frexpf.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 frexpf = __frexpf
#endif
#include "libm.h"
float
__frexpf(float x, int *exp) {
union {
unsigned i;
float f;
} xx;
unsigned hx;
int e;
xx.f = x;
hx = xx.i & ~0x80000000;
if (hx >= 0x7f800000) { /* x is infinite or NaN */
*exp = 0;
return (x);
}
e = 0;
if (hx < 0x00800000) { /* x is subnormal or zero */
if (hx == 0) {
*exp = 0;
return (x);
}
/* normalize x by regarding it as an integer */
xx.f = (int) xx.i < 0 ? -(int) hx : (int) hx;
hx = xx.i & ~0x80000000;
e = -149;
}
/* now xx.f is normal */
xx.i = (xx.i & ~0x7f800000) | 0x3f000000;
*exp = e + (hx >> 23) - 0x7e;
return (xx.f);
}