Changeset e1d7e8 in git

Timestamp:

Jul 24, 2019, 3:14:08 PM (4 years ago)

Author:

Hans Schoenemann <hannes@…>

Branches:

(u'spielwiese', '828514cf6e480e4bafc26df99217bf2a1ed1ef45')

Children:

c9824e54c705dcaedb3b991c6bf81f9f974e758d

Parents:

20e7303a3d50b30117c53a232ad724297637ac0e

Message:

add: pqLengthApprox: find a lower bound on the length of p and q

File:

• libpolys/polys/operations/p_Mult_q.cc (modified) (5 diffs)

libpolys/polys/operations/p_Mult_q.cc

@@ -67 +67 @@
 }
 
+static void pqLengthApprox(poly p, poly q, int &lp, int &lq, const int min)
+{
+  int l = 0;
+
+  do
+  {
+    if (p == NULL)
+    {
+      lp=l;
+      lq=l+(q!=NULL);
+      return;
+    }
+    if (q == NULL) /* && p!=NULL */
+    {
+      lp=l+1;
+      lq=l;
+      return;
+    }
+    if (l>min) /* && p,q!=NULL */
+    {
+      lp=l; lq=l;
+      return;
+    }
+    pIter(p);
+    pIter(q);
+    l++;
+  }
+  while (1);
+}
+
 
 static poly _p_Mult_q_Bucket(poly p, const int lp,
@@ -290 +320 @@
   poly pt;
 
-  pqLength(p, q, lp, lq, MIN_LENGTH_FACTORY);
+  // MIN_LENGTH_FACTORY must be >= MIN_LENGTH_FACTORY_QQ, MIN_FLINT_QQ, MIN_FLINT_Zp 20
+  pqLengthApprox(p, q, lp, lq, MIN_LENGTH_FACTORY);
 
   if (lp < lq)
@@ -309 +340 @@
     if (pure_polys && rField_is_Q(r) && !convSingRFlintR(ctx,r))
     {
-      lp=pLength(p);
-      //printf("mul in flint\n");
-      poly res=Flint_Mult_MP(p,lp,q,lq,ctx,r);
+      // lq is a lower bound for the length of p and  q
+      poly res=Flint_Mult_MP(p,lq,q,lq,ctx,r);
       if (!copy)
       {
@@ -325 +355 @@
     if (pure_polys && rField_is_Zp(r) && !convSingRFlintR(ctx,r))
     {
-      lp=pLength(p);
-      //printf("mul in flint\n");
-      poly res=Flint_Mult_MP(p,lp,q,lq,ctx,r);
+      // lq is a lower bound for the length of p and  q
+      poly res=Flint_Mult_MP(p,lq,q,lq,ctx,r);
       if (!copy)
       {
@@ -357 +386 @@
   {
     lp=pLength(p);
-    assume(lq == pLength(q));
+    lq=pLength(q);
     return _p_Mult_q_Bucket(p, lp, q, lq, copy, r);
   }