[Openmp-commits] [PATCH] D70971: [libomptarget] Build a minimal deviceRTL for amdgcn

[Johannes Doerfert via Phabricator via Openmp-commits]

jdoerfert added inline comments.


================
Comment at: openmp/libomptarget/deviceRTLs/amdgcn/CMakeLists.txt:16-18
+  $ENV{HOME}/rocm/aomp
+  /opt/rocm/aomp
+  /usr/lib/rocm/aomp
----------------
ABataev wrote:
> JonChesterfield wrote:
> > JonChesterfield wrote:
> > > ABataev wrote:
> > > > JonChesterfield wrote:
> > > > > ABataev wrote:
> > > > > > We can't build the runtime with regular clang?
> > > > > Sure, it builds fine with trunk. I'm using a local build of clang 9.0 on one machine and the openmp/fortran fork on a second.
> > > > > 
> > > > > The find package seems to be a list of anywhere that clang might plausibly be found. Copied straight out of our fork, happy to remove any entries you don't like the look of.
> > > > > 
> > > > > The NVPTX_CUDA_COMPILER_DIR doesn't seem especially appropriately named. I use the same compiler for nvptx and for amdgcn.
> > > > Can we then just use the clang (I think, you proposed this for nvcc) to build the runtime? Why shall we lookup for `rocm/aomp`?
> > > Which clang? CMAKE_CXX_COMPILER_DIR may resolve to gcc. Or do you mean introduce LIBOMPTARGET_AMDGCN_CUDA_COMPILER_DIR and expect the user to match that up to a clang build?
> > rocm/aomp is a likely location to find clang if using the rocm developer tools stack, and I think it gets installed into different places depending on whether it's from apt-get or github.
> > 
> > I'm a little unclear on how in tree compiler plus out of tree library (e.g. libc, opencl runtime, or the cuda toolchain) is supposed to work logistically.
> Freshly built clang which is used to build `.bc` library for nvptx. Plus, if need it in some cases, I think it would be good to have a cmake configuration option for the user so he could point to his own installation of AOMP. Thoughts?
Take the cmake flag that is used to build the .bc file of the library. 


Repository:
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  https://reviews.llvm.org/D70971/new/

https://reviews.llvm.org/D70971