/* ffs -- find first set bit in a word, counted from least significant end. This file is part of the GNU C Library. Copyright (C) 2000, 2001 Free Software Foundation, Inc. Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. The GNU C Library 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #define ffsl __something_else #include #undef ffs /* * ffs: find first bit set. This is defined the same way as * the libc and compiler builtin ffs routines, therefore * differs in spirit from the above ffz (man ffs). */ int __ffs (x) int x; { int r; if (x == 0) return 0; __asm__(" lr %%r1,%1\n" " sr %0,%0\n" " tml %%r1,0xFFFF\n" " jnz 0f\n" " ahi %0,16\n" " srl %%r1,16\n" "0: tml %%r1,0x00FF\n" " jnz 1f\n" " ahi %0,8\n" " srl %%r1,8\n" "1: tml %%r1,0x000F\n" " jnz 2f\n" " ahi %0,4\n" " srl %%r1,4\n" "2: tml %%r1,0x0003\n" " jnz 3f\n" " ahi %0,2\n" " srl %%r1,2\n" "3: tml %%r1,0x0001\n" " jnz 4f\n" " ahi %0,1\n" "4:" : "=&d" (r) : "d" (x) : "cc", "1" ); return r+1; } weak_alias (__ffs, ffs) #undef ffsl weak_alias (__ffs, ffsl)