RegionDescPtr selectTraceletLegacy(const RegionContext& rCtx,
const Transl::Tracelet& tlet) {
typedef RegionDesc::Block Block;
auto region = std::make_shared<RegionDesc>();
SrcKey sk(tlet.m_sk);
auto unit = tlet.func()->unit();
const Func* topFunc = nullptr;
Block* curBlock = nullptr;
auto newBlock = [&](const Func* func, SrcKey start, Offset spOff) {
assert(curBlock == nullptr || curBlock->length() > 0);
region->blocks.push_back(
std::make_shared<Block>(func, start.offset(), 0, spOff));
curBlock = region->blocks.back().get();
};
newBlock(tlet.func(), sk, rCtx.spOffset);
for (auto ni = tlet.m_instrStream.first; ni; ni = ni->next) {
assert(sk == ni->source);
assert(ni->unit() == unit);
Offset curSpOffset = rCtx.spOffset + ni->stackOffset;
curBlock->addInstruction();
if ((curBlock->length() == 1 && ni->funcd != nullptr) ||
ni->funcd != topFunc) {
topFunc = ni->funcd;
curBlock->setKnownFunc(sk, topFunc);
}
if (ni->calleeTrace && !ni->calleeTrace->m_inliningFailed) {
assert(ni->op() == OpFCall);
assert(ni->funcd == ni->calleeTrace->func());
// This should be translated as an inlined call. Insert the blocks of the
// callee in the region.
auto const& callee = *ni->calleeTrace;
curBlock->setInlinedCallee(ni->funcd);
SrcKey cSk = callee.m_sk;
Unit* cUnit = callee.func()->unit();
newBlock(callee.func(), cSk, curSpOffset);
for (auto cni = callee.m_instrStream.first; cni; cni = cni->next) {
assert(cSk == cni->source);
assert(cni->op() == OpRetC ||
cni->op() == OpContRetC ||
cni->op() == OpNativeImpl ||
!instrIsNonCallControlFlow(cni->op()));
curBlock->addInstruction();
cSk.advance(cUnit);
}
if (ni->next) {
sk.advance(unit);
newBlock(tlet.func(), sk, curSpOffset);
}
continue;
}
if (!ni->noOp && isFPassStar(ni->op())) {
curBlock->setParamByRef(sk, ni->preppedByRef);
}
if (ni->next && ni->op() == OpJmp) {
// A Jmp that isn't the final instruction in a Tracelet means we traced
// through a forward jump in analyze. Update sk to point to the next NI
// in the stream.
auto dest = ni->offset() + ni->imm[0].u_BA;
assert(dest > sk.offset()); // We only trace for forward Jmps for now.
sk.setOffset(dest);
// The Jmp terminates this block.
newBlock(tlet.func(), sk, curSpOffset);
} else {
sk.advance(unit);
}
}
auto& frontBlock = *region->blocks.front();
// Add tracelet guards as predictions on the first instruction. Predictions
// and known types from static analysis will be applied by
// Translator::translateRegion.
for (auto const& dep : tlet.m_dependencies) {
if (dep.second->rtt.isVagueValue() ||
dep.second->location.isThis()) continue;
typedef RegionDesc R;
auto addPred = [&](const R::Location& loc) {
auto type = Type(dep.second->rtt);
frontBlock.addPredicted(tlet.m_sk, {loc, type});
};
switch (dep.first.space) {
case Transl::Location::Stack: {
uint32_t offsetFromSp = uint32_t(-dep.first.offset - 1);
uint32_t offsetFromFp = rCtx.spOffset - offsetFromSp;
addPred(R::Location::Stack{offsetFromSp, offsetFromFp});
break;
}
case Transl::Location::Local:
addPred(R::Location::Local{uint32_t(dep.first.offset)});
break;
default: not_reached();
}
}
// Add reffiness dependencies as predictions on the first instruction.
for (auto const& dep : tlet.m_refDeps.m_arMap) {
RegionDesc::ReffinessPred pred{dep.second.m_mask,
dep.second.m_vals,
dep.first};
frontBlock.addReffinessPred(tlet.m_sk, pred);
}
FTRACE(2, "Converted Tracelet:\n{}\nInto RegionDesc:\n{}\n",
tlet.toString(), show(*region));
return region;
}
bool propagate_constants(const Bytecode& op, const State& state, Gen gen) {
auto const numPop = op.numPop();
auto const numPush = op.numPush();
auto const stkSize = state.stack.size();
// All outputs of the instruction must have constant types for this
// to be allowed.
for (auto i = size_t{0}; i < numPush; ++i) {
if (!tv(state.stack[stkSize - i - 1])) return false;
}
// Pop the inputs, and push the constants.
for (auto i = size_t{0}; i < numPop; ++i) {
switch (op.popFlavor(i)) {
case Flavor::C: gen(bc::PopC {}); break;
case Flavor::V: gen(bc::PopV {}); break;
case Flavor::A: gen(bc::PopA {}); break;
case Flavor::R: not_reached(); break;
case Flavor::F: not_reached(); break;
case Flavor::U: not_reached(); break;
}
}
for (auto i = size_t{0}; i < numPush; ++i) {
auto const v = tv(state.stack[stkSize - i - 1]);
switch (v->m_type) {
case KindOfUninit: not_reached(); break;
case KindOfNull: gen(bc::Null {}); break;
case KindOfBoolean:
if (v->m_data.num) {
gen(bc::True {});
} else {
gen(bc::False {});
}
break;
case KindOfInt64:
gen(bc::Int { v->m_data.num });
break;
case KindOfDouble:
gen(bc::Double { v->m_data.dbl });
break;
case KindOfStaticString:
gen(bc::String { v->m_data.pstr });
break;
case KindOfArray:
gen(bc::Array { v->m_data.parr });
break;
case KindOfRef:
case KindOfResource:
case KindOfString:
default:
always_assert(0 && "invalid constant in propagate_constants");
}
// Special case for FPass* instructions. We just put a C on the
// stack, so we need to get it to be an F.
if (isFPassStar(op.op)) {
// We should only ever const prop for FPassL right now.
always_assert(numPush == 1 && op.op == Op::FPassL);
gen(bc::FPassC { op.FPassL.arg1 });
}
}
return true;
}