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Re: [GLIBC][PATCH] Remove strcmp inlines
On Mon, Dec 12, 2016 at 7:48 AM, Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
> On 12/12/2016 10:40, Zack Weinberg wrote:
>> I'm inclined to say that the strcmp expansion should stick around
>> until after it _is_ added to GCC.
>
> But I hardly see this as a performance hotstop for any significant workload,
> but rather as a microptimization that has driven string2.h creation as a
> whole.
>
> Also the idea is to avoid rely on specific libc implementation to actually
> get these kind of optimization (if it is worth).
I'd agree with this if we were talking about a new addition to
string2.h - those should be justified by something beyond just
optimization. (For instance, the explicit_bzero inline is a partial
mitigation for the problem with variables whose address otherwise
wouldn't be taken.)
With an _existing_ string2.h microoptimization though, I think we need
to be able to argue that it is too infrequently used to be worth it
(e.g. strdup) or that it's been subsumed by compiler optimizations.
Long lists of short strcmp() operations are very common.
zw