| ffs.S (97748) | ffs.S (184548) |
|---|---|
| 1/* 2 * Copyright (c) 1993 Winning Strategies, Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 15 unchanged lines hidden (view full) --- 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <machine/asm.h> | 1/* 2 * Copyright (c) 1993 Winning Strategies, Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright --- 15 unchanged lines hidden (view full) --- 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <machine/asm.h> |
| 32__FBSDID("$FreeBSD: head/lib/libc/i386/string/ffs.S 97748 2002-06-02 20:05:59Z schweikh $"); | 32__FBSDID("$FreeBSD: head/lib/libc/i386/string/ffs.S 184548 2008-11-02 01:28:47Z peter $"); |
| 33 34/* 35 * ffs(value) 36 * finds the first bit set in value and returns the index of 37 * that bit. Bits are numbered starting from 1, starting at the 38 * rightmost bit. A return value of 0 means that the argument 39 * was zero. 40 * --- 5 unchanged lines hidden (view full) --- 46 bsfl 4(%esp),%eax 47 jz L1 /* ZF is set if all bits are 0 */ 48 incl %eax /* bits numbered from 1, not 0 */ 49 ret 50 51 .align 2 52L1: xorl %eax,%eax /* clear result */ 53 ret | 33 34/* 35 * ffs(value) 36 * finds the first bit set in value and returns the index of 37 * that bit. Bits are numbered starting from 1, starting at the 38 * rightmost bit. A return value of 0 means that the argument 39 * was zero. 40 * --- 5 unchanged lines hidden (view full) --- 46 bsfl 4(%esp),%eax 47 jz L1 /* ZF is set if all bits are 0 */ 48 incl %eax /* bits numbered from 1, not 0 */ 49 ret 50 51 .align 2 52L1: xorl %eax,%eax /* clear result */ 53 ret |
| 54END(ffs) |
|