[X86] Part 1 to fix x86-64 fp128 calling convention.

[oota-llvm.git] / lib / CodeGen / SelectionDAG / LegalizeTypesGeneric.cpp

diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp b/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp
index eb545982ed025dde94edd22dc6def4f9ad07ad46..593c346df770eab4294fdf6702efadf85c23bd81 100644 (file)
--- a/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeTypesGeneric.cpp
@@ -53,12 +53,17 @@ void DAGTypeLegalizer::ExpandRes_BITCAST(SDNode *N, SDValue &Lo, SDValue &Hi) {
     case TargetLowering::TypePromoteFloat:
       llvm_unreachable("Bitcast of a promotion-needing float should never need"
                        "expansion");
-    case TargetLowering::TypeSoftenFloat:
-      // Convert the integer operand instead.
-      SplitInteger(GetSoftenedFloat(InOp), Lo, Hi);
+    case TargetLowering::TypeSoftenFloat: {
+      // Expand the floating point operand only if it was converted to integers.
+      // Otherwise, it is a legal type like f128 that can be saved in a register.
+      auto SoftenedOp = GetSoftenedFloat(InOp);
+      if (SoftenedOp == InOp)
+        break;
+      SplitInteger(SoftenedOp, Lo, Hi);
       Lo = DAG.getNode(ISD::BITCAST, dl, NOutVT, Lo);
       Hi = DAG.getNode(ISD::BITCAST, dl, NOutVT, Hi);
       return;
+    }
     case TargetLowering::TypeExpandInteger:
     case TargetLowering::TypeExpandFloat: {
       auto &DL = DAG.getDataLayout();