scott.linder added a comment. In D77923#1978261 <https://reviews.llvm.org/D77923#1978261>, @arsenm wrote:
> In D77923#1978172 <https://reviews.llvm.org/D77923#1978172>, @scott.linder > wrote: > > > https://www.khronos.org/registry/OpenCL/sdk/2.0/docs/man/xhtml/preprocessorDirectives.html > > describes `__OPENCL_VERSION__` as "an integer reflecting the version > > number of the OpenCL supported by the OpenCL device." as contrasted with > > `__OPENCL_C_VERSION__` which is described as "an integer reflecting the > > OpenCL C version specified by the -cl-std build option to clBuildProgram or > > clCompileProgram. If the -cl-std build option is not specified, the OpenCL > > C version supported by the compiler for this OpenCL device will be used." > > > > But I don't see where the correct use of these is defined? How should the > > user decide which to use? It does seem like `__OPENCL_VERSION__` and > > `__OPENCL_C_VERSION__` can differ, e.g. if you compile for a device > > supporting 2.0 with `-cl-std=1.2`, but why would `__OPENCL_VERSION__` ever > > be referenced then? > > > I don't know why you would ever use this; but the standard says it should be > defined, so I guess we have to define it Right, I just want to understand the actual semantics and it doesn't seem clear. I agree that I don't see a use for `__OPENCL_VERSION__` but we define it so I'm sure people are using it, so likely we need to be careful that this patch preserves the existing behavior of the runtime. In D77923#1976497 <https://reviews.llvm.org/D77923#1976497>, @jvesely wrote: > OPENCL_VERSION is something that should be really set by the opencl driver > rather than the compiler. > coarse-grained SVM can be done without FEATURE_FLAT_ADDRESS_SPACE, so those > gpus can get over 1.2, while the compiler can be used in an implementation > that doesn't go above 1.2 even for gfx700+ I don't know why this would imply we can't just have a static `__OPENCL_VERSION__` for each device in Clang? I don't see anything in the standard that says you are not allowed to have (going with your example) `__OPENCL_VERSION__=200` and `__OPENCL_C_VERSION=120` at the same time. It seems like we should be able to just have `__OPENCL_VERSION__` defined in Clang, and let the runtime control setting `__OPENCL_C_VERSION__` via `-cl-std=`. If the current patch sets `__OPENCL_VERSION__` differently than the runtime does then it seems like we should make it match, but I'm not sure how best to confirm that. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D77923/new/ https://reviews.llvm.org/D77923 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
