From aa58281979710a1cee6f1635dc1074c4dfc44650 Mon Sep 17 00:00:00 2001
From: Matthias Springer <springerm@google.com>
Date: Tue, 4 May 2021 10:43:10 +0900
Subject: [PATCH] [mlir] Fix bug in TransferOpReduceRank when all dims are
 broadcasts

TransferReadOps that are a scalar read + broadcast are handled by TransferReadToVectorLoadLowering.

Differential Revision: https://reviews.llvm.org/D101808
---
 mlir/lib/Dialect/Vector/VectorTransforms.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mlir/lib/Dialect/Vector/VectorTransforms.cpp b/mlir/lib/Dialect/Vector/VectorTransforms.cpp
index 2c8b3379..3804295 100644
--- a/mlir/lib/Dialect/Vector/VectorTransforms.cpp
+++ b/mlir/lib/Dialect/Vector/VectorTransforms.cpp
@@ -2970,6 +2970,9 @@ struct TransferOpReduceRank : public OpRewritePattern<vector::TransferReadOp> {
       return failure();
     SmallVector<int64_t> newShape = llvm::to_vector<4>(
         originalVecType.getShape().take_back(reducedShapeRank));
+    // Vector rank cannot be zero. Handled by TransferReadToVectorLoadLowering.
+    if (newShape.empty())
+      return failure();
     VectorType newReadType =
         VectorType::get(newShape, originalVecType.getElementType());
     ArrayAttr newInBounds =
-- 
2.7.4