From 81c03447fc6358197258903e3fc6ee65b16ee768 Mon Sep 17 00:00:00 2001
From: Eric Christopher <echristo@apple.com>
Date: Sat, 27 Mar 2010 01:54:00 +0000
Subject: [PATCH] When we promote a load of an argument make sure to take the
 alignment of the previous load - it's usually important.  For example, we
 don't want to blindly turn an unaligned load into an aligned one.

llvm-svn: 99699
---
 llvm/lib/Transforms/IPO/ArgumentPromotion.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
index 00b147e8851e2..40a87e880d7bf 100644
--- a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -687,7 +687,11 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
             Ops.clear();
             AA.copyValue(OrigLoad->getOperand(0), V);
           }
-          Args.push_back(new LoadInst(V, V->getName()+".val", Call));
+          // Since we're replacing a load make sure we take the alignment
+          // of the previous load.
+          LoadInst *newLoad = new LoadInst(V, V->getName()+".val", Call);
+          newLoad->setAlignment(OrigLoad->getAlignment());
+          Args.push_back(newLoad);
           AA.copyValue(OrigLoad, Args.back());
         }
       }