CS 240A Lecture 3 OpenMP, MPI, and MatlabP examples

1
CS 240A Lecture 3OpenMP, MPI, and MatlabP
examples

• Cluster stuff (Viral) HW1 due Wed 4/14 (HW2
  still due 4/26)
• Quick MPI, OpenMP, MatlabP intros
• Computing pi (embarrassingly) in parallel
• Matrix multiplication, intro to blocked
  algorithms

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Hello, world in MPI

• include ltstdio.hgt
• include "mpi.h"
• int main( int argc, char argv)
• int rank, size
• MPI_Init( argc, argv )
• MPI_Comm_size( MPI_COMM_WORLD, size )
• MPI_Comm_rank( MPI_COMM_WORLD, rank )
• printf( "Hello world from process d of
  d\n", rank, size )
• MPI_Finalize()
• return 0

3
MPI quick intro

• See GroppMPItutorial.ps

4
Hello, world in OpenMP

• include ltomp.hgt
• include ltstdio.hgt
• int main()
• pragma omp parallel
• int ID omp_get_thread_num()
• printf(" hello(d) \n", ID)
• printf(" world(d) \n", ID)

5
OpenMP quick intro

• See OpenMP_sc99_tutorial.pdf

6
MatlabP quick demo

• See starpdemo.m

7
Pi by quadrature of 4/(1x2)

• Sequential code (see pi_sequential.c)
• OpenMP code (see pi_openmp.c)
• MPI code (see pi_mpi.c)
• MatlabP code (see pi_starp.m)

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Matrix multiplication intro

• See Yelick/Demmel slides, http//www.cs.berkeley
  .edu/yelick/cs267/lectures/03/lect03-matmul.ppt