libc/test/src/math/ILogbTest.h

   1 //===-- Utility class to test different flavors of ilogb --------*- 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 #ifndef LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
  10 #define LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H
  11
  12 #include "src/__support/FPUtil/FPBits.h"
  13 #include "src/__support/FPUtil/ManipulationFunctions.h"
  14 #include "test/UnitTest/Test.h"
  15 #include <math.h>
  16
  17 #include <limits.h>
  18
  19 class LlvmLibcILogbTest : public LIBC_NAMESPACE::testing::Test {
  20 public:
  21   template <typename T> struct ILogbFunc {
  22     typedef int (*Func)(T);
  23   };
  24
  25   template <typename T>
  26   void test_special_numbers(typename ILogbFunc<T>::Func func) {
  27     EXPECT_EQ(FP_ILOGB0, func(T(LIBC_NAMESPACE::fputil::FPBits<T>::zero())));
  28     EXPECT_EQ(FP_ILOGB0,
  29               func(T(LIBC_NAMESPACE::fputil::FPBits<T>::neg_zero())));
  30
  31     EXPECT_EQ(FP_ILOGBNAN,
  32               func(T(LIBC_NAMESPACE::fputil::FPBits<T>::build_quiet_nan(1))));
  33
  34     EXPECT_EQ(INT_MAX, func(T(LIBC_NAMESPACE::fputil::FPBits<T>::inf())));
  35     EXPECT_EQ(INT_MAX, func(T(LIBC_NAMESPACE::fputil::FPBits<T>::neg_inf())));
  36   }
  37
  38   template <typename T>
  39   void test_powers_of_two(typename ILogbFunc<T>::Func func) {
  40     EXPECT_EQ(0, func(T(1.0)));
  41     EXPECT_EQ(0, func(T(-1.0)));
  42
  43     EXPECT_EQ(1, func(T(2.0)));
  44     EXPECT_EQ(1, func(T(-2.0)));
  45
  46     EXPECT_EQ(2, func(T(4.0)));
  47     EXPECT_EQ(2, func(T(-4.0)));
  48
  49     EXPECT_EQ(3, func(T(8.0)));
  50     EXPECT_EQ(3, func(-8.0));
  51
  52     EXPECT_EQ(4, func(16.0));
  53     EXPECT_EQ(4, func(-16.0));
  54
  55     EXPECT_EQ(5, func(32.0));
  56     EXPECT_EQ(5, func(-32.0));
  57   }
  58
  59   template <typename T>
  60   void test_some_integers(typename ILogbFunc<T>::Func func) {
  61     EXPECT_EQ(1, func(T(3.0)));
  62     EXPECT_EQ(1, func(T(-3.0)));
  63
  64     EXPECT_EQ(2, func(T(7.0)));
  65     EXPECT_EQ(2, func(T(-7.0)));
  66
  67     EXPECT_EQ(3, func(T(10.0)));
  68     EXPECT_EQ(3, func(T(-10.0)));
  69
  70     EXPECT_EQ(4, func(T(31.0)));
  71     EXPECT_EQ(4, func(-31.0));
  72
  73     EXPECT_EQ(5, func(55.0));
  74     EXPECT_EQ(5, func(-55.0));
  75   }
  76
  77   template <typename T>
  78   void test_subnormal_range(typename ILogbFunc<T>::Func func) {
  79     using FPBits = LIBC_NAMESPACE::fputil::FPBits<T>;
  80     using UIntType = typename FPBits::UIntType;
  81     constexpr UIntType COUNT = 10'001;
  82     constexpr UIntType STEP =
  83         (UIntType(FPBits::MAX_SUBNORMAL) - UIntType(FPBits::MIN_SUBNORMAL)) /
  84         COUNT;
  85     for (UIntType v = FPBits::MIN_SUBNORMAL; v <= FPBits::MAX_SUBNORMAL;
  86          v += STEP) {
  87       T x = T(FPBits(v));
  88       if (isnan(x) || isinf(x) || x == 0.0)
  89         continue;
  90
  91       int exponent;
  92       LIBC_NAMESPACE::fputil::frexp(x, exponent);
  93       ASSERT_EQ(exponent, func(x) + 1);
  94     }
  95   }
  96
  97   template <typename T>
  98   void test_normal_range(typename ILogbFunc<T>::Func func) {
  99     using FPBits = LIBC_NAMESPACE::fputil::FPBits<T>;
 100     using UIntType = typename FPBits::UIntType;
 101     constexpr UIntType COUNT = 10'001;
 102     constexpr UIntType STEP =
 103         (UIntType(FPBits::MAX_NORMAL) - UIntType(FPBits::MIN_NORMAL)) / COUNT;
 104     for (UIntType v = FPBits::MIN_NORMAL; v <= FPBits::MAX_NORMAL; v += STEP) {
 105       T x = T(FPBits(v));
 106       if (isnan(x) || isinf(x) || x == 0.0)
 107         continue;
 108
 109       int exponent;
 110       LIBC_NAMESPACE::fputil::frexp(x, exponent);
 111       ASSERT_EQ(exponent, func(x) + 1);
 112     }
 113   }
 114 };
 115
 116 #endif // LLVM_LIBC_TEST_SRC_MATH_ILOGBTEST_H