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.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     unsigned BitSize = Ty->getPrimitiveSizeInBits();
  56     // There is no cost model for constants with a bit size of 0. Return
  57     // TCC_Free here, so that constant hoisting will ignore this constant.
  58     if (BitSize == 0)
  59       return TTI::TCC_Free;
  60     // No cost model for operations on integers larger than 64 bit implemented
  61     // yet.
  62     if (BitSize > 64)
  63       return TTI::TCC_Free;
  64
  65     if (Imm == 0)
  66       return TTI::TCC_Free;
  67     if (isInt<16>(Imm.getSExtValue()))
  68       return TTI::TCC_Basic;
  69     if (isInt<21>(Imm.getZExtValue()))
  70       return TTI::TCC_Basic;
  71     if (isInt<32>(Imm.getSExtValue())) {
  72       if ((Imm.getSExtValue() & 0xFFFF) == 0)
  73         return TTI::TCC_Basic;
  74       return 2 * TTI::TCC_Basic;
  75     }
  76
  77     return 4 * TTI::TCC_Basic;
  78   }
  79
  80   InstructionCost getIntImmCostInst(unsigned Opc, unsigned Idx,
  81                                     const APInt &Imm, Type *Ty,
  82                                     TTI::TargetCostKind CostKind,
  83                                     Instruction *Inst = nullptr) {
  84     return getIntImmCost(Imm, Ty, CostKind);
  85   }
  86
  87   InstructionCost getIntImmCostIntrin(Intrinsic::ID IID, unsigned Idx,
  88                                       const APInt &Imm, Type *Ty,
  89                                       TTI::TargetCostKind CostKind) {
  90     return getIntImmCost(Imm, Ty, CostKind);
  91   }
  92
  93   InstructionCost getArithmeticInstrCost(
  94       unsigned Opcode, Type *Ty, TTI::TargetCostKind CostKind,
  95       TTI::OperandValueInfo Op1Info = {TTI::OK_AnyValue, TTI::OP_None},
  96       TTI::OperandValueInfo Op2Info = {TTI::OK_AnyValue, TTI::OP_None},
  97       ArrayRef<const Value *> Args = std::nullopt,
  98       const Instruction *CxtI = nullptr) {
  99     int ISD = TLI->InstructionOpcodeToISD(Opcode);
 100
 101     switch (ISD) {
 102     default:
 103       return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Op1Info,
 104                                            Op2Info);
 105     case ISD::MUL:
 106     case ISD::SDIV:
 107     case ISD::UDIV:
 108     case ISD::UREM:
 109       // This increases the cost associated with multiplication and division
 110       // to 64 times what the baseline arithmetic cost is. The arithmetic
 111       // instruction cost was arbitrarily chosen to reduce the desirability
 112       // of emitting arithmetic instructions that are emulated in software.
 113       // TODO: Investigate the performance impact given specialized lowerings.
 114       return 64 * BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Op1Info,
 115                                                 Op2Info);
 116     }
 117   }
 118 };
 119
 120 } // end namespace llvm
 121
 122 #endif // LLVM_LIB_TARGET_LANAI_LANAITARGETTRANSFORMINFO_H