1 /* Copyright (C) 1996 Free Software Foundation, Inc.
2 Contributed by David Mosberger (davidm@cs.arizona.edu).
4 This file is part of the GNU C Library.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If
18 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
19 Cambridge, MA 02139, USA. */
21 /* Finds the first bit set in an integer. Optimized for the Alpha
32 ldq_u zero, 0(sp) # on the 21064, this helps dual-issuing
33 addl a0, zero, a0 # the last insn and reduces the stall
34 negq a0, t0 # due to the srl instruction
39 # now do binary search for first non-zero bit