From cd38485b8ae2928cc8cb3bb67dcff7c7b7529ebe Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Mon, 27 Feb 2012 23:16:46 +0000
Subject: [PATCH] Duncan pointed out that if the alignment isn't explicitly
 specified, it defaults to the ABI alignment.  Given that, make this code a
 bit more aggressive in such cases.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151584 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/BasicAliasAnalysis.cpp  | 8 ++++----
 test/Analysis/BasicAA/global-size.ll | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index 23b89ddf75f..20ecfd26a98 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -120,11 +120,11 @@ static uint64_t getObjectSize(const Value *V, const TargetData &TD,
     return AliasAnalysis::UnknownSize;
 
   uint64_t Size = TD.getTypeAllocSize(AccessTy);
-  if (RoundToAlign) {
-    if (!Align)
-      return AliasAnalysis::UnknownSize;
+  // If there is an explicitly specified alignment, and we need to
+  // take alignment into account, round up the size. (If the alignment
+  // is implicit, getTypeAllocSize is sufficient.)
+  if (RoundToAlign && Align)
     Size = RoundUpToAlignment(Size, Align);
-  }
 
   return Size;
 }
diff --git a/test/Analysis/BasicAA/global-size.ll b/test/Analysis/BasicAA/global-size.ll
index 617f4c3d9db..a7e5aab6c1f 100644
--- a/test/Analysis/BasicAA/global-size.ll
+++ b/test/Analysis/BasicAA/global-size.ll
@@ -4,7 +4,7 @@
 ; RUN: opt < %s -basicaa -gvn -S | FileCheck %s
 target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
 
-@B = global i16 8, align 2
+@B = global i16 8
 
 ; CHECK: @test1
 define i16 @test1(i32* %P) {