Index: lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1315,7 +1315,9 @@
   assert((TargetFlags == 0 || isTarget) &&
          "Cannot set target flags on target-independent globals");
   if (Alignment == 0)
-    Alignment = getDataLayout().getPrefTypeAlignment(C->getType());
+    Alignment = MF->getFunction()->optForSize()
+                    ? getDataLayout().getABITypeAlignment(C->getType())
+                    : getDataLayout().getPrefTypeAlignment(C->getType());
   unsigned Opc = isTarget ? ISD::TargetConstantPool : ISD::ConstantPool;
   FoldingSetNodeID ID;
   AddNodeIDNode(ID, Opc, getVTList(VT), None);
Index: test/CodeGen/ARM/constantpool-align.ll
===================================================================
--- /dev/null
+++ test/CodeGen/ARM/constantpool-align.ll
@@ -0,0 +1,19 @@
+; RUN: llc < %s | FileCheck %s
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "thumbv7-arm-none-eabi"
+
+; CHECK-LABEL: f:
+; CHECK: vld1.64 {{.*}}, [r1:128]
+; CHECK: .p2align 4
+define void @f(<4 x i32>* %p) {
+  store <4 x i32> <i32 -1, i32 0, i32 0, i32 -1>, <4 x i32>* %p, align 4
+  ret void 
+}
+
+; CHECK-LABEL: f_optsize:
+; CHECK: vld1.64 {{.*}}, [r1]
+; CHECK: .p2align 3
+define void @f_optsize(<4 x i32>* %p) optsize {
+  store <4 x i32> <i32 -1, i32 0, i32 0, i32 -1>, <4 x i32>* %p, align 4
+  ret void 
+}