5261 libm should stop using synonyms.h
5298 fabs is 0-sized, confuses dis(1) and others
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Approved by: Gordon Ross <gwr@nexenta.com>

          --- old/usr/src/lib/libm/i386/src/round.s
          +++ new/usr/src/lib/libm/i386/src/round.s

   1    1  /*
   2    2   * CDDL HEADER START
   3    3   *
   4    4   * The contents of this file are subject to the terms of the
   5    5   * Common Development and Distribution License (the "License").
   6    6   * You may not use this file except in compliance with the License.
   7    7   *
   8    8   * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9    9   * or http://www.opensolaris.org/os/licensing.
  10   10   * See the License for the specific language governing permissions
  11   11   * and limitations under the License.
  12   12   *
  13   13   * When distributing Covered Code, include this CDDL HEADER in each
  14   14   * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15   15   * If applicable, add the following below this CDDL HEADER, with the
  16   16   * fields enclosed by brackets "[]" replaced with your own identifying
  17   17   * information: Portions Copyright [yyyy] [name of copyright owner]
  18   18   *
  19   19   * CDDL HEADER END
  20   20   */
  21   21  /*
  22   22   * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.

  23   23   */
  24   24  /*
  25   25   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  26   26   * Use is subject to license terms.
  27   27   */
  28   28  
  29   29          .file   "round.s"
  30   30  
  31   31  #include "libm.h"
  32   32  LIBM_ANSI_PRAGMA_WEAK(round,function)
  33      -#include "libm_synonyms.h"
  34      -#undef fabs
  35   33  
  36   34          .section .rodata
  37   35          .align  4
  38   36  .Lhalf: .float  0.5
  39   37  
  40   38          ENTRY(round)
  41   39          movl    %esp,%ecx
  42   40          subl    $8,%esp
  43   41          fstcw   -8(%ecx)
  44   42          fldl    4(%ecx)

  45   43          movw    -8(%ecx),%dx
  46   44          andw    $0xf3ff,%dx
  47   45          movw    %dx,-4(%ecx)
  48   46          fldcw   -4(%ecx)                / set RD = to_nearest
  49   47          fld     %st(0)
  50   48          frndint                         / [x],x
  51   49          fstcw   -4(%ecx)
  52   50          movw    -4(%ecx),%dx
  53   51          andw    $0xf3ff,%dx
  54   52          movw    -8(%ecx),%ax
  55   53          andw    $0x0c00,%ax
  56   54          orw     %dx,%ax
  57   55          movw    %ax,-8(%ecx)
  58   56          fldcw   -8(%ecx)                / restore RD
  59   57          fucom                           / check if x is already an integer
  60   58          fstsw   %ax
  61   59          sahf
  62   60          jp      0f
  63   61          je      0f
  64   62          fxch                            / x,[x]
  65   63          fsub    %st(1),%st              / x-[x],[x]
  66   64          fabs                            / |x-[x]|,[x]
  67   65          PIC_SETUP(1)
  68   66          fcoms   PIC_L(.Lhalf)
  69   67          PIC_WRAPUP
  70   68          fnstsw  %ax
  71   69          sahf
  72   70          jae     2f                      / if |x-[x]| = 0.5 goto halfway, 
  73   71                                          / most cases will not take branch.
  74   72  0:
  75   73          addl    $8,%esp
  76   74          fstp    %st(0)
  77   75          ret
  78   76  2:
  79   77      / x = n+0.5, recompute round(x) as x+sign(x)*0.5
  80   78          fldl    4(%ecx)                 / x, 0.5, [x]
  81   79          movl    8(%ecx),%eax            / high part of x
  82   80          andl    $0x80000000,%eax
  83   81          jnz     3f
  84   82          faddp
  85   83          addl    $8,%esp
  86   84          fstp    %st(1)
  87   85          ret
  88   86  3:
  89   87          / here, x is negative, so return x-0.5
  90   88          fsubp   %st,%st(1)              / x-0.5,[x]
  91   89          addl    $8,%esp
  92   90          fstp    %st(1)
  93   91          ret
  94   92          .align  4
  95   93          SET_SIZE(round)

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