[X86] Remove X86ProcFamilyEnum::IntelSLM

[RKSimon]

Summary

Replace X86ProcFamilyEnum::IntelSLM enum with a TuningUseSLMArithCosts flag instead, matching what we already do for Goldmont.

This just leaves X86ProcFamilyEnum::IntelAtom to replace with general Tuning/Feature flags and we can finally get rid of the old X86ProcFamilyEnum enum.

[pengfei]

LGTM.

llvm/lib/Target/X86/X86.td

576

Why we call it "arithmetic costs"?

[RKSimon]

Thanks @pengfei

llvm/lib/Target/X86/X86.td

576

No reason really, it sort of matched what we did for GLM - UseSLMCosts / UseGLMCosts would be cleaner tbh

llvm/lib/Target/X86/X86.td

def TuningFastVectorShiftMasks
     : SubtargetFeature<
         "fast-vector-shift-masks", "HasFastVectorShiftMasks", "true",
         "Prefer a left/right vector logical shift pair over a shift+and pair">;
 
 def TuningFastMOVBE
     : SubtargetFeature<"fast-movbe", "HasFastMOVBE", "true",
     "Prefer a movbe over a single-use load + bswap / single-use bswap + store">;
 
+def TuningUseSLMArithCosts
+    : SubtargetFeature<"use-slm-arith-costs", "UseSLMArithCosts", "true",
+        "Use Silvermont specific arithmetic costs">;
+
 def TuningUseGLMDivSqrtCosts
     : SubtargetFeature<"use-glm-div-sqrt-costs", "UseGLMDivSqrtCosts", "true",
         "Use Goldmont specific floating point div/sqrt costs">;
 
 // Enable use of alias analysis during code generation.
 def FeatureUseAA : SubtargetFeature<"use-aa", "UseAA", "true",
                                     "Use alias analysis during codegen">;
 
 //===----------------------------------------------------------------------===//
 // X86 CPU Families
 // TODO: Remove these - use general tuning features to determine codegen.
 //===----------------------------------------------------------------------===//
 
 // Bonnell
 def ProcIntelAtom : SubtargetFeature<"", "X86ProcFamily", "IntelAtom", "">;
-// Silvermont
-def ProcIntelSLM  : SubtargetFeature<"", "X86ProcFamily", "IntelSLM", "">;
 
 //===----------------------------------------------------------------------===//
 // Register File Description
 //===----------------------------------------------------------------------===//
 
 include "X86RegisterInfo.td"
 include "X86RegisterBanks.td"
 
def ProcessorFeatures {
 
   // Silvermont
   list<SubtargetFeature> SLMAdditionalFeatures = [FeatureSSE42,
                                                   FeatureCRC32,
                                                   FeaturePOPCNT,
                                                   FeaturePCLMUL,
                                                   FeaturePRFCHW,
                                                   FeatureRDRAND];
-  list<SubtargetFeature> SLMTuning = [ProcIntelSLM,
+  list<SubtargetFeature> SLMTuning = [TuningUseSLMArithCosts,
                                       TuningSlowTwoMemOps,
                                       TuningSlowLEA,
                                       TuningSlowIncDec,
                                       TuningSlowDivide64,
                                       TuningSlowPMULLD,
                                       TuningFast7ByteNOP,
                                       TuningFastMOVBE,
                                       TuningPOPCNTFalseDeps,

llvm/lib/Target/X86/X86Subtarget.h

 
 } // end namespace PICStyles
 
 class X86Subtarget final : public X86GenSubtargetInfo {
   // NOTE: Do not add anything new to this list. Coarse, CPU name based flags
   // are not a good idea. We should be migrating away from these.
   enum X86ProcFamilyEnum {
     Others,
-    IntelAtom,
-    IntelSLM
+    IntelAtom
   };
 
   enum X86SSEEnum {
     NoSSE, SSE1, SSE2, SSE3, SSSE3, SSE41, SSE42, AVX, AVX2, AVX512F
   };
 
   enum X863DNowEnum {
     NoThreeDNow, MMX, ThreeDNow, ThreeDNowA
class X86Subtarget final : public X86GenSubtargetInfo {
   bool Prefer128Bit = false;
 
   /// Indicates target prefers 256 bit instructions.
   bool Prefer256Bit = false;
 
   /// Indicates target prefers AVX512 mask registers.
   bool PreferMaskRegisters = false;
 
+  /// Use Silvermont specific arithmetic costs.
+  bool UseSLMArithCosts = false;
+
   /// Use Goldmont specific floating point div/sqrt costs.
   bool UseGLMDivSqrtCosts = false;
 
   /// What processor and OS we're targeting.
   Triple TargetTriple;
 
   /// GlobalISel related APIs.
   std::unique_ptr<CallLowering> CallLoweringInfo;
public:
   bool useIndirectThunkCalls() const {
     return useRetpolineIndirectCalls() || useLVIControlFlowIntegrity();
   }
   bool useIndirectThunkBranches() const {
     return useRetpolineIndirectBranches() || useLVIControlFlowIntegrity();
   }
 
   bool preferMaskRegisters() const { return PreferMaskRegisters; }
+  bool useSLMArithCosts() const { return UseSLMArithCosts; }
   bool useGLMDivSqrtCosts() const { return UseGLMDivSqrtCosts; }
   bool useLVIControlFlowIntegrity() const { return UseLVIControlFlowIntegrity; }
   bool allowTaggedGlobals() const { return AllowTaggedGlobals; }
   bool useLVILoadHardening() const { return UseLVILoadHardening; }
   bool useSpeculativeExecutionSideEffectSuppression() const {
     return UseSpeculativeExecutionSideEffectSuppression;
   }
 
public:
   bool useBWIRegs() const {
     return hasBWI() && useAVX512Regs();
   }
 
   bool isXRaySupported() const override { return is64Bit(); }
 
   /// TODO: to be removed later and replaced with suitable properties
   bool isAtom() const { return X86ProcFamily == IntelAtom; }
-  bool isSLM() const { return X86ProcFamily == IntelSLM; }
   bool useSoftFloat() const { return UseSoftFloat; }
   bool useAA() const override { return UseAA; }
 
   /// Use mfence if we have SSE2 or we're on x86-64 (even if we asked for
   /// no-sse2). There isn't any reason to disable it if the target processor
   /// supports it.
   bool hasMFence() const { return hasSSE2() || is64Bit(); }
 

llvm/lib/Target/X86/X86TargetTransformInfo.h

const FeatureBitset InlineFeatureIgnoreList = {
       X86::TuningSlowLEA,
       X86::TuningSlowPMADDWD,
       X86::TuningSlowPMULLD,
       X86::TuningSlowSHLD,
       X86::TuningSlowTwoMemOps,
       X86::TuningSlowUAMem16,
       X86::TuningPreferMaskRegisters,
       X86::TuningInsertVZEROUPPER,
+      X86::TuningUseSLMArithCosts,
       X86::TuningUseGLMDivSqrtCosts,
 
       // Perf-tuning flags.
       X86::TuningFastGather,
       X86::TuningSlowUAMem32,
 
       // Based on whether user set the -mprefer-vector-width command line.
       X86::TuningPrefer128Bit,
       X86::TuningPrefer256Bit,
 
       // CPU name enums. These just follow CPU string.
-      X86::ProcIntelAtom,
-      X86::ProcIntelSLM,
+      X86::ProcIntelAtom
   };
 
 public:
   explicit X86TTIImpl(const X86TargetMachine *TM, const Function &F)
       : BaseT(TM, F.getParent()->getDataLayout()), ST(TM->getSubtargetImpl(F)),
         TLI(ST->getTargetLowering()) {}
 
   /// \name Scalar TTI Implementations

llvm/lib/Target/X86/X86TargetTransformInfo.cpp

static const CostTblEntry SLMCostTable[] = {
     // thus: 3X2 (muldq throughput) + 3X1 (shift throughput) +
     //       3X4 (addq throughput) = 17
     { ISD::MUL,   MVT::v2i64, 17 },
     // slm addq\subq throughput is 4
     { ISD::ADD,   MVT::v2i64, 4  },
     { ISD::SUB,   MVT::v2i64, 4  },
   };
 
-  if (ST->isSLM()) {
+  if (ST->useSLMArithCosts()) {
     if (Args.size() == 2 && ISD == ISD::MUL && LT.second == MVT::v4i32) {
       // Check if the operands can be shrinked into a smaller datatype.
       // TODO: Merge this into generiic vXi32 MUL patterns above.
       bool Op1Signed = false;
       unsigned Op1MinSize = BaseT::minRequiredElementSize(Args[0], Op1Signed);
       bool Op2Signed = false;
       unsigned Op2MinSize = BaseT::minRequiredElementSize(Args[1], Op2Signed);
 
InstructionCost X86TTIImpl::getCmpSelInstrCost(unsigned Opcode, Type *ValTy,
 
   static const CostTblEntry SSE1CostTbl[] = {
     { ISD::SETCC,   MVT::v4f32,   2 },
     { ISD::SETCC,   MVT::f32,     1 },
 
     { ISD::SELECT,  MVT::v4f32,   3 }, // andps + andnps + orps
   };
 
-  if (ST->isSLM())
+  if (ST->useSLMArithCosts())
     if (const auto *Entry = CostTableLookup(SLMCostTbl, ISD, MTy))
       return LT.first * (ExtraCost + Entry->Cost);
 
   if (ST->hasBWI())
     if (const auto *Entry = CostTableLookup(AVX512BWCostTbl, ISD, MTy))
       return LT.first * (ExtraCost + Entry->Cost);
 
   if (ST->hasAVX512())
auto adjustTableCost = [](const CostTblEntry &Entry,
       }
       return LegalizationCost * (int)Entry.Cost;
     };
 
     if (ST->useGLMDivSqrtCosts())
       if (const auto *Entry = CostTableLookup(GLMCostTbl, ISD, MTy))
         return adjustTableCost(*Entry, LT.first, ICA.getFlags());
 
-    if (ST->isSLM())
+    if (ST->useSLMArithCosts())
       if (const auto *Entry = CostTableLookup(SLMCostTbl, ISD, MTy))
         return adjustTableCost(*Entry, LT.first, ICA.getFlags());
 
     if (ST->hasBITALG())
       if (const auto *Entry = CostTableLookup(AVX512BITALGCostTbl, ISD, MTy))
         return adjustTableCost(*Entry, LT.first, ICA.getFlags());
 
     if (ST->hasVPOPCNTDQ())
if (Index == 0) {
       // Assume movd/movq XMM -> GPR is relatively cheap on all targets.
       if (ScalarType->isIntegerTy() && Opcode == Instruction::ExtractElement)
         return 1 + RegisterFileMoveCost;
     }
 
     int ISD = TLI->InstructionOpcodeToISD(Opcode);
     assert(ISD && "Unexpected vector opcode");
     MVT MScalarTy = LT.second.getScalarType();
-    if (ST->isSLM())
+    if (ST->useSLMArithCosts())
       if (auto *Entry = CostTableLookup(SLMCostTbl, ISD, MScalarTy))
         return Entry->Cost + RegisterFileMoveCost;
 
     // Assume pinsr/pextr XMM <-> GPR is relatively cheap on all targets.
     if ((MScalarTy == MVT::i16 && ST->hasSSE2()) ||
         (MScalarTy.isInteger() && ST->hasSSE41()))
       return 1 + RegisterFileMoveCost;
 
X86TTIImpl::getArithmeticReductionCost(unsigned Opcode, VectorType *ValTy,
   assert(ISD && "Invalid opcode");
 
   // Before legalizing the type, give a chance to look up illegal narrow types
   // in the table.
   // FIXME: Is there a better way to do this?
   EVT VT = TLI->getValueType(DL, ValTy);
   if (VT.isSimple()) {
     MVT MTy = VT.getSimpleVT();
-    if (ST->isSLM())
+    if (ST->useSLMArithCosts())
       if (const auto *Entry = CostTableLookup(SLMCostTblNoPairWise, ISD, MTy))
         return Entry->Cost;
 
     if (ST->hasAVX())
       if (const auto *Entry = CostTableLookup(AVX1CostTblNoPairWise, ISD, MTy))
         return Entry->Cost;
 
     if (ST->hasSSE2())
if (LT.first != 1 && MTy.isVector() &&
       MTy.getVectorNumElements() < ValVTy->getNumElements()) {
     // Type needs to be split. We need LT.first - 1 arithmetic ops.
     auto *SingleOpTy = FixedVectorType::get(ValVTy->getElementType(),
                                             MTy.getVectorNumElements());
     ArithmeticCost = getArithmeticInstrCost(Opcode, SingleOpTy, CostKind);
     ArithmeticCost *= LT.first - 1;
   }
 
-  if (ST->isSLM())
+  if (ST->useSLMArithCosts())
     if (const auto *Entry = CostTableLookup(SLMCostTblNoPairWise, ISD, MTy))
       return ArithmeticCost + Entry->Cost;
 
   if (ST->hasAVX())
     if (const auto *Entry = CostTableLookup(AVX1CostTblNoPairWise, ISD, MTy))
       return ArithmeticCost + Entry->Cost;
 
   if (ST->hasSSE2())