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