[llvm] [BOLT] Add optional flag to Relocations (PR #131638)
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Mon Mar 17 09:26:11 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-bolt
Author: Paschalis Mpeis (paschalis-mpeis)
<details>
<summary>Changes</summary>
---
Full diff: https://github.com/llvm/llvm-project/pull/131638.diff
13 Files Affected:
- (modified) bolt/include/bolt/Core/BinaryContext.h (+2-2)
- (modified) bolt/include/bolt/Core/BinaryFunction.h (+1-1)
- (modified) bolt/include/bolt/Core/BinarySection.h (+9-6)
- (modified) bolt/include/bolt/Core/Relocation.h (+3)
- (modified) bolt/lib/Core/BinaryContext.cpp (+6-6)
- (modified) bolt/lib/Core/BinaryFunction.cpp (+3-3)
- (modified) bolt/lib/Core/BinarySection.cpp (+4-3)
- (modified) bolt/lib/Core/JumpTable.cpp (+2-1)
- (modified) bolt/lib/Rewrite/LinuxKernelRewriter.cpp (+12-9)
- (modified) bolt/lib/Rewrite/RewriteInstance.cpp (+13-10)
- (modified) bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp (+2-1)
- (modified) bolt/lib/Target/X86/X86MCPlusBuilder.cpp (+2-1)
- (modified) bolt/unittests/Core/BinaryContext.cpp (+8-8)
``````````diff
diff --git a/bolt/include/bolt/Core/BinaryContext.h b/bolt/include/bolt/Core/BinaryContext.h
index 9a0485989201f..0da3815306a60 100644
--- a/bolt/include/bolt/Core/BinaryContext.h
+++ b/bolt/include/bolt/Core/BinaryContext.h
@@ -1296,7 +1296,7 @@ class BinaryContext {
/// Add a Section relocation at a given \p Address.
void addRelocation(uint64_t Address, MCSymbol *Symbol, uint32_t Type,
- uint64_t Addend = 0, uint64_t Value = 0);
+ bool Optional, uint64_t Addend = 0, uint64_t Value = 0);
/// Return a relocation registered at a given \p Address, or nullptr if there
/// is no relocation at such address.
@@ -1309,7 +1309,7 @@ class BinaryContext {
/// Register dynamic relocation at \p Address.
void addDynamicRelocation(uint64_t Address, MCSymbol *Symbol, uint32_t Type,
- uint64_t Addend, uint64_t Value = 0);
+ bool Optional, uint64_t Addend, uint64_t Value = 0);
/// Return a dynamic relocation registered at a given \p Address, or nullptr
/// if there is no dynamic relocation at such address.
diff --git a/bolt/include/bolt/Core/BinaryFunction.h b/bolt/include/bolt/Core/BinaryFunction.h
index a92cb466c5992..09e19a33986de 100644
--- a/bolt/include/bolt/Core/BinaryFunction.h
+++ b/bolt/include/bolt/Core/BinaryFunction.h
@@ -1261,7 +1261,7 @@ class BinaryFunction {
/// against \p Symbol.
/// Assert if the \p Address is not inside this function.
void addRelocation(uint64_t Address, MCSymbol *Symbol, uint32_t RelType,
- uint64_t Addend, uint64_t Value);
+ bool Optional, uint64_t Addend, uint64_t Value);
/// Return the name of the section this function originated from.
std::optional<StringRef> getOriginSectionName() const {
diff --git a/bolt/include/bolt/Core/BinarySection.h b/bolt/include/bolt/Core/BinarySection.h
index ad2fed2cf27eb..10f633fda6640 100644
--- a/bolt/include/bolt/Core/BinarySection.h
+++ b/bolt/include/bolt/Core/BinarySection.h
@@ -359,15 +359,18 @@ class BinarySection {
/// Add a new relocation at the given /p Offset.
void addRelocation(uint64_t Offset, MCSymbol *Symbol, uint32_t Type,
- uint64_t Addend, uint64_t Value = 0) {
+ bool Optional, uint64_t Addend, uint64_t Value = 0) {
assert(Offset < getSize() && "offset not within section bounds");
- Relocations.emplace(Relocation{Offset, Symbol, Type, Addend, Value});
+ Relocations.emplace(
+ Relocation{Offset, Symbol, Type, Optional, Addend, Value});
}
/// Add a dynamic relocation at the given /p Offset.
void addDynamicRelocation(uint64_t Offset, MCSymbol *Symbol, uint32_t Type,
- uint64_t Addend, uint64_t Value = 0) {
- addDynamicRelocation(Relocation{Offset, Symbol, Type, Addend, Value});
+ bool Optional, uint64_t Addend,
+ uint64_t Value = 0) {
+ addDynamicRelocation(
+ Relocation{Offset, Symbol, Type, Optional, Addend, Value});
}
void addDynamicRelocation(const Relocation &Reloc) {
@@ -401,13 +404,13 @@ class BinarySection {
/// Lookup the relocation (if any) at the given /p Offset.
const Relocation *getDynamicRelocationAt(uint64_t Offset) const {
- Relocation Key{Offset, 0, 0, 0, 0};
+ Relocation Key{Offset, 0, 0, 0, 0, 0};
auto Itr = DynamicRelocations.find(Key);
return Itr != DynamicRelocations.end() ? &*Itr : nullptr;
}
std::optional<Relocation> takeDynamicRelocationAt(uint64_t Offset) {
- Relocation Key{Offset, 0, 0, 0, 0};
+ Relocation Key{Offset, 0, 0, 0, 0, 0};
auto Itr = DynamicRelocations.find(Key);
if (Itr == DynamicRelocations.end())
diff --git a/bolt/include/bolt/Core/Relocation.h b/bolt/include/bolt/Core/Relocation.h
index 1f18dad008ca2..3a18249fa6bf9 100644
--- a/bolt/include/bolt/Core/Relocation.h
+++ b/bolt/include/bolt/Core/Relocation.h
@@ -47,6 +47,9 @@ struct Relocation {
/// Relocation type.
uint32_t Type;
+ /// Relocations added by optimizations can be optional.
+ bool Optional;
+
/// The offset from the \p Symbol base used to compute the final
/// value of this relocation.
uint64_t Addend;
diff --git a/bolt/lib/Core/BinaryContext.cpp b/bolt/lib/Core/BinaryContext.cpp
index 7466d2f8c91eb..f6d191eef5b41 100644
--- a/bolt/lib/Core/BinaryContext.cpp
+++ b/bolt/lib/Core/BinaryContext.cpp
@@ -2284,21 +2284,21 @@ ErrorOr<int64_t> BinaryContext::getSignedValueAtAddress(uint64_t Address,
}
void BinaryContext::addRelocation(uint64_t Address, MCSymbol *Symbol,
- uint32_t Type, uint64_t Addend,
+ uint32_t Type, bool Optional, uint64_t Addend,
uint64_t Value) {
ErrorOr<BinarySection &> Section = getSectionForAddress(Address);
assert(Section && "cannot find section for address");
- Section->addRelocation(Address - Section->getAddress(), Symbol, Type, Addend,
- Value);
+ Section->addRelocation(Address - Section->getAddress(), Symbol, Type,
+ Optional, Addend, Value);
}
void BinaryContext::addDynamicRelocation(uint64_t Address, MCSymbol *Symbol,
- uint32_t Type, uint64_t Addend,
- uint64_t Value) {
+ uint32_t Type, bool Optional,
+ uint64_t Addend, uint64_t Value) {
ErrorOr<BinarySection &> Section = getSectionForAddress(Address);
assert(Section && "cannot find section for address");
Section->addDynamicRelocation(Address - Section->getAddress(), Symbol, Type,
- Addend, Value);
+ Optional, Addend, Value);
}
bool BinaryContext::removeRelocationAt(uint64_t Address) {
diff --git a/bolt/lib/Core/BinaryFunction.cpp b/bolt/lib/Core/BinaryFunction.cpp
index acf04cee769c1..4b97aebe37c3c 100644
--- a/bolt/lib/Core/BinaryFunction.cpp
+++ b/bolt/lib/Core/BinaryFunction.cpp
@@ -4623,8 +4623,8 @@ bool BinaryFunction::isAArch64Veneer() const {
}
void BinaryFunction::addRelocation(uint64_t Address, MCSymbol *Symbol,
- uint32_t RelType, uint64_t Addend,
- uint64_t Value) {
+ uint32_t RelType, bool Optional,
+ uint64_t Addend, uint64_t Value) {
assert(Address >= getAddress() && Address < getAddress() + getMaxSize() &&
"address is outside of the function");
uint64_t Offset = Address - getAddress();
@@ -4635,7 +4635,7 @@ void BinaryFunction::addRelocation(uint64_t Address, MCSymbol *Symbol,
std::map<uint64_t, Relocation> &Rels =
IsCI ? Islands->Relocations : Relocations;
if (BC.MIB->shouldRecordCodeRelocation(RelType))
- Rels[Offset] = Relocation{Offset, Symbol, RelType, Addend, Value};
+ Rels[Offset] = Relocation{Offset, Symbol, RelType, Optional, Addend, Value};
}
} // namespace bolt
diff --git a/bolt/lib/Core/BinarySection.cpp b/bolt/lib/Core/BinarySection.cpp
index b16e0a4333aa2..a4968c27f3a25 100644
--- a/bolt/lib/Core/BinarySection.cpp
+++ b/bolt/lib/Core/BinarySection.cpp
@@ -49,8 +49,8 @@ BinarySection::hash(const BinaryData &BD,
uint64_t Offset = BD.getAddress() - getAddress();
const uint64_t EndOffset = BD.getEndAddress() - getAddress();
- auto Begin = Relocations.lower_bound(Relocation{Offset, 0, 0, 0, 0});
- auto End = Relocations.upper_bound(Relocation{EndOffset, 0, 0, 0, 0});
+ auto Begin = Relocations.lower_bound(Relocation{Offset, 0, 0, 0, 0, 0});
+ auto End = Relocations.upper_bound(Relocation{EndOffset, 0, 0, 0, 0, 0});
const StringRef Contents = getContents();
while (Begin != End) {
@@ -275,7 +275,8 @@ void BinarySection::reorderContents(const std::vector<BinaryData *> &Order,
// of the reordered segment to force LLVM to recognize and map this
// section.
MCSymbol *ZeroSym = BC.registerNameAtAddress("Zero", 0, 0, 0);
- addRelocation(OS.tell(), ZeroSym, Relocation::getAbs64(), 0xdeadbeef);
+ addRelocation(OS.tell(), ZeroSym, Relocation::getAbs64(),
+ /*Optional*/ false, 0xdeadbeef);
uint64_t Zero = 0;
OS.write(reinterpret_cast<const char *>(&Zero), sizeof(Zero));
diff --git a/bolt/lib/Core/JumpTable.cpp b/bolt/lib/Core/JumpTable.cpp
index 6f588d2b95fd6..b8124fc9dd129 100644
--- a/bolt/lib/Core/JumpTable.cpp
+++ b/bolt/lib/Core/JumpTable.cpp
@@ -92,7 +92,8 @@ void bolt::JumpTable::updateOriginal() {
// to the original jump table.
if (BC.HasRelocations)
getOutputSection().removeRelocationAt(EntryOffset);
- getOutputSection().addRelocation(EntryOffset, Entry, RelType, RelAddend);
+ getOutputSection().addRelocation(EntryOffset, Entry, RelType,
+ /*Optional*/ false, RelAddend);
EntryOffset += EntrySize;
}
}
diff --git a/bolt/lib/Rewrite/LinuxKernelRewriter.cpp b/bolt/lib/Rewrite/LinuxKernelRewriter.cpp
index 5a5e044184d0b..d142e002128e2 100644
--- a/bolt/lib/Rewrite/LinuxKernelRewriter.cpp
+++ b/bolt/lib/Rewrite/LinuxKernelRewriter.cpp
@@ -487,8 +487,8 @@ void LinuxKernelRewriter::processLKKSymtab(bool IsGPL) {
if (!BF)
continue;
- BC.addRelocation(EntryAddress, BF->getSymbol(), Relocation::getPC32(), 0,
- *Offset);
+ BC.addRelocation(EntryAddress, BF->getSymbol(), Relocation::getPC32(),
+ /*Optional*/ false, 0, *Offset);
}
}
@@ -559,7 +559,7 @@ void LinuxKernelRewriter::processInstructionFixups() {
Fixup.Section.addRelocation(Fixup.Offset, &Fixup.Label,
Fixup.IsPCRelative ? ELF::R_X86_64_PC32
: ELF::R_X86_64_64,
- /*Addend*/ 0);
+ /*Optional*/ false, /*Addend*/ 0);
}
}
@@ -828,7 +828,8 @@ Error LinuxKernelRewriter::rewriteORCTables() {
if (Label)
ORCUnwindIPSection->addRelocation(UnwindIPWriter.getOffset(), Label,
- Relocation::getPC32(), /*Addend*/ 0);
+ Relocation::getPC32(),
+ /*Optional*/ false, /*Addend*/ 0);
const int32_t IPValue =
IP - ORCUnwindIPSection->getAddress() - UnwindIPWriter.getOffset();
@@ -1074,7 +1075,8 @@ Error LinuxKernelRewriter::rewriteStaticCalls() {
StaticCallSection->getAddress() +
(Entry.ID - 1) * STATIC_CALL_ENTRY_SIZE;
StaticCallSection->addRelocation(EntryOffset, Entry.Label,
- ELF::R_X86_64_PC32, /*Addend*/ 0);
+ ELF::R_X86_64_PC32, /*Optional*/ false,
+ /*Addend*/ 0);
}
return Error::success();
@@ -1378,7 +1380,7 @@ Error LinuxKernelRewriter::rewriteBugTable() {
BC.MIB->getOrCreateInstLabel(Inst, "__BUG_", BC.Ctx.get());
const uint64_t EntryOffset = (ID - 1) * BUG_TABLE_ENTRY_SIZE;
BugTableSection->addRelocation(EntryOffset, Label, ELF::R_X86_64_PC32,
- /*Addend*/ 0);
+ /*Optional*/ false, /*Addend*/ 0);
}
}
@@ -1388,7 +1390,7 @@ Error LinuxKernelRewriter::rewriteBugTable() {
if (!EmittedIDs.count(ID)) {
const uint64_t EntryOffset = (ID - 1) * BUG_TABLE_ENTRY_SIZE;
BugTableSection->addRelocation(EntryOffset, nullptr, ELF::R_X86_64_PC32,
- /*Addend*/ 0);
+ /*Optional*/ false, /*Addend*/ 0);
}
}
}
@@ -1904,9 +1906,10 @@ Error LinuxKernelRewriter::rewriteStaticKeysJumpTable() {
(EntryID - 1) * 16;
StaticKeysJumpSection->addRelocation(EntryOffset, Label,
ELF::R_X86_64_PC32,
- /*Addend*/ 0);
+ /*Optional*/ false, /*Addend*/ 0);
StaticKeysJumpSection->addRelocation(EntryOffset + 4, Target,
- ELF::R_X86_64_PC32, /*Addend*/ 0);
+ ELF::R_X86_64_PC32,
+ /*Optional*/ false, /*Addend*/ 0);
}
}
}
diff --git a/bolt/lib/Rewrite/RewriteInstance.cpp b/bolt/lib/Rewrite/RewriteInstance.cpp
index 560b30c6c676c..5c9fa0edf0f55 100644
--- a/bolt/lib/Rewrite/RewriteInstance.cpp
+++ b/bolt/lib/Rewrite/RewriteInstance.cpp
@@ -1420,7 +1420,7 @@ void RewriteInstance::updateRtFiniReloc() {
// desired value.
FiniArraySection->addPendingRelocation(Relocation{
/*Offset*/ 0, /*Symbol*/ nullptr, /*Type*/ Relocation::getAbs64(),
- /*Addend*/ RT->getRuntimeFiniAddress(), /*Value*/ 0});
+ /*Optional*/ false, /*Addend*/ RT->getRuntimeFiniAddress(), /*Value*/ 0});
}
void RewriteInstance::registerFragments() {
@@ -1919,7 +1919,8 @@ void RewriteInstance::relocateEHFrameSection() {
// Create a relocation against an absolute value since the goal is to
// preserve the contents of the section independent of the new values
// of referenced symbols.
- RelocatedEHFrameSection->addRelocation(Offset, nullptr, RelType, Value);
+ RelocatedEHFrameSection->addRelocation(Offset, nullptr, RelType,
+ /*Optional*/ false, Value);
};
Error E = EHFrameParser::parse(DE, EHFrameSection->getAddress(), createReloc);
@@ -2455,7 +2456,8 @@ void RewriteInstance::readDynamicRelocations(const SectionRef &Section,
if (Symbol)
SymbolIndex[Symbol] = getRelocationSymbol(InputFile, Rel);
- BC->addDynamicRelocation(Rel.getOffset(), Symbol, RType, Addend);
+ BC->addDynamicRelocation(Rel.getOffset(), Symbol, RType, /*Optional*/ false,
+ Addend);
}
}
@@ -2486,7 +2488,8 @@ void RewriteInstance::readDynamicRelrRelocations(BinarySection &Section) {
LLVM_DEBUG(dbgs() << "BOLT-DEBUG: R_*_RELATIVE relocation at 0x"
<< Twine::utohexstr(Address) << " to 0x"
<< Twine::utohexstr(Addend) << '\n';);
- BC->addDynamicRelocation(Address, nullptr, RType, Addend);
+ BC->addDynamicRelocation(Address, nullptr, RType, /*Optional*/ false,
+ Addend);
};
DataExtractor DE = DataExtractor(Section.getContents(),
@@ -2686,8 +2689,8 @@ void RewriteInstance::handleRelocation(const SectionRef &RelocatedSection,
// This might be a relocation for an ABS symbols like __global_pointer$ on
// RISC-V
ContainingBF->addRelocation(Rel.getOffset(), ReferencedSymbol,
- Relocation::getType(Rel), 0,
- cantFail(Symbol.getValue()));
+ Relocation::getType(Rel), /*Optional*/ false,
+ 0, cantFail(Symbol.getValue()));
return;
}
}
@@ -2719,7 +2722,7 @@ void RewriteInstance::handleRelocation(const SectionRef &RelocatedSection,
// the code. It's required to properly handle cases where
// "symbol + addend" references an object different from "symbol".
ContainingBF->addRelocation(Rel.getOffset(), ReferencedSymbol, RType,
- Addend, ExtractedValue);
+ /*Optional*/ false, Addend, ExtractedValue);
} else {
LLVM_DEBUG({
dbgs() << "BOLT-DEBUG: not creating PC-relative relocation at"
@@ -2953,10 +2956,10 @@ void RewriteInstance::handleRelocation(const SectionRef &RelocatedSection,
if (IsFromCode)
ContainingBF->addRelocation(Rel.getOffset(), ReferencedSymbol, RType,
- Addend, ExtractedValue);
+ /*Optional*/ false, Addend, ExtractedValue);
else if (IsToCode || ForceRelocation)
- BC->addRelocation(Rel.getOffset(), ReferencedSymbol, RType, Addend,
- ExtractedValue);
+ BC->addRelocation(Rel.getOffset(), ReferencedSymbol, RType,
+ /*Optional*/ false, Addend, ExtractedValue);
else
LLVM_DEBUG(dbgs() << "BOLT-DEBUG: ignoring relocation from data to data\n");
}
diff --git a/bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp b/bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp
index 613b24c4553e2..54422eb6103b7 100644
--- a/bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp
+++ b/bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp
@@ -2291,7 +2291,8 @@ class AArch64MCPlusBuilder : public MCPlusBuilder {
auto [RelSymbol, RelAddend] = extractFixupExpr(Fixup);
- return Relocation({RelOffset, RelSymbol, RelType, RelAddend, 0});
+ return Relocation(
+ {RelOffset, RelSymbol, RelType, /*Optional*/ false, RelAddend, 0});
}
uint16_t getMinFunctionAlignment() const override { return 4; }
diff --git a/bolt/lib/Target/X86/X86MCPlusBuilder.cpp b/bolt/lib/Target/X86/X86MCPlusBuilder.cpp
index 51550857ae5ea..cb754af3943cb 100644
--- a/bolt/lib/Target/X86/X86MCPlusBuilder.cpp
+++ b/bolt/lib/Target/X86/X86MCPlusBuilder.cpp
@@ -2467,7 +2467,8 @@ class X86MCPlusBuilder : public MCPlusBuilder {
auto [RelSymbol, RelAddend] = extractFixupExpr(Fixup);
- return Relocation({RelOffset, RelSymbol, RelType, RelAddend, 0});
+ return Relocation(
+ {RelOffset, RelSymbol, RelType, /*Optional*/ false, RelAddend, 0});
}
bool replaceImmWithSymbolRef(MCInst &Inst, const MCSymbol *Symbol,
diff --git a/bolt/unittests/Core/BinaryContext.cpp b/bolt/unittests/Core/BinaryContext.cpp
index 09d16966334da..de041becedf4e 100644
--- a/bolt/unittests/Core/BinaryContext.cpp
+++ b/bolt/unittests/Core/BinaryContext.cpp
@@ -96,12 +96,12 @@ TEST_P(BinaryContextTester, FlushPendingRelocCALL26) {
DataSize, 4);
MCSymbol *RelSymbol1 = BC->getOrCreateGlobalSymbol(4, "Func1");
ASSERT_TRUE(RelSymbol1);
- BS.addPendingRelocation(
- Relocation{8, RelSymbol1, ELF::R_AARCH64_CALL26, 0, 0});
+ BS.addPendingRelocation(Relocation{8, RelSymbol1, ELF::R_AARCH64_CALL26,
+ /*Optional*/ false, 0, 0});
MCSymbol *RelSymbol2 = BC->getOrCreateGlobalSymbol(16, "Func2");
ASSERT_TRUE(RelSymbol2);
- BS.addPendingRelocation(
- Relocation{12, RelSymbol2, ELF::R_AARCH64_CALL26, 0, 0});
+ BS.addPendingRelocation(Relocation{12, RelSymbol2, ELF::R_AARCH64_CALL26,
+ /*Optional*/ false, 0, 0});
SmallVector<char> Vect(DataSize);
raw_svector_ostream OS(Vect);
@@ -138,12 +138,12 @@ TEST_P(BinaryContextTester, FlushPendingRelocJUMP26) {
(uint8_t *)Data, Size, 4);
MCSymbol *RelSymbol1 = BC->getOrCreateGlobalSymbol(4, "Func1");
ASSERT_TRUE(RelSymbol1);
- BS.addPendingRelocation(
- Relocation{8, RelSymbol1, ELF::R_AARCH64_JUMP26, 0, 0});
+ BS.addPendingRelocation(Relocation{8, RelSymbol1, ELF::R_AARCH64_JUMP26,
+ /*Optional*/ false, 0, 0});
MCSymbol *RelSymbol2 = BC->getOrCreateGlobalSymbol(16, "Func2");
ASSERT_TRUE(RelSymbol2);
- BS.addPendingRelocation(
- Relocation{12, RelSymbol2, ELF::R_AARCH64_JUMP26, 0, 0});
+ BS.addPendingRelocation(Relocation{12, RelSymbol2, ELF::R_AARCH64_JUMP26,
+ /*Optional*/ false, 0, 0});
SmallVector<char> Vect(Size);
raw_svector_ostream OS(Vect);
``````````
</details>
https://github.com/llvm/llvm-project/pull/131638
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