From 3257b8ae1ec0253729cc0943854cd92a2b601581 Mon Sep 17 00:00:00 2001
From: "Emil J. Tywoniak" <emil@tywoniak.eu>
Date: Tue, 17 Mar 2026 16:34:41 +0100
Subject: [PATCH] abstract: skip $input_port cells

---
 passes/cmds/abstract.cc | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/passes/cmds/abstract.cc b/passes/cmds/abstract.cc
index 968cf9db5..7965394d6 100644
--- a/passes/cmds/abstract.cc
+++ b/passes/cmds/abstract.cc
@@ -265,6 +265,8 @@ unsigned int abstract_value(Module* mod, EnableLogic enable, const std::vector<S
 	unsigned int changed = 0;
 	std::vector<Cell*> cells_snapshot = mod->cells();
 	for (auto cell : cells_snapshot) {
+		if (cell->type == ID($input_port))
+			continue;
 		for (auto conn : cell->connections())
 			if (cell->output(conn.first)) {
 				std::set<int> offsets_to_abstract;