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1 //===- RegisterUsageInfo.cpp - Register Usage Informartion Storage --------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 ///
10 /// This pass is required to take advantage of the interprocedural register
11 /// allocation infrastructure.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/CodeGen/RegisterUsageInfo.h"
16 #include "llvm/CodeGen/MachineOperand.h"
17 #include "llvm/IR/Module.h"
18 #include "llvm/Support/Debug.h"
19 #include "llvm/Support/raw_ostream.h"
20 
21 using namespace llvm;
22 
23 #define DEBUG_TYPE "ip-regalloc"
24 
25 cl::opt<bool> DumpRegUsage(
26     "print-regusage", cl::init(false), cl::Hidden,
27     cl::desc("print register usage details collected for analysis."));
28 
29 INITIALIZE_PASS(PhysicalRegisterUsageInfo, "reg-usage-info",
30                 "Register Usage Informartion Stroage", false, true)
31 
32 char PhysicalRegisterUsageInfo::ID = 0;
33 
anchor()34 void PhysicalRegisterUsageInfo::anchor() {}
35 
doInitialization(Module & M)36 bool PhysicalRegisterUsageInfo::doInitialization(Module &M) {
37   RegMasks.grow(M.size());
38   return false;
39 }
40 
doFinalization(Module & M)41 bool PhysicalRegisterUsageInfo::doFinalization(Module &M) {
42   if (DumpRegUsage)
43     print(errs());
44 
45   RegMasks.shrink_and_clear();
46   return false;
47 }
48 
storeUpdateRegUsageInfo(const Function * FP,std::vector<uint32_t> RegMask)49 void PhysicalRegisterUsageInfo::storeUpdateRegUsageInfo(
50     const Function *FP, std::vector<uint32_t> RegMask) {
51   assert(FP != nullptr && "Function * can't be nullptr.");
52   RegMasks[FP] = std::move(RegMask);
53 }
54 
55 const std::vector<uint32_t> *
getRegUsageInfo(const Function * FP)56 PhysicalRegisterUsageInfo::getRegUsageInfo(const Function *FP) {
57   if (RegMasks.find(FP) != RegMasks.end())
58     return &(RegMasks.find(FP)->second);
59   return nullptr;
60 }
61 
print(raw_ostream & OS,const Module * M) const62 void PhysicalRegisterUsageInfo::print(raw_ostream &OS, const Module *M) const {
63   const TargetRegisterInfo *TRI;
64 
65   typedef std::pair<const Function *, std::vector<uint32_t>> FuncPtrRegMaskPair;
66 
67   SmallVector<const FuncPtrRegMaskPair *, 64> FPRMPairVector;
68 
69   // Create a vector of pointer to RegMasks entries
70   for (const auto &RegMask : RegMasks)
71     FPRMPairVector.push_back(&RegMask);
72 
73   // sort the vector to print analysis in alphabatic order of function name.
74   std::sort(
75       FPRMPairVector.begin(), FPRMPairVector.end(),
76       [](const FuncPtrRegMaskPair *A, const FuncPtrRegMaskPair *B) -> bool {
77         return A->first->getName() < B->first->getName();
78       });
79 
80   for (const FuncPtrRegMaskPair *FPRMPair : FPRMPairVector) {
81     OS << FPRMPair->first->getName() << " "
82        << "Clobbered Registers: ";
83     TRI = TM->getSubtarget<TargetSubtargetInfo>(*(FPRMPair->first))
84               .getRegisterInfo();
85 
86     for (unsigned PReg = 1, PRegE = TRI->getNumRegs(); PReg < PRegE; ++PReg) {
87       if (MachineOperand::clobbersPhysReg(&(FPRMPair->second[0]), PReg))
88         OS << TRI->getName(PReg) << " ";
89     }
90     OS << "\n";
91   }
92 }
93