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- ;===========================================================================
- ;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
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