If a global variable has a specified alignment that is less than the preferred

alignment for its type, use the minimum of the specified alignment and the ABI
alignment. This fixes <rdar://problem/9275290>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129428 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/TargetData.cpp b/lib/Target/TargetData.cpp
index c628df04e710c9feaed7ea46d9b8546e3a37aac1..d15855ce12690651fe14e1744824372f56020c44 100644 (file)
--- a/lib/Target/TargetData.cpp
+++ b/lib/Target/TargetData.cpp
@@ -617,8 +617,12 @@ uint64_t TargetData::getIndexedOffset(const Type *ptrTy, Value* const* Indices,
 unsigned TargetData::getPreferredAlignment(const GlobalVariable *GV) const {
   const Type *ElemType = GV->getType()->getElementType();
   unsigned Alignment = getPrefTypeAlignment(ElemType);
-  if (GV->getAlignment() > Alignment)
-    Alignment = GV->getAlignment();
+  unsigned GVAlignment = GV->getAlignment();
+  if (GVAlignment >= Alignment) {
+    Alignment = GVAlignment;
+  } else if (GVAlignment != 0) {
+    Alignment = std::min(GVAlignment, getABITypeAlignment(ElemType));
+  }
 
   if (GV->hasInitializer()) {
     if (Alignment < 16) {

diff --git a/test/CodeGen/ARM/2011-04-12-AlignBug.ll b/test/CodeGen/ARM/2011-04-12-AlignBug.ll
new file mode 100644 (file)
index 0000000..c657b79
--- /dev/null
+++ b/test/CodeGen/ARM/2011-04-12-AlignBug.ll
@@ -0,0 +1,9 @@
+; RUN: llc < %s | FileCheck %s
+target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:32-f32:32:32-f64:32:32-v64:32:64-v128:32:128-a0:0:32-n32"
+target triple = "thumbv7-apple-darwin10.0.0"
+
+; CHECK: align 2
+@.strA = linker_private unnamed_addr constant [4 x i8] c"bar\00"
+; CHECK-NOT: align
+@.strB = linker_private unnamed_addr constant [4 x i8] c"foo\00", align 1
+@.strC = linker_private unnamed_addr constant [4 x i8] c"baz\00", section "__TEXT,__cstring,cstring_literals", align 1