[Openmp-commits] [PATCH] D96667: [OpenMP][FIX] Avoid use of stack allocations in asynchronous calls

[Johannes Doerfert via Phabricator via Openmp-commits]

jdoerfert updated this revision to Diff 323644.
jdoerfert added a comment.

Minor update


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D96667/new/

https://reviews.llvm.org/D96667

Files:
  openmp/libomptarget/include/omptarget.h
  openmp/libomptarget/src/omptarget.cpp


Index: openmp/libomptarget/src/omptarget.cpp
===================================================================
--- openmp/libomptarget/src/omptarget.cpp
+++ openmp/libomptarget/src/omptarget.cpp
@@ -31,6 +31,11 @@
   return Result;
 }
 
+void *&AsyncInfoTy::getVoidPtrLocation() {
+  BufferLocations.push_back(nullptr);
+  return BufferLocations.back();
+}
+
 /* All begin addresses for partially mapped structs must be 8-aligned in order
  * to ensure proper alignment of members. E.g.
  *
@@ -433,7 +438,8 @@
       DP("Update pointer (" DPxMOD ") -> [" DPxMOD "]\n",
          DPxPTR(PointerTgtPtrBegin), DPxPTR(TgtPtrBegin));
       uint64_t Delta = (uint64_t)HstPtrBegin - (uint64_t)HstPtrBase;
-      void *TgtPtrBase = (void *)((uint64_t)TgtPtrBegin - Delta);
+      void *&TgtPtrBase = AsyncInfo.getVoidPtrLocation();
+      TgtPtrBase = (void *)((uint64_t)TgtPtrBegin - Delta);
       int rt = Device.submitData(PointerTgtPtrBegin, &TgtPtrBase,
                                  sizeof(void *), AsyncInfo);
       if (rt != OFFLOAD_SUCCESS) {
@@ -1120,8 +1126,9 @@
         DP("Parent lambda base " DPxMOD "\n", DPxPTR(TgtPtrBase));
         uint64_t Delta = (uint64_t)HstPtrBegin - (uint64_t)HstPtrBase;
         void *TgtPtrBegin = (void *)((uintptr_t)TgtPtrBase + Delta);
-        void *PointerTgtPtrBegin = Device.getTgtPtrBegin(
-            HstPtrVal, ArgSizes[I], IsLast, false, IsHostPtr);
+        void *&PointerTgtPtrBegin = AsyncInfo.getVoidPtrLocation();
+        PointerTgtPtrBegin = Device.getTgtPtrBegin(HstPtrVal, ArgSizes[I],
+                                                   IsLast, false, IsHostPtr);
         if (!PointerTgtPtrBegin) {
           DP("No lambda captured variable mapped (" DPxMOD ") - ignored\n",
              DPxPTR(HstPtrVal));
Index: openmp/libomptarget/include/omptarget.h
===================================================================
--- openmp/libomptarget/include/omptarget.h
+++ openmp/libomptarget/include/omptarget.h
@@ -14,6 +14,7 @@
 #ifndef _OMPTARGET_H_
 #define _OMPTARGET_H_
 
+#include <deque>
 #include <stddef.h>
 #include <stdint.h>
 
@@ -136,6 +137,10 @@
 /// associated with a libomptarget layer device. RAII semantics to avoid
 /// mistakes.
 class AsyncInfoTy {
+  /// Locations we used in (potentially) asynchronous calls which should live
+  /// as long as this AsyncInfoTy object.
+  std::deque<void *> BufferLocations;
+
   __tgt_async_info AsyncInfo;
   DeviceTy &Device;
 
@@ -151,6 +156,10 @@
   ///
   /// \returns OFFLOAD_FAIL or OFFLOAD_SUCCESS appropriately.
   int synchronize();
+
+  /// Return a void* reference with a lifetime that is at least as long as this
+  /// AsyncInfoTy object. The location can be used as intermediate buffer.
+  void *&getVoidPtrLocation();
 };
 
 /// This struct is a record of non-contiguous information


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