opt_expr: Sx to Sz; spotted by @Xiretza

diff --git a/passes/opt/opt_expr.cc b/passes/opt/opt_expr.cc
index 63811c1a1f88c95a25b2cd3abcb9b182e02aa912..777a24777f3cc005771751b9ed2d2a778c4cd251 100644 (file)
--- a/passes/opt/opt_expr.cc
+++ b/passes/opt/opt_expr.cc
@@ -175,7 +175,7 @@ bool group_cell_inputs(RTLIL::Module *module, RTLIL::Cell *cell, bool commutativ
                        }
                }
 
-               bool def = (bit_a != State::Sx && bit_a != State::Sz && bit_b != State::Sx && bit_b != State::Sx);
+               bool def = (bit_a != State::Sx && bit_a != State::Sz && bit_b != State::Sx && bit_b != State::Sz);
                if (def || !keepdc) {
                        if (bit_a.wire == NULL && bit_b.wire == NULL)
                                group_idx = GRP_CONST_AB;