Use the alignment from lvalue emission to more accurately compute the alignment

of a pointer for builtin emission, instead of just depending on the type of the
pointee.  <rdar://problem/11314941>.

llvm-svn: 162425

1 files changed, 20 insertions, 0 deletions

diff --git a/clang/test/CodeGen/builtin-memfns.c b/clang/test/CodeGen/builtin-memfns.c
index 72d340619f3..4a06160ccbc 100644
--- a/clang/test/CodeGen/builtin-memfns.c
+++ b/clang/test/CodeGen/builtin-memfns.c
@@ -63,3 +63,23 @@ int test7(int *p) {
   __builtin_memset(hwparams, 0, 256);  // No crash alignment = 1
   // CHECK: call void @llvm.memset{{.*}}256, i32 1, i1 false)
 }
+
+// <rdar://problem/11314941>
+// Make sure we don't over-estimate the alignment of fields of
+// packed structs.
+struct PS {
+  int modes[4];
+} __attribute__((packed));
+struct PS ps;
+void test8(int *arg) {
+  // CHECK: @test8
+  // CHECK: call void @llvm.memcpy{{.*}} 16, i32 1, i1 false)
+  __builtin_memcpy(arg, ps.modes, sizeof(struct PS));
+}
+
+__attribute((aligned(16))) int x[4], y[4];
+void test9() {
+  // CHECK: @test9
+  // CHECK: call void @llvm.memcpy{{.*}} 16, i32 16, i1 false)
+  __builtin_memcpy(x, y, sizeof(y));
+}