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 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 __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 } 59