Consider a geometry shader that contains code like this:
some_out = expr;
if (cond) {
...
EmitVertex();
} else {
...
EmitVertex();
}
Both branches should see the correct value of some_out.
Since this is a rather subtle and rare case, I'm submitting a piglit test
for this as well.
GLSL says that the values of output variables are undefined after
EmitVertex(). With this change, the values will now be defined and
unmodified. This may reduce optimization opportunities in the probably
quite rare case where subsequent compiler passes cannot prove that the
value of the output variable is overwritten.
Cc: 13.0 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
(cherry picked from commit
0d383a79a8f13bb00ed5e5d84f41071b43c7e92d)
output_read_remover::visit_leave(ir_emit_vertex *ir)
{
hash_table_call_foreach(replacements, emit_return_copy, ir);
- _mesa_hash_table_clear(replacements, NULL);
return visit_continue;
}