| xj | b04a402 | 2021-11-25 15:01:52 +0800 | [diff] [blame] | 1 | /* lshrdi3.c extracted from gcc-2.7.2/libgcc2.c which is: */ |
| 2 | /* Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GNU CC. |
| 5 | |
| 6 | GNU CC is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2, or (at your option) |
| 9 | any later version. |
| 10 | |
| 11 | GNU CC is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. */ |
| 15 | |
| 16 | #include <linux/compiler.h> |
| 17 | #include <linux/export.h> |
| 18 | |
| 19 | #define BITS_PER_UNIT 8 |
| 20 | |
| 21 | typedef int SItype __mode(SI); |
| 22 | typedef unsigned int USItype __mode(SI); |
| 23 | typedef int DItype __mode(DI); |
| 24 | typedef int word_type __mode(__word__); |
| 25 | |
| 26 | struct DIstruct {SItype high, low;}; |
| 27 | |
| 28 | typedef union |
| 29 | { |
| 30 | struct DIstruct s; |
| 31 | DItype ll; |
| 32 | } DIunion; |
| 33 | |
| 34 | DItype |
| 35 | __lshrdi3 (DItype u, word_type b) |
| 36 | { |
| 37 | DIunion w; |
| 38 | word_type bm; |
| 39 | DIunion uu; |
| 40 | |
| 41 | if (b == 0) |
| 42 | return u; |
| 43 | |
| 44 | uu.ll = u; |
| 45 | |
| 46 | bm = (sizeof (SItype) * BITS_PER_UNIT) - b; |
| 47 | if (bm <= 0) |
| 48 | { |
| 49 | w.s.high = 0; |
| 50 | w.s.low = (USItype)uu.s.high >> -bm; |
| 51 | } |
| 52 | else |
| 53 | { |
| 54 | USItype carries = (USItype)uu.s.high << bm; |
| 55 | w.s.high = (USItype)uu.s.high >> b; |
| 56 | w.s.low = ((USItype)uu.s.low >> b) | carries; |
| 57 | } |
| 58 | |
| 59 | return w.ll; |
| 60 | } |
| 61 | EXPORT_SYMBOL(__lshrdi3); |