1 //===-- RISCVInstructionSelector.cpp -----------------------------*- 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 /// \file
9 /// This file implements the targeting of the InstructionSelector class for
10 /// RISCV.
11 /// \todo This should be generated by TableGen.
12 //===----------------------------------------------------------------------===//
13 
14 #include "RISCVRegisterBankInfo.h"
15 #include "RISCVSubtarget.h"
16 #include "RISCVTargetMachine.h"
17 #include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
18 #include "llvm/CodeGen/GlobalISel/InstructionSelectorImpl.h"
19 #include "llvm/Support/Debug.h"
20 
21 #define DEBUG_TYPE "riscv-isel"
22 
23 using namespace llvm;
24 
25 #define GET_GLOBALISEL_PREDICATE_BITSET
26 #include "RISCVGenGlobalISel.inc"
27 #undef GET_GLOBALISEL_PREDICATE_BITSET
28 
29 namespace {
30 
31 class RISCVInstructionSelector : public InstructionSelector {
32 public:
33   RISCVInstructionSelector(const RISCVTargetMachine &TM,
34                            const RISCVSubtarget &STI,
35                            const RISCVRegisterBankInfo &RBI);
36 
37   bool select(MachineInstr &I) override;
38   static const char *getName() { return DEBUG_TYPE; }
39 
40 private:
41   bool selectImpl(MachineInstr &I, CodeGenCoverage &CoverageInfo) const;
42 
43   const RISCVSubtarget &STI;
44   const RISCVInstrInfo &TII;
45   const RISCVRegisterInfo &TRI;
46   const RISCVRegisterBankInfo &RBI;
47 
48   // FIXME: This is necessary because DAGISel uses "Subtarget->" and GlobalISel
49   // uses "STI." in the code generated by TableGen. We need to unify the name of
50   // Subtarget variable.
51   const RISCVSubtarget *Subtarget = &STI;
52 
53 #define GET_GLOBALISEL_PREDICATES_DECL
54 #include "RISCVGenGlobalISel.inc"
55 #undef GET_GLOBALISEL_PREDICATES_DECL
56 
57 #define GET_GLOBALISEL_TEMPORARIES_DECL
58 #include "RISCVGenGlobalISel.inc"
59 #undef GET_GLOBALISEL_TEMPORARIES_DECL
60 };
61 
62 } // end anonymous namespace
63 
64 #define GET_GLOBALISEL_IMPL
65 #include "RISCVGenGlobalISel.inc"
66 #undef GET_GLOBALISEL_IMPL
67 
68 RISCVInstructionSelector::RISCVInstructionSelector(
69     const RISCVTargetMachine &TM, const RISCVSubtarget &STI,
70     const RISCVRegisterBankInfo &RBI)
71     : InstructionSelector(), STI(STI), TII(*STI.getInstrInfo()),
72       TRI(*STI.getRegisterInfo()), RBI(RBI),
73 
74 #define GET_GLOBALISEL_PREDICATES_INIT
75 #include "RISCVGenGlobalISel.inc"
76 #undef GET_GLOBALISEL_PREDICATES_INIT
77 #define GET_GLOBALISEL_TEMPORARIES_INIT
78 #include "RISCVGenGlobalISel.inc"
79 #undef GET_GLOBALISEL_TEMPORARIES_INIT
80 {
81 }
82 
83 bool RISCVInstructionSelector::select(MachineInstr &I) {
84 
85   if (!isPreISelGenericOpcode(I.getOpcode())) {
86     // Certain non-generic instructions also need some special handling.
87     return true;
88   }
89 
90   if (selectImpl(I, *CoverageInfo))
91     return true;
92 
93   return false;
94 }
95 
96 namespace llvm {
97 InstructionSelector *
98 createRISCVInstructionSelector(const RISCVTargetMachine &TM,
99                                RISCVSubtarget &Subtarget,
100                                RISCVRegisterBankInfo &RBI) {
101   return new RISCVInstructionSelector(TM, Subtarget, RBI);
102 }
103 } // end namespace llvm
104