[Runtime] Build multiple Lightning simulators against the monorepo (#277

)

**Context:**
This PR adds support for building multiple lightning simulators
(`lightning.qubit` and `lightning.kokkos` atm) against the master branch
of the Lightning monorepo. This should be merged after PR
PennyLaneAI/pennylane-lightning#497.

**Description of the Change:**
- Remove the runtime's dependency to the pl-lightning-kokkos repository
- Update function names/signatures and namespaces

[sc-43458]

.github/workflows/build-wheel-linux-x86_64.yaml

@@ -196,7 +196,7 @@ jobs:
         fail-on-cache-miss: True
 
     # Build Catalyst-Runtime
-    # TODO: remove v0.31.0 after lightning monorepo upgrade
+    # TODO: remove master after lightning monorepo upgrade
     - name: Build Catalyst-Runtime
       run: |
         cmake -S runtime -B runtime-build -G Ninja \
@@ -205,8 +205,7 @@ jobs:
               -DPYTHON_EXECUTABLE=$(which python${{ matrix.python_version }}) \
               -Dpybind11_DIR=$(python${{ matrix.python_version }} -c "import pybind11; print(pybind11.get_cmake_dir())") \
               -DENABLE_LIGHTNING_KOKKOS=ON \
-              -DLIGHTNING_GIT_TAG=v0.31.0 \
-              -DLIGHTNING_KOKKOS_GIT_TAG=latest_release \
+              -DLIGHTNING_GIT_TAG="master" \
               -DKokkos_ENABLE_SERIAL=ON \
               -DKokkos_ENABLE_OPENMP=ON \
               -DENABLE_OPENQASM=ON

doc/changelog.md

@@ -5,7 +5,10 @@
 <h3>Improvements</h3>
 
 * Update the Lightning backend device to work with the PL-Lightning monorepo.
-[(#259)](https://github.com/PennyLaneAI/catalyst/pull/259)
+  [(#259)](https://github.com/PennyLaneAI/catalyst/pull/259)
+
+* Build both `"lightning.qubit"` and `"lightning.kokkos"` against the PL-Lightning monorepo.
+  [(#277)](https://github.com/PennyLaneAI/catalyst/pull/277)
 
 <h3>Breaking changes</h3>
 

runtime/Makefile

@@ -13,8 +13,7 @@ ENABLE_LIGHTNING_KOKKOS?=OFF
 ENABLE_OPENQASM?=OFF
 BUILD_QIR_STDLIB_FROM_SRC?=OFF
 # TODO: Update to latest_release after v0.33.0
-LIGHTNING_GIT_TAG_VALUE=master
-LIGHTNING_KOKKOS_GIT_TAG_VALUE?=latest_release
+LIGHTNING_GIT_TAG_VALUE= "master"
 NPROC?=$(shell python -c "import os; print(os.cpu_count())")
 
 coverage: CODE_COVERAGE=ON
@@ -45,7 +44,6 @@ configure:
 		-DCMAKE_BUILD_TYPE=$(BUILD_TYPE) \
 		-DCMAKE_LIBRARY_OUTPUT_DIRECTORY=$(RT_BUILD_DIR)/lib \
 		-DLIGHTNING_GIT_TAG=$(LIGHTNING_GIT_TAG_VALUE) \
-		-DLIGHTNING_KOKKOS_GIT_TAG=$(LIGHTNING_KOKKOS_GIT_TAG_VALUE) \
 		-DENABLE_LIGHTNING_KOKKOS=$(ENABLE_LIGHTNING_KOKKOS) \
 		-DENABLE_OPENQASM=$(ENABLE_OPENQASM) \
 		-DCMAKE_C_COMPILER=$(C_COMPILER) \

runtime/extensions/CMakeLists.txt

@@ -12,6 +12,15 @@ FetchContent_Declare(
 )
 set(CMAKE_POSITION_INDEPENDENT_CODE ON) # build with -fPIC
 set(ENABLE_KOKKOS OFF CACHE BOOL "Enable Kokkos")
+
+if(ENABLE_LIGHTNING AND ENABLE_LIGHTNING_KOKKOS)
+    set(PL_BACKEND "lightning_qubit;lightning_kokkos" CACHE STRING "PennyLane Lightning backend")
+elseif(ENABLE_LIGHTNING)
+    set(PL_BACKEND "lightning_qubit" CACHE STRING "PennyLane Lightning backend")
+elseif(ENABLE_LIGHTNING_KOKKOS)
+    set(PL_BACKEND "lightning_kokkos" CACHE STRING "PennyLane Lightning backend")
+endif()
+
 set(ENABLE_PYTHON OFF CACHE BOOL "Enable compilation of the Python module")
 FetchContent_MakeAvailable(pennylane_lightning)
 
@@ -22,19 +31,6 @@ target_include_directories(rt_interfaces INTERFACE .)
 
 set(LIGHTNING_KOKKOS_GIT_TAG "main" CACHE STRING "GIT_TAG value to build Lightning-Kokkos")
 
-if(ENABLE_LIGHTNING_KOKKOS)
-    FetchContent_Declare(
-        pennylane_lightning_kokkos
-        GIT_REPOSITORY https://github.com/PennyLaneAI/pennylane-lightning-kokkos.git
-        GIT_TAG        ${LIGHTNING_KOKKOS_GIT_TAG}
-    )
-
-    set(PL_BACKEND "lightning_qubit")
-    set(PLKOKKOS_ENABLE_PYTHON OFF CACHE BOOL "Enable compilation of the Python bindings")
-    FetchContent_MakeAvailable(pennylane_lightning_kokkos)
-
-    target_link_libraries(rt_interfaces INTERFACE pennylane_lightning_kokkos)
-endif()
 
 if(ENABLE_OPENQASM)
     find_package(pybind11 CONFIG)

runtime/lib/backend/common/Utils.hpp

@@ -25,10 +25,6 @@
 
 #include "Types.h"
 
-#if __has_include("StateVectorKokkos.hpp")
-#include "UtilKokkos.hpp"
-#endif
-
 #if __has_include("StateVectorLQubitDynamic.hpp")
 #include "Util.hpp"
 #endif

runtime/lib/backend/lightning-kokkos/LightningKokkosObsManager.hpp

@@ -33,16 +33,8 @@ namespace Catalyst::Runtime::Simulator {
  */
 template <typename PrecisionT> class LightningKokkosObsManager {
   private:
-    using ObservableClassName =
-        Pennylane::Lightning_Kokkos::Simulators::ObservableKokkos<PrecisionT>;
-    using NamedObsClassName = Pennylane::Lightning_Kokkos::Simulators::NamedObsKokkos<PrecisionT>;
-    using HermitianObsClassName =
-        Pennylane::Lightning_Kokkos::Simulators::HermitianObsKokkos<PrecisionT>;
-    using TensorProdObsClassName =
-        Pennylane::Lightning_Kokkos::Simulators::TensorProdObsKokkos<PrecisionT>;
-    using HamiltonianClassName =
-        Pennylane::Lightning_Kokkos::Simulators::HamiltonianKokkos<PrecisionT>;
-
+    using VectorStateT = Pennylane::LightningKokkos::StateVectorKokkos<PrecisionT>;
+    using ObservableClassName = Pennylane::Observables::Observable<VectorStateT>;
     using ObservablePairType = std::pair<std::shared_ptr<ObservableClassName>, ObsType>;
     std::vector<ObservablePairType> observables_{};
 
@@ -105,8 +97,10 @@ template <typename PrecisionT> class LightningKokkosObsManager {
             std::string(Lightning::lookup_obs<Lightning::simulator_observable_support_size>(
                 Lightning::simulator_observable_support, obsId));
 
-        this->observables_.push_back(
-            std::make_pair(std::make_shared<NamedObsClassName>(obs_str, wires), ObsType::Basic));
+        this->observables_.push_back(std::make_pair(
+            std::make_shared<Pennylane::LightningKokkos::Observables::NamedObs<VectorStateT>>(
+                obs_str, wires),
+            ObsType::Basic));
         return static_cast<ObsIdType>(this->observables_.size() - 1);
     }
 
@@ -120,8 +114,16 @@ template <typename PrecisionT> class LightningKokkosObsManager {
     [[nodiscard]] auto createHermitianObs(const std::vector<std::complex<PrecisionT>> &matrix,
                                           const std::vector<size_t> &wires) -> ObsIdType
     {
+        std::vector<Kokkos::complex<PrecisionT>> matrix_k;
+        matrix_k.reserve(matrix.size());
+        for (const auto &elem : matrix) {
+            matrix_k.push_back(static_cast<Kokkos::complex<PrecisionT>>(elem));
+        }
+
         this->observables_.push_back(std::make_pair(
-            std::make_shared<HermitianObsClassName>(HermitianObsClassName{matrix, wires}),
+            std::make_shared<Pennylane::LightningKokkos::Observables::HermitianObs<VectorStateT>>(
+                Pennylane::LightningKokkos::Observables::HermitianObs<VectorStateT>{matrix_k,
+                                                                                    wires}),
             ObsType::Basic));
 
         return static_cast<ObsIdType>(this->observables_.size() - 1);
@@ -149,7 +151,9 @@ template <typename PrecisionT> class LightningKokkosObsManager {
         }
 
         this->observables_.push_back(std::make_pair(
-            std::make_shared<TensorProdObsClassName>(TensorProdObsClassName::create(obs_vec)),
+            std::make_shared<Pennylane::LightningKokkos::Observables::TensorProdObs<VectorStateT>>(
+                Pennylane::LightningKokkos::Observables::TensorProdObs<VectorStateT>::create(
+                    obs_vec)),
             ObsType::TensorProd));
 
         return static_cast<ObsIdType>(obs_size);
@@ -182,10 +186,11 @@ template <typename PrecisionT> class LightningKokkosObsManager {
             obs_vec.push_back(obs);
         }
 
-        this->observables_.push_back(
-            std::make_pair(std::make_shared<HamiltonianClassName>(
-                               HamiltonianClassName(coeffs, std::move(obs_vec))),
-                           ObsType::Hamiltonian));
+        this->observables_.push_back(std::make_pair(
+            std::make_shared<Pennylane::LightningKokkos::Observables::Hamiltonian<VectorStateT>>(
+                Pennylane::LightningKokkos::Observables::Hamiltonian<VectorStateT>(
+                    coeffs, std::move(obs_vec))),
+            ObsType::Hamiltonian));
 
         return static_cast<ObsIdType>(obs_size);
     }