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[BOLT][NFC] Un-inline indirect branch handling out of disassemble loop 

Summary:
Move the `processIndirectBranch` switch statement out of a for-loop
in `BinaryFunction::disassemble`

(cherry picked from FBD29411346)
This commit is contained in:
Amir Ayupov 2021-06-25 17:49:43 -07:00 committed by Maksim Panchenko
parent 8f751bc058
commit c7c0803b59
1 changed files with 42 additions and 39 deletions
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81
bolt/src/BinaryFunction.cpp
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@ -1157,6 +1157,46 @@ bool BinaryFunction::disassemble() {
return TargetSymbol;
};
auto handleIndirectBranch = [&](MCInst &Instruction, uint64_t Size,
uint64_t Offset) {
uint64_t IndirectTarget = 0;
IndirectBranchType Result =
processIndirectBranch(Instruction, Size, Offset, IndirectTarget);
switch (Result) {
default:
llvm_unreachable("unexpected result");
case IndirectBranchType::POSSIBLE_TAIL_CALL: {
bool Result = MIB->convertJmpToTailCall(Instruction);
(void)Result;
assert(Result);
break;
}
case IndirectBranchType::POSSIBLE_JUMP_TABLE:
case IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE:
if (opts::JumpTables == JTS_NONE)
IsSimple = false;
break;
case IndirectBranchType::POSSIBLE_FIXED_BRANCH: {
if (containsAddress(IndirectTarget)) {
const MCSymbol *TargetSymbol = getOrCreateLocalLabel(IndirectTarget);
Instruction.clear();
MIB->createUncondBranch(Instruction, TargetSymbol, BC.Ctx.get());
TakenBranches.emplace_back(Offset, IndirectTarget - getAddress());
HasFixedIndirectBranch = true;
} else {
MIB->convertJmpToTailCall(Instruction);
InterproceduralReferences.insert(IndirectTarget);
}
break;
}
case IndirectBranchType::UNKNOWN:
// Keep processing. We'll do more checks and fixes in
// postProcessIndirectBranches().
UnknownIndirectBranchOffsets.emplace(Offset);
break;
}
};
uint64_t Size = 0; // instruction size
for (uint64_t Offset = 0; Offset < getSize(); Offset += Size) {
MCInst Instruction;
@ -1351,45 +1391,8 @@ bool BinaryFunction::disassemble() {
} else {
// Could not evaluate branch. Should be an indirect call or an
// indirect branch. Bail out on the latter case.
if (MIB->isIndirectBranch(Instruction)) {
uint64_t IndirectTarget = 0;
IndirectBranchType Result =
processIndirectBranch(Instruction, Size, Offset, IndirectTarget);
switch (Result) {
default:
llvm_unreachable("unexpected result");
case IndirectBranchType::POSSIBLE_TAIL_CALL: {
bool Result = MIB->convertJmpToTailCall(Instruction);
(void)Result;
assert(Result);
break;
}
case IndirectBranchType::POSSIBLE_JUMP_TABLE:
case IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE:
if (opts::JumpTables == JTS_NONE)
IsSimple = false;
break;
case IndirectBranchType::POSSIBLE_FIXED_BRANCH: {
if (containsAddress(IndirectTarget)) {
const MCSymbol *TargetSymbol =
getOrCreateLocalLabel(IndirectTarget);
Instruction.clear();
MIB->createUncondBranch(Instruction, TargetSymbol, BC.Ctx.get());
TakenBranches.emplace_back(Offset, IndirectTarget - getAddress());
HasFixedIndirectBranch = true;
} else {
MIB->convertJmpToTailCall(Instruction);
InterproceduralReferences.insert(IndirectTarget);
}
break;
}
case IndirectBranchType::UNKNOWN:
// Keep processing. We'll do more checks and fixes in
// postProcessIndirectBranches().
UnknownIndirectBranchOffsets.emplace(Offset);
break;
};
}
if (MIB->isIndirectBranch(Instruction))
handleIndirectBranch(Instruction, Size, Offset);
// Indirect call. We only need to fix it if the operand is RIP-relative.
if (IsSimple && MIB->hasPCRelOperand(Instruction))
handlePCRelOperand(Instruction, AbsoluteInstrAddr, Size);