[MC] Make MCAsmBackend::fixupNeedsRelaxation not pure virtual

This hook only needs to be implemented if mayNeedRelaxation may return
true.

Author: MaskRay

llvm/include/llvm/MC/MCAsmBackend.h

@@ -167,7 +167,9 @@ class MCAsmBackend {
   /// Simple predicate for targets where !Resolved implies requiring relaxation
   virtual bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
                                     const MCRelaxableFragment *DF,
-                                    const MCAsmLayout &Layout) const = 0;
+                                    const MCAsmLayout &Layout) const {
+    llvm_unreachable("Needed if mayNeedRelaxation may return true");
+  }
 
   /// Relax the instruction in the given fragment to the next wider instruction.
   ///

llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.h

@@ -49,13 +49,6 @@ class AVRAsmBackend : public MCAsmBackend {
     return AVR::NumTargetFixupKinds;
   }
 
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                            const MCRelaxableFragment *DF,
-                            const MCAsmLayout &Layout) const override {
-    llvm_unreachable("RelaxInstruction() unimplemented");
-    return false;
-  }
-
   bool writeNopData(raw_ostream &OS, uint64_t Count,
                     const MCSubtargetInfo *STI) const override;
 

llvm/lib/Target/BPF/MCTargetDesc/BPFAsmBackend.cpp

@@ -36,13 +36,6 @@ class BPFAsmBackend : public MCAsmBackend {
   std::unique_ptr<MCObjectTargetWriter>
   createObjectTargetWriter() const override;
 
-  // No instruction requires relaxation
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                            const MCRelaxableFragment *DF,
-                            const MCAsmLayout &Layout) const override {
-    return false;
-  }
-
   unsigned getNumFixupKinds() const override {
     return BPF::NumTargetFixupKinds;
   }

llvm/lib/Target/Hexagon/MCTargetDesc/HexagonAsmBackend.cpp

@@ -644,13 +644,6 @@ class HexagonAsmBackend : public MCAsmBackend {
     return false;
   }
 
-  /// Simple predicate for targets where !Resolved implies requiring relaxation
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                            const MCRelaxableFragment *DF,
-                            const MCAsmLayout &Layout) const override {
-    llvm_unreachable("Handled by fixupNeedsRelaxationAdvanced");
-  }
-
   void relaxInstruction(MCInst &Inst,
                         const MCSubtargetInfo &STI) const override {
     assert(HexagonMCInstrInfo::isBundle(Inst) &&

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h

@@ -60,12 +60,6 @@ class LoongArchAsmBackend : public MCAsmBackend {
                              const MCValue &Target,
                              const MCSubtargetInfo *STI) override;
 
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                            const MCRelaxableFragment *DF,
-                            const MCAsmLayout &Layout) const override {
-    return false;
-  }
-
   unsigned getNumFixupKinds() const override {
     return LoongArch::NumTargetFixupKinds;
   }

llvm/lib/Target/MSP430/MCTargetDesc/MSP430AsmBackend.cpp

@@ -47,12 +47,6 @@ class MSP430AsmBackend : public MCAsmBackend {
     return createMSP430ELFObjectWriter(OSABI);
   }
 
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                            const MCRelaxableFragment *DF,
-                            const MCAsmLayout &Layout) const override {
-    return false;
-  }
-
   bool fixupNeedsRelaxationAdvanced(const MCAssembler &Asm,
                                     const MCFixup &Fixup, bool Resolved,
                                     uint64_t Value,

llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.h

@@ -51,19 +51,6 @@ class MipsAsmBackend : public MCAsmBackend {
     return Mips::NumTargetFixupKinds;
   }
 
-  /// @name Target Relaxation Interfaces
-  /// @{
-
-  /// fixupNeedsRelaxation - Target specific predicate for whether a given
-  /// fixup requires the associated instruction to be relaxed.
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                            const MCRelaxableFragment *DF,
-                            const MCAsmLayout &Layout) const override {
-    // FIXME.
-    llvm_unreachable("RelaxInstruction() unimplemented");
-    return false;
-  }
-
   bool writeNopData(raw_ostream &OS, uint64_t Count,
                     const MCSubtargetInfo *STI) const override;
 

llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp

@@ -122,11 +122,6 @@ class SystemZMCAsmBackend : public MCAsmBackend {
                   const MCValue &Target, MutableArrayRef<char> Data,
                   uint64_t Value, bool IsResolved,
                   const MCSubtargetInfo *STI) const override;
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                            const MCRelaxableFragment *Fragment,
-                            const MCAsmLayout &Layout) const override {
-    return false;
-  }
   bool writeNopData(raw_ostream &OS, uint64_t Count,
                     const MCSubtargetInfo *STI) const override;
 };

llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyAsmBackend.cpp

@@ -52,13 +52,6 @@ class WebAssemblyAsmBackend final : public MCAsmBackend {
   std::unique_ptr<MCObjectTargetWriter>
   createObjectTargetWriter() const override;
 
-  // No instruction requires relaxation
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                            const MCRelaxableFragment *DF,
-                            const MCAsmLayout &Layout) const override {
-    return false;
-  }
-
   bool writeNopData(raw_ostream &OS, uint64_t Count,
                     const MCSubtargetInfo *STI) const override;
 };

llvm/lib/Target/Xtensa/MCTargetDesc/XtensaAsmBackend.cpp

@@ -43,9 +43,6 @@ class XtensaMCAsmBackend : public MCAsmBackend {
                   const MCSubtargetInfo *STI) const override;
   bool mayNeedRelaxation(const MCInst &Inst,
                          const MCSubtargetInfo &STI) const override;
-  bool fixupNeedsRelaxation(const MCFixup &Fixup, uint64_t Value,
-                            const MCRelaxableFragment *Fragment,
-                            const MCAsmLayout &Layout) const override;
   void relaxInstruction(MCInst &Inst,
                         const MCSubtargetInfo &STI) const override;
   bool writeNopData(raw_ostream &OS, uint64_t Count,
@@ -172,12 +169,6 @@ bool XtensaMCAsmBackend::mayNeedRelaxation(const MCInst &Inst,
   return false;
 }
 
-bool XtensaMCAsmBackend::fixupNeedsRelaxation(
-    const MCFixup &Fixup, uint64_t Value, const MCRelaxableFragment *Fragment,
-    const MCAsmLayout &Layout) const {
-  return false;
-}
-
 void XtensaMCAsmBackend::relaxInstruction(MCInst &Inst,
                                           const MCSubtargetInfo &STI) const {}