From 7fe817c52f51591eaeb780e3022fe8f2a4114abc Mon Sep 17 00:00:00 2001
From: "Emil J. Tywoniak" <emil@tywoniak.eu>
Date: Thu, 10 Jul 2025 18:54:43 +0200
Subject: [PATCH] dfflibmap: test negated state next_state with mixed
 polarities

---
 tests/techmap/dfflibmap.ys                 | 16 ++++++++++
 tests/techmap/dfflibmap_dffsr_mixedpol.lib | 35 ++++++++++++++++++++++
 2 files changed, 51 insertions(+)
 create mode 100644 tests/techmap/dfflibmap_dffsr_mixedpol.lib

diff --git a/tests/techmap/dfflibmap.ys b/tests/techmap/dfflibmap.ys
index 77488d60f..822d87a36 100644
--- a/tests/techmap/dfflibmap.ys
+++ b/tests/techmap/dfflibmap.ys
@@ -81,3 +81,19 @@ clean
 select -assert-count 0 t:dffn
 select -assert-count 5 t:dffsr
 select -assert-count 1 t:dffe
+
+design -load orig
+dfflibmap -liberty dfflibmap.lib -liberty dfflibmap_dffsr_mixedpol.lib -dont_use dffsr
+clean
+# We have one more _NOT_ than with the regular dffsr
+select -assert-count 6 t:$_NOT_
+select -assert-count 1 t:dffn
+select -assert-count 4 t:dffsr_mixedpol
+select -assert-count 1 t:dffe
+# The additional NOT is on ff2.
+# Originally, ff2.R is an active high "set".
+# dffsr_mixedpol has functionally swapped labels due to the next_state inversion,
+# so we use its CLEAR port for the "set",
+# but we have to invert it because the CLEAR pin is active low.
+# ff2.CLEAR = !R
+select -assert-count 1 c:ff2 %x:+[CLEAR] %ci t:$_NOT_ %i
diff --git a/tests/techmap/dfflibmap_dffsr_mixedpol.lib b/tests/techmap/dfflibmap_dffsr_mixedpol.lib
new file mode 100644
index 000000000..8c6a2f509
--- /dev/null
+++ b/tests/techmap/dfflibmap_dffsr_mixedpol.lib
@@ -0,0 +1,35 @@
+library(test) {
+  cell (dffsr_mixedpol) {
+    area : 6;
+    ff("IQ", "IQN") {
+      // look here
+      next_state : "!D";
+      clocked_on : "CLK";
+      // look here
+      clear      : "!CLEAR";
+      preset     : "PRESET";
+      clear_preset_var1 : L;
+      clear_preset_var2 : L;
+    }
+    pin(D) {
+      direction : input;
+    }
+    pin(CLK) {
+      direction : input;
+    }
+    pin(CLEAR) {
+      direction : input;
+    }
+    pin(PRESET) {
+      direction : input;
+    }
+    pin(Q) {
+      direction: output;
+      function : "IQ";
+    }
+    pin(QN) {
+      direction: output;
+      function : "IQN";
+    }
+  }
+}