On 6/3/2011 7:45, Invisible wrote:
> (By contrast, a *real* 32-bit chip like the Motorola 68000 has registers A0
> through A7 and D0 through D7, and when you do an operation,

Which is fine if you're not trying to be assembly-language compatible.

> In short, they kept kludging more and more stuff in. Having a stack-based
> FPU register file is a stupid, stupid idea.

Not when your FPU is a separate chip from your CPU.

> But now all our software depends on this arrangement,

Not any longer. For example, I believe gcc has a command-line switch to say 
"use x87 instructions" instead of loading floats via the MMX instructions.

> Aliasing the MMX registers to the FPU registers was stupid,

No, it saved chip space.

> The list goes on...

It would be nice if it was practical to throw out all software and start 
over every time we had a new idea, wouldn't it? But then, everything would 
be as successful as Haskell. ;-)

-- 
Darren New, San Diego CA, USA (PST)
   "Coding without comments is like
    driving without turn signals."

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