Optimise Konieczny (libsemigroups#491)

* return early from is_group_index * Format with clang-format v15 --------- Co-authored-by: Finn Smith <[email protected]> Co-authored-by: James D. Mitchell <[email protected]>
james-d-mitchell · Jan 14, 2024 · e0d041b · e0d041b
1 parent 8e10e35
commit e0d041b
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Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/include/libsemigroups/containers.hpp b/include/libsemigroups/containers.hpp
@@ -786,6 +786,11 @@ namespace libsemigroups {
                && std::equal(cbegin(), cend(), that.cbegin());
       }
 
+      // not noexcept because == is not
+      bool operator!=(StaticVector1 const& that) const {
+        return !(*this == that);
+      }
+
       void clear() noexcept {
         _size = 0;
       }

diff --git a/include/libsemigroups/konieczny.hpp b/include/libsemigroups/konieczny.hpp
@@ -1411,12 +1411,16 @@ namespace libsemigroups {
                 this->to_external_const(y),
                 this->to_external_const(x));
       Lambda()(_tmp_lambda_value1, this->to_external(tmp));
-      Rho()(_tmp_rho_value1, this->to_external(tmp));
       Lambda()(_tmp_lambda_value2, this->to_external_const(x));
+
+      if (_tmp_lambda_value1 != _tmp_lambda_value2) {
+        return false;
+      }
+
+      Rho()(_tmp_rho_value1, this->to_external(tmp));
       Rho()(_tmp_rho_value2, this->to_external_const(y));
 
-      return _tmp_lambda_value1 == _tmp_lambda_value2
-             && _tmp_rho_value1 == _tmp_rho_value2;
+      return _tmp_rho_value1 == _tmp_rho_value2;
     }
 
     // pass full_check = true to use the contains method of the D-classes