58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
/*-
|
|
* Copyright (c) 1990 The Regents of the University of California.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* the Systems Programming Group of the University of Utah Computer
|
|
* Science Department.
|
|
*
|
|
* Redistribution and use in source and binary forms are permitted
|
|
* provided that: (1) source distributions retain this entire copyright
|
|
* notice and comment, and (2) distributions including binaries display
|
|
* the following acknowledgement: ``This product includes software
|
|
* developed by the University of California, Berkeley and its contributors''
|
|
* in the documentation or other materials provided with the distribution
|
|
* and in all advertising materials mentioning features or use of this
|
|
* software. Neither the name of the University nor the names of its
|
|
* contributors may be used to endorse or promote products derived
|
|
* from this software without specific prior written permission.
|
|
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
|
|
*/
|
|
|
|
/* bit = ffs(value) */
|
|
|
|
#ifdef __PPC__
|
|
|
|
asm("
|
|
.text
|
|
.globl ffs
|
|
ffs:
|
|
addi 4,3,-1
|
|
xor 3,4,3
|
|
cntlzw 4,3
|
|
li 3,32
|
|
subf 3,4,3
|
|
andi. 3,3,31
|
|
blr
|
|
");
|
|
|
|
#else
|
|
#include "defs.h"
|
|
|
|
ENTRY(ffs)
|
|
asm(" \n\
|
|
moveq #-1,d0 \n\
|
|
movl sp@(4),d1 \n\
|
|
beq done \n\
|
|
again: \n\
|
|
addql #1,d0 \n\
|
|
btst d0,d1 \n\
|
|
beq again \n\
|
|
done: \n\
|
|
addql #1,d0 \n\
|
|
rts \n\
|
|
");
|
|
#endif
|