From d2e31f3044d74b5e74bd3c5800101b6b9eed6396 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 11:05:50 -0400
Subject: [PATCH 01/27] Debug controlled and ISWAP gates

---
 pennylane_qrack/qrack_device.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 5417f74..9d2b35c 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -121,7 +121,11 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             if (wires.size() != 2U) {
                 throw std::invalid_argument("ISWAP must have exactly two target qubits!");
             }
-            qsim->ISwap(wires[0U], wires[1U]);
+            if (inverse) {
+                qsim->ISwap(wires[0U], wires[1U]);
+            } else {
+                qsim->IISwap(wires[0U], wires[1U]);
+            }
         } else if (name == "PSWAP") {
             if (wires.size() != 2U) {
                 throw std::invalid_argument("PSWAP must have exactly two target qubits!");
@@ -310,9 +314,9 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             }
             std::vector<bitLenInt> mcp_wires(control_wires);
             mcp_wires.push_back(wires[0U]);
-            qsim->MCPhase(mcp_wires, Qrack::I_CMPLX, Qrack::ONE_CMPLX, wires[1U]);
+            qsim->MCPhase(mcp_wires, inverse ? -Qrack::I_CMPLX : Qrack::I_CMPLX, Qrack::ONE_CMPLX, wires[1U]);
             qsim->CSwap(control_wires, wires[0U], wires[1U]);
-            qsim->MCPhase(mcp_wires, Qrack::I_CMPLX, Qrack::ONE_CMPLX, wires[1U]);
+            qsim->MCPhase(mcp_wires, inverse ? -Qrack::I_CMPLX : Qrack::I_CMPLX, Qrack::ONE_CMPLX, wires[1U]);
             for (bitLenInt i = 0U; i < control_wires.size(); ++i) {
                 if (!control_values[i]) {
                     qsim->X(control_wires[i]);
@@ -697,6 +701,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             || (name == "CZ")
             || (name == "CSWAP")
             || (name == "ControlledPhaseShift")
+            || (name == "CPhase")
             || (name == "CRX")
             || (name == "CRY")
             || (name == "CRZ")

From 4c5f6f98e45f7b8a3158ab0754e02ec4b0f1014d Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 12:30:01 -0400
Subject: [PATCH 02/27] Debugging and simplifying phase gates

---
 pennylane_qrack/_version.py      |  2 +-
 pennylane_qrack/qrack_device.cpp | 34 ++------------------------------
 2 files changed, 3 insertions(+), 33 deletions(-)

diff --git a/pennylane_qrack/_version.py b/pennylane_qrack/_version.py
index a4d0467..b88df1e 100644
--- a/pennylane_qrack/_version.py
+++ b/pennylane_qrack/_version.py
@@ -16,4 +16,4 @@
    Version number (major.minor.patch[-label])
 """
 
-__version__ = "0.6.3"
+__version__ = "0.6.4"
diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 9d2b35c..077e2f2 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -134,14 +134,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             qsim->CU(c, wires[1U], ZERO_R1, ZERO_R1, inverse ? -params[0U] : params[0U]);
             qsim->Swap(wires[0U], wires[1U]);
             qsim->CU(c, wires[1U], ZERO_R1, ZERO_R1, inverse ? -params[0U] : params[0U]);
-        } else if (name == "PhaseShift") {
-            const Qrack::real1 cosine = (Qrack::real1)cos(inverse ? -params[0U] : params[0U]);
-            const Qrack::real1 sine = (Qrack::real1)sin(inverse ? -params[0U] : params[0U]);
-            const Qrack::complex bottomRight(cosine, sine);
-            for (const bitLenInt& target : wires) {
-                qsim->Phase(Qrack::ONE_CMPLX, bottomRight, target);
-            }
-        } else if (name == "PhaseShift") {
+        } else if ((name == "PhaseShift") || (name == "U1")) {
             const Qrack::real1 cosine = (Qrack::real1)cos(inverse ? -params[0U] : params[0U]);
             const Qrack::real1 sine = (Qrack::real1)sin(inverse ? -params[0U] : params[0U]);
             const Qrack::complex bottomRight(cosine, sine);
@@ -193,14 +186,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                     qsim->U(target, Qrack::PI_R1 / 2, params[0U], params[1U]);
                 }
             }
-        } else if (name == "U1") {
-            for (const bitLenInt& target : wires) {
-                if (inverse) {
-                    qsim->U(target, ZERO_R1, ZERO_R1, -params[0U]);
-                } else {
-                    qsim->U(target, ZERO_R1, ZERO_R1, params[0U]);
-                }
-            }
         } else if (name == "QFT") {
             const size_t maxLcv = wires.size() >> 1U;
             const size_t end = wires.size() - 1U;
@@ -322,7 +307,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                     qsim->X(control_wires[i]);
                 }
             }
-        } else if ((name == "PhaseShift") || (name == "ControlledPhaseShift") || (name == "CPhase")) {
+        } else if ((name == "PhaseShift") || (name == "U1") || (name == "ControlledPhaseShift") || (name == "CPhase")) {
             const Qrack::real1 cosine = (Qrack::real1)cos(inverse ? -params[0U] : params[0U]);
             const Qrack::real1 sine = (Qrack::real1)sin(inverse ? -params[0U] : params[0U]);
             const Qrack::complex bottomRight(cosine, sine);
@@ -408,21 +393,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             for (const bitLenInt& target : wires) {
                 qsim->UCMtrx(control_wires, mtrx, target, controlPerm);
             }
-        } else if (name == "U1") {
-            const Qrack::real1 theta = ZERO_R1;
-            const Qrack::real1 phi = ZERO_R1;
-            const Qrack::real1 lambda = inverse ? -params[0U] : params[0U];
-            const Qrack::real1 cos0 = (Qrack::real1)cos(theta / 2);
-            const Qrack::real1 sin0 = (Qrack::real1)sin(theta / 2);
-            const Qrack::complex mtrx[4U]{
-                Qrack::complex(cos0, ZERO_R1), sin0 * Qrack::complex((Qrack::real1)(-cos(lambda)),
-                (Qrack::real1)(-sin(lambda))),
-                sin0 * Qrack::complex((Qrack::real1)cos(phi), (Qrack::real1)sin(phi)),
-                cos0 * Qrack::complex((Qrack::real1)cos(phi + lambda), (Qrack::real1)sin(phi + lambda))
-            };
-            for (const bitLenInt& target : wires) {
-                qsim->UCMtrx(control_wires, mtrx, target, controlPerm);
-            }
         } else if (name != "Identity") {
             throw std::domain_error("Unrecognized gate name: " + name);
         }

From 738ca3eb627eb192b76a43f273280d28f2adc4e1 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 12:41:11 -0400
Subject: [PATCH 03/27] Simplify Catalyst control handling

---
 pennylane_qrack/qrack_device.cpp | 35 ++++++++++++++------------------
 1 file changed, 15 insertions(+), 20 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 077e2f2..653d3fd 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -653,33 +653,28 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         auto &&dev_wires = getDeviceWires(wires);
         auto &&dev_controlled_wires = getDeviceWires(controlled_wires);
         std::vector<bool> dev_controlled_values(controlled_values);
-        if (name == "MultiControlledX") {
-            while (wires.size() > 1U) {
-                dev_controlled_wires.push_back(dev_wires[0]);
-                dev_controlled_values.push_back(true);
-                dev_wires.erase(dev_wires.begin());
-            }
-        } else if (name == "Toffoli") {
-            dev_controlled_wires.push_back(dev_wires[0]);
-            dev_controlled_values.push_back(true);
-            dev_wires.erase(dev_wires.begin());
-            dev_controlled_wires.push_back(dev_wires[0]);
-            dev_controlled_values.push_back(true);
-            dev_wires.erase(dev_wires.begin());
-        } else if ((name == "CNOT")
+        if ((name == "MultiControlledX")
+            || (name == "CNOT")
             || (name == "CY")
             || (name == "CZ")
-            || (name == "CSWAP")
             || (name == "ControlledPhaseShift")
             || (name == "CPhase")
             || (name == "CRX")
             || (name == "CRY")
             || (name == "CRZ")
-            || (name == "CRot"))
-        {
-            dev_controlled_wires.push_back(dev_wires[0]);
-            dev_controlled_values.push_back(true);
-            dev_wires.erase(dev_wires.begin());
+            || (name == "CRot")
+            || (name == "Toffoli")) {
+            while (dev_wires.size() > 1U) {
+                dev_controlled_wires.push_back(dev_wires[0]);
+                dev_controlled_values.push_back(true);
+                dev_wires.erase(dev_wires.begin());
+            }
+        } else if (name == "CSWAP") {
+            while (dev_wires.size() > 2U) {
+                dev_controlled_wires.push_back(dev_wires[0]);
+                dev_controlled_values.push_back(true);
+                dev_wires.erase(dev_wires.begin());
+            }
         }
 
         // Update the state-vector

From 9bcdbd1f84fb719d96992767c1224b748d535e71 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 13:10:58 -0400
Subject: [PATCH 04/27] Debug and generalize PyQrack back end

---
 pennylane_qrack/qrack_device.py | 137 +++++++++++++++++---------------
 1 file changed, 72 insertions(+), 65 deletions(-)

diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index 32d8551..33eabd6 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -409,84 +409,89 @@ def _apply_gate(self, op):
         elif opname in ["CZ", "CZ.inv", "C(CZ)", "C(CZ).inv"]:
             self._state.mcz(device_wires.labels[:-1], device_wires.labels[-1])
         elif opname == "S":
-            self._state.s(device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.s(label)
         elif opname == "S.inv":
-            self._state.adjs(device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.adjs(label)
         elif opname == "C(S)":
             self._state.mcs(device_wires.labels[:-1], device_wires.labels[-1])
         elif opname == "C(S).inv":
             self._state.mcadjs(device_wires.labels[:-1], device_wires.labels[-1])
         elif opname == "T":
-            self._state.t(device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.t(label)
         elif opname == "T.inv":
-            self._state.adjt(device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.adjt(label)
         elif opname == "C(T)":
             self._state.mct(device_wires.labels[:-1], device_wires.labels[-1])
         elif opname == "C(T).inv":
             self._state.mcadjt(device_wires.labels[:-1], device_wires.labels[-1])
         elif opname == "RX":
-            self._state.r(Pauli.PauliX, par[0], device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.r(Pauli.PauliX, par[0], label)
         elif opname == "RX.inv":
-            self._state.r(Pauli.PauliX, -par[0], device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.r(Pauli.PauliX, -par[0], label)
         elif opname in ["CRX", "C(RX)", "C(CRX)"]:
             self._state.mcr(Pauli.PauliX, par[0], device_wires.labels[:-1], device_wires.labels[-1])
         elif opname in ["CRX.inv", "C(RX).inv", "C(CRX).inv"]:
             self._state.mcr(Pauli.PauliX, par[0], device_wires.labels[:-1], device_wires.labels[-1])
         elif opname == "RY":
-            self._state.r(Pauli.PauliY, par[0], device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.r(Pauli.PauliY, par[0], label)
         elif opname == "RY.inv":
-            self._state.r(Pauli.PauliY, -par[0], device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.r(Pauli.PauliY, -par[0], label)
         elif opname in ["CRY", "C(RY)", "C(CRY)"]:
             self._state.mcr(Pauli.PauliY, par[0], device_wires.labels[:-1], device_wires.labels[-1])
         elif opname in ["CRY.inv", "C(RY).inv", "C(CRY).inv"]:
             self._state.mcr(Pauli.PauliY, par[0], device_wires.labels[:-1], device_wires.labels[-1])
         elif opname == "RZ":
-            self._state.r(Pauli.PauliZ, par[0], device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.r(Pauli.PauliZ, par[0], label)
         elif opname == "RZ.inv":
-            self._state.r(Pauli.PauliZ, -par[0], device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.r(Pauli.PauliZ, -par[0], label)
         elif opname in ["CRZ", "C(RZ)", "C(CRZ)"]:
             self._state.mcr(Pauli.PauliZ, par[0], device_wires.labels[:-1], device_wires.labels[-1])
         elif opname in ["CRZ.inv", "C(RZ).inv", "C(CRZ).inv"]:
             self._state.mcr(Pauli.PauliY, par[0], device_wires.labels[:-1], device_wires.labels[-1])
         elif opname in ["PauliX", "PauliX.inv"]:
-            self._state.x(device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.x(label)
         elif opname in ["PauliY", "PauliY.inv"]:
-            self._state.y(device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.y(label)
         elif opname in ["PauliZ", "PauliZ.inv"]:
-            self._state.z(device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.z(label)
         elif opname in ["Hadamard", "Hadamard.inv"]:
-            self._state.h(device_wires.labels[0])
+            for label in device_wires.labels:
+                self._state.h(label)
         elif opname == "SX":
-            self._state.mtrx(
-                [(1 + 1j) / 2, (1 - 1j) / 2, (1 - 1j) / 2, (1 + 1j) / 2],
-                device_wires.labels[0],
-            )
+            sx_mtrx = [(1 + 1j) / 2, (1 - 1j) / 2, (1 - 1j) / 2, (1 + 1j) / 2]
+            for label in device_wires.labels:
+                self._state.mtrx(sx_mtrx, label)
         elif opname == "SX.inv":
-            self._state.mtrx(
-                [(1 - 1j) / 2, (1 + 1j) / 2, (1 + 1j) / 2, (1 - 1j) / 2],
-                device_wires.labels[0],
-            )
+            isx_mtrx = [(1 - 1j) / 2, (1 + 1j) / 2, (1 + 1j) / 2, (1 - 1j) / 2]
+            for label in device_wires.labels:
+                self._state.mtrx(isx_mtrx, label)
         elif opname == "C(SX)":
             self._state.mcmtrx(
                 device_wires.labels[:-1],
                 [(1 + 1j) / 2, (1 - 1j) / 2, (1 - 1j) / 2, (1 + 1j) / 2],
                 device_wires.labels[-1],
             )
-        elif opname == "SX.inv":
-            self._state.mtrx(
-                [(1 - 1j) / 2, (1 + 1j) / 2, (1 + 1j) / 2, (1 - 1j) / 2],
-                device_wires.labels[0],
-            )
-        elif opname == "C(SX).inc":
-            self._state.mcmtrx(
-                device_wires.labels[:-1],
-                [(1 - 1j) / 2, (1 + 1j) / 2, (1 + 1j) / 2, (1 - 1j) / 2],
-                device_wires.labels[-1],
-            )
         elif opname in ["PhaseShift", "U1"]:
-            self._state.mtrx([1, 0, 0, cmath.exp(1j * par[0])], device_wires.labels[0])
+            p_mtrx = [1, 0, 0, cmath.exp(1j * par[0])]
+            for label in device_wires.labels:
+                self._state.mtrx(p_mtrx, label)
         elif opname in ["PhaseShift.inv", "U1.inv"]:
-            self._state.mtrx([1, 0, 0, cmath.exp(1j * -par[0])], device_wires.labels[0])
+            ip_mtrx = [1, 0, 0, cmath.exp(1j * -par[0])]
+            for label in device_wires.labels:
+                self._state.mtrx(p_mtrx, label)
         elif opname in ["C(PhaseShift)", "C(U1)"]:
             self._state.mtrx(
                 device_wires.labels[:-1],
@@ -522,25 +527,23 @@ def _apply_gate(self, op):
                 device_wires.labels[-1],
             )
         elif opname == "U2":
-            self._state.mtrx(
-                [
-                    1,
-                    cmath.exp(1j * par[1]),
-                    cmath.exp(1j * par[0]),
-                    cmath.exp(1j * (par[0] + par[1])),
-                ],
-                device_wires.labels[0],
-            )
+            u2_mtrx = [
+                1,
+                cmath.exp(1j * par[1]),
+                cmath.exp(1j * par[0]),
+                cmath.exp(1j * (par[0] + par[1])),
+            ]
+            for label in device_wires.labels:
+                self._state.mtrx(u2_mtrx, label)
         elif opname == "U2.inv":
-            self._state.mtrx(
-                [
-                    1,
-                    cmath.exp(1j * -par[1]),
-                    cmath.exp(1j * -par[0]),
-                    cmath.exp(1j * (-par[0] - par[1])),
-                ],
-                device_wires.labels[0],
-            )
+            iu2_mtrx = [
+                1,
+                cmath.exp(1j * -par[1]),
+                cmath.exp(1j * -par[0]),
+                cmath.exp(1j * (-par[0] - par[1])),
+            ]
+            for label in device_wires.labels:
+                self._state.mtrx(iu2_mtrx, label)
         elif opname == "C(U2)":
             self._state.mcmtrx(
                 device_wires.labels[:-1],
@@ -564,17 +567,21 @@ def _apply_gate(self, op):
                 device_wires.labels[-1],
             )
         elif opname == "U3":
-            self._state.u(device_wires.labels[-1], par[0], par[1], par[2])
+            for label in device_wires.labels:
+                self._state.u(label, par[0], par[1], par[2])
         elif opname == "U3.inv":
-            self._state.u(device_wires.labels[-1], -par[0], -par[1], -par[2])
+            for label in device_wires.labels:
+                self._state.u(label, -par[0], -par[1], -par[2])
         elif opname == "Rot":
-            self._state.r(Pauli.PauliZ, par[0], device_wires.labels[-1])
-            self._state.r(Pauli.PauliY, par[1], device_wires.labels[-1])
-            self._state.r(Pauli.PauliZ, par[2], device_wires.labels[-1])
+            for label in device_wires.labels:
+                self._state.r(Pauli.PauliZ, par[0], label)
+                self._state.r(Pauli.PauliY, par[1], label)
+                self._state.r(Pauli.PauliZ, par[2], label)
         elif opname == "Rot.inv":
-            self._state.r(Pauli.PauliZ, -par[2], device_wires.labels[-1])
-            self._state.r(Pauli.PauliY, -par[1], device_wires.labels[-1])
-            self._state.r(Pauli.PauliZ, -par[0], device_wires.labels[-1])
+            for label in device_wires.labels:
+                self._state.r(Pauli.PauliZ, -par[2], label)
+                self._state.r(Pauli.PauliY, -par[1], label)
+                self._state.r(Pauli.PauliZ, -par[0], label)
         elif opname == "C(U3)":
             self._state.mcu(
                 device_wires.labels[:-1],
@@ -593,11 +600,11 @@ def _apply_gate(self, op):
             )
         elif opname == "QFT":
             self._state.qft(device_wires.labels)
-            for i in range(len(wires) >> 1):
-                self._state.swap(wires[i], wires[-i])
+            for i in range(len(device_wires.labels) >> 1):
+                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
         elif opname == "QFT.inv":
-            for i in range(len(wires) >> 1):
-                self._state.swap(wires[i], wires[-i])
+            for i in range(len(device_wires.labels) >> 1):
+                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
             self._state.iqft(device_wires.labels)
         elif opname not in [
             "Identity",

From de6f5e085eae8ac71b16622017fdb9f3fa17e568 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 13:38:40 -0400
Subject: [PATCH 05/27] Decompose QFT

---
 pennylane_qrack/QrackDeviceConfig.toml |  2 +-
 pennylane_qrack/qrack_device.cpp       | 14 --------------
 pennylane_qrack/qrack_device.py        |  9 ---------
 3 files changed, 1 insertion(+), 24 deletions(-)

diff --git a/pennylane_qrack/QrackDeviceConfig.toml b/pennylane_qrack/QrackDeviceConfig.toml
index 24ec83d..ca3a67e 100644
--- a/pennylane_qrack/QrackDeviceConfig.toml
+++ b/pennylane_qrack/QrackDeviceConfig.toml
@@ -48,7 +48,6 @@ U2 = { properties = [ "controllable", "invertible" ] }
 U1 = { properties = [ "controllable", "invertible" ] }
 MultiControlledX = { properties = [ "controllable", "invertible" ] }
 Identity = { properties = [ "controllable", "invertible" ] }
-QFT = { properties = [ "invertible" ] }
 
 # Operators that should be decomposed according to the algorithm used
 # by PennyLane's device API.
@@ -79,6 +78,7 @@ QFT = { properties = [ "invertible" ] }
 # IsingYY = {}
 # IsingZZ = {}
 # IsingXY = {}
+# QFT = {}
 
 # Gates which should be translated to QubitUnitary
 # [operators.gates.matrix]
diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 653d3fd..73780dd 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -186,20 +186,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                     qsim->U(target, Qrack::PI_R1 / 2, params[0U], params[1U]);
                 }
             }
-        } else if (name == "QFT") {
-            const size_t maxLcv = wires.size() >> 1U;
-            const size_t end = wires.size() - 1U;
-            if (inverse) {
-                for (size_t i = 0U; i < maxLcv; ++i) {
-                    qsim->Swap(wires[i], wires[end - i]);
-                }
-                qsim->IQFTR(wires);
-            } else {
-                qsim->QFTR(wires);
-                for (size_t i = 0U; i < maxLcv; ++i) {
-                    qsim->Swap(wires[i], wires[end - i]);
-                }
-            }
         } else if (name != "Identity") {
             throw std::domain_error("Unrecognized gate name: " + name);
         }
diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index 33eabd6..6a058e9 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -154,7 +154,6 @@ class QrackDevice(QubitDevice):
         "C(CPhase)",
         "MultiControlledX",
         "C(MultiControlledX)",
-        "QFT",
     }
 
     config = pathlib.Path(
@@ -598,14 +597,6 @@ def _apply_gate(self, op):
                 -par[1],
                 -par[2],
             )
-        elif opname == "QFT":
-            self._state.qft(device_wires.labels)
-            for i in range(len(device_wires.labels) >> 1):
-                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
-        elif opname == "QFT.inv":
-            for i in range(len(device_wires.labels) >> 1):
-                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
-            self._state.iqft(device_wires.labels)
         elif opname not in [
             "Identity",
             "Identity.inv",

From dc9d6e474f85bad4fb30cd4e3bab04c5ef76aeb2 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 13:51:26 -0400
Subject: [PATCH 06/27] Debugging ControlledPhaseShift

---
 pennylane_qrack/qrack_device.cpp | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 73780dd..97742f6 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -141,11 +141,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             for (const bitLenInt& target : wires) {
                 qsim->Phase(Qrack::ONE_CMPLX, bottomRight, target);
             }
-        } else if ((name == "ControlledPhaseShift") || (name == "CPhase")) {
-            const Qrack::real1 cosine = (Qrack::real1)cos(inverse ? -params[0U] : params[0U]);
-            const Qrack::real1 sine = (Qrack::real1)sin(inverse ? -params[0U] : params[0U]);
-            const Qrack::complex bottomRight(cosine, sine);
-            qsim->MCPhase(std::vector<bitLenInt>(wires.begin(), wires.end() - 1U), Qrack::ONE_CMPLX, bottomRight, wires.back());
         } else if (name == "RX") {
             for (const bitLenInt& target : wires) {
                 qsim->RX(inverse ? -params[0U] : params[0U], target);
@@ -664,7 +659,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         }
 
         // Update the state-vector
-        if (controlled_wires.empty()) {
+        if (dev_controlled_wires.empty()) {
             applyNamedOperation(name, dev_wires, inverse, params);
         } else {
             applyNamedOperation(name, dev_controlled_wires, dev_controlled_values, dev_wires, inverse, params);
@@ -690,7 +685,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         Qrack::inv2x2(mtrx, inv);
 
         // Update the state-vector
-        if (controlled_wires.empty()) {
+        if (dev_controlled_wires.empty()) {
             qsim->Mtrx(inverse ? inv : mtrx, wires[0U]);
         } else {
             bitCapInt controlPerm = 0U;

From 8b47722d4568997298118c4736003fec65fcc98e Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 13:56:52 -0400
Subject: [PATCH 07/27] Fix Catalyst control wire order

---
 pennylane_qrack/qrack_device.cpp | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 97742f6..bf8f294 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -191,11 +191,10 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                              const std::vector<bitLenInt> &wires, const bool& inverse,
                              const std::vector<double> &params)
     {
-        bitCapInt controlPerm = 0U;
-        for (size_t i = 0U; i < control_values.size(); ++i) {
-            controlPerm = controlPerm << 1U;
+        bitCapInt controlPerm = Qrack::ZERO_BCI;
+        for (bitLenInt i = 0U; i < control_values.size(); ++i) {
             if (control_values[i]) {
-                controlPerm = controlPerm | 1U;
+                controlPerm = controlPerm | Qrack::pow2(i);
             }
         }
 

From f1a21b97b1279eecbd6b9ef3feca94cda1a6db70 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 14:20:04 -0400
Subject: [PATCH 08/27] Debug MatrixOperation()

---
 pennylane_qrack/qrack_device.cpp | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index bf8f294..73c10ce 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -685,16 +685,15 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
 
         // Update the state-vector
         if (dev_controlled_wires.empty()) {
-            qsim->Mtrx(inverse ? inv : mtrx, wires[0U]);
+            qsim->Mtrx(inverse ? inv : mtrx, dev_wires[0U]);
         } else {
-            bitCapInt controlPerm = 0U;
-            for (size_t i = 0U; i < controlled_values.size(); ++i) {
-                controlPerm = controlPerm << 1U;
+            bitCapInt controlPerm = Qrack::ZERO_BCI;
+            for (bitLenInt i = 0U; i < controlled_values.size(); ++i) {
                 if (controlled_values[i]) {
-                    controlPerm = controlPerm | 1U;
+                    controlPerm = controlPerm | Qrack::pow2(i);
                 }
             }
-            qsim->UCMtrx(dev_controlled_wires, inverse ? inv : mtrx, wires[0U], controlPerm);
+            qsim->UCMtrx(dev_controlled_wires, inverse ? inv : mtrx, dev_wires[0U], controlPerm);
         }
     }
     auto Expval(ObsIdType id) -> double override

From 1dd3d70da18a00b0e404c1ee5107d57ec7d3fd27 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 14:54:06 -0400
Subject: [PATCH 09/27] Debug Catalyst observables

---
 pennylane_qrack/qrack_device.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 73c10ce..981e9e8 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -541,6 +541,9 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     auto Observable(ObsId id, const std::vector<std::complex<double>> &matrix,
                     const std::vector<QubitIdType> &wires) -> ObsIdType override
     {
+        RT_FAIL_IF(wires.size() != 1U, "Cannot have observables besides tensor products of Pauli observables");
+        auto &&dev_wires = getDeviceWires(wires);
+
         Qrack::Pauli basis = Qrack::PauliI;
         switch (id) {
             case ObsId::PauliX:
@@ -555,7 +558,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             default:
                 break;
         }
-        obs_cache.push_back(QrackObservable({ basis }, { (bitLenInt)wires[0U] }));
+        obs_cache.push_back(QrackObservable({ basis }, { (bitLenInt)dev_wires[0U] }));
 
         return obs_cache.size() - 1U;
     }

From df35d6f884abb7fc46f1b24aa2699d2c858a24ae Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 15:19:59 -0400
Subject: [PATCH 10/27] Fix tests

---
 pennylane_qrack/qrack_device.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index 6a058e9..035718e 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -490,7 +490,7 @@ def _apply_gate(self, op):
         elif opname in ["PhaseShift.inv", "U1.inv"]:
             ip_mtrx = [1, 0, 0, cmath.exp(1j * -par[0])]
             for label in device_wires.labels:
-                self._state.mtrx(p_mtrx, label)
+                self._state.mtrx(ip_mtrx, label)
         elif opname in ["C(PhaseShift)", "C(U1)"]:
             self._state.mtrx(
                 device_wires.labels[:-1],

From e9e8326236dfb253ef4e7a8a19488f3baaf52cf8 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 16:22:24 -0400
Subject: [PATCH 11/27] Fix off-by-one

---
 pennylane_qrack/qrack_device.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 981e9e8..d4ad9e9 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -442,7 +442,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                 wires = 0U;
                 size_t q;
                 while ((q = value.find(",")) != std::string::npos) {
-                    const bitLenInt label = stoi(value.substr(0, q));
+                    const bitLenInt label = stoi(value.substr(0, q)) + 1U;
                     value.erase(0, q + 1U);
                     if (label > wires) {
                         wires = label;

From 3f572a856eb814e1315dd01efc3bbb8635e65151 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 16:40:56 -0400
Subject: [PATCH 12/27] Reverse wire order

---
 pennylane_qrack/qrack_device.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index d4ad9e9..dd022fd 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -42,7 +42,8 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     {
         std::vector<bitLenInt> res;
         res.reserve(wires.size());
-        std::transform(wires.begin(), wires.end(), std::back_inserter(res), [](auto w) { return (bitLenInt)w; });
+        const bitLenInt end = qsim->GetQubitCount() - 1U;
+        std::transform(wires.begin(), wires.end(), std::back_inserter(res), [end](auto w) { return end - (bitLenInt)w; });
         return res;
     }
 

From 9cd319e5b9ae54e4513fcc0229bf5b1e322b7212 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 17:16:47 -0400
Subject: [PATCH 13/27] reverseWires()

---
 pennylane_qrack/qrack_device.cpp | 33 ++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index dd022fd..66f3a99 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -38,6 +38,16 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     static constexpr bool QRACK_RESULT_TRUE_CONST = true;
     static constexpr bool QRACK_RESULT_FALSE_CONST = false;
 
+    inline auto reverseWires() -> void
+    {
+        const bitLenInt count = qsim->GetQubitCount();
+        const bitLenInt end = count - 1U;
+        const bitLenInt maxLcv = count >> 1U;
+        for (bitLenInt i = 0U; i < maxLcv; ++i) {
+            qsim->Swap(i, end - i);
+        }
+    }
+
     inline auto getDeviceWires(const std::vector<QubitIdType> &wires) -> std::vector<bitLenInt>
     {
         std::vector<bitLenInt> res;
@@ -735,15 +745,16 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     void PartialProbs(DataView<double, 1> &p, const std::vector<QubitIdType> &wires) override
     {
         RT_FAIL_IF((size_t)Qrack::pow2(wires.size()) != p.size(), "Invalid size for the pre-allocated probabilities vector");
-        std::vector<bitLenInt> ids(wires.size());
-        std::transform(wires.begin(), wires.end(), ids.end(), [](QubitIdType a) { return (bitLenInt)a; });
+        auto &&dev_wires = getDeviceWires(wires);
+        reverseWires();
 #if FPPOW == 6
-        qsim->ProbBitsAll(ids, &(*(p.begin())));
+        qsim->ProbBitsAll(dev_wires, &(*(p.begin())));
 #else
         std::unique_ptr<Qrack::real1> _p(new Qrack::real1[p.size()]);
-        qsim->ProbBitsAll(ids, _p.get());
+        qsim->ProbBitsAll(dev_wires, _p.get());
         std::copy(_p.get(), _p.get() + p.size(), p.begin());
 #endif
+        reverseWires();
     }
     void Sample(DataView<double, 2> &samples, size_t shots) override
     {
@@ -771,11 +782,14 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         // that could be instead implied by the size of "samples."
         RT_FAIL_IF(samples.size() != shots, "Invalid size for the pre-allocated samples");
 
-        std::vector<bitCapInt> qPowers(wires.size());
+        auto &&dev_wires = getDeviceWires(wires);
+        std::vector<bitCapInt> qPowers(dev_wires.size());
         for (size_t i = 0U; i < qPowers.size(); ++i) {
-            qPowers[i] = Qrack::pow2((bitLenInt)wires[i]);
+            qPowers[i] = Qrack::pow2((bitLenInt)dev_wires[i]);
         }
+        reverseWires();
         auto q_samples = qsim->MultiShotMeasureMask(qPowers, shots);
+        reverseWires();
 
         auto samplesIter = samples.begin();
         for (size_t shot = 0U; shot < shots; ++shot) {
@@ -827,11 +841,14 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         RT_FAIL_IF(eigvals.size() != numElements || counts.size() != numElements,
                    "Invalid size for the pre-allocated counts");
 
-        std::vector<bitCapInt> qPowers(wires.size());
+        auto &&dev_wires = getDeviceWires(wires);
+        std::vector<bitCapInt> qPowers(dev_wires.size());
         for (size_t i = 0U; i < qPowers.size(); ++i) {
-            qPowers[i] = Qrack::pow2(wires[i]);
+            qPowers[i] = Qrack::pow2(dev_wires[i]);
         }
+        reverseWires();
         auto q_samples = qsim->MultiShotMeasureMask(qPowers, shots);
+        reverseWires();
 
         std::iota(eigvals.begin(), eigvals.end(), 0);
         std::fill(counts.begin(), counts.end(), 0);

From 0ea3c8088b33a69ffac841661042ddc181634f15 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 17:27:21 -0400
Subject: [PATCH 14/27] Revert "Decompose QFT"

This reverts commit de6f5e085eae8ac71b16622017fdb9f3fa17e568.
---
 pennylane_qrack/QrackDeviceConfig.toml |  2 +-
 pennylane_qrack/qrack_device.cpp       | 14 ++++++++++++++
 pennylane_qrack/qrack_device.py        |  9 +++++++++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/pennylane_qrack/QrackDeviceConfig.toml b/pennylane_qrack/QrackDeviceConfig.toml
index ca3a67e..24ec83d 100644
--- a/pennylane_qrack/QrackDeviceConfig.toml
+++ b/pennylane_qrack/QrackDeviceConfig.toml
@@ -48,6 +48,7 @@ U2 = { properties = [ "controllable", "invertible" ] }
 U1 = { properties = [ "controllable", "invertible" ] }
 MultiControlledX = { properties = [ "controllable", "invertible" ] }
 Identity = { properties = [ "controllable", "invertible" ] }
+QFT = { properties = [ "invertible" ] }
 
 # Operators that should be decomposed according to the algorithm used
 # by PennyLane's device API.
@@ -78,7 +79,6 @@ Identity = { properties = [ "controllable", "invertible" ] }
 # IsingYY = {}
 # IsingZZ = {}
 # IsingXY = {}
-# QFT = {}
 
 # Gates which should be translated to QubitUnitary
 # [operators.gates.matrix]
diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 66f3a99..bbfe850 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -192,6 +192,20 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                     qsim->U(target, Qrack::PI_R1 / 2, params[0U], params[1U]);
                 }
             }
+        } else if (name == "QFT") {
+            const size_t maxLcv = wires.size() >> 1U;
+            const size_t end = wires.size() - 1U;
+            if (inverse) {
+                for (size_t i = 0U; i < maxLcv; ++i) {
+                    qsim->Swap(wires[i], wires[end - i]);
+                }
+                qsim->IQFTR(wires);
+            } else {
+                qsim->QFTR(wires);
+                for (size_t i = 0U; i < maxLcv; ++i) {
+                    qsim->Swap(wires[i], wires[end - i]);
+                }
+            }
         } else if (name != "Identity") {
             throw std::domain_error("Unrecognized gate name: " + name);
         }
diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index 035718e..d7295f7 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -154,6 +154,7 @@ class QrackDevice(QubitDevice):
         "C(CPhase)",
         "MultiControlledX",
         "C(MultiControlledX)",
+        "QFT",
     }
 
     config = pathlib.Path(
@@ -597,6 +598,14 @@ def _apply_gate(self, op):
                 -par[1],
                 -par[2],
             )
+        elif opname == "QFT":
+            self._state.qft(device_wires.labels)
+            for i in range(len(device_wires.labels) >> 1):
+                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
+        elif opname == "QFT.inv":
+            for i in range(len(device_wires.labels) >> 1):
+                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
+            self._state.iqft(device_wires.labels)
         elif opname not in [
             "Identity",
             "Identity.inv",

From 9b67ca5de27830d56bf22e0b3134dcf85bea72a7 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 18:11:15 -0400
Subject: [PATCH 15/27] Decompose QFT

---
 pennylane_qrack/QrackDeviceConfig.toml |  2 +-
 pennylane_qrack/qrack_device.cpp       | 14 --------------
 pennylane_qrack/qrack_device.py        |  9 ---------
 3 files changed, 1 insertion(+), 24 deletions(-)

diff --git a/pennylane_qrack/QrackDeviceConfig.toml b/pennylane_qrack/QrackDeviceConfig.toml
index 24ec83d..ca3a67e 100644
--- a/pennylane_qrack/QrackDeviceConfig.toml
+++ b/pennylane_qrack/QrackDeviceConfig.toml
@@ -48,7 +48,6 @@ U2 = { properties = [ "controllable", "invertible" ] }
 U1 = { properties = [ "controllable", "invertible" ] }
 MultiControlledX = { properties = [ "controllable", "invertible" ] }
 Identity = { properties = [ "controllable", "invertible" ] }
-QFT = { properties = [ "invertible" ] }
 
 # Operators that should be decomposed according to the algorithm used
 # by PennyLane's device API.
@@ -79,6 +78,7 @@ QFT = { properties = [ "invertible" ] }
 # IsingYY = {}
 # IsingZZ = {}
 # IsingXY = {}
+# QFT = {}
 
 # Gates which should be translated to QubitUnitary
 # [operators.gates.matrix]
diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index bbfe850..66f3a99 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -192,20 +192,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                     qsim->U(target, Qrack::PI_R1 / 2, params[0U], params[1U]);
                 }
             }
-        } else if (name == "QFT") {
-            const size_t maxLcv = wires.size() >> 1U;
-            const size_t end = wires.size() - 1U;
-            if (inverse) {
-                for (size_t i = 0U; i < maxLcv; ++i) {
-                    qsim->Swap(wires[i], wires[end - i]);
-                }
-                qsim->IQFTR(wires);
-            } else {
-                qsim->QFTR(wires);
-                for (size_t i = 0U; i < maxLcv; ++i) {
-                    qsim->Swap(wires[i], wires[end - i]);
-                }
-            }
         } else if (name != "Identity") {
             throw std::domain_error("Unrecognized gate name: " + name);
         }
diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index d7295f7..035718e 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -154,7 +154,6 @@ class QrackDevice(QubitDevice):
         "C(CPhase)",
         "MultiControlledX",
         "C(MultiControlledX)",
-        "QFT",
     }
 
     config = pathlib.Path(
@@ -598,14 +597,6 @@ def _apply_gate(self, op):
                 -par[1],
                 -par[2],
             )
-        elif opname == "QFT":
-            self._state.qft(device_wires.labels)
-            for i in range(len(device_wires.labels) >> 1):
-                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
-        elif opname == "QFT.inv":
-            for i in range(len(device_wires.labels) >> 1):
-                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
-            self._state.iqft(device_wires.labels)
         elif opname not in [
             "Identity",
             "Identity.inv",

From 79793ddf3ec46f26eeffbb34150c0dfdcb8506c7 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 18:39:05 -0400
Subject: [PATCH 16/27] reverseWires() -> getReverseWires()

---
 pennylane_qrack/qrack_device.cpp | 30 +++++++++++-------------------
 1 file changed, 11 insertions(+), 19 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 66f3a99..a0f18a3 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -38,16 +38,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     static constexpr bool QRACK_RESULT_TRUE_CONST = true;
     static constexpr bool QRACK_RESULT_FALSE_CONST = false;
 
-    inline auto reverseWires() -> void
-    {
-        const bitLenInt count = qsim->GetQubitCount();
-        const bitLenInt end = count - 1U;
-        const bitLenInt maxLcv = count >> 1U;
-        for (bitLenInt i = 0U; i < maxLcv; ++i) {
-            qsim->Swap(i, end - i);
-        }
-    }
-
     inline auto getDeviceWires(const std::vector<QubitIdType> &wires) -> std::vector<bitLenInt>
     {
         std::vector<bitLenInt> res;
@@ -57,6 +47,14 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         return res;
     }
 
+    inline auto getReverseWires(const std::vector<QubitIdType> &wires) -> std::vector<bitLenInt>
+    {
+        std::vector<bitLenInt> res;
+        res.reserve(wires.size());
+        std::transform(wires.begin(), wires.end(), std::back_inserter(res), [](auto w) { return (bitLenInt)w; });
+        return res;
+    }
+
     inline auto wiresToMask(const std::vector<bitLenInt> &wires) -> bitCapInt
     {
         bitCapInt mask = Qrack::ZERO_BCI;
@@ -745,8 +743,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     void PartialProbs(DataView<double, 1> &p, const std::vector<QubitIdType> &wires) override
     {
         RT_FAIL_IF((size_t)Qrack::pow2(wires.size()) != p.size(), "Invalid size for the pre-allocated probabilities vector");
-        auto &&dev_wires = getDeviceWires(wires);
-        reverseWires();
+        auto &&dev_wires = getReverseWires(wires);
 #if FPPOW == 6
         qsim->ProbBitsAll(dev_wires, &(*(p.begin())));
 #else
@@ -754,7 +751,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         qsim->ProbBitsAll(dev_wires, _p.get());
         std::copy(_p.get(), _p.get() + p.size(), p.begin());
 #endif
-        reverseWires();
     }
     void Sample(DataView<double, 2> &samples, size_t shots) override
     {
@@ -782,14 +778,12 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         // that could be instead implied by the size of "samples."
         RT_FAIL_IF(samples.size() != shots, "Invalid size for the pre-allocated samples");
 
-        auto &&dev_wires = getDeviceWires(wires);
+        auto &&dev_wires = getReverseWires(wires);
         std::vector<bitCapInt> qPowers(dev_wires.size());
         for (size_t i = 0U; i < qPowers.size(); ++i) {
             qPowers[i] = Qrack::pow2((bitLenInt)dev_wires[i]);
         }
-        reverseWires();
         auto q_samples = qsim->MultiShotMeasureMask(qPowers, shots);
-        reverseWires();
 
         auto samplesIter = samples.begin();
         for (size_t shot = 0U; shot < shots; ++shot) {
@@ -841,14 +835,12 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         RT_FAIL_IF(eigvals.size() != numElements || counts.size() != numElements,
                    "Invalid size for the pre-allocated counts");
 
-        auto &&dev_wires = getDeviceWires(wires);
+        auto &&dev_wires = getReverseWires(wires);
         std::vector<bitCapInt> qPowers(dev_wires.size());
         for (size_t i = 0U; i < qPowers.size(); ++i) {
             qPowers[i] = Qrack::pow2(dev_wires[i]);
         }
-        reverseWires();
         auto q_samples = qsim->MultiShotMeasureMask(qPowers, shots);
-        reverseWires();
 
         std::iota(eigvals.begin(), eigvals.end(), 0);
         std::fill(counts.begin(), counts.end(), 0);

From cf6ac8a07df6fbc4057086b8d28136cb6ca37c3c Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Fri, 31 May 2024 18:47:47 -0400
Subject: [PATCH 17/27] Remove inefficient while loop

---
 pennylane_qrack/qrack_device.cpp | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index a0f18a3..0eadf57 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -656,17 +656,17 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             || (name == "CRZ")
             || (name == "CRot")
             || (name == "Toffoli")) {
-            while (dev_wires.size() > 1U) {
-                dev_controlled_wires.push_back(dev_wires[0]);
-                dev_controlled_values.push_back(true);
-                dev_wires.erase(dev_wires.begin());
-            }
+            const size_t end = dev_wires.size() - 1U;
+            dev_controlled_wires.insert(dev_controlled_wires.end(), dev_wires.begin(), dev_wires.begin() + end);
+            dev_wires.erase(dev_wires.begin(), dev_wires.begin() + end);
+            const std::vector<bool> t(end, true);
+            dev_controlled_values.insert(dev_controlled_values.end(), t.begin(), t.end());
         } else if (name == "CSWAP") {
-            while (dev_wires.size() > 2U) {
-                dev_controlled_wires.push_back(dev_wires[0]);
-                dev_controlled_values.push_back(true);
-                dev_wires.erase(dev_wires.begin());
-            }
+            const size_t end = dev_wires.size() - 2U;
+            dev_controlled_wires.insert(dev_controlled_wires.end(), dev_wires.begin(), dev_wires.begin() + end);
+            dev_wires.erase(dev_wires.begin(), dev_wires.begin() + end);
+            const std::vector<bool> t(end, true);
+            dev_controlled_values.insert(dev_controlled_values.end(), t.begin(), t.end());
         }
 
         // Update the state-vector

From b7c4c519052e2a33c4a412782c35895edf48b415 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Sat, 1 Jun 2024 08:16:45 -0400
Subject: [PATCH 18/27] Simplify phase gates

---
 pennylane_qrack/qrack_device.cpp | 22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 0eadf57..b95b888 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -144,9 +144,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             qsim->Swap(wires[0U], wires[1U]);
             qsim->CU(c, wires[1U], ZERO_R1, ZERO_R1, inverse ? -params[0U] : params[0U]);
         } else if ((name == "PhaseShift") || (name == "U1")) {
-            const Qrack::real1 cosine = (Qrack::real1)cos(inverse ? -params[0U] : params[0U]);
-            const Qrack::real1 sine = (Qrack::real1)sin(inverse ? -params[0U] : params[0U]);
-            const Qrack::complex bottomRight(cosine, sine);
+            const Qrack::complex bottomRight = exp(Qrack::I_CMPLX * (Qrack::real1)(inverse ? -params[0U] : params[0U]));
             for (const bitLenInt& target : wires) {
                 qsim->Phase(Qrack::ONE_CMPLX, bottomRight, target);
             }
@@ -243,12 +241,9 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                 qsim->UCMtrx(control_wires, inverse ? iSqrtX : sqrtX, target, controlPerm);
             }
         } else if (name == "MultiRZ") {
-            const Qrack::real1 cosine = (Qrack::real1)cos((inverse ? -params[0U] : params[0U]) / 2);
-            const Qrack::real1 sine = (Qrack::real1)sin((inverse ? -params[0U] : params[0U]) / 2);
-            const Qrack::complex topLeft(cosine, -sine);
-            const Qrack::complex bottomRight(cosine, sine);
+            const Qrack::complex bottomRight = exp(Qrack::I_CMPLX * (Qrack::real1)((inverse ? -params[0U] : params[0U]) / 2));
             for (const bitLenInt& target : wires) {
-                qsim->UCPhase(control_wires, topLeft, bottomRight, target, controlPerm);
+                qsim->UCPhase(control_wires, conj(bottomRight), bottomRight, target, controlPerm);
             }
         } else if (name == "Hadamard") {
             for (const bitLenInt& target : wires) {
@@ -297,9 +292,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                 }
             }
         } else if ((name == "PhaseShift") || (name == "U1") || (name == "ControlledPhaseShift") || (name == "CPhase")) {
-            const Qrack::real1 cosine = (Qrack::real1)cos(inverse ? -params[0U] : params[0U]);
-            const Qrack::real1 sine = (Qrack::real1)sin(inverse ? -params[0U] : params[0U]);
-            const Qrack::complex bottomRight(cosine, sine);
+            const Qrack::complex bottomRight = exp(Qrack::I_CMPLX * (Qrack::real1)(inverse ? -params[0U] : params[0U]));
             for (const bitLenInt& target : wires) {
                 qsim->UCPhase(control_wires, Qrack::ONE_CMPLX, bottomRight, target, controlPerm);
             }
@@ -330,12 +323,9 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                 qsim->UCMtrx(control_wires, mtrx, target, controlPerm);
             }
         } else if ((name == "RZ") || (name == "CRZ")) {
-            const Qrack::real1 cosine = (Qrack::real1)cos((inverse ? -params[0U] : params[0U]) / 2);
-            const Qrack::real1 sine = (Qrack::real1)sin((inverse ? -params[0U] : params[0U]) / 2);
-            const Qrack::complex topLeft(cosine, -sine);
-            const Qrack::complex bottomRight(cosine, sine);
+            const Qrack::complex bottomRight = exp(Qrack::I_CMPLX * (Qrack::real1)((inverse ? -params[0U] : params[0U]) / 2));
             for (const bitLenInt& target : wires) {
-                qsim->UCPhase(control_wires, topLeft, bottomRight, target, controlPerm);
+                qsim->UCPhase(control_wires, conj(bottomRight), bottomRight, target, controlPerm);
             }
         } else if ((name == "Rot") || (name == "CRot")) {
             const Qrack::real1 phi = inverse ? -params[0U] : params[0U];

From 3d9183f2e2316e8b949453a78775bbe7df64666f Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Sun, 2 Jun 2024 11:02:57 -0400
Subject: [PATCH 19/27] Fix wire map parsing

---
 pennylane_qrack/qrack_device.cpp | 63 +++++++++++++++++++++-----------
 1 file changed, 41 insertions(+), 22 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index b95b888..07d2a60 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -32,6 +32,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     bool tapeRecording;
     size_t shots;
     Qrack::QInterfacePtr qsim;
+    std::map<QubitIdType, bitLenInt> qubit_map;
     std::vector<QrackObservable> obs_cache;
 
     // static constants for RESULT values
@@ -42,8 +43,13 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     {
         std::vector<bitLenInt> res;
         res.reserve(wires.size());
-        const bitLenInt end = qsim->GetQubitCount() - 1U;
-        std::transform(wires.begin(), wires.end(), std::back_inserter(res), [end](auto w) { return end - (bitLenInt)w; });
+        std::transform(wires.begin(), wires.end(), std::back_inserter(res), [this](auto w) {
+            const auto& it = qubit_map.find(w);
+            if (it == qubit_map.end()) {
+                throw std::invalid_argument("Qubit ID not in wire map: " + std::to_string(w));
+            }
+            return it->second;
+        });
         return res;
     }
 
@@ -51,7 +57,14 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     {
         std::vector<bitLenInt> res;
         res.reserve(wires.size());
-        std::transform(wires.begin(), wires.end(), std::back_inserter(res), [](auto w) { return (bitLenInt)w; });
+        const bitLenInt end = qsim->GetQubitCount() - 1U;
+        std::transform(wires.begin(), wires.end(), std::back_inserter(res), [this, end](auto w) {
+            const auto& it = qubit_map.find(w);
+            if (it == qubit_map.end()) {
+                throw std::invalid_argument("Qubit ID not in wire map: " + std::to_string(w));
+            }
+            return end - it->second;
+        });
         return res;
     }
 
@@ -389,15 +402,15 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         kwargs = trim(kwargs);
 
         std::map<std::string, int> keyMap;
-        keyMap["wires"] = 1;
-        keyMap["shots"] = 2;
-        keyMap["is_hybrid_stabilizer"] = 3;
-        keyMap["is_tensor_network"] = 4;
-        keyMap["is_schmidt_decomposed"] = 5;
-        keyMap["is_schmidt_decomposition_parallel"] = 6;
-        keyMap["is_qbdd"] = 7;
-        keyMap["is_gpu"] = 8;
-        keyMap["is_host_pointer"] = 9;
+        keyMap["'wires'"] = 1;
+        keyMap["'shots'"] = 2;
+        keyMap["'is_hybrid_stabilizer'"] = 3;
+        keyMap["'is_tensor_network'"] = 4;
+        keyMap["'is_schmidt_decomposed'"] = 5;
+        keyMap["'is_schmidt_decomposition_parallel'"] = 6;
+        keyMap["'is_qbdd'"] = 7;
+        keyMap["'is_gpu'"] = 8;
+        keyMap["'is_host_pointer'"] = 9;
 
         bitLenInt wires = 0U;
         bool is_hybrid_stabilizer = true;
@@ -410,13 +423,10 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
 
         size_t pos;
         while ((pos = kwargs.find(":")) != std::string::npos) {
-            std::string key = kwargs.substr(0, pos);
+            std::string key = trim(kwargs.substr(0, pos));
             kwargs.erase(0, pos + 1U);
-            // Leading and trailing quotes:
-            key.erase(0U, 1U);
-            key.erase(key.size() - 1U);
 
-            if (key == "wires") {
+            if (key == "'wires'") {
                 // Handle if integer
                 pos = kwargs.find(",");
                 bool isInt = true;
@@ -428,12 +438,16 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                 }
                 if (isInt) {
                     wires = stoi(trim(kwargs.substr(0, pos)));
+                    for (size_t i = 0U; i < wires; ++i) {
+                        qubit_map[i] = wires - (i + 1U);
+                    }
                     kwargs.erase(0, pos + 1U);
+
                     continue;
                 }
 
                 // Handles if Wires object
-                pos = kwargs.find("]>,");
+                pos = kwargs.find("]>");
                 std::string value = kwargs.substr(0, pos);
                 kwargs.erase(0, pos + 3U);
                 size_t p = value.find("[");
@@ -441,13 +455,18 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                 wires = 0U;
                 size_t q;
                 while ((q = value.find(",")) != std::string::npos) {
-                    const bitLenInt label = stoi(value.substr(0, q)) + 1U;
+                    qubit_map[(QubitIdType)stoi(trim(value.substr(0, q)))] = wires;
+                    ++wires;
                     value.erase(0, q + 1U);
-                    if (label > wires) {
-                        wires = label;
-                    }
                 }
+                qubit_map[stoi(trim(value))] = wires;
                 ++wires;
+
+                for (auto it = qubit_map.begin(); it != qubit_map.end(); ++it) {
+                    it->second = wires - (it->second + 1U);
+                    std::cout << (size_t)it->first << ", " << (size_t)it->second << std::endl;
+                }
+
                 continue;
             }
 

From e563ee6230cf5ac81da87d3832e8bb3520b3c310 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Sun, 2 Jun 2024 11:26:12 -0400
Subject: [PATCH 20/27] Remove getReverseWires()

---
 pennylane_qrack/qrack_device.cpp | 21 +++------------------
 1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 07d2a60..7ff2359 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -53,21 +53,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         return res;
     }
 
-    inline auto getReverseWires(const std::vector<QubitIdType> &wires) -> std::vector<bitLenInt>
-    {
-        std::vector<bitLenInt> res;
-        res.reserve(wires.size());
-        const bitLenInt end = qsim->GetQubitCount() - 1U;
-        std::transform(wires.begin(), wires.end(), std::back_inserter(res), [this, end](auto w) {
-            const auto& it = qubit_map.find(w);
-            if (it == qubit_map.end()) {
-                throw std::invalid_argument("Qubit ID not in wire map: " + std::to_string(w));
-            }
-            return end - it->second;
-        });
-        return res;
-    }
-
     inline auto wiresToMask(const std::vector<bitLenInt> &wires) -> bitCapInt
     {
         bitCapInt mask = Qrack::ZERO_BCI;
@@ -752,7 +737,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     void PartialProbs(DataView<double, 1> &p, const std::vector<QubitIdType> &wires) override
     {
         RT_FAIL_IF((size_t)Qrack::pow2(wires.size()) != p.size(), "Invalid size for the pre-allocated probabilities vector");
-        auto &&dev_wires = getReverseWires(wires);
+        auto &&dev_wires = getDeviceWires(wires);
 #if FPPOW == 6
         qsim->ProbBitsAll(dev_wires, &(*(p.begin())));
 #else
@@ -787,7 +772,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         // that could be instead implied by the size of "samples."
         RT_FAIL_IF(samples.size() != shots, "Invalid size for the pre-allocated samples");
 
-        auto &&dev_wires = getReverseWires(wires);
+        auto &&dev_wires = getDeviceWires(wires);
         std::vector<bitCapInt> qPowers(dev_wires.size());
         for (size_t i = 0U; i < qPowers.size(); ++i) {
             qPowers[i] = Qrack::pow2((bitLenInt)dev_wires[i]);
@@ -844,7 +829,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         RT_FAIL_IF(eigvals.size() != numElements || counts.size() != numElements,
                    "Invalid size for the pre-allocated counts");
 
-        auto &&dev_wires = getReverseWires(wires);
+        auto &&dev_wires = getDeviceWires(wires);
         std::vector<bitCapInt> qPowers(dev_wires.size());
         for (size_t i = 0U; i < qPowers.size(); ++i) {
             qPowers[i] = Qrack::pow2(dev_wires[i]);

From 3900119ffb59bd565cf8a4c21d4791055394b81a Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Sun, 2 Jun 2024 12:09:05 -0400
Subject: [PATCH 21/27] Default to wires=1

---
 pennylane_qrack/qrack_device.cpp | 6 +++++-
 pennylane_qrack/qrack_device.py  | 2 +-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 7ff2359..056e81c 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -397,7 +397,8 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         keyMap["'is_gpu'"] = 8;
         keyMap["'is_host_pointer'"] = 9;
 
-        bitLenInt wires = 0U;
+        bitLenInt wires = 1U;
+        qubit_map[0U] = 0U;
         bool is_hybrid_stabilizer = true;
         bool is_tensor_network = false;
         bool is_schmidt_decomposed = true;
@@ -412,6 +413,9 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             kwargs.erase(0, pos + 1U);
 
             if (key == "'wires'") {
+                wires = 0U;
+                qubit_map.clear();
+
                 // Handle if integer
                 pos = kwargs.find(",");
                 bool isInt = true;
diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index 035718e..c0d58c3 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -167,7 +167,7 @@ def get_c_interface():
             os.path.dirname(sys.modules[__name__].__file__) + "/libqrack_device.so",
         )
 
-    def __init__(self, wires=0, shots=None, **kwargs):
+    def __init__(self, wires=1, shots=None, **kwargs):
         super().__init__(wires=wires, shots=shots)
 
         if "isTensorNetwork" in kwargs:

From 4cc3f5ebbb790e4cb28e83b9e7422e7493247158 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Sun, 2 Jun 2024 18:24:59 -0400
Subject: [PATCH 22/27] Remove logging statement

---
 pennylane_qrack/QubitManager.hpp | 145 +++++++++++++++++++++++++++++++
 pennylane_qrack/qrack_device.cpp |   1 -
 2 files changed, 145 insertions(+), 1 deletion(-)
 create mode 100644 pennylane_qrack/QubitManager.hpp

diff --git a/pennylane_qrack/QubitManager.hpp b/pennylane_qrack/QubitManager.hpp
new file mode 100644
index 0000000..7fb0610
--- /dev/null
+++ b/pennylane_qrack/QubitManager.hpp
@@ -0,0 +1,145 @@
+// Copyright 2022-2023 Xanadu Quantum Technologies Inc.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <algorithm>
+#include <map>
+
+#include "Exception.hpp"
+#include "Types.h"
+
+namespace Catalyst::Runtime {
+
+/**
+ * Qubit Manager
+ *
+ * @brief That maintains mapping of qubit IDs between runtime and device
+ * ids (e.g., Lightning-Dynamic). When user allocates a qubit, the
+ * `QubitManager` adds the qubit as an active qubit that operations
+ * can act on. When user releases a qubit, the `QubitManager` removes
+ * that qubit from the list of active wires.
+ */
+template <typename SimQubitIdType = QubitIdType, typename DevQubitIdType = size_t>
+class QubitManager {
+  private:
+    using LQMapT = std::map<SimQubitIdType, DevQubitIdType>;
+
+    SimQubitIdType next_idx{0};
+    LQMapT qubits_map{};
+
+    template <class OIter = typename LQMapT::iterator>
+    [[nodiscard]] inline OIter _remove_simulator_qubit_id(SimQubitIdType s_idx)
+    {
+        const auto &&s_idx_iter = this->qubits_map.find(s_idx);
+        RT_FAIL_IF(s_idx_iter == this->qubits_map.end(), "Invalid simulator qubit index");
+
+        return this->qubits_map.erase(s_idx_iter);
+    }
+
+    template <class IIter = typename LQMapT::iterator>
+    inline void _update_qubits_mapfrom(IIter s_idx_iter)
+    {
+        for (; s_idx_iter != this->qubits_map.end(); s_idx_iter++) {
+            s_idx_iter->second--;
+        }
+    }
+
+  public:
+    QubitManager() = default;
+    ~QubitManager() = default;
+
+    QubitManager(const QubitManager &) = delete;
+    QubitManager &operator=(const QubitManager &) = delete;
+    QubitManager(QubitManager &&) = delete;
+    QubitManager &operator=(QubitManager &&) = delete;
+
+    [[nodiscard]] auto isValidQubitId(SimQubitIdType s_idx) -> bool
+    {
+        return this->qubits_map.contains(s_idx);
+    }
+
+    [[nodiscard]] auto isValidQubitId(const std::vector<SimQubitIdType> &ss_idx) -> bool
+    {
+        return std::all_of(ss_idx.begin(), ss_idx.end(),
+                           [this](SimQubitIdType s) { return isValidQubitId(s); });
+    }
+
+    [[nodiscard]] auto getAllQubitIds() -> std::vector<SimQubitIdType>
+    {
+        std::vector<SimQubitIdType> ids;
+        ids.reserve(this->qubits_map.size());
+        for (const auto &it : this->qubits_map) {
+            ids.push_back(it.first);
+        }
+
+        return ids;
+    }
+
+    [[nodiscard]] auto getDeviceId(SimQubitIdType s_idx) -> DevQubitIdType
+    {
+        RT_FAIL_IF(!isValidQubitId(s_idx), "Invalid device qubit index");
+
+        return this->qubits_map[s_idx];
+    }
+
+    auto getDeviceIds(const std::vector<SimQubitIdType> &ss_idx) -> std::vector<DevQubitIdType>
+    {
+        std::vector<DevQubitIdType> dd_idx;
+        dd_idx.reserve(ss_idx.size());
+        for (const auto &s : ss_idx) {
+            dd_idx.push_back(getDeviceId(s));
+        }
+        return dd_idx;
+    }
+
+    [[nodiscard]] auto getSimulatorId(DevQubitIdType d_idx) -> SimQubitIdType
+    {
+        auto s_idx = std::find_if(this->qubits_map.begin(), this->qubits_map.end(),
+                                  [&d_idx](auto &&p) { return p.second == d_idx; });
+
+        RT_FAIL_IF(s_idx == this->qubits_map.end(), "Invalid simulator qubit index");
+
+        return s_idx->first;
+    }
+
+    [[nodiscard]] auto Allocate(DevQubitIdType d_next_idx) -> SimQubitIdType
+    {
+        this->qubits_map[this->next_idx++] = d_next_idx;
+        return this->next_idx - 1;
+    }
+
+    auto AllocateRange(DevQubitIdType start_idx, size_t size) -> std::vector<SimQubitIdType>
+    {
+        std::vector<SimQubitIdType> ids;
+        ids.reserve(size);
+        for (DevQubitIdType i = start_idx; i < start_idx + size; i++) {
+            ids.push_back(this->next_idx);
+            this->qubits_map[this->next_idx++] = i;
+        }
+        return ids;
+    }
+
+    void Release(SimQubitIdType s_idx)
+    {
+        _update_qubits_mapfrom(_remove_simulator_qubit_id(s_idx));
+    }
+
+    void ReleaseAll()
+    {
+        // Release all qubits by clearing the map.
+        this->qubits_map.clear();
+    }
+};
+} // namespace Catalyst::Runtime
diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 056e81c..595992e 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -453,7 +453,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
 
                 for (auto it = qubit_map.begin(); it != qubit_map.end(); ++it) {
                     it->second = wires - (it->second + 1U);
-                    std::cout << (size_t)it->first << ", " << (size_t)it->second << std::endl;
                 }
 
                 continue;

From 752f910490623b86248620acfc73ff208d966d4b Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Mon, 3 Jun 2024 08:58:46 -0400
Subject: [PATCH 23/27] Don't reverse wires until output

---
 pennylane_qrack/qrack_device.cpp | 46 +++++++++++++++++++++++---------
 pennylane_qrack/qrack_device.py  | 11 ++++----
 2 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
index 595992e..dddd8d5 100644
--- a/pennylane_qrack/qrack_device.cpp
+++ b/pennylane_qrack/qrack_device.cpp
@@ -39,6 +39,15 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     static constexpr bool QRACK_RESULT_TRUE_CONST = true;
     static constexpr bool QRACK_RESULT_FALSE_CONST = false;
 
+    inline void reverseWires()
+    {
+        const bitLenInt end = qsim->GetQubitCount() - 1U;
+        const bitLenInt mid = qsim->GetQubitCount() >> 1U;
+        for (bitLenInt i = 0U; i < mid; ++i) {
+            qsim->Swap(i, end - i);
+        }
+    }
+
     inline auto getDeviceWires(const std::vector<QubitIdType> &wires) -> std::vector<bitLenInt>
     {
         std::vector<bitLenInt> res;
@@ -397,8 +406,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         keyMap["'is_gpu'"] = 8;
         keyMap["'is_host_pointer'"] = 9;
 
-        bitLenInt wires = 1U;
-        qubit_map[0U] = 0U;
+        bitLenInt wires = 0U;
         bool is_hybrid_stabilizer = true;
         bool is_tensor_network = false;
         bool is_schmidt_decomposed = true;
@@ -413,9 +421,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             kwargs.erase(0, pos + 1U);
 
             if (key == "'wires'") {
-                wires = 0U;
-                qubit_map.clear();
-
                 // Handle if integer
                 pos = kwargs.find(",");
                 bool isInt = true;
@@ -428,7 +433,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                 if (isInt) {
                     wires = stoi(trim(kwargs.substr(0, pos)));
                     for (size_t i = 0U; i < wires; ++i) {
-                        qubit_map[i] = wires - (i + 1U);
+                        qubit_map[i] = i;
                     }
                     kwargs.erase(0, pos + 1U);
 
@@ -451,10 +456,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                 qubit_map[stoi(trim(value))] = wires;
                 ++wires;
 
-                for (auto it = qubit_map.begin(); it != qubit_map.end(); ++it) {
-                    it->second = wires - (it->second + 1U);
-                }
-
                 continue;
             }
 
@@ -533,12 +534,16 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     QrackDevice &operator=(QuantumDevice &&) = delete;
 
     auto AllocateQubit() -> QubitIdType override {
-        return qsim->Allocate(1U);
+        const QubitIdType label = qubit_map.rbegin()->first + 1U;
+        qubit_map[label] = qsim->Allocate(1U);
+        return label;
     }
     auto AllocateQubits(size_t num_qubits) -> std::vector<QubitIdType> override {
         std::vector<QubitIdType> ids(num_qubits);
         for (size_t i = 0U; i < num_qubits; ++i) {
-            ids[i] = qsim->Allocate(1U);
+            const QubitIdType label = qubit_map.rbegin()->first + 1U;
+            qubit_map[label] = qsim->Allocate(1U);
+            ids[i] = label;
         }
         return ids;
     }
@@ -595,17 +600,20 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         return ret;
     }
 
-    void ReleaseQubit(QubitIdType id) override
+    void ReleaseQubit(QubitIdType label) override
     {
         // Measure to prevent denormalization
+        const bitLenInt id = qubit_map[label];
         qsim->M(id);
         // Deallocate
         qsim->Dispose(id, 1U);
+        qubit_map.erase(label);
     }
     void ReleaseAllQubits() override
     {
         // State vector is left empty
         qsim->Dispose(0U, qsim->GetQubitCount());
+        qubit_map.clear();
     }
     [[nodiscard]] auto GetNumQubits() const -> size_t override
     {
@@ -718,6 +726,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
     void State(DataView<std::complex<double>, 1>& sv) override
     {
         RT_FAIL_IF(sv.size() != (size_t)qsim->GetMaxQPower(), "Invalid size for the pre-allocated state vector");
+        reverseWires();
 #if FPPOW == 6
         qsim->GetQuantumState(&(*(sv.begin())));
 #else
@@ -725,10 +734,12 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         qsim->GetQuantumState(_sv.get());
         std::copy(_sv.get(), _sv.get() + sv.size(), sv.begin());
 #endif
+        reverseWires();
     }
     void Probs(DataView<double, 1>& p) override
     {
         RT_FAIL_IF(p.size() != (size_t)qsim->GetMaxQPower(), "Invalid size for the pre-allocated probabilities vector");
+        reverseWires();
 #if FPPOW == 6
         qsim->GetProbs(&(*(p.begin())));
 #else
@@ -736,6 +747,7 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         qsim->GetProbs(_p.get());
         std::copy(_p.get(), _p.get() + p.size(), p.begin());
 #endif
+        reverseWires();
     }
     void PartialProbs(DataView<double, 1> &p, const std::vector<QubitIdType> &wires) override
     {
@@ -755,6 +767,8 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         // that could be instead implied by the size of "samples."
         RT_FAIL_IF(samples.size() != shots, "Invalid size for the pre-allocated samples");
 
+        reverseWires();
+
         std::vector<bitCapInt> qPowers(qsim->GetQubitCount());
         for (bitLenInt i = 0U; i < qPowers.size(); ++i) {
             qPowers[i] = Qrack::pow2(i);
@@ -768,6 +782,8 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                 *(samplesIter++) = bi_to_double((sample >> wire) & 1U);
             }
         }
+
+        reverseWires();
     }
     void PartialSample(DataView<double, 2> &samples, const std::vector<QubitIdType> &wires, size_t shots) override
     {
@@ -801,6 +817,8 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
         RT_FAIL_IF(eigvals.size() != numElements || counts.size() != numElements,
                    "Invalid size for the pre-allocated counts");
 
+        reverseWires();
+
         std::vector<bitCapInt> qPowers(numQubits);
         for (bitLenInt i = 0U; i < qPowers.size(); ++i) {
             qPowers[i] = Qrack::pow2(i);
@@ -819,6 +837,8 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
             }
             ++counts(static_cast<size_t>(basisState.to_ulong()));
         }
+
+        reverseWires();
     }
 
     void PartialCounts(DataView<double, 1> &eigvals, DataView<int64_t, 1> &counts,
diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index c0d58c3..4812ee7 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -167,7 +167,7 @@ def get_c_interface():
             os.path.dirname(sys.modules[__name__].__file__) + "/libqrack_device.so",
         )
 
-    def __init__(self, wires=1, shots=None, **kwargs):
+    def __init__(self, wires=0, shots=None, **kwargs):
         super().__init__(wires=wires, shots=shots)
 
         if "isTensorNetwork" in kwargs:
@@ -176,8 +176,7 @@ def __init__(self, wires=1, shots=None, **kwargs):
             self._state = QrackSimulator(self.num_wires, isTensorNetwork=False, **kwargs)
 
     def define_wire_map(self, wires):
-        consecutive_wires = Wires(range(self.num_wires - 1, -1, -1))
-
+        consecutive_wires = Wires(range(self.num_wires))
         wire_map = zip(wires, consecutive_wires)
         return OrderedDict(wire_map)
 
@@ -625,7 +624,7 @@ def analytic_probability(self, wires=None):
         if self._state is None:
             return None
 
-        all_probs = _reverse_state(self._abs(self.state) ** 2)
+        all_probs = self._abs(self.state) ** 2
         prob = self.marginal_prob(all_probs, wires)
 
         if (not "QRACK_FPPOW" in os.environ) or (6 > int(os.environ.get("QRACK_FPPOW"))):
@@ -671,7 +670,7 @@ def generate_samples(self):
             )
 
         samples = np.array(
-            self._state.measure_shots(list(range(self.num_wires - 1, -1, -1)), self.shots)
+            self._state.measure_shots(list(range(self.num_wires)), self.shots)
         )
         self._samples = QubitDevice.states_to_binary(samples, self.num_wires)
 
@@ -680,7 +679,7 @@ def generate_samples(self):
     @property
     def state(self):
         # returns the state after all operations are applied
-        return self._state.out_ket()
+        return _reverse_state(self._state.out_ket())
 
     def reset(self):
         self._state.reset_all()

From bb1b69517beb77eceb22d945c8df02deeefe4f83 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Mon, 3 Jun 2024 09:49:59 -0400
Subject: [PATCH 24/27] Revert Python wire map

---
 pennylane_qrack/QubitManager.hpp | 145 -------------------------------
 pennylane_qrack/qrack_device.py  |   9 +-
 2 files changed, 5 insertions(+), 149 deletions(-)
 delete mode 100644 pennylane_qrack/QubitManager.hpp

diff --git a/pennylane_qrack/QubitManager.hpp b/pennylane_qrack/QubitManager.hpp
deleted file mode 100644
index 7fb0610..0000000
--- a/pennylane_qrack/QubitManager.hpp
+++ /dev/null
@@ -1,145 +0,0 @@
-// Copyright 2022-2023 Xanadu Quantum Technologies Inc.
-
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-
-//     http://www.apache.org/licenses/LICENSE-2.0
-
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#pragma once
-
-#include <algorithm>
-#include <map>
-
-#include "Exception.hpp"
-#include "Types.h"
-
-namespace Catalyst::Runtime {
-
-/**
- * Qubit Manager
- *
- * @brief That maintains mapping of qubit IDs between runtime and device
- * ids (e.g., Lightning-Dynamic). When user allocates a qubit, the
- * `QubitManager` adds the qubit as an active qubit that operations
- * can act on. When user releases a qubit, the `QubitManager` removes
- * that qubit from the list of active wires.
- */
-template <typename SimQubitIdType = QubitIdType, typename DevQubitIdType = size_t>
-class QubitManager {
-  private:
-    using LQMapT = std::map<SimQubitIdType, DevQubitIdType>;
-
-    SimQubitIdType next_idx{0};
-    LQMapT qubits_map{};
-
-    template <class OIter = typename LQMapT::iterator>
-    [[nodiscard]] inline OIter _remove_simulator_qubit_id(SimQubitIdType s_idx)
-    {
-        const auto &&s_idx_iter = this->qubits_map.find(s_idx);
-        RT_FAIL_IF(s_idx_iter == this->qubits_map.end(), "Invalid simulator qubit index");
-
-        return this->qubits_map.erase(s_idx_iter);
-    }
-
-    template <class IIter = typename LQMapT::iterator>
-    inline void _update_qubits_mapfrom(IIter s_idx_iter)
-    {
-        for (; s_idx_iter != this->qubits_map.end(); s_idx_iter++) {
-            s_idx_iter->second--;
-        }
-    }
-
-  public:
-    QubitManager() = default;
-    ~QubitManager() = default;
-
-    QubitManager(const QubitManager &) = delete;
-    QubitManager &operator=(const QubitManager &) = delete;
-    QubitManager(QubitManager &&) = delete;
-    QubitManager &operator=(QubitManager &&) = delete;
-
-    [[nodiscard]] auto isValidQubitId(SimQubitIdType s_idx) -> bool
-    {
-        return this->qubits_map.contains(s_idx);
-    }
-
-    [[nodiscard]] auto isValidQubitId(const std::vector<SimQubitIdType> &ss_idx) -> bool
-    {
-        return std::all_of(ss_idx.begin(), ss_idx.end(),
-                           [this](SimQubitIdType s) { return isValidQubitId(s); });
-    }
-
-    [[nodiscard]] auto getAllQubitIds() -> std::vector<SimQubitIdType>
-    {
-        std::vector<SimQubitIdType> ids;
-        ids.reserve(this->qubits_map.size());
-        for (const auto &it : this->qubits_map) {
-            ids.push_back(it.first);
-        }
-
-        return ids;
-    }
-
-    [[nodiscard]] auto getDeviceId(SimQubitIdType s_idx) -> DevQubitIdType
-    {
-        RT_FAIL_IF(!isValidQubitId(s_idx), "Invalid device qubit index");
-
-        return this->qubits_map[s_idx];
-    }
-
-    auto getDeviceIds(const std::vector<SimQubitIdType> &ss_idx) -> std::vector<DevQubitIdType>
-    {
-        std::vector<DevQubitIdType> dd_idx;
-        dd_idx.reserve(ss_idx.size());
-        for (const auto &s : ss_idx) {
-            dd_idx.push_back(getDeviceId(s));
-        }
-        return dd_idx;
-    }
-
-    [[nodiscard]] auto getSimulatorId(DevQubitIdType d_idx) -> SimQubitIdType
-    {
-        auto s_idx = std::find_if(this->qubits_map.begin(), this->qubits_map.end(),
-                                  [&d_idx](auto &&p) { return p.second == d_idx; });
-
-        RT_FAIL_IF(s_idx == this->qubits_map.end(), "Invalid simulator qubit index");
-
-        return s_idx->first;
-    }
-
-    [[nodiscard]] auto Allocate(DevQubitIdType d_next_idx) -> SimQubitIdType
-    {
-        this->qubits_map[this->next_idx++] = d_next_idx;
-        return this->next_idx - 1;
-    }
-
-    auto AllocateRange(DevQubitIdType start_idx, size_t size) -> std::vector<SimQubitIdType>
-    {
-        std::vector<SimQubitIdType> ids;
-        ids.reserve(size);
-        for (DevQubitIdType i = start_idx; i < start_idx + size; i++) {
-            ids.push_back(this->next_idx);
-            this->qubits_map[this->next_idx++] = i;
-        }
-        return ids;
-    }
-
-    void Release(SimQubitIdType s_idx)
-    {
-        _update_qubits_mapfrom(_remove_simulator_qubit_id(s_idx));
-    }
-
-    void ReleaseAll()
-    {
-        // Release all qubits by clearing the map.
-        this->qubits_map.clear();
-    }
-};
-} // namespace Catalyst::Runtime
diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index 4812ee7..035718e 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -176,7 +176,8 @@ def __init__(self, wires=0, shots=None, **kwargs):
             self._state = QrackSimulator(self.num_wires, isTensorNetwork=False, **kwargs)
 
     def define_wire_map(self, wires):
-        consecutive_wires = Wires(range(self.num_wires))
+        consecutive_wires = Wires(range(self.num_wires - 1, -1, -1))
+
         wire_map = zip(wires, consecutive_wires)
         return OrderedDict(wire_map)
 
@@ -624,7 +625,7 @@ def analytic_probability(self, wires=None):
         if self._state is None:
             return None
 
-        all_probs = self._abs(self.state) ** 2
+        all_probs = _reverse_state(self._abs(self.state) ** 2)
         prob = self.marginal_prob(all_probs, wires)
 
         if (not "QRACK_FPPOW" in os.environ) or (6 > int(os.environ.get("QRACK_FPPOW"))):
@@ -670,7 +671,7 @@ def generate_samples(self):
             )
 
         samples = np.array(
-            self._state.measure_shots(list(range(self.num_wires)), self.shots)
+            self._state.measure_shots(list(range(self.num_wires - 1, -1, -1)), self.shots)
         )
         self._samples = QubitDevice.states_to_binary(samples, self.num_wires)
 
@@ -679,7 +680,7 @@ def generate_samples(self):
     @property
     def state(self):
         # returns the state after all operations are applied
-        return _reverse_state(self._state.out_ket())
+        return self._state.out_ket()
 
     def reset(self):
         self._state.reset_all()

From 57370ce0a9dc25c5f7a2bc074fce4308347ab7b1 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Mon, 3 Jun 2024 10:31:21 -0400
Subject: [PATCH 25/27] Dynamic _reverse_state()

---
 pennylane_qrack/qrack_device.py | 36 ++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index 035718e..fbc86e2 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -43,19 +43,6 @@
 tolerance = 1e-10
 
 
-def _reverse_state(state_vector):
-    """Reverse the qubit order for a vector of amplitudes.
-    Args:
-        state_vector (iterable[complex]): vector containing the amplitudes
-    Returns:
-        list[complex]
-    """
-    state_vector = np.array(state_vector)
-    N = int(math.log2(len(state_vector)))
-    reversed_state = state_vector.reshape([2] * N).T.flatten()
-    return reversed_state
-
-
 class QrackDevice(QubitDevice):
     """Qrack device"""
 
@@ -176,11 +163,16 @@ def __init__(self, wires=0, shots=None, **kwargs):
             self._state = QrackSimulator(self.num_wires, isTensorNetwork=False, **kwargs)
 
     def define_wire_map(self, wires):
-        consecutive_wires = Wires(range(self.num_wires - 1, -1, -1))
-
+        consecutive_wires = Wires(range(self.num_wires))
         wire_map = zip(wires, consecutive_wires)
         return OrderedDict(wire_map)
 
+    def _reverse_state(self):
+        end = self.num_wires - 1
+        mid = self.num_wires >> 1
+        for i in range(mid):
+            self._state.swap(i, end - i)
+
     def apply(self, operations, **kwargs):
         rotations = kwargs.get("rotations", [])
 
@@ -242,11 +234,13 @@ def _apply_qubit_state_vector(self, op):
         if not np.isclose(np.linalg.norm(input_state, 2), 1.0, atol=tolerance):
             raise ValueError("Sum of amplitudes-squared does not equal one.")
 
+        self._reverse_state()
         if len(wires) != self.num_wires or sorted(wires, reverse=True) != wires:
             input_state = self._expand_state(input_state, wires)
 
         # call qrack' state initialization
         self._state.in_ket(input_state)
+        self._reverse_state()
 
     def _apply_basis_state(self, op):
         """Initialize a basis state"""
@@ -625,7 +619,7 @@ def analytic_probability(self, wires=None):
         if self._state is None:
             return None
 
-        all_probs = _reverse_state(self._abs(self.state) ** 2)
+        all_probs = self._abs(self.state) ** 2
         prob = self.marginal_prob(all_probs, wires)
 
         if (not "QRACK_FPPOW" in os.environ) or (6 > int(os.environ.get("QRACK_FPPOW"))):
@@ -650,7 +644,10 @@ def expval(self, observable, **kwargs):
 
             if None not in b:
                 q = self.map_wires(observable.wires)
-                return self._state.pauli_expectation(q, b)
+                self._reverse_state()
+                o = self._state.pauli_expectation(q, b)
+                self._reverse_state()
+                return o
 
             # exact expectation value
             if callable(observable.eigvals):
@@ -680,7 +677,10 @@ def generate_samples(self):
     @property
     def state(self):
         # returns the state after all operations are applied
-        return self._state.out_ket()
+        self._reverse_state()
+        o = self._state.out_ket()
+        self._reverse_state()
+        return o
 
     def reset(self):
         self._state.reset_all()

From 578ad15ca8597ae2f4a634b5bcc3874db6c0b8d6 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Mon, 3 Jun 2024 10:36:25 -0400
Subject: [PATCH 26/27] Fix observables

---
 pennylane_qrack/qrack_device.py | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index fbc86e2..d8bf2bc 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -644,10 +644,7 @@ def expval(self, observable, **kwargs):
 
             if None not in b:
                 q = self.map_wires(observable.wires)
-                self._reverse_state()
-                o = self._state.pauli_expectation(q, b)
-                self._reverse_state()
-                return o
+                return self._state.pauli_expectation(q, b)
 
             # exact expectation value
             if callable(observable.eigvals):

From fcc43d896ed3ec140ce2c3d6b23615f5c51cf658 Mon Sep 17 00:00:00 2001
From: WrathfulSpatula <stranoj@gmail.com>
Date: Mon, 3 Jun 2024 10:44:01 -0400
Subject: [PATCH 27/27] Don't override define_wire_map()

---
 pennylane_qrack/qrack_device.py | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
index d8bf2bc..8394afa 100644
--- a/pennylane_qrack/qrack_device.py
+++ b/pennylane_qrack/qrack_device.py
@@ -162,11 +162,6 @@ def __init__(self, wires=0, shots=None, **kwargs):
         else:
             self._state = QrackSimulator(self.num_wires, isTensorNetwork=False, **kwargs)
 
-    def define_wire_map(self, wires):
-        consecutive_wires = Wires(range(self.num_wires))
-        wire_map = zip(wires, consecutive_wires)
-        return OrderedDict(wire_map)
-
     def _reverse_state(self):
         end = self.num_wires - 1
         mid = self.num_wires >> 1