LaneBitmask.h revision 314564
1//===-- llvm/MC/LaneBitmask.h -----------------------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9/// 10/// \file 11/// A common definition of LaneBitmask for use in TableGen and CodeGen. 12/// 13/// A lane mask is a bitmask representing the covering of a register with 14/// sub-registers. 15/// 16/// This is typically used to track liveness at sub-register granularity. 17/// Lane masks for sub-register indices are similar to register units for 18/// physical registers. The individual bits in a lane mask can't be assigned 19/// any specific meaning. They can be used to check if two sub-register 20/// indices overlap. 21/// 22/// Iff the target has a register such that: 23/// 24/// getSubReg(Reg, A) overlaps getSubReg(Reg, B) 25/// 26/// then: 27/// 28/// (getSubRegIndexLaneMask(A) & getSubRegIndexLaneMask(B)) != 0 29 30#ifndef LLVM_MC_LANEBITMASK_H 31#define LLVM_MC_LANEBITMASK_H 32 33#include "llvm/Support/Format.h" 34#include "llvm/Support/Printable.h" 35#include "llvm/Support/raw_ostream.h" 36 37namespace llvm { 38 struct LaneBitmask { 39 // When changing the underlying type, change the format string as well. 40 typedef unsigned Type; 41 enum : unsigned { BitWidth = 8*sizeof(Type) }; 42 constexpr static const char *const FormatStr = "%08X"; 43 44 constexpr LaneBitmask() = default; 45 explicit constexpr LaneBitmask(Type V) : Mask(V) {} 46 47 constexpr bool operator== (LaneBitmask M) const { return Mask == M.Mask; } 48 constexpr bool operator!= (LaneBitmask M) const { return Mask != M.Mask; } 49 constexpr bool operator< (LaneBitmask M) const { return Mask < M.Mask; } 50 constexpr bool none() const { return Mask == 0; } 51 constexpr bool any() const { return Mask != 0; } 52 constexpr bool all() const { return ~Mask == 0; } 53 54 constexpr LaneBitmask operator~() const { 55 return LaneBitmask(~Mask); 56 } 57 constexpr LaneBitmask operator|(LaneBitmask M) const { 58 return LaneBitmask(Mask | M.Mask); 59 } 60 constexpr LaneBitmask operator&(LaneBitmask M) const { 61 return LaneBitmask(Mask & M.Mask); 62 } 63 LaneBitmask &operator|=(LaneBitmask M) { 64 Mask |= M.Mask; 65 return *this; 66 } 67 LaneBitmask &operator&=(LaneBitmask M) { 68 Mask &= M.Mask; 69 return *this; 70 } 71 72 constexpr Type getAsInteger() const { return Mask; } 73 74 static LaneBitmask getNone() { return LaneBitmask(0); } 75 static LaneBitmask getAll() { return ~LaneBitmask(0); } 76 77 private: 78 Type Mask = 0; 79 }; 80 81 /// Create Printable object to print LaneBitmasks on a \ref raw_ostream. 82 static LLVM_ATTRIBUTE_UNUSED Printable PrintLaneMask(LaneBitmask LaneMask) { 83 return Printable([LaneMask](raw_ostream &OS) { 84 OS << format(LaneBitmask::FormatStr, LaneMask.getAsInteger()); 85 }); 86 } 87} 88 89#endif // LLVM_MC_LANEBITMASK_H 90