1 //===-- Unittests for exp2f -----------------------------------------------===// 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/exp2f.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(LlvmLibcExp2fTest, SpecialNumbers) { 24 errno = 0; 25 26 EXPECT_FP_EQ(aNaN, __llvm_libc::exp2f(aNaN)); 27 EXPECT_MATH_ERRNO(0); 28 29 EXPECT_FP_EQ(inf, __llvm_libc::exp2f(inf)); 30 EXPECT_MATH_ERRNO(0); 31 32 EXPECT_FP_EQ(0.0f, __llvm_libc::exp2f(neg_inf)); 33 EXPECT_MATH_ERRNO(0); 34 35 EXPECT_FP_EQ(1.0f, __llvm_libc::exp2f(0.0f)); 36 EXPECT_MATH_ERRNO(0); 37 38 EXPECT_FP_EQ(1.0f, __llvm_libc::exp2f(-0.0f)); 39 EXPECT_MATH_ERRNO(0); 40 } 41 42 TEST(LlvmLibcExp2fTest, Overflow) { 43 errno = 0; 44 EXPECT_FP_EQ(inf, __llvm_libc::exp2f(float(FPBits(0x7f7fffffU)))); 45 EXPECT_MATH_ERRNO(ERANGE); 46 47 EXPECT_FP_EQ(inf, __llvm_libc::exp2f(float(FPBits(0x43000000U)))); 48 EXPECT_MATH_ERRNO(ERANGE); 49 50 EXPECT_FP_EQ(inf, __llvm_libc::exp2f(float(FPBits(0x43000001U)))); 51 EXPECT_MATH_ERRNO(ERANGE); 52 } 53 54 // Test with inputs which are the borders of underflow/overflow but still 55 // produce valid results without setting errno. 56 TEST(LlvmLibcExp2fTest, Borderline) { 57 float x; 58 59 errno = 0; 60 x = float(FPBits(0x42fa0001U)); 61 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 62 __llvm_libc::exp2f(x), 0.5); 63 EXPECT_MATH_ERRNO(0); 64 65 x = float(FPBits(0x42ffffffU)); 66 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 67 __llvm_libc::exp2f(x), 0.5); 68 EXPECT_MATH_ERRNO(0); 69 70 x = float(FPBits(0xc2fa0001U)); 71 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 72 __llvm_libc::exp2f(x), 0.5); 73 EXPECT_MATH_ERRNO(0); 74 75 x = float(FPBits(0xc2fc0000U)); 76 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 77 __llvm_libc::exp2f(x), 0.5); 78 EXPECT_MATH_ERRNO(0); 79 80 x = float(FPBits(0xc2fc0001U)); 81 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 82 __llvm_libc::exp2f(x), 0.5); 83 EXPECT_MATH_ERRNO(0); 84 85 x = float(FPBits(0xc3150000U)); 86 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 87 __llvm_libc::exp2f(x), 0.5); 88 EXPECT_MATH_ERRNO(0); 89 90 x = float(FPBits(0x3b42'9d37U)); 91 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 92 __llvm_libc::exp2f(x), 0.5); 93 EXPECT_MATH_ERRNO(0); 94 95 x = float(FPBits(0xbcf3'a937U)); 96 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 97 __llvm_libc::exp2f(x), 0.5); 98 EXPECT_MATH_ERRNO(0); 99 } 100 101 TEST(LlvmLibcExp2fTest, Underflow) { 102 errno = 0; 103 EXPECT_FP_EQ(0.0f, __llvm_libc::exp2f(float(FPBits(0xff7fffffU)))); 104 EXPECT_MATH_ERRNO(ERANGE); 105 106 float x = float(FPBits(0xc3158000U)); 107 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 108 __llvm_libc::exp2f(x), 0.5); 109 EXPECT_MATH_ERRNO(0); 110 111 x = float(FPBits(0xc3160000U)); 112 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 113 __llvm_libc::exp2f(x), 0.5); 114 EXPECT_MATH_ERRNO(ERANGE); 115 116 x = float(FPBits(0xc3165432U)); 117 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 118 __llvm_libc::exp2f(x), 0.5); 119 EXPECT_MATH_ERRNO(ERANGE); 120 } 121 122 TEST(LlvmLibcExp2fTest, InFloatRange) { 123 constexpr uint32_t COUNT = 1000000; 124 constexpr uint32_t STEP = UINT32_MAX / COUNT; 125 for (uint32_t i = 0, v = 0; i <= COUNT; ++i, v += STEP) { 126 float x = float(FPBits(v)); 127 if (isnan(x) || isinf(x)) 128 continue; 129 errno = 0; 130 float result = __llvm_libc::exp2f(x); 131 132 // If the computation resulted in an error or did not produce valid result 133 // in the single-precision floating point range, then ignore comparing with 134 // MPFR result as MPFR can still produce valid results because of its 135 // wider precision. 136 if (isnan(result) || isinf(result) || errno != 0) 137 continue; 138 ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 139 __llvm_libc::exp2f(x), 0.5); 140 } 141 } 142