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Re: Suboptimal bb ordering with -Os on arm


> On Nov 10, 2016, at 8:16 PM, Nicolai Stange <nicstange@gmail.com> wrote:
> ...
> 
>> There is no way to ask for somewhat fast and somewhat small at the
>> same time, which seems to be what you want?
> 
> No, I want small, possibly at the cost of performance to the extent of
> what's sensible. What sensible actually is is what my question is about.
> 
> Example: A (hypothetical) code size saving of 0.00000000001% at the cost
> of 10000000000x slower code certainly isn't. But 0.1% at the cost of
> some additional 0.5us here and there -- no clue.
> 
> So, summarizing, I'm not asking whether I should use -O2 or -Os or
> whatever, but whether the current behaviour I'm seeing with -Os is
> intended/expected quantitatively.

If you care enough to ask this question, my answer is that you should compile your application a bunch of different ways -- -Os, -O2, -O3, as well as a variety of the fine grained optimization flags -- and pick the result that best achieves what you're looking for.  

	paul


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