[DAGCombiner] Merge SIGN_EXTEND_INREG vector constant folding methods. NCI.

visitSIGN_EXTEND_INREG calls SelectionDAG::getNode to constant fold scalar constants but handles vector constants itself, despite getNode being capable of dealing with them.

This required a minor change to the getNode implementation to actually deal with cases where the scalars of a BUILD_VECTOR were wider integers than the vector type - which was the only extra ability of the visitSIGN_EXTEND_INREG implementation.

No codegen intended and all existing tests remain the same.

llvm-svn: 249236

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index a968e965a0d..7e02d3ab1fc 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3576,13 +3576,13 @@ SDValue SelectionDAG::getNode(unsigned Opcode, SDLoc DL, EVT VT, SDValue N1,
       SmallVector<SDValue, 8> Ops;
       for (int i = 0, e = VT.getVectorNumElements(); i != e; ++i) {
         SDValue Op = N1.getOperand(i);
-        if (Op.getValueType() != VT.getScalarType()) break;
         if (Op.getOpcode() == ISD::UNDEF) {
-          Ops.push_back(Op);
+          Ops.push_back(getUNDEF(VT.getScalarType()));
           continue;
         }
         if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
           APInt Val = C->getAPIntValue();
+          Val = Val.zextOrTrunc(VT.getScalarSizeInBits());
           Ops.push_back(SignExtendInReg(Val));
           continue;
         }