POV-Ray : Newsgroups : povray.off-topic : An idle observation : Re: An idle observation Server Time
4 Sep 2024 03:22:43 EDT (-0400)
  Re: An idle observation  
From: Darren New
Date: 2 Aug 2010 23:57:56
Message: <4c5793c4$1@news.povray.org>
clipka wrote:
> It is "top" and "bottom", "left" and "right" that are meaningless in the 
> context of memory layout, but "start" and "end" are absolutely not:

If you have a machine whose instructions are all 32-bits long, asking the 
order of bytes within a machine word might not make much sense.

But OK, I'll grant you that "low address" chronologically comes before "high 
address" for at least some instructions, generally speaking.

> They're called "big-endian" and "little-endian" not because a particular 
> byte is on the "biggest" (or "smallest") address, but because the 
> "biggest" byte (=MSB, or "smallest" byte =LSB) comes first in memory.

I know that. I was arguing about "first" in memory, not "biggest" address. 
Indeed, I'd say "bigger address" makes more sense / is less ambiguous than 
"first address".  But all the memory is there all the time. To call one 
memory address "before" another, you have to have some chronological 
ordering of memory addresses.  Which you pointed out is the auto-increment 
types of instructions, including the implicit auto-increment of the PC.

> ... which, as a matter of fact, is exactly why the terms "big-endian" 
> and "little-endian" so beautifully hit home.

Yep.

-- 
Darren New, San Diego CA, USA (PST)
    C# - a language whose greatest drawback
    is that its best implementation comes
    from a company that doesn't hate Microsoft.


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