* Restore speed lost in GiNaC-1.3.2 [V. Kisil].

[ginac.git] / ginac / mul.cpp

diff --git a/ginac/mul.cpp b/ginac/mul.cpp
index 90fd772ec2b16552c390e4697bfc30d3ca2871a8..f5c202252ba4f8f9a351107075680673ba0f6995 100644 (file)
--- a/ginac/mul.cpp
+++ b/ginac/mul.cpp
@@ -895,16 +895,33 @@ ex mul::expand(unsigned options) const
                                // Compute the new overall coefficient and put it together:
                                ex tmp_accu = (new add(distrseq, add1.overall_coeff*add2.overall_coeff))->setflag(status_flags::dynallocated);
 
+                               exvector add1_dummy_indices, add2_dummy_indices, add_indices;
+
+                               for (epvector::const_iterator i=add1begin; i!=add1end; ++i) {
+                                       add_indices = get_all_dummy_indices(i->rest);
+                                       add1_dummy_indices.insert(add1_dummy_indices.end(), add_indices.begin(), add_indices.end());
+                               }
+                               for (epvector::const_iterator i=add2begin; i!=add2end; ++i) {
+                                       add_indices = get_all_dummy_indices(i->rest);
+                                       add2_dummy_indices.insert(add2_dummy_indices.end(), add_indices.begin(), add_indices.end());
+                               }
+
+                               sort(add1_dummy_indices.begin(), add1_dummy_indices.end(), ex_is_less());
+                               sort(add2_dummy_indices.begin(), add2_dummy_indices.end(), ex_is_less());
+                               lst dummy_subs = rename_dummy_indices_uniquely(add1_dummy_indices, add2_dummy_indices);
+
                                // Multiply explicitly all non-numeric terms of add1 and add2:
-                               for (epvector::const_iterator i1=add1begin; i1!=add1end; ++i1) {
+                               for (epvector::const_iterator i2=add2begin; i2!=add2end; ++i2) {
                                        // We really have to combine terms here in order to compactify
                                        // the result.  Otherwise it would become waayy tooo bigg.
                                        numeric oc;
                                        distrseq.clear();
-                                       for (epvector::const_iterator i2=add2begin; i2!=add2end; ++i2) {
+                                       ex i2_new = (dummy_subs.op(0).nops()>0? 
+                                                                i2->rest.subs((lst)dummy_subs.op(0), (lst)dummy_subs.op(1), subs_options::no_pattern) : i2->rest);
+                                       for (epvector::const_iterator i1=add1begin; i1!=add1end; ++i1) {
                                                // Don't push_back expairs which might have a rest that evaluates to a numeric,
                                                // since that would violate an invariant of expairseq:
-                                               const ex rest = (new mul(i1->rest, rename_dummy_indices_uniquely(i1->rest, i2->rest)))->setflag(status_flags::dynallocated);
+                                               const ex rest = (new mul(i1->rest, i2_new))->setflag(status_flags::dynallocated);
                                                if (is_exactly_a<numeric>(rest)) {
                                                        oc += ex_to<numeric>(rest).mul(ex_to<numeric>(i1->coeff).mul(ex_to<numeric>(i2->coeff)));
                                                } else {
@@ -932,10 +949,12 @@ ex mul::expand(unsigned options) const
                size_t n = last_expanded.nops();
                exvector distrseq;
                distrseq.reserve(n);
+               exvector va = get_all_dummy_indices(mul(non_adds));
+               sort(va.begin(), va.end(), ex_is_less());
 
                for (size_t i=0; i<n; ++i) {
                        epvector factors = non_adds;
-                       factors.push_back(split_ex_to_pair(rename_dummy_indices_uniquely(mul(non_adds), last_expanded.op(i))));
+                       factors.push_back(split_ex_to_pair(rename_dummy_indices_uniquely(va, last_expanded.op(i))));
                        ex term = (new mul(factors, overall_coeff))->setflag(status_flags::dynallocated);
                        if (can_be_further_expanded(term)) {
                                distrseq.push_back(term.expand());