1 //===- bolt/Passes/ADRRelaxationPass.cpp ----------------------------------===//
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 file implements the ADRRelaxationPass class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "bolt/Passes/ADRRelaxationPass.h"
14 #include "bolt/Core/ParallelUtilities.h"
15 
16 using namespace llvm;
17 
18 namespace opts {
19 extern cl::OptionCategory BoltCategory;
20 
21 static cl::opt<bool>
22     AdrPassOpt("adr-relaxation",
23                cl::desc("Replace ARM non-local ADR instructions with ADRP"),
24                cl::init(true), cl::cat(BoltCategory), cl::ReallyHidden);
25 } // namespace opts
26 
27 namespace llvm {
28 namespace bolt {
29 
30 void ADRRelaxationPass::runOnFunction(BinaryFunction &BF) {
31   BinaryContext &BC = BF.getBinaryContext();
32   for (BinaryBasicBlock *BB : BF.layout()) {
33     for (auto It = BB->begin(); It != BB->end(); ++It) {
34       MCInst &Inst = *It;
35       if (!BC.MIB->isADR(Inst))
36         continue;
37 
38       const MCSymbol *Symbol = BC.MIB->getTargetSymbol(Inst);
39       if (!Symbol)
40         continue;
41 
42       if (BF.hasIslandsInfo()) {
43         BinaryFunction::IslandInfo &Islands = BF.getIslandInfo();
44         if (Islands.Symbols.count(Symbol) || Islands.ProxySymbols.count(Symbol))
45           continue;
46       }
47 
48       BinaryFunction *TargetBF = BC.getFunctionForSymbol(Symbol);
49       if (TargetBF && TargetBF == &BF)
50         continue;
51 
52       MCPhysReg Reg;
53       BC.MIB->getADRReg(Inst, Reg);
54       int64_t Addend = BC.MIB->getTargetAddend(Inst);
55       InstructionListType Addr =
56           BC.MIB->materializeAddress(Symbol, BC.Ctx.get(), Reg, Addend);
57       It = BB->replaceInstruction(It, Addr);
58     }
59   }
60 }
61 
62 void ADRRelaxationPass::runOnFunctions(BinaryContext &BC) {
63   if (!opts::AdrPassOpt || !BC.HasRelocations)
64     return;
65 
66   ParallelUtilities::WorkFuncTy WorkFun = [&](BinaryFunction &BF) {
67     runOnFunction(BF);
68   };
69 
70   ParallelUtilities::runOnEachFunction(
71       BC, ParallelUtilities::SchedulingPolicy::SP_TRIVIAL, WorkFun, nullptr,
72       "ADRRelaxationPass", /* ForceSequential */ true);
73 }
74 
75 } // end namespace bolt
76 } // end namespace llvm
77