[Mlir-commits] [mlir] [mlir] Fix MemRefType alignment in ConvertVectorToLLVM (PR #137389)

[Lily Orth-Smith]

https://github.com/electriclilies updated https://github.com/llvm/llvm-project/pull/137389

>From 18dfae0f4cddc8a255319f2c27546e66cd3ace42 Mon Sep 17 00:00:00 2001
From: Lily Orth-Smith <lorthsmith at microsoft.com>
Date: Fri, 25 Apr 2025 19:51:30 +0000
Subject: [PATCH] Fix how we get alignment for memrefs

---
 .../Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp    | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp b/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
index 076e5512f375b..79be34b204649 100644
--- a/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
+++ b/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp
@@ -70,15 +70,19 @@ static Value extractOne(ConversionPatternRewriter &rewriter,
 // Helper that returns data layout alignment of a memref.
 LogicalResult getMemRefAlignment(const LLVMTypeConverter &typeConverter,
                                  MemRefType memrefType, unsigned &align) {
-  Type elementTy = typeConverter.convertType(memrefType.getElementType());
-  if (!elementTy)
+  // Align MemRefTypes to the alignment of a VectorType with the same
+  // size and dtype.
+  Type convertedVecType = typeConverter.convertType(
+      VectorType::get(memrefType.getShape(), memrefType.getElementType()));
+  if (!convertedVecType)
     return failure();
 
   // TODO: this should use the MLIR data layout when it becomes available and
   // stop depending on translation.
   llvm::LLVMContext llvmContext;
   align = LLVM::TypeToLLVMIRTranslator(llvmContext)
-              .getPreferredAlignment(elementTy, typeConverter.getDataLayout());
+              .getPreferredAlignment(convertedVecType,
+                                     typeConverter.getDataLayout());
   return success();
 }