xref: /aosp_15_r20/external/llvm-libc/test/src/math/exp10_test.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Unittests for 10^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/exp10.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 LlvmLibcExp10Test = LIBC_NAMESPACE::testing::FPTest<double>;
20 
21 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
22 using LIBC_NAMESPACE::testing::tlog;
23 
TEST_F(LlvmLibcExp10Test,SpecialNumbers)24 TEST_F(LlvmLibcExp10Test, SpecialNumbers) {
25   EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::exp10(aNaN));
26   EXPECT_FP_EQ(inf, LIBC_NAMESPACE::exp10(inf));
27   EXPECT_FP_EQ_ALL_ROUNDING(zero, LIBC_NAMESPACE::exp10(neg_inf));
28   EXPECT_FP_EQ_WITH_EXCEPTION(zero, LIBC_NAMESPACE::exp10(-0x1.0p20),
29                               FE_UNDERFLOW);
30   EXPECT_FP_EQ_WITH_EXCEPTION(inf, LIBC_NAMESPACE::exp10(0x1.0p20),
31                               FE_OVERFLOW);
32   EXPECT_FP_EQ_ALL_ROUNDING(1.0, LIBC_NAMESPACE::exp10(0.0));
33   EXPECT_FP_EQ_ALL_ROUNDING(1.0, LIBC_NAMESPACE::exp10(-0.0));
34 }
35 
TEST_F(LlvmLibcExp10Test,TrickyInputs)36 TEST_F(LlvmLibcExp10Test, TrickyInputs) {
37   constexpr int N = 41;
38   constexpr uint64_t INPUTS[N] = {
39       0x40033093317082F8, 0x3FD79289C6E6A5C0,
40       0x3FD05DE80A173EA0, // 0x1.05de80a173eap-2
41       0xbf1eb7a4cb841fcc, // -0x1.eb7a4cb841fccp-14
42       0xbf19a61fb925970d,
43       0x3fda7b764e2cf47a, // 0x1.a7b764e2cf47ap-2
44       0xc04757852a4b93aa, // -0x1.757852a4b93aap+5
45       0x4044c19e5712e377, // x=0x1.4c19e5712e377p+5
46       0xbf19a61fb925970d, // x=-0x1.9a61fb925970dp-14
47       0xc039a74cdab36c28, // x=-0x1.9a74cdab36c28p+4
48       0xc085b3e4e2e3bba9, // x=-0x1.5b3e4e2e3bba9p+9
49       0xc086960d591aec34, // x=-0x1.6960d591aec34p+9
50       0xc086232c09d58d91, // x=-0x1.6232c09d58d91p+9
51       0xc0874910d52d3051, // x=-0x1.74910d52d3051p9
52       0xc0867a172ceb0990, // x=-0x1.67a172ceb099p+9
53       0xc08ff80000000000, // x=-0x1.ff8p+9
54       0xbc971547652b82fe, // x=-0x1.71547652b82fep-54
55       0x0000000000000000, // x = 0
56       0x3ff0000000000000, // x = 1
57       0x4000000000000000, // x = 2
58       0x4008000000000000, // x = 3
59       0x4010000000000000, // x = 4
60       0x4014000000000000, // x = 5
61       0x4018000000000000, // x = 6
62       0x401c000000000000, // x = 7
63       0x4020000000000000, // x = 8
64       0x4022000000000000, // x = 9
65       0x4024000000000000, // x = 10
66       0x4026000000000000, // x = 11
67       0x4028000000000000, // x = 12
68       0x402a000000000000, // x = 13
69       0x402c000000000000, // x = 14
70       0x402e000000000000, // x = 15
71       0x4030000000000000, // x = 16
72       0x4031000000000000, // x = 17
73       0x4032000000000000, // x = 18
74       0x4033000000000000, // x = 19
75       0x4034000000000000, // x = 20
76       0x4035000000000000, // x = 21
77       0x4036000000000000, // x = 22
78       0x4037000000000000, // x = 23
79   };
80   for (int i = 0; i < N; ++i) {
81     double x = FPBits(INPUTS[i]).get_val();
82     EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Exp10, x,
83                                    LIBC_NAMESPACE::exp10(x), 0.5);
84   }
85 }
86 
TEST_F(LlvmLibcExp10Test,InDoubleRange)87 TEST_F(LlvmLibcExp10Test, InDoubleRange) {
88   constexpr uint64_t COUNT = 1'231;
89   uint64_t START = LIBC_NAMESPACE::fputil::FPBits<double>(0.25).uintval();
90   uint64_t STOP = LIBC_NAMESPACE::fputil::FPBits<double>(4.0).uintval();
91   uint64_t STEP = (STOP - START) / COUNT;
92 
93   auto test = [&](mpfr::RoundingMode rounding_mode) {
94     mpfr::ForceRoundingMode __r(rounding_mode);
95     if (!__r.success)
96       return;
97 
98     uint64_t fails = 0;
99     uint64_t count = 0;
100     uint64_t cc = 0;
101     double mx, mr = 0.0;
102     double tol = 0.5;
103 
104     for (uint64_t i = 0, v = START; i <= COUNT; ++i, v += STEP) {
105       double x = FPBits(v).get_val();
106       if (FPBits(v).is_nan() || FPBits(v).is_inf() || x < 0.0)
107         continue;
108       LIBC_NAMESPACE::libc_errno = 0;
109       double result = LIBC_NAMESPACE::exp10(x);
110       ++cc;
111       if (FPBits(result).is_nan() || FPBits(result).is_inf())
112         continue;
113 
114       ++count;
115 
116       if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Exp10, x, result,
117                                              0.5, rounding_mode)) {
118         ++fails;
119         while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Exp10, x,
120                                                   result, tol, rounding_mode)) {
121           mx = x;
122           mr = result;
123 
124           if (tol > 1000.0)
125             break;
126 
127           tol *= 2.0;
128         }
129       }
130     }
131     tlog << " Exp10 failed: " << fails << "/" << count << "/" << cc
132          << " tests.\n";
133     tlog << "   Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
134     if (fails) {
135       EXPECT_MPFR_MATCH(mpfr::Operation::Exp10, mx, mr, 0.5, rounding_mode);
136     }
137   };
138 
139   tlog << " Test Rounding To Nearest...\n";
140   test(mpfr::RoundingMode::Nearest);
141 
142   tlog << " Test Rounding Downward...\n";
143   test(mpfr::RoundingMode::Downward);
144 
145   tlog << " Test Rounding Upward...\n";
146   test(mpfr::RoundingMode::Upward);
147 
148   tlog << " Test Rounding Toward Zero...\n";
149   test(mpfr::RoundingMode::TowardZero);
150 }
151