From 50ed34a6d0fe1013fae0a14165fc4fce1d1a3685 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Thu, 23 May 2019 11:26:18 -0700 Subject: [PATCH] opt_rmdff to work on $dffe and $_DFFE_* --- passes/opt/opt_rmdff.cc | 35 ++++++++++++++++++++++++++++++++--- 1 file changed, 32 insertions(+), 3 deletions(-) diff --git a/passes/opt/opt_rmdff.cc b/passes/opt/opt_rmdff.cc index e8570f0eb..a4ed582cb 100644 --- a/passes/opt/opt_rmdff.cc +++ b/passes/opt/opt_rmdff.cc @@ -260,8 +260,8 @@ delete_dlatch: bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff) { - RTLIL::SigSpec sig_d, sig_q, sig_c, sig_r; - RTLIL::Const val_cp, val_rp, val_rv; + RTLIL::SigSpec sig_d, sig_q, sig_c, sig_r, sig_e; + RTLIL::Const val_cp, val_rp, val_rv, val_ep; if (dff->type == "$_FF_") { sig_d = dff->getPort("\\D"); @@ -285,6 +285,16 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff) val_rp = RTLIL::Const(dff->type[7] == 'P', 1); val_rv = RTLIL::Const(dff->type[8] == '1', 1); } + else if (dff->type.substr(0,7) == "$_DFFE_" && dff->type.substr(9) == "_" && + (dff->type[7] == 'N' || dff->type[7] == 'P') && + (dff->type[8] == 'N' || dff->type[8] == 'P')) { + sig_d = dff->getPort("\\D"); + sig_q = dff->getPort("\\Q"); + sig_c = dff->getPort("\\C"); + sig_e = dff->getPort("\\E"); + val_cp = RTLIL::Const(dff->type[6] == 'P', 1); + val_ep = RTLIL::Const(dff->type[7] == 'P', 1); + } else if (dff->type == "$ff") { sig_d = dff->getPort("\\D"); sig_q = dff->getPort("\\Q"); @@ -295,6 +305,14 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff) sig_c = dff->getPort("\\CLK"); val_cp = RTLIL::Const(dff->parameters["\\CLK_POLARITY"].as_bool(), 1); } + else if (dff->type == "$dffe") { + sig_e = dff->getPort("\\EN"); + sig_d = dff->getPort("\\D"); + sig_q = dff->getPort("\\Q"); + sig_c = dff->getPort("\\CLK"); + val_cp = RTLIL::Const(dff->parameters["\\CLK_POLARITY"].as_bool(), 1); + val_ep = RTLIL::Const(dff->parameters["\\EN_POLARITY"].as_bool(), 1); + } else if (dff->type == "$adff") { sig_d = dff->getPort("\\D"); sig_q = dff->getPort("\\Q"); @@ -320,6 +338,16 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff) val_init.bits.push_back(bit.wire == NULL ? bit.data : RTLIL::State::Sx); } + if (sig_e.size()) { + if (!sig_e.is_fully_const()) + return false; + if (sig_e != val_ep) { + if (has_init) + mod->connect(sig_q, val_init); + goto delete_dff; + } + } + if (dff->type.in("$ff", "$dff") && mux_drivers.has(sig_d)) { std::set muxes; mux_drivers.find(sig_d, muxes); @@ -489,7 +517,8 @@ struct OptRmdffPass : public Pass { if (cell->type.in("$_FF_", "$_DFF_N_", "$_DFF_P_", "$_DFF_NN0_", "$_DFF_NN1_", "$_DFF_NP0_", "$_DFF_NP1_", "$_DFF_PN0_", "$_DFF_PN1_", "$_DFF_PP0_", "$_DFF_PP1_", - "$ff", "$dff", "$adff")) + "$_DFFE_NN_", "$_DFFE_NP_", "$_DFFE_PN_", "$_DFFE_PP_", + "$ff", "$dff", "$dffe", "$adff")) dff_list.push_back(cell->name); if (cell->type.in("$dlatch", "$_DLATCH_P_", "$_DLATCH_N_")) -- 2.30.2