Smaller c_Continuation

Save 16 bytes in c_Continuation by moving running and done flags to o_subclassData and making labels 2-byte.

hphp/runtime/ext/asio/continuation_wait_handle.cpp

@@ -98,7 +98,7 @@ void c_ContinuationWaitHandle::Create(c_Continuation* continuation) {
 
   if (UNLIKELY(continuation->m_index != -1)) {
     Object e(SystemLib::AllocInvalidOperationExceptionObject(
-      continuation->m_running
+      continuation->running()
       ? "Encountered an attempt to start currently running continuation"
       : "Encountered an attempt to start tainted continuation"));
     throw e;
@@ -159,7 +159,7 @@ void c_ContinuationWaitHandle::run() {
       }
 
       // continuation finished, retrieve result from its m_value
-      if (m_continuation->m_done) {
+      if (m_continuation->done()) {
         markAsSucceeded(m_continuation->m_value.asTypedValue());
         return;
       }

hphp/runtime/ext/ext_continuation.cpp

@@ -49,8 +49,9 @@ c_Continuation::c_Continuation(Class* cb) :
     m_index(-1LL),
     m_value(Variant::NullInit()),
     m_received(Variant::NullInit()),
-    m_done(false), m_running(false),
-    m_vmFunc(nullptr), m_label(0ll) {
+    m_origFunc(nullptr),
+    m_label(0) {
+  o_subclassData.u16 = 0;
 }
 
 c_Continuation::~c_Continuation() {
@@ -66,7 +67,7 @@ c_Continuation::~c_Continuation() {
   if (ar->hasVarEnv()) {
     ar->getVarEnv()->detach(ar);
   } else {
-    frame_free_locals_inl(ar, m_vmFunc->numLocals());
+    frame_free_locals_inl(ar, ar->m_func->numLocals());
   }
 }
 
@@ -74,6 +75,7 @@ void c_Continuation::t___construct() {}
 
 void c_Continuation::t_update(int64_t label, CVarRef value) {
   m_label = label;
+  assert(m_label == label); // check m_label for truncation
   m_value.assignVal(value);
 }
 
@@ -128,7 +130,7 @@ void c_Continuation::t_rewind() {
 
 bool c_Continuation::t_valid() {
   const_assert(false);
-  return !m_done;
+  return !done();
 }
 
 void c_Continuation::t_send(CVarRef v) {
@@ -140,7 +142,11 @@ void c_Continuation::t_raise(CVarRef v) {
 }
 
 String c_Continuation::t_getorigfuncname() {
-  return String(const_cast<StringData*>(m_origFuncName));
+  static auto const closureName = StringData::GetStaticString("{closure}");
+  auto const origName = m_origFunc->isClosureBody() ? closureName
+                                                    : m_origFunc->name();
+  assert(origName->isStatic());
+  return String(const_cast<StringData*>(origName));
 }
 
 String c_Continuation::t_getcalledclass() {

hphp/runtime/ext/ext_continuation.h

@@ -38,22 +38,18 @@ class c_Continuation : public ExtObjectData {
   virtual void sweep();
   void operator delete(void* p) {
     c_Continuation* this_ = (c_Continuation*)p;
-    DELETEOBJSZ(sizeForLocalsAndIters(this_->m_vmFunc->numLocals(),
-                                      this_->m_vmFunc->numIterators()))(this_);
+    DELETEOBJSZ((char*)(this_->m_arPtr + 1) - (char*)p)(this_);
   }
 
   explicit c_Continuation(Class* cls = c_Continuation::s_cls);
   ~c_Continuation();
 
 public:
-  void init(const Func* vmFunc,
-            const StringData* origFuncName,
+  void init(const Func* origFunc,
             ObjectData* thisPtr,
             ArrayData* args) noexcept {
-    m_vmFunc = const_cast<Func*>(vmFunc);
-    assert(m_vmFunc);
-    m_origFuncName = origFuncName;
-    assert(m_origFuncName->isStatic());
+    m_origFunc = const_cast<Func*>(origFunc);
+    assert(m_origFunc);
 
     if (thisPtr != nullptr) {
       m_obj = thisPtr;
@@ -64,6 +60,17 @@ public:
     m_args = args;
   }
 
+  bool done() const { return o_subclassData.u8[0]; }
+  bool running() const { return o_subclassData.u8[1]; }
+  void setDone(bool done) { o_subclassData.u8[0] = done; }
+  void setRunning(bool running) { o_subclassData.u8[1] = running; }
+  static constexpr uint doneOffset() {
+    return offsetof(c_Continuation, o_subclassData);
+  }
+  static constexpr uint runningOffset() {
+    return offsetof(c_Continuation, o_subclassData) + 1;
+  }
+
   void t___construct();
   void t_update(int64_t label, CVarRef value);
   Object t_getwaithandle();
@@ -101,15 +108,15 @@ public:
   void call_raise(ObjectData* e);
 
   inline void preNext() {
-    if (m_done) {
+    if (done()) {
       throw_exception(Object(SystemLib::AllocExceptionObject(
                                "Continuation is already finished")));
     }
-    if (m_running) {
+    if (running()) {
       throw_exception(Object(SystemLib::AllocExceptionObject(
                                "Continuation is already running")));
     }
-    m_running = true;
+    setRunning(true);
     ++m_index;
   }
 
@@ -126,13 +133,10 @@ public:
   int64_t m_index;
   Variant m_value;
   Variant m_received;
-  const StringData* m_origFuncName;
-  bool m_done;
-  bool m_running;
+  Func *m_origFunc;
 
+  int32_t m_label;
   int m_localsOffset;
-  Func *m_vmFunc;
-  int64_t m_label;
   ActRec* m_arPtr;
 
   p_ContinuationWaitHandle m_waitHandle;

hphp/runtime/vm/bytecode.cpp

@@ -7036,12 +7036,7 @@ VMExecutionContext::createContinuationHelper(const Func* origFunc,
   );
   cont->incRefCount();
   cont->setNoDestruct();
-
-  static auto const closureName = StringData::GetStaticString("{closure}");
-  auto const origName = origFunc->isClosureBody() ? closureName
-                                                  : origFunc->name();
-
-  cont->init(genFunc, origName, thisPtr, args);
+  cont->init(origFunc, thisPtr, args);
 
   // The ActRec corresponding to the generator body lives as long as the object
   // does. We set it up once, here, and then just change FP to point to it when
@@ -7290,7 +7285,7 @@ inline void OPTBLD_INLINE VMExecutionContext::iopContReceive(PC& pc) {
 inline void OPTBLD_INLINE VMExecutionContext::iopContRetC(PC& pc) {
   NEXT();
   c_Continuation* cont = frame_continuation(m_fp);
-  cont->m_done = true;
+  cont->setDone(true);
   tvSetIgnoreRef(m_stack.topC(), cont->m_value.asTypedValue());
   m_stack.popC();
 
@@ -7333,7 +7328,7 @@ inline void OPTBLD_INLINE VMExecutionContext::iopContValid(PC& pc) {
   NEXT();
   TypedValue* tv = m_stack.allocTV();
   tvWriteUninit(tv);
-  tvAsVariant(tv) = !this_continuation(m_fp)->m_done;
+  tvAsVariant(tv) = !this_continuation(m_fp)->done();
 }
 
 inline void OPTBLD_INLINE VMExecutionContext::iopContCurrent(PC& pc) {
@@ -7348,14 +7343,14 @@ inline void OPTBLD_INLINE VMExecutionContext::iopContCurrent(PC& pc) {
 
 inline void OPTBLD_INLINE VMExecutionContext::iopContStopped(PC& pc) {
   NEXT();
-  this_continuation(m_fp)->m_running = false;
+  this_continuation(m_fp)->setRunning(false);
 }
 
 inline void OPTBLD_INLINE VMExecutionContext::iopContHandle(PC& pc) {
   NEXT();
   c_Continuation* cont = this_continuation(m_fp);
-  cont->m_running = false;
-  cont->m_done = true;
+  cont->setRunning(false);
+  cont->setDone(true);
   cont->m_value.setNull();
 
   Variant exn = tvAsVariant(m_stack.topTV());

hphp/runtime/vm/jit/codegen.cpp

@@ -5135,17 +5135,17 @@ void CodeGenerator::cgLinkContVarEnv(IRInstruction* inst) {
 void CodeGenerator::cgContPreNext(IRInstruction* inst) {
   auto contReg = m_regs[inst->src(0)].reg();
 
-  const Offset doneOffset = CONTOFF(m_done);
-  static_assert((doneOffset + 1) == CONTOFF(m_running),
-                "m_done should immediately precede m_running");
-  // Check m_done and m_running at the same time
-  m_as.test_imm32_disp_reg32(0x0101, doneOffset, contReg);
+  const Offset doneOffset = c_Continuation::doneOffset();
+  static_assert((doneOffset + 1) == c_Continuation::runningOffset(),
+                "done should immediately precede running");
+  // Check done and running at the same time
+  m_as.test_imm16_disp_reg16(0x0101, doneOffset, contReg);
   emitFwdJcc(CC_NZ, inst->taken());
 
   // ++m_index
   m_as.add_imm64_disp_reg64(0x1, CONTOFF(m_index), contReg);
-  // m_running = true
-  m_as.store_imm8_disp_reg(0x1, CONTOFF(m_running), contReg);
+  // running = true
+  m_as.store_imm8_disp_reg(0x1, c_Continuation::runningOffset(), contReg);
 }
 
 void CodeGenerator::cgContStartedCheck(IRInstruction* inst) {

hphp/runtime/vm/jit/ir.h

@@ -788,15 +788,17 @@ class RawMemSlot {
     : m_offset(offset), m_size(size), m_type(type), m_allowExtra(allowExtra) { }
 
   static RawMemSlot& GetContLabel() {
-    static RawMemSlot m(CONTOFF(m_label), Transl::sz::qword, Type::Int);
+    static RawMemSlot m(CONTOFF(m_label), Transl::sz::dword, Type::Int);
     return m;
   }
   static RawMemSlot& GetContDone() {
-    static RawMemSlot m(CONTOFF(m_done), Transl::sz::byte, Type::Bool);
+    static RawMemSlot m(c_Continuation::doneOffset(), Transl::sz::byte,
+                        Type::Bool);
     return m;
   }
   static RawMemSlot& GetContRunning() {
-    static RawMemSlot m(CONTOFF(m_running), Transl::sz::byte, Type::Bool);
+    static RawMemSlot m(c_Continuation::runningOffset(), Transl::sz::byte,
+                        Type::Bool);
     return m;
   }
   static RawMemSlot& GetContARPtr() {

hphp/util/asm-x64.h

@@ -1794,6 +1794,12 @@ struct X64Assembler {
             sz::byte);
   }
 
+  void emitIM16(X64Instr op, RegNumber br, RegNumber ir, int s,
+                int disp, ssize_t imm) ALWAYS_INLINE {
+    emitCMX(op, 0, br, ir, s, disp, reg::noreg, false, imm, true,
+            sz::word);
+  }
+
   void emitIM32(X64Instr op, RegNumber br, RegNumber ir, int s,
                 int disp, ssize_t imm) ALWAYS_INLINE {
     emitCMX(op, 0, br, ir, s, disp, reg::noreg, false, imm, true,
@@ -2039,6 +2045,12 @@ public:
   inline void name ## _imm32_reg32(int64_t imm, RegNumber rdest) { \
     emitIR32(instr_ ## name, rdest, safe_cast<int32_t>(imm));           \
   }                                                                     \
+  /* op imm, disp(rdest) */ \
+  inline void name ## _imm16_disp_reg16(int64_t imm, int disp,          \
+                                        RegNumber rdest) {        \
+    emitIM16(instr_ ## name, rdest, reg::noreg,                         \
+             sz::byte, disp, safe_cast<int16_t>(imm));                  \
+  }                                                                     \
   /* opl imm, disp(rdest) */                                            \
   inline void name ## _imm32_disp_reg32(int64_t imm, int disp,          \
                                         RegNumber rdest) {        \