diff options
Diffstat (limited to 'grub-core/tests/shift_test.c')
| -rw-r--r-- | grub-core/tests/shift_test.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/grub-core/tests/shift_test.c b/grub-core/tests/shift_test.c new file mode 100644 index 0000000..4120f52 --- /dev/null +++ b/grub-core/tests/shift_test.c @@ -0,0 +1,157 @@ +/* + * 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[] = { + 0xffffffffffffffffULL, 1, 2, 0, 0x0102030405060708ULL +}; + +/* We're testing shifts, don't replace access to this with a shift. */ +static const grub_uint8_t bitmask[] = + { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 }; + +typedef union { + grub_uint64_t v64; + grub_uint8_t v8[8]; +} grub_raw_u64_t; + +static int +get_bit64 (grub_uint64_t v, int b) +{ + grub_raw_u64_t vr = { .v64 = v }; + grub_uint8_t *p = vr.v8; + if (b >= 64) + return 0; +#ifdef GRUB_CPU_WORDS_BIGENDIAN + p += 7 - b / 8; +#else + p += b / 8; +#endif + return !!(*p & bitmask[b % 8]); +} + +static grub_uint64_t +set_bit64 (grub_uint64_t v, int b) +{ + grub_raw_u64_t vr = { .v64 = v }; + grub_uint8_t *p = vr.v8; + if (b >= 64) + return v; +#ifdef GRUB_CPU_WORDS_BIGENDIAN + p += 7 - b / 8; +#else + p += b / 8; +#endif + *p |= bitmask[b % 8]; + return vr.v64; +} + +static grub_uint64_t +left_shift64 (grub_uint64_t v, int s) +{ + grub_uint64_t r = 0; + int i; + for (i = 0; i + s < 64; i++) + if (get_bit64 (v, i)) + r = set_bit64 (r, i + s); + return r; +} + +static grub_uint64_t +right_shift64 (grub_uint64_t v, int s) +{ + grub_uint64_t r = 0; + int i; + for (i = s; i < 64; i++) + if (get_bit64 (v, i)) + r = set_bit64 (r, i - s); + return r; +} + +static grub_uint64_t +arithmetic_right_shift64 (grub_uint64_t v, int s) +{ + grub_uint64_t r = 0; + int i; + for (i = s; i < 64; i++) + if (get_bit64 (v, i)) + r = set_bit64 (r, i - s); + if (get_bit64 (v, 63)) + for (i -= s; i < 64; i++) + r = set_bit64 (r, i); + + return r; +} + +static void +test64 (grub_uint64_t v) +{ + int i; + for (i = 0; i < 64; i++) + { + grub_test_assert ((v << i) == left_shift64 (v, i), + "lshift wrong: 0x%llx << %d: 0x%llx, 0x%llx", + (long long) v, i, + (long long) (v << i), (long long) left_shift64 (v, i)); + grub_test_assert ((v >> i) == right_shift64 (v, i), + "rshift wrong: 0x%llx >> %d: 0x%llx, 0x%llx", + (long long) v, i, + (long long) (v >> i), (long long) right_shift64 (v, i)); + grub_test_assert ((((grub_int64_t) v) >> i) == (grub_int64_t) arithmetic_right_shift64 (v, i), + "arithmetic rshift wrong: ((grub_int64_t) 0x%llx) >> %d: 0x%llx, 0x%llx", + (long long) v, i, + (long long) (((grub_int64_t) v) >> i), (long long) arithmetic_right_shift64 (v, i)); + } +} + +static void +test_all(grub_uint64_t a) +{ + test64 (a); +} + +static void +shift_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]); + } + for (i = 0; i < 4000; i++) + { + a = 17 * a + 13 * b; + b = 23 * a + 29 * b; + if (b == 0) + b = 1; + if (a == 0) + a = 1; + test_all (a); + test_all (b); + } +} + +/* Register example_test method as a functional test. */ +GRUB_FUNCTIONAL_TEST (shift_test, shift_test); |