void IRTranslator::translateInstr(const NormalizedInstruction& ni) {
auto& ht = m_hhbcTrans;
ht.setBcOff(ni.source.offset(),
ni.breaksTracelet && !m_hhbcTrans.isInlining());
FTRACE(1, "\n{:-^60}\n", folly::format("Translating {}: {} with stack:\n{}",
ni.offset(), ni.toString(),
ht.showStack()));
// When profiling, we disable type predictions to avoid side exits
assert(IMPLIES(JIT::tx->mode() == TransProfile, !ni.outputPredicted));
if (ni.guardedThis) {
// Task #2067635: This should really generate an AssertThis
ht.setThisAvailable();
}
if (moduleEnabled(HPHP::Trace::stats, 2)) {
ht.emitIncStat(Stats::opcodeToIRPreStatCounter(ni.op()), 1, false);
}
if (RuntimeOption::EnableInstructionCounts ||
moduleEnabled(HPHP::Trace::stats, 3)) {
// If the instruction takes a slow exit, the exit trace will
// decrement the post counter for that opcode.
ht.emitIncStat(Stats::opcodeToIRPostStatCounter(ni.op()), 1, true);
}
ht.emitRB(RBTypeBytecodeStart, ni.source, 2);
auto pc = reinterpret_cast<const Op*>(ni.pc());
for (auto i = 0, num = instrNumPops(pc); i < num; ++i) {
auto const type = flavorToType(instrInputFlavor(pc, i));
if (type != Type::Gen) m_hhbcTrans.assertTypeStack(i, type);
}
if (RuntimeOption::EvalHHIRGenerateAsserts >= 2) {
ht.emitDbgAssertRetAddr();
}
if (instrMustInterp(ni) || ni.interp) {
interpretInstr(ni);
} else {
translateInstrWork(ni);
}
passPredictedAndInferredTypes(ni);
}
void initInstructions(Trace* trace, IRInstruction::List& wl) {
IRInstruction::List instructions = trace->getInstructionList();
IRInstruction::Iterator it;
bool unreachable = false;
TRACE(5, "DCE:vvvvvvvvvvvvvvvvvvvv\n");
for (it = instructions.begin(); it != instructions.end(); it++) {
IRInstruction* inst = *it;
ASSERT(inst->getParent() == trace);
Simplifier::copyProp(inst);
// if this is a load that does not generate a guard, then get rid
// of its label so that its not an essential control-flow
// instruction
if (isUnguardedLoad(inst)) {
// LdStack and LdLoc instructions that produce generic types
// and LdStack instruction that produce Cell types will not
// generate guards, so remove the label from this instruction so
// that its no longer an essential control-flow instruction
inst->setLabel(NULL);
}
Opcode opc = inst->getOpcode();
// decref of anything that isn't ref counted is a nop
if ((opc == DecRef || opc == DecRefNZ) && !isRefCounted(inst->getSrc(0))) {
inst->setId(DEAD);
continue;
}
if (!unreachable && inst->isControlFlowInstruction()) {
// mark the destination label so that the destination trace
// is marked reachable
inst->getLabel()->setId(LIVE);
}
if (!unreachable && isEssential(inst)) {
inst->setId(LIVE);
wl.push_back(inst);
} else {
if (moduleEnabled(HPHP::Trace::hhir, 5)) {
std::ostringstream ss1;
inst->printSrcs(ss1);
TRACE(5, "DCE: %s\n", ss1.str().c_str());
std::ostringstream ss2;
inst->print(ss2);
TRACE(5, "DCE: %s\n", ss2.str().c_str());
}
inst->setId(DEAD);
}
if (inst->getOpcode() == Jmp_) {
unreachable = true;
}
}
TRACE(5, "DCE:^^^^^^^^^^^^^^^^^^^^\n");
}