[X86][AVX] Add support for shuffle decoding of vperm2f128/vperm2i128 with zero'd...

[oota-llvm.git] / lib / Target / X86 / Utils / X86ShuffleDecode.cpp

diff --git a/lib/Target/X86/Utils/X86ShuffleDecode.cpp b/lib/Target/X86/Utils/X86ShuffleDecode.cpp
index 9777c0d85e9bd3a27ffdff355456c3110695b6c3..b1c69e779f3fdf8c224c8fd0ff2b9c966ac1ab3d 100644 (file)
--- a/lib/Target/X86/Utils/X86ShuffleDecode.cpp
+++ b/lib/Target/X86/Utils/X86ShuffleDecode.cpp
@@ -255,15 +255,13 @@ void DecodeUNPCKLMask(MVT VT, SmallVectorImpl<int> &ShuffleMask) {
 
 void DecodeVPERM2X128Mask(MVT VT, unsigned Imm,
                           SmallVectorImpl<int> &ShuffleMask) {
-  if (Imm & 0x88)
-    return; // Not a shuffle
-
   unsigned HalfSize = VT.getVectorNumElements() / 2;
 
   for (unsigned l = 0; l != 2; ++l) {
-    unsigned HalfBegin = ((Imm >> (l * 4)) & 0x3) * HalfSize;
+    unsigned HalfMask = Imm >> (l * 4);
+    unsigned HalfBegin = (HalfMask & 0x3) * HalfSize;
     for (unsigned i = HalfBegin, e = HalfBegin + HalfSize; i != e; ++i)
-      ShuffleMask.push_back(i);
+      ShuffleMask.push_back(HalfMask & 8 ? SM_SentinelZero : i);
   }
 }