Revert revisions r234755, r234759, r234760

Revert "Remove default in fully-covered switch (to fix Clang -Werror -Wcovered-switch-default)"
Revert "R600: Add carry and borrow instructions. Use them to implement UADDO/USUBO"
Revert "LegalizeDAG: Try to use Overflow operations when expanding ADD/SUB"

Using overflow operations fails CodeGen/Generic/2011-07-07-ScheduleDAGCrash.ll
on hexagon, nvptx, and r600. Revert while I investigate.

llvm-svn: 234768

1 files changed, 0 insertions, 32 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index e4fc3ff318f..25e80b9c736 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -1629,38 +1629,6 @@ void DAGTypeLegalizer::ExpandIntRes_ADDSUB(SDNode *N,
     return;
   }
 
-  bool hasOVF =
-    TLI.isOperationLegalOrCustom(N->getOpcode() == ISD::ADD ?
-                                   ISD::UADDO : ISD::USUBO,
-                                 TLI.getTypeToExpandTo(*DAG.getContext(), NVT));
-  if (hasOVF) {
-    SDVTList VTList = DAG.getVTList(NVT, NVT);
-    TargetLoweringBase::BooleanContent BoolType = TLI.getBooleanContents(NVT);
-    int RevOpc;
-    if (N->getOpcode() == ISD::ADD) {
-      RevOpc = ISD::SUB;
-      Lo = DAG.getNode(ISD::UADDO, dl, VTList, LoOps);
-      Hi = DAG.getNode(ISD::ADD, dl, NVT, makeArrayRef(HiOps, 2));
-    } else {
-      RevOpc = ISD::ADD;
-      Lo = DAG.getNode(ISD::USUBO, dl, VTList, LoOps);
-      Hi = DAG.getNode(ISD::SUB, dl, NVT, makeArrayRef(HiOps, 2));
-    }
-    SDValue OVF = Lo.getValue(1);
-
-    switch (BoolType) {
-    case TargetLoweringBase::UndefinedBooleanContent:
-      OVF = DAG.getNode(ISD::AND, dl, NVT, DAG.getConstant(1, NVT), OVF);
-      // Fallthrough
-    case TargetLoweringBase::ZeroOrOneBooleanContent:
-      Hi = DAG.getNode(N->getOpcode(), dl, NVT, Hi, OVF);
-      break;
-    case TargetLoweringBase::ZeroOrNegativeOneBooleanContent:
-      Hi = DAG.getNode(RevOpc, dl, NVT, Hi, OVF);
-    }
-    return;
-  }
-
   if (N->getOpcode() == ISD::ADD) {
     Lo = DAG.getNode(ISD::ADD, dl, NVT, LoOps);
     Hi = DAG.getNode(ISD::ADD, dl, NVT, makeArrayRef(HiOps, 2));