From b444f2e1c438c2fe7e71945ca7033ae767ec7dc1 Mon Sep 17 00:00:00 2001
From: CalMacCQ <93673602+CalMacCQ@users.noreply.github.com>
Date: Tue, 12 Dec 2023 16:44:57 +0000
Subject: [PATCH] Add `KAKDecompostion` pass to `optimisation_level=2` after
 routing (#51)

* add post-routing KAKDecomposition pass to OL=2

* consistent syntax

* fix bad syntax
---
 pytket/extensions/pyquil/backends/forest.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/pytket/extensions/pyquil/backends/forest.py b/pytket/extensions/pyquil/backends/forest.py
index 6429d10..4444cb0 100644
--- a/pytket/extensions/pyquil/backends/forest.py
+++ b/pytket/extensions/pyquil/backends/forest.py
@@ -46,6 +46,7 @@
     EulerAngleReduction,
     CXMappingPass,
     auto_rebase_pass,
+    KAKDecomposition,
     SequencePass,
     SynthesiseTket,
     DecomposeBoxes,
@@ -165,7 +166,10 @@ def default_compilation_pass(self, optimisation_level: int = 2) -> BasePass:
         )
         passlist.append(NaivePlacementPass(self.backend_info.architecture))  # type: ignore
         if optimisation_level == 2:
-            passlist.append(CliffordSimp(False))
+            # Add some connectivity preserving optimisations after routing.
+            passlist.extend(
+                [KAKDecomposition(allow_swaps=False), CliffordSimp(allow_swaps=False)]
+            )
         if optimisation_level > 0:
             passlist.append(SynthesiseTket())
         passlist.append(self.rebase_pass())