Ignore undef shuffle indices when checking for a VTRN shuffle. Radar 8290937.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111208 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 5a03a07dccac1b72d4d39d111ea2c7d3e1e1579f..b05c5dd25977fe126f67c07066822500005c5496 100644 (file)
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -3229,6 +3229,7 @@ static bool isVTRN_v_undef_Mask(const SmallVectorImpl<int> &M, EVT VT,
   unsigned NumElts = VT.getVectorNumElements();
   WhichResult = (M[0] == 0 ? 0 : 1);
   for (unsigned i = 0; i < NumElts; i += 2) {
+    if (M[i] < 0) continue;
     if ((unsigned) M[i] != i + WhichResult ||
         (unsigned) M[i+1] != i + WhichResult)
       return false;