Optimization_4x4_13

Copy the contents of file MMult_4x4_12.c into a file named MMult_4x4_13.c and change the contents:

Change the first lines in the makefile to

OLD  := MMult_4x4_12
NEW  := MMult_4x4_13

• make run

octave:3> PlotAll        % this will create the plot

This time the performance graph will look something like

This version saves the packed blocks of A so that after the first iteration of the outer loop of InnerKernel, the saved version is used. The performance gain is noticeable! The only change from the last version is the addition of if ( j== 0 ):

      if ( j == 0 ) PackMatrixA( k, &A( i, 0 ), lda, &packedA[ i*k ] );