fminf.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 fminf = __fminf
#endif
#include "libm.h" /* for islessequal macro */
float
__fminf(float x, float y) {
/*
* On SPARC v8plus/v9, this could be implemented as follows
* (assuming %f0 = x, %f1 = y, return value left in %f0):
*
* fcmps %fcc0,%f1,%f1
* fmovsu %fcc0,%f0,%f1
* fcmps %fcc0,%f0,%f1
* fmovsug %fcc0,%f1,%f0
* st %f0,[x]
* st %f1,[y]
* ld [x],%l0
* ld [y],%l1
* or %l0,%l1,%l2
* sethi %hi(0x80000000),%l3
* and %l3,%l2,%l2
* or %l0,%l2,%l0
* st %l0,[x]
* ld [x],%f0
*
* If VIS instructions are available, use this code instead:
*
* fcmps %fcc0,%f1,%f1
* fmovsu %fcc0,%f0,%f1
* fcmps %fcc0,%f0,%f1
* fmovsug %fcc0,%f1,%f0
* fors %f0,%f1,%f2
* fzeros %f3
* fnegs %f3,%f3
* fands %f3,%f2,%f2
* fors %f0,%f2,%f0
*
* If VIS 3.0 instructions are available, use this:
*
* flcmps %fcc0,%f0,%f1
* fmovsge %fcc0,%f1,%f0 ! move if %fcc0 is 0 or 2
*/
union {
unsigned i;
float f;
} xx, yy;
unsigned s;
/* if y is nan, replace it by x */
if (y != y)
y = x;
/* if x is nan, replace it by y */
if (x != x)
x = y;
/* At this point, x and y are either both numeric, or both NaN */
if (!isnan(x) && !islessequal(x, y))
x = y;
/*
* set the sign of the result if either x or y has its sign set
*/
xx.f = x;
yy.f = y;
s = (xx.i | yy.i) & 0x80000000;
xx.i |= s;
return (xx.f);
}