Merge Fix the preference for Threads

This PR fixes the circular dep compilation by fix the preference for Threads before any `find_package`

Related PR: #1388

CMakeLists.txt

@@ -3,6 +3,8 @@ cmake_minimum_required(VERSION 3.16)
 project(Ginkgo LANGUAGES C CXX VERSION 1.7.0 DESCRIPTION "A numerical linear algebra library targeting many-core architectures")
 set(Ginkgo_VERSION_TAG "develop")
 set(PROJECT_VERSION_TAG ${Ginkgo_VERSION_TAG})
+# Cuda and Hip also look for Threads. Set it before any find_package to ensure the Threads setting is not changed.
+set(THREADS_PREFER_PTHREAD_FLAG ON)
 
 # Determine which modules can be compiled
 include(cmake/hip_path.cmake)
@@ -98,7 +100,7 @@ endif()
 if(GINKGO_BUILD_OMP)
     find_package(OpenMP 3.0 REQUIRED)
 endif()
-set(THREADS_PREFER_PTHREAD_FLAG ON)
+
 find_package(Threads REQUIRED)
 include(cmake/build_type_helpers.cmake)
 

cmake/GinkgoConfig.cmake.in

@@ -139,6 +139,9 @@ set(GINKGO_HAVE_VTUNE "@GINKGO_HAVE_VTUNE@")
 set(GINKGO_HAVE_METIS "@GINKGO_HAVE_METIS@")
 set(VTune_PATH "@VTune_PATH@")
 
+# ensure Threads settings 
+set(THREADS_PREFER_PTHREAD_FLAG ON)
+
 # NOTE: we do not export benchmarks, examples, tests or devel tools
 #     so `third_party` libraries are currently unneeded.
 

core/base/mixed_precision_types.hpp

@@ -75,7 +75,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #else
 
 #define GKO_INSTANTIATE_FOR_EACH_MIXED_VALUE_TYPE_SPLIT1(_macro, ...) \
-    template _macro(float, float, float, __VA_ARGS__);
+    template _macro(float, float, float, __VA_ARGS__)
 
 #define GKO_INSTANTIATE_FOR_EACH_MIXED_VALUE_TYPE_SPLIT2(_macro, ...) \
     template _macro(double, double, double, __VA_ARGS__)