idx], %cst {in_bounds = [true, true]} : memref<?x?xf32>, vector<10x5xf32>
+ %elem = vector.extract %vec[%row_offset, %col_offset] : f32 from vector<10x5xf32>
+ return %elem : f32
+}
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