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Just a Loop

Photo by Tine Ivanič on Unsplash
Hey everyone! This post is dedicated to Lab 5. I’ll say upfront that this was the most challenging loop of my career. Yes! If you told assembly, you were right. Our professor was kind to provide necessary codes from each platform. He also gave us access to several machines with different hardware capabilities for both architectures. Combined with the previous lecture, we had everything that we need to succeed.

The goal was to create a program that shows “loop” ten times. Next, we had to change it to include the index number. Finally, extend it to show thirty times with the index suppressing the leading zero. Don’t forget, on BOTH architectures! If it were on C, C++, Java, JavaScript or Bash, I would have time to a coffee.

To be fair, the first task was to put the “hello world” with the script provided. That was easy, and the only one that I accomplished. To compile it, I added a new target to the make file provided. The result you can see below.




The next is the indexed loop. Remembering the previous lecture, if we use a place holder in the message and change it before displaying, it would produce the desired output. Easy to say, hard to do it! I got stuck on how to change that little “X.” Even with my professor’s tip – use the binary move – I couldn’t figure it out. Hey Siri, could replace the X placeholder with the loop index, please? Siri just put some music on – Dammit, Blink-182! Here is the result of my failure.


The last challenge, I know some ways. We could use an “if” statement to see if the value is less than 10 to hide the leading zero. We could separate the index into two “variables” (one for decimals and the other for the units). However, I lack the knowledge of the language and the hardware to make it happen. Do I get some marks doing it in C or C++? Dammit is still playing in the background.

This is it! Epic failure and a great time playing with x86_64 and ARMv8. See you.
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