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// 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,
// 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 "jump-target-inl.h"
#include "register-allocator-inl.h"
namespace v8 {
namespace internal {
// -------------------------------------------------------------------------
// JumpTarget implementation.
bool JumpTarget::compiling_deferred_code_ = false;
void JumpTarget::Unuse() {
reaching_frames_.Clear();
merge_labels_.Clear();
entry_frame_ = NULL;
entry_label_.Unuse();
}
void JumpTarget::Jump() {
DoJump();
}
void JumpTarget::Branch(Condition cc, Hint hint) {
DoBranch(cc, hint);
}
void JumpTarget::Bind() {
DoBind();
}
void JumpTarget::AddReachingFrame(VirtualFrame* frame) {
ASSERT(reaching_frames_.length() == merge_labels_.length());
ASSERT(entry_frame_ == NULL);
Label fresh;
merge_labels_.Add(fresh);
reaching_frames_.Add(frame);
}
// -------------------------------------------------------------------------
// BreakTarget implementation.
void BreakTarget::set_direction(Directionality direction) {
JumpTarget::set_direction(direction);
ASSERT(cgen()->has_valid_frame());
expected_height_ = cgen()->frame()->height();
}
void BreakTarget::CopyTo(BreakTarget* destination) {
ASSERT(destination != NULL);
destination->direction_ = direction_;
destination->reaching_frames_.Rewind(0);
destination->reaching_frames_.AddAll(reaching_frames_);
destination->merge_labels_.Rewind(0);
destination->merge_labels_.AddAll(merge_labels_);
destination->entry_frame_ = entry_frame_;
destination->entry_label_ = entry_label_;
destination->expected_height_ = expected_height_;
}
void BreakTarget::Branch(Condition cc, Hint hint) {
ASSERT(cgen()->has_valid_frame());
int count = cgen()->frame()->height() - expected_height_;
if (count > 0) {
// We negate and branch here rather than using DoBranch's negate
// and branch. This gives us a hook to remove statement state
// from the frame.
JumpTarget fall_through;
// Branch to fall through will not negate, because it is a
// forward-only target.
fall_through.Branch(NegateCondition(cc), NegateHint(hint));
Jump(); // May emit merge code here.
fall_through.Bind();
} else {
DoBranch(cc, hint);
}
}
// -------------------------------------------------------------------------
// ShadowTarget implementation.
ShadowTarget::ShadowTarget(BreakTarget* shadowed) {
ASSERT(shadowed != NULL);
other_target_ = shadowed;
#ifdef DEBUG
is_shadowing_ = true;
#endif
// While shadowing this shadow target saves the state of the original.
shadowed->CopyTo(this);
// The original's state is reset.
shadowed->Unuse();
ASSERT(cgen()->has_valid_frame());
shadowed->set_expected_height(cgen()->frame()->height());
}
void ShadowTarget::StopShadowing() {
ASSERT(is_shadowing_);
// The states of this target, which was shadowed, and the original
// target, which was shadowing, are swapped.
BreakTarget temp;
other_target_->CopyTo(&temp);
CopyTo(other_target_);
temp.CopyTo(this);
temp.Unuse();
#ifdef DEBUG
is_shadowing_ = false;
#endif
}
} } // namespace v8::internal
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