00001 // 00002 // Copyright (c) 2005-2008 Kenichi Watanabe. 00003 // Copyright (c) 2005-2008 Yasuhiro Watari. 00004 // Copyright (c) 2005-2008 Hironori Ichibayashi. 00005 // Copyright (c) 2008-2009 Kazuo Horio. 00006 // Copyright (c) 2009-2013 Naruki Kurata. 00007 // Copyright (c) 2005-2013 Ryota Shioya. 00008 // Copyright (c) 2005-2013 Masahiro Goshima. 00009 // 00010 // This software is provided 'as-is', without any express or implied 00011 // warranty. In no event will the authors be held liable for any damages 00012 // arising from the use of this software. 00013 // 00014 // Permission is granted to anyone to use this software for any purpose, 00015 // including commercial applications, and to alter it and redistribute it 00016 // freely, subject to the following restrictions: 00017 // 00018 // 1. The origin of this software must not be misrepresented; you must not 00019 // claim that you wrote the original software. If you use this software 00020 // in a product, an acknowledgment in the product documentation would be 00021 // appreciated but is not required. 00022 // 00023 // 2. Altered source versions must be plainly marked as such, and must not be 00024 // misrepresented as being the original software. 00025 // 00026 // 3. This notice may not be removed or altered from any source 00027 // distribution. 00028 // 00029 // 00030 00031 00032 #include <pch.h> 00033 00034 #include "Sim/Predictor/BPred/PHT.h" 00035 00036 using namespace Onikiri; 00037 using namespace shttl; 00038 00039 00040 PHT::PHT() : 00041 m_counterBits(0), 00042 m_entryBits(0) 00043 { 00044 } 00045 00046 PHT::~PHT() 00047 { 00048 ReleaseParam(); 00049 } 00050 00051 void PHT::Initialize(InitPhase phase) 00052 { 00053 if(phase == INIT_PRE_CONNECTION){ 00054 LoadParam(); 00055 u8 max = (1 << m_counterBits) - 1; 00056 m_table.construct( 00057 1 << m_entryBits, // size 00058 (max + 1) / 2, // init 00059 0, // min 00060 max, // max 00061 1, // add 00062 1, // sub 00063 (max + 1) / 2 // threshold 00064 ); 00065 } 00066 } 00067 00068 void PHT::Update(int index, bool taken) 00069 { 00070 if(taken) 00071 m_table[index].inc(); 00072 else 00073 m_table[index].dec(); 00074 } 00075 00076 bool PHT::Predict(int index) 00077 { 00078 return m_table[index].above_threshold(); 00079 }