Changeset cb4f0c in git

Timestamp:

Oct 20, 2012, 12:03:23 AM (11 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', '0604212ebb110535022efecad887940825b97c3f')

Children:

7964658e19c1f9b2949f81ae9f46b6395fee757c

Parents:

0851b018d4d94918ad78eea2f6350c7012d2a9aa

git-author:

Martin Lee <martinlee84@web.de>2012-10-20 00:03:23+02:00

git-committer:

Martin Lee <martinlee84@web.de>2012-10-24 12:32:43+02:00

Message:

chg: switch to modular gcd if psr can get dense
chg: optimization of Hi computation

File:

• factory/cf_gcd.cc (modified) (2 diffs)

factory/cf_gcd.cc

@@ -573 +573 @@
     Variable v = f.mvar();
     Hi = power( LC( pi1, v ), delta );
+    int maxNumVars= tmax (getNumVars (pi), getNumVars (pi1));
+
+    if (!(pi.isUnivariate() && pi1.isUnivariate()))
+    {
+      if (size (Hi)*size (pi)/(maxNumVars*3) > 500) //maybe this needs more tuning
+      {
+        On (SW_USE_FF_MOD_GCD);
+        C *= gcd (pi, pi1);
+        Off (SW_USE_FF_MOD_GCD);
+        return C;
+      }
+    }
+
     if ( (delta+1) % 2 )
         bi = 1;
     else
         bi = -1;
-    int maxNumVars= tmax (getNumVars (pi), getNumVars (pi1));
-    CanonicalForm oldPi= pi, oldPi1= pi1;
+    CanonicalForm oldPi= pi, oldPi1= pi1, powHi;
     while ( degree( pi1, v ) > 0 )
     {
@@ -605 +617 @@
         {
             delta = degree( pi, v ) - degree( pi1, v );
+            powHi= power (Hi, delta-1);
             if ( (delta+1) % 2 )
-                bi = LC( pi, v ) * power( Hi, delta );
+                bi = LC( pi, v ) * powHi*Hi;
             else
-                bi = -LC( pi, v ) * power( Hi, delta );
-            Hi = power( LC( pi1, v ), delta ) / power( Hi, delta-1 );
+                bi = -LC( pi, v ) * powHi*Hi;
+            Hi = power( LC( pi1, v ), delta ) / powHi;
+            if (!(pi.isUnivariate() && pi1.isUnivariate()))
+            {
+              if (size (Hi)*size (pi)/(maxNumVars*3) > 500) //maybe this needs more tuning
+              {
+                On (SW_USE_FF_MOD_GCD);
+                C *= gcd (oldPi, oldPi1);
+                Off (SW_USE_FF_MOD_GCD);
+                return C;
+              }
+            }
         }
     }