[Libclc-dev] AMD and libclc (progress)

[Tom Stellard via Libclc-dev]

On Fri, May 20, 2016 at 11:49:57AM +0100, Ricardo Nobre wrote:
> What about this?
> 
> https://github.com/RadeonOpenCompute/HCC-Native-GCN-ISA/wiki
> 

This is probably the easiest way to run code on the gpu.  HCC is a modified
version of clang which supports the hcc language, which is a single
source c++ like language that lets you mix GPU and CPU code.

> What is the different between this and the methods you pointed to?
>

The only difference is how you compile code, and interact with the roc
runtime.  HCC uses the roc stack too.

> I have access to a R9 Nano (same chip as the Fury X).
> 
> 
> Thanks,
> Ricardo
> 
> 
> 2016-05-18 23:11 GMT+01:00 Tom Stellard <tom at stellard.net>:
> 
> > On Tue, Apr 26, 2016 at 08:59:40PM +0100, Ricardo Nobre via Libclc-dev
> > wrote:
> > > I compiled and installed the latest 'libclc' from the repository and I
> > > successfully generated AMD GCN ASM from the GEMM kernel of the
> > > polybench-gpu benchmark (
> > > http://web.cse.ohio-state.edu/~pouchet/software/polybench/GPU/)
> > executing
> > > the following commands:
> > >
> > > /opt/clang+llvm-3.7.1-x86_64-linux-gnu-ubuntu-15.10/bin/clang
> > > -Dcl_clang_storage_class_specifiers -isystem /opt/libclc/include -include
> > > clc/clc.h -target amdgcn -S -emit-llvm -xcl -o gemm.ll gemm.cl
> > >
> > > /opt/clang-3.9/bin/llvm-link gemm.ll
> > /opt/libclc/lib/clc/verde-amdgcn--.bc
> > > -o gemm.linked.bc
> > >
> > > /opt/clang-3.9/bin/clang -target amdgcn gemm.linked.bc -S -o gemm.verde.s
> > >
> > > Now what should I do with the assembly file (i.e., 'gemm.verde.s')?
> > > Can I use an assembler such as GCNASM (
> > https://github.com/balidani/gcnasm)
> > > or CLRadeonExtender (http://clrx.nativeboinc.org/) to generate a binary
> > > compatible with AMD Catalyst?
> > > I tried using both assemblers and they both complained with many of the
> > > instructing generated by Clang.
> > >
> > > Can you give me some pointers on how to progress?
> > >
> > >
> >
> > Hi,
> >
> > clang uses an integrated assembler for the amdgcn target so you can
> > compile directly to binary with clang.
> >
> > These binaries are not compatible with catalyst.
> >
> > If you have one of the GPU/CPU/Motherboard combinations supported by the
> > Radeon Open Compute (ROC) driver (which can be found here:
> > http://gpuopen.com/compute-product/rocm/), then you can use the
> > ROC apis to upload an execute code.
> >
> > You can find driver installation instructions for ROC here:
> > https://github.com/RadeonOpenCompute/ROCm
> >
> > There are a few examples here that demonstrate how to use the API
> > to upload code:
> > https://github.com/RadeonOpenCompute/LLVM-AMDGPU-Assembler-Extra
> >
> > You can actually combine all the commands you used into a single
> > invocation, like this:
> >
> > ${CLANG} -x cl -Dcl_clang_storage_class_specifiers -target
> > amdgcn--amdhsa -mcpu=fiji -B -Xclang -mlink-bitcode-file -Xclang
> > $BITCODE_LIBRARY -include $BITCODE_LIBARY_HEADER -o ${f}.co
> > ${CMAKE_CURRENT_SOURCE_DIR}/${f}.cl
> >
> >
> > Since you are using a tonga, which isn't officially supported by ROC,
> > the only way you can execute the code is by using the Open Source
> > OpenCL implementation known as clover, which is part of Mesa.
> > For more details see here:
> > https://dri.freedesktop.org/wiki/GalliumCompute/
> > Also, if you want to compile code using clang for clover, you
> > need to use the amdgcn-- triple instead of amdgcn--amdhsa.
> >
> >
> > However, the binary format accepted by this implementation is
> > a container which includes the code output by clang in addition
> > to some other information.  If you do want to use clover, it will
> > be easier to just to use the OpenCL APIs to compile the kernel
> > for you.
> >
> > Note that clover is not a complete implementation, so there may be
> > things that don't work if you try it.
> >
> > Let me know if you have any other questions.
> >
> > -Tom
> >
> >
> >
> >
> >
> >
> > > Ricardo
> >
> > > _______________________________________________
> > > Libclc-dev mailing list
> > > Libclc-dev at lists.llvm.org
> > > http://lists.llvm.org/cgi-bin/mailman/listinfo/libclc-dev
> >
> >