1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
|
;===========================================================================
;Copyright (C) 1999-2005 Id Software, Inc.
;
;This file is part of Quake III Arena source code.
;
;Quake III Arena source code is free software; you can redistribute it
;and/or modify it under the terms of the GNU General Public License as
;published by the Free Software Foundation; either version 2 of the License,
;or (at your option) any later version.
;
;Quake III Arena source code is distributed in the hope that it will be
;useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
;MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;GNU General Public License for more details.
;
;You should have received a copy of the GNU General Public License
;along with Foobar; if not, write to the Free Software
;Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
;===========================================================================
;
; Sys_SnapVector NASM code (Andrew Henderson)
; See win32/win_shared.c for the Win32 equivalent
; This code is provided to ensure that the
; rounding behavior (and, if necessary, the
; precision) of DLL and QVM code are identical
; e.g. for network-visible operations.
; See ftol.nasm for operations on a single float,
; as used in compiled VM and DLL code that does
; not use this system trap.
;
segment .data
fpucw dd 0
cw037F dd 0x037F ; Rounding to nearest (even).
segment .text
; void Sys_SnapVector( float *v )
global Sys_SnapVector
Sys_SnapVector:
push eax
push ebp
mov ebp, esp
fnstcw [fpucw]
mov eax, dword [ebp + 12]
fldcw [cw037F]
fld dword [eax]
fistp dword [eax]
fild dword [eax]
fstp dword [eax]
fld dword [eax + 4]
fistp dword [eax + 4]
fild dword [eax + 4]
fstp dword [eax + 4]
fld dword [eax + 8]
fistp dword [eax + 8]
fild dword [eax + 8]
fstp dword [eax + 8]
fldcw [fpucw]
pop ebp
pop eax
ret
; void Sys_SnapVectorCW( float *v, unsigned short int cw )
global Sys_SnapVectorCW
Sys_SnapVector_cw:
push eax
push ebp
mov ebp, esp
fnstcw [fpucw]
mov eax, dword [ebp + 12]
fldcw [ebp + 16]
fld dword [eax]
fistp dword [eax]
fild dword [eax]
fstp dword [eax]
fld dword [eax + 4]
fistp dword [eax + 4]
fild dword [eax + 4]
fstp dword [eax + 4]
fld dword [eax + 8]
fistp dword [eax + 8]
fild dword [eax + 8]
fstp dword [eax + 8]
fldcw [fpucw]
pop ebp
pop eax
ret
|
