llvm/lib/Target/Lanai/LanaiTargetTransformInfo.h

   1 //===-- LanaiTargetTransformInfo.h - Lanai specific TTI ---------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file a TargetTransformInfo::Concept conforming object specific to the
  10 // Lanai target machine. It uses the target's detailed information to
  11 // provide more precise answers to certain TTI queries, while letting the
  12 // target independent and default TTI implementations handle the rest.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #ifndef LLVM_LIB_TARGET_LANAI_LANAITARGETTRANSFORMINFO_H
  17 #define LLVM_LIB_TARGET_LANAI_LANAITARGETTRANSFORMINFO_H
  18
  19 #include "Lanai.h"
  20 #include "LanaiSubtarget.h"
  21 #include "LanaiTargetMachine.h"
  22 #include "llvm/Analysis/TargetTransformInfo.h"
  23 #include "llvm/CodeGen/BasicTTIImpl.h"
  24 #include "llvm/CodeGen/TargetLowering.h"
  25 #include "llvm/Support/MathExtras.h"
  26
  27 namespace llvm {
  28 class LanaiTTIImpl : public BasicTTIImplBase<LanaiTTIImpl> {
  29   typedef BasicTTIImplBase<LanaiTTIImpl> BaseT;
  30   typedef TargetTransformInfo TTI;
  31   friend BaseT;
  32
  33   const LanaiSubtarget *ST;
  34   const LanaiTargetLowering *TLI;
  35
  36   const LanaiSubtarget *getST() const { return ST; }
  37   const LanaiTargetLowering *getTLI() const { return TLI; }
  38
  39 public:
  40   explicit LanaiTTIImpl(const LanaiTargetMachine *TM, const Function &F)
  41       : BaseT(TM, F.getParent()->getDataLayout()), ST(TM->getSubtargetImpl(F)),
  42         TLI(ST->getTargetLowering()) {}
  43
  44   bool shouldBuildLookupTables() const { return false; }
  45
  46   TargetTransformInfo::PopcntSupportKind getPopcntSupport(unsigned TyWidth) {
  47     if (TyWidth == 32)
  48       return TTI::PSK_FastHardware;
  49     return TTI::PSK_Software;
  50   }
  51
  52   InstructionCost getIntImmCost(const APInt &Imm, Type *Ty,
  53                                 TTI::TargetCostKind CostKind) {
  54     assert(Ty->isIntegerTy());
  55     if (Imm == 0)
  56       return TTI::TCC_Free;
  57     if (isInt<16>(Imm.getSExtValue()))
  58       return TTI::TCC_Basic;
  59     if (isInt<21>(Imm.getZExtValue()))
  60       return TTI::TCC_Basic;
  61     if (isInt<32>(Imm.getSExtValue())) {
  62       if ((Imm.getSExtValue() & 0xFFFF) == 0)
  63         return TTI::TCC_Basic;
  64       return 2 * TTI::TCC_Basic;
  65     }
  66
  67     return 4 * TTI::TCC_Basic;
  68   }
  69
  70   InstructionCost getIntImmCostInst(unsigned Opc, unsigned Idx,
  71                                     const APInt &Imm, Type *Ty,
  72                                     TTI::TargetCostKind CostKind,
  73                                     Instruction *Inst = nullptr) {
  74     return getIntImmCost(Imm, Ty, CostKind);
  75   }
  76
  77   InstructionCost getIntImmCostIntrin(Intrinsic::ID IID, unsigned Idx,
  78                                       const APInt &Imm, Type *Ty,
  79                                       TTI::TargetCostKind CostKind) {
  80     return getIntImmCost(Imm, Ty, CostKind);
  81   }
  82
  83   InstructionCost getArithmeticInstrCost(
  84       unsigned Opcode, Type *Ty,
  85       TTI::TargetCostKind CostKind = TTI::TCK_RecipThroughput,
  86       TTI::OperandValueKind Opd1Info = TTI::OK_AnyValue,
  87       TTI::OperandValueKind Opd2Info = TTI::OK_AnyValue,
  88       TTI::OperandValueProperties Opd1PropInfo = TTI::OP_None,
  89       TTI::OperandValueProperties Opd2PropInfo = TTI::OP_None,
  90       ArrayRef<const Value *> Args = ArrayRef<const Value *>(),
  91       const Instruction *CxtI = nullptr) {
  92     int ISD = TLI->InstructionOpcodeToISD(Opcode);
  93
  94     switch (ISD) {
  95     default:
  96       return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Opd1Info,
  97                                            Opd2Info,
  98                                            Opd1PropInfo, Opd2PropInfo);
  99     case ISD::MUL:
 100     case ISD::SDIV:
 101     case ISD::UDIV:
 102     case ISD::UREM:
 103       // This increases the cost associated with multiplication and division
 104       // to 64 times what the baseline arithmetic cost is. The arithmetic
 105       // instruction cost was arbitrarily chosen to reduce the desirability
 106       // of emitting arithmetic instructions that are emulated in software.
 107       // TODO: Investigate the performance impact given specialized lowerings.
 108       return 64 * BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Opd1Info,
 109                                                 Opd2Info,
 110                                                 Opd1PropInfo, Opd2PropInfo);
 111     }
 112   }
 113 };
 114
 115 } // end namespace llvm
 116
 117 #endif // LLVM_LIB_TARGET_LANAI_LANAITARGETTRANSFORMINFO_H