| 1 | //===----------------------------------------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | // UNSUPPORTED: c++03, c++11, c++14, c++17 |
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| 9 | // <cmath> |
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| 10 | |
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| 11 | // constexpr float lerp(float a, float b, float t) noexcept; |
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| 12 | // constexpr double lerp(double a, double b, double t) noexcept; |
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| 13 | // constexpr long double lerp(long double a, long double b, long double t) noexcept; |
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| 14 | |
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| 15 | #include <cmath> |
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| 16 | #include <limits> |
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| 17 | #include <type_traits> |
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| 18 | #include <cassert> |
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| 19 | |
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| 20 | #include "test_macros.h" |
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| 21 | #include "fp_compare.h" |
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| 22 | |
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| 23 | template <typename T> |
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| 24 | constexpr bool constexpr_test() |
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| 25 | { |
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| 26 | return std::lerp(T( 0), T(12), T(0)) == T(0) |
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| 27 | && std::lerp(T(12), T( 0), T(0.5)) == T(6) |
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| 28 | && std::lerp(T( 0), T(12), T(2)) == T(24); |
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| 29 | } |
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| 30 | |
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| 31 | |
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| 32 | template <typename T> |
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| 33 | void test() |
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| 34 | { |
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| 35 | ASSERT_SAME_TYPE(T, decltype(std::lerp(T(), T(), T()))); |
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| 36 | LIBCPP_ASSERT_NOEXCEPT( std::lerp(T(), T(), T())); |
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| 37 | |
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| 38 | // constexpr T minV = std::numeric_limits<T>::min(); |
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| 39 | constexpr T maxV = std::numeric_limits<T>::max(); |
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| 40 | constexpr T inf = std::numeric_limits<T>::infinity(); |
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| 41 | |
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| 42 | // Things that can be compared exactly |
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| 43 | assert((std::lerp(T( 0), T(12), T(0)) == T(0))); |
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| 44 | assert((std::lerp(T( 0), T(12), T(1)) == T(12))); |
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| 45 | assert((std::lerp(T(12), T( 0), T(0)) == T(12))); |
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| 46 | assert((std::lerp(T(12), T( 0), T(1)) == T(0))); |
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| 47 | |
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| 48 | assert((std::lerp(T( 0), T(12), T(0.5)) == T(6))); |
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| 49 | assert((std::lerp(T(12), T( 0), T(0.5)) == T(6))); |
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| 50 | assert((std::lerp(T( 0), T(12), T(2)) == T(24))); |
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| 51 | assert((std::lerp(T(12), T( 0), T(2)) == T(-12))); |
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| 52 | |
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| 53 | assert((std::lerp(maxV, maxV/10, T(0)) == maxV)); |
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| 54 | assert((std::lerp(maxV/10, maxV, T(1)) == maxV)); |
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| 55 | |
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| 56 | assert((std::lerp(T(2.3), T(2.3), inf) == T(2.3))); |
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| 57 | |
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| 58 | assert(std::lerp(T( 0), T( 0), T(23)) == T(0)); |
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| 59 | assert(std::isnan(std::lerp(T( 0), T( 0), inf))); |
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| 60 | } |
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| 61 | |
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| 62 | |
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| 63 | int main(int, char**) |
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| 64 | { |
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| 65 | static_assert(constexpr_test<float>(), "" ); |
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| 66 | static_assert(constexpr_test<double>(), "" ); |
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| 67 | static_assert(constexpr_test<long double>(), "" ); |
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| 68 | |
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| 69 | test<float>(); |
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| 70 | test<double>(); |
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| 71 | test<long double>(); |
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| 72 | |
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| 73 | return 0; |
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| 74 | } |
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| 75 | |
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