[Bug tree-optimization/126710] missed ifcvt optimization with clz

"pinskia at gcc dot gnu.org via Gcc-bugs" <[email protected]> Sat, 08 Aug 2026 00:35:58 +0000

Newsgroups	gmane.comp.gcc.bugs
Message-ID	<[email protected]/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126710

--- Comment #4 from Drea Pinski <pinskia at gcc dot gnu.org> ---
Note LLVM produces:
        lsr     w9, w0, #1
        mov     w8, #32
        cmp     w0, #0
        clz     w9, w9
        sub     w9, w9, #1
        csel    w0, w8, w9, eq
        ret

Which is still clz shifted by 1 and subtraction of 1 followed by selection.