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 "src/__support/FPUtil/FPBits.h" 10 #include "src/math/expf.h" 11 #include "utils/MPFRWrapper/MPFRUtils.h" 12 #include "utils/UnitTest/FPMatcher.h" 13 #include "utils/UnitTest/Test.h" 14 #include <math.h> 15 16 #include <errno.h> 17 #include <stdint.h> 18 19 namespace mpfr = __llvm_libc::testing::mpfr; 20 21 DECLARE_SPECIAL_CONSTANTS(float) 22 23 TEST(LlvmLibcExpfTest, SpecialNumbers) { 24 errno = 0; 25 26 EXPECT_FP_EQ(aNaN, __llvm_libc::expf(aNaN)); 27 EXPECT_MATH_ERRNO(0); 28 29 EXPECT_FP_EQ(inf, __llvm_libc::expf(inf)); 30 EXPECT_MATH_ERRNO(0); 31 32 EXPECT_FP_EQ(0.0f, __llvm_libc::expf(neg_inf)); 33 EXPECT_MATH_ERRNO(0); 34 35 EXPECT_FP_EQ(1.0f, __llvm_libc::expf(0.0f)); 36 EXPECT_MATH_ERRNO(0); 37 38 EXPECT_FP_EQ(1.0f, __llvm_libc::expf(-0.0f)); 39 EXPECT_MATH_ERRNO(0); 40 } 41 42 TEST(LlvmLibcExpfTest, Overflow) { 43 errno = 0; 44 EXPECT_FP_EQ(inf, __llvm_libc::expf(float(FPBits(0x7f7fffffU)))); 45 EXPECT_MATH_ERRNO(ERANGE); 46 47 EXPECT_FP_EQ(inf, __llvm_libc::expf(float(FPBits(0x42cffff8U)))); 48 EXPECT_MATH_ERRNO(ERANGE); 49 50 EXPECT_FP_EQ(inf, __llvm_libc::expf(float(FPBits(0x42d00008U)))); 51 EXPECT_MATH_ERRNO(ERANGE); 52 } 53 54 TEST(LlvmLibcExpfTest, Underflow) { 55 errno = 0; 56 EXPECT_FP_EQ(0.0f, __llvm_libc::expf(float(FPBits(0xff7fffffU)))); 57 EXPECT_MATH_ERRNO(ERANGE); 58 59 float x = float(FPBits(0xc2cffff8U)); 60 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, __llvm_libc::expf(x), 61 0.5); 62 EXPECT_MATH_ERRNO(ERANGE); 63 64 x = float(FPBits(0xc2d00008U)); 65 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, __llvm_libc::expf(x), 66 0.5); 67 EXPECT_MATH_ERRNO(ERANGE); 68 } 69 70 // Test with inputs which are the borders of underflow/overflow but still 71 // produce valid results without setting errno. 72 TEST(LlvmLibcExpfTest, Borderline) { 73 float x; 74 75 errno = 0; 76 x = float(FPBits(0x42affff8U)); 77 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, __llvm_libc::expf(x), 78 0.5); 79 EXPECT_MATH_ERRNO(0); 80 81 x = float(FPBits(0x42b00008U)); 82 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, __llvm_libc::expf(x), 83 0.5); 84 EXPECT_MATH_ERRNO(0); 85 86 x = float(FPBits(0xc2affff8U)); 87 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, __llvm_libc::expf(x), 88 0.5); 89 EXPECT_MATH_ERRNO(0); 90 91 x = float(FPBits(0xc2b00008U)); 92 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, __llvm_libc::expf(x), 93 0.5); 94 EXPECT_MATH_ERRNO(0); 95 96 x = float(FPBits(0xc236bd8cU)); 97 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, __llvm_libc::expf(x), 98 0.5); 99 EXPECT_MATH_ERRNO(0); 100 } 101 102 TEST(LlvmLibcExpfTest, InFloatRange) { 103 constexpr uint32_t COUNT = 1000000; 104 constexpr uint32_t STEP = UINT32_MAX / COUNT; 105 for (uint32_t i = 0, v = 0; i <= COUNT; ++i, v += STEP) { 106 float x = float(FPBits(v)); 107 if (isnan(x) || isinf(x)) 108 continue; 109 errno = 0; 110 float result = __llvm_libc::expf(x); 111 112 // If the computation resulted in an error or did not produce valid result 113 // in the single-precision floating point range, then ignore comparing with 114 // MPFR result as MPFR can still produce valid results because of its 115 // wider precision. 116 if (isnan(result) || isinf(result) || errno != 0) 117 continue; 118 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp, x, 119 __llvm_libc::expf(x), 0.5); 120 } 121 } 122