Changeset 9118cc in git for libpolys/coeffs/ffields.cc

Timestamp:

Mar 20, 2018, 2:54:30 PM (6 years ago)

Author:

Hans Schoenemann <hannes@…>

Branches:

(u'spielwiese', 'fe61d9c35bf7c61f2b6cbf1b56e25e2f08d536cc')

Children:

65fb130c82c5b41756b646064fa062c3f6d16bf2

Parents:

3e8b644fceec8f73a275e8539c415a775f4aa015

Message:

fix: nfInt/nfWrite (for GP(p^n))

File:

• libpolys/coeffs/ffields.cc (modified) (5 diffs)

libpolys/coeffs/ffields.cc

@@ -10 +10 @@
 #include "misc/mylimits.h"
 #include "misc/sirandom.h"
+#include "misc/prime.h"
 
 #include "reporter/reporter.h"
@@ -237 +238 @@
 * number -> int
 */
-static long nfInt (number &n, const coeffs )
-{
-  return (long)n;
+static long nfInt (number &n, const coeffs r )
+{
+  unsigned short c=0;
+  unsigned short nn=(unsigned short)(long)n;
+  if (nn==r->m_nfCharQ) return 0;
+  long i=1; /* 1==a^0 */
+  while ((c!=nn)&&(i<r->m_nfCharQ))
+  {
+    c=r->m_nfPlus1Table[c];
+    i++;
+  }
+  if (c==nn) return i;
+  else       return 0;
 }
 
@@ -403 +414 @@
   else
   {
-    StringAppendS(n_ParameterNames(r)[0]);
-    if ((long)a!=1L)
-    {
-      StringAppend("^%d",(int)((long)a)); // long output!
+    int i=1; /* 1==a^0 */
+    unsigned short c=0;
+    unsigned short nn=(unsigned short)(long)a;
+    while ((c!=nn)&&(i<r->m_nfCharQ))
+    {
+      c=r->m_nfPlus1Table[c];
+      i++;
+    }
+    if (c==nn) StringAppend("%d",i);
+    else
+    {
+      StringAppendS(n_ParameterNames(r)[0]);
+      if ((long)a!=1L)
+      {
+        StringAppend("^%d",(int)((long)a)); // long output!
+      }
     }
   }
@@ -425 +448 @@
   else
   {
-    StringAppendS(n_ParameterNames(r)[0]);
-    if ((long)a!=1L)
-    {
-      StringAppend("%d",(int)((long)a));
+    int i=1; /* 1==a^0 */
+    unsigned short c=0;
+    unsigned short nn=(unsigned short)(long)a;
+    while ((c!=nn)&&(i<r->m_nfCharQ))
+    {
+      c=r->m_nfPlus1Table[c];
+      i++;
+    }
+    if (c==nn) StringAppend("%d",i);
+    else
+    {
+      StringAppendS(n_ParameterNames(r)[0]);
+      if ((long)a!=1L)
+      {
+        StringAppend("%d",(int)((long)a));
+      }
     }
   }
@@ -571 +606 @@
 {
   //Print("GF(%d)\n",c);
-  if ((c==r->m_nfCharQ)||(c==-r->m_nfCharQ))
+  if ((c==r->m_nfCharQ)||(c== -r->m_nfCharQ))
     /*this field is already set*/  return;
   int i=0;
 
-  while ((fftable[i]!=c) && (fftable[i]!=0))
-    i++;
-
-  if (fftable[i]==0)
-  {
-    // illegal GF-table size: c
-    return;
+  if ((c>255) ||(c!=IsPrime(c)))
+  {
+    while ((fftable[i]!=c) && (fftable[i]!=0))
+      i++;
+
+    if (fftable[i]==0)
+    {
+      // illegal GF-table size: c
+      return;
+    }
   }