064360e667
libgcc for boot environment isn't always present and compatible. libgcc is often absent if endianness or bit-size at boot is different from running OS. libgcc may use optimised opcodes that aren't available on boot time. So instead of relying on libgcc shipped with the compiler, supply the functions in GRUB directly. Tests are present to ensure that those replacement functions behave the way compiler expects them to.
190 lines
5.9 KiB
C
190 lines
5.9 KiB
C
/*
|
|
* 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);
|