Allocate AtomicSDNode operands in SelectionDAG's allocator to stop leakage.

SDNode destructors are never called. As an optimization use AtomicSDNode's
internal storage if we have a small number of operands.

llvm-svn: 191636

1 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index b96c4b18d11..62ceb8b3a25 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -4125,10 +4125,18 @@ SDValue SelectionDAG::getAtomic(unsigned Opcode, SDLoc dl, EVT MemVT,
     cast<AtomicSDNode>(E)->refineAlignment(MMO);
     return SDValue(E, 0);
   }
+
+  // Allocate the operands array for the node out of the BumpPtrAllocator, since
+  // SDNode doesn't have access to it.  This memory will be "leaked" when
+  // the node is deallocated, but recovered when the allocator is released.
+  // If the number of operands is less than 5 we use AtomicSDNode's internal
+  // storage.
+  SDUse *DynOps = NumOps > 4 ? OperandAllocator.Allocate<SDUse>(NumOps) : 0;
+
   SDNode *N = new (NodeAllocator) AtomicSDNode(Opcode, dl.getIROrder(),
                                                dl.getDebugLoc(), VTList, MemVT,
-                                               Ops, NumOps, MMO, Ordering,
-                                               SynchScope);
+                                               Ops, DynOps, NumOps, MMO,
+                                               Ordering, SynchScope);
   CSEMap.InsertNode(N, IP);
   AllNodes.push_back(N);
   return SDValue(N, 0);