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 #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 __lshrdi3 (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 = 0; 47 w.s.low = (USItype)uu.s.high >> -bm; 48 } 49 else 50 { 51 USItype carries = (USItype)uu.s.high << bm; 52 w.s.high = (USItype)uu.s.high >> b; 53 w.s.low = ((USItype)uu.s.low >> b) | carries; 54 } 55 56 return w.ll; 57 } 58