diff options
author | Yang Zhang <yang.z.zhang@intel.com> | 2015-08-28 09:58:54 +0800 |
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committer | Yang Zhang <yang.z.zhang@intel.com> | 2015-09-01 12:44:00 +0800 |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/roms/ipxe/src/core/isqrt.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/roms/ipxe/src/core/isqrt.c')
-rw-r--r-- | qemu/roms/ipxe/src/core/isqrt.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/core/isqrt.c b/qemu/roms/ipxe/src/core/isqrt.c new file mode 100644 index 000000000..35c918d19 --- /dev/null +++ b/qemu/roms/ipxe/src/core/isqrt.c @@ -0,0 +1,52 @@ +/* + * Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>. + * + * 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 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., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +/** @file + * + * Integer square root + * + */ + +#include <ipxe/isqrt.h> + +/** + * Find integer square root + * + * @v value Value + * @v isqrt Integer square root of value + */ +unsigned long isqrt ( unsigned long value ) { + unsigned long result = 0; + unsigned long bit = ( 1UL << ( ( 8 * sizeof ( bit ) ) - 2 ) ); + + while ( bit > value ) + bit >>= 2; + while ( bit ) { + if ( value >= ( result + bit ) ) { + value -= ( result + bit ); + result = ( ( result >> 1 ) + bit ); + } else { + result >>= 1; + } + bit >>= 2; + } + return result; +} |