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.
