libc/test/src/math/log10_test.cpp

   1 //===-- Unittests for log10 -----------------------------------------------===//
   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/errno/libc_errno.h"
  11 #include "src/math/log10.h"
  12 #include "test/UnitTest/FPMatcher.h"
  13 #include "test/UnitTest/Test.h"
  14 #include "utils/MPFRWrapper/MPFRUtils.h"
  15 #include <math.h>
  16
  17 #include <errno.h>
  18 #include <stdint.h>
  19
  20 using LlvmLibcLog10Test = LIBC_NAMESPACE::testing::FPTest<double>;
  21
  22 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
  23 using LIBC_NAMESPACE::testing::tlog;
  24
  25 TEST_F(LlvmLibcLog10Test, SpecialNumbers) {
  26   EXPECT_FP_EQ(aNaN, LIBC_NAMESPACE::log10(aNaN));
  27   EXPECT_FP_EQ(inf, LIBC_NAMESPACE::log10(inf));
  28   EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log10(neg_inf), FE_INVALID);
  29   EXPECT_FP_EQ_WITH_EXCEPTION(neg_inf, LIBC_NAMESPACE::log10(0.0),
  30                               FE_DIVBYZERO);
  31   EXPECT_FP_EQ_WITH_EXCEPTION(neg_inf, LIBC_NAMESPACE::log10(-0.0),
  32                               FE_DIVBYZERO);
  33   EXPECT_FP_IS_NAN_WITH_EXCEPTION(LIBC_NAMESPACE::log10(-1.0), FE_INVALID);
  34   EXPECT_FP_EQ_ALL_ROUNDING(zero, LIBC_NAMESPACE::log10(1.0));
  35 }
  36
  37 TEST_F(LlvmLibcLog10Test, TrickyInputs) {
  38   constexpr int N = 36;
  39   constexpr uint64_t INPUTS[N] = {
  40       0x3ff0000000000000, // x = 1.0
  41       0x4024000000000000, // x = 10.0
  42       0x4059000000000000, // x = 10^2
  43       0x408f400000000000, // x = 10^3
  44       0x40c3880000000000, // x = 10^4
  45       0x40f86a0000000000, // x = 10^5
  46       0x412e848000000000, // x = 10^6
  47       0x416312d000000000, // x = 10^7
  48       0x4197d78400000000, // x = 10^8
  49       0x41cdcd6500000000, // x = 10^9
  50       0x4202a05f20000000, // x = 10^10
  51       0x42374876e8000000, // x = 10^11
  52       0x426d1a94a2000000, // x = 10^12
  53       0x42a2309ce5400000, // x = 10^13
  54       0x42d6bcc41e900000, // x = 10^14
  55       0x430c6bf526340000, // x = 10^15
  56       0x4341c37937e08000, // x = 10^16
  57       0x4376345785d8a000, // x = 10^17
  58       0x43abc16d674ec800, // x = 10^18
  59       0x43e158e460913d00, // x = 10^19
  60       0x4415af1d78b58c40, // x = 10^20
  61       0x444b1ae4d6e2ef50, // x = 10^21
  62       0x4480f0cf064dd592, // x = 10^22
  63       0x3fefffffffef06ad, 0x3fefde0f22c7d0eb, 0x225e7812faadb32f,
  64       0x3fee1076964c2903, 0x3fdfe93fff7fceb0, 0x3ff012631ad8df10,
  65       0x3fefbfdaa448ed98, 0x44b0c9705a25ce02, 0x2c88d301065c7f9b,
  66       0x30160580e7268a99, 0x5ca04103b7eaa345, 0x19ad77dc4a40093f,
  67       0x0000449fb5c8a96e};
  68   for (int i = 0; i < N; ++i) {
  69     double x = double(FPBits(INPUTS[i]));
  70     EXPECT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log10, x,
  71                                    LIBC_NAMESPACE::log10(x), 0.5);
  72   }
  73 }
  74
  75 TEST_F(LlvmLibcLog10Test, AllExponents) {
  76   double x = 0x1.0p-1074;
  77   for (int i = -1074; i < 1024; ++i, x *= 2.0) {
  78     ASSERT_MPFR_MATCH_ALL_ROUNDING(mpfr::Operation::Log10, x,
  79                                    LIBC_NAMESPACE::log10(x), 0.5);
  80   }
  81 }
  82
  83 TEST_F(LlvmLibcLog10Test, InDoubleRange) {
  84   constexpr uint64_t COUNT = 1'001;
  85   constexpr uint64_t START = 0x3FD0'0000'0000'0000ULL; // 0.25
  86   constexpr uint64_t STOP = 0x4010'0000'0000'0000ULL;  // 4.0
  87   // constexpr uint64_t START = 0x3FF0'0000'0000'0000ULL;  // 1.0
  88   // constexpr uint64_t STOP = 0x4000'0000'0000'0000ULL;   // 2.0
  89   constexpr uint64_t STEP = (STOP - START) / COUNT;
  90
  91   auto test = [&](mpfr::RoundingMode rounding_mode) {
  92     mpfr::ForceRoundingMode __r(rounding_mode);
  93     if (!__r.success)
  94       return;
  95     uint64_t fails = 0;
  96     uint64_t count = 0;
  97     uint64_t cc = 0;
  98     double mx, mr = 0.0;
  99     double tol = 0.5;
 100
 101     for (uint64_t i = 0, v = START; i <= COUNT; ++i, v += STEP) {
 102       double x = FPBits(v).get_val();
 103       if (isnan(x) || isinf(x) || x < 0.0)
 104         continue;
 105       libc_errno = 0;
 106       double result = LIBC_NAMESPACE::log10(x);
 107       ++cc;
 108       if (isnan(result) || isinf(result))
 109         continue;
 110
 111       ++count;
 112       // ASSERT_MPFR_MATCH(mpfr::Operation::Log10, x, result, 0.5);
 113       if (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log10, x, result,
 114                                              0.5, rounding_mode)) {
 115         ++fails;
 116         while (!TEST_MPFR_MATCH_ROUNDING_SILENTLY(mpfr::Operation::Log10, x,
 117                                                   result, tol, rounding_mode)) {
 118           mx = x;
 119           mr = result;
 120           tol *= 2.0;
 121         }
 122       }
 123     }
 124     tlog << " Log10 failed: " << fails << "/" << count << "/" << cc
 125          << " tests.\n";
 126     tlog << "   Max ULPs is at most: " << static_cast<uint64_t>(tol) << ".\n";
 127     if (fails) {
 128       EXPECT_MPFR_MATCH(mpfr::Operation::Log10, mx, mr, 0.5, rounding_mode);
 129     }
 130   };
 131
 132   tlog << " Test Rounding To Nearest...\n";
 133   test(mpfr::RoundingMode::Nearest);
 134
 135   tlog << " Test Rounding Downward...\n";
 136   test(mpfr::RoundingMode::Downward);
 137
 138   tlog << " Test Rounding Upward...\n";
 139   test(mpfr::RoundingMode::Upward);
 140
 141   tlog << " Test Rounding Toward Zero...\n";
 142   test(mpfr::RoundingMode::TowardZero);
 143 }