/* -*- 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/. */
template <typename In, typename Out> void checkBoundariesFloating(In aEpsilon = {}, Out aIntegerOffset = {}) { // Check the max value of the input float can't be represented as an integer. // This is true for all floating point and integer width.
MOZ_RELEASE_ASSERT((!IsInBounds<In, Out>(std::numeric_limits<In>::max()))); // Check that the max value of the integer, as a float, minus an offset that // depends on the magnitude, can be represented as an integer.
MOZ_RELEASE_ASSERT((IsInBounds<In, Out>( static_cast<In>(std::numeric_limits<Out>::max() - aIntegerOffset)))); // Check that the max value of the integer, plus a number that depends on the // magnitude of the number, can't be represented as this integer (because it // becomes too big).
MOZ_RELEASE_ASSERT((!IsInBounds<In, Out>(
aEpsilon + static_cast<In>(std::numeric_limits<Out>::max())))); if constexpr (std::is_signed_v<In>) { // Same for negative numbers.
MOZ_RELEASE_ASSERT(
(!IsInBounds<In, Out>(std::numeric_limits<In>::lowest())));
MOZ_RELEASE_ASSERT((IsInBounds<In, Out>( static_cast<In>(std::numeric_limits<Out>::lowest()))));
MOZ_RELEASE_ASSERT((!IsInBounds<In, Out>( static_cast<In>(std::numeric_limits<Out>::lowest()) - aEpsilon)));
} else { // Check for negative floats and unsigned integer types.
MOZ_RELEASE_ASSERT((!IsInBounds<In, Out>(static_cast<In>(-1))));
}
}
// Bound check for float to unsigned integer conversion. The parameters are // espilons and offsets allowing to check boundaries, that depend on the // magnitude of the numbers.
checkBoundariesFloating<double, uint64_t>(2049.);
checkBoundariesFloating<double, uint32_t>(1.);
checkBoundariesFloating<double, uint16_t>(1.);
checkBoundariesFloating<double, uint8_t>(1.); // Large number because of the lack of precision of floats at this magnitude
checkBoundariesFloating<float, uint64_t>(1.1e12f);
checkBoundariesFloating<float, uint32_t>(1.f, 128u);
checkBoundariesFloating<float, uint16_t>(1.f);
checkBoundariesFloating<float, uint8_t>(1.f);
checkBoundariesFloating<double, int64_t>(1025.);
checkBoundariesFloating<double, int32_t>(1.);
checkBoundariesFloating<double, int16_t>(1.);
checkBoundariesFloating<double, int8_t>(1.); // Large number because of the lack of precision of floats at this magnitude
checkBoundariesFloating<float, int64_t>(1.1e12f);
checkBoundariesFloating<float, int32_t>(256.f, 64u);
checkBoundariesFloating<float, int16_t>(1.f);
checkBoundariesFloating<float, int8_t>(1.f);
template <typename In, typename Out> void TestTypePairImpl() {
std::cout << __PRETTY_FUNCTION__ << std::endl;
std::cout << std::fixed; // Test casting infinities to integer works if constexpr (std::is_floating_point_v<In> &&
!std::is_floating_point_v<Out>) {
Out v = SaturatingCast<Out>(std::numeric_limits<In>::infinity());
ASSERT_EQ(v, std::numeric_limits<Out>::max());
v = SaturatingCast<Out>(-std::numeric_limits<In>::infinity());
ASSERT_EQ(v, std::numeric_limits<Out>::lowest());
} // Saturation of a floating point value that is infinity is infinity if constexpr (std::is_floating_point_v<Out> && std::is_floating_point_v<In>) {
In in = std::numeric_limits<In>::infinity();
Out v = SaturatingCast<Out>(in);
DEBUG_PRINT(in, v);
ASSERT_EQ(v, std::numeric_limits<Out>::infinity());
in = -std::numeric_limits<In>::infinity();
v = SaturatingCast<In>(in);
DEBUG_PRINT(in, v);
ASSERT_EQ(v, -std::numeric_limits<Out>::infinity()); return;
} else { if constexpr (sizeof(In) > sizeof(Out) && std::is_integral_v<Out>) { // Test with a value just outside the range of the output type
In in = static_cast<In>(std::numeric_limits<Out>::max()) + 1ull;
Out v = SaturatingCast<Out>(in);
DEBUG_PRINT(in, v);
ASSERT_EQ(v, std::numeric_limits<Out>::max());
if (std::is_signed_v<In>) { // Test with a value just below the range of the output type
Out lowest = std::numeric_limits<Out>::lowest();
in = static_cast<In>(lowest) - 1;
v = SaturatingCast<Out>(in);
DEBUG_PRINT(in, v); if constexpr (std::is_signed_v<In> && !std::is_signed_v<Out>) {
ASSERT_EQ(v, 0);
} else {
ASSERT_EQ(v, std::numeric_limits<Out>::lowest());
}
}
} elseif constexpr (std::is_integral_v<In> && std::is_integral_v<Out> && sizeof(In) == sizeof(Out) && !std::is_signed_v<In> &&
std::is_signed_v<Out>) { // Test that max uintXX_t saturates to max intXX_t
In in = static_cast<In>(std::numeric_limits<Out>::max()) + 1;
Out v = SaturatingCast<Out>(in);
DEBUG_PRINT(in, v);
ASSERT_EQ(v, std::numeric_limits<Out>::max());
}
// SaturatingCast of zero is zero
In in = static_cast<In>(0);
Out v = SaturatingCast<Out>(in);
DEBUG_PRINT(in, v);
ASSERT_EQ(v, 0);
if constexpr (sizeof(In) >= sizeof(Out) && std::is_signed_v<Out> &&
std::is_signed_v<In>) { // Test with a value within the range of the output type
In in = static_cast<In>(std::numeric_limits<Out>::max() / 2);
Out v = SaturatingCast<Out>(in);
DEBUG_PRINT(in, v);
ASSERT_EQ(v, in);
// Test with a negative value within the range of the output type
in = static_cast<In>(std::numeric_limits<Out>::lowest() / 2);
v = SaturatingCast<Out>(in);
DEBUG_PRINT(in, v);
ASSERT_EQ(v, in);
}
}
}
template <typename In, typename Out> void TestTypePair() {
constexpr bool fromFloat = std::is_floating_point_v<In>;
constexpr bool toFloat = std::is_floating_point_v<Out>; // Don't test casting to the same type if constexpr (!std::is_same_v<In, Out>) { if constexpr ((fromFloat && !toFloat) || (!fromFloat && !toFloat)) {
TestTypePairImpl<In, Out>();
}
}
}
void TestSaturatingCast() { // Each integer type against every other
TestSaturatingCastImpl<short, int, long, int8_t, uint8_t, int16_t, uint16_t,
int32_t, uint32_t, int64_t, uint64_t>();
// Floating point types to every integer type
TestFirstToOthers<float, short, int, long, int8_t, uint8_t, int16_t, uint16_t,
int32_t, uint32_t, int64_t, uint64_t>();
TestFirstToOthers<double, short, int, long, int8_t, uint8_t, int16_t,
uint16_t, int32_t, uint32_t, int64_t, uint64_t>();
}
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