include/llvm/CodeGen/Register.h

   1 //===-- llvm/CodeGen/Register.h ---------------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #ifndef LLVM_CODEGEN_REGISTER_H
  10 #define LLVM_CODEGEN_REGISTER_H
  11
  12 #include <cassert>
  13
  14 namespace llvm {
  15
  16 /// Wrapper class representing virtual and physical registers. Should be passed
  17 /// by value.
  18 class Register {
  19   unsigned Reg;
  20
  21 public:
  22   Register(unsigned Val = 0): Reg(Val) {}
  23
  24   /// Return true if the specified register number is in the virtual register
  25   /// namespace.
  26   bool isVirtual() const {
  27     return int(Reg) < 0;
  28   }
  29
  30   /// Return true if the specified register number is in the physical register
  31   /// namespace.
  32   bool isPhysical() const {
  33     return int(Reg) > 0;
  34   }
  35
  36   /// Convert a virtual register number to a 0-based index. The first virtual
  37   /// register in a function will get the index 0.
  38   unsigned virtRegIndex() const {
  39     assert(isVirtual() && "Not a virtual register");
  40     return Reg & ~(1u << 31);
  41   }
  42
  43   /// Convert a 0-based index to a virtual register number.
  44   /// This is the inverse operation of VirtReg2IndexFunctor below.
  45   static Register index2VirtReg(unsigned Index) {
  46     return Register(Index | (1u << 31));
  47   }
  48
  49   operator unsigned() const {
  50     return Reg;
  51   }
  52
  53   bool isValid() const {
  54     return Reg != 0;
  55   }
  56 };
  57
  58 }
  59
  60 #endif