Name: Matrix Multiplication
Contact Person: support-compss@bsc.es
Access Level: public
License Agreement: Apache2
Platform: COMPSs

Description

Matrix multiplication is a binary operation that takes a pair of matrices and produces another matrix.

If A is an n×m matrix and B is an m×p matrix, the result AB of their multiplication is an n×p matrix defined only if the number of columns m in A is equal to the number of rows m in B. When multiplying A and B, the elements of the rows in A are multiplied with corresponding columns in B.

In this implementation, A and B are square matrices (same number of rows and columns), and so it is the result matrix C. Each matrix is divided in N blocks of M doubles. The multiplication of two blocks is done by a multiply task method with a simple three-nested-loop implementation. When executed with COMPSs, the main program generates N^3^ tasks arranged as N^2^ chains of N tasks in the dependency graph.

Versions

There are three versions of Matrix Multiplication, depending on the data types used to store the blocks.

Version 1

''files'', where the matrix blocks are stored in files.

Version 2

''objects'', where the matrix blocks are represented by objects.

Version 3

''arrays'', where the matrix blocks are stored in arrays.

Execution instructions

Usage:

runcompss matmul.files.Matmul numberOfBlocks blockSize
runcompss matmul.objects.Matmul numberOfBlocks blockSize
runcompss matmul.arrays.Matmul numberOfBlocks blockSize

where:

• numberOfBlocks: Number of blocks inside each matrix
• blockSize: Size of each block

Execution Example

runcompss matmul.objects.Matmul 16 4
runcompss matmul.files.Matmul 16 4
runcompss matmul.arrays.Matmul 16 4  

Build

Option 1: Native java

cd ~/tutorial_apps/java/matmul/; javac src/main/java/matmul/*/*.java
cd src/main/java/; jar cf matmul.jar matmul/
cd ../../../; mv src/main/java/matmul.jar jar/

Option 2: Maven

cd ~/tutorial_apps/java/matmul/
mvn clean package