usr/src/lib/libm/i386/src/acos.s

   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 "acos.s"
  30
  31 #include "libm.h"
  32 LIBM_ANSI_PRAGMA_WEAK(acos,function)
  33 #include "libm_protos.h"
  34
  35         ENTRY(acos)
  36         fldl    4(%esp)                 / push x
  37         fld1                            / push 1
  38         fld     %st(1)                  / x , 1 , x
  39         fabs                            / |x| , 1 , x
  40         fucomp
  41         fstsw   %ax
  42         sahf
  43         ja      .ERR
  44         fadd    %st(1),%st              / 1+x,x
  45         fldz
  46         fucomp
  47         fstsw   %ax
  48         sahf
  49         jp      .L1
  50         jne     .L1
  51         / x is -1
  52         fstp    %st(0)                  / -1
  53         fstp    %st(0)                  / empty NPX stack
  54         fldpi
  55         ret
  56 .L1:
  57         fxch    %st(1)                  / x,1+x
  58         fld1                            / 1,x,1+x
  59         fsubp   %st,%st(1)              / 1-x,1+x
  60         fdivp   %st,%st(1)              / (1-x)/(1+x)
  61         fsqrt
  62         fld1                            / 1,sqrt((1-x)/(1+x))
  63         fpatan
  64         fadd    %st(0),%st
  65         ret
  66
  67 .ERR:
  68         / |x| > 1
  69         pushl   %ebp
  70         movl    %esp,%ebp
  71         PIC_SETUP(1)
  72         fstp    %st(0)                  / x
  73         fstp    %st(0)                  / empty NPX stack
  74         pushl   $1
  75         pushl   12(%ebp)                / high x
  76         pushl   8(%ebp)                 / low x
  77         pushl   12(%ebp)                / high x
  78         pushl   8(%ebp)                 / low x
  79         call    PIC_F(_SVID_libm_err)   / report SVID result/error
  80         addl    $20,%esp
  81         PIC_WRAPUP
  82         leave
  83         ret
  84         .align  4
  85         SET_SIZE(acos)