[X86][NFC]Move and rephrase the comment, NFC

diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
index 5b6c7d8..d153fb9 100644 (file)
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -4333,6 +4333,8 @@ InstructionCost X86TTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val,
 
     MVT MScalarTy = LT.second.getScalarType();
     auto IsCheapPInsrPExtrInsertPS = [&]() {
+      // Assume pinsr/pextr XMM <-> GPR is relatively cheap on all targets.
+      // Also, assume insertps is relatively cheap on all >= SSE41 targets.
       return (MScalarTy == MVT::i16 && ST->hasSSE2()) ||
              (MScalarTy.isInteger() && ST->hasSSE41()) ||
              (MScalarTy == MVT::f32 && ST->hasSSE41() &&
@@ -4371,8 +4373,7 @@ InstructionCost X86TTIImpl::getVectorInstrCost(unsigned Opcode, Type *Val,
       if (auto *Entry = CostTableLookup(SLMCostTbl, ISD, MScalarTy))
         return Entry->Cost + RegisterFileMoveCost;
 
-    // Assume pinsr/pextr XMM <-> GPR is relatively cheap on all targets.
-    // Assume insertps is relatively cheap on all targets.
+    // Consider cheap cases.
     if (IsCheapPInsrPExtrInsertPS())
       return 1 + RegisterFileMoveCost;