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 "testutils/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 } // namespace
  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 floatingPointToBiasedInteger(const FloatingPoint<FloatType>& value)
 127 {
 128     if (value.sign_bit())
 129     {
 130         return ~value.bits() + 1;
 131     }
 132     else
 133     {
 134         return value.bits() | FloatingPoint<FloatType>::kSignBitMask;
 135     }
 136 }
 137
 138 /*! \brief
 139  * Computes the magnitude of the difference in ULPs between two numbers,
 140  * treating also values of different sign.
 141  */
 142 template<typename FloatType>
 143 uint64_t calculateUlpDifference(const FloatingPoint<FloatType>& value1, const FloatingPoint<FloatType>& value2)
 144 {
 145     typename FloatingPoint<FloatType>::Bits biased1 = floatingPointToBiasedInteger(value1);
 146     typename FloatingPoint<FloatType>::Bits biased2 = floatingPointToBiasedInteger(value2);
 147     return biased1 > biased2 ? biased1 - biased2 : biased2 - biased1;
 148 }
 149
 150 /*! \brief
 151  * Helper to implement the constructors for FloatingPointDifference.
 152  */
 153 template<typename FloatType>
 154 void initDifference(FloatType raw1, FloatType raw2, double* absoluteDifference, uint64_t* ulpDifference, bool* bSignDifference)
 155 {
 156     FloatingPoint<FloatType> value1(raw1);
 157     FloatingPoint<FloatType> value2(raw2);
 158
 159     if (value1.is_nan() || value2.is_nan())
 160     {
 161         *absoluteDifference = std::numeric_limits<double>::quiet_NaN();
 162         *bSignDifference    = false;
 163         *ulpDifference      = 0;
 164         return;
 165     }
 166     *absoluteDifference = std::fabs(raw1 - raw2);
 167     *bSignDifference    = (value1.sign_bit() != value2.sign_bit());
 168     *ulpDifference      = calculateUlpDifference(value1, value2);
 169 }
 170
 171 /*! \brief
 172  * Converts a relative tolerance into an ULP difference.
 173  */
 174 template<typename FloatType>
 175 uint64_t relativeToleranceToUlp(FloatType tolerance)
 176 {
 177     FloatingPoint<FloatType> m(1.0);
 178     FloatingPoint<FloatType> t(1.0 + tolerance);
 179     return calculateUlpDifference<FloatType>(m, t);
 180 }
 181
 182 //! \}
 183 //! \}
 184
 185 } // namespace
 186
 187 /********************************************************************
 188  * FloatingPointDifference
 189  */
 190
 191 FloatingPointDifference::FloatingPointDifference(float ref, float value) :
 192     termMagnitude_(std::abs(ref))
 193 {
 194     initDifference(ref, value, &absoluteDifference_, &ulpDifference_, &bSignDifference_);
 195     bDouble_ = false;
 196 }
 197
 198 FloatingPointDifference::FloatingPointDifference(double ref, double value) :
 199     termMagnitude_(std::abs(ref))
 200 {
 201     initDifference(ref, value, &absoluteDifference_, &ulpDifference_, &bSignDifference_);
 202     bDouble_ = true;
 203 }
 204
 205 bool FloatingPointDifference::isNaN() const
 206 {
 207     return FloatingPoint<double>(absoluteDifference_).is_nan();
 208 }
 209
 210 std::string FloatingPointDifference::toString() const
 211 {
 212     std::string relDiffStr;
 213
 214     if (termMagnitude_ > 0)
 215     {
 216         // If the reference value is finite we calculate the proper quotient
 217         relDiffStr = formatString("%.3g", std::abs(absoluteDifference_ / termMagnitude_));
 218     }
 219     else if (absoluteDifference_ == 0.0)
 220     {
 221         // If the numbers are identical the quotient is strictly NaN here, but
 222         // there no reason to worry when we have a perfect match.
 223         relDiffStr = formatString("%.3g", 0.0);
 224     }
 225     else
 226     {
 227         // If the reference value is zero and numbers are non-identical, relative difference is infinite.
 228         relDiffStr = formatString("Inf");
 229     }
 230
 231     return formatString("%g (%" PRIu64 " %s-prec. ULPs, rel. %s)%s", absoluteDifference_,
 232                         ulpDifference_, isDouble() ? "double" : "single", relDiffStr.c_str(),
 233                         bSignDifference_ ? ", signs differ" : "");
 234 }
 235
 236 /********************************************************************
 237  * FloatingPointTolerance
 238  */
 239
 240 bool FloatingPointTolerance::isWithin(const FloatingPointDifference& difference) const
 241 {
 242     if (difference.isNaN())
 243     {
 244         return false;
 245     }
 246
 247     if (bSignMustMatch_ && difference.signsDiffer())
 248     {
 249         return false;
 250     }
 251
 252     const double absoluteTolerance =
 253             difference.isDouble() ? doubleAbsoluteTolerance_ : singleAbsoluteTolerance_;
 254     if (difference.asAbsolute() < absoluteTolerance)
 255     {
 256         return true;
 257     }
 258
 259     // By using smaller-than-or-equal below, we allow the test to pass if
 260     // the numbers are identical, even if the term magnitude is 0, which seems
 261     // a reasonable thing to do...
 262     const double relativeTolerance =
 263             difference.isDouble() ? doubleRelativeTolerance_ : singleRelativeTolerance_;
 264
 265     if (difference.asAbsolute() <= relativeTolerance * difference.termMagnitude())
 266     {
 267         return true;
 268     }
 269
 270     const uint64_t ulpTolerance = difference.isDouble() ? doubleUlpTolerance_ : singleUlpTolerance_;
 271     return ulpTolerance < UINT64_MAX && difference.asUlps() <= ulpTolerance;
 272 }
 273
 274 std::string FloatingPointTolerance::toString(const FloatingPointDifference& difference) const
 275 {
 276     std::string  result;
 277     const double absoluteTolerance =
 278             difference.isDouble() ? doubleAbsoluteTolerance_ : singleAbsoluteTolerance_;
 279     const double relativeTolerance =
 280             difference.isDouble() ? doubleRelativeTolerance_ : singleRelativeTolerance_;
 281     const uint64_t ulpTolerance = difference.isDouble() ? doubleUlpTolerance_ : singleUlpTolerance_;
 282
 283     if (absoluteTolerance > 0.0)
 284     {
 285         result.append(formatString("abs. %g", absoluteTolerance));
 286     }
 287     if (relativeTolerance > 0.0)
 288     {
 289         if (!result.empty())
 290         {
 291             result.append(", ");
 292         }
 293         result.append(formatString("rel. %.3g", relativeTolerance));
 294     }
 295     if (ulpTolerance < UINT64_MAX)
 296     {
 297         if (!result.empty())
 298         {
 299             result.append(", ");
 300         }
 301         result.append(formatString("%" PRIu64 " ULPs", ulpTolerance));
 302     }
 303     if (bSignMustMatch_)
 304     {
 305         if (!result.empty())
 306         {
 307             result.append(", ");
 308         }
 309         result.append("sign must match");
 310     }
 311     return result;
 312 }
 313
 314 // Doxygen does not recognize this as the same function as in the header...
 315 //! \cond
 316 FloatingPointTolerance relativeToleranceAsFloatingPoint(double magnitude, double tolerance)
 317 {
 318     return relativeToleranceAsPrecisionDependentFloatingPoint(magnitude, float(tolerance), tolerance);
 319 }
 320
 321 FloatingPointTolerance relativeToleranceAsPrecisionDependentFloatingPoint(double magnitude,
 322                                                                           float  singleTolerance,
 323                                                                           double doubleTolerance)
 324 {
 325     const float  absoluteSingleTolerance = std::abs(float(magnitude)) * singleTolerance;
 326     const double absoluteDoubleTolerance = std::abs(magnitude) * doubleTolerance;
 327     return {
 328         absoluteSingleTolerance, absoluteDoubleTolerance, singleTolerance, doubleTolerance, UINT64_MAX, UINT64_MAX, false
 329     };
 330 }
 331 //! \endcond
 332
 333 } // namespace test
 334 } // namespace gmx