ref: d0a49f42e8b88797f63b02c45b00c461f62a70a6
dir: /rott/rt_sqrt.h/
/*
Copyright (C) 1994-1995 Apogee Software, Ltd.
This program 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.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef _rt_sqrt_public
#define _rt_sqrt_public
/*
FUNCTION:
Fixed32 FixedSqrtHP(Fixed32 n);
DESCRIPTION:
This does a high-precision square root of a Fixed32. It has
8.16 bit accuracy. For more speed use FixedSqrtLP().
FUNCTION:
Fixed32 FixedSqrtLP(Fixed32 n);
DESCRIPTION:
This does a low-precision square root of a Fixed32. It has
8.8 bit accuracy. For more accuracy use FixedSqrtHP().
*/
long FixedSqrtLP(long n); // Low Precision (8.8)
long FixedSqrtHP(long n); // High Precision (8.16)
#ifdef __WATCOMC__
#pragma aux FixedSqrtLP = \
" xor eax, eax" \
" mov ebx, 40000000h" \
"sqrtLP1: mov edx, ecx" \
" sub edx, ebx" \
" jl sqrtLP2" \
" sub edx, eax" \
" jl sqrtLP2" \
" mov ecx,edx" \
" shr eax, 1" \
" or eax, ebx" \
" shr ebx, 2" \
" jnz sqrtLP1" \
" shl eax, 8" \
" jmp sqrtLP3" \
"sqrtLP2: shr eax, 1" \
" shr ebx, 2" \
" jnz sqrtLP1" \
" shl eax, 8" \
"sqrtLP3: nop" \
parm caller [ecx] \
value [eax] \
modify [eax ebx ecx edx];
#pragma aux FixedSqrtHP = \
" xor eax, eax" \
" mov ebx, 40000000h" \
"sqrtHP1: mov edx, ecx" \
" sub edx, ebx" \
" jb sqrtHP2" \
" sub edx, eax" \
" jb sqrtHP2" \
" mov ecx,edx" \
" shr eax, 1" \
" or eax, ebx" \
" shr ebx, 2" \
" jnz sqrtHP1" \
" jz sqrtHP5" \
"sqrtHP2: shr eax, 1" \
" shr ebx, 2" \
" jnz sqrtHP1" \
"sqrtHP5: mov ebx, 00004000h" \
" shl eax, 16" \
" shl ecx, 16" \
"sqrtHP3: mov edx, ecx" \
" sub edx, ebx" \
" jb sqrtHP4" \
" sub edx, eax" \
" jb sqrtHP4" \
" mov ecx, edx" \
" shr eax, 1" \
" or eax, ebx" \
" shr ebx, 2" \
" jnz sqrtHP3" \
" jmp sqrtHP6" \
"sqrtHP4: shr eax, 1" \
" shr ebx, 2" \
" jnz sqrtHP3" \
"sqrtHP6: nop" \
parm caller [ecx] \
value [eax] \
modify [eax ebx ecx edx];
#endif
#endif