libgcc/config/rl78/rl78-mul.h

   1 /* libgcc routines for RL78
   2    Copyright (C) 2005-2018 Free Software Foundation, Inc.
   3    Contributed by Red Hat.
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published
   9    by the Free Software Foundation; either version 3, or (at your
  10    option) any later version.
  11
  12    GCC is distributed in the hope that it will be useful, but WITHOUT
  13    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  15    License for more details.
  16
  17    Under Section 7 of GPL version 3, you are granted additional
  18    permissions described in the GCC Runtime Library Exception, version
  19    3.1, as published by the Free Software Foundation.
  20
  21    You should have received a copy of the GNU General Public License and
  22    a copy of the GCC Runtime Library Exception along with this program;
  23    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24    <http://www.gnu.org/licenses/>.  */
  25
  26 UINT_TYPE C3(__mul,NAME_MODE,3)   (UINT_TYPE, UINT_TYPE);
  27 UINT_TYPE
  28 C3(__mul,NAME_MODE,3) (UINT_TYPE a, UINT_TYPE b)
  29 {
  30   UINT_TYPE rv = 0;
  31
  32   char bit;
  33
  34   for (bit=0; b && bit<sizeof(UINT_TYPE)*8; bit++)
  35     {
  36       if (b & 1)
  37         rv += a;
  38       a <<= 1;
  39       b >>= 1;
  40     }
  41   return rv;
  42 }