gem5/ext/mcpat/bus_interconnect.cc
Yasuko Eckert 0deef376d9 ext: McPAT interface changes and fixes
This patch includes software engineering changes and some generic bug fixes
Joel Hestness and Yasuko Eckert made to McPAT 0.8. There are still known
issues/concernts we did not have a chance to address in this patch.

High-level changes in this patch include:
 1) Making XML parsing modular and hierarchical:
   - Shift parsing responsibility into the components
   - Read XML in a (mostly) context-free recursive manner so that McPAT input
     files can contain arbitrary component hierarchies
 2) Making power, energy, and area calculations a hierarchical and recursive
    process
   - Components track their subcomponents and recursively call compute
     functions in stages
   - Make C++ object hierarchy reflect inheritance of classes of components
     with similar structures
   - Simplify computeArea() and computeEnergy() functions to eliminate
     successive calls to calculate separate TDP vs. runtime energy
   - Remove Processor component (now unnecessary) and introduce a more abstract
     System component
 3) Standardizing McPAT output across all components
   - Use a single, common data structure for storing and printing McPAT output
   - Recursively call print functions through component hierarchy
 4) For caches, allow splitting data array and tag array reads and writes for
    better accuracy
 5) Improving the usability of CACTI by printing more helpful warning and error
    messages
 6) Minor: Impose more rigorous code style for clarity (more work still to be
    done)
Overall, these changes greatly reduce the amount of replicated code, and they
improve McPAT runtime and decrease memory footprint.
2014-06-03 13:32:59 -07:00

180 lines
6.9 KiB
C++

/*****************************************************************************
* McPAT
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* 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
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* Author: Joel Hestness
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***************************************************************************/
#include <algorithm>
#include <cassert>
#include <cmath>
#include <iostream>
#include <string>
#include "basic_circuit.h"
#include "bus_interconnect.h"
#include "common.h"
#include "const.h"
#include "io.h"
#include "parameter.h"
BusInterconnect::BusInterconnect(XMLNode* _xml_data,
InputParameter* interface_ip_)
: McPATComponent(_xml_data), link_bus(NULL), interface_ip(*interface_ip_) {
name = "Bus Interconnect";
set_param_stats();
local_result = init_interface(&interface_ip, name);
scktRatio = g_tp.sckt_co_eff;
interface_ip.throughput = bus_params.link_throughput / bus_params.clockRate;
interface_ip.latency = bus_params.link_latency / bus_params.clockRate;
link_len /= bus_params.total_nodes;
if (bus_params.total_nodes > 1) {
//All links are shared by neighbors
link_len /= 2;
}
link_bus = new Interconnect(xml_data, "Link", Uncore_device,
bus_params.link_base_width,
bus_params.link_base_height,
bus_params.flit_size, link_len, &interface_ip,
bus_params.link_start_wiring_level,
bus_params.clockRate,
bus_params.pipelinable,
bus_params.route_over_perc);
children.push_back(link_bus);
}
void BusInterconnect::computeEnergy() {
// Initialize stats for TDP
tdp_stats.reset();
tdp_stats.readAc.access = bus_stats.duty_cycle;
link_bus->int_params.active_ports = bus_params.min_ports - 1;
link_bus->int_stats.duty_cycle =
bus_params.M_traffic_pattern * bus_stats.duty_cycle;
// Initialize stats for runtime energy and power
rtp_stats.reset();
rtp_stats.readAc.access = bus_stats.total_access;
link_bus->int_stats.accesses = bus_stats.total_access;
// Recursively compute energy
McPATComponent::computeEnergy();
}
void BusInterconnect::set_param_stats() {
memset(&bus_params, 0, sizeof(BusInterconnectParameters));
int num_children = xml_data->nChildNode("param");
int i;
int mat_type;
for (i = 0; i < num_children; i++) {
XMLNode* paramNode = xml_data->getChildNodePtr("param", &i);
XMLCSTR node_name = paramNode->getAttribute("name");
XMLCSTR value = paramNode->getAttribute("value");
if (!node_name)
warnMissingParamName(paramNode->getAttribute("id"));
ASSIGN_FP_IF("clockrate", bus_params.clockRate);
ASSIGN_INT_IF("flit_bits", bus_params.flit_size);
ASSIGN_FP_IF("link_throughput", bus_params.link_throughput);
ASSIGN_FP_IF("link_latency", bus_params.link_latency);
ASSIGN_INT_IF("total_nodes", bus_params.total_nodes);
ASSIGN_INT_IF("input_ports", bus_params.input_ports);
ASSIGN_INT_IF("output_ports", bus_params.output_ports);
ASSIGN_INT_IF("global_linked_ports", bus_params.global_linked_ports);
ASSIGN_FP_IF("chip_coverage", bus_params.chip_coverage);
ASSIGN_INT_IF("pipelinable", bus_params.pipelinable);
ASSIGN_FP_IF("link_routing_over_percentage",
bus_params.route_over_perc);
ASSIGN_INT_IF("virtual_channel_per_port",
bus_params.virtual_channel_per_port);
ASSIGN_FP_IF("M_traffic_pattern", bus_params.M_traffic_pattern);
ASSIGN_FP_IF("link_len", link_len);
ASSIGN_FP_IF("link_base_width", bus_params.link_base_width);
ASSIGN_FP_IF("link_base_height", bus_params.link_base_height);
ASSIGN_FP_IF("link_start_wiring_level",
bus_params.link_start_wiring_level);
ASSIGN_INT_IF("wire_mat_type", mat_type);
ASSIGN_ENUM_IF("wire_type", interface_ip.wt, Wire_type);
else {
warnUnrecognizedParam(node_name);
}
}
// Change from MHz to Hz
bus_params.clockRate *= 1e6;
interface_ip.wire_is_mat_type = mat_type;
interface_ip.wire_os_mat_type = mat_type;
num_children = xml_data->nChildNode("stat");
for (i = 0; i < num_children; i++) {
XMLNode* statNode = xml_data->getChildNodePtr("stat", &i);
XMLCSTR node_name = statNode->getAttribute("name");
XMLCSTR value = statNode->getAttribute("value");
if (!node_name)
warnMissingStatName(statNode->getAttribute("id"));
ASSIGN_FP_IF("duty_cycle", bus_stats.duty_cycle);
ASSIGN_FP_IF("total_accesses", bus_stats.total_access);
else {
warnUnrecognizedStat(node_name);
}
}
clockRate = bus_params.clockRate;
bus_params.min_ports =
min(bus_params.input_ports, bus_params.output_ports);
assert(bus_params.chip_coverage <= 1);
assert(bus_params.route_over_perc <= 1);
assert(link_len > 0);
}
void
BusInterconnect::set_duty_cycle(double duty_cycle) {
bus_stats.duty_cycle = duty_cycle;
}
void
BusInterconnect::set_number_of_accesses(double total_accesses) {
bus_stats.total_access = total_accesses;
}
BusInterconnect::~BusInterconnect() {
delete link_bus;
link_bus = NULL;
}