gcc/libgcc/config/lm32/_mulsi3.c

49 lines
1.3 KiB
C

/* _mulsi3 for Lattice Mico32.
Contributed by Jon Beniston <jon@beniston.com>
Copyright (C) 2009 Free Software Foundation, Inc.
This file 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 3, or (at your option) any
later version.
This file 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.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "libgcc_lm32.h"
/* Integer multiplication. */
USItype
__mulsi3 (USItype a, USItype b)
{
USItype result;
result = 0;
if (a == 0)
return 0;
while (b != 0)
{
if (b & 1)
result += a;
a <<= 1;
b >>= 1;
}
return result;
}