Fix DerivGaussV2 target indexing for size-1 integral sets

handle_trivial_nodes() used default_dims() (hardcoded "1") before
adapt_dims_() provided correct runtime dims ("lowdim"/"highdim").
Pass localdims through optimize_rr_out → handle_trivial_nodes.

Author: kshitij-05

src/bin/libint/dg.cc

@@ -499,10 +499,11 @@ void DirectedGraph::apply_to(const std::shared_ptr<DGVertex>& vertex,
 
 // Optimize out simple recurrence relations
 void DirectedGraph::optimize_rr_out(
-    const std::shared_ptr<CodeContext>& context) {
+    const std::shared_ptr<CodeContext>& context,
+    const std::shared_ptr<ImplicitDimensions>& dims) {
   replace_rr_with_expr();
   remove_trivial_arithmetics();
-  handle_trivial_nodes(context);
+  handle_trivial_nodes(context, dims);
   remove_disconnected_vertices();
   find_subtrees();
 }
@@ -797,7 +798,8 @@ inline std::string to_vector_symbol(const std::shared_ptr<DGVertex>& v) {
 // refer to another node so that no code is generated for it.
 //
 void DirectedGraph::handle_trivial_nodes(
-    const std::shared_ptr<CodeContext>& context) {
+    const std::shared_ptr<CodeContext>& context,
+    const std::shared_ptr<ImplicitDimensions>& dims) {
   typedef vertices::iterator iter;
   for (iter v = stack_.begin(); v != stack_.end(); ++v) {
     const ver_ptr& vptr = vertex_ptr(*v);
@@ -821,8 +823,6 @@ void DirectedGraph::handle_trivial_nodes(
           // if (child->symbol_set() == false)
           {
             const std::string stack_name("stack");
-            const std::shared_ptr<ImplicitDimensions>& dims =
-                ImplicitDimensions::default_dims();
             std::string low_rank = dims->low_label();
             std::string veclen = dims->vecdim_label();
 

src/bin/libint/dg.h

@@ -22,6 +22,7 @@
 #define _libint2_src_bin_libint_dg_h_
 
 #include <dgvertex.h>
+#include <dims.h>
 #include <exception.h>
 #include <global_macros.h>
 #include <key.h>
@@ -253,7 +254,9 @@ class DirectedGraph : public std::enable_shared_from_this<DirectedGraph> {
       optimized away. optimize_rr_out() will replace all simple recurrence
      relations with code representing them.
    */
-  void optimize_rr_out(const std::shared_ptr<CodeContext>& context);
+  void optimize_rr_out(const std::shared_ptr<CodeContext>& context,
+                       const std::shared_ptr<ImplicitDimensions>& dims =
+                           ImplicitDimensions::default_dims());
 
   /** after all apply's have been called, traverse()
       construct a heuristic order of traversal for the graph.
@@ -438,7 +441,9 @@ class DirectedGraph : public std::enable_shared_from_this<DirectedGraph> {
   to their equivalents (such as (ss|ss) shell quartet can only be connected to
   (ss|ss) integral)
    */
-  void handle_trivial_nodes(const std::shared_ptr<CodeContext>& context);
+  void handle_trivial_nodes(const std::shared_ptr<CodeContext>& context,
+                            const std::shared_ptr<ImplicitDimensions>& dims =
+                                ImplicitDimensions::default_dims());
   /// This functions removes vertices not connected to other vertices
   void remove_disconnected_vertices();
   /** Finds (binary) subtrees. The subtrees correspond to a single-line code (no

src/bin/libint/rr.cc

@@ -127,8 +127,11 @@ void RecurrenceRelation::generate_code(
   // Assign symbols for the target and source integral sets
   std::shared_ptr<CodeSymbols> symbols(new CodeSymbols);
   assign_symbols_(symbols);
+  // Compute local dimensions before optimize_rr_out so that
+  // handle_trivial_nodes uses the correct dims (e.g., "lowdim" instead of "1")
+  std::shared_ptr<ImplicitDimensions> localdims = adapt_dims_(dims);
   // Traverse the graph
-  dg->optimize_rr_out(context);
+  dg->optimize_rr_out(context, localdims);
   dg->traverse();
 #if PRINT_DAG_GRAPHVIZ
   {
@@ -138,7 +141,6 @@ void RecurrenceRelation::generate_code(
 #endif
   // Generate code
   std::shared_ptr<MemoryManager> memman(new WorstFitMemoryManager());
-  std::shared_ptr<ImplicitDimensions> localdims = adapt_dims_(dims);
   dg->generate_code(context, memman, localdims, symbols, funcname, decl, def);
 
   // extract all external symbols -- these will be members of the evaluator