root/arch/microblaze/lib/muldi3.c

DEFINITIONS

1. __muldi3

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/export.h>
   3 
   4 #include "libgcc.h"
   5 
   6 #define W_TYPE_SIZE 32
   7 
   8 #define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
   9 #define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
  10 #define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))
  11 
  12 /* If we still don't have umul_ppmm, define it using plain C.  */
  13 #if !defined(umul_ppmm)
  14 #define umul_ppmm(w1, w0, u, v)                                         \
  15         do {                                                            \
  16                 unsigned long __x0, __x1, __x2, __x3;                   \
  17                 unsigned short __ul, __vl, __uh, __vh;                  \
  18                                                                         \
  19                 __ul = __ll_lowpart(u);                                 \
  20                 __uh = __ll_highpart(u);                                \
  21                 __vl = __ll_lowpart(v);                                 \
  22                 __vh = __ll_highpart(v);                                \
  23                                                                         \
  24                 __x0 = (unsigned long) __ul * __vl;                     \
  25                 __x1 = (unsigned long) __ul * __vh;                     \
  26                 __x2 = (unsigned long) __uh * __vl;                     \
  27                 __x3 = (unsigned long) __uh * __vh;                     \
  28                                                                         \
  29                 __x1 += __ll_highpart(__x0); /* this can't give carry */\
  30                 __x1 += __x2; /* but this indeed can */                 \
  31                 if (__x1 < __x2) /* did we get it? */                   \
  32                 __x3 += __ll_B; /* yes, add it in the proper pos */     \
  33                                                                         \
  34                 (w1) = __x3 + __ll_highpart(__x1);                      \
  35                 (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
  36         } while (0)
  37 #endif
  38 
  39 #if !defined(__umulsidi3)
  40 #define __umulsidi3(u, v) ({                            \
  41         DWunion __w;                                    \
  42         umul_ppmm(__w.s.high, __w.s.low, u, v);         \
  43         __w.ll;                                         \
  44         })
  45 #endif
  46 
  47 long long __muldi3(long long u, long long v)
  48 {
  49         const DWunion uu = {.ll = u};
  50         const DWunion vv = {.ll = v};
  51         DWunion w = {.ll = __umulsidi3(uu.s.low, vv.s.low)};
  52 
  53         w.s.high += ((unsigned long) uu.s.low * (unsigned long) vv.s.high
  54                 + (unsigned long) uu.s.high * (unsigned long) vv.s.low);
  55 
  56         return w.ll;
  57 }
  58 EXPORT_SYMBOL(__muldi3);