IRgen: Set the alignment correctly when creating LValue for a decls.

 - Fixes PR5598.
 - Review appreciated.

llvm-svn: 111726

1 files changed, 89 insertions, 0 deletions

diff --git a/clang/test/CodeGen/packed-structure.c b/clang/test/CodeGen/packed-structure.c
new file mode 100644
index 00000000000..2934d01d649
--- /dev/null
+++ b/clang/test/CodeGen/packed-structure.c
@@ -0,0 +1,89 @@
+// RUN: %clang_cc1 -triple x86_64 -emit-llvm -o - %s | opt -S -strip -o %t
+// RUX: llvm-gcc -flto -S -O3 -o %t %s
+// RUN: FileCheck --check-prefix=CHECK-GLOBAL < %t %s
+// RUN: FileCheck --check-prefix=CHECK-FUNCTIONS < %t %s
+
+struct s0 {
+  int x;
+  int y __attribute__((packed));
+};
+
+// CHECK-GLOBAL: @s0_align_x = global i32 4
+
+// FIXME: This should be 1 to match gcc. PR7951.
+// CHECK-GLOBAL: @s0_align_y = global i32 4
+
+// CHECK-GLOBAL: @s0_align = global i32 4
+int s0_align_x = __alignof(((struct s0*)0)->x);
+int s0_align_y = __alignof(((struct s0*)0)->y);
+int s0_align   = __alignof(struct s0);
+
+// CHECK-FUNCTIONS: define i32 @s0_load_x
+// CHECK-FUNCTIONS: [[s0_load_x:%.*]] = load i32* {{.*}}, align 4
+// CHECK-FUNCTIONS: ret i32 [[s0_load_x]]
+int s0_load_x(struct s0 *a) { return a->x; }
+// FIXME: This seems like it should be align 1. This is actually something which
+// has changed in llvm-gcc recently, previously both x and y would be loaded
+// with align 1 (in 2363.1 at least).
+//
+// CHECK-FUNCTIONS: define i32 @s0_load_y
+// CHECK-FUNCTIONS: [[s0_load_y:%.*]] = load i32* {{.*}}, align 4
+// CHECK-FUNCTIONS: ret i32 [[s0_load_y]]
+int s0_load_y(struct s0 *a) { return a->y; }
+// CHECK-FUNCTIONS: define void @s0_copy
+// CHECK-FUNCTIONS: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}, i8* {{.*}}, i64 8, i32 4, i1 false)
+void s0_copy(struct s0 *a, struct s0 *b) { *b = *a; }
+
+//
+
+struct s1 {
+  int x;
+  int y;
+} __attribute__((packed));
+
+// CHECK-GLOBAL: @s1_align_x = global i32 1
+// CHECK-GLOBAL: @s1_align_y = global i32 1
+// CHECK-GLOBAL: @s1_align = global i32 1
+int s1_align_x = __alignof(((struct s1*)0)->x);
+int s1_align_y = __alignof(((struct s1*)0)->y);
+int s1_align   = __alignof(struct s1);
+
+// CHECK-FUNCTIONS: define i32 @s1_load_x
+// CHECK-FUNCTIONS: [[s1_load_x:%.*]] = load i32* {{.*}}, align 1
+// CHECK-FUNCTIONS: ret i32 [[s1_load_x]]
+int s1_load_x(struct s1 *a) { return a->x; }
+// CHECK-FUNCTIONS: define i32 @s1_load_y
+// CHECK-FUNCTIONS: [[s1_load_y:%.*]] = load i32* {{.*}}, align 1
+// CHECK-FUNCTIONS: ret i32 [[s1_load_y]]
+int s1_load_y(struct s1 *a) { return a->y; }
+// CHECK-FUNCTIONS: define void @s1_copy
+// CHECK-FUNCTIONS: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}, i8* {{.*}}, i64 8, i32 1, i1 false)
+void s1_copy(struct s1 *a, struct s1 *b) { *b = *a; }
+
+//
+
+#pragma pack(push,2)
+struct s2 {
+  int x;
+  int y;
+};
+#pragma pack(pop)
+
+// CHECK-GLOBAL: @s2_align_x = global i32 2
+// CHECK-GLOBAL: @s2_align_y = global i32 2
+// CHECK-GLOBAL: @s2_align = global i32 2
+int s2_align_x = __alignof(((struct s2*)0)->x);
+int s2_align_y = __alignof(((struct s2*)0)->y);
+int s2_align   = __alignof(struct s2);
+
+// CHECK-FUNCTIONS: define i32 @s2_load_x
+// CHECK-FUNCTIONS: [[s2_load_y:%.*]] = load i32* {{.*}}, align 2
+// CHECK-FUNCTIONS: ret i32 [[s2_load_y]]
+int s2_load_x(struct s2 *a) { return a->x; }
+// CHECK-FUNCTIONS: define i32 @s2_load_y
+// CHECK-FUNCTIONS: [[s2_load_y:%.*]] = load i32* {{.*}}, align 2
+// CHECK-FUNCTIONS: ret i32 [[s2_load_y]]
+int s2_load_y(struct s2 *a) { return a->y; }
+// CHECK-FUNCTIONS: define void @s2_copy
+// CHECK-FUNCTIONS: call void @llvm.memcpy.p0i8.p0i8.i64(i8* {{.*}}, i8* {{.*}}, i64 8, i32 2, i1 false)
+void s2_copy(struct s2 *a, struct s2 *b) { *b = *a; }