Skip to content

[mlir][memref] Add HoistCastPos pattern to castOp #168337

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 3 commits into
base: main
Choose a base branch
from
+73 −2
Open

[mlir][memref] Add HoistCastPos pattern to castOp #168337

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
b025178
add foldUseDominateCast to castOp.
linuxlonelyeagle Nov 17, 2025
f3127f0
add HoistCastPos pattern.
linuxlonelyeagle Nov 18, 2025
6f0497c
cleanup code.
linuxlonelyeagle Nov 18, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions mlir/include/mlir/Dialect/MemRef/IR/MemRefOps.td
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -565,6 +565,7 @@ def MemRef_CastOp : MemRef_Op<"cast", [
}];

let hasFolder = 1;
let hasCanonicalizer = 1;
}

//===----------------------------------------------------------------------===//
Expand Down
29 changes: 29 additions & 0 deletions mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -797,6 +797,35 @@ OpFoldResult CastOp::fold(FoldAdaptor adaptor) {
return succeeded(foldMemRefCast(*this)) ? getResult() : Value();
}

namespace {
struct HoistCastPos : public OpRewritePattern<CastOp> {
using OpRewritePattern<CastOp>::OpRewritePattern;
LogicalResult matchAndRewrite(CastOp castOp,
PatternRewriter &rewriter) const override {
if (auto *defineOp = castOp.getSource().getDefiningOp()) {
if (defineOp->getBlock() != castOp->getBlock()) {
rewriter.moveOpAfter(castOp.getOperation(), defineOp);
return success();
}
return failure();
} else {
Copy link
Collaborator

@joker-eph joker-eph Nov 18, 2025

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
} else {
}

Nit: no else-after-return

auto argument = cast<BlockArgument>(castOp.getSource());
if (argument.getOwner() != castOp->getBlock()) {
rewriter.moveOpBefore(castOp.getOperation(),
&argument.getOwner()->front());
return success();
}
return failure();
}
}
};
} // namespace

void CastOp::getCanonicalizationPatterns(RewritePatternSet &results,
MLIRContext *context) {
results.add<HoistCastPos>(context);
}

FailureOr<std::optional<SmallVector<Value>>>
CastOp::bubbleDownCasts(OpBuilder &builder) {
return bubbleDownCastsPassthroughOpImpl(*this, builder, getSourceMutable());
Expand Down
41 changes: 41 additions & 0 deletions mlir/test/Dialect/MemRef/canonicalize.mlir
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1367,3 +1367,44 @@ func.func @non_fold_view_same_source_res_types(%0: memref<?xi8>, %arg0 : index)
%res = memref.view %0[%c0][%arg0] : memref<?xi8> to memref<?xi8>
return %res : memref<?xi8>
}

// -----

// CHECK-LABEL: func @hoist_cast_pos
// CHECK-SAME: %[[ARG0:.*]]: memref<10xf32>,
// CHECK-SAME: %[[ARG1:.*]]: i1
func.func @hoist_cast_pos(%arg: memref<10xf32>, %arg1: i1) -> (memref<?xf32>) {
// CHECK: %[[CAST_0:.*]] = memref.cast %[[ARG0]]
// CHECK: %[[CAST_1:.*]] = memref.cast %[[ARG0]]
// CHECK-NEXT: cf.cond_br %[[ARG1]]
cf.cond_br %arg1, ^bb1, ^bb2
^bb1:
%cast = memref.cast %arg : memref<10xf32> to memref<?xf32>
// CHECK: return %[[CAST_1]]
return %cast : memref<?xf32>
^bb2:
%cast1 = memref.cast %arg : memref<10xf32> to memref<?xf32>
// CHECK: return %[[CAST_0]]
return %cast1 : memref<?xf32>
}

// -----

// CHECK-LABEL: func.func @hoist_cast_pos_alloc
// CHECK-SAME: %[[ARG0:.*]]: i1
func.func @hoist_cast_pos_alloc(%arg: i1) -> (memref<?xf32>) {
// CHECK: %[[ALLOC_0:.*]] = memref.alloc()
// CHECK: %[[CAST_0:.*]] = memref.cast %[[ALLOC_0]]
// CHECK: %[[CAST_1:.*]] = memref.cast %[[ALLOC_0]]
// CHECK-NEXT: cf.cond_br %[[ARG0]]
%alloc = memref.alloc() : memref<10xf32>
cf.cond_br %arg, ^bb1, ^bb2
^bb1:
%cast = memref.cast %alloc : memref<10xf32> to memref<?xf32>
// CHECK: return %[[CAST_1]]
return %cast : memref<?xf32>
^bb2:
%cast1 = memref.cast %alloc : memref<10xf32> to memref<?xf32>
// CHECK: return %[[CAST_0]]
return %cast1 : memref<?xf32>
}
4 changes: 2 additions & 2 deletions mlir/test/Dialect/SCF/one-shot-bufferize.mlir
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -922,13 +922,13 @@ func.func @elide_copy_of_non_writing_scf_if(%c: i1, %p1: index, %p2: index, %f:
// CHECK-SAME: %[[pred:.*]]: index, %[[b:.*]]: memref<{{.*}}>, %[[c:.*]]: memref<{{.*}}>) -> memref<{{.*}}>
func.func @index_switch(%pred: index, %b: tensor<5xf32>, %c: tensor<5xf32>) -> tensor<5xf32> {
// Throw in a tensor that bufferizes to a different layout map.
// CHECK: %[[a:.*]] = memref.alloc() {{.*}} : memref<5xf32>
// CHECK: %[[a:.*]] = memref.alloc() {{.*}} : memref<5xf32>
// CHECK: %[[cast:.*]] = memref.cast %[[a]] : memref<5xf32> to memref<5xf32, strided<[?], offset: ?>>
%a = bufferization.alloc_tensor() : tensor<5xf32>

// CHECK: %[[r:.*]] = scf.index_switch %[[pred]] -> memref<5xf32, strided<[?], offset: ?>>
%0 = scf.index_switch %pred -> tensor<5xf32>
// CHECK: case 2 {
// CHECK: %[[cast:.*]] = memref.cast %[[a]] : memref<5xf32> to memref<5xf32, strided<[?], offset: ?>>
// CHECK: scf.yield %[[cast]]
case 2 {
scf.yield %a: tensor<5xf32>
Expand Down
Loading