don't insert an and node if it isn't needed here, this can prevent folding

of lowered target nodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25804 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 44ce9981a62377b7dc546849d12d769a07f9ca8c..04fef370171effbb31f9b4ff04953125c6234550 100644 (file)
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -1284,7 +1284,9 @@ SDOperand SelectionDAGLegalize::LegalizeOp(SDOperand Op) {
       } else {
         // Make sure the condition is either zero or one.  It may have been
         // promoted from something else.
-        Tmp1 = DAG.getZeroExtendInReg(Tmp1, MVT::i1);
+        unsigned NumBits = MVT::getSizeInBits(Tmp1.getValueType());
+        if (!TLI.MaskedValueIsZero(Tmp1, (~0ULL >> (64-NumBits))^1))
+          Tmp1 = DAG.getZeroExtendInReg(Tmp1, MVT::i1);
         Result = DAG.getSelectCC(Tmp1, 
                                  DAG.getConstant(0, Tmp1.getValueType()),
                                  Tmp2, Tmp3, ISD::SETNE);