Prevent errors due to unsafe math optimizations

.github/workflows/main.yml

@@ -315,7 +315,8 @@ jobs:
         run: |
           scons build extra_inc_dirs=$CONDA_PREFIX/include:$CONDA_PREFIX/include/eigen3 \
           extra_lib_dirs=$CONDA_PREFIX/lib system_fmt=y system_eigen=y system_yamlcpp=y \
-          system_sundials=y blas_lapack_libs='lapack,blas' -j2 VERBOSE=True debug=n
+          system_sundials=y blas_lapack_libs='lapack,blas' -j2 VERBOSE=True debug=n \
+          optimize_flags='-O3 -ffast-math -fno-finite-math-only'
       - name: Test Cantera
         run: scons test show_long_tests=yes verbose_tests=yes
 

SConstruct

@@ -960,8 +960,6 @@ int main(int argc, char** argv) {
     context.Result(result)
     return result
 
-conf = Configure(env, custom_tests={'CheckStatement': CheckStatement})
-
 # Set up compiler options before running configuration tests
 env['CXXFLAGS'] = listify(env['cxx_flags'])
 env['CCFLAGS'] = listify(env['cc_flags']) + listify(env['thread_flags'])
@@ -1007,6 +1005,8 @@ def config_error(message):
         print("See 'config.log' for details.")
     sys.exit(1)
 
+conf = Configure(env, custom_tests={'CheckStatement': CheckStatement})
+
 # First, a sanity check:
 if not conf.CheckCXXHeader('cmath', '<>'):
     config_error('The C++ compiler is not correctly configured.')
@@ -1027,6 +1027,16 @@ def get_expression_value(includes, expression, defines=()):
               '}\n'))
     return '\n'.join(s)
 
+# Check that NaN is treated correctly
+nan_check_source = get_expression_value(["<cmath>"], 'std::isnan(NAN + argc)')
+retcode, nan_works = conf.TryRun(nan_check_source, ".cpp")
+if nan_works.strip() != "1":
+    config_error(
+        "Cantera requires a working implementation of 'std::isnan'.\n"
+        "If you have specified '-ffast-math' or equivalent as an optimization option,\n"
+        "either remove this option or add the '-fno-finite-math-only option'."
+    )
+
 # Check for fmt library and checkout submodule if needed
 # Test for 'ostream.h' to ensure that version >= 3.0.0 is available
 if env['system_fmt'] in ('y', 'default'):

interfaces/cython/cantera/test/test_kinetics.py

@@ -255,8 +255,7 @@ def test_surface(self):
                              r2.rate.pre_exponential_factor)
             self.assertEqual(r1.rate.temperature_exponent,
                              r2.rate.temperature_exponent)
-            self.assertEqual(r1.rate.activation_energy,
-                             r2.rate.activation_energy)
+            self.assertNear(r1.rate.activation_energy, r2.rate.activation_energy)
 
         self.assertArrayNear(surf1.delta_enthalpy,
                              surf2.delta_enthalpy)
@@ -1342,7 +1341,7 @@ def test_Blowers_Masel_change_enthalpy(self):
         species.thermo = ct.NasaPoly2(species.thermo.min_temp, species.thermo.max_temp,
                             species.thermo.reference_pressure, perturbed_coeffs)
         gas.modify_species(index, species)
-        self.assertEqual(deltaH_high, gas.reaction(0).rate.activation_energy(deltaH_high))
+        self.assertNear(deltaH_high, gas.reaction(0).rate.activation_energy(deltaH_high))
         self.assertNear(A*gas.T**b*np.exp(-deltaH_high/ct.gas_constant/gas.T), gas.forward_rate_constants[0])
 
         perturbed_coeffs = species.thermo.coeffs.copy()

interfaces/cython/cantera/test/test_reaction.py

@@ -231,7 +231,7 @@ def test_from_parts(self):
         rate = self.from_parts()
         self.assertEqual(self._parts["A"], rate.pre_exponential_factor)
         self.assertEqual(self._parts["b"], rate.temperature_exponent)
-        self.assertEqual(self._parts["Ea"], rate.activation_energy)
+        self.assertNear(self._parts["Ea"], rate.activation_energy)
         self.check_rate(rate)
 
     def test_negative_A(self):
@@ -273,8 +273,8 @@ def test_from_parts(self):
         rate = self.from_parts()
         self.assertEqual(self._parts["A"], rate.pre_exponential_factor)
         self.assertEqual(self._parts["b"], rate.temperature_exponent)
-        self.assertEqual(self._parts["Ea0"], rate.intrinsic_activation_energy)
-        self.assertEqual(self._parts["w"], rate.bond_energy)
+        self.assertNear(self._parts["Ea0"], rate.intrinsic_activation_energy)
+        self.assertNear(self._parts["w"], rate.bond_energy)
         self.check_rate(rate)
 
     def test_negative_A(self):

src/equil/vcs_solve_TP.cpp

@@ -1943,20 +1943,8 @@ bool VCS_SOLVE::vcs_globStepDamp()
         plogf("   --- subroutine FORCE: End Slope       = %g\n", s2);
     }
 
-    if (s1 > 0.0) {
-        if (m_debug_print_lvl >= 2) {
-            plogf("   --- subroutine FORCE produced no adjustments,");
-            if (s1 < 1.0E-40) {
-                plogf(" s1 positive but really small\n");
-            } else {
-                plogf(" failed s1 test\n");
-            }
-        }
-        return false;
-    }
-
-    if (s2 <= 0.0) {
-        debuglog("   --- subroutine FORCE produced no adjustments, s2 < 0\n", m_debug_print_lvl >= 2);
+    if (s1 > 0.0 || s2 <= 0.0) {
+        debuglog("   --- subroutine FORCE produced no adjustments\n", m_debug_print_lvl >= 2);
         return false;
     }
 
@@ -1966,9 +1954,7 @@ bool VCS_SOLVE::vcs_globStepDamp()
         al = s1 / (s1 - s2);
     }
     if (al >= 0.95 || al < 0.0) {
-        if (m_debug_print_lvl >= 2) {
-            plogf("   --- subroutine FORCE produced no adjustments (al = %g)\n", al);
-        }
+        debuglog("   --- subroutine FORCE produced no adjustments\n", m_debug_print_lvl >= 2);
         return false;
     }
     if (m_debug_print_lvl >= 2) {

test/kinetics/kineticsFromYaml.cpp

@@ -494,10 +494,10 @@ class ReactionToYaml : public testing::Test
         kin->getRevRateConstants(kr.data());
         kin->getFwdRatesOfProgress(ropf.data());
         kin->getRevRatesOfProgress(ropr.data());
-        EXPECT_DOUBLE_EQ(kf[iOld], kf[iNew]);
-        EXPECT_DOUBLE_EQ(kr[iOld], kr[iNew]);
-        EXPECT_DOUBLE_EQ(ropf[iOld], ropf[iNew]);
-        EXPECT_DOUBLE_EQ(ropr[iOld], ropr[iNew]);
+        EXPECT_NEAR(kf[iOld], kf[iNew], 1e-13 * kf[iOld]);
+        EXPECT_NEAR(kr[iOld], kr[iNew], 1e-13 * kr[iOld]);
+        EXPECT_NEAR(ropf[iOld], ropf[iNew], 1e-13 * ropf[iOld]);
+        EXPECT_NEAR(ropr[iOld], ropr[iNew], 1e-13 * ropr[iOld]);
     }
 
     shared_ptr<Solution> soln;

test/thermo/PengRobinson_Test.cpp

@@ -186,13 +186,13 @@ TEST_F(PengRobinson_Test, setTP)
         const double temp = 294 + i*2;
         set_r(0.999);
         test_phase->setState_TP(temp, 5542027.5);
-        EXPECT_NEAR(test_phase->density(),rho1[i],1.e-8);
+        EXPECT_NEAR(test_phase->density(), rho1[i], 1.e-8);
 
         test_phase->setState_TP(temp, 7388370.);
-        EXPECT_NEAR(test_phase->density(),rho2[i],1.e-8);
+        EXPECT_NEAR(test_phase->density(), rho2[i], 1.e-7);
 
         test_phase->setState_TP(temp, 9236712.5);
-        EXPECT_NEAR(test_phase->density(),rho3[i],1.e-8);
+        EXPECT_NEAR(test_phase->density(), rho3[i], 1.e-8);
     }
 }
 

test/thermo/water_iapws.cpp

@@ -138,6 +138,6 @@ TEST_F(WaterPropsIAPWS_Test, expansion_coeffs)
         EXPECT_NEAR(water.coeffThermExp(), alpha[i], 2e-14);
         EXPECT_NEAR(water.coeffPresExp(), beta[i], beta[i] * 2e-12);
         EXPECT_NEAR(dPdT(TT[i], PP[i]) * 18.015268 / (8.314371E3 * rho),
-                    beta_num[i], 2e-10 * beta_num[i]);
+                    beta_num[i], 4e-10 * beta_num[i]);
     }
 }

test_problems/SConscript

@@ -253,7 +253,7 @@ Test('cxx-flamespeed', 'cxx_samples', '#build/samples/cxx/flamespeed/flamespeed'
      options='0.9 0 0')
 Test('cxx-kinetics1', 'cxx_samples', '#build/samples/cxx/kinetics1/kinetics1', None,
      comparisons=[('kin1_blessed.csv', 'kin1.csv')],
-     artifacts=['kin1.dat'], slow=True)
+     artifacts=['kin1.dat'], slow=True, tolerance=2e-4)
 Test('cxx-gas-transport', 'cxx_samples',
      '#build/samples/cxx/gas_transport/gas_transport', None, slow=True,
      comparisons=[('transport_mix_blessed.csv', 'transport_mix.csv'),

test_problems/VCSnonideal/LatticeSolid_LiSi/verbose_blessed.txt

@@ -227,7 +227,7 @@ VCS CALCULATION METHOD
    --- Total tentative Dimensionless Gibbs Free Energy = -4.1206752525561E+03
    --- subroutine FORCE: Beginning Slope = -0.109397
    --- subroutine FORCE: End Slope       = -0.0989949
-   --- subroutine FORCE produced no adjustments, s2 < 0
+   --- subroutine FORCE produced no adjustments
    -------------------------------------------------------------------------------------------------------
    --- Summary of the Update  (all species):
    ---      Species Status Initial_KMoles Final_KMoles Initial_Mu/RT     Mu/RT     Init_Del_G/RT   Delta_G/RT
@@ -285,7 +285,7 @@ VCS CALCULATION METHOD
    --- Total tentative Dimensionless Gibbs Free Energy = -4.1206857517346E+03
    --- subroutine FORCE: Beginning Slope = -0.0109994
    --- subroutine FORCE: End Slope       = 5.0022e-07
-   --- subroutine FORCE produced no adjustments (al = 0.999955)
+   --- subroutine FORCE produced no adjustments
    -------------------------------------------------------------------------------------------------------
    --- Summary of the Update  (all species):
    ---      Species Status Initial_KMoles Final_KMoles Initial_Mu/RT     Mu/RT     Init_Del_G/RT   Delta_G/RT
@@ -342,7 +342,7 @@ VCS CALCULATION METHOD
    --- Total tentative Dimensionless Gibbs Free Energy = -4.1206857517346E+03
    --- subroutine FORCE: Beginning Slope = -1.39826e-19
    --- subroutine FORCE: End Slope       = 9.31017e-32
-   --- subroutine FORCE produced no adjustments, s2 < 0
+   --- subroutine FORCE produced no adjustments
    -------------------------------------------------------------------------------------------------------
    --- Summary of the Update  (all species):
    ---      Species Status Initial_KMoles Final_KMoles Initial_Mu/RT     Mu/RT     Init_Del_G/RT   Delta_G/RT