Features

Memory Management

• Structured model — purely device-allocated memory returned as Fortran pointer arrays (dev_alloc, dev_free, dev_memcpy_*). Device memory is not mapped to any host memory.
• Unstructured model — host allocatable arrays mapped onto the device (dev_alloc_unstr, dev_free_unstr, dev_memcpy_*_unstr).
• Assignment-style copy — dev_assign_to_device / dev_assign_from_device deallocate and reallocate automatically on size change, mimicking Fortran's left-hand-side reallocation for allocatables.

Device Handling

• Query and set the current device ID (dev_get_device_num, dev_set_device_num)
• Query device type, host ID, number of available devices, and device memory
• Pretty-printed device property string for diagnostics (dev_get_property_string)

MPI Multi-Device

The fundal_mpih_object module provides an auxiliary mpih_object class for MPI-enabled applications:

• MPI initialisation and finalisation wrappers
• Automatic device assignment per MPI rank
• Barrier, abort, and error-stop helpers
• Tic/toc wall-clock timing utilities
• Global environment variables (mydev, myhos, devtype, etc.) are exposed as pointers on the object for convenience

Supported Array Types

Numeric kind	Ranks
real(R8P) (real64)	1–7
real(R4P) (real32)	1–7
integer(I8P) (int64)	1–7
integer(I4P) (int32)	1–7
integer(I2P) (int16)	1–7
integer(I1P) (int8)	1–7

Implementation Status

Device memory handling

Routine	OpenACC	OpenMP
dev_alloc	✅	✅
dev_free	✅	✅
dev_memcpy_to_device	✅	✅
dev_memcpy_from_device	✅	✅
dev_assign_to_device	✅	✅
dev_assign_from_device	✅	✅
dev_alloc_unstr / dev_free_unstr	✅	✅
dev_memcpy_*_unstr	✅	✅

Device handling

Routine	OpenACC	OpenMP
dev_get_device_num	✅	✅
dev_get_host_num	✅	✅
dev_get_num_devices	✅	✅
dev_get_device_type	✅	❌ (returns 0)
dev_get_property_string	✅	❌ (returns empty string)

Compiler Support

Compiler	Backend	Status
NVIDIA nvfortran ≥ 12.3	OpenACC	Fully supported
Intel IFX ≥ 2024.0.2	OpenMP	Fully supported
GNU gfortran ≥ 13.1	OpenACC	Partial — compiles, some tests fail
AMD Flang	OpenMP	Supported