1 //===-- Unittests for 2^x -------------------------------------------------===// 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/exp2.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 LlvmLibcExp2Test = LIBC_NAMESPACE::testing::FPTest<double>; 20 21 namespace mpfr = LIBC_NAMESPACE::testing::mpfr; 22 using LIBC_NAMESPACE::testing::tlog; 23 24 TEST_F(LlvmLibcExp2Test, SpecialNumbers) { 25 EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::exp2(aNaN)); 26 EXPECT_FP_EQ(inf, LIBC_NAMESPACE::exp2(inf)); 27 EXPECT_FP_EQ_ALL_ROUNDING(zero, LIBC_NAMESPACE::exp2(neg_inf)); 28 EXPECT_FP_EQ_WITH_EXCEPTION(zero, LIBC_NAMESPACE::exp2(-0x1.0p20), 29 FE_UNDERFLOW); 30 EXPECT_FP_EQ_WITH_EXCEPTION(inf, LIBC_NAMESPACE::exp2(0x1.0p20), FE_OVERFLOW); 31 EXPECT_FP_EQ_ALL_ROUNDING(1.0, LIBC_NAMESPACE::exp2(0.0)); 32 EXPECT_FP_EQ_ALL_ROUNDING(1.0, LIBC_NAMESPACE::exp2(-0.0)); 33 } 34 35 TEST_F(LlvmLibcExp2Test, TrickyInputs) { 36 constexpr int N = 16; 37 constexpr uint64_t INPUTS[N] = { 38 0x3FD79289C6E6A5C0, 39 0x3FD05DE80A173EA0, // 0x1.05de80a173eap-2 40 0xbf1eb7a4cb841fcc, // -0x1.eb7a4cb841fccp-14 41 0xbf19a61fb925970d, 42 0x3fda7b764e2cf47a, // 0x1.a7b764e2cf47ap-2 43 0xc04757852a4b93aa, // -0x1.757852a4b93aap+5 44 0x4044c19e5712e377, // x=0x1.4c19e5712e377p+5 45 0xbf19a61fb925970d, // x=-0x1.9a61fb925970dp-14 46 0xc039a74cdab36c28, // x=-0x1.9a74cdab36c28p+4 47 0xc085b3e4e2e3bba9, // x=-0x1.5b3e4e2e3bba9p+9 48 0xc086960d591aec34, // x=-0x1.6960d591aec34p+9 49 0xc086232c09d58d91, // x=-0x1.6232c09d58d91p+9 50 0xc0874910d52d3051, // x=-0x1.74910d52d3051p9 51 0xc0867a172ceb0990, // x=-0x1.67a172ceb099p+9 52 0xc08ff80000000000, // x=-0x1.ff8p+9 53 0xbc971547652b82fe, // x=-0x1.71547652b82fep-54 54 }; 55 for (int i = 0; i < N; ++i) { 56 double x = FPBits(INPUTS[i]).get_val(); 57 EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp2, x, 58 LIBC_NAMESPACE::exp2(x), 0.5); 59 } 60 } 61 62 TEST_F(LlvmLibcExp2Test, InDoubleRange) { 63 constexpr uint64_t COUNT = 1'231; 64 uint64_t START = LIBC_NAMESPACE::fputil::FPBits<double>(0.25).uintval(); 65 uint64_t STOP = LIBC_NAMESPACE::fputil::FPBits<double>(4.0).uintval(); 66 uint64_t STEP = (STOP - START) / COUNT; 67 68 auto test = [&](mpfr::RoundingMode rounding_mode) { 69 mpfr::ForceRoundingMode __r(rounding_mode); 70 if (!__r.success) 71 return; 72 73 uint64_t fails = 0; 74 uint64_t count = 0; 75 uint64_t cc = 0; 76 double mx, mr = 0.0; 77 double tol = 0.5; 78 79 for (uint64_t i = 0, v = START; i <= COUNT; ++i, v += STEP) { 80 double x = FPBits(v).get_val(); 81 if (FPBits(v).is_nan() || FPBits(v).is_inf() || x < 0.0) 82 continue; 83 LIBC_NAMESPACE::libc_errno = 0; 84 double result = LIBC_NAMESPACE::exp2(x); 85 ++cc; 86 if (FPBits(result).is_nan() || FPBits(result).is_inf()) 87 continue; 88 89 ++count; 90 91 if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Exp2, x, result, 92 0.5, rounding_mode)) { 93 ++fails; 94 while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Exp2, x, 95 result, tol, rounding_mode)) { 96 mx = x; 97 mr = result; 98 99 if (tol > 1000.0) 100 break; 101 102 tol *= 2.0; 103 } 104 } 105 } 106 tlog << " Exp2 failed: " << fails << "/" << count << "/" << cc 107 << " tests.\n"; 108 tlog << " Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n"; 109 if (fails) { 110 EXPECT_MPFR_MATCH(mpfr::Operation::Exp2, mx, mr, 0.5, rounding_mode); 111 } 112 }; 113 114 tlog << " Test Rounding To Nearest...\n"; 115 test(mpfr::RoundingMode::Nearest); 116 117 tlog << " Test Rounding Downward...\n"; 118 test(mpfr::RoundingMode::Downward); 119 120 tlog << " Test Rounding Upward...\n"; 121 test(mpfr::RoundingMode::Upward); 122 123 tlog << " Test Rounding Toward Zero...\n"; 124 test(mpfr::RoundingMode::TowardZero); 125 } 126