[Mlir-commits] [mlir] 7db98d6 - [mlir][affine] Avoid folding out-of-bounds constant loads (#224076)

[llvmlistbot at llvm.org]

Author: purnima shrivastava
Date: 2026-09-17T16:53:50+09:00
New Revision: 7db98d674027942e7ac16c90229dead25d9cc2fd

URL: https://github.com/llvm/llvm-project/commit/7db98d674027942e7ac16c90229dead25d9cc2fd
DIFF: https://github.com/llvm/llvm-project/commit/7db98d674027942e7ac16c90229dead25d9cc2fd.diff

LOG: [mlir][affine] Avoid folding out-of-bounds constant loads (#224076)

`AffineLoadOp::fold` could crash when folding a constant load with
out-of-bounds indices, including loads from zero-sized constant memrefs.

Check `ElementsAttr::isValidIndex` before indexing the constant
attribute and skip folding when the access is invalid.

Adds a regression test for `memref<0xi8>`.

Fixes #223949

Co-authored-by: Purnima Shrivastava <purnimashrivastava05 at .com>

Added: 
    

Modified: 
    mlir/lib/Dialect/Affine/IR/AffineOps.cpp
    mlir/test/Dialect/Affine/constant-fold.mlir

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
index 83a9e06374457..0b14c7de07058 100644
--- a/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
+++ b/mlir/lib/Dialect/Affine/IR/AffineOps.cpp
@@ -3520,7 +3520,10 @@ OpFoldResult AffineLoadOp::fold(FoldAdaptor adaptor) {
   auto indices =
       llvm::map_to_vector<4>(getAffineMap().getConstantResults(),
                              [](int64_t v) -> uint64_t { return v; });
-  return cstAttr.getValues<Attribute>()[indices];
+  ElementsAttr elementsAttr = cstAttr;
+  if (!elementsAttr.isValidIndex(indices))
+    return {};
+  return elementsAttr.getValues<Attribute>()[indices];
 }
 
 //===----------------------------------------------------------------------===//

diff  --git a/mlir/test/Dialect/Affine/constant-fold.mlir b/mlir/test/Dialect/Affine/constant-fold.mlir
index 8bddacc024751..ace83e49974c7 100644
--- a/mlir/test/Dialect/Affine/constant-fold.mlir
+++ b/mlir/test/Dialect/Affine/constant-fold.mlir
@@ -90,3 +90,15 @@ func.func @affine_apply_poison_division_zero_2() -> index {
   %0 = affine.apply affine_map<(d0)[s0] -> (d0 mod (s0 - s0))>(%c16)[%c16]
   return %0 : index
 }
+
+// -----
+
+memref.global "private" constant @empty : memref<0xi8> = dense<>
+
+// CHECK-LABEL: func.func @load_from_empty_global
+func.func @load_from_empty_global() -> i8 {
+  %0 = memref.get_global @empty : memref<0xi8>
+  // CHECK: affine.load %{{.*}}[0] : memref<0xi8>
+  %1 = affine.load %0[0] : memref<0xi8>
+  return %1 : i8
+}