From 60a9f604fdfe8cca5824276307979c1bc8fc1c9d Mon Sep 17 00:00:00 2001
From: Tom Peham <pehamtom@gmx.at>
Date: Fri, 12 Aug 2022 20:50:04 +0200
Subject: [PATCH] Global phase (#166)

---
 extern/json                              |  2 +-
 extern/zx                                |  2 +-
 src/zx/FunctionalityConstruction.cpp     | 12 ++++++++++++
 test/unittests/test_zx_functionality.cpp | 23 ++++++++++++++++++++++-
 4 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/extern/json b/extern/json
index a92ccafd..954b10ad 160000
--- a/extern/json
+++ b/extern/json
@@ -1 +1 @@
-Subproject commit a92ccafd2c7709243451e947a21ad08203273483
+Subproject commit 954b10ad3baa5d92bb9cd5bb93c7258433cd2bb2
diff --git a/extern/zx b/extern/zx
index 41cb6f03..86429cb9 160000
--- a/extern/zx
+++ b/extern/zx
@@ -1 +1 @@
-Subproject commit 41cb6f03ffcc933445bbc3acdb543d666050d635
+Subproject commit 86429cb98036e6a2a754b5dce849d0903145d56c
diff --git a/src/zx/FunctionalityConstruction.cpp b/src/zx/FunctionalityConstruction.cpp
index c026eb7e..3e3e16bb 100644
--- a/src/zx/FunctionalityConstruction.cpp
+++ b/src/zx/FunctionalityConstruction.cpp
@@ -1,6 +1,7 @@
 #include "zx/FunctionalityConstruction.hpp"
 
 #include "Definitions.hpp"
+#include "Rational.hpp"
 #include "ZXDiagram.hpp"
 
 #include <algorithm>
@@ -115,6 +116,11 @@ namespace zx {
                     break;
 
                 case qc::OpType::RZ:
+                    diag.addGlobalPhase(-PiRational(op->getParameter().front()) / 2);
+                    addZSpider(
+                            diag, target, qubits,
+                            Expression(PiRational(op->getParameter().front())));
+                    break;
                 case qc::OpType::Phase:
                     addZSpider(
                             diag, target, qubits,
@@ -126,12 +132,15 @@ namespace zx {
                     break;
 
                 case qc::OpType::RX:
+                    diag.addGlobalPhase(-PiRational(op->getParameter().front()) / 2);
                     addXSpider(
                             diag, target, qubits,
                             Expression(PiRational(op->getParameter().front())));
                     break;
 
                 case qc::OpType::Y:
+                    diag.addGlobalPhase(-PiRational(1, 2));
+
                     addZSpider(diag, target, qubits,
                                Expression(PiRational(1, 1)));
                     addXSpider(diag, target, qubits,
@@ -139,6 +148,9 @@ namespace zx {
                     break;
 
                 case qc::OpType::RY:
+                    diag.addGlobalPhase(-PiRational(op->getParameter().front()) / 2 +
+                                        PiRational(1, 2) + PiRational(3, 2));
+
                     addXSpider(diag, target, qubits,
                                Expression(PiRational(1, 2)));
                     addZSpider(diag, target, qubits,
diff --git a/test/unittests/test_zx_functionality.cpp b/test/unittests/test_zx_functionality.cpp
index 816c6e54..12ae31a0 100644
--- a/test/unittests/test_zx_functionality.cpp
+++ b/test/unittests/test_zx_functionality.cpp
@@ -11,6 +11,7 @@
 #include "zx/FunctionalityConstruction.hpp"
 
 #include "gtest/gtest.h"
+#include <cstddef>
 #include <iostream>
 #include <sstream>
 
@@ -120,7 +121,9 @@ TEST_F(ZXDiagramTest, complex_circuit) {
     zx::fullReduce(diag);
     EXPECT_EQ(diag.getNVertices(), 6);
     EXPECT_EQ(diag.getNEdges(), 3);
-    EXPECT_TRUE(diag.isIdentity());
+    EXPECT_TRUE(diag.connected(diag.getInput(0), diag.getOutput(0)));
+    EXPECT_TRUE(diag.connected(diag.getInput(1), diag.getOutput(1)));
+    EXPECT_TRUE(diag.connected(diag.getInput(2), diag.getOutput(2)));
 }
 
 TEST_F(ZXDiagramTest, Phase) {
@@ -201,3 +204,21 @@ TEST_F(ZXDiagramTest, InitialLayout) {
     zx::fullReduce(d);
     EXPECT_TRUE(d.isIdentity());
 }
+
+TEST_F(ZXDiagramTest, RZ) {
+    qc = qc::QuantumComputation(1);
+    qc.rz(0, zx::PI / 8);
+
+    auto qcPrime = qc::QuantumComputation(1);
+    qcPrime.phase(0, zx::PI / 8);
+
+    auto d      = zx::FunctionalityConstruction::buildFunctionality(&qc);
+    auto dPrime = zx::FunctionalityConstruction::buildFunctionality(&qcPrime);
+
+    d.concat(dPrime.invert());
+
+    zx::fullReduce(d);
+    EXPECT_FALSE(d.isIdentity());
+    EXPECT_FALSE(d.globalPhaseIsZero());
+    EXPECT_TRUE(d.connected(d.getInput(0), d.getOutput(0)));
+}