pgcd(), chinrem_gcd(): use appropriate definition of the degree.

[ginac.git] / ginac / polynomial / mgcd.cpp

diff --git a/ginac/polynomial/mgcd.cpp b/ginac/polynomial/mgcd.cpp
index b0c1b70a23219c0e414642c1d1ee23e91fe7bfdd..24da934690237e42e26a97caa35b09080eabc672 100644 (file)
--- a/ginac/polynomial/mgcd.cpp
+++ b/ginac/polynomial/mgcd.cpp
@@ -3,7 +3,7 @@
  *  Chinese remainder algorithm. */
 
 /*
  *  Chinese remainder algorithm. */
 
 /*

- *  GiNaC Copyright (C) 1999-2009 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2010 Johannes Gutenberg University Mainz, Germany

  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by


@@ -27,6 +27,7 @@
 #include "primes_factory.h"
 #include "divide_in_z_p.h"
 #include "poly_cra.h"
 #include "primes_factory.h"
 #include "divide_in_z_p.h"
 #include "poly_cra.h"

+#include <numeric> // std::accumulate

 
 #include <cln/integer.h>
 
 
 #include <cln/integer.h>
 


@@ -58,12 +59,15 @@ ex chinrem_gcd(const ex& A_, const ex& B_, const exvector& vars)
        const cln::cl_I g_lc = cln::gcd(a_lc, b_lc);
 
        const ex& x(vars.back());
        const cln::cl_I g_lc = cln::gcd(a_lc, b_lc);
 
        const ex& x(vars.back());

-       int n = std::min(A.degree(x), B.degree(x));
+       exp_vector_t n = std::min(degree_vector(A, vars), degree_vector(B, vars));
+       const int nTot = std::accumulate(n.begin(), n.end(), 0);

        const cln::cl_I A_max_coeff = to_cl_I(A.max_coefficient()); 
        const cln::cl_I B_max_coeff = to_cl_I(B.max_coefficient());
        const cln::cl_I A_max_coeff = to_cl_I(A.max_coefficient()); 
        const cln::cl_I B_max_coeff = to_cl_I(B.max_coefficient());

-       const cln::cl_I lcoeff_limit = (cln::cl_I(1) << n)*cln::abs(g_lc)*
+
+       const cln::cl_I lcoeff_limit = (cln::cl_I(1) << nTot)*cln::abs(g_lc)*

                std::min(A_max_coeff, B_max_coeff);
 
                std::min(A_max_coeff, B_max_coeff);
 

+

        cln::cl_I q = 0;
        ex H = 0;
 
        cln::cl_I q = 0;
        ex H = 0;
 


@@ -83,8 +87,8 @@ ex chinrem_gcd(const ex& A_, const ex& B_, const exvector& vars)
                const cln::cl_I Cp_lc = integer_lcoeff(Cp, vars);
                const cln::cl_I nlc = smod(recip(Cp_lc, p)*g_lcp, p);
                Cp = (Cp*numeric(nlc)).expand().smod(pnum);
                const cln::cl_I Cp_lc = integer_lcoeff(Cp, vars);
                const cln::cl_I nlc = smod(recip(Cp_lc, p)*g_lcp, p);
                Cp = (Cp*numeric(nlc)).expand().smod(pnum);

-               int cp_deg = Cp.degree(x);
-               if (cp_deg == 0)
+               exp_vector_t cp_deg = degree_vector(Cp, vars);
+               if (zerop(cp_deg))

                        return numeric(g_lc);
                if (zerop(q)) {
                        H = Cp;
                        return numeric(g_lc);
                if (zerop(q)) {
                        H = Cp;