xref: /reactos/sdk/lib/crt/math/i386/ftol_asm.s (revision cdf90707)
1/*
2 * COPYRIGHT:         See COPYING in the top level directory
3 * PROJECT:           ReactOS kernel
4 * PURPOSE:           Run-Time Library
5 * FILE:              lib/sdk/crt/math/i386/ftol_asm.s
6 * PROGRAMER:         Alex Ionescu (alex@relsoft.net)
7 *
8 * Copyright (C) 2002 Michael Ringgaard.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 *
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the project nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES// LOSS OF USE, DATA, OR PROFITS// OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#include <asm.inc>
38
39PUBLIC __ftol
40
41/* FUNCTIONS ***************************************************************/
42.code
43
44/*
45 * This routine is called by MSVC-generated code to convert from floating point
46 * to integer representation. The floating point number to be converted is
47 * on the top of the floating point stack.
48 */
49__ftol:
50    /* Set up stack frame */
51    push ebp
52    mov ebp, esp
53
54    /* Set "round towards zero" mode */
55    fstcw [ebp-2]
56    wait
57    mov ax, [ebp-2]
58    or ah, 12
59    mov [ebp-4], ax
60    fldcw [ebp-4]
61
62    /* Do the conversion */
63    fistp qword ptr [ebp-12]
64
65    /* Restore rounding mode */
66    fldcw [ebp-2]
67
68    /* Return value */
69    mov eax, [ebp-12]
70    mov edx, [ebp-8]
71
72    /* Remove stack frame and return*/
73    leave
74    ret
75
76END
77