Re: [tlug] Assembly Language v C and Embedded Development: !gcc for PIC16F84

[Josh Glover <jmglov@example.com>]

On 10 March 2011 07:54,  <jep200404@example.com> wrote:

> On Wed, 9 Mar 2011 13:09:07 +0100, Josh Glover <jmglov@example.com> wrote:
>
>> I think this is a fallacy. I challenge you [Lewske Wada] to profile your
>> code and show that you can regularly beat gcc with the optimiser turned up.
>
> It can not be done because gcc is not available for the PIC16F84 that
> Lewske Wada is using. Would you like to restate your challenge using
> some open source compiler that you recommend for the PIC16F84?

No, I'd like to restate my challenge as follows:

For any architecture (MCU or otherwise) for which a decent quality
compiler (such as gcc) is available, show that you can regularly beat
the compiler with hand-rolled assembly.

Qualified enough for you? ;)

>> OK Jim, stop beating around the bush and empty both barrels! ;)
>
> By playing along, you will be led to a better understanding of
> the embedded world that Lewske Wada and I are familiar with.
> Read section 2.4.1 on page 11 of the PIC16F84 datasheet[1],
> and discuss how you would write a compiler to do stack relative
> addressing that C loves so much. Others are welcome to comment also.
>
> [1] http://ww1.microchip.com/downloads/en/devicedoc/35007b.pdf

Challenge accepted! But give me a few days / weeks / months. ;)

-- 
Cheers,
Josh