[Libomptarget] Introduce new globalization runtime calls

[jhuber6]

Summary

This patch introduces the new globalization runtime to be used by D97680. These
runtime calls will replace the __kmpc_data_sharing_push_stack and
__kmpc_data_sharing_pop_stack functions.

[tianshilei1992]

LGTM

[jhuber6]

This interface doesn't use __kmpc_init_stack so the data sharing buffer needs to be initialized differently.

[jhuber6]

Changing implementation, had some bugs.

openmp/libomptarget/deviceRTLs/common/src/data_sharing.cu

 // initialization). This function is called only by the MASTER thread of each
 // team in non-SPMD mode.
 EXTERN void __kmpc_data_sharing_init_stack() {
   ASSERT0(LT_FUSSY, isRuntimeInitialized(), "Runtime must be initialized.");
   // This function initializes the stack pointer with the pointer to the
   // statically allocated shared memory slots. The size of a shared memory
   // slot is pre-determined to be 256 bytes.
   data_sharing_init_stack_common();
-  omptarget_nvptx_globalArgs.Init();
+}
+
+EXTERN void *__kmpc_alloc_shared(size_t DataSize) {
+  return (void *)SafeMalloc(DataSize, "Alloc Shared");
+}
+
+EXTERN void __kmpc_free_shared(void *FrameStart) {
+  SafeFree(FrameStart, "Free Shared");
 }
 
 // Initialize data sharing data structure. This function needs to be called
 // once at the beginning of a data sharing context (coincides with the kernel
 // initialization). This function is called in SPMD mode only.
 EXTERN void __kmpc_data_sharing_init_stack_spmd() {
   ASSERT0(LT_FUSSY, isRuntimeInitialized(), "Runtime must be initialized.");
   // This function initializes the stack pointer with the pointer to the

openmp/libomptarget/deviceRTLs/common/src/omptarget.cu

EXTERN void __kmpc_kernel_init(int ThreadLimit, int16_t RequiresOMPRuntime) {
   omptarget_nvptx_threadPrivateContext->SetTopLevelTaskDescr(
       threadId, currTeamDescr.LevelZeroTaskDescr());
 
   // set number of threads and thread limit in team to started value
   omptarget_nvptx_TaskDescr *currTaskDescr =
       omptarget_nvptx_threadPrivateContext->GetTopLevelTaskDescr(threadId);
   nThreads = GetNumberOfThreadsInBlock();
   threadLimit = ThreadLimit;
+
+  if (!isSPMDMode())
+    omptarget_nvptx_globalArgs.Init();
+
   __kmpc_impl_target_init();
 }
 
 EXTERN void __kmpc_kernel_deinit(int16_t IsOMPRuntimeInitialized) {
   PRINT0(LD_IO, "call to __kmpc_kernel_deinit\n");
   ASSERT0(LT_FUSSY, IsOMPRuntimeInitialized,
           "Generic always requires initialized runtime.");
   // Enqueue omp state object for use by another team.

openmp/libomptarget/deviceRTLs/interface.h

 
 EXTERN void __kmpc_get_team_static_memory(int16_t isSPMDExecutionMode,
                                           const void *buf, size_t size,
                                           int16_t is_shared, const void **res);
 
 EXTERN void __kmpc_restore_team_static_memory(int16_t isSPMDExecutionMode,
                                               int16_t is_shared);
 
+/// Allocate \p Bytes in "shareable" memory and return the address. Needs to be
+/// called balanced with __kmpc_free_shared like a stack (push/pop). Can be
+/// called by any thread, allocation happens per-thread.
+EXTERN void *__kmpc_alloc_shared(uint64_t Bytes);
+
+/// Deallocate \p Ptr. Needs to be called balanced with __kmpc_alloc_shared like
+/// a stack (push/pop). Can be called by any thread. \p Ptr must be allocated by
+/// __kmpc_alloc_shared by the same thread.
+EXTERN void __kmpc_free_shared(void *Ptr);
+
 #endif