static void rattr(unsigned verb, SkStream& s, BMLW& rec, SkXMLWriter& writer)
{
int data = verb & 31;
verb >>= 5;
int nameIndex, valueIndex;
switch (verb) {
case kAttr_Value_Value_Verb:
nameIndex = rec.fNextName; // record before the ++
set(rec.fNames, rec.fNextName++, s, data);
valueIndex = rec.fNextValue; // record before the ++
set(rec.fValues, rec.fNextValue++, s, 31);
break;
case kAttr_Value_Index_Verb:
nameIndex = rec.fNextName; // record before the ++
set(rec.fNames, rec.fNextName++, s, data);
valueIndex = rbyte(s);
break;
case kAttr_Index_Value_Verb:
nameIndex = rdata(s, data);
valueIndex = rec.fNextValue; // record before the ++
set(rec.fValues, rec.fNextValue++, s, 31);
break;
case kAttr_Index_Index_Verb:
nameIndex = rdata(s, data);
valueIndex = rbyte(s);
break;
default:
SkDEBUGFAIL("bad verb");
return;
}
writer.addAttribute(rec.fNames[nameIndex], rec.fValues[valueIndex]);
}
static int rdata(SkStream& s, int data)
{
SkASSERT((data & ~31) == 0);
if (data == 31)
{
data = rbyte(s);
if (data == 0xFF)
{
data = rbyte(s);
data = (data << 8) | rbyte(s);
}
}
return data;
}
void addDbgGuardImpl(SrcKey sk) {
Asm a { tx64->mainCode };
// Emit the checks for debugger attach
emitTLSLoad<ThreadInfo>(a, ThreadInfo::s_threadInfo, reg::rAsm);
a. load_reg64_disp_reg32(reg::rAsm, dbgOff, reg::rAsm);
a. testb((int8_t)0xff, rbyte(reg::rAsm));
// Branch to a special REQ_INTERPRET if attached
TCA fallback =
emitServiceReq(tx64->stubsCode, REQ_INTERPRET, sk.offset(), 0);
a. jnz(fallback);
}
/*
* Read 32 bits of data + 8 bit checksum from the
* DHT sensor. Returns relative humidity and
* temperature in Celcius when successful. The
* function returns zero if there was a checksum
* error.
*/
static int
rsensor(int *relhumidity,int *celsius) {
unsigned char u[5], cs = 0, x;
for ( x=0; x<5; ++x ) {
u[x] = rbyte();
if ( x < 4 ) /* Only checksum data.. */
cs += u[x]; /* Checksum */
}
if ( (cs & 0xFF) == u[4] ) {
*relhumidity = (int)u[0];
*celsius = (int)u[2];
return 1;
}
return 0;
}
static void relem(unsigned verb, SkStream& s, BMLW& rec, SkXMLWriter& writer)
{
int data = verb & 31;
verb >>= 5;
int elemIndex;
if (verb == kStartElem_Value_Verb)
{
elemIndex = rec.fNextElem; // record before the ++
set(rec.fElems, rec.fNextElem++, s, data);
}
else
{
SkASSERT(verb == kStartElem_Index_Verb);
elemIndex = rdata(s, data);
}
writer.startElement(rec.fElems[elemIndex]);
for (;;)
{
verb = rbyte(s);
switch (verb >> 5) {
case kAttr_Value_Value_Verb:
case kAttr_Value_Index_Verb:
case kAttr_Index_Value_Verb:
case kAttr_Index_Index_Verb:
rattr(verb, s, rec, writer);
break;
case kStartElem_Value_Verb:
case kStartElem_Index_Verb:
relem(verb, s, rec, writer);
break;
case kEndElem_Verb:
writer.endElement();
return;
default:
SkDEBUGFAIL("bad verb");
}
}
}
/*
* Service request stub emitter.
*
* Emit a service request stub of type `sr' at `start' in `cb'.
*/
void emit_svcreq(CodeBlock& cb,
TCA start,
bool persist,
folly::Optional<FPInvOffset> spOff,
ServiceRequest sr,
const ArgVec& argv) {
FTRACE(2, "svcreq @{} {}(", start, to_name(sr));
auto const is_reused = start != cb.frontier();
CodeBlock stub;
stub.init(start, stub_size(), "svcreq_stub");
{ Vauto vasm{stub};
auto& v = vasm.main();
// If we have an spOff, materialize rvmsp() so that handleSRHelper() can do
// a VM reg sync. (When we don't have an spOff, the caller of the service
// request was responsible for making sure rvmsp already contained the top
// of the stack.)
if (spOff) {
v << lea{rvmfp()[-cellsToBytes(spOff->offset)], rvmsp()};
}
auto live_out = leave_trace_regs();
assert(argv.size() <= kMaxArgs);
// Pick up CondCode arguments first---vasm may optimize immediate loads
// into operations which clobber status flags.
for (auto i = 0; i < argv.size(); ++i) {
auto const& arg = argv[i];
if (arg.kind != Arg::Kind::CondCode) continue;
FTRACE(2, "c({}), ", cc_names[arg.cc]);
v << setcc{arg.cc, r_svcreq_sf(), rbyte(r_svcreq_arg(i))};
}
for (auto i = 0; i < argv.size(); ++i) {
auto const& arg = argv[i];
auto const r = r_svcreq_arg(i);
switch (arg.kind) {
case Arg::Kind::Immed:
FTRACE(2, "{}, ", arg.imm);
v << copy{v.cns(arg.imm), r};
break;
case Arg::Kind::Address:
FTRACE(2, "{}(%rip), ", arg.imm);
v << leap{reg::rip[arg.imm], r};
break;
case Arg::Kind::CondCode:
break;
}
live_out |= r;
}
FTRACE(2, ") : stub@");
if (persist) {
FTRACE(2, "<none>");
v << copy{v.cns(0), r_svcreq_stub()};
} else {
FTRACE(2, "{}", stub.base());
v << leap{reg::rip[int64_t(stub.base())], r_svcreq_stub()};
}
v << copy{v.cns(sr), r_svcreq_req()};
live_out |= r_svcreq_stub();
live_out |= r_svcreq_req();
v << jmpi{TCA(handleSRHelper), live_out};
// We pad ephemeral stubs unconditionally. This is required for
// correctness by the x64 code relocator.
vasm.unit().padding = !persist;
}
if (!is_reused) cb.skip(stub.used());
}
void BML_XMLParser::Read(SkStream& s, SkXMLWriter& writer)
{
BMLW rec;
writer.writeHeader();
relem(rbyte(s), s, rec, writer);
}
TCA
emitServiceReqWork(CodeBlock& cb, TCA start, bool persist, SRFlags flags,
ServiceRequest req, const ServiceReqArgVec& argv) {
assert(start);
const bool align = flags & SRFlags::Align;
Asm as { cb };
/*
* Remember previous state of the code cache.
*/
folly::Optional<CodeCursor> maybeCc = folly::none;
if (start != as.frontier()) {
maybeCc.emplace(cb, start);
}
/* max space for moving to align, saving VM regs plus emitting args */
static const int
kVMRegSpace = 0x14,
kMovSize = 0xa,
kNumServiceRegs = sizeof(serviceReqArgRegs) / sizeof(PhysReg),
kMaxStubSpace = kJmpTargetAlign - 1 + kVMRegSpace +
kNumServiceRegs * kMovSize;
if (align) {
moveToAlign(cb);
}
TCA retval = as.frontier();
TRACE(3, "Emit Service Req @%p %s(", start, serviceReqName(req));
/*
* Move args into appropriate regs. Eager VMReg save may bash flags,
* so set the CondCode arguments first.
*/
for (int i = 0; i < argv.size(); ++i) {
assert(i < kNumServiceReqArgRegs);
auto reg = serviceReqArgRegs[i];
const auto& argInfo = argv[i];
switch(argv[i].m_kind) {
case ServiceReqArgInfo::Immediate: {
TRACE(3, "%" PRIx64 ", ", argInfo.m_imm);
as. emitImmReg(argInfo.m_imm, reg);
} break;
case ServiceReqArgInfo::CondCode: {
// Already set before VM reg save.
DEBUG_ONLY TCA start = as.frontier();
as. setcc(argInfo.m_cc, rbyte(reg));
assert(start - as.frontier() <= kMovSize);
TRACE(3, "cc(%x), ", argInfo.m_cc);
} break;
default: not_reached();
}
}
emitEagerVMRegSave(as, RegSaveFlags::SaveFP);
if (persist) {
as. emitImmReg(0, JIT::X64::rAsm);
} else {
as. emitImmReg((uint64_t)start, JIT::X64::rAsm);
}
TRACE(3, ")\n");
as. emitImmReg(req, JIT::reg::rdi);
/*
* Weird hand-shaking with enterTC: reverse-call a service routine.
*
* In the case of some special stubs (m_callToExit, m_retHelper), we
* have already unbalanced the return stack by doing a ret to
* something other than enterTCHelper. In that case
* SRJmpInsteadOfRet indicates to fake the return.
*/
if (flags & SRFlags::JmpInsteadOfRet) {
as. pop(JIT::reg::rax);
as. jmp(JIT::reg::rax);
} else {
as. ret();
}
// TODO(2796856): we should record an OpServiceRequest pseudo-bytecode here.
if (debug) {
// not reached
as.ud2();
}
if (!persist) {
/*
* Recycled stubs need to be uniformly sized. Make space for the
* maximal possible service requests.
*/
assert(as.frontier() - start <= kMaxStubSpace);
as.emitNop(start + kMaxStubSpace - as.frontier());
assert(as.frontier() - start == kMaxStubSpace);
}
return retval;
}
