LLVM  13.0.0git
VirtRegMap.h
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1 //===- llvm/CodeGen/VirtRegMap.h - Virtual Register Map ---------*- 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 // This file implements a virtual register map. This maps virtual registers to
10 // physical registers and virtual registers to stack slots. It is created and
11 // updated by a register allocator and then used by a machine code rewriter that
12 // adds spill code and rewrites virtual into physical register references.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_CODEGEN_VIRTREGMAP_H
17 #define LLVM_CODEGEN_VIRTREGMAP_H
18 
19 #include "llvm/ADT/IndexedMap.h"
23 #include "llvm/Pass.h"
24 #include <cassert>
25 
26 namespace llvm {
27 
28 class MachineFunction;
29 class MachineRegisterInfo;
30 class raw_ostream;
31 class TargetInstrInfo;
32 
34  public:
35  enum {
37  NO_STACK_SLOT = (1L << 30)-1,
38  MAX_STACK_SLOT = (1L << 18)-1
39  };
40 
41  private:
43  const TargetInstrInfo *TII;
44  const TargetRegisterInfo *TRI;
45  MachineFunction *MF;
46 
47  /// Virt2PhysMap - This is a virtual to physical register
48  /// mapping. Each virtual register is required to have an entry in
49  /// it; even spilled virtual registers (the register mapped to a
50  /// spilled register is the temporary used to load it from the
51  /// stack).
53 
54  /// Virt2StackSlotMap - This is virtual register to stack slot
55  /// mapping. Each spilled virtual register has an entry in it
56  /// which corresponds to the stack slot this register is spilled
57  /// at.
58  IndexedMap<int, VirtReg2IndexFunctor> Virt2StackSlotMap;
59 
60  /// Virt2SplitMap - This is virtual register to splitted virtual register
61  /// mapping.
63 
64  /// Virt2ShapeMap - For X86 AMX register whose register is bound shape
65  /// information.
66  DenseMap<unsigned, ShapeT> Virt2ShapeMap;
67 
68  /// createSpillSlot - Allocate a spill slot for RC from MFI.
69  unsigned createSpillSlot(const TargetRegisterClass *RC);
70 
71  public:
72  static char ID;
73 
75  : MachineFunctionPass(ID), MRI(nullptr), TII(nullptr), TRI(nullptr),
76  MF(nullptr), Virt2PhysMap(NO_PHYS_REG),
77  Virt2StackSlotMap(NO_STACK_SLOT), Virt2SplitMap(0) {}
78  VirtRegMap(const VirtRegMap &) = delete;
79  VirtRegMap &operator=(const VirtRegMap &) = delete;
80 
81  bool runOnMachineFunction(MachineFunction &MF) override;
82 
83  void getAnalysisUsage(AnalysisUsage &AU) const override {
84  AU.setPreservesAll();
86  }
87 
89  assert(MF && "getMachineFunction called before runOnMachineFunction");
90  return *MF;
91  }
92 
93  MachineRegisterInfo &getRegInfo() const { return *MRI; }
94  const TargetRegisterInfo &getTargetRegInfo() const { return *TRI; }
95 
96  void grow();
97 
98  /// returns true if the specified virtual register is
99  /// mapped to a physical register
100  bool hasPhys(Register virtReg) const {
101  return getPhys(virtReg) != NO_PHYS_REG;
102  }
103 
104  /// returns the physical register mapped to the specified
105  /// virtual register
106  MCRegister getPhys(Register virtReg) const {
107  assert(virtReg.isVirtual());
108  return MCRegister::from(Virt2PhysMap[virtReg.id()]);
109  }
110 
111  /// creates a mapping for the specified virtual register to
112  /// the specified physical register
113  void assignVirt2Phys(Register virtReg, MCPhysReg physReg);
114 
115  bool isShapeMapEmpty() const { return Virt2ShapeMap.empty(); }
116 
117  bool hasShape(Register virtReg) const {
118  return getShape(virtReg).isValid();
119  }
120 
121  ShapeT getShape(Register virtReg) const {
122  assert(virtReg.isVirtual());
123  return Virt2ShapeMap.lookup(virtReg);
124  }
125 
126  void assignVirt2Shape(Register virtReg, ShapeT shape) {
127  Virt2ShapeMap[virtReg.id()] = shape;
128  }
129 
130  /// clears the specified virtual register's, physical
131  /// register mapping
132  void clearVirt(Register virtReg) {
133  assert(virtReg.isVirtual());
134  assert(Virt2PhysMap[virtReg.id()] != NO_PHYS_REG &&
135  "attempt to clear a not assigned virtual register");
136  Virt2PhysMap[virtReg.id()] = NO_PHYS_REG;
137  }
138 
139  /// clears all virtual to physical register mappings
140  void clearAllVirt() {
141  Virt2PhysMap.clear();
142  grow();
143  }
144 
145  /// returns true if VirtReg is assigned to its preferred physreg.
146  bool hasPreferredPhys(Register VirtReg) const;
147 
148  /// returns true if VirtReg has a known preferred register.
149  /// This returns false if VirtReg has a preference that is a virtual
150  /// register that hasn't been assigned yet.
151  bool hasKnownPreference(Register VirtReg) const;
152 
153  /// records virtReg is a split live interval from SReg.
154  void setIsSplitFromReg(Register virtReg, Register SReg) {
155  Virt2SplitMap[virtReg.id()] = SReg;
156  if (hasShape(SReg)) {
157  Virt2ShapeMap[virtReg.id()] = getShape(SReg);
158  }
159  }
160 
161  /// returns the live interval virtReg is split from.
163  return Virt2SplitMap[virtReg.id()];
164  }
165 
166  /// getOriginal - Return the original virtual register that VirtReg descends
167  /// from through splitting.
168  /// A register that was not created by splitting is its own original.
169  /// This operation is idempotent.
170  Register getOriginal(Register VirtReg) const {
171  Register Orig = getPreSplitReg(VirtReg);
172  return Orig ? Orig : VirtReg;
173  }
174 
175  /// returns true if the specified virtual register is not
176  /// mapped to a stack slot or rematerialized.
177  bool isAssignedReg(Register virtReg) const {
178  if (getStackSlot(virtReg) == NO_STACK_SLOT)
179  return true;
180  // Split register can be assigned a physical register as well as a
181  // stack slot or remat id.
182  return (Virt2SplitMap[virtReg.id()] &&
183  Virt2PhysMap[virtReg.id()] != NO_PHYS_REG);
184  }
185 
186  /// returns the stack slot mapped to the specified virtual
187  /// register
188  int getStackSlot(Register virtReg) const {
189  assert(virtReg.isVirtual());
190  return Virt2StackSlotMap[virtReg.id()];
191  }
192 
193  /// create a mapping for the specifed virtual register to
194  /// the next available stack slot
195  int assignVirt2StackSlot(Register virtReg);
196 
197  /// create a mapping for the specified virtual register to
198  /// the specified stack slot
199  void assignVirt2StackSlot(Register virtReg, int SS);
200 
201  void print(raw_ostream &OS, const Module* M = nullptr) const override;
202  void dump() const;
203  };
204 
205  inline raw_ostream &operator<<(raw_ostream &OS, const VirtRegMap &VRM) {
206  VRM.print(OS);
207  return OS;
208  }
209 
210 } // end llvm namespace
211 
212 #endif // LLVM_CODEGEN_VIRTREGMAP_H
TileShapeInfo.h
IndexedMap.h
llvm::VirtRegMap::ID
static char ID
Definition: VirtRegMap.h:72
llvm
Definition: AllocatorList.h:23
llvm::VirtRegMap::isShapeMapEmpty
bool isShapeMapEmpty() const
Definition: VirtRegMap.h:115
llvm::MachineRegisterInfo
MachineRegisterInfo - Keep track of information for virtual and physical registers,...
Definition: MachineRegisterInfo.h:52
llvm::VirtRegMap::hasPreferredPhys
bool hasPreferredPhys(Register VirtReg) const
returns true if VirtReg is assigned to its preferred physreg.
Definition: VirtRegMap.cpp:102
llvm::MCRegister::from
static MCRegister from(unsigned Val)
Check the provided unsigned value is a valid MCRegister.
Definition: MCRegister.h:65
llvm::DenseMapBase< DenseMap< KeyT, ValueT, DenseMapInfo< KeyT >, llvm::detail::DenseMapPair< KeyT, ValueT > >, KeyT, ValueT, DenseMapInfo< KeyT >, llvm::detail::DenseMapPair< KeyT, ValueT > >::lookup
ValueT lookup(const_arg_type_t< KeyT > Val) const
lookup - Return the entry for the specified key, or a default constructed value if no such entry exis...
Definition: DenseMap.h:197
Pass.h
llvm::Register::id
unsigned id() const
Definition: Register.h:111
llvm::VirtRegMap::hasKnownPreference
bool hasKnownPreference(Register VirtReg) const
returns true if VirtReg has a known preferred register.
Definition: VirtRegMap.cpp:111
llvm::VirtRegMap::getOriginal
Register getOriginal(Register VirtReg) const
getOriginal - Return the original virtual register that VirtReg descends from through splitting.
Definition: VirtRegMap.h:170
llvm::VirtRegMap::print
void print(raw_ostream &OS, const Module *M=nullptr) const override
print - Print out the internal state of the pass.
Definition: VirtRegMap.cpp:138
llvm::VirtRegMap
Definition: VirtRegMap.h:33
llvm::VirtRegMap::NO_PHYS_REG
@ NO_PHYS_REG
Definition: VirtRegMap.h:36
llvm::VirtRegMap::assignVirt2Phys
void assignVirt2Phys(Register virtReg, MCPhysReg physReg)
creates a mapping for the specified virtual register to the specified physical register
Definition: VirtRegMap.cpp:84
llvm::MachineFunctionPass
MachineFunctionPass - This class adapts the FunctionPass interface to allow convenient creation of pa...
Definition: MachineFunctionPass.h:30
llvm::X86AS::SS
@ SS
Definition: X86.h:184
llvm::TargetRegisterInfo
TargetRegisterInfo base class - We assume that the target defines a static array of TargetRegisterDes...
Definition: TargetRegisterInfo.h:231
llvm::IndexedMap::clear
void clear()
Definition: IndexedMap.h:63
llvm::VirtRegMap::getMachineFunction
MachineFunction & getMachineFunction() const
Definition: VirtRegMap.h:88
llvm::ShapeT
Definition: TileShapeInfo.h:31
llvm::VirtRegMap::getPreSplitReg
Register getPreSplitReg(Register virtReg) const
returns the live interval virtReg is split from.
Definition: VirtRegMap.h:162
TRI
unsigned const TargetRegisterInfo * TRI
Definition: MachineSink.cpp:1567
llvm::MachineFunctionPass::getAnalysisUsage
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.
Definition: MachineFunctionPass.cpp:102
llvm::TargetInstrInfo
TargetInstrInfo - Interface to description of machine instruction set.
Definition: TargetInstrInfo.h:97
llvm::VirtRegMap::getAnalysisUsage
void getAnalysisUsage(AnalysisUsage &AU) const override
getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.
Definition: VirtRegMap.h:83
llvm::IndexedMap
Definition: IndexedMap.h:29
llvm::AnalysisUsage
Represent the analysis usage information of a pass.
Definition: PassAnalysisSupport.h:47
llvm::TargetRegisterClass
Definition: TargetRegisterInfo.h:46
TII
const HexagonInstrInfo * TII
Definition: HexagonCopyToCombine.cpp:129
llvm::VirtRegMap::dump
void dump() const
Definition: VirtRegMap.cpp:160
llvm::raw_ostream
This class implements an extremely fast bulk output stream that can only output to a stream.
Definition: raw_ostream.h:50
llvm::operator<<
raw_ostream & operator<<(raw_ostream &OS, const APFixedPoint &FX)
Definition: APFixedPoint.h:230
llvm::VirtRegMap::isAssignedReg
bool isAssignedReg(Register virtReg) const
returns true if the specified virtual register is not mapped to a stack slot or rematerialized.
Definition: VirtRegMap.h:177
llvm::VirtRegMap::hasPhys
bool hasPhys(Register virtReg) const
returns true if the specified virtual register is mapped to a physical register
Definition: VirtRegMap.h:100
llvm::VirtRegMap::setIsSplitFromReg
void setIsSplitFromReg(Register virtReg, Register SReg)
records virtReg is a split live interval from SReg.
Definition: VirtRegMap.h:154
llvm::VirtRegMap::getRegInfo
MachineRegisterInfo & getRegInfo() const
Definition: VirtRegMap.h:93
llvm::Register::isVirtual
bool isVirtual() const
Return true if the specified register number is in the virtual register namespace.
Definition: Register.h:91
llvm::DenseMap
Definition: DenseMap.h:714
llvm::VirtRegMap::getPhys
MCRegister getPhys(Register virtReg) const
returns the physical register mapped to the specified virtual register
Definition: VirtRegMap.h:106
llvm::VirtRegMap::runOnMachineFunction
bool runOnMachineFunction(MachineFunction &MF) override
runOnMachineFunction - This method must be overloaded to perform the desired machine code transformat...
Definition: VirtRegMap.cpp:62
MachineFunctionPass.h
assert
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
llvm::VirtRegMap::hasShape
bool hasShape(Register virtReg) const
Definition: VirtRegMap.h:117
llvm::Module
A Module instance is used to store all the information related to an LLVM module.
Definition: Module.h:67
llvm::MachineFunction
Definition: MachineFunction.h:227
llvm::VirtRegMap::assignVirt2Shape
void assignVirt2Shape(Register virtReg, ShapeT shape)
Definition: VirtRegMap.h:126
llvm::VirtRegMap::getShape
ShapeT getShape(Register virtReg) const
Definition: VirtRegMap.h:121
llvm::VirtRegMap::clearAllVirt
void clearAllVirt()
clears all virtual to physical register mappings
Definition: VirtRegMap.h:140
MRI
unsigned const MachineRegisterInfo * MRI
Definition: AArch64AdvSIMDScalarPass.cpp:105
llvm::Register
Wrapper class representing virtual and physical registers.
Definition: Register.h:19
llvm::DenseMapBase< DenseMap< KeyT, ValueT, DenseMapInfo< KeyT >, llvm::detail::DenseMapPair< KeyT, ValueT > >, KeyT, ValueT, DenseMapInfo< KeyT >, llvm::detail::DenseMapPair< KeyT, ValueT > >::empty
LLVM_NODISCARD bool empty() const
Definition: DenseMap.h:97
llvm::VirtRegMap::grow
void grow()
Definition: VirtRegMap.cpp:77
llvm::AnalysisUsage::setPreservesAll
void setPreservesAll()
Set by analyses that do not transform their input at all.
Definition: PassAnalysisSupport.h:130
uint16_t
llvm::VirtRegMap::clearVirt
void clearVirt(Register virtReg)
clears the specified virtual register's, physical register mapping
Definition: VirtRegMap.h:132
llvm::VirtRegMap::assignVirt2StackSlot
int assignVirt2StackSlot(Register virtReg)
create a mapping for the specifed virtual register to the next available stack slot
Definition: VirtRegMap.cpp:120
llvm::VirtRegMap::VirtRegMap
VirtRegMap()
Definition: VirtRegMap.h:74
llvm::VirtRegMap::getTargetRegInfo
const TargetRegisterInfo & getTargetRegInfo() const
Definition: VirtRegMap.h:94
llvm::VirtRegMap::MAX_STACK_SLOT
@ MAX_STACK_SLOT
Definition: VirtRegMap.h:38
llvm::VirtRegMap::NO_STACK_SLOT
@ NO_STACK_SLOT
Definition: VirtRegMap.h:37
llvm::VirtRegMap::operator=
VirtRegMap & operator=(const VirtRegMap &)=delete
TargetRegisterInfo.h
llvm::ShapeT::isValid
bool isValid()
Definition: TileShapeInfo.h:66
llvm::MCRegister
Wrapper class representing physical registers. Should be passed by value.
Definition: MCRegister.h:22
llvm::VirtRegMap::getStackSlot
int getStackSlot(Register virtReg) const
returns the stack slot mapped to the specified virtual register
Definition: VirtRegMap.h:188