From c36bac0e109b2a7192247cd3df9319f6f10a3e84 Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Sun, 19 Jan 2014 15:37:56 +0100
Subject: [PATCH] Added $assert support to satgen

---
 kernel/satgen.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/kernel/satgen.h b/kernel/satgen.h
index a668c73a4..0909e58ef 100644
--- a/kernel/satgen.h
+++ b/kernel/satgen.h
@@ -38,6 +38,7 @@ struct SatGen
 	SigMap *sigmap;
 	std::string prefix;
 	SigPool initial_state;
+	RTLIL::SigSpec asserts_a, asserts_en;
 	bool ignore_div_by_zero;
 	bool model_undef;
 
@@ -96,6 +97,19 @@ struct SatGen
 		return importSigSpecWorker(sig, pf, true, false);
 	}
 
+	int importAsserts(int timestep = -1)
+	{
+		std::vector<int> check_bits, enable_bits;
+		if (model_undef) {
+			check_bits = ez->vec_and(ez->vec_not(importUndefSigSpec(asserts_a, timestep)), importDefSigSpec(asserts_a, timestep));
+			enable_bits = ez->vec_and(ez->vec_not(importUndefSigSpec(asserts_en, timestep)), importDefSigSpec(asserts_en, timestep));
+		} else {
+			check_bits = importDefSigSpec(asserts_a, timestep);
+			enable_bits = importDefSigSpec(asserts_en, timestep);
+		}
+		return ez->vec_reduce_and(ez->vec_or(check_bits, ez->vec_not(enable_bits)));
+	}
+
 	int signals_eq(RTLIL::SigSpec lhs, RTLIL::SigSpec rhs, int timestep_lhs = -1, int timestep_rhs = -1)
 	{
 		if (timestep_rhs < 0)
@@ -765,6 +779,13 @@ struct SatGen
 			return true;
 		}
 
+		if (cell->type == "$assert")
+		{
+			asserts_a.append((*sigmap)(cell->connections.at("\\A")));
+			asserts_en.append((*sigmap)(cell->connections.at("\\EN")));
+			return true;
+		}
+
 		// Unsupported internal cell types: $pow $lut
 		// .. and all sequential cells except $dff and $_DFF_[NP]_
 		return false;
-- 
2.30.2