CSE2410 Fall 2014 Bounce

// 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 "register-allocator-inl.h"

namespace v8 { namespace internal {

// -------------------------------------------------------------------------

// Result implementation.

void Result::ToRegister() {

  ASSERT(is_valid());

  if (is_constant()) {

    Result fresh = cgen_->allocator()->Allocate();

    ASSERT(fresh.is_valid());

    if (cgen_->IsUnsafeSmi(handle())) {

      cgen_->LoadUnsafeSmi(fresh.reg(), handle());

    } else {

      cgen_->masm()->Set(fresh.reg(), Immediate(handle()));

    }

    // This result becomes a copy of the fresh one.

    *this = fresh;

  }

  ASSERT(is_register());

}

void Result::ToRegister(Register target) {

  ASSERT(is_valid());

  if (!is_register() || !reg().is(target)) {

    Result fresh = cgen_->allocator()->Allocate(target);

    ASSERT(fresh.is_valid());

    if (is_register()) {

      cgen_->masm()->mov(fresh.reg(), reg());

    } else {

      ASSERT(is_constant());

      if (cgen_->IsUnsafeSmi(handle())) {

        cgen_->LoadUnsafeSmi(fresh.reg(), handle());

      } else {

        cgen_->masm()->Set(fresh.reg(), Immediate(handle()));

      }

    }

    *this = fresh;

  } else if (is_register() && reg().is(target)) {

    ASSERT(cgen_->has_valid_frame());

    cgen_->frame()->Spill(target);

    ASSERT(cgen_->allocator()->count(target) == 1);

  }

  ASSERT(is_register());

  ASSERT(reg().is(target));

}

// -------------------------------------------------------------------------

// RegisterAllocator implementation.

RegisterFile RegisterAllocator::Reserved() {

  RegisterFile reserved;

  reserved.Use(esp);

  reserved.Use(ebp);

  reserved.Use(esi);

  return reserved;

}

void RegisterAllocator::UnuseReserved(RegisterFile* register_file) {

  register_file->ref_counts_[esp.code()] = 0;

  register_file->ref_counts_[ebp.code()] = 0;

  register_file->ref_counts_[esi.code()] = 0;

}

void RegisterAllocator::Initialize() {

  Reset();

  // The following register is live on function entry, saved in the

  // frame, and available for allocation during execution.

  Use(edi);  // JS function.

}

void RegisterAllocator::Reset() {

  registers_.Reset();

  // The following registers are live on function entry and reserved

  // during execution.

  Use(esp);  // Stack pointer.

  Use(ebp);  // Frame pointer (caller's frame pointer on entry).

  Use(esi);  // Context (callee's context on entry).

}

Result RegisterAllocator::AllocateByteRegisterWithoutSpilling() {

  Result result = AllocateWithoutSpilling();

  // Check that the register is a byte register.  If not, unuse the

  // register if valid and return an invalid result.

  if (result.is_valid() && !result.reg().is_byte_register()) {

    result.Unuse();

    return Result(cgen_);

  }

  return result;

}

} }  // namespace v8::internal