jit/ScratchRegisterAllocator.h

   1 /*
   2  * Copyright (C) 2012, 2014 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef ScratchRegisterAllocator_h
  27 #define ScratchRegisterAllocator_h
  28
  29 #if ENABLE(JIT)
  30
  31 #include "MacroAssembler.h"
  32 #include "RegisterSet.h"
  33 #include "TempRegisterSet.h"
  34
  35 namespace JSC {
  36
  37 struct ScratchBuffer;
  38
  39 // This class provides a low-level register allocator for use in stubs.
  40
  41 class ScratchRegisterAllocator {
  42 public:
  43     ScratchRegisterAllocator(const RegisterSet& usedRegisters);
  44     ~ScratchRegisterAllocator();
  45
  46     void lock(GPRReg reg);
  47     void lock(FPRReg reg);
  48
  49     template<typename BankInfo>
  50     typename BankInfo::RegisterType allocateScratch();
  51
  52     GPRReg allocateScratchGPR();
  53     FPRReg allocateScratchFPR();
  54
  55     bool didReuseRegisters() const
  56     {
  57         return !!m_numberOfReusedRegisters;
  58     }
  59
  60     unsigned numberOfReusedRegisters() const
  61     {
  62         return m_numberOfReusedRegisters;
  63     }
  64
  65     void preserveReusedRegistersByPushing(MacroAssembler& jit);
  66     void restoreReusedRegistersByPopping(MacroAssembler& jit);
  67
  68     RegisterSet usedRegistersForCall() const;
  69
  70     unsigned desiredScratchBufferSizeForCall() const;
  71
  72     void preserveUsedRegistersToScratchBufferForCall(MacroAssembler& jit, ScratchBuffer* scratchBuffer, GPRReg scratchGPR = InvalidGPRReg);
  73
  74     void restoreUsedRegistersFromScratchBufferForCall(MacroAssembler& jit, ScratchBuffer* scratchBuffer, GPRReg scratchGPR = InvalidGPRReg);
  75
  76 private:
  77     RegisterSet m_usedRegisters;
  78     TempRegisterSet m_lockedRegisters;
  79     TempRegisterSet m_scratchRegisters;
  80     unsigned m_numberOfReusedRegisters;
  81 };
  82
  83 } // namespace JSC
  84
  85 #endif // ENABLE(JIT)
  86
  87 #endif // ScratchRegisterAllocator_h