From b923d2f5f5958719214472906e9810de262ab447 Mon Sep 17 00:00:00 2001
From: Ahmed Bougacha <ahmed.bougacha@gmail.com>
Date: Sun, 17 Nov 2013 21:24:41 +0000
Subject: [PATCH] TableGen: Generate an enum for all named Operand types in
 tblgen'd InstrInfo.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194978 91177308-0d34-0410-b5e6-96231b3b80d8
---
 docs/WritingAnLLVMBackend.rst       | 44 +++++++++++++++++++++++++++++
 utils/TableGen/InstrInfoEmitter.cpp | 31 ++++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/docs/WritingAnLLVMBackend.rst b/docs/WritingAnLLVMBackend.rst
index 5dd55d08adc..35c853e5ed0 100644
--- a/docs/WritingAnLLVMBackend.rst
+++ b/docs/WritingAnLLVMBackend.rst
@@ -955,6 +955,50 @@ XXXInstrInfo.h:
     int16_t getNamedOperandIdx(uint16_t Opcode, uint16_t NamedIndex);
   } // End namespace XXX
 
+Instruction Operand Types
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+TableGen will also generate an enumeration consisting of all named Operand
+types defined in the backend, in the llvm::XXX::OpTypes namespace.
+Some common immediate Operand types (for instance i8, i32, i64, f32, f64)
+are defined for all targets in ``include/llvm/Target/Target.td``, and are
+available in each Target's OpTypes enum.  Also, only named Operand types appear
+in the enumeration: anonymous types are ignored.
+For example, the X86 backend defines ``brtarget`` and ``brtarget8``, both
+instances of the TableGen ``Operand`` class, which represent branch target
+operands:
+
+.. code-block:: llvm
+
+  def brtarget : Operand<OtherVT>;
+  def brtarget8 : Operand<OtherVT>;
+
+This results in:
+
+.. code-block:: c++
+  namespace X86 {
+  namespace OpTypes {
+  enum OperandType {
+    ...
+    brtarget,
+    brtarget8,
+    ...
+    i32imm,
+    i64imm,
+    ...
+    OPERAND_TYPE_LIST_END
+  } // End namespace OpTypes
+  } // End namespace X86
+
+In typical TableGen fashion, to use the enum, you will need to define a
+preprocessor macro:
+
+.. code-block:: c++
+
+  #define GET_INSTRINFO_OPERAND_TYPES_ENUM // For OpTypes enum
+  #include "XXXGenInstrInfo.inc"
+
+
 Instruction Scheduling
 ----------------------
 
diff --git a/utils/TableGen/InstrInfoEmitter.cpp b/utils/TableGen/InstrInfoEmitter.cpp
index 9e0b74e793c..d3d9cc1fd62 100644
--- a/utils/TableGen/InstrInfoEmitter.cpp
+++ b/utils/TableGen/InstrInfoEmitter.cpp
@@ -57,6 +57,7 @@ private:
                   std::map<std::vector<Record*>, unsigned> &EL,
                   const OperandInfoMapTy &OpInfo,
                   raw_ostream &OS);
+  void emitOperandTypesEnum(raw_ostream &OS, const CodeGenTarget &Target);
   void initOperandMapData(
              const std::vector<const CodeGenInstruction *> NumberedInstructions,
              const std::string &Namespace,
@@ -311,6 +312,34 @@ void InstrInfoEmitter::emitOperandNameMappings(raw_ostream &OS,
 
 }
 
+/// Generate an enum for all the operand types for this target, under the
+/// llvm::TargetNamespace::OpTypes namespace.
+/// Operand types are all definitions derived of the Operand Target.td class.
+void InstrInfoEmitter::emitOperandTypesEnum(raw_ostream &OS,
+                                            const CodeGenTarget &Target) {
+
+  const std::string &Namespace = Target.getInstNamespace();
+  std::vector<Record *> Operands = Records.getAllDerivedDefinitions("Operand");
+
+  OS << "\n#ifdef GET_INSTRINFO_OPERAND_TYPES_ENUM\n";
+  OS << "#undef GET_INSTRINFO_OPERAND_TYPES_ENUM\n";
+  OS << "namespace llvm {";
+  OS << "namespace " << Namespace << " {\n";
+  OS << "namespace OpTypes { \n";
+  OS << "enum OperandType {\n";
+
+  for (unsigned oi = 0, oe = Operands.size(); oi != oe; ++oi) {
+    if (!Operands[oi]->isAnonymous())
+      OS << "  " << Operands[oi]->getName() << " = " << oi << ",\n";
+  }
+
+  OS << "  OPERAND_TYPE_LIST_END" << "\n};\n";
+  OS << "} // End namespace OpTypes\n";
+  OS << "} // End namespace " << Namespace << "\n";
+  OS << "} // End namespace llvm\n";
+  OS << "#endif // GET_INSTRINFO_OPERAND_TYPES_ENUM\n";
+}
+
 //===----------------------------------------------------------------------===//
 // Main Output.
 //===----------------------------------------------------------------------===//
@@ -432,6 +461,8 @@ void InstrInfoEmitter::run(raw_ostream &OS) {
   OS << "#endif // GET_INSTRINFO_CTOR_DTOR\n\n";
 
   emitOperandNameMappings(OS, Target, NumberedInstructions);
+
+  emitOperandTypesEnum(OS, Target);
 }
 
 void InstrInfoEmitter::emitRecord(const CodeGenInstruction &Inst, unsigned Num,