gcc/libgcc/config/nios2/lib2-mul.c

/* Copyright (C) 2012-2020 Free Software Foundation, Inc.
   Contributed by Altera and Mentor Graphics, 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 "lib2-nios2.h"

/* 32-bit SI multiply for Nios II.  */

SItype
__mulsi3 (SItype a, SItype b)
{
  SItype res = 0;
  USItype cnt = a;
  
  while (cnt)
    {
      if (cnt & 1)
	res += b;	  
      b <<= 1;
      cnt >>= 1;
    }
    
  return res;
}