1 // RUN: %clang_cc1 -triple x86_64-unk-unk -emit-llvm -Os -o %t %s
2 // RUN: FileCheck < %t %s
3
4 struct s0 {
5 unsigned int x[2] __attribute__((packed));
6 };
7
8 struct s1 {
9 unsigned int x[2] __attribute__((packed));
10 unsigned int y;
11 unsigned int z __attribute__((packed));
12 };
13
14 struct s2 {
15 unsigned int x[2] __attribute__((packed));
16 unsigned int y __attribute__((packed));
17 unsigned int z __attribute__((packed));
18 };
19
20 struct __attribute__((packed)) s3 {
21 unsigned int x[2];
22 unsigned int y;
23 unsigned int z;
24 };
25
26 // CHECK: @align0 = local_unnamed_addr global i32 1
27 int align0 = __alignof(struct s0);
28 // CHECK: @align1 = local_unnamed_addr global i32 4
29 int align1 = __alignof(struct s1);
30 // CHECK: @align2 = local_unnamed_addr global i32 1
31 int align2 = __alignof(struct s2);
32 // CHECK: @align3 = local_unnamed_addr global i32 1
33 int align3 = __alignof(struct s3);
34
35 // CHECK: @align0_x = local_unnamed_addr global i32 1
36 int align0_x = __alignof(((struct s0*) 0)->x);
37 //
38 // CHECK: @align1_x = local_unnamed_addr global i32 1
39 int align1_x = __alignof(((struct s1*) 0)->x);
40 // CHECK: @align2_x = local_unnamed_addr global i32 1
41 int align2_x = __alignof(((struct s2*) 0)->x);
42 // CHECK: @align3_x = local_unnamed_addr global i32 1
43 int align3_x = __alignof(((struct s3*) 0)->x);
44
45 // CHECK: @align0_x0 = local_unnamed_addr global i32 4
46 int align0_x0 = __alignof(((struct s0*) 0)->x[0]);
47 // CHECK: @align1_x0 = local_unnamed_addr global i32 4
48 int align1_x0 = __alignof(((struct s1*) 0)->x[0]);
49 // CHECK: @align2_x0 = local_unnamed_addr global i32 4
50 int align2_x0 = __alignof(((struct s2*) 0)->x[0]);
51 // CHECK: @align3_x0 = local_unnamed_addr global i32 4
52 int align3_x0 = __alignof(((struct s3*) 0)->x[0]);
53
54 // CHECK-LABEL: define i32 @f0_a
55 // CHECK: load i32, i32* %{{.*}}, align 1
56 // CHECK: }
57 // CHECK-LABEL: define i32 @f0_b
58 // CHECK: load i32, i32* %{{.*}}, align 4
59 // CHECK: }
f0_a(struct s0 * a)60 int f0_a(struct s0 *a) {
61 return a->x[1];
62 }
f0_b(struct s0 * a)63 int f0_b(struct s0 *a) {
64 return *(a->x + 1);
65 }
66
67 // Note that 'y' still causes struct s1 to be four-byte aligned.
68
69 // Note that we are incompatible with GCC on this example.
70 //
71 // CHECK-LABEL: define i32 @f1_a
72 // CHECK: load i32, i32* %{{.*}}, align 4
73 // CHECK: }
74 // CHECK-LABEL: define i32 @f1_b
75 // CHECK: load i32, i32* %{{.*}}, align 4
76 // CHECK: }
77
78 // Note that we are incompatible with GCC on this example.
79 //
80 // CHECK-LABEL: define i32 @f1_c
81 // CHECK: load i32, i32* %{{.*}}, align 4
82 // CHECK: }
83 // CHECK-LABEL: define i32 @f1_d
84 // CHECK: load i32, i32* %{{.*}}, align 4
85 // CHECK: }
f1_a(struct s1 * a)86 int f1_a(struct s1 *a) {
87 return a->x[1];
88 }
f1_b(struct s1 * a)89 int f1_b(struct s1 *a) {
90 return *(a->x + 1);
91 }
f1_c(struct s1 * a)92 int f1_c(struct s1 *a) {
93 return a->y;
94 }
f1_d(struct s1 * a)95 int f1_d(struct s1 *a) {
96 return a->z;
97 }
98
99 // CHECK-LABEL: define i32 @f2_a
100 // CHECK: load i32, i32* %{{.*}}, align 1
101 // CHECK: }
102 // CHECK-LABEL: define i32 @f2_b
103 // CHECK: load i32, i32* %{{.*}}, align 4
104 // CHECK: }
105 // CHECK-LABEL: define i32 @f2_c
106 // CHECK: load i32, i32* %{{.*}}, align 1
107 // CHECK: }
108 // CHECK-LABEL: define i32 @f2_d
109 // CHECK: load i32, i32* %{{.*}}, align 1
110 // CHECK: }
f2_a(struct s2 * a)111 int f2_a(struct s2 *a) {
112 return a->x[1];
113 }
f2_b(struct s2 * a)114 int f2_b(struct s2 *a) {
115 return *(a->x + 1);
116 }
f2_c(struct s2 * a)117 int f2_c(struct s2 *a) {
118 return a->y;
119 }
f2_d(struct s2 * a)120 int f2_d(struct s2 *a) {
121 return a->z;
122 }
123
124 // CHECK-LABEL: define i32 @f3_a
125 // CHECK: load i32, i32* %{{.*}}, align 1
126 // CHECK: }
127 // CHECK-LABEL: define i32 @f3_b
128 // CHECK: load i32, i32* %{{.*}}, align 4
129 // CHECK: }
130 // CHECK-LABEL: define i32 @f3_c
131 // CHECK: load i32, i32* %{{.*}}, align 1
132 // CHECK: }
133 // CHECK-LABEL: define i32 @f3_d
134 // CHECK: load i32, i32* %{{.*}}, align 1
135 // CHECK: }
f3_a(struct s3 * a)136 int f3_a(struct s3 *a) {
137 return a->x[1];
138 }
f3_b(struct s3 * a)139 int f3_b(struct s3 *a) {
140 return *(a->x + 1);
141 }
f3_c(struct s3 * a)142 int f3_c(struct s3 *a) {
143 return a->y;
144 }
f3_d(struct s3 * a)145 int f3_d(struct s3 *a) {
146 return a->z;
147 }
148
149 // Verify we don't claim things are overaligned.
150 //
151 // CHECK-LABEL: define double @f4
152 // CHECK: load double, double* {{.*}}, align 8
153 // CHECK: }
154 extern double g4[5] __attribute__((aligned(16)));
f4()155 double f4() {
156 return g4[1];
157 }
158