Question about assembly language

[simonpro]

Hey, I'm looking at this simple assembly code:

loop: beq r0,r0,loop

Which keeps looping whilst the processor is idle. Will this code perform read operations on the memory, or does it simply involve loading from on-processor registers?

 

[Eagle]

Looks like its only using register zero... and that it will loop infinitely.

 

[simonpro]

Yeah, it's supposed to be an infinite loop. It gets broken by a reset switch elsewhere.
the memory issue was what was worrying me, but if it's read from a register then all is good.

 

[Eagle]

generally speaking, busy waiting isn't the best idea. Its usually better to block the thread and have another thread unblock it. But thread concepts become rather difficult to do at the assembly level.

 

[Artlav]

loop: beq r0,r0,loop

Um. Which CPU?

Why should it read from memory?
It compares r0 register to itself (if the thing uses standard notation of rx being registers), and does a branching back to itself.
No memory reads, as far as i understand.

 

[simonpro]

Why should it read from memory?

I don't know, I don't use assembly language (I'm an engineer, not a computer scientist). Hence why I posted here to check that it didn't.

generally speaking, busy waiting isn't the best idea.

Yeah, this is supposed to be an example of an inefficient system. Hence why it doesn't use the best methods.