LegalizeTypes support for scalarizing a vector store

and splitting extract_subvector.  This fixes nine
"make check" testcases, for example
2008-02-04-ExtractSubvector.ll and (partially)
CodeGen/Generic/vector.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47384 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 23 insertions, 0 deletions

diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypesSplit.cpp b/lib/CodeGen/SelectionDAG/LegalizeTypesSplit.cpp
index 549afe9c6f..489aea4c64 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeTypesSplit.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeTypesSplit.cpp
@@ -339,6 +339,8 @@ bool DAGTypeLegalizer::SplitOperand(SDNode *N, unsigned OpNo) {
       abort();
     case ISD::STORE: Res = SplitOp_STORE(cast<StoreSDNode>(N), OpNo); break;
     case ISD::RET:   Res = SplitOp_RET(N, OpNo); break;
+
+    case ISD::EXTRACT_SUBVECTOR: Res = SplitOp_EXTRACT_SUBVECTOR(N); break;
     }
   }
   
@@ -399,3 +401,24 @@ SDOperand DAGTypeLegalizer::SplitOp_RET(SDNode *N, unsigned OpNo) {
   
   return DAG.getNode(ISD::RET, MVT::Other, Chain, Lo, Sign, Hi, Sign);
 }
+
+SDOperand DAGTypeLegalizer::SplitOp_EXTRACT_SUBVECTOR(SDNode *N) {
+  // We know that the extracted result type is legal.  For now, assume the index
+  // is a constant.
+  MVT::ValueType SubVT = N->getValueType(0);
+  SDOperand Idx = N->getOperand(1);
+  SDOperand Lo, Hi;
+  GetSplitOp(N->getOperand(0), Lo, Hi);
+
+  uint64_t LoElts = MVT::getVectorNumElements(Lo.getValueType());
+  uint64_t IdxVal = cast<ConstantSDNode>(Idx)->getValue();
+
+  if (IdxVal < LoElts) {
+    assert(IdxVal + MVT::getVectorNumElements(SubVT) <= LoElts &&
+           "Extracted subvector crosses vector split!");
+    return DAG.getNode(ISD::EXTRACT_SUBVECTOR, SubVT, Lo, Idx);
+  } else {
+    return DAG.getNode(ISD::EXTRACT_SUBVECTOR, SubVT, Hi,
+                       DAG.getConstant(IdxVal - LoElts, Idx.getValueType()));
+  }
+}