lib/Target/ARM/MCTargetDesc/ARMAsmBackend.h

   1 //===-- ARMAsmBackend.h - ARM Assembler Backend -----------------*- 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 #ifndef LLVM_LIB_TARGET_ARM_ARMASMBACKEND_H
  10 #define LLVM_LIB_TARGET_ARM_ARMASMBACKEND_H
  11
  12 #include "MCTargetDesc/ARMFixupKinds.h"
  13 #include "MCTargetDesc/ARMMCTargetDesc.h"
  14 #include "llvm/MC/MCAsmBackend.h"
  15 #include "llvm/MC/MCSubtargetInfo.h"
  16 #include "llvm/Support/TargetRegistry.h"
  17
  18 namespace llvm {
  19
  20 class ARMAsmBackend : public MCAsmBackend {
  21   // The STI from the target triple the MCAsmBackend was instantiated with
  22   // note that MCFragments may have a different local STI that should be
  23   // used in preference.
  24   const MCSubtargetInfo &STI;
  25   bool isThumbMode;    // Currently emitting Thumb code.
  26 public:
  27   ARMAsmBackend(const Target &T, const MCSubtargetInfo &STI,
  28                 support::endianness Endian)
  29       : MCAsmBackend(Endian), STI(STI),
  30         isThumbMode(STI.getTargetTriple().isThumb()) {}
  31
  32   unsigned getNumFixupKinds() const override {
  33     return ARM::NumTargetFixupKinds;
  34   }
  35
  36   // FIXME: this should be calculated per fragment as the STI may be
  37   // different.
  38   bool hasNOP() const { return STI.getFeatureBits()[ARM::HasV6T2Ops]; }
  39
  40   Optional<MCFixupKind> getFixupKind(StringRef Name) const override;
  41
  42   const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const override;
  43
  44   bool shouldForceRelocation(const MCAssembler &Asm, const MCFixup &Fixup,
  45                              const MCValue &Target) override;
  46
  47   unsigned adjustFixupValue(const MCAssembler &Asm, const MCFixup &Fixup,
  48                             const MCValue &Target, uint64_t Value,
  49                             bool IsResolved, MCContext &Ctx,
  50                             const MCSubtargetInfo *STI) const;
  51
  52   void applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
  53                   const MCValue &Target, MutableArrayRef<char> Data,
  54                   uint64_t Value, bool IsResolved,
  55                   const MCSubtargetInfo *STI) const override;
  56
  57   unsigned getRelaxedOpcode(unsigned Op, const MCSubtargetInfo &STI) const;
  58
  59   bool mayNeedRelaxation(const MCInst &Inst,
  60                          const MCSubtargetInfo &STI) const override;
  61
  62   const char *reasonForFixupRelaxation(const MCFixup &Fixup,
  63                                        uint64_t Value) const;
  64
  65   bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
  66                             const MCRelaxableFragment *DF,
  67                             const MCAsmLayout &Layout) const override;
  68
  69   void relaxInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
  70                         MCInst &Res) const override;
  71
  72   bool writeNopData(raw_ostream &OS, uint64_t Count) const override;
  73
  74   void handleAssemblerFlag(MCAssemblerFlag Flag) override;
  75
  76   unsigned getPointerSize() const { return 4; }
  77   bool isThumb() const { return isThumbMode; }
  78   void setIsThumb(bool it) { isThumbMode = it; }
  79 };
  80 } // end namespace llvm
  81
  82 #endif