SPO 600 - Lab 5

In Lab 5, I will be looking at Algorithm Selection and how the algorithm affect the system's performance. For more information, click here.

I will be doing this lab on Aarch64, and I will compile my programs with -O3 optimization.

Original version

Right now I will checking if it produces the same result every single time, how long it takes to scaling the sound samples, and how long it takes to run. (Note: to view how long it takes for the system to execute a command, type time before it. For more information, consult the man page of time.)

In each run, the program always produces the same result, but the time of scaling the sound samples and the run-time in each run are slightly different.

Yes, the difference is so small, but at the end the numbers are still different, right?



Version 2 - Lookup table

In this version, I will create a lookup table of all possible sample values multiplied by the volume factor.

Like the original, in each run, it also always produces the same result, the time of scaling the sound samples is very close, and the run-time is exactly the same.
But overall it takes less time to scale the sound samples and run (largely because it only have two loops to execute and doesn't have the scale_sample function).











Version 3 - Bit-shifting and Conversion

In this version, I will convert the volume factor (0.75) to a fix-point integer by multiplying by a binary number (0b100000000 in my case) representing a fixed-point value of 1. Then I will shift result to the right by 8, since I am using 256 as the multiplier.

In each run, it also always produces the same result, the time of scaling the sound samples is very close, and the run-time is exactly the same.
It takes longer to run than version 2 (after all, it still has three loops to execute), yet it is slightly faster than version 1, since it is using bit-shifting to scale the sample.
In conclusion, version 2 is the fastest, while version 3 is the second and the original is the third.

You can find the source code of the three versions, the header file and the Makefile from here:
https://github.com/wu-geoff/SPO600/blob/master/aarchie/lab5/spo600_20181_vol_skel/Makefile
https://github.com/wu-geoff/SPO600/blob/master/aarchie/lab5/spo600_20181_vol_skel/vol.h
https://github.com/wu-geoff/SPO600/blob/master/aarchie/lab5/spo600_20181_vol_skel/vol1.c
https://github.com/wu-geoff/SPO600/blob/master/aarchie/lab5/spo600_20181_vol_skel/vol2.c
https://github.com/wu-geoff/SPO600/blob/master/aarchie/lab5/spo600_20181_vol_skel/vol3.c 

Comments

  1. Village TalkiesMay 8, 2022 at 10:41 PM

    Great information!!! Thanks for your wonderful informative blog.
    Village Talkies a top-quality professional corporate video production company in Bangalore and also best explainer video company in Bangalore & animation video makers in Bangalore, Chennai, India & Maryland, Baltimore, USA provides Corporate & Brand films, Promotional, Marketing videos & Training videos, Product demo videos, Employee videos, Product video explainers, eLearning videos, 2d Animation, 3d Animation, Motion Graphics, Whiteboard Explainer videos Client Testimonial Videos, Video Presentation and more for all start-ups, industries, and corporate companies. From scripting to corporate video production services, explainer & 3d, 2d animation video production , our solutions are customized to your budget, timeline, and to meet the company goals and objectives.
    As a best video production company in Bangalore, we produce quality and creative videos to our clients.

    ReplyDelete

Post a Comment

Popular posts from this blog

SPO 600 Project - Stage 1

For the SPO600 course, I need to complete a project of identifying a CPU-intensive function/method - let's say a checksum or hash algorithm - that is implemented in a language that compiles to machine code (e.g. C, C++, or Assembler) in an open-source project, improving its performance, then get that optimization accepted by the upstream. For more information, click here . Find an open source package For this project, I chose Tengine , a fork of the web server nginx  developed by Taobao . When I'm reading its source code in Github, I noticed that it also uses the MurmurHash , just like nginx. Since MurmurHash itself is a simple hash function, it would be difficult to improve it (I still remembered my professor once said an easy program is the most difficult one to optimize), I decided to accept the challenge, because why not? Benchmark the performance on AArch64 As the function is very simple, testing its performance is much simpler than I imagine: I just extract the
Read more

SPO 600 - Lab 1

In this blog post, I will compare Visual Studio Code, a lightweight source code editor developed by Microsoft and Wine, a compatibility layer that allows Unix-like Operating Systems to run Windows programs. Visual Studio Code License: MIT  Procedure for accepting new code: Visual Studio Code uses a git repository on GitHub . The contributor would open an issue on the "Issues" section, then vscodebot would assign it to a Microsoft developer. After reviewing the issue, if the developer thinks it makes sense, he/she would add an "help wanted" label on the issue. When a contributor fixes the issue, he/she has to sign a Contributor License Agreement (CLA) if that hasn't been done before, performs a pull request and commit the changes, a developer from Microsoft would check the commit, and merge the commit to master if it is approved. Patch:  https://github.com/Microsoft/vscode/pull/41653 How many people are involved: 3, and one of them seems to work for
Read more