Properly expand extract-element for non-power-of-2 codegen

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46486 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index 54cfad69309e11afd0fd2f768c844954586c4cdc..d18d4d959b4c1b905b2b5f6429309e495e530dc2 100644 (file)
--- a/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -4405,14 +4405,15 @@ SDOperand SelectionDAGLegalize::ExpandEXTRACT_VECTOR_ELT(SDOperand Op) {
     // This must be an access of the only element.  Return it.
     Op = ScalarizeVectorOp(Vec);
   } else if (!TLI.isTypeLegal(TVT) && isa<ConstantSDNode>(Idx)) {
+    unsigned NumLoElts =  1 << Log2_32(NumElems-1);
     ConstantSDNode *CIdx = cast<ConstantSDNode>(Idx);
     SDOperand Lo, Hi;
     SplitVectorOp(Vec, Lo, Hi);
-    if (CIdx->getValue() < NumElems/2) {
+    if (CIdx->getValue() < NumLoElts) {
       Vec = Lo;
     } else {
       Vec = Hi;
-      Idx = DAG.getConstant(CIdx->getValue() - NumElems/2,
+      Idx = DAG.getConstant(CIdx->getValue() - NumLoElts,
                             Idx.getValueType());
     }