view Python/fmod.c @ 13694:b54f11ada91e legacy-trunk

Create a new section of pyport.h to hold all external function declarations for systems that are missing those declarations from system include files. Start by moving a pointy-haired ones from their previous locations to the new section. (The gethostname() one, for instance, breaks on several systems, because some define it as (char *, size_t) and some as (char *, int).) I purposely decided not to include the summary of used #defines like Tim did in the first section of pyport.h. In my opinion, the number of #defines likedly to be used by this section would make such an overview unwieldy. I would suggest documenting the non-obvious ones, though.
author Thomas Wouters <thomas@python.org>
date Mon, 24 Jul 2000 16:06:23 +0000
parents 87ee82e5c56d
children 59f8cedcf049
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/***********************************************************
Copyright (c) 2000, BeOpen.com.
Copyright (c) 1995-2000, Corporation for National Research Initiatives.
Copyright (c) 1990-1995, Stichting Mathematisch Centrum.
All rights reserved.

See the file "Misc/COPYRIGHT" for information on usage and
redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
******************************************************************/

/* Portable fmod(x, y) implementation for systems that don't have it */

#include "config.h"

#include "mymath.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;
}