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     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::OperandValueKind Opd1Info = TTI::OK_AnyValue,
96       TTI::OperandValueKind Opd2Info = TTI::OK_AnyValue,
97       TTI::OperandValueProperties Opd1PropInfo = TTI::OP_None,
98       TTI::OperandValueProperties Opd2PropInfo = TTI::OP_None,
99       ArrayRef<const Value *> Args = ArrayRef<const Value *>(),
100       const Instruction *CxtI = nullptr) {
101     int ISD = TLI->InstructionOpcodeToISD(Opcode);
102 
103     switch (ISD) {
104     default:
105       return BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Opd1Info,
106                                            Opd2Info,
107                                            Opd1PropInfo, Opd2PropInfo);
108     case ISD::MUL:
109     case ISD::SDIV:
110     case ISD::UDIV:
111     case ISD::UREM:
112       // This increases the cost associated with multiplication and division
113       // to 64 times what the baseline arithmetic cost is. The arithmetic
114       // instruction cost was arbitrarily chosen to reduce the desirability
115       // of emitting arithmetic instructions that are emulated in software.
116       // TODO: Investigate the performance impact given specialized lowerings.
117       return 64 * BaseT::getArithmeticInstrCost(Opcode, Ty, CostKind, Opd1Info,
118                                                 Opd2Info,
119                                                 Opd1PropInfo, Opd2PropInfo);
120     }
121   }
122 };
123 
124 } // end namespace llvm
125 
126 #endif // LLVM_LIB_TARGET_LANAI_LANAITARGETTRANSFORMINFO_H
127