xref: /openbmc/qemu/tests/unit/test-int128.c (revision af531756)
1 /*
2  * Test Int128 arithmetic
3  *
4  * This work is licensed under the terms of the GNU LGPL, version 2 or later.
5  * See the COPYING.LIB file in the top-level directory.
6  *
7  */
8 
9 #include "qemu/osdep.h"
10 #include "qemu/int128.h"
11 
12 /* clang doesn't support __noclone__ but it does have a mechanism for
13  * telling us this. We assume that if we don't have __has_attribute()
14  * then this is GCC and that GCC always supports __noclone__.
15  */
16 #if defined(__has_attribute)
17 #if !__has_attribute(__noclone__)
18 #define ATTRIBUTE_NOCLONE
19 #endif
20 #endif
21 #ifndef ATTRIBUTE_NOCLONE
22 #define ATTRIBUTE_NOCLONE __attribute__((__noclone__))
23 #endif
24 
25 static uint32_t tests[8] = {
26     0x00000000, 0x00000001, 0x7FFFFFFE, 0x7FFFFFFF,
27     0x80000000, 0x80000001, 0xFFFFFFFE, 0xFFFFFFFF,
28 };
29 
30 #define LOW    3ULL
31 #define HIGH   (1ULL << 63)
32 #define MIDDLE (-1ULL & ~LOW & ~HIGH)
33 
34 static uint64_t expand16(unsigned x)
35 {
36     return (x & LOW) | ((x & 4) ? MIDDLE : 0) | (x & 0x8000 ? HIGH : 0);
37 }
38 
39 static Int128 expand(uint32_t x)
40 {
41     uint64_t l, h;
42     l = expand16(x & 65535);
43     h = expand16(x >> 16);
44     return (Int128) int128_make128(l, h);
45 };
46 
47 static void test_and(void)
48 {
49     int i, j;
50 
51     for (i = 0; i < ARRAY_SIZE(tests); ++i) {
52         for (j = 0; j < ARRAY_SIZE(tests); ++j) {
53             Int128 a = expand(tests[i]);
54             Int128 b = expand(tests[j]);
55             Int128 r = expand(tests[i] & tests[j]);
56             Int128 s = int128_and(a, b);
57             g_assert_cmpuint(int128_getlo(r), ==, int128_getlo(s));
58             g_assert_cmpuint(int128_gethi(r), ==, int128_gethi(s));
59         }
60     }
61 }
62 
63 static void test_add(void)
64 {
65     int i, j;
66 
67     for (i = 0; i < ARRAY_SIZE(tests); ++i) {
68         for (j = 0; j < ARRAY_SIZE(tests); ++j) {
69             Int128 a = expand(tests[i]);
70             Int128 b = expand(tests[j]);
71             Int128 r = expand(tests[i] + tests[j]);
72             Int128 s = int128_add(a, b);
73             g_assert_cmpuint(int128_getlo(r), ==, int128_getlo(s));
74             g_assert_cmpuint(int128_gethi(r), ==, int128_gethi(s));
75         }
76     }
77 }
78 
79 static void test_sub(void)
80 {
81     int i, j;
82 
83     for (i = 0; i < ARRAY_SIZE(tests); ++i) {
84         for (j = 0; j < ARRAY_SIZE(tests); ++j) {
85             Int128 a = expand(tests[i]);
86             Int128 b = expand(tests[j]);
87             Int128 r = expand(tests[i] - tests[j]);
88             Int128 s = int128_sub(a, b);
89             g_assert_cmpuint(int128_getlo(r), ==, int128_getlo(s));
90             g_assert_cmpuint(int128_gethi(r), ==, int128_gethi(s));
91         }
92     }
93 }
94 
95 static void test_neg(void)
96 {
97     int i;
98 
99     for (i = 0; i < ARRAY_SIZE(tests); ++i) {
100         Int128 a = expand(tests[i]);
101         Int128 r = expand(-tests[i]);
102         Int128 s = int128_neg(a);
103         g_assert_cmpuint(int128_getlo(r), ==, int128_getlo(s));
104         g_assert_cmpuint(int128_gethi(r), ==, int128_gethi(s));
105     }
106 }
107 
108 static void test_nz(void)
109 {
110     int i, j;
111 
112     for (i = 0; i < ARRAY_SIZE(tests); ++i) {
113         for (j = 0; j < ARRAY_SIZE(tests); ++j) {
114             Int128 a = expand(tests[i]);
115             g_assert_cmpuint(int128_nz(a), ==, tests[i] != 0);
116         }
117     }
118 }
119 
120 static void test_le(void)
121 {
122     int i, j;
123 
124     for (i = 0; i < ARRAY_SIZE(tests); ++i) {
125         for (j = 0; j < ARRAY_SIZE(tests); ++j) {
126             /* Signed comparison */
127             int32_t a = (int32_t) tests[i];
128             int32_t b = (int32_t) tests[j];
129             g_assert_cmpuint(int128_le(expand(a), expand(b)), ==, a <= b);
130         }
131     }
132 }
133 
134 static void test_lt(void)
135 {
136     int i, j;
137 
138     for (i = 0; i < ARRAY_SIZE(tests); ++i) {
139         for (j = 0; j < ARRAY_SIZE(tests); ++j) {
140             /* Signed comparison */
141             int32_t a = (int32_t) tests[i];
142             int32_t b = (int32_t) tests[j];
143             g_assert_cmpuint(int128_lt(expand(a), expand(b)), ==, a < b);
144         }
145     }
146 }
147 
148 static void test_ge(void)
149 {
150     int i, j;
151 
152     for (i = 0; i < ARRAY_SIZE(tests); ++i) {
153         for (j = 0; j < ARRAY_SIZE(tests); ++j) {
154             /* Signed comparison */
155             int32_t a = (int32_t) tests[i];
156             int32_t b = (int32_t) tests[j];
157             g_assert_cmpuint(int128_ge(expand(a), expand(b)), ==, a >= b);
158         }
159     }
160 }
161 
162 static void test_gt(void)
163 {
164     int i, j;
165 
166     for (i = 0; i < ARRAY_SIZE(tests); ++i) {
167         for (j = 0; j < ARRAY_SIZE(tests); ++j) {
168             /* Signed comparison */
169             int32_t a = (int32_t) tests[i];
170             int32_t b = (int32_t) tests[j];
171             g_assert_cmpuint(int128_gt(expand(a), expand(b)), ==, a > b);
172         }
173     }
174 }
175 
176 /* Make sure to test undefined behavior at runtime! */
177 
178 static void __attribute__((__noinline__)) ATTRIBUTE_NOCLONE
179 test_rshift_one(uint32_t x, int n, uint64_t h, uint64_t l)
180 {
181     Int128 a = expand(x);
182     Int128 r = int128_rshift(a, n);
183     g_assert_cmpuint(int128_getlo(r), ==, l);
184     g_assert_cmpuint(int128_gethi(r), ==, h);
185 }
186 
187 static void test_rshift(void)
188 {
189     test_rshift_one(0x00010000U, 64, 0x0000000000000000ULL, 0x0000000000000001ULL);
190     test_rshift_one(0x80010000U, 64, 0xFFFFFFFFFFFFFFFFULL, 0x8000000000000001ULL);
191     test_rshift_one(0x7FFE0000U, 64, 0x0000000000000000ULL, 0x7FFFFFFFFFFFFFFEULL);
192     test_rshift_one(0xFFFE0000U, 64, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFFEULL);
193     test_rshift_one(0x00010000U, 60, 0x0000000000000000ULL, 0x0000000000000010ULL);
194     test_rshift_one(0x80010000U, 60, 0xFFFFFFFFFFFFFFF8ULL, 0x0000000000000010ULL);
195     test_rshift_one(0x00018000U, 60, 0x0000000000000000ULL, 0x0000000000000018ULL);
196     test_rshift_one(0x80018000U, 60, 0xFFFFFFFFFFFFFFF8ULL, 0x0000000000000018ULL);
197     test_rshift_one(0x7FFE0000U, 60, 0x0000000000000007ULL, 0xFFFFFFFFFFFFFFE0ULL);
198     test_rshift_one(0xFFFE0000U, 60, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFE0ULL);
199     test_rshift_one(0x7FFE8000U, 60, 0x0000000000000007ULL, 0xFFFFFFFFFFFFFFE8ULL);
200     test_rshift_one(0xFFFE8000U, 60, 0xFFFFFFFFFFFFFFFFULL, 0xFFFFFFFFFFFFFFE8ULL);
201     test_rshift_one(0x00018000U,  0, 0x0000000000000001ULL, 0x8000000000000000ULL);
202     test_rshift_one(0x80018000U,  0, 0x8000000000000001ULL, 0x8000000000000000ULL);
203     test_rshift_one(0x7FFE0000U,  0, 0x7FFFFFFFFFFFFFFEULL, 0x0000000000000000ULL);
204     test_rshift_one(0xFFFE0000U,  0, 0xFFFFFFFFFFFFFFFEULL, 0x0000000000000000ULL);
205     test_rshift_one(0x7FFE8000U,  0, 0x7FFFFFFFFFFFFFFEULL, 0x8000000000000000ULL);
206     test_rshift_one(0xFFFE8000U,  0, 0xFFFFFFFFFFFFFFFEULL, 0x8000000000000000ULL);
207 }
208 
209 int main(int argc, char **argv)
210 {
211     g_test_init(&argc, &argv, NULL);
212     g_test_add_func("/int128/int128_and", test_and);
213     g_test_add_func("/int128/int128_add", test_add);
214     g_test_add_func("/int128/int128_sub", test_sub);
215     g_test_add_func("/int128/int128_neg", test_neg);
216     g_test_add_func("/int128/int128_nz", test_nz);
217     g_test_add_func("/int128/int128_le", test_le);
218     g_test_add_func("/int128/int128_lt", test_lt);
219     g_test_add_func("/int128/int128_ge", test_ge);
220     g_test_add_func("/int128/int128_gt", test_gt);
221     g_test_add_func("/int128/int128_rshift", test_rshift);
222     return g_test_run();
223 }
224