From b7deaceadde865fa8bca47cfeeb43a82dc936076 Mon Sep 17 00:00:00 2001
From: Eddie Hung <eddie@fpgeh.com>
Date: Mon, 24 Jun 2019 18:33:06 -0700
Subject: [PATCH] Walk through as many muxes as exist for rd_en
---
passes/memory/memory_dff.cc | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/passes/memory/memory_dff.cc b/passes/memory/memory_dff.cc
index 220d29295..d37cac28e 100644
--- a/passes/memory/memory_dff.cc
+++ b/passes/memory/memory_dff.cc
@@ -182,20 +182,28 @@ struct MemoryDffWorker
if (mux_cells_a.count(sig_data) || mux_cells_b.count(sig_data))
{
- bool enable_invert = mux_cells_a.count(sig_data) != 0;
- Cell *mux = enable_invert ? mux_cells_a.at(sig_data) : mux_cells_b.at(sig_data);
- SigSpec check_q = sigmap(mux->getPort(enable_invert ? "\\B" : "\\A"));
+ RTLIL::SigSpec en;
+ RTLIL::SigSpec check_q;
- sig_data = sigmap(mux->getPort("\\Y"));
- for (auto bit : sig_data)
- if (sigbit_users_count[bit] > 1)
- goto skip_ff_after_read_merging;
+ do {
+ bool enable_invert = mux_cells_a.count(sig_data) != 0;
+ Cell *mux = enable_invert ? mux_cells_a.at(sig_data) : mux_cells_b.at(sig_data);
+ check_q = sigmap(mux->getPort(enable_invert ? "\\B" : "\\A"));
+
+ sig_data = sigmap(mux->getPort("\\Y"));
+ for (auto bit : sig_data)
+ if (sigbit_users_count[bit] > 1) {
+ goto skip_ff_after_read_merging;
+ }
+
+ en.append(enable_invert ? module->LogicNot(NEW_ID, mux->getPort("\\S")) : mux->getPort("\\S"));
+ } while (mux_cells_a.count(sig_data) || mux_cells_b.count(sig_data));
if (find_sig_before_dff(sig_data, clk_data, clk_polarity, true) && clk_data != RTLIL::SigSpec(RTLIL::State::Sx) && sig_data == check_q)
{
disconnect_dff(sig_data);
cell->setPort("\\CLK", clk_data);
- cell->setPort("\\EN", enable_invert ? module->LogicNot(NEW_ID, mux->getPort("\\S")) : mux->getPort("\\S"));
+ cell->setPort("\\EN", en.size() > 1 ? module->ReduceAnd(NEW_ID, en) : en);
cell->setPort("\\DATA", sig_data);
cell->parameters["\\CLK_ENABLE"] = RTLIL::Const(1);
cell->parameters["\\CLK_POLARITY"] = RTLIL::Const(clk_polarity);
--
2.30.2