Add a FIXME about the VECTOR_SHUFFLE evil hack.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47676 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypesSplit.cpp b/lib/CodeGen/SelectionDAG/LegalizeTypesSplit.cpp
index c0168f0..f6fdd2b 100644 (file)
--- a/lib/CodeGen/SelectionDAG/LegalizeTypesSplit.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeTypesSplit.cpp
@@ -547,6 +547,8 @@ SDOperand DAGTypeLegalizer::SplitOp_VECTOR_SHUFFLE(SDNode *N, unsigned OpNo) {
 
     // If the element type is not legal, find a larger legal type to use for
     // the BUILD_VECTOR operands.  This is an ugly hack, but seems to work!
+    // FIXME: The real solution is to change VECTOR_SHUFFLE into a variadic
+    // node where the shuffle mask is a list of integer operands, #2 .. #2+n.
     for (MVT::SimpleValueType OpVT = EltVT; OpVT <= MVT::LAST_INTEGER_VALUETYPE;
          // Integer values types are consecutively numbered.  Exploit this.
          OpVT = MVT::SimpleValueType(OpVT + 1)) {