Simplify wide bit-field layout in CGRecordLayoutBuilder, and also fix a bug where assigning to a bit-field member would overwrite other parts of the struct.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@101681 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGenCXX/bitfield-layout.cpp b/test/CodeGenCXX/bitfield-layout.cpp
index 9425019..15f33d2 100644
--- a/test/CodeGenCXX/bitfield-layout.cpp
+++ b/test/CodeGenCXX/bitfield-layout.cpp
@@ -1,17 +1,43 @@
-// RUN: %clang_cc1 %s -triple=x86_64-apple-darwin10 -emit-llvm -o - | FileCheck %s
+// RUN: %clang_cc1 %s -triple=x86_64-apple-darwin10 -emit-llvm -o - -O3 | FileCheck -check-prefix LP64 %s
+// RUN: %clang_cc1 %s -triple=i386-apple-darwin10 -emit-llvm -o - -O3 | FileCheck -check-prefix LP32 %s
 
-// CHECK: %union.Test1 = type { i32, [4 x i8] }
+// CHECK-LP64: %union.Test1 = type { i32, [4 x i8] }
 union Test1 {
   int a;
   int b: 39;
 } t1;
 
-// CHECK: %union.Test2 = type { i8 }
+// CHECK-LP64: %union.Test2 = type { i8 }
 union Test2 {
   int : 6;
 } t2;
 
-// CHECK: %union.Test3 = type { [2 x i8] }
+// CHECK-LP64: %union.Test3 = type { [2 x i8] }
 union Test3 {
   int : 9;
 } t3;
+
+
+#define CHECK(x) if (!(x)) return __LINE__
+
+int f() {
+  struct {
+    int a;
+
+    unsigned long long b : 65;
+
+    int c;
+  } c;
+  
+  c.a = 0;
+  c.b = (unsigned long long)-1;
+  c.c = 0;
+
+  CHECK(c.a == 0);
+  CHECK(c.b == (unsigned long long)-1);
+  CHECK(c.c == 0);
+
+// CHECK-LP64: ret i32 0
+// CHECK-LP32: ret i32 0
+  return 0;
+}