/* * Copyright (C) 2015-2017 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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. */ #pragma once #if ENABLE(B3_JIT) #include "AirArg.h" namespace JSC { namespace B3 { namespace Air { class Code; class TmpWidth { public: TmpWidth(); TmpWidth(Code&); ~TmpWidth(); template <Bank bank> void recompute(Code&); // The width of a Tmp is the number of bits that you need to be able to track without some trivial // recovery. A Tmp may have a "subwidth" (say, Width32 on a 64-bit system) if either of the following // is true: // // - The high bits are never read. // - The high bits are always zero. // // This doesn't tell you which of those properties holds, but you can query that using the other // methods. Width width(Tmp tmp) const { Widths tmpWidths = widths(tmp); return std::min(tmpWidths.use, tmpWidths.def); } // Return the minimum required width for all defs/uses of this Tmp. Width requiredWidth(Tmp tmp) { Widths tmpWidths = widths(tmp); return std::max(tmpWidths.use, tmpWidths.def); } // This indirectly tells you how much of the tmp's high bits are guaranteed to be zero. The number of // high bits that are zero are: // // TotalBits - defWidth(tmp) // // Where TotalBits are the total number of bits in the register, so 64 on a 64-bit system. Width defWidth(Tmp tmp) const { return widths(tmp).def; } // This tells you how much of Tmp is going to be read. Width useWidth(Tmp tmp) const { return widths(tmp).use; } private: struct Widths { Widths() { } Widths(Bank bank) : use(minimumWidth(bank)) , def(minimumWidth(bank)) { } Widths(Width useArg, Width defArg) : use(useArg) , def(defArg) { } void dump(PrintStream& out) const; Width use; Width def; }; inline Widths& widths(Tmp); const Widths& widths(Tmp tmp) const { return const_cast<TmpWidth*>(this)->widths(tmp); } void addWidths(Tmp tmp, Widths tmpWidths) { widths(tmp) = tmpWidths; } Vector<Widths>& widthsVector(Bank bank) { return bank == GP ? m_widthGP : m_widthFP; } // These are initialized at the beginning of recompute<bank>, which is called in the constructor for both values of bank. Vector<Widths> m_widthGP; Vector<Widths> m_widthFP; }; } } } // namespace JSC::B3::Air #endif // ENABLE(B3_JIT)