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 38 namespace 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; LaneBitmaskLaneBitmask47 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; } noneLaneBitmask52 constexpr bool none() const { return Mask == 0; } anyLaneBitmask53 constexpr bool any() const { return Mask != 0; } allLaneBitmask54 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 getAsIntegerLaneBitmask74 constexpr Type getAsInteger() const { return Mask; } 75 getNumLanesLaneBitmask76 unsigned getNumLanes() const { 77 return countPopulation(Mask); 78 } getHighestLaneLaneBitmask79 unsigned getHighestLane() const { 80 return Log2_32(Mask); 81 } 82 getNoneLaneBitmask83 static constexpr LaneBitmask getNone() { return LaneBitmask(0); } getAllLaneBitmask84 static constexpr LaneBitmask getAll() { return ~LaneBitmask(0); } getLaneLaneBitmask85 static constexpr 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. PrintLaneMask(LaneBitmask LaneMask)94 inline 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