Explain Assemble Please

[Halsafar]

I've always been curious, because I believe this is the method of choice for writing new video games, especially on console.

It has been my current theory that assemble is like c++, cept like assembling units of code..i can't explain it.

Someone care to give me an explanation?

[Darkwraith]

Assembly is considered to be one of the lowest levels of programming (besides going into straight hex. This has and is done.) C++ is considered to be a high-level language (HLL).

C++ compilers take the code that you write and then (after some effort and intermediate steps) translates it into machine code. Depending on what you are using, assembly takes the assembly and translates it into machine code. Both approaches do the same thing but with assembly, you have a greater control over the application that you are writing.

Assembly is NOT a good method to write an entire video game in (Believe me. I saw it. It was not pretty.) Its not a safe langauge. If you have like 472397 lines of assembly, it is very easy to do a lot of bad things (spaghetti code, pointer overruns, blowing the stack, etc.) Assembly, however, is excellent to optimize code.

I hope that answered your question.

[Acidic]

Here's a very good page to help you learn ASM if you are interested

[Darkwraith]

However, that is just one flavor of assembler... There are several other instruction sets, each with their own way of doing things.

You have 80x86 (i386), 680x0, 6805, Z-80, 8080... We also have the HLA (high level assembly) creature which in itself is the biggest oxymoron that I have ever seen.

[Halsafar]

Thanks for the info guys.

So even tho it is not the language of complete choice for gaming. It is necessary in some case's...So if programming games is my career choice, it is time to learn right?

[NoteMe]

ASM is more or less never used anymore in games...they where hevily used in the mid 90's, but the rate of ASM is dropping incresingly. And before you are ready to take any jobs as a game programmer it is probably 100% out. Comiplers today is usualy much better then a programmer to optimize speed. So it is much better to be a REALY good C++ programmer, so you can make the code a certain way that it becomes easier for the compiler to optimize it...

[Darkwraith]

I think it depends on the application and your level of skill. If you are able to optimize a part of your code to handle features such as pipelining and MMX AND if your development environment is such that you do not have to worry about your code being machine independent, then assembler is a great choice for chunks of code. I mean you cannot use assembler in Java.

You should learn assembler for programming experience, but do think that you will be able to build a gaming career off of it.

[Maven]

Originally posted by NoteMe
ASM is more or less never used anymore in games...they where hevily used in the mid 90's, but the rate of ASM is dropping incresingly. And before you are ready to take any jobs as a game programmer it is probably 100% out. Comiplers today is usualy much better then a programmer to optimize speed. So it is much better to be a REALY good C++ programmer, so you can make the code a certain way that it becomes easier for the compiler to optimize it...

Well that's not entirely true. Compilers do a very good job yes, but their is always room for improvment. Loops and arrays for example are an ideal place to start when you want to "Hand Optimize" code.

I'm sure you use more handwritten asm code then what you are aware. A lot of string handling librarys are hand written in ASM which you call from c++. Reason being is that you can load up 4 bytes of a string into a doubleword interger and do test on it. IE: finding out where the null charector is for example which is used to terminate strings.

Just so you know, if you want to be good at ASM, you must also be good at math. Combine the 2 and you can make some sweet algorithms.

[Shaggy Hiker]

Furthermore, I think that at least a comfortable introductory understanding of assembler can make you a much better coder for high speed C++, even if you are not doing custom optimization.

After all, the only way to really speed up a program is to test it. If you don't have any understanding of what is happening behind the scenes, what are you testing for? Will you start trying different things at random to see what works best, and build up a series of rules of thumb? You can do that, but you might as well have some foundational knowledge to start with.

Also, if you start debugging C++, you will be able to find compiler bugs more easily if you can read assembler. Compiler bugs are FUN! I've found a few in VB, but without being able to see what is generated, there's always a chance that the behavior is not a bug (just a feature).

[Darkwraith]

I would not be going on a bug hunt on each error that I get, but in the rare instance that you do need to check the compiler, then, assembly (or even just plain display statements) is a useful tool.

[Shaggy Hiker]

Bug hunts are a last resort, but I confess to feeling a bit like a prospector with a nugget whenever I find one. I realize they are mostly annoying, but it's oddly satisfying when the bug isn't my doing.