Add MCInstBuilder, a utility class to simplify MCInst creation similar to MachineInstrBuilder.

Simplify some repetitive code with it. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168587 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCInstBuilder.h

@@ -0,0 +1,70 @@
+//===-- llvm/MC/MCInstBuilder.h - Simplify creation of MCInsts --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the MCInstBuilder class for convenient creation of
+// MCInsts.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_MC_MCINSTBUILDER_H
+#define LLVM_MC_MCINSTBUILDER_H
+
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCStreamer.h"
+
+namespace llvm {
+
+class MCInstBuilder {
+  MCInst Inst;
+
+public:
+  /// \brief Create a new MCInstBuilder for an MCInst with a specific opcode.
+  MCInstBuilder(unsigned Opcode) {
+    Inst.setOpcode(Opcode);
+  }
+
+  /// \brief Add a new register operand.
+  MCInstBuilder &addReg(unsigned Reg) {
+    Inst.addOperand(MCOperand::CreateReg(Reg));
+    return *this;
+  }
+
+  /// \brief Add a new integer immediate operand.
+  MCInstBuilder &addImm(int64_t Val) {
+    Inst.addOperand(MCOperand::CreateImm(Val));
+    return *this;
+  }
+
+  /// \brief Add a new floating point immediate operand.
+  MCInstBuilder &addFPImm(double Val) {
+    Inst.addOperand(MCOperand::CreateFPImm(Val));
+    return *this;
+  }
+
+  /// \brief Add a new MCExpr operand.
+  MCInstBuilder &addExpr(const MCExpr *Val) {
+    Inst.addOperand(MCOperand::CreateExpr(Val));
+    return *this;
+  }
+
+  /// \brief Add a new MCInst operand.
+  MCInstBuilder &addInst(const MCInst *Val) {
+    Inst.addOperand(MCOperand::CreateInst(Val));
+    return *this;
+  }
+
+  /// \brief Emit the built instruction to an MCStreamer.
+  void emit(MCStreamer &OutStreamer) {
+    OutStreamer.EmitInstruction(Inst);
+  }
+};
+
+} // end namespace llvm
+
+#endif