Slightly change the way stackmap and patchpoint intrinsics are lowered.

MorphNodeTo is not safe to call during DAG building. It eagerly
deletes dependent DAG nodes which invalidates the NodeMap. We could
expose a safe interface for morphing nodes, but I don't think it's
worth it. Just create a new MachineNode and replaceAllUsesWith.

My understaning of the SD design has been that we want to support
early target opcode selection. That isn't very well supported, but
generally works. It seems reasonable to rely on this feature even if
it isn't widely used.

llvm-svn: 194102

1 files changed, 27 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index a0b965c6976..d8a2cfb64a2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -6806,11 +6806,19 @@ void SelectionDAGBuilder::visitStackmap(const CallInst &CI) {
   if (hasGlue)
     Ops.push_back(*(Call->op_end()-1));
 
-  // Replace the target specific call node with STACKMAP in-place. This way we
-  // don't have to call ReplaceAllUsesWith and STACKMAP will take the call's
-  // place in the chain.
   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
-  DAG.SelectNodeTo(Call, TargetOpcode::STACKMAP, NodeTys, &Ops[0], Ops.size());
+
+  // Replace the target specific call node with a STACKMAP node.
+  MachineSDNode *MN = DAG.getMachineNode(TargetOpcode::STACKMAP, getCurSDLoc(),
+                                         NodeTys, Ops);
+
+  // StackMap generates no value, so nothing goes in the NodeMap.
+
+  // Fixup the consumers of the intrinsic. The chain and glue may be used in the
+  // call sequence.
+  DAG.ReplaceAllUsesWith(Call, MN);
+
+  DAG.DeleteNode(Call);
 }
 
 /// \brief Lower llvm.experimental.patchpoint directly to its target opcode.
@@ -6898,12 +6906,22 @@ void SelectionDAGBuilder::visitPatchpoint(const CallInst &CI) {
   if (hasGlue)
     Ops.push_back(*(Call->op_end()-1));
 
-  // Replace the target specific call node with PATCHPOINT in-place. This
-  // way we don't have to call ReplaceAllUsesWith and PATCHPOINT will
-  // take the call's place in the chain.
   SDVTList NodeTys = DAG.getVTList(MVT::Other, MVT::Glue);
-  DAG.SelectNodeTo(Call, TargetOpcode::PATCHPOINT, NodeTys, &Ops[0],
-                   Ops.size());
+
+  // Replace the target specific call node with a STACKMAP node.
+  MachineSDNode *MN = DAG.getMachineNode(TargetOpcode::PATCHPOINT,
+                                         getCurSDLoc(), NodeTys, Ops);
+
+  // PatchPoint generates no value, so nothing goes in the NodeMap.
+  //
+  // FIXME: with anyregcc calling convention it will need to be in the NodeMap
+  // and replace values.
+
+  // Fixup the consumers of the intrinsic. The chain and glue may be used in the
+  // call sequence.
+  DAG.ReplaceAllUsesWith(Call, MN);
+
+  DAG.DeleteNode(Call);
 }
 
 /// TargetLowering::LowerCallTo - This is the default LowerCallTo