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[CSSPGO][llvm-profgen] Continue disassembling after illegal instruction is seen. 

Previously we errored out when disassembling illegal instructions and there would be no profile generated. In fact illegal instructions are not uncommon and we'd better skip them and print "unknown" instead of erroring out. This matches the behavior of llvm-objdump (see disassembleObject in llvm-objdump.cpp).

Reviewed By: wlei, wenlei

Differential Revision: https://reviews.llvm.org/D97776
This commit is contained in:
Hongtao Yu 2021-03-01 22:34:30 -08:00
parent 9d8a3e75b4
commit 55356c011b
1 changed files with 46 additions and 21 deletions
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67
llvm/tools/llvm-profgen/ProfiledBinary.cpp
View File

@ -217,14 +217,25 @@ bool ProfiledBinary::dissassembleSymbol(std::size_t SI, ArrayRef<uint8_t> Bytes,
if (ShowDisassemblyOnly)
outs() << '<' << SymbolName << ">:\n";
auto WarnInvalidInsts = [](uint64_t Start, uint64_t End) {
WithColor::warning() << "Invalid instructions at "
<< format("%8" PRIx64, Start) << " - "
<< format("%8" PRIx64, End) << "\n";
};
uint64_t Offset = StartOffset;
// Size of a consecutive invalid instruction range starting from Offset -1
// backwards.
uint64_t InvalidInstLength = 0;
while (Offset < EndOffset) {
MCInst Inst;
uint64_t Size;
// Disassemble an instruction.
if (!DisAsm->getInstruction(Inst, Size, Bytes.slice(Offset - SectionOffset),
Offset + PreferredBaseAddress, nulls()))
return false;
bool Disassembled =
DisAsm->getInstruction(Inst, Size, Bytes.slice(Offset - SectionOffset),
Offset + PreferredBaseAddress, nulls());
if (Size == 0)
Size = 1;
if (ShowDisassemblyOnly) {
if (ShowPseudoProbe) {
@ -233,38 +244,52 @@ bool ProfiledBinary::dissassembleSymbol(std::size_t SI, ArrayRef<uint8_t> Bytes,
}
outs() << format("%8" PRIx64 ":", Offset);
size_t Start = outs().tell();
IPrinter->printInst(&Inst, Offset + Size, "", *STI.get(), outs());
if (Disassembled)
IPrinter->printInst(&Inst, Offset + Size, "", *STI.get(), outs());
else
outs() << "\t<unknown>";
if (ShowSourceLocations) {
unsigned Cur = outs().tell() - Start;
if (Cur < 40)
outs().indent(40 - Cur);
InstructionPointer Inst(this, Offset);
outs() << getReversedLocWithContext(symbolize(Inst));
InstructionPointer IP(this, Offset);
outs() << getReversedLocWithContext(symbolize(IP));
}
outs() << "\n";
}
const MCInstrDesc &MCDesc = MII->get(Inst.getOpcode());
if (Disassembled) {
const MCInstrDesc &MCDesc = MII->get(Inst.getOpcode());
// Populate a vector of the symbolized callsite at this location
// We don't need symbolized info for probe-based profile, just use an
// empty stack as an entry to indicate a valid binary offset
FrameLocationStack SymbolizedCallStack;
if (!UsePseudoProbes) {
InstructionPointer IP(this, Offset);
SymbolizedCallStack = symbolize(IP, true);
}
Offset2LocStackMap[Offset] = SymbolizedCallStack;
// Populate address maps.
CodeAddrs.push_back(Offset);
if (MCDesc.isCall())
CallAddrs.insert(Offset);
else if (MCDesc.isReturn())
RetAddrs.insert(Offset);
// Populate a vector of the symbolized callsite at this location
// We don't need symbolized info for probe-based profile, just use an empty
// stack as an entry to indicate a valid binary offset
FrameLocationStack SymbolizedCallStack;
if (!UsePseudoProbes) {
InstructionPointer IP(this, Offset);
SymbolizedCallStack = symbolize(IP, true);
if (InvalidInstLength) {
WarnInvalidInsts(Offset - InvalidInstLength, Offset - 1);
InvalidInstLength = 0;
}
} else {
InvalidInstLength += Size;
}
Offset2LocStackMap[Offset] = SymbolizedCallStack;
// Populate address maps.
CodeAddrs.push_back(Offset);
if (MCDesc.isCall())
CallAddrs.insert(Offset);
else if (MCDesc.isReturn())
RetAddrs.insert(Offset);
Offset += Size;
}
if (InvalidInstLength)
WarnInvalidInsts(Offset - InvalidInstLength, Offset - 1);
if (ShowDisassemblyOnly)
outs() << "\n";