/* * Copyright (c) 1994 The University of Utah and * the Center for Software Science (CSS). All rights reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * THE UNIVERSITY OF UTAH AND CSS ALLOW FREE USE OF THIS SOFTWARE IN ITS "AS * IS" CONDITION. THE UNIVERSITY OF UTAH AND CSS DISCLAIM ANY LIABILITY OF * ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * CSS requests users of this software to return to css-dist@cs.utah.edu any * improvements that they make and grant CSS redistribution rights. * * Author: Bryan Ford, University of Utah CSS */ #ifndef _MACH_I386_PROC_OPS_H_ #define _MACH_I386_PROC_OPS_H_ #include #include /* Returns the bit number of the most-significant set bit in `val', e.g. 0 for 1, 1 for 2-3, 2 for 4-7, etc. If `val' is 0 (i.e. no bits are set), the behavior is undefined. */ MACH_INLINE int find_msb_set(natural_t val) { int msb; asm(" bsr %0,%0 " : "=r" (msb) : "0" (val)); return msb; } #endif _MACH_I386_PROC_OPS_H_