| | 1 | /* |
| | 2 | * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. |
| | 3 | * |
| | 4 | * @APPLE_LICENSE_HEADER_START@ |
| | 5 | * |
| | 6 | * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved. |
| | 7 | * |
| | 8 | * This file contains Original Code and/or Modifications of Original Code |
| | 9 | * as defined in and that are subject to the Apple Public Source License |
| | 10 | * Version 2.0 (the 'License'). You may not use this file except in |
| | 11 | * compliance with the License. Please obtain a copy of the License at |
| | 12 | * http://www.opensource.apple.com/apsl/ and read it before using this |
| | 13 | * file. |
| | 14 | * |
| | 15 | * The Original Code and all software distributed under the License are |
| | 16 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
| | 17 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| | 18 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
| | 19 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
| | 20 | * Please see the License for the specific language governing rights and |
| | 21 | * limitations under the License. |
| | 22 | * |
| | 23 | * @APPLE_LICENSE_HEADER_END@ |
| | 24 | */ |
| | 25 | /* Copyright (c) 1992, 1997-1998 Apple Computer, Inc. All rights reserved. |
| | 26 | * |
| | 27 | * File: machdep/ppc/libc/ffs.s |
| | 28 | * |
| | 29 | * int ffs(int value) |
| | 30 | * |
| | 31 | * DESCRIPTION |
| | 32 | * The ffs() function finds the first bit set in value and returns the |
| | 33 | * index of that bit. Bits are numbered starting from 1, starting at |
| | 34 | * the right-most bit. A return value of 0 means that the argument was |
| | 35 | * |
| | 36 | * HISTORY |
| | 37 | * 14-Aug-1998 Umesh Vaishampayan (umeshv@apple.com) |
| | 38 | * Optimized! |
| | 39 | * |
| | 40 | * 10-Mar-1998 Matt Watson (mwatson@apple.com) |
| | 41 | * Correctified |
| | 42 | * |
| | 43 | * 19-Jan-1998 Matt Watson (mwatson@apple.com) |
| | 44 | * Simplified |
| | 45 | * |
| | 46 | * 24-Jan-1997 Umesh Vaishampayan (umeshv@NeXT.com) |
| | 47 | * Ported to PPC. |
| | 48 | */ |
| | 49 | |
| | 50 | .text |
| | 51 | .align 4 |
| | 52 | .globl _ffs |
| | 53 | _ffs: /* Cycles */ |
| | 54 | neg r0,r3 /* 0 */ |
| | 55 | and r3,r0,r3 /* 1 */ |
| | 56 | li r4, 32 /* 1 */ |
| | 57 | cntlzw r3,r3 /* 2 */ |
| | 58 | subf r3,r3,r4 /* 3 */ |
| | 59 | blr |
| | 60 | |
| | 61 | .globl _abs |
| | 62 | _abs: |
| | 63 | srawi r0,r3,31 |
| | 64 | xor r3,r0,r3 |
| | 65 | subf r3,r0,r3 |
| | 66 | blr |
| | 67 | |
projects / apple / xnu.git / blame_incremental