[avr-gcc-list] Re: sprintf

[David Brown]

David Kelly wrote:
> On Mon, Mar 02, 2009 at 10:16:39AM -0500, David VanHorn wrote:
> > > Disable optimizations, -O0 I believe, and the source code debugger
> > > will more closely track the actual lines of code.
> > Ouch!  That takes me from about 1.8k to over 7k.
>
> Yes, but the larger code is a more literal translation of your source
> code which the debugger can more easily map source code 1:1 to generated
> assembly.
>
> -O0 is handy when learning C and wanting to see an assembly translation.

I find it a lot easier with -O1 than -O0.  With no optimisation, there 
is so much extra code handling local variables on the stack and the like 
that it is difficult to follow what is actually happening.  With -O1 you 
get a fairly literal translation, but local data is in registers.

> Code should be debugged using the same optimization one will ultimately
> ship code no matter the debugger seems to jump around.
>

That depends on why you are debugging.  If you are debugging your 
algorithms, it doesn't matter what optimisation you are using.  If you 
are debugging timing or implementation problems, then obviously it does 
matter.