1/* 2 * Copyright (C) 2011 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 VirtualRegister_h 27#define VirtualRegister_h 28 29#include "CallFrame.h" 30 31#include <wtf/PrintStream.h> 32 33namespace JSC { 34 35inline bool operandIsLocal(int operand) 36{ 37 return operand < 0; 38} 39 40inline bool operandIsArgument(int operand) 41{ 42 return operand >= 0; 43} 44 45 46class VirtualRegister { 47public: 48 friend VirtualRegister virtualRegisterForLocal(int); 49 friend VirtualRegister virtualRegisterForArgument(int, int); 50 51 VirtualRegister() 52 : m_virtualRegister(s_invalidVirtualRegister) 53 { } 54 55 explicit VirtualRegister(int virtualRegister) 56 : m_virtualRegister(virtualRegister) 57 { } 58 59 bool isValid() const { return (m_virtualRegister != s_invalidVirtualRegister); } 60 bool isLocal() const { return operandIsLocal(m_virtualRegister); } 61 bool isArgument() const { return operandIsArgument(m_virtualRegister); } 62 bool isConstant() const { return m_virtualRegister >= s_firstConstantRegisterIndex; } 63 int toLocal() const { ASSERT(isLocal()); return operandToLocal(m_virtualRegister); } 64 int toArgument() const { ASSERT(isArgument()); return operandToArgument(m_virtualRegister); } 65 int toConstantIndex() const { ASSERT(isConstant()); return m_virtualRegister - s_firstConstantRegisterIndex; } 66 int offset() const { return m_virtualRegister; } 67 int offsetInBytes() const { return m_virtualRegister * sizeof(Register); } 68 69 bool operator==(const VirtualRegister other) const { return m_virtualRegister == other.m_virtualRegister; } 70 bool operator!=(const VirtualRegister other) const { return m_virtualRegister != other.m_virtualRegister; } 71 72private: 73 static const int s_invalidVirtualRegister = 0x3fffffff; 74 static const int s_firstConstantRegisterIndex = 0x40000000; 75 76 static int localToOperand(int local) { return -1 - local; } 77 static int operandToLocal(int operand) { return -1 - operand; } 78 static int operandToArgument(int operand) { return operand - CallFrame::thisArgumentOffset(); } 79 static int argumentToOperand(int argument) { return argument + CallFrame::thisArgumentOffset(); } 80 81 int m_virtualRegister; 82}; 83 84COMPILE_ASSERT(sizeof(VirtualRegister) == sizeof(int), VirtualRegister_is_32bit); 85 86inline VirtualRegister virtualRegisterForLocal(int local) 87{ 88 return VirtualRegister(VirtualRegister::localToOperand(local)); 89} 90 91inline VirtualRegister virtualRegisterForArgument(int argument, int offset = 0) 92{ 93 return VirtualRegister(VirtualRegister::argumentToOperand(argument) + offset); 94} 95 96} // namespace JSC 97 98namespace WTF { 99 100inline void printInternal(PrintStream& out, JSC::VirtualRegister value) 101{ 102 out.print(value.offset()); 103} 104 105} // namespace WTF 106 107#endif // VirtualRegister_h 108