decode_cache.hh (8541:27aaee8ec7cc) | decode_cache.hh (9021:736048daf279) |
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1/* 2 * Copyright (c) 2011 Google 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; --- 34 unchanged lines hidden (view full) --- 43class DecodeCache 44{ 45 private: 46 typedef TheISA::ExtMachInst ExtMachInst; 47 48 /// Hash of decoded instructions. 49 typedef m5::hash_map<ExtMachInst, StaticInstPtr> InstMap; 50 InstMap instMap; | 1/* 2 * Copyright (c) 2011 Google 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; --- 34 unchanged lines hidden (view full) --- 43class DecodeCache 44{ 45 private: 46 typedef TheISA::ExtMachInst ExtMachInst; 47 48 /// Hash of decoded instructions. 49 typedef m5::hash_map<ExtMachInst, StaticInstPtr> InstMap; 50 InstMap instMap; |
51 52 /// A table of instructions which are already been decoded, indexed by 53 /// page offset. 54 class DecodePage 55 { 56 protected: 57 StaticInstPtr instructions[TheISA::PageBytes]; 58 59 // A helper function to compute the index of an address in the table. 60 Addr offset(Addr addr) { return addr & (TheISA::PageBytes - 1); } 61 62 public: 63 /// Decode the given instruction. First attempt to find it in the 64 /// table, then in the generic decode cache, and finally call the 65 /// actual decode function. 66 /// 67 /// @param mach_inst The predecoded instruction to decode. 68 /// @param addr The address the instruction came from. 69 /// @param cache A cache of already decoded instructions. 70 /// @retval The decoded instruction object. 71 StaticInstPtr 72 decode(const ExtMachInst &mach_inst, Addr addr, InstMap &instMap) 73 { 74 StaticInstPtr si = instructions[offset(addr)]; 75 if (si && (si->machInst == mach_inst)) { 76 return si; 77 } 78 79 InstMap::iterator iter = instMap.find(mach_inst); 80 if (iter != instMap.end()) { 81 si = iter->second; 82 } else { 83 si = decodeInstFunc(mach_inst); 84 instMap[mach_inst] = si; 85 } 86 87 instructions[offset(addr)] = si; 88 return si; 89 } | 51 struct DecodePage { 52 StaticInstPtr insts[TheISA::PageBytes]; |
90 }; 91 92 /// A store of DecodePages. Basically a slightly smarter hash_map. 93 class DecodePages 94 { 95 protected: 96 typedef typename m5::hash_map<Addr, DecodePage *> PageMap; 97 typedef typename PageMap::iterator PageIt; --- 4 unchanged lines hidden (view full) --- 102 /// @param recentest The most recent result; 103 void 104 update(PageIt recentest) 105 { 106 recent[1] = recent[0]; 107 recent[0] = recentest; 108 } 109 | 53 }; 54 55 /// A store of DecodePages. Basically a slightly smarter hash_map. 56 class DecodePages 57 { 58 protected: 59 typedef typename m5::hash_map<Addr, DecodePage *> PageMap; 60 typedef typename PageMap::iterator PageIt; --- 4 unchanged lines hidden (view full) --- 65 /// @param recentest The most recent result; 66 void 67 update(PageIt recentest) 68 { 69 recent[1] = recent[0]; 70 recent[0] = recentest; 71 } 72 |
73 void 74 addPage(Addr addr, DecodePage *page) 75 { 76 Addr page_addr = addr & ~(TheISA::PageBytes - 1); 77 typename PageMap::value_type to_insert(page_addr, page); 78 update(pageMap.insert(to_insert).first); 79 } 80 |
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110 public: 111 /// Constructor 112 DecodePages() 113 { 114 recent[0] = recent[1] = pageMap.end(); 115 } 116 117 /// Attempt to find the DecodePage which goes with a particular 118 /// address. First check the small cache of recent results, then 119 /// actually look in the hash_map. 120 /// @param addr The address to look up. 121 DecodePage * | 81 public: 82 /// Constructor 83 DecodePages() 84 { 85 recent[0] = recent[1] = pageMap.end(); 86 } 87 88 /// Attempt to find the DecodePage which goes with a particular 89 /// address. First check the small cache of recent results, then 90 /// actually look in the hash_map. 91 /// @param addr The address to look up. 92 DecodePage * |
122 findPage(Addr addr) | 93 getPage(Addr addr) |
123 { 124 Addr page_addr = addr & ~(TheISA::PageBytes - 1); 125 126 // Check against recent lookups. 127 if (recent[0] != pageMap.end()) { 128 if (recent[0]->first == page_addr) 129 return recent[0]->second; 130 if (recent[1] != pageMap.end() && --- 6 unchanged lines hidden (view full) --- 137 138 // Actually look in the has_map. 139 PageIt it = pageMap.find(page_addr); 140 if (it != pageMap.end()) { 141 update(it); 142 return it->second; 143 } 144 | 94 { 95 Addr page_addr = addr & ~(TheISA::PageBytes - 1); 96 97 // Check against recent lookups. 98 if (recent[0] != pageMap.end()) { 99 if (recent[0]->first == page_addr) 100 return recent[0]->second; 101 if (recent[1] != pageMap.end() && --- 6 unchanged lines hidden (view full) --- 108 109 // Actually look in the has_map. 110 PageIt it = pageMap.find(page_addr); 111 if (it != pageMap.end()) { 112 update(it); 113 return it->second; 114 } 115 |
145 // Didn't find it so return NULL. 146 return NULL; | 116 // Didn't find an existing page, so add a new one. 117 DecodePage *newPage = new DecodePage; 118 addPage(page_addr, newPage); 119 return newPage; |
147 } | 120 } |
148 149 void 150 addPage(Addr addr, DecodePage *page) 151 { 152 Addr page_addr = addr & ~(TheISA::PageBytes - 1); 153 typename PageMap::value_type to_insert(page_addr, page); 154 update(pageMap.insert(to_insert).first); 155 } | |
156 } decodePages; 157 158 public: 159 /// Decode a machine instruction. 160 /// @param mach_inst The binary instruction to decode. 161 /// @retval A pointer to the corresponding StaticInst object. 162 StaticInstPtr 163 decode(ExtMachInst mach_inst, Addr addr) 164 { 165 // Try to find a matching address based table of instructions. | 121 } decodePages; 122 123 public: 124 /// Decode a machine instruction. 125 /// @param mach_inst The binary instruction to decode. 126 /// @retval A pointer to the corresponding StaticInst object. 127 StaticInstPtr 128 decode(ExtMachInst mach_inst, Addr addr) 129 { 130 // Try to find a matching address based table of instructions. |
166 DecodePage *page = decodePages.findPage(addr); 167 if (!page) { 168 // Nothing was found, so create a new one. 169 page = new DecodePage; 170 decodePages.addPage(addr, page); 171 } | 131 DecodePage *page = decodePages.getPage(addr); |
172 173 // Use the table to decode the instruction. It will fall back to other 174 // mechanisms if it needs to. | 132 133 // Use the table to decode the instruction. It will fall back to other 134 // mechanisms if it needs to. |
175 return page->decode(mach_inst, addr, instMap); | 135 Addr offset = addr & (TheISA::PageBytes - 1); 136 StaticInstPtr si = page->insts[offset]; 137 if (si && (si->machInst == mach_inst)) 138 return si; 139 140 InstMap::iterator iter = instMap.find(mach_inst); 141 if (iter != instMap.end()) { 142 si = iter->second; 143 page->insts[offset] = si; 144 return si; 145 } 146 147 si = decodeInstFunc(mach_inst); 148 instMap[mach_inst] = si; 149 page->insts[offset] = si; 150 return si; |
176 } 177}; 178 179#endif // __CPU_DECODE_CACHE_HH__ | 151 } 152}; 153 154#endif // __CPU_DECODE_CACHE_HH__ |