Initial (stub) port of jump targets to the ARM platform....

src/jump-target-ia32.cc

+// Copyright 2008 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.h"
+#include "jump-target.h"
+
+namespace v8 { namespace internal {
+
+// -------------------------------------------------------------------------
+// JumpTarget implementation.
+
+#define __ masm_->
+
+JumpTarget::JumpTarget(CodeGenerator* cgen) {
+  ASSERT(cgen != NULL);
+  expected_frame_ = NULL;
+  code_generator_ = cgen;
+  masm_ = cgen->masm();
+}
+
+
+JumpTarget::JumpTarget()
+    : expected_frame_(NULL),
+      code_generator_(NULL),
+      masm_(NULL) {
+}
+
+
+void JumpTarget::set_code_generator(CodeGenerator* cgen) {
+  ASSERT(cgen != NULL);
+  ASSERT(code_generator_ == NULL);
+  code_generator_ = cgen;
+  masm_ = cgen->masm();
+}
+
+
+bool JumpTarget::IsActualFunctionReturn() {
+  return (this == &code_generator_->function_return_ &&
+          !code_generator_->function_return_is_shadowed_);
+}
+
+
+void JumpTarget::Jump() {
+  // Precondition: there is a current frame.  There may or may not be an
+  // expected frame at the label.
+  ASSERT(code_generator_ != NULL);
+  ASSERT(masm_ != NULL);
+
+  VirtualFrame* current_frame = code_generator_->frame();
+  ASSERT(current_frame != NULL);
+
+  if (expected_frame_ == NULL) {
+    expected_frame_ = current_frame;
+    code_generator_->set_frame(NULL);
+    // The frame at the actual function return will always have height
+    // zero.
+    if (IsActualFunctionReturn()) expected_frame_->height_ = 0;
+  } else {
+    // No code needs to be emitted to merge to the expected frame at the
+    // actual function return.
+    if (!IsActualFunctionReturn()) current_frame->MergeTo(expected_frame_);
+    code_generator_->delete_frame();
+  }
+
+  __ jmp(&label_);
+  // Postcondition: there is no current frame but there is an expected frame
+  // at the label.
+}
+
+
+void JumpTarget::Branch(Condition cc, Hint hint) {
+  // Precondition: there is a current frame.  There may or may not be an
+  // expected frame at the label.
+  ASSERT(code_generator_ != NULL);
+  ASSERT(masm_ != NULL);
+
+  VirtualFrame* current_frame = code_generator_->frame();
+  ASSERT(current_frame != NULL);
+
+  if (expected_frame_ == NULL) {
+    expected_frame_ = new VirtualFrame(current_frame);
+    // The frame at the actual function return will always have height
+    // zero.
+    if (IsActualFunctionReturn()) expected_frame_->height_ = 0;
+  } else {
+    // No code needs to be emitted to merge to the expected frame at the
+    // actual function return.
+    if (!IsActualFunctionReturn()) current_frame->MergeTo(expected_frame_);
+  }
+
+  __ j(cc, &label_, hint);
+  // Postcondition: there is both a current frame and an expected frame at
+  // the label and they match.
+}
+
+
+void JumpTarget::Call() {
+  // Precondition: there is a current frame, and there is no expected frame
+  // at the label.
+  ASSERT(code_generator_ != NULL);
+  ASSERT(masm_ != NULL);
+  ASSERT(!IsActualFunctionReturn());
+
+  VirtualFrame* current_frame = code_generator_->frame();
+  ASSERT(current_frame != NULL);
+  ASSERT(expected_frame_ == NULL);
+
+  expected_frame_ = new VirtualFrame(current_frame);
+  // Adjust the expected frame's height to account for the return address
+  // pushed by the call instruction.
+  expected_frame_->height_++;
+
+  __ call(&label_);
+
+  // Postcondition: there is both a current frame and an expected frame at
+  // the label.  The current frame is one shorter than the one at the label
+  // (which contains the 'return address', ie, the eip register and possibly
+  // cs register).
+}
+
+
+void JumpTarget::Bind() {
+  ASSERT(code_generator_ != NULL);
+  ASSERT(masm_ != NULL);
+
+  // Precondition: there is either a current frame or an expected frame at
+  // the label (and possibly both).  The label is unbound.
+  VirtualFrame* current_frame = code_generator_->frame();
+  ASSERT(current_frame != NULL || expected_frame_ != NULL);
+  ASSERT(!label_.is_bound());
+
+  if (expected_frame_ == NULL) {
+    expected_frame_ = new VirtualFrame(current_frame);
+    // The frame at the actual function return will always have height
+    // zero.
+    if (IsActualFunctionReturn()) expected_frame_->height_ = 0;
+  } else if (current_frame == NULL) {
+    code_generator_->set_frame(new VirtualFrame(expected_frame_));
+  } else {
+    // No code needs to be emitted to merge to the expected frame at the
+    // actual function return.
+    if (!IsActualFunctionReturn()) current_frame->MergeTo(expected_frame_);
+  }
+
+  __ bind(&label_);
+  // Postcondition: there is both a current frame and an expected frame at
+  // the label and they match.  The label is bound.
+}
+
+
+// -------------------------------------------------------------------------
+// ShadowTarget implementation.
+
+ShadowTarget::ShadowTarget(JumpTarget* original) {
+  ASSERT(original != NULL);
+  original_target_ = original;
+  original_pos_ = original->label()->pos_;
+  original_expected_frame_ = original->expected_frame();
+
+  // We do not call Unuse() on the orginal jump target, because we do not
+  // want to delete the expected frame.
+  original->label()->pos_ = 0;
+  original->set_expected_frame(NULL);
+#ifdef DEBUG
+  is_shadowing_ = true;
+#endif
+}
+
+
+void ShadowTarget::StopShadowing() {
+  ASSERT(is_shadowing_);
+  ASSERT(is_unused());
+
+  set_code_generator(original_target_->code_generator());
+  label_.pos_ = original_target_->label()->pos_;
+  expected_frame_ = original_target_->expected_frame();
+
+  original_target_->label()->pos_ = original_pos_;
+  original_target_->set_expected_frame(original_expected_frame_);
+
+#ifdef DEBUG
+  is_shadowing_ = false;
+#endif
+}
+
+#undef __
+
+
+} }  // namespace v8::internal