[llvm] LowerAtomic: Use explicit alignment in lowerAtomicCmpXchgInst (PR #103767)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/103767

None

>From 7a86f00b33f0a07da9dbb8c8dfce857fed37bdfb Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Wed, 14 Aug 2024 13:53:27 +0400
Subject: [PATCH] LowerAtomic: Use explicit alignment in lowerAtomicCmpXchgInst

---
 llvm/lib/Transforms/Utils/LowerAtomic.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/Transforms/Utils/LowerAtomic.cpp b/llvm/lib/Transforms/Utils/LowerAtomic.cpp
index b203970ef9c5a0..f9bf419fb02252 100644
--- a/llvm/lib/Transforms/Utils/LowerAtomic.cpp
+++ b/llvm/lib/Transforms/Utils/LowerAtomic.cpp
@@ -25,10 +25,11 @@ bool llvm::lowerAtomicCmpXchgInst(AtomicCmpXchgInst *CXI) {
   Value *Cmp = CXI->getCompareOperand();
   Value *Val = CXI->getNewValOperand();
 
-  LoadInst *Orig = Builder.CreateLoad(Val->getType(), Ptr);
+  LoadInst *Orig =
+      Builder.CreateAlignedLoad(Val->getType(), Ptr, CXI->getAlign());
   Value *Equal = Builder.CreateICmpEQ(Orig, Cmp);
   Value *Res = Builder.CreateSelect(Equal, Val, Orig);
-  Builder.CreateStore(Res, Ptr);
+  Builder.CreateAlignedStore(Res, Ptr, CXI->getAlign());
 
   Res = Builder.CreateInsertValue(PoisonValue::get(CXI->getType()), Orig, 0);
   Res = Builder.CreateInsertValue(Res, Equal, 1);