view Python/fmod.c @ 38418:708eaf0896bf legacy-trunk

Patch 1145039. set_exc_info(), reset_exc_info(): By exploiting the likely (who knows?) invariant that when an exception's `type` is NULL, its `value` and `traceback` are also NULL, save some cycles in heavily-executed code. This is a "a kronar saved is a kronar earned" patch: the speedup isn't reliably measurable, but it obviously does reduce the operation count in the normal (no exception raised) path through PyEval_EvalFrameEx(). The tim-exc_sanity branch tries to push this harder, but is still blowing up (at least in part due to pre-existing subtle bugs that appear to have no other visible consequences!). Not a bugfix candidate.
author Tim Peters <tim.peters@gmail.com>
date Fri, 26 May 2006 23:14:37 +0000
parents 2dea40e40d9d
children
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/* 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;
}