xref: /gem5/ext/mcpat/array.cc

/*****************************************************************************
 *                                McPAT
 *                      SOFTWARE LICENSE AGREEMENT
 *            Copyright 2012 Hewlett-Packard Development Company, L.P.
 *                          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.”
 *
 ***************************************************************************/

#define  GLOBALVAR
#include <cassert>
#include <cmath>
#include <iostream>

#include "area.h"
#include "array.h"
#include "decoder.h"
#include "globalvar.h"
#include "parameter.h"

using namespace std;

ArrayST::ArrayST(const InputParameter *configure_interface,
                               string _name,
                               enum Device_ty device_ty_,
                               bool opt_local_,
                               enum Core_type core_ty_,
                               bool _is_default)
:l_ip(*configure_interface),
 name(_name),
 device_ty(device_ty_),
 opt_local(opt_local_),
 core_ty(core_ty_),
 is_default(_is_default)
    {

        if (l_ip.cache_sz<64) l_ip.cache_sz=64;
        l_ip.error_checking();//not only do the error checking but also fill some missing parameters
        optimize_array();

}


void ArrayST::compute_base_power()
    {
        //l_ip.out_w               =l_ip.line_sz*8;
    local_result=cacti_interface(&l_ip);

    }

void ArrayST::optimize_array()
{
        list<uca_org_t > candidate_solutions(0);
        list<uca_org_t >::iterator candidate_iter, min_dynamic_energy_iter;

        uca_org_t * temp_res = 0;
        local_result.valid=false;

        double 	throughput=l_ip.throughput, latency=l_ip.latency;
        double  area_efficiency_threshold = 20.0;
        bool 	throughput_overflow=true, latency_overflow=true;
        compute_base_power();

        if ((local_result.cycle_time - throughput) <= 1e-10 )
                throughput_overflow=false;
        if ((local_result.access_time - latency)<= 1e-10)
                latency_overflow=false;

        if (opt_for_clk && opt_local)
        {
                if (throughput_overflow || latency_overflow)
                {
                        l_ip.ed=0;

                        l_ip.delay_wt                = 100;//Fixed number, make sure timing can be satisfied.
                        l_ip.cycle_time_wt           = 1000;

                        l_ip.area_wt                 = 10;//Fixed number, This is used to exhaustive search for individual components.
                        l_ip.dynamic_power_wt        = 10;//Fixed number, This is used to exhaustive search for individual components.
                        l_ip.leakage_power_wt        = 10;

                        l_ip.delay_dev               = 1000000;//Fixed number, make sure timing can be satisfied.
                        l_ip.cycle_time_dev          = 100;

                        l_ip.area_dev                = 1000000;//Fixed number, This is used to exhaustive search for individual components.
                        l_ip.dynamic_power_dev       = 1000000;//Fixed number, This is used to exhaustive search for individual components.
                        l_ip.leakage_power_dev       = 1000000;

                        throughput_overflow=true; //Reset overflow flag before start optimization iterations
                        latency_overflow=true;

                        temp_res = &local_result; //Clean up the result for optimized for ED^2P
                        temp_res->cleanup();
                }


                while ((throughput_overflow || latency_overflow)&&l_ip.cycle_time_dev > 10)// && l_ip.delay_dev > 10
                {
                        compute_base_power();

                        l_ip.cycle_time_dev-=10;//This is the time_dev to be used for next iteration

                        //		from best area to worst area -->worst timing to best timing
                        if ((((local_result.cycle_time - throughput) <= 1e-10 ) && (local_result.access_time - latency)<= 1e-10)||
                                        (local_result.data_array2->area_efficiency < area_efficiency_threshold && l_ip.assoc == 0))
                        {  //if no satisfiable solution is found,the most aggressive one is left
                                candidate_solutions.push_back(local_result);
                                //output_data_csv(candidate_solutions.back());
                                if (((local_result.cycle_time - throughput) <= 1e-10) && ((local_result.access_time - latency)<= 1e-10))
                                        //ensure stop opt not because of cam
                                {
                                        throughput_overflow=false;
                                        latency_overflow=false;
                                }

                        }
                        else
                        {
                                //TODO: whether checking the partial satisfied results too, or just change the mark???
                                if ((local_result.cycle_time - throughput) <= 1e-10)
                                                                                throughput_overflow=false;
                                if ((local_result.access_time - latency)<= 1e-10)
                                                                                latency_overflow=false;

                                if (l_ip.cycle_time_dev > 10)
                                {   //if not >10 local_result is the last result, it cannot be cleaned up
                                        temp_res = &local_result; //Only solutions not saved in the list need to be cleaned up
                                        temp_res->cleanup();
                                }
                        }
//			l_ip.cycle_time_dev-=10;
//			l_ip.delay_dev-=10;

                }


        if (l_ip.assoc > 0)
        {
                //For array structures except CAM and FA, Give warning but still provide a result with best timing found
                if (throughput_overflow==true)
                        cout<< "Warning: " << name<<" array structure cannot satisfy throughput constraint." << endl;
                if (latency_overflow==true)
                        cout<< "Warning: " << name<<" array structure cannot satisfy latency constraint." << endl;
        }

//	else
//	{
//		/*According to "Content-Addressable Memory (CAM) Circuits and
//				Architectures": A Tutorial and Survey
//				by Kostas Pagiamtzis et al.
//				CAM structures can be heavily pipelined and use look-ahead techniques,
//				therefore timing can be relaxed. But McPAT does not model the advanced
//				techniques. If continue optimizing, the area efficiency will be too low
//		*/
//		//For CAM and FA, stop opt if area efficiency is too low
//		if (throughput_overflow==true)
//			cout<< "Warning: " <<" McPAT stopped optimization on throughput for "<< name
//				<<" array structure because its area efficiency is below "<<area_efficiency_threshold<<"% " << endl;
//		if (latency_overflow==true)
//			cout<< "Warning: " <<" McPAT stopped optimization on latency for "<< name
//				<<" array structure because its area efficiency is below "<<area_efficiency_threshold<<"% " << endl;
//	}

                //double min_dynamic_energy, min_dynamic_power, min_leakage_power, min_cycle_time;
                double min_dynamic_energy=BIGNUM;
                if (candidate_solutions.empty()==false)
                {
                        local_result.valid=true;
                        for (candidate_iter = candidate_solutions.begin(); candidate_iter != candidate_solutions.end(); ++candidate_iter)

                        {
                                if (min_dynamic_energy > (candidate_iter)->power.readOp.dynamic)
                                {
                                        min_dynamic_energy = (candidate_iter)->power.readOp.dynamic;
                                        min_dynamic_energy_iter = candidate_iter;
                                        local_result = *(min_dynamic_energy_iter);
                                        //TODO: since results are reordered results and l_ip may miss match. Therefore, the final output spread sheets may show the miss match.

                                }
                                else
                                {
                                        candidate_iter->cleanup() ;
                                }

                        }


                }
        candidate_solutions.clear();
        }

        double long_channel_device_reduction = longer_channel_device_reduction(device_ty,core_ty);

        double macro_layout_overhead   = g_tp.macro_layout_overhead;
        double chip_PR_overhead        = g_tp.chip_layout_overhead;
        double total_overhead          = macro_layout_overhead*chip_PR_overhead;
        local_result.area *= total_overhead;

        //maintain constant power density
        double pppm_t[4]    = {total_overhead,1,1,total_overhead};

        double sckRation = g_tp.sckt_co_eff;
        local_result.power.readOp.dynamic *= sckRation;
        local_result.power.writeOp.dynamic *= sckRation;
        local_result.power.searchOp.dynamic *= sckRation;
        local_result.power.readOp.leakage *= l_ip.nbanks;
        local_result.power.readOp.longer_channel_leakage =
                local_result.power.readOp.leakage*long_channel_device_reduction;
        local_result.power = local_result.power* pppm_t;

        local_result.data_array2->power.readOp.dynamic *= sckRation;
        local_result.data_array2->power.writeOp.dynamic *= sckRation;
        local_result.data_array2->power.searchOp.dynamic *= sckRation;
        local_result.data_array2->power.readOp.leakage *= l_ip.nbanks;
        local_result.data_array2->power.readOp.longer_channel_leakage =
                local_result.data_array2->power.readOp.leakage*long_channel_device_reduction;
        local_result.data_array2->power = local_result.data_array2->power* pppm_t;


        if (!(l_ip.pure_cam || l_ip.pure_ram || l_ip.fully_assoc) && l_ip.is_cache)
        {
                local_result.tag_array2->power.readOp.dynamic *= sckRation;
                local_result.tag_array2->power.writeOp.dynamic *= sckRation;
                local_result.tag_array2->power.searchOp.dynamic *= sckRation;
                local_result.tag_array2->power.readOp.leakage *= l_ip.nbanks;
                local_result.tag_array2->power.readOp.longer_channel_leakage =
                        local_result.tag_array2->power.readOp.leakage*long_channel_device_reduction;
                local_result.tag_array2->power = local_result.tag_array2->power* pppm_t;
        }


}

void ArrayST::leakage_feedback(double temperature)
{
  // Update the temperature. l_ip is already set and error-checked in the creator function.
  l_ip.temp = (unsigned int)round(temperature/10.0)*10;

  // This corresponds to cacti_interface() in the initialization process. Leakage power is updated here.
  reconfigure(&l_ip,&local_result);

  // Scale the power values. This is part of ArrayST::optimize_array().
  double long_channel_device_reduction = longer_channel_device_reduction(device_ty,core_ty);

  double macro_layout_overhead   = g_tp.macro_layout_overhead;
  double chip_PR_overhead        = g_tp.chip_layout_overhead;
  double total_overhead          = macro_layout_overhead*chip_PR_overhead;

  double pppm_t[4]    = {total_overhead,1,1,total_overhead};

  double sckRation = g_tp.sckt_co_eff;
  local_result.power.readOp.dynamic *= sckRation;
  local_result.power.writeOp.dynamic *= sckRation;
  local_result.power.searchOp.dynamic *= sckRation;
  local_result.power.readOp.leakage *= l_ip.nbanks;
  local_result.power.readOp.longer_channel_leakage = local_result.power.readOp.leakage*long_channel_device_reduction;
  local_result.power = local_result.power* pppm_t;

  local_result.data_array2->power.readOp.dynamic *= sckRation;
  local_result.data_array2->power.writeOp.dynamic *= sckRation;
  local_result.data_array2->power.searchOp.dynamic *= sckRation;
  local_result.data_array2->power.readOp.leakage *= l_ip.nbanks;
  local_result.data_array2->power.readOp.longer_channel_leakage = local_result.data_array2->power.readOp.leakage*long_channel_device_reduction;
  local_result.data_array2->power = local_result.data_array2->power* pppm_t;

  if (!(l_ip.pure_cam || l_ip.pure_ram || l_ip.fully_assoc) && l_ip.is_cache)
  {
    local_result.tag_array2->power.readOp.dynamic *= sckRation;
    local_result.tag_array2->power.writeOp.dynamic *= sckRation;
    local_result.tag_array2->power.searchOp.dynamic *= sckRation;
    local_result.tag_array2->power.readOp.leakage *= l_ip.nbanks;
    local_result.tag_array2->power.readOp.longer_channel_leakage = local_result.tag_array2->power.readOp.leakage*long_channel_device_reduction;
    local_result.tag_array2->power = local_result.tag_array2->power* pppm_t;
  }
}

ArrayST:: ~ArrayST()
{
        local_result.cleanup();
}