Another simple xform
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21317 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 3058cea..a52289f 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -964,6 +964,14 @@
return getSetCC(Result, LHS->getValueType(0), LL, LR);
}
}
+
+ // and/or zext(a), zext(b) -> zext(and/or a, b)
+ if (N1.getOpcode() == ISD::ZERO_EXTEND &&
+ N2.getOpcode() == ISD::ZERO_EXTEND &&
+ N1.getOperand(0).getValueType() == N2.getOperand(0).getValueType())
+ return getNode(ISD::ZERO_EXTEND, VT,
+ getNode(Opcode, N1.getOperand(0).getValueType(),
+ N1.getOperand(0), N2.getOperand(0)));
break;
case ISD::XOR:
if (N1 == N2) return getConstant(0, VT); // xor X, Y -> 0