mirror of
https://github.com/RPCS3/llvm.git
synced 2024-12-14 23:48:56 +00:00
[CUDA] Add documentation explaining how to detect clang vs nvcc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@264002 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
parent
3f4c92194f
commit
9dd6a5392f
@ -119,6 +119,34 @@ your GPU <https://developer.nvidia.com/cuda-gpus>`_. For example, if you want
|
||||
to run your program on a GPU with compute capability of 3.5, you should specify
|
||||
``--cuda-gpu-arch=sm_35``.
|
||||
|
||||
Detecting clang vs NVCC
|
||||
=======================
|
||||
|
||||
Although clang's CUDA implementation is largely compatible with NVCC's, you may
|
||||
still want to detect when you're compiling CUDA code specifically with clang.
|
||||
|
||||
This is tricky, because clang defines the ``__NVCC__`` macro, and because NVCC
|
||||
may invoke clang as part of its own compilation process! For example, NVCC
|
||||
uses the host compiler's preprocessor when compiling for device code, and that
|
||||
host compiler may in fact be clang.
|
||||
|
||||
When clang is actually compiling CUDA code -- rather than being used as a
|
||||
subtool of NVCC's -- it defines the ``__CUDA__`` macro. ``__CUDA_ARCH__`` is
|
||||
defined only in device mode (but will be defined if NVCC is using clang as a
|
||||
preprocessor). So you can use the following incantations to detect clang CUDA
|
||||
compilation, in host and device modes:
|
||||
|
||||
.. code-block:: c++
|
||||
|
||||
#if defined(__clang__) && defined(__CUDA__) && !defined(__CUDA_ARCH__)
|
||||
// clang compiling CUDA code, host mode.
|
||||
#endif
|
||||
|
||||
#if defined(__clang__) && defined(__CUDA__) && defined(__CUDA_ARCH__)
|
||||
// clang compiling CUDA code, device mode.
|
||||
#endif
|
||||
|
||||
|
||||
Optimizations
|
||||
=============
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user