free_list.hh revision 1689
1/* 2 * Copyright (c) 2004-2005 The Regents of The University of Michigan 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; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#ifndef __CPU_BETA_CPU_FREE_LIST_HH__ 30#define __CPU_BETA_CPU_FREE_LIST_HH__ 31 32#include <iostream> 33#include <queue> 34 35#include "arch/alpha/isa_traits.hh" 36#include "base/trace.hh" 37#include "base/traceflags.hh" 38#include "cpu/beta_cpu/comm.hh" 39 40/** 41 * FreeList class that simply holds the list of free integer and floating 42 * point registers. Can request for a free register of either type, and 43 * also send back free registers of either type. This is a very simple 44 * class, but it should be sufficient for most implementations. Like all 45 * other classes, it assumes that the indices for the floating point 46 * registers starts after the integer registers end. Hence the variable 47 * numPhysicalIntRegs is logically equivalent to the baseFP dependency. 48 * Note that 49 * while this most likely should be called FreeList, the name "FreeList" 50 * is used in a typedef within the CPU Policy, and therefore no class 51 * can be named simply "FreeList". 52 * @todo: Give a better name to the base FP dependency. 53 */ 54class SimpleFreeList 55{ 56 private: 57 /** The list of free integer registers. */ 58 std::queue<PhysRegIndex> freeIntRegs; 59 60 /** The list of free floating point registers. */ 61 std::queue<PhysRegIndex> freeFloatRegs; 62 63 /** Number of logical integer registers. */ 64 int numLogicalIntRegs; 65 66 /** Number of physical integer registers. */ 67 int numPhysicalIntRegs; 68 69 /** Number of logical floating point registers. */ 70 int numLogicalFloatRegs; 71 72 /** Number of physical floating point registers. */ 73 int numPhysicalFloatRegs; 74 75 /** Total number of physical registers. */ 76 int numPhysicalRegs; 77 78 /** DEBUG stuff below. */ 79 std::vector<int> freeIntRegsScoreboard; 80 81 std::vector<bool> freeFloatRegsScoreboard; 82 83 public: 84 SimpleFreeList(unsigned _numLogicalIntRegs, 85 unsigned _numPhysicalIntRegs, 86 unsigned _numLogicalFloatRegs, 87 unsigned _numPhysicalFloatRegs); 88 89 inline PhysRegIndex getIntReg(); 90 91 inline PhysRegIndex getFloatReg(); 92 93 inline void addReg(PhysRegIndex freed_reg); 94 95 inline void addIntReg(PhysRegIndex freed_reg); 96 97 inline void addFloatReg(PhysRegIndex freed_reg); 98 99 bool hasFreeIntRegs() 100 { return !freeIntRegs.empty(); } 101 102 bool hasFreeFloatRegs() 103 { return !freeFloatRegs.empty(); } 104 105 int numFreeIntRegs() 106 { return freeIntRegs.size(); } 107 108 int numFreeFloatRegs() 109 { return freeFloatRegs.size(); } 110}; 111 112inline PhysRegIndex 113SimpleFreeList::getIntReg() 114{ 115 DPRINTF(Rename, "FreeList: Trying to get free integer register.\n"); 116 if (freeIntRegs.empty()) { 117 panic("No free integer registers!"); 118 } 119 120 PhysRegIndex free_reg = freeIntRegs.front(); 121 122 freeIntRegs.pop(); 123 124 // DEBUG 125 assert(freeIntRegsScoreboard[free_reg]); 126 freeIntRegsScoreboard[free_reg] = 0; 127 128 return(free_reg); 129} 130 131inline PhysRegIndex 132SimpleFreeList::getFloatReg() 133{ 134 DPRINTF(Rename, "FreeList: Trying to get free float register.\n"); 135 if (freeFloatRegs.empty()) { 136 panic("No free integer registers!"); 137 } 138 139 PhysRegIndex free_reg = freeFloatRegs.front(); 140 141 freeFloatRegs.pop(); 142 143 // DEBUG 144 assert(freeFloatRegsScoreboard[free_reg]); 145 freeFloatRegsScoreboard[free_reg] = 0; 146 147 return(free_reg); 148} 149 150inline void 151SimpleFreeList::addReg(PhysRegIndex freed_reg) 152{ 153 DPRINTF(Rename, "Freelist: Freeing register %i.\n", freed_reg); 154 //Might want to add in a check for whether or not this register is 155 //already in there. A bit vector or something similar would be useful. 156 if (freed_reg < numPhysicalIntRegs) { 157 freeIntRegs.push(freed_reg); 158 159 // DEBUG 160 assert(freeIntRegsScoreboard[freed_reg] == false); 161 freeIntRegsScoreboard[freed_reg] = 1; 162 } else if (freed_reg < numPhysicalRegs) { 163 freeFloatRegs.push(freed_reg); 164 165 // DEBUG 166 assert(freeFloatRegsScoreboard[freed_reg] == false); 167 freeFloatRegsScoreboard[freed_reg] = 1; 168 } 169} 170 171inline void 172SimpleFreeList::addIntReg(PhysRegIndex freed_reg) 173{ 174 DPRINTF(Rename, "Freelist: Freeing int register %i.\n", freed_reg); 175 176 // DEBUG 177 assert(!freeIntRegsScoreboard[freed_reg]); 178 freeIntRegsScoreboard[freed_reg] = 1; 179 180 freeIntRegs.push(freed_reg); 181} 182 183inline void 184SimpleFreeList::addFloatReg(PhysRegIndex freed_reg) 185{ 186 DPRINTF(Rename, "Freelist: Freeing float register %i.\n", freed_reg); 187 188 // DEBUG 189 assert(!freeFloatRegsScoreboard[freed_reg]); 190 freeFloatRegsScoreboard[freed_reg] = 1; 191 192 freeFloatRegs.push(freed_reg); 193} 194 195#endif // __CPU_BETA_CPU_FREE_LIST_HH__ 196