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/arch/arm26/lib/udivdi3.c

https://bitbucket.org/evzijst/gittest
C | 242 lines | 146 code | 41 blank | 55 comment | 26 complexity | cef8f674e44720bb4bc0e9e0aa1e1c0a MD5 | raw file
  1/* More subroutines needed by GCC output code on some machines.  */
  2/* Compile this one with gcc.  */
  3/* Copyright (C) 1989, 92-98, 1999 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/* As a special exception, if you link this library with other files,
 23   some of which are compiled with GCC, to produce an executable,
 24   this library does not by itself cause the resulting executable
 25   to be covered by the GNU General Public License.
 26   This exception does not however invalidate any other reasons why
 27   the executable file might be covered by the GNU General Public License.
 28 */
 29/* support functions required by the kernel. based on code from gcc-2.95.3 */
 30/* I Molton     29/07/01 */
 31
 32#include "gcclib.h"
 33#include "longlong.h"
 34
 35static const UQItype __clz_tab[] =
 36{
 37  0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
 38  6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
 39  7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
 40  7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
 41  8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
 42  8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
 43  8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
 44  8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
 45};
 46
 47UDItype
 48__udivmoddi4 (UDItype n, UDItype d, UDItype *rp)
 49{
 50  DIunion ww;
 51  DIunion nn, dd;
 52  DIunion rr;
 53  USItype d0, d1, n0, n1, n2;
 54  USItype q0, q1;
 55  USItype b, bm;
 56
 57  nn.ll = n;
 58  dd.ll = d;
 59
 60  d0 = dd.s.low;
 61  d1 = dd.s.high;
 62  n0 = nn.s.low;
 63  n1 = nn.s.high;
 64
 65  if (d1 == 0)
 66    {
 67      if (d0 > n1)
 68        {
 69          /* 0q = nn / 0D */
 70
 71          count_leading_zeros (bm, d0);
 72
 73          if (bm != 0)
 74            {
 75              /* Normalize, i.e. make the most significant bit of the
 76                 denominator set.  */
 77
 78              d0 = d0 << bm;
 79              n1 = (n1 << bm) | (n0 >> (SI_TYPE_SIZE - bm));
 80              n0 = n0 << bm;
 81            }
 82
 83          udiv_qrnnd (q0, n0, n1, n0, d0);
 84          q1 = 0;
 85
 86          /* Remainder in n0 >> bm.  */
 87        }
 88      else
 89        {
 90          /* qq = NN / 0d */
 91
 92          if (d0 == 0)
 93            d0 = 1 / d0;        /* Divide intentionally by zero.  */
 94
 95          count_leading_zeros (bm, d0);
 96
 97          if (bm == 0)
 98            {
 99              /* From (n1 >= d0) /\ (the most significant bit of d0 is set),
100                 conclude (the most significant bit of n1 is set) /\ (the
101                 leading quotient digit q1 = 1).
102
103                 This special case is necessary, not an optimization.
104                 (Shifts counts of SI_TYPE_SIZE are undefined.)  */
105
106              n1 -= d0;
107              q1 = 1;
108            }
109          else
110            {
111              /* Normalize.  */
112
113              b = SI_TYPE_SIZE - bm;
114
115              d0 = d0 << bm;
116              n2 = n1 >> b;
117              n1 = (n1 << bm) | (n0 >> b);
118              n0 = n0 << bm;
119
120              udiv_qrnnd (q1, n1, n2, n1, d0);
121            }
122
123          /* n1 != d0...  */
124
125          udiv_qrnnd (q0, n0, n1, n0, d0);
126
127          /* Remainder in n0 >> bm.  */
128        }
129
130      if (rp != 0)
131        {
132          rr.s.low = n0 >> bm;
133          rr.s.high = 0;
134          *rp = rr.ll;
135        }
136    }
137  else
138    {
139      if (d1 > n1)
140        {
141          /* 00 = nn / DD */
142
143          q0 = 0;
144          q1 = 0;
145
146          /* Remainder in n1n0.  */
147          if (rp != 0)
148            {
149              rr.s.low = n0;
150              rr.s.high = n1;
151              *rp = rr.ll;
152            }
153        }
154      else
155        {
156          /* 0q = NN / dd */
157
158          count_leading_zeros (bm, d1);
159          if (bm == 0)
160            {
161              /* From (n1 >= d1) /\ (the most significant bit of d1 is set),
162                 conclude (the most significant bit of n1 is set) /\ (the
163                 quotient digit q0 = 0 or 1).
164
165                 This special case is necessary, not an optimization.  */
166
167              /* The condition on the next line takes advantage of that
168                 n1 >= d1 (true due to program flow).  */
169              if (n1 > d1 || n0 >= d0)
170                {
171                  q0 = 1;
172                  sub_ddmmss (n1, n0, n1, n0, d1, d0);
173                }
174              else
175                q0 = 0;
176
177              q1 = 0;
178
179              if (rp != 0)
180                {
181                  rr.s.low = n0;
182                  rr.s.high = n1;
183                  *rp = rr.ll;
184                }
185            }
186          else
187            {
188              USItype m1, m0;
189              /* Normalize.  */
190
191              b = SI_TYPE_SIZE - bm;
192
193              d1 = (d1 << bm) | (d0 >> b);
194              d0 = d0 << bm;
195              n2 = n1 >> b;
196              n1 = (n1 << bm) | (n0 >> b);
197              n0 = n0 << bm;
198
199              udiv_qrnnd (q0, n1, n2, n1, d1);
200              umul_ppmm (m1, m0, q0, d0);
201
202              if (m1 > n1 || (m1 == n1 && m0 > n0))
203                {
204                  q0--;
205                  sub_ddmmss (m1, m0, m1, m0, d1, d0);
206                }
207
208              q1 = 0;
209
210              /* Remainder in (n1n0 - m1m0) >> bm.  */
211              if (rp != 0)
212                {
213                  sub_ddmmss (n1, n0, n1, n0, m1, m0);
214                  rr.s.low = (n1 << b) | (n0 >> bm);
215                  rr.s.high = n1 >> bm;
216                  *rp = rr.ll;
217                }
218            }
219        }
220    }
221
222  ww.s.low = q0;
223  ww.s.high = q1;
224  return ww.ll;
225}
226
227UDItype
228__udivdi3 (UDItype n, UDItype d)
229{
230  return __udivmoddi4 (n, d, (UDItype *) 0);
231}
232
233UDItype
234__umoddi3 (UDItype u, UDItype v)
235{
236  UDItype w;
237
238  (void) __udivmoddi4 (u ,v, &w);
239
240  return w;
241}
242