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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2013 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 }
};
static void
test32 (grub_uint32_t a, grub_uint32_t b)
{
grub_uint64_t q, r;
if (b == 0)
return;
q = grub_divmod64 (a, b, &r);
grub_test_assert (r < b, "remainder is larger than dividend: 0x%llx %% 0x%llx = 0x%llx",
(long long) a, (long long) b, (long long) r);
grub_test_assert (q * b + r == a, "division doesn't satisfy base property: 0x%llx * 0x%llx + 0x%llx != 0x%llx", (long long) q, (long long) b, (long long) r,
(long long) a);
/* Overflow check. */
grub_test_assert ((q >> 32) == 0,
"division overflow in 0x%llx, 0x%llx", (long long) a, (long long) b);
grub_test_assert ((r >> 32) == 0,
"division overflow in 0x%llx, 0x%llx", (long long) a, (long long) b);
/* q * b + r is at most:
0xffffffff * 0xffffffff + 0xffffffff = 0xffffffff00000000
so no overflow
*/
grub_test_assert (q == (a / b),
"C compiler division failure in 0x%llx, 0x%llx", (long long) a, (long long) b);
grub_test_assert (r == (a % b),
"C compiler modulo failure in 0x%llx, 0x%llx", (long long) a, (long long) b);
}
static void
test64 (grub_uint64_t a, grub_uint64_t b)
{
grub_uint64_t q, r;
grub_uint64_t x1, x2;
q = grub_divmod64 (a, b, &r);
grub_test_assert (r < b, "remainder is larger than dividend: 0x%llx %% 0x%llx = 0x%llx",
(long long) a, (long long) b, (long long) r);
grub_test_assert (q * b + r == a, "division doesn't satisfy base property: 0x%llx * 0x%llx + 0x%llx != 0x%llx", (long long) q, (long long) b, (long long) r,
(long long) a);
/* Overflow checks. */
grub_test_assert ((q >> 32) * (b >> 32) == 0,
"division overflow in 0x%llx, 0x%llx", (long long) a, (long long) b);
x1 = (q >> 32) * (b & 0xffffffff);
grub_test_assert (x1 < (1LL << 32),
"division overflow in 0x%llx, 0x%llx", (long long) a, (long long) b);
x1 <<= 32;
x2 = (b >> 32) * (q & 0xffffffff);
grub_test_assert (x2 < (1LL << 32),
"division overflow in 0x%llx, 0x%llx", (long long) a, (long long) b);
x2 <<= 32;
grub_test_assert (x1 <= ~x2,
"division overflow in 0x%llx, 0x%llx", (long long) a, (long long) b);
x1 += x2;
x2 = (q & 0xffffffff) * (b & 0xffffffff);
grub_test_assert (x1 <= ~x2,
"division overflow in 0x%llx, 0x%llx", (long long) a, (long long) b);
x1 += x2;
grub_test_assert (x1 <= ~r,
"division overflow in 0x%llx, 0x%llx", (long long) a, (long long) b);
x1 += r;
grub_test_assert (a == x1,
"division overflow test failure in 0x%llx, 0x%llx", (long long) a, (long long) b);
#if GRUB_TARGET_SIZEOF_VOID_P == 8
grub_test_assert (q == (a / b),
"C compiler division failure in 0x%llx, 0x%llx", (long long) a, (long long) b);
grub_test_assert (r == (a % b),
"C compiler modulo failure in 0x%llx, 0x%llx", (long long) a, (long long) b);
#endif
}
static grub_int64_t
abs64(grub_int64_t a)
{
return a > 0 ? a : -a;
}
static void
test32s (grub_int32_t a, grub_int32_t b)
{
grub_int64_t q, r;
if (b == 0)
return;
q = grub_divmod64s (a, b, &r);
grub_test_assert (a > 0 ? r >= 0 : r <= 0, "remainder sign mismatch: %lld %% %lld = %lld",
(long long) a, (long long) b, (long long) r);
grub_test_assert (((a > 0) == (b > 0)) ? q >= 0 : q <= 0, "quotient sign mismatch: %lld / %lld = %lld",
(long long) a, (long long) b, (long long) q);
grub_test_assert (abs64(r) < abs64(b), "remainder is larger than dividend: %lld %% %lld = %lld",
(long long) a, (long long) b, (long long) r);
grub_test_assert (q * b + r == a, "division doesn't satisfy base property: %lld * %lld + %lld != %lld", (long long) q, (long long) b, (long long) r,
(long long) a);
if (0) { grub_test_assert (q == (a / b),
"C compiler division failure in 0x%llx, 0x%llx", (long long) a, (long long) b);
grub_test_assert (r == (a % b),
"C compiler modulo failure in 0x%llx, 0x%llx", (long long) a, (long long) b);
}
}
static void
test64s (grub_int64_t a, grub_int64_t b)
{
grub_int64_t q, r;
q = grub_divmod64s (a, b, &r);
grub_test_assert (a > 0 ? r >= 0 : r <= 0, "remainder sign mismatch: %lld %% %lld = %lld",
(long long) a, (long long) b, (long long) r);
grub_test_assert (((a > 0) == (b > 0)) ? q >= 0 : q <= 0, "quotient sign mismatch: %lld / %lld = %lld",
(long long) a, (long long) b, (long long) q);
grub_test_assert (abs64(r) < abs64(b), "remainder is larger than dividend: %lld %% %lld = %lld",
(long long) a, (long long) b, (long long) r);
grub_test_assert (q * b + r == a, "division doesn't satisfy base property: 0x%llx * 0x%llx + 0x%llx != 0x%llx", (long long) q, (long long) b, (long long) r,
(long long) a);
#if GRUB_TARGET_SIZEOF_VOID_P == 8
grub_test_assert (q == (a / b),
"C compiler division failure in 0x%llx, 0x%llx", (long long) a, (long long) b);
grub_test_assert (r == (a % b),
"C compiler modulo failure in 0x%llx, 0x%llx", (long long) a, (long long) b);
#endif
}
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
div_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 (div_test, div_test);
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