]> www.ginac.de Git - ginac.git/blobdiff - ginac/expairseq.cpp
Add some minor optimizations.
[ginac.git] / ginac / expairseq.cpp
index 9f580d9e768ff4ac58c5fcaaa0865124ad7069fd..b29f3802c13f2be0f0a55977d6b129c00dd2cdad 100644 (file)
@@ -3,7 +3,7 @@
  *  Implementation of sequences of expression pairs. */
 
 /*
- *  GiNaC Copyright (C) 1999-2005 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2015 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
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include <iostream>
-#include <algorithm>
-#include <string>
-#include <stdexcept>
-
 #include "expairseq.h"
 #include "lst.h"
+#include "add.h"
 #include "mul.h"
 #include "power.h"
 #include "relational.h"
 #include "archive.h"
 #include "operators.h"
 #include "utils.h"
+#include "hash_seed.h"
 #include "indexed.h"
+#include "compiler.h"
 
+#include <algorithm>
 #if EXPAIRSEQ_USE_HASHTAB
 #include <cmath>
 #endif // EXPAIRSEQ_USE_HASHTAB
+#include <iostream>
+#include <iterator>
+#include <stdexcept>
+#include <string>
 
 namespace GiNaC {
 
@@ -67,9 +70,9 @@ public:
 
 // public
 
-expairseq::expairseq() : inherited(TINFO_expairseq)
+expairseq::expairseq() 
 #if EXPAIRSEQ_USE_HASHTAB
-                                                   , hashtabsize(0)
+       : hashtabsize(0)
 #endif // EXPAIRSEQ_USE_HASHTAB
 {}
 
@@ -106,32 +109,32 @@ void expairseq::copy(const expairseq &other)
 // other constructors
 //////////
 
-expairseq::expairseq(const ex &lh, const ex &rh) : inherited(TINFO_expairseq)
+expairseq::expairseq(const ex &lh, const ex &rh)
 {
        construct_from_2_ex(lh,rh);
        GINAC_ASSERT(is_canonical());
 }
 
-expairseq::expairseq(const exvector &v) : inherited(TINFO_expairseq)
+expairseq::expairseq(const exvector &v)
 {
        construct_from_exvector(v);
        GINAC_ASSERT(is_canonical());
 }
 
-expairseq::expairseq(const epvector &v, const ex &oc)
-  : inherited(TINFO_expairseq), overall_coeff(oc)
+expairseq::expairseq(const epvector &v, const ex &oc, bool do_index_renaming)
+  :  overall_coeff(oc)
 {
        GINAC_ASSERT(is_a<numeric>(oc));
-       construct_from_epvector(v);
+       construct_from_epvector(v, do_index_renaming);
        GINAC_ASSERT(is_canonical());
 }
 
-expairseq::expairseq(std::auto_ptr<epvector> vp, const ex &oc)
-  : inherited(TINFO_expairseq), overall_coeff(oc)
+expairseq::expairseq(std::auto_ptr<epvector> vp, const ex &oc, bool do_index_renaming)
+  :  overall_coeff(oc)
 {
        GINAC_ASSERT(vp.get()!=0);
        GINAC_ASSERT(is_a<numeric>(oc));
-       construct_from_epvector(*vp);
+       construct_from_epvector(*vp, do_index_renaming);
        GINAC_ASSERT(is_canonical());
 }
 
@@ -139,18 +142,20 @@ expairseq::expairseq(std::auto_ptr<epvector> vp, const ex &oc)
 // archiving
 //////////
 
-expairseq::expairseq(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
-#if EXPAIRSEQ_USE_HASHTAB
-       , hashtabsize(0)
-#endif
+void expairseq::read_archive(const archive_node &n, lst &sym_lst) 
 {
-       for (unsigned int i=0; true; i++) {
+       inherited::read_archive(n, sym_lst);
+       archive_node::archive_node_cit first = n.find_first("rest");
+       archive_node::archive_node_cit last = n.find_last("coeff");
+       ++last;
+       seq.reserve((last-first)/2);
+
+       for (archive_node::archive_node_cit loc = first; loc < last;) {
                ex rest;
                ex coeff;
-               if (n.find_ex("rest", rest, sym_lst, i) && n.find_ex("coeff", coeff, sym_lst, i))
-                       seq.push_back(expair(rest, coeff));
-               else
-                       break;
+               n.find_ex_by_loc(loc++, rest, sym_lst);
+               n.find_ex_by_loc(loc++, coeff, sym_lst);
+               seq.push_back(expair(rest, coeff));
        }
 
        n.find_ex("overall_coeff", overall_coeff, sym_lst);
@@ -171,7 +176,6 @@ void expairseq::archive(archive_node &n) const
        n.add_ex("overall_coeff", overall_coeff);
 }
 
-DEFAULT_UNARCHIVE(expairseq)
 
 //////////
 // functions overriding virtual functions from base classes
@@ -262,6 +266,26 @@ void expairseq::do_print_tree(const print_tree & c, unsigned level) const
 
 bool expairseq::info(unsigned inf) const
 {
+       switch(inf) {
+               case info_flags::expanded:
+                       return (flags & status_flags::expanded);
+               case info_flags::has_indices: {
+                       if (flags & status_flags::has_indices)
+                               return true;
+                       else if (flags & status_flags::has_no_indices)
+                               return false;
+                       for (epvector::const_iterator i = seq.begin(); i != seq.end(); ++i) {
+                               if (i->rest.info(info_flags::has_indices)) {
+                                       this->setflag(status_flags::has_indices);
+                                       this->clearflag(status_flags::has_no_indices);
+                                       return true;
+                               }
+                       }
+                       this->clearflag(status_flags::has_indices);
+                       this->setflag(status_flags::has_no_indices);
+                       return false;
+               }
+       }
        return inherited::info(inf);
 }
 
@@ -284,7 +308,7 @@ ex expairseq::op(size_t i) const
 ex expairseq::map(map_function &f) const
 {
        std::auto_ptr<epvector> v(new epvector);
-       v->reserve(seq.size());
+       v->reserve(seq.size()+1);
 
        epvector::const_iterator cit = seq.begin(), last = seq.end();
        while (cit != last) {
@@ -293,9 +317,16 @@ ex expairseq::map(map_function &f) const
        }
 
        if (overall_coeff.is_equal(default_overall_coeff()))
-               return thisexpairseq(v, default_overall_coeff());
-       else
-               return thisexpairseq(v, f(overall_coeff));
+               return thisexpairseq(v, default_overall_coeff(), true);
+       else {
+               ex newcoeff = f(overall_coeff);
+               if(is_a<numeric>(newcoeff))
+                       return thisexpairseq(v, newcoeff, true);
+               else {
+                       v->push_back(split_ex_to_pair(newcoeff));
+                       return thisexpairseq(v, default_overall_coeff(), true);
+               }
+       }
 }
 
 /** Perform coefficient-wise automatic term rewriting rules in this class. */
@@ -341,18 +372,16 @@ ex expairseq::conjugate() const
                return *this;
        }
        ex result = thisexpairseq(newepv ? *newepv : seq, x);
-       if (newepv) {
-               delete newepv;
-       }
+       delete newepv;
        return result;
 }
 
-bool expairseq::match(const ex & pattern, lst & repl_lst) const
+bool expairseq::match(const ex & pattern, exmap & repl_lst) const
 {
        // This differs from basic::match() because we want "a+b+c+d" to
        // match "d+*+b" with "*" being "a+c", and we want to honor commutativity
 
-       if (this->tinfo() == ex_to<basic>(pattern).tinfo()) {
+       if (typeid(*this) == typeid(ex_to<basic>(pattern))) {
 
                // Check whether global wildcard (one that matches the "rest of the
                // expression", like "*" above) is present
@@ -366,6 +395,12 @@ bool expairseq::match(const ex & pattern, lst & repl_lst) const
                        }
                }
 
+               // Even if the expression does not match the pattern, some of
+               // its subexpressions could match it. For example, x^5*y^(-1)
+               // does not match the pattern $0^5, but its subexpression x^5
+               // does. So, save repl_lst in order to not add bogus entries.
+               exmap tmp_repl = repl_lst;
+
                // Unfortunately, this is an O(N^2) operation because we can't
                // sort the pattern in a useful way...
 
@@ -383,7 +418,7 @@ bool expairseq::match(const ex & pattern, lst & repl_lst) const
                                continue;
                        exvector::iterator it = ops.begin(), itend = ops.end();
                        while (it != itend) {
-                               if (it->match(p, repl_lst)) {
+                               if (it->match(p, tmp_repl)) {
                                        ops.erase(it);
                                        goto found;
                                }
@@ -404,18 +439,28 @@ found:            ;
                        for (size_t i=0; i<num; i++)
                                vp->push_back(split_ex_to_pair(ops[i]));
                        ex rest = thisexpairseq(vp, default_overall_coeff());
-                       for (lst::const_iterator it = repl_lst.begin(); it != repl_lst.end(); ++it) {
-                               if (it->op(0).is_equal(global_wildcard))
-                                       return rest.is_equal(it->op(1));
+                       for (exmap::const_iterator it = tmp_repl.begin(); it != tmp_repl.end(); ++it) {
+                               if (it->first.is_equal(global_wildcard)) {
+                                       if (rest.is_equal(it->second)) {
+                                               repl_lst = tmp_repl;
+                                               return true;
+                                       }
+                                       return false;
+                               }
                        }
-                       repl_lst.append(global_wildcard == rest);
+                       repl_lst = tmp_repl;
+                       repl_lst[global_wildcard] = rest;
                        return true;
 
                } else {
 
                        // No global wildcard, then the match fails if there are any
                        // unmatched terms left
-                       return ops.empty();
+                       if (ops.empty()) {
+                               repl_lst = tmp_repl;
+                               return true;
+                       }
+                       return false;
                }
        }
        return inherited::match(pattern, repl_lst);
@@ -425,7 +470,7 @@ ex expairseq::subs(const exmap & m, unsigned options) const
 {
        std::auto_ptr<epvector> vp = subschildren(m, options);
        if (vp.get())
-               return ex_to<basic>(thisexpairseq(vp, overall_coeff));
+               return ex_to<basic>(thisexpairseq(vp, overall_coeff, (options & subs_options::no_index_renaming) == 0));
        else if ((options & subs_options::algebraic) && is_exactly_a<mul>(*this))
                return static_cast<const mul *>(this)->algebraic_subs_mul(m, options);
        else
@@ -571,7 +616,7 @@ unsigned expairseq::return_type() const
 
 unsigned expairseq::calchash() const
 {
-       unsigned v = golden_ratio_hash(this->tinfo());
+       unsigned v = make_hash_seed(typeid(*this));
        epvector::const_iterator i = seq.begin();
        const epvector::const_iterator end = seq.end();
        while (i != end) {
@@ -617,17 +662,17 @@ ex expairseq::expand(unsigned options) const
  *  has (at least) two possible different semantics but we want to inherit
  *  methods thus avoiding code duplication.  Sometimes a method in expairseq
  *  has to create a new one of the same semantics, which cannot be done by a
- *  ctor because the name (add, mul,...) is unknown on the expaiseq level.  In
+ *  ctor because the name (add, mul,...) is unknown on the expairseq level.  In
  *  order for this trick to work a derived class must of course override this
  *  definition. */
-ex expairseq::thisexpairseq(const epvector &v, const ex &oc) const
+ex expairseq::thisexpairseq(const epvector &v, const ex &oc, bool do_index_renaming) const
 {
-       return expairseq(v, oc);
+       return expairseq(v, oc, do_index_renaming);
 }
 
-ex expairseq::thisexpairseq(std::auto_ptr<epvector> vp, const ex &oc) const
+ex expairseq::thisexpairseq(std::auto_ptr<epvector> vp, const ex &oc, bool do_index_renaming) const
 {
-       return expairseq(vp, oc);
+       return expairseq(vp, oc, do_index_renaming);
 }
 
 void expairseq::printpair(const print_context & c, const expair & p, unsigned upper_precedence) const
@@ -749,8 +794,8 @@ void expairseq::construct_from_2_ex_via_exvector(const ex &lh, const ex &rh)
 
 void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
 {
-       if (ex_to<basic>(lh).tinfo()==this->tinfo()) {
-               if (ex_to<basic>(rh).tinfo()==this->tinfo()) {
+       if (typeid(ex_to<basic>(lh)) == typeid(*this)) {
+               if (typeid(ex_to<basic>(rh)) == typeid(*this)) {
 #if EXPAIRSEQ_USE_HASHTAB
                        unsigned totalsize = ex_to<expairseq>(lh).seq.size() +
                                             ex_to<expairseq>(rh).seq.size();
@@ -758,8 +803,8 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
                                construct_from_2_ex_via_exvector(lh,rh);
                        } else {
 #endif // EXPAIRSEQ_USE_HASHTAB
-                               if(is_a<mul>(lh))
-                               {       
+                               if (is_a<mul>(lh) && lh.info(info_flags::has_indices) && 
+                                       rh.info(info_flags::has_indices)) {
                                        ex newrh=rename_dummy_indices_uniquely(lh, rh);
                                        construct_from_2_expairseq(ex_to<expairseq>(lh),
                                                                   ex_to<expairseq>(newrh));
@@ -784,7 +829,7 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
 #endif // EXPAIRSEQ_USE_HASHTAB
                        return;
                }
-       } else if (ex_to<basic>(rh).tinfo()==this->tinfo()) {
+       } else if (typeid(ex_to<basic>(rh)) == typeid(*this)) {
 #if EXPAIRSEQ_USE_HASHTAB
                unsigned totalsize=ex_to<expairseq>(rh).seq.size()+1;
                if (calc_hashtabsize(totalsize)!=0) {
@@ -845,7 +890,7 @@ void expairseq::construct_from_2_ex(const ex &lh, const ex &rh)
 }
 
 void expairseq::construct_from_2_expairseq(const expairseq &s1,
-                                                                                  const expairseq &s2)
+                                           const expairseq &s2)
 {
        combine_overall_coeff(s1.overall_coeff);
        combine_overall_coeff(s2.overall_coeff);
@@ -861,6 +906,7 @@ void expairseq::construct_from_2_expairseq(const expairseq &s1,
        
        while (first1!=last1 && first2!=last2) {
                int cmpval = (*first1).rest.compare((*first2).rest);
+
                if (cmpval==0) {
                        // combine terms
                        const numeric &newcoeff = ex_to<numeric>(first1->coeff).
@@ -899,7 +945,7 @@ void expairseq::construct_from_2_expairseq(const expairseq &s1,
 }
 
 void expairseq::construct_from_expairseq_ex(const expairseq &s,
-                                                                                       const ex &e)
+                                            const ex &e)
 {
        combine_overall_coeff(s.overall_coeff);
        if (is_exactly_a<numeric>(e)) {
@@ -964,7 +1010,7 @@ void expairseq::construct_from_exvector(const exvector &v)
 {
        // simplifications: +(a,+(b,c),d) -> +(a,b,c,d) (associativity)
        //                  +(d,b,c,a) -> +(a,b,c,d) (canonicalization)
-       //                  +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric())
+       //                  +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric)
        //                  (same for (+,*) -> (*,^)
 
        make_flat(v);
@@ -976,14 +1022,14 @@ void expairseq::construct_from_exvector(const exvector &v)
 #endif // EXPAIRSEQ_USE_HASHTAB
 }
 
-void expairseq::construct_from_epvector(const epvector &v)
+void expairseq::construct_from_epvector(const epvector &v, bool do_index_renaming)
 {
        // simplifications: +(a,+(b,c),d) -> +(a,b,c,d) (associativity)
        //                  +(d,b,c,a) -> +(a,b,c,d) (canonicalization)
-       //                  +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric())
-       //                  (same for (+,*) -> (*,^)
+       //                  +(...,x,*(x,c1),*(x,c2)) -> +(...,*(x,1+c1+c2)) (c1, c2 numeric)
+       //                  same for (+,*) -> (*,^)
 
-       make_flat(v);
+       make_flat(v, do_index_renaming);
 #if EXPAIRSEQ_USE_HASHTAB
        combine_same_terms();
 #else
@@ -1002,13 +1048,17 @@ void expairseq::make_flat(const exvector &v)
        // and their cumulative number of operands
        int nexpairseqs = 0;
        int noperands = 0;
+       bool do_idx_rename = false;
        
        cit = v.begin();
        while (cit!=v.end()) {
-               if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
+               if (typeid(ex_to<basic>(*cit)) == typeid(*this)) {
                        ++nexpairseqs;
                        noperands += ex_to<expairseq>(*cit).seq.size();
                }
+               if (is_a<mul>(*this) && (!do_idx_rename) &&
+                               cit->info(info_flags::has_indices))
+                       do_idx_rename = true;
                ++cit;
        }
        
@@ -1016,35 +1066,25 @@ void expairseq::make_flat(const exvector &v)
        seq.reserve(v.size()+noperands-nexpairseqs);
        
        // copy elements and split off numerical part
-       exvector dummy_indices;
+       make_flat_inserter mf(v, do_idx_rename);
        cit = v.begin();
        while (cit!=v.end()) {
-               if (ex_to<basic>(*cit).tinfo()==this->tinfo()) {
-                       const expairseq *subseqref;
-                       ex newfactor;
-                       if(is_a<mul>(*cit))
-                       {
-                               exvector dummies_of_factor = get_all_dummy_indices(*cit);
-                               sort(dummies_of_factor.begin(), dummies_of_factor.end(), ex_is_less());
-                               newfactor = rename_dummy_indices_uniquely(dummy_indices, dummies_of_factor, *cit);
-                               subseqref = &(ex_to<expairseq>(newfactor));
-                               exvector new_dummy_indices;
-                               set_union(dummy_indices.begin(), dummy_indices.end(), dummies_of_factor.begin(), dummies_of_factor.end(), std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-                               dummy_indices.swap(new_dummy_indices);
-                       }
-                       else
-                               subseqref = &ex_to<expairseq>(*cit);
-                       combine_overall_coeff(subseqref->overall_coeff);
-                       epvector::const_iterator cit_s = subseqref->seq.begin();
-                       while (cit_s!=subseqref->seq.end()) {
+               if (typeid(ex_to<basic>(*cit)) == typeid(*this)) {
+                       ex newfactor = mf.handle_factor(*cit, _ex1);
+                       const expairseq &subseqref = ex_to<expairseq>(newfactor);
+                       combine_overall_coeff(subseqref.overall_coeff);
+                       epvector::const_iterator cit_s = subseqref.seq.begin();
+                       while (cit_s!=subseqref.seq.end()) {
                                seq.push_back(*cit_s);
                                ++cit_s;
                        }
                } else {
                        if (is_exactly_a<numeric>(*cit))
                                combine_overall_coeff(*cit);
-                       else
-                               seq.push_back(split_ex_to_pair(*cit));
+                       else {
+                               ex newfactor = mf.handle_factor(*cit, _ex1);
+                               seq.push_back(split_ex_to_pair(newfactor));
+                       }
                }
                ++cit;
        }
@@ -1052,7 +1092,7 @@ void expairseq::make_flat(const exvector &v)
 
 /** Combine this expairseq with argument epvector.
  *  It cares for associativity as well as for special handling of numerics. */
-void expairseq::make_flat(const epvector &v)
+void expairseq::make_flat(const epvector &v, bool do_index_renaming)
 {
        epvector::const_iterator cit;
        
@@ -1060,25 +1100,32 @@ void expairseq::make_flat(const epvector &v)
        // and their cumulative number of operands
        int nexpairseqs = 0;
        int noperands = 0;
+       bool really_need_rename_inds = false;
        
        cit = v.begin();
        while (cit!=v.end()) {
-               if (ex_to<basic>(cit->rest).tinfo()==this->tinfo()) {
+               if (typeid(ex_to<basic>(cit->rest)) == typeid(*this)) {
                        ++nexpairseqs;
                        noperands += ex_to<expairseq>(cit->rest).seq.size();
                }
+               if ((!really_need_rename_inds) && is_a<mul>(*this) &&
+                               cit->rest.info(info_flags::has_indices))
+                       really_need_rename_inds = true;
                ++cit;
        }
+       do_index_renaming = do_index_renaming && really_need_rename_inds;
        
        // reserve seq and coeffseq which will hold all operands
        seq.reserve(v.size()+noperands-nexpairseqs);
+       make_flat_inserter mf(v, do_index_renaming);
        
        // copy elements and split off numerical part
        cit = v.begin();
        while (cit!=v.end()) {
-               if (ex_to<basic>(cit->rest).tinfo()==this->tinfo() &&
+               if ((typeid(ex_to<basic>(cit->rest)) == typeid(*this)) &&
                    this->can_make_flat(*cit)) {
-                       const expairseq &subseqref = ex_to<expairseq>(cit->rest);
+                       ex newrest = mf.handle_factor(cit->rest, cit->coeff);
+                       const expairseq &subseqref = ex_to<expairseq>(newrest);
                        combine_overall_coeff(ex_to<numeric>(subseqref.overall_coeff),
                                                            ex_to<numeric>(cit->coeff));
                        epvector::const_iterator cit_s = subseqref.seq.begin();
@@ -1091,9 +1138,15 @@ void expairseq::make_flat(const epvector &v)
                        }
                } else {
                        if (cit->is_canonical_numeric())
-                               combine_overall_coeff(cit->rest);
-                       else
-                               seq.push_back(*cit);
+                               combine_overall_coeff(mf.handle_factor(cit->rest, _ex1));
+                       else {
+                               ex rest = cit->rest;
+                               ex newrest = mf.handle_factor(rest, cit->coeff);
+                               if (are_ex_trivially_equal(newrest, rest))
+                                       seq.push_back(*cit);
+                               else
+                                       seq.push_back(expair(newrest, cit->coeff));
+                       }
                }
                ++cit;
        }
@@ -1396,7 +1449,7 @@ bool expairseq::has_coeff_0() const
 }
 
 void expairseq::add_numerics_to_hashtab(epvector::iterator first_numeric,
-                                                                               epvector::const_iterator last_non_zero)
+                                        epvector::const_iterator last_non_zero)
 {
        if (first_numeric == seq.end()) return; // no numerics
        
@@ -1472,7 +1525,7 @@ bool expairseq::is_canonical() const
                return 1;
        
 #if EXPAIRSEQ_USE_HASHTAB
-       if (hashtabsize > 0) return 1; // not canoncalized
+       if (hashtabsize > 0) return 1; // not canonicalized
 #endif // EXPAIRSEQ_USE_HASHTAB
        
        epvector::const_iterator it = seq.begin(), itend = seq.end();
@@ -1558,7 +1611,7 @@ std::auto_ptr<epvector> expairseq::evalchildren(int level) const
        // returns a pointer to a newly created epvector otherwise
        // (which has to be deleted somewhere else)
 
-       if (level==1)
+       if (likely(level==1))
                return std::auto_ptr<epvector>(0);
        
        if (level == -max_recursion_level)
@@ -1601,68 +1654,6 @@ std::auto_ptr<epvector> expairseq::evalchildren(int level) const
        return std::auto_ptr<epvector>(0); // signalling nothing has changed
 }
 
-class safe_inserter
-{
-       public:
-               safe_inserter(const ex&, const bool disable_renaming=false);
-               std::auto_ptr<epvector> getseq(){return epv;}
-               void insert_old_pair(const expair &p)
-               {
-                       epv->push_back(p);
-               }
-               void insert_new_pair(const expair &p, const ex &orig_ex);
-       private:
-               std::auto_ptr<epvector> epv;
-               bool dodummies;
-               exvector dummy_indices;
-               void update_dummy_indices(const exvector&);
-};
-
-safe_inserter::safe_inserter(const ex&e, const bool disable_renaming)
-               :epv(new epvector)
-{
-       epv->reserve(e.nops());
-       dodummies=is_a<mul>(e);
-       if(disable_renaming)
-               dodummies=false;
-       if(dodummies) {
-               dummy_indices = get_all_dummy_indices(e);
-               sort(dummy_indices.begin(), dummy_indices.end(), ex_is_less());
-       }
-}
-
-void safe_inserter::update_dummy_indices(const exvector &v)
-{
-       exvector new_dummy_indices;
-       set_union(dummy_indices.begin(), dummy_indices.end(), v.begin(), v.end(),
-               std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-       dummy_indices.swap(new_dummy_indices);
-}
-
-void safe_inserter::insert_new_pair(const expair &p, const ex &orig_ex)
-{
-       if(!dodummies) {
-               epv->push_back(p);
-               return;
-       }
-       exvector dummies_of_factor = get_all_dummy_indices(p.rest);
-       if(dummies_of_factor.size() == 0) {
-               epv->push_back(p);
-               return;
-       }
-       sort(dummies_of_factor.begin(), dummies_of_factor.end(), ex_is_less());
-       exvector dummies_of_orig_ex = get_all_dummy_indices(orig_ex);
-       sort(dummies_of_orig_ex.begin(), dummies_of_orig_ex.end(), ex_is_less());
-       exvector new_dummy_indices;
-       new_dummy_indices.reserve(dummy_indices.size());
-       set_difference(dummy_indices.begin(), dummy_indices.end(), dummies_of_orig_ex.begin(), dummies_of_orig_ex.end(),
-               std::back_insert_iterator<exvector>(new_dummy_indices), ex_is_less());
-       dummy_indices.swap(new_dummy_indices);
-       ex newfactor = rename_dummy_indices_uniquely(dummy_indices, dummies_of_factor, p.rest);
-       update_dummy_indices(dummies_of_factor);
-       epv -> push_back(expair(newfactor, p.coeff));
-}
-
 /** Member-wise substitute in this sequence.
  *
  *  @see expairseq::subs()
@@ -1697,27 +1688,22 @@ std::auto_ptr<epvector> expairseq::subschildren(const exmap & m, unsigned option
                        if (!are_ex_trivially_equal(orig_ex, subsed_ex)) {
 
                                // Something changed, copy seq, subs and return it
-                               safe_inserter s(*this, options & subs_options::no_index_renaming);
+                               std::auto_ptr<epvector> s(new epvector);
+                               s->reserve(seq.size());
 
                                // Copy parts of seq which are known not to have changed
-                               for(epvector::const_iterator i=seq.begin(); i!=cit; ++i)
-                                       s.insert_old_pair(*i);
+                               s->insert(s->begin(), seq.begin(), cit);
 
                                // Copy first changed element
-                               s.insert_new_pair(split_ex_to_pair(subsed_ex), orig_ex);
+                               s->push_back(split_ex_to_pair(subsed_ex));
                                ++cit;
 
                                // Copy rest
                                while (cit != last) {
-                                       ex orig_ex = recombine_pair_to_ex(*cit);
-                                       ex subsed_ex = orig_ex.subs(m, options);
-                                       if(are_ex_trivially_equal(orig_ex, subsed_ex))
-                                               s.insert_old_pair(*cit);
-                                       else
-                                               s.insert_new_pair(split_ex_to_pair(subsed_ex), orig_ex);
+                                       s->push_back(split_ex_to_pair(recombine_pair_to_ex(*cit).subs(m, options)));
                                        ++cit;
                                }
-                               return s.getseq();
+                               return s;
                        }
 
                        ++cit;
@@ -1733,27 +1719,22 @@ std::auto_ptr<epvector> expairseq::subschildren(const exmap & m, unsigned option
                        if (!are_ex_trivially_equal(cit->rest, subsed_ex)) {
                        
                                // Something changed, copy seq, subs and return it
-                               safe_inserter s(*this, options & subs_options::no_index_renaming);
+                               std::auto_ptr<epvector> s(new epvector);
+                               s->reserve(seq.size());
 
                                // Copy parts of seq which are known not to have changed
-                               for(epvector::const_iterator i=seq.begin(); i!=cit; ++i)
-                                       s.insert_old_pair(*i);
+                               s->insert(s->begin(), seq.begin(), cit);
                        
                                // Copy first changed element
-                               s.insert_new_pair(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff), cit->rest);
+                               s->push_back(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff));
                                ++cit;
 
                                // Copy rest
                                while (cit != last) {
-                                       const ex &orig_ex = cit->rest;
-                                       const ex &subsed_ex = cit->rest.subs(m, options);
-                                       if(are_ex_trivially_equal(orig_ex, subsed_ex))
-                                               s.insert_old_pair(*cit);
-                                       else
-                                               s.insert_new_pair(combine_ex_with_coeff_to_pair(subsed_ex, cit->coeff), orig_ex);
+                                       s->push_back(combine_ex_with_coeff_to_pair(cit->rest.subs(m, options), cit->coeff));
                                        ++cit;
                                }
-                               return s.getseq();
+                               return s;
                        }
 
                        ++cit;