1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  23  */
  24 /*
  25  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  26  * Use is subject to license terms.
  27  */
  28 
  29         .file "acosl.s"
  30 
  31 #include "libm.h"
  32 LIBM_ANSI_PRAGMA_WEAK(acosl,function)
  33 #include "libm_synonyms.h"
  34 
  35 #undef fabs
  36 
  37         ENTRY(acosl)
  38         fldt    4(%esp)                 / push x
  39         fld1                            / push 1
  40         fld     %st(1)                  / x , 1 , x
  41         fabs                            / |x| , 1 , x
  42         fucomp
  43         fstsw   %ax
  44         sahf
  45         ja      9f
  46         fadd    %st(1),%st              / 1+x,x
  47         fldz
  48         fucomp  
  49         fstsw   %ax
  50         sahf
  51         jp      .L1
  52         jne     .L1
  53         / x is -1 
  54         fstp    %st(0)                  / -1
  55         fstp    %st(0)                  / empty NPX stack
  56         fldpi
  57         ret
  58 .L1:
  59         fxch    %st(1)                  / x,1+x
  60         fld1                            / 1,x,1+x
  61         fsubp   %st,%st(1)              / 1-x,1+x
  62         fdivp   %st,%st(1)              / (1-x)/(1+x)
  63         fsqrt
  64         fld1                            / 1,sqrt((1-x)/(1+x))
  65         fpatan
  66         fadd    %st(0),%st
  67         ret
  68 9:
  69         / |x| > 1
  70         fstp    %st(0)                  / x
  71         fsub    %st,%st(0)              / +/-0 or NaN+invalid
  72         fdiv    %st,%st(0)              / NaN+invalid or NaN
  73         ret
  74         .align  4
  75         SET_SIZE(acosl)