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/MathExtras.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 = uint64_t; |
43 | enum : unsigned { BitWidth = 8*sizeof(Type) }; |
44 | constexpr static const char *const FormatStr = "%016llX" ; |
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 { return llvm::popcount(Value: Mask); } |
77 | unsigned getHighestLane() const { |
78 | return Log2_64(Value: Mask); |
79 | } |
80 | |
81 | static constexpr LaneBitmask getNone() { return LaneBitmask(0); } |
82 | static constexpr LaneBitmask getAll() { return ~LaneBitmask(0); } |
83 | static constexpr LaneBitmask getLane(unsigned Lane) { |
84 | return LaneBitmask(Type(1) << Lane); |
85 | } |
86 | |
87 | private: |
88 | Type Mask = 0; |
89 | }; |
90 | |
91 | /// Create Printable object to print LaneBitmasks on a \ref raw_ostream. |
92 | inline Printable PrintLaneMask(LaneBitmask LaneMask) { |
93 | return Printable([LaneMask](raw_ostream &OS) { |
94 | OS << format(Fmt: LaneBitmask::FormatStr, Vals: LaneMask.getAsInteger()); |
95 | }); |
96 | } |
97 | |
98 | } // end namespace llvm |
99 | |
100 | #endif // LLVM_MC_LANEBITMASK_H |
101 | |