[Mlir-commits] [mlir] 6020a97 - [MLIR] Fix use-after-scope when interchanging ploops (#196076)

[llvmlistbot at llvm.org]

Author: Benjamin Kramer
Date: 2026-05-06T14:01:04Z
New Revision: 6020a97f68bb56349a68d99063a2ff41fda162dc

URL: https://github.com/llvm/llvm-project/commit/6020a97f68bb56349a68d99063a2ff41fda162dc
DIFF: https://github.com/llvm/llvm-project/commit/6020a97f68bb56349a68d99063a2ff41fda162dc.diff

LOG: [MLIR] Fix use-after-scope when interchanging ploops (#196076)

getInductionVars returns a SmallVector, so going through zip+reverse
gets us a dangling reference. Quite a footgun.

Found by asan.

Added: 
    

Modified: 
    mlir/lib/Dialect/SCF/Transforms/ParallelLoopFusion.cpp

Removed: 
    


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diff  --git a/mlir/lib/Dialect/SCF/Transforms/ParallelLoopFusion.cpp b/mlir/lib/Dialect/SCF/Transforms/ParallelLoopFusion.cpp
index cbbe45a00163f..bdaade59e99df 100644
--- a/mlir/lib/Dialect/SCF/Transforms/ParallelLoopFusion.cpp
+++ b/mlir/lib/Dialect/SCF/Transforms/ParallelLoopFusion.cpp
@@ -748,8 +748,9 @@ static std::optional<ParallelOp> interchangeLoops(OpBuilder &builder,
                                   loop.getUpperBound(), loop.getStep(),
                                   loop.getInitVals(), nullptr);
   IRMapping mapping;
-  for (auto [iv, riv] : llvm::zip(loop.getInductionVars(),
-                                  llvm::reverse(newOp.getInductionVars()))) {
+  auto ivs = loop.getInductionVars();
+  auto newIvs = newOp.getInductionVars();
+  for (auto [iv, riv] : llvm::zip(ivs, llvm::reverse(newIvs))) {
     mapping.map(iv, riv);
   }
   // Copy parallel loop body