https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98426
--- Comment #3 from martin <mscfd at gmx dot net> ---
Sorry for the noise, but as this gives big reductions in compilation time it is
quite important to me (and probably other big module based projects).
I just realised that I mixed up gfc_symtree->name and gfc_symtree->n.sym->name.
The reason why find_symbol traverses the whole tree in the worst case is that
it is ordered by gfc_symtree->name but it looks for gfc_symtree->n.sym->name.
So far I got the impression that either gfc_symtree->name is a unique name
("@xxx") or equal to gfc_symtree->n.sym->name (if n.sym!=NULL). In this case,
the following patch should do the trick and traverse only log(N) of the tree:
diff --git a/gcc/fortran/module.c b/gcc/fortran/module.c
index 4c6ff22d5c1..8dc59e25d46 100644
--- a/gcc/fortran/module.c
+++ b/gcc/fortran/module.c
@@ -4659,10 +4659,20 @@ find_symbol (gfc_symtree *st, const char *name,
return st;
}
+ c = strcmp (name, st->name);
+ if (c < 0)
+ retval = find_symbol (st->left, name, module, generic);
+ else if (c > 0)
+ retval = find_symbol (st->right, name, module, generic);
+ else
+ retval = NULL;
+
+/* original traverse
retval = find_symbol (st->left, name, module, generic);
if (retval == NULL)
retval = find_symbol (st->right, name, module, generic);
+*/
return retval;
}
