(i32 sext_in_reg (i32 aext (i16 x)), i16) -> (i32 sext x). No known test case until -promote-16bit is enabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101551 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 5c53a7f..9ba9bb5 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3748,7 +3748,8 @@
// if x is small enough.
if (N0.getOpcode() == ISD::SIGN_EXTEND || N0.getOpcode() == ISD::ANY_EXTEND) {
SDValue N00 = N0.getOperand(0);
- if (N00.getValueType().getScalarType().getSizeInBits() < EVTBits)
+ if (N00.getValueType().getScalarType().getSizeInBits() <= EVTBits &&
+ (!LegalOperations || TLI.isOperationLegal(ISD::SIGN_EXTEND, VT)))
return DAG.getNode(ISD::SIGN_EXTEND, N->getDebugLoc(), VT, N00, N1);
}