Implement cond ? -1 : 0 with sbb.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94490 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 8883064df9..640bdc091c 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3220,6 +3220,14 @@ SDValue DAGCombiner::visitSIGN_EXTEND(SDNode *N) {
                        NegOne, DAG.getConstant(0, VT),
                        cast<CondCodeSDNode>(N0.getOperand(2))->get(), true);
     if (SCC.getNode()) return SCC;
+    if (!LegalOperations ||
+        TLI.isOperationLegal(ISD::SETCC, TLI.getSetCCResultType(VT)))
+      return DAG.getNode(ISD::SELECT, N->getDebugLoc(), VT,
+                         DAG.getSetCC(N->getDebugLoc(),
+                                      TLI.getSetCCResultType(VT),
+                                      N0.getOperand(0), N0.getOperand(1),
+                                 cast<CondCodeSDNode>(N0.getOperand(2))->get()),
+                         NegOne, DAG.getConstant(0, VT));
   }