From 0b7d648c6a71594f8a17e78aef8f62b6f6448390 Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Wed, 26 Jun 2019 17:54:17 +0200
Subject: [PATCH] Improve opt_clean handling of unused public wires
Signed-off-by: Clifford Wolf <clifford@clifford.at>
---
passes/opt/opt_clean.cc | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/passes/opt/opt_clean.cc b/passes/opt/opt_clean.cc
index 5f75288e2..a8a8e0bc7 100644
--- a/passes/opt/opt_clean.cc
+++ b/passes/opt/opt_clean.cc
@@ -326,8 +326,8 @@ bool rmunused_module_signals(RTLIL::Module *module, bool purge_mode, bool verbos
if (wire->port_id != 0 || wire->get_bool_attribute("\\keep") || !initval.is_fully_undef()) {
// do not delete anything with "keep" or module ports or initialized wires
} else
- if (!purge_mode && check_public_name(wire->name)) {
- // do not get rid of public names unless in purge mode
+ if (!purge_mode && check_public_name(wire->name) && (raw_used_signals.check_any(s1) || used_signals.check_any(s2) || s1 != s2)) {
+ // do not get rid of public names unless in purge mode or if the wire is entirely unused, not even aliased
} else
if (!raw_used_signals.check_any(s1)) {
// delete wires that aren't used by anything directly