diff options
Diffstat (limited to 'grub-core/tests/cmp_test.c')
| -rw-r--r-- | grub-core/tests/cmp_test.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/grub-core/tests/cmp_test.c b/grub-core/tests/cmp_test.c new file mode 100644 index 0000000..af5b395 --- /dev/null +++ b/grub-core/tests/cmp_test.c @@ -0,0 +1,190 @@ +/* + * GRUB -- GRand Unified Bootloader + * Copyright (C) 2015 Free Software Foundation, Inc. + * + * GRUB is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * GRUB is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GRUB. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <grub/test.h> +#include <grub/dl.h> +#include <grub/misc.h> + +GRUB_MOD_LICENSE ("GPLv3+"); + +static grub_uint64_t vectors[][2] = { + { 0xffffffffffffffffULL, 1}, + { 1, 0xffffffffffffffffULL}, + { 0xffffffffffffffffULL, 0xffffffffffffffffULL}, + { 1, 1 }, + { 2, 1 } +}; + +/* Don't change those to use shift as shift may call to compile rt + functions and we're not testing them now. + */ +static int +leading_bit64 (grub_uint64_t a) +{ + return !!(a & 0x8000000000000000LL); +} + +static int +leading_bit32 (grub_uint32_t a) +{ + return !!(a & 0x80000000); +} + +/* Computes (a < b) without involving comparison operator. */ +static int +is_less32 (grub_uint32_t a, grub_uint32_t b) +{ + if (leading_bit32(a) && !leading_bit32(b)) + return 0; + if (!leading_bit32(a) && leading_bit32(b)) + return 1; + return leading_bit32(a - b); +} + +static void +test32 (grub_uint32_t a, grub_uint32_t b) +{ + grub_test_assert ((a < b) == is_less32(a, b), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((a > b) == is_less32(b, a), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((b < a) == is_less32(b, a), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((b > a) == is_less32(a, b), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert (!(is_less32(a, b) && is_less32(b, a)), "comparison inconsistent: %lld, %lld", + (long long) a, (long long) b); +} + +/* Computes (a > b) without involving comparison operator. */ +static int +is_less32s (grub_int32_t a, grub_int32_t b) +{ + if (leading_bit32(a) && !leading_bit32(b)) + return 1; /* a < 0 && b >= 0. */ + if (!leading_bit32(a) && leading_bit32(b)) + return 0; /* b < 0 && a >= 0. */ + return leading_bit32(a - b); +} + +static void +test32s (grub_int32_t a, grub_int32_t b) +{ + grub_test_assert ((a < b) == is_less32s(a, b), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((a > b) == is_less32s(b, a), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((b < a) == is_less32s(b, a), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((b > a) == is_less32s(a, b), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert (!(is_less32s(a, b) && is_less32s(b, a)), "comparison inconsistent: %lld, %lld", + (long long) a, (long long) b); +} + +/* Computes (a > b) without involving comparison operator. */ +static int +is_less64 (grub_uint64_t a, grub_uint64_t b) +{ + if (leading_bit64(a) && !leading_bit64(b)) + return 0; + if (!leading_bit64(a) && leading_bit64(b)) + return 1; + return leading_bit64(a - b); +} + +static void +test64 (grub_uint64_t a, grub_uint64_t b) +{ + grub_test_assert ((a < b) == is_less64(a, b), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((a > b) == is_less64(b, a), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((b < a) == is_less64(b, a), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((b > a) == is_less64(a, b), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert (!(is_less64(a, b) && is_less64(b, a)), "comparison inconsistent: %lld, %lld", + (long long) a, (long long) b); +} + +/* Computes (a > b) without involving comparison operator. */ +static int +is_less64s (grub_int64_t a, grub_int64_t b) +{ + if (leading_bit64(a) && !leading_bit64(b)) + return 1; /* a < 0 && b >= 0. */ + if (!leading_bit64(a) && leading_bit64(b)) + return 0; /* b < 0 && a >= 0. */ + return leading_bit64(a - b); +} + +static void +test64s (grub_int64_t a, grub_int64_t b) +{ + grub_test_assert ((a < b) == is_less64s(a, b), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((a > b) == is_less64s(b, a), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((b < a) == is_less64s(b, a), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert ((b > a) == is_less64s(a, b), "comparison result mismatch: %lld, %lld", + (long long) a, (long long) b); + grub_test_assert (!(is_less64s(a, b) && is_less64s(b, a)), "comparison inconsistent: %lld, %lld", + (long long) a, (long long) b); +} + +static void +test_all(grub_uint64_t a, grub_uint64_t b) +{ + test64 (a, b); + test32 (a, b); + test64s (a, b); + test32s (a, b); + test64s (a, -b); + test32s (a, -b); + test64s (-a, b); + test32s (-a, b); + test64s (-a, -b); + test32s (-a, -b); +} + +static void +cmp_test (void) +{ + grub_uint64_t a = 404, b = 7; + grub_size_t i; + + for (i = 0; i < ARRAY_SIZE (vectors); i++) + { + test_all (vectors[i][0], vectors[i][1]); + } + for (i = 0; i < 40000; i++) + { + a = 17 * a + 13 * b; + b = 23 * a + 29 * b; + if (b == 0) + b = 1; + if (a == 0) + a = 1; + test_all (a, b); + } +} + +/* Register example_test method as a functional test. */ +GRUB_FUNCTIONAL_TEST (cmp_test, cmp_test); 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