/*
* 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 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
.file "acosf.s"
#include "libm.h"
LIBM_ANSI_PRAGMA_WEAK(acosf,function)
#include "libm_protos.h"
ENTRY(acosf)
flds 4(%esp) / push x
fld1 / push 1
fld %st(1) / x , 1 , x
fabs / |x| , 1 , x
fucomp
fstsw %ax
sahf
ja .ERR
fadd %st(1),%st / 1+x,x
fldz
fucomp
fstsw %ax
sahf
jp .L1
jne .L1
/ x is -1
fstp %st(0) / x
fstp %st(0) / empty NPX stack
fldpi
ret
.L1:
fxch %st(1) / x,1+x
fld1 / 1,x,1+x
fsubp %st,%st(1) / 1-x,1+x
fdivp %st,%st(1) / (1-x)/(1+x)
fsqrt
fld1 / 1,sqrt((1-x)/(1+x))
fpatan
fadd %st(0),%st
ret
.ERR:
/ |x| > 1
fstp %st(0) / x
fstp %st(0) / empty NPX stack
fldz
fdiv %st(0),%st / 0/0
ret
.align 4
SET_SIZE(acosf)