1 //===- RegisterUsageInfo.cpp - Register Usage Information Storage ---------===//
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 pass is required to take advantage of the interprocedural register
10 /// allocation infrastructure.
11 ///
12 //===----------------------------------------------------------------------===//
13
14 #include "llvm/CodeGen/RegisterUsageInfo.h"
15 #include "llvm/ADT/SmallVector.h"
16 #include "llvm/CodeGen/MachineOperand.h"
17 #include "llvm/CodeGen/TargetRegisterInfo.h"
18 #include "llvm/CodeGen/TargetSubtargetInfo.h"
19 #include "llvm/IR/Analysis.h"
20 #include "llvm/IR/Function.h"
21 #include "llvm/IR/Module.h"
22 #include "llvm/IR/PassManager.h"
23 #include "llvm/Pass.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/raw_ostream.h"
26 #include "llvm/Target/TargetMachine.h"
27 #include <cstdint>
28 #include <utility>
29 #include <vector>
30
31 using namespace llvm;
32
33 static cl::opt<bool> DumpRegUsage(
34 "print-regusage", cl::init(false), cl::Hidden,
35 cl::desc("print register usage details collected for analysis."));
36
37 INITIALIZE_PASS(PhysicalRegisterUsageInfoWrapperLegacy, "reg-usage-info",
38 "Register Usage Information Storage", false, true)
39
40 char PhysicalRegisterUsageInfoWrapperLegacy::ID = 0;
41
setTargetMachine(const TargetMachine & TM)42 void PhysicalRegisterUsageInfo::setTargetMachine(const TargetMachine &TM) {
43 this->TM = &TM;
44 }
45
doInitialization(Module & M)46 bool PhysicalRegisterUsageInfo::doInitialization(Module &M) {
47 RegMasks.grow(M.size());
48 return false;
49 }
50
doFinalization(Module & M)51 bool PhysicalRegisterUsageInfo::doFinalization(Module &M) {
52 if (DumpRegUsage)
53 print(errs());
54
55 RegMasks.shrink_and_clear();
56 return false;
57 }
58
storeUpdateRegUsageInfo(const Function & FP,ArrayRef<uint32_t> RegMask)59 void PhysicalRegisterUsageInfo::storeUpdateRegUsageInfo(
60 const Function &FP, ArrayRef<uint32_t> RegMask) {
61 RegMasks[&FP] = RegMask;
62 }
63
64 ArrayRef<uint32_t>
getRegUsageInfo(const Function & FP)65 PhysicalRegisterUsageInfo::getRegUsageInfo(const Function &FP) {
66 auto It = RegMasks.find(&FP);
67 if (It != RegMasks.end())
68 return ArrayRef<uint32_t>(It->second);
69 return ArrayRef<uint32_t>();
70 }
71
print(raw_ostream & OS,const Module * M) const72 void PhysicalRegisterUsageInfo::print(raw_ostream &OS, const Module *M) const {
73 using FuncPtrRegMaskPair = std::pair<const Function *, std::vector<uint32_t>>;
74
75 // Create a vector of pointer to RegMasks entries
76 SmallVector<const FuncPtrRegMaskPair *, 64> FPRMPairVector(
77 llvm::make_pointer_range(RegMasks));
78
79 // sort the vector to print analysis in alphabatic order of function name.
80 llvm::sort(
81 FPRMPairVector,
82 [](const FuncPtrRegMaskPair *A, const FuncPtrRegMaskPair *B) -> bool {
83 return A->first->getName() < B->first->getName();
84 });
85
86 for (const FuncPtrRegMaskPair *FPRMPair : FPRMPairVector) {
87 OS << FPRMPair->first->getName() << " "
88 << "Clobbered Registers: ";
89 const TargetRegisterInfo *TRI
90 = TM->getSubtarget<TargetSubtargetInfo>(*(FPRMPair->first))
91 .getRegisterInfo();
92
93 for (unsigned PReg = 1, PRegE = TRI->getNumRegs(); PReg < PRegE; ++PReg) {
94 if (MachineOperand::clobbersPhysReg(&(FPRMPair->second[0]), PReg))
95 OS << printReg(PReg, TRI) << " ";
96 }
97 OS << "\n";
98 }
99 }
100
invalidate(Module & M,const PreservedAnalyses & PA,ModuleAnalysisManager::Invalidator &)101 bool PhysicalRegisterUsageInfo::invalidate(
102 Module &M, const PreservedAnalyses &PA,
103 ModuleAnalysisManager::Invalidator &) {
104 auto PAC = PA.getChecker<PhysicalRegisterUsageAnalysis>();
105 return !PAC.preservedWhenStateless();
106 }
107
108 AnalysisKey PhysicalRegisterUsageAnalysis::Key;
109 PhysicalRegisterUsageInfo
run(Module & M,ModuleAnalysisManager &)110 PhysicalRegisterUsageAnalysis::run(Module &M, ModuleAnalysisManager &) {
111 PhysicalRegisterUsageInfo PRUI;
112 PRUI.doInitialization(M);
113 return PRUI;
114 }
115
116 PreservedAnalyses
run(Module & M,ModuleAnalysisManager & AM)117 PhysicalRegisterUsageInfoPrinterPass::run(Module &M,
118 ModuleAnalysisManager &AM) {
119 auto *PRUI = &AM.getResult<PhysicalRegisterUsageAnalysis>(M);
120 PRUI->print(OS, &M);
121 return PreservedAnalyses::all();
122 }
123