Re: ****tability: Harmony between PC and microcontroller

Tomás Ó hÉilidhe wrote:

> On May 6, 12:33 pm, Chris Dollin <chris.dol...@[EMAIL PROTECTED]
> wrote:
> 
>> That just means that those microcontrollers aren't a natural fit
>> to C, so programmers writing looks-like-C for them need to be
>> aware that natural-C idioms might not work as nicely.
> 
> 
> This is what I'm against. When I first started programming in C for
> embedded systems, I was weary of the compiler's compliance to the
> Standard. I was hesitant to rely on rules from the Standard when it
> came to things like:
>     * Minimum size of integer types
>     * Behaviour of overflow
>     * Existance and usage of a stack
> 
> Having written a fully working program though in C for embedded
> systems, and also having looked at the assembler produced to check
> what it's actually doing, I've seen that my embedded compile is
> extremely compliant. I defined an object as "long unsigned", and lo
> and behold the assembler produced used four bytes to store it (even
> though it can only do arithmetic on 8-Bit numbers).
> 
> 
>> I don't see a problem here.
> 
> 
> The problem comes with writing ****table code.

No, it doesn't. Not if the compiler conforms to the standard.

> For instance, I'm 
> currently writing code to implement an internet protocol router. The
> code show be able to run on both a microcontroller and on a PC.
> However, if the code uses "int" then the code will be less efficient
> on a microcontroller. 

Your problem is not with ****tability; it's with performance.
Different platforms can have differing performance profiles
at whim, and ****table code may need tweaking for best performance
on /any/ of them. Singling out performance issues on 8-bit
micros and thinking everyone should write code so that it
(by /hypothesis/) performs equally (well, badly) on those
implementations is, I think, obsession over microefficiency.

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