1 #include "llvm/CodeGen/MachineRegionInfo.h"
2 #include "llvm/ADT/Statistic.h"
3 #include "llvm/Analysis/RegionInfoImpl.h"
4 #include "llvm/CodeGen/MachinePostDominators.h"
5 
6 #define DEBUG_TYPE "machine-region-info"
7 
8 using namespace llvm;
9 
10 STATISTIC(numMachineRegions,       "The # of machine regions");
11 STATISTIC(numMachineSimpleRegions, "The # of simple machine regions");
12 
13 namespace llvm {
14 template class RegionBase<RegionTraits<MachineFunction>>;
15 template class RegionNodeBase<RegionTraits<MachineFunction>>;
16 template class RegionInfoBase<RegionTraits<MachineFunction>>;
17 }
18 
19 //===----------------------------------------------------------------------===//
20 // MachineRegion implementation
21 //
22 
23 MachineRegion::MachineRegion(MachineBasicBlock *Entry, MachineBasicBlock *Exit,
24                              MachineRegionInfo* RI,
25                              MachineDominatorTree *DT, MachineRegion *Parent) :
26   RegionBase<RegionTraits<MachineFunction>>(Entry, Exit, RI, DT, Parent) {
27 
28 }
29 
30 MachineRegion::~MachineRegion() { }
31 
32 //===----------------------------------------------------------------------===//
33 // MachineRegionInfo implementation
34 //
35 
36 MachineRegionInfo::MachineRegionInfo() :
37   RegionInfoBase<RegionTraits<MachineFunction>>() {
38 
39 }
40 
41 MachineRegionInfo::~MachineRegionInfo() {
42 
43 }
44 
45 void MachineRegionInfo::updateStatistics(MachineRegion *R) {
46   ++numMachineRegions;
47 
48   // TODO: Slow. Should only be enabled if -stats is used.
49   if (R->isSimple())
50     ++numMachineSimpleRegions;
51 }
52 
53 void MachineRegionInfo::recalculate(MachineFunction &F,
54                                     MachineDominatorTree *DT_,
55                                     MachinePostDominatorTree *PDT_,
56                                     MachineDominanceFrontier *DF_) {
57   DT = DT_;
58   PDT = PDT_;
59   DF = DF_;
60 
61   MachineBasicBlock *Entry = GraphTraits<MachineFunction*>::getEntryNode(&F);
62 
63   TopLevelRegion = new MachineRegion(Entry, nullptr, this, DT, nullptr);
64   updateStatistics(TopLevelRegion);
65   calculate(F);
66 }
67 
68 //===----------------------------------------------------------------------===//
69 // MachineRegionInfoPass implementation
70 //
71 
72 MachineRegionInfoPass::MachineRegionInfoPass() : MachineFunctionPass(ID) {
73   initializeMachineRegionInfoPassPass(*PassRegistry::getPassRegistry());
74 }
75 
76 MachineRegionInfoPass::~MachineRegionInfoPass() {
77 
78 }
79 
80 bool MachineRegionInfoPass::runOnMachineFunction(MachineFunction &F) {
81   releaseMemory();
82 
83   auto DT = &getAnalysis<MachineDominatorTree>();
84   auto PDT = &getAnalysis<MachinePostDominatorTree>();
85   auto DF = &getAnalysis<MachineDominanceFrontier>();
86 
87   RI.recalculate(F, DT, PDT, DF);
88 
89   DEBUG(RI.dump());
90 
91   return false;
92 }
93 
94 void MachineRegionInfoPass::releaseMemory() {
95   RI.releaseMemory();
96 }
97 
98 void MachineRegionInfoPass::verifyAnalysis() const {
99   // Only do verification when user wants to, otherwise this expensive check
100   // will be invoked by PMDataManager::verifyPreservedAnalysis when
101   // a regionpass (marked PreservedAll) finish.
102   if (MachineRegionInfo::VerifyRegionInfo)
103     RI.verifyAnalysis();
104 }
105 
106 void MachineRegionInfoPass::getAnalysisUsage(AnalysisUsage &AU) const {
107   AU.setPreservesAll();
108   AU.addRequired<MachineDominatorTree>();
109   AU.addRequired<MachinePostDominatorTree>();
110   AU.addRequired<MachineDominanceFrontier>();
111   MachineFunctionPass::getAnalysisUsage(AU);
112 }
113 
114 void MachineRegionInfoPass::print(raw_ostream &OS, const Module *) const {
115   RI.print(OS);
116 }
117 
118 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
119 LLVM_DUMP_METHOD void MachineRegionInfoPass::dump() const {
120   RI.dump();
121 }
122 #endif
123 
124 char MachineRegionInfoPass::ID = 0;
125 char &MachineRegionInfoPassID = MachineRegionInfoPass::ID;
126 
127 INITIALIZE_PASS_BEGIN(MachineRegionInfoPass, DEBUG_TYPE,
128                       "Detect single entry single exit regions", true, true)
129 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
130 INITIALIZE_PASS_DEPENDENCY(MachinePostDominatorTree)
131 INITIALIZE_PASS_DEPENDENCY(MachineDominanceFrontier)
132 INITIALIZE_PASS_END(MachineRegionInfoPass, DEBUG_TYPE,
133                     "Detect single entry single exit regions", true, true)
134 
135 // Create methods available outside of this file, to use them
136 // "include/llvm/LinkAllPasses.h". Otherwise the pass would be deleted by
137 // the link time optimization.
138 
139 namespace llvm {
140   FunctionPass *createMachineRegionInfoPass() {
141     return new MachineRegionInfoPass();
142   }
143 }
144 
145