openmp target offload gpu

**OpenMP Target Offloading: GPU Acceleration via Pragmas — extending OpenMP directive-based parallelism to GPUs** OpenMP target offloading extends CPU-focused OpenMP directives to GPUs via pragmas specifying kernels and data movement, enabling GPU acceleration without rewriting code. **Target Construct and Data Mapping** #pragma omp target { ... } offloads code region to GPU. Map clause specifies data transfer: map(to:x) copies x from host to device, map(from:y) copies y device-to-host, map(tofrom:z) copies bidirectionally, map(alloc:w) allocates on device without initialization. map(delete:...) deallocates after region. Implicit data mapping (firstprivate, private) defaults to tofrom for scalars; arrays are private (not mapped). Data persistence across targets requires enter/exit data directives. **GPU Thread Hierarchy** teams distribute over GPU thread blocks. distribute parallelizes outer loop over teams. parallel for parallelizes inner loop over threads within team. Combined: #pragma omp target teams distribute parallel for { for (i=0; i