Revert "[OpenMP][Runtime] remove dead prepareAndSubmitData function from omptarget"

This reverts commit 304b51b.

Author: ronlieb

offload/libomptarget/omptarget.cpp

@@ -309,6 +309,38 @@ int targetDataMapper(ident_t *Loc, DeviceTy &Device, void *ArgBase, void *Arg,
   return Rc;
 }
 
+static int prepareAndSubmitData(DeviceTy &Device, void *HstPtrBegin,
+                                void *HstPtrBase, void *LocalTgtPtrBegin,
+                                TargetPointerResultTy &PointerTpr,
+                                void *PointerHstPtrBegin,
+                                void *PointerTgtPtrBegin,
+                                AsyncInfoTy &AsyncInfo) {
+  uint64_t Delta = (uint64_t)HstPtrBegin - (uint64_t)HstPtrBase;
+  void *ExpectedTgtPtrBase = (void *)((uint64_t)LocalTgtPtrBegin - Delta);
+
+  if (PointerTpr.getEntry()->addShadowPointer(
+          ShadowPtrInfoTy{(void **)PointerHstPtrBegin,
+                          (void **)PointerTgtPtrBegin, ExpectedTgtPtrBase, sizeof(void*)})) {
+    DP("USM_SPECIAL: Update pointer (" DPxMOD ") -> [" DPxMOD "]\n",
+       DPxPTR(PointerTgtPtrBegin), DPxPTR(LocalTgtPtrBegin));
+
+    void *&LocalTgtPtrBase = AsyncInfo.getVoidPtrLocation();
+    LocalTgtPtrBase = ExpectedTgtPtrBase;
+
+    int Ret =
+        Device.submitData(PointerTgtPtrBegin, &LocalTgtPtrBase, sizeof(void *),
+                          AsyncInfo, PointerTpr.getEntry());
+    if (Ret != OFFLOAD_SUCCESS) {
+      REPORT("Copying data to device failed.\n");
+      return OFFLOAD_FAIL;
+    }
+    if (PointerTpr.getEntry()->addEventIfNecessary(Device, AsyncInfo) !=
+        OFFLOAD_SUCCESS)
+      return OFFLOAD_FAIL;
+  }
+  return OFFLOAD_SUCCESS;
+}
+
 /// Utility function to perform a pointer attachment operation.
 ///
 /// For something like:
@@ -640,7 +672,14 @@ int targetDataBegin(ident_t *Loc, DeviceTy &Device, int32_t ArgNum,
     // Perhaps OMP_TGT_MAPTYPE_DESCRIPTOR would help here, not sure.
     if ((ArgTypes[I] & OMP_TGT_MAPTYPE_PTR_AND_OBJ) &&
         (!IsHostPtr || (PointerTpr.getEntry() != nullptr &&
-                        PointerHstPtrBegin != PointerTgtPtrBegin))) {
+                        PointerHstPtrBegin != PointerTgtPtrBegin)))
+      if (prepareAndSubmitData(Device, HstPtrBegin, HstPtrBase, TgtPtrBegin,
+                               PointerTpr, PointerHstPtrBegin,
+                               PointerTgtPtrBegin,
+                               AsyncInfo) != OFFLOAD_SUCCESS)
+        return OFFLOAD_FAIL;
+
+    if (ArgTypes[I] & OMP_TGT_MAPTYPE_PTR_AND_OBJ && !IsHostPtr) {
       int Ret = performPointerAttachment(
           Device, AsyncInfo, reinterpret_cast<void **>(PointerHstPtrBegin),
           HstPtrBase, HstPtrBegin,