patch-2.4.13 linux/arch/arm/lib/udivdi3.c

• Lines: 232
• Date: Thu Oct 11 09:04:57 2001
• Orig file: v2.4.12/linux/arch/arm/lib/udivdi3.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.12/linux/arch/arm/lib/udivdi3.c linux/arch/arm/lib/udivdi3.c
@@ -0,0 +1,231 @@
+/* More subroutines needed by GCC output code on some machines.  */
+/* Compile this one with gcc.  */
+/* Copyright (C) 1989, 92-98, 1999 Free Software Foundation, Inc.
+
+This file is part of GNU CC.
+
+GNU CC is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU CC is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU CC; see the file COPYING.  If not, write to
+the Free Software Foundation, 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+/* As a special exception, if you link this library with other files,
+   some of which are compiled with GCC, to produce an executable,
+   this library does not by itself cause the resulting executable
+   to be covered by the GNU General Public License.
+   This exception does not however invalidate any other reasons why
+   the executable file might be covered by the GNU General Public License.
+ */
+/* support functions required by the kernel. based on code from gcc-2.95.3 */
+/* I Molton     29/07/01 */
+
+#include "gcclib.h"
+#include "longlong.h"
+
+static const UQItype __clz_tab[] =
+{
+  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,
+  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,
+  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,
+  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,
+  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,
+  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,
+  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,
+  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,
+};
+
+UDItype
+__udivmoddi4 (UDItype n, UDItype d, UDItype *rp)
+{
+  DIunion ww;
+  DIunion nn, dd;
+  DIunion rr;
+  USItype d0, d1, n0, n1, n2;
+  USItype q0, q1;
+  USItype b, bm;
+
+  nn.ll = n;
+  dd.ll = d;
+
+  d0 = dd.s.low;
+  d1 = dd.s.high;
+  n0 = nn.s.low;
+  n1 = nn.s.high;
+
+  if (d1 == 0)
+    {
+      if (d0 > n1)
+        {
+          /* 0q = nn / 0D */
+
+          count_leading_zeros (bm, d0);
+
+          if (bm != 0)
+            {
+              /* Normalize, i.e. make the most significant bit of the
+                 denominator set.  */
+
+              d0 = d0 << bm;
+              n1 = (n1 << bm) | (n0 >> (SI_TYPE_SIZE - bm));
+              n0 = n0 << bm;
+            }
+
+          udiv_qrnnd (q0, n0, n1, n0, d0);
+          q1 = 0;
+
+          /* Remainder in n0 >> bm.  */
+        }
+      else
+        {
+          /* qq = NN / 0d */
+
+          if (d0 == 0)
+            d0 = 1 / d0;        /* Divide intentionally by zero.  */
+
+          count_leading_zeros (bm, d0);
+
+          if (bm == 0)
+            {
+              /* From (n1 >= d0) /\ (the most significant bit of d0 is set),
+                 conclude (the most significant bit of n1 is set) /\ (the
+                 leading quotient digit q1 = 1).
+
+                 This special case is necessary, not an optimization.
+                 (Shifts counts of SI_TYPE_SIZE are undefined.)  */
+
+              n1 -= d0;
+              q1 = 1;
+            }
+          else
+            {
+              /* Normalize.  */
+
+              b = SI_TYPE_SIZE - bm;
+
+              d0 = d0 << bm;
+              n2 = n1 >> b;
+              n1 = (n1 << bm) | (n0 >> b);
+              n0 = n0 << bm;
+
+              udiv_qrnnd (q1, n1, n2, n1, d0);
+            }
+
+          /* n1 != d0...  */
+
+          udiv_qrnnd (q0, n0, n1, n0, d0);
+
+          /* Remainder in n0 >> bm.  */
+        }
+
+      if (rp != 0)
+        {
+          rr.s.low = n0 >> bm;
+          rr.s.high = 0;
+          *rp = rr.ll;
+        }
+    }
+  else
+    {
+      if (d1 > n1)
+        {
+          /* 00 = nn / DD */
+
+          q0 = 0;
+          q1 = 0;
+
+          /* Remainder in n1n0.  */
+          if (rp != 0)
+            {
+              rr.s.low = n0;
+              rr.s.high = n1;
+              *rp = rr.ll;
+            }
+        }
+      else
+        {
+          /* 0q = NN / dd */
+
+          count_leading_zeros (bm, d1);
+          if (bm == 0)
+            {
+              /* From (n1 >= d1) /\ (the most significant bit of d1 is set),
+                 conclude (the most significant bit of n1 is set) /\ (the
+                 quotient digit q0 = 0 or 1).
+
+                 This special case is necessary, not an optimization.  */
+
+              /* The condition on the next line takes advantage of that
+                 n1 >= d1 (true due to program flow).  */
+              if (n1 > d1 || n0 >= d0)
+                {
+                  q0 = 1;
+                  sub_ddmmss (n1, n0, n1, n0, d1, d0);
+                }
+              else
+                q0 = 0;
+
+              q1 = 0;
+
+              if (rp != 0)
+                {
+                  rr.s.low = n0;
+                  rr.s.high = n1;
+                  *rp = rr.ll;
+                }
+            }
+          else
+            {
+              USItype m1, m0;
+              /* Normalize.  */
+
+              b = SI_TYPE_SIZE - bm;
+
+              d1 = (d1 << bm) | (d0 >> b);
+              d0 = d0 << bm;
+              n2 = n1 >> b;
+              n1 = (n1 << bm) | (n0 >> b);
+              n0 = n0 << bm;
+
+              udiv_qrnnd (q0, n1, n2, n1, d1);
+              umul_ppmm (m1, m0, q0, d0);
+
+              if (m1 > n1 || (m1 == n1 && m0 > n0))
+                {
+                  q0--;
+                  sub_ddmmss (m1, m0, m1, m0, d1, d0);
+                }
+
+              q1 = 0;
+
+              /* Remainder in (n1n0 - m1m0) >> bm.  */
+              if (rp != 0)
+                {
+                  sub_ddmmss (n1, n0, n1, n0, m1, m0);
+                  rr.s.low = (n1 << b) | (n0 >> bm);
+                  rr.s.high = n1 >> bm;
+                  *rp = rr.ll;
+                }
+            }
+        }
+    }
+
+  ww.s.low = q0;
+  ww.s.high = q1;
+  return ww.ll;
+}
+
+UDItype
+__udivdi3 (UDItype n, UDItype d)
+{
+  return __udivmoddi4 (n, d, (UDItype *) 0);
+}