Add an assert to catch invalid VECTOR_SHUFFLE mask indices.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54329 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 7870cb0..da1bd93 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -3665,6 +3665,7 @@
       Locs[i] = std::make_pair(-1, -1);
     } else {
       unsigned Val = cast<ConstantSDNode>(Elt)->getValue();
+      assert(Val < 8 && "Invalid VECTOR_SHUFFLE index!");
       if (Val < 4) {
         Locs[i] = std::make_pair(0, NumLo);
         Mask1[NumLo] = Elt;