opt_rmdff to work on $dffe and $_DFFE_*

diff --git a/passes/opt/opt_rmdff.cc b/passes/opt/opt_rmdff.cc
index e8570f0ebe75869cf49e827558ef028060361a12..a4ed582cb3400160a6d2a647cd10afa4cffe6f2c 100644 (file)
--- 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<RTLIL::Cell*> 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_"))