1998-07-30 20:38:08 +08:00
|
|
|
/* Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
|
1996-03-20 03:53:56 +08:00
|
|
|
Contributed by David Mosberger (davidm@cs.arizona.edu).
|
1997-06-27 06:16:52 +08:00
|
|
|
This file is part of the GNU C Library.
|
1996-03-20 03:53:56 +08:00
|
|
|
|
1997-06-27 06:16:52 +08:00
|
|
|
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.
|
1996-03-20 03:53:56 +08:00
|
|
|
|
1997-06-27 06:16:52 +08:00
|
|
|
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.
|
1996-03-20 03:53:56 +08:00
|
|
|
|
1997-06-27 06:16:52 +08:00
|
|
|
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. */
|
1996-03-20 03:53:56 +08:00
|
|
|
|
|
|
|
|
/* Finds the first bit set in an integer. Optimized for the Alpha
|
1997-06-27 06:16:52 +08:00
|
|
|
architecture. */
|
1996-03-20 03:53:56 +08:00
|
|
|
|
|
|
|
|
#include <sysdep.h>
|
|
|
|
|
|
1997-06-27 06:16:52 +08:00
|
|
|
.set noreorder
|
|
|
|
|
.set noat
|
1996-03-20 03:53:56 +08:00
|
|
|
|
1998-07-30 20:38:08 +08:00
|
|
|
|
1998-03-09 17:09:46 +08:00
|
|
|
ENTRY(__ffs)
|
1996-11-06 12:24:11 +08:00
|
|
|
#ifdef PROF
|
|
|
|
|
ldgp gp, 0(pv)
|
|
|
|
|
lda AT, _mcount
|
|
|
|
|
jsr AT, (AT), _mcount
|
|
|
|
|
.prologue 1
|
1998-07-30 20:38:08 +08:00
|
|
|
zap $16, 0xF0, $16
|
|
|
|
|
br $ffsl..ng
|
1996-11-06 12:24:11 +08:00
|
|
|
#else
|
1996-03-20 03:53:56 +08:00
|
|
|
.prologue 0
|
1998-07-30 20:38:08 +08:00
|
|
|
zap $16, 0xF0, $16
|
|
|
|
|
# FALLTHRU
|
1996-11-06 12:24:11 +08:00
|
|
|
#endif
|
1998-07-30 20:38:08 +08:00
|
|
|
END(__ffs)
|
1996-03-20 03:53:56 +08:00
|
|
|
|
1998-07-30 20:38:08 +08:00
|
|
|
.align 4
|
|
|
|
|
ENTRY(ffsl)
|
|
|
|
|
#ifdef PROF
|
|
|
|
|
ldgp gp, 0(pv)
|
|
|
|
|
lda AT, _mcount
|
|
|
|
|
jsr AT, (AT), _mcount
|
|
|
|
|
.prologue 1
|
|
|
|
|
$ffsl..ng:
|
|
|
|
|
#else
|
|
|
|
|
.prologue 0
|
|
|
|
|
#endif
|
|
|
|
|
not $16, $1 # e0 :
|
|
|
|
|
ldi $2, -1 # .. e1 :
|
|
|
|
|
cmpbge $1, $2, $3 # e0 : bit N == 1 for byte N == 0
|
|
|
|
|
clr $0 # .. e1 :
|
|
|
|
|
addq $3, 1, $4 # e0 :
|
|
|
|
|
bic $4, $3, $3 # e1 : bit N == 1 for first byte N != 0
|
|
|
|
|
and $3, 0xF0, $4 # e0 :
|
|
|
|
|
and $3, 0xCC, $5 # .. e1 :
|
|
|
|
|
and $3, 0xAA, $6 # e0 :
|
|
|
|
|
cmovne $4, 4, $0 # .. e1 :
|
|
|
|
|
cmovne $5, 2, $5 # e0 :
|
|
|
|
|
cmovne $6, 1, $6 # .. e1 :
|
|
|
|
|
addl $0, $5, $0 # e0 :
|
|
|
|
|
addl $0, $6, $0 # e1 : $0 == N
|
|
|
|
|
extbl $16, $0, $1 # e0 : $1 == byte N
|
|
|
|
|
ldi $2, 1 # .. e1 :
|
|
|
|
|
negq $1, $3 # e0 :
|
|
|
|
|
and $3, $1, $3 # e1 : bit N == least bit set of byte N
|
|
|
|
|
and $3, 0xF0, $4 # e0 :
|
|
|
|
|
and $3, 0xCC, $5 # .. e1 :
|
|
|
|
|
and $3, 0xAA, $6 # e0 :
|
|
|
|
|
cmovne $4, 5, $2 # .. e1 :
|
|
|
|
|
cmovne $5, 2, $5 # e0 :
|
|
|
|
|
cmovne $6, 1, $6 # .. e1 :
|
|
|
|
|
s8addl $0, $2, $0 # e0 : mult byte ofs by 8 and sum
|
|
|
|
|
addl $5, $6, $5 # .. e1 :
|
|
|
|
|
addl $0, $5, $0 # e0 :
|
|
|
|
|
nop # .. e1 :
|
|
|
|
|
cmoveq $16, 0, $0 # e0 : trap input == 0 case.
|
|
|
|
|
ret # .. e1 : 18
|
|
|
|
|
|
|
|
|
|
END(ffsl)
|
1996-03-20 03:53:56 +08:00
|
|
|
|
1998-03-09 17:09:46 +08:00
|
|
|
weak_alias (__ffs, ffs)
|
1998-07-30 20:38:08 +08:00
|
|
|
weak_extern (ffsl)
|
|
|
|
|
weak_alias (ffsl, ffsll)
|
