[CostModel][X86] Fix AVX512BW vector shift costs for vXi16 types

We already have patterns in place to support 128/256-bit shifts without AVX512VL

llvm-svn: 292077
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
index dfc2a8d..567ef74 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -323,6 +323,14 @@
       return LT.first * Entry->Cost;
 
   static const CostTblEntry AVX512BWCostTable[] = {
+    { ISD::SHL,   MVT::v8i16,      1 }, // vpsllvw
+    { ISD::SRL,   MVT::v8i16,      1 }, // vpsrlvw
+    { ISD::SRA,   MVT::v8i16,      1 }, // vpsravw
+
+    { ISD::SHL,   MVT::v16i16,     1 }, // vpsllvw
+    { ISD::SRL,   MVT::v16i16,     1 }, // vpsrlvw
+    { ISD::SRA,   MVT::v16i16,     1 }, // vpsravw
+
     { ISD::SHL,   MVT::v32i16,     1 }, // vpsllvw
     { ISD::SRL,   MVT::v32i16,     1 }, // vpsrlvw
     { ISD::SRA,   MVT::v32i16,     1 }, // vpsravw