projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* ashrdi3.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 | |
| d6410efa | 14 | GNU General Public License for more details. */ |
| 1da177e4 LT |
15 | |
| 16 | #define BITS_PER_UNIT 8 | |
| 17 | ||
| 18 | typedef int SItype __attribute__ ((mode (SI))); | |
| 19 | typedef unsigned int USItype __attribute__ ((mode (SI))); | |
| 20 | typedef int DItype __attribute__ ((mode (DI))); | |
| 21 | typedef int word_type __attribute__ ((mode (__word__))); | |
| 22 | ||
| 23 | struct DIstruct {SItype high, low;}; | |
| 24 | ||
| 25 | typedef union | |
| 26 | { | |
| 27 | struct DIstruct s; | |
| 28 | DItype ll; | |
| 29 | } DIunion; | |
| 30 | ||
| 31 | DItype | |
| 32 | __ashrdi3 (DItype u, word_type b) | |
| 33 | { | |
| 34 | DIunion w; | |
| 35 | word_type bm; | |
| 36 | DIunion uu; | |
| 37 | ||
| 38 | if (b == 0) | |
| 39 | return u; | |
| 40 | ||
| 41 | uu.ll = u; | |
| 42 | ||
| 43 | bm = (sizeof (SItype) * BITS_PER_UNIT) - b; | |
| 44 | if (bm <= 0) | |
| 45 | { | |
| 46 | /* w.s.high = 1..1 or 0..0 */ | |
| 47 | w.s.high = uu.s.high >> (sizeof (SItype) * BITS_PER_UNIT - 1); | |
| 48 | w.s.low = uu.s.high >> -bm; | |
| 49 | } | |
| 50 | else | |
| 51 | { | |
| 52 | USItype carries = (USItype)uu.s.high << bm; | |
| 53 | w.s.high = uu.s.high >> b; | |
| 54 | w.s.low = ((USItype)uu.s.low >> b) | carries; | |
| 55 | } | |
| 56 | ||
| 57 | return w.ll; | |
| 58 | } |