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linux/arch/blackfin/lib/lshrdi3.c
Jie Zhang 8399a74f61 Blackfin: fix miscompilation in lshrdi3
The code used in the Blackfin lshrdi3 utilizes gcc constructs.  However,
the structures declared don't line up with the code gcc generates, so
under certain optimizations, we get bad code and things crap out in fun
random ways.  So rather than trying to maintain different gcc definitions
ourselves, just use the ones available in gcclib.h.

URL: http://blackfin.uclinux.org/gf/tracker/5286
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2009-07-16 01:52:23 -04:00

59 lines
1.5 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
*/
#include "gcclib.h"
#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;
}