--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang/test/CodeGen/packed-arrays.c	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,157 @@
+// RUN: %clang_cc1 -triple x86_64-unk-unk -emit-llvm -Os -o %t %s
+// RUN: FileCheck < %t %s
+
+struct s0 {
+  unsigned int x[2] __attribute__((packed));
+};
+
+struct s1 {
+  unsigned int x[2] __attribute__((packed));
+  unsigned int y;
+  unsigned int z __attribute__((packed));
+};
+
+struct s2 {
+  unsigned int x[2] __attribute__((packed));
+  unsigned int y __attribute__((packed));
+  unsigned int z __attribute__((packed));
+};
+
+struct __attribute__((packed)) s3 {
+  unsigned int x[2];
+  unsigned int y;
+  unsigned int z;
+};
+
+// CHECK: @align0 = local_unnamed_addr global i32 1
+int align0 = __alignof(struct s0);
+// CHECK: @align1 = local_unnamed_addr global i32 4
+int align1 = __alignof(struct s1);
+// CHECK: @align2 = local_unnamed_addr global i32 1
+int align2 = __alignof(struct s2);
+// CHECK: @align3 = local_unnamed_addr global i32 1
+int align3 = __alignof(struct s3);
+
+// CHECK: @align0_x = local_unnamed_addr global i32 1
+int align0_x = __alignof(((struct s0*) 0)->x);
+//
+// CHECK: @align1_x = local_unnamed_addr global i32 1
+int align1_x = __alignof(((struct s1*) 0)->x);
+// CHECK: @align2_x = local_unnamed_addr global i32 1
+int align2_x = __alignof(((struct s2*) 0)->x);
+// CHECK: @align3_x = local_unnamed_addr global i32 1
+int align3_x = __alignof(((struct s3*) 0)->x);
+
+// CHECK: @align0_x0 = local_unnamed_addr global i32 4
+int align0_x0 = __alignof(((struct s0*) 0)->x[0]);
+// CHECK: @align1_x0 = local_unnamed_addr global i32 4
+int align1_x0 = __alignof(((struct s1*) 0)->x[0]);
+// CHECK: @align2_x0 = local_unnamed_addr global i32 4
+int align2_x0 = __alignof(((struct s2*) 0)->x[0]);
+// CHECK: @align3_x0 = local_unnamed_addr global i32 4
+int align3_x0 = __alignof(((struct s3*) 0)->x[0]);
+
+// CHECK-LABEL: define i32 @f0_a
+// CHECK:   load i32, i32* %{{.*}}, align 1
+// CHECK: }
+// CHECK-LABEL: define i32 @f0_b
+// CHECK:   load i32, i32* %{{.*}}, align 4
+// CHECK: }
+int f0_a(struct s0 *a) {
+  return a->x[1];
+}
+int f0_b(struct s0 *a) {
+  return *(a->x + 1);
+}
+
+// Note that 'y' still causes struct s1 to be four-byte aligned.
+
+// Note that we are incompatible with GCC on this example.
+// 
+// CHECK-LABEL: define i32 @f1_a
+// CHECK:   load i32, i32* %{{.*}}, align 4
+// CHECK: }
+// CHECK-LABEL: define i32 @f1_b
+// CHECK:   load i32, i32* %{{.*}}, align 4
+// CHECK: }
+
+// Note that we are incompatible with GCC on this example.
+//
+// CHECK-LABEL: define i32 @f1_c
+// CHECK:   load i32, i32* %{{.*}}, align 4
+// CHECK: }
+// CHECK-LABEL: define i32 @f1_d
+// CHECK:   load i32, i32* %{{.*}}, align 4
+// CHECK: }
+int f1_a(struct s1 *a) {
+  return a->x[1];
+}
+int f1_b(struct s1 *a) {
+  return *(a->x + 1);
+}
+int f1_c(struct s1 *a) {
+  return a->y;
+}
+int f1_d(struct s1 *a) {
+  return a->z;
+}
+
+// CHECK-LABEL: define i32 @f2_a
+// CHECK:   load i32, i32* %{{.*}}, align 1
+// CHECK: }
+// CHECK-LABEL: define i32 @f2_b
+// CHECK:   load i32, i32* %{{.*}}, align 4
+// CHECK: }
+// CHECK-LABEL: define i32 @f2_c
+// CHECK:   load i32, i32* %{{.*}}, align 1
+// CHECK: }
+// CHECK-LABEL: define i32 @f2_d
+// CHECK:   load i32, i32* %{{.*}}, align 1
+// CHECK: }
+int f2_a(struct s2 *a) {
+  return a->x[1];
+}
+int f2_b(struct s2 *a) {
+  return *(a->x + 1);
+}
+int f2_c(struct s2 *a) {
+  return a->y;
+}
+int f2_d(struct s2 *a) {
+  return a->z;
+}
+
+// CHECK-LABEL: define i32 @f3_a
+// CHECK:   load i32, i32* %{{.*}}, align 1
+// CHECK: }
+// CHECK-LABEL: define i32 @f3_b
+// CHECK:   load i32, i32* %{{.*}}, align 4
+// CHECK: }
+// CHECK-LABEL: define i32 @f3_c
+// CHECK:   load i32, i32* %{{.*}}, align 1
+// CHECK: }
+// CHECK-LABEL: define i32 @f3_d
+// CHECK:   load i32, i32* %{{.*}}, align 1
+// CHECK: }
+int f3_a(struct s3 *a) {
+  return a->x[1];
+}
+int f3_b(struct s3 *a) {
+  return *(a->x + 1);
+}
+int f3_c(struct s3 *a) {
+  return a->y;
+}
+int f3_d(struct s3 *a) {
+  return a->z;
+}
+
+// Verify we don't claim things are overaligned.
+//
+// CHECK-LABEL: define double @f4
+// CHECK:   load double, double* {{.*}}, align 8
+// CHECK: }
+extern double g4[5] __attribute__((aligned(16)));
+double f4() {
+  return g4[1];
+}