src/arm/jump-target-arm.cc - platform/external/v8 - Git at Google

 // 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-inl.h"
 #include "jump-target-inl.h"
 #include "register-allocator-inl.h"

 namespace v8 {
 namespace internal {

 // -------------------------------------------------------------------------
 // JumpTarget implementation.

 #define __ ACCESS_MASM(cgen()->masm())

 void JumpTarget::DoJump() {
   ASSERT(cgen()->has_valid_frame());
   // Live non-frame registers are not allowed at unconditional jumps
   // because we have no way of invalidating the corresponding results
   // which are still live in the C++ code.
   ASSERT(cgen()->HasValidEntryRegisters());

   if (is_bound()) {
     // Backward jump.  There already a frame expectation at the target.
     ASSERT(direction_ == BIDIRECTIONAL);
     cgen()->frame()->MergeTo(entry_frame_);
     cgen()->DeleteFrame();
   } else {
     // Use the current frame as the expected one at the target if necessary.
     if (entry_frame_ == NULL) {
       entry_frame_ = cgen()->frame();
       RegisterFile empty;
       cgen()->SetFrame(NULL, &empty);
     } else {
       cgen()->frame()->MergeTo(entry_frame_);
       cgen()->DeleteFrame();
     }

     // The predicate is_linked() should be made true.  Its implementation
     // detects the presence of a frame pointer in the reaching_frames_ list.
     if (!is_linked()) {
       reaching_frames_.Add(NULL);
       ASSERT(is_linked());
     }
   }
   __ jmp(&entry_label_);
 }


 void JumpTarget::DoBranch(Condition cc, Hint ignored) {
   ASSERT(cgen()->has_valid_frame());

   if (is_bound()) {
     ASSERT(direction_ == BIDIRECTIONAL);
     // Backward branch.  We have an expected frame to merge to on the
     // backward edge.
     cgen()->frame()->MergeTo(entry_frame_);
   } else {
     // Clone the current frame to use as the expected one at the target if
     // necessary.
     if (entry_frame_ == NULL) {
       entry_frame_ = new VirtualFrame(cgen()->frame());
     }
     // The predicate is_linked() should be made true.  Its implementation
     // detects the presence of a frame pointer in the reaching_frames_ list.
     if (!is_linked()) {
       reaching_frames_.Add(NULL);
       ASSERT(is_linked());
     }
   }
   __ b(cc, &entry_label_);
 }


 void JumpTarget::Call() {
   // Call is used to push the address of the catch block on the stack as
   // a return address when compiling try/catch and try/finally.  We
   // fully spill the frame before making the call.  The expected frame
   // at the label (which should be the only one) is the spilled current
   // frame plus an in-memory return address.  The "fall-through" frame
   // at the return site is the spilled current frame.
   ASSERT(cgen()->has_valid_frame());
   // There are no non-frame references across the call.
   ASSERT(cgen()->HasValidEntryRegisters());
   ASSERT(!is_linked());

   // Calls are always 'forward' so we use a copy of the current frame (plus
   // one for a return address) as the expected frame.
   ASSERT(entry_frame_ == NULL);
   VirtualFrame* target_frame = new VirtualFrame(cgen()->frame());
   target_frame->Adjust(1);
   entry_frame_ = target_frame;

   // The predicate is_linked() should now be made true.  Its implementation
   // detects the presence of a frame pointer in the reaching_frames_ list.
   reaching_frames_.Add(NULL);
   ASSERT(is_linked());

   __ bl(&entry_label_);
 }


 void JumpTarget::DoBind() {
   ASSERT(!is_bound());

   // Live non-frame registers are not allowed at the start of a basic
   // block.
   ASSERT(!cgen()->has_valid_frame() || cgen()->HasValidEntryRegisters());

   if (cgen()->has_valid_frame()) {
     // If there is a current frame we can use it on the fall through.
     if (entry_frame_ == NULL) {
       entry_frame_ = new VirtualFrame(cgen()->frame());
     } else {
       ASSERT(cgen()->frame()->Equals(entry_frame_));
     }
   } else {
     // If there is no current frame we must have an entry frame which we can
     // copy.
     ASSERT(entry_frame_ != NULL);
     RegisterFile empty;
     cgen()->SetFrame(new VirtualFrame(entry_frame_), &empty);
   }

   // The predicate is_linked() should be made false.  Its implementation
   // detects the presence (or absence) of frame pointers in the
   // reaching_frames_ list.  If we inserted a bogus frame to make
   // is_linked() true, remove it now.
   if (is_linked()) {
     reaching_frames_.Clear();
   }

   __ bind(&entry_label_);
 }


 void BreakTarget::Jump() {
   // On ARM we do not currently emit merge code for jumps, so we need to do
   // it explicitly here.  The only merging necessary is to drop extra
   // statement state from the stack.
   ASSERT(cgen()->has_valid_frame());
   int count = cgen()->frame()->height() - expected_height_;
   cgen()->frame()->Drop(count);
   DoJump();
 }


 void BreakTarget::Jump(Result* arg) {
   // On ARM we do not currently emit merge code for jumps, so we need to do
   // it explicitly here.  The only merging necessary is to drop extra
   // statement state from the stack.
   ASSERT(cgen()->has_valid_frame());
   int count = cgen()->frame()->height() - expected_height_;
   cgen()->frame()->Drop(count);
   cgen()->frame()->Push(arg);
   DoJump();
 }


 void BreakTarget::Bind() {
 #ifdef DEBUG
   // All the forward-reaching frames should have been adjusted at the
   // jumps to this target.
   for (int i = 0; i < reaching_frames_.length(); i++) {
     ASSERT(reaching_frames_[i] == NULL ||
            reaching_frames_[i]->height() == expected_height_);
   }
 #endif
   // Drop leftover statement state from the frame before merging, even
   // on the fall through.  This is so we can bind the return target
   // with state on the frame.
   if (cgen()->has_valid_frame()) {
     int count = cgen()->frame()->height() - expected_height_;
     // On ARM we do not currently emit merge code at binding sites, so we need
     // to do it explicitly here.  The only merging necessary is to drop extra
     // statement state from the stack.
     cgen()->frame()->Drop(count);
   }

   DoBind();
 }


 void BreakTarget::Bind(Result* arg) {
 #ifdef DEBUG
   // All the forward-reaching frames should have been adjusted at the
   // jumps to this target.
   for (int i = 0; i < reaching_frames_.length(); i++) {
     ASSERT(reaching_frames_[i] == NULL ||
            reaching_frames_[i]->height() == expected_height_ + 1);
   }
 #endif
   // Drop leftover statement state from the frame before merging, even
   // on the fall through.  This is so we can bind the return target
   // with state on the frame.
   if (cgen()->has_valid_frame()) {
     int count = cgen()->frame()->height() - expected_height_;
     // On ARM we do not currently emit merge code at binding sites, so we need
     // to do it explicitly here.  The only merging necessary is to drop extra
     // statement state from the stack.
     cgen()->frame()->ForgetElements(count);
     cgen()->frame()->Push(arg);
   }
   DoBind();
   *arg = cgen()->frame()->Pop();
 }


 #undef __


 } }  // namespace v8::internal
	// 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-inl.h"
	#include "jump-target-inl.h"
	#include "register-allocator-inl.h"

	namespace v8 {
	namespace internal {

	// -------------------------------------------------------------------------
	// JumpTarget implementation.

	#define __ ACCESS_MASM(cgen()->masm())

	void JumpTarget::DoJump() {
	ASSERT(cgen()->has_valid_frame());
	// Live non-frame registers are not allowed at unconditional jumps
	// because we have no way of invalidating the corresponding results
	// which are still live in the C++ code.
	ASSERT(cgen()->HasValidEntryRegisters());

	if (is_bound()) {
	// Backward jump. There already a frame expectation at the target.
	ASSERT(direction_ == BIDIRECTIONAL);
	cgen()->frame()->MergeTo(entry_frame_);
	cgen()->DeleteFrame();
	} else {
	// Use the current frame as the expected one at the target if necessary.
	if (entry_frame_ == NULL) {
	entry_frame_ = cgen()->frame();
	RegisterFile empty;
	cgen()->SetFrame(NULL, &empty);
	} else {
	cgen()->frame()->MergeTo(entry_frame_);
	cgen()->DeleteFrame();
	}

	// The predicate is_linked() should be made true. Its implementation
	// detects the presence of a frame pointer in the reaching_frames_ list.
	if (!is_linked()) {
	reaching_frames_.Add(NULL);
	ASSERT(is_linked());
	}
	}
	__ jmp(&entry_label_);
	}


	void JumpTarget::DoBranch(Condition cc, Hint ignored) {
	ASSERT(cgen()->has_valid_frame());

	if (is_bound()) {
	ASSERT(direction_ == BIDIRECTIONAL);
	// Backward branch. We have an expected frame to merge to on the
	// backward edge.
	cgen()->frame()->MergeTo(entry_frame_);
	} else {
	// Clone the current frame to use as the expected one at the target if
	// necessary.
	if (entry_frame_ == NULL) {
	entry_frame_ = new VirtualFrame(cgen()->frame());
	}
	// The predicate is_linked() should be made true. Its implementation
	// detects the presence of a frame pointer in the reaching_frames_ list.
	if (!is_linked()) {
	reaching_frames_.Add(NULL);
	ASSERT(is_linked());
	}
	}
	__ b(cc, &entry_label_);
	}


	void JumpTarget::Call() {
	// Call is used to push the address of the catch block on the stack as
	// a return address when compiling try/catch and try/finally. We
	// fully spill the frame before making the call. The expected frame
	// at the label (which should be the only one) is the spilled current
	// frame plus an in-memory return address. The "fall-through" frame
	// at the return site is the spilled current frame.
	ASSERT(cgen()->has_valid_frame());
	// There are no non-frame references across the call.
	ASSERT(cgen()->HasValidEntryRegisters());
	ASSERT(!is_linked());

	// Calls are always 'forward' so we use a copy of the current frame (plus
	// one for a return address) as the expected frame.
	ASSERT(entry_frame_ == NULL);
	VirtualFrame* target_frame = new VirtualFrame(cgen()->frame());
	target_frame->Adjust(1);
	entry_frame_ = target_frame;

	// The predicate is_linked() should now be made true. Its implementation
	// detects the presence of a frame pointer in the reaching_frames_ list.
	reaching_frames_.Add(NULL);
	ASSERT(is_linked());

	__ bl(&entry_label_);
	}


	void JumpTarget::DoBind() {
	ASSERT(!is_bound());

	// Live non-frame registers are not allowed at the start of a basic
	// block.
	ASSERT(!cgen()->has_valid_frame() \|\| cgen()->HasValidEntryRegisters());

	if (cgen()->has_valid_frame()) {
	// If there is a current frame we can use it on the fall through.
	if (entry_frame_ == NULL) {
	entry_frame_ = new VirtualFrame(cgen()->frame());
	} else {
	ASSERT(cgen()->frame()->Equals(entry_frame_));
	}
	} else {
	// If there is no current frame we must have an entry frame which we can
	// copy.
	ASSERT(entry_frame_ != NULL);
	RegisterFile empty;
	cgen()->SetFrame(new VirtualFrame(entry_frame_), &empty);
	}

	// The predicate is_linked() should be made false. Its implementation
	// detects the presence (or absence) of frame pointers in the
	// reaching_frames_ list. If we inserted a bogus frame to make
	// is_linked() true, remove it now.
	if (is_linked()) {
	reaching_frames_.Clear();
	}

	__ bind(&entry_label_);
	}


	void BreakTarget::Jump() {
	// On ARM we do not currently emit merge code for jumps, so we need to do
	// it explicitly here. The only merging necessary is to drop extra
	// statement state from the stack.
	ASSERT(cgen()->has_valid_frame());
	int count = cgen()->frame()->height() - expected_height_;
	cgen()->frame()->Drop(count);
	DoJump();
	}


	void BreakTarget::Jump(Result* arg) {
	// On ARM we do not currently emit merge code for jumps, so we need to do
	// it explicitly here. The only merging necessary is to drop extra
	// statement state from the stack.
	ASSERT(cgen()->has_valid_frame());
	int count = cgen()->frame()->height() - expected_height_;
	cgen()->frame()->Drop(count);
	cgen()->frame()->Push(arg);
	DoJump();
	}


	void BreakTarget::Bind() {
	#ifdef DEBUG
	// All the forward-reaching frames should have been adjusted at the
	// jumps to this target.
	for (int i = 0; i < reaching_frames_.length(); i++) {
	ASSERT(reaching_frames_[i] == NULL \|\|
	reaching_frames_[i]->height() == expected_height_);
	}
	#endif
	// Drop leftover statement state from the frame before merging, even
	// on the fall through. This is so we can bind the return target
	// with state on the frame.
	if (cgen()->has_valid_frame()) {
	int count = cgen()->frame()->height() - expected_height_;
	// On ARM we do not currently emit merge code at binding sites, so we need
	// to do it explicitly here. The only merging necessary is to drop extra
	// statement state from the stack.
	cgen()->frame()->Drop(count);
	}

	DoBind();
	}


	void BreakTarget::Bind(Result* arg) {
	#ifdef DEBUG
	// All the forward-reaching frames should have been adjusted at the
	// jumps to this target.
	for (int i = 0; i < reaching_frames_.length(); i++) {
	ASSERT(reaching_frames_[i] == NULL \|\|
	reaching_frames_[i]->height() == expected_height_ + 1);
	}
	#endif
	// Drop leftover statement state from the frame before merging, even
	// on the fall through. This is so we can bind the return target
	// with state on the frame.
	if (cgen()->has_valid_frame()) {
	int count = cgen()->frame()->height() - expected_height_;
	// On ARM we do not currently emit merge code at binding sites, so we need
	// to do it explicitly here. The only merging necessary is to drop extra
	// statement state from the stack.
	cgen()->frame()->ForgetElements(count);
	cgen()->frame()->Push(arg);
	}
	DoBind();
	*arg = cgen()->frame()->Pop();
	}


	#undef __


	} } // namespace v8::internal