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39 #include "utilities.h"
51 //! Floating point exception set that we use and care about
52 constexpr int c_FPexceptions = FE_DIVBYZERO | FE_INVALID | FE_OVERFLOW;
54 bool gmx_within_tol(double f1, double f2, double tol)
56 /* The or-equal is important - otherwise we return false if f1==f2==0 */
57 return fabs(f1 - f2) <= tol * 0.5 * (fabs(f1) + fabs(f2));
60 bool gmx_numzero(double a)
62 return gmx_within_tol(a, 0.0, GMX_REAL_MIN / GMX_REAL_EPS);
66 gmx_bool check_int_multiply_for_overflow(int64_t a, int64_t b, int64_t* result)
69 if ((0 == a) || (0 == b))
84 if (INT64_MAX / b < a)
86 *result = (sign > 0) ? INT64_MAX : INT64_MIN;
89 *result = sign * a * b;
93 int gmx_greatest_common_divisor(int p, int q)
105 int gmx_feenableexcept()
107 #if HAVE_FEENABLEEXCEPT
108 return feenableexcept(c_FPexceptions);
109 #elif (defined(__i386__) || defined(__x86_64__)) && defined(__APPLE__)
110 /* Author: David N. Williams
111 * License: Public Domain
113 * Might also work on non-Apple Unix. But should be tested
117 unsigned int new_excepts = c_FPexceptions & FE_ALL_EXCEPT;
125 fenv.__control &= ~new_excepts;
126 fenv.__mxcsr &= ~(new_excepts << 7);
128 return fesetenv(&fenv);
134 int gmx_fedisableexcept()
136 #if HAVE_FEDISABLEEXCEPT
137 return fedisableexcept(c_FPexceptions);
138 #elif (defined(__i386__) || defined(__x86_64__)) && defined(__APPLE__)
140 unsigned int new_excepts = c_FPexceptions & FE_ALL_EXCEPT;
147 fenv.__control |= new_excepts;
148 fenv.__mxcsr |= new_excepts << 7;
150 return fesetenv(&fenv);
156 real max_cutoff(real cutoff1, real cutoff2)
158 if (cutoff1 == 0 || cutoff2 == 0)
164 return std::max(cutoff1, cutoff2);