1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/Target/X86/Utils/X86ShuffleDecode.cpp b/llvm/lib/Target/X86/Utils/X86ShuffleDecode.cpp
index fe567f4cece..4bd5df44abd 100644
--- a/llvm/lib/Target/X86/Utils/X86ShuffleDecode.cpp
+++ b/llvm/lib/Target/X86/Utils/X86ShuffleDecode.cpp
@@ -501,6 +501,10 @@ void DecodeVPERMILPMask(unsigned NumElts, unsigned ScalarBits,
 
   for (unsigned i = 0, e = RawMask.size(); i < e; ++i) {
     uint64_t M = RawMask[i];
+    if (M == (uint64_t)SM_SentinelUndef) {
+      ShuffleMask.push_back(M);
+      continue;
+    }
     M = (ScalarBits == 64 ? ((M >> 1) & 0x1) : (M & 0x3));
     unsigned LaneOffset = i & ~(NumEltsPerLane - 1);
     ShuffleMask.push_back((int)(LaneOffset + M));