Optimization_1x4_7

Copy the contents of file MMult_1x4_6.c into a file named MMult_1x4_7.c and change the contents:

|| from || to || ||<^> -Include(HowToOptimizeGemm/Details/MMult_1x4_6)- ||<^> -Include(HowToOptimizeGemm/Details/MMult_1x4_7)- ||

Change the first lines in the makefile to {{{ OLD := MMult_1x4_6 NEW := MMult_1x4_7
}}}

• make run {{{ octave:3> PlotAll % this will create the plot }}}

This time the performance graph will look something like

ImageLink(http://www.cs.utexas.edu/users/rvdg/HowToOptimizeGemm/Graphs/compare_MMult-1x4-6_MMult-1x4-7.png,http://www.cs.utexas.edu/users/rvdg/HowToOptimizeGemm/Graphs/compare_MMult-1x4-6_MMult-1x4-7.png,width=40%)

We now use four pointers, bp0_pntr, bp1_pntr, bp2_pntr, and bp3_pntr, to access the elements B( p, 0 ), B( p, 1 ), B( p, 2 ), B( p, 3 ). This reduces indexing overhead.