Size reduction of VirtualFrame objects. Remove the code generator and...

src/arm/virtual-frame-arm.h

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_ARM_VIRTUAL_FRAME_ARM_H_
 #define V8_ARM_VIRTUAL_FRAME_ARM_H_
 
 #include "register-allocator.h"
+#include "scopes.h"
 
 namespace v8 { namespace internal {
 
 // -------------------------------------------------------------------------
 // Virtual frames
 //
 // The virtual frame is an abstraction of the physical stack frame.  It
 // encapsulates the parameters, frame-allocated locals, and the expression
 // stack.  It supports push/pop operations on the expression stack, as well
 // as random access to the expression stack elements, locals, and
 // parameters.
 
 class VirtualFrame : public ZoneObject {
  public:
   // A utility class to introduce a scope where the virtual frame is
   // expected to remain spilled.  The constructor spills the code
   // generator's current frame, but no attempt is made to require it
   // to stay spilled.  It is intended as documentation while the code
   // generator is being transformed.
   class SpilledScope BASE_EMBEDDED {
    public:
-    explicit SpilledScope(CodeGenerator* cgen)
-        : cgen_(cgen),
-          previous_state_(cgen->in_spilled_code()) {
-      ASSERT(cgen->has_valid_frame());
-      cgen->frame()->SpillAll();
-      cgen->set_in_spilled_code(true);
+    SpilledScope() : previous_state_(cgen()->in_spilled_code()) {
+      ASSERT(cgen()->has_valid_frame());
+      cgen()->frame()->SpillAll();
+      cgen()->set_in_spilled_code(true);
     }
 
     ~SpilledScope() {
-      cgen_->set_in_spilled_code(previous_state_);
+      cgen()->set_in_spilled_code(previous_state_);
     }
 
    private:
-    CodeGenerator* cgen_;
     bool previous_state_;
+
+    CodeGenerator* cgen() { return CodeGeneratorScope::Current(); }
   };
 
   // An illegal index into the virtual frame.
   static const int kIllegalIndex = -1;
 
   // Construct an initial virtual frame on entry to a JS function.
-  explicit VirtualFrame(CodeGenerator* cgen);
+  VirtualFrame();
 
   // Construct a virtual frame as a clone of an existing one.
   explicit VirtualFrame(VirtualFrame* original);
 
+  CodeGenerator* cgen() { return CodeGeneratorScope::Current(); }
+  MacroAssembler* masm() { return cgen()->masm(); }
+
   // Create a duplicate of an existing valid frame element.
   FrameElement CopyElementAt(int index);
 
   // The height of the virtual expression stack.
-  int height() const {
+  int height() {
     return elements_.length() - expression_base_index();
   }
 
   int register_index(Register reg) {
     return register_locations_[reg.code()];
   }
 
   bool is_used(int reg_code) {
     return register_locations_[reg_code] != kIllegalIndex;
   }
@@ skipping 42 matching lines @@
   // Make this virtual frame have a state identical to an expected virtual
   // frame.  As a side effect, code may be emitted to make this frame match
   // the expected one.
   void MergeTo(VirtualFrame* expected);
 
   // Detach a frame from its code generator, perhaps temporarily.  This
   // tells the register allocator that it is free to use frame-internal
   // registers.  Used when the code generator's frame is switched from this
   // one to NULL by an unconditional jump.
   void DetachFromCodeGenerator() {
-    RegisterAllocator* cgen_allocator = cgen_->allocator();
+    RegisterAllocator* cgen_allocator = cgen()->allocator();
     for (int i = 0; i < kNumRegisters; i++) {
       if (is_used(i)) {
         Register temp = { i };
         cgen_allocator->Unuse(temp);
       }
     }
   }
 
   // (Re)attach a frame to its code generator.  This informs the register
   // allocator that the frame-internal register references are active again.
   // Used when a code generator's frame is switched from NULL to this one by
   // binding a label.
   void AttachToCodeGenerator() {
-    RegisterAllocator* cgen_allocator = cgen_->allocator();
+    RegisterAllocator* cgen_allocator = cgen()->allocator();
     for (int i = 0; i < kNumRegisters; i++) {
       if (is_used(i)) {
         Register temp = { i };
         cgen_allocator->Use(temp);
       }
     }
   }
 
   // Emit code for the physical JS entry and exit frame sequences.  After
   // calling Enter, the virtual frame is ready for use; and after calling
   // Exit it should not be used.  Note that Enter does not allocate space in
   // the physical frame for storing frame-allocated locals.
   void Enter();
   void Exit();
 
   // Prepare for returning from the frame by spilling locals and
   // dropping all non-locals elements in the virtual frame.  This
   // avoids generating unnecessary merge code when jumping to the
   // shared return site.  Emits code for spills.
   void PrepareForReturn();
 
   // Allocate and initialize the frame-allocated locals.
-  void AllocateStackSlots(int count);
+  void AllocateStackSlots();
 
   // The current top of the expression stack as an assembly operand.
-  MemOperand Top() const { return MemOperand(sp, 0); }
+  MemOperand Top() { return MemOperand(sp, 0); }
 
   // An element of the expression stack as an assembly operand.
-  MemOperand ElementAt(int index) const {
+  MemOperand ElementAt(int index) {
     return MemOperand(sp, index * kPointerSize);
   }
 
   // Random-access store to a frame-top relative frame element.  The result
   // becomes owned by the frame and is invalidated.
   void SetElementAt(int index, Result* value);
 
   // Set a frame element to a constant.  The index is frame-top relative.
   void SetElementAt(int index, Handle<Object> value) {
     Result temp(value);
     SetElementAt(index, &temp);
   }
 
   void PushElementAt(int index) {
     PushFrameSlotAt(elements_.length() - index - 1);
   }
 
   // A frame-allocated local as an assembly operand.
-  MemOperand LocalAt(int index) const {
+  MemOperand LocalAt(int index) {
     ASSERT(0 <= index);
-    ASSERT(index < local_count_);
+    ASSERT(index < local_count());
     return MemOperand(fp, kLocal0Offset - index * kPointerSize);
   }
 
   // Push a copy of the value of a local frame slot on top of the frame.
   void PushLocalAt(int index) {
     PushFrameSlotAt(local0_index() + index);
   }
 
   // Push the value of a local frame slot on top of the frame and invalidate
   // the local slot.  The slot should be written to before trying to read
   // from it again.
   void TakeLocalAt(int index) {
     TakeFrameSlotAt(local0_index() + index);
   }
 
   // Store the top value on the virtual frame into a local frame slot.  The
   // value is left in place on top of the frame.
   void StoreToLocalAt(int index) {
     StoreToFrameSlotAt(local0_index() + index);
   }
 
   // Push the address of the receiver slot on the frame.
   void PushReceiverSlotAddress();
 
   // The function frame slot.
-  MemOperand Function() const { return MemOperand(fp, kFunctionOffset); }
+  MemOperand Function() { return MemOperand(fp, kFunctionOffset); }
 
   // Push the function on top of the frame.
   void PushFunction() { PushFrameSlotAt(function_index()); }
 
   // The context frame slot.
-  MemOperand Context() const { return MemOperand(fp, kContextOffset); }
+  MemOperand Context() { return MemOperand(fp, kContextOffset); }
 
   // Save the value of the esi register to the context frame slot.
   void SaveContextRegister();
 
   // Restore the esi register from the value of the context frame
   // slot.
   void RestoreContextRegister();
 
   // A parameter as an assembly operand.
-  MemOperand ParameterAt(int index) const {
+  MemOperand ParameterAt(int index) {
     // Index -1 corresponds to the receiver.
-    ASSERT(-1 <= index && index <= parameter_count_);
-    return MemOperand(fp, (1 + parameter_count_ - index) * kPointerSize);
+    ASSERT(-1 <= index);  // -1 is the receiver.
+    ASSERT(index <= parameter_count());
+    return MemOperand(fp, (1 + parameter_count() - index) * kPointerSize);
   }
 
   // Push a copy of the value of a parameter frame slot on top of the frame.
   void PushParameterAt(int index) {
     PushFrameSlotAt(param0_index() + index);
   }
 
   // Push the value of a paramter frame slot on top of the frame and
   // invalidate the parameter slot.  The slot should be written to before
   // trying to read from it again.
   void TakeParameterAt(int index) {
     TakeFrameSlotAt(param0_index() + index);
   }
 
   // Store the top value on the virtual frame into a parameter frame slot.
   // The value is left in place on top of the frame.
   void StoreToParameterAt(int index) {
     StoreToFrameSlotAt(param0_index() + index);
   }
 
   // The receiver frame slot.
-  MemOperand Receiver() const { return ParameterAt(-1); }
+  MemOperand Receiver() { return ParameterAt(-1); }
 
   // Push a try-catch or try-finally handler on top of the virtual frame.
   void PushTryHandler(HandlerType type);
 
   // Call stub given the number of arguments it expects on (and
   // removes from) the stack.
   Result CallStub(CodeStub* stub, int arg_count) {
     PrepareForCall(arg_count, arg_count);
     return RawCallStub(stub);
   }
@@ skipping 79 matching lines @@
   void Nip(int num_dropped);
 
  private:
   static const int kLocal0Offset = JavaScriptFrameConstants::kLocal0Offset;
   static const int kFunctionOffset = JavaScriptFrameConstants::kFunctionOffset;
   static const int kContextOffset = StandardFrameConstants::kContextOffset;
 
   static const int kHandlerSize = StackHandlerConstants::kSize / kPointerSize;
   static const int kPreallocatedElements = 5 + 8;  // 8 expression stack slots.
 
-  CodeGenerator* cgen_;
-  MacroAssembler* masm_;
-
   ZoneList<FrameElement> elements_;
 
-  // The number of frame-allocated locals and parameters respectively.
-  int parameter_count_;
-  int local_count_;
-
   // The index of the element that is at the processor's stack pointer
   // (the sp register).
   int stack_pointer_;
 
-  // The index of the element that is at the processor's frame pointer
-  // (the fp register).
-  int frame_pointer_;
-
   // The index of the register frame element using each register, or
   // kIllegalIndex if a register is not on the frame.
   int register_locations_[kNumRegisters];
 
+  // The number of frame-allocated locals and parameters respectively.
+  int parameter_count() { return cgen()->scope()->num_parameters(); }
+  int local_count() { return cgen()->scope()->num_stack_slots(); }
+
+  // The index of the element that is at the processor's frame pointer
+  // (the fp register).  The parameters, receiver, function, and context
+  // are below the frame pointer.
+  int frame_pointer() { return parameter_count() + 3; }
+
   // The index of the first parameter.  The receiver lies below the first
   // parameter.
-  int param0_index() const { return 1; }
+  int param0_index() { return 1; }
 
-  // The index of the context slot in the frame.
-  int context_index() const {
-    ASSERT(frame_pointer_ != kIllegalIndex);
-    return frame_pointer_ - 1;
-  }
+  // The index of the context slot in the frame.  It is immediately
+  // below the frame pointer.
+  int context_index() { return frame_pointer() - 1; }
 
-  // The index of the function slot in the frame.  It lies above the context
-  // slot.
-  int function_index() const {
-    ASSERT(frame_pointer_ != kIllegalIndex);
-    return frame_pointer_ - 2;
-  }
+  // The index of the function slot in the frame.  It is below the frame
+  // pointer and context slot.
+  int function_index() { return frame_pointer() - 2; }
 
-  // The index of the first local.  Between the parameters and the locals
-  // lie the return address, the saved frame pointer, the context, and the
-  // function.
-  int local0_index() const {
-    ASSERT(frame_pointer_ != kIllegalIndex);
-    return frame_pointer_ + 2;
-  }
+  // The index of the first local.  Between the frame pointer and the
+  // locals lies the return address.
+  int local0_index() { return frame_pointer() + 2; }
 
   // The index of the base of the expression stack.
-  int expression_base_index() const { return local0_index() + local_count_; }
+  int expression_base_index() { return local0_index() + local_count(); }
 
   // Convert a frame index into a frame pointer relative offset into the
   // actual stack.
-  int fp_relative(int index) const {
-    return (frame_pointer_ - index) * kPointerSize;
+  int fp_relative(int index) {
+    ASSERT(index < elements_.length());
+    ASSERT(frame_pointer() < elements_.length());  // FP is on the frame.
+    return (frame_pointer() - index) * kPointerSize;
   }
 
   // Record an occurrence of a register in the virtual frame.  This has the
   // effect of incrementing the register's external reference count and
   // of updating the index of the register's location in the frame.
   void Use(Register reg, int index) {
     ASSERT(!is_used(reg));
     register_locations_[reg.code()] = index;
-    cgen_->allocator()->Use(reg);
+    cgen()->allocator()->Use(reg);
   }
 
   // Record that a register reference has been dropped from the frame.  This
   // decrements the register's external reference count and invalidates the
   // index of the register's location in the frame.
   void Unuse(Register reg) {
     ASSERT(register_locations_[reg.code()] != kIllegalIndex);
     register_locations_[reg.code()] = kIllegalIndex;
-    cgen_->allocator()->Unuse(reg);
+    cgen()->allocator()->Unuse(reg);
   }
 
   // Spill the element at a particular index---write it to memory if
   // necessary, free any associated register, and forget its value if
   // constant.
   void SpillElementAt(int index);
 
   // Sync the element at a particular index.  If it is a register or
   // constant that disagrees with the value on the stack, write it to memory.
   // Keep the element type as register or constant, and clear the dirty bit.
@@ skipping 63 matching lines @@
 
   bool Equals(VirtualFrame* other);
 
   friend class JumpTarget;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ARM_VIRTUAL_FRAME_ARM_H_