Changeset b7c8bd in git for factory

Timestamp:

Apr 14, 1998, 5:17:16 PM (26 years ago)

Author:

Wilfred Pohl <pohl@…>

Branches:

(u'spielwiese', '2fa36c576e6a4ddbb1093b43c7f8e9835e17e52a')

Children:

43580ac75b66829291eab1ba0e001075ecf7e429

Parents:

9388d44d66568ee4423a1b5b0cb6898306a4928b

Message:

version for Metrowerks and new invers


git-svn-id: file:///usr/local/Singular/svn/trunk@1372 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• factory/ffops.cc (modified) (3 diffs)

factory/ffops.cc

@@ -1 +1 @@
 /* emacs edit mode for this file is -*- C++ -*- */
-/* $Id: ffops.cc,v 1.7 1998-03-11 09:40:31 schmidt Exp $ */
+/* $Id: ffops.cc,v 1.8 1998-04-14 15:17:16 pohl Exp $ */
 
 #include <config.h>
@@ -16 +16 @@
 short * ff_invtab = new short [32767];
 
+#ifdef __MWERKS__
+#include <stuff_64.h>
+int ff_mul( const int a, const int b )
+{
+  Int_64 c;
+  unsigned int ua, ub;
+  int res;
+  
+  if ((!a) || (!b)) return 0;
+  if (a>0)
+    ua = a;
+  else
+    ua = -a;
+  if (b>0)
+    ub = b;
+  else
+    ub = -b;
+  mul_64(&c, ua, ub);
+  res = rem_64(&c, ff_prime);
+  if ((a>0) != (b>0))
+    res = ff_prime-res;
+  return res;
+}
+#endif
+
 void ff_setprime ( const int p )
 {
@@ -28 +53 @@
 int ff_newinv ( const int a )
 {
-    int u, r0 = a, r1 = ff_prime, q0 = 1, q1 = 0;
-    while ( ( r0 > 0 ) && ( r1 > 0 ) ) {
-        u = r0 / r1;
-        r0 = r0 % r1;
-        q0 = u*q1 + q0;
-        if ( r0 > 0 ) {
-            u = r1 / r0;
-            r1 = r1 % r0;
-            q1 = u*q0 + q1;
-        }
+    int p, q, r1, r2, y1, y2;
+    if (a < 2)
+          return (ff_invtab[a] = a);
+    r1 = p = ff_prime;
+    q = r1 / a;
+    y1 = -q;
+    r1 -= a * q;
+    if (r1 == 1)
+    {
+      y1 += p;
+      ff_invtab[y1] = a;
+      return (ff_invtab[a] = y1);
     }
-    if ( r0 == 0 )
-        return (ff_invtab[a] = -q1);
-    else
-        return (ff_invtab[a] = q0);
+    r2 = a;
+    y2 = 1;
+    for (;;)
+    {
+      q = r2 / r1;
+      y2 -= y1 * q;
+      r2 -= r1 * q;
+      if (r2 == 1)
+      {
+        if (y2 < 0)
+          y2 += p;
+        ff_invtab[y2] = a;
+        return (ff_invtab[a] = y2);
+      }
+      q = r1 / r2;
+      y1 -= y2 * q;
+      r1 -= r2 * q;
+      if (r1 == 1)
+      {
+        if (y1 < 0)
+          y1 += p;
+        ff_invtab[y1] = a;
+        return (ff_invtab[a] = y1);
+      }
+    }
 }
 
 int ff_biginv ( const int a )
 {
-    INT64 u, r0 = a, r1 = ff_prime, q0 = 1, q1 = 0;
-    while ( ( r0 > 0 ) && ( r1 > 0 ) ) {
-        u = r0 / r1;
-        r0 = r0 % r1;
-        q0 = u*q1 + q0;
-        if ( r0 > 0 ) {
-            u = r1 / r0;
-            r1 = r1 % r0;
-            q1 = u*q0 + q1;
-        }
+    int p, q, r1, r2, y1, y2;
+    if (a < 2)
+      return a;
+    r1 = p = ff_prime;
+    q = r1 / a;
+    y1 = -q;
+    r1 -= a * q;
+    if (r1 == 1)
+      return p + y1;
+    r2 = a;
+    y2 = 1;
+    for (;;)
+    {
+      q = r2 / r1;
+      y2 -= y1 * q;
+      r2 -= r1 * q;
+      if (r2 == 1)
+      {
+        if (y2 > 0)
+          return y2;
+        else
+          return p + y2;
+      }
+      q = r1 / r2;
+      y1 -= y2 * q;
+      r1 -= r2 * q;
+      if (r1 == 1)
+      {
+        if (y1 > 0)
+          return y1;
+        else
+          return p + y1;
+      }
     }
-    if ( r0 == 0 )
-        return -(int)q1;
-    else
-        return (int)q0;
 }