[OpenMP][libomptarget] Enable usage of unified memory for declare target link variables

Summary: This patch enables the usage of a host variable on the device for declare target link variables when unified memory is available.

Reviewers: ABataev, caomhin, grokos

Reviewed By: grokos

Subscribers: Hahnfeld, guansong, jdoerfert, openmp-commits

Tags: #openmp

Differential Revision: https://reviews.llvm.org/D60884

llvm-svn: 362505

3 files changed, 12 insertions, 2 deletions

diff --git a/openmp/libomptarget/src/device.cpp b/openmp/libomptarget/src/device.cpp
index a946b928be9..5ecba5759eb 100644
--- a/openmp/libomptarget/src/device.cpp
+++ b/openmp/libomptarget/src/device.cpp
@@ -275,6 +275,9 @@ int DeviceTy::deallocTgtPtr(void *HstPtrBegin, int64_t Size, bool ForceDelete) {
 
 /// Init device, should not be called directly.
 void DeviceTy::init() {
+  // Make call to init_requires if it exists for this plugin.
+  if (RTL->init_requires)
+    RTL->init_requires(RTLRequiresFlags);
   int32_t rc = RTL->init_device(RTLDeviceID);
   if (rc == OFFLOAD_SUCCESS) {
     IsInit = true;
diff --git a/openmp/libomptarget/src/rtl.cpp b/openmp/libomptarget/src/rtl.cpp
index 770ae36a829..4eb7ab71489 100644
--- a/openmp/libomptarget/src/rtl.cpp
+++ b/openmp/libomptarget/src/rtl.cpp
@@ -107,6 +107,10 @@ void RTLsTy::LoadRTLs() {
               dynlib_handle, "__tgt_rtl_run_target_team_region")))
       continue;
 
+    // Optional functions
+    *((void**) &R.init_requires) = dlsym(
+        dynlib_handle, "__tgt_rtl_init_requires");
+
     // No devices are supported by this RTL?
     if (!(R.NumberOfDevices = R.number_of_devices())) {
       DP("No devices supported in this RTL\n");
diff --git a/openmp/libomptarget/src/rtl.h b/openmp/libomptarget/src/rtl.h
index 381f23ea054..8148e81e7df 100644
--- a/openmp/libomptarget/src/rtl.h
+++ b/openmp/libomptarget/src/rtl.h
@@ -36,6 +36,7 @@ struct RTLInfoTy {
                                  int32_t);
   typedef int32_t(run_team_region_ty)(int32_t, void *, void **, ptrdiff_t *,
                                       int32_t, int32_t, int32_t, uint64_t);
+  typedef int64_t(init_requires_ty)(int64_t);
 
   int32_t Idx;                     // RTL index, index is the number of devices
                                    // of other RTLs that were registered before,
@@ -60,6 +61,7 @@ struct RTLInfoTy {
   data_delete_ty *data_delete;
   run_region_ty *run_region;
   run_team_region_ty *run_team_region;
+  init_requires_ty *init_requires;
 
   // Are there images associated with this RTL.
   bool isUsed;
@@ -78,8 +80,8 @@ struct RTLInfoTy {
 #endif
         is_valid_binary(0), number_of_devices(0), init_device(0),
         load_binary(0), data_alloc(0), data_submit(0), data_retrieve(0),
-        data_delete(0), run_region(0), run_team_region(0), isUsed(false),
-        Mtx() {}
+        data_delete(0), run_region(0), run_team_region(0),
+        init_requires(0), isUsed(false), Mtx() {}
 
   RTLInfoTy(const RTLInfoTy &r) : Mtx() {
     Idx = r.Idx;
@@ -98,6 +100,7 @@ struct RTLInfoTy {
     data_delete = r.data_delete;
     run_region = r.run_region;
     run_team_region = r.run_team_region;
+    init_requires = r.init_requires;
     isUsed = r.isUsed;
   }
 };