| // Copyright 2010 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, |
| // 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. |
| |
| #include "v8.h" |
| |
| #include "codegen-inl.h" |
| #include "register-allocator-inl.h" |
| #include "scopes.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| #define __ ACCESS_MASM(masm()) |
| |
| // ------------------------------------------------------------------------- |
| // VirtualFrame implementation. |
| |
| // On entry to a function, the virtual frame already contains the receiver, |
| // the parameters, and a return address. All frame elements are in memory. |
| VirtualFrame::VirtualFrame() |
| : elements_(parameter_count() + local_count() + kPreallocatedElements), |
| stack_pointer_(parameter_count() + 1) { // 0-based index of TOS. |
| for (int i = 0; i <= stack_pointer_; i++) { |
| elements_.Add(FrameElement::MemoryElement(NumberInfo::kUnknown)); |
| } |
| for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) { |
| register_locations_[i] = kIllegalIndex; |
| } |
| } |
| |
| |
| void VirtualFrame::Enter() { |
| // Registers live on entry to a JS frame: |
| // rsp: stack pointer, points to return address from this function. |
| // rbp: base pointer, points to previous JS, ArgumentsAdaptor, or |
| // Trampoline frame. |
| // rsi: context of this function call. |
| // rdi: pointer to this function object. |
| Comment cmnt(masm(), "[ Enter JS frame"); |
| |
| #ifdef DEBUG |
| if (FLAG_debug_code) { |
| // Verify that rdi contains a JS function. The following code |
| // relies on rax being available for use. |
| Condition not_smi = NegateCondition(masm()->CheckSmi(rdi)); |
| __ Check(not_smi, |
| "VirtualFrame::Enter - rdi is not a function (smi check)."); |
| __ CmpObjectType(rdi, JS_FUNCTION_TYPE, rax); |
| __ Check(equal, |
| "VirtualFrame::Enter - rdi is not a function (map check)."); |
| } |
| #endif |
| |
| EmitPush(rbp); |
| |
| __ movq(rbp, rsp); |
| |
| // Store the context in the frame. The context is kept in rsi and a |
| // copy is stored in the frame. The external reference to rsi |
| // remains. |
| EmitPush(rsi); |
| |
| // Store the function in the frame. The frame owns the register |
| // reference now (ie, it can keep it in rdi or spill it later). |
| Push(rdi); |
| SyncElementAt(element_count() - 1); |
| cgen()->allocator()->Unuse(rdi); |
| } |
| |
| |
| void VirtualFrame::Exit() { |
| Comment cmnt(masm(), "[ Exit JS frame"); |
| // Record the location of the JS exit code for patching when setting |
| // break point. |
| __ RecordJSReturn(); |
| |
| // Avoid using the leave instruction here, because it is too |
| // short. We need the return sequence to be a least the size of a |
| // call instruction to support patching the exit code in the |
| // debugger. See GenerateReturnSequence for the full return sequence. |
| // TODO(X64): A patched call will be very long now. Make sure we |
| // have enough room. |
| __ movq(rsp, rbp); |
| stack_pointer_ = frame_pointer(); |
| for (int i = element_count() - 1; i > stack_pointer_; i--) { |
| FrameElement last = elements_.RemoveLast(); |
| if (last.is_register()) { |
| Unuse(last.reg()); |
| } |
| } |
| |
| EmitPop(rbp); |
| } |
| |
| |
| void VirtualFrame::AllocateStackSlots() { |
| int count = local_count(); |
| if (count > 0) { |
| Comment cmnt(masm(), "[ Allocate space for locals"); |
| // The locals are initialized to a constant (the undefined value), but |
| // we sync them with the actual frame to allocate space for spilling |
| // them later. First sync everything above the stack pointer so we can |
| // use pushes to allocate and initialize the locals. |
| SyncRange(stack_pointer_ + 1, element_count() - 1); |
| Handle<Object> undefined = Factory::undefined_value(); |
| FrameElement initial_value = |
| FrameElement::ConstantElement(undefined, FrameElement::SYNCED); |
| if (count == 1) { |
| __ Push(undefined); |
| } else if (count < kLocalVarBound) { |
| // For less locals the unrolled loop is more compact. |
| __ movq(kScratchRegister, undefined, RelocInfo::EMBEDDED_OBJECT); |
| for (int i = 0; i < count; i++) { |
| __ push(kScratchRegister); |
| } |
| } else { |
| // For more locals a loop in generated code is more compact. |
| Label alloc_locals_loop; |
| Result cnt = cgen()->allocator()->Allocate(); |
| ASSERT(cnt.is_valid()); |
| __ movq(cnt.reg(), Immediate(count)); |
| __ movq(kScratchRegister, undefined, RelocInfo::EMBEDDED_OBJECT); |
| __ bind(&alloc_locals_loop); |
| __ push(kScratchRegister); |
| __ decl(cnt.reg()); |
| __ j(not_zero, &alloc_locals_loop); |
| } |
| for (int i = 0; i < count; i++) { |
| elements_.Add(initial_value); |
| stack_pointer_++; |
| } |
| } |
| } |
| |
| |
| void VirtualFrame::SaveContextRegister() { |
| ASSERT(elements_[context_index()].is_memory()); |
| __ movq(Operand(rbp, fp_relative(context_index())), rsi); |
| } |
| |
| |
| void VirtualFrame::RestoreContextRegister() { |
| ASSERT(elements_[context_index()].is_memory()); |
| __ movq(rsi, Operand(rbp, fp_relative(context_index()))); |
| } |
| |
| |
| void VirtualFrame::PushReceiverSlotAddress() { |
| Result temp = cgen()->allocator()->Allocate(); |
| ASSERT(temp.is_valid()); |
| __ lea(temp.reg(), ParameterAt(-1)); |
| Push(&temp); |
| } |
| |
| |
| void VirtualFrame::EmitPop(Register reg) { |
| ASSERT(stack_pointer_ == element_count() - 1); |
| stack_pointer_--; |
| elements_.RemoveLast(); |
| __ pop(reg); |
| } |
| |
| |
| void VirtualFrame::EmitPop(const Operand& operand) { |
| ASSERT(stack_pointer_ == element_count() - 1); |
| stack_pointer_--; |
| elements_.RemoveLast(); |
| __ pop(operand); |
| } |
| |
| |
| void VirtualFrame::EmitPush(Register reg, NumberInfo::Type info) { |
| ASSERT(stack_pointer_ == element_count() - 1); |
| elements_.Add(FrameElement::MemoryElement(info)); |
| stack_pointer_++; |
| __ push(reg); |
| } |
| |
| |
| void VirtualFrame::EmitPush(const Operand& operand, NumberInfo::Type info) { |
| ASSERT(stack_pointer_ == element_count() - 1); |
| elements_.Add(FrameElement::MemoryElement(info)); |
| stack_pointer_++; |
| __ push(operand); |
| } |
| |
| |
| void VirtualFrame::EmitPush(Immediate immediate, NumberInfo::Type info) { |
| ASSERT(stack_pointer_ == element_count() - 1); |
| elements_.Add(FrameElement::MemoryElement(info)); |
| stack_pointer_++; |
| __ push(immediate); |
| } |
| |
| |
| void VirtualFrame::EmitPush(Smi* smi_value) { |
| ASSERT(stack_pointer_ == element_count() - 1); |
| elements_.Add(FrameElement::MemoryElement(NumberInfo::kSmi)); |
| stack_pointer_++; |
| __ Push(smi_value); |
| } |
| |
| |
| void VirtualFrame::EmitPush(Handle<Object> value) { |
| ASSERT(stack_pointer_ == element_count() - 1); |
| NumberInfo::Type info = NumberInfo::kUnknown; |
| if (value->IsSmi()) { |
| info = NumberInfo::kSmi; |
| } else if (value->IsHeapNumber()) { |
| info = NumberInfo::kHeapNumber; |
| } |
| elements_.Add(FrameElement::MemoryElement(info)); |
| stack_pointer_++; |
| __ Push(value); |
| } |
| |
| |
| void VirtualFrame::EmitPush(Heap::RootListIndex index, NumberInfo::Type info) { |
| ASSERT(stack_pointer_ == element_count() - 1); |
| elements_.Add(FrameElement::MemoryElement(info)); |
| stack_pointer_++; |
| __ PushRoot(index); |
| } |
| |
| |
| void VirtualFrame::Drop(int count) { |
| ASSERT(count >= 0); |
| ASSERT(height() >= count); |
| int num_virtual_elements = (element_count() - 1) - stack_pointer_; |
| |
| // Emit code to lower the stack pointer if necessary. |
| if (num_virtual_elements < count) { |
| int num_dropped = count - num_virtual_elements; |
| stack_pointer_ -= num_dropped; |
| __ addq(rsp, Immediate(num_dropped * kPointerSize)); |
| } |
| |
| // Discard elements from the virtual frame and free any registers. |
| for (int i = 0; i < count; i++) { |
| FrameElement dropped = elements_.RemoveLast(); |
| if (dropped.is_register()) { |
| Unuse(dropped.reg()); |
| } |
| } |
| } |
| |
| |
| int VirtualFrame::InvalidateFrameSlotAt(int index) { |
| FrameElement original = elements_[index]; |
| |
| // Is this element the backing store of any copies? |
| int new_backing_index = kIllegalIndex; |
| if (original.is_copied()) { |
| // Verify it is copied, and find first copy. |
| for (int i = index + 1; i < element_count(); i++) { |
| if (elements_[i].is_copy() && elements_[i].index() == index) { |
| new_backing_index = i; |
| break; |
| } |
| } |
| } |
| |
| if (new_backing_index == kIllegalIndex) { |
| // No copies found, return kIllegalIndex. |
| if (original.is_register()) { |
| Unuse(original.reg()); |
| } |
| elements_[index] = FrameElement::InvalidElement(); |
| return kIllegalIndex; |
| } |
| |
| // This is the backing store of copies. |
| Register backing_reg; |
| if (original.is_memory()) { |
| Result fresh = cgen()->allocator()->Allocate(); |
| ASSERT(fresh.is_valid()); |
| Use(fresh.reg(), new_backing_index); |
| backing_reg = fresh.reg(); |
| __ movq(backing_reg, Operand(rbp, fp_relative(index))); |
| } else { |
| // The original was in a register. |
| backing_reg = original.reg(); |
| set_register_location(backing_reg, new_backing_index); |
| } |
| // Invalidate the element at index. |
| elements_[index] = FrameElement::InvalidElement(); |
| // Set the new backing element. |
| if (elements_[new_backing_index].is_synced()) { |
| elements_[new_backing_index] = |
| FrameElement::RegisterElement(backing_reg, |
| FrameElement::SYNCED, |
| original.number_info()); |
| } else { |
| elements_[new_backing_index] = |
| FrameElement::RegisterElement(backing_reg, |
| FrameElement::NOT_SYNCED, |
| original.number_info()); |
| } |
| // Update the other copies. |
| for (int i = new_backing_index + 1; i < element_count(); i++) { |
| if (elements_[i].is_copy() && elements_[i].index() == index) { |
| elements_[i].set_index(new_backing_index); |
| elements_[new_backing_index].set_copied(); |
| } |
| } |
| return new_backing_index; |
| } |
| |
| |
| void VirtualFrame::TakeFrameSlotAt(int index) { |
| ASSERT(index >= 0); |
| ASSERT(index <= element_count()); |
| FrameElement original = elements_[index]; |
| int new_backing_store_index = InvalidateFrameSlotAt(index); |
| if (new_backing_store_index != kIllegalIndex) { |
| elements_.Add(CopyElementAt(new_backing_store_index)); |
| return; |
| } |
| |
| switch (original.type()) { |
| case FrameElement::MEMORY: { |
| // Emit code to load the original element's data into a register. |
| // Push that register as a FrameElement on top of the frame. |
| Result fresh = cgen()->allocator()->Allocate(); |
| ASSERT(fresh.is_valid()); |
| FrameElement new_element = |
| FrameElement::RegisterElement(fresh.reg(), |
| FrameElement::NOT_SYNCED, |
| original.number_info()); |
| Use(fresh.reg(), element_count()); |
| elements_.Add(new_element); |
| __ movq(fresh.reg(), Operand(rbp, fp_relative(index))); |
| break; |
| } |
| case FrameElement::REGISTER: |
| Use(original.reg(), element_count()); |
| // Fall through. |
| case FrameElement::CONSTANT: |
| case FrameElement::COPY: |
| original.clear_sync(); |
| elements_.Add(original); |
| break; |
| case FrameElement::INVALID: |
| UNREACHABLE(); |
| break; |
| } |
| } |
| |
| |
| void VirtualFrame::StoreToFrameSlotAt(int index) { |
| // Store the value on top of the frame to the virtual frame slot at |
| // a given index. The value on top of the frame is left in place. |
| // This is a duplicating operation, so it can create copies. |
| ASSERT(index >= 0); |
| ASSERT(index < element_count()); |
| |
| int top_index = element_count() - 1; |
| FrameElement top = elements_[top_index]; |
| FrameElement original = elements_[index]; |
| if (top.is_copy() && top.index() == index) return; |
| ASSERT(top.is_valid()); |
| |
| InvalidateFrameSlotAt(index); |
| |
| // InvalidateFrameSlotAt can potentially change any frame element, due |
| // to spilling registers to allocate temporaries in order to preserve |
| // the copy-on-write semantics of aliased elements. Reload top from |
| // the frame. |
| top = elements_[top_index]; |
| |
| if (top.is_copy()) { |
| // There are two cases based on the relative positions of the |
| // stored-to slot and the backing slot of the top element. |
| int backing_index = top.index(); |
| ASSERT(backing_index != index); |
| if (backing_index < index) { |
| // 1. The top element is a copy of a slot below the stored-to |
| // slot. The stored-to slot becomes an unsynced copy of that |
| // same backing slot. |
| elements_[index] = CopyElementAt(backing_index); |
| } else { |
| // 2. The top element is a copy of a slot above the stored-to |
| // slot. The stored-to slot becomes the new (unsynced) backing |
| // slot and both the top element and the element at the former |
| // backing slot become copies of it. The sync state of the top |
| // and former backing elements is preserved. |
| FrameElement backing_element = elements_[backing_index]; |
| ASSERT(backing_element.is_memory() || backing_element.is_register()); |
| if (backing_element.is_memory()) { |
| // Because sets of copies are canonicalized to be backed by |
| // their lowest frame element, and because memory frame |
| // elements are backed by the corresponding stack address, we |
| // have to move the actual value down in the stack. |
| // |
| // TODO(209): considering allocating the stored-to slot to the |
| // temp register. Alternatively, allow copies to appear in |
| // any order in the frame and lazily move the value down to |
| // the slot. |
| __ movq(kScratchRegister, Operand(rbp, fp_relative(backing_index))); |
| __ movq(Operand(rbp, fp_relative(index)), kScratchRegister); |
| } else { |
| set_register_location(backing_element.reg(), index); |
| if (backing_element.is_synced()) { |
| // If the element is a register, we will not actually move |
| // anything on the stack but only update the virtual frame |
| // element. |
| backing_element.clear_sync(); |
| } |
| } |
| elements_[index] = backing_element; |
| |
| // The old backing element becomes a copy of the new backing |
| // element. |
| FrameElement new_element = CopyElementAt(index); |
| elements_[backing_index] = new_element; |
| if (backing_element.is_synced()) { |
| elements_[backing_index].set_sync(); |
| } |
| |
| // All the copies of the old backing element (including the top |
| // element) become copies of the new backing element. |
| for (int i = backing_index + 1; i < element_count(); i++) { |
| if (elements_[i].is_copy() && elements_[i].index() == backing_index) { |
| elements_[i].set_index(index); |
| } |
| } |
| } |
| return; |
| } |
| |
| // Move the top element to the stored-to slot and replace it (the |
| // top element) with a copy. |
| elements_[index] = top; |
| if (top.is_memory()) { |
| // TODO(209): consider allocating the stored-to slot to the temp |
| // register. Alternatively, allow copies to appear in any order |
| // in the frame and lazily move the value down to the slot. |
| FrameElement new_top = CopyElementAt(index); |
| new_top.set_sync(); |
| elements_[top_index] = new_top; |
| |
| // The sync state of the former top element is correct (synced). |
| // Emit code to move the value down in the frame. |
| __ movq(kScratchRegister, Operand(rsp, 0)); |
| __ movq(Operand(rbp, fp_relative(index)), kScratchRegister); |
| } else if (top.is_register()) { |
| set_register_location(top.reg(), index); |
| // The stored-to slot has the (unsynced) register reference and |
| // the top element becomes a copy. The sync state of the top is |
| // preserved. |
| FrameElement new_top = CopyElementAt(index); |
| if (top.is_synced()) { |
| new_top.set_sync(); |
| elements_[index].clear_sync(); |
| } |
| elements_[top_index] = new_top; |
| } else { |
| // The stored-to slot holds the same value as the top but |
| // unsynced. (We do not have copies of constants yet.) |
| ASSERT(top.is_constant()); |
| elements_[index].clear_sync(); |
| } |
| } |
| |
| |
| void VirtualFrame::MakeMergable() { |
| for (int i = 0; i < element_count(); i++) { |
| FrameElement element = elements_[i]; |
| |
| // In all cases we have to reset the number type information |
| // to unknown for a mergable frame because of incoming back edges. |
| if (element.is_constant() || element.is_copy()) { |
| if (element.is_synced()) { |
| // Just spill. |
| elements_[i] = FrameElement::MemoryElement(NumberInfo::kUnknown); |
| } else { |
| // Allocate to a register. |
| FrameElement backing_element; // Invalid if not a copy. |
| if (element.is_copy()) { |
| backing_element = elements_[element.index()]; |
| } |
| Result fresh = cgen()->allocator()->Allocate(); |
| ASSERT(fresh.is_valid()); // A register was spilled if all were in use. |
| elements_[i] = |
| FrameElement::RegisterElement(fresh.reg(), |
| FrameElement::NOT_SYNCED, |
| NumberInfo::kUnknown); |
| Use(fresh.reg(), i); |
| |
| // Emit a move. |
| if (element.is_constant()) { |
| __ Move(fresh.reg(), element.handle()); |
| } else { |
| ASSERT(element.is_copy()); |
| // Copies are only backed by register or memory locations. |
| if (backing_element.is_register()) { |
| // The backing store may have been spilled by allocating, |
| // but that's OK. If it was, the value is right where we |
| // want it. |
| if (!fresh.reg().is(backing_element.reg())) { |
| __ movq(fresh.reg(), backing_element.reg()); |
| } |
| } else { |
| ASSERT(backing_element.is_memory()); |
| __ movq(fresh.reg(), Operand(rbp, fp_relative(element.index()))); |
| } |
| } |
| } |
| // No need to set the copied flag --- there are no copies. |
| } else { |
| // Clear the copy flag of non-constant, non-copy elements. |
| // They cannot be copied because copies are not allowed. |
| // The copy flag is not relied on before the end of this loop, |
| // including when registers are spilled. |
| elements_[i].clear_copied(); |
| elements_[i].set_number_info(NumberInfo::kUnknown); |
| } |
| } |
| } |
| |
| |
| void VirtualFrame::MergeTo(VirtualFrame* expected) { |
| Comment cmnt(masm(), "[ Merge frame"); |
| // We should always be merging the code generator's current frame to an |
| // expected frame. |
| ASSERT(cgen()->frame() == this); |
| |
| // Adjust the stack pointer upward (toward the top of the virtual |
| // frame) if necessary. |
| if (stack_pointer_ < expected->stack_pointer_) { |
| int difference = expected->stack_pointer_ - stack_pointer_; |
| stack_pointer_ = expected->stack_pointer_; |
| __ subq(rsp, Immediate(difference * kPointerSize)); |
| } |
| |
| MergeMoveRegistersToMemory(expected); |
| MergeMoveRegistersToRegisters(expected); |
| MergeMoveMemoryToRegisters(expected); |
| |
| // Adjust the stack pointer downward if necessary. |
| if (stack_pointer_ > expected->stack_pointer_) { |
| int difference = stack_pointer_ - expected->stack_pointer_; |
| stack_pointer_ = expected->stack_pointer_; |
| __ addq(rsp, Immediate(difference * kPointerSize)); |
| } |
| |
| // At this point, the frames should be identical. |
| ASSERT(Equals(expected)); |
| } |
| |
| |
| void VirtualFrame::MergeMoveRegistersToMemory(VirtualFrame* expected) { |
| ASSERT(stack_pointer_ >= expected->stack_pointer_); |
| |
| // Move registers, constants, and copies to memory. Perform moves |
| // from the top downward in the frame in order to leave the backing |
| // stores of copies in registers. |
| for (int i = element_count() - 1; i >= 0; i--) { |
| FrameElement target = expected->elements_[i]; |
| if (target.is_register()) continue; // Handle registers later. |
| if (target.is_memory()) { |
| FrameElement source = elements_[i]; |
| switch (source.type()) { |
| case FrameElement::INVALID: |
| // Not a legal merge move. |
| UNREACHABLE(); |
| break; |
| |
| case FrameElement::MEMORY: |
| // Already in place. |
| break; |
| |
| case FrameElement::REGISTER: |
| Unuse(source.reg()); |
| if (!source.is_synced()) { |
| __ movq(Operand(rbp, fp_relative(i)), source.reg()); |
| } |
| break; |
| |
| case FrameElement::CONSTANT: |
| if (!source.is_synced()) { |
| __ Move(Operand(rbp, fp_relative(i)), source.handle()); |
| } |
| break; |
| |
| case FrameElement::COPY: |
| if (!source.is_synced()) { |
| int backing_index = source.index(); |
| FrameElement backing_element = elements_[backing_index]; |
| if (backing_element.is_memory()) { |
| __ movq(kScratchRegister, |
| Operand(rbp, fp_relative(backing_index))); |
| __ movq(Operand(rbp, fp_relative(i)), kScratchRegister); |
| } else { |
| ASSERT(backing_element.is_register()); |
| __ movq(Operand(rbp, fp_relative(i)), backing_element.reg()); |
| } |
| } |
| break; |
| } |
| } |
| elements_[i] = target; |
| } |
| } |
| |
| |
| void VirtualFrame::MergeMoveRegistersToRegisters(VirtualFrame* expected) { |
| // We have already done X-to-memory moves. |
| ASSERT(stack_pointer_ >= expected->stack_pointer_); |
| |
| for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) { |
| // Move the right value into register i if it is currently in a register. |
| int index = expected->register_location(i); |
| int use_index = register_location(i); |
| // Skip if register i is unused in the target or else if source is |
| // not a register (this is not a register-to-register move). |
| if (index == kIllegalIndex || !elements_[index].is_register()) continue; |
| |
| Register target = RegisterAllocator::ToRegister(i); |
| Register source = elements_[index].reg(); |
| if (index != use_index) { |
| if (use_index == kIllegalIndex) { // Target is currently unused. |
| // Copy contents of source from source to target. |
| // Set frame element register to target. |
| Use(target, index); |
| Unuse(source); |
| __ movq(target, source); |
| } else { |
| // Exchange contents of registers source and target. |
| // Nothing except the register backing use_index has changed. |
| elements_[use_index].set_reg(source); |
| set_register_location(target, index); |
| set_register_location(source, use_index); |
| __ xchg(source, target); |
| } |
| } |
| |
| if (!elements_[index].is_synced() && |
| expected->elements_[index].is_synced()) { |
| __ movq(Operand(rbp, fp_relative(index)), target); |
| } |
| elements_[index] = expected->elements_[index]; |
| } |
| } |
| |
| |
| void VirtualFrame::MergeMoveMemoryToRegisters(VirtualFrame* expected) { |
| // Move memory, constants, and copies to registers. This is the |
| // final step and since it is not done from the bottom up, but in |
| // register code order, we have special code to ensure that the backing |
| // elements of copies are in their correct locations when we |
| // encounter the copies. |
| for (int i = 0; i < RegisterAllocator::kNumRegisters; i++) { |
| int index = expected->register_location(i); |
| if (index != kIllegalIndex) { |
| FrameElement source = elements_[index]; |
| FrameElement target = expected->elements_[index]; |
| Register target_reg = RegisterAllocator::ToRegister(i); |
| ASSERT(target.reg().is(target_reg)); |
| switch (source.type()) { |
| case FrameElement::INVALID: // Fall through. |
| UNREACHABLE(); |
| break; |
| case FrameElement::REGISTER: |
| ASSERT(source.Equals(target)); |
| // Go to next iteration. Skips Use(target_reg) and syncing |
| // below. It is safe to skip syncing because a target |
| // register frame element would only be synced if all source |
| // elements were. |
| continue; |
| break; |
| case FrameElement::MEMORY: |
| ASSERT(index <= stack_pointer_); |
| __ movq(target_reg, Operand(rbp, fp_relative(index))); |
| break; |
| |
| case FrameElement::CONSTANT: |
| __ Move(target_reg, source.handle()); |
| break; |
| |
| case FrameElement::COPY: { |
| int backing_index = source.index(); |
| FrameElement backing = elements_[backing_index]; |
| ASSERT(backing.is_memory() || backing.is_register()); |
| if (backing.is_memory()) { |
| ASSERT(backing_index <= stack_pointer_); |
| // Code optimization if backing store should also move |
| // to a register: move backing store to its register first. |
| if (expected->elements_[backing_index].is_register()) { |
| FrameElement new_backing = expected->elements_[backing_index]; |
| Register new_backing_reg = new_backing.reg(); |
| ASSERT(!is_used(new_backing_reg)); |
| elements_[backing_index] = new_backing; |
| Use(new_backing_reg, backing_index); |
| __ movq(new_backing_reg, |
| Operand(rbp, fp_relative(backing_index))); |
| __ movq(target_reg, new_backing_reg); |
| } else { |
| __ movq(target_reg, Operand(rbp, fp_relative(backing_index))); |
| } |
| } else { |
| __ movq(target_reg, backing.reg()); |
| } |
| } |
| } |
| // Ensure the proper sync state. |
| if (target.is_synced() && !source.is_synced()) { |
| __ movq(Operand(rbp, fp_relative(index)), target_reg); |
| } |
| Use(target_reg, index); |
| elements_[index] = target; |
| } |
| } |
| } |
| |
| |
| Result VirtualFrame::Pop() { |
| FrameElement element = elements_.RemoveLast(); |
| int index = element_count(); |
| ASSERT(element.is_valid()); |
| |
| // Get number type information of the result. |
| NumberInfo::Type info; |
| if (!element.is_copy()) { |
| info = element.number_info(); |
| } else { |
| info = elements_[element.index()].number_info(); |
| } |
| |
| bool pop_needed = (stack_pointer_ == index); |
| if (pop_needed) { |
| stack_pointer_--; |
| if (element.is_memory()) { |
| Result temp = cgen()->allocator()->Allocate(); |
| ASSERT(temp.is_valid()); |
| __ pop(temp.reg()); |
| temp.set_number_info(info); |
| return temp; |
| } |
| |
| __ addq(rsp, Immediate(kPointerSize)); |
| } |
| ASSERT(!element.is_memory()); |
| |
| // The top element is a register, constant, or a copy. Unuse |
| // registers and follow copies to their backing store. |
| if (element.is_register()) { |
| Unuse(element.reg()); |
| } else if (element.is_copy()) { |
| ASSERT(element.index() < index); |
| index = element.index(); |
| element = elements_[index]; |
| } |
| ASSERT(!element.is_copy()); |
| |
| // The element is memory, a register, or a constant. |
| if (element.is_memory()) { |
| // Memory elements could only be the backing store of a copy. |
| // Allocate the original to a register. |
| ASSERT(index <= stack_pointer_); |
| Result temp = cgen()->allocator()->Allocate(); |
| ASSERT(temp.is_valid()); |
| Use(temp.reg(), index); |
| FrameElement new_element = |
| FrameElement::RegisterElement(temp.reg(), |
| FrameElement::SYNCED, |
| element.number_info()); |
| // Preserve the copy flag on the element. |
| if (element.is_copied()) new_element.set_copied(); |
| elements_[index] = new_element; |
| __ movq(temp.reg(), Operand(rbp, fp_relative(index))); |
| return Result(temp.reg(), info); |
| } else if (element.is_register()) { |
| return Result(element.reg(), info); |
| } else { |
| ASSERT(element.is_constant()); |
| return Result(element.handle()); |
| } |
| } |
| |
| |
| Result VirtualFrame::RawCallStub(CodeStub* stub) { |
| ASSERT(cgen()->HasValidEntryRegisters()); |
| __ CallStub(stub); |
| Result result = cgen()->allocator()->Allocate(rax); |
| ASSERT(result.is_valid()); |
| return result; |
| } |
| |
| |
| Result VirtualFrame::CallStub(CodeStub* stub, Result* arg) { |
| PrepareForCall(0, 0); |
| arg->ToRegister(rax); |
| arg->Unuse(); |
| return RawCallStub(stub); |
| } |
| |
| |
| Result VirtualFrame::CallStub(CodeStub* stub, Result* arg0, Result* arg1) { |
| PrepareForCall(0, 0); |
| |
| if (arg0->is_register() && arg0->reg().is(rax)) { |
| if (arg1->is_register() && arg1->reg().is(rdx)) { |
| // Wrong registers. |
| __ xchg(rax, rdx); |
| } else { |
| // Register rdx is free for arg0, which frees rax for arg1. |
| arg0->ToRegister(rdx); |
| arg1->ToRegister(rax); |
| } |
| } else { |
| // Register rax is free for arg1, which guarantees rdx is free for |
| // arg0. |
| arg1->ToRegister(rax); |
| arg0->ToRegister(rdx); |
| } |
| |
| arg0->Unuse(); |
| arg1->Unuse(); |
| return RawCallStub(stub); |
| } |
| |
| |
| void VirtualFrame::SyncElementBelowStackPointer(int index) { |
| // Emit code to write elements below the stack pointer to their |
| // (already allocated) stack address. |
| ASSERT(index <= stack_pointer_); |
| FrameElement element = elements_[index]; |
| ASSERT(!element.is_synced()); |
| switch (element.type()) { |
| case FrameElement::INVALID: |
| break; |
| |
| case FrameElement::MEMORY: |
| // This function should not be called with synced elements. |
| // (memory elements are always synced). |
| UNREACHABLE(); |
| break; |
| |
| case FrameElement::REGISTER: |
| __ movq(Operand(rbp, fp_relative(index)), element.reg()); |
| break; |
| |
| case FrameElement::CONSTANT: |
| __ Move(Operand(rbp, fp_relative(index)), element.handle()); |
| break; |
| |
| case FrameElement::COPY: { |
| int backing_index = element.index(); |
| FrameElement backing_element = elements_[backing_index]; |
| if (backing_element.is_memory()) { |
| __ movq(kScratchRegister, Operand(rbp, fp_relative(backing_index))); |
| __ movq(Operand(rbp, fp_relative(index)), kScratchRegister); |
| } else { |
| ASSERT(backing_element.is_register()); |
| __ movq(Operand(rbp, fp_relative(index)), backing_element.reg()); |
| } |
| break; |
| } |
| } |
| elements_[index].set_sync(); |
| } |
| |
| |
| void VirtualFrame::SyncElementByPushing(int index) { |
| // Sync an element of the frame that is just above the stack pointer |
| // by pushing it. |
| ASSERT(index == stack_pointer_ + 1); |
| stack_pointer_++; |
| FrameElement element = elements_[index]; |
| |
| switch (element.type()) { |
| case FrameElement::INVALID: |
| __ Push(Smi::FromInt(0)); |
| break; |
| |
| case FrameElement::MEMORY: |
| // No memory elements exist above the stack pointer. |
| UNREACHABLE(); |
| break; |
| |
| case FrameElement::REGISTER: |
| __ push(element.reg()); |
| break; |
| |
| case FrameElement::CONSTANT: |
| __ Move(kScratchRegister, element.handle()); |
| __ push(kScratchRegister); |
| break; |
| |
| case FrameElement::COPY: { |
| int backing_index = element.index(); |
| FrameElement backing = elements_[backing_index]; |
| ASSERT(backing.is_memory() || backing.is_register()); |
| if (backing.is_memory()) { |
| __ push(Operand(rbp, fp_relative(backing_index))); |
| } else { |
| __ push(backing.reg()); |
| } |
| break; |
| } |
| } |
| elements_[index].set_sync(); |
| } |
| |
| |
| // Clear the dirty bits for the range of elements in |
| // [min(stack_pointer_ + 1,begin), end]. |
| void VirtualFrame::SyncRange(int begin, int end) { |
| ASSERT(begin >= 0); |
| ASSERT(end < element_count()); |
| // Sync elements below the range if they have not been materialized |
| // on the stack. |
| int start = Min(begin, stack_pointer_ + 1); |
| |
| // If positive we have to adjust the stack pointer. |
| int delta = end - stack_pointer_; |
| if (delta > 0) { |
| stack_pointer_ = end; |
| __ subq(rsp, Immediate(delta * kPointerSize)); |
| } |
| |
| for (int i = start; i <= end; i++) { |
| if (!elements_[i].is_synced()) SyncElementBelowStackPointer(i); |
| } |
| } |
| |
| |
| Result VirtualFrame::InvokeBuiltin(Builtins::JavaScript id, |
| InvokeFlag flag, |
| int arg_count) { |
| PrepareForCall(arg_count, arg_count); |
| ASSERT(cgen()->HasValidEntryRegisters()); |
| __ InvokeBuiltin(id, flag); |
| Result result = cgen()->allocator()->Allocate(rax); |
| ASSERT(result.is_valid()); |
| return result; |
| } |
| |
| |
| //------------------------------------------------------------------------------ |
| // Virtual frame stub and IC calling functions. |
| |
| Result VirtualFrame::RawCallCodeObject(Handle<Code> code, |
| RelocInfo::Mode rmode) { |
| ASSERT(cgen()->HasValidEntryRegisters()); |
| __ Call(code, rmode); |
| Result result = cgen()->allocator()->Allocate(rax); |
| ASSERT(result.is_valid()); |
| return result; |
| } |
| |
| |
| Result VirtualFrame::CallRuntime(Runtime::Function* f, int arg_count) { |
| PrepareForCall(arg_count, arg_count); |
| ASSERT(cgen()->HasValidEntryRegisters()); |
| __ CallRuntime(f, arg_count); |
| Result result = cgen()->allocator()->Allocate(rax); |
| ASSERT(result.is_valid()); |
| return result; |
| } |
| |
| |
| Result VirtualFrame::CallRuntime(Runtime::FunctionId id, int arg_count) { |
| PrepareForCall(arg_count, arg_count); |
| ASSERT(cgen()->HasValidEntryRegisters()); |
| __ CallRuntime(id, arg_count); |
| Result result = cgen()->allocator()->Allocate(rax); |
| ASSERT(result.is_valid()); |
| return result; |
| } |
| |
| |
| #ifdef ENABLE_DEBUGGER_SUPPORT |
| void VirtualFrame::DebugBreak() { |
| PrepareForCall(0, 0); |
| ASSERT(cgen()->HasValidEntryRegisters()); |
| __ DebugBreak(); |
| Result result = cgen()->allocator()->Allocate(rax); |
| ASSERT(result.is_valid()); |
| } |
| #endif |
| |
| |
| Result VirtualFrame::CallLoadIC(RelocInfo::Mode mode) { |
| // Name and receiver are on the top of the frame. The IC expects |
| // name in rcx and receiver on the stack. It does not drop the |
| // receiver. |
| Handle<Code> ic(Builtins::builtin(Builtins::LoadIC_Initialize)); |
| Result name = Pop(); |
| PrepareForCall(1, 0); // One stack arg, not callee-dropped. |
| name.ToRegister(rcx); |
| name.Unuse(); |
| return RawCallCodeObject(ic, mode); |
| } |
| |
| |
| Result VirtualFrame::CallKeyedLoadIC(RelocInfo::Mode mode) { |
| // Key and receiver are on top of the frame. The IC expects them on |
| // the stack. It does not drop them. |
| Handle<Code> ic(Builtins::builtin(Builtins::KeyedLoadIC_Initialize)); |
| PrepareForCall(2, 0); // Two stack args, neither callee-dropped. |
| return RawCallCodeObject(ic, mode); |
| } |
| |
| |
| Result VirtualFrame::CallKeyedStoreIC() { |
| // Value, key, and receiver are on the top of the frame. The IC |
| // expects value in rax and key and receiver on the stack. It does |
| // not drop the key and receiver. |
| Handle<Code> ic(Builtins::builtin(Builtins::KeyedStoreIC_Initialize)); |
| Result value = Pop(); |
| PrepareForCall(2, 0); // Two stack args, neither callee-dropped. |
| value.ToRegister(rax); |
| value.Unuse(); |
| return RawCallCodeObject(ic, RelocInfo::CODE_TARGET); |
| } |
| |
| |
| Result VirtualFrame::CallCallIC(RelocInfo::Mode mode, |
| int arg_count, |
| int loop_nesting) { |
| // Function name, arguments, and receiver are found on top of the frame |
| // and dropped by the call. The IC expects the name in rcx and the rest |
| // on the stack, and drops them all. |
| InLoopFlag in_loop = loop_nesting > 0 ? IN_LOOP : NOT_IN_LOOP; |
| Handle<Code> ic = cgen()->ComputeCallInitialize(arg_count, in_loop); |
| Result name = Pop(); |
| // Spill args, receiver, and function. The call will drop args and |
| // receiver. |
| PrepareForCall(arg_count + 1, arg_count + 1); |
| name.ToRegister(rcx); |
| name.Unuse(); |
| return RawCallCodeObject(ic, mode); |
| } |
| |
| |
| Result VirtualFrame::CallConstructor(int arg_count) { |
| // Arguments, receiver, and function are on top of the frame. The |
| // IC expects arg count in rax, function in rdi, and the arguments |
| // and receiver on the stack. |
| Handle<Code> ic(Builtins::builtin(Builtins::JSConstructCall)); |
| // Duplicate the function before preparing the frame. |
| PushElementAt(arg_count + 1); |
| Result function = Pop(); |
| PrepareForCall(arg_count + 1, arg_count + 1); // Spill args and receiver. |
| function.ToRegister(rdi); |
| |
| // Constructors are called with the number of arguments in register |
| // rax for now. Another option would be to have separate construct |
| // call trampolines per different arguments counts encountered. |
| Result num_args = cgen()->allocator()->Allocate(rax); |
| ASSERT(num_args.is_valid()); |
| __ movq(num_args.reg(), Immediate(arg_count)); |
| |
| function.Unuse(); |
| num_args.Unuse(); |
| return RawCallCodeObject(ic, RelocInfo::CONSTRUCT_CALL); |
| } |
| |
| |
| Result VirtualFrame::CallStoreIC() { |
| // Name, value, and receiver are on top of the frame. The IC |
| // expects name in rcx, value in rax, and receiver in edx. |
| Handle<Code> ic(Builtins::builtin(Builtins::StoreIC_Initialize)); |
| Result name = Pop(); |
| Result value = Pop(); |
| Result receiver = Pop(); |
| PrepareForCall(0, 0); |
| |
| // Optimized for case in which name is a constant value. |
| if (name.is_register() && (name.reg().is(rdx) || name.reg().is(rax))) { |
| if (!is_used(rcx)) { |
| name.ToRegister(rcx); |
| } else if (!is_used(rbx)) { |
| name.ToRegister(rbx); |
| } else { |
| ASSERT(!is_used(rdi)); // Only three results are live, so rdi is free. |
| name.ToRegister(rdi); |
| } |
| } |
| // Now name is not in edx or eax, so we can fix them, then move name to ecx. |
| if (value.is_register() && value.reg().is(rdx)) { |
| if (receiver.is_register() && receiver.reg().is(rax)) { |
| // Wrong registers. |
| __ xchg(rax, rdx); |
| } else { |
| // Register rax is free for value, which frees rcx for receiver. |
| value.ToRegister(rax); |
| receiver.ToRegister(rdx); |
| } |
| } else { |
| // Register rcx is free for receiver, which guarantees rax is free for |
| // value. |
| receiver.ToRegister(rdx); |
| value.ToRegister(rax); |
| } |
| // Receiver and value are in the right place, so rcx is free for name. |
| name.ToRegister(rcx); |
| name.Unuse(); |
| value.Unuse(); |
| receiver.Unuse(); |
| return RawCallCodeObject(ic, RelocInfo::CODE_TARGET); |
| } |
| |
| |
| void VirtualFrame::PushTryHandler(HandlerType type) { |
| ASSERT(cgen()->HasValidEntryRegisters()); |
| // Grow the expression stack by handler size less one (the return |
| // address is already pushed by a call instruction). |
| Adjust(kHandlerSize - 1); |
| __ PushTryHandler(IN_JAVASCRIPT, type); |
| } |
| |
| |
| #undef __ |
| |
| } } // namespace v8::internal |
