ref: 52cacba37c6f3a125ef931afa4b9c2cdb7438fef
dir: /sys/src/cmd/python/Python/fmod.c/
/* Portable fmod(x, y) implementation for systems that don't have it */ #include "pyconfig.h" #include "pyport.h" #include <errno.h> double fmod(double x, double y) { double i, f; if (y == 0.0) { errno = EDOM; return 0.0; } /* return f such that x = i*y + f for some integer i such that |f| < |y| and f has the same sign as x */ i = floor(x/y); f = x - i*y; if ((x < 0.0) != (y < 0.0)) f = f-y; return f; }