LLVM 20.0.0git
MCRegister.h
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1//===-- llvm/MC/Register.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#ifndef LLVM_MC_MCREGISTER_H
10#define LLVM_MC_MCREGISTER_H
11
13#include "llvm/ADT/Hashing.h"
14#include <cassert>
15#include <limits>
16
17namespace llvm {
18
19/// An unsigned integer type large enough to represent all physical registers,
20/// but not necessarily virtual registers.
22
23/// Register units are used to compute register aliasing. Every register has at
24/// least one register unit, but it can have more. Two registers overlap if and
25/// only if they have a common register unit.
26///
27/// A target with a complicated sub-register structure will typically have many
28/// fewer register units than actual registers. MCRI::getNumRegUnits() returns
29/// the number of register units in the target.
31
32/// Wrapper class representing physical registers. Should be passed by value.
34 friend hash_code hash_value(const MCRegister &);
35 unsigned Reg;
36
37public:
38 constexpr MCRegister(unsigned Val = 0) : Reg(Val) {}
39
40 // Register numbers can represent physical registers, virtual registers, and
41 // sometimes stack slots. The unsigned values are divided into these ranges:
42 //
43 // 0 Not a register, can be used as a sentinel.
44 // [1;2^30) Physical registers assigned by TableGen.
45 // [2^30;2^31) Stack slots. (Rarely used.)
46 // [2^31;2^32) Virtual registers assigned by MachineRegisterInfo.
47 //
48 // Further sentinels can be allocated from the small negative integers.
49 // DenseMapInfo<unsigned> uses -1u and -2u.
50 static_assert(std::numeric_limits<decltype(Reg)>::max() >= 0xFFFFFFFF,
51 "Reg isn't large enough to hold full range.");
52 static constexpr unsigned NoRegister = 0u;
53 static constexpr unsigned FirstPhysicalReg = 1u;
54 static constexpr unsigned FirstStackSlot = 1u << 30;
55 static constexpr unsigned VirtualRegFlag = 1u << 31;
56
57 /// This is the portion of the positive number space that is not a physical
58 /// register. StackSlot values do not exist in the MC layer, see
59 /// Register::isStackSlot() for the more information on them.
60 ///
61 static constexpr bool isStackSlot(unsigned Reg) {
62 return FirstStackSlot <= Reg && Reg < VirtualRegFlag;
63 }
64
65 /// Return true if the specified register number is in
66 /// the physical register namespace.
67 static constexpr bool isPhysicalRegister(unsigned Reg) {
68 return FirstPhysicalReg <= Reg && Reg < FirstStackSlot;
69 }
70
71 constexpr operator unsigned() const { return Reg; }
72
73 /// Check the provided unsigned value is a valid MCRegister.
74 static MCRegister from(unsigned Val) {
75 assert(Val == NoRegister || isPhysicalRegister(Val));
76 return MCRegister(Val);
77 }
78
79 constexpr unsigned id() const { return Reg; }
80
81 constexpr bool isValid() const { return Reg != NoRegister; }
82
83 /// Comparisons between register objects
84 constexpr bool operator==(const MCRegister &Other) const {
85 return Reg == Other.Reg;
86 }
87 constexpr bool operator!=(const MCRegister &Other) const {
88 return Reg != Other.Reg;
89 }
90
91 /// Comparisons against register constants. E.g.
92 /// * R == AArch64::WZR
93 /// * R == 0
94 /// * R == VirtRegMap::NO_PHYS_REG
95 constexpr bool operator==(unsigned Other) const { return Reg == Other; }
96 constexpr bool operator!=(unsigned Other) const { return Reg != Other; }
97 constexpr bool operator==(int Other) const { return Reg == unsigned(Other); }
98 constexpr bool operator!=(int Other) const { return Reg != unsigned(Other); }
99 // MSVC requires that we explicitly declare these two as well.
100 constexpr bool operator==(MCPhysReg Other) const {
101 return Reg == unsigned(Other);
102 }
103 constexpr bool operator!=(MCPhysReg Other) const {
104 return Reg != unsigned(Other);
105 }
106};
107
108// Provide DenseMapInfo for MCRegister
109template <> struct DenseMapInfo<MCRegister> {
110 static inline unsigned getEmptyKey() {
112 }
113 static inline unsigned getTombstoneKey() {
115 }
116 static unsigned getHashValue(const MCRegister &Val) {
118 }
119 static bool isEqual(const MCRegister &LHS, const MCRegister &RHS) {
120 return DenseMapInfo<unsigned>::isEqual(LHS.id(), RHS.id());
121 }
122};
123
125 return hash_value(Reg.id());
126}
127} // namespace llvm
128
129#endif // LLVM_MC_MCREGISTER_H
This file defines DenseMapInfo traits for DenseMap.
unsigned Reg
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Value * RHS
Value * LHS
Wrapper class representing physical registers. Should be passed by value.
Definition: MCRegister.h:33
static constexpr bool isStackSlot(unsigned Reg)
This is the portion of the positive number space that is not a physical register.
Definition: MCRegister.h:61
constexpr bool isValid() const
Definition: MCRegister.h:81
static constexpr unsigned FirstPhysicalReg
Definition: MCRegister.h:53
constexpr bool operator==(const MCRegister &Other) const
Comparisons between register objects.
Definition: MCRegister.h:84
constexpr bool operator!=(MCPhysReg Other) const
Definition: MCRegister.h:103
static constexpr unsigned NoRegister
Definition: MCRegister.h:52
constexpr bool operator!=(int Other) const
Definition: MCRegister.h:98
static constexpr bool isPhysicalRegister(unsigned Reg)
Return true if the specified register number is in the physical register namespace.
Definition: MCRegister.h:67
constexpr MCRegister(unsigned Val=0)
Definition: MCRegister.h:38
static MCRegister from(unsigned Val)
Check the provided unsigned value is a valid MCRegister.
Definition: MCRegister.h:74
constexpr bool operator==(unsigned Other) const
Comparisons against register constants.
Definition: MCRegister.h:95
static constexpr unsigned FirstStackSlot
Definition: MCRegister.h:54
constexpr bool operator==(int Other) const
Definition: MCRegister.h:97
constexpr bool operator!=(const MCRegister &Other) const
Definition: MCRegister.h:87
friend hash_code hash_value(const MCRegister &)
Definition: MCRegister.h:124
constexpr bool operator==(MCPhysReg Other) const
Definition: MCRegister.h:100
static constexpr unsigned VirtualRegFlag
Definition: MCRegister.h:55
constexpr bool operator!=(unsigned Other) const
Definition: MCRegister.h:96
constexpr unsigned id() const
Definition: MCRegister.h:79
An opaque object representing a hash code.
Definition: Hashing.h:75
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
GCNRegPressure max(const GCNRegPressure &P1, const GCNRegPressure &P2)
hash_code hash_value(const FixedPointSemantics &Val)
Definition: APFixedPoint.h:127
@ Other
Any other memory.
static unsigned getEmptyKey()
Definition: MCRegister.h:110
static bool isEqual(const MCRegister &LHS, const MCRegister &RHS)
Definition: MCRegister.h:119
static unsigned getHashValue(const MCRegister &Val)
Definition: MCRegister.h:116
static unsigned getTombstoneKey()
Definition: MCRegister.h:113
An information struct used to provide DenseMap with the various necessary components for a given valu...
Definition: DenseMapInfo.h:52