w.r.t, https://gcc.gnu.org/wiki/Speedup_areas where we want to improve the
performance of splay trees.
The function `splay_tree_node splay_tree_lookup (splay_tree, splay_tree_key);'
updates the nodes every time a lookup is done.
IIUC, There are places where we call this function in a loop i.e., we lookup
different elements every time.
e.g.,
In this exaple we are looking for a different `t' in each iteration.
gcc/gimplify.c:1096: splay_tree_lookup (ctx->variables, (splay_tree_key) t) ==
NULL)
Here, we change the tree itself `ctx'
gcc/gimplify.c:5532: n = splay_tree_lookup (ctx->variables,
(splay_tree_key)decl);
I think we don't need to update the tree in these cases at least.
-Aditya
