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1//===-- Utility class to test different flavors of [l|ll]round --*- C++ -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef LLVM_LIBC_TEST_SRC_MATH_ROUNDTOINTEGERTEST_H10#define LLVM_LIBC_TEST_SRC_MATH_ROUNDTOINTEGERTEST_H11 12#include "src/__support/CPP/algorithm.h"13#include "src/__support/FPUtil/FEnvImpl.h"14#include "src/__support/FPUtil/FPBits.h"15#include "src/__support/macros/properties/architectures.h"16#include "test/UnitTest/FEnvSafeTest.h"17#include "test/UnitTest/FPMatcher.h"18#include "test/UnitTest/Test.h"19#include "utils/MPFRWrapper/MPFRUtils.h"20 21#include "hdr/math_macros.h"22 23namespace mpfr = LIBC_NAMESPACE::testing::mpfr;24using LIBC_NAMESPACE::Sign;25 26static constexpr int ROUNDING_MODES[4] = {FE_UPWARD, FE_DOWNWARD, FE_TOWARDZERO,27 FE_TONEAREST};28 29template <typename FloatType, typename IntType, bool TestModes = false>30class RoundToIntegerTestTemplate31 : public LIBC_NAMESPACE::testing::FEnvSafeTest {32public:33 typedef IntType (*RoundToIntegerFunc)(FloatType);34 35private:36 using FPBits = LIBC_NAMESPACE::fputil::FPBits<FloatType>;37 using StorageType = typename FPBits::StorageType;38 39 const FloatType zero = FPBits::zero().get_val();40 const FloatType neg_zero = FPBits::zero(Sign::NEG).get_val();41 const FloatType inf = FPBits::inf().get_val();42 const FloatType neg_inf = FPBits::inf(Sign::NEG).get_val();43 const FloatType nan = FPBits::quiet_nan().get_val();44 45 static constexpr StorageType MAX_NORMAL = FPBits::max_normal().uintval();46 static constexpr StorageType MIN_NORMAL = FPBits::min_normal().uintval();47 static constexpr StorageType MAX_SUBNORMAL =48 FPBits::max_subnormal().uintval();49 static constexpr StorageType MIN_SUBNORMAL =50 FPBits::min_subnormal().uintval();51 52 static constexpr IntType INTEGER_MIN = IntType(1)53 << (sizeof(IntType) * 8 - 1);54 static constexpr IntType INTEGER_MAX = -(INTEGER_MIN + 1);55 56 void test_one_input(RoundToIntegerFunc func, FloatType input,57 IntType expected, bool expectError) {58 libc_errno = 0;59 LIBC_NAMESPACE::fputil::clear_except(FE_ALL_EXCEPT);60 61 ASSERT_EQ(func(input), expected);62 63 // TODO: Handle the !expectError case. It used to expect64 // 0 for errno and exceptions, but this doesn't hold for65 // all math functions using RoundToInteger test:66 // https://github.com/llvm/llvm-project/pull/8881667 if (expectError) {68 ASSERT_FP_EXCEPTION(FE_INVALID);69 ASSERT_MATH_ERRNO(EDOM);70 }71 }72 73 static inline mpfr::RoundingMode to_mpfr_rounding_mode(int mode) {74 switch (mode) {75 case FE_UPWARD:76 return mpfr::RoundingMode::Upward;77 case FE_DOWNWARD:78 return mpfr::RoundingMode::Downward;79 case FE_TOWARDZERO:80 return mpfr::RoundingMode::TowardZero;81 case FE_TONEAREST:82 return mpfr::RoundingMode::Nearest;83 default:84 __builtin_unreachable();85 }86 }87 88public:89 void SetUp() override {90 LIBC_NAMESPACE::testing::FEnvSafeTest::SetUp();91 92 if (math_errhandling & MATH_ERREXCEPT) {93 // We will disable all exceptions so that the test will not94 // crash with SIGFPE. We can still use fetestexcept to check95 // if the appropriate flag was raised.96 LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT);97 }98 }99 100 void do_infinity_and_na_n_test(RoundToIntegerFunc func) {101 test_one_input(func, inf, INTEGER_MAX, true);102 test_one_input(func, neg_inf, INTEGER_MIN, true);103 // This is currently never enabled, the104 // LLVM_LIBC_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR CMake option in105 // libc/CMakeLists.txt is not forwarded to C++.106#if LIBC_COPT_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR107 // Result is not well-defined, we always returns INTEGER_MAX108 test_one_input(func, nan, INTEGER_MAX, true);109#endif // LIBC_COPT_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR110 }111 112 void testInfinityAndNaN(RoundToIntegerFunc func) {113 if (TestModes) {114 for (int mode : ROUNDING_MODES) {115 LIBC_NAMESPACE::fputil::set_round(mode);116 do_infinity_and_na_n_test(func);117 }118 } else {119 do_infinity_and_na_n_test(func);120 }121 }122 123 void do_round_numbers_test(RoundToIntegerFunc func) {124 test_one_input(func, zero, IntType(0), false);125 test_one_input(func, neg_zero, IntType(0), false);126 test_one_input(func, FloatType(1.0), IntType(1), false);127 test_one_input(func, FloatType(-1.0), IntType(-1), false);128 test_one_input(func, FloatType(10.0), IntType(10), false);129 test_one_input(func, FloatType(-10.0), IntType(-10), false);130 test_one_input(func, FloatType(1232.0), IntType(1232), false);131 test_one_input(func, FloatType(-1232.0), IntType(-1232), false);132 133 // The rest of this function compares with an equivalent MPFR function134 // which rounds floating point numbers to long values. There is no MPFR135 // function to round to long long or wider integer values. So, we will136 // the remaining tests only if the width of IntType less than equal to that137 // of long.138 if (sizeof(IntType) > sizeof(long))139 return;140 141 constexpr int EXPONENT_LIMIT = sizeof(IntType) * 8 - 1;142 constexpr int BIASED_EXPONENT_LIMIT = EXPONENT_LIMIT + FPBits::EXP_BIAS;143 if (BIASED_EXPONENT_LIMIT > FPBits::MAX_BIASED_EXPONENT)144 return;145 // We start with 1.0 so that the implicit bit for x86 long doubles146 // is set.147 FPBits bits(FloatType(1.0));148 bits.set_biased_exponent(BIASED_EXPONENT_LIMIT);149 bits.set_sign(Sign::NEG);150 bits.set_mantissa(0);151 152 FloatType x = bits.get_val();153 long mpfr_result;154 bool erangeflag = mpfr::round_to_long(x, mpfr_result);155 ASSERT_FALSE(erangeflag);156 test_one_input(func, x, mpfr_result, false);157 }158 159 void testRoundNumbers(RoundToIntegerFunc func) {160 if (TestModes) {161 for (int mode : ROUNDING_MODES) {162 LIBC_NAMESPACE::fputil::set_round(mode);163 do_round_numbers_test(func);164 }165 } else {166 do_round_numbers_test(func);167 }168 }169 170 void do_fractions_test(RoundToIntegerFunc func, int mode) {171 constexpr FloatType FRACTIONS[] = {172 FloatType(0.5), FloatType(-0.5), FloatType(0.115),173 FloatType(-0.115), FloatType(0.715), FloatType(-0.715),174 };175 for (FloatType x : FRACTIONS) {176 long mpfr_long_result;177 bool erangeflag;178 if (TestModes)179 erangeflag = mpfr::round_to_long(x, to_mpfr_rounding_mode(mode),180 mpfr_long_result);181 else182 erangeflag = mpfr::round_to_long(x, mpfr_long_result);183 ASSERT_FALSE(erangeflag);184 IntType mpfr_result = mpfr_long_result;185 test_one_input(func, x, mpfr_result, false);186 }187 }188 189 void testFractions(RoundToIntegerFunc func) {190 if (TestModes) {191 for (int mode : ROUNDING_MODES) {192 LIBC_NAMESPACE::fputil::set_round(mode);193 do_fractions_test(func, mode);194 }195 } else {196 // Passing 0 for mode has no effect as it is not used in doFractionsTest197 // when `TestModes` is false;198 do_fractions_test(func, 0);199 }200 }201 202 void testIntegerOverflow(RoundToIntegerFunc func) {203 // This function compares with an equivalent MPFR function which rounds204 // floating point numbers to long values. There is no MPFR function to205 // round to long long or wider integer values. So, we will peform the206 // comparisons in this function only if the width of IntType less than equal207 // to that of long.208 if (sizeof(IntType) > sizeof(long))209 return;210 211 constexpr int EXPONENT_LIMIT = sizeof(IntType) * 8 - 1;212 constexpr int BIASED_EXPONENT_LIMIT = EXPONENT_LIMIT + FPBits::EXP_BIAS;213 if (BIASED_EXPONENT_LIMIT > FPBits::MAX_BIASED_EXPONENT)214 return;215 // We start with 1.0 so that the implicit bit for x86 long doubles216 // is set.217 FPBits bits(FloatType(1.0));218 bits.set_biased_exponent(BIASED_EXPONENT_LIMIT);219 bits.set_sign(Sign::NEG);220 bits.set_mantissa(FPBits::FRACTION_MASK);221 222 FloatType x = bits.get_val();223 if (TestModes) {224 for (int m : ROUNDING_MODES) {225 LIBC_NAMESPACE::fputil::set_round(m);226 long mpfr_long_result;227 bool erangeflag =228 mpfr::round_to_long(x, to_mpfr_rounding_mode(m), mpfr_long_result);229 ASSERT_TRUE(erangeflag);230 test_one_input(func, x, INTEGER_MIN, true);231 }232 } else {233 long mpfr_long_result;234 bool erangeflag = mpfr::round_to_long(x, mpfr_long_result);235 ASSERT_TRUE(erangeflag);236 test_one_input(func, x, INTEGER_MIN, true);237 }238 }239 240 void testSubnormalRange(RoundToIntegerFunc func) {241 constexpr int COUNT = 1'000'001;242 constexpr StorageType STEP = LIBC_NAMESPACE::cpp::max(243 static_cast<StorageType>((MAX_SUBNORMAL - MIN_SUBNORMAL) / COUNT),244 StorageType(1));245 for (StorageType i = MIN_SUBNORMAL; i <= MAX_SUBNORMAL; i += STEP) {246 FloatType x = FPBits(i).get_val();247 if (x == FloatType(0.0))248 continue;249 // All subnormal numbers should round to zero.250 if (TestModes) {251 if (x > 0) {252 LIBC_NAMESPACE::fputil::set_round(FE_UPWARD);253 test_one_input(func, x, IntType(1), false);254 LIBC_NAMESPACE::fputil::set_round(FE_DOWNWARD);255 test_one_input(func, x, IntType(0), false);256 LIBC_NAMESPACE::fputil::set_round(FE_TOWARDZERO);257 test_one_input(func, x, IntType(0), false);258 LIBC_NAMESPACE::fputil::set_round(FE_TONEAREST);259 test_one_input(func, x, IntType(0), false);260 } else {261 LIBC_NAMESPACE::fputil::set_round(FE_UPWARD);262 test_one_input(func, x, IntType(0), false);263 LIBC_NAMESPACE::fputil::set_round(FE_DOWNWARD);264 test_one_input(func, x, IntType(-1), false);265 LIBC_NAMESPACE::fputil::set_round(FE_TOWARDZERO);266 test_one_input(func, x, IntType(0), false);267 LIBC_NAMESPACE::fputil::set_round(FE_TONEAREST);268 test_one_input(func, x, IntType(0), false);269 }270 } else {271 test_one_input(func, x, 0L, false);272 }273 }274 }275 276 void testNormalRange(RoundToIntegerFunc func) {277 // This function compares with an equivalent MPFR function which rounds278 // floating point numbers to long values. There is no MPFR function to279 // round to long long or wider integer values. So, we will peform the280 // comparisons in this function only if the width of IntType less than equal281 // to that of long.282 if (sizeof(IntType) > sizeof(long))283 return;284 285 constexpr int COUNT = 1'000'001;286 constexpr StorageType STEP = LIBC_NAMESPACE::cpp::max(287 static_cast<StorageType>((MAX_NORMAL - MIN_NORMAL) / COUNT),288 StorageType(1));289 for (StorageType i = MIN_NORMAL; i <= MAX_NORMAL; i += STEP) {290 FPBits xbits(i);291 FloatType x = xbits.get_val();292 // In normal range on x86 platforms, the long double implicit 1 bit can be293 // zero making the numbers NaN. We will skip them.294 if (xbits.is_nan())295 continue;296 297 if (TestModes) {298 for (int m : ROUNDING_MODES) {299 long mpfr_long_result;300 bool erangeflag = mpfr::round_to_long(x, to_mpfr_rounding_mode(m),301 mpfr_long_result);302 IntType mpfr_result = mpfr_long_result;303 LIBC_NAMESPACE::fputil::set_round(m);304 if (erangeflag)305 test_one_input(func, x, x > 0 ? INTEGER_MAX : INTEGER_MIN, true);306 else307 test_one_input(func, x, mpfr_result, false);308 }309 } else {310 long mpfr_long_result;311 bool erangeflag = mpfr::round_to_long(x, mpfr_long_result);312 IntType mpfr_result = mpfr_long_result;313 if (erangeflag)314 test_one_input(func, x, x > 0 ? INTEGER_MAX : INTEGER_MIN, true);315 else316 test_one_input(func, x, mpfr_result, false);317 }318 }319 }320};321 322#define LIST_ROUND_TO_INTEGER_TESTS_HELPER(FloatType, IntType, func, \323 TestModes) \324 using LlvmLibcRoundToIntegerTest = \325 RoundToIntegerTestTemplate<FloatType, IntType, TestModes>; \326 TEST_F(LlvmLibcRoundToIntegerTest, InfinityAndNaN) { \327 testInfinityAndNaN(&func); \328 } \329 TEST_F(LlvmLibcRoundToIntegerTest, RoundNumbers) { \330 testRoundNumbers(&func); \331 } \332 TEST_F(LlvmLibcRoundToIntegerTest, Fractions) { testFractions(&func); } \333 TEST_F(LlvmLibcRoundToIntegerTest, IntegerOverflow) { \334 testIntegerOverflow(&func); \335 } \336 TEST_F(LlvmLibcRoundToIntegerTest, SubnormalRange) { \337 testSubnormalRange(&func); \338 } \339 TEST_F(LlvmLibcRoundToIntegerTest, NormalRange) { testNormalRange(&func); }340 341#define LIST_ROUND_TO_INTEGER_TESTS(FloatType, IntType, func) \342 LIST_ROUND_TO_INTEGER_TESTS_HELPER(FloatType, IntType, func, false)343 344#define LIST_ROUND_TO_INTEGER_TESTS_WITH_MODES(FloatType, IntType, func) \345 LIST_ROUND_TO_INTEGER_TESTS_HELPER(FloatType, IntType, func, true)346 347#endif // LLVM_LIBC_TEST_SRC_MATH_ROUNDTOINTEGERTEST_H348