From 583f00e0b8efe2832f63efb478a51d3ad35e92ed Mon Sep 17 00:00:00 2001 From: Nicolas Schodet Date: Sun, 7 Oct 2007 22:16:03 +0200 Subject: Included SI2E avr modules. Well, this need more works... --- digital/avr/modules/math/fixed/fixed_sqrt_ui32.c | 48 ++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 digital/avr/modules/math/fixed/fixed_sqrt_ui32.c (limited to 'digital/avr/modules/math/fixed/fixed_sqrt_ui32.c') diff --git a/digital/avr/modules/math/fixed/fixed_sqrt_ui32.c b/digital/avr/modules/math/fixed/fixed_sqrt_ui32.c new file mode 100644 index 00000000..88de5841 --- /dev/null +++ b/digital/avr/modules/math/fixed/fixed_sqrt_ui32.c @@ -0,0 +1,48 @@ +/* fixed_sqrt_ui32.c */ +/* avr.math.fixed - Fixed point math module. {{{ + * + * Copyright (C) 2005 Nicolas Schodet + * + * Robot APB Team/Efrei 2006. + * Web: http://assos.efrei.fr/robot/ + * Email: robot AT efrei DOT fr + * + * 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. + * + * }}} */ +#include "common.h" +#include "fixed.h" + +/** Compute square root, ui32 -> ui16. */ +uint16_t +fixed_sqrt_ui32 (uint32_t x) +{ + uint32_t root, bit, test; + root = 0; + bit = 1L << 30; + do + { + test = root + bit; + if (x >= test) + { + x -= test; + root = test + bit; + } + root >>= 1; + bit >>= 2; + } while (bit); + return root; +} + -- cgit v1.2.3