src/testutils/testasserts.cpp

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  35 /*! \internal \file
  36  * \brief
  37  * Implements floating-point comparison routines from testasserts.h.
  38  *
  39  * \author Teemu Murtola <teemu.murtola@gmail.com>
  40  * \ingroup module_testutils
  41  */
  42 #include "gmxpre.h"
  43
  44 #include "testasserts.h"
  45
  46 #include <cmath>
  47 #include <cstdio>
  48
  49 #include <limits>
  50
  51 #include <gtest/gtest.h>
  52
  53 #include "gromacs/options/basicoptions.h"
  54 #include "gromacs/options/ioptionscontainer.h"
  55 #include "gromacs/utility/basedefinitions.h"
  56 #include "gromacs/utility/exceptions.h"
  57 #include "gromacs/utility/stringutil.h"
  58
  59 #include "testutils/testoptions.h"
  60
  61 namespace gmx
  62 {
  63
  64 namespace test
  65 {
  66
  67 namespace
  68 {
  69
  70 //! Whether to print the message from expected exceptions.
  71 bool g_showExpectedExceptions = false;
  72
  73 //! \cond
  74 GMX_TEST_OPTIONS(ExceptionOptions, options)
  75 {
  76     options->addOption(BooleanOption("show-error-messages")
  77                            .store(&g_showExpectedExceptions)
  78                            .description("Show error messages from expected "
  79                                         "exceptions"));
  80 }
  81 //! \endcond
  82 }
  83
  84 namespace internal
  85 {
  86
  87 //! \cond internal
  88 void processExpectedException(const std::exception &ex)
  89 {
  90     if (g_showExpectedExceptions)
  91     {
  92         std::printf("Exception message (from expected exception):\n");
  93         formatExceptionMessageToFile(stdout, ex);
  94     }
  95 }
  96 //! \endcond
  97
  98 }       // namespace internal
  99
 100 namespace
 101 {
 102
 103 using ::testing::internal::FloatingPoint;
 104
 105 //! \internal \addtogroup module_testutils
 106 //! \{
 107
 108 /*! \name Helper functions for computing floating-point differences
 109  *
 110  * These routines are used to initialize FloatingPointDifference.
 111  * They peek into some internal types from Google Test (gtest-internal.h),
 112  * and duplicate some other functionality from there, but that is likely
 113  * a better alternative than just copying all that code here.
 114  */
 115 //! \{
 116
 117 /*! \brief
 118  * Computes biased integer representation for a floating-point value.
 119  *
 120  * This moves the integer representation from a sign-and-magnitude
 121  * representation to a biased representation where the 0x8000... represents
 122  * zero, and the order of the integer values matches the order of the
 123  * floating-point values.
 124  */
 125 template <typename FloatType>
 126 typename FloatingPoint<FloatType>::Bits
 127 floatingPointToBiasedInteger(const FloatingPoint<FloatType> &value)
 128 {
 129     if (value.sign_bit())
 130     {
 131         return ~value.bits() + 1;
 132     }
 133     else
 134     {
 135         return value.bits() | FloatingPoint<FloatType>::kSignBitMask;
 136     }
 137 }
 138
 139 /*! \brief
 140  * Computes the magnitude of the difference in ULPs between two numbers,
 141  * treating also values of different sign.
 142  */
 143 template <typename FloatType>
 144 gmx_uint64_t calculateUlpDifference(const FloatingPoint<FloatType> &value1,
 145                                     const FloatingPoint<FloatType> &value2)
 146 {
 147     typename FloatingPoint<FloatType>::Bits biased1
 148         = floatingPointToBiasedInteger(value1);
 149     typename FloatingPoint<FloatType>::Bits biased2
 150         = floatingPointToBiasedInteger(value2);
 151     return biased1 > biased2 ? biased1 - biased2 : biased2 - biased1;
 152 }
 153
 154 /*! \brief
 155  * Helper to implement the constructors for FloatingPointDifference.
 156  */
 157 template <typename FloatType>
 158 void initDifference(FloatType raw1, FloatType raw2, double *absoluteDifference,
 159                     gmx_uint64_t *ulpDifference, bool *bSignDifference)
 160 {
 161     FloatingPoint<FloatType> value1(raw1);
 162     FloatingPoint<FloatType> value2(raw2);
 163
 164     if (value1.is_nan() || value2.is_nan())
 165     {
 166         *absoluteDifference = std::numeric_limits<double>::quiet_NaN();
 167         *bSignDifference    = false;
 168         *ulpDifference      = 0;
 169         return;
 170     }
 171     *absoluteDifference = std::fabs(raw1 - raw2);
 172     *bSignDifference    = (value1.sign_bit() != value2.sign_bit());
 173     *ulpDifference      = calculateUlpDifference(value1, value2);
 174 }
 175
 176 /*! \brief
 177  * Converts a relative tolerance into an ULP difference.
 178  */
 179 template <typename FloatType>
 180 gmx_uint64_t relativeToleranceToUlp(FloatType tolerance)
 181 {
 182     FloatingPoint<FloatType> m(1.0);
 183     FloatingPoint<FloatType> t(1.0 + tolerance);
 184     return calculateUlpDifference<FloatType>(m, t);
 185 }
 186
 187 //! \}
 188 //! \}
 189
 190 }       // namespace
 191
 192 /********************************************************************
 193  * FloatingPointDifference
 194  */
 195
 196 FloatingPointDifference::FloatingPointDifference(float ref, float value)
 197     : termMagnitude_(std::abs(ref))
 198 {
 199     initDifference(ref, value,
 200                    &absoluteDifference_, &ulpDifference_, &bSignDifference_);
 201     bDouble_ = false;
 202 }
 203
 204 FloatingPointDifference::FloatingPointDifference(double ref, double value)
 205     : termMagnitude_(std::abs(ref))
 206 {
 207     initDifference(ref, value,
 208                    &absoluteDifference_, &ulpDifference_, &bSignDifference_);
 209     bDouble_ = true;
 210 }
 211
 212 bool FloatingPointDifference::isNaN() const
 213 {
 214     return FloatingPoint<double>(absoluteDifference_).is_nan();
 215 }
 216
 217 std::string FloatingPointDifference::toString() const
 218 {
 219     std::string relDiffStr;
 220
 221     if (termMagnitude_ > 0)
 222     {
 223         // If the reference value is finite we calculate the proper quotient
 224         relDiffStr = formatString("%.3g", std::abs(absoluteDifference_/termMagnitude_));
 225     }
 226     else if (absoluteDifference_ == 0.0)
 227     {
 228         // If the numbers are identical the quotient is strictly NaN here, but
 229         // there no reason to worry when we have a perfect match.
 230         relDiffStr = formatString("%.3g", 0.0);
 231     }
 232     else
 233     {
 234         // If the reference value is zero and numbers are non-identical, relative difference is infinite.
 235         relDiffStr = formatString("Inf");
 236     }
 237
 238     return formatString("%g (%" GMX_PRIu64 " %s-prec. ULPs, rel. %s)%s",
 239                         absoluteDifference_, ulpDifference_,
 240                         isDouble() ? "double" : "single",
 241                         relDiffStr.c_str(),
 242                         bSignDifference_ ? ", signs differ" : "");
 243 }
 244
 245 /********************************************************************
 246  * FloatingPointTolerance
 247  */
 248
 249 bool FloatingPointTolerance::isWithin(
 250         const FloatingPointDifference &difference) const
 251 {
 252     if (difference.isNaN())
 253     {
 254         return false;
 255     }
 256
 257     if (bSignMustMatch_ && difference.signsDiffer())
 258     {
 259         return false;
 260     }
 261
 262     const double absoluteTolerance
 263         = difference.isDouble() ? doubleAbsoluteTolerance_ : singleAbsoluteTolerance_;
 264     if (difference.asAbsolute() < absoluteTolerance)
 265     {
 266         return true;
 267     }
 268
 269     // By using smaller-than-or-equal below, we allow the test to pass if
 270     // the numbers are identical, even if the term magnitude is 0, which seems
 271     // a reasonable thing to do...
 272     const double relativeTolerance
 273         = difference.isDouble() ? doubleRelativeTolerance_ : singleRelativeTolerance_;
 274
 275     if (difference.asAbsolute() <= relativeTolerance * difference.termMagnitude())
 276     {
 277         return true;
 278     }
 279
 280     const gmx_uint64_t ulpTolerance
 281         = difference.isDouble() ? doubleUlpTolerance_ : singleUlpTolerance_;
 282     if (ulpTolerance < GMX_UINT64_MAX && difference.asUlps() <= ulpTolerance)
 283     {
 284         return true;
 285     }
 286
 287     return false;
 288 }
 289
 290 std::string FloatingPointTolerance::toString(const FloatingPointDifference &difference) const
 291 {
 292     std::string        result;
 293     const double       absoluteTolerance
 294         = difference.isDouble() ? doubleAbsoluteTolerance_ : singleAbsoluteTolerance_;
 295     const double       relativeTolerance
 296         = difference.isDouble() ? doubleRelativeTolerance_ : singleRelativeTolerance_;
 297     const gmx_uint64_t ulpTolerance
 298         = difference.isDouble() ? doubleUlpTolerance_ : singleUlpTolerance_;
 299
 300     if (absoluteTolerance > 0.0)
 301     {
 302         result.append(formatString("abs. %g", absoluteTolerance));
 303     }
 304     if (relativeTolerance > 0.0)
 305     {
 306         if (!result.empty())
 307         {
 308             result.append(", ");
 309         }
 310         result.append(formatString("rel. %.3g", relativeTolerance));
 311     }
 312     if (ulpTolerance < GMX_UINT64_MAX)
 313     {
 314         if (!result.empty())
 315         {
 316             result.append(", ");
 317         }
 318         result.append(formatString("%" GMX_PRIu64 " ULPs", ulpTolerance));
 319     }
 320     if (bSignMustMatch_)
 321     {
 322         if (!result.empty())
 323         {
 324             result.append(", ");
 325         }
 326         result.append("sign must match");
 327     }
 328     return result;
 329 }
 330
 331 // Doxygen does not recognize this as the same function as in the header...
 332 //! \cond
 333 FloatingPointTolerance
 334 relativeToleranceAsFloatingPoint(double magnitude, double tolerance)
 335 {
 336     const double absoluteTolerance = std::abs(magnitude) * tolerance;
 337     return FloatingPointTolerance(absoluteTolerance, absoluteTolerance,
 338                                   tolerance, tolerance,
 339                                   GMX_UINT64_MAX, GMX_UINT64_MAX,
 340                                   false);
 341 }
 342 //! \endcond
 343
 344 } // namespace test
 345 } // namespace gmx