[BOLT][NFC] Define AArch64 jump table types #132109
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Created using spr 1.3.4
Created using spr 1.3.4
aaupov
requested review from
maksfb,
rafaelauler,
ayermolo,
dcci and
yota9
as code owners
|
@llvm/pr-subscribers-bolt Author: Amir Ayupov (aaupov) ChangesDefine new JumpTable types for AArch64 based on definitions llvm-project/llvm/lib/Target/AArch64/AArch64InstrInfo.td Lines 1217 to 1225 in 335a461 Parsing and basic support is in a follow up PR #132114. Depends on #132108. Full diff: https://github.com/llvm/llvm-project/pull/132109.diff 8 Files Affected:
diff --git a/bolt/include/bolt/Core/BinaryContext.h b/bolt/include/bolt/Core/BinaryContext.h
index 485979f1a55a1..d713f1b3721f6 100644
--- a/bolt/include/bolt/Core/BinaryContext.h
+++ b/bolt/include/bolt/Core/BinaryContext.h
@@ -435,7 +435,18 @@ class BinaryContext {
/// Return size of an entry for the given jump table \p Type.
uint64_t getJumpTableEntrySize(JumpTable::JumpTableType Type) const {
- return Type == JumpTable::JTT_PIC ? 4 : AsmInfo->getCodePointerSize();
+ switch (Type) {
+ case JumpTable::JTT_X86_64_PIC4:
+ return 4;
+ case JumpTable::JTT_X86_64_ABS:
+ return AsmInfo->getCodePointerSize();
+ case JumpTable::JTT_AARCH64_REL1:
+ return 1;
+ case JumpTable::JTT_AARCH64_REL2:
+ return 2;
+ case JumpTable::JTT_AARCH64_REL4:
+ return 4;
+ }
}
/// Return JumpTable containing a given \p Address.
diff --git a/bolt/include/bolt/Core/JumpTable.h b/bolt/include/bolt/Core/JumpTable.h
index 52b9ccee1f7e1..7dc0c6581b233 100644
--- a/bolt/include/bolt/Core/JumpTable.h
+++ b/bolt/include/bolt/Core/JumpTable.h
@@ -47,10 +47,34 @@ class JumpTable : public BinaryData {
public:
enum JumpTableType : char {
- JTT_NORMAL,
- JTT_PIC,
+ JTT_X86_64_FIRST = 0,
+ JTT_X86_64_ABS = JTT_X86_64_FIRST,
+ JTT_X86_64_PIC4,
+ JTT_X86_64_LAST = JTT_X86_64_PIC4,
+ JTT_AARCH64_FIRST,
+ JTT_AARCH64_REL1 = JTT_AARCH64_FIRST,
+ JTT_AARCH64_REL2,
+ JTT_AARCH64_REL4,
+ JTT_AARCH64_LAST = JTT_AARCH64_REL4
};
+ static StringRef getTypeStr(JumpTableType Type) {
+ switch (Type) {
+ case JTT_X86_64_ABS:
+ return "X86_64_ABS";
+ case JTT_X86_64_PIC4:
+ return "X86_64_PIC4";
+ case JTT_AARCH64_REL1:
+ return "AARCH64_REL1";
+ case JTT_AARCH64_REL2:
+ return "AARCH64_REL2";
+ case JTT_AARCH64_REL4:
+ return "AARCH64_REL4";
+ }
+ }
+
+ const StringRef getTypeStr() { return getTypeStr(Type); }
+
/// Branch statistics for jump table entries.
struct JumpInfo {
uint64_t Mispreds{0};
diff --git a/bolt/lib/Core/BinaryContext.cpp b/bolt/lib/Core/BinaryContext.cpp
index c4902653a9b01..f557f4c06ccd3 100644
--- a/bolt/lib/Core/BinaryContext.cpp
+++ b/bolt/lib/Core/BinaryContext.cpp
@@ -496,7 +496,7 @@ BinaryContext::handleAddressRef(uint64_t Address, BinaryFunction &BF,
const MemoryContentsType MemType = analyzeMemoryAt(Address, BF);
if (MemType == MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE && IsPCRel) {
const MCSymbol *Symbol =
- getOrCreateJumpTable(BF, Address, JumpTable::JTT_PIC);
+ getOrCreateJumpTable(BF, Address, JumpTable::JTT_X86_64_PIC4);
return std::make_pair(Symbol, 0);
}
@@ -540,10 +540,10 @@ MemoryContentsType BinaryContext::analyzeMemoryAt(uint64_t Address,
// Start with checking for PIC jump table. We expect non-PIC jump tables
// to have high 32 bits set to 0.
- if (analyzeJumpTable(Address, JumpTable::JTT_PIC, BF))
+ if (analyzeJumpTable(Address, JumpTable::JTT_X86_64_PIC4, BF))
return MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE;
- if (analyzeJumpTable(Address, JumpTable::JTT_NORMAL, BF))
+ if (analyzeJumpTable(Address, JumpTable::JTT_X86_64_ABS, BF))
return MemoryContentsType::POSSIBLE_JUMP_TABLE;
return MemoryContentsType::UNKNOWN;
@@ -594,12 +594,9 @@ bool BinaryContext::analyzeJumpTable(const uint64_t Address,
if (NextJTAddress)
UpperBound = std::min(NextJTAddress, UpperBound);
- LLVM_DEBUG({
- using JTT = JumpTable::JumpTableType;
- dbgs() << formatv("BOLT-DEBUG: analyzeJumpTable @{0:x} in {1}, JTT={2}\n",
- Address, BF.getPrintName(),
- Type == JTT::JTT_PIC ? "PIC" : "Normal");
- });
+ LLVM_DEBUG(
+ dbgs() << formatv("BOLT-DEBUG: analyzeJumpTable @{0:x} in {1}, JTT={2}\n",
+ Address, BF, JumpTable::getTypeStr(Type)));
const uint64_t EntrySize = getJumpTableEntrySize(Type);
for (uint64_t EntryAddress = Address; EntryAddress <= UpperBound - EntrySize;
EntryAddress += EntrySize) {
@@ -607,13 +604,13 @@ bool BinaryContext::analyzeJumpTable(const uint64_t Address,
<< " -> ");
// Check if there's a proper relocation against the jump table entry.
if (HasRelocations) {
- if (Type == JumpTable::JTT_PIC &&
+ if (Type == JumpTable::JTT_X86_64_PIC4 &&
!DataPCRelocations.count(EntryAddress)) {
LLVM_DEBUG(
dbgs() << "FAIL: JTT_PIC table, no relocation for this address\n");
break;
}
- if (Type == JumpTable::JTT_NORMAL && !getRelocationAt(EntryAddress)) {
+ if (Type == JumpTable::JTT_X86_64_ABS && !getRelocationAt(EntryAddress)) {
LLVM_DEBUG(
dbgs()
<< "FAIL: JTT_NORMAL table, no relocation for this address\n");
@@ -621,10 +618,17 @@ bool BinaryContext::analyzeJumpTable(const uint64_t Address,
}
}
- const uint64_t Value =
- (Type == JumpTable::JTT_PIC)
- ? Address + *getSignedValueAtAddress(EntryAddress, EntrySize)
- : *getPointerAtAddress(EntryAddress);
+ uint64_t Value = 0;
+ switch (Type) {
+ case JumpTable::JTT_X86_64_PIC4:
+ Value = Address + *getSignedValueAtAddress(EntryAddress, EntrySize);
+ break;
+ case JumpTable::JTT_X86_64_ABS:
+ Value = *getPointerAtAddress(EntryAddress);
+ break;
+ default:
+ llvm_unreachable("Unhandled jump table type");
+ }
// __builtin_unreachable() case.
if (Value == UnreachableAddress) {
@@ -679,7 +683,7 @@ bool BinaryContext::analyzeJumpTable(const uint64_t Address,
// Trim direct/normal jump table to exclude trailing unreachable entries that
// can collide with a function address.
- if (Type == JumpTable::JTT_NORMAL && EntriesAsAddress &&
+ if (Type == JumpTable::JTT_X86_64_ABS && EntriesAsAddress &&
TrimmedSize != EntriesAsAddress->size() &&
getBinaryFunctionAtAddress(UnreachableAddress))
EntriesAsAddress->resize(TrimmedSize);
@@ -736,7 +740,7 @@ void BinaryContext::populateJumpTables() {
// In strict mode, erase PC-relative relocation record. Later we check that
// all such records are erased and thus have been accounted for.
- if (opts::StrictMode && JT->Type == JumpTable::JTT_PIC) {
+ if (opts::StrictMode && JT->Type == JumpTable::JTT_X86_64_PIC4) {
for (uint64_t Address = JT->getAddress();
Address < JT->getAddress() + JT->getSize();
Address += JT->EntrySize) {
diff --git a/bolt/lib/Core/BinaryEmitter.cpp b/bolt/lib/Core/BinaryEmitter.cpp
index 1aad25242712f..77272045d5bac 100644
--- a/bolt/lib/Core/BinaryEmitter.cpp
+++ b/bolt/lib/Core/BinaryEmitter.cpp
@@ -850,7 +850,7 @@ void BinaryEmitter::emitJumpTable(const JumpTable &JT, MCSection *HotSection,
}
LastLabel = LI->second;
}
- if (JT.Type == JumpTable::JTT_NORMAL) {
+ if (JT.Type == JumpTable::JTT_X86_64_ABS) {
Streamer.emitSymbolValue(Entry, JT.OutputEntrySize);
} else { // JTT_PIC
const MCSymbolRefExpr *JTExpr =
diff --git a/bolt/lib/Core/BinaryFunction.cpp b/bolt/lib/Core/BinaryFunction.cpp
index b46ba1a0d1a85..effd3c4799bf6 100644
--- a/bolt/lib/Core/BinaryFunction.cpp
+++ b/bolt/lib/Core/BinaryFunction.cpp
@@ -912,7 +912,7 @@ BinaryFunction::processIndirectBranch(MCInst &Instruction, unsigned Size,
"Invalid memory instruction");
const MCExpr *FixedEntryDispExpr = FixedEntryDispOperand->getExpr();
const uint64_t EntryAddress = getExprValue(FixedEntryDispExpr);
- uint64_t EntrySize = BC.getJumpTableEntrySize(JumpTable::JTT_PIC);
+ uint64_t EntrySize = BC.getJumpTableEntrySize(JumpTable::JTT_X86_64_PIC4);
ErrorOr<int64_t> Value =
BC.getSignedValueAtAddress(EntryAddress, EntrySize);
if (!Value)
@@ -982,12 +982,14 @@ BinaryFunction::processIndirectBranch(MCInst &Instruction, unsigned Size,
MemoryContentsType MemType;
if (JumpTable *JT = BC.getJumpTableContainingAddress(ArrayStart)) {
switch (JT->Type) {
- case JumpTable::JTT_NORMAL:
+ case JumpTable::JTT_X86_64_ABS:
MemType = MemoryContentsType::POSSIBLE_JUMP_TABLE;
break;
- case JumpTable::JTT_PIC:
+ case JumpTable::JTT_X86_64_PIC4:
MemType = MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE;
break;
+ default:
+ llvm_unreachable("Unhandled jump table type");
}
} else {
MemType = BC.analyzeMemoryAt(ArrayStart, *this);
@@ -998,7 +1000,7 @@ BinaryFunction::processIndirectBranch(MCInst &Instruction, unsigned Size,
if (BranchType == IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE) {
if (MemType != MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE)
return IndirectBranchType::UNKNOWN;
- JTType = JumpTable::JTT_PIC;
+ JTType = JumpTable::JTT_X86_64_PIC4;
} else {
if (MemType == MemoryContentsType::POSSIBLE_PIC_JUMP_TABLE)
return IndirectBranchType::UNKNOWN;
@@ -1007,7 +1009,7 @@ BinaryFunction::processIndirectBranch(MCInst &Instruction, unsigned Size,
return IndirectBranchType::POSSIBLE_TAIL_CALL;
BranchType = IndirectBranchType::POSSIBLE_JUMP_TABLE;
- JTType = JumpTable::JTT_NORMAL;
+ JTType = JumpTable::JTT_X86_64_ABS;
}
// Convert the instruction into jump table branch.
@@ -1779,7 +1781,8 @@ void BinaryFunction::postProcessJumpTables() {
// Create labels for all entries.
for (auto &JTI : JumpTables) {
JumpTable &JT = *JTI.second;
- if (JT.Type == JumpTable::JTT_PIC && opts::JumpTables == JTS_BASIC) {
+ if (JT.Type == JumpTable::JTT_X86_64_PIC4 &&
+ opts::JumpTables == JTS_BASIC) {
opts::JumpTables = JTS_MOVE;
BC.outs() << "BOLT-INFO: forcing -jump-tables=move as PIC jump table was "
"detected in function "
@@ -1974,7 +1977,7 @@ bool BinaryFunction::postProcessIndirectBranches(
BC.MIB->unsetJumpTable(Instr);
JumpTable *JT = BC.getJumpTableContainingAddress(LastJT);
- if (JT->Type == JumpTable::JTT_NORMAL) {
+ if (JT->Type == JumpTable::JTT_X86_64_ABS) {
// Invalidating the jump table may also invalidate other jump table
// boundaries. Until we have/need a support for this, mark the
// function as non-simple.
diff --git a/bolt/lib/Core/JumpTable.cpp b/bolt/lib/Core/JumpTable.cpp
index 65e1032c579b5..e780c737c56b5 100644
--- a/bolt/lib/Core/JumpTable.cpp
+++ b/bolt/lib/Core/JumpTable.cpp
@@ -85,9 +85,9 @@ void bolt::JumpTable::updateOriginal() {
uint64_t EntryOffset = BaseOffset;
for (MCSymbol *Entry : Entries) {
const uint64_t RelType =
- Type == JTT_NORMAL ? ELF::R_X86_64_64 : ELF::R_X86_64_PC32;
+ Type == JTT_X86_64_ABS ? ELF::R_X86_64_64 : ELF::R_X86_64_PC32;
const uint64_t RelAddend =
- Type == JTT_NORMAL ? 0 : EntryOffset - BaseOffset;
+ Type == JTT_X86_64_ABS ? 0 : EntryOffset - BaseOffset;
// Replace existing relocation with the new one to allow any modifications
// to the original jump table.
if (BC.HasRelocations)
@@ -99,7 +99,7 @@ void bolt::JumpTable::updateOriginal() {
void bolt::JumpTable::print(raw_ostream &OS) const {
uint64_t Offset = 0;
- if (Type == JTT_PIC)
+ if (Type == JTT_X86_64_PIC4)
OS << "PIC ";
ListSeparator LS;
diff --git a/bolt/lib/Passes/IndirectCallPromotion.cpp b/bolt/lib/Passes/IndirectCallPromotion.cpp
index 2b5a591f4c7a2..d70fd0e72e560 100644
--- a/bolt/lib/Passes/IndirectCallPromotion.cpp
+++ b/bolt/lib/Passes/IndirectCallPromotion.cpp
@@ -246,7 +246,7 @@ IndirectCallPromotion::getCallTargets(BinaryBasicBlock &BB,
if (const JumpTable *JT = BF.getJumpTable(Inst)) {
// Don't support PIC jump tables for now
- if (!opts::ICPJumpTablesByTarget && JT->Type == JumpTable::JTT_PIC)
+ if (!opts::ICPJumpTablesByTarget && JT->Type == JumpTable::JTT_X86_64_PIC4)
return Targets;
const Location From(BF.getSymbol());
const std::pair<size_t, size_t> Range =
@@ -256,7 +256,7 @@ IndirectCallPromotion::getCallTargets(BinaryBasicBlock &BB,
const JumpTable::JumpInfo *JI =
JT->Counts.empty() ? &DefaultJI : &JT->Counts[Range.first];
const size_t JIAdj = JT->Counts.empty() ? 0 : 1;
- assert(JT->Type == JumpTable::JTT_PIC ||
+ assert(JT->Type == JumpTable::JTT_X86_64_PIC4 ||
JT->EntrySize == BC.AsmInfo->getCodePointerSize());
for (size_t I = Range.first; I < Range.second; ++I, JI += JIAdj) {
MCSymbol *Entry = JT->Entries[I];
diff --git a/bolt/lib/Passes/JTFootprintReduction.cpp b/bolt/lib/Passes/JTFootprintReduction.cpp
index 71bdbba950df1..13b37dc3bc6ff 100644
--- a/bolt/lib/Passes/JTFootprintReduction.cpp
+++ b/bolt/lib/Passes/JTFootprintReduction.cpp
@@ -202,7 +202,7 @@ bool JTFootprintReduction::tryOptimizePIC(BinaryContext &BC,
JumpTable->OutputEntrySize = 4;
// DePICify
- JumpTable->Type = JumpTable::JTT_NORMAL;
+ JumpTable->Type = JumpTable::JTT_X86_64_ABS;
BB.replaceInstruction(Inst, NewFrag.begin(), NewFrag.end());
return true;
|
maksfb
reviewed
Apr 10, 2025
There was a problem hiding this comment.
I expect that eventually we will get RISC-V support for jump tables. In this context, I would prefer to keep the format of the jump table itself separate from the underlying architecture. I.e. we can use JTs with an absolute 64-bit addressing on any platform with a proper compiler support. Having one type, e.g. JTT_ABS64, sounds more convenient. And we can always lookup the target architecture if needed, but again it should be orthogonal to the format itself. What could be different is endianness, but we can handle it during serialization.
Also, in most places we use the number of bits for naming "things". Let's stick to this scheme.
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Define new JumpTable types for AArch64 based on definitions
used in LLVM:
llvm-project/llvm/lib/Target/AArch64/AArch64InstrInfo.td
Lines 1217 to 1225 in 335a461
Parsing and basic support is in a follow up PR #132114.
Depends on #132108.