1 /* 2 * Copyright (C) 2008 Apple Inc. All rights reserved. 3 * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca> 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 15 * its contributors may be used to endorse or promote products derived 16 * from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 21 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 22 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 25 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #ifndef JumpTable_h 31 #define JumpTable_h 32 33 #include "UString.h" 34 #include <wtf/HashMap.h> 35 #include <wtf/Vector.h> 36 37 namespace JSC { 38 39 struct OffsetLocation { 40 int32_t branchOffset; 41 #if ENABLE(JIT) 42 void* ctiOffset; 43 #endif 44 }; 45 46 struct StringJumpTable { 47 typedef HashMap<RefPtr<UString::Rep>, OffsetLocation> StringOffsetTable; 48 StringOffsetTable offsetTable; 49 #if ENABLE(JIT) 50 void* ctiDefault; // FIXME: it should not be necessary to store this. 51 #endif 52 offsetForValueStringJumpTable53 inline int32_t offsetForValue(UString::Rep* value, int32_t defaultOffset) 54 { 55 StringOffsetTable::const_iterator end = offsetTable.end(); 56 StringOffsetTable::const_iterator loc = offsetTable.find(value); 57 if (loc == end) 58 return defaultOffset; 59 return loc->second.branchOffset; 60 } 61 62 #if ENABLE(JIT) ctiForValueStringJumpTable63 inline void* ctiForValue(UString::Rep* value) 64 { 65 StringOffsetTable::const_iterator end = offsetTable.end(); 66 StringOffsetTable::const_iterator loc = offsetTable.find(value); 67 if (loc == end) 68 return ctiDefault; 69 return loc->second.ctiOffset; 70 } 71 #endif 72 }; 73 74 struct SimpleJumpTable { 75 // FIXME: The two Vectors can be combind into one Vector<OffsetLocation> 76 Vector<int32_t> branchOffsets; 77 int32_t min; 78 #if ENABLE(JIT) 79 Vector<void*> ctiOffsets; 80 void* ctiDefault; 81 #endif 82 83 int32_t offsetForValue(int32_t value, int32_t defaultOffset); addSimpleJumpTable84 void add(int32_t key, int32_t offset) 85 { 86 if (!branchOffsets[key]) 87 branchOffsets[key] = offset; 88 } 89 90 #if ENABLE(JIT) ctiForValueSimpleJumpTable91 inline void* ctiForValue(int32_t value) 92 { 93 if (value >= min && static_cast<uint32_t>(value - min) < ctiOffsets.size()) 94 return ctiOffsets[value - min]; 95 return ctiDefault; 96 } 97 #endif 98 }; 99 100 } // namespace JSC 101 102 #endif // JumpTable_h 103