[lld/mac] Simplify encodeDylibOrdinal() a bit

[thakis]

Summary

Only one of the two callers used the lastBinding parameter, so
do that work at that one call site. Extract a ordinalForDylibSymbol()
helper to make this tidy.

No behavior change.

[int3]

Nice :)

lld/MachO/SyntheticSections.cpp

static void encodeBinding(const Symbol *sym, const OutputSection *osec,
   os << flags << sym->getName() << '\0'
      << static_cast<uint8_t>(BIND_OPCODE_SET_TYPE_IMM | BIND_TYPE_POINTER)
      << static_cast<uint8_t>(BIND_OPCODE_DO_BIND);
   // DO_BIND causes dyld to both perform the binding and increment the offset
   lastBinding.offset += WordSize;
 }
 
 // Non-weak bindings need to have their dylib ordinal encoded as well.
-static void encodeDylibOrdinal(const DylibSymbol *dysym, Binding *lastBinding,
-                               raw_svector_ostream &os) {
-  using namespace llvm::MachO;
-
-  int16_t ordinal = dysym->isDynamicLookup() ? BIND_SPECIAL_DYLIB_FLAT_LOOKUP
-                                             : dysym->getFile()->ordinal;
+static int16_t ordinalForDylibSymbol(const DylibSymbol &dysym) {
+  return dysym.isDynamicLookup() ? MachO::BIND_SPECIAL_DYLIB_FLAT_LOOKUP
+                                 : dysym.getFile()->ordinal;
+}
 
-  if (lastBinding == nullptr ||
-      lastBinding->ordinal != ordinal) {
-    if (ordinal <= 0) {
-      os << static_cast<uint8_t>(
-          BIND_OPCODE_SET_DYLIB_SPECIAL_IMM |
+static void encodeDylibOrdinal(int16_t ordinal, raw_svector_ostream &os) {
+  using namespace llvm::MachO;
+    os << static_cast<uint8_t>(BIND_OPCODE_SET_DYLIB_SPECIAL_IMM |
                                (ordinal & BIND_IMMEDIATE_MASK));
-    } else if (ordinal <= BIND_IMMEDIATE_MASK) {
-      os << static_cast<uint8_t>(BIND_OPCODE_SET_DYLIB_ORDINAL_IMM |
-                                 ordinal);
-    } else {
-      os << static_cast<uint8_t>(BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB);
-      encodeULEB128(ordinal, os);
-    }
-    if (lastBinding != nullptr)
-      lastBinding->ordinal = ordinal;
-  }
+    os << static_cast<uint8_t>(BIND_OPCODE_SET_DYLIB_ORDINAL_IMM | ordinal);
 }
 
 static void encodeWeakOverride(const Defined *defined,
                                raw_svector_ostream &os) {
   using namespace llvm::MachO;
   os << static_cast<uint8_t>(BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM |
                              BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION)
      << defined->getName() << '\0';
void BindingSection::finalizeContents() {
 
   // Since bindings are delta-encoded, sorting them allows for a more compact
   // result. Note that sorting by address alone ensures that bindings for the
   // same segment / section are located together.
   llvm::sort(bindings, [](const BindingEntry &a, const BindingEntry &b) {
     return a.target.getVA() < b.target.getVA();
   });
   for (const BindingEntry &b : bindings) {
-    encodeDylibOrdinal(b.dysym, &lastBinding, os);
+    int16_t ordinal = ordinalForDylibSymbol(*b.dysym);
+    if (ordinal != lastBinding.ordinal) {
+      encodeDylibOrdinal(ordinal, os);
+      lastBinding.ordinal = ordinal;
+    }
     if (auto *isec = b.target.section.dyn_cast<const InputSection *>()) {
       encodeBinding(b.dysym, isec->parent, isec->outSecOff + b.target.offset,
                     b.addend, /*isWeakBinding=*/false, lastBinding, os);
     } else {
       auto *osec = b.target.section.get<const OutputSection *>();
       encodeBinding(b.dysym, osec, b.target.offset, b.addend,
                     /*isWeakBinding=*/false, lastBinding, os);
     }

 uint32_t LazyBindingSection::encode(const DylibSymbol &sym) {
   uint32_t opstreamOffset = contents.size();
   OutputSegment *dataSeg = in.lazyPointers->parent;
   os << static_cast<uint8_t>(MachO::BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB |
                              dataSeg->index);
   uint64_t offset = in.lazyPointers->addr - dataSeg->firstSection()->addr +
                     sym.stubsIndex * WordSize;
   encodeULEB128(offset, os);
-  encodeDylibOrdinal(&sym, nullptr, os);
+  encodeDylibOrdinal(ordinalForDylibSymbol(sym), os);
 
   uint8_t flags = MachO::BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM;
   if (sym.isWeakRef())
     flags |= MachO::BIND_SYMBOL_FLAGS_WEAK_IMPORT;
 
   os << flags << sym.getName() << '\0'
      << static_cast<uint8_t>(MachO::BIND_OPCODE_DO_BIND)
      << static_cast<uint8_t>(MachO::BIND_OPCODE_DONE);