--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/Transforms/InstCombine/constant-fold-alias.ll	Wed Feb 18 14:55:36 2015 +0900
@@ -0,0 +1,40 @@
+; RUN: opt -S < %s -instcombine | FileCheck %s
+
+target datalayout = "e-p1:16:16-p2:32:32-p3:64:64"
+
+@G1 = global i32 42, align 1
+@G2 = global i32 42
+@G3 = global [4 x i8] zeroinitializer, align 1
+
+@A1 = alias bitcast (i8* getelementptr inbounds ([4 x i8]* @G3, i32 0, i32 2) to i32*)
+@A2 = alias inttoptr (i64 and (i64 ptrtoint (i8* getelementptr inbounds ([4 x i8]* @G3, i32 0, i32 3) to i64), i64 -4) to i32*)
+
+define i64 @f1() {
+; This cannot be constant folded because G1 is underaligned.
+; CHECK-LABEL: @f1(
+; CHECK: ret i64 and
+  ret i64 and (i64 ptrtoint (i32* @G1 to i64), i64 1)
+}
+
+define i64 @f2() {
+; The preferred alignment for G2 allows this one to foled to zero.
+; CHECK-LABEL: @f2(
+; CHECK: ret i64 0
+  ret i64 and (i64 ptrtoint (i32* @G2 to i64), i64 1)
+}
+
+define i64 @g1() {
+; This cannot be constant folded because A1 aliases G3 which is underalaigned.
+; CHECK-LABEL: @g1(
+; CHECK: ret i64 and
+  ret i64 and (i64 ptrtoint (i32* @A1 to i64), i64 1)
+}
+
+define i64 @g2() {
+; While A2 also aliases G3 which is underaligned, the math of A2 forces a
+; certain alignment allowing this to fold to zero.
+; CHECK-LABEL: @g2(
+; CHECK: ret i64 0
+  ret i64 and (i64 ptrtoint (i32* @A2 to i64), i64 1)
+}
+