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/*
* Copyright © 2018 Intel Corporation
* Copyright © 2019 Valve Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#undef NDEBUG
#include <gtest/gtest.h>
#include "util/fast_urem_by_const.h"
#define RAND_TEST_ITERATIONS 100000
static uint32_t
rand_uint(unsigned min)
{
/* Make sure we get some small and large numbers and powers of two every
* once in a while
*/
int k = rand() % 64;
if (k == 17) {
return min + (rand() % 16);
} else if (k == 42) {
return UINT32_MAX - (rand() % 16);
} else if (k == 9) {
uint32_t r;
do {
r = 1ull << (rand() % 32);
} while (r < min);
return r;
}
if (min == 0) {
uint32_t r = 0;
for (unsigned i = 0; i < 4; i++)
r |= ((uint32_t)rand() & 0xf) << i * 8;
return r >> (31 - (rand() % 32));
} else {
uint64_t r;
do {
r = rand_uint(0);
} while (r < min);
return r;
}
}
static void
test_case(uint32_t n, uint32_t d)
{
assert(d >= 1);
uint64_t magic = REMAINDER_MAGIC(d);
/* Note: there's already an assert inside util_fast_urem32(), so the
* EXPECT_EQ is only here to make sure the test fails with a wrong result
* even if asserts are disabled. Ideally we could disable the assert just
* for the test to get a better error message, but that doesn't seem too
* easy.
*/
EXPECT_EQ(util_fast_urem32(n, d, magic), n % d);
}
TEST(fast_urem_by_const, random)
{
for (unsigned i = 0; i < RAND_TEST_ITERATIONS; i++) {
uint64_t n = rand_uint(0);
uint64_t d = rand_uint(1);
test_case(n, d);
}
}
TEST(fast_urem_by_const, special_cases)
{
test_case(0, 1);
test_case(0, UINT32_MAX);
test_case(UINT32_MAX, 1);
test_case(1, UINT32_MAX);
test_case(UINT32_MAX, UINT32_MAX);
test_case(UINT32_MAX, UINT32_MAX - 1);
test_case(UINT32_MAX - 1, UINT32_MAX - 1);
test_case(UINT32_MAX - 2, UINT32_MAX - 1);
}
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