path: root/mfbt/tests/TestFloatingPoint.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/Assertions.h"
#include "mozilla/FloatingPoint.h"

#include <math.h>

using mozilla::ExponentComponent;
using mozilla::FloatingPoint;
using mozilla::FuzzyEqualsAdditive;
using mozilla::FuzzyEqualsMultiplicative;
using mozilla::IsFloat32Representable;
using mozilla::IsNegative;
using mozilla::IsNegativeZero;
using mozilla::IsPositiveZero;
using mozilla::NegativeInfinity;
using mozilla::NumberEqualsInt32;
using mozilla::NumberEqualsInt64;
using mozilla::NumberIsInt32;
using mozilla::NumberIsInt64;
using mozilla::NumbersAreIdentical;
using mozilla::PositiveInfinity;
using mozilla::SpecificNaN;
using mozilla::UnspecifiedNaN;
using std::exp2;
using std::exp2f;

#define A(a) MOZ_RELEASE_ASSERT(a)

template <typename T>
static void ShouldBeIdentical(T aD1, T aD2) {
  A(NumbersAreIdentical(aD1, aD2));
  A(NumbersAreIdentical(aD2, aD1));
}

template <typename T>
static void ShouldNotBeIdentical(T aD1, T aD2) {
  A(!NumbersAreIdentical(aD1, aD2));
  A(!NumbersAreIdentical(aD2, aD1));
}

static void TestDoublesAreIdentical() {
  ShouldBeIdentical(+0.0, +0.0);
  ShouldBeIdentical(-0.0, -0.0);
  ShouldNotBeIdentical(+0.0, -0.0);

  ShouldBeIdentical(1.0, 1.0);
  ShouldNotBeIdentical(-1.0, 1.0);
  ShouldBeIdentical(4294967295.0, 4294967295.0);
  ShouldNotBeIdentical(-4294967295.0, 4294967295.0);
  ShouldBeIdentical(4294967296.0, 4294967296.0);
  ShouldBeIdentical(4294967297.0, 4294967297.0);
  ShouldBeIdentical(1e300, 1e300);

  ShouldBeIdentical(PositiveInfinity<double>(), PositiveInfinity<double>());
  ShouldBeIdentical(NegativeInfinity<double>(), NegativeInfinity<double>());
  ShouldNotBeIdentical(PositiveInfinity<double>(), NegativeInfinity<double>());

  ShouldNotBeIdentical(-0.0, NegativeInfinity<double>());
  ShouldNotBeIdentical(+0.0, NegativeInfinity<double>());
  ShouldNotBeIdentical(1e300, NegativeInfinity<double>());
  ShouldNotBeIdentical(3.141592654, NegativeInfinity<double>());

  ShouldBeIdentical(UnspecifiedNaN<double>(), UnspecifiedNaN<double>());
  ShouldBeIdentical(-UnspecifiedNaN<double>(), UnspecifiedNaN<double>());
  ShouldBeIdentical(UnspecifiedNaN<double>(), -UnspecifiedNaN<double>());

  ShouldBeIdentical(SpecificNaN<double>(0, 17), SpecificNaN<double>(0, 42));
  ShouldBeIdentical(SpecificNaN<double>(1, 17), SpecificNaN<double>(1, 42));
  ShouldBeIdentical(SpecificNaN<double>(0, 17), SpecificNaN<double>(1, 42));
  ShouldBeIdentical(SpecificNaN<double>(1, 17), SpecificNaN<double>(0, 42));

  const uint64_t Mask = 0xfffffffffffffULL;
  for (unsigned i = 0; i < 52; i++) {
    for (unsigned j = 0; j < 52; j++) {
      for (unsigned sign = 0; i < 2; i++) {
        ShouldBeIdentical(SpecificNaN<double>(0, 1ULL << i),
                          SpecificNaN<double>(sign, 1ULL << j));
        ShouldBeIdentical(SpecificNaN<double>(1, 1ULL << i),
                          SpecificNaN<double>(sign, 1ULL << j));

        ShouldBeIdentical(SpecificNaN<double>(0, Mask & ~(1ULL << i)),
                          SpecificNaN<double>(sign, Mask & ~(1ULL << j)));
        ShouldBeIdentical(SpecificNaN<double>(1, Mask & ~(1ULL << i)),
                          SpecificNaN<double>(sign, Mask & ~(1ULL << j)));
      }
    }
  }
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x8000000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x4000000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x2000000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x1000000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x0800000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x0400000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x0200000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x0100000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x0080000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x0040000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x0020000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(0, 17),
                    SpecificNaN<double>(0, 0x0010000000000ULL));
  ShouldBeIdentical(SpecificNaN<double>(1, 17),
                    SpecificNaN<double>(0, 0xff0ffffffffffULL));
  ShouldBeIdentical(SpecificNaN<double>(1, 17),
                    SpecificNaN<double>(0, 0xfffffffffff0fULL));

  ShouldNotBeIdentical(UnspecifiedNaN<double>(), +0.0);
  ShouldNotBeIdentical(UnspecifiedNaN<double>(), -0.0);
  ShouldNotBeIdentical(UnspecifiedNaN<double>(), 1.0);
  ShouldNotBeIdentical(UnspecifiedNaN<double>(), -1.0);
  ShouldNotBeIdentical(UnspecifiedNaN<double>(), PositiveInfinity<double>());
  ShouldNotBeIdentical(UnspecifiedNaN<double>(), NegativeInfinity<double>());
}

static void TestFloatsAreIdentical() {
  ShouldBeIdentical(+0.0f, +0.0f);
  ShouldBeIdentical(-0.0f, -0.0f);
  ShouldNotBeIdentical(+0.0f, -0.0f);

  ShouldBeIdentical(1.0f, 1.0f);
  ShouldNotBeIdentical(-1.0f, 1.0f);
  ShouldBeIdentical(8388607.0f, 8388607.0f);
  ShouldNotBeIdentical(-8388607.0f, 8388607.0f);
  ShouldBeIdentical(8388608.0f, 8388608.0f);
  ShouldBeIdentical(8388609.0f, 8388609.0f);
  ShouldBeIdentical(1e36f, 1e36f);

  ShouldBeIdentical(PositiveInfinity<float>(), PositiveInfinity<float>());
  ShouldBeIdentical(NegativeInfinity<float>(), NegativeInfinity<float>());
  ShouldNotBeIdentical(PositiveInfinity<float>(), NegativeInfinity<float>());

  ShouldNotBeIdentical(-0.0f, NegativeInfinity<float>());
  ShouldNotBeIdentical(+0.0f, NegativeInfinity<float>());
  ShouldNotBeIdentical(1e36f, NegativeInfinity<float>());
  ShouldNotBeIdentical(3.141592654f, NegativeInfinity<float>());

  ShouldBeIdentical(UnspecifiedNaN<float>(), UnspecifiedNaN<float>());
  ShouldBeIdentical(-UnspecifiedNaN<float>(), UnspecifiedNaN<float>());
  ShouldBeIdentical(UnspecifiedNaN<float>(), -UnspecifiedNaN<float>());

  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 42));
  ShouldBeIdentical(SpecificNaN<float>(1, 17), SpecificNaN<float>(1, 42));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(1, 42));
  ShouldBeIdentical(SpecificNaN<float>(1, 17), SpecificNaN<float>(0, 42));

  const uint32_t Mask = 0x7fffffUL;
  for (unsigned i = 0; i < 23; i++) {
    for (unsigned j = 0; j < 23; j++) {
      for (unsigned sign = 0; i < 2; i++) {
        ShouldBeIdentical(SpecificNaN<float>(0, 1UL << i),
                          SpecificNaN<float>(sign, 1UL << j));
        ShouldBeIdentical(SpecificNaN<float>(1, 1UL << i),
                          SpecificNaN<float>(sign, 1UL << j));

        ShouldBeIdentical(SpecificNaN<float>(0, Mask & ~(1UL << i)),
                          SpecificNaN<float>(sign, Mask & ~(1UL << j)));
        ShouldBeIdentical(SpecificNaN<float>(1, Mask & ~(1UL << i)),
                          SpecificNaN<float>(sign, Mask & ~(1UL << j)));
      }
    }
  }
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x700000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x400000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x200000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x100000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x080000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x040000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x020000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x010000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x008000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x004000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x002000));
  ShouldBeIdentical(SpecificNaN<float>(0, 17), SpecificNaN<float>(0, 0x001000));
  ShouldBeIdentical(SpecificNaN<float>(1, 17), SpecificNaN<float>(0, 0x7f0fff));
  ShouldBeIdentical(SpecificNaN<float>(1, 17), SpecificNaN<float>(0, 0x7fff0f));

  ShouldNotBeIdentical(UnspecifiedNaN<float>(), +0.0f);
  ShouldNotBeIdentical(UnspecifiedNaN<float>(), -0.0f);
  ShouldNotBeIdentical(UnspecifiedNaN<float>(), 1.0f);
  ShouldNotBeIdentical(UnspecifiedNaN<float>(), -1.0f);
  ShouldNotBeIdentical(UnspecifiedNaN<float>(), PositiveInfinity<float>());
  ShouldNotBeIdentical(UnspecifiedNaN<float>(), NegativeInfinity<float>());
}

static void TestAreIdentical() {
  TestDoublesAreIdentical();
  TestFloatsAreIdentical();
}

static void TestDoubleExponentComponent() {
  A(ExponentComponent(0.0) ==
    -int_fast16_t(FloatingPoint<double>::kExponentBias));
  A(ExponentComponent(-0.0) ==
    -int_fast16_t(FloatingPoint<double>::kExponentBias));
  A(ExponentComponent(0.125) == -3);
  A(ExponentComponent(0.5) == -1);
  A(ExponentComponent(1.0) == 0);
  A(ExponentComponent(1.5) == 0);
  A(ExponentComponent(2.0) == 1);
  A(ExponentComponent(7.0) == 2);
  A(ExponentComponent(PositiveInfinity<double>()) ==
    FloatingPoint<double>::kExponentBias + 1);
  A(ExponentComponent(NegativeInfinity<double>()) ==
    FloatingPoint<double>::kExponentBias + 1);
  A(ExponentComponent(UnspecifiedNaN<double>()) ==
    FloatingPoint<double>::kExponentBias + 1);
}

static void TestFloatExponentComponent() {
  A(ExponentComponent(0.0f) ==
    -int_fast16_t(FloatingPoint<float>::kExponentBias));
  A(ExponentComponent(-0.0f) ==
    -int_fast16_t(FloatingPoint<float>::kExponentBias));
  A(ExponentComponent(0.125f) == -3);
  A(ExponentComponent(0.5f) == -1);
  A(ExponentComponent(1.0f) == 0);
  A(ExponentComponent(1.5f) == 0);
  A(ExponentComponent(2.0f) == 1);
  A(ExponentComponent(7.0f) == 2);
  A(ExponentComponent(PositiveInfinity<float>()) ==
    FloatingPoint<float>::kExponentBias + 1);
  A(ExponentComponent(NegativeInfinity<float>()) ==
    FloatingPoint<float>::kExponentBias + 1);
  A(ExponentComponent(UnspecifiedNaN<float>()) ==
    FloatingPoint<float>::kExponentBias + 1);
}

static void TestExponentComponent() {
  TestDoubleExponentComponent();
  TestFloatExponentComponent();
}

// Used to test Number{Is,Equals}{Int32,Int64} for -0.0, the only case where
// NumberEquals* and NumberIs* aren't equivalent.
template <typename T>
static void TestEqualsIsForNegativeZero() {
  T negZero = T(-0.0);

  int32_t i32;
  A(!NumberIsInt32(negZero, &i32));
  A(NumberEqualsInt32(negZero, &i32));
  A(i32 == 0);

  int64_t i64;
  A(!NumberIsInt64(negZero, &i64));
  A(NumberEqualsInt64(negZero, &i64));
  A(i64 == 0);
}

// Used to test Number{Is,Equals}{Int32,Int64} for int32 values.
template <typename T>
static void TestEqualsIsForInt32(T aVal) {
  int32_t i32;
  A(NumberIsInt32(aVal, &i32));
  MOZ_RELEASE_ASSERT(i32 == aVal);
  A(NumberEqualsInt32(aVal, &i32));
  MOZ_RELEASE_ASSERT(i32 == aVal);

  int64_t i64;
  A(NumberIsInt64(aVal, &i64));
  MOZ_RELEASE_ASSERT(i64 == aVal);
  A(NumberEqualsInt64(aVal, &i64));
  MOZ_RELEASE_ASSERT(i64 == aVal);
};

// Used to test Number{Is,Equals}{Int32,Int64} for values that fit in int64 but
// not int32.
template <typename T>
static void TestEqualsIsForInt64(T aVal) {
  int32_t i32;
  A(!NumberIsInt32(aVal, &i32));
  A(!NumberEqualsInt32(aVal, &i32));

  int64_t i64;
  A(NumberIsInt64(aVal, &i64));
  MOZ_RELEASE_ASSERT(i64 == aVal);
  A(NumberEqualsInt64(aVal, &i64));
  MOZ_RELEASE_ASSERT(i64 == aVal);
};

// Used to test Number{Is,Equals}{Int32,Int64} for values that aren't equal to
// any int32 or int64.
template <typename T>
static void TestEqualsIsForNonInteger(T aVal) {
  int32_t i32;
  A(!NumberIsInt32(aVal, &i32));
  A(!NumberEqualsInt32(aVal, &i32));

  int64_t i64;
  A(!NumberIsInt64(aVal, &i64));
  A(!NumberEqualsInt64(aVal, &i64));
};

static void TestDoublesPredicates() {
  A(std::isnan(UnspecifiedNaN<double>()));
  A(std::isnan(SpecificNaN<double>(1, 17)));
  ;
  A(std::isnan(SpecificNaN<double>(0, 0xfffffffffff0fULL)));
  A(!std::isnan(PositiveInfinity<double>()));
  A(!std::isnan(NegativeInfinity<double>()));

  A(std::isinf(PositiveInfinity<double>()));
  A(std::isinf(NegativeInfinity<double>()));
  A(!std::isinf(UnspecifiedNaN<double>()));

  A(!std::isfinite(PositiveInfinity<double>()));
  A(!std::isfinite(NegativeInfinity<double>()));
  A(!std::isfinite(UnspecifiedNaN<double>()));

  A(!IsNegative(PositiveInfinity<double>()));
  A(IsNegative(NegativeInfinity<double>()));
  A(IsNegative(-0.0));
  A(!IsNegative(0.0));
  A(IsNegative(-1.0));
  A(!IsNegative(1.0));

  A(!IsNegativeZero(PositiveInfinity<double>()));
  A(!IsNegativeZero(NegativeInfinity<double>()));
  A(!IsNegativeZero(SpecificNaN<double>(1, 17)));
  ;
  A(!IsNegativeZero(SpecificNaN<double>(1, 0xfffffffffff0fULL)));
  A(!IsNegativeZero(SpecificNaN<double>(0, 17)));
  ;
  A(!IsNegativeZero(SpecificNaN<double>(0, 0xfffffffffff0fULL)));
  A(!IsNegativeZero(UnspecifiedNaN<double>()));
  A(IsNegativeZero(-0.0));
  A(!IsNegativeZero(0.0));
  A(!IsNegativeZero(-1.0));
  A(!IsNegativeZero(1.0));

  // Edge case: negative zero.
  TestEqualsIsForNegativeZero<double>();

  // Int32 values.
  auto testInt32 = TestEqualsIsForInt32<double>;
  testInt32(0.0);
  testInt32(1.0);
  testInt32(INT32_MIN);
  testInt32(INT32_MAX);

  // Int64 values that don't fit in int32.
  auto testInt64 = TestEqualsIsForInt64<double>;
  testInt64(2147483648);
  testInt64(2147483649);
  testInt64(-2147483649);
  testInt64(INT64_MIN);
  // Note: INT64_MAX can't be represented exactly as double. Use a large double
  // very close to it.
  testInt64(9223372036854772000.0);

  constexpr double MinSafeInteger = -9007199254740991.0;
  constexpr double MaxSafeInteger = 9007199254740991.0;
  testInt64(MinSafeInteger);
  testInt64(MaxSafeInteger);

  // Doubles that aren't equal to any int32 or int64.
  auto testNonInteger = TestEqualsIsForNonInteger<double>;
  testNonInteger(NegativeInfinity<double>());
  testNonInteger(PositiveInfinity<double>());
  testNonInteger(UnspecifiedNaN<double>());
  testNonInteger(-double(1ULL << 52) + 0.5);
  testNonInteger(double(1ULL << 52) - 0.5);
  testNonInteger(double(INT32_MAX) + 0.1);
  testNonInteger(double(INT32_MIN) - 0.1);
  testNonInteger(0.5);
  testNonInteger(-0.0001);
  testNonInteger(-9223372036854778000.0);
  testNonInteger(9223372036854776000.0);

  // Sanity-check that the IEEE-754 double-precision-derived literals used in
  // testing here work as we intend them to.
  A(exp2(-1075.0) == 0.0);
  A(exp2(-1074.0) != 0.0);
  testNonInteger(exp2(-1074.0));
  testNonInteger(2 * exp2(-1074.0));

  A(1.0 - exp2(-54.0) == 1.0);
  A(1.0 - exp2(-53.0) != 1.0);
  testNonInteger(1.0 - exp2(-53.0));
  testNonInteger(1.0 - exp2(-52.0));

  A(1.0 + exp2(-53.0) == 1.0f);
  A(1.0 + exp2(-52.0) != 1.0f);
  testNonInteger(1.0 + exp2(-52.0));
}

static void TestFloatsPredicates() {
  A(std::isnan(UnspecifiedNaN<float>()));
  A(std::isnan(SpecificNaN<float>(1, 17)));
  ;
  A(std::isnan(SpecificNaN<float>(0, 0x7fff0fUL)));
  A(!std::isnan(PositiveInfinity<float>()));
  A(!std::isnan(NegativeInfinity<float>()));

  A(std::isinf(PositiveInfinity<float>()));
  A(std::isinf(NegativeInfinity<float>()));
  A(!std::isinf(UnspecifiedNaN<float>()));

  A(!std::isfinite(PositiveInfinity<float>()));
  A(!std::isfinite(NegativeInfinity<float>()));
  A(!std::isfinite(UnspecifiedNaN<float>()));

  A(!IsNegative(PositiveInfinity<float>()));
  A(IsNegative(NegativeInfinity<float>()));
  A(IsNegative(-0.0f));
  A(!IsNegative(0.0f));
  A(IsNegative(-1.0f));
  A(!IsNegative(1.0f));

  A(!IsNegativeZero(PositiveInfinity<float>()));
  A(!IsNegativeZero(NegativeInfinity<float>()));
  A(!IsNegativeZero(SpecificNaN<float>(1, 17)));
  ;
  A(!IsNegativeZero(SpecificNaN<float>(1, 0x7fff0fUL)));
  A(!IsNegativeZero(SpecificNaN<float>(0, 17)));
  ;
  A(!IsNegativeZero(SpecificNaN<float>(0, 0x7fff0fUL)));
  A(!IsNegativeZero(UnspecifiedNaN<float>()));
  A(IsNegativeZero(-0.0f));
  A(!IsNegativeZero(0.0f));
  A(!IsNegativeZero(-1.0f));
  A(!IsNegativeZero(1.0f));

  A(!IsPositiveZero(PositiveInfinity<float>()));
  A(!IsPositiveZero(NegativeInfinity<float>()));
  A(!IsPositiveZero(SpecificNaN<float>(1, 17)));
  ;
  A(!IsPositiveZero(SpecificNaN<float>(1, 0x7fff0fUL)));
  A(!IsPositiveZero(SpecificNaN<float>(0, 17)));
  ;
  A(!IsPositiveZero(SpecificNaN<float>(0, 0x7fff0fUL)));
  A(!IsPositiveZero(UnspecifiedNaN<float>()));
  A(IsPositiveZero(0.0f));
  A(!IsPositiveZero(-0.0f));
  A(!IsPositiveZero(-1.0f));
  A(!IsPositiveZero(1.0f));

  // Edge case: negative zero.
  TestEqualsIsForNegativeZero<float>();

  // Int32 values.
  auto testInt32 = TestEqualsIsForInt32<float>;
  testInt32(0.0f);
  testInt32(1.0f);
  testInt32(INT32_MIN);
  testInt32(float(2147483648 - 128));  // max int32_t fitting in float
  const int32_t BIG = 2097151;
  testInt32(BIG);

  // Int64 values that don't fit in int32.
  auto testInt64 = TestEqualsIsForInt64<float>;
  testInt64(INT64_MIN);
  testInt64(9007199254740992.0f);
  testInt64(-float(2147483648) - 256);
  testInt64(float(2147483648));
  testInt64(float(2147483648) + 256);

  // Floats that aren't equal to any int32 or int64.
  auto testNonInteger = TestEqualsIsForNonInteger<float>;
  testNonInteger(NegativeInfinity<float>());
  testNonInteger(PositiveInfinity<float>());
  testNonInteger(UnspecifiedNaN<float>());
  testNonInteger(0.5f);
  testNonInteger(1.5f);
  testNonInteger(-0.0001f);
  testNonInteger(-19223373116872850000.0f);
  testNonInteger(19223373116872850000.0f);
  testNonInteger(float(BIG) + 0.1f);

  A(powf(2.0f, -150.0f) == 0.0f);
  A(powf(2.0f, -149.0f) != 0.0f);
  testNonInteger(powf(2.0f, -149.0f));
  testNonInteger(2 * powf(2.0f, -149.0f));

  A(1.0f - powf(2.0f, -25.0f) == 1.0f);
  A(1.0f - powf(2.0f, -24.0f) != 1.0f);
  testNonInteger(1.0f - powf(2.0f, -24.0f));
  testNonInteger(1.0f - powf(2.0f, -23.0f));

  A(1.0f + powf(2.0f, -24.0f) == 1.0f);
  A(1.0f + powf(2.0f, -23.0f) != 1.0f);
  testNonInteger(1.0f + powf(2.0f, -23.0f));
}

static void TestPredicates() {
  TestFloatsPredicates();
  TestDoublesPredicates();
}

static void TestFloatsAreApproximatelyEqual() {
  float epsilon = mozilla::detail::FuzzyEqualsEpsilon<float>::value();
  float lessThanEpsilon = epsilon / 2.0f;
  float moreThanEpsilon = epsilon * 2.0f;

  // Additive tests using the default epsilon
  // ... around 1.0
  A(FuzzyEqualsAdditive(1.0f, 1.0f + lessThanEpsilon));
  A(FuzzyEqualsAdditive(1.0f, 1.0f - lessThanEpsilon));
  A(FuzzyEqualsAdditive(1.0f, 1.0f + epsilon));
  A(FuzzyEqualsAdditive(1.0f, 1.0f - epsilon));
  A(!FuzzyEqualsAdditive(1.0f, 1.0f + moreThanEpsilon));
  A(!FuzzyEqualsAdditive(1.0f, 1.0f - moreThanEpsilon));
  // ... around 1.0e2 (this is near the upper bound of the range where
  // adding moreThanEpsilon will still be representable and return false)
  A(FuzzyEqualsAdditive(1.0e2f, 1.0e2f + lessThanEpsilon));
  A(FuzzyEqualsAdditive(1.0e2f, 1.0e2f + epsilon));
  A(!FuzzyEqualsAdditive(1.0e2f, 1.0e2f + moreThanEpsilon));
  // ... around 1.0e-10
  A(FuzzyEqualsAdditive(1.0e-10f, 1.0e-10f + lessThanEpsilon));
  A(FuzzyEqualsAdditive(1.0e-10f, 1.0e-10f + epsilon));
  A(!FuzzyEqualsAdditive(1.0e-10f, 1.0e-10f + moreThanEpsilon));
  // ... straddling 0
  A(FuzzyEqualsAdditive(1.0e-6f, -1.0e-6f));
  A(!FuzzyEqualsAdditive(1.0e-5f, -1.0e-5f));
  // Using a small epsilon
  A(FuzzyEqualsAdditive(1.0e-5f, 1.0e-5f + 1.0e-10f, 1.0e-9f));
  A(!FuzzyEqualsAdditive(1.0e-5f, 1.0e-5f + 1.0e-10f, 1.0e-11f));
  // Using a big epsilon
  A(FuzzyEqualsAdditive(1.0e20f, 1.0e20f + 1.0e15f, 1.0e16f));
  A(!FuzzyEqualsAdditive(1.0e20f, 1.0e20f + 1.0e15f, 1.0e14f));

  // Multiplicative tests using the default epsilon
  // ... around 1.0
  A(FuzzyEqualsMultiplicative(1.0f, 1.0f + lessThanEpsilon));
  A(FuzzyEqualsMultiplicative(1.0f, 1.0f - lessThanEpsilon));
  A(FuzzyEqualsMultiplicative(1.0f, 1.0f + epsilon));
  A(!FuzzyEqualsMultiplicative(1.0f, 1.0f - epsilon));
  A(!FuzzyEqualsMultiplicative(1.0f, 1.0f + moreThanEpsilon));
  A(!FuzzyEqualsMultiplicative(1.0f, 1.0f - moreThanEpsilon));
  // ... around 1.0e10
  A(FuzzyEqualsMultiplicative(1.0e10f, 1.0e10f + (lessThanEpsilon * 1.0e10f)));
  A(!FuzzyEqualsMultiplicative(1.0e10f, 1.0e10f + (moreThanEpsilon * 1.0e10f)));
  // ... around 1.0e-10
  A(FuzzyEqualsMultiplicative(1.0e-10f,
                              1.0e-10f + (lessThanEpsilon * 1.0e-10f)));
  A(!FuzzyEqualsMultiplicative(1.0e-10f,
                               1.0e-10f + (moreThanEpsilon * 1.0e-10f)));
  // ... straddling 0
  A(!FuzzyEqualsMultiplicative(1.0e-6f, -1.0e-6f));
  A(FuzzyEqualsMultiplicative(1.0e-6f, -1.0e-6f, 1.0e2f));
  // Using a small epsilon
  A(FuzzyEqualsMultiplicative(1.0e-5f, 1.0e-5f + 1.0e-10f, 1.0e-4f));
  A(!FuzzyEqualsMultiplicative(1.0e-5f, 1.0e-5f + 1.0e-10f, 1.0e-5f));
  // Using a big epsilon
  A(FuzzyEqualsMultiplicative(1.0f, 2.0f, 1.0f));
  A(!FuzzyEqualsMultiplicative(1.0f, 2.0f, 0.1f));

  // "real world case"
  float oneThird = 10.0f / 3.0f;
  A(FuzzyEqualsAdditive(10.0f, 3.0f * oneThird));
  A(FuzzyEqualsMultiplicative(10.0f, 3.0f * oneThird));
  // NaN check
  A(!FuzzyEqualsAdditive(SpecificNaN<float>(1, 1), SpecificNaN<float>(1, 1)));
  A(!FuzzyEqualsAdditive(SpecificNaN<float>(1, 2), SpecificNaN<float>(0, 8)));
  A(!FuzzyEqualsMultiplicative(SpecificNaN<float>(1, 1),
                               SpecificNaN<float>(1, 1)));
  A(!FuzzyEqualsMultiplicative(SpecificNaN<float>(1, 2),
                               SpecificNaN<float>(0, 200)));
}

static void TestDoublesAreApproximatelyEqual() {
  double epsilon = mozilla::detail::FuzzyEqualsEpsilon<double>::value();
  double lessThanEpsilon = epsilon / 2.0;
  double moreThanEpsilon = epsilon * 2.0;

  // Additive tests using the default epsilon
  // ... around 1.0
  A(FuzzyEqualsAdditive(1.0, 1.0 + lessThanEpsilon));
  A(FuzzyEqualsAdditive(1.0, 1.0 - lessThanEpsilon));
  A(FuzzyEqualsAdditive(1.0, 1.0 + epsilon));
  A(FuzzyEqualsAdditive(1.0, 1.0 - epsilon));
  A(!FuzzyEqualsAdditive(1.0, 1.0 + moreThanEpsilon));
  A(!FuzzyEqualsAdditive(1.0, 1.0 - moreThanEpsilon));
  // ... around 1.0e4 (this is near the upper bound of the range where
  // adding moreThanEpsilon will still be representable and return false)
  A(FuzzyEqualsAdditive(1.0e4, 1.0e4 + lessThanEpsilon));
  A(FuzzyEqualsAdditive(1.0e4, 1.0e4 + epsilon));
  A(!FuzzyEqualsAdditive(1.0e4, 1.0e4 + moreThanEpsilon));
  // ... around 1.0e-25
  A(FuzzyEqualsAdditive(1.0e-25, 1.0e-25 + lessThanEpsilon));
  A(FuzzyEqualsAdditive(1.0e-25, 1.0e-25 + epsilon));
  A(!FuzzyEqualsAdditive(1.0e-25, 1.0e-25 + moreThanEpsilon));
  // ... straddling 0
  A(FuzzyEqualsAdditive(1.0e-13, -1.0e-13));
  A(!FuzzyEqualsAdditive(1.0e-12, -1.0e-12));
  // Using a small epsilon
  A(FuzzyEqualsAdditive(1.0e-15, 1.0e-15 + 1.0e-30, 1.0e-29));
  A(!FuzzyEqualsAdditive(1.0e-15, 1.0e-15 + 1.0e-30, 1.0e-31));
  // Using a big epsilon
  A(FuzzyEqualsAdditive(1.0e40, 1.0e40 + 1.0e25, 1.0e26));
  A(!FuzzyEqualsAdditive(1.0e40, 1.0e40 + 1.0e25, 1.0e24));

  // Multiplicative tests using the default epsilon
  // ... around 1.0
  A(FuzzyEqualsMultiplicative(1.0, 1.0 + lessThanEpsilon));
  A(FuzzyEqualsMultiplicative(1.0, 1.0 - lessThanEpsilon));
  A(FuzzyEqualsMultiplicative(1.0, 1.0 + epsilon));
  A(!FuzzyEqualsMultiplicative(1.0, 1.0 - epsilon));
  A(!FuzzyEqualsMultiplicative(1.0, 1.0 + moreThanEpsilon));
  A(!FuzzyEqualsMultiplicative(1.0, 1.0 - moreThanEpsilon));
  // ... around 1.0e30
  A(FuzzyEqualsMultiplicative(1.0e30, 1.0e30 + (lessThanEpsilon * 1.0e30)));
  A(!FuzzyEqualsMultiplicative(1.0e30, 1.0e30 + (moreThanEpsilon * 1.0e30)));
  // ... around 1.0e-30
  A(FuzzyEqualsMultiplicative(1.0e-30, 1.0e-30 + (lessThanEpsilon * 1.0e-30)));
  A(!FuzzyEqualsMultiplicative(1.0e-30, 1.0e-30 + (moreThanEpsilon * 1.0e-30)));
  // ... straddling 0
  A(!FuzzyEqualsMultiplicative(1.0e-6, -1.0e-6));
  A(FuzzyEqualsMultiplicative(1.0e-6, -1.0e-6, 1.0e2));
  // Using a small epsilon
  A(FuzzyEqualsMultiplicative(1.0e-15, 1.0e-15 + 1.0e-30, 1.0e-15));
  A(!FuzzyEqualsMultiplicative(1.0e-15, 1.0e-15 + 1.0e-30, 1.0e-16));
  // Using a big epsilon
  A(FuzzyEqualsMultiplicative(1.0e40, 2.0e40, 1.0));
  A(!FuzzyEqualsMultiplicative(1.0e40, 2.0e40, 0.1));

  // "real world case"
  double oneThird = 10.0 / 3.0;
  A(FuzzyEqualsAdditive(10.0, 3.0 * oneThird));
  A(FuzzyEqualsMultiplicative(10.0, 3.0 * oneThird));
  // NaN check
  A(!FuzzyEqualsAdditive(SpecificNaN<double>(1, 1), SpecificNaN<double>(1, 1)));
  A(!FuzzyEqualsAdditive(SpecificNaN<double>(1, 2), SpecificNaN<double>(0, 8)));
  A(!FuzzyEqualsMultiplicative(SpecificNaN<double>(1, 1),
                               SpecificNaN<double>(1, 1)));
  A(!FuzzyEqualsMultiplicative(SpecificNaN<double>(1, 2),
                               SpecificNaN<double>(0, 200)));
}

static void TestAreApproximatelyEqual() {
  TestFloatsAreApproximatelyEqual();
  TestDoublesAreApproximatelyEqual();
}

static void TestIsFloat32Representable() {
  // Zeroes are representable.
  A(IsFloat32Representable(+0.0));
  A(IsFloat32Representable(-0.0));

  // NaN and infinities are representable.
  A(IsFloat32Representable(UnspecifiedNaN<double>()));
  A(IsFloat32Representable(SpecificNaN<double>(0, 1)));
  A(IsFloat32Representable(SpecificNaN<double>(0, 71389)));
  A(IsFloat32Representable(SpecificNaN<double>(0, (uint64_t(1) << 52) - 2)));
  A(IsFloat32Representable(SpecificNaN<double>(1, 1)));
  A(IsFloat32Representable(SpecificNaN<double>(1, 71389)));
  A(IsFloat32Representable(SpecificNaN<double>(1, (uint64_t(1) << 52) - 2)));
  A(IsFloat32Representable(PositiveInfinity<double>()));
  A(IsFloat32Representable(NegativeInfinity<double>()));

  // Sanity-check that the IEEE-754 double-precision-derived literals used in
  // testing here work as we intend them to.
  A(exp2(-1075.0) == 0.0);
  A(exp2(-1074.0) != 0.0);

  for (double littleExp = -1074.0; littleExp < -149.0; littleExp++) {
    // Powers of two representable as doubles but not as floats aren't
    // representable.
    A(!IsFloat32Representable(exp2(littleExp)));
  }

  // Sanity-check that the IEEE-754 single-precision-derived literals used in
  // testing here work as we intend them to.
  A(exp2f(-150.0f) == 0.0);
  A(exp2f(-149.0f) != 0.0);

  // Exact powers of two within the available range are representable.
  for (double exponent = -149.0; exponent < 128.0; exponent++) {
    A(IsFloat32Representable(exp2(exponent)));
  }

  // Powers of two above the available range aren't representable.
  for (double bigExp = 128.0; bigExp < 1024.0; bigExp++) {
    A(!IsFloat32Representable(exp2(bigExp)));
  }

  // Various denormal (i.e. super-small) doubles with MSB and LSB as far apart
  // as possible are representable (but taken one bit further apart are not
  // representable).
  //
  // Note that the final iteration tests non-denormal with exponent field
  // containing (biased) 1, as |oneTooSmall| and |widestPossible| happen still
  // to be correct for that exponent due to the extra bit of precision in the
  // implicit-one bit.
  double oneTooSmall = exp2(-150.0);
  for (double denormExp = -149.0;
       denormExp < 1 - double(FloatingPoint<double>::kExponentBias) + 1;
       denormExp++) {
    double baseDenorm = exp2(denormExp);
    double tooWide = baseDenorm + oneTooSmall;
    A(!IsFloat32Representable(tooWide));

    double widestPossible = baseDenorm;
    if (oneTooSmall * 2.0 != baseDenorm) {
      widestPossible += oneTooSmall * 2.0;
    }

    A(IsFloat32Representable(widestPossible));
  }

  // Finally, check certain interesting/special values for basic sanity.
  A(!IsFloat32Representable(2147483647.0));
  A(!IsFloat32Representable(-2147483647.0));
}

#undef A

int main() {
  TestAreIdentical();
  TestExponentComponent();
  TestPredicates();
  TestAreApproximatelyEqual();
  TestIsFloat32Representable();
  return 0;
}