LXR linux/arch/m68k/lib/muldi3.c

   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
  17#include <linux/compiler.h>
  18#include <linux/export.h>
  19
  20#ifdef CONFIG_CPU_HAS_NO_MULDIV64
  21
  22#define SI_TYPE_SIZE 32
  23#define __BITS4 (SI_TYPE_SIZE / 4)
  24#define __ll_B (1L << (SI_TYPE_SIZE / 2))
  25#define __ll_lowpart(t) ((USItype) (t) % __ll_B)
  26#define __ll_highpart(t) ((USItype) (t) / __ll_B)
  27
  28#define umul_ppmm(w1, w0, u, v)                                         \
  29  do {                                                                  \
  30    USItype __x0, __x1, __x2, __x3;                                     \
  31    USItype __ul, __vl, __uh, __vh;                                     \
  32                                                                        \
  33    __ul = __ll_lowpart (u);                                            \
  34    __uh = __ll_highpart (u);                                           \
  35    __vl = __ll_lowpart (v);                                            \
  36    __vh = __ll_highpart (v);                                           \
  37                                                                        \
  38    __x0 = (USItype) __ul * __vl;                                       \
  39    __x1 = (USItype) __ul * __vh;                                       \
  40    __x2 = (USItype) __uh * __vl;                                       \
  41    __x3 = (USItype) __uh * __vh;                                       \
  42                                                                        \
  43    __x1 += __ll_highpart (__x0);/* this can't give carry */            \
  44    __x1 += __x2;               /* but this indeed can */               \
  45    if (__x1 < __x2)            /* did we get it? */                    \
  46      __x3 += __ll_B;           /* yes, add it in the proper pos. */    \
  47                                                                        \
  48    (w1) = __x3 + __ll_highpart (__x1);                                 \
  49    (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);          \
  50  } while (0)
  51
  52#else
  53
  54#define umul_ppmm(w1, w0, u, v) \
  55  __asm__ ("mulu%.l %3,%1:%0"                                           \
  56           : "=d" ((USItype)(w0)),                                      \
  57             "=d" ((USItype)(w1))                                       \
  58           : "%0" ((USItype)(u)),                                       \
  59             "dmi" ((USItype)(v)))
  60
  61#endif
  62
  63#define __umulsidi3(u, v) \
  64  ({DIunion __w;                                                        \
  65    umul_ppmm (__w.s.high, __w.s.low, u, v);                            \
  66    __w.ll; })
  67
  68typedef          int SItype     __mode(SI);
  69typedef unsigned int USItype    __mode(SI);
  70typedef          int DItype     __mode(DI);
  71typedef int word_type           __mode(__word__);
  72
  73struct DIstruct {SItype high, low;};
  74
  75typedef union
  76{
  77  struct DIstruct s;
  78  DItype ll;
  79} DIunion;
  80
  81DItype
  82__muldi3 (DItype u, DItype v)
  83{
  84  DIunion w;
  85  DIunion uu, vv;
  86
  87  uu.ll = u,
  88  vv.ll = v;
  89
  90  w.ll = __umulsidi3 (uu.s.low, vv.s.low);
  91  w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
  92               + (USItype) uu.s.high * (USItype) vv.s.low);
  93
  94  return w.ll;
  95}
  96EXPORT_SYMBOL(__muldi3);
  97