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 "MacroAssembler.h" 34 #include "UString.h" 35 #include <wtf/HashMap.h> 36 #include <wtf/Vector.h> 37 38 namespace JSC { 39 40 struct OffsetLocation { 41 int32_t branchOffset; 42 #if ENABLE(JIT) 43 CodeLocationLabel ctiOffset; 44 #endif 45 }; 46 47 struct StringJumpTable { 48 typedef HashMap<RefPtr<UString::Rep>, OffsetLocation> StringOffsetTable; 49 StringOffsetTable offsetTable; 50 #if ENABLE(JIT) 51 CodeLocationLabel ctiDefault; // FIXME: it should not be necessary to store this. 52 #endif 53 offsetForValueStringJumpTable54 inline int32_t offsetForValue(UString::Rep* value, int32_t defaultOffset) 55 { 56 StringOffsetTable::const_iterator end = offsetTable.end(); 57 StringOffsetTable::const_iterator loc = offsetTable.find(value); 58 if (loc == end) 59 return defaultOffset; 60 return loc->second.branchOffset; 61 } 62 63 #if ENABLE(JIT) ctiForValueStringJumpTable64 inline CodeLocationLabel ctiForValue(UString::Rep* value) 65 { 66 StringOffsetTable::const_iterator end = offsetTable.end(); 67 StringOffsetTable::const_iterator loc = offsetTable.find(value); 68 if (loc == end) 69 return ctiDefault; 70 return loc->second.ctiOffset; 71 } 72 #endif 73 }; 74 75 struct SimpleJumpTable { 76 // FIXME: The two Vectors can be combind into one Vector<OffsetLocation> 77 Vector<int32_t> branchOffsets; 78 int32_t min; 79 #if ENABLE(JIT) 80 Vector<CodeLocationLabel> ctiOffsets; 81 CodeLocationLabel ctiDefault; 82 #endif 83 84 int32_t offsetForValue(int32_t value, int32_t defaultOffset); addSimpleJumpTable85 void add(int32_t key, int32_t offset) 86 { 87 if (!branchOffsets[key]) 88 branchOffsets[key] = offset; 89 } 90 91 #if ENABLE(JIT) ctiForValueSimpleJumpTable92 inline CodeLocationLabel ctiForValue(int32_t value) 93 { 94 if (value >= min && static_cast<uint32_t>(value - min) < ctiOffsets.size()) 95 return ctiOffsets[value - min]; 96 return ctiDefault; 97 } 98 #endif 99 }; 100 101 } // namespace JSC 102 103 #endif // JumpTable_h 104