From: Clifford Wolf <clifford@clifford.at>
Date: Wed, 26 Jun 2019 09:00:44 +0000 (+0200)
Subject: Do not clean up buffer cells with "keep" attribute, closes #1128
X-Git-Tag: yosys-0.9~42
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=8e9ef891febb47f512710de591401539ad521634;p=yosys.git

Do not clean up buffer cells with "keep" attribute, closes #1128

Signed-off-by: Clifford Wolf <clifford@clifford.at>
---

diff --git a/passes/opt/opt_clean.cc b/passes/opt/opt_clean.cc
index cfb0f788a..5f75288e2 100644
--- a/passes/opt/opt_clean.cc
+++ b/passes/opt/opt_clean.cc
@@ -480,7 +480,7 @@ void rmunused_module(RTLIL::Module *module, bool purge_mode, bool verbose, bool
 
 	std::vector<RTLIL::Cell*> delcells;
 	for (auto cell : module->cells())
-		if (cell->type.in("$pos", "$_BUF_")) {
+		if (cell->type.in("$pos", "$_BUF_") && !cell->has_keep_attr()) {
 			bool is_signed = cell->type == "$pos" && cell->getParam("\\A_SIGNED").as_bool();
 			RTLIL::SigSpec a = cell->getPort("\\A");
 			RTLIL::SigSpec y = cell->getPort("\\Y");