1 //===- llvm/MC/LaneBitmask.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 /// \file 10 /// A common definition of LaneBitmask for use in TableGen and CodeGen. 11 /// 12 /// A lane mask is a bitmask representing the covering of a register with 13 /// sub-registers. 14 /// 15 /// This is typically used to track liveness at sub-register granularity. 16 /// Lane masks for sub-register indices are similar to register units for 17 /// physical registers. The individual bits in a lane mask can't be assigned 18 /// any specific meaning. They can be used to check if two sub-register 19 /// indices overlap. 20 /// 21 /// Iff the target has a register such that: 22 /// 23 /// getSubReg(Reg, A) overlaps getSubReg(Reg, B) 24 /// 25 /// then: 26 /// 27 /// (getSubRegIndexLaneMask(A) & getSubRegIndexLaneMask(B)) != 0 28 29 #ifndef LLVM_MC_LANEBITMASK_H 30 #define LLVM_MC_LANEBITMASK_H 31 32 #include "llvm/Support/Compiler.h" 33 #include "llvm/Support/Format.h" 34 #include "llvm/Support/Printable.h" 35 #include "llvm/Support/raw_ostream.h" 36 37 namespace llvm { 38 39 struct LaneBitmask { 40 // When changing the underlying type, change the format string as well. 41 using Type = unsigned; 42 enum : unsigned { BitWidth = 8*sizeof(Type) }; 43 constexpr static const char *const FormatStr = "%08X"; 44 45 constexpr LaneBitmask() = default; LaneBitmaskLaneBitmask46 explicit constexpr LaneBitmask(Type V) : Mask(V) {} 47 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 operator< (LaneBitmask M) const { return Mask < M.Mask; } noneLaneBitmask51 constexpr bool none() const { return Mask == 0; } anyLaneBitmask52 constexpr bool any() const { return Mask != 0; } allLaneBitmask53 constexpr bool all() const { return ~Mask == 0; } 54 55 constexpr LaneBitmask operator~() const { 56 return LaneBitmask(~Mask); 57 } 58 constexpr LaneBitmask operator|(LaneBitmask M) const { 59 return LaneBitmask(Mask | M.Mask); 60 } 61 constexpr LaneBitmask operator&(LaneBitmask M) const { 62 return LaneBitmask(Mask & M.Mask); 63 } 64 LaneBitmask &operator|=(LaneBitmask M) { 65 Mask |= M.Mask; 66 return *this; 67 } 68 LaneBitmask &operator&=(LaneBitmask M) { 69 Mask &= M.Mask; 70 return *this; 71 } 72 getAsIntegerLaneBitmask73 constexpr Type getAsInteger() const { return Mask; } 74 getNumLanesLaneBitmask75 unsigned getNumLanes() const { 76 return countPopulation(Mask); 77 } getHighestLaneLaneBitmask78 unsigned getHighestLane() const { 79 return Log2_32(Mask); 80 } 81 getNoneLaneBitmask82 static constexpr LaneBitmask getNone() { return LaneBitmask(0); } getAllLaneBitmask83 static constexpr LaneBitmask getAll() { return ~LaneBitmask(0); } getLaneLaneBitmask84 static constexpr LaneBitmask getLane(unsigned Lane) { 85 return LaneBitmask(Type(1) << Lane); 86 } 87 88 private: 89 Type Mask = 0; 90 }; 91 92 /// Create Printable object to print LaneBitmasks on a \ref raw_ostream. PrintLaneMask(LaneBitmask LaneMask)93 inline Printable PrintLaneMask(LaneBitmask LaneMask) { 94 return Printable([LaneMask](raw_ostream &OS) { 95 OS << format(LaneBitmask::FormatStr, LaneMask.getAsInteger()); 96 }); 97 } 98 99 } // end namespace llvm 100 101 #endif // LLVM_MC_LANEBITMASK_H 102