* mul::expand(): Considerable speedup through caching in nested loop.

[ginac.git] / ginac / mul.cpp

diff --git a/ginac/mul.cpp b/ginac/mul.cpp
index 83bebb2638f3d8f3264fa4f3ba2100fd8329271d..c7fb32a1527123a02b9fd82ffc677672af49c870 100644 (file)
--- a/ginac/mul.cpp
+++ b/ginac/mul.cpp
@@ -20,6 +20,7 @@
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <iostream>
 #include <vector>
 #include <stdexcept>
 
@@ -140,7 +141,7 @@ void mul::print(const print_context & c, unsigned level) const
                while (it != itend) {
 
                        // If the first argument is a negative integer power, it gets printed as "1.0/<expr>"
-                       if (it == seq.begin() && ex_to<numeric>(it->coeff).is_integer() && it->coeff.compare(_num0) < 0) {
+                       if (it == seq.begin() && ex_to<numeric>(it->coeff).is_integer() && it->coeff.info(info_flags::negative)) {
                                if (is_a<print_csrc_cl_N>(c))
                                        c.s << "recip(";
                                else
@@ -148,7 +149,7 @@ void mul::print(const print_context & c, unsigned level) const
                        }
 
                        // If the exponent is 1 or -1, it is left out
-                       if (it->coeff.compare(_ex1) == 0 || it->coeff.compare(_num_1) == 0)
+                       if (it->coeff.is_equal(_ex1) || it->coeff.is_equal(_ex_1))
                                it->rest.print(c, precedence());
                        else {
                                // Outer parens around ex needed for broken gcc-2.95 parser:
@@ -158,7 +159,7 @@ void mul::print(const print_context & c, unsigned level) const
                        // Separator is "/" for negative integer powers, "*" otherwise
                        ++it;
                        if (it != itend) {
-                               if (ex_to<numeric>(it->coeff).is_integer() && it->coeff.compare(_num0) < 0)
+                               if (ex_to<numeric>(it->coeff).is_integer() && it->coeff.info(info_flags::negative))
                                        c.s << "/";
                                else
                                        c.s << "*";
@@ -168,6 +169,14 @@ void mul::print(const print_context & c, unsigned level) const
                if (precedence() <= level)
                        c.s << ")";
 
+       } else if (is_a<print_python_repr>(c)) {
+               c.s << class_name() << '(';
+               op(0).print(c);
+               for (unsigned i=1; i<nops(); ++i) {
+                       c.s << ',';
+                       op(i).print(c);
+               }
+               c.s << ')';
        } else {
 
                if (precedence() <= level) {
@@ -684,9 +693,10 @@ ex mul::expand(unsigned options) const
                                exvector distrseq;
                                distrseq.reserve(n1*n2);
                                for (int i1=0; i1<n1; ++i1) {
-                                       for (int i2=0; i2<n2; ++i2) {
-                                               distrseq.push_back(add1.op(i1) * add2.op(i2));
-                                       }
+                                       // cache the first operand (for efficiency):
+                                       const ex op1 = add1.op(i1);
+                                       for (int i2=0; i2<n2; ++i2)
+                                               distrseq.push_back(op1 * add2.op(i2));
                                }
                                last_expanded = (new add(distrseq))->
                                                 setflag(status_flags::dynallocated | (options == 0 ? status_flags::expanded : 0));
@@ -744,7 +754,7 @@ ex mul::expand(unsigned options) const
  *  pointer, if sequence is unchanged. */
 epvector * mul::expandchildren(unsigned options) const
 {
-       epvector::const_iterator last = seq.end();
+       const epvector::const_iterator last = seq.end();
        epvector::const_iterator cit = seq.begin();
        while (cit!=last) {
                const ex & factor = recombine_pair_to_ex(*cit);