| // 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 |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #ifndef V8_IA32_VIRTUAL_FRAME_IA32_H_ |
| #define V8_IA32_VIRTUAL_FRAME_IA32_H_ |
| |
| #include "number-info.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: |
| 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_); |
| } |
| |
| private: |
| 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. |
| 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, |
| NumberInfo::Type info = NumberInfo::kUninitialized); |
| |
| // The number of elements on the virtual frame. |
| int element_count() { return elements_.length(); } |
| |
| // The height of the virtual expression stack. |
| int height() { return element_count() - expression_base_index(); } |
| |
| int register_location(int num) { |
| ASSERT(num >= 0 && num < RegisterAllocator::kNumRegisters); |
| return register_locations_[num]; |
| } |
| |
| int register_location(Register reg) { |
| return register_locations_[RegisterAllocator::ToNumber(reg)]; |
| } |
| |
| void set_register_location(Register reg, int index) { |
| register_locations_[RegisterAllocator::ToNumber(reg)] = index; |
| } |
| |
| bool is_used(int num) { |
| ASSERT(num >= 0 && num < RegisterAllocator::kNumRegisters); |
| return register_locations_[num] != kIllegalIndex; |
| } |
| |
| bool is_used(Register reg) { |
| return register_locations_[RegisterAllocator::ToNumber(reg)] |
| != kIllegalIndex; |
| } |
| |
| // Add extra in-memory elements to the top of the frame to match an actual |
| // frame (eg, the frame after an exception handler is pushed). No code is |
| // emitted. |
| void Adjust(int count); |
| |
| // Forget count elements from the top of the frame all in-memory |
| // (including synced) and adjust the stack pointer downward, to |
| // match an external frame effect (examples include a call removing |
| // its arguments, and exiting a try/catch removing an exception |
| // handler). No code will be emitted. |
| void Forget(int count) { |
| ASSERT(count >= 0); |
| ASSERT(stack_pointer_ == element_count() - 1); |
| stack_pointer_ -= count; |
| ForgetElements(count); |
| } |
| |
| // Forget count elements from the top of the frame without adjusting |
| // the stack pointer downward. This is used, for example, before |
| // merging frames at break, continue, and return targets. |
| void ForgetElements(int count); |
| |
| // Spill all values from the frame to memory. |
| void SpillAll(); |
| |
| // Spill all occurrences of a specific register from the frame. |
| void Spill(Register reg) { |
| if (is_used(reg)) SpillElementAt(register_location(reg)); |
| } |
| |
| // Spill all occurrences of an arbitrary register if possible. Return the |
| // register spilled or no_reg if it was not possible to free any register |
| // (ie, they all have frame-external references). |
| Register SpillAnyRegister(); |
| |
| // Sync the range of elements in [begin, end] with memory. |
| void SyncRange(int begin, int end); |
| |
| // Make this frame so that an arbitrary frame of the same height can |
| // be merged to it. Copies and constants are removed from the frame. |
| void MakeMergable(); |
| |
| // Prepare this virtual frame for merging to an expected frame by |
| // performing some state changes that do not require generating |
| // code. It is guaranteed that no code will be generated. |
| void PrepareMergeTo(VirtualFrame* expected); |
| |
| // 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(); |
| for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) { |
| if (is_used(i)) cgen_allocator->Unuse(i); |
| } |
| } |
| |
| // (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(); |
| for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) { |
| if (is_used(i)) cgen_allocator->Use(i); |
| } |
| } |
| |
| // 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. This |
| // avoids generating unnecessary merge code when jumping to the |
| // shared return site. Emits code for spills. |
| void PrepareForReturn(); |
| |
| // Number of local variables after when we use a loop for allocating. |
| static const int kLocalVarBound = 10; |
| |
| // Allocate and initialize the frame-allocated locals. |
| void AllocateStackSlots(); |
| |
| // An element of the expression stack as an assembly operand. |
| Operand ElementAt(int index) const { |
| return Operand(esp, 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(element_count() - index - 1); |
| } |
| |
| void StoreToElementAt(int index) { |
| StoreToFrameSlotAt(element_count() - index - 1); |
| } |
| |
| // A frame-allocated local as an assembly operand. |
| Operand LocalAt(int index) { |
| ASSERT(0 <= index); |
| ASSERT(index < local_count()); |
| return Operand(ebp, 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(); |
| |
| // Push the function on top of the frame. |
| void PushFunction() { |
| PushFrameSlotAt(function_index()); |
| } |
| |
| // 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. |
| Operand ParameterAt(int index) { |
| ASSERT(-1 <= index); // -1 is the receiver. |
| ASSERT(index < parameter_count()); |
| return Operand(ebp, (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. |
| Operand 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); |
| } |
| |
| // Call stub that takes a single argument passed in eax. The |
| // argument is given as a result which does not have to be eax or |
| // even a register. The argument is consumed by the call. |
| Result CallStub(CodeStub* stub, Result* arg); |
| |
| // Call stub that takes a pair of arguments passed in edx (arg0) and |
| // eax (arg1). The arguments are given as results which do not have |
| // to be in the proper registers or even in registers. The |
| // arguments are consumed by the call. |
| Result CallStub(CodeStub* stub, Result* arg0, Result* arg1); |
| |
| // Call runtime given the number of arguments expected on (and |
| // removed from) the stack. |
| Result CallRuntime(Runtime::Function* f, int arg_count); |
| Result CallRuntime(Runtime::FunctionId id, int arg_count); |
| |
| #ifdef ENABLE_DEBUGGER_SUPPORT |
| void DebugBreak(); |
| #endif |
| |
| // Invoke builtin given the number of arguments it expects on (and |
| // removes from) the stack. |
| Result InvokeBuiltin(Builtins::JavaScript id, InvokeFlag flag, int arg_count); |
| |
| // Call load IC. Name and receiver are found on top of the frame. |
| // Both are dropped. |
| Result CallLoadIC(RelocInfo::Mode mode); |
| |
| // Call keyed load IC. Key and receiver are found on top of the |
| // frame. They are not dropped. |
| Result CallKeyedLoadIC(RelocInfo::Mode mode); |
| |
| // Call store IC. Name, value, and receiver are found on top of the |
| // frame. Receiver is not dropped. |
| Result CallStoreIC(); |
| |
| // Call keyed store IC. Value, key, and receiver are found on top |
| // of the frame. Key and receiver are not dropped. |
| Result CallKeyedStoreIC(); |
| |
| // Call call IC. Function name, arguments, and receiver are found on top |
| // of the frame and dropped by the call. The argument count does not |
| // include the receiver. |
| Result CallCallIC(RelocInfo::Mode mode, int arg_count, int loop_nesting); |
| |
| // Allocate and call JS function as constructor. Arguments, |
| // receiver (global object), and function are found on top of the |
| // frame. Function is not dropped. The argument count does not |
| // include the receiver. |
| Result CallConstructor(int arg_count); |
| |
| // Drop a number of elements from the top of the expression stack. May |
| // emit code to affect the physical frame. Does not clobber any registers |
| // excepting possibly the stack pointer. |
| void Drop(int count); |
| |
| // Drop one element. |
| void Drop() { |
| Drop(1); |
| } |
| |
| // Duplicate the top element of the frame. |
| void Dup() { |
| PushFrameSlotAt(element_count() - 1); |
| } |
| |
| // Pop an element from the top of the expression stack. Returns a |
| // Result, which may be a constant or a register. |
| Result Pop(); |
| |
| // Pop and save an element from the top of the expression stack and |
| // emit a corresponding pop instruction. |
| void EmitPop(Register reg); |
| void EmitPop(Operand operand); |
| |
| // Push an element on top of the expression stack and emit a |
| // corresponding push instruction. |
| void EmitPush(Register reg, |
| NumberInfo::Type info = NumberInfo::kUnknown); |
| void EmitPush(Operand operand, |
| NumberInfo::Type info = NumberInfo::kUnknown); |
| void EmitPush(Immediate immediate, |
| NumberInfo::Type info = NumberInfo::kUnknown); |
| |
| // Push an element on the virtual frame. |
| void Push(Register reg, NumberInfo::Type info = NumberInfo::kUnknown); |
| void Push(Handle<Object> value); |
| void Push(Smi* value) { |
| Push(Handle<Object> (value)); |
| } |
| |
| // Pushing a result invalidates it (its contents become owned by the |
| // frame). |
| void Push(Result* result) { |
| // This assert will trigger if you try to push the same value twice. |
| ASSERT(result->is_valid()); |
| if (result->is_register()) { |
| Push(result->reg(), result->number_info()); |
| } else { |
| ASSERT(result->is_constant()); |
| Push(result->handle()); |
| } |
| result->Unuse(); |
| } |
| |
| // Nip removes zero or more elements from immediately below the top |
| // of the frame, leaving the previous top-of-frame value on top of |
| // the frame. Nip(k) is equivalent to x = Pop(), Drop(k), Push(x). |
| 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. |
| |
| ZoneList<FrameElement> elements_; |
| |
| // The index of the element that is at the processor's stack pointer |
| // (the esp register). |
| int stack_pointer_; |
| |
| // The index of the register frame element using each register, or |
| // kIllegalIndex if a register is not on the frame. |
| int register_locations_[RegisterAllocator::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 ebp register). The parameters, receiver, and return address |
| // are below the frame pointer. |
| int frame_pointer() { |
| return parameter_count() + 2; |
| } |
| |
| // The index of the first parameter. The receiver lies below the first |
| // parameter. |
| int param0_index() { |
| return 1; |
| } |
| |
| // The index of the context slot in the frame. It is immediately |
| // above the frame pointer. |
| int context_index() { |
| return frame_pointer() + 1; |
| } |
| |
| // The index of the function slot in the frame. It is above the frame |
| // pointer and the context slot. |
| int function_index() { |
| return frame_pointer() + 2; |
| } |
| |
| // The index of the first local. Between the frame pointer and the |
| // locals lie the context and the function. |
| int local0_index() { |
| return frame_pointer() + 3; |
| } |
| |
| // The index of the base of the expression stack. |
| 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) { |
| ASSERT(index < element_count()); |
| ASSERT(frame_pointer() < element_count()); // 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)); |
| set_register_location(reg, index); |
| 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(is_used(reg)); |
| set_register_location(reg, kIllegalIndex); |
| 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. |
| void SyncElementAt(int index); |
| |
| // Sync a single unsynced element that lies beneath or at the stack pointer. |
| void SyncElementBelowStackPointer(int index); |
| |
| // Sync a single unsynced element that lies just above the stack pointer. |
| void SyncElementByPushing(int index); |
| |
| // Push a copy of a frame slot (typically a local or parameter) on top of |
| // the frame. |
| void PushFrameSlotAt(int index); |
| |
| // Push a the value of a frame slot (typically a local or parameter) on |
| // top of the frame and invalidate the slot. |
| void TakeFrameSlotAt(int index); |
| |
| // Store the value on top of the frame to a frame slot (typically a local |
| // or parameter). |
| void StoreToFrameSlotAt(int index); |
| |
| // Spill all elements in registers. Spill the top spilled_args elements |
| // on the frame. Sync all other frame elements. |
| // Then drop dropped_args elements from the virtual frame, to match |
| // the effect of an upcoming call that will drop them from the stack. |
| void PrepareForCall(int spilled_args, int dropped_args); |
| |
| // Move frame elements currently in registers or constants, that |
| // should be in memory in the expected frame, to memory. |
| void MergeMoveRegistersToMemory(VirtualFrame* expected); |
| |
| // Make the register-to-register moves necessary to |
| // merge this frame with the expected frame. |
| // Register to memory moves must already have been made, |
| // and memory to register moves must follow this call. |
| // This is because some new memory-to-register moves are |
| // created in order to break cycles of register moves. |
| // Used in the implementation of MergeTo(). |
| void MergeMoveRegistersToRegisters(VirtualFrame* expected); |
| |
| // Make the memory-to-register and constant-to-register moves |
| // needed to make this frame equal the expected frame. |
| // Called after all register-to-memory and register-to-register |
| // moves have been made. After this function returns, the frames |
| // should be equal. |
| void MergeMoveMemoryToRegisters(VirtualFrame* expected); |
| |
| // Invalidates a frame slot (puts an invalid frame element in it). |
| // Copies on the frame are correctly handled, and if this slot was |
| // the backing store of copies, the index of the new backing store |
| // is returned. Otherwise, returns kIllegalIndex. |
| // Register counts are correctly updated. |
| int InvalidateFrameSlotAt(int index); |
| |
| // Call a code stub that has already been prepared for calling (via |
| // PrepareForCall). |
| Result RawCallStub(CodeStub* stub); |
| |
| // Calls a code object which has already been prepared for calling |
| // (via PrepareForCall). |
| Result RawCallCodeObject(Handle<Code> code, RelocInfo::Mode rmode); |
| |
| bool Equals(VirtualFrame* other); |
| |
| // Classes that need raw access to the elements_ array. |
| friend class DeferredCode; |
| friend class JumpTarget; |
| }; |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_IA32_VIRTUAL_FRAME_IA32_H_ |