1/* 2 * Copyright (c) 2014-2015 Advanced Micro Devices, Inc. 3 * All rights reserved. 4 * 5 * For use for simulation and test purposes only 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright notice, 11 * this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright notice, 14 * this list of conditions and the following disclaimer in the documentation 15 * and/or other materials provided with the distribution. 16 * 17 * 3. Neither the name of the copyright holder nor the names of its 18 * contributors may be used to endorse or promote products derived from this 19 * software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 * POSSIBILITY OF SUCH DAMAGE. 32 * 33 * Authors: John Kalamatianos, 34 * Sooraj Puthoor, 35 * Mark Wyse 36 */ 37 38#include "gpu-compute/scoreboard_check_stage.hh" 39 40#include "gpu-compute/compute_unit.hh" 41#include "gpu-compute/gpu_static_inst.hh" 42#include "gpu-compute/shader.hh" 43#include "gpu-compute/wavefront.hh" 44#include "params/ComputeUnit.hh" 45 46ScoreboardCheckStage::ScoreboardCheckStage(const ComputeUnitParams *p) 47 : numSIMDs(p->num_SIMDs), 48 numMemUnits(p->num_global_mem_pipes + p->num_shared_mem_pipes), 49 numShrMemPipes(p->num_shared_mem_pipes), 50 vectorAluInstAvail(nullptr), 51 lastGlbMemSimd(-1), 52 lastShrMemSimd(-1), glbMemInstAvail(nullptr), 53 shrMemInstAvail(nullptr) 54{ 55} 56 57ScoreboardCheckStage::~ScoreboardCheckStage() 58{ 59 readyList.clear(); 60 waveStatusList.clear(); 61 shrMemInstAvail = nullptr; 62 glbMemInstAvail = nullptr; 63} 64 65void 66ScoreboardCheckStage::init(ComputeUnit *cu) 67{ 68 computeUnit = cu; 69 _name = computeUnit->name() + ".ScoreboardCheckStage"; 70 71 for (int unitId = 0; unitId < numSIMDs + numMemUnits; ++unitId) { 72 readyList.push_back(&computeUnit->readyList[unitId]); 73 } 74 75 for (int unitId = 0; unitId < numSIMDs; ++unitId) { 76 waveStatusList.push_back(&computeUnit->waveStatusList[unitId]); 77 } 78 79 vectorAluInstAvail = &computeUnit->vectorAluInstAvail; 80 glbMemInstAvail= &computeUnit->glbMemInstAvail; 81 shrMemInstAvail= &computeUnit->shrMemInstAvail; 82} 83 84void 85ScoreboardCheckStage::initStatistics() 86{ 87 lastGlbMemSimd = -1; 88 lastShrMemSimd = -1; 89 *glbMemInstAvail = 0; 90 *shrMemInstAvail = 0; 91 92 for (int unitId = 0; unitId < numSIMDs; ++unitId) 93 vectorAluInstAvail->at(unitId) = false; 94} 95 96void 97ScoreboardCheckStage::collectStatistics(Wavefront *curWave, int unitId) 98{ 99 if (curWave->instructionBuffer.empty()) 100 return; 101 102 // track which vector SIMD unit has at least one WV with a vector 103 // ALU as the oldest instruction in its Instruction buffer 104 vectorAluInstAvail->at(unitId) = vectorAluInstAvail->at(unitId) || 105 curWave->isOldestInstALU(); 106 107 // track how many vector SIMD units have at least one WV with a 108 // vector Global memory instruction as the oldest instruction 109 // in its Instruction buffer 110 if ((curWave->isOldestInstGMem() || curWave->isOldestInstPrivMem() || 111 curWave->isOldestInstFlatMem()) && lastGlbMemSimd != unitId && 112 *glbMemInstAvail <= 1) { 113 (*glbMemInstAvail)++; 114 lastGlbMemSimd = unitId; 115 } 116 117 // track how many vector SIMD units have at least one WV with a 118 // vector shared memory (LDS) instruction as the oldest instruction 119 // in its Instruction buffer 120 // TODO: parametrize the limit of the LDS units 121 if (curWave->isOldestInstLMem() && (*shrMemInstAvail <= numShrMemPipes) && 122 lastShrMemSimd != unitId) { 123 (*shrMemInstAvail)++; 124 lastShrMemSimd = unitId; 125 } 126} 127 128void 129ScoreboardCheckStage::exec() 130{ 131 initStatistics(); 132 133 // reset the ready list for all execution units; it will be 134 // constructed every cycle since resource availability may change 135 for (int unitId = 0; unitId < numSIMDs + numMemUnits; ++unitId) { 136 readyList[unitId]->clear(); 137 } 138 139 // iterate over the Wavefronts of all SIMD units 140 for (int unitId = 0; unitId < numSIMDs; ++unitId) { 141 for (int wvId = 0; wvId < computeUnit->shader->n_wf; ++wvId) { 142 // reset the ready status of each wavefront 143 waveStatusList[unitId]->at(wvId).second = BLOCKED; 144 Wavefront *curWave = waveStatusList[unitId]->at(wvId).first; 145 collectStatistics(curWave, unitId); 146 147 if (curWave->ready(Wavefront::I_ALU)) { 148 readyList[unitId]->push_back(curWave); 149 waveStatusList[unitId]->at(wvId).second = READY; 150 } else if (curWave->ready(Wavefront::I_GLOBAL)) { 151 if (computeUnit->cedeSIMD(unitId, wvId)) { 152 continue; 153 } 154 155 readyList[computeUnit->GlbMemUnitId()]->push_back(curWave); 156 waveStatusList[unitId]->at(wvId).second = READY; 157 } else if (curWave->ready(Wavefront::I_SHARED)) { 158 readyList[computeUnit->ShrMemUnitId()]->push_back(curWave); 159 waveStatusList[unitId]->at(wvId).second = READY; 160 } else if (curWave->ready(Wavefront::I_FLAT)) { 161 readyList[computeUnit->GlbMemUnitId()]->push_back(curWave); 162 waveStatusList[unitId]->at(wvId).second = READY; 163 } else if (curWave->ready(Wavefront::I_PRIVATE)) { 164 readyList[computeUnit->GlbMemUnitId()]->push_back(curWave); 165 waveStatusList[unitId]->at(wvId).second = READY; 166 } 167 } 168 } 169} 170 171void 172ScoreboardCheckStage::regStats() 173{ 174} 175