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Diffstat (limited to 'Source/JavaScriptCore/dfg/DFGBinarySwitch.h')
-rw-r--r-- | Source/JavaScriptCore/dfg/DFGBinarySwitch.h | 142 |
1 files changed, 0 insertions, 142 deletions
diff --git a/Source/JavaScriptCore/dfg/DFGBinarySwitch.h b/Source/JavaScriptCore/dfg/DFGBinarySwitch.h deleted file mode 100644 index be39cb19a..000000000 --- a/Source/JavaScriptCore/dfg/DFGBinarySwitch.h +++ /dev/null @@ -1,142 +0,0 @@ -/* - * Copyright (C) 2013 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. - */ - -#ifndef DFGBinarySwitch_h -#define DFGBinarySwitch_h - -#include <wtf/Platform.h> - -#if ENABLE(DFG_JIT) - -#include "GPRInfo.h" -#include "MacroAssembler.h" - -namespace JSC { namespace DFG { - -// The BinarySwitch class makes it easy to emit a switch statement over either -// 32-bit integers or pointers, where the switch uses a tree of branches -// rather than a jump table. This makes it particularly useful if the case -// values are too far apart to make a jump table practical, or if there are -// sufficiently few cases that the total cost of log(numCases) branches is -// less than the cost of an indirected jump. -// -// In an effort to simplify the logic of emitting code for each case, this -// uses an iterator style, rather than a functor callback style. This makes -// sense because even the iterator implementation found herein is relatively -// simple, whereas the code it's used from is usually quite complex - one -// example being the trie-of-trees string switch implementation, where the -// code emitted for each case involves recursing to emit code for a sub-trie. -// -// Use this like so: -// -// BinarySwitch switch(valueReg, casesVector, BinarySwitch::Int32); -// while (switch.advance(jit)) { -// int value = switch.caseValue(); -// unsigned index = switch.caseIndex(); // index into casesVector, above -// ... // generate code for this case -// } -// switch.fallThrough().link(&jit); - -class BinarySwitch { -public: - enum Type { - Int32, - IntPtr - }; - - BinarySwitch(GPRReg value, const Vector<int64_t>& cases, Type); - - unsigned caseIndex() const { return m_cases[m_caseIndex].index; } - int64_t caseValue() const { return m_cases[m_caseIndex].value; } - - bool advance(MacroAssembler&); - - MacroAssembler::JumpList& fallThrough() { return m_fallThrough; } - -private: - void build(unsigned start, unsigned end); - - GPRReg m_value; - - struct Case { - Case() { } - - Case(int64_t value, unsigned index) - : value(value) - , index(index) - { - } - - bool operator<(const Case& other) const - { - return value < other.value; - } - - int64_t value; - unsigned index; - }; - - Vector<Case> m_cases; - - enum BranchKind { - NotEqualToFallThrough, - NotEqualToPush, - LessThanToPush, - Pop, - ExecuteCase - }; - - struct BranchCode { - BranchCode() { } - - BranchCode(BranchKind kind, unsigned index = UINT_MAX) - : kind(kind) - , index(index) - { - } - - BranchKind kind; - unsigned index; - }; - - Vector<BranchCode> m_branches; - - unsigned m_index; - unsigned m_caseIndex; - Vector<MacroAssembler::Jump> m_jumpStack; - - MacroAssembler::JumpList m_fallThrough; - - unsigned m_medianBias; - - Type m_type; -}; - -} } // namespace JSC::DFG - -#endif // ENABLE(DFG_JIT) - -#endif // DFGBinarySwitch_h - |