linux/arch/blackfin/lib/lshrdi3.c

73 lines
1.8 KiB
C

/*
* File: arch/blackfin/lib/lshrdi3.c
* Based on:
* Author:
*
* Created:
* Description:
*
* Modified:
* Copyright 2004-2006 Analog Devices Inc.
*
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#define BITS_PER_UNIT 8
typedef int SItype __attribute__ ((mode(SI)));
typedef unsigned int USItype __attribute__ ((mode(SI)));
typedef int DItype __attribute__ ((mode(DI)));
typedef int word_type __attribute__ ((mode(__word__)));
struct DIstruct {
SItype high, low;
};
typedef union {
struct DIstruct s;
DItype ll;
} DIunion;
#ifdef CONFIG_ARITHMETIC_OPS_L1
DItype __lshrdi3(DItype u, word_type b)__attribute__((l1_text));
#endif
DItype __lshrdi3(DItype u, word_type b)
{
DIunion w;
word_type bm;
DIunion uu;
if (b == 0)
return u;
uu.ll = u;
bm = (sizeof(SItype) * BITS_PER_UNIT) - b;
if (bm <= 0) {
w.s.high = 0;
w.s.low = (USItype) uu.s.high >> -bm;
} else {
USItype carries = (USItype) uu.s.high << bm;
w.s.high = (USItype) uu.s.high >> b;
w.s.low = ((USItype) uu.s.low >> b) | carries;
}
return w.ll;
}