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 "atan2.s"
  30 
  31 #include "libm.h"
  32 LIBM_ANSI_PRAGMA_WEAK(atan2,function)
  33 #include "libm_synonyms.h"
  34 #include "libm_protos.h"
  35 
  36         ENTRY(atan2)
  37         movl    4(%esp),%eax            / low part of y
  38         movl    12(%esp),%ecx           / low part of x
  39         orl     %eax,%ecx
  40         jz      .maybe_0s
  41 
  42         / not both x and y are 0's
  43 1:
  44         fldl    4(%esp)                 / push y
  45         fldl    12(%esp)                / push x
  46         fpatan                          / return atan2(y,x)
  47         ret
  48 
  49 .maybe_0s:
  50         movl    8(%esp),%eax            / high part of y
  51         movl    16(%esp),%ecx           / high part of x
  52         orl     %eax,%ecx
  53         andl    $0x7fffffff,%ecx        / clear sign
  54         jnz     1b
  55         / both x and y are 0's
  56         pushl   %ebp
  57         movl    %esp,%ebp
  58         PIC_SETUP(1)
  59         pushl   $3
  60         pushl   12(%ebp)                / high y
  61         pushl   8(%ebp)                 / low y
  62         pushl   20(%ebp)                / high x
  63         pushl   16(%ebp)                / low x
  64         call    PIC_F(_SVID_libm_err)   / report SVID result/error
  65         addl    $20,%esp
  66         PIC_WRAPUP
  67         leave
  68         ret
  69         .align  4
  70         SET_SIZE(atan2)