Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 1 | /* ashldi3.c extracted from gcc-2.95.2/libgcc2.c which is: */ |
| 2 | /* Copyright (C) 1989, 92-98, 1999 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 | You should have received a copy of the GNU General Public License |
| 17 | along with GNU CC; see the file COPYING. If not, write to |
| 18 | the Free Software Foundation, 59 Temple Place - Suite 330, |
| 19 | Boston, MA 02111-1307, USA. */ |
| 20 | |
| 21 | #define BITS_PER_UNIT 8 |
| 22 | |
| 23 | typedef int SItype __attribute__ ((mode (SI))); |
| 24 | typedef unsigned int USItype __attribute__ ((mode (SI))); |
| 25 | typedef int DItype __attribute__ ((mode (DI))); |
| 26 | typedef int word_type __attribute__ ((mode (__word__))); |
| 27 | |
| 28 | struct DIstruct {SItype high, low;}; |
| 29 | |
| 30 | typedef union |
| 31 | { |
| 32 | struct DIstruct s; |
| 33 | DItype ll; |
| 34 | } DIunion; |
| 35 | |
| 36 | DItype |
| 37 | __ashldi3 (DItype u, word_type b) |
| 38 | { |
| 39 | DIunion w; |
| 40 | word_type bm; |
| 41 | DIunion uu; |
| 42 | |
| 43 | if (b == 0) |
| 44 | return u; |
| 45 | |
| 46 | uu.ll = u; |
| 47 | |
| 48 | bm = (sizeof (SItype) * BITS_PER_UNIT) - b; |
| 49 | if (bm <= 0) |
| 50 | { |
| 51 | w.s.low = 0; |
| 52 | w.s.high = (USItype)uu.s.low << -bm; |
| 53 | } |
| 54 | else |
| 55 | { |
| 56 | USItype carries = (USItype)uu.s.low >> bm; |
| 57 | w.s.low = (USItype)uu.s.low << b; |
| 58 | w.s.high = ((USItype)uu.s.high << b) | carries; |
| 59 | } |
| 60 | |
| 61 | return w.ll; |
| 62 | } |