Revert "Add Clifford-only simulator (Stim) (#2193)"

This reverts commit 70d00f3.

.gitmodules

@@ -45,6 +45,3 @@
 	path = tpls/Crow
 	url = https://github.com/CrowCpp/Crow.git
 	ignore = dirty
-[submodule "tpls/Stim"]
-	path = tpls/Stim
-	url = https://github.com/quantumlib/Stim

NOTICE

@@ -172,11 +172,3 @@ Tweedledum - MIT License
 License at <https://github.com/boschmitt/tweedledum/blob/master/LICENSE>
 
 ----------------------------------------------------------------
-
-Stim - Apache License 2.0
-<https://github.com/quantumlib/Stim>
-
-The incorporated source code and its license can be found as a submodule on the CUDA-Q repository.
-License at <https://github.com/quantumlib/Stim/blob/main/LICENSE>
-
-----------------------------------------------------------------

docs/sphinx/using/backends/backends.rst

@@ -26,7 +26,6 @@ CUDA-Q Backends
 * :ref:`qpp-cpu <qpp-cpu-backend>`
 * :ref:`quantinuum <quantinuum-backend>`
 * :ref:`remote-mqpu <mqpu-platform>`
-* :ref:`stim <stim-backend>`
 * :ref:`tensornet <tensor-backends>`
 * :ref:`tensornet-mps <tensor-backends>`
 

docs/sphinx/using/backends/simulators.rst

@@ -300,40 +300,6 @@ use the following commands:
         ./program.x
 
 
-Clifford-Only Simulation (CPU)
-++++++++++++++++++++++++++++++++++
-
-.. _stim-backend:
-
-This target provides a fast simulator for circuits containing *only* Clifford
-gates. Any non-Clifford gates (such as T gates and Toffoli gates) are not
-supported. This simulator is based on the `Stim <https://github.com/quantumlib/Stim>`_
-library.
-
-To execute a program on the :code:`stim` target, use the following commands:
-
-.. tab:: Python
-
-    .. code:: bash 
-
-        python3 program.py [...] --target stim
-
-    The target can also be defined in the application code by calling
-
-    .. code:: python 
-
-        cudaq.set_target('stim')
-
-    If a target is set in the application code, this target will override the :code:`--target` command line flag given during program invocation.
-
-.. tab:: C++
-
-    .. code:: bash 
-
-        nvq++ --target stim program.cpp [...] -o program.x
-        ./program.x
-
-
 Tensor Network Simulators
 ==================================
 

runtime/nvqir/CMakeLists.txt

@@ -38,7 +38,6 @@ install(TARGETS ${LIBRARY_NAME}
         INCLUDES DESTINATION include/nvqir)
 
 add_subdirectory(qpp)
-add_subdirectory(stim)
 
 if (CUSTATEVEC_ROOT AND CUDA_FOUND) 
   add_subdirectory(custatevec)

runtime/nvqir/CircuitSimulator.h

@@ -750,17 +750,7 @@ class CircuitSimulatorBase : public CircuitSimulator {
         summaryData.svGateUpdate(
             next.controls.size(), next.targets.size(), stateDimension,
             stateDimension * sizeof(std::complex<ScalarType>));
-      try {
-        applyGate(next);
-      } catch (std::exception &e) {
-        while (!gateQueue.empty())
-          gateQueue.pop();
-        throw e;
-      } catch (...) {
-        while (!gateQueue.empty())
-          gateQueue.pop();
-        throw std::runtime_error("Unknown exception in applyGate");
-      }
+      applyGate(next);
       if (executionContext && executionContext->noiseModel) {
         std::vector<std::size_t> noiseQubits{next.controls.begin(),
                                              next.controls.end()};