How computer processors run conditions and loops
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- Опубліковано 28 жов 2024
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In the final episode of this low-level series, we learn the fundamentals of how computers evaluate conditions and loops, a very important feature that makes them as useful as they are today.
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the AI voice ruined the experience
@@ysblt1069 don't agree, this channel offers a lot of valuable information and even though the ai voice may not be that pleasant for some people, everything else makes up for it
I still cannot believe this channel exists man. Generational content
where the fuck was this during my CS degree ffs
@@Dreamer66617 I don’t mean to sound like a grandpa, but kids really don’t understand how lucky they are to have these sorts of resources these days. NONE of this existed when I was in school. You read a textbook and that was it.
This is what I learned in the programming courses I undertook.
Is it, really, though? I am pretty sure there is a human controlling the AI, and all the AI does is like speak for him and elaborate and stuff. I mean, the AI definitely isnt making the visuals.
@@dalejulson3175 but the work is increasingly getting difficult and so is the exams and couseworks
Dude not only do you have the talent to explain low level concepts in an intuitive way to understand. You provide stunning visuals as well, what a gem for the computer science community
Because it's AI. Not a real person.
We're truly living in a golden age of educational content on UA-cam when we have access to these kinds of videos. I love it and thank you for it.
Question: Have you considered making a video about Virtual Memory sometime in the future? I still remember how mindblown I was when I learnt about it in college.
I would LOVE a video about virtual memory
Core Dumped is the GOAT of Computer Science teaching videos
i honestly was barely even interested in learning about how lower level programming works until i stumbled across this channel. truly incredible content
OMG BRO THANK YOU!!!!!!!!!!!!!!!!!I built a computer about a month ago in minecraft and still couldn't figure out how to make conditions and cycles, but thanks to you, I can complete my computer and present it to my subscribers. If I do make a video and post it, I will definitely leave a link to your video
Glad I was helpful!
You are seriously talented.
I am learning embedded software programming right now and your channel is helping me deeply understand what is going on at the low level.
Also, the CPU emulator tool you made is beautiful.
I hope you get the recognition you deserve && get to do what ever you want to do (which I selfishly hope is to continue to make great content like this) && be properly compensated for it.
You are making a difference.
At 8:15 I was like, wonder if it would be turing complete.. and you just made a cliffhanger 😂
With all the instructions in this video it's Turing Complete.
My dude just made assembly look simple and easy !
That's the thing, it really is simple. Just verbose and fiddly with all the memory management and different for each architecture.
Your videos are so great! It would be excellent if you could also explain how multistate conditions using AND/OR are processed in your future videos
I think for AND, first do the check for the first condition, and then do a conditional jump to the code after the if branch when the first condition is not met. Then, put the code to check the second condition right after the jump. Then after the code checking for the second condition, put a conditional jump to the code after if when the second condition is not met. Then put the body of the if statement after that jump.
For OR, first check for the first condition and do a conditional jump to the start of the if branch code when the first condition is met. After the jump, put the code checking for the second condition and then do a conditional jump to the code after if branch when the second condition is not met. Then put the if branch's code after the jump
This also implies the short-circuit-ness of the logical AND and OR
Here's some example code, where "jump_if cond location" means to jump to the location if the condition is satisfied. Addresses are replaced by flags (such as code_start) because that's how you write assembly without having to change address locations all the time. code_start is obvious, but code_end always refers to immediately after the code, not the last line of the code. "any" just means that the instruction doesn't matter for the integrity of the conditional logic.
OR:
jump_if A code_start
jump_if B code_start
jump code_end
code_start: any
...
code_end: any
AND:
jump_if A b_cond
jump code_end
b_cond: jump_if B code_start
jump code_end
code_start: any
...
code_end: any
I am developer, as job. Man, the "from the transistor to the code" thing was bugging me for years. This channel exists and explained it all to me, and continues to do excelent job at that. The amount of questions I happened to have over +- 15 years that are just casually explained in plain english and plain animations here.... Insane. Since these questions were bugging me in long time, I had fragments of knowlage that I managed to get on my own, you managed to fill in the gaps and make it make sense in total. Nobody in uni managed to make it happen.
Thank you very much for this channel. Like, actually. Thank you for this. I mean it.
I come from the electronics world, first - doing band filters, op amps, and flip flops before getting into logic gates and registers.
I always thought I was missing something when I would go to program in C. I could easily dissect what other programs were doing, but I always felt like I was not understanding what the computer was actually doing or how to actually tell it how to move the data as I visualized things.
Then, I started playing ExaPunks and realized the problem is that I should have just learned assembly, as assembly is exactly what I was expecting a programming language to be and made sense to me.
I can work in higher level languages, but it is so much easier, now that I understand just how fundamentally different "programming languages" are from hardware programming. Programming languages are math languages - platonic constructs which are mapped onto assembly instructions by glorified macros. The people writing in them may know assembly and what is going on in the computer, but the language itself is not usually designed to control the machine, but to describe an abstract flow of concepts without knowing anything about the machine.
I envy CPU architecture students. When I studied it, there wasn't all this high quality content available online. You're doing a wonderful job!
Incredible, most people think assembly is worse compared to hlls but that always confused me.
Since most ppl with any hll experience usually start with coding before undertanding the circuits at the hardware level that would naturally be the case.
Meanwhile, I began my journey trying to build something turing complete with just a clock, some memory and some gates in a simulator.
It came naturally to me as I designed the ram and alu(alu needs at least only add and invert functions, rest can be derived), that you just need 3 special registers(accumulator, instruction reg, address reg), the ability to define variables, and most importantly the final piece; at least one flag and a instruction for conditional jumping to finally make something turing complete.
Most people want results . Python gives them ML . Do you meet people who claim to understand C++, Haskell, and all of C# ?
When I see a new video, I am excited as same as the release of a new episode of my favorite TV show.
This is one of the best channels I have ever encountered in UA-cam. Thanks for your work, man!
Bro is helping me make a 16bit CPU inside a game running on a cpu inside a plastic box
These past couple videos have been very amazing in learning the architecture about how a CPU, memory, addressing, instructions, everything else works. I remember in one of those videos you mentioned that you will explain the importance of Clock and why it is needed for all these components to sync with each other and how does it do that. Please try to cover that topic in one of your future videos, it is a humble request. Thank you very much for the immense knowledge that you have provided me. I will be grateful to you forever.
Very clearly explained.
Your instruction set is very close to the language I started with at school, many years ago (using 3B pencil and 40-column cards).
It was CESIL (Computer Education in Schools Instruction Language), which had only 14 instructions.
All operations (IN OUT LOAD STORE ADD SUBTRACT MULTIPLY DIVIDE) were done through the accumulator and numeric constants or user-named variables.
It had JUMP JINEG JIZERO, which is enough to do most things.
And the remaining instructions:
PRINT [some_text] to the printer
LINE to start a new line on the printer (sometimes useful after OUT and PRINT).
Finally, HALT to end the program.
It was a good introduction to programming, makign you think about every step required to solve your problem.
On the subject of educational programming, I recently encountered Scratch. Looking at its available blocks, I think it is a very good educational tool.
Dude is making an "all of computer science" series, amazing :)
This channel is underrated. Great work!
Man i really love this channel, it makes low lever programning easier
Congrats man, I can't believe how those basic concepts weren't explained this good in my university. Fantastic content keep it up!
I can't believe how good these videos are, I remember taking computer architecture at uni and its was nowhere near as clear and well said as this video, congrats!
Man, your videos have really helped me get into computer science and understand the process behind coding. You completely changed my perception of coding and finally answered my questions about how computers work in a clear and enlightening manner. Please continue!
I'm taking a coumputer architecture course at uni. This is super useful and easy to understand. Thank you very much!
when youtube notifications actually work:
Please, don't stop uploading these videos
You content and production is awesome. Great channel, congrats. 🎉How do you do your animations ?
I just wanted to thank you deeply for your videos. As a neurodivergent person, it is very important and good for me to get visual illustrations about how things work, and your videos are a spot on! I've been reading my course book dozens of times and it really lacks visual and illustrative explanations... By watching your videos BOOM everything just clicked in within one day.
Much love and appreciation!
Please keep up the great work! Your educational videos are the best and this scope doesn't have good coverage on UA-cam yet.
You are genuinely my favourite youtuber - please never stop making these videos man!!
what a stunning explanation and illustration, pretty useful♥.
Look forward to your Turing completeness video ;) good job!
While watching this video I realized something. While loops use mutiple jump instructions but if we place the body of the while loop first and place the conditional jump at the end of it, we will get a do-while loop which takes less lines of code. I always found do-while loops useless but now I see why they exist. Thanks for making this video. I always learn something new with each video.
The more you make videos, the more I get hyped for the next ones !
Couldn’t find better content explaining this concept
No decepcionas nunca Jorge :) gracias por el video ❤
Oh that last slide of the making from ur set to the arm/x86
Pure gold
Very clear explanation, thanks!
Best explanation I've seen so far
Sweet!
Makes me want to learn Assembly more :)
This is very well explained. Thank you!
Can't wait to see your next videos
Thanks for all the work, time and love you put into this, it's awesome
oh my God, bro I cannot believe that there is such a channel you're amazing bro please can you make the same tutorial videos with that low level but this time with functions and objects and classes how are these things and entities are implemented in the hardware level, please I've been searching for all of that the whole of my life.
Thank you very much for making this high quality and free accessible video for us ❤
Now you gotta explain how a MMU works.
this video inspired me to learn assembly… and i am currently writing my first
rogram, a guessing game, in x86_64! well done sir.
Really excited for scheduling and threading.
Btw, a little optimization could've been made with the conditional code: instead of a JMP_NEG addr followed by a JMP halt_addr, a JMP_ZERO halt_addr would've been enough. :)
You are so great at teaching!
Assembly always seemed like it was orders of magnitude more complex and arcane than C.
But if what you said in this video was in any way accurate, i feel like i could make comparable program in x86 assembly if i took the time to learn it.
This channel is pure gold
I would rather binge watch your content than any content available on Netflix. It's just so GOOD!
do function call next.
very interested in this and vtables as well
In case you can't wait, this is my barely self-educated understanding for a simple subroutine that doesn't take arguments or return a value:
Store the address of the next instruction to be run after the function returns into a memory location (the current position in the call stack) then increment or decrement (depending on which way your call stack grows) the current position in the call stack (push operation) then jump to the address of the function you are calling (might want to check for stack overflow during the push operation)
At the end of the function, roll back the current position on the call stack (pop operation) and jump to the location stored there.
There are assembly instructions that will do some of this work for you. You don't actually have to manually manage your own call stack (although you can if you want more stuff to manage), there are 'call (address)' and 'return' instructions that do the pushing popping and jumping.
To pass values to and from functions you will need a stack that also stores the size of the data pushed in each push operation in order to be able to pass arbitrary amounts of data and pop the stack later (for the simple call stack, addresses are all the same size and only one at a time is pushed so no need). The reason you want to use stacks for function calls is so that you can call functions from within functions from within functions etc. including recursive functions that each have their own memory that isn't overridden by other calls and doesn't require complicated code to keep track of where each part of the memory is.
One way you can make (non-recursive) functions with arguments and return values is to:
- Write input values to parts of memory dedicated to the function's input
- Write an address to the end of the function for it to jump to when finished
- Jump to the start of the function, have it do whatever it does (with input and output addresses in mind)
- Read from a dedicated output location in memory to get results after the function finishes
It could do with a better explanation than what I've given, but that's a way to do it if you have a process that can only have one instance running at a time. If you do want to get multiple instances/recursive functions involved, you need to get list management involved and all that jazz, which isn't the worst but takes a little extra work.
You can add to a list of values without worrying about it running into something else by splitting it into blocks, with each one specifying its length and where the next list block starts for if you need to look up something beyond the current block. All you need is a way to check where is allocated and where isn't so you know when and where to make a new block, which isn't too bad.
Once you can make lists, you can convert each function's input set and exit location to jump to (but not necessarily the output set) into a few lists, and you can read the input values of the current stack layer by looking up the last values in the list. Assuming you remove items from the list after you use them, you have a functioning stack. It'll still work if you don't deallocate, but you'll have a memory leak identical to one on a modern framework and eventually will run out of memory and run into whatever edge case you've set up for when you cannot make more list blocks.
The simpler way to do this if you're fine with a limited number of stack layers is to make arrays instead of lists, (the difference being an array has a set length while a list does not) and use an address to keep track of which stack layer you're currently on. This is all fine and good, but if you want to continue recursing you'll want my previous solution.
I hope this explanation is good enough until we get a video on it, and if there's anything to clarify or correct I'm happy to hear it. Bot-ass way to finish a comment but still.
This making me more and more excited to learn assembly!
Incrivel como seu canal cresceu rapido cara ! parabens !
Info surrounding these concepts is usually very dense. You do an amazing job of making them not.
This video was really great I really enjoyed and learned a lot, I am so thankful that channels like yours exist ❤❤❤❤
We did this in our subject Assembly, we had a simple loop code in c++ and we need to convert that loop statement into assembly code
Absolutely Goated Channel!
This was perfect, thank you !
This is like the best channel. Now i wonder how functions work? Or r they just variables interconnected to each other
It's the compiler doing it's job, the compiler is essentially a library of how high level complex functions are performed by a series of low level instructions, and replaces the text of a typed function with a longer list of instructions automatically before feeding it to the computer.
What an amazing video. Please do more of assembly videos❤❤❤
This video is great, easy to understand! Thank you for the amazing content!
this is amazing , great explanation
The PDP-11 did this much more efficiently with its macro-11 assembly language.
Back in the 70's (when taking Comp Sci courses in college..)
I used a text book called "Structured Computer Organization" -- Tanenbaum (pub: Prentice Hall 1976)
It explains all this kind of low level "machine code" for different popular machine "architectures" of the day.
I guess books like that don't get written anymore...still have that book...
But your automation makes it all the more "comprehensible" than just reading about it with B&W illustrations.
Also the classic work: "The Art of Computer Programming Vol 1" (Donald Knuth) introduces the student to "Assembly language"
using the "make believe" MIX language. I guess today if you need super fast code..you just write it in "C".
"No Assembly Required" 🤗
Forth and a class on 6502 helped me figure this stuff a long time ago. Although you're going on to other topics, a part 2 for this video would be the case statement. When done in assembly language its an exercise in table lookup.
Great and simple explanation ❤
Beautifully explained! Ive always loved assembly language
I am learning so much from your videos. Incredible content. Thank you so much.
This channel is a treasure 🪙
Great job man!, love this kind of videos. Thanks!
Been trying to implement an optimizing compiler for a while now. I would LOVE a video on the topic.
What if you don’t have a linker or some JIT? I think that it should be possible to assign registers for small procedures and blocks. Callers will probably run out of registers and will have to shuffle around some.
Many thanks for another great video on computer science !
Absolutely amazing man!
True! UA-cam Education is a revolution in itself. My COA professor taught me this topic and this weird assembly syntax just yesterday and no one understood anything, and today I see this video. Truly Brillant!
I like that preview picture in this video with randomly added code
It's Core Dumped Again!!🙌🏾 Timeless!
I love your content. It has been the most clear and thorough explanation of low level computer processes i've seen on youtube. And I honestly don't mind that you are using an AI generated voice. if anything its a testament to what kind of absurdly complex things you can make with simple switches. It really kind of drives the point home how ridicilous modern computers actually are and it just makes me appreciate what we have more.
Please make a video about how instructions (commands) are decoded and encoded in the processor at the binary level
Thank god you exist bro
It is not a video about computer programming, it is art of presentation on its best
🤯 what a video!! Amazing, I finally understood asambly, ty
I second the compiler optimizations video
This one was exceptionally good 👏👏👏
Pls do more videos on making optimised programs. Or rather explaining the underlying stuff so we can write good code. Love ur work ❤
The content of this channel is pure gold on information, thank you so much sir😎😎
👍👍👍👍👍Well, I pushed the "Like button" even though I did not learn some new thing, but I very much enjoy the way you made it. I would have learn with such videos 50 years ago. I envy a lot the young programmers who can learn from your content. You might want to elaborate on the different Assembler syntax, the Intel syntax type {operand / destination / source} opposite to AT&T syntax {operand / source / destination } Peace & Prosper. ❤🖖
This is great stuff! I built a 12-bit (16-bit if you're talking about the address data length, but 12-bit numbers) computer in Scrap Mechanic with programming it in mind, and this is the exact thing I have to do! I mean, I built the jump operations around comparing the two registers it has instead of ALU flags, (my computer doesn't have an ALU, the registers do incrementing/decrementing and there's no other arithmetic other than the comparison I've mentioned) but the style of code I have to make is identical. I'm looking forward to upgrading it to 256 or even 4096 addresses and seeing what I can make with it!
I LOVE this , really really LOVE it.
Amazing job bro!
Great video! I only have one minor note. I think it would be more consistent to name the instruction JMP_POS instead of JMP_ABV.
This is the best channel i could ever discover
Just awesome, thank you!
That's why with a NPU we just need to input the values we need to calculate and let it iterates, respecting the flags conditions. 12:05
Your videos would've helped me tremendously when I was a CS major, 22 years ago.
One of the things I would add is that "modern" processors have had the ability to load immediate values from the stream of instructions for many decades. It's a significant improvement on data loading efficiency and that's how it should be modeled. Also, optimizing compilers would convert that addition in the code into a single value. Some will do it without optimizations turned on.
We'll discuss this in the video about Compiler-Optimizations.
I watched every single video you uploaded. Thank you.
Thank you,
I have a question please,
What program do you use to create such great video like this?
PowerPoint
@@CoreDumpped thank you sir
That is an amazing video, but I have a few questions, how about multiple conditions with logic operators in while loops and if statements, like "AND" and "OR"? Does it feed all inputs to logic gates and only one logic gate can have an output from a binary decoder, just like how all of the inputs of the ALU are fed?
Im pretty sure there would be instructions for the bitwise and/or that would return 1 or 0 and you would check the flags to decide to jump based on the condition being true or not
George is the man!! Fantastic content