Add support for Pennylane Lightning backend to QIR-EE

.github/workflows/build-lightning.yml

@@ -0,0 +1,98 @@
+# Build directly on the GitHub runner with caching
+name: build-lightning
+on:
+  workflow_dispatch:
+  workflow_call:
+
+concurrency:
+  group: build-lightning-${{github.ref}}-${{github.event.pull_request.number || github.run_number}}-${{github.workflow}}
+  cancel-in-progress: true
+
+jobs:
+  linux:
+    name: ${{matrix.runner}}-${{matrix.compiler}}-${{matrix.version}}-llvm${{matrix.llvm}}
+    strategy:
+      matrix:
+        include:
+          - runner: jammy
+            compiler: gcc
+            version: 12
+            llvm: 14
+          - runner: jammy
+            compiler: clang
+            version: 15
+            llvm: 15
+    runs-on: >-
+      ${{  matrix.runner == 'focal' && 'ubuntu-20.04'
+        || matrix.runner == 'jammy' && 'ubuntu-22.04'
+        || null
+      }}
+    env:
+      CCACHE_DIR: "${{github.workspace}}/.ccache"
+      CCACHE_MAXSIZE: "10G"
+      CC: ${{matrix.compiler}}-${{matrix.version}}
+      CXX: ${{matrix.compiler == 'gcc' && 'g++' || 'clang++'}}-${{matrix.version}}
+    steps:
+      - uses: actions/setup-python@v5
+        name: Install Python
+        with:
+          python-version: '3.10'
+      - name: Install dependencies
+        run: |
+          sudo apt-get -q -y update
+          sudo apt-get -q -y install \
+            ccache cmake ninja-build libgtest-dev \
+            llvm-${{matrix.llvm}}-dev \
+            ${{matrix.compiler}}-${{matrix.version}} \
+            ${{matrix.compiler == 'gcc' && format('g++-{0}', matrix.version) || ''}}
+          echo "Installed toolchain:"
+          ld --version | head -1
+          $CC --version | head -1
+          $CXX --version | head -1
+          llvm-config-${{matrix.llvm}} --version | head -1
+          python -m pip install pennylane-lightning
+      - name: Check out
+        uses: actions/checkout@v4
+      - name: Set up ccache
+        uses: actions/cache@v4
+        with:
+          path: ${{env.CCACHE_DIR}}
+          key: ccache-${{matrix.runner}}-${{matrix.compiler}}-${{matrix.version}}-${{github.run_id}}
+          restore-keys: ccache-${{matrix.runner}}-${{matrix.compiler}}-${{matrix.version}}
+      - name: Zero ccache stats
+        run: |
+          ccache -z
+      - name: Configure
+        run: |
+          export LIGHTNING_SIM_PATH=$(python -c "import site; print( f'{site.getsitepackages()[0]}/pennylane_lightning')")/liblightning_qubit_catalyst.so
+          mkdir build && cd build
+          cmake -GNinja \
+            -DQIREE_GIT_DESCRIBE="${{github.event.pull_request
+              && format(';-pr.{0};', github.event.pull_request.number)
+              || format(';-{0};', github.ref_name)}}" \
+            -DQIREE_BUILD_TESTS:BOOL=ON \
+            -DQIREE_DEBUG:BOOL=ON \
+            -DQIREE_USE_XACC:BOOL=OFF \
+            -DQIREE_USE_LIGHTNING:BOOL=ON \
+            -DCMAKE_BUILD_TYPE="Release" \
+            -DCMAKE_INSTALL_PREFIX="${{github.workspace}}/install" \
+            -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
+            -DCMAKE_CXX_FLAGS="-Wall -Wextra -pedantic" \
+            ..
+      - name: Build all
+        working-directory: build
+        run: |
+          ninja
+      - name: Run tests
+        working-directory: build
+        run: |
+          ctest --parallel 2 --timeout 15 --output-on-failure
+      - name: Install
+        working-directory: build
+        run: |
+          ninja install
+      - name: Show ccache stats
+        run: |
+          ccache -s
+
+# vim: set nowrap tw=100:

.github/workflows/pr.yml

@@ -17,11 +17,14 @@ concurrency:
 jobs:
   build-fast:
     uses: ./.github/workflows/build-fast.yml
+  build-lightning:
+    uses: ./.github/workflows/build-lightning.yml
   # Specifying a dependent job allows us to select a single "requires" check in the project GitHub settings
   all:
     if: ${{ always() }}
     needs:
     - build-fast
+    - build-lightning
     runs-on: ubuntu-latest
     steps:
     - name: Decide whether the needed jobs succeeded or failed

.github/workflows/push.yml

@@ -12,9 +12,12 @@ concurrency:
 jobs:
   build-fast:
     uses: ./.github/workflows/build-fast.yml
+  build-lightning:
+    uses: ./.github/workflows/build-lightning.yml
   all:
     needs:
       - build-fast
+      - build-lightning
     runs-on: ubuntu-latest
     steps:
     - name: Success

CMakeLists.txt

@@ -36,8 +36,9 @@ endmacro()
 option(QIREE_BUILD_DOCS "Build QIR-EE documentation" OFF)
 option(QIREE_BUILD_TESTS "Build QIR-EE unit tests" ON)
 option(QIREE_BUILD_EXAMPLES "Build QIR-EE examples" OFF)
-option(QIREE_USE_QSIM "Download and build Google qsim backend" OFF)
-option(QIREE_USE_XACC "Build XACC interface" ON)
+option(QIREE_USE_QSIM "Download and build Google qsim backend" ON)
+option(QIREE_USE_XACC "Build XACC interface" OFF)
+option(QIREE_USE_LIGHTNING "Build Pennylane Lightning backend" OFF)
 
 qiree_set_default(BUILD_TESTING ${QIREE_BUILD_TESTS})
 
@@ -137,6 +138,16 @@ if(QIREE_USE_QSIM)
   )
 endif()
 
+if(QIREE_USE_LIGHTNING)
+qiree_add_library(qiree_lightning INTERFACE)
+add_library(QIREE::lightning ALIAS qiree_lightning)
+target_include_directories(qiree_lightning SYSTEM INTERFACE
+  "$<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/external>"
+  "$<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}/external>"
+)
+endif()
+
+
 if(QIREE_USE_XACC)
   find_package(XACC REQUIRED)
 endif()

app/CMakeLists.txt

@@ -28,6 +28,20 @@ if(QIREE_USE_QSIM)
   )
 endif()
 
+#-----------------------------------------------------------------------------#
+# LIGHTNING FRONT END
+#-----------------------------------------------------------------------------#
+
+if(QIREE_USE_LIGHTNING)
+  qiree_add_executable(qir-lightning
+    qir-lightning.cc
+  )
+  target_link_libraries(qir-lightning
+    PUBLIC QIREE::qiree QIREE::qirlightning
+    PRIVATE CLI11::CLI11
+  )
+endif()
+
 #-----------------------------------------------------------------------------#
 # XACC FRONT END
 #-----------------------------------------------------------------------------#

app/qir-lightning.cc

@@ -0,0 +1,74 @@
+//----------------------------------*-C++-*----------------------------------//
+// Copyright 2024 UT-Battelle, LLC, and other QIR-EE developers.
+// See the top-level COPYRIGHT file for details.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//---------------------------------------------------------------------------//
+//! \file app/qir-lightning.cc
+//---------------------------------------------------------------------------//
+#include <cstdlib>
+#include <iostream>
+#include <string>
+#include <CLI/CLI.hpp>
+
+#include "qiree/Executor.hh"
+#include "qiree/Module.hh"
+#include "qiree/ResultDistribution.hh"
+#include "qirlightning/LightningQuantum.hh"
+#include "qirlightning/LightningRuntime.hh"
+
+using namespace std::string_view_literals;
+
+namespace qiree
+{
+namespace app
+{
+//---------------------------------------------------------------------------//
+void run(std::string const& filename, int num_shots)
+{
+    // Load the input
+    Executor execute{Module{filename}};
+
+    // Set up qsim
+    LightningQuantum sim(std::cout, 0);
+    LightningRuntime rt(std::cout, sim);
+    ResultDistribution distribution;
+
+    // Run several time = shots (default 1)
+    for (int i = 0; i < num_shots; i++)
+    {
+        execute(sim, rt);
+        distribution.accumulate(rt.result());
+    }
+
+    std::cout << distribution.to_json() << std::endl;
+}
+
+//---------------------------------------------------------------------------//
+}  // namespace app
+}  // namespace qiree
+
+//---------------------------------------------------------------------------//
+/*!
+ * Execute and run.
+ */
+int main(int argc, char* argv[])
+{
+    int num_shots{1};
+    std::string filename;
+
+    CLI::App app;
+
+    auto* filename_opt
+        = app.add_option("--input,-i,input", filename, "QIR input file");
+    filename_opt->required();
+
+    auto* nshot_opt
+        = app.add_option("-s,--shots", num_shots, "Number of shots");
+    nshot_opt->capture_default_str();
+
+    CLI11_PARSE(app, argc, argv);
+
+    qiree::app::run(filename, num_shots);
+
+    return EXIT_SUCCESS;
+}

src/CMakeLists.txt

@@ -22,4 +22,8 @@ if(QIREE_USE_QSIM)
   add_subdirectory(qirqsim)
 endif()
 
+if(QIREE_USE_LIGHTNING)
+  add_subdirectory(qirlightning)
+endif()
+
 #---------------------------------------------------------------------------##

src/qirlightning/CMakeLists.txt

@@ -0,0 +1,69 @@
+#---------------------------------*-CMake-*----------------------------------#
+# Copyright 2024 UT-Battelle, LLC, and other QIR-EE developers.
+# See the top-level COPYRIGHT file for details.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+#----------------------------------------------------------------------------#
+
+# Fetch Catalyst runtime include files
+include(FetchContent)
+
+include("${CMAKE_CURRENT_SOURCE_DIR}/support_catalyst.cmake")
+FindCatalyst(qirlightning)
+
+# Set the path to the lightning simulator shared library
+if(DEFINED ENV{LIGHTNING_SIM_PATH})
+  set(RTDLIB_PATH "$ENV{LIGHTNING_SIM_PATH}")
+  message(STATUS "RTDLIB_PATH set from environment variable LIGHTNING_SIM_PATH: ${RTDLIB_PATH}")
+else()
+  # Throw an error if the environment variable is not defined
+  message(FATAL_ERROR "Environment variable LIGHTNING_SIM_PATH is not defined. Please set it to the path of the Lightning simulator shared library.")
+endif()
+
+# Set the device name for the lightning simulator
+execute_process(
+    COMMAND nm -DC "${RTDLIB_PATH}" | grep " Factory"
+    OUTPUT_VARIABLE GREP_OUTPUT
+    ERROR_QUIET
+    OUTPUT_STRIP_TRAILING_WHITESPACE
+  )
+
+if(GREP_OUTPUT)
+  string(REGEX MATCH "T (.*)Factory" SYMBOL_MATCH "${GREP_OUTPUT}")
+  if(SYMBOL_MATCH)
+    string(REGEX REPLACE "T (.*)Factory" "\\1" RTDDEVICE_NAME "${SYMBOL_MATCH}")
+    message(STATUS "Found Lightning Simulator. Extracted RTDDEVICE_NAME: ${RTDDEVICE_NAME}")
+  else()
+    message(FATAL_ERROR "Symbol 'Factory' found, but regex failed to extract.")
+  endif()
+else()
+  message(FATAL_ERROR "Symbol 'Factory' not found in ${RTDLIB_PATH}. Please ensure LIGHTNING_SIM_PATH is set correctly.")
+endif()
+
+
+# Adding lightning as a library to qiree
+qiree_add_library(qirlightning
+LightningQuantum.cc
+LightningRuntime.cc
+)
+
+target_compile_definitions(qirlightning PRIVATE
+    RTDLIB="${RTDLIB_PATH}"
+    RTDDEVICE="${RTDDEVICE_NAME}"
+)
+
+#Link the lightning library to qiree and any other relevant libraries
+target_link_libraries(qirlightning
+  PUBLIC QIREE::qiree  # Link to qiree
+  PRIVATE QIREE::lightning
+)
+
+#----------------------------------------------------------------------------#
+# HEADERS
+#----------------------------------------------------------------------------#
+
+# Install headers, matching the relevant .hh files for qsim integration
+install(DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/"
+  DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/qirlightning"
+  COMPONENT development
+  FILES_MATCHING REGEX ".*\\.hh?$"
+)