arch/blackfin/lib/ashrdi3.c

   1 /*
   2  * Copyright 2004-2009 Analog Devices Inc.
   3  *
   4  * Licensed under the GPL-2 or later.
   5  */
   6
   7 #include "gcclib.h"
   8
   9 #ifdef CONFIG_ARITHMETIC_OPS_L1
  10 DItype __ashrdi3(DItype u, word_type b)__attribute__((l1_text));
  11 #endif
  12
  13 DItype __ashrdi3(DItype u, word_type b)
  14 {
  15         DIunion w;
  16         word_type bm;
  17         DIunion uu;
  18
  19         if (b == 0)
  20                 return u;
  21
  22         uu.ll = u;
  23
  24         bm = (sizeof(SItype) * BITS_PER_UNIT) - b;
  25         if (bm <= 0) {
  26                 /* w.s.high = 1..1 or 0..0 */
  27                 w.s.high = uu.s.high >> (sizeof(SItype) * BITS_PER_UNIT - 1);
  28                 w.s.low = uu.s.high >> -bm;
  29         } else {
  30                 USItype carries = (USItype) uu.s.high << bm;
  31                 w.s.high = uu.s.high >> b;
  32                 w.s.low = ((USItype) uu.s.low >> b) | carries;
  33         }
  34
  35         return w.ll;
  36 }