tests/unit/test-int128.c

   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 }