Fix some invalid alignments for Neon vld-dup and vld/st-lane instructions.
Alignments smaller than the total size of the memory being loaded or stored,
unless the alignment is 8 bytes, are not allowed.  Add tests for this, too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121506 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index bfba114..f96f68f 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -1622,6 +1622,8 @@
     unsigned NumBytes = NumVecs * VT.getVectorElementType().getSizeInBits()/8;
     if (Alignment > NumBytes)
       Alignment = NumBytes;
+    if (Alignment < 8 && Alignment < NumBytes)
+      Alignment = 0;
     // Alignment must be a power of two; make sure of that.
     Alignment = (Alignment & -Alignment);
     if (Alignment == 1)
@@ -1720,6 +1722,8 @@
     unsigned NumBytes = NumVecs * VT.getVectorElementType().getSizeInBits()/8;
     if (Alignment > NumBytes)
       Alignment = NumBytes;
+    if (Alignment < 8 && Alignment < NumBytes)
+      Alignment = 0;
     // Alignment must be a power of two; make sure of that.
     Alignment = (Alignment & -Alignment);
     if (Alignment == 1)