diff options
Diffstat (limited to 'passes/opt/opt_expr.cc')
-rw-r--r-- | passes/opt/opt_expr.cc | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/passes/opt/opt_expr.cc b/passes/opt/opt_expr.cc index 723830aa0..1a9de7f40 100644 --- a/passes/opt/opt_expr.cc +++ b/passes/opt/opt_expr.cc @@ -496,6 +496,42 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons } } + if (cell->type.in(ID($_XOR_), ID($_XNOR_)) || (cell->type.in(ID($xor), ID($xnor)) && GetSize(cell->getPort(ID::A)) == 1 && GetSize(cell->getPort(ID::B)) == 1 && !cell->getParam(ID(A_SIGNED)).as_bool())) + { + SigBit sig_a = assign_map(cell->getPort(ID::A)); + SigBit sig_b = assign_map(cell->getPort(ID::B)); + if (!sig_a.wire) + std::swap(sig_a, sig_b); + if (sig_b == State::S0 || sig_b == State::S1) { + if (cell->type.in(ID($xor), ID($_XOR_))) { + cover("opt.opt_expr.xor_buffer"); + SigSpec sig_y; + if (cell->type == ID($xor)) + sig_y = (sig_b == State::S1 ? module->Not(NEW_ID, sig_a).as_bit() : sig_a); + else if (cell->type == ID($_XOR_)) + sig_y = (sig_b == State::S1 ? module->NotGate(NEW_ID, sig_a) : sig_a); + else log_abort(); + replace_cell(assign_map, module, cell, "xor_buffer", ID::Y, sig_y); + goto next_cell; + } + if (cell->type.in(ID($xnor), ID($_XNOR_))) { + cover("opt.opt_expr.xnor_buffer"); + SigSpec sig_y; + if (cell->type == ID($xnor)) { + sig_y = (sig_b == State::S1 ? sig_a : module->Not(NEW_ID, sig_a).as_bit()); + int width = cell->getParam(ID(Y_WIDTH)).as_int(); + sig_y.append(RTLIL::Const(State::S1, width-1)); + } + else if (cell->type == ID($_XNOR_)) + sig_y = (sig_b == State::S1 ? sig_a : module->NotGate(NEW_ID, sig_a)); + else log_abort(); + replace_cell(assign_map, module, cell, "xnor_buffer", ID::Y, sig_y); + goto next_cell; + } + log_abort(); + } + } + if (cell->type.in(ID($reduce_and), ID($reduce_or), ID($reduce_bool), ID($reduce_xor), ID($reduce_xnor), ID($neg)) && GetSize(cell->getPort(ID::A)) == 1 && GetSize(cell->getPort(ID::Y)) == 1) { @@ -850,8 +886,6 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons if (input.match("11")) ACTION_DO_Y(0); if (input.match(" *")) ACTION_DO_Y(x); if (input.match("* ")) ACTION_DO_Y(x); - if (input.match(" 0")) ACTION_DO(ID::Y, input.extract(1, 1)); - if (input.match("0 ")) ACTION_DO(ID::Y, input.extract(0, 1)); } if (cell->type == ID($_MUX_)) { @@ -1622,7 +1656,7 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons } int const_bit_set = get_highest_hot_index(const_sig); - if(const_bit_set >= var_width) + if (const_bit_set >= var_width) { string cmp_name; if (cmp_type == ID($lt) || cmp_type == ID($le)) |