Limitations and unsupported APIs

Limitations and unsupported APIs#

2026-10-01

3 min read time

Applies to Linux and Windows

libhipcxx has the following platform limitations.

libhipcxx does not support the CUDA backend or NVIDIA hardware.
cuda::std::chrono::system_clock::now() does not return a UNIX timestamp. The host system clock and the device system clock are not synchronized and may run at different clock rates.

The following APIs from libcudacxx are not supported in libhipcxx:

Group	API	Description
Synchronization Library	`<cuda/std/latch>`	Single-phase asynchronous thread-coordination mechanism.
Synchronization Library	`<cuda/std/barrier>`	Multi-phase asynchronous thread-coordination mechanism.
Synchronization Library	`<cuda/std/semaphore>`	Primitives for constraining concurrent access.
Extended Synchronization Library	`<cuda/latch>`	System-wide `cuda::std::latch` single-phase asynchronous thread coordination mechanism.
Extended Synchronization Library	`<cuda/barrier>`	System-wide `cuda::std::barrier` multi-phase asynchronous thread coordination mechanism.
Extended Synchronization Library	`<cuda/semaphore>`	System-wide primitives for constraining concurrent access.
Extended Synchronization Library	`<cuda/pipeline>`	Coordination mechanisms to sequence asynchronous operations.
Extended Memory Access Properties Library	`<cuda/annotated_ptr>`	Memory access properties for pointers.
PTX API	`<cuda/ptx>`	The `cuda::ptx` namespace contains functions that map to NVIDIA PTX instructions.