Teach lowering to correctly handle invoke statepoint and gc results tied to them. Note that we still can not lower gc.relocates for invoke statepoints.

Also it extracts getCopyFromRegs helper function in SelectionDAGBuilder as we need to be able to customize type of the register exported from basic block during lowering of the gc.result.
(Resubmitting this change after not being able to reproduce buildbot failure)

Differential Revision: http://reviews.llvm.org/D7760

llvm-svn: 231800

1 files changed, 29 insertions, 10 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index a5f0868894b..6fc6eb174e0 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1016,6 +1016,24 @@ void SelectionDAGBuilder::resolveDanglingDebugInfo(const Value *V,
   }
 }
 
+/// getCopyFromRegs - If there was virtual register allocated for the value V
+/// emit CopyFromReg of the specified type Ty. Return empty SDValue() otherwise.
+SDValue SelectionDAGBuilder::getCopyFromRegs(const Value *V, Type *Ty) {
+  DenseMap<const Value *, unsigned>::iterator It = FuncInfo.ValueMap.find(V);
+  SDValue res;
+
+  if (It != FuncInfo.ValueMap.end()) {
+    unsigned InReg = It->second;
+    RegsForValue RFV(*DAG.getContext(), DAG.getTargetLoweringInfo(), InReg,
+                     Ty);
+    SDValue Chain = DAG.getEntryNode();
+    res = RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, V);
+    resolveDanglingDebugInfo(V, res);
+  }
+
+  return res;
+}
+
 /// getValue - Return an SDValue for the given Value.
 SDValue SelectionDAGBuilder::getValue(const Value *V) {
   // If we already have an SDValue for this value, use it. It's important
@@ -1026,15 +1044,9 @@ SDValue SelectionDAGBuilder::getValue(const Value *V) {
 
   // If there's a virtual register allocated and initialized for this
   // value, use it.
-  DenseMap<const Value *, unsigned>::iterator It = FuncInfo.ValueMap.find(V);
-  if (It != FuncInfo.ValueMap.end()) {
-    unsigned InReg = It->second;
-    RegsForValue RFV(*DAG.getContext(), DAG.getTargetLoweringInfo(), InReg,
-                     V->getType());
-    SDValue Chain = DAG.getEntryNode();
-    N = RFV.getCopyFromRegs(DAG, FuncInfo, getCurSDLoc(), Chain, nullptr, V);
-    resolveDanglingDebugInfo(V, N);
-    return N;
+  SDValue copyFromReg = getCopyFromRegs(V, V->getType());
+  if (copyFromReg.getNode()) {
+    return copyFromReg;
   }
 
   // Otherwise create a new SDValue and remember it.
@@ -2027,13 +2039,20 @@ void SelectionDAGBuilder::visitInvoke(const InvokeInst &I) {
     case Intrinsic::experimental_patchpoint_i64:
       visitPatchpoint(&I, LandingPad);
       break;
+    case Intrinsic::experimental_gc_statepoint:
+      LowerStatepoint(ImmutableStatepoint(&I), LandingPad);
+      break;
     }
   } else
     LowerCallTo(&I, getValue(Callee), false, LandingPad);
 
   // If the value of the invoke is used outside of its defining block, make it
   // available as a virtual register.
-  CopyToExportRegsIfNeeded(&I);
+  // We already took care of the exported value for the statepoint instruction
+  // during call to the LowerStatepoint.
+  if (!isStatepoint(I)) {
+    CopyToExportRegsIfNeeded(&I);
+  }
 
   // Update successor info
   addSuccessorWithWeight(InvokeMBB, Return);