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Diffstat (limited to 'src/mem/ruby/structures/LRUPolicy.hh')
-rw-r--r-- | src/mem/ruby/structures/LRUPolicy.hh | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/mem/ruby/structures/LRUPolicy.hh b/src/mem/ruby/structures/LRUPolicy.hh new file mode 100644 index 000000000..bb61b9d50 --- /dev/null +++ b/src/mem/ruby/structures/LRUPolicy.hh @@ -0,0 +1,95 @@ +/* + * Copyright (c) 2007 Mark D. Hill and David A. Wood + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * 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; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "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 THE COPYRIGHT + * OWNER 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 __MEM_RUBY_SYSTEM_LRUPOLICY_HH__ +#define __MEM_RUBY_SYSTEM_LRUPOLICY_HH__ + +#include "mem/ruby/structures/AbstractReplacementPolicy.hh" + +/* Simple true LRU replacement policy */ + +class LRUPolicy : public AbstractReplacementPolicy +{ + public: + LRUPolicy(Index num_sets, Index assoc); + ~LRUPolicy(); + + void touch(Index set, Index way, Tick time); + Index getVictim(Index set) const; +}; + +inline +LRUPolicy::LRUPolicy(Index num_sets, Index assoc) + : AbstractReplacementPolicy(num_sets, assoc) +{ +} + +inline +LRUPolicy::~LRUPolicy() +{ +} + +inline void +LRUPolicy::touch(Index set, Index index, Tick time) +{ + assert(index >= 0 && index < m_assoc); + assert(set >= 0 && set < m_num_sets); + + m_last_ref_ptr[set][index] = time; +} + +inline Index +LRUPolicy::getVictim(Index set) const +{ + // assert(m_assoc != 0); + Tick time, smallest_time; + Index smallest_index; + + smallest_index = 0; + smallest_time = m_last_ref_ptr[set][0]; + + for (unsigned i = 0; i < m_assoc; i++) { + time = m_last_ref_ptr[set][i]; + // assert(m_cache[cacheSet][i].m_Permission != + // AccessPermission_NotPresent); + + if (time < smallest_time) { + smallest_index = i; + smallest_time = time; + } + } + + // DEBUG_EXPR(CACHE_COMP, MedPrio, cacheSet); + // DEBUG_EXPR(CACHE_COMP, MedPrio, smallest_index); + // DEBUG_EXPR(CACHE_COMP, MedPrio, m_cache[cacheSet][smallest_index]); + // DEBUG_EXPR(CACHE_COMP, MedPrio, *this); + + return smallest_index; +} + +#endif // __MEM_RUBY_SYSTEM_LRUPOLICY_HH__ |