Re: [avr-chat] Missed Optimisation ?

[Michael Hennebry]

On Thu, 3 Mar 2011, Erik Christiansen wrote:

> A distrust of possible regressions in optimisation between compiler
> versions (and these have occurred in our toolchain) is one of my
> motivations for writing ISRs in assembler to start with. Being able to
> upgrade gcc to gain bugfixes or size optimisations, with zero risk of
> ISR timing change, leaves the developer with more time to build a good
> product, I think.

Agreed.
If one needs cycle-accurate timing, write in assembler.
I have some rather lengthy ISRs written in assembler for just that reason.
If faster is better, C is often good enough, but not always.

--
Michael   address@hidden
"Pessimist: The glass is half empty.
Optimist:   The glass is half full.
Engineer:   The glass is twice as big as it needs to be."