linux/arch/m68knommu/lib/muldi3.c
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   1/* muldi3.c extracted from gcc-2.7.2.3/libgcc2.c and 
   2                           gcc-2.7.2.3/longlong.h which is: */
   3/* Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
   4
   5This file is part of GNU CC.
   6
   7GNU CC is free software; you can redistribute it and/or modify
   8it under the terms of the GNU General Public License as published by
   9the Free Software Foundation; either version 2, or (at your option)
  10any later version.
  11
  12GNU CC is distributed in the hope that it will be useful,
  13but WITHOUT ANY WARRANTY; without even the implied warranty of
  14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15GNU General Public License for more details.
  16
  17You should have received a copy of the GNU General Public License
  18along with GNU CC; see the file COPYING.  If not, write to
  19the Free Software Foundation, 59 Temple Place - Suite 330,
  20Boston, MA 02111-1307, USA.  */
  21
  22#define BITS_PER_UNIT 8
  23#define SI_TYPE_SIZE 32
  24
  25#define __BITS4 (SI_TYPE_SIZE / 4)
  26#define __ll_B (1L << (SI_TYPE_SIZE / 2))
  27#define __ll_lowpart(t) ((USItype) (t) % __ll_B)
  28#define __ll_highpart(t) ((USItype) (t) / __ll_B)
  29
  30#define umul_ppmm(w1, w0, u, v)                                         \
  31  do {                                                                  \
  32    USItype __x0, __x1, __x2, __x3;                                     \
  33    USItype __ul, __vl, __uh, __vh;                                     \
  34                                                                        \
  35    __ul = __ll_lowpart (u);                                            \
  36    __uh = __ll_highpart (u);                                           \
  37    __vl = __ll_lowpart (v);                                            \
  38    __vh = __ll_highpart (v);                                           \
  39                                                                        \
  40    __x0 = (USItype) __ul * __vl;                                       \
  41    __x1 = (USItype) __ul * __vh;                                       \
  42    __x2 = (USItype) __uh * __vl;                                       \
  43    __x3 = (USItype) __uh * __vh;                                       \
  44                                                                        \
  45    __x1 += __ll_highpart (__x0);/* this can't give carry */            \
  46    __x1 += __x2;               /* but this indeed can */               \
  47    if (__x1 < __x2)            /* did we get it? */                    \
  48      __x3 += __ll_B;           /* yes, add it in the proper pos. */    \
  49                                                                        \
  50    (w1) = __x3 + __ll_highpart (__x1);                                 \
  51    (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);          \
  52  } while (0)
  53
  54#define __umulsidi3(u, v) \
  55  ({DIunion __w;                                                        \
  56    umul_ppmm (__w.s.high, __w.s.low, u, v);                            \
  57    __w.ll; })
  58
  59typedef          int SItype     __attribute__ ((mode (SI)));
  60typedef unsigned int USItype    __attribute__ ((mode (SI)));
  61typedef          int DItype     __attribute__ ((mode (DI)));
  62typedef int word_type __attribute__ ((mode (__word__)));
  63
  64struct DIstruct {SItype high, low;};
  65
  66typedef union
  67{
  68  struct DIstruct s;
  69  DItype ll;
  70} DIunion;
  71
  72DItype
  73__muldi3 (DItype u, DItype v)
  74{
  75  DIunion w;
  76  DIunion uu, vv;
  77
  78  uu.ll = u,
  79  vv.ll = v;
  80
  81  w.ll = __umulsidi3 (uu.s.low, vv.s.low);
  82  w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
  83               + (USItype) uu.s.high * (USItype) vv.s.low);
  84
  85  return w.ll;
  86}
  87