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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_LIBC_TEST_SRC_MATH_ROUNDTOINTEGERTEST_H 10 #define LLVM_LIBC_TEST_SRC_MATH_ROUNDTOINTEGERTEST_H 11 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 23 namespace mpfr = LIBC_NAMESPACE::testing::mpfr; 24 using LIBC_NAMESPACE::Sign; 25 26 static constexpr int ROUNDING_MODES[4] = {FE_UPWARD, FE_DOWNWARD, FE_TOWARDZERO, 27 FE_TONEAREST}; 28 29 template <typename FloatType, typename IntType, bool TestModes = false> 30 class RoundToIntegerTestTemplate 31 : public LIBC_NAMESPACE::testing::FEnvSafeTest { 32 public: 33 typedef IntType (*RoundToIntegerFunc)(FloatType); 34 35 private: 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 test_one_input(RoundToIntegerFunc func,FloatType input,IntType expected,bool expectError)56 void test_one_input(RoundToIntegerFunc func, FloatType input, 57 IntType expected, bool expectError) { 58 LIBC_NAMESPACE::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 expect 64 // 0 for errno and exceptions, but this doesn't hold for 65 // all math functions using RoundToInteger test: 66 // https://github.com/llvm/llvm-project/pull/88816 67 if (expectError) { 68 ASSERT_FP_EXCEPTION(FE_INVALID); 69 ASSERT_MATH_ERRNO(EDOM); 70 } 71 } 72 to_mpfr_rounding_mode(int mode)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 88 public: SetUp()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 not 94 // crash with SIGFPE. We can still use fetestexcept to check 95 // if the appropriate flag was raised. 96 LIBC_NAMESPACE::fputil::disable_except(FE_ALL_EXCEPT); 97 } 98 } 99 do_infinity_and_na_n_test(RoundToIntegerFunc func)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, the 104 // LLVM_LIBC_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR CMake option in 105 // libc/CMakeLists.txt is not forwarded to C++. 106 #if LIBC_COPT_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR 107 // Result is not well-defined, we always returns INTEGER_MAX 108 test_one_input(func, nan, INTEGER_MAX, true); 109 #endif // LIBC_COPT_IMPLEMENTATION_DEFINED_TEST_BEHAVIOR 110 } 111 testInfinityAndNaN(RoundToIntegerFunc func)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 do_round_numbers_test(RoundToIntegerFunc func)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(1234.0), IntType(1234), false); 131 test_one_input(func, FloatType(-1234.0), IntType(-1234), false); 132 133 // The rest of this function compares with an equivalent MPFR function 134 // which rounds floating point numbers to long values. There is no MPFR 135 // function to round to long long or wider integer values. So, we will 136 // the remaining tests only if the width of IntType less than equal to that 137 // 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 doubles 146 // 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 testRoundNumbers(RoundToIntegerFunc func)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 do_fractions_test(RoundToIntegerFunc func,int mode)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 else 182 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 testFractions(RoundToIntegerFunc func)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 doFractionsTest 197 // when `TestModes` is false; 198 do_fractions_test(func, 0); 199 } 200 } 201 testIntegerOverflow(RoundToIntegerFunc func)202 void testIntegerOverflow(RoundToIntegerFunc func) { 203 // This function compares with an equivalent MPFR function which rounds 204 // floating point numbers to long values. There is no MPFR function to 205 // round to long long or wider integer values. So, we will peform the 206 // comparisons in this function only if the width of IntType less than equal 207 // 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 doubles 216 // 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 testSubnormalRange(RoundToIntegerFunc func)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 testNormalRange(RoundToIntegerFunc func)276 void testNormalRange(RoundToIntegerFunc func) { 277 // This function compares with an equivalent MPFR function which rounds 278 // floating point numbers to long values. There is no MPFR function to 279 // round to long long or wider integer values. So, we will peform the 280 // comparisons in this function only if the width of IntType less than equal 281 // 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 be 293 // 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 else 307 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 else 316 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_H 348