[Openmp-commits] [PATCH] D106674: Runtime for Interop directive

[Shilei Tian via Phabricator via Openmp-commits]

tianshilei1992 added inline comments.


================
Comment at: openmp/libomptarget/src/private.h:117
 int __kmpc_get_target_offload(void) __attribute__((weak));
+void __kmpc_omp_wait_deps(ident_t *loc_ref, kmp_int32 gtid, kmp_int32 ndeps,
+                          kmp_depend_info_t *dep_list, kmp_int32 ndeps_noalias,
----------------
jdoerfert wrote:
> tianshilei1992 wrote:
> > jdoerfert wrote:
> > > tianshilei1992 wrote:
> > > > If this function is not defined in `libomp`, please don't use `__kmpc`.
> > > It is in libomp, this is a forward decl. All good here.
> > Is it necessary to implement it in `libomp`? `interop` is for target.
> eventually it is. if you don't add -fopenmp-targets you would otherwise get link errors, which sounds pretty bad.
Well, we can implement a wrapper in `libomp`, just like `omp_get_num_devices`.
```
// Get number of NON-HOST devices.
// libomptarget, if loaded, provides this function in api.cpp.
int FTN_STDCALL KMP_EXPAND_NAME(FTN_GET_NUM_DEVICES)(void)
    KMP_WEAK_ATTRIBUTE_EXTERNAL;
int FTN_STDCALL KMP_EXPAND_NAME(FTN_GET_NUM_DEVICES)(void) {
#if KMP_MIC || KMP_OS_DARWIN || defined(KMP_STUB)
  return 0;
#else
  int (*fptr)();
  if ((*(void **)(&fptr) = KMP_DLSYM("__tgt_get_num_devices"))) {
    return (*fptr)();
  } else if ((*(void **)(&fptr) = KMP_DLSYM_NEXT("omp_get_num_devices"))) {
    return (*fptr)();
  } else if ((*(void **)(&fptr) = KMP_DLSYM("_Offload_number_of_devices"))) {
    return (*fptr)();
  } else { // liboffload & libomptarget don't exist
    return 0;
  }
#endif // KMP_MIC || KMP_OS_DARWIN || KMP_OS_WINDOWS || defined(KMP_STUB)
}
```


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D106674/new/

https://reviews.llvm.org/D106674