ref: 761946b93cf45a3b9e47868a704fb165af760333
dir: /code/unix/snapvector.nasm/
;=========================================================================== ;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