[llvm] [TableGen] Emit OpName as an enum class instead of a namespace (PR #125313)

[Craig Topper via llvm-commits]

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@@ -282,20 +282,23 @@ void InstrInfoEmitter::emitOperandNameMappings(
 
   OS << "#ifdef GET_INSTRINFO_OPERAND_ENUM\n";
   OS << "#undef GET_INSTRINFO_OPERAND_ENUM\n";
-  OS << "namespace llvm::" << Namespace << "::OpName {\n";
-  OS << "enum {\n";
+  OS << "namespace llvm::" << Namespace << " {\n";
+  OS << "enum class OpName {\n";
   for (const auto &[I, Op] : enumerate(OperandNameToID))
     OS << "  " << Op.first << " = " << I << ",\n";
-  OS << "  OPERAND_LAST = " << NumOperandNames << ",\n";
-  OS << "};\n";
-  OS << "} // end namespace llvm::" << Namespace << "::OpName\n";
+  OS << "  NUM_OPERAND_NAMES = " << NumOperandNames << ",\n";
+  OS << "}; // enum class OpName\n\n";
+  OS << "LLVM_READONLY\n";
+  OS << "int16_t getNamedOperandIdx(uint16_t Opcode, OpName NamedIdx);\n";
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topperc wrote:

`NamedIdx` is called `Name` when we emit the definition on line 300.

https://github.com/llvm/llvm-project/pull/125313