foo

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299618 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index d3ccdcd5ffdd07bad324eb93189a5b6fb3567687..753e5281bfc7fe27331c6210d45d64534f3f23e3 100644 (file)
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -791,6 +791,9 @@ bool TargetLowering::SimplifyDemandedBits(SDValue Op,
       // TODO: Should we check for other forms of sign-bit comparisons?
       // Examples: X <= -1, X >= 0
     }
+    if (getBooleanContents(Op.getOperand(0).getValueType()) ==
+            BooleanContent::ZeroOrOneBooleanContent && BitWidth > 1)
+      KnownZero.setBitsFrom(1);
     break;
   }
   case ISD::SHL: