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/Compiler.h" 34#include "llvm/Support/Format.h" 35#include "llvm/Support/Printable.h" 36#include "llvm/Support/raw_ostream.h" 37 38namespace llvm { 39 40 struct LaneBitmask { 41 // When changing the underlying type, change the format string as well. 42 using Type = unsigned; 43 enum : unsigned { BitWidth = 8*sizeof(Type) }; 44 constexpr static const char *const FormatStr = "%08X"; 45 46 constexpr LaneBitmask() = default; 47 explicit constexpr LaneBitmask(Type V) : Mask(V) {} 48 49 constexpr bool operator== (LaneBitmask M) const { return Mask == M.Mask; } 50 constexpr bool operator!= (LaneBitmask M) const { return Mask != M.Mask; } 51 constexpr bool operator< (LaneBitmask M) const { return Mask < M.Mask; } 52 constexpr bool none() const { return Mask == 0; } 53 constexpr bool any() const { return Mask != 0; } 54 constexpr bool all() const { return ~Mask == 0; } 55 56 constexpr LaneBitmask operator~() const { 57 return LaneBitmask(~Mask); 58 } 59 constexpr LaneBitmask operator|(LaneBitmask M) const { 60 return LaneBitmask(Mask | M.Mask); 61 } 62 constexpr LaneBitmask operator&(LaneBitmask M) const { 63 return LaneBitmask(Mask & M.Mask); 64 } 65 LaneBitmask &operator|=(LaneBitmask M) { 66 Mask |= M.Mask; 67 return *this; 68 } 69 LaneBitmask &operator&=(LaneBitmask M) { 70 Mask &= M.Mask; 71 return *this; 72 } 73 74 constexpr Type getAsInteger() const { return Mask; } 75 76 unsigned getNumLanes() const { 77 return countPopulation(Mask); 78 } 79 unsigned getHighestLane() const { 80 return Log2_32(Mask); 81 } 82 83 static LaneBitmask getNone() { return LaneBitmask(0); } 84 static LaneBitmask getAll() { return ~LaneBitmask(0); } 85 static LaneBitmask getLane(unsigned Lane) { 86 return LaneBitmask(Type(1) << Lane); 87 } 88 89 private: 90 Type Mask = 0; 91 }; 92 93 /// Create Printable object to print LaneBitmasks on a \ref raw_ostream. 94 static LLVM_ATTRIBUTE_UNUSED Printable PrintLaneMask(LaneBitmask LaneMask) { 95 return Printable([LaneMask](raw_ostream &OS) { 96 OS << format(LaneBitmask::FormatStr, LaneMask.getAsInteger()); 97 }); 98 } 99 100} // end namespace llvm 101 102#endif // LLVM_MC_LANEBITMASK_H 103