[PATCH] D80222: Replace Clang's createRuntimeFunction with the definitions in OMPKinds.def

[Andrey Churbanov via Phabricator via cfe-commits]

AndreyChurbanov added inline comments.


================
Comment at: openmp/runtime/test/tasking/kmp_taskloop.c:100
         th_counter[i] = 0;
-    #pragma omp parallel num_threads(N)
+    #pragma omp parallel // num_threads(N)
     {
----------------
jhuber6 wrote:
> jhuber6 wrote:
> > jdoerfert wrote:
> > > jhuber6 wrote:
> > > > I am not entirely sure why, but commenting this out causes the problem to go away. I tried adding proper names to the forward-declared functions but since clang already knew I had something called ident_t, I couldn't declare a new struct with the same name.
> > > This is not good. The difference should only be that the `kmpc_fork_call` has a different argument, right? Does the segfault happen at compile or runtime?
> > > 
> > > You can just use the ident_t clang created, right? Did you print the function names requested by clang as we discussed?
> > I added an assertion and debug statements. If I try to declare a struct named "Ident_t" I get the following error message in the seg-fault. I think the seg-fault is compile-time.
> > 
> > Found OpenMP runtime function __kmpc_global_thread_num with type i32 (%struct.ident_t.0*). Expected type is i32 (%struct.ident_t*)
> > clang: /home/jhuber/Documents/llvm-project/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp:124: static llvm::Function* llvm::OpenMPIRBuilder::getOrCreateRuntimeFunction(llvm::Module&, llvm::omp::RuntimeFunction): Assertion `FnTy == Fn->getFunctionType() && "Found OpenMP runtime function has mismatched types"' failed.
> I'm not sure if there's a way around this without changing the getOrCreateRuntimeFunction method to return a FunctionCallee and removing the assertion. Clang doesn't know about the ident_t struct when it's compiling the file, but when its doing the codegen it sees two structs with the same name and creates a new name. So when it gets the types it says that ident_t and ident_t.0 don't match. As you said the old version got around this by adding a bitcasting instruction so it knew how to turn it into an ident_t pointer.
Note that this change breaks the test on any system with more that 4 procs.  Because array th_counter[4] is indexed by thread number which can easily be greater than 3 if number of threads is not limited.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D80222/new/

https://reviews.llvm.org/D80222