[Mlir-commits] [mlir] [mlir][scf] Fix `for-loop-peeling` crash (PR #77697)

[Matthias Springer]

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@@ -123,8 +123,9 @@ static LogicalResult peelForLoop(RewriterBase &b, ForOp forOp,
   auto ubInt = getConstantIntValue(forOp.getUpperBound());
   auto stepInt = getConstantIntValue(forOp.getStep());
 
-  // No specialization necessary if step size is 1.
-  if (getConstantIntValue(forOp.getStep()) == static_cast<int64_t>(1))
+  // No specialization necessary if step size is 1. Also bail out in case of an
+  // invalid zero or negative step which might have happened during folding.
+  if (stepInt && *stepInt <= 1)
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matthias-springer wrote:

Interesting, I thought that negative step sizes were allowed, but the documentations says otherwise: `The step is a value of same type but required to be positive. `

https://github.com/llvm/llvm-project/pull/77697