[clang] [mlir][affine] Check the input vector sizes to be greater than 0 (PR #65293)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-mlir-affine

<details>
<summary>Changes</summary>

In the process of vectorization of the affine loop, the 0 vector size causes the crash with building the invalid AffineForOp. We can catch the case beforehand propagating to the assertion.

See: https://github.com/llvm/llvm-project/issues/64262

---
Full diff: https://github.com/llvm/llvm-project/pull/65293.diff


3 Files Affected:

- (modified) mlir/include/mlir/Dialect/Affine/Passes.td (+2-1) 
- (modified) mlir/lib/Dialect/Affine/Transforms/SuperVectorize.cpp (+5) 
- (added) mlir/test/Dialect/Affine/SuperVectorize/invalid-zero-size.mlir (+9) 


``````````diff
diff --git a/mlir/include/mlir/Dialect/Affine/Passes.td b/mlir/include/mlir/Dialect/Affine/Passes.td
index 891a6661ca87be7..1036e93a0392409 100644
--- a/mlir/include/mlir/Dialect/Affine/Passes.td
+++ b/mlir/include/mlir/Dialect/Affine/Passes.td
@@ -349,7 +349,8 @@ def AffineVectorize : Pass<"affine-super-vectorize", "func::FuncOp"> {
   let dependentDialects = ["vector::VectorDialect"];
   let options = [
     ListOption<"vectorSizes", "virtual-vector-size", "int64_t",
-               "Specify an n-D virtual vector size for vectorization">,
+               "Specify an n-D virtual vector size for vectorization. "
+               "This must be greater than zero.">,
     // Optionally, the fixed mapping from loop to fastest varying MemRef
     // dimension for all the MemRefs within a loop pattern:
     //   the index represents the loop depth, the value represents the k^th
diff --git a/mlir/lib/Dialect/Affine/Transforms/SuperVectorize.cpp b/mlir/lib/Dialect/Affine/Transforms/SuperVectorize.cpp
index 85c2602aa266d67..a1d9c7b56c4e154 100644
--- a/mlir/lib/Dialect/Affine/Transforms/SuperVectorize.cpp
+++ b/mlir/lib/Dialect/Affine/Transforms/SuperVectorize.cpp
@@ -1732,6 +1732,11 @@ void Vectorize::runOnOperation() {
     return signalPassFailure();
   }
 
+  if (llvm::any_of(vectorSizes, [](int64_t size) { return size <= 0; })) {
+    f.emitError("Vectorization factor must be greater than zero.");
+    return signalPassFailure();
+  }
+
   DenseSet<Operation *> parallelLoops;
   ReductionLoopMap reductionLoops;
 
diff --git a/mlir/test/Dialect/Affine/SuperVectorize/invalid-zero-size.mlir b/mlir/test/Dialect/Affine/SuperVectorize/invalid-zero-size.mlir
new file mode 100644
index 000000000000000..396cc933e25bcf4
--- /dev/null
+++ b/mlir/test/Dialect/Affine/SuperVectorize/invalid-zero-size.mlir
@@ -0,0 +1,9 @@
+// RUN: mlir-opt %s -verify-diagnostics --affine-super-vectorize=virtual-vector-size=0
+
+// expected-error at +1 {{Vectorization factor must be greater than zero}} 
+func.func @with_zero_vector_size(%arg0: memref<21x12x12xi1>) {
+  affine.for %arg1 = 0 to 84 step 4294967295 {
+  }
+  return
+}
+

``````````

</details>


https://github.com/llvm/llvm-project/pull/65293