1 //===- bolt/Core/BinaryFunction.cpp - Low-level function ------------------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file implements the BinaryFunction class.
11 //===----------------------------------------------------------------------===//
13 #include "bolt/Core/BinaryFunction.h"
14 #include "bolt/Core/BinaryBasicBlock.h"
15 #include "bolt/Core/DynoStats.h"
16 #include "bolt/Core/HashUtilities.h"
17 #include "bolt/Core/MCPlusBuilder.h"
18 #include "bolt/Utils/NameResolver.h"
19 #include "bolt/Utils/NameShortener.h"
20 #include "bolt/Utils/Utils.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/SmallSet.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/ADT/StringRef.h"
25 #include "llvm/Demangle/Demangle.h"
26 #include "llvm/MC/MCAsmInfo.h"
27 #include "llvm/MC/MCContext.h"
28 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
29 #include "llvm/MC/MCExpr.h"
30 #include "llvm/MC/MCInst.h"
31 #include "llvm/MC/MCInstPrinter.h"
32 #include "llvm/MC/MCRegisterInfo.h"
33 #include "llvm/MC/MCSymbol.h"
34 #include "llvm/Object/ObjectFile.h"
35 #include "llvm/Support/CommandLine.h"
36 #include "llvm/Support/Debug.h"
37 #include "llvm/Support/GenericDomTreeConstruction.h"
38 #include "llvm/Support/GenericLoopInfoImpl.h"
39 #include "llvm/Support/GraphWriter.h"
40 #include "llvm/Support/LEB128.h"
41 #include "llvm/Support/Regex.h"
42 #include "llvm/Support/Timer.h"
43 #include "llvm/Support/raw_ostream.h"
44 #include "llvm/Support/xxhash.h"
51 #define DEBUG_TYPE "bolt"
58 extern cl::OptionCategory BoltCategory
;
59 extern cl::OptionCategory BoltOptCategory
;
61 extern cl::opt
<bool> EnableBAT
;
62 extern cl::opt
<bool> Instrument
;
63 extern cl::opt
<bool> StrictMode
;
64 extern cl::opt
<bool> UpdateDebugSections
;
65 extern cl::opt
<unsigned> Verbosity
;
67 extern bool processAllFunctions();
69 cl::opt
<bool> CheckEncoding(
71 cl::desc("perform verification of LLVM instruction encoding/decoding. "
72 "Every instruction in the input is decoded and re-encoded. "
73 "If the resulting bytes do not match the input, a warning message "
75 cl::Hidden
, cl::cat(BoltCategory
));
77 static cl::opt
<bool> DotToolTipCode(
79 cl::desc("add basic block instructions as tool tips on nodes"), cl::Hidden
,
80 cl::cat(BoltCategory
));
82 cl::opt
<JumpTableSupportLevel
>
83 JumpTables("jump-tables",
84 cl::desc("jump tables support (default=basic)"),
87 clEnumValN(JTS_NONE
, "none",
88 "do not optimize functions with jump tables"),
89 clEnumValN(JTS_BASIC
, "basic",
90 "optimize functions with jump tables"),
91 clEnumValN(JTS_MOVE
, "move",
92 "move jump tables to a separate section"),
93 clEnumValN(JTS_SPLIT
, "split",
94 "split jump tables section into hot and cold based on "
95 "function execution frequency"),
96 clEnumValN(JTS_AGGRESSIVE
, "aggressive",
97 "aggressively split jump tables section based on usage "
100 cl::cat(BoltOptCategory
));
102 static cl::opt
<bool> NoScan(
105 "do not scan cold functions for external references (may result in "
107 cl::Hidden
, cl::cat(BoltOptCategory
));
110 PreserveBlocksAlignment("preserve-blocks-alignment",
111 cl::desc("try to preserve basic block alignment"),
112 cl::cat(BoltOptCategory
));
114 static cl::opt
<bool> PrintOutputAddressRange(
115 "print-output-address-range",
117 "print output address range for each basic block in the function when"
118 "BinaryFunction::print is called"),
119 cl::Hidden
, cl::cat(BoltOptCategory
));
122 PrintDynoStats("dyno-stats",
123 cl::desc("print execution info based on profile"),
124 cl::cat(BoltCategory
));
127 PrintDynoStatsOnly("print-dyno-stats-only",
128 cl::desc("while printing functions output dyno-stats and skip instructions"),
131 cl::cat(BoltCategory
));
133 static cl::list
<std::string
>
134 PrintOnly("print-only",
136 cl::desc("list of functions to print"),
137 cl::value_desc("func1,func2,func3,..."),
139 cl::cat(BoltCategory
));
142 TimeBuild("time-build",
143 cl::desc("print time spent constructing binary functions"),
144 cl::Hidden
, cl::cat(BoltCategory
));
147 TrapOnAVX512("trap-avx512",
148 cl::desc("in relocation mode trap upon entry to any function that uses "
149 "AVX-512 instructions"),
153 cl::cat(BoltCategory
));
155 bool shouldPrint(const BinaryFunction
&Function
) {
156 if (Function
.isIgnored())
159 if (PrintOnly
.empty())
162 for (std::string
&Name
: opts::PrintOnly
) {
163 if (Function
.hasNameRegex(Name
)) {
168 std::optional
<StringRef
> Origin
= Function
.getOriginSectionName();
169 if (Origin
&& llvm::any_of(opts::PrintOnly
, [&](const std::string
&Name
) {
170 return Name
== *Origin
;
182 template <typename R
> static bool emptyRange(const R
&Range
) {
183 return Range
.begin() == Range
.end();
186 /// Gets debug line information for the instruction located at the given
187 /// address in the original binary. The SMLoc's pointer is used
188 /// to point to this information, which is represented by a
189 /// DebugLineTableRowRef. The returned pointer is null if no debug line
190 /// information for this instruction was found.
191 static SMLoc
findDebugLineInformationForInstructionAt(
192 uint64_t Address
, DWARFUnit
*Unit
,
193 const DWARFDebugLine::LineTable
*LineTable
) {
194 // We use the pointer in SMLoc to store an instance of DebugLineTableRowRef,
195 // which occupies 64 bits. Thus, we can only proceed if the struct fits into
196 // the pointer itself.
198 sizeof(decltype(SMLoc().getPointer())) >= sizeof(DebugLineTableRowRef
),
199 "Cannot fit instruction debug line information into SMLoc's pointer");
201 SMLoc NullResult
= DebugLineTableRowRef::NULL_ROW
.toSMLoc();
202 uint32_t RowIndex
= LineTable
->lookupAddress(
203 {Address
, object::SectionedAddress::UndefSection
});
204 if (RowIndex
== LineTable
->UnknownRowIndex
)
207 assert(RowIndex
< LineTable
->Rows
.size() &&
208 "Line Table lookup returned invalid index.");
210 decltype(SMLoc().getPointer()) Ptr
;
211 DebugLineTableRowRef
*InstructionLocation
=
212 reinterpret_cast<DebugLineTableRowRef
*>(&Ptr
);
214 InstructionLocation
->DwCompileUnitIndex
= Unit
->getOffset();
215 InstructionLocation
->RowIndex
= RowIndex
+ 1;
217 return SMLoc::getFromPointer(Ptr
);
220 static std::string
buildSectionName(StringRef Prefix
, StringRef Name
,
221 const BinaryContext
&BC
) {
223 return (Prefix
+ Name
).str();
224 static NameShortener NS
;
225 return (Prefix
+ Twine(NS
.getID(Name
))).str();
228 static raw_ostream
&operator<<(raw_ostream
&OS
,
229 const BinaryFunction::State State
) {
231 case BinaryFunction::State::Empty
: OS
<< "empty"; break;
232 case BinaryFunction::State::Disassembled
: OS
<< "disassembled"; break;
233 case BinaryFunction::State::CFG
: OS
<< "CFG constructed"; break;
234 case BinaryFunction::State::CFG_Finalized
: OS
<< "CFG finalized"; break;
235 case BinaryFunction::State::EmittedCFG
: OS
<< "emitted with CFG"; break;
236 case BinaryFunction::State::Emitted
: OS
<< "emitted"; break;
242 std::string
BinaryFunction::buildCodeSectionName(StringRef Name
,
243 const BinaryContext
&BC
) {
244 return buildSectionName(BC
.isELF() ? ".local.text." : ".l.text.", Name
, BC
);
247 std::string
BinaryFunction::buildColdCodeSectionName(StringRef Name
,
248 const BinaryContext
&BC
) {
249 return buildSectionName(BC
.isELF() ? ".local.cold.text." : ".l.c.text.", Name
,
253 uint64_t BinaryFunction::Count
= 0;
255 std::optional
<StringRef
>
256 BinaryFunction::hasNameRegex(const StringRef Name
) const {
257 const std::string RegexName
= (Twine("^") + StringRef(Name
) + "$").str();
258 Regex
MatchName(RegexName
);
260 [&MatchName
](StringRef Name
) { return MatchName
.match(Name
); });
263 std::optional
<StringRef
>
264 BinaryFunction::hasRestoredNameRegex(const StringRef Name
) const {
265 const std::string RegexName
= (Twine("^") + StringRef(Name
) + "$").str();
266 Regex
MatchName(RegexName
);
267 return forEachName([&MatchName
](StringRef Name
) {
268 return MatchName
.match(NameResolver::restore(Name
));
272 std::string
BinaryFunction::getDemangledName() const {
273 StringRef MangledName
= NameResolver::restore(getOneName());
274 return demangle(MangledName
.str());
278 BinaryFunction::getBasicBlockContainingOffset(uint64_t Offset
) {
282 if (BasicBlockOffsets
.empty())
286 * This is commented out because it makes BOLT too slow.
287 * assert(std::is_sorted(BasicBlockOffsets.begin(),
288 * BasicBlockOffsets.end(),
289 * CompareBasicBlockOffsets())));
292 llvm::upper_bound(BasicBlockOffsets
, BasicBlockOffset(Offset
, nullptr),
293 CompareBasicBlockOffsets());
294 assert(I
!= BasicBlockOffsets
.begin() && "first basic block not at offset 0");
296 BinaryBasicBlock
*BB
= I
->second
;
297 return (Offset
< BB
->getOffset() + BB
->getOriginalSize()) ? BB
: nullptr;
300 void BinaryFunction::markUnreachableBlocks() {
301 std::stack
<BinaryBasicBlock
*> Stack
;
303 for (BinaryBasicBlock
&BB
: blocks())
306 // Add all entries and landing pads as roots.
307 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
308 if (isEntryPoint(*BB
) || BB
->isLandingPad()) {
314 // Also mark BBs with indirect jumps as reachable, since we do not
315 // support removing unused jump tables yet (GH-issue20).
316 for (const MCInst
&Inst
: *BB
) {
317 if (BC
.MIB
->getJumpTable(Inst
)) {
325 // Determine reachable BBs from the entry point
326 while (!Stack
.empty()) {
327 BinaryBasicBlock
*BB
= Stack
.top();
329 for (BinaryBasicBlock
*Succ
: BB
->successors()) {
332 Succ
->markValid(true);
338 // Any unnecessary fallthrough jumps revealed after calling eraseInvalidBBs
339 // will be cleaned up by fixBranches().
340 std::pair
<unsigned, uint64_t>
341 BinaryFunction::eraseInvalidBBs(const MCCodeEmitter
*Emitter
) {
342 DenseSet
<const BinaryBasicBlock
*> InvalidBBs
;
345 for (BinaryBasicBlock
*const BB
: BasicBlocks
) {
346 if (!BB
->isValid()) {
347 assert(!isEntryPoint(*BB
) && "all entry blocks must be valid");
348 InvalidBBs
.insert(BB
);
350 Bytes
+= BC
.computeCodeSize(BB
->begin(), BB
->end(), Emitter
);
354 Layout
.eraseBasicBlocks(InvalidBBs
);
356 BasicBlockListType NewBasicBlocks
;
357 for (auto I
= BasicBlocks
.begin(), E
= BasicBlocks
.end(); I
!= E
; ++I
) {
358 BinaryBasicBlock
*BB
= *I
;
359 if (InvalidBBs
.contains(BB
)) {
360 // Make sure the block is removed from the list of predecessors.
361 BB
->removeAllSuccessors();
362 DeletedBasicBlocks
.push_back(BB
);
364 NewBasicBlocks
.push_back(BB
);
367 BasicBlocks
= std::move(NewBasicBlocks
);
369 assert(BasicBlocks
.size() == Layout
.block_size());
371 // Update CFG state if needed
373 recomputeLandingPads();
375 return std::make_pair(Count
, Bytes
);
378 bool BinaryFunction::isForwardCall(const MCSymbol
*CalleeSymbol
) const {
379 // This function should work properly before and after function reordering.
380 // In order to accomplish this, we use the function index (if it is valid).
381 // If the function indices are not valid, we fall back to the original
382 // addresses. This should be ok because the functions without valid indices
383 // should have been ordered with a stable sort.
384 const BinaryFunction
*CalleeBF
= BC
.getFunctionForSymbol(CalleeSymbol
);
386 if (CalleeBF
->isInjected())
389 if (hasValidIndex() && CalleeBF
->hasValidIndex()) {
390 return getIndex() < CalleeBF
->getIndex();
391 } else if (hasValidIndex() && !CalleeBF
->hasValidIndex()) {
393 } else if (!hasValidIndex() && CalleeBF
->hasValidIndex()) {
396 return getAddress() < CalleeBF
->getAddress();
400 ErrorOr
<uint64_t> CalleeAddressOrError
= BC
.getSymbolValue(*CalleeSymbol
);
401 assert(CalleeAddressOrError
&& "unregistered symbol found");
402 return *CalleeAddressOrError
> getAddress();
406 void BinaryFunction::dump() const {
407 // getDynoStats calls FunctionLayout::updateLayoutIndices and
408 // BasicBlock::analyzeBranch. The former cannot be const, but should be
409 // removed, the latter should be made const, but seems to require refactoring.
410 // Forcing all callers to have a non-const reference to BinaryFunction to call
411 // dump non-const however is not ideal either. Adding this const_cast is right
412 // now the best solution. It is safe, because BinaryFunction itself is not
413 // modified. Only BinaryBasicBlocks are actually modified (if it all) and we
414 // have mutable pointers to those regardless whether this function is
415 // const-qualified or not.
416 const_cast<BinaryFunction
&>(*this).print(dbgs(), "");
419 void BinaryFunction::print(raw_ostream
&OS
, std::string Annotation
) {
420 if (!opts::shouldPrint(*this))
423 StringRef SectionName
=
424 OriginSection
? OriginSection
->getName() : "<no origin section>";
425 OS
<< "Binary Function \"" << *this << "\" " << Annotation
<< " {";
426 std::vector
<StringRef
> AllNames
= getNames();
427 if (AllNames
.size() > 1) {
428 OS
<< "\n All names : ";
429 const char *Sep
= "";
430 for (const StringRef
&Name
: AllNames
) {
435 OS
<< "\n Number : " << FunctionNumber
;
436 OS
<< "\n State : " << CurrentState
;
437 OS
<< "\n Address : 0x" << Twine::utohexstr(Address
);
438 OS
<< "\n Size : 0x" << Twine::utohexstr(Size
);
439 OS
<< "\n MaxSize : 0x" << Twine::utohexstr(MaxSize
);
440 OS
<< "\n Offset : 0x" << Twine::utohexstr(getFileOffset());
441 OS
<< "\n Section : " << SectionName
;
442 OS
<< "\n Orc Section : " << getCodeSectionName();
443 OS
<< "\n LSDA : 0x" << Twine::utohexstr(getLSDAAddress());
444 OS
<< "\n IsSimple : " << IsSimple
;
445 OS
<< "\n IsMultiEntry: " << isMultiEntry();
446 OS
<< "\n IsSplit : " << isSplit();
447 OS
<< "\n BB Count : " << size();
449 if (HasUnknownControlFlow
)
450 OS
<< "\n Unknown CF : true";
451 if (getPersonalityFunction())
452 OS
<< "\n Personality : " << getPersonalityFunction()->getName();
454 OS
<< "\n IsFragment : true";
456 OS
<< "\n FoldedInto : " << *getFoldedIntoFunction();
457 for (BinaryFunction
*ParentFragment
: ParentFragments
)
458 OS
<< "\n Parent : " << *ParentFragment
;
459 if (!Fragments
.empty()) {
460 OS
<< "\n Fragments : ";
462 for (BinaryFunction
*Frag
: Fragments
)
466 OS
<< "\n Hash : " << Twine::utohexstr(computeHash());
467 if (isMultiEntry()) {
468 OS
<< "\n Secondary Entry Points : ";
470 for (const auto &KV
: SecondaryEntryPoints
)
471 OS
<< LS
<< KV
.second
->getName();
473 if (FrameInstructions
.size())
474 OS
<< "\n CFI Instrs : " << FrameInstructions
.size();
475 if (!Layout
.block_empty()) {
476 OS
<< "\n BB Layout : ";
478 for (const BinaryBasicBlock
*BB
: Layout
.blocks())
479 OS
<< LS
<< BB
->getName();
481 if (getImageAddress())
482 OS
<< "\n Image : 0x" << Twine::utohexstr(getImageAddress());
483 if (ExecutionCount
!= COUNT_NO_PROFILE
) {
484 OS
<< "\n Exec Count : " << ExecutionCount
;
485 OS
<< "\n Branch Count: " << RawBranchCount
;
486 OS
<< "\n Profile Acc : " << format("%.1f%%", ProfileMatchRatio
* 100.0f
);
489 if (opts::PrintDynoStats
&& !getLayout().block_empty()) {
491 DynoStats dynoStats
= getDynoStats(*this);
497 if (opts::PrintDynoStatsOnly
|| !BC
.InstPrinter
)
500 // Offset of the instruction in function.
503 if (BasicBlocks
.empty() && !Instructions
.empty()) {
504 // Print before CFG was built.
505 for (const std::pair
<const uint32_t, MCInst
> &II
: Instructions
) {
508 // Print label if exists at this offset.
509 auto LI
= Labels
.find(Offset
);
510 if (LI
!= Labels
.end()) {
511 if (const MCSymbol
*EntrySymbol
=
512 getSecondaryEntryPointSymbol(LI
->second
))
513 OS
<< EntrySymbol
->getName() << " (Entry Point):\n";
514 OS
<< LI
->second
->getName() << ":\n";
517 BC
.printInstruction(OS
, II
.second
, Offset
, this);
521 StringRef SplitPointMsg
= "";
522 for (const FunctionFragment
&FF
: Layout
.fragments()) {
524 SplitPointMsg
= "------- HOT-COLD SPLIT POINT -------\n\n";
525 for (const BinaryBasicBlock
*BB
: FF
) {
526 OS
<< BB
->getName() << " (" << BB
->size()
527 << " instructions, align : " << BB
->getAlignment() << ")\n";
529 if (opts::PrintOutputAddressRange
)
530 OS
<< formatv(" Output Address Range: [{0:x}, {1:x}) ({2} bytes)\n",
531 BB
->getOutputAddressRange().first
,
532 BB
->getOutputAddressRange().second
, BB
->getOutputSize());
534 if (isEntryPoint(*BB
)) {
535 if (MCSymbol
*EntrySymbol
= getSecondaryEntryPointSymbol(*BB
))
536 OS
<< " Secondary Entry Point: " << EntrySymbol
->getName() << '\n';
538 OS
<< " Entry Point\n";
541 if (BB
->isLandingPad())
542 OS
<< " Landing Pad\n";
544 uint64_t BBExecCount
= BB
->getExecutionCount();
545 if (hasValidProfile()) {
546 OS
<< " Exec Count : ";
547 if (BB
->getExecutionCount() != BinaryBasicBlock::COUNT_NO_PROFILE
)
548 OS
<< BBExecCount
<< '\n';
553 OS
<< " CFI State : " << BB
->getCFIState() << '\n';
554 if (opts::EnableBAT
) {
555 OS
<< " Input offset: 0x" << Twine::utohexstr(BB
->getInputOffset())
558 if (!BB
->pred_empty()) {
559 OS
<< " Predecessors: ";
561 for (BinaryBasicBlock
*Pred
: BB
->predecessors())
562 OS
<< LS
<< Pred
->getName();
565 if (!BB
->throw_empty()) {
568 for (BinaryBasicBlock
*Throw
: BB
->throwers())
569 OS
<< LS
<< Throw
->getName();
573 Offset
= alignTo(Offset
, BB
->getAlignment());
575 // Note: offsets are imprecise since this is happening prior to
577 Offset
= BC
.printInstructions(OS
, BB
->begin(), BB
->end(), Offset
, this);
579 if (!BB
->succ_empty()) {
580 OS
<< " Successors: ";
581 // For more than 2 successors, sort them based on frequency.
582 std::vector
<uint64_t> Indices(BB
->succ_size());
583 std::iota(Indices
.begin(), Indices
.end(), 0);
584 if (BB
->succ_size() > 2 && BB
->getKnownExecutionCount()) {
585 llvm::stable_sort(Indices
, [&](const uint64_t A
, const uint64_t B
) {
586 return BB
->BranchInfo
[B
] < BB
->BranchInfo
[A
];
590 for (unsigned I
= 0; I
< Indices
.size(); ++I
) {
591 BinaryBasicBlock
*Succ
= BB
->Successors
[Indices
[I
]];
592 const BinaryBasicBlock::BinaryBranchInfo
&BI
=
593 BB
->BranchInfo
[Indices
[I
]];
594 OS
<< LS
<< Succ
->getName();
595 if (ExecutionCount
!= COUNT_NO_PROFILE
&&
596 BI
.MispredictedCount
!= BinaryBasicBlock::COUNT_INFERRED
) {
597 OS
<< " (mispreds: " << BI
.MispredictedCount
598 << ", count: " << BI
.Count
<< ")";
599 } else if (ExecutionCount
!= COUNT_NO_PROFILE
&&
600 BI
.Count
!= BinaryBasicBlock::COUNT_NO_PROFILE
) {
601 OS
<< " (inferred count: " << BI
.Count
<< ")";
607 if (!BB
->lp_empty()) {
608 OS
<< " Landing Pads: ";
610 for (BinaryBasicBlock
*LP
: BB
->landing_pads()) {
611 OS
<< LS
<< LP
->getName();
612 if (ExecutionCount
!= COUNT_NO_PROFILE
) {
613 OS
<< " (count: " << LP
->getExecutionCount() << ")";
619 // In CFG_Finalized state we can miscalculate CFI state at exit.
620 if (CurrentState
== State::CFG
&& hasCFI()) {
621 const int32_t CFIStateAtExit
= BB
->getCFIStateAtExit();
622 if (CFIStateAtExit
>= 0)
623 OS
<< " CFI State: " << CFIStateAtExit
<< '\n';
630 // Dump new exception ranges for the function.
631 if (!CallSites
.empty()) {
633 for (const FunctionFragment
&FF
: getLayout().fragments()) {
634 for (const auto &FCSI
: getCallSites(FF
.getFragmentNum())) {
635 const CallSite
&CSI
= FCSI
.second
;
636 OS
<< " [" << *CSI
.Start
<< ", " << *CSI
.End
<< ") landing pad : ";
641 OS
<< ", action : " << CSI
.Action
<< '\n';
647 // Print all jump tables.
648 for (const std::pair
<const uint64_t, JumpTable
*> &JTI
: JumpTables
)
649 JTI
.second
->print(OS
);
651 OS
<< "DWARF CFI Instructions:\n";
652 if (OffsetToCFI
.size()) {
653 // Pre-buildCFG information
654 for (const std::pair
<const uint32_t, uint32_t> &Elmt
: OffsetToCFI
) {
655 OS
<< format(" %08x:\t", Elmt
.first
);
656 assert(Elmt
.second
< FrameInstructions
.size() && "Incorrect CFI offset");
657 BinaryContext::printCFI(OS
, FrameInstructions
[Elmt
.second
]);
661 // Post-buildCFG information
662 for (uint32_t I
= 0, E
= FrameInstructions
.size(); I
!= E
; ++I
) {
663 const MCCFIInstruction
&CFI
= FrameInstructions
[I
];
664 OS
<< format(" %d:\t", I
);
665 BinaryContext::printCFI(OS
, CFI
);
669 if (FrameInstructions
.empty())
672 OS
<< "End of Function \"" << *this << "\"\n\n";
675 void BinaryFunction::printRelocations(raw_ostream
&OS
, uint64_t Offset
,
676 uint64_t Size
) const {
677 const char *Sep
= " # Relocs: ";
679 auto RI
= Relocations
.lower_bound(Offset
);
680 while (RI
!= Relocations
.end() && RI
->first
< Offset
+ Size
) {
681 OS
<< Sep
<< "(R: " << RI
->second
<< ")";
687 static std::string
mutateDWARFExpressionTargetReg(const MCCFIInstruction
&Instr
,
689 StringRef ExprBytes
= Instr
.getValues();
690 assert(ExprBytes
.size() > 1 && "DWARF expression CFI is too short");
691 uint8_t Opcode
= ExprBytes
[0];
692 assert((Opcode
== dwarf::DW_CFA_expression
||
693 Opcode
== dwarf::DW_CFA_val_expression
) &&
694 "invalid DWARF expression CFI");
696 const uint8_t *const Start
=
697 reinterpret_cast<const uint8_t *>(ExprBytes
.drop_front(1).data());
698 const uint8_t *const End
=
699 reinterpret_cast<const uint8_t *>(Start
+ ExprBytes
.size() - 1);
701 decodeULEB128(Start
, &Size
, End
);
702 assert(Size
> 0 && "Invalid reg encoding for DWARF expression CFI");
704 raw_svector_ostream
OSE(Tmp
);
705 encodeULEB128(NewReg
, OSE
);
706 return Twine(ExprBytes
.slice(0, 1))
708 .concat(ExprBytes
.drop_front(1 + Size
))
712 void BinaryFunction::mutateCFIRegisterFor(const MCInst
&Instr
,
714 const MCCFIInstruction
*OldCFI
= getCFIFor(Instr
);
715 assert(OldCFI
&& "invalid CFI instr");
716 switch (OldCFI
->getOperation()) {
718 llvm_unreachable("Unexpected instruction");
719 case MCCFIInstruction::OpDefCfa
:
720 setCFIFor(Instr
, MCCFIInstruction::cfiDefCfa(nullptr, NewReg
,
721 OldCFI
->getOffset()));
723 case MCCFIInstruction::OpDefCfaRegister
:
724 setCFIFor(Instr
, MCCFIInstruction::createDefCfaRegister(nullptr, NewReg
));
726 case MCCFIInstruction::OpOffset
:
727 setCFIFor(Instr
, MCCFIInstruction::createOffset(nullptr, NewReg
,
728 OldCFI
->getOffset()));
730 case MCCFIInstruction::OpRegister
:
731 setCFIFor(Instr
, MCCFIInstruction::createRegister(nullptr, NewReg
,
732 OldCFI
->getRegister2()));
734 case MCCFIInstruction::OpSameValue
:
735 setCFIFor(Instr
, MCCFIInstruction::createSameValue(nullptr, NewReg
));
737 case MCCFIInstruction::OpEscape
:
739 MCCFIInstruction::createEscape(
741 StringRef(mutateDWARFExpressionTargetReg(*OldCFI
, NewReg
))));
743 case MCCFIInstruction::OpRestore
:
744 setCFIFor(Instr
, MCCFIInstruction::createRestore(nullptr, NewReg
));
746 case MCCFIInstruction::OpUndefined
:
747 setCFIFor(Instr
, MCCFIInstruction::createUndefined(nullptr, NewReg
));
752 const MCCFIInstruction
*BinaryFunction::mutateCFIOffsetFor(const MCInst
&Instr
,
754 const MCCFIInstruction
*OldCFI
= getCFIFor(Instr
);
755 assert(OldCFI
&& "invalid CFI instr");
756 switch (OldCFI
->getOperation()) {
758 llvm_unreachable("Unexpected instruction");
759 case MCCFIInstruction::OpDefCfaOffset
:
760 setCFIFor(Instr
, MCCFIInstruction::cfiDefCfaOffset(nullptr, NewOffset
));
762 case MCCFIInstruction::OpAdjustCfaOffset
:
764 MCCFIInstruction::createAdjustCfaOffset(nullptr, NewOffset
));
766 case MCCFIInstruction::OpDefCfa
:
767 setCFIFor(Instr
, MCCFIInstruction::cfiDefCfa(nullptr, OldCFI
->getRegister(),
770 case MCCFIInstruction::OpOffset
:
771 setCFIFor(Instr
, MCCFIInstruction::createOffset(
772 nullptr, OldCFI
->getRegister(), NewOffset
));
775 return getCFIFor(Instr
);
779 BinaryFunction::processIndirectBranch(MCInst
&Instruction
, unsigned Size
,
781 uint64_t &TargetAddress
) {
782 const unsigned PtrSize
= BC
.AsmInfo
->getCodePointerSize();
784 // The instruction referencing memory used by the branch instruction.
785 // It could be the branch instruction itself or one of the instructions
786 // setting the value of the register used by the branch.
789 // The instruction loading the fixed PIC jump table entry value.
790 MCInst
*FixedEntryLoadInstr
;
792 // Address of the table referenced by MemLocInstr. Could be either an
793 // array of function pointers, or a jump table.
794 uint64_t ArrayStart
= 0;
796 unsigned BaseRegNum
, IndexRegNum
;
798 const MCExpr
*DispExpr
;
800 // In AArch, identify the instruction adding the PC-relative offset to
801 // jump table entries to correctly decode it.
802 MCInst
*PCRelBaseInstr
;
803 uint64_t PCRelAddr
= 0;
805 auto Begin
= Instructions
.begin();
806 if (BC
.isAArch64()) {
807 PreserveNops
= BC
.HasRelocations
;
808 // Start at the last label as an approximation of the current basic block.
809 // This is a heuristic, since the full set of labels have yet to be
811 for (const uint32_t Offset
:
812 llvm::make_first_range(llvm::reverse(Labels
))) {
813 auto II
= Instructions
.find(Offset
);
814 if (II
!= Instructions
.end()) {
821 IndirectBranchType BranchType
= BC
.MIB
->analyzeIndirectBranch(
822 Instruction
, Begin
, Instructions
.end(), PtrSize
, MemLocInstr
, BaseRegNum
,
823 IndexRegNum
, DispValue
, DispExpr
, PCRelBaseInstr
, FixedEntryLoadInstr
);
825 if (BranchType
== IndirectBranchType::UNKNOWN
&& !MemLocInstr
)
828 if (MemLocInstr
!= &Instruction
)
829 IndexRegNum
= BC
.MIB
->getNoRegister();
831 if (BC
.isAArch64()) {
832 const MCSymbol
*Sym
= BC
.MIB
->getTargetSymbol(*PCRelBaseInstr
, 1);
833 assert(Sym
&& "Symbol extraction failed");
834 ErrorOr
<uint64_t> SymValueOrError
= BC
.getSymbolValue(*Sym
);
835 if (SymValueOrError
) {
836 PCRelAddr
= *SymValueOrError
;
838 for (std::pair
<const uint32_t, MCSymbol
*> &Elmt
: Labels
) {
839 if (Elmt
.second
== Sym
) {
840 PCRelAddr
= Elmt
.first
+ getAddress();
845 uint64_t InstrAddr
= 0;
846 for (auto II
= Instructions
.rbegin(); II
!= Instructions
.rend(); ++II
) {
847 if (&II
->second
== PCRelBaseInstr
) {
848 InstrAddr
= II
->first
+ getAddress();
852 assert(InstrAddr
!= 0 && "instruction not found");
853 // We do this to avoid spurious references to code locations outside this
854 // function (for example, if the indirect jump lives in the last basic
855 // block of the function, it will create a reference to the next function).
856 // This replaces a symbol reference with an immediate.
857 BC
.MIB
->replaceMemOperandDisp(*PCRelBaseInstr
,
858 MCOperand::createImm(PCRelAddr
- InstrAddr
));
859 // FIXME: Disable full jump table processing for AArch64 until we have a
860 // proper way of determining the jump table limits.
861 return IndirectBranchType::UNKNOWN
;
864 auto getExprValue
= [&](const MCExpr
*Expr
) {
865 const MCSymbol
*TargetSym
;
866 uint64_t TargetOffset
;
867 std::tie(TargetSym
, TargetOffset
) = BC
.MIB
->getTargetSymbolInfo(Expr
);
868 ErrorOr
<uint64_t> SymValueOrError
= BC
.getSymbolValue(*TargetSym
);
869 assert(SymValueOrError
&& "Global symbol needs a value");
870 return *SymValueOrError
+ TargetOffset
;
873 // RIP-relative addressing should be converted to symbol form by now
874 // in processed instructions (but not in jump).
876 ArrayStart
= getExprValue(DispExpr
);
877 BaseRegNum
= BC
.MIB
->getNoRegister();
878 if (BC
.isAArch64()) {
879 ArrayStart
&= ~0xFFFULL
;
880 ArrayStart
+= DispValue
& 0xFFFULL
;
883 ArrayStart
= static_cast<uint64_t>(DispValue
);
886 if (BaseRegNum
== BC
.MRI
->getProgramCounter())
887 ArrayStart
+= getAddress() + Offset
+ Size
;
889 if (FixedEntryLoadInstr
) {
890 assert(BranchType
== IndirectBranchType::POSSIBLE_PIC_FIXED_BRANCH
&&
891 "Invalid IndirectBranch type");
892 MCInst::iterator FixedEntryDispOperand
=
893 BC
.MIB
->getMemOperandDisp(*FixedEntryLoadInstr
);
894 assert(FixedEntryDispOperand
!= FixedEntryLoadInstr
->end() &&
895 "Invalid memory instruction");
896 const MCExpr
*FixedEntryDispExpr
= FixedEntryDispOperand
->getExpr();
897 const uint64_t EntryAddress
= getExprValue(FixedEntryDispExpr
);
898 uint64_t EntrySize
= BC
.getJumpTableEntrySize(JumpTable::JTT_PIC
);
899 ErrorOr
<int64_t> Value
=
900 BC
.getSignedValueAtAddress(EntryAddress
, EntrySize
);
902 return IndirectBranchType::UNKNOWN
;
904 BC
.outs() << "BOLT-INFO: fixed PIC indirect branch detected in " << *this
905 << " at 0x" << Twine::utohexstr(getAddress() + Offset
)
906 << " referencing data at 0x" << Twine::utohexstr(EntryAddress
)
907 << " the destination value is 0x"
908 << Twine::utohexstr(ArrayStart
+ *Value
) << '\n';
910 TargetAddress
= ArrayStart
+ *Value
;
912 // Remove spurious JumpTable at EntryAddress caused by PIC reference from
913 // the load instruction.
914 BC
.deleteJumpTable(EntryAddress
);
916 // Replace FixedEntryDispExpr used in target address calculation with outer
917 // jump table reference.
918 JumpTable
*JT
= BC
.getJumpTableContainingAddress(ArrayStart
);
919 assert(JT
&& "Must have a containing jump table for PIC fixed branch");
920 BC
.MIB
->replaceMemOperandDisp(*FixedEntryLoadInstr
, JT
->getFirstLabel(),
921 EntryAddress
- ArrayStart
, &*BC
.Ctx
);
926 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: addressed memory is 0x"
927 << Twine::utohexstr(ArrayStart
) << '\n');
929 ErrorOr
<BinarySection
&> Section
= BC
.getSectionForAddress(ArrayStart
);
931 // No section - possibly an absolute address. Since we don't allow
932 // internal function addresses to escape the function scope - we
933 // consider it a tail call.
934 if (opts::Verbosity
>= 1) {
935 BC
.errs() << "BOLT-WARNING: no section for address 0x"
936 << Twine::utohexstr(ArrayStart
) << " referenced from function "
939 return IndirectBranchType::POSSIBLE_TAIL_CALL
;
941 if (Section
->isVirtual()) {
942 // The contents are filled at runtime.
943 return IndirectBranchType::POSSIBLE_TAIL_CALL
;
946 if (BranchType
== IndirectBranchType::POSSIBLE_FIXED_BRANCH
) {
947 ErrorOr
<uint64_t> Value
= BC
.getPointerAtAddress(ArrayStart
);
949 return IndirectBranchType::UNKNOWN
;
951 if (BC
.getSectionForAddress(ArrayStart
)->isWritable())
952 return IndirectBranchType::UNKNOWN
;
954 BC
.outs() << "BOLT-INFO: fixed indirect branch detected in " << *this
955 << " at 0x" << Twine::utohexstr(getAddress() + Offset
)
956 << " referencing data at 0x" << Twine::utohexstr(ArrayStart
)
957 << " the destination value is 0x" << Twine::utohexstr(*Value
)
960 TargetAddress
= *Value
;
964 // Check if there's already a jump table registered at this address.
965 MemoryContentsType MemType
;
966 if (JumpTable
*JT
= BC
.getJumpTableContainingAddress(ArrayStart
)) {
968 case JumpTable::JTT_NORMAL
:
969 MemType
= MemoryContentsType::POSSIBLE_JUMP_TABLE
;
971 case JumpTable::JTT_PIC
:
972 MemType
= MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE
;
976 MemType
= BC
.analyzeMemoryAt(ArrayStart
, *this);
979 // Check that jump table type in instruction pattern matches memory contents.
980 JumpTable::JumpTableType JTType
;
981 if (BranchType
== IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE
) {
982 if (MemType
!= MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE
)
983 return IndirectBranchType::UNKNOWN
;
984 JTType
= JumpTable::JTT_PIC
;
986 if (MemType
== MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE
)
987 return IndirectBranchType::UNKNOWN
;
989 if (MemType
== MemoryContentsType::UNKNOWN
)
990 return IndirectBranchType::POSSIBLE_TAIL_CALL
;
992 BranchType
= IndirectBranchType::POSSIBLE_JUMP_TABLE
;
993 JTType
= JumpTable::JTT_NORMAL
;
996 // Convert the instruction into jump table branch.
997 const MCSymbol
*JTLabel
= BC
.getOrCreateJumpTable(*this, ArrayStart
, JTType
);
998 BC
.MIB
->replaceMemOperandDisp(*MemLocInstr
, JTLabel
, BC
.Ctx
.get());
999 BC
.MIB
->setJumpTable(Instruction
, ArrayStart
, IndexRegNum
);
1001 JTSites
.emplace_back(Offset
, ArrayStart
);
1006 MCSymbol
*BinaryFunction::getOrCreateLocalLabel(uint64_t Address
,
1007 bool CreatePastEnd
) {
1008 const uint64_t Offset
= Address
- getAddress();
1010 if ((Offset
== getSize()) && CreatePastEnd
)
1011 return getFunctionEndLabel();
1013 auto LI
= Labels
.find(Offset
);
1014 if (LI
!= Labels
.end())
1017 // For AArch64, check if this address is part of a constant island.
1018 if (BC
.isAArch64()) {
1019 if (MCSymbol
*IslandSym
= getOrCreateIslandAccess(Address
))
1023 MCSymbol
*Label
= BC
.Ctx
->createNamedTempSymbol();
1024 Labels
[Offset
] = Label
;
1029 ErrorOr
<ArrayRef
<uint8_t>> BinaryFunction::getData() const {
1030 BinarySection
&Section
= *getOriginSection();
1031 assert(Section
.containsRange(getAddress(), getMaxSize()) &&
1032 "wrong section for function");
1034 if (!Section
.isText() || Section
.isVirtual() || !Section
.getSize())
1035 return std::make_error_code(std::errc::bad_address
);
1037 StringRef SectionContents
= Section
.getContents();
1039 assert(SectionContents
.size() == Section
.getSize() &&
1040 "section size mismatch");
1042 // Function offset from the section start.
1043 uint64_t Offset
= getAddress() - Section
.getAddress();
1044 auto *Bytes
= reinterpret_cast<const uint8_t *>(SectionContents
.data());
1045 return ArrayRef
<uint8_t>(Bytes
+ Offset
, getMaxSize());
1048 size_t BinaryFunction::getSizeOfDataInCodeAt(uint64_t Offset
) const {
1052 if (!llvm::is_contained(Islands
->DataOffsets
, Offset
))
1055 auto Iter
= Islands
->CodeOffsets
.upper_bound(Offset
);
1056 if (Iter
!= Islands
->CodeOffsets
.end())
1057 return *Iter
- Offset
;
1058 return getSize() - Offset
;
1061 bool BinaryFunction::isZeroPaddingAt(uint64_t Offset
) const {
1062 ArrayRef
<uint8_t> FunctionData
= *getData();
1063 uint64_t EndOfCode
= getSize();
1065 auto Iter
= Islands
->DataOffsets
.upper_bound(Offset
);
1066 if (Iter
!= Islands
->DataOffsets
.end())
1069 for (uint64_t I
= Offset
; I
< EndOfCode
; ++I
)
1070 if (FunctionData
[I
] != 0)
1076 Error
BinaryFunction::handlePCRelOperand(MCInst
&Instruction
, uint64_t Address
,
1079 uint64_t TargetAddress
= 0;
1080 if (!MIB
->evaluateMemOperandTarget(Instruction
, TargetAddress
, Address
,
1083 raw_string_ostream
SS(Msg
);
1084 SS
<< "BOLT-ERROR: PC-relative operand can't be evaluated:\n";
1085 BC
.InstPrinter
->printInst(&Instruction
, 0, "", *BC
.STI
, SS
);
1087 Instruction
.dump_pretty(SS
, BC
.InstPrinter
.get());
1089 SS
<< "BOLT-ERROR: cannot handle PC-relative operand at 0x"
1090 << Twine::utohexstr(Address
) << ". Skipping function " << *this << ".\n";
1091 if (BC
.HasRelocations
)
1092 return createFatalBOLTError(Msg
);
1094 return createNonFatalBOLTError(Msg
);
1096 if (TargetAddress
== 0 && opts::Verbosity
>= 1) {
1097 BC
.outs() << "BOLT-INFO: PC-relative operand is zero in function " << *this
1101 const MCSymbol
*TargetSymbol
;
1102 uint64_t TargetOffset
;
1103 std::tie(TargetSymbol
, TargetOffset
) =
1104 BC
.handleAddressRef(TargetAddress
, *this, /*IsPCRel*/ true);
1106 bool ReplaceSuccess
= MIB
->replaceMemOperandDisp(
1107 Instruction
, TargetSymbol
, static_cast<int64_t>(TargetOffset
), &*BC
.Ctx
);
1108 (void)ReplaceSuccess
;
1109 assert(ReplaceSuccess
&& "Failed to replace mem operand with symbol+off.");
1110 return Error::success();
1113 MCSymbol
*BinaryFunction::handleExternalReference(MCInst
&Instruction
,
1116 uint64_t TargetAddress
,
1120 const uint64_t AbsoluteInstrAddr
= getAddress() + Offset
;
1121 BC
.addInterproceduralReference(this, TargetAddress
);
1122 if (opts::Verbosity
>= 2 && !IsCall
&& Size
== 2 && !BC
.HasRelocations
) {
1123 BC
.errs() << "BOLT-WARNING: relaxed tail call detected at 0x"
1124 << Twine::utohexstr(AbsoluteInstrAddr
) << " in function " << *this
1125 << ". Code size will be increased.\n";
1128 assert(!MIB
->isTailCall(Instruction
) &&
1129 "synthetic tail call instruction found");
1131 // This is a call regardless of the opcode.
1132 // Assign proper opcode for tail calls, so that they could be
1133 // treated as calls.
1135 if (!MIB
->convertJmpToTailCall(Instruction
)) {
1136 assert(MIB
->isConditionalBranch(Instruction
) &&
1137 "unknown tail call instruction");
1138 if (opts::Verbosity
>= 2) {
1139 BC
.errs() << "BOLT-WARNING: conditional tail call detected in "
1140 << "function " << *this << " at 0x"
1141 << Twine::utohexstr(AbsoluteInstrAddr
) << ".\n";
1147 if (opts::Verbosity
>= 2 && TargetAddress
== 0) {
1148 // We actually see calls to address 0 in presence of weak
1149 // symbols originating from libraries. This code is never meant
1151 BC
.outs() << "BOLT-INFO: Function " << *this
1152 << " has a call to address zero.\n";
1155 return BC
.getOrCreateGlobalSymbol(TargetAddress
, "FUNCat");
1158 void BinaryFunction::handleIndirectBranch(MCInst
&Instruction
, uint64_t Size
,
1161 uint64_t IndirectTarget
= 0;
1162 IndirectBranchType Result
=
1163 processIndirectBranch(Instruction
, Size
, Offset
, IndirectTarget
);
1166 llvm_unreachable("unexpected result");
1167 case IndirectBranchType::POSSIBLE_TAIL_CALL
: {
1168 bool Result
= MIB
->convertJmpToTailCall(Instruction
);
1173 case IndirectBranchType::POSSIBLE_JUMP_TABLE
:
1174 case IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE
:
1175 case IndirectBranchType::POSSIBLE_PIC_FIXED_BRANCH
:
1176 if (opts::JumpTables
== JTS_NONE
)
1179 case IndirectBranchType::POSSIBLE_FIXED_BRANCH
: {
1180 if (containsAddress(IndirectTarget
)) {
1181 const MCSymbol
*TargetSymbol
= getOrCreateLocalLabel(IndirectTarget
);
1182 Instruction
.clear();
1183 MIB
->createUncondBranch(Instruction
, TargetSymbol
, BC
.Ctx
.get());
1184 TakenBranches
.emplace_back(Offset
, IndirectTarget
- getAddress());
1185 addEntryPointAtOffset(IndirectTarget
- getAddress());
1187 MIB
->convertJmpToTailCall(Instruction
);
1188 BC
.addInterproceduralReference(this, IndirectTarget
);
1192 case IndirectBranchType::UNKNOWN
:
1193 // Keep processing. We'll do more checks and fixes in
1194 // postProcessIndirectBranches().
1195 UnknownIndirectBranchOffsets
.emplace(Offset
);
1200 void BinaryFunction::handleAArch64IndirectCall(MCInst
&Instruction
,
1201 const uint64_t Offset
) {
1203 const uint64_t AbsoluteInstrAddr
= getAddress() + Offset
;
1204 MCInst
*TargetHiBits
, *TargetLowBits
;
1205 uint64_t TargetAddress
, Count
;
1206 Count
= MIB
->matchLinkerVeneer(Instructions
.begin(), Instructions
.end(),
1207 AbsoluteInstrAddr
, Instruction
, TargetHiBits
,
1208 TargetLowBits
, TargetAddress
);
1210 MIB
->addAnnotation(Instruction
, "AArch64Veneer", true);
1212 for (auto It
= std::prev(Instructions
.end()); Count
!= 0;
1213 It
= std::prev(It
), --Count
) {
1214 MIB
->addAnnotation(It
->second
, "AArch64Veneer", true);
1217 BC
.addAdrpAddRelocAArch64(*this, *TargetLowBits
, *TargetHiBits
,
1222 std::optional
<MCInst
>
1223 BinaryFunction::disassembleInstructionAtOffset(uint64_t Offset
) const {
1224 assert(CurrentState
== State::Empty
&& "Function should not be disassembled");
1225 assert(Offset
< MaxSize
&& "Invalid offset");
1226 ErrorOr
<ArrayRef
<unsigned char>> FunctionData
= getData();
1227 assert(FunctionData
&& "Cannot get function as data");
1229 uint64_t InstrSize
= 0;
1230 const uint64_t InstrAddress
= getAddress() + Offset
;
1231 if (BC
.DisAsm
->getInstruction(Instr
, InstrSize
, FunctionData
->slice(Offset
),
1232 InstrAddress
, nulls()))
1234 return std::nullopt
;
1237 Error
BinaryFunction::disassemble() {
1238 NamedRegionTimer
T("disassemble", "Disassemble function", "buildfuncs",
1239 "Build Binary Functions", opts::TimeBuild
);
1240 ErrorOr
<ArrayRef
<uint8_t>> ErrorOrFunctionData
= getData();
1241 assert(ErrorOrFunctionData
&& "function data is not available");
1242 ArrayRef
<uint8_t> FunctionData
= *ErrorOrFunctionData
;
1243 assert(FunctionData
.size() == getMaxSize() &&
1244 "function size does not match raw data size");
1249 BC
.SymbolicDisAsm
->setSymbolizer(MIB
->createTargetSymbolizer(*this));
1251 // Insert a label at the beginning of the function. This will be our first
1253 Labels
[0] = Ctx
->createNamedTempSymbol("BB0");
1255 // Map offsets in the function to a label that should always point to the
1256 // corresponding instruction. This is used for labels that shouldn't point to
1257 // the start of a basic block but always to a specific instruction. This is
1258 // used, for example, on RISC-V where %pcrel_lo relocations point to the
1259 // corresponding %pcrel_hi.
1260 LabelsMapType InstructionLabels
;
1262 uint64_t Size
= 0; // instruction size
1263 for (uint64_t Offset
= 0; Offset
< getSize(); Offset
+= Size
) {
1265 const uint64_t AbsoluteInstrAddr
= getAddress() + Offset
;
1267 // Check for data inside code and ignore it
1268 if (const size_t DataInCodeSize
= getSizeOfDataInCodeAt(Offset
)) {
1269 Size
= DataInCodeSize
;
1273 if (!BC
.SymbolicDisAsm
->getInstruction(Instruction
, Size
,
1274 FunctionData
.slice(Offset
),
1275 AbsoluteInstrAddr
, nulls())) {
1276 // Functions with "soft" boundaries, e.g. coming from assembly source,
1277 // can have 0-byte padding at the end.
1278 if (isZeroPaddingAt(Offset
))
1282 << "BOLT-WARNING: unable to disassemble instruction at offset 0x"
1283 << Twine::utohexstr(Offset
) << " (address 0x"
1284 << Twine::utohexstr(AbsoluteInstrAddr
) << ") in function " << *this
1286 // Some AVX-512 instructions could not be disassembled at all.
1287 if (BC
.HasRelocations
&& opts::TrapOnAVX512
&& BC
.isX86()) {
1289 BC
.TrappedFunctions
.push_back(this);
1297 // Check integrity of LLVM assembler/disassembler.
1298 if (opts::CheckEncoding
&& !BC
.MIB
->isBranch(Instruction
) &&
1299 !BC
.MIB
->isCall(Instruction
) && !BC
.MIB
->isNoop(Instruction
)) {
1300 if (!BC
.validateInstructionEncoding(FunctionData
.slice(Offset
, Size
))) {
1301 BC
.errs() << "BOLT-WARNING: mismatching LLVM encoding detected in "
1302 << "function " << *this << " for instruction :\n";
1303 BC
.printInstruction(BC
.errs(), Instruction
, AbsoluteInstrAddr
);
1308 // Special handling for AVX-512 instructions.
1309 if (MIB
->hasEVEXEncoding(Instruction
)) {
1310 if (BC
.HasRelocations
&& opts::TrapOnAVX512
) {
1312 BC
.TrappedFunctions
.push_back(this);
1316 if (!BC
.validateInstructionEncoding(FunctionData
.slice(Offset
, Size
))) {
1317 BC
.errs() << "BOLT-WARNING: internal assembler/disassembler error "
1318 "detected for AVX512 instruction:\n";
1319 BC
.printInstruction(BC
.errs(), Instruction
, AbsoluteInstrAddr
);
1320 BC
.errs() << " in function " << *this << '\n';
1326 bool IsUnsupported
= BC
.MIB
->isUnsupportedInstruction(Instruction
);
1330 if (MIB
->isBranch(Instruction
) || MIB
->isCall(Instruction
)) {
1331 uint64_t TargetAddress
= 0;
1332 if (MIB
->evaluateBranch(Instruction
, AbsoluteInstrAddr
, Size
,
1334 // Check if the target is within the same function. Otherwise it's
1335 // a call, possibly a tail call.
1337 // If the target *is* the function address it could be either a branch
1338 // or a recursive call.
1339 bool IsCall
= MIB
->isCall(Instruction
);
1340 const bool IsCondBranch
= MIB
->isConditionalBranch(Instruction
);
1341 MCSymbol
*TargetSymbol
= nullptr;
1344 if (auto *TargetFunc
=
1345 BC
.getBinaryFunctionContainingAddress(TargetAddress
))
1346 TargetFunc
->setIgnored();
1348 if (IsCall
&& TargetAddress
== getAddress()) {
1349 // A recursive call. Calls to internal blocks are handled by
1350 // ValidateInternalCalls pass.
1351 TargetSymbol
= getSymbol();
1354 if (!TargetSymbol
) {
1355 // Create either local label or external symbol.
1356 if (containsAddress(TargetAddress
)) {
1357 TargetSymbol
= getOrCreateLocalLabel(TargetAddress
);
1359 if (TargetAddress
== getAddress() + getSize() &&
1360 TargetAddress
< getAddress() + getMaxSize() &&
1362 BC
.handleAArch64Veneer(TargetAddress
, /*MatchOnly*/ true))) {
1363 // Result of __builtin_unreachable().
1364 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: jump past end detected at 0x"
1365 << Twine::utohexstr(AbsoluteInstrAddr
)
1366 << " in function " << *this
1367 << " : replacing with nop.\n");
1368 BC
.MIB
->createNoop(Instruction
);
1370 // Register branch offset for profile validation.
1371 IgnoredBranches
.emplace_back(Offset
, Offset
+ Size
);
1373 goto add_instruction
;
1375 // May update Instruction and IsCall
1376 TargetSymbol
= handleExternalReference(Instruction
, Size
, Offset
,
1377 TargetAddress
, IsCall
);
1382 // Add taken branch info.
1383 TakenBranches
.emplace_back(Offset
, TargetAddress
- getAddress());
1385 BC
.MIB
->replaceBranchTarget(Instruction
, TargetSymbol
, &*Ctx
);
1388 if (IsCondBranch
&& IsCall
)
1389 MIB
->setConditionalTailCall(Instruction
, TargetAddress
);
1391 // Could not evaluate branch. Should be an indirect call or an
1392 // indirect branch. Bail out on the latter case.
1393 if (MIB
->isIndirectBranch(Instruction
))
1394 handleIndirectBranch(Instruction
, Size
, Offset
);
1395 // Indirect call. We only need to fix it if the operand is RIP-relative.
1396 if (IsSimple
&& MIB
->hasPCRelOperand(Instruction
)) {
1397 if (auto NewE
= handleErrors(
1398 handlePCRelOperand(Instruction
, AbsoluteInstrAddr
, Size
),
1399 [&](const BOLTError
&E
) -> Error
{
1401 return Error(std::make_unique
<BOLTError
>(std::move(E
)));
1402 if (!E
.getMessage().empty())
1404 return Error::success();
1406 return Error(std::move(NewE
));
1411 handleAArch64IndirectCall(Instruction
, Offset
);
1413 } else if (BC
.isAArch64() || BC
.isRISCV()) {
1414 // Check if there's a relocation associated with this instruction.
1415 bool UsedReloc
= false;
1416 for (auto Itr
= Relocations
.lower_bound(Offset
),
1417 ItrE
= Relocations
.lower_bound(Offset
+ Size
);
1418 Itr
!= ItrE
; ++Itr
) {
1419 const Relocation
&Relocation
= Itr
->second
;
1420 MCSymbol
*Symbol
= Relocation
.Symbol
;
1422 if (Relocation::isInstructionReference(Relocation
.Type
)) {
1423 uint64_t RefOffset
= Relocation
.Value
- getAddress();
1424 LabelsMapType::iterator LI
= InstructionLabels
.find(RefOffset
);
1426 if (LI
== InstructionLabels
.end()) {
1427 Symbol
= BC
.Ctx
->createNamedTempSymbol();
1428 InstructionLabels
.emplace(RefOffset
, Symbol
);
1430 Symbol
= LI
->second
;
1434 int64_t Value
= Relocation
.Value
;
1435 const bool Result
= BC
.MIB
->replaceImmWithSymbolRef(
1436 Instruction
, Symbol
, Relocation
.Addend
, Ctx
.get(), Value
,
1439 assert(Result
&& "cannot replace immediate with relocation");
1441 // For aarch64, if we replaced an immediate with a symbol from a
1442 // relocation, we mark it so we do not try to further process a
1443 // pc-relative operand. All we need is the symbol.
1447 if (!BC
.isRISCV() && MIB
->hasPCRelOperand(Instruction
) && !UsedReloc
) {
1448 if (auto NewE
= handleErrors(
1449 handlePCRelOperand(Instruction
, AbsoluteInstrAddr
, Size
),
1450 [&](const BOLTError
&E
) -> Error
{
1452 return Error(std::make_unique
<BOLTError
>(std::move(E
)));
1453 if (!E
.getMessage().empty())
1455 return Error::success();
1457 return Error(std::move(NewE
));
1462 if (getDWARFLineTable()) {
1463 Instruction
.setLoc(findDebugLineInformationForInstructionAt(
1464 AbsoluteInstrAddr
, getDWARFUnit(), getDWARFLineTable()));
1467 // Record offset of the instruction for profile matching.
1468 if (BC
.keepOffsetForInstruction(Instruction
))
1469 MIB
->setOffset(Instruction
, static_cast<uint32_t>(Offset
));
1471 if (BC
.isX86() && BC
.MIB
->isNoop(Instruction
)) {
1472 // NOTE: disassembly loses the correct size information for noops on x86.
1473 // E.g. nopw 0x0(%rax,%rax,1) is 9 bytes, but re-encoded it's only
1474 // 5 bytes. Preserve the size info using annotations.
1475 MIB
->setSize(Instruction
, Size
);
1478 addInstruction(Offset
, std::move(Instruction
));
1481 for (auto [Offset
, Label
] : InstructionLabels
) {
1482 InstrMapType::iterator II
= Instructions
.find(Offset
);
1483 assert(II
!= Instructions
.end() && "reference to non-existing instruction");
1485 BC
.MIB
->setInstLabel(II
->second
, Label
);
1488 // Reset symbolizer for the disassembler.
1489 BC
.SymbolicDisAsm
->setSymbolizer(nullptr);
1491 if (uint64_t Offset
= getFirstInstructionOffset())
1492 Labels
[Offset
] = BC
.Ctx
->createNamedTempSymbol();
1494 clearList(Relocations
);
1497 clearList(Instructions
);
1498 return createNonFatalBOLTError("");
1501 updateState(State::Disassembled
);
1503 return Error::success();
1506 MCSymbol
*BinaryFunction::registerBranch(uint64_t Src
, uint64_t Dst
) {
1507 assert(CurrentState
== State::Disassembled
&&
1508 "Cannot register branch unless function is in disassembled state.");
1509 assert(containsAddress(Src
) && containsAddress(Dst
) &&
1510 "Cannot register external branch.");
1511 MCSymbol
*Target
= getOrCreateLocalLabel(Dst
);
1512 TakenBranches
.emplace_back(Src
- getAddress(), Dst
- getAddress());
1516 bool BinaryFunction::scanExternalRefs() {
1517 bool Success
= true;
1518 bool DisassemblyFailed
= false;
1520 // Ignore pseudo functions.
1525 clearList(Relocations
);
1526 clearList(ExternallyReferencedOffsets
);
1531 // List of external references for this function.
1532 std::vector
<Relocation
> FunctionRelocations
;
1534 static BinaryContext::IndependentCodeEmitter Emitter
=
1535 BC
.createIndependentMCCodeEmitter();
1537 ErrorOr
<ArrayRef
<uint8_t>> ErrorOrFunctionData
= getData();
1538 assert(ErrorOrFunctionData
&& "function data is not available");
1539 ArrayRef
<uint8_t> FunctionData
= *ErrorOrFunctionData
;
1540 assert(FunctionData
.size() == getMaxSize() &&
1541 "function size does not match raw data size");
1543 BC
.SymbolicDisAsm
->setSymbolizer(
1544 BC
.MIB
->createTargetSymbolizer(*this, /*CreateSymbols*/ false));
1546 // Disassemble contents of the function. Detect code entry points and create
1547 // relocations for references to code that will be moved.
1548 uint64_t Size
= 0; // instruction size
1549 for (uint64_t Offset
= 0; Offset
< getSize(); Offset
+= Size
) {
1550 // Check for data inside code and ignore it
1551 if (const size_t DataInCodeSize
= getSizeOfDataInCodeAt(Offset
)) {
1552 Size
= DataInCodeSize
;
1556 const uint64_t AbsoluteInstrAddr
= getAddress() + Offset
;
1558 if (!BC
.SymbolicDisAsm
->getInstruction(Instruction
, Size
,
1559 FunctionData
.slice(Offset
),
1560 AbsoluteInstrAddr
, nulls())) {
1561 if (opts::Verbosity
>= 1 && !isZeroPaddingAt(Offset
)) {
1563 << "BOLT-WARNING: unable to disassemble instruction at offset 0x"
1564 << Twine::utohexstr(Offset
) << " (address 0x"
1565 << Twine::utohexstr(AbsoluteInstrAddr
) << ") in function " << *this
1569 DisassemblyFailed
= true;
1573 // Return true if we can skip handling the Target function reference.
1574 auto ignoreFunctionRef
= [&](const BinaryFunction
&Target
) {
1575 if (&Target
== this)
1578 // Note that later we may decide not to emit Target function. In that
1579 // case, we conservatively create references that will be ignored or
1580 // resolved to the same function.
1581 if (!BC
.shouldEmit(Target
))
1587 // Return true if we can ignore reference to the symbol.
1588 auto ignoreReference
= [&](const MCSymbol
*TargetSymbol
) {
1592 if (BC
.forceSymbolRelocations(TargetSymbol
->getName()))
1595 BinaryFunction
*TargetFunction
= BC
.getFunctionForSymbol(TargetSymbol
);
1596 if (!TargetFunction
)
1599 return ignoreFunctionRef(*TargetFunction
);
1602 // Handle calls and branches separately as symbolization doesn't work for
1604 MCSymbol
*BranchTargetSymbol
= nullptr;
1605 if (BC
.MIB
->isCall(Instruction
) || BC
.MIB
->isBranch(Instruction
)) {
1606 uint64_t TargetAddress
= 0;
1607 BC
.MIB
->evaluateBranch(Instruction
, AbsoluteInstrAddr
, Size
,
1610 // Create an entry point at reference address if needed.
1611 BinaryFunction
*TargetFunction
=
1612 BC
.getBinaryFunctionContainingAddress(TargetAddress
);
1614 if (!TargetFunction
|| ignoreFunctionRef(*TargetFunction
))
1617 const uint64_t FunctionOffset
=
1618 TargetAddress
- TargetFunction
->getAddress();
1619 BranchTargetSymbol
=
1620 FunctionOffset
? TargetFunction
->addEntryPointAtOffset(FunctionOffset
)
1621 : TargetFunction
->getSymbol();
1624 // Can't find more references. Not creating relocations since we are not
1626 if (!BC
.HasRelocations
)
1629 if (BranchTargetSymbol
) {
1630 BC
.MIB
->replaceBranchTarget(Instruction
, BranchTargetSymbol
,
1631 Emitter
.LocalCtx
.get());
1632 } else if (!llvm::any_of(Instruction
,
1633 [](const MCOperand
&Op
) { return Op
.isExpr(); })) {
1634 // Skip assembly if the instruction may not have any symbolic operands.
1638 // Emit the instruction using temp emitter and generate relocations.
1639 SmallString
<256> Code
;
1640 SmallVector
<MCFixup
, 4> Fixups
;
1641 Emitter
.MCE
->encodeInstruction(Instruction
, Code
, Fixups
, *BC
.STI
);
1643 // Create relocation for every fixup.
1644 for (const MCFixup
&Fixup
: Fixups
) {
1645 std::optional
<Relocation
> Rel
= BC
.MIB
->createRelocation(Fixup
, *BC
.MAB
);
1651 if (ignoreReference(Rel
->Symbol
))
1654 if (Relocation::getSizeForType(Rel
->Type
) < 4) {
1655 // If the instruction uses a short form, then we might not be able
1656 // to handle the rewrite without relaxation, and hence cannot reliably
1657 // create an external reference relocation.
1661 Rel
->Offset
+= getAddress() - getOriginSection()->getAddress() + Offset
;
1662 FunctionRelocations
.push_back(*Rel
);
1669 // Reset symbolizer for the disassembler.
1670 BC
.SymbolicDisAsm
->setSymbolizer(nullptr);
1672 // Add relocations unless disassembly failed for this function.
1673 if (!DisassemblyFailed
)
1674 for (Relocation
&Rel
: FunctionRelocations
)
1675 getOriginSection()->addPendingRelocation(Rel
);
1677 // Inform BinaryContext that this function symbols will not be defined and
1678 // relocations should not be created against them.
1679 if (BC
.HasRelocations
) {
1680 for (std::pair
<const uint32_t, MCSymbol
*> &LI
: Labels
)
1681 BC
.UndefinedSymbols
.insert(LI
.second
);
1682 for (MCSymbol
*const EndLabel
: FunctionEndLabels
)
1684 BC
.UndefinedSymbols
.insert(EndLabel
);
1687 clearList(Relocations
);
1688 clearList(ExternallyReferencedOffsets
);
1690 if (Success
&& BC
.HasRelocations
)
1691 HasExternalRefRelocations
= true;
1693 if (opts::Verbosity
>= 1 && !Success
)
1694 BC
.outs() << "BOLT-INFO: failed to scan refs for " << *this << '\n';
1699 void BinaryFunction::postProcessEntryPoints() {
1703 for (auto &KV
: Labels
) {
1704 MCSymbol
*Label
= KV
.second
;
1705 if (!getSecondaryEntryPointSymbol(Label
))
1708 // In non-relocation mode there's potentially an external undetectable
1709 // reference to the entry point and hence we cannot move this entry
1710 // point. Optimizing without moving could be difficult.
1711 // In BAT mode, register any known entry points for CFG construction.
1712 if (!BC
.HasRelocations
&& !BC
.HasBATSection
)
1715 const uint32_t Offset
= KV
.first
;
1717 // If we are at Offset 0 and there is no instruction associated with it,
1718 // this means this is an empty function. Just ignore. If we find an
1719 // instruction at this offset, this entry point is valid.
1720 if (!Offset
|| getInstructionAtOffset(Offset
))
1723 // On AArch64 there are legitimate reasons to have references past the
1724 // end of the function, e.g. jump tables.
1725 if (BC
.isAArch64() && Offset
== getSize())
1728 BC
.errs() << "BOLT-WARNING: reference in the middle of instruction "
1729 "detected in function "
1730 << *this << " at offset 0x" << Twine::utohexstr(Offset
) << '\n';
1731 if (BC
.HasRelocations
)
1738 void BinaryFunction::postProcessJumpTables() {
1739 // Create labels for all entries.
1740 for (auto &JTI
: JumpTables
) {
1741 JumpTable
&JT
= *JTI
.second
;
1742 if (JT
.Type
== JumpTable::JTT_PIC
&& opts::JumpTables
== JTS_BASIC
) {
1743 opts::JumpTables
= JTS_MOVE
;
1744 BC
.outs() << "BOLT-INFO: forcing -jump-tables=move as PIC jump table was "
1745 "detected in function "
1748 const uint64_t BDSize
=
1749 BC
.getBinaryDataAtAddress(JT
.getAddress())->getSize();
1751 BC
.setBinaryDataSize(JT
.getAddress(), JT
.getSize());
1753 assert(BDSize
>= JT
.getSize() &&
1754 "jump table cannot be larger than the containing object");
1756 if (!JT
.Entries
.empty())
1759 bool HasOneParent
= (JT
.Parents
.size() == 1);
1760 for (uint64_t EntryAddress
: JT
.EntriesAsAddress
) {
1761 // builtin_unreachable does not belong to any function
1762 // Need to handle separately
1763 bool IsBuiltinUnreachable
=
1764 llvm::any_of(JT
.Parents
, [&](const BinaryFunction
*Parent
) {
1765 return EntryAddress
== Parent
->getAddress() + Parent
->getSize();
1767 if (IsBuiltinUnreachable
) {
1768 MCSymbol
*Label
= getOrCreateLocalLabel(EntryAddress
, true);
1769 JT
.Entries
.push_back(Label
);
1772 // Create a local label for targets that cannot be reached by other
1773 // fragments. Otherwise, create a secondary entry point in the target
1775 BinaryFunction
*TargetBF
=
1776 BC
.getBinaryFunctionContainingAddress(EntryAddress
);
1778 if (HasOneParent
&& TargetBF
== this) {
1779 Label
= getOrCreateLocalLabel(EntryAddress
, true);
1781 const uint64_t Offset
= EntryAddress
- TargetBF
->getAddress();
1782 Label
= Offset
? TargetBF
->addEntryPointAtOffset(Offset
)
1783 : TargetBF
->getSymbol();
1785 JT
.Entries
.push_back(Label
);
1789 // Add TakenBranches from JumpTables.
1791 // We want to do it after initial processing since we don't know jump tables'
1792 // boundaries until we process them all.
1793 for (auto &JTSite
: JTSites
) {
1794 const uint64_t JTSiteOffset
= JTSite
.first
;
1795 const uint64_t JTAddress
= JTSite
.second
;
1796 const JumpTable
*JT
= getJumpTableContainingAddress(JTAddress
);
1797 assert(JT
&& "cannot find jump table for address");
1799 uint64_t EntryOffset
= JTAddress
- JT
->getAddress();
1800 while (EntryOffset
< JT
->getSize()) {
1801 uint64_t EntryAddress
= JT
->EntriesAsAddress
[EntryOffset
/ JT
->EntrySize
];
1802 uint64_t TargetOffset
= EntryAddress
- getAddress();
1803 if (TargetOffset
< getSize()) {
1804 TakenBranches
.emplace_back(JTSiteOffset
, TargetOffset
);
1806 if (opts::StrictMode
)
1807 registerReferencedOffset(TargetOffset
);
1810 EntryOffset
+= JT
->EntrySize
;
1812 // A label at the next entry means the end of this jump table.
1813 if (JT
->Labels
.count(EntryOffset
))
1819 // Conservatively populate all possible destinations for unknown indirect
1821 if (opts::StrictMode
&& hasInternalReference()) {
1822 for (uint64_t Offset
: UnknownIndirectBranchOffsets
) {
1823 for (uint64_t PossibleDestination
: ExternallyReferencedOffsets
) {
1824 // Ignore __builtin_unreachable().
1825 if (PossibleDestination
== getSize())
1827 TakenBranches
.emplace_back(Offset
, PossibleDestination
);
1833 bool BinaryFunction::validateExternallyReferencedOffsets() {
1834 SmallPtrSet
<MCSymbol
*, 4> JTTargets
;
1835 for (const JumpTable
*JT
: llvm::make_second_range(JumpTables
))
1836 JTTargets
.insert(JT
->Entries
.begin(), JT
->Entries
.end());
1838 bool HasUnclaimedReference
= false;
1839 for (uint64_t Destination
: ExternallyReferencedOffsets
) {
1840 // Ignore __builtin_unreachable().
1841 if (Destination
== getSize())
1843 // Ignore constant islands
1844 if (isInConstantIsland(Destination
+ getAddress()))
1847 if (BinaryBasicBlock
*BB
= getBasicBlockAtOffset(Destination
)) {
1848 // Check if the externally referenced offset is a recognized jump table
1850 if (JTTargets
.contains(BB
->getLabel()))
1853 if (opts::Verbosity
>= 1) {
1854 BC
.errs() << "BOLT-WARNING: unclaimed data to code reference (possibly "
1855 << "an unrecognized jump table entry) to " << BB
->getName()
1856 << " in " << *this << "\n";
1858 auto L
= BC
.scopeLock();
1861 BC
.errs() << "BOLT-WARNING: unknown data to code reference to offset "
1862 << Twine::utohexstr(Destination
) << " in " << *this << "\n";
1865 HasUnclaimedReference
= true;
1867 return !HasUnclaimedReference
;
1870 bool BinaryFunction::postProcessIndirectBranches(
1871 MCPlusBuilder::AllocatorIdTy AllocId
) {
1872 auto addUnknownControlFlow
= [&](BinaryBasicBlock
&BB
) {
1873 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: adding unknown control flow in " << *this
1874 << " for " << BB
.getName() << "\n");
1875 HasUnknownControlFlow
= true;
1876 BB
.removeAllSuccessors();
1877 for (uint64_t PossibleDestination
: ExternallyReferencedOffsets
)
1878 if (BinaryBasicBlock
*SuccBB
= getBasicBlockAtOffset(PossibleDestination
))
1879 BB
.addSuccessor(SuccBB
);
1882 uint64_t NumIndirectJumps
= 0;
1883 MCInst
*LastIndirectJump
= nullptr;
1884 BinaryBasicBlock
*LastIndirectJumpBB
= nullptr;
1885 uint64_t LastJT
= 0;
1886 uint16_t LastJTIndexReg
= BC
.MIB
->getNoRegister();
1887 for (BinaryBasicBlock
&BB
: blocks()) {
1888 for (BinaryBasicBlock::iterator II
= BB
.begin(); II
!= BB
.end(); ++II
) {
1889 MCInst
&Instr
= *II
;
1890 if (!BC
.MIB
->isIndirectBranch(Instr
))
1893 // If there's an indirect branch in a single-block function -
1894 // it must be a tail call.
1895 if (BasicBlocks
.size() == 1) {
1896 BC
.MIB
->convertJmpToTailCall(Instr
);
1902 if (opts::StrictMode
&& !hasInternalReference()) {
1903 BC
.MIB
->convertJmpToTailCall(Instr
);
1907 // Validate the tail call or jump table assumptions now that we know
1908 // basic block boundaries.
1909 if (BC
.MIB
->isTailCall(Instr
) || BC
.MIB
->getJumpTable(Instr
)) {
1910 const unsigned PtrSize
= BC
.AsmInfo
->getCodePointerSize();
1911 MCInst
*MemLocInstr
;
1912 unsigned BaseRegNum
, IndexRegNum
;
1914 const MCExpr
*DispExpr
;
1915 MCInst
*PCRelBaseInstr
;
1916 MCInst
*FixedEntryLoadInstr
;
1917 IndirectBranchType Type
= BC
.MIB
->analyzeIndirectBranch(
1918 Instr
, BB
.begin(), II
, PtrSize
, MemLocInstr
, BaseRegNum
,
1919 IndexRegNum
, DispValue
, DispExpr
, PCRelBaseInstr
,
1920 FixedEntryLoadInstr
);
1921 if (Type
!= IndirectBranchType::UNKNOWN
|| MemLocInstr
!= nullptr)
1924 if (!opts::StrictMode
)
1927 if (BC
.MIB
->isTailCall(Instr
)) {
1928 BC
.MIB
->convertTailCallToJmp(Instr
);
1930 LastIndirectJump
= &Instr
;
1931 LastIndirectJumpBB
= &BB
;
1932 LastJT
= BC
.MIB
->getJumpTable(Instr
);
1933 LastJTIndexReg
= BC
.MIB
->getJumpTableIndexReg(Instr
);
1934 BC
.MIB
->unsetJumpTable(Instr
);
1936 JumpTable
*JT
= BC
.getJumpTableContainingAddress(LastJT
);
1937 if (JT
->Type
== JumpTable::JTT_NORMAL
) {
1938 // Invalidating the jump table may also invalidate other jump table
1939 // boundaries. Until we have/need a support for this, mark the
1940 // function as non-simple.
1941 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: rejected jump table reference"
1942 << JT
->getName() << " in " << *this << '\n');
1947 addUnknownControlFlow(BB
);
1951 // If this block contains an epilogue code and has an indirect branch,
1952 // then most likely it's a tail call. Otherwise, we cannot tell for sure
1953 // what it is and conservatively reject the function's CFG.
1954 bool IsEpilogue
= llvm::any_of(BB
, [&](const MCInst
&Instr
) {
1955 return BC
.MIB
->isLeave(Instr
) || BC
.MIB
->isPop(Instr
);
1958 BC
.MIB
->convertJmpToTailCall(Instr
);
1959 BB
.removeAllSuccessors();
1963 if (opts::Verbosity
>= 2) {
1964 BC
.outs() << "BOLT-INFO: rejected potential indirect tail call in "
1965 << "function " << *this << " in basic block " << BB
.getName()
1967 LLVM_DEBUG(BC
.printInstructions(dbgs(), BB
.begin(), BB
.end(),
1968 BB
.getOffset(), this, true));
1971 if (!opts::StrictMode
)
1974 addUnknownControlFlow(BB
);
1978 if (HasInternalLabelReference
)
1981 // If there's only one jump table, and one indirect jump, and no other
1982 // references, then we should be able to derive the jump table even if we
1983 // fail to match the pattern.
1984 if (HasUnknownControlFlow
&& NumIndirectJumps
== 1 &&
1985 JumpTables
.size() == 1 && LastIndirectJump
&&
1986 !BC
.getJumpTableContainingAddress(LastJT
)->IsSplit
) {
1987 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: unsetting unknown control flow in "
1989 BC
.MIB
->setJumpTable(*LastIndirectJump
, LastJT
, LastJTIndexReg
, AllocId
);
1990 HasUnknownControlFlow
= false;
1992 LastIndirectJumpBB
->updateJumpTableSuccessors();
1995 // Validate that all data references to function offsets are claimed by
1996 // recognized jump tables. Register externally referenced blocks as entry
1998 if (!opts::StrictMode
&& hasInternalReference()) {
1999 if (!validateExternallyReferencedOffsets())
2003 if (HasUnknownControlFlow
&& !BC
.HasRelocations
)
2009 void BinaryFunction::recomputeLandingPads() {
2012 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
2013 BB
->LandingPads
.clear();
2014 BB
->Throwers
.clear();
2017 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
2018 std::unordered_set
<const BinaryBasicBlock
*> BBLandingPads
;
2019 for (MCInst
&Instr
: *BB
) {
2020 if (!BC
.MIB
->isInvoke(Instr
))
2023 const std::optional
<MCPlus::MCLandingPad
> EHInfo
=
2024 BC
.MIB
->getEHInfo(Instr
);
2025 if (!EHInfo
|| !EHInfo
->first
)
2028 BinaryBasicBlock
*LPBlock
= getBasicBlockForLabel(EHInfo
->first
);
2029 if (!BBLandingPads
.count(LPBlock
)) {
2030 BBLandingPads
.insert(LPBlock
);
2031 BB
->LandingPads
.emplace_back(LPBlock
);
2032 LPBlock
->Throwers
.emplace_back(BB
);
2038 Error
BinaryFunction::buildCFG(MCPlusBuilder::AllocatorIdTy AllocatorId
) {
2042 assert(!BC
.HasRelocations
&&
2043 "cannot process file with non-simple function in relocs mode");
2044 return createNonFatalBOLTError("");
2047 if (CurrentState
!= State::Disassembled
)
2048 return createNonFatalBOLTError("");
2050 assert(BasicBlocks
.empty() && "basic block list should be empty");
2051 assert((Labels
.find(getFirstInstructionOffset()) != Labels
.end()) &&
2052 "first instruction should always have a label");
2054 // Create basic blocks in the original layout order:
2056 // * Every instruction with associated label marks
2057 // the beginning of a basic block.
2058 // * Conditional instruction marks the end of a basic block,
2059 // except when the following instruction is an
2060 // unconditional branch, and the unconditional branch is not
2061 // a destination of another branch. In the latter case, the
2062 // basic block will consist of a single unconditional branch
2063 // (missed "double-jump" optimization).
2065 // Created basic blocks are sorted in layout order since they are
2066 // created in the same order as instructions, and instructions are
2067 // sorted by offsets.
2068 BinaryBasicBlock
*InsertBB
= nullptr;
2069 BinaryBasicBlock
*PrevBB
= nullptr;
2070 bool IsLastInstrNop
= false;
2071 // Offset of the last non-nop instruction.
2072 uint64_t LastInstrOffset
= 0;
2074 auto addCFIPlaceholders
= [this](uint64_t CFIOffset
,
2075 BinaryBasicBlock
*InsertBB
) {
2076 for (auto FI
= OffsetToCFI
.lower_bound(CFIOffset
),
2077 FE
= OffsetToCFI
.upper_bound(CFIOffset
);
2079 addCFIPseudo(InsertBB
, InsertBB
->end(), FI
->second
);
2083 // For profiling purposes we need to save the offset of the last instruction
2084 // in the basic block.
2085 // NOTE: nops always have an Offset annotation. Annotate the last non-nop as
2086 // older profiles ignored nops.
2087 auto updateOffset
= [&](uint64_t Offset
) {
2088 assert(PrevBB
&& PrevBB
!= InsertBB
&& "invalid previous block");
2089 MCInst
*LastNonNop
= nullptr;
2090 for (BinaryBasicBlock::reverse_iterator RII
= PrevBB
->getLastNonPseudo(),
2093 if (!BC
.MIB
->isPseudo(*RII
) && !BC
.MIB
->isNoop(*RII
)) {
2098 if (LastNonNop
&& !MIB
->getOffset(*LastNonNop
))
2099 MIB
->setOffset(*LastNonNop
, static_cast<uint32_t>(Offset
));
2102 for (auto I
= Instructions
.begin(), E
= Instructions
.end(); I
!= E
; ++I
) {
2103 const uint32_t Offset
= I
->first
;
2104 MCInst
&Instr
= I
->second
;
2106 auto LI
= Labels
.find(Offset
);
2107 if (LI
!= Labels
.end()) {
2108 // Always create new BB at branch destination.
2109 PrevBB
= InsertBB
? InsertBB
: PrevBB
;
2110 InsertBB
= addBasicBlockAt(LI
->first
, LI
->second
);
2111 if (opts::PreserveBlocksAlignment
&& IsLastInstrNop
)
2112 InsertBB
->setDerivedAlignment();
2115 updateOffset(LastInstrOffset
);
2118 // Mark all nops with Offset for profile tracking purposes.
2119 if (MIB
->isNoop(Instr
) && !MIB
->getOffset(Instr
)) {
2120 // If "Offset" annotation is not present, set it and mark the nop for
2122 MIB
->setOffset(Instr
, static_cast<uint32_t>(Offset
));
2123 // Annotate ordinary nops, so we can safely delete them if required.
2124 MIB
->addAnnotation(Instr
, "NOP", static_cast<uint32_t>(1), AllocatorId
);
2128 // It must be a fallthrough or unreachable code. Create a new block unless
2129 // we see an unconditional branch following a conditional one. The latter
2130 // should not be a conditional tail call.
2131 assert(PrevBB
&& "no previous basic block for a fall through");
2132 MCInst
*PrevInstr
= PrevBB
->getLastNonPseudoInstr();
2133 assert(PrevInstr
&& "no previous instruction for a fall through");
2134 if (MIB
->isUnconditionalBranch(Instr
) &&
2135 !MIB
->isIndirectBranch(*PrevInstr
) &&
2136 !MIB
->isUnconditionalBranch(*PrevInstr
) &&
2137 !MIB
->getConditionalTailCall(*PrevInstr
) &&
2138 !MIB
->isReturn(*PrevInstr
)) {
2139 // Temporarily restore inserter basic block.
2144 auto L
= BC
.scopeLock();
2145 Label
= BC
.Ctx
->createNamedTempSymbol("FT");
2147 InsertBB
= addBasicBlockAt(Offset
, Label
);
2148 if (opts::PreserveBlocksAlignment
&& IsLastInstrNop
)
2149 InsertBB
->setDerivedAlignment();
2150 updateOffset(LastInstrOffset
);
2153 if (Offset
== getFirstInstructionOffset()) {
2154 // Add associated CFI pseudos in the first offset
2155 addCFIPlaceholders(Offset
, InsertBB
);
2158 const bool IsBlockEnd
= MIB
->isTerminator(Instr
);
2159 IsLastInstrNop
= MIB
->isNoop(Instr
);
2160 if (!IsLastInstrNop
)
2161 LastInstrOffset
= Offset
;
2162 InsertBB
->addInstruction(std::move(Instr
));
2164 // Add associated CFI instrs. We always add the CFI instruction that is
2165 // located immediately after this instruction, since the next CFI
2166 // instruction reflects the change in state caused by this instruction.
2167 auto NextInstr
= std::next(I
);
2170 CFIOffset
= NextInstr
->first
;
2172 CFIOffset
= getSize();
2174 // Note: this potentially invalidates instruction pointers/iterators.
2175 addCFIPlaceholders(CFIOffset
, InsertBB
);
2183 if (BasicBlocks
.empty()) {
2185 return createNonFatalBOLTError("");
2188 // Intermediate dump.
2189 LLVM_DEBUG(print(dbgs(), "after creating basic blocks"));
2191 // TODO: handle properly calls to no-return functions,
2192 // e.g. exit(3), etc. Otherwise we'll see a false fall-through
2195 // Remove duplicates branches. We can get a bunch of them from jump tables.
2196 // Without doing jump table value profiling we don't have a use for extra
2197 // (duplicate) branches.
2198 llvm::sort(TakenBranches
);
2199 auto NewEnd
= std::unique(TakenBranches
.begin(), TakenBranches
.end());
2200 TakenBranches
.erase(NewEnd
, TakenBranches
.end());
2202 for (std::pair
<uint32_t, uint32_t> &Branch
: TakenBranches
) {
2203 LLVM_DEBUG(dbgs() << "registering branch [0x"
2204 << Twine::utohexstr(Branch
.first
) << "] -> [0x"
2205 << Twine::utohexstr(Branch
.second
) << "]\n");
2206 BinaryBasicBlock
*FromBB
= getBasicBlockContainingOffset(Branch
.first
);
2207 BinaryBasicBlock
*ToBB
= getBasicBlockAtOffset(Branch
.second
);
2208 if (!FromBB
|| !ToBB
) {
2210 BC
.errs() << "BOLT-ERROR: cannot find BB containing the branch.\n";
2213 << "BOLT-ERROR: cannot find BB containing branch destination.\n";
2214 return createFatalBOLTError(BC
.generateBugReportMessage(
2215 "disassembly failed - inconsistent branch found.", *this));
2218 FromBB
->addSuccessor(ToBB
);
2221 // Add fall-through branches.
2223 bool IsPrevFT
= false; // Is previous block a fall-through.
2224 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
2226 PrevBB
->addSuccessor(BB
);
2234 MCInst
*LastInstr
= BB
->getLastNonPseudoInstr();
2236 "should have non-pseudo instruction in non-empty block");
2238 if (BB
->succ_size() == 0) {
2239 // Since there's no existing successors, we know the last instruction is
2240 // not a conditional branch. Thus if it's a terminator, it shouldn't be a
2243 // Conditional tail call is a special case since we don't add a taken
2244 // branch successor for it.
2245 IsPrevFT
= !MIB
->isTerminator(*LastInstr
) ||
2246 MIB
->getConditionalTailCall(*LastInstr
);
2247 } else if (BB
->succ_size() == 1) {
2248 IsPrevFT
= MIB
->isConditionalBranch(*LastInstr
);
2256 // Assign landing pads and throwers info.
2257 recomputeLandingPads();
2259 // Assign CFI information to each BB entry.
2262 // Annotate invoke instructions with GNU_args_size data.
2263 propagateGnuArgsSizeInfo(AllocatorId
);
2265 // Set the basic block layout to the original order and set end offsets.
2267 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
2268 Layout
.addBasicBlock(BB
);
2270 PrevBB
->setEndOffset(BB
->getOffset());
2273 PrevBB
->setEndOffset(getSize());
2275 Layout
.updateLayoutIndices();
2277 normalizeCFIState();
2279 // Clean-up memory taken by intermediate structures.
2281 // NB: don't clear Labels list as we may need them if we mark the function
2282 // as non-simple later in the process of discovering extra entry points.
2283 clearList(Instructions
);
2284 clearList(OffsetToCFI
);
2285 clearList(TakenBranches
);
2287 // Update the state.
2288 CurrentState
= State::CFG
;
2290 // Make any necessary adjustments for indirect branches.
2291 if (!postProcessIndirectBranches(AllocatorId
)) {
2292 if (opts::Verbosity
) {
2293 BC
.errs() << "BOLT-WARNING: failed to post-process indirect branches for "
2296 // In relocation mode we want to keep processing the function but avoid
2301 clearList(ExternallyReferencedOffsets
);
2302 clearList(UnknownIndirectBranchOffsets
);
2304 return Error::success();
2307 void BinaryFunction::postProcessCFG() {
2308 if (isSimple() && !BasicBlocks
.empty()) {
2309 // Convert conditional tail call branches to conditional branches that jump
2311 removeConditionalTailCalls();
2313 postProcessProfile();
2315 // Eliminate inconsistencies between branch instructions and CFG.
2316 postProcessBranches();
2319 // The final cleanup of intermediate structures.
2320 clearList(IgnoredBranches
);
2322 // Remove "Offset" annotations, unless we need an address-translation table
2323 // later. This has no cost, since annotations are allocated by a bumpptr
2324 // allocator and won't be released anyway until late in the pipeline.
2325 if (!requiresAddressTranslation() && !opts::Instrument
) {
2326 for (BinaryBasicBlock
&BB
: blocks())
2327 for (MCInst
&Inst
: BB
)
2328 BC
.MIB
->clearOffset(Inst
);
2331 assert((!isSimple() || validateCFG()) &&
2332 "invalid CFG detected after post-processing");
2335 void BinaryFunction::removeTagsFromProfile() {
2336 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
2337 if (BB
->ExecutionCount
== BinaryBasicBlock::COUNT_NO_PROFILE
)
2338 BB
->ExecutionCount
= 0;
2339 for (BinaryBasicBlock::BinaryBranchInfo
&BI
: BB
->branch_info()) {
2340 if (BI
.Count
!= BinaryBasicBlock::COUNT_NO_PROFILE
&&
2341 BI
.MispredictedCount
!= BinaryBasicBlock::COUNT_NO_PROFILE
)
2344 BI
.MispredictedCount
= 0;
2349 void BinaryFunction::removeConditionalTailCalls() {
2350 // Blocks to be appended at the end.
2351 std::vector
<std::unique_ptr
<BinaryBasicBlock
>> NewBlocks
;
2353 for (auto BBI
= begin(); BBI
!= end(); ++BBI
) {
2354 BinaryBasicBlock
&BB
= *BBI
;
2355 MCInst
*CTCInstr
= BB
.getLastNonPseudoInstr();
2359 std::optional
<uint64_t> TargetAddressOrNone
=
2360 BC
.MIB
->getConditionalTailCall(*CTCInstr
);
2361 if (!TargetAddressOrNone
)
2364 // Gather all necessary information about CTC instruction before
2365 // annotations are destroyed.
2366 const int32_t CFIStateBeforeCTC
= BB
.getCFIStateAtInstr(CTCInstr
);
2367 uint64_t CTCTakenCount
= BinaryBasicBlock::COUNT_NO_PROFILE
;
2368 uint64_t CTCMispredCount
= BinaryBasicBlock::COUNT_NO_PROFILE
;
2369 if (hasValidProfile()) {
2370 CTCTakenCount
= BC
.MIB
->getAnnotationWithDefault
<uint64_t>(
2371 *CTCInstr
, "CTCTakenCount");
2372 CTCMispredCount
= BC
.MIB
->getAnnotationWithDefault
<uint64_t>(
2373 *CTCInstr
, "CTCMispredCount");
2376 // Assert that the tail call does not throw.
2377 assert(!BC
.MIB
->getEHInfo(*CTCInstr
) &&
2378 "found tail call with associated landing pad");
2380 // Create a basic block with an unconditional tail call instruction using
2381 // the same destination.
2382 const MCSymbol
*CTCTargetLabel
= BC
.MIB
->getTargetSymbol(*CTCInstr
);
2383 assert(CTCTargetLabel
&& "symbol expected for conditional tail call");
2384 MCInst TailCallInstr
;
2385 BC
.MIB
->createTailCall(TailCallInstr
, CTCTargetLabel
, BC
.Ctx
.get());
2387 // Move offset from CTCInstr to TailCallInstr.
2388 if (const std::optional
<uint32_t> Offset
= BC
.MIB
->getOffset(*CTCInstr
)) {
2389 BC
.MIB
->setOffset(TailCallInstr
, *Offset
);
2390 BC
.MIB
->clearOffset(*CTCInstr
);
2393 // Link new BBs to the original input offset of the BB where the CTC
2394 // is, so we can map samples recorded in new BBs back to the original BB
2395 // seem in the input binary (if using BAT)
2396 std::unique_ptr
<BinaryBasicBlock
> TailCallBB
=
2397 createBasicBlock(BC
.Ctx
->createNamedTempSymbol("TC"));
2398 TailCallBB
->setOffset(BB
.getInputOffset());
2399 TailCallBB
->addInstruction(TailCallInstr
);
2400 TailCallBB
->setCFIState(CFIStateBeforeCTC
);
2402 // Add CFG edge with profile info from BB to TailCallBB.
2403 BB
.addSuccessor(TailCallBB
.get(), CTCTakenCount
, CTCMispredCount
);
2405 // Add execution count for the block.
2406 TailCallBB
->setExecutionCount(CTCTakenCount
);
2408 BC
.MIB
->convertTailCallToJmp(*CTCInstr
);
2410 BC
.MIB
->replaceBranchTarget(*CTCInstr
, TailCallBB
->getLabel(),
2413 // Add basic block to the list that will be added to the end.
2414 NewBlocks
.emplace_back(std::move(TailCallBB
));
2416 // Swap edges as the TailCallBB corresponds to the taken branch.
2417 BB
.swapConditionalSuccessors();
2419 // This branch is no longer a conditional tail call.
2420 BC
.MIB
->unsetConditionalTailCall(*CTCInstr
);
2423 insertBasicBlocks(std::prev(end()), std::move(NewBlocks
),
2424 /* UpdateLayout */ true,
2425 /* UpdateCFIState */ false);
2428 uint64_t BinaryFunction::getFunctionScore() const {
2429 if (FunctionScore
!= -1)
2430 return FunctionScore
;
2432 if (!isSimple() || !hasValidProfile()) {
2434 return FunctionScore
;
2437 uint64_t TotalScore
= 0ULL;
2438 for (const BinaryBasicBlock
&BB
: blocks()) {
2439 uint64_t BBExecCount
= BB
.getExecutionCount();
2440 if (BBExecCount
== BinaryBasicBlock::COUNT_NO_PROFILE
)
2442 TotalScore
+= BBExecCount
* BB
.getNumNonPseudos();
2444 FunctionScore
= TotalScore
;
2445 return FunctionScore
;
2448 void BinaryFunction::annotateCFIState() {
2449 assert(CurrentState
== State::Disassembled
&& "unexpected function state");
2450 assert(!BasicBlocks
.empty() && "basic block list should not be empty");
2452 // This is an index of the last processed CFI in FDE CFI program.
2455 // This is an index of RememberState CFI reflecting effective state right
2456 // after execution of RestoreState CFI.
2458 // It differs from State iff the CFI at (State-1)
2459 // was RestoreState (modulo GNU_args_size CFIs, which are ignored).
2461 // This allows us to generate shorter replay sequences when producing new
2463 uint32_t EffectiveState
= 0;
2465 // For tracking RememberState/RestoreState sequences.
2466 std::stack
<uint32_t> StateStack
;
2468 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
2469 BB
->setCFIState(EffectiveState
);
2471 for (const MCInst
&Instr
: *BB
) {
2472 const MCCFIInstruction
*CFI
= getCFIFor(Instr
);
2478 switch (CFI
->getOperation()) {
2479 case MCCFIInstruction::OpRememberState
:
2480 StateStack
.push(EffectiveState
);
2481 EffectiveState
= State
;
2483 case MCCFIInstruction::OpRestoreState
:
2484 assert(!StateStack
.empty() && "corrupt CFI stack");
2485 EffectiveState
= StateStack
.top();
2488 case MCCFIInstruction::OpGnuArgsSize
:
2489 // OpGnuArgsSize CFIs do not affect the CFI state.
2492 // Any other CFI updates the state.
2493 EffectiveState
= State
;
2499 if (opts::Verbosity
>= 1 && !StateStack
.empty()) {
2500 BC
.errs() << "BOLT-WARNING: non-empty CFI stack at the end of " << *this
2507 /// Our full interpretation of a DWARF CFI machine state at a given point
2508 struct CFISnapshot
{
2509 /// CFA register number and offset defining the canonical frame at this
2510 /// point, or the number of a rule (CFI state) that computes it with a
2511 /// DWARF expression. This number will be negative if it refers to a CFI
2512 /// located in the CIE instead of the FDE.
2516 /// Mapping of rules (CFI states) that define the location of each
2517 /// register. If absent, no rule defining the location of such register
2518 /// was ever read. This number will be negative if it refers to a CFI
2519 /// located in the CIE instead of the FDE.
2520 DenseMap
<int32_t, int32_t> RegRule
;
2522 /// References to CIE, FDE and expanded instructions after a restore state
2523 const BinaryFunction::CFIInstrMapType
&CIE
;
2524 const BinaryFunction::CFIInstrMapType
&FDE
;
2525 const DenseMap
<int32_t, SmallVector
<int32_t, 4>> &FrameRestoreEquivalents
;
2527 /// Current FDE CFI number representing the state where the snapshot is at
2530 /// Used when we don't have information about which state/rule to apply
2531 /// to recover the location of either the CFA or a specific register
2532 constexpr static int32_t UNKNOWN
= std::numeric_limits
<int32_t>::min();
2535 /// Update our snapshot by executing a single CFI
2536 void update(const MCCFIInstruction
&Instr
, int32_t RuleNumber
) {
2537 switch (Instr
.getOperation()) {
2538 case MCCFIInstruction::OpSameValue
:
2539 case MCCFIInstruction::OpRelOffset
:
2540 case MCCFIInstruction::OpOffset
:
2541 case MCCFIInstruction::OpRestore
:
2542 case MCCFIInstruction::OpUndefined
:
2543 case MCCFIInstruction::OpRegister
:
2544 RegRule
[Instr
.getRegister()] = RuleNumber
;
2546 case MCCFIInstruction::OpDefCfaRegister
:
2547 CFAReg
= Instr
.getRegister();
2550 // This shouldn't happen according to the spec but GNU binutils on RISC-V
2551 // emits a DW_CFA_def_cfa_register in CIE's which leaves the offset
2552 // unspecified. Both readelf and llvm-dwarfdump interpret the offset as 0
2553 // in this case so let's do the same.
2554 if (CFAOffset
== UNKNOWN
)
2557 case MCCFIInstruction::OpDefCfaOffset
:
2558 CFAOffset
= Instr
.getOffset();
2561 case MCCFIInstruction::OpDefCfa
:
2562 CFAReg
= Instr
.getRegister();
2563 CFAOffset
= Instr
.getOffset();
2566 case MCCFIInstruction::OpEscape
: {
2567 std::optional
<uint8_t> Reg
=
2568 readDWARFExpressionTargetReg(Instr
.getValues());
2569 // Handle DW_CFA_def_cfa_expression
2571 CFARule
= RuleNumber
;
2574 RegRule
[*Reg
] = RuleNumber
;
2577 case MCCFIInstruction::OpAdjustCfaOffset
:
2578 case MCCFIInstruction::OpWindowSave
:
2579 case MCCFIInstruction::OpNegateRAState
:
2580 case MCCFIInstruction::OpNegateRAStateWithPC
:
2581 case MCCFIInstruction::OpLLVMDefAspaceCfa
:
2582 case MCCFIInstruction::OpLabel
:
2583 case MCCFIInstruction::OpValOffset
:
2584 llvm_unreachable("unsupported CFI opcode");
2586 case MCCFIInstruction::OpRememberState
:
2587 case MCCFIInstruction::OpRestoreState
:
2588 case MCCFIInstruction::OpGnuArgsSize
:
2589 // do not affect CFI state
2595 /// Advance state reading FDE CFI instructions up to State number
2596 void advanceTo(int32_t State
) {
2597 for (int32_t I
= CurState
, E
= State
; I
!= E
; ++I
) {
2598 const MCCFIInstruction
&Instr
= FDE
[I
];
2599 if (Instr
.getOperation() != MCCFIInstruction::OpRestoreState
) {
2603 // If restore state instruction, fetch the equivalent CFIs that have
2604 // the same effect of this restore. This is used to ensure remember-
2605 // restore pairs are completely removed.
2606 auto Iter
= FrameRestoreEquivalents
.find(I
);
2607 if (Iter
== FrameRestoreEquivalents
.end())
2609 for (int32_t RuleNumber
: Iter
->second
)
2610 update(FDE
[RuleNumber
], RuleNumber
);
2613 assert(((CFAReg
!= (uint32_t)UNKNOWN
&& CFAOffset
!= UNKNOWN
) ||
2614 CFARule
!= UNKNOWN
) &&
2615 "CIE did not define default CFA?");
2620 /// Interpret all CIE and FDE instructions up until CFI State number and
2621 /// populate this snapshot
2623 const BinaryFunction::CFIInstrMapType
&CIE
,
2624 const BinaryFunction::CFIInstrMapType
&FDE
,
2625 const DenseMap
<int32_t, SmallVector
<int32_t, 4>> &FrameRestoreEquivalents
,
2627 : CIE(CIE
), FDE(FDE
), FrameRestoreEquivalents(FrameRestoreEquivalents
) {
2629 CFAOffset
= UNKNOWN
;
2633 for (int32_t I
= 0, E
= CIE
.size(); I
!= E
; ++I
) {
2634 const MCCFIInstruction
&Instr
= CIE
[I
];
2642 /// A CFI snapshot with the capability of checking if incremental additions to
2643 /// it are redundant. This is used to ensure we do not emit two CFI instructions
2644 /// back-to-back that are doing the same state change, or to avoid emitting a
2645 /// CFI at all when the state at that point would not be modified after that CFI
2646 struct CFISnapshotDiff
: public CFISnapshot
{
2647 bool RestoredCFAReg
{false};
2648 bool RestoredCFAOffset
{false};
2649 DenseMap
<int32_t, bool> RestoredRegs
;
2651 CFISnapshotDiff(const CFISnapshot
&S
) : CFISnapshot(S
) {}
2654 const BinaryFunction::CFIInstrMapType
&CIE
,
2655 const BinaryFunction::CFIInstrMapType
&FDE
,
2656 const DenseMap
<int32_t, SmallVector
<int32_t, 4>> &FrameRestoreEquivalents
,
2658 : CFISnapshot(CIE
, FDE
, FrameRestoreEquivalents
, State
) {}
2660 /// Return true if applying Instr to this state is redundant and can be
2662 bool isRedundant(const MCCFIInstruction
&Instr
) {
2663 switch (Instr
.getOperation()) {
2664 case MCCFIInstruction::OpSameValue
:
2665 case MCCFIInstruction::OpRelOffset
:
2666 case MCCFIInstruction::OpOffset
:
2667 case MCCFIInstruction::OpRestore
:
2668 case MCCFIInstruction::OpUndefined
:
2669 case MCCFIInstruction::OpRegister
:
2670 case MCCFIInstruction::OpEscape
: {
2672 if (Instr
.getOperation() != MCCFIInstruction::OpEscape
) {
2673 Reg
= Instr
.getRegister();
2675 std::optional
<uint8_t> R
=
2676 readDWARFExpressionTargetReg(Instr
.getValues());
2677 // Handle DW_CFA_def_cfa_expression
2679 if (RestoredCFAReg
&& RestoredCFAOffset
)
2681 RestoredCFAReg
= true;
2682 RestoredCFAOffset
= true;
2687 if (RestoredRegs
[Reg
])
2689 RestoredRegs
[Reg
] = true;
2690 const int32_t CurRegRule
= RegRule
.contains(Reg
) ? RegRule
[Reg
] : UNKNOWN
;
2691 if (CurRegRule
== UNKNOWN
) {
2692 if (Instr
.getOperation() == MCCFIInstruction::OpRestore
||
2693 Instr
.getOperation() == MCCFIInstruction::OpSameValue
)
2697 const MCCFIInstruction
&LastDef
=
2698 CurRegRule
< 0 ? CIE
[-CurRegRule
] : FDE
[CurRegRule
];
2699 return LastDef
== Instr
;
2701 case MCCFIInstruction::OpDefCfaRegister
:
2704 RestoredCFAReg
= true;
2705 return CFAReg
== Instr
.getRegister();
2706 case MCCFIInstruction::OpDefCfaOffset
:
2707 if (RestoredCFAOffset
)
2709 RestoredCFAOffset
= true;
2710 return CFAOffset
== Instr
.getOffset();
2711 case MCCFIInstruction::OpDefCfa
:
2712 if (RestoredCFAReg
&& RestoredCFAOffset
)
2714 RestoredCFAReg
= true;
2715 RestoredCFAOffset
= true;
2716 return CFAReg
== Instr
.getRegister() && CFAOffset
== Instr
.getOffset();
2717 case MCCFIInstruction::OpAdjustCfaOffset
:
2718 case MCCFIInstruction::OpWindowSave
:
2719 case MCCFIInstruction::OpNegateRAState
:
2720 case MCCFIInstruction::OpNegateRAStateWithPC
:
2721 case MCCFIInstruction::OpLLVMDefAspaceCfa
:
2722 case MCCFIInstruction::OpLabel
:
2723 case MCCFIInstruction::OpValOffset
:
2724 llvm_unreachable("unsupported CFI opcode");
2726 case MCCFIInstruction::OpRememberState
:
2727 case MCCFIInstruction::OpRestoreState
:
2728 case MCCFIInstruction::OpGnuArgsSize
:
2729 // do not affect CFI state
2736 } // end anonymous namespace
2738 bool BinaryFunction::replayCFIInstrs(int32_t FromState
, int32_t ToState
,
2739 BinaryBasicBlock
*InBB
,
2740 BinaryBasicBlock::iterator InsertIt
) {
2741 if (FromState
== ToState
)
2743 assert(FromState
< ToState
&& "can only replay CFIs forward");
2745 CFISnapshotDiff
CFIDiff(CIEFrameInstructions
, FrameInstructions
,
2746 FrameRestoreEquivalents
, FromState
);
2748 std::vector
<uint32_t> NewCFIs
;
2749 for (int32_t CurState
= FromState
; CurState
< ToState
; ++CurState
) {
2750 MCCFIInstruction
*Instr
= &FrameInstructions
[CurState
];
2751 if (Instr
->getOperation() == MCCFIInstruction::OpRestoreState
) {
2752 auto Iter
= FrameRestoreEquivalents
.find(CurState
);
2753 assert(Iter
!= FrameRestoreEquivalents
.end());
2754 NewCFIs
.insert(NewCFIs
.end(), Iter
->second
.begin(), Iter
->second
.end());
2755 // RestoreState / Remember will be filtered out later by CFISnapshotDiff,
2756 // so we might as well fall-through here.
2758 NewCFIs
.push_back(CurState
);
2761 // Replay instructions while avoiding duplicates
2762 for (int32_t State
: llvm::reverse(NewCFIs
)) {
2763 if (CFIDiff
.isRedundant(FrameInstructions
[State
]))
2765 InsertIt
= addCFIPseudo(InBB
, InsertIt
, State
);
2771 SmallVector
<int32_t, 4>
2772 BinaryFunction::unwindCFIState(int32_t FromState
, int32_t ToState
,
2773 BinaryBasicBlock
*InBB
,
2774 BinaryBasicBlock::iterator
&InsertIt
) {
2775 SmallVector
<int32_t, 4> NewStates
;
2777 CFISnapshot
ToCFITable(CIEFrameInstructions
, FrameInstructions
,
2778 FrameRestoreEquivalents
, ToState
);
2779 CFISnapshotDiff
FromCFITable(ToCFITable
);
2780 FromCFITable
.advanceTo(FromState
);
2782 auto undoStateDefCfa
= [&]() {
2783 if (ToCFITable
.CFARule
== CFISnapshot::UNKNOWN
) {
2784 FrameInstructions
.emplace_back(MCCFIInstruction::cfiDefCfa(
2785 nullptr, ToCFITable
.CFAReg
, ToCFITable
.CFAOffset
));
2786 if (FromCFITable
.isRedundant(FrameInstructions
.back())) {
2787 FrameInstructions
.pop_back();
2790 NewStates
.push_back(FrameInstructions
.size() - 1);
2791 InsertIt
= addCFIPseudo(InBB
, InsertIt
, FrameInstructions
.size() - 1);
2793 } else if (ToCFITable
.CFARule
< 0) {
2794 if (FromCFITable
.isRedundant(CIEFrameInstructions
[-ToCFITable
.CFARule
]))
2796 NewStates
.push_back(FrameInstructions
.size());
2797 InsertIt
= addCFIPseudo(InBB
, InsertIt
, FrameInstructions
.size());
2799 FrameInstructions
.emplace_back(CIEFrameInstructions
[-ToCFITable
.CFARule
]);
2800 } else if (!FromCFITable
.isRedundant(
2801 FrameInstructions
[ToCFITable
.CFARule
])) {
2802 NewStates
.push_back(ToCFITable
.CFARule
);
2803 InsertIt
= addCFIPseudo(InBB
, InsertIt
, ToCFITable
.CFARule
);
2808 auto undoState
= [&](const MCCFIInstruction
&Instr
) {
2809 switch (Instr
.getOperation()) {
2810 case MCCFIInstruction::OpRememberState
:
2811 case MCCFIInstruction::OpRestoreState
:
2813 case MCCFIInstruction::OpSameValue
:
2814 case MCCFIInstruction::OpRelOffset
:
2815 case MCCFIInstruction::OpOffset
:
2816 case MCCFIInstruction::OpRestore
:
2817 case MCCFIInstruction::OpUndefined
:
2818 case MCCFIInstruction::OpEscape
:
2819 case MCCFIInstruction::OpRegister
: {
2821 if (Instr
.getOperation() != MCCFIInstruction::OpEscape
) {
2822 Reg
= Instr
.getRegister();
2824 std::optional
<uint8_t> R
=
2825 readDWARFExpressionTargetReg(Instr
.getValues());
2826 // Handle DW_CFA_def_cfa_expression
2834 if (!ToCFITable
.RegRule
.contains(Reg
)) {
2835 FrameInstructions
.emplace_back(
2836 MCCFIInstruction::createRestore(nullptr, Reg
));
2837 if (FromCFITable
.isRedundant(FrameInstructions
.back())) {
2838 FrameInstructions
.pop_back();
2841 NewStates
.push_back(FrameInstructions
.size() - 1);
2842 InsertIt
= addCFIPseudo(InBB
, InsertIt
, FrameInstructions
.size() - 1);
2846 const int32_t Rule
= ToCFITable
.RegRule
[Reg
];
2848 if (FromCFITable
.isRedundant(CIEFrameInstructions
[-Rule
]))
2850 NewStates
.push_back(FrameInstructions
.size());
2851 InsertIt
= addCFIPseudo(InBB
, InsertIt
, FrameInstructions
.size());
2853 FrameInstructions
.emplace_back(CIEFrameInstructions
[-Rule
]);
2856 if (FromCFITable
.isRedundant(FrameInstructions
[Rule
]))
2858 NewStates
.push_back(Rule
);
2859 InsertIt
= addCFIPseudo(InBB
, InsertIt
, Rule
);
2863 case MCCFIInstruction::OpDefCfaRegister
:
2864 case MCCFIInstruction::OpDefCfaOffset
:
2865 case MCCFIInstruction::OpDefCfa
:
2868 case MCCFIInstruction::OpAdjustCfaOffset
:
2869 case MCCFIInstruction::OpWindowSave
:
2870 case MCCFIInstruction::OpNegateRAState
:
2871 case MCCFIInstruction::OpNegateRAStateWithPC
:
2872 case MCCFIInstruction::OpLLVMDefAspaceCfa
:
2873 case MCCFIInstruction::OpLabel
:
2874 case MCCFIInstruction::OpValOffset
:
2875 llvm_unreachable("unsupported CFI opcode");
2877 case MCCFIInstruction::OpGnuArgsSize
:
2878 // do not affect CFI state
2883 // Undo all modifications from ToState to FromState
2884 for (int32_t I
= ToState
, E
= FromState
; I
!= E
; ++I
) {
2885 const MCCFIInstruction
&Instr
= FrameInstructions
[I
];
2886 if (Instr
.getOperation() != MCCFIInstruction::OpRestoreState
) {
2890 auto Iter
= FrameRestoreEquivalents
.find(I
);
2891 if (Iter
== FrameRestoreEquivalents
.end())
2893 for (int32_t State
: Iter
->second
)
2894 undoState(FrameInstructions
[State
]);
2900 void BinaryFunction::normalizeCFIState() {
2901 // Reordering blocks with remember-restore state instructions can be specially
2902 // tricky. When rewriting the CFI, we omit remember-restore state instructions
2903 // entirely. For restore state, we build a map expanding each restore to the
2904 // equivalent unwindCFIState sequence required at that point to achieve the
2905 // same effect of the restore. All remember state are then just ignored.
2906 std::stack
<int32_t> Stack
;
2907 for (BinaryBasicBlock
*CurBB
: Layout
.blocks()) {
2908 for (auto II
= CurBB
->begin(); II
!= CurBB
->end(); ++II
) {
2909 if (const MCCFIInstruction
*CFI
= getCFIFor(*II
)) {
2910 if (CFI
->getOperation() == MCCFIInstruction::OpRememberState
) {
2911 Stack
.push(II
->getOperand(0).getImm());
2914 if (CFI
->getOperation() == MCCFIInstruction::OpRestoreState
) {
2915 const int32_t RememberState
= Stack
.top();
2916 const int32_t CurState
= II
->getOperand(0).getImm();
2917 FrameRestoreEquivalents
[CurState
] =
2918 unwindCFIState(CurState
, RememberState
, CurBB
, II
);
2926 bool BinaryFunction::finalizeCFIState() {
2928 dbgs() << "Trying to fix CFI states for each BB after reordering.\n");
2929 LLVM_DEBUG(dbgs() << "This is the list of CFI states for each BB of " << *this
2932 const char *Sep
= "";
2934 for (FunctionFragment
&FF
: Layout
.fragments()) {
2935 // Hot-cold border: at start of each region (with a different FDE) we need
2936 // to reset the CFI state.
2939 for (BinaryBasicBlock
*BB
: FF
) {
2940 const int32_t CFIStateAtExit
= BB
->getCFIStateAtExit();
2942 // We need to recover the correct state if it doesn't match expected
2943 // state at BB entry point.
2944 if (BB
->getCFIState() < State
) {
2945 // In this case, State is currently higher than what this BB expect it
2946 // to be. To solve this, we need to insert CFI instructions to undo
2947 // the effect of all CFI from BB's state to current State.
2948 auto InsertIt
= BB
->begin();
2949 unwindCFIState(State
, BB
->getCFIState(), BB
, InsertIt
);
2950 } else if (BB
->getCFIState() > State
) {
2951 // If BB's CFI state is greater than State, it means we are behind in
2952 // the state. Just emit all instructions to reach this state at the
2953 // beginning of this BB. If this sequence of instructions involve
2954 // remember state or restore state, bail out.
2955 if (!replayCFIInstrs(State
, BB
->getCFIState(), BB
, BB
->begin()))
2959 State
= CFIStateAtExit
;
2960 LLVM_DEBUG(dbgs() << Sep
<< State
; Sep
= ", ");
2963 LLVM_DEBUG(dbgs() << "\n");
2965 for (BinaryBasicBlock
&BB
: blocks()) {
2966 for (auto II
= BB
.begin(); II
!= BB
.end();) {
2967 const MCCFIInstruction
*CFI
= getCFIFor(*II
);
2968 if (CFI
&& (CFI
->getOperation() == MCCFIInstruction::OpRememberState
||
2969 CFI
->getOperation() == MCCFIInstruction::OpRestoreState
)) {
2970 II
= BB
.eraseInstruction(II
);
2980 bool BinaryFunction::requiresAddressTranslation() const {
2981 return opts::EnableBAT
|| hasSDTMarker() || hasPseudoProbe();
2984 bool BinaryFunction::requiresAddressMap() const {
2988 return opts::UpdateDebugSections
|| isMultiEntry() ||
2989 requiresAddressTranslation();
2992 uint64_t BinaryFunction::getInstructionCount() const {
2994 for (const BinaryBasicBlock
&BB
: blocks())
2995 Count
+= BB
.getNumNonPseudos();
2999 void BinaryFunction::clearDisasmState() {
3000 clearList(Instructions
);
3001 clearList(IgnoredBranches
);
3002 clearList(TakenBranches
);
3004 if (BC
.HasRelocations
) {
3005 for (std::pair
<const uint32_t, MCSymbol
*> &LI
: Labels
)
3006 BC
.UndefinedSymbols
.insert(LI
.second
);
3007 for (MCSymbol
*const EndLabel
: FunctionEndLabels
)
3009 BC
.UndefinedSymbols
.insert(EndLabel
);
3013 void BinaryFunction::setTrapOnEntry() {
3016 forEachEntryPoint([&](uint64_t Offset
, const MCSymbol
*Label
) -> bool {
3018 BC
.MIB
->createTrap(TrapInstr
);
3019 addInstruction(Offset
, std::move(TrapInstr
));
3023 TrapsOnEntry
= true;
3026 void BinaryFunction::setIgnored() {
3027 if (opts::processAllFunctions()) {
3028 // We can accept ignored functions before they've been disassembled.
3029 // In that case, they would still get disassembled and emited, but not
3031 assert(CurrentState
== State::Empty
&&
3032 "cannot ignore non-empty functions in current mode");
3039 // Clear CFG state too.
3043 for (BinaryBasicBlock
*BB
: BasicBlocks
)
3045 clearList(BasicBlocks
);
3047 for (BinaryBasicBlock
*BB
: DeletedBasicBlocks
)
3049 clearList(DeletedBasicBlocks
);
3054 CurrentState
= State::Empty
;
3058 LLVM_DEBUG(dbgs() << "Ignoring " << getPrintName() << '\n');
3061 void BinaryFunction::duplicateConstantIslands() {
3062 assert(Islands
&& "function expected to have constant islands");
3064 for (BinaryBasicBlock
*BB
: getLayout().blocks()) {
3068 for (MCInst
&Inst
: *BB
) {
3070 for (MCOperand
&Operand
: Inst
) {
3071 if (!Operand
.isExpr()) {
3075 const MCSymbol
*Symbol
= BC
.MIB
->getTargetSymbol(Inst
, OpNum
);
3076 // Check if this is an island symbol
3077 if (!Islands
->Symbols
.count(Symbol
) &&
3078 !Islands
->ProxySymbols
.count(Symbol
))
3081 // Create cold symbol, if missing
3082 auto ISym
= Islands
->ColdSymbols
.find(Symbol
);
3083 MCSymbol
*ColdSymbol
;
3084 if (ISym
!= Islands
->ColdSymbols
.end()) {
3085 ColdSymbol
= ISym
->second
;
3087 ColdSymbol
= BC
.Ctx
->getOrCreateSymbol(Symbol
->getName() + ".cold");
3088 Islands
->ColdSymbols
[Symbol
] = ColdSymbol
;
3089 // Check if this is a proxy island symbol and update owner proxy map
3090 if (Islands
->ProxySymbols
.count(Symbol
)) {
3091 BinaryFunction
*Owner
= Islands
->ProxySymbols
[Symbol
];
3092 auto IProxiedSym
= Owner
->Islands
->Proxies
[this].find(Symbol
);
3093 Owner
->Islands
->ColdProxies
[this][IProxiedSym
->second
] = ColdSymbol
;
3097 // Update instruction reference
3098 Operand
= MCOperand::createExpr(BC
.MIB
->getTargetExprFor(
3100 MCSymbolRefExpr::create(ColdSymbol
, MCSymbolRefExpr::VK_None
,
3110 #define MAX_PATH 255
3113 static std::string
constructFilename(std::string Filename
,
3114 std::string Annotation
,
3115 std::string Suffix
) {
3116 std::replace(Filename
.begin(), Filename
.end(), '/', '-');
3117 if (!Annotation
.empty())
3118 Annotation
.insert(0, "-");
3119 if (Filename
.size() + Annotation
.size() + Suffix
.size() > MAX_PATH
) {
3120 assert(Suffix
.size() + Annotation
.size() <= MAX_PATH
);
3121 Filename
.resize(MAX_PATH
- (Suffix
.size() + Annotation
.size()));
3123 Filename
+= Annotation
;
3128 static std::string
formatEscapes(const std::string
&Str
) {
3130 for (unsigned I
= 0; I
< Str
.size(); ++I
) {
3146 void BinaryFunction::dumpGraph(raw_ostream
&OS
) const {
3147 OS
<< "digraph \"" << getPrintName() << "\" {\n"
3148 << "node [fontname=courier, shape=box, style=filled, colorscheme=brbg9]\n";
3149 uint64_t Offset
= Address
;
3150 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
3151 auto LayoutPos
= find(Layout
.blocks(), BB
);
3152 unsigned LayoutIndex
= LayoutPos
- Layout
.block_begin();
3153 const char *ColdStr
= BB
->isCold() ? " (cold)" : "";
3154 std::vector
<std::string
> Attrs
;
3155 // Bold box for entry points
3156 if (isEntryPoint(*BB
))
3157 Attrs
.push_back("penwidth=2");
3158 if (BLI
&& BLI
->getLoopFor(BB
)) {
3159 // Distinguish innermost loops
3160 const BinaryLoop
*Loop
= BLI
->getLoopFor(BB
);
3161 if (Loop
->isInnermost())
3162 Attrs
.push_back("fillcolor=6");
3163 else // some outer loop
3164 Attrs
.push_back("fillcolor=4");
3165 } else { // non-loopy code
3166 Attrs
.push_back("fillcolor=5");
3169 OS
<< "\"" << BB
->getName() << "\" [";
3170 for (StringRef Attr
: Attrs
)
3173 OS
<< format("\"%s\" [label=\"%s%s\\n(C:%lu,O:%lu,I:%u,L:%u,CFI:%u)\\n",
3174 BB
->getName().data(), BB
->getName().data(), ColdStr
,
3175 BB
->getKnownExecutionCount(), BB
->getOffset(), getIndex(BB
),
3176 LayoutIndex
, BB
->getCFIState());
3178 if (opts::DotToolTipCode
) {
3180 raw_string_ostream
CS(Str
);
3181 Offset
= BC
.printInstructions(CS
, BB
->begin(), BB
->end(), Offset
, this,
3182 /* PrintMCInst = */ false,
3183 /* PrintMemData = */ false,
3184 /* PrintRelocations = */ false,
3185 /* Endl = */ R
"(\\l)");
3186 OS
<< formatEscapes(CS
.str()) << '\n';
3190 // analyzeBranch is just used to get the names of the branch
3192 const MCSymbol
*TBB
= nullptr;
3193 const MCSymbol
*FBB
= nullptr;
3194 MCInst
*CondBranch
= nullptr;
3195 MCInst
*UncondBranch
= nullptr;
3196 const bool Success
= BB
->analyzeBranch(TBB
, FBB
, CondBranch
, UncondBranch
);
3198 const MCInst
*LastInstr
= BB
->getLastNonPseudoInstr();
3199 const bool IsJumpTable
= LastInstr
&& BC
.MIB
->getJumpTable(*LastInstr
);
3201 auto BI
= BB
->branch_info_begin();
3202 for (BinaryBasicBlock
*Succ
: BB
->successors()) {
3205 if (Succ
== BB
->getConditionalSuccessor(true)) {
3206 Branch
= CondBranch
? std::string(BC
.InstPrinter
->getOpcodeName(
3207 CondBranch
->getOpcode()))
3209 } else if (Succ
== BB
->getConditionalSuccessor(false)) {
3210 Branch
= UncondBranch
? std::string(BC
.InstPrinter
->getOpcodeName(
3211 UncondBranch
->getOpcode()))
3219 OS
<< format("\"%s\" -> \"%s\" [label=\"%s", BB
->getName().data(),
3220 Succ
->getName().data(), Branch
.c_str());
3222 if (BB
->getExecutionCount() != COUNT_NO_PROFILE
&&
3223 BI
->MispredictedCount
!= BinaryBasicBlock::COUNT_INFERRED
) {
3224 OS
<< "\\n(C:" << BI
->Count
<< ",M:" << BI
->MispredictedCount
<< ")";
3225 } else if (ExecutionCount
!= COUNT_NO_PROFILE
&&
3226 BI
->Count
!= BinaryBasicBlock::COUNT_NO_PROFILE
) {
3227 OS
<< "\\n(IC:" << BI
->Count
<< ")";
3233 for (BinaryBasicBlock
*LP
: BB
->landing_pads()) {
3234 OS
<< format("\"%s\" -> \"%s\" [constraint=false style=dashed]\n",
3235 BB
->getName().data(), LP
->getName().data());
3241 void BinaryFunction::viewGraph() const {
3242 SmallString
<MAX_PATH
> Filename
;
3243 if (std::error_code EC
=
3244 sys::fs::createTemporaryFile("bolt-cfg", "dot", Filename
)) {
3245 BC
.errs() << "BOLT-ERROR: " << EC
.message() << ", unable to create "
3246 << " bolt-cfg-XXXXX.dot temporary file.\n";
3249 dumpGraphToFile(std::string(Filename
));
3250 if (DisplayGraph(Filename
))
3251 BC
.errs() << "BOLT-ERROR: Can't display " << Filename
3252 << " with graphviz.\n";
3253 if (std::error_code EC
= sys::fs::remove(Filename
)) {
3254 BC
.errs() << "BOLT-WARNING: " << EC
.message() << ", failed to remove "
3255 << Filename
<< "\n";
3259 void BinaryFunction::dumpGraphForPass(std::string Annotation
) const {
3260 if (!opts::shouldPrint(*this))
3263 std::string Filename
= constructFilename(getPrintName(), Annotation
, ".dot");
3264 if (opts::Verbosity
>= 1)
3265 BC
.outs() << "BOLT-INFO: dumping CFG to " << Filename
<< "\n";
3266 dumpGraphToFile(Filename
);
3269 void BinaryFunction::dumpGraphToFile(std::string Filename
) const {
3271 raw_fd_ostream
of(Filename
, EC
, sys::fs::OF_None
);
3273 if (opts::Verbosity
>= 1) {
3274 BC
.errs() << "BOLT-WARNING: " << EC
.message() << ", unable to open "
3275 << Filename
<< " for output.\n";
3282 bool BinaryFunction::validateCFG() const {
3283 // Skip the validation of CFG after it is finalized
3284 if (CurrentState
== State::CFG_Finalized
)
3287 for (BinaryBasicBlock
*BB
: BasicBlocks
)
3288 if (!BB
->validateSuccessorInvariants())
3291 // Make sure all blocks in CFG are valid.
3292 auto validateBlock
= [this](const BinaryBasicBlock
*BB
, StringRef Desc
) {
3293 if (!BB
->isValid()) {
3294 BC
.errs() << "BOLT-ERROR: deleted " << Desc
<< " " << BB
->getName()
3295 << " detected in:\n";
3301 for (const BinaryBasicBlock
*BB
: BasicBlocks
) {
3302 if (!validateBlock(BB
, "block"))
3304 for (const BinaryBasicBlock
*PredBB
: BB
->predecessors())
3305 if (!validateBlock(PredBB
, "predecessor"))
3307 for (const BinaryBasicBlock
*SuccBB
: BB
->successors())
3308 if (!validateBlock(SuccBB
, "successor"))
3310 for (const BinaryBasicBlock
*LP
: BB
->landing_pads())
3311 if (!validateBlock(LP
, "landing pad"))
3313 for (const BinaryBasicBlock
*Thrower
: BB
->throwers())
3314 if (!validateBlock(Thrower
, "thrower"))
3318 for (const BinaryBasicBlock
*BB
: BasicBlocks
) {
3319 std::unordered_set
<const BinaryBasicBlock
*> BBLandingPads
;
3320 for (const BinaryBasicBlock
*LP
: BB
->landing_pads()) {
3321 if (BBLandingPads
.count(LP
)) {
3322 BC
.errs() << "BOLT-ERROR: duplicate landing pad detected in"
3323 << BB
->getName() << " in function " << *this << '\n';
3326 BBLandingPads
.insert(LP
);
3329 std::unordered_set
<const BinaryBasicBlock
*> BBThrowers
;
3330 for (const BinaryBasicBlock
*Thrower
: BB
->throwers()) {
3331 if (BBThrowers
.count(Thrower
)) {
3332 BC
.errs() << "BOLT-ERROR: duplicate thrower detected in"
3333 << BB
->getName() << " in function " << *this << '\n';
3336 BBThrowers
.insert(Thrower
);
3339 for (const BinaryBasicBlock
*LPBlock
: BB
->landing_pads()) {
3340 if (!llvm::is_contained(LPBlock
->throwers(), BB
)) {
3341 BC
.errs() << "BOLT-ERROR: inconsistent landing pad detected in "
3342 << *this << ": " << BB
->getName()
3343 << " is in LandingPads but not in " << LPBlock
->getName()
3348 for (const BinaryBasicBlock
*Thrower
: BB
->throwers()) {
3349 if (!llvm::is_contained(Thrower
->landing_pads(), BB
)) {
3350 BC
.errs() << "BOLT-ERROR: inconsistent thrower detected in " << *this
3351 << ": " << BB
->getName() << " is in Throwers list but not in "
3352 << Thrower
->getName() << " LandingPads\n";
3361 void BinaryFunction::fixBranches() {
3363 MCContext
*Ctx
= BC
.Ctx
.get();
3365 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
3366 const MCSymbol
*TBB
= nullptr;
3367 const MCSymbol
*FBB
= nullptr;
3368 MCInst
*CondBranch
= nullptr;
3369 MCInst
*UncondBranch
= nullptr;
3370 if (!BB
->analyzeBranch(TBB
, FBB
, CondBranch
, UncondBranch
))
3373 // We will create unconditional branch with correct destination if needed.
3375 BB
->eraseInstruction(BB
->findInstruction(UncondBranch
));
3377 // Basic block that follows the current one in the final layout.
3378 const BinaryBasicBlock
*const NextBB
=
3379 Layout
.getBasicBlockAfter(BB
, /*IgnoreSplits=*/false);
3381 if (BB
->succ_size() == 1) {
3382 // __builtin_unreachable() could create a conditional branch that
3383 // falls-through into the next function - hence the block will have only
3384 // one valid successor. Since behaviour is undefined - we replace
3385 // the conditional branch with an unconditional if required.
3387 BB
->eraseInstruction(BB
->findInstruction(CondBranch
));
3388 if (BB
->getSuccessor() == NextBB
)
3390 BB
->addBranchInstruction(BB
->getSuccessor());
3391 } else if (BB
->succ_size() == 2) {
3392 assert(CondBranch
&& "conditional branch expected");
3393 const BinaryBasicBlock
*TSuccessor
= BB
->getConditionalSuccessor(true);
3394 const BinaryBasicBlock
*FSuccessor
= BB
->getConditionalSuccessor(false);
3396 // Eliminate unnecessary conditional branch.
3397 if (TSuccessor
== FSuccessor
) {
3398 // FIXME: at the moment, we cannot safely remove static key branches.
3399 if (MIB
->isDynamicBranch(*CondBranch
)) {
3400 if (opts::Verbosity
) {
3402 << "BOLT-INFO: unable to remove redundant dynamic branch in "
3408 BB
->removeDuplicateConditionalSuccessor(CondBranch
);
3409 if (TSuccessor
!= NextBB
)
3410 BB
->addBranchInstruction(TSuccessor
);
3414 // Reverse branch condition and swap successors.
3415 auto swapSuccessors
= [&]() {
3416 if (!MIB
->isReversibleBranch(*CondBranch
)) {
3417 if (opts::Verbosity
) {
3418 BC
.outs() << "BOLT-INFO: unable to swap successors in " << *this
3423 std::swap(TSuccessor
, FSuccessor
);
3424 BB
->swapConditionalSuccessors();
3425 auto L
= BC
.scopeLock();
3426 MIB
->reverseBranchCondition(*CondBranch
, TSuccessor
->getLabel(), Ctx
);
3430 // Check whether the next block is a "taken" target and try to swap it
3431 // with a "fall-through" target.
3432 if (TSuccessor
== NextBB
&& swapSuccessors())
3435 // Update conditional branch destination if needed.
3436 if (MIB
->getTargetSymbol(*CondBranch
) != TSuccessor
->getLabel()) {
3437 auto L
= BC
.scopeLock();
3438 MIB
->replaceBranchTarget(*CondBranch
, TSuccessor
->getLabel(), Ctx
);
3441 // No need for the unconditional branch.
3442 if (FSuccessor
== NextBB
)
3446 // We are going to generate two branches. Check if their targets are in
3447 // the same fragment as this block. If only one target is in the same
3448 // fragment, make it the destination of the conditional branch. There
3449 // is a chance it will be a short branch which takes 4 bytes fewer than
3450 // a long conditional branch. For unconditional branch, the difference
3452 if (BB
->getFragmentNum() != TSuccessor
->getFragmentNum() &&
3453 BB
->getFragmentNum() == FSuccessor
->getFragmentNum())
3457 BB
->addBranchInstruction(FSuccessor
);
3459 // Cases where the number of successors is 0 (block ends with a
3460 // terminator) or more than 2 (switch table) don't require branch
3461 // instruction adjustments.
3463 assert((!isSimple() || validateCFG()) &&
3464 "Invalid CFG detected after fixing branches");
3467 void BinaryFunction::propagateGnuArgsSizeInfo(
3468 MCPlusBuilder::AllocatorIdTy AllocId
) {
3469 assert(CurrentState
== State::Disassembled
&& "unexpected function state");
3471 if (!hasEHRanges() || !usesGnuArgsSize())
3474 // The current value of DW_CFA_GNU_args_size affects all following
3475 // invoke instructions until the next CFI overrides it.
3476 // It is important to iterate basic blocks in the original order when
3477 // assigning the value.
3478 uint64_t CurrentGnuArgsSize
= 0;
3479 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
3480 for (auto II
= BB
->begin(); II
!= BB
->end();) {
3481 MCInst
&Instr
= *II
;
3482 if (BC
.MIB
->isCFI(Instr
)) {
3483 const MCCFIInstruction
*CFI
= getCFIFor(Instr
);
3484 if (CFI
->getOperation() == MCCFIInstruction::OpGnuArgsSize
) {
3485 CurrentGnuArgsSize
= CFI
->getOffset();
3486 // Delete DW_CFA_GNU_args_size instructions and only regenerate
3487 // during the final code emission. The information is embedded
3488 // inside call instructions.
3489 II
= BB
->erasePseudoInstruction(II
);
3492 } else if (BC
.MIB
->isInvoke(Instr
)) {
3493 // Add the value of GNU_args_size as an extra operand to invokes.
3494 BC
.MIB
->addGnuArgsSize(Instr
, CurrentGnuArgsSize
);
3501 void BinaryFunction::postProcessBranches() {
3504 for (BinaryBasicBlock
&BB
: blocks()) {
3505 auto LastInstrRI
= BB
.getLastNonPseudo();
3506 if (BB
.succ_size() == 1) {
3507 if (LastInstrRI
!= BB
.rend() &&
3508 BC
.MIB
->isConditionalBranch(*LastInstrRI
)) {
3509 // __builtin_unreachable() could create a conditional branch that
3510 // falls-through into the next function - hence the block will have only
3511 // one valid successor. Such behaviour is undefined and thus we remove
3512 // the conditional branch while leaving a valid successor.
3513 BB
.eraseInstruction(std::prev(LastInstrRI
.base()));
3514 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: erasing conditional branch in "
3515 << BB
.getName() << " in function " << *this << '\n');
3517 } else if (BB
.succ_size() == 0) {
3518 // Ignore unreachable basic blocks.
3519 if (BB
.pred_size() == 0 || BB
.isLandingPad())
3522 // If it's the basic block that does not end up with a terminator - we
3523 // insert a return instruction unless it's a call instruction.
3524 if (LastInstrRI
== BB
.rend()) {
3526 dbgs() << "BOLT-DEBUG: at least one instruction expected in BB "
3527 << BB
.getName() << " in function " << *this << '\n');
3530 if (!BC
.MIB
->isTerminator(*LastInstrRI
) &&
3531 !BC
.MIB
->isCall(*LastInstrRI
)) {
3532 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: adding return to basic block "
3533 << BB
.getName() << " in function " << *this << '\n');
3535 BC
.MIB
->createReturn(ReturnInstr
);
3536 BB
.addInstruction(ReturnInstr
);
3540 assert(validateCFG() && "invalid CFG");
3543 MCSymbol
*BinaryFunction::addEntryPointAtOffset(uint64_t Offset
) {
3544 assert(Offset
&& "cannot add primary entry point");
3545 assert(CurrentState
== State::Empty
|| CurrentState
== State::Disassembled
);
3547 const uint64_t EntryPointAddress
= getAddress() + Offset
;
3548 MCSymbol
*LocalSymbol
= getOrCreateLocalLabel(EntryPointAddress
);
3550 MCSymbol
*EntrySymbol
= getSecondaryEntryPointSymbol(LocalSymbol
);
3554 if (BinaryData
*EntryBD
= BC
.getBinaryDataAtAddress(EntryPointAddress
)) {
3555 EntrySymbol
= EntryBD
->getSymbol();
3557 EntrySymbol
= BC
.getOrCreateGlobalSymbol(
3558 EntryPointAddress
, Twine("__ENTRY_") + getOneName() + "@");
3560 SecondaryEntryPoints
[LocalSymbol
] = EntrySymbol
;
3562 BC
.setSymbolToFunctionMap(EntrySymbol
, this);
3567 MCSymbol
*BinaryFunction::addEntryPoint(const BinaryBasicBlock
&BB
) {
3568 assert(CurrentState
== State::CFG
&&
3569 "basic block can be added as an entry only in a function with CFG");
3571 if (&BB
== BasicBlocks
.front())
3574 MCSymbol
*EntrySymbol
= getSecondaryEntryPointSymbol(BB
);
3579 BC
.Ctx
->getOrCreateSymbol("__ENTRY_" + BB
.getLabel()->getName());
3581 SecondaryEntryPoints
[BB
.getLabel()] = EntrySymbol
;
3583 BC
.setSymbolToFunctionMap(EntrySymbol
, this);
3588 MCSymbol
*BinaryFunction::getSymbolForEntryID(uint64_t EntryID
) {
3592 if (!isMultiEntry())
3595 uint64_t NumEntries
= 1;
3597 for (BinaryBasicBlock
*BB
: BasicBlocks
) {
3598 MCSymbol
*EntrySymbol
= getSecondaryEntryPointSymbol(*BB
);
3601 if (NumEntries
== EntryID
)
3606 for (std::pair
<const uint32_t, MCSymbol
*> &KV
: Labels
) {
3607 MCSymbol
*EntrySymbol
= getSecondaryEntryPointSymbol(KV
.second
);
3610 if (NumEntries
== EntryID
)
3619 uint64_t BinaryFunction::getEntryIDForSymbol(const MCSymbol
*Symbol
) const {
3620 if (!isMultiEntry())
3623 for (const MCSymbol
*FunctionSymbol
: getSymbols())
3624 if (FunctionSymbol
== Symbol
)
3627 // Check all secondary entries available as either basic blocks or lables.
3628 uint64_t NumEntries
= 1;
3629 for (const BinaryBasicBlock
*BB
: BasicBlocks
) {
3630 MCSymbol
*EntrySymbol
= getSecondaryEntryPointSymbol(*BB
);
3633 if (EntrySymbol
== Symbol
)
3638 for (const std::pair
<const uint32_t, MCSymbol
*> &KV
: Labels
) {
3639 MCSymbol
*EntrySymbol
= getSecondaryEntryPointSymbol(KV
.second
);
3642 if (EntrySymbol
== Symbol
)
3647 llvm_unreachable("symbol not found");
3650 bool BinaryFunction::forEachEntryPoint(EntryPointCallbackTy Callback
) const {
3651 bool Status
= Callback(0, getSymbol());
3652 if (!isMultiEntry())
3655 for (const std::pair
<const uint32_t, MCSymbol
*> &KV
: Labels
) {
3659 MCSymbol
*EntrySymbol
= getSecondaryEntryPointSymbol(KV
.second
);
3663 Status
= Callback(KV
.first
, EntrySymbol
);
3669 BinaryFunction::BasicBlockListType
BinaryFunction::dfs() const {
3670 BasicBlockListType DFS
;
3671 std::stack
<BinaryBasicBlock
*> Stack
;
3672 std::set
<BinaryBasicBlock
*> Visited
;
3674 // Push entry points to the stack in reverse order.
3676 // NB: we rely on the original order of entries to match.
3677 SmallVector
<BinaryBasicBlock
*> EntryPoints
;
3678 llvm::copy_if(BasicBlocks
, std::back_inserter(EntryPoints
),
3679 [&](const BinaryBasicBlock
*const BB
) { return isEntryPoint(*BB
); });
3680 // Sort entry points by their offset to make sure we got them in the right
3682 llvm::stable_sort(EntryPoints
, [](const BinaryBasicBlock
*const A
,
3683 const BinaryBasicBlock
*const B
) {
3684 return A
->getOffset() < B
->getOffset();
3686 for (BinaryBasicBlock
*const BB
: reverse(EntryPoints
))
3689 while (!Stack
.empty()) {
3690 BinaryBasicBlock
*BB
= Stack
.top();
3693 if (!Visited
.insert(BB
).second
)
3697 for (BinaryBasicBlock
*SuccBB
: BB
->landing_pads()) {
3701 const MCSymbol
*TBB
= nullptr;
3702 const MCSymbol
*FBB
= nullptr;
3703 MCInst
*CondBranch
= nullptr;
3704 MCInst
*UncondBranch
= nullptr;
3705 if (BB
->analyzeBranch(TBB
, FBB
, CondBranch
, UncondBranch
) && CondBranch
&&
3706 BB
->succ_size() == 2) {
3707 if (BC
.MIB
->getCanonicalBranchCondCode(BC
.MIB
->getCondCode(
3708 *CondBranch
)) == BC
.MIB
->getCondCode(*CondBranch
)) {
3709 Stack
.push(BB
->getConditionalSuccessor(true));
3710 Stack
.push(BB
->getConditionalSuccessor(false));
3712 Stack
.push(BB
->getConditionalSuccessor(false));
3713 Stack
.push(BB
->getConditionalSuccessor(true));
3716 for (BinaryBasicBlock
*SuccBB
: BB
->successors()) {
3725 size_t BinaryFunction::computeHash(bool UseDFS
, HashFunction HashFunction
,
3726 OperandHashFuncTy OperandHashFunc
) const {
3728 dbgs() << "BOLT-DEBUG: computeHash " << getPrintName() << ' '
3729 << (UseDFS
? "dfs" : "bin") << " order "
3730 << (HashFunction
== HashFunction::StdHash
? "std::hash" : "xxh3")
3737 assert(hasCFG() && "function is expected to have CFG");
3739 SmallVector
<const BinaryBasicBlock
*, 0> Order
;
3741 llvm::copy(dfs(), std::back_inserter(Order
));
3743 llvm::copy(Layout
.blocks(), std::back_inserter(Order
));
3745 // The hash is computed by creating a string of all instruction opcodes and
3746 // possibly their operands and then hashing that string with std::hash.
3747 std::string HashString
;
3748 for (const BinaryBasicBlock
*BB
: Order
)
3749 HashString
.append(hashBlock(BC
, *BB
, OperandHashFunc
));
3751 switch (HashFunction
) {
3752 case HashFunction::StdHash
:
3753 return Hash
= std::hash
<std::string
>{}(HashString
);
3754 case HashFunction::XXH3
:
3755 return Hash
= llvm::xxh3_64bits(HashString
);
3757 llvm_unreachable("Unhandled HashFunction");
3760 void BinaryFunction::insertBasicBlocks(
3761 BinaryBasicBlock
*Start
,
3762 std::vector
<std::unique_ptr
<BinaryBasicBlock
>> &&NewBBs
,
3763 const bool UpdateLayout
, const bool UpdateCFIState
,
3764 const bool RecomputeLandingPads
) {
3765 const int64_t StartIndex
= Start
? getIndex(Start
) : -1LL;
3766 const size_t NumNewBlocks
= NewBBs
.size();
3768 BasicBlocks
.insert(BasicBlocks
.begin() + (StartIndex
+ 1), NumNewBlocks
,
3771 int64_t I
= StartIndex
+ 1;
3772 for (std::unique_ptr
<BinaryBasicBlock
> &BB
: NewBBs
) {
3773 assert(!BasicBlocks
[I
]);
3774 BasicBlocks
[I
++] = BB
.release();
3777 if (RecomputeLandingPads
)
3778 recomputeLandingPads();
3783 updateLayout(Start
, NumNewBlocks
);
3786 updateCFIState(Start
, NumNewBlocks
);
3789 BinaryFunction::iterator
BinaryFunction::insertBasicBlocks(
3790 BinaryFunction::iterator StartBB
,
3791 std::vector
<std::unique_ptr
<BinaryBasicBlock
>> &&NewBBs
,
3792 const bool UpdateLayout
, const bool UpdateCFIState
,
3793 const bool RecomputeLandingPads
) {
3794 const unsigned StartIndex
= getIndex(&*StartBB
);
3795 const size_t NumNewBlocks
= NewBBs
.size();
3797 BasicBlocks
.insert(BasicBlocks
.begin() + StartIndex
+ 1, NumNewBlocks
,
3799 auto RetIter
= BasicBlocks
.begin() + StartIndex
+ 1;
3801 unsigned I
= StartIndex
+ 1;
3802 for (std::unique_ptr
<BinaryBasicBlock
> &BB
: NewBBs
) {
3803 assert(!BasicBlocks
[I
]);
3804 BasicBlocks
[I
++] = BB
.release();
3807 if (RecomputeLandingPads
)
3808 recomputeLandingPads();
3813 updateLayout(*std::prev(RetIter
), NumNewBlocks
);
3816 updateCFIState(*std::prev(RetIter
), NumNewBlocks
);
3821 void BinaryFunction::updateBBIndices(const unsigned StartIndex
) {
3822 for (unsigned I
= StartIndex
; I
< BasicBlocks
.size(); ++I
)
3823 BasicBlocks
[I
]->Index
= I
;
3826 void BinaryFunction::updateCFIState(BinaryBasicBlock
*Start
,
3827 const unsigned NumNewBlocks
) {
3828 const int32_t CFIState
= Start
->getCFIStateAtExit();
3829 const unsigned StartIndex
= getIndex(Start
) + 1;
3830 for (unsigned I
= 0; I
< NumNewBlocks
; ++I
)
3831 BasicBlocks
[StartIndex
+ I
]->setCFIState(CFIState
);
3834 void BinaryFunction::updateLayout(BinaryBasicBlock
*Start
,
3835 const unsigned NumNewBlocks
) {
3836 BasicBlockListType::iterator Begin
;
3837 BasicBlockListType::iterator End
;
3839 // If start not provided copy new blocks from the beginning of BasicBlocks
3841 Begin
= BasicBlocks
.begin();
3842 End
= BasicBlocks
.begin() + NumNewBlocks
;
3844 unsigned StartIndex
= getIndex(Start
);
3845 Begin
= std::next(BasicBlocks
.begin(), StartIndex
+ 1);
3846 End
= std::next(BasicBlocks
.begin(), StartIndex
+ NumNewBlocks
+ 1);
3849 // Insert new blocks in the layout immediately after Start.
3850 Layout
.insertBasicBlocks(Start
, {Begin
, End
});
3851 Layout
.updateLayoutIndices();
3854 bool BinaryFunction::checkForAmbiguousJumpTables() {
3855 SmallSet
<uint64_t, 4> JumpTables
;
3856 for (BinaryBasicBlock
*&BB
: BasicBlocks
) {
3857 for (MCInst
&Inst
: *BB
) {
3858 if (!BC
.MIB
->isIndirectBranch(Inst
))
3860 uint64_t JTAddress
= BC
.MIB
->getJumpTable(Inst
);
3863 // This address can be inside another jump table, but we only consider
3864 // it ambiguous when the same start address is used, not the same JT
3866 if (!JumpTables
.count(JTAddress
)) {
3867 JumpTables
.insert(JTAddress
);
3876 void BinaryFunction::disambiguateJumpTables(
3877 MCPlusBuilder::AllocatorIdTy AllocId
) {
3878 assert((opts::JumpTables
!= JTS_BASIC
&& isSimple()) || !BC
.HasRelocations
);
3879 SmallPtrSet
<JumpTable
*, 4> JumpTables
;
3880 for (BinaryBasicBlock
*&BB
: BasicBlocks
) {
3881 for (MCInst
&Inst
: *BB
) {
3882 if (!BC
.MIB
->isIndirectBranch(Inst
))
3884 JumpTable
*JT
= getJumpTable(Inst
);
3887 if (JumpTables
.insert(JT
).second
)
3889 // This instruction is an indirect jump using a jump table, but it is
3890 // using the same jump table of another jump. Try all our tricks to
3891 // extract the jump table symbol and make it point to a new, duplicated JT
3894 const MCSymbol
*Target
;
3895 // In case we match if our first matcher, first instruction is the one to
3897 MCInst
*JTLoadInst
= &Inst
;
3898 // Try a standard indirect jump matcher, scale 8
3899 std::unique_ptr
<MCPlusBuilder::MCInstMatcher
> IndJmpMatcher
=
3900 BC
.MIB
->matchIndJmp(BC
.MIB
->matchReg(BaseReg1
),
3901 BC
.MIB
->matchImm(Scale
), BC
.MIB
->matchReg(),
3902 /*Offset=*/BC
.MIB
->matchSymbol(Target
));
3903 if (!IndJmpMatcher
->match(
3905 MutableArrayRef
<MCInst
>(&*BB
->begin(), &Inst
+ 1), -1) ||
3906 BaseReg1
!= BC
.MIB
->getNoRegister() || Scale
!= 8) {
3909 // Standard JT matching failed. Trying now:
3910 // movq "jt.2397/1"(,%rax,8), %rax
3912 std::unique_ptr
<MCPlusBuilder::MCInstMatcher
> LoadMatcherOwner
=
3913 BC
.MIB
->matchLoad(BC
.MIB
->matchReg(BaseReg1
),
3914 BC
.MIB
->matchImm(Scale
), BC
.MIB
->matchReg(),
3915 /*Offset=*/BC
.MIB
->matchSymbol(Target
));
3916 MCPlusBuilder::MCInstMatcher
*LoadMatcher
= LoadMatcherOwner
.get();
3917 std::unique_ptr
<MCPlusBuilder::MCInstMatcher
> IndJmpMatcher2
=
3918 BC
.MIB
->matchIndJmp(std::move(LoadMatcherOwner
));
3919 if (!IndJmpMatcher2
->match(
3921 MutableArrayRef
<MCInst
>(&*BB
->begin(), &Inst
+ 1), -1) ||
3922 BaseReg1
!= BC
.MIB
->getNoRegister() || Scale
!= 8) {
3923 // JT matching failed. Trying now:
3924 // PIC-style matcher, scale 4
3927 // leaq DATAat0x402450(%rip), %r11
3928 // movslq (%r11,%rdx,4), %rcx
3930 // jmpq *%rcx # JUMPTABLE @0x402450
3931 std::unique_ptr
<MCPlusBuilder::MCInstMatcher
> PICIndJmpMatcher
=
3932 BC
.MIB
->matchIndJmp(BC
.MIB
->matchAdd(
3933 BC
.MIB
->matchReg(BaseReg1
),
3934 BC
.MIB
->matchLoad(BC
.MIB
->matchReg(BaseReg2
),
3935 BC
.MIB
->matchImm(Scale
), BC
.MIB
->matchReg(),
3936 BC
.MIB
->matchImm(Offset
))));
3937 std::unique_ptr
<MCPlusBuilder::MCInstMatcher
> LEAMatcherOwner
=
3938 BC
.MIB
->matchLoadAddr(BC
.MIB
->matchSymbol(Target
));
3939 MCPlusBuilder::MCInstMatcher
*LEAMatcher
= LEAMatcherOwner
.get();
3940 std::unique_ptr
<MCPlusBuilder::MCInstMatcher
> PICBaseAddrMatcher
=
3941 BC
.MIB
->matchIndJmp(BC
.MIB
->matchAdd(std::move(LEAMatcherOwner
),
3942 BC
.MIB
->matchAnyOperand()));
3943 if (!PICIndJmpMatcher
->match(
3945 MutableArrayRef
<MCInst
>(&*BB
->begin(), &Inst
+ 1), -1) ||
3946 Scale
!= 4 || BaseReg1
!= BaseReg2
|| Offset
!= 0 ||
3947 !PICBaseAddrMatcher
->match(
3949 MutableArrayRef
<MCInst
>(&*BB
->begin(), &Inst
+ 1), -1)) {
3950 llvm_unreachable("Failed to extract jump table base");
3953 // Matched PIC, identify the instruction with the reference to the JT
3954 JTLoadInst
= LEAMatcher
->CurInst
;
3957 JTLoadInst
= LoadMatcher
->CurInst
;
3961 uint64_t NewJumpTableID
= 0;
3962 const MCSymbol
*NewJTLabel
;
3963 std::tie(NewJumpTableID
, NewJTLabel
) =
3964 BC
.duplicateJumpTable(*this, JT
, Target
);
3966 auto L
= BC
.scopeLock();
3967 BC
.MIB
->replaceMemOperandDisp(*JTLoadInst
, NewJTLabel
, BC
.Ctx
.get());
3969 // We use a unique ID with the high bit set as address for this "injected"
3970 // jump table (not originally in the input binary).
3971 BC
.MIB
->setJumpTable(Inst
, NewJumpTableID
, 0, AllocId
);
3976 bool BinaryFunction::replaceJumpTableEntryIn(BinaryBasicBlock
*BB
,
3977 BinaryBasicBlock
*OldDest
,
3978 BinaryBasicBlock
*NewDest
) {
3979 MCInst
*Instr
= BB
->getLastNonPseudoInstr();
3980 if (!Instr
|| !BC
.MIB
->isIndirectBranch(*Instr
))
3982 uint64_t JTAddress
= BC
.MIB
->getJumpTable(*Instr
);
3983 assert(JTAddress
&& "Invalid jump table address");
3984 JumpTable
*JT
= getJumpTableContainingAddress(JTAddress
);
3985 assert(JT
&& "No jump table structure for this indirect branch");
3986 bool Patched
= JT
->replaceDestination(JTAddress
, OldDest
->getLabel(),
3987 NewDest
->getLabel());
3989 assert(Patched
&& "Invalid entry to be replaced in jump table");
3993 BinaryBasicBlock
*BinaryFunction::splitEdge(BinaryBasicBlock
*From
,
3994 BinaryBasicBlock
*To
) {
3995 // Create intermediate BB
3998 auto L
= BC
.scopeLock();
3999 Tmp
= BC
.Ctx
->createNamedTempSymbol("SplitEdge");
4001 // Link new BBs to the original input offset of the From BB, so we can map
4002 // samples recorded in new BBs back to the original BB seem in the input
4003 // binary (if using BAT)
4004 std::unique_ptr
<BinaryBasicBlock
> NewBB
= createBasicBlock(Tmp
);
4005 NewBB
->setOffset(From
->getInputOffset());
4006 BinaryBasicBlock
*NewBBPtr
= NewBB
.get();
4009 auto I
= From
->succ_begin();
4010 auto BI
= From
->branch_info_begin();
4011 for (; I
!= From
->succ_end(); ++I
) {
4016 assert(I
!= From
->succ_end() && "Invalid CFG edge in splitEdge!");
4017 uint64_t OrigCount
= BI
->Count
;
4018 uint64_t OrigMispreds
= BI
->MispredictedCount
;
4019 replaceJumpTableEntryIn(From
, To
, NewBBPtr
);
4020 From
->replaceSuccessor(To
, NewBBPtr
, OrigCount
, OrigMispreds
);
4022 NewBB
->addSuccessor(To
, OrigCount
, OrigMispreds
);
4023 NewBB
->setExecutionCount(OrigCount
);
4024 NewBB
->setIsCold(From
->isCold());
4026 // Update CFI and BB layout with new intermediate BB
4027 std::vector
<std::unique_ptr
<BinaryBasicBlock
>> NewBBs
;
4028 NewBBs
.emplace_back(std::move(NewBB
));
4029 insertBasicBlocks(From
, std::move(NewBBs
), true, true,
4030 /*RecomputeLandingPads=*/false);
4034 void BinaryFunction::deleteConservativeEdges() {
4035 // Our goal is to aggressively remove edges from the CFG that we believe are
4036 // wrong. This is used for instrumentation, where it is safe to remove
4037 // fallthrough edges because we won't reorder blocks.
4038 for (auto I
= BasicBlocks
.begin(), E
= BasicBlocks
.end(); I
!= E
; ++I
) {
4039 BinaryBasicBlock
*BB
= *I
;
4040 if (BB
->succ_size() != 1 || BB
->size() == 0)
4043 auto NextBB
= std::next(I
);
4044 MCInst
*Last
= BB
->getLastNonPseudoInstr();
4045 // Fallthrough is a landing pad? Delete this edge (as long as we don't
4046 // have a direct jump to it)
4047 if ((*BB
->succ_begin())->isLandingPad() && NextBB
!= E
&&
4048 *BB
->succ_begin() == *NextBB
&& Last
&& !BC
.MIB
->isBranch(*Last
)) {
4049 BB
->removeAllSuccessors();
4053 // Look for suspicious calls at the end of BB where gcc may optimize it and
4054 // remove the jump to the epilogue when it knows the call won't return.
4055 if (!Last
|| !BC
.MIB
->isCall(*Last
))
4058 const MCSymbol
*CalleeSymbol
= BC
.MIB
->getTargetSymbol(*Last
);
4062 StringRef CalleeName
= CalleeSymbol
->getName();
4063 if (CalleeName
!= "__cxa_throw@PLT" && CalleeName
!= "_Unwind_Resume@PLT" &&
4064 CalleeName
!= "__cxa_rethrow@PLT" && CalleeName
!= "exit@PLT" &&
4065 CalleeName
!= "abort@PLT")
4068 BB
->removeAllSuccessors();
4072 bool BinaryFunction::isSymbolValidInScope(const SymbolRef
&Symbol
,
4073 uint64_t SymbolSize
) const {
4074 // If this symbol is in a different section from the one where the
4075 // function symbol is, don't consider it as valid.
4076 if (!getOriginSection()->containsAddress(
4077 cantFail(Symbol
.getAddress(), "cannot get symbol address")))
4080 // Some symbols are tolerated inside function bodies, others are not.
4081 // The real function boundaries may not be known at this point.
4082 if (BC
.isMarker(Symbol
))
4085 // It's okay to have a zero-sized symbol in the middle of non-zero-sized
4087 if (SymbolSize
== 0 && containsAddress(cantFail(Symbol
.getAddress())))
4090 if (cantFail(Symbol
.getType()) != SymbolRef::ST_Unknown
)
4093 if (cantFail(Symbol
.getFlags()) & SymbolRef::SF_Global
)
4099 void BinaryFunction::adjustExecutionCount(uint64_t Count
) {
4100 if (getKnownExecutionCount() == 0 || Count
== 0)
4103 if (ExecutionCount
< Count
)
4104 Count
= ExecutionCount
;
4106 double AdjustmentRatio
= ((double)ExecutionCount
- Count
) / ExecutionCount
;
4107 if (AdjustmentRatio
< 0.0)
4108 AdjustmentRatio
= 0.0;
4110 for (BinaryBasicBlock
&BB
: blocks())
4111 BB
.adjustExecutionCount(AdjustmentRatio
);
4113 ExecutionCount
-= Count
;
4116 BinaryFunction::~BinaryFunction() {
4117 for (BinaryBasicBlock
*BB
: BasicBlocks
)
4119 for (BinaryBasicBlock
*BB
: DeletedBasicBlocks
)
4123 void BinaryFunction::constructDomTree() {
4124 BDT
.reset(new BinaryDominatorTree
);
4125 BDT
->recalculate(*this);
4128 void BinaryFunction::calculateLoopInfo() {
4132 BLI
.reset(new BinaryLoopInfo());
4133 BLI
->analyze(getDomTree());
4135 // Traverse discovered loops and add depth and profile information.
4136 std::stack
<BinaryLoop
*> St
;
4137 for (auto I
= BLI
->begin(), E
= BLI
->end(); I
!= E
; ++I
) {
4142 while (!St
.empty()) {
4143 BinaryLoop
*L
= St
.top();
4146 BLI
->MaximumDepth
= std::max(L
->getLoopDepth(), BLI
->MaximumDepth
);
4148 // Add nested loops in the stack.
4149 for (BinaryLoop::iterator I
= L
->begin(), E
= L
->end(); I
!= E
; ++I
)
4152 // Skip if no valid profile is found.
4153 if (!hasValidProfile()) {
4154 L
->EntryCount
= COUNT_NO_PROFILE
;
4155 L
->ExitCount
= COUNT_NO_PROFILE
;
4156 L
->TotalBackEdgeCount
= COUNT_NO_PROFILE
;
4160 // Compute back edge count.
4161 SmallVector
<BinaryBasicBlock
*, 1> Latches
;
4162 L
->getLoopLatches(Latches
);
4164 for (BinaryBasicBlock
*Latch
: Latches
) {
4165 auto BI
= Latch
->branch_info_begin();
4166 for (BinaryBasicBlock
*Succ
: Latch
->successors()) {
4167 if (Succ
== L
->getHeader()) {
4168 assert(BI
->Count
!= BinaryBasicBlock::COUNT_NO_PROFILE
&&
4169 "profile data not found");
4170 L
->TotalBackEdgeCount
+= BI
->Count
;
4176 // Compute entry count.
4177 L
->EntryCount
= L
->getHeader()->getExecutionCount() - L
->TotalBackEdgeCount
;
4179 // Compute exit count.
4180 SmallVector
<BinaryLoop::Edge
, 1> ExitEdges
;
4181 L
->getExitEdges(ExitEdges
);
4182 for (BinaryLoop::Edge
&Exit
: ExitEdges
) {
4183 const BinaryBasicBlock
*Exiting
= Exit
.first
;
4184 const BinaryBasicBlock
*ExitTarget
= Exit
.second
;
4185 auto BI
= Exiting
->branch_info_begin();
4186 for (BinaryBasicBlock
*Succ
: Exiting
->successors()) {
4187 if (Succ
== ExitTarget
) {
4188 assert(BI
->Count
!= BinaryBasicBlock::COUNT_NO_PROFILE
&&
4189 "profile data not found");
4190 L
->ExitCount
+= BI
->Count
;
4198 void BinaryFunction::updateOutputValues(const BOLTLinker
&Linker
) {
4200 assert(!isInjected() && "injected function should be emitted");
4201 setOutputAddress(getAddress());
4202 setOutputSize(getSize());
4206 const auto SymbolInfo
= Linker
.lookupSymbolInfo(getSymbol()->getName());
4207 assert(SymbolInfo
&& "Cannot find function entry symbol");
4208 setOutputAddress(SymbolInfo
->Address
);
4209 setOutputSize(SymbolInfo
->Size
);
4211 if (BC
.HasRelocations
|| isInjected()) {
4212 if (hasConstantIsland()) {
4213 const auto DataAddress
=
4214 Linker
.lookupSymbol(getFunctionConstantIslandLabel()->getName());
4215 assert(DataAddress
&& "Cannot find function CI symbol");
4216 setOutputDataAddress(*DataAddress
);
4217 for (auto It
: Islands
->Offsets
) {
4218 const uint64_t OldOffset
= It
.first
;
4219 BinaryData
*BD
= BC
.getBinaryDataAtAddress(getAddress() + OldOffset
);
4223 MCSymbol
*Symbol
= It
.second
;
4224 const auto NewAddress
= Linker
.lookupSymbol(Symbol
->getName());
4225 assert(NewAddress
&& "Cannot find CI symbol");
4226 auto &Section
= *getCodeSection();
4227 const auto NewOffset
= *NewAddress
- Section
.getOutputAddress();
4228 BD
->setOutputLocation(Section
, NewOffset
);
4232 for (FunctionFragment
&FF
: getLayout().getSplitFragments()) {
4233 ErrorOr
<BinarySection
&> ColdSection
=
4234 getCodeSection(FF
.getFragmentNum());
4235 // If fragment is empty, cold section might not exist
4236 if (FF
.empty() && ColdSection
.getError())
4239 const MCSymbol
*ColdStartSymbol
= getSymbol(FF
.getFragmentNum());
4240 // If fragment is empty, symbol might have not been emitted
4241 if (FF
.empty() && (!ColdStartSymbol
|| !ColdStartSymbol
->isDefined()) &&
4242 !hasConstantIsland())
4244 assert(ColdStartSymbol
&& ColdStartSymbol
->isDefined() &&
4245 "split function should have defined cold symbol");
4246 const auto ColdStartSymbolInfo
=
4247 Linker
.lookupSymbolInfo(ColdStartSymbol
->getName());
4248 assert(ColdStartSymbolInfo
&& "Cannot find cold start symbol");
4249 FF
.setAddress(ColdStartSymbolInfo
->Address
);
4250 FF
.setImageSize(ColdStartSymbolInfo
->Size
);
4251 if (hasConstantIsland()) {
4252 const auto DataAddress
= Linker
.lookupSymbol(
4253 getFunctionColdConstantIslandLabel()->getName());
4254 assert(DataAddress
&& "Cannot find cold CI symbol");
4255 setOutputColdDataAddress(*DataAddress
);
4261 // Update basic block output ranges for the debug info, if we have
4262 // secondary entry points in the symbol table to update or if writing BAT.
4263 if (!requiresAddressMap())
4266 // AArch64 may have functions that only contains a constant island (no code).
4267 if (getLayout().block_empty())
4270 for (FunctionFragment
&FF
: getLayout().fragments()) {
4274 const uint64_t FragmentBaseAddress
=
4275 getCodeSection(isSimple() ? FF
.getFragmentNum() : FragmentNum::main())
4276 ->getOutputAddress();
4278 BinaryBasicBlock
*PrevBB
= nullptr;
4279 for (BinaryBasicBlock
*const BB
: FF
) {
4280 assert(BB
->getLabel()->isDefined() && "symbol should be defined");
4281 if (!BC
.HasRelocations
) {
4283 assert(FragmentBaseAddress
== FF
.getAddress());
4285 assert(FragmentBaseAddress
== getOutputAddress());
4286 (void)FragmentBaseAddress
;
4289 // Injected functions likely will fail lookup, as they have no
4290 // input range. Just assign the BB the output address of the
4292 auto MaybeBBAddress
= BC
.getIOAddressMap().lookup(BB
->getLabel());
4293 const uint64_t BBAddress
= MaybeBBAddress
? *MaybeBBAddress
4294 : BB
->isSplit() ? FF
.getAddress()
4295 : getOutputAddress();
4296 BB
->setOutputStartAddress(BBAddress
);
4299 assert(PrevBB
->getOutputAddressRange().first
<= BBAddress
&&
4300 "Bad output address for basic block.");
4301 assert((PrevBB
->getOutputAddressRange().first
!= BBAddress
||
4302 !hasInstructions() || !PrevBB
->getNumNonPseudos()) &&
4303 "Bad output address for basic block.");
4304 PrevBB
->setOutputEndAddress(BBAddress
);
4309 PrevBB
->setOutputEndAddress(PrevBB
->isSplit()
4310 ? FF
.getAddress() + FF
.getImageSize()
4311 : getOutputAddress() + getOutputSize());
4314 // Reset output addresses for deleted blocks.
4315 for (BinaryBasicBlock
*BB
: DeletedBasicBlocks
) {
4316 BB
->setOutputStartAddress(0);
4317 BB
->setOutputEndAddress(0);
4321 DebugAddressRangesVector
BinaryFunction::getOutputAddressRanges() const {
4322 DebugAddressRangesVector OutputRanges
;
4325 return OutputRanges
;
4328 return OutputRanges
;
4330 OutputRanges
.emplace_back(getOutputAddress(),
4331 getOutputAddress() + getOutputSize());
4333 assert(isEmitted() && "split function should be emitted");
4334 for (const FunctionFragment
&FF
: getLayout().getSplitFragments())
4335 OutputRanges
.emplace_back(FF
.getAddress(),
4336 FF
.getAddress() + FF
.getImageSize());
4340 return OutputRanges
;
4342 for (BinaryFunction
*Frag
: Fragments
) {
4343 assert(!Frag
->isSimple() &&
4344 "fragment of non-simple function should also be non-simple");
4345 OutputRanges
.emplace_back(Frag
->getOutputAddress(),
4346 Frag
->getOutputAddress() + Frag
->getOutputSize());
4349 return OutputRanges
;
4352 uint64_t BinaryFunction::translateInputToOutputAddress(uint64_t Address
) const {
4356 // If the function hasn't changed return the same address.
4360 if (Address
< getAddress())
4363 // Check if the address is associated with an instruction that is tracked
4364 // by address translation.
4365 if (auto OutputAddress
= BC
.getIOAddressMap().lookup(Address
))
4366 return *OutputAddress
;
4368 // FIXME: #18950828 - we rely on relative offsets inside basic blocks to stay
4369 // intact. Instead we can use pseudo instructions and/or annotations.
4370 const uint64_t Offset
= Address
- getAddress();
4371 const BinaryBasicBlock
*BB
= getBasicBlockContainingOffset(Offset
);
4373 // Special case for address immediately past the end of the function.
4374 if (Offset
== getSize())
4375 return getOutputAddress() + getOutputSize();
4380 return std::min(BB
->getOutputAddressRange().first
+ Offset
- BB
->getOffset(),
4381 BB
->getOutputAddressRange().second
);
4384 DebugAddressRangesVector
4385 BinaryFunction::translateInputToOutputRange(DebugAddressRange InRange
) const {
4386 DebugAddressRangesVector OutRanges
;
4388 // The function was removed from the output. Return an empty range.
4392 // If the function hasn't changed return the same range.
4394 OutRanges
.emplace_back(InRange
);
4398 if (!containsAddress(InRange
.LowPC
))
4401 // Special case of an empty range [X, X). Some tools expect X to be updated.
4402 if (InRange
.LowPC
== InRange
.HighPC
) {
4403 if (uint64_t NewPC
= translateInputToOutputAddress(InRange
.LowPC
))
4404 OutRanges
.push_back(DebugAddressRange
{NewPC
, NewPC
});
4408 uint64_t InputOffset
= InRange
.LowPC
- getAddress();
4409 const uint64_t InputEndOffset
=
4410 std::min(InRange
.HighPC
- getAddress(), getSize());
4412 auto BBI
= llvm::upper_bound(BasicBlockOffsets
,
4413 BasicBlockOffset(InputOffset
, nullptr),
4414 CompareBasicBlockOffsets());
4415 assert(BBI
!= BasicBlockOffsets
.begin());
4417 // Iterate over blocks in the input order using BasicBlockOffsets.
4418 for (--BBI
; InputOffset
< InputEndOffset
&& BBI
!= BasicBlockOffsets
.end();
4419 InputOffset
= BBI
->second
->getEndOffset(), ++BBI
) {
4420 const BinaryBasicBlock
&BB
= *BBI
->second
;
4421 if (InputOffset
< BB
.getOffset() || InputOffset
>= BB
.getEndOffset()) {
4423 dbgs() << "BOLT-DEBUG: invalid debug address range detected for "
4424 << *this << " : [0x" << Twine::utohexstr(InRange
.LowPC
)
4425 << ", 0x" << Twine::utohexstr(InRange
.HighPC
) << "]\n");
4429 // Skip the block if it wasn't emitted.
4430 if (!BB
.getOutputAddressRange().first
)
4433 // Find output address for an instruction with an offset greater or equal
4434 // to /p Offset. The output address should fall within the same basic
4435 // block boundaries.
4436 auto translateBlockOffset
= [&](const uint64_t Offset
) {
4437 const uint64_t OutAddress
= BB
.getOutputAddressRange().first
+ Offset
;
4438 return std::min(OutAddress
, BB
.getOutputAddressRange().second
);
4441 uint64_t OutLowPC
= BB
.getOutputAddressRange().first
;
4442 if (InputOffset
> BB
.getOffset())
4443 OutLowPC
= translateBlockOffset(InputOffset
- BB
.getOffset());
4445 uint64_t OutHighPC
= BB
.getOutputAddressRange().second
;
4446 if (InputEndOffset
< BB
.getEndOffset()) {
4447 assert(InputEndOffset
>= BB
.getOffset());
4448 OutHighPC
= translateBlockOffset(InputEndOffset
- BB
.getOffset());
4451 // Check if we can expand the last translated range.
4452 if (!OutRanges
.empty() && OutRanges
.back().HighPC
== OutLowPC
)
4453 OutRanges
.back().HighPC
= std::max(OutRanges
.back().HighPC
, OutHighPC
);
4455 OutRanges
.emplace_back(OutLowPC
, std::max(OutLowPC
, OutHighPC
));
4459 dbgs() << "BOLT-DEBUG: translated address range " << InRange
<< " -> ";
4460 for (const DebugAddressRange
&R
: OutRanges
)
4468 MCInst
*BinaryFunction::getInstructionAtOffset(uint64_t Offset
) {
4469 if (CurrentState
== State::Disassembled
) {
4470 auto II
= Instructions
.find(Offset
);
4471 return (II
== Instructions
.end()) ? nullptr : &II
->second
;
4472 } else if (CurrentState
== State::CFG
) {
4473 BinaryBasicBlock
*BB
= getBasicBlockContainingOffset(Offset
);
4477 for (MCInst
&Inst
: *BB
) {
4478 constexpr uint32_t InvalidOffset
= std::numeric_limits
<uint32_t>::max();
4479 if (Offset
== BC
.MIB
->getOffsetWithDefault(Inst
, InvalidOffset
))
4483 if (MCInst
*LastInstr
= BB
->getLastNonPseudoInstr()) {
4484 if (std::optional
<uint32_t> Size
= BC
.MIB
->getSize(*LastInstr
)) {
4485 if (BB
->getEndOffset() - Offset
== Size
) {
4493 llvm_unreachable("invalid CFG state to use getInstructionAtOffset()");
4497 MCInst
*BinaryFunction::getInstructionContainingOffset(uint64_t Offset
) {
4498 assert(CurrentState
== State::Disassembled
&& "Wrong function state");
4503 auto II
= Instructions
.upper_bound(Offset
);
4504 assert(II
!= Instructions
.begin() && "First instruction not at offset 0");
4509 void BinaryFunction::printLoopInfo(raw_ostream
&OS
) const {
4510 if (!opts::shouldPrint(*this))
4513 OS
<< "Loop Info for Function \"" << *this << "\"";
4514 if (hasValidProfile())
4515 OS
<< " (count: " << getExecutionCount() << ")";
4518 std::stack
<BinaryLoop
*> St
;
4519 for (BinaryLoop
*L
: *BLI
)
4521 while (!St
.empty()) {
4522 BinaryLoop
*L
= St
.top();
4525 for (BinaryLoop
*Inner
: *L
)
4528 if (!hasValidProfile())
4531 OS
<< (L
->getLoopDepth() > 1 ? "Nested" : "Outer")
4532 << " loop header: " << L
->getHeader()->getName();
4534 OS
<< "Loop basic blocks: ";
4536 for (BinaryBasicBlock
*BB
: L
->blocks())
4537 OS
<< LS
<< BB
->getName();
4539 if (hasValidProfile()) {
4540 OS
<< "Total back edge count: " << L
->TotalBackEdgeCount
<< "\n";
4541 OS
<< "Loop entry count: " << L
->EntryCount
<< "\n";
4542 OS
<< "Loop exit count: " << L
->ExitCount
<< "\n";
4543 if (L
->EntryCount
> 0) {
4544 OS
<< "Average iters per entry: "
4545 << format("%.4lf", (double)L
->TotalBackEdgeCount
/ L
->EntryCount
)
4552 OS
<< "Total number of loops: " << BLI
->TotalLoops
<< "\n";
4553 OS
<< "Number of outer loops: " << BLI
->OuterLoops
<< "\n";
4554 OS
<< "Maximum nested loop depth: " << BLI
->MaximumDepth
<< "\n\n";
4557 bool BinaryFunction::isAArch64Veneer() const {
4558 if (empty() || hasIslandsInfo())
4561 BinaryBasicBlock
&BB
= **BasicBlocks
.begin();
4562 for (MCInst
&Inst
: BB
)
4563 if (!BC
.MIB
->hasAnnotation(Inst
, "AArch64Veneer"))
4566 for (auto I
= BasicBlocks
.begin() + 1, E
= BasicBlocks
.end(); I
!= E
; ++I
) {
4567 for (MCInst
&Inst
: **I
)
4568 if (!BC
.MIB
->isNoop(Inst
))
4575 void BinaryFunction::addRelocation(uint64_t Address
, MCSymbol
*Symbol
,
4576 uint64_t RelType
, uint64_t Addend
,
4578 assert(Address
>= getAddress() && Address
< getAddress() + getMaxSize() &&
4579 "address is outside of the function");
4580 uint64_t Offset
= Address
- getAddress();
4581 LLVM_DEBUG(dbgs() << "BOLT-DEBUG: addRelocation in "
4582 << formatv("{0}@{1:x} against {2}\n", *this, Offset
,
4583 (Symbol
? Symbol
->getName() : "<undef>")));
4584 bool IsCI
= BC
.isAArch64() && isInConstantIsland(Address
);
4585 std::map
<uint64_t, Relocation
> &Rels
=
4586 IsCI
? Islands
->Relocations
: Relocations
;
4587 if (BC
.MIB
->shouldRecordCodeRelocation(RelType
))
4588 Rels
[Offset
] = Relocation
{Offset
, Symbol
, RelType
, Addend
, Value
};