void emitSSwitch(HTS& env, const ImmVector& iv) {
const int numCases = iv.size() - 1;
/*
* We use a fast path translation with a hashtable if none of the
* cases are numeric strings and if the input is actually a string.
*
* Otherwise we do a linear search through the cases calling string
* conversion routines.
*/
const bool fastPath =
topC(env)->isA(Type::Str) &&
std::none_of(iv.strvec(), iv.strvec() + numCases,
[&](const StrVecItem& item) {
return curUnit(env)->lookupLitstrId(item.str)->isNumeric();
}
);
auto const testVal = popC(env);
std::vector<LdSSwitchData::Elm> cases(numCases);
for (int i = 0; i < numCases; ++i) {
auto const& kv = iv.strvec()[i];
cases[i].str = curUnit(env)->lookupLitstrId(kv.str);
cases[i].dest = SrcKey{curSrcKey(env), bcOff(env) + kv.dest};
}
LdSSwitchData data;
data.numCases = numCases;
data.cases = &cases[0];
data.defaultSk = SrcKey{curSrcKey(env),
bcOff(env) + iv.strvec()[iv.size() - 1].dest};
auto const dest = gen(env,
fastPath ? LdSSwitchDestFast
: LdSSwitchDestSlow,
data,
testVal);
gen(env, DecRef, testVal);
gen(env, AdjustSP, IRSPOffsetData { offsetFromIRSP(env, BCSPOffset{0}) },
sp(env));
gen(env, JmpSSwitchDest, dest, sp(env));
}
void emitIterBreak(IRGS& env, Offset relOffset, const ImmVector& iv) {
for (int iterIndex = 0; iterIndex < iv.size(); iterIndex += 2) {
IterKind iterKind = (IterKind)iv.vec32()[iterIndex];
Id iterId = iv.vec32()[iterIndex + 1];
switch (iterKind) {
case KindOfIter: gen(env, IterFree, IterId(iterId), fp(env)); break;
case KindOfMIter: gen(env, MIterFree, IterId(iterId), fp(env)); break;
case KindOfCIter: gen(env, CIterFree, IterId(iterId), fp(env)); break;
}
}
jmpImpl(env, bcOff(env) + relOffset);
}
void emitIterBreak(IRGS& env,
const ImmVector& iv,
Offset relOffset) {
always_assert(env.currentNormalizedInstruction->endsRegion);
for (int iterIndex = 0; iterIndex < iv.size(); iterIndex += 2) {
IterKind iterKind = (IterKind)iv.vec32()[iterIndex];
Id iterId = iv.vec32()[iterIndex + 1];
switch (iterKind) {
case KindOfIter: gen(env, IterFree, IterId(iterId), fp(env)); break;
case KindOfMIter: gen(env, MIterFree, IterId(iterId), fp(env)); break;
case KindOfCIter: gen(env, CIterFree, IterId(iterId), fp(env)); break;
}
}
// Would need to change this if we support not ending regions on this:
gen(env, Jmp, makeExit(env, bcOff(env) + relOffset));
}
void emitNewStructArray(HTS& env, const ImmVector& immVec) {
auto const numArgs = immVec.size();
auto const ids = immVec.vec32();
// The NewPackedArray opcode's helper needs array values passed to it
// via the stack. We use spillStack() to flush the eval stack and
// obtain a pointer to the topmost item; if over-flushing becomes
// a problem then we should refactor the NewPackedArray opcode to
// take its values directly as SSA operands.
spillStack(env);
NewStructData extra;
extra.offset = offsetFromSP(env, 0);
extra.numKeys = numArgs;
extra.keys = new (env.unit.arena()) StringData*[numArgs];
for (auto i = size_t{0}; i < numArgs; ++i) {
extra.keys[i] = curUnit(env)->lookupLitstrId(ids[i]);
}
discard(env, numArgs);
push(env, gen(env, NewStructArray, extra, sp(env)));
}
void emitSwitch(HTS& env,
const ImmVector& iv,
int64_t base,
int32_t bounded) {
int nTargets = bounded ? iv.size() - 2 : iv.size();
SSATmp* const switchVal = popC(env);
Type type = switchVal->type();
assert(IMPLIES(!(type <= Type::Int), bounded));
assert(IMPLIES(bounded, iv.size() > 2));
SSATmp* index;
SSATmp* ssabase = cns(env, base);
SSATmp* ssatargets = cns(env, nTargets);
Offset defaultOff = bcOff(env) + iv.vec32()[iv.size() - 1];
Offset zeroOff = 0;
if (base <= 0 && (base + nTargets) > 0) {
zeroOff = bcOff(env) + iv.vec32()[0 - base];
} else {
zeroOff = defaultOff;
}
if (type <= Type::Null) {
gen(env, Jmp, makeExit(env, zeroOff));
return;
}
if (type <= Type::Bool) {
Offset nonZeroOff = bcOff(env) + iv.vec32()[iv.size() - 2];
gen(env, JmpNZero, makeExit(env, nonZeroOff), switchVal);
gen(env, Jmp, makeExit(env, zeroOff));
return;
}
if (type <= Type::Int) {
// No special treatment needed
index = switchVal;
} else if (type <= Type::Dbl) {
// switch(Double|String|Obj)Helper do bounds-checking for us, so
// we need to make sure the default case is in the jump table,
// and don't emit our own bounds-checking code
bounded = false;
index = gen(env, LdSwitchDblIndex, switchVal, ssabase, ssatargets);
} else if (type <= Type::Str) {
bounded = false;
index = gen(env, LdSwitchStrIndex, switchVal, ssabase, ssatargets);
} else if (type <= Type::Obj) {
// switchObjHelper can throw exceptions and reenter the VM so we use the
// catch block here.
bounded = false;
index = gen(env, LdSwitchObjIndex, switchVal, ssabase, ssatargets);
} else if (type <= Type::Arr) {
gen(env, DecRef, switchVal);
gen(env, Jmp, makeExit(env, defaultOff));
return;
} else {
PUNT(Switch-UnknownType);
}
std::vector<Offset> targets(iv.size());
for (int i = 0; i < iv.size(); i++) {
targets[i] = bcOff(env) + iv.vec32()[i];
}
JmpSwitchData data;
data.base = base;
data.bounded = bounded;
data.cases = iv.size();
data.defaultOff = defaultOff;
data.targets = &targets[0];
spillStack(env);
gen(env, AdjustSP, StackOffset { offsetFromSP(env, 0) }, sp(env));
gen(env, JmpSwitchDest, data, index, sp(env));
}
