https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61515
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
All time is spent in invalidate_equivalencies.
/* A new value has been assigned to LHS. If necessary, invalidate any
equivalences that are no longer valid. */
static void
invalidate_equivalences (tree lhs, vec<tree> *stack)
{
for (unsigned int i = 1; i < num_ssa_names; i++)
if (ssa_name (i) && SSA_NAME_VALUE (ssa_name (i)) == lhs)
record_temporary_equivalence (ssa_name (i), NULL_TREE, stack);
if (SSA_NAME_VALUE (lhs))
record_temporary_equivalence (lhs, NULL_TREE, stack);
}
this is obviously quadratic ... nearly all calls are from
static gimple
record_temporary_equivalences_from_stmts_at_dest (edge e,
vec<tree> *stack,
tree (*simplify) (gimple,
gimple),
bool backedge_seen)
{
...
else if (backedge_seen)
invalidate_equivalences (gimple_get_lhs (stmt), stack);
}
return stmt;
}
I think you should record a bitmap of SSA names you need to invalidate
equivalences to and only at the end of this do a single scan over all SSA
names.
