Re: [PATCH v2] fixdep: faster CONFIG_ search

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Dne 24.8.2016 v 20:03 Alexey Dobriyan napsal(a):
> Do you think kernel build is 100% dominated by gcc? You are wrong!
> One small utility called "fixdep" consistently manages to sneak into
> profile's first page (unless you have small monitor of course).
> 
> The choke point is this clever code:
> 
> 	for (; m < end; m++) {
> 		if (*m == INT_CONF) { p = (char *) m  ; goto conf; }
> 		if (*m == INT_ONFI) { p = (char *) m-1; goto conf; }
> 		if (*m == INT_NFIG) { p = (char *) m-2; goto conf; }
> 		if (*m == INT_FIG_) { p = (char *) m-3; goto conf; }
> 
> 4 branches per 4 characters is not fast.
> 
> Use strstr(3), so that SSE2 etc can be used.
> 
> With this patch, fixdep is so deep at the bottom, it is hard to find it.
> 
> Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
> ---

Thanks, applied to kbuild.git#kbuild.

Michal

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