1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
//===- bolt/Passes/ADRRelaxationPass.cpp ----------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the ADRRelaxationPass class.
//
//===----------------------------------------------------------------------===//
#include "bolt/Passes/ADRRelaxationPass.h"
#include "bolt/Core/ParallelUtilities.h"
#include "bolt/Utils/CommandLineOpts.h"
#include <iterator>
using namespace llvm;
namespace opts {
extern cl::OptionCategory BoltCategory;
static cl::opt<bool>
AdrPassOpt("adr-relaxation",
cl::desc("Replace ARM non-local ADR instructions with ADRP"),
cl::init(true), cl::cat(BoltCategory), cl::ReallyHidden);
} // namespace opts
namespace llvm {
namespace bolt {
void ADRRelaxationPass::runOnFunction(BinaryFunction &BF) {
BinaryContext &BC = BF.getBinaryContext();
for (BinaryBasicBlock &BB : BF) {
for (auto It = BB.begin(); It != BB.end(); ++It) {
MCInst &Inst = *It;
if (!BC.MIB->isADR(Inst))
continue;
const MCSymbol *Symbol = BC.MIB->getTargetSymbol(Inst);
if (!Symbol)
continue;
if (BF.hasIslandsInfo()) {
BinaryFunction::IslandInfo &Islands = BF.getIslandInfo();
if (Islands.Symbols.count(Symbol) || Islands.ProxySymbols.count(Symbol))
continue;
}
BinaryFunction *TargetBF = BC.getFunctionForSymbol(Symbol);
if (TargetBF && TargetBF == &BF)
continue;
MCPhysReg Reg;
BC.MIB->getADRReg(Inst, Reg);
int64_t Addend = BC.MIB->getTargetAddend(Inst);
InstructionListType Addr =
BC.MIB->materializeAddress(Symbol, BC.Ctx.get(), Reg, Addend);
if (It != BB.begin() && BC.MIB->isNoop(*std::prev(It))) {
It = BB.eraseInstruction(std::prev(It));
} else if (opts::StrictMode && !BF.isSimple()) {
// If the function is not simple, it may contain a jump table undetected
// by us. This jump table may use an offset from the branch instruction
// to land in the desired place. If we add new instructions, we
// invalidate this offset, so we have to rely on linker-inserted NOP to
// replace it with ADRP, and abort if it is not present.
errs() << formatv("BOLT-ERROR: Cannot relax adr in non-simple function "
"{0}. Can't proceed in current mode.\n",
BF.getOneName());
exit(1);
}
It = BB.replaceInstruction(It, Addr);
}
}
}
void ADRRelaxationPass::runOnFunctions(BinaryContext &BC) {
if (!opts::AdrPassOpt || !BC.HasRelocations)
return;
ParallelUtilities::WorkFuncTy WorkFun = [&](BinaryFunction &BF) {
runOnFunction(BF);
};
ParallelUtilities::runOnEachFunction(
BC, ParallelUtilities::SchedulingPolicy::SP_TRIVIAL, WorkFun, nullptr,
"ADRRelaxationPass", /* ForceSequential */ true);
}
} // end namespace bolt
} // end namespace llvm
|
