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fixdep: faster CONFIG_ search

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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@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
This commit is contained in:
Alexey Dobriyan 2016-08-24 21:03:05 +03:00 • committed by Michal Marek
commit dee81e9886
1 changed files with 28 additions and 58 deletions
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