| Chris Metcalf | 1efea40 | 2012-03-29 13:30:31 -0400 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2011 Tilera Corporation. All Rights Reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation, version 2. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or |
| 11 | * NON INFRINGEMENT. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * Provide a mask based on the pointer alignment that |
| 15 | * sets up non-zero bytes before the beginning of the string. |
| 16 | * The MASK expression works because shift counts are taken mod 64. |
| 17 | * Also, specify how to count "first" and "last" bits |
| 18 | * when the bits have been read as a word. |
| 19 | */ |
| 20 | |
| 21 | #include <asm/byteorder.h> |
| 22 | |
| 23 | #ifdef __LITTLE_ENDIAN |
| 24 | #define MASK(x) (__insn_shl(1ULL, (x << 3)) - 1) |
| 25 | #define NULMASK(x) ((2ULL << x) - 1) |
| 26 | #define CFZ(x) __insn_ctz(x) |
| 27 | #define REVCZ(x) __insn_clz(x) |
| 28 | #else |
| 29 | #define MASK(x) (__insn_shl(-2LL, ((-x << 3) - 1))) |
| 30 | #define NULMASK(x) (-2LL << (63 - x)) |
| 31 | #define CFZ(x) __insn_clz(x) |
| 32 | #define REVCZ(x) __insn_ctz(x) |
| 33 | #endif |