fold noop vbitconvert instructions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35943 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index a51f79f..7c8a94e 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1484,6 +1484,15 @@
MVT::getVectorNumElements(VT) == N3.getNumOperands() &&
"Illegal VECTOR_SHUFFLE node!");
break;
+ case ISD::VBIT_CONVERT:
+ // Fold vbit_convert nodes from a type to themselves.
+ if (N1.getValueType() == MVT::Vector) {
+ assert(isa<ConstantSDNode>(*(N1.Val->op_end()-2)) &&
+ isa<VTSDNode>(*(N1.Val->op_end()-1)) && "Malformed vector input!");
+ if (*(N1.Val->op_end()-2) == N2 && *(N1.Val->op_end()-1) == N3)
+ return N1;
+ }
+ break;
}
// Memoize node if it doesn't produce a flag.