freebsd-skq/lib/msun/src/e_scalbf.c
David Schultz 7a773faadc Fix a problem where libm compiled under 5.X would depend on features
that are only in libc.so.5.  This broke some 4.X applications linked
to libm and run under 5.X.

Background:
In C99, isinf() and isnan() cannot be implemented as regular
functions.  We use macros that call libc functions in 5.X, but for
libm-internal use, we need to use the old versions until the next
time libm's major version number is bumped.

Submitted by:	bde
Reported by:	imp, kris
2003-10-27 01:28:07 +00:00

48 lines
1.2 KiB
C

/* e_scalbf.c -- float version of e_scalb.c.
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
#ifndef lint
static char rcsid[] = "$FreeBSD$";
#endif
#include "math.h"
#include "math_private.h"
/* XXX lost declaration of this and isnan() in math.h but still have funcs. */
int (isnanf)(float x);
#ifdef _SCALB_INT
float
__ieee754_scalbf(float x, int fn)
#else
float
__ieee754_scalbf(float x, float fn)
#endif
{
#ifdef _SCALB_INT
return scalbnf(x,fn);
#else
if ((isnanf)(x)||(isnanf)(fn)) return x*fn;
if (!finitef(fn)) {
if(fn>(float)0.0) return x*fn;
else return x/(-fn);
}
if (rintf(fn)!=fn) return (fn-fn)/(fn-fn);
if ( fn > (float)65000.0) return scalbnf(x, 65000);
if (-fn > (float)65000.0) return scalbnf(x,-65000);
return scalbnf(x,(int)fn);
#endif
}