Initial support for PSTL's OpenMP target backend

src/std-indices/dpl_shim.h

@@ -34,6 +34,21 @@ static constexpr auto exec_policy = dpl::execution::par_unseq;
 
 #endif
 
+#elif defined(USE_LLVM_OMPT)
+
+#include <algorithm>
+#include <execution>
+#include <numeric>
+#include <omp.h>
+
+inline auto &&exec_policy = std::execution::par_unseq;
+
+template <typename T> T *alloc_raw(size_t size) {
+  return (T *)omp_alloc(size * sizeof(T), llvm_omp_target_shared_mem_alloc);
+}
+
+template <typename T> void dealloc_raw(T *ptr) { omp_free(ptr, llvm_omp_target_shared_mem_alloc); }
+
 #else
 
 // Normal C++17 PSTL

src/std-indices/model.cmake

@@ -23,6 +23,10 @@ register_flag_optional(USE_TBB
         "Link against an in-tree oneTBB via FetchContent_Declare, see top level CMakeLists.txt for details."
         "OFF")
 
+register_flag_optional(USE_LLVM_OMPT
+        "Use LLVM's PTSL offload"
+        "OFF")
+
 register_flag_optional(USE_ONEDPL
         "Link oneDPL which implements C++17 executor policies (via execution_policy_tag) for different backends.
 
@@ -47,6 +51,15 @@ macro(setup)
         register_link_library(oneDPL)
     endif ()
 
+
+    if(USE_LLVM_OMPT)
+        register_definitions(USE_LLVM_OMPT)
+        #        find_package(OpenMP REQUIRED)
+        #        register_link_library(OpenMP::OpenMP_CXX)
+        # TODO target flags
+    endif ()
+
+
     if (NVHPC_OFFLOAD)
         set(NVHPC_FLAGS
                 -stdpar