xref: /freebsd/contrib/llvm-project/llvm/lib/CodeGen/RegisterUsageInfo.cpp (revision 770cf0a5f02dc8983a89c6568d741fbc25baa999)
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 
42 void PhysicalRegisterUsageInfo::setTargetMachine(const TargetMachine &TM) {
43   this->TM = &TM;
44 }
45 
46 bool PhysicalRegisterUsageInfo::doInitialization(Module &M) {
47   RegMasks.grow(M.size());
48   return false;
49 }
50 
51 bool PhysicalRegisterUsageInfo::doFinalization(Module &M) {
52   if (DumpRegUsage)
53     print(errs());
54 
55   RegMasks.shrink_and_clear();
56   return false;
57 }
58 
59 void PhysicalRegisterUsageInfo::storeUpdateRegUsageInfo(
60     const Function &FP, ArrayRef<uint32_t> RegMask) {
61   RegMasks[&FP] = RegMask;
62 }
63 
64 ArrayRef<uint32_t>
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 
72 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 
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
110 PhysicalRegisterUsageAnalysis::run(Module &M, ModuleAnalysisManager &) {
111   PhysicalRegisterUsageInfo PRUI;
112   PRUI.doInitialization(M);
113   return PRUI;
114 }
115 
116 PreservedAnalyses
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