[X86][AVX512] Fix MUL v8i64 costs on non-AVX512DQ targets

llvm-svn: 285329
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
index f8d3a04..d115eb2 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -522,6 +522,7 @@
     // multiplies(3), shifts(4) and adds(2).
     { ISD::MUL,     MVT::v2i64,    9 },
     { ISD::MUL,     MVT::v4i64,    9 },
+    { ISD::MUL,     MVT::v8i64,    9 }
   };
   if (const auto *Entry = CostTableLookup(CustomLowered, ISD, LT.second))
     return LT.first * Entry->Cost;