Changeset 96f9fdf in git

Timestamp:

Sep 5, 2011, 1:52:09 PM (12 years ago)

Author:

Martin Lee <martinlee84@…>

Branches:

(u'jengelh-datetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', 'cdfcdb8287f66bc6070028082cbbc6eff10e609b')

Children:

3426de24a82fe29ddf501d02bcb6bd50a782f43f

Parents:

38ffb7aa68530ae0bcc0c2bb95142f15951ff00c

Message:

minor fixes and optimizations to Kronecker substitution multiplication


git-svn-id: file:///usr/local/Singular/svn/trunk@14379 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• factory/facHensel.cc (modified) (12 diffs)

factory/facHensel.cc

@@ -573 +573 @@
 {
   int degAy= degree (A);
-  subA1.rep.SetLength ((long) d*(degAy + 1));
-  subA2.rep.SetLength ((long) d*(degAy + 1));
+  subA1.rep.SetLength ((long) d*(degAy + 2));
+  subA2.rep.SetLength ((long) d*(degAy + 2));
 
   Variable v;
@@ -602 +602 @@
     for (int j= 0; j < bufRepLength; j++)
     {
-      subA1p [j + k]= bufp [j];
-      subA2p [j + kk]= bufp [j];
+      subA1p [j + k] += bufp [j];
+      subA2p [j + kk] += bufp [j];
     }
   }
@@ -614 +614 @@
 {
   int degAy= degree (A);
-  subA1.rep.SetLength ((long) d*(degAy + 1));
-  subA2.rep.SetLength ((long) d*(degAy + 1));
-
-  Variable v;
+  subA1.rep.SetLength ((long) d*(degAy + 2));
+  subA2.rep.SetLength ((long) d*(degAy + 2));
+
   zz_p *subA1p;
   zz_p *subA2p;
@@ -635 +634 @@
     for (int j= 0; j < bufRepLength; j++)
     {
-      subA1p [j + k]= bufp [j];
-      subA2p [j + kk]= bufp [j];
+      subA1p [j + k] += bufp [j];
+      subA2p [j + kk] += bufp [j];
     }
   }
@@ -739 +738 @@
       if (repLengthBuf2 > degfSubLf + 1)
         degfSubLf= repLengthBuf2 - 1;
-      int tmp= tmin (repLengthBuf1, deggSubLg);
+      int tmp= tmin (repLengthBuf1, deggSubLg + 1);
       for (int ind= 0; ind < tmp; ind++)
         gp [ind + lg] -= buf1p [ind];
@@ -853 +852 @@
       if (repLengthBuf2 > degfSubLf + 1)
         degfSubLf= repLengthBuf2 - 1;
-      int tmp= tmin (repLengthBuf1, deggSubLg);
+      int tmp= tmin (repLengthBuf1, deggSubLg + 1);
       for (int ind= 0; ind < tmp; ind++)
         gp [ind + lg] -= buf1p [ind];
@@ -952 +951 @@
                   CanonicalForm& M)
 {
-  int d1= tmax (degree (F, 1), degree (G, 1)) + 1;
-  int d2= tmax (degree (F, 2), degree (G, 2));
+  int d1= degree (F, 1) + degree (G, 1) + 1;
+  d1 /= 2;
+  d1 += 1;
 
   zz_pX F1, F2;
@@ -963 +963 @@
   MulTrunc (F1, F1, G1, (long) k);
 
-  mul (F2, F2, G2);
-  if (deg (F2) > k - 2)
-    F2 >>= (deg (F2) - k + 2);
-
+  int degtailF= degree (tailcoeff (F), 1);
+  int degtailG= degree (tailcoeff (G), 1);
+  int taildegF= taildegree (F);
+  int taildegG= taildegree (G);
+  int b= k + degtailF + degtailG - d1*(2+taildegF+taildegG);
+
+  reverse (F2, F2);
+  reverse (G2, G2);
+  MulTrunc (F2, F2, G2, b + 1);
+  reverse (F2, F2, b);
+
+  int d2= tmax (deg (F2)/d1, deg (F1)/d1);
   return reverseSubst (F1, F2, d1, d2);
 }
@@ -983 +991 @@
   int degBy= degree (B, 2);
   int d1= degAx + 1 + degBx;
-  int d2= tmax (degree (A, 2), degree (B, 2));
+  int d2= tmax (degAy, degBy);
 
   if (d1 > 128 && d2 > 160 && (degAy == degBy) && (2*degAy > degree (M)))
@@ -1004 +1012 @@
                   CanonicalForm& M, const Variable& alpha)
 {
-  int d1= tmax (degree (F, 1), degree (G, 1)) + 1;
-  int d2= tmax (degree (F, 2), degree (G, 2));
+  int d1= degree (F, 1) + degree (G, 1) + 1;
+  d1 /= 2;
+  d1 += 1;
 
   zz_pEX F1, F2;
@@ -1015 +1024 @@
   MulTrunc (F1, F1, G1, (long) k);
 
-  mul (F2, F2, G2);
-  if (deg (F2) > k - 2)
-    F2 >>= (deg (F2) - k + 2);
-
-  CanonicalForm result= reverseSubst (F1, F2, d1, d2, alpha);
-
-  return result;
+  int degtailF= degree (tailcoeff (F), 1);
+  int degtailG= degree (tailcoeff (G), 1);
+  int taildegF= taildegree (F);
+  int taildegG= taildegree (G);
+  int b= k + degtailF + degtailG - d1*(2+taildegF+taildegG);
+
+  reverse (F2, F2);
+  reverse (G2, G2);
+  MulTrunc (F2, F2, G2, b + 1);
+  reverse (F2, F2, b);
+
+  int d2= tmax (deg (F2)/d1, deg (F1)/d1);
+  return reverseSubst (F1, F2, d1, d2, alpha);
 }
 
@@ -1039 +1054 @@
     int degBy= degree (B, 2);
     int d1= degAx + degBx + 1;
-    int d2= tmax (degree (A, 2), degree (B, 2));
+    int d2= tmax (degAy, degBy);
     zz_p::init (getCharacteristic());
     zz_pX NTLMipo= convertFacCF2NTLzzpX (getMipo (alpha));