void clobberFuncGuards(const Func* func) {
int maxNumPrologues = func->getMaxNumPrologues(func->numParams());
int numPrologues =
maxNumPrologues > kNumFixedPrologues ? maxNumPrologues
: kNumFixedPrologues;
for (auto i = 0; i < numPrologues; ++i) {
auto const guard = funcGuardFromPrologue(func->getPrologue(i), func);
if (funcGuardMatches(guard, func)) {
clobberFuncGuard(guard, func);
}
}
}
void emitFuncGuard(const Func* func, CodeBlock& cb, CGMeta& fixups) {
ppc64_asm::Assembler a { cb };
const auto tmp1 = ppc64_asm::reg::r3;
const auto tmp2 = ppc64_asm::reg::r4;
assertx(ppc64::abi(CodeKind::CrossTrace).gpUnreserved.contains(tmp1));
assertx(ppc64::abi(CodeKind::CrossTrace).gpUnreserved.contains(tmp2));
emitSmashableMovq(a.code(), fixups, uint64_t(func), tmp1);
a. ld (tmp2, rvmfp()[AROFF(m_func)]);
a. cmpd (tmp1, tmp2);
a. branchFar(tc::ustubs().funcPrologueRedispatch,
ppc64_asm::BranchConditions::NotEqual);
DEBUG_ONLY auto guard = funcGuardFromPrologue(a.frontier(), func);
assertx(funcGuardMatches(guard, func));
}
folly::Optional<std::pair<SrcKey,TransID>>
updateFuncPrologue(TCA start, ProfTransRec* rec) {
auto func = rec->func();
auto nArgs = rec->prologueArgs();
auto codeLock = lockCode();
// Smash callers of the old prologue with the address of the new one.
for (auto toSmash : rec->mainCallers()) {
smashCall(toSmash, start);
}
// If the prologue has a matching guard, then smash its guard-callers as
// well.
auto const guard = funcGuardFromPrologue(start, func);
if (funcGuardMatches(guard, func)) {
for (auto toSmash : rec->guardCallers()) {
smashCall(toSmash, guard);
}
}
rec->clearAllCallers();
// If this prologue has a DV funclet, then invalidate it and return its SrcKey
// and TransID
if (nArgs < func->numNonVariadicParams()) {
auto paramInfo = func->params()[nArgs];
if (paramInfo.hasDefaultValue()) {
SrcKey funcletSK(func, paramInfo.funcletOff, false);
auto funcletTransId = profData()->dvFuncletTransId(func, nArgs);
if (funcletTransId != kInvalidTransID) {
invalidateSrcKey(funcletSK);
return std::make_pair(funcletSK, funcletTransId);
}
}
}
return folly::none;
}
static TCA emitFuncPrologueImpl(Func* func, int argc, TransKind kind) {
if (!newTranslation()) {
return nullptr;
}
const int nparams = func->numNonVariadicParams();
const int paramIndex = argc <= nparams ? argc : nparams + 1;
auto const funcBody = SrcKey{func, func->getEntryForNumArgs(argc), false};
profileSetHotFuncAttr();
auto codeLock = lockCode();
auto codeView = code().view(kind);
TCA mainOrig = codeView.main().frontier();
CGMeta fixups;
// If we're close to a cache line boundary, just burn some space to
// try to keep the func and its body on fewer total lines.
align(codeView.main(), &fixups, Alignment::CacheLineRoundUp,
AlignContext::Dead);
TransLocMaker maker(codeView);
maker.markStart();
// Careful: this isn't necessarily the real entry point. For funcIsMagic
// prologues, this is just a possible prologue.
TCA aStart = codeView.main().frontier();
// Give the prologue a TransID if we have profiling data.
auto const transID = [&]{
if (kind == TransKind::ProfPrologue) {
auto const profData = jit::profData();
auto const id = profData->allocTransID();
profData->addTransProfPrologue(id, funcBody, paramIndex);
return id;
}
if (profData() && transdb::enabled()) {
return profData()->allocTransID();
}
return kInvalidTransID;
}();
TCA start = genFuncPrologue(transID, kind, func, argc, codeView, fixups);
auto loc = maker.markEnd();
auto metaLock = lockMetadata();
if (RuntimeOption::EvalEnableReusableTC) {
TCA UNUSED ms = loc.mainStart(), me = loc.mainEnd(),
cs = loc.coldStart(), ce = loc.coldEnd(),
fs = loc.frozenStart(), fe = loc.frozenEnd(),
oldStart = start;
auto const did_relocate = relocateNewTranslation(loc, codeView, fixups,
&start);
if (did_relocate) {
FTRACE_MOD(Trace::reusetc, 1,
"Relocated prologue for func {} (id = {}) "
"from M[{}, {}], C[{}, {}], F[{}, {}] to M[{}, {}] "
"C[{}, {}] F[{}, {}] orig start @ {} new start @ {}\n",
func->fullName()->data(), func->getFuncId(),
ms, me, cs, ce, fs, fe, loc.mainStart(), loc.mainEnd(),
loc.coldStart(), loc.coldEnd(), loc.frozenStart(),
loc.frozenEnd(), oldStart, start);
} else {
FTRACE_MOD(Trace::reusetc, 1,
"Created prologue for func {} (id = {}) at "
"M[{}, {}], C[{}, {}], F[{}, {}] start @ {}\n",
func->fullName()->data(), func->getFuncId(),
ms, me, cs, ce, fs, fe, oldStart);
}
recordFuncPrologue(func, loc);
if (loc.mainStart() != aStart) {
codeView.main().setFrontier(mainOrig); // we may have shifted to align
}
}
if (RuntimeOption::EvalPerfRelocate) {
GrowableVector<IncomingBranch> incomingBranches;
recordPerfRelocMap(loc.mainStart(), loc.mainEnd(),
loc.coldCodeStart(), loc.coldEnd(),
funcBody, paramIndex,
incomingBranches,
fixups);
}
fixups.process(nullptr);
assertx(funcGuardMatches(funcGuardFromPrologue(start, func), func));
assertx(code().isValidCodeAddress(start));
TRACE(2, "funcPrologue %s(%d) setting prologue %p\n",
func->fullName()->data(), argc, start);
func->setPrologue(paramIndex, start);
assertx(kind == TransKind::LivePrologue ||
kind == TransKind::ProfPrologue ||
kind == TransKind::OptPrologue);
auto tr = maker.rec(funcBody, transID, kind);
transdb::addTranslation(tr);
if (RuntimeOption::EvalJitUseVtuneAPI) {
reportTraceletToVtune(func->unit(), func, tr);
}
recordGdbTranslation(funcBody, func, codeView.main(), loc.mainStart(),
false, true);
recordBCInstr(OpFuncPrologue, loc.mainStart(), loc.mainEnd(), false);
return start;
}