llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.h

   1 //===-- RISCVAsmBackend.h - RISC-V Assembler Backend ----------------------===//
   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 #ifndef LLVM_LIB_TARGET_RISCV_MCTARGETDESC_RISCVASMBACKEND_H
  10 #define LLVM_LIB_TARGET_RISCV_MCTARGETDESC_RISCVASMBACKEND_H
  11
  12 #include "MCTargetDesc/RISCVBaseInfo.h"
  13 #include "MCTargetDesc/RISCVFixupKinds.h"
  14 #include "MCTargetDesc/RISCVMCTargetDesc.h"
  15 #include "llvm/MC/MCAsmBackend.h"
  16 #include "llvm/MC/MCFixupKindInfo.h"
  17 #include "llvm/MC/MCSubtargetInfo.h"
  18
  19 namespace llvm {
  20 class MCAssembler;
  21 class MCObjectTargetWriter;
  22 class raw_ostream;
  23
  24 class RISCVAsmBackend : public MCAsmBackend {
  25   const MCSubtargetInfo &STI;
  26   uint8_t OSABI;
  27   bool Is64Bit;
  28   bool ForceRelocs = false;
  29   const MCTargetOptions &TargetOptions;
  30
  31 public:
  32   RISCVAsmBackend(const MCSubtargetInfo &STI, uint8_t OSABI, bool Is64Bit,
  33                   const MCTargetOptions &Options)
  34       : MCAsmBackend(llvm::endianness::little, RISCV::fixup_riscv_relax),
  35         STI(STI), OSABI(OSABI), Is64Bit(Is64Bit), TargetOptions(Options) {
  36     RISCVFeatures::validate(STI.getTargetTriple(), STI.getFeatureBits());
  37   }
  38   ~RISCVAsmBackend() override = default;
  39
  40   void setForceRelocs() { ForceRelocs = true; }
  41
  42   // Return Size with extra Nop Bytes for alignment directive in code section.
  43   bool shouldInsertExtraNopBytesForCodeAlign(const MCAlignFragment &AF,
  44                                              unsigned &Size) override;
  45
  46   // Insert target specific fixup type for alignment directive in code section.
  47   bool shouldInsertFixupForCodeAlign(MCAssembler &Asm,
  48                                      const MCAsmLayout &Layout,
  49                                      MCAlignFragment &AF) override;
  50
  51   bool evaluateTargetFixup(const MCAssembler &Asm, const MCAsmLayout &Layout,
  52                            const MCFixup &Fixup, const MCFragment *DF,
  53                            const MCValue &Target, uint64_t &Value,
  54                            bool &WasForced) override;
  55
  56   bool handleAddSubRelocations(const MCAsmLayout &Layout, const MCFragment &F,
  57                                const MCFixup &Fixup, const MCValue &Target,
  58                                uint64_t &FixedValue) const override;
  59
  60   void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
  61                   const MCValue &Target, MutableArrayRef<char> Data,
  62                   uint64_t Value, bool IsResolved,
  63                   const MCSubtargetInfo *STI) const override;
  64
  65   std::unique_ptr<MCObjectTargetWriter>
  66   createObjectTargetWriter() const override;
  67
  68   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
  69                              const MCValue &Target) override;
  70
  71   bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
  72                             const MCRelaxableFragment *DF,
  73                             const MCAsmLayout &Layout) const override {
  74     llvm_unreachable("Handled by fixupNeedsRelaxationAdvanced");
  75   }
  76
  77   bool fixupNeedsRelaxationAdvanced(const MCFixup &Fixup, bool Resolved,
  78                                     uint64_t Value,
  79                                     const MCRelaxableFragment *DF,
  80                                     const MCAsmLayout &Layout,
  81                                     const bool WasForced) const override;
  82
  83   unsigned getNumFixupKinds() const override {
  84     return RISCV::NumTargetFixupKinds;
  85   }
  86
  87   std::optional<MCFixupKind> getFixupKind(StringRef Name) const override;
  88
  89   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
  90
  91   bool mayNeedRelaxation(const MCInst &Inst,
  92                          const MCSubtargetInfo &STI) const override;
  93   unsigned getRelaxedOpcode(unsigned Op) const;
  94
  95   void relaxInstruction(MCInst &Inst,
  96                         const MCSubtargetInfo &STI) const override;
  97
  98   bool relaxDwarfLineAddr(MCDwarfLineAddrFragment &DF, MCAsmLayout &Layout,
  99                           bool &WasRelaxed) const override;
 100   bool relaxDwarfCFA(MCDwarfCallFrameFragment &DF, MCAsmLayout &Layout,
 101                      bool &WasRelaxed) const override;
 102
 103   bool writeNopData(raw_ostream &OS, uint64_t Count,
 104                     const MCSubtargetInfo *STI) const override;
 105
 106   const MCTargetOptions &getTargetOptions() const { return TargetOptions; }
 107 };
 108 }
 109
 110 #endif