Assignment, Stage 2 - Profiling

For this stage of the project, we were required to profile the program to see which functions were eating up the most time. I used the same file for compression as I did in stage 1 of the assignment for Aarchie, 8.192 mb. The program took 197.52 seconds to run in this gprof profile. I added the options -pg -g -0g to the compilation options.

Compiler Options

AArch 64

gprof for zopfli on Aarchie

As you can see, 42.52% of the time is spent in the zopfliUpdateHash. zopfliStoreLitLenDistance comes in a distant second using 12.54% of the time in the profile. Everything else trails by a good bit. 

x86_64

On x86_64, I used a file that was roughly 10 times as big as the file I used on AArchie. The file is roughly 83mb in size. 

gprof on x86_64

Same kind of thing going on on x86_64. zopfliUpdateHash takes the bulk of the time. Interestingly, it takes an increased portion of the overall time compared to AArch64. zopfliStoreLitLenDistance is once again a distant second this time taking 9% of the time, with zopfliMaxCachedSublen taking 8.9%. 

It's somewhat interesting to see the different percentages of time that each function takes compared to AArch64. It's worth noting that it could be due to different file sizes, unfortunately it was unavoidable due to the difference in the power of the machines I used. Either way, the function that takes far and away the most time to run is zopfliUpdateHash so that is likely the one I'll be looking into for stage 3 of the project.