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Differential D45330

subr_pctrie: use ilog2(x) instead of fls(x)-1
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Authored by dougm on May 24 2024, 5:01 AM.
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rG749c249dc3b6: subr_pctrie: use ilog2(x) instead of fls(x)-1
rG574ef6506950: subr_pctrie: use ilog2(x) instead of fls(x)-1
Summary

In a GENERIC-NODEBUG kernel, each instance of using ilog2 in place of fls()-1 saves about 4 amd64 instructions, including a conditional, and 16 or so bytes.

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rG FreeBSD src repository
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PathSize
sys/
kern/
6 lines
vm/
4 lines
5 lines
2 lines
123 lines
33 lines

Diff 139371

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sys/kern/subr_pctrie.c

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sys/vm/_vm_phys.h

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sys/vm/vm_page.c

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sys/vm/vm_phys.h

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sys/vm/vm_phys.c

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sys/vm/vm_reserv.c

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