Disable FPEs at end of runner

In mdrun unit tests the exceptions enabled for one test were
still active in the next. This caused issues with group
kernel which is known to throw FPEs.

Related #2404

Change-Id: Ie347a29f25ed16836a3164b61c9fca87ca66fc44

diff --git a/src/gromacs/math/utilities.cpp b/src/gromacs/math/utilities.cpp
index 4cdbae41e49c2071fb7fc65ec54d32d7bc730811..652f1e603e2656993fef6c41d177b73c94b73ef5 100644 (file)
--- a/src/gromacs/math/utilities.cpp
+++ b/src/gromacs/math/utilities.cpp
@@ -146,6 +146,28 @@ int gmx_feenableexcept()
 #endif
 }
 
+int gmx_fedisableexcept()
+{
+#if HAVE_FEDISABLEEXCEPT
+    return fedisableexcept(c_FPexceptions);
+#elif (defined(__i386__) || defined(__x86_64__)) && defined(__APPLE__)
+    static fenv_t fenv;
+    unsigned int  new_excepts = c_FPexceptions & FE_ALL_EXCEPT;
+    if (fegetenv (&fenv) )
+    {
+        return -1;
+    }
+
+    // mask
+    fenv.__control |= new_excepts;
+    fenv.__mxcsr   |= new_excepts << 7;
+
+    return fesetenv(&fenv);
+#else
+    return -1;
+#endif
+}
+
 real max_cutoff(real cutoff1, real cutoff2)
 {
     if (cutoff1 == 0 || cutoff2 == 0)

diff --git a/src/gromacs/math/utilities.h b/src/gromacs/math/utilities.h
index eba796a91027c48aaf0ce88b541d1bb282201293..a90cb2b6b55bf1b276f077ecddb9a29cd5e57e92 100644 (file)
--- a/src/gromacs/math/utilities.h
+++ b/src/gromacs/math/utilities.h
@@ -167,6 +167,14 @@ gmx_greatest_common_divisor(int p, int q);
  */
 int gmx_feenableexcept();
 
+/*! \brief Disable floating-point exceptions if supported on OS
+ *
+ * Disables division-by-zero, invalid value, and overflow.
+ *
+ * \returns 0 if successful in disabling exceptions, anything else in case of failure/unsupported OS.
+ */
+int gmx_fedisableexcept();
+
 /*! \brief Return cut-off to use
  *
  * Takes the max of two cut-offs. However a cut-off of 0

diff --git a/src/gromacs/mdrun/runner.cpp b/src/gromacs/mdrun/runner.cpp
index 290ddc998fc0e87b6242373075c3a9a282ec35fa..672a93368c0def2232ab8c0bf5be428ad2aaa2ed 100644 (file)
--- a/src/gromacs/mdrun/runner.cpp
+++ b/src/gromacs/mdrun/runner.cpp
@@ -1377,6 +1377,16 @@ int Mdrunner::mdrunner()
         fplog = nullptr;
     }
 
+    /* Reset FPEs (important for unit tests) by disabling them. Assumes no
+     * exceptions were enabled before function was called. */
+#if !defined NDEBUG && !(defined __clang__ && defined __OPTIMIZE__)
+    if (!EI_TPI(inputrec->eI) &&
+        inputrec->cutoff_scheme == ecutsVERLET)
+    {
+        gmx_fedisableexcept();
+    }
+#endif
+
     rc = (int)gmx_get_stop_condition();
 
 #if GMX_THREAD_MPI