| // 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 |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| // (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" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // This dummy class is only used to create invalid virtual frames. |
| extern class InvalidVirtualFrameInitializer {}* kInvalidVirtualFrameInitializer; |
| |
| |
| // ------------------------------------------------------------------------- |
| // 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: |
| class RegisterAllocationScope; |
| // 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, and keeps it spilled. |
| class SpilledScope BASE_EMBEDDED { |
| public: |
| explicit SpilledScope(VirtualFrame* frame) |
| : old_is_spilled_(is_spilled_) { |
| if (frame != NULL) { |
| if (!is_spilled_) { |
| frame->SpillAll(); |
| } else { |
| frame->AssertIsSpilled(); |
| } |
| } |
| is_spilled_ = true; |
| } |
| ~SpilledScope() { |
| is_spilled_ = old_is_spilled_; |
| } |
| static bool is_spilled() { return is_spilled_; } |
| |
| private: |
| static bool is_spilled_; |
| int old_is_spilled_; |
| |
| SpilledScope() { } |
| |
| friend class RegisterAllocationScope; |
| }; |
| |
| class RegisterAllocationScope BASE_EMBEDDED { |
| public: |
| // A utility class to introduce a scope where the virtual frame |
| // is not spilled, ie. where register allocation occurs. Eventually |
| // when RegisterAllocationScope is ubiquitous it can be removed |
| // along with the (by then unused) SpilledScope class. |
| inline explicit RegisterAllocationScope(CodeGenerator* cgen); |
| inline ~RegisterAllocationScope(); |
| |
| private: |
| CodeGenerator* cgen_; |
| bool old_is_spilled_; |
| |
| RegisterAllocationScope() { } |
| }; |
| |
| // An illegal index into the virtual frame. |
| static const int kIllegalIndex = -1; |
| |
| // Construct an initial virtual frame on entry to a JS function. |
| inline VirtualFrame(); |
| |
| // Construct an invalid virtual frame, used by JumpTargets. |
| inline VirtualFrame(InvalidVirtualFrameInitializer* dummy); |
| |
| // Construct a virtual frame as a clone of an existing one. |
| explicit inline VirtualFrame(VirtualFrame* original); |
| |
| inline CodeGenerator* cgen() const; |
| inline MacroAssembler* masm(); |
| |
| // The number of elements on the virtual frame. |
| int element_count() const { return element_count_; } |
| |
| // The height of the virtual expression stack. |
| inline int height() const; |
| |
| bool is_used(int num) { |
| switch (num) { |
| case 0: { // r0. |
| return kR0InUse[top_of_stack_state_]; |
| } |
| case 1: { // r1. |
| return kR1InUse[top_of_stack_state_]; |
| } |
| case 2: |
| case 3: |
| case 4: |
| case 5: |
| case 6: { // r2 to r6. |
| ASSERT(num - kFirstAllocatedRegister < kNumberOfAllocatedRegisters); |
| ASSERT(num >= kFirstAllocatedRegister); |
| if ((register_allocation_map_ & |
| (1 << (num - kFirstAllocatedRegister))) == 0) { |
| return false; |
| } else { |
| return true; |
| } |
| } |
| default: { |
| ASSERT(num < kFirstAllocatedRegister || |
| num >= kFirstAllocatedRegister + kNumberOfAllocatedRegisters); |
| return false; |
| } |
| } |
| } |
| |
| // 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 elements from the top of the frame to match an actual frame (eg, |
| // the frame after a runtime call). No code is emitted except to bring the |
| // frame to a spilled state. |
| void Forget(int count); |
| |
| // Spill all values from the frame to memory. |
| void SpillAll(); |
| |
| void AssertIsSpilled() const { |
| ASSERT(top_of_stack_state_ == NO_TOS_REGISTERS); |
| ASSERT(register_allocation_map_ == 0); |
| } |
| |
| void AssertIsNotSpilled() { |
| ASSERT(!SpilledScope::is_spilled()); |
| } |
| |
| // Spill all occurrences of a specific register from the frame. |
| void Spill(Register reg) { |
| UNIMPLEMENTED(); |
| } |
| |
| // 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). Unimplemented. |
| Register SpillAnyRegister(); |
| |
| // 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, Condition cond = al); |
| void MergeTo(const VirtualFrame* expected, Condition cond = al); |
| |
| // Checks whether this frame can be branched to by the other frame. |
| bool IsCompatibleWith(const VirtualFrame* other) const { |
| return (tos_known_smi_map_ & (~other->tos_known_smi_map_)) == 0; |
| } |
| |
| inline void ForgetTypeInfo() { |
| tos_known_smi_map_ = 0; |
| } |
| |
| // 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() { |
| } |
| |
| // (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() { |
| } |
| |
| // 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 elements in the virtual frame. This |
| // avoids generating unnecessary merge code when jumping to the |
| // shared return site. No spill code emitted. Value to return should be in r0. |
| inline void PrepareForReturn(); |
| |
| // Number of local variables after when we use a loop for allocating. |
| static const int kLocalVarBound = 5; |
| |
| // Allocate and initialize the frame-allocated locals. |
| void AllocateStackSlots(); |
| |
| // The current top of the expression stack as an assembly operand. |
| MemOperand Top() { |
| AssertIsSpilled(); |
| return MemOperand(sp, 0); |
| } |
| |
| // An element of the expression stack as an assembly operand. |
| MemOperand ElementAt(int index) { |
| int adjusted_index = index - kVirtualElements[top_of_stack_state_]; |
| ASSERT(adjusted_index >= 0); |
| return MemOperand(sp, adjusted_index * kPointerSize); |
| } |
| |
| bool KnownSmiAt(int index) { |
| if (index >= kTOSKnownSmiMapSize) return false; |
| return (tos_known_smi_map_ & (1 << index)) != 0; |
| } |
| |
| // A frame-allocated local as an assembly operand. |
| inline MemOperand LocalAt(int index); |
| |
| // Push the address of the receiver slot on the frame. |
| void PushReceiverSlotAddress(); |
| |
| // The function frame slot. |
| MemOperand Function() { return MemOperand(fp, kFunctionOffset); } |
| |
| // The context frame slot. |
| MemOperand Context() { return MemOperand(fp, kContextOffset); } |
| |
| // A parameter as an assembly operand. |
| inline MemOperand ParameterAt(int index); |
| |
| // The receiver frame slot. |
| inline MemOperand Receiver(); |
| |
| // 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. |
| inline void CallStub(CodeStub* stub, int arg_count); |
| |
| // Call JS function from top of the stack with arguments |
| // taken from the stack. |
| void CallJSFunction(int arg_count); |
| |
| // Call runtime given the number of arguments expected on (and |
| // removed from) the stack. |
| void CallRuntime(Runtime::Function* f, int arg_count); |
| void 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. |
| void InvokeBuiltin(Builtins::JavaScript id, |
| InvokeJSFlags flag, |
| int arg_count); |
| |
| // Call load IC. Receiver is on the stack and is consumed. Result is returned |
| // in r0. |
| void CallLoadIC(Handle<String> name, RelocInfo::Mode mode); |
| |
| // Call store IC. If the load is contextual, value is found on top of the |
| // frame. If not, value and receiver are on the frame. Both are consumed. |
| // Result is returned in r0. |
| void CallStoreIC(Handle<String> name, bool is_contextual, |
| StrictModeFlag strict_mode); |
| |
| // Call keyed load IC. Key and receiver are on the stack. Both are consumed. |
| // Result is returned in r0. |
| void CallKeyedLoadIC(); |
| |
| // Call keyed store IC. Value, key and receiver are on the stack. All three |
| // are consumed. Result is returned in r0. |
| void CallKeyedStoreIC(); |
| |
| // Call into an IC stub given the number of arguments it removes |
| // from the stack. Register arguments to the IC stub are implicit, |
| // and depend on the type of IC stub. |
| void CallCodeObject(Handle<Code> ic, |
| RelocInfo::Mode rmode, |
| int dropped_args); |
| |
| // 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); } |
| |
| // Pop an element from the top of the expression stack. Discards |
| // the result. |
| void Pop(); |
| |
| // Pop an element from the top of the expression stack. The register |
| // will be one normally used for the top of stack register allocation |
| // so you can't hold on to it if you push on the stack. |
| Register PopToRegister(Register but_not_to_this_one = no_reg); |
| |
| // Look at the top of the stack. The register returned is aliased and |
| // must be copied to a scratch register before modification. |
| Register Peek(); |
| |
| // Look at the value beneath the top of the stack. The register returned is |
| // aliased and must be copied to a scratch register before modification. |
| Register Peek2(); |
| |
| // Duplicate the top of stack. |
| void Dup(); |
| |
| // Duplicate the two elements on top of stack. |
| void Dup2(); |
| |
| // Flushes all registers, but it puts a copy of the top-of-stack in r0. |
| void SpillAllButCopyTOSToR0(); |
| |
| // Flushes all registers, but it puts a copy of the top-of-stack in r1. |
| void SpillAllButCopyTOSToR1(); |
| |
| // Flushes all registers, but it puts a copy of the top-of-stack in r1 |
| // and the next value on the stack in r0. |
| void SpillAllButCopyTOSToR1R0(); |
| |
| // Pop and save an element from the top of the expression stack and |
| // emit a corresponding pop instruction. |
| void EmitPop(Register reg); |
| |
| // Takes the top two elements and puts them in r0 (top element) and r1 |
| // (second element). |
| void PopToR1R0(); |
| |
| // Takes the top element and puts it in r1. |
| void PopToR1(); |
| |
| // Takes the top element and puts it in r0. |
| void PopToR0(); |
| |
| // Push an element on top of the expression stack and emit a |
| // corresponding push instruction. |
| void EmitPush(Register reg, TypeInfo type_info = TypeInfo::Unknown()); |
| void EmitPush(Operand operand, TypeInfo type_info = TypeInfo::Unknown()); |
| void EmitPush(MemOperand operand, TypeInfo type_info = TypeInfo::Unknown()); |
| void EmitPushRoot(Heap::RootListIndex index); |
| |
| // Overwrite the nth thing on the stack. If the nth position is in a |
| // register then this turns into a mov, otherwise an str. Afterwards |
| // you can still use the register even if it is a register that can be |
| // used for TOS (r0 or r1). |
| void SetElementAt(Register reg, int this_far_down); |
| |
| // Get a register which is free and which must be immediately used to |
| // push on the top of the stack. |
| Register GetTOSRegister(); |
| |
| // Push multiple registers on the stack and the virtual frame |
| // Register are selected by setting bit in src_regs and |
| // are pushed in decreasing order: r15 .. r0. |
| void EmitPushMultiple(int count, int src_regs); |
| |
| static Register scratch0() { return r7; } |
| static Register scratch1() { return r9; } |
| |
| 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. |
| |
| // 5 states for the top of stack, which can be in memory or in r0 and r1. |
| enum TopOfStack { |
| NO_TOS_REGISTERS, |
| R0_TOS, |
| R1_TOS, |
| R1_R0_TOS, |
| R0_R1_TOS, |
| TOS_STATES |
| }; |
| |
| static const int kMaxTOSRegisters = 2; |
| |
| static const bool kR0InUse[TOS_STATES]; |
| static const bool kR1InUse[TOS_STATES]; |
| static const int kVirtualElements[TOS_STATES]; |
| static const TopOfStack kStateAfterPop[TOS_STATES]; |
| static const TopOfStack kStateAfterPush[TOS_STATES]; |
| static const Register kTopRegister[TOS_STATES]; |
| static const Register kBottomRegister[TOS_STATES]; |
| |
| // We allocate up to 5 locals in registers. |
| static const int kNumberOfAllocatedRegisters = 5; |
| // r2 to r6 are allocated to locals. |
| static const int kFirstAllocatedRegister = 2; |
| |
| static const Register kAllocatedRegisters[kNumberOfAllocatedRegisters]; |
| |
| static Register AllocatedRegister(int r) { |
| ASSERT(r >= 0 && r < kNumberOfAllocatedRegisters); |
| return kAllocatedRegisters[r]; |
| } |
| |
| // The number of elements on the stack frame. |
| int element_count_; |
| TopOfStack top_of_stack_state_:3; |
| int register_allocation_map_:kNumberOfAllocatedRegisters; |
| static const int kTOSKnownSmiMapSize = 4; |
| unsigned tos_known_smi_map_:kTOSKnownSmiMapSize; |
| |
| // The index of the element that is at the processor's stack pointer |
| // (the sp register). For now since everything is in memory it is given |
| // by the number of elements on the not-very-virtual stack frame. |
| int stack_pointer() { return element_count_ - 1; } |
| |
| // The number of frame-allocated locals and parameters respectively. |
| inline int parameter_count() const; |
| inline int local_count() const; |
| |
| // 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. |
| inline int frame_pointer() const; |
| |
| // 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 |
| // below the frame pointer. |
| inline int context_index(); |
| |
| // The index of the function slot in the frame. It is below the frame |
| // pointer and context slot. |
| inline int function_index(); |
| |
| // The index of the first local. Between the frame pointer and the |
| // locals lies the return address. |
| inline int local0_index() const; |
| |
| // The index of the base of the expression stack. |
| inline int expression_base_index() const; |
| |
| // Convert a frame index into a frame pointer relative offset into the |
| // actual stack. |
| inline int fp_relative(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); |
| |
| // If all top-of-stack registers are in use then the lowest one is pushed |
| // onto the physical stack and made free. |
| void EnsureOneFreeTOSRegister(); |
| |
| // Emit instructions to get the top of stack state from where we are to where |
| // we want to be. |
| void MergeTOSTo(TopOfStack expected_state, Condition cond = al); |
| |
| inline bool Equals(const VirtualFrame* other); |
| |
| inline void LowerHeight(int count) { |
| element_count_ -= count; |
| if (count >= kTOSKnownSmiMapSize) { |
| tos_known_smi_map_ = 0; |
| } else { |
| tos_known_smi_map_ >>= count; |
| } |
| } |
| |
| inline void RaiseHeight(int count, unsigned known_smi_map = 0) { |
| ASSERT(count >= 32 || known_smi_map < (1u << count)); |
| element_count_ += count; |
| if (count >= kTOSKnownSmiMapSize) { |
| tos_known_smi_map_ = known_smi_map; |
| } else { |
| tos_known_smi_map_ = ((tos_known_smi_map_ << count) | known_smi_map); |
| } |
| } |
| |
| friend class JumpTarget; |
| }; |
| |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_ARM_VIRTUAL_FRAME_ARM_H_ |