992 lines
33 KiB
C++
992 lines
33 KiB
C++
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// Copyright 2008 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#include "v8.h"
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#include "codegen.h"
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#include "codegen-inl.h"
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#include "virtual-frame.h"
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namespace v8 { namespace internal {
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#define __ masm_->
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// -------------------------------------------------------------------------
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// VirtualFrame implementation.
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// On entry to a function, the virtual frame already contains the receiver,
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// the parameters, and a return address. All frame elements are in memory.
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VirtualFrame::VirtualFrame(CodeGenerator* cgen)
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: cgen_(cgen),
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masm_(cgen->masm()),
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elements_(0),
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parameter_count_(cgen->scope()->num_parameters()),
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local_count_(0),
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stack_pointer_(parameter_count_ + 1), // 0-based index of TOS.
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frame_pointer_(kIllegalIndex) {
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for (int i = 0; i < parameter_count_ + 2; i++) {
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elements_.Add(FrameElement::MemoryElement());
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}
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}
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// Clear the dirty bit for the element at a given index if it is a
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// valid element. The stack address corresponding to the element must
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// be allocated on the physical stack, or the first element above the
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// stack pointer so it can be allocated by a single push instruction.
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void VirtualFrame::RawSyncElementAt(int index) {
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FrameElement element = elements_[index];
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if (!element.is_valid() || element.is_synced()) return;
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if (index <= stack_pointer_) {
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// Emit code to write elements below the stack pointer to their
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// (already allocated) stack address.
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switch (element.type()) {
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case FrameElement::INVALID: // Fall through.
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case FrameElement::MEMORY:
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// There was an early bailout for invalid and synced elements
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// (memory elements are always synced).
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UNREACHABLE();
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break;
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case FrameElement::REGISTER:
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__ mov(Operand(ebp, fp_relative(index)), element.reg());
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break;
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case FrameElement::CONSTANT:
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if (cgen_->IsUnsafeSmi(element.handle())) {
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Result temp = cgen_->allocator()->Allocate();
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ASSERT(temp.is_valid());
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cgen_->LoadUnsafeSmi(temp.reg(), element.handle());
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__ mov(Operand(ebp, fp_relative(index)), temp.reg());
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} else {
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__ Set(Operand(ebp, fp_relative(index)),
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Immediate(element.handle()));
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}
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break;
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case FrameElement::COPY: {
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int backing_index = element.index();
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FrameElement backing_element = elements_[backing_index];
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if (backing_element.is_memory()) {
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Result temp = cgen_->allocator()->Allocate();
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ASSERT(temp.is_valid());
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__ mov(temp.reg(), Operand(ebp, fp_relative(backing_index)));
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__ mov(Operand(ebp, fp_relative(index)), temp.reg());
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} else {
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ASSERT(backing_element.is_register());
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__ mov(Operand(ebp, fp_relative(index)), backing_element.reg());
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}
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break;
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}
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}
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} else {
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// Push elements above the stack pointer to allocate space and
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// sync them. Space should have already been allocated in the
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// actual frame for all the elements below this one.
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ASSERT(index == stack_pointer_ + 1);
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stack_pointer_++;
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switch (element.type()) {
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case FrameElement::INVALID: // Fall through.
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case FrameElement::MEMORY:
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// There was an early bailout for invalid and synced elements
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// (memory elements are always synced).
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UNREACHABLE();
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break;
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case FrameElement::REGISTER:
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__ push(element.reg());
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break;
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case FrameElement::CONSTANT:
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if (cgen_->IsUnsafeSmi(element.handle())) {
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Result temp = cgen_->allocator()->Allocate();
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ASSERT(temp.is_valid());
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cgen_->LoadUnsafeSmi(temp.reg(), element.handle());
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__ push(temp.reg());
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} else {
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__ push(Immediate(element.handle()));
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}
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break;
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case FrameElement::COPY: {
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int backing_index = element.index();
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FrameElement backing = elements_[backing_index];
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ASSERT(backing.is_memory() || backing.is_register());
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if (backing.is_memory()) {
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__ push(Operand(ebp, fp_relative(backing_index)));
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} else {
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__ push(backing.reg());
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}
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break;
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}
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}
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}
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elements_[index].set_sync();
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}
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void VirtualFrame::MergeTo(VirtualFrame* expected) {
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Comment cmnt(masm_, "[ Merge frame");
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// We should always be merging the code generator's current frame to an
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// expected frame.
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ASSERT(cgen_->frame() == this);
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// Adjust the stack pointer upward (toward the top of the virtual
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// frame) if necessary.
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if (stack_pointer_ < expected->stack_pointer_) {
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int difference = expected->stack_pointer_ - stack_pointer_;
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stack_pointer_ = expected->stack_pointer_;
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__ sub(Operand(esp), Immediate(difference * kPointerSize));
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}
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MergeMoveRegistersToMemory(expected);
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MergeMoveRegistersToRegisters(expected);
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MergeMoveMemoryToRegisters(expected);
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// Fix any sync bit problems.
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for (int i = 0; i <= stack_pointer_; i++) {
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FrameElement source = elements_[i];
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FrameElement target = expected->elements_[i];
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if (source.is_synced() && !target.is_synced()) {
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elements_[i].clear_sync();
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} else if (!source.is_synced() && target.is_synced()) {
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SyncElementAt(i);
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}
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}
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// Adjust the stack point downard if necessary.
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if (stack_pointer_ > expected->stack_pointer_) {
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int difference = stack_pointer_ - expected->stack_pointer_;
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stack_pointer_ = expected->stack_pointer_;
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__ add(Operand(esp), Immediate(difference * kPointerSize));
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}
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// At this point, the frames should be identical.
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ASSERT(Equals(expected));
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}
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void VirtualFrame::MergeMoveRegistersToMemory(VirtualFrame* expected) {
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ASSERT(stack_pointer_ >= expected->stack_pointer_);
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// Move registers, constants, and copies to memory. Perform moves
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// from the top downward in the frame in order to leave the backing
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// stores of copies in registers.
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//
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// Moving memory-backed copies to memory requires a spare register
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// for the memory-to-memory moves. Since we are performing a merge,
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// we use esi (which is already saved in the frame). We keep track
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// of the index of the frame element esi is caching or kIllegalIndex
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// if esi has not been disturbed.
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int esi_caches = kIllegalIndex;
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// A "singleton" memory element.
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FrameElement memory_element = FrameElement::MemoryElement();
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for (int i = stack_pointer_; i >= 0; i--) {
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FrameElement target = expected->elements_[i];
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if (target.is_memory()) {
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FrameElement source = elements_[i];
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switch (source.type()) {
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case FrameElement::INVALID:
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// Not a legal merge move.
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UNREACHABLE();
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break;
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case FrameElement::MEMORY:
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// Already in place.
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break;
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case FrameElement::REGISTER:
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Unuse(source.reg());
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if (!source.is_synced()) {
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__ mov(Operand(ebp, fp_relative(i)), source.reg());
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}
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break;
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case FrameElement::CONSTANT:
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if (!source.is_synced()) {
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if (cgen_->IsUnsafeSmi(source.handle())) {
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esi_caches = i;
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cgen_->LoadUnsafeSmi(esi, source.handle());
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__ mov(Operand(ebp, fp_relative(i)), esi);
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} else {
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__ Set(Operand(ebp, fp_relative(i)), Immediate(source.handle()));
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}
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}
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break;
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case FrameElement::COPY:
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if (!source.is_synced()) {
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int backing_index = source.index();
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FrameElement backing_element = elements_[backing_index];
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if (backing_element.is_memory()) {
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// If we have to spill a register, we spill esi.
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if (esi_caches != backing_index) {
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esi_caches = backing_index;
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__ mov(esi, Operand(ebp, fp_relative(backing_index)));
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}
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__ mov(Operand(ebp, fp_relative(i)), esi);
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} else {
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ASSERT(backing_element.is_register());
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__ mov(Operand(ebp, fp_relative(i)), backing_element.reg());
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}
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}
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break;
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}
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elements_[i] = memory_element;
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}
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}
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if (esi_caches != kIllegalIndex) {
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__ mov(esi, Operand(ebp, fp_relative(context_index())));
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}
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}
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void VirtualFrame::MergeMoveRegistersToRegisters(VirtualFrame* expected) {
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// We have already done X-to-memory moves.
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ASSERT(stack_pointer_ >= expected->stack_pointer_);
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// Perform register-to-register moves.
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int start = 0;
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int end = elements_.length() - 1;
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bool any_moves_blocked; // Did we fail to make some moves this iteration?
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bool should_break_cycles = false;
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bool any_moves_made; // Did we make any progress this iteration?
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do {
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any_moves_blocked = false;
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any_moves_made = false;
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int first_move_blocked = kIllegalIndex;
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int last_move_blocked = kIllegalIndex;
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for (int i = start; i <= end; i++) {
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FrameElement source = elements_[i];
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FrameElement target = expected->elements_[i];
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if (source.is_register() && target.is_register()) {
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if (target.reg().is(source.reg())) {
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if (target.is_synced() && !source.is_synced()) {
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__ mov(Operand(ebp, fp_relative(i)), source.reg());
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}
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elements_[i] = target;
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} else {
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// We need to move source to target.
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if (frame_registers_.is_used(target.reg())) {
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// The move is blocked because the target contains valid data.
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// If we are stuck with only cycles remaining, then we spill source.
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// Otherwise, we just need more iterations.
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if (should_break_cycles) {
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SpillElementAt(i);
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should_break_cycles = false;
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} else { // Record a blocked move.
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if (!any_moves_blocked) {
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first_move_blocked = i;
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}
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last_move_blocked = i;
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any_moves_blocked = true;
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}
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} else {
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// The move is not blocked. This frame element can be moved from
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// its source register to its target register.
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if (target.is_synced() && !source.is_synced()) {
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SyncElementAt(i);
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}
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Use(target.reg());
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Unuse(source.reg());
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elements_[i] = target;
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__ mov(target.reg(), source.reg());
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any_moves_made = true;
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}
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}
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}
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}
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// Update control flags for next iteration.
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should_break_cycles = (any_moves_blocked && !any_moves_made);
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if (any_moves_blocked) {
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start = first_move_blocked;
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end = last_move_blocked;
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}
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} while (any_moves_blocked);
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}
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void VirtualFrame::MergeMoveMemoryToRegisters(VirtualFrame *expected) {
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// Move memory, constants, and copies to registers. This is the
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// final step and is done from the bottom up so that the backing
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// elements of copies are in their correct locations when we
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// encounter the copies.
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for (int i = 0; i < elements_.length(); i++) {
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FrameElement source = elements_[i];
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FrameElement target = expected->elements_[i];
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if (target.is_register() && !source.is_register()) {
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switch (source.type()) {
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case FrameElement::INVALID: // Fall through.
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case FrameElement::REGISTER:
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UNREACHABLE();
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break;
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case FrameElement::MEMORY:
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ASSERT(i <= stack_pointer_);
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__ mov(target.reg(), Operand(ebp, fp_relative(i)));
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break;
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case FrameElement::CONSTANT:
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if (cgen_->IsUnsafeSmi(source.handle())) {
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cgen_->LoadUnsafeSmi(target.reg(), source.handle());
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} else {
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__ Set(target.reg(), Immediate(source.handle()));
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}
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break;
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case FrameElement::COPY: {
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FrameElement backing = elements_[source.index()];
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ASSERT(backing.is_memory() || backing.is_register());
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if (backing.is_memory()) {
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ASSERT(source.index() <= stack_pointer_);
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__ mov(target.reg(), Operand(ebp, fp_relative(source.index())));
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} else {
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__ mov(target.reg(), backing.reg());
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}
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}
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}
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// Ensure the proper sync state. If the source was memory no
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// code needs to be emitted.
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if (target.is_synced() && !source.is_memory()) {
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SyncElementAt(i);
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}
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Use(target.reg());
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elements_[i] = target;
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}
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}
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}
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void VirtualFrame::Enter() {
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// Registers live on entry: esp, ebp, esi, edi.
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Comment cmnt(masm_, "[ Enter JS frame");
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#ifdef DEBUG
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// Verify that edi contains a JS function. The following code
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// relies on eax being available for use.
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__ test(edi, Immediate(kSmiTagMask));
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__ Check(not_zero,
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"VirtualFrame::Enter - edi is not a function (smi check).");
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__ mov(eax, FieldOperand(edi, HeapObject::kMapOffset));
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__ movzx_b(eax, FieldOperand(eax, Map::kInstanceTypeOffset));
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__ cmp(eax, JS_FUNCTION_TYPE);
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__ Check(equal,
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"VirtualFrame::Enter - edi is not a function (map check).");
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#endif
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EmitPush(ebp);
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frame_pointer_ = stack_pointer_;
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__ mov(ebp, Operand(esp));
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// Store the context in the frame. The context is kept in esi and a
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// copy is stored in the frame. The external reference to esi
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// remains.
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EmitPush(esi);
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// Store the function in the frame. The frame owns the register
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// reference now (ie, it can keep it in edi or spill it later).
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Push(edi);
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SyncElementAt(elements_.length() - 1);
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cgen_->allocator()->Unuse(edi);
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}
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void VirtualFrame::Exit() {
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Comment cmnt(masm_, "[ Exit JS frame");
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// Record the location of the JS exit code for patching when setting
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// break point.
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__ RecordJSReturn();
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||
|
// 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 VisitReturnStatement for the full return sequence.
|
||
|
__ mov(esp, Operand(ebp));
|
||
|
stack_pointer_ = frame_pointer_;
|
||
|
for (int i = elements_.length() - 1; i > stack_pointer_; i--) {
|
||
|
FrameElement last = elements_.RemoveLast();
|
||
|
if (last.is_register()) {
|
||
|
Unuse(last.reg());
|
||
|
}
|
||
|
}
|
||
|
|
||
|
frame_pointer_ = kIllegalIndex;
|
||
|
EmitPop(ebp);
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::AllocateStackSlots(int count) {
|
||
|
ASSERT(height() == 0);
|
||
|
local_count_ = 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, elements_.length());
|
||
|
Handle<Object> undefined = Factory::undefined_value();
|
||
|
FrameElement initial_value =
|
||
|
FrameElement::ConstantElement(undefined, FrameElement::SYNCED);
|
||
|
Result temp = cgen_->allocator()->Allocate();
|
||
|
ASSERT(temp.is_valid());
|
||
|
__ Set(temp.reg(), Immediate(undefined));
|
||
|
for (int i = 0; i < count; i++) {
|
||
|
elements_.Add(initial_value);
|
||
|
stack_pointer_++;
|
||
|
__ push(temp.reg());
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::SaveContextRegister() {
|
||
|
ASSERT(elements_[context_index()].is_memory());
|
||
|
__ mov(Operand(ebp, fp_relative(context_index())), esi);
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::RestoreContextRegister() {
|
||
|
ASSERT(elements_[context_index()].is_memory());
|
||
|
__ mov(esi, Operand(ebp, fp_relative(context_index())));
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::PushReceiverSlotAddress() {
|
||
|
Result temp = cgen_->allocator()->Allocate();
|
||
|
ASSERT(temp.is_valid());
|
||
|
__ lea(temp.reg(), ParameterAt(-1));
|
||
|
Push(&temp);
|
||
|
}
|
||
|
|
||
|
|
||
|
// Before changing an element which is copied, adjust so that the
|
||
|
// first copy becomes the new backing store and all the other copies
|
||
|
// are updated. If the original was in memory, the new backing store
|
||
|
// is allocated to a register. Return a copy of the new backing store
|
||
|
// or an invalid element if the original was not a copy.
|
||
|
FrameElement VirtualFrame::AdjustCopies(int index) {
|
||
|
FrameElement original = elements_[index];
|
||
|
ASSERT(original.is_memory() || original.is_register());
|
||
|
|
||
|
// Go looking for a first copy above index.
|
||
|
int i = index + 1;
|
||
|
while (i < elements_.length()) {
|
||
|
FrameElement elt = elements_[i];
|
||
|
if (elt.is_copy() && elt.index() == index) break;
|
||
|
i++;
|
||
|
}
|
||
|
|
||
|
if (i < elements_.length()) {
|
||
|
// There was a first copy. Make it the new backing element.
|
||
|
Register backing_reg;
|
||
|
if (original.is_memory()) {
|
||
|
Result fresh = cgen_->allocator()->Allocate();
|
||
|
ASSERT(fresh.is_valid());
|
||
|
backing_reg = fresh.reg();
|
||
|
__ mov(backing_reg, Operand(ebp, fp_relative(index)));
|
||
|
} else {
|
||
|
// The original was in a register.
|
||
|
backing_reg = original.reg();
|
||
|
}
|
||
|
FrameElement new_backing_element =
|
||
|
FrameElement::RegisterElement(backing_reg, FrameElement::NOT_SYNCED);
|
||
|
if (elements_[i].is_synced()) {
|
||
|
new_backing_element.set_sync();
|
||
|
}
|
||
|
Use(backing_reg);
|
||
|
elements_[i] = new_backing_element;
|
||
|
|
||
|
// Update the other copies.
|
||
|
FrameElement copy = CopyElementAt(i);
|
||
|
for (int j = i; j < elements_.length(); j++) {
|
||
|
FrameElement elt = elements_[j];
|
||
|
if (elt.is_copy() && elt.index() == index) {
|
||
|
if (elt.is_synced()) {
|
||
|
copy.set_sync();
|
||
|
} else {
|
||
|
copy.clear_sync();
|
||
|
}
|
||
|
elements_[j] = copy;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
copy.clear_sync();
|
||
|
return copy;
|
||
|
}
|
||
|
|
||
|
return FrameElement::InvalidElement();
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::TakeFrameSlotAt(int index) {
|
||
|
ASSERT(index >= 0);
|
||
|
ASSERT(index <= elements_.length());
|
||
|
FrameElement original = elements_[index];
|
||
|
|
||
|
switch (original.type()) {
|
||
|
case FrameElement::INVALID:
|
||
|
UNREACHABLE();
|
||
|
break;
|
||
|
|
||
|
case FrameElement::MEMORY: {
|
||
|
// Allocate the element to a register. If it is not copied,
|
||
|
// push that register on top of the frame. If it is copied,
|
||
|
// make the first copy the backing store and push a fresh copy
|
||
|
// on top of the frame.
|
||
|
FrameElement copy = AdjustCopies(index);
|
||
|
if (copy.is_valid()) {
|
||
|
// The original element was a copy. Push the copy of the new
|
||
|
// backing store.
|
||
|
elements_.Add(copy);
|
||
|
} else {
|
||
|
// The element was not a copy. Move it to a register and push
|
||
|
// that.
|
||
|
Result fresh = cgen_->allocator()->Allocate();
|
||
|
ASSERT(fresh.is_valid());
|
||
|
FrameElement new_element =
|
||
|
FrameElement::RegisterElement(fresh.reg(),
|
||
|
FrameElement::NOT_SYNCED);
|
||
|
Use(fresh.reg());
|
||
|
elements_.Add(new_element);
|
||
|
__ mov(fresh.reg(), Operand(ebp, fp_relative(index)));
|
||
|
}
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
case FrameElement::REGISTER: {
|
||
|
// If the element is not copied, push it on top of the frame.
|
||
|
// If it is copied, make the first copy be the new backing store
|
||
|
// and push a fresh copy on top of the frame.
|
||
|
FrameElement copy = AdjustCopies(index);
|
||
|
if (copy.is_valid()) {
|
||
|
// The original element was a copy. Push the copy of the new
|
||
|
// backing store.
|
||
|
elements_.Add(copy);
|
||
|
// This is the only case where we have to unuse the original
|
||
|
// register. The original is still counted and so is the new
|
||
|
// backing store of the copies.
|
||
|
Unuse(original.reg());
|
||
|
} else {
|
||
|
// The element was not a copy. Push it.
|
||
|
original.clear_sync();
|
||
|
elements_.Add(original);
|
||
|
}
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
case FrameElement::CONSTANT:
|
||
|
original.clear_sync();
|
||
|
elements_.Add(original);
|
||
|
break;
|
||
|
|
||
|
case FrameElement::COPY:
|
||
|
original.clear_sync();
|
||
|
elements_.Add(original);
|
||
|
break;
|
||
|
}
|
||
|
elements_[index] = FrameElement::InvalidElement();
|
||
|
}
|
||
|
|
||
|
|
||
|
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 < elements_.length());
|
||
|
|
||
|
FrameElement original = elements_[index];
|
||
|
// If the stored-to slot may be copied, adjust to preserve the
|
||
|
// copy-on-write semantics of copied elements.
|
||
|
if (original.is_register() || original.is_memory()) {
|
||
|
FrameElement ignored = AdjustCopies(index);
|
||
|
}
|
||
|
|
||
|
// If the stored-to slot is a register reference, deallocate it.
|
||
|
if (original.is_register()) {
|
||
|
Unuse(original.reg());
|
||
|
}
|
||
|
|
||
|
int top_index = elements_.length() - 1;
|
||
|
FrameElement top = elements_[top_index];
|
||
|
ASSERT(top.is_valid());
|
||
|
|
||
|
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.
|
||
|
Result temp = cgen_->allocator()->Allocate();
|
||
|
ASSERT(temp.is_valid());
|
||
|
__ mov(temp.reg(), Operand(ebp, fp_relative(backing_index)));
|
||
|
__ mov(Operand(ebp, fp_relative(index)), temp.reg());
|
||
|
} else 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 < elements_.length(); i++) {
|
||
|
FrameElement current = elements_[i];
|
||
|
if (current.is_copy() && current.index() == backing_index) {
|
||
|
elements_[i] = new_element;
|
||
|
if (current.is_synced()) {
|
||
|
elements_[i].set_sync();
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
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.
|
||
|
Result temp = cgen_->allocator()->Allocate();
|
||
|
ASSERT(temp.is_valid());
|
||
|
__ mov(temp.reg(), Operand(esp, 0));
|
||
|
__ mov(Operand(ebp, fp_relative(index)), temp.reg());
|
||
|
} else if (top.is_register()) {
|
||
|
// 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::PushTryHandler(HandlerType type) {
|
||
|
ASSERT(cgen_->HasValidEntryRegisters());
|
||
|
// Grow the expression stack by handler size less two (the return address
|
||
|
// is already pushed by a call instruction, and PushTryHandler from the
|
||
|
// macro assembler will leave the top of stack in the eax register to be
|
||
|
// pushed separately).
|
||
|
Adjust(kHandlerSize - 2);
|
||
|
__ PushTryHandler(IN_JAVASCRIPT, type);
|
||
|
// TODO(1222589): remove the reliance of PushTryHandler on a cached TOS
|
||
|
EmitPush(eax);
|
||
|
}
|
||
|
|
||
|
|
||
|
Result VirtualFrame::RawCallStub(CodeStub* stub, int frame_arg_count) {
|
||
|
ASSERT(cgen_->HasValidEntryRegisters());
|
||
|
__ CallStub(stub);
|
||
|
Result result = cgen_->allocator()->Allocate(eax);
|
||
|
ASSERT(result.is_valid());
|
||
|
return result;
|
||
|
}
|
||
|
|
||
|
|
||
|
Result VirtualFrame::CallRuntime(Runtime::Function* f,
|
||
|
int frame_arg_count) {
|
||
|
PrepareForCall(frame_arg_count, frame_arg_count);
|
||
|
ASSERT(cgen_->HasValidEntryRegisters());
|
||
|
__ CallRuntime(f, frame_arg_count);
|
||
|
Result result = cgen_->allocator()->Allocate(eax);
|
||
|
ASSERT(result.is_valid());
|
||
|
return result;
|
||
|
}
|
||
|
|
||
|
|
||
|
Result VirtualFrame::CallRuntime(Runtime::FunctionId id,
|
||
|
int frame_arg_count) {
|
||
|
PrepareForCall(frame_arg_count, frame_arg_count);
|
||
|
ASSERT(cgen_->HasValidEntryRegisters());
|
||
|
__ CallRuntime(id, frame_arg_count);
|
||
|
Result result = cgen_->allocator()->Allocate(eax);
|
||
|
ASSERT(result.is_valid());
|
||
|
return result;
|
||
|
}
|
||
|
|
||
|
|
||
|
Result VirtualFrame::InvokeBuiltin(Builtins::JavaScript id,
|
||
|
InvokeFlag flag,
|
||
|
int frame_arg_count) {
|
||
|
PrepareForCall(frame_arg_count, frame_arg_count);
|
||
|
ASSERT(cgen_->HasValidEntryRegisters());
|
||
|
__ InvokeBuiltin(id, flag);
|
||
|
Result result = cgen_->allocator()->Allocate(eax);
|
||
|
ASSERT(result.is_valid());
|
||
|
return result;
|
||
|
}
|
||
|
|
||
|
|
||
|
Result VirtualFrame::RawCallCodeObject(Handle<Code> code,
|
||
|
RelocInfo::Mode rmode) {
|
||
|
ASSERT(cgen_->HasValidEntryRegisters());
|
||
|
__ call(code, rmode);
|
||
|
Result result = cgen_->allocator()->Allocate(eax);
|
||
|
ASSERT(result.is_valid());
|
||
|
return result;
|
||
|
}
|
||
|
|
||
|
|
||
|
Result VirtualFrame::CallCodeObject(Handle<Code> code,
|
||
|
RelocInfo::Mode rmode,
|
||
|
Result* arg,
|
||
|
int dropped_args) {
|
||
|
int spilled_args = 0;
|
||
|
switch (code->kind()) {
|
||
|
case Code::CALL_IC:
|
||
|
ASSERT(arg->reg().is(eax));
|
||
|
spilled_args = dropped_args + 1;
|
||
|
break;
|
||
|
case Code::LOAD_IC:
|
||
|
ASSERT(arg->reg().is(ecx));
|
||
|
ASSERT(dropped_args == 0);
|
||
|
spilled_args = 1;
|
||
|
break;
|
||
|
case Code::KEYED_STORE_IC:
|
||
|
ASSERT(arg->reg().is(eax));
|
||
|
ASSERT(dropped_args == 0);
|
||
|
spilled_args = 2;
|
||
|
break;
|
||
|
default:
|
||
|
// No other types of code objects are called with values
|
||
|
// in exactly one register.
|
||
|
UNREACHABLE();
|
||
|
break;
|
||
|
}
|
||
|
PrepareForCall(spilled_args, dropped_args);
|
||
|
arg->Unuse();
|
||
|
return RawCallCodeObject(code, rmode);
|
||
|
}
|
||
|
|
||
|
|
||
|
Result VirtualFrame::CallCodeObject(Handle<Code> code,
|
||
|
RelocInfo::Mode rmode,
|
||
|
Result* arg0,
|
||
|
Result* arg1,
|
||
|
int dropped_args) {
|
||
|
int spilled_args = 1;
|
||
|
switch (code->kind()) {
|
||
|
case Code::STORE_IC:
|
||
|
ASSERT(arg0->reg().is(eax));
|
||
|
ASSERT(arg1->reg().is(ecx));
|
||
|
ASSERT(dropped_args == 0);
|
||
|
spilled_args = 1;
|
||
|
break;
|
||
|
case Code::BUILTIN:
|
||
|
ASSERT(*code == Builtins::builtin(Builtins::JSConstructCall));
|
||
|
ASSERT(arg0->reg().is(eax));
|
||
|
ASSERT(arg1->reg().is(edi));
|
||
|
spilled_args = dropped_args + 1;
|
||
|
break;
|
||
|
default:
|
||
|
// No other types of code objects are called with values
|
||
|
// in exactly two registers.
|
||
|
UNREACHABLE();
|
||
|
break;
|
||
|
}
|
||
|
PrepareForCall(spilled_args, dropped_args);
|
||
|
arg0->Unuse();
|
||
|
arg1->Unuse();
|
||
|
return RawCallCodeObject(code, rmode);
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::Drop(int count) {
|
||
|
ASSERT(height() >= count);
|
||
|
int num_virtual_elements = (elements_.length() - 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;
|
||
|
__ add(Operand(esp), 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());
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
Result VirtualFrame::Pop() {
|
||
|
FrameElement element = elements_.RemoveLast();
|
||
|
int index = elements_.length();
|
||
|
ASSERT(element.is_valid());
|
||
|
|
||
|
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());
|
||
|
return temp;
|
||
|
}
|
||
|
|
||
|
__ add(Operand(esp), 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());
|
||
|
FrameElement new_element =
|
||
|
FrameElement::RegisterElement(temp.reg(), FrameElement::SYNCED);
|
||
|
elements_[index] = new_element;
|
||
|
__ mov(temp.reg(), Operand(ebp, fp_relative(index)));
|
||
|
return Result(temp.reg(), cgen_);
|
||
|
} else if (element.is_register()) {
|
||
|
return Result(element.reg(), cgen_);
|
||
|
} else {
|
||
|
ASSERT(element.is_constant());
|
||
|
return Result(element.handle(), cgen_);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::EmitPop(Register reg) {
|
||
|
ASSERT(stack_pointer_ == elements_.length() - 1);
|
||
|
stack_pointer_--;
|
||
|
elements_.RemoveLast();
|
||
|
__ pop(reg);
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::EmitPop(Operand operand) {
|
||
|
ASSERT(stack_pointer_ == elements_.length() - 1);
|
||
|
stack_pointer_--;
|
||
|
elements_.RemoveLast();
|
||
|
__ pop(operand);
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::EmitPush(Register reg) {
|
||
|
ASSERT(stack_pointer_ == elements_.length() - 1);
|
||
|
elements_.Add(FrameElement::MemoryElement());
|
||
|
stack_pointer_++;
|
||
|
__ push(reg);
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::EmitPush(Operand operand) {
|
||
|
ASSERT(stack_pointer_ == elements_.length() - 1);
|
||
|
elements_.Add(FrameElement::MemoryElement());
|
||
|
stack_pointer_++;
|
||
|
__ push(operand);
|
||
|
}
|
||
|
|
||
|
|
||
|
void VirtualFrame::EmitPush(Immediate immediate) {
|
||
|
ASSERT(stack_pointer_ == elements_.length() - 1);
|
||
|
elements_.Add(FrameElement::MemoryElement());
|
||
|
stack_pointer_++;
|
||
|
__ push(immediate);
|
||
|
}
|
||
|
|
||
|
|
||
|
#undef __
|
||
|
|
||
|
} } // namespace v8::internal
|