| // 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 "register-allocator-inl.h" |
| |
| namespace v8 { namespace internal { |
| |
| // ------------------------------------------------------------------------- |
| // Result implementation. |
| |
| Result::Result(Register reg, CodeGenerator* cgen) |
| : type_(REGISTER), |
| cgen_(cgen) { |
| data_.reg_ = reg; |
| ASSERT(reg.is_valid()); |
| cgen_->allocator()->Use(reg); |
| } |
| |
| |
| void Result::CopyTo(Result* destination) const { |
| destination->type_ = type(); |
| destination->cgen_ = cgen_; |
| |
| if (is_register()) { |
| destination->data_.reg_ = reg(); |
| cgen_->allocator()->Use(reg()); |
| } else if (is_constant()) { |
| destination->data_.handle_ = data_.handle_; |
| } else { |
| ASSERT(!is_valid()); |
| } |
| } |
| |
| |
| // ------------------------------------------------------------------------- |
| // RegisterFile implementation. |
| |
| void RegisterFile::CopyTo(RegisterFile* other) { |
| for (int i = 0; i < kNumRegisters; i++) { |
| other->ref_counts_[i] = ref_counts_[i]; |
| } |
| } |
| |
| |
| // ------------------------------------------------------------------------- |
| // RegisterAllocator implementation. |
| |
| |
| Result RegisterAllocator::AllocateWithoutSpilling() { |
| // Return the first free register, if any. |
| int free_reg = registers_.ScanForFreeRegister(); |
| if (free_reg < kNumRegisters) { |
| Register free_result = { free_reg }; |
| return Result(free_result, cgen_); |
| } |
| return Result(cgen_); |
| } |
| |
| |
| Result RegisterAllocator::Allocate() { |
| Result result = AllocateWithoutSpilling(); |
| if (!result.is_valid()) { |
| // Ask the current frame to spill a register. |
| ASSERT(cgen_->has_valid_frame()); |
| Register free_reg = cgen_->frame()->SpillAnyRegister(); |
| if (free_reg.is_valid()) { |
| ASSERT(!is_used(free_reg)); |
| return Result(free_reg, cgen_); |
| } |
| } |
| return result; |
| } |
| |
| |
| Result RegisterAllocator::Allocate(Register target) { |
| // If the target is not referenced, it can simply be allocated. |
| if (!is_used(target)) { |
| return Result(target, cgen_); |
| } |
| // If the target is only referenced in the frame, it can be spilled and |
| // then allocated. |
| ASSERT(cgen_->has_valid_frame()); |
| if (count(target) == cgen_->frame()->register_count(target)) { |
| cgen_->frame()->Spill(target); |
| ASSERT(!is_used(target)); |
| return Result(target, cgen_); |
| } |
| // Otherwise (if it's referenced outside the frame) we cannot allocate it. |
| return Result(cgen_); |
| } |
| |
| |
| } } // namespace v8::internal |