Cache SelectionDAGISel TargetInstrInfo lookups on the class and

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

diff --git a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index 435ecfabd3fec99bf7e8d848a09dc10ab4e42113..6b00bb108242e7995b44a8883cfe62548136c0cd 100644 (file)
--- a/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -862,7 +862,26 @@ void DAGTypeLegalizer::PromoteSetCCOperands(SDValue &NewLHS,SDValue &NewRHS,
   switch (CCCode) {
   default: llvm_unreachable("Unknown integer comparison!");
   case ISD::SETEQ:
-  case ISD::SETNE:
+  case ISD::SETNE: {
+    SDValue OpL = GetPromotedInteger(NewLHS);
+    SDValue OpR = GetPromotedInteger(NewRHS);
+
+    // We would prefer to promote the comparison operand with sign extension,
+    // if we find the operand is actually to truncate an AssertSext. With this
+    // optimization, we can avoid inserting real truncate instruction, which
+    // is redudant eventually.
+    if (OpL->getOpcode() == ISD::AssertSext &&
+        cast<VTSDNode>(OpL->getOperand(1))->getVT() == NewLHS.getValueType() &&
+        OpR->getOpcode() == ISD::AssertSext &&
+        cast<VTSDNode>(OpR->getOperand(1))->getVT() == NewRHS.getValueType()) {
+      NewLHS = OpL;
+      NewRHS = OpR;
+    } else {
+      NewLHS = ZExtPromotedInteger(NewLHS);
+      NewRHS = ZExtPromotedInteger(NewRHS);
+    }
+    break;
+  }
   case ISD::SETUGE:
   case ISD::SETUGT:
   case ISD::SETULE: