azabaznov added inline comments.
================ Comment at: clang/include/clang/Basic/OpenCLExtensions.def:113 OPENCL_OPTIONALCOREFEATURE(__opencl_c_atomic_order_seq_cst, false, 300, OCL_C_30) +OPENCL_OPTIONALCOREFEATURE(__opencl_c_atomic_scope_all_devices, false, 300, OCL_C_30) OPENCL_OPTIONALCOREFEATURE(__opencl_c_subgroups, false, 300, OCL_C_30) ---------------- Anastasia wrote: > azabaznov wrote: > > Anastasia wrote: > > > svenvh wrote: > > > > Anastasia wrote: > > > > > azabaznov wrote: > > > > > > This feature is header only. We had a lot of discussions on that > > > > > > and the main idea was not to declare header only > > > > > > features/extensions in `OpenCLExtensions.def` and use > > > > > > `-D__opencl_c_atomic_scope_all_devices=1` instead, @Anastasia can > > > > > > comment on this. > > > > > > > > > > > > I personally would like to introduce new flag for OpenCL options in > > > > > > `OpenCLExtensions.def` which will indicate that feature/extension > > > > > > is header-only, and thus all of such options can be declared in > > > > > > `OpenCLExtensions.def`: if flag is set to true it can be stripped > > > > > > out from the parser. What do you think about this? > > > > > Yes, I agree the idea is to align with C/C++ directions for > > > > > scalability i.e. we should only add what is absolutely necessary to > > > > > the compiler and implement the rest using libraries - just like > > > > > regular C and C++. We won't be able to scale if we keep adding > > > > > everything in the compiler. In fact, we already have a huge > > > > > scalability issue with our builtin functions. If we look at modern > > > > > C++ - more than 70% of features are not in the compiler at all. > > > > > > > > > > Would it be possible to do something like suggested here: > > > > > https://reviews.llvm.org/D91531#change-AKXhB4ko4nAO for > > > > > `cl_khr_depth_images`? > > > > > > > > > > > I personally would like to introduce new flag for OpenCL options in > > > > > > OpenCLExtensions.def which will indicate that feature/extension is > > > > > > header-only, and thus all of such options can be declared in > > > > > > OpenCLExtensions.def: if flag is set to true it can be stripped out > > > > > > from the parser. What do you think about this? > > > > > > > > > > Hmm, I think the macros should either be declared in the headers or > > > > > using a flag `-D`. I don't know why would adding them in > > > > > `OpenCLExtensions.def` be beneficial if we can use conventional > > > > > approaches? This allows avoiding the complexity and makes things more > > > > > modular. If we look at the OpenCL vendor extensions for example - we > > > > > probably don't want them all in one place? > > > > > This feature is header only. > > > > > > > > Good catch! I have updated the patch to define the feature macro in > > > > the header instead. Currently that definition is not optional, since > > > > we don't have finalized the solution for handling this yet (though the > > > > __undef proposal seems to be compatible with this change). > > > > > > > > > I personally would like to introduce new flag for OpenCL options in > > > > > OpenCLExtensions.def which will indicate that feature/extension is > > > > > header-only > > > > > > > > If we still need to add header-only features to OpenCLExtensions.def, > > > > then they aren't really header-only anymore I'd argue (as @Anastasia > > > > pointed out above). So I'm not sure we need it either, or perhaps I > > > > missed something. > > > FYI we have already added extended subgroups extension macros for SPIR in > > > `opencl-c-base.h` without the `__undef<...>` trick. > > > > > > ``` > > > #if defined(__SPIR__) > > > #define cl_khr_subgroup_extended_types 1 > > > #define cl_khr_subgroup_non_uniform_vote 1 > > > #define cl_khr_subgroup_ballot 1 > > > #define cl_khr_subgroup_non_uniform_arithmetic 1 > > > #define cl_khr_subgroup_shuffle 1 > > > #define cl_khr_subgroup_shuffle_relative 1 > > > #define cl_khr_subgroup_clustered_reduce 1 > > > #endif // defined(__SPIR__) > > > ``` > > > > > > But extra conditions can be added any time if we get the agreement on the > > > route forward. > > > Hmm, I think the macros should either be declared in the headers or using > > > a flag -D. I don't know why would adding them in OpenCLExtensions.def be > > > beneficial if we can use conventional approaches? This allows avoiding > > > the complexity and makes things more modular. If we look at the OpenCL > > > vendor extensions for example - we probably don't want them all in one > > > place? > > > > Well, IMO separating extensions/features into two classes of options > > exactly brings new complexities :) I'm not sure why do we need to have a > > separate interface for them if there already exists unified one. For > > example, Intel compute-runtime uses `-cl-ext` flag to forward options : > > https://github.com/intel/compute-runtime/blob/master/opencl/source/platform/extensions.cpp#L156. > > > > > > Can we use this header mechanism to define header-only > > features/extensions while `-cl-ext`interface is preserved? > I think if we can have a unified interface at no extra cost then sure we > should do so. But adding everything into the compiler source code seems like > a high cost to me. > > > > Can we use this header mechanism to define header-only > > features/extensions while -cl-extinterface is preserved? > > Perhaps I am missing something but why would using `-cl-ext` be better than > `-D`? If you use `-D` you don't need to add anything to clang source code at > all so it seems better. Of course, it means that you have to pass an extra > flag to the compiler. But it still seems easier than modifying the compiler > source code... > Perhaps I am missing something but why would using -cl-ext be better than -D? > If you use -D you don't need to add anything to clang source code at all so > it seems better. Of course, it means that you have to pass an extra flag to > the compiler. But it still seems easier than modifying the compiler source > code... I see the main advantage is having the unified interface for all type of extensions/features: either it affects language semantics or it is a header-only. Also, I don't think it requires a lot of changes in clang: we only need to extend `-cl-ext` to add unknown extensions/features (which are not in `OpenCLExtensions.def`) and add a flag that extension/feature is header-only. Alternatively, we could add a new mode when compiling for SPIR target when not support all the features/extensions to not use the `-D__undef` trick. I think we can proceed with this and have further discussions. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D103241/new/ https://reviews.llvm.org/D103241 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
