JavaScriptCore-7601.1.46.3.tar.gz

[apple/javascriptcore.git] / dfg / DFGBinarySwitch.h

diff --git a/dfg/DFGBinarySwitch.h b/dfg/DFGBinarySwitch.h
deleted file mode 100644 (file)
index 45d4a6a..0000000
--- a/dfg/DFGBinarySwitch.h
+++ /dev/null
@@ -1,140 +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
-
-#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
-