usr/src/lib/libm/i386/src/acosl.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 "acosl.s"
  30
  31 #include "libm.h"
  32 LIBM_ANSI_PRAGMA_WEAK(acosl,function)
  33
  34         ENTRY(acosl)
  35         fldt    4(%esp)                 / push x
  36         fld1                            / push 1
  37         fld     %st(1)                  / x , 1 , x
  38         fabs                            / |x| , 1 , x
  39         fucomp
  40         fstsw   %ax
  41         sahf
  42         ja      9f
  43         fadd    %st(1),%st              / 1+x,x
  44         fldz
  45         fucomp
  46         fstsw   %ax
  47         sahf
  48         jp      .L1
  49         jne     .L1
  50         / x is -1
  51         fstp    %st(0)                  / -1
  52         fstp    %st(0)                  / empty NPX stack
  53         fldpi
  54         ret
  55 .L1:
  56         fxch    %st(1)                  / x,1+x
  57         fld1                            / 1,x,1+x
  58         fsubp   %st,%st(1)              / 1-x,1+x
  59         fdivp   %st,%st(1)              / (1-x)/(1+x)
  60         fsqrt
  61         fld1                            / 1,sqrt((1-x)/(1+x))
  62         fpatan
  63         fadd    %st(0),%st
  64         ret
  65 9:
  66         / |x| > 1
  67         fstp    %st(0)                  / x
  68         fsub    %st,%st(0)              / +/-0 or NaN+invalid
  69         fdiv    %st,%st(0)              / NaN+invalid or NaN
  70         ret
  71         .align  4
  72         SET_SIZE(acosl)