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 "hdr/math_macros.h" 10 #include "src/__support/FPUtil/FPBits.h" 11 #include "src/errno/libc_errno.h" 12 #include "src/math/expf.h" 13 #include "test/UnitTest/FPMatcher.h" 14 #include "test/UnitTest/Test.h" 15 #include "utils/MPFRWrapper/MPFRUtils.h" 16 17 #include <stdint.h> 18 19 using LlvmLibcExpfTest = LIBC_NAMESPACE::testing::FPTest<float>; 20 21 namespace mpfr = LIBC_NAMESPACE::testing::mpfr; 22 23 TEST_F(LlvmLibcExpfTest, SpecialNumbers) { 24 LIBC_NAMESPACE::libc_errno = 0; 25 26 EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::expf(aNaN)); 27 EXPECT_MATH_ERRNO(0); 28 29 EXPECT_FP_EQ(inf, LIBC_NAMESPACE::expf(inf)); 30 EXPECT_MATH_ERRNO(0); 31 32 EXPECT_FP_EQ(0.0f, LIBC_NAMESPACE::expf(neg_inf)); 33 EXPECT_MATH_ERRNO(0); 34 35 EXPECT_FP_EQ(1.0f, LIBC_NAMESPACE::expf(0.0f)); 36 EXPECT_MATH_ERRNO(0); 37 38 EXPECT_FP_EQ(1.0f, LIBC_NAMESPACE::expf(-0.0f)); 39 EXPECT_MATH_ERRNO(0); 40 } 41 42 TEST_F(LlvmLibcExpfTest, Overflow) { 43 LIBC_NAMESPACE::libc_errno = 0; 44 EXPECT_FP_EQ_WITH_EXCEPTION( 45 inf, LIBC_NAMESPACE::expf(FPBits(0x7f7fffffU).get_val()), FE_OVERFLOW); 46 EXPECT_MATH_ERRNO(ERANGE); 47 48 EXPECT_FP_EQ_WITH_EXCEPTION( 49 inf, LIBC_NAMESPACE::expf(FPBits(0x42cffff8U).get_val()), FE_OVERFLOW); 50 EXPECT_MATH_ERRNO(ERANGE); 51 52 EXPECT_FP_EQ_WITH_EXCEPTION( 53 inf, LIBC_NAMESPACE::expf(FPBits(0x42d00008U).get_val()), FE_OVERFLOW); 54 EXPECT_MATH_ERRNO(ERANGE); 55 } 56 57 TEST_F(LlvmLibcExpfTest, Underflow) { 58 LIBC_NAMESPACE::libc_errno = 0; 59 EXPECT_FP_EQ_WITH_EXCEPTION( 60 0.0f, LIBC_NAMESPACE::expf(FPBits(0xff7fffffU).get_val()), FE_UNDERFLOW); 61 EXPECT_MATH_ERRNO(ERANGE); 62 63 float x = FPBits(0xc2cffff8U).get_val(); 64 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, 65 LIBC_NAMESPACE::expf(x), 0.5); 66 EXPECT_MATH_ERRNO(ERANGE); 67 68 x = FPBits(0xc2d00008U).get_val(); 69 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, 70 LIBC_NAMESPACE::expf(x), 0.5); 71 EXPECT_MATH_ERRNO(ERANGE); 72 } 73 74 // Test with inputs which are the borders of underflow/overflow but still 75 // produce valid results without setting errno. 76 TEST_F(LlvmLibcExpfTest, Borderline) { 77 float x; 78 79 LIBC_NAMESPACE::libc_errno = 0; 80 x = FPBits(0x42affff8U).get_val(); 81 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, 82 LIBC_NAMESPACE::expf(x), 0.5); 83 EXPECT_MATH_ERRNO(0); 84 85 x = FPBits(0x42b00008U).get_val(); 86 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, 87 LIBC_NAMESPACE::expf(x), 0.5); 88 EXPECT_MATH_ERRNO(0); 89 90 x = FPBits(0xc2affff8U).get_val(); 91 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, 92 LIBC_NAMESPACE::expf(x), 0.5); 93 EXPECT_MATH_ERRNO(0); 94 95 x = FPBits(0xc2b00008U).get_val(); 96 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, 97 LIBC_NAMESPACE::expf(x), 0.5); 98 EXPECT_MATH_ERRNO(0); 99 100 x = FPBits(0xc236bd8cU).get_val(); 101 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, 102 LIBC_NAMESPACE::expf(x), 0.5); 103 EXPECT_MATH_ERRNO(0); 104 } 105 106 TEST_F(LlvmLibcExpfTest, InFloatRange) { 107 constexpr uint32_t COUNT = 100'000; 108 constexpr uint32_t STEP = UINT32_MAX / COUNT; 109 for (uint32_t i = 0, v = 0; i <= COUNT; ++i, v += STEP) { 110 float x = FPBits(v).get_val(); 111 if (FPBits(v).is_nan() || FPBits(v).is_inf()) 112 continue; 113 LIBC_NAMESPACE::libc_errno = 0; 114 float result = LIBC_NAMESPACE::expf(x); 115 116 // If the computation resulted in an error or did not produce valid result 117 // in the single-precision floating point range, then ignore comparing with 118 // MPFR result as MPFR can still produce valid results because of its 119 // wider precision. 120 if (FPBits(result).is_nan() || FPBits(result).is_inf() || 121 LIBC_NAMESPACE::libc_errno != 0) 122 continue; 123 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, 124 LIBC_NAMESPACE::expf(x), 0.5); 125 } 126 } 127