Separated math and memory functions into their own files to limit the amount of objec...
[reactos.git] / reactos / lib / rtl / i386 / ftol_asm.s
1 /*
2 * COPYRIGHT: See COPYING in the top level directory
3 * PROJECT: ReactOS kernel
4 * PURPOSE: Run-Time Library
5 * FILE: lib/rtl/i386/ftol.S
6 * PROGRAMER: Alex Ionescu (alex@relsoft.net)
7 * Eric Kohl (ekohl@rz-online.de)
8 *
9 * Copyright (C) 2002 Michael Ringgaard.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 *
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the project nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES// LOSS OF USE, DATA, OR PROFITS// OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38 .globl __ftol
39
40 /* DATA ********************************************************************/
41
42 fzero:
43 .long 0 // Floating point zero
44 .long 0 // Floating point zero
45
46 __fltused:
47 .long 0x9875
48
49 .intel_syntax noprefix
50
51 /* FUNCTIONS ***************************************************************/
52
53 /*
54 * This routine is called by MSVC-generated code to convert from floating point
55 * to integer representation. The floating point number to be converted is
56 * on the top of the floating point stack.
57 */
58 __ftol:
59 /* Set up stack frame */
60 push ebp
61 mov ebp, esp
62
63 /* Set "round towards zero" mode */
64 fstcw [ebp-2]
65 wait
66 mov ax, [ebp-2]
67 or ah, 0xC
68 mov [ebp-4], ax
69 fldcw [ebp-4]
70
71 /* Do the conversion */
72 fistp qword ptr [ebp-12]
73
74 /* Restore rounding mode */
75 fldcw [ebp-2]
76
77 /* Return value */
78 mov eax, [ebp-12]
79 mov edx, [ebp-8]
80
81 /* Remove stack frame and return*/
82 leave
83 ret