Messages in this thread | | | Date | Tue, 23 Aug 2022 19:43:59 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v5 2/2] x86/asm/bitops: __ffs,ffz: use __builtin_ctzl to evaluate constant expressions |
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On Tue, Aug 23, 2022 at 10:12:17AM -0700, Nick Desaulniers wrote: > Callers of these need to guard against zero input, as the pre-existing > comment notes: > > >> Undefined if no bit exists, so code should check against 0 first.
This is just silly.
And then there's
* ffs(value) returns 0 if value is 0 or the position of the first * set bit if value is nonzero. The first (least significant) bit * is at position 1. */ static __always_inline int ffs(int x)
Can we unify the two and move the guard against 0 inside the function or, like ffs() does, have it return 0 if value is 0?
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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