1 //===-- Unittests for expf ------------------------------------------------===// 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 #include "include/errno.h" 10 #include "include/math.h" 11 #include "src/errno/llvmlibc_errno.h" 12 #include "src/math/expf.h" 13 #include "utils/FPUtil/BitPatterns.h" 14 #include "utils/FPUtil/FloatOperations.h" 15 #include "utils/FPUtil/FloatProperties.h" 16 #include "utils/MPFRWrapper/MPFRUtils.h" 17 #include "utils/UnitTest/Test.h" 18 19 #include <stdint.h> 20 21 using __llvm_libc::fputil::isNegativeQuietNaN; 22 using __llvm_libc::fputil::isQuietNaN; 23 using __llvm_libc::fputil::valueAsBits; 24 using __llvm_libc::fputil::valueFromBits; 25 26 using BitPatterns = __llvm_libc::fputil::BitPatterns<float>; 27 28 namespace mpfr = __llvm_libc::testing::mpfr; 29 30 // 12 additional bits of precision over the base precision of a |float| 31 // value. 32 static constexpr mpfr::Tolerance tolerance{mpfr::Tolerance::floatPrecision, 12, 33 0xFFF}; 34 35 TEST(ExpfTest, SpecialNumbers) { 36 llvmlibc_errno = 0; 37 38 EXPECT_TRUE( 39 isQuietNaN(__llvm_libc::expf(valueFromBits(BitPatterns::aQuietNaN)))); 40 EXPECT_EQ(llvmlibc_errno, 0); 41 42 EXPECT_TRUE(isNegativeQuietNaN( 43 __llvm_libc::expf(valueFromBits(BitPatterns::aNegativeQuietNaN)))); 44 EXPECT_EQ(llvmlibc_errno, 0); 45 46 EXPECT_TRUE(isQuietNaN( 47 __llvm_libc::expf(valueFromBits(BitPatterns::aSignallingNaN)))); 48 EXPECT_EQ(llvmlibc_errno, 0); 49 50 EXPECT_TRUE(isNegativeQuietNaN( 51 __llvm_libc::expf(valueFromBits(BitPatterns::aNegativeSignallingNaN)))); 52 EXPECT_EQ(llvmlibc_errno, 0); 53 54 EXPECT_EQ(BitPatterns::inf, 55 valueAsBits(__llvm_libc::expf(valueFromBits(BitPatterns::inf)))); 56 EXPECT_EQ(llvmlibc_errno, 0); 57 58 EXPECT_EQ(BitPatterns::zero, 59 valueAsBits(__llvm_libc::expf(valueFromBits(BitPatterns::negInf)))); 60 EXPECT_EQ(llvmlibc_errno, 0); 61 62 EXPECT_EQ(BitPatterns::one, 63 valueAsBits(__llvm_libc::expf(valueFromBits(BitPatterns::zero)))); 64 EXPECT_EQ(llvmlibc_errno, 0); 65 66 EXPECT_EQ(BitPatterns::one, valueAsBits(__llvm_libc::expf( 67 valueFromBits(BitPatterns::negZero)))); 68 EXPECT_EQ(llvmlibc_errno, 0); 69 } 70 71 TEST(ExpfTest, Overflow) { 72 llvmlibc_errno = 0; 73 EXPECT_EQ(BitPatterns::inf, 74 valueAsBits(__llvm_libc::expf(valueFromBits(0x7f7fffffU)))); 75 EXPECT_EQ(llvmlibc_errno, ERANGE); 76 77 llvmlibc_errno = 0; 78 EXPECT_EQ(BitPatterns::inf, 79 valueAsBits(__llvm_libc::expf(valueFromBits(0x42cffff8U)))); 80 EXPECT_EQ(llvmlibc_errno, ERANGE); 81 82 llvmlibc_errno = 0; 83 EXPECT_EQ(BitPatterns::inf, 84 valueAsBits(__llvm_libc::expf(valueFromBits(0x42d00008U)))); 85 EXPECT_EQ(llvmlibc_errno, ERANGE); 86 } 87 88 TEST(ExpfTest, Underflow) { 89 llvmlibc_errno = 0; 90 EXPECT_EQ(BitPatterns::zero, 91 valueAsBits(__llvm_libc::expf(valueFromBits(0xff7fffffU)))); 92 EXPECT_EQ(llvmlibc_errno, ERANGE); 93 94 llvmlibc_errno = 0; 95 EXPECT_EQ(BitPatterns::zero, 96 valueAsBits(__llvm_libc::expf(valueFromBits(0xc2cffff8U)))); 97 EXPECT_EQ(llvmlibc_errno, ERANGE); 98 99 llvmlibc_errno = 0; 100 EXPECT_EQ(BitPatterns::zero, 101 valueAsBits(__llvm_libc::expf(valueFromBits(0xc2d00008U)))); 102 EXPECT_EQ(llvmlibc_errno, ERANGE); 103 } 104 105 // Test with inputs which are the borders of underflow/overflow but still 106 // produce valid results without setting errno. 107 TEST(ExpfTest, Borderline) { 108 float x; 109 110 llvmlibc_errno = 0; 111 x = valueFromBits(0x42affff8U); 112 ASSERT_MPFR_MATCH(mpfr::OP_Exp, x, __llvm_libc::expf(x), tolerance); 113 EXPECT_EQ(llvmlibc_errno, 0); 114 115 x = valueFromBits(0x42b00008U); 116 ASSERT_MPFR_MATCH(mpfr::OP_Exp, x, __llvm_libc::expf(x), tolerance); 117 EXPECT_EQ(llvmlibc_errno, 0); 118 119 x = valueFromBits(0xc2affff8U); 120 ASSERT_MPFR_MATCH(mpfr::OP_Exp, x, __llvm_libc::expf(x), tolerance); 121 EXPECT_EQ(llvmlibc_errno, 0); 122 123 x = valueFromBits(0xc2b00008U); 124 ASSERT_MPFR_MATCH(mpfr::OP_Exp, x, __llvm_libc::expf(x), tolerance); 125 EXPECT_EQ(llvmlibc_errno, 0); 126 } 127 128 TEST(ExpfTest, InFloatRange) { 129 constexpr uint32_t count = 1000000; 130 constexpr uint32_t step = UINT32_MAX / count; 131 for (uint32_t i = 0, v = 0; i <= count; ++i, v += step) { 132 float x = valueFromBits(v); 133 if (isnan(x) || isinf(x)) 134 continue; 135 llvmlibc_errno = 0; 136 float result = __llvm_libc::expf(x); 137 138 // If the computation resulted in an error or did not produce valid result 139 // in the single-precision floating point range, then ignore comparing with 140 // MPFR result as MPFR can still produce valid results because of its 141 // wider precision. 142 if (isnan(result) || isinf(result) || llvmlibc_errno != 0) 143 continue; 144 ASSERT_MPFR_MATCH(mpfr::OP_Exp, x, __llvm_libc::expf(x), tolerance); 145 } 146 } 147