mirror of
https://github.com/catchorg/Catch2.git
synced 2024-11-17 03:02:24 +01:00
Added Google's support for floating comparison. Refer to http://stackoverflow.com/questions/17333/most-effective-way-for-float-and-double-comparison.
This commit is contained in:
student-t
parent
35f4266d00
commit
ec5ca60a60
@ -24,6 +24,7 @@
|
||||
|
||||
#include "internal/catch_notimplemented_exception.h"
|
||||
#include "internal/catch_context.h"
|
||||
#include "internal/catch_float.hpp"
|
||||
#include "internal/catch_test_registry.hpp"
|
||||
#include "internal/catch_capture.hpp"
|
||||
#include "internal/catch_section.h"
|
||||
@ -129,6 +130,9 @@
|
||||
#define REQUIRE( expr ) INTERNAL_CATCH_TEST( expr, Catch::ResultDisposition::Normal, "REQUIRE" )
|
||||
#define REQUIRE_FALSE( expr ) INTERNAL_CATCH_TEST( expr, Catch::ResultDisposition::Normal | Catch::ResultDisposition::FalseTest, "REQUIRE_FALSE" )
|
||||
|
||||
#define REQUIRE_FLOAT(x, y) FloatingPoint<float>(x).AlmostEquals(FloatingPoint<float>(y))
|
||||
#define REQUIRE_DOUBLE(x, y) FloatingPoint<double>(x).AlmostEquals(FloatingPoint<double>(y))
|
||||
|
||||
#define REQUIRE_THROWS( expr ) INTERNAL_CATCH_THROWS( expr, Catch::ResultDisposition::Normal, "REQUIRE_THROWS" )
|
||||
#define REQUIRE_THROWS_AS( expr, exceptionType ) INTERNAL_CATCH_THROWS_AS( expr, exceptionType, Catch::ResultDisposition::Normal, "REQUIRE_THROWS_AS" )
|
||||
#define REQUIRE_NOTHROW( expr ) INTERNAL_CATCH_NO_THROW( expr, Catch::ResultDisposition::Normal, "REQUIRE_NOTHROW" )
|
||||
|
||||
263
include/internal/catch_float.hpp
Normal file
263
include/internal/catch_float.hpp
Normal file
@ -0,0 +1,263 @@
|
||||
#include <iostream>
|
||||
|
||||
// Copyright 2005, Google Inc.
|
||||
// All rights reserved.
|
||||
//
|
||||
// Redistribution and use in source and binary forms, with or without
|
||||
// modification, are permitted provided that the following conditions are
|
||||
// met:
|
||||
//
|
||||
// * Redistributions of source code must retain the above copyright
|
||||
// notice, this list of conditions and the following disclaimer.
|
||||
// * Redistributions in binary form must reproduce the above
|
||||
// copyright notice, this list of conditions and the following disclaimer
|
||||
// in the documentation and/or other materials provided with the
|
||||
// distribution.
|
||||
// * Neither the name of Google Inc. nor the names of its
|
||||
// contributors may be used to endorse or promote products derived from
|
||||
// this software without specific prior written permission.
|
||||
//
|
||||
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||||
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||||
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
||||
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
||||
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
||||
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
||||
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
||||
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
||||
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
||||
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
//
|
||||
// Authors: wan@google.com (Zhanyong Wan), eefacm@gmail.com (Sean Mcafee)
|
||||
//
|
||||
// The Google C++ Testing Framework (Google Test)
|
||||
|
||||
|
||||
// This template class serves as a compile-time function from size to
|
||||
// type. It maps a size in bytes to a primitive type with that
|
||||
// size. e.g.
|
||||
//
|
||||
// TypeWithSize<4>::UInt
|
||||
//
|
||||
// is typedef-ed to be unsigned int (unsigned integer made up of 4
|
||||
// bytes).
|
||||
//
|
||||
// Such functionality should belong to STL, but I cannot find it
|
||||
// there.
|
||||
//
|
||||
// Google Test uses this class in the implementation of floating-point
|
||||
// comparison.
|
||||
//
|
||||
// For now it only handles UInt (unsigned int) as that's all Google Test
|
||||
// needs. Other types can be easily added in the future if need
|
||||
// arises.
|
||||
template <size_t size>
|
||||
class TypeWithSize {
|
||||
public:
|
||||
// This prevents the user from using TypeWithSize<N> with incorrect
|
||||
// values of N.
|
||||
typedef void UInt;
|
||||
};
|
||||
|
||||
// The specialization for size 4.
|
||||
template <>
|
||||
class TypeWithSize<4> {
|
||||
public:
|
||||
// unsigned int has size 4 in both gcc and MSVC.
|
||||
//
|
||||
// As base/basictypes.h doesn't compile on Windows, we cannot use
|
||||
// uint32, uint64, and etc here.
|
||||
typedef int Int;
|
||||
typedef unsigned int UInt;
|
||||
};
|
||||
|
||||
// The specialization for size 8.
|
||||
template <>
|
||||
class TypeWithSize<8> {
|
||||
public:
|
||||
#if GTEST_OS_WINDOWS
|
||||
typedef __int64 Int;
|
||||
typedef unsigned __int64 UInt;
|
||||
#else
|
||||
typedef long long Int; // NOLINT
|
||||
typedef unsigned long long UInt; // NOLINT
|
||||
#endif // GTEST_OS_WINDOWS
|
||||
};
|
||||
|
||||
|
||||
// This template class represents an IEEE floating-point number
|
||||
// (either single-precision or double-precision, depending on the
|
||||
// template parameters).
|
||||
//
|
||||
// The purpose of this class is to do more sophisticated number
|
||||
// comparison. (Due to round-off error, etc, it's very unlikely that
|
||||
// two floating-points will be equal exactly. Hence a naive
|
||||
// comparison by the == operation often doesn't work.)
|
||||
//
|
||||
// Format of IEEE floating-point:
|
||||
//
|
||||
// The most-significant bit being the leftmost, an IEEE
|
||||
// floating-point looks like
|
||||
//
|
||||
// sign_bit exponent_bits fraction_bits
|
||||
//
|
||||
// Here, sign_bit is a single bit that designates the sign of the
|
||||
// number.
|
||||
//
|
||||
// For float, there are 8 exponent bits and 23 fraction bits.
|
||||
//
|
||||
// For double, there are 11 exponent bits and 52 fraction bits.
|
||||
//
|
||||
// More details can be found at
|
||||
// http://en.wikipedia.org/wiki/IEEE_floating-point_standard.
|
||||
//
|
||||
// Template parameter:
|
||||
//
|
||||
// RawType: the raw floating-point type (either float or double)
|
||||
template <typename RawType>
|
||||
class FloatingPoint {
|
||||
public:
|
||||
// Defines the unsigned integer type that has the same size as the
|
||||
// floating point number.
|
||||
typedef typename TypeWithSize<sizeof(RawType)>::UInt Bits;
|
||||
|
||||
// Constants.
|
||||
|
||||
// # of bits in a number.
|
||||
static const size_t kBitCount = 8*sizeof(RawType);
|
||||
|
||||
// # of fraction bits in a number.
|
||||
static const size_t kFractionBitCount =
|
||||
std::numeric_limits<RawType>::digits - 1;
|
||||
|
||||
// # of exponent bits in a number.
|
||||
static const size_t kExponentBitCount = kBitCount - 1 - kFractionBitCount;
|
||||
|
||||
// The mask for the sign bit.
|
||||
static const Bits kSignBitMask = static_cast<Bits>(1) << (kBitCount - 1);
|
||||
|
||||
// The mask for the fraction bits.
|
||||
static const Bits kFractionBitMask =
|
||||
~static_cast<Bits>(0) >> (kExponentBitCount + 1);
|
||||
|
||||
// The mask for the exponent bits.
|
||||
static const Bits kExponentBitMask = ~(kSignBitMask | kFractionBitMask);
|
||||
|
||||
// How many ULP's (Units in the Last Place) we want to tolerate when
|
||||
// comparing two numbers. The larger the value, the more error we
|
||||
// allow. A 0 value means that two numbers must be exactly the same
|
||||
// to be considered equal.
|
||||
//
|
||||
// The maximum error of a single floating-point operation is 0.5
|
||||
// units in the last place. On Intel CPU's, all floating-point
|
||||
// calculations are done with 80-bit precision, while double has 64
|
||||
// bits. Therefore, 4 should be enough for ordinary use.
|
||||
//
|
||||
// See the following article for more details on ULP:
|
||||
// http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm.
|
||||
static const size_t kMaxUlps = 4;
|
||||
|
||||
// Constructs a FloatingPoint from a raw floating-point number.
|
||||
//
|
||||
// On an Intel CPU, passing a non-normalized NAN (Not a Number)
|
||||
// around may change its bits, although the new value is guaranteed
|
||||
// to be also a NAN. Therefore, don't expect this constructor to
|
||||
// preserve the bits in x when x is a NAN.
|
||||
explicit FloatingPoint(const RawType& x) { u_.value_ = x; }
|
||||
|
||||
// Static methods
|
||||
|
||||
// Reinterprets a bit pattern as a floating-point number.
|
||||
//
|
||||
// This function is needed to test the AlmostEquals() method.
|
||||
static RawType ReinterpretBits(const Bits bits) {
|
||||
FloatingPoint fp(0);
|
||||
fp.u_.bits_ = bits;
|
||||
return fp.u_.value_;
|
||||
}
|
||||
|
||||
// Returns the floating-point number that represent positive infinity.
|
||||
static RawType Infinity() {
|
||||
return ReinterpretBits(kExponentBitMask);
|
||||
}
|
||||
|
||||
// Non-static methods
|
||||
|
||||
// Returns the bits that represents this number.
|
||||
const Bits &bits() const { return u_.bits_; }
|
||||
|
||||
// Returns the exponent bits of this number.
|
||||
Bits exponent_bits() const { return kExponentBitMask & u_.bits_; }
|
||||
|
||||
// Returns the fraction bits of this number.
|
||||
Bits fraction_bits() const { return kFractionBitMask & u_.bits_; }
|
||||
|
||||
// Returns the sign bit of this number.
|
||||
Bits sign_bit() const { return kSignBitMask & u_.bits_; }
|
||||
|
||||
// Returns true iff this is NAN (not a number).
|
||||
bool is_nan() const {
|
||||
// It's a NAN if the exponent bits are all ones and the fraction
|
||||
// bits are not entirely zeros.
|
||||
return (exponent_bits() == kExponentBitMask) && (fraction_bits() != 0);
|
||||
}
|
||||
|
||||
// Returns true iff this number is at most kMaxUlps ULP's away from
|
||||
// rhs. In particular, this function:
|
||||
//
|
||||
// - returns false if either number is (or both are) NAN.
|
||||
// - treats really large numbers as almost equal to infinity.
|
||||
// - thinks +0.0 and -0.0 are 0 DLP's apart.
|
||||
bool AlmostEquals(const FloatingPoint& rhs) const {
|
||||
// The IEEE standard says that any comparison operation involving
|
||||
// a NAN must return false.
|
||||
if (is_nan() || rhs.is_nan()) return false;
|
||||
|
||||
return DistanceBetweenSignAndMagnitudeNumbers(u_.bits_, rhs.u_.bits_)
|
||||
<= kMaxUlps;
|
||||
}
|
||||
|
||||
private:
|
||||
// The data type used to store the actual floating-point number.
|
||||
union FloatingPointUnion {
|
||||
RawType value_; // The raw floating-point number.
|
||||
Bits bits_; // The bits that represent the number.
|
||||
};
|
||||
|
||||
// Converts an integer from the sign-and-magnitude representation to
|
||||
// the biased representation. More precisely, let N be 2 to the
|
||||
// power of (kBitCount - 1), an integer x is represented by the
|
||||
// unsigned number x + N.
|
||||
//
|
||||
// For instance,
|
||||
//
|
||||
// -N + 1 (the most negative number representable using
|
||||
// sign-and-magnitude) is represented by 1;
|
||||
// 0 is represented by N; and
|
||||
// N - 1 (the biggest number representable using
|
||||
// sign-and-magnitude) is represented by 2N - 1.
|
||||
//
|
||||
// Read http://en.wikipedia.org/wiki/Signed_number_representations
|
||||
// for more details on signed number representations.
|
||||
static Bits SignAndMagnitudeToBiased(const Bits &sam) {
|
||||
if (kSignBitMask & sam) {
|
||||
// sam represents a negative number.
|
||||
return ~sam + 1;
|
||||
} else {
|
||||
// sam represents a positive number.
|
||||
return kSignBitMask | sam;
|
||||
}
|
||||
}
|
||||
|
||||
// Given two numbers in the sign-and-magnitude representation,
|
||||
// returns the distance between them as an unsigned number.
|
||||
static Bits DistanceBetweenSignAndMagnitudeNumbers(const Bits &sam1,
|
||||
const Bits &sam2) {
|
||||
const Bits biased1 = SignAndMagnitudeToBiased(sam1);
|
||||
const Bits biased2 = SignAndMagnitudeToBiased(sam2);
|
||||
return (biased1 >= biased2) ? (biased1 - biased2) : (biased2 - biased1);
|
||||
}
|
||||
|
||||
FloatingPointUnion u_;
|
||||
};
|
||||
Loading…
Reference in New Issue
Block a user