libc/test/src/math/LogbTest.h

   1 //===-- Utility class to test logb[f|l] -------------------------*- C++ -*-===//
   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/ManipulationFunctions.h"
  10 #include "test/UnitTest/FPMatcher.h"
  11 #include "test/UnitTest/Test.h"
  12 #include "utils/MPFRWrapper/MPFRUtils.h"
  13
  14 #include <math.h>
  15
  16 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
  17
  18 template <typename T> class LogbTest : public LIBC_NAMESPACE::testing::Test {
  19
  20   DECLARE_SPECIAL_CONSTANTS(T)
  21
  22   static constexpr UIntType HIDDEN_BIT =
  23       UIntType(1) << LIBC_NAMESPACE::fputil::MantissaWidth<T>::VALUE;
  24
  25 public:
  26   typedef T (*LogbFunc)(T);
  27
  28   void testSpecialNumbers(LogbFunc func) {
  29     ASSERT_FP_EQ(aNaN, func(aNaN));
  30     ASSERT_FP_EQ(inf, func(inf));
  31     ASSERT_FP_EQ(inf, func(neg_inf));
  32     ASSERT_FP_EQ(neg_inf, func(0.0));
  33     ASSERT_FP_EQ(neg_inf, func(-0.0));
  34   }
  35
  36   void testPowersOfTwo(LogbFunc func) {
  37     EXPECT_FP_EQ(T(0.0), func(T(1.0)));
  38     EXPECT_FP_EQ(T(0.0), func(T(-1.0)));
  39
  40     EXPECT_FP_EQ(T(1.0), func(T(2.0)));
  41     EXPECT_FP_EQ(T(1.0), func(T(-2.0)));
  42
  43     EXPECT_FP_EQ(T(2.0), func(T(4.0)));
  44     EXPECT_FP_EQ(T(2.0), func(T(-4.0)));
  45
  46     EXPECT_FP_EQ(T(3.0), func(T(8.0)));
  47     EXPECT_FP_EQ(T(3.0), func(T(-8.0)));
  48
  49     EXPECT_FP_EQ(T(4.0), func(T(16.0)));
  50     EXPECT_FP_EQ(T(4.0), func(T(-16.0)));
  51
  52     EXPECT_FP_EQ(T(5.0), func(T(32.0)));
  53     EXPECT_FP_EQ(T(5.0), func(T(-32.0)));
  54   }
  55
  56   void testSomeIntegers(LogbFunc func) {
  57     EXPECT_FP_EQ(T(1.0), func(T(3.0)));
  58     EXPECT_FP_EQ(T(1.0), func(T(-3.0)));
  59
  60     EXPECT_FP_EQ(T(2.0), func(T(7.0)));
  61     EXPECT_FP_EQ(T(2.0), func(T(-7.0)));
  62
  63     EXPECT_FP_EQ(T(3.0), func(T(10.0)));
  64     EXPECT_FP_EQ(T(3.0), func(T(-10.0)));
  65
  66     EXPECT_FP_EQ(T(4.0), func(T(31.0)));
  67     EXPECT_FP_EQ(T(4.0), func(T(-31.0)));
  68
  69     EXPECT_FP_EQ(T(5.0), func(T(55.0)));
  70     EXPECT_FP_EQ(T(5.0), func(T(-55.0)));
  71   }
  72
  73   void testRange(LogbFunc func) {
  74     using UIntType = typename FPBits::UIntType;
  75     constexpr UIntType COUNT = 100'000;
  76     constexpr UIntType STEP = UIntType(-1) / COUNT;
  77     for (UIntType i = 0, v = 0; i <= COUNT; ++i, v += STEP) {
  78       T x = static_cast<T>(FPBits(v));
  79       if (isnan(x) || isinf(x) || x == 0.0l)
  80         continue;
  81
  82       int exponent;
  83       LIBC_NAMESPACE::fputil::frexp(x, exponent);
  84       ASSERT_FP_EQ(T(exponent), func(x) + T(1.0));
  85     }
  86   }
  87 };
  88
  89 #define LIST_LOGB_TESTS(T, func)                                               \
  90   using LlvmLibcLogbTest = LogbTest<T>;                                        \
  91   TEST_F(LlvmLibcLogbTest, SpecialNumbers) { testSpecialNumbers(&func); }      \
  92   TEST_F(LlvmLibcLogbTest, PowersOfTwo) { testPowersOfTwo(&func); }            \
  93   TEST_F(LlvmLibcLogbTest, SomeIntegers) { testSomeIntegers(&func); }          \
  94   TEST_F(LlvmLibcLogbTest, InRange) { testRange(&func); }