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- /*
- * 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;
- }
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