1 //===- MachineSSAContext.cpp ------------------------------------*- 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 /// \file
9 ///
10 /// This file defines a specialization of the GenericSSAContext<X>
11 /// template class for Machine IR.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/CodeGen/MachineSSAContext.h"
16 #include "llvm/CodeGen/MachineBasicBlock.h"
17 #include "llvm/CodeGen/MachineFunction.h"
18 #include "llvm/CodeGen/MachineInstr.h"
19 #include "llvm/CodeGen/MachineRegisterInfo.h"
20 #include "llvm/Support/raw_ostream.h"
21 
22 using namespace llvm;
23 
24 const Register MachineSSAContext::ValueRefNull{};
25 
26 void MachineSSAContext::setFunction(MachineFunction &Fn) {
27   MF = &Fn;
28   RegInfo = &MF->getRegInfo();
29 }
30 
31 MachineBasicBlock *MachineSSAContext::getEntryBlock(MachineFunction &F) {
32   return &F.front();
33 }
34 
35 void MachineSSAContext::appendBlockTerms(
36     SmallVectorImpl<const MachineInstr *> &terms,
37     const MachineBasicBlock &block) {
38   for (auto &T : block.terminators())
39     terms.push_back(&T);
40 }
41 
42 void MachineSSAContext::appendBlockDefs(SmallVectorImpl<Register> &defs,
43                                         const MachineBasicBlock &block) {
44   for (const MachineInstr &instr : block.instrs()) {
45     for (const MachineOperand &op : instr.operands()) {
46       if (op.isReg() && op.isDef())
47         defs.push_back(op.getReg());
48     }
49   }
50 }
51 
52 /// Get the defining block of a value.
53 MachineBasicBlock *MachineSSAContext::getDefBlock(Register value) const {
54   if (!value)
55     return nullptr;
56   return RegInfo->getVRegDef(value)->getParent();
57 }
58 
59 bool MachineSSAContext::isConstantValuePhi(const MachineInstr &Phi) {
60   return Phi.isConstantValuePHI();
61 }
62 
63 Printable MachineSSAContext::print(const MachineBasicBlock *Block) const {
64   if (!Block)
65     return Printable([](raw_ostream &Out) { Out << "<nullptr>"; });
66   return Printable([Block](raw_ostream &Out) { Block->printName(Out); });
67 }
68 
69 Printable MachineSSAContext::print(const MachineInstr *I) const {
70   return Printable([I](raw_ostream &Out) { I->print(Out); });
71 }
72 
73 Printable MachineSSAContext::print(Register Value) const {
74   auto *MRI = RegInfo;
75   return Printable([MRI, Value](raw_ostream &Out) {
76     Out << printReg(Value, MRI->getTargetRegisterInfo(), 0, MRI);
77 
78     if (Value) {
79       // Try to print the definition.
80       if (auto *Instr = MRI->getUniqueVRegDef(Value)) {
81         Out << ": ";
82         Instr->print(Out);
83       }
84     }
85   });
86 }
87