111420Sdavid.guillen@arm.com/* 211420Sdavid.guillen@arm.com * Copyright (c) 2015 ARM Limited 311420Sdavid.guillen@arm.com * All rights reserved 411420Sdavid.guillen@arm.com * 511420Sdavid.guillen@arm.com * The license below extends only to copyright in the software and shall 611420Sdavid.guillen@arm.com * not be construed as granting a license to any other intellectual 711420Sdavid.guillen@arm.com * property including but not limited to intellectual property relating 811420Sdavid.guillen@arm.com * to a hardware implementation of the functionality of the software 911420Sdavid.guillen@arm.com * licensed hereunder. You may use the software subject to the license 1011420Sdavid.guillen@arm.com * terms below provided that you ensure that this notice is replicated 1111420Sdavid.guillen@arm.com * unmodified and in its entirety in all distributions of the software, 1211420Sdavid.guillen@arm.com * modified or unmodified, in source code or in binary form. 1311420Sdavid.guillen@arm.com * 1411420Sdavid.guillen@arm.com * Redistribution and use in source and binary forms, with or without 1511420Sdavid.guillen@arm.com * modification, are permitted provided that the following conditions are 1611420Sdavid.guillen@arm.com * met: redistributions of source code must retain the above copyright 1711420Sdavid.guillen@arm.com * notice, this list of conditions and the following disclaimer; 1811420Sdavid.guillen@arm.com * redistributions in binary form must reproduce the above copyright 1911420Sdavid.guillen@arm.com * notice, this list of conditions and the following disclaimer in the 2011420Sdavid.guillen@arm.com * documentation and/or other materials provided with the distribution; 2111420Sdavid.guillen@arm.com * neither the name of the copyright holders nor the names of its 2211420Sdavid.guillen@arm.com * contributors may be used to endorse or promote products derived from 2311420Sdavid.guillen@arm.com * this software without specific prior written permission. 2411420Sdavid.guillen@arm.com * 2511420Sdavid.guillen@arm.com * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 2611420Sdavid.guillen@arm.com * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 2711420Sdavid.guillen@arm.com * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 2811420Sdavid.guillen@arm.com * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 2911420Sdavid.guillen@arm.com * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 3011420Sdavid.guillen@arm.com * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 3111420Sdavid.guillen@arm.com * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 3211420Sdavid.guillen@arm.com * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 3311420Sdavid.guillen@arm.com * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 3411420Sdavid.guillen@arm.com * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 3511420Sdavid.guillen@arm.com * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 3611420Sdavid.guillen@arm.com * 3711420Sdavid.guillen@arm.com * Authors: David Guillen Fandos 3811420Sdavid.guillen@arm.com */ 3911420Sdavid.guillen@arm.com 4011420Sdavid.guillen@arm.com#include "sim/linear_solver.hh" 4111420Sdavid.guillen@arm.com 4211420Sdavid.guillen@arm.comstd::vector <double> 4311420Sdavid.guillen@arm.comLinearSystem::solve() const 4411420Sdavid.guillen@arm.com{ 4511420Sdavid.guillen@arm.com // Solve using gauss elimination, not ideal for big matrices 4611420Sdavid.guillen@arm.com std::vector < LinearEquation > smatrix = this->matrix; 4711420Sdavid.guillen@arm.com 4811420Sdavid.guillen@arm.com unsigned order = smatrix.size(); 4911420Sdavid.guillen@arm.com for (unsigned row = 0; row < order - 1; row++) { 5011420Sdavid.guillen@arm.com // Look for a non-zero row, and swap 5111420Sdavid.guillen@arm.com for (unsigned i = row; i < order; i++) { 5211420Sdavid.guillen@arm.com if (smatrix[i][row] != 0.0f) { 5311420Sdavid.guillen@arm.com if (i != row) { 5411420Sdavid.guillen@arm.com LinearEquation tmp = smatrix[i]; 5511420Sdavid.guillen@arm.com smatrix[i] = smatrix[row]; 5611420Sdavid.guillen@arm.com smatrix[row] = tmp; 5711420Sdavid.guillen@arm.com } 5811420Sdavid.guillen@arm.com break; 5911420Sdavid.guillen@arm.com } 6011420Sdavid.guillen@arm.com } 6111420Sdavid.guillen@arm.com 6211420Sdavid.guillen@arm.com // Divide row by leading number to make it 1.0 6311420Sdavid.guillen@arm.com smatrix[row] *= (1.0f / smatrix[row][row]); 6411420Sdavid.guillen@arm.com 6511420Sdavid.guillen@arm.com // Add it (properly scaled) to the rows below 6611420Sdavid.guillen@arm.com for (unsigned i = row + 1; i < order; i++) { 6711420Sdavid.guillen@arm.com LinearEquation t = smatrix[row]; 6811420Sdavid.guillen@arm.com t *= -1.0f * smatrix[i][row]; 6911420Sdavid.guillen@arm.com smatrix[i] = smatrix[i] + t; 7011420Sdavid.guillen@arm.com } 7111420Sdavid.guillen@arm.com } 7211420Sdavid.guillen@arm.com 7311420Sdavid.guillen@arm.com // smatrix is now a triangular matrix with diagonal being 1 7411420Sdavid.guillen@arm.com // Just backproagate variable values from order-1 till 0 7511420Sdavid.guillen@arm.com std::vector <double> ret(order, 0.0f); 7611420Sdavid.guillen@arm.com for (int row = order - 1; row >= 0; row--) { 7711420Sdavid.guillen@arm.com // Unknown value 7811420Sdavid.guillen@arm.com ret[row] = -smatrix[row][smatrix[row].cnt()] / smatrix[row][row]; 7911420Sdavid.guillen@arm.com // Propagate variable in the cnt term 8011420Sdavid.guillen@arm.com for (int i = row - 1; i >= 0; i--) { 8111420Sdavid.guillen@arm.com smatrix[i][smatrix[i].cnt()] += ret[row] * smatrix[i][row]; 8211420Sdavid.guillen@arm.com smatrix[i][row] = 0.0f; 8311420Sdavid.guillen@arm.com } 8411420Sdavid.guillen@arm.com } 8511420Sdavid.guillen@arm.com 8611420Sdavid.guillen@arm.com return ret; 8711420Sdavid.guillen@arm.com} 88