MCFixup: Add isRelocation/isRelocRelocation helpers

MaskRay · MaskRay · commit f9bd89b7ac35 · 2025-04-18T18:18:31.000-07:00
Add two helper functions to simplify checks for relocation types,
replacing direct comparisons with FirstRelocationKind and
FirstLiteralRelocationKind. Note: Some targets haven't utilized
isRelocation yet.

Also, update RelaxFixupKind to use 0 as the sentinel value.
diff --git a/llvm/include/llvm/MC/MCAsmBackend.h b/llvm/include/llvm/MC/MCAsmBackend.h
@@ -41,7 +41,7 @@ class raw_ostream;
 /// Generic interface to target specific assembler backends.
 class MCAsmBackend {
 protected: // Can only create subclasses.
-  MCAsmBackend(llvm::endianness Endian, unsigned RelaxFixupKind = MaxFixupKind);
+  MCAsmBackend(llvm::endianness Endian, unsigned RelaxFixupKind = 0);
 
 public:
   MCAsmBackend(const MCAsmBackend &) = delete;
@@ -53,7 +53,7 @@ class MCAsmBackend {
   /// Fixup kind used for linker relaxation. Currently only used by RISC-V
   /// and LoongArch.
   const unsigned RelaxFixupKind;
-  bool allowLinkerRelaxation() const { return RelaxFixupKind != MaxFixupKind; }
+  bool allowLinkerRelaxation() const { return RelaxFixupKind != 0; }
 
   /// Return true if this target might automatically pad instructions and thus
   /// need to emit padding enable/disable directives around sensative code.
diff --git a/llvm/include/llvm/MC/MCFixup.h b/llvm/include/llvm/MC/MCFixup.h
@@ -122,6 +122,21 @@ class MCFixup {
   SMLoc getLoc() const { return Loc; }
 };
 
+namespace mc {
+// Check if the fixup kind is a relocation type. Return false if the fixup can
+// be resolved without a relocation.
+inline bool isRelocation(MCFixupKind FixupKind) {
+  return FixupKind >= FirstRelocationKind;
+}
+
+// Check if the fixup kind represents a relocation type from a .reloc directive.
+// In ELF, this skips STT_SECTION adjustment and STT_TLS symbol type setting for
+// TLS relocations.
+inline bool isRelocRelocation(MCFixupKind FixupKind) {
+  return FixupKind >= FirstLiteralRelocationKind;
+}
+} // namespace mc
+
 } // End llvm namespace
 
 #endif
diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -1385,7 +1385,7 @@ void ELFObjectWriter::recordRelocation(MCAssembler &Asm,
 
   auto EMachine = TargetObjectWriter->getEMachine();
   unsigned Type;
-  if (Fixup.getKind() >= FirstLiteralRelocationKind)
+  if (mc::isRelocRelocation(Fixup.getKind()))
     Type = Fixup.getKind() - FirstLiteralRelocationKind;
   else
     Type = TargetObjectWriter->getRelocType(Ctx, Target, Fixup, IsPCRel);
@@ -1396,7 +1396,7 @@ void ELFObjectWriter::recordRelocation(MCAssembler &Asm,
     UseSectionSym = useSectionSymbol(Asm, Target, SymA, C, Type);
 
     // Disable STT_SECTION adjustment for .reloc directives.
-    UseSectionSym &= Fixup.getKind() < FirstLiteralRelocationKind;
+    UseSectionSym &= !mc::isRelocRelocation(Fixup.getKind());
   }
 
   uint64_t Addend = UseSectionSym ? C + Asm.getSymbolOffset(*SymA) : C;
diff --git a/llvm/lib/MC/MCAsmStreamer.cpp b/llvm/lib/MC/MCAsmStreamer.cpp
@@ -2403,7 +2403,7 @@ void MCAsmStreamer::AddEncodingComment(const MCInst &Inst,
        << "offset: " << F.getOffset() << ", value: ";
     F.getValue()->print(OS, MAI);
     auto Kind = F.getKind();
-    if (FirstRelocationKind <= Kind)
+    if (mc::isRelocation(Kind))
       OS << ", relocation type: " << (Kind - FirstRelocationKind);
     else
       OS << ", kind: "
diff --git a/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp b/llvm/lib/Target/AArch64/MCTargetDesc/AArch64AsmBackend.cpp
@@ -69,7 +69,7 @@ class AArch64AsmBackend : public MCAsmBackend {
 
     // Fixup kinds from raw relocation types and .reloc directives force
     // relocations and do not need these fields.
-    if (Kind >= FirstRelocationKind)
+    if (mc::isRelocation(Kind))
       return MCAsmBackend::getFixupKindInfo(FK_NONE);
 
     if (Kind < FirstTargetFixupKind)
diff --git a/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp b/llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp
@@ -135,7 +135,7 @@ void AMDGPUAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
                                   MutableArrayRef<char> Data, uint64_t Value,
                                   bool IsResolved,
                                   const MCSubtargetInfo *STI) const {
-  if (Fixup.getKind() >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Fixup.getKind()))
     return;
 
   Value = adjustFixupValue(Fixup, Value, &Asm.getContext());
@@ -179,7 +179,7 @@ const MCFixupKindInfo &AMDGPUAsmBackend::getFixupKindInfo(
     { "fixup_si_sopp_br",     0,     16,   MCFixupKindInfo::FKF_IsPCRel },
   };
 
-  if (Kind >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Kind))
     return MCAsmBackend::getFixupKindInfo(FK_NONE);
 
   if (Kind < FirstTargetFixupKind)
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp
@@ -193,7 +193,7 @@ const MCFixupKindInfo &ARMAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
 
   // Fixup kinds from .reloc directive are like R_ARM_NONE. They do not require
   // any extra processing.
-  if (Kind >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Kind))
     return MCAsmBackend::getFixupKindInfo(FK_NONE);
 
   if (Kind < FirstTargetFixupKind)
@@ -1146,8 +1146,8 @@ void ARMAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
                                MutableArrayRef<char> Data, uint64_t Value,
                                bool IsResolved,
                                const MCSubtargetInfo* STI) const {
-  unsigned Kind = Fixup.getKind();
-  if (Kind >= FirstLiteralRelocationKind)
+  auto Kind = Fixup.getKind();
+  if (mc::isRelocation(Kind))
     return;
   MCContext &Ctx = Asm.getContext();
   Value = adjustFixupValue(Asm, Fixup, Target, Value, IsResolved, Ctx, STI);
diff --git a/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp b/llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp
@@ -373,7 +373,7 @@ void AVRAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
                                MutableArrayRef<char> Data, uint64_t Value,
                                bool IsResolved,
                                const MCSubtargetInfo *STI) const {
-  if (Fixup.getKind() >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Fixup.getKind()))
     return;
   adjustFixupValue(Fixup, Target, Value, &Asm.getContext());
   if (Value == 0)
@@ -475,7 +475,7 @@ MCFixupKindInfo const &AVRAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
 
   // Fixup kinds from .reloc directive are like R_AVR_NONE. They do not require
   // any extra processing.
-  if (Kind >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Kind))
     return MCAsmBackend::getFixupKindInfo(FK_NONE);
 
   if (Kind < FirstTargetFixupKind)
diff --git a/llvm/lib/Target/CSKY/MCTargetDesc/CSKYAsmBackend.cpp b/llvm/lib/Target/CSKY/MCTargetDesc/CSKYAsmBackend.cpp
@@ -201,7 +201,7 @@ void CSKYAsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
                                 bool IsResolved,
                                 const MCSubtargetInfo *STI) const {
   MCFixupKind Kind = Fixup.getKind();
-  if (Kind >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Kind))
     return;
   MCContext &Ctx = Asm.getContext();
   MCFixupKindInfo Info = getFixupKindInfo(Kind);
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsAsmBackend.cpp
@@ -527,7 +527,7 @@ getFixupKindInfo(MCFixupKind Kind) const {
   static_assert(std::size(BigEndianInfos) == Mips::NumTargetFixupKinds,
                 "Not all MIPS big endian fixup kinds added!");
 
-  if (Kind >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Kind))
     return MCAsmBackend::getFixupKindInfo(FK_NONE);
   if (Kind < FirstTargetFixupKind)
     return MCAsmBackend::getFixupKindInfo(Kind);
diff --git a/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp b/llvm/lib/Target/PowerPC/MCTargetDesc/PPCAsmBackend.cpp
@@ -120,7 +120,7 @@ class PPCAsmBackend : public MCAsmBackend {
 
     // Fixup kinds from .reloc directive are like R_PPC_NONE/R_PPC64_NONE. They
     // do not require any extra processing.
-    if (Kind >= FirstLiteralRelocationKind)
+    if (mc::isRelocation(Kind))
       return MCAsmBackend::getFixupKindInfo(FK_NONE);
 
     if (Kind < FirstTargetFixupKind)
@@ -138,7 +138,7 @@ class PPCAsmBackend : public MCAsmBackend {
                   uint64_t Value, bool IsResolved,
                   const MCSubtargetInfo *STI) const override {
     MCFixupKind Kind = Fixup.getKind();
-    if (Kind >= FirstLiteralRelocationKind)
+    if (mc::isRelocation(Kind))
       return;
     Value = adjustFixupValue(Kind, Value);
     if (!Value) return;           // Doesn't change encoding.
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVAsmBackend.cpp
@@ -94,9 +94,9 @@ RISCVAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
   static_assert((std::size(Infos)) == RISCV::NumTargetFixupKinds,
                 "Not all fixup kinds added to Infos array");
 
-  // Fixup kinds from raw relocation types and .reloc directive are like
-  // R_RISCV_NONE. They do not require any extra processing.
-  if (Kind >= FirstRelocationKind)
+  // Fixup kinds from raw relocation types and .reloc directives force
+  // relocations and do not use these fields.
+  if (mc::isRelocation(Kind))
     return MCAsmBackend::getFixupKindInfo(FK_NONE);
 
   if (Kind < FirstTargetFixupKind)
diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVELFObjectWriter.cpp
@@ -75,7 +75,7 @@ unsigned RISCVELFObjectWriter::getRelocType(MCContext &Ctx,
 
   // Extract the relocation type from the fixup kind, after applying STT_TLS as
   // needed.
-  if (Kind >= FirstRelocationKind)
+  if (mc::isRelocation(Fixup.getKind()))
     return Kind - FirstRelocationKind;
 
   if (IsPCRel) {
diff --git a/llvm/lib/Target/Sparc/MCTargetDesc/SparcAsmBackend.cpp b/llvm/lib/Target/Sparc/MCTargetDesc/SparcAsmBackend.cpp
@@ -255,7 +255,7 @@ namespace {
 
       // Fixup kinds from .reloc directive are like R_SPARC_NONE. They do
       // not require any extra processing.
-      if (Kind >= FirstLiteralRelocationKind)
+      if (mc::isRelocation(Kind))
         return MCAsmBackend::getFixupKindInfo(FK_NONE);
 
       if (Kind < FirstTargetFixupKind)
@@ -335,7 +335,7 @@ namespace {
                     uint64_t Value, bool IsResolved,
                     const MCSubtargetInfo *STI) const override {
 
-      if (Fixup.getKind() >= FirstLiteralRelocationKind)
+      if (mc::isRelocation(Fixup.getKind()))
         return;
       Value = adjustFixupValue(Fixup.getKind(), Value);
       if (!Value) return;           // Doesn't change encoding.
diff --git a/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp b/llvm/lib/Target/SystemZ/MCTargetDesc/SystemZMCAsmBackend.cpp
@@ -142,7 +142,7 @@ const MCFixupKindInfo &
 SystemZMCAsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
   // Fixup kinds from .reloc directive are like R_390_NONE. They
   // do not require any extra processing.
-  if (Kind >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Kind))
     return MCAsmBackend::getFixupKindInfo(FK_NONE);
 
   if (Kind < FirstTargetFixupKind)
@@ -160,7 +160,7 @@ void SystemZMCAsmBackend::applyFixup(const MCAssembler &Asm,
                                      bool IsResolved,
                                      const MCSubtargetInfo *STI) const {
   MCFixupKind Kind = Fixup.getKind();
-  if (Kind >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Kind))
     return;
   unsigned Offset = Fixup.getOffset();
   unsigned BitSize = getFixupKindInfo(Kind).TargetSize;
diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
@@ -639,7 +639,7 @@ const MCFixupKindInfo &X86AsmBackend::getFixupKindInfo(MCFixupKind Kind) const {
 
   // Fixup kinds from .reloc directive are like R_386_NONE/R_X86_64_NONE. They
   // do not require any extra processing.
-  if (Kind >= FirstLiteralRelocationKind)
+  if (mc::isRelocation(Kind))
     return MCAsmBackend::getFixupKindInfo(FK_NONE);
 
   if (Kind < FirstTargetFixupKind)
@@ -691,8 +691,8 @@ void X86AsmBackend::applyFixup(const MCAssembler &Asm, const MCFixup &Fixup,
                                const MCValue &, MutableArrayRef<char> Data,
                                uint64_t Value, bool IsResolved,
                                const MCSubtargetInfo *STI) const {
-  unsigned Kind = Fixup.getKind();
-  if (Kind >= FirstLiteralRelocationKind)
+  auto Kind = Fixup.getKind();
+  if (mc::isRelocation(Kind))
     return;
   unsigned Size = getFixupKindSize(Kind);
 
