modff.c revision 25c28e83beb90e7c80452a7c818c5e6f73a07dc8
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#if defined(ELFOBJ)
#pragma weak modff = __modff
#pragma weak _modff = __modff
#endif
#include "libm.h"
float
__modff(float x, float *iptr) {
union {
unsigned i;
float f;
} xx, yy;
unsigned hx, s;
xx.f = x;
hx = xx.i & ~0x80000000;
if (hx >= 0x4b000000) { /* x is NaN, infinite, or integral */
*iptr = x;
if (hx <= 0x7f800000)
xx.i &= 0x80000000;
return (xx.f);
}
if (hx < 0x3f800000) { /* |x| < 1 */
xx.i &= 0x80000000;
*iptr = xx.f;
return (x);
}
/* split x at the binary point */
s = xx.i & 0x80000000;
yy.i = xx.i & ~((1 << (0x96 - (hx >> 23))) - 1);
*iptr = yy.f;
xx.f -= yy.f;
xx.i = (xx.i & ~0x80000000) | s;
/* restore sign in case difference is 0 */
return (xx.f);
}