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 "rndintl.s"
  30 
  31 #include "libm.h"
  32 
  33         ENTRY(aintl)
  34         movl    %esp,%eax
  35         subl    $8,%esp
  36         fstcw   -8(%eax)
  37         fldt    4(%eax)
  38         movw    -8(%eax),%cx
  39         orw     $0x0c00,%cx
  40         movw    %cx,-4(%eax)
  41         fldcw   -4(%eax)                / set RD = to_zero
  42         frndint
  43         fstcw   -4(%eax)
  44         movw    -4(%eax),%dx
  45         andw    $0xf3ff,%dx
  46         movw    -8(%eax),%cx
  47         andw    $0x0c00,%cx
  48         orw     %dx,%cx
  49         movw    %cx,-8(%eax)
  50         fldcw   -8(%eax)                / restore RD
  51         addl    $8,%esp
  52         ret
  53         .align  4
  54         SET_SIZE(aintl)
  55 
  56         ENTRY(irintl)
  57         movl    %esp,%ecx
  58         subl    $8,%esp
  59         fldt    4(%ecx)                 / load x
  60         fistpl  -8(%ecx)                / [x]
  61         fwait
  62         movl    -8(%ecx),%eax
  63         addl    $8,%esp
  64         ret
  65         .align  4
  66         SET_SIZE(irintl)
  67 
  68         .data
  69         .align  4
  70 half:   .float  0.5
  71 
  72         ENTRY(anintl)
  73 .Lanintl:
  74         movl    %esp,%ecx
  75         subl    $8,%esp
  76         fstcw   -8(%ecx)
  77         fldt    4(%ecx)
  78         movw    -8(%ecx),%dx
  79         andw    $0xf3ff,%dx
  80         movw    %dx,-4(%ecx)
  81         fldcw   -4(%ecx)                / set RD = to_nearest
  82         fld     %st(0)
  83         frndint                         / [x],x
  84         fstcw   -4(%ecx)
  85         movw    -4(%ecx),%dx
  86         andw    $0xf3ff,%dx
  87         movw    -8(%ecx),%ax
  88         andw    $0x0c00,%ax
  89         orw     %dx,%ax
  90         movw    %ax,-8(%ecx)
  91         fldcw   -8(%ecx)                / restore RD
  92         fucom                           / check if x is already an integer
  93         fstsw   %ax
  94         sahf
  95         jp      .L0
  96         je      .L0
  97         fxch                            / x,[x]
  98         fsub    %st(1),%st              / x-[x],[x]
  99         fabs                            / |x-[x]|,[x]
 100         PIC_SETUP(1)
 101         fcoms   PIC_L(half)
 102         PIC_WRAPUP
 103         fnstsw  %ax
 104         sahf
 105         jae     .halfway                / if |x-[x]| = 0.5 goto halfway, 
 106                                         / most cases will not take branch.
 107 .L0:
 108         addl    $8,%esp
 109         fstp    %st(0)
 110         ret
 111 .halfway:
 112         / x = n+0.5, recompute anint(x) as x+sign(x)*0.5
 113         fldt    4(%ecx)                 / x, 0.5, [x]
 114         movw    12(%ecx),%ax            / sign+exp part of x
 115         andw    $0x8000,%ax             / look at sign bit
 116         jnz     .x_neg
 117         faddp
 118         addl    $8,%esp
 119         fstp    %st(1)
 120         ret
 121 .x_neg:
 122         / here, x is negative, so return x-0.5
 123         fsubp   %st,%st(1)              / x-0.5,[x]
 124         addl    $8,%esp
 125         fstp    %st(1)
 126         ret
 127         .align  4
 128         SET_SIZE(anintl)
 129 
 130         ENTRY(nintl)
 131         pushl   %ebp
 132         movl    %esp,%ebp
 133         subl    $8,%esp
 134         pushl   16(%ebp)
 135         pushl   12(%ebp)
 136         pushl   8(%ebp)
 137         call    .Lanintl                /// LOCAL
 138         fistpl  -8(%ebp)
 139         fwait
 140         movl    -8(%ebp),%eax
 141         leave
 142         ret
 143         .align  4
 144         SET_SIZE(nintl)