DAG: Fix promote of half freeze (#131844)

Author: arsenm

llvm/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp

@@ -2763,7 +2763,12 @@ void DAGTypeLegalizer::PromoteFloatResult(SDNode *N, unsigned ResNo) {
 #endif
       report_fatal_error("Do not know how to promote this operator's result!");
 
-    case ISD::BITCAST:    R = PromoteFloatRes_BITCAST(N); break;
+    case ISD::BITCAST:
+      R = PromoteFloatRes_BITCAST(N);
+      break;
+    case ISD::FREEZE:
+      R = PromoteFloatRes_FREEZE(N);
+      break;
     case ISD::ConstantFP: R = PromoteFloatRes_ConstantFP(N); break;
     case ISD::EXTRACT_VECTOR_ELT:
                           R = PromoteFloatRes_EXTRACT_VECTOR_ELT(N); break;
@@ -2876,6 +2881,18 @@ SDValue DAGTypeLegalizer::PromoteFloatRes_BITCAST(SDNode *N) {
   return DAG.getNode(GetPromotionOpcode(VT, NVT), SDLoc(N), NVT, Cast);
 }
 
+SDValue DAGTypeLegalizer::PromoteFloatRes_FREEZE(SDNode *N) {
+  EVT VT = N->getValueType(0);
+  EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), VT);
+  // Input type isn't guaranteed to be a scalar int so bitcast if not. The
+  // bitcast will be legalized further if necessary.
+  EVT IVT = EVT::getIntegerVT(*DAG.getContext(),
+                              N->getOperand(0).getValueType().getSizeInBits());
+  SDValue Cast = DAG.getBitcast(IVT, N->getOperand(0));
+  return DAG.getNode(GetPromotionOpcode(VT, NVT), SDLoc(N), NVT,
+                     DAG.getFreeze(Cast));
+}
+
 SDValue DAGTypeLegalizer::PromoteFloatRes_ConstantFP(SDNode *N) {
   ConstantFPSDNode *CFPNode = cast<ConstantFPSDNode>(N);
   EVT VT = N->getValueType(0);

llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h

@@ -756,6 +756,7 @@ class LLVM_LIBRARY_VISIBILITY DAGTypeLegalizer {
 
   void PromoteFloatResult(SDNode *N, unsigned ResNo);
   SDValue PromoteFloatRes_BITCAST(SDNode *N);
+  SDValue PromoteFloatRes_FREEZE(SDNode *N);
   SDValue PromoteFloatRes_BinOp(SDNode *N);
   SDValue PromoteFloatRes_UnaryWithTwoFPResults(SDNode *N);
   SDValue PromoteFloatRes_ConstantFP(SDNode *N);