Changeset 00f64a in git

Timestamp:

Apr 28, 2014, 8:51:02 PM (10 years ago)

Author:

Oleksandr Motsak <motsak@…>

Branches:

(u'spielwiese', '6e5adcba05493683b94648c659a729c189812c77')

Children:

443b19314835facbdbe5cfa061a4c8b9e5f9dfe5

Parents:

14814e396e2e71a6313759aa91824d349e14bb30

git-author:

Oleksandr Motsak <motsak@mathematik.uni-kl.de>2014-04-28 20:51:02+02:00

git-committer:

Oleksandr Motsak <motsak@mathematik.uni-kl.de>2014-04-30 17:09:44+02:00

Message:

p_GetShortExpVector for products (in order to avoid the actual multiplication)

Location:

libpolys/polys/monomials

Files:

• p_polys.cc (modified) (1 diff)
• p_polys.h (modified) (1 diff)

libpolys/polys/monomials/p_polys.cc

@@ -4620 +4620 @@
 }
 
+
+unsigned long p_GetShortExpVector(const poly p, const poly pp, const ring r)
+{
+  assume(p != NULL);
+  assume(pp != NULL);
+  if (p == NULL || pp == NULL) return 0;
+  
+  unsigned long ev = 0; // short exponent vector
+  unsigned int n = BIT_SIZEOF_LONG / r->N; // number of bits per exp
+  unsigned int m1; // highest bit which is filled with (n+1)
+  unsigned int i = 0, j=1;
+
+  if (n == 0)
+  {
+    if (r->N <2*BIT_SIZEOF_LONG)
+    {
+      n=1;
+      m1=0;
+    }
+    else
+    {
+      for (; j<=(unsigned long) r->N; j++)
+      {
+        if (p_GetExp(p,j,r) > 0 || p_GetExp(pp,j,r) > 0) i++;
+        if (i == BIT_SIZEOF_LONG) break;
+      }
+      if (i>0)
+        ev = ~((unsigned long)0) >> ((unsigned long) (BIT_SIZEOF_LONG - i));
+      return ev;
+    }
+  }
+  else
+  {
+    m1 = (n+1)*(BIT_SIZEOF_LONG - n*r->N);
+  }
+
+  n++;
+  while (i<m1)
+  {
+    ev |= GetBitFields(p_GetExp(p, j,r) + p_GetExp(pp, j,r), i, n);
+    i += n;
+    j++;
+  }
+
+  n--;
+  while (i<BIT_SIZEOF_LONG)
+  {
+    ev |= GetBitFields(p_GetExp(p, j,r) + p_GetExp(pp, j,r), i, n);
+    i += n;
+    j++;
+  }
+  return ev;
+}
+
+
+
 /***************************************************************
  *

libpolys/polys/monomials/p_polys.h

@@ -52 +52 @@
  ***************************************************************/
 unsigned long p_GetShortExpVector(poly a, const ring r);
+
+/// p_GetShortExpVector of p * pp
+unsigned long p_GetShortExpVector(const poly p, const poly pp, const ring r);
 
 #ifdef HAVE_RINGS