arch/m68k/lib/muldi3.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * muldi3.c extracted from gcc-2.7.2.3/libgcc2.c and
   4  *                         gcc-2.7.2.3/longlong.h
   5  *
   6  * Copyright (C) 1989, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
   7  */
   8
   9 #define SI_TYPE_SIZE 32
  10 #define __BITS4 (SI_TYPE_SIZE / 4)
  11 #define __ll_B (1L << (SI_TYPE_SIZE / 2))
  12 #define __ll_lowpart(t) ((USItype) (t) % __ll_B)
  13 #define __ll_highpart(t) ((USItype) (t) / __ll_B)
  14
  15 #define umul_ppmm(w1, w0, u, v)                                         \
  16   do {                                                                  \
  17     USItype __x0, __x1, __x2, __x3;                                     \
  18     USItype __ul, __vl, __uh, __vh;                                     \
  19                                                                         \
  20     __ul = __ll_lowpart (u);                                            \
  21     __uh = __ll_highpart (u);                                           \
  22     __vl = __ll_lowpart (v);                                            \
  23     __vh = __ll_highpart (v);                                           \
  24                                                                         \
  25     __x0 = (USItype) __ul * __vl;                                       \
  26     __x1 = (USItype) __ul * __vh;                                       \
  27     __x2 = (USItype) __uh * __vl;                                       \
  28     __x3 = (USItype) __uh * __vh;                                       \
  29                                                                         \
  30     __x1 += __ll_highpart (__x0);/* this can't give carry */            \
  31     __x1 += __x2;               /* but this indeed can */               \
  32     if (__x1 < __x2)            /* did we get it? */                    \
  33       __x3 += __ll_B;           /* yes, add it in the proper pos. */    \
  34                                                                         \
  35     (w1) = __x3 + __ll_highpart (__x1);                                 \
  36     (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);          \
  37   } while (0)
  38
  39 #define __umulsidi3(u, v) \
  40   ({DIunion __w;                                                        \
  41     umul_ppmm (__w.s.high, __w.s.low, u, v);                            \
  42     __w.ll; })
  43
  44 typedef          int SItype     __attribute__ ((mode (SI)));
  45 typedef unsigned int USItype    __attribute__ ((mode (SI)));
  46 typedef          int DItype     __attribute__ ((mode (DI)));
  47 typedef int word_type __attribute__ ((mode (__word__)));
  48
  49 struct DIstruct {SItype high, low;};
  50
  51 typedef union
  52 {
  53         struct DIstruct s;
  54         DItype ll;
  55 } DIunion;
  56
  57 DItype __muldi3 (DItype u, DItype v)
  58 {
  59         DIunion w;
  60         DIunion uu, vv;
  61
  62         uu.ll = u,
  63         vv.ll = v;
  64
  65         w.ll = __umulsidi3 (uu.s.low, vv.s.low);
  66         w.s.high += ((USItype) uu.s.low * (USItype) vv.s.high
  67                 + (USItype) uu.s.high * (USItype) vv.s.low);
  68
  69         return w.ll;
  70 }