https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67295
--- Comment #2 from ktkachov at gcc dot gnu.org ---
(In reply to Alexandre Oliva from comment #1)
> I get exactly the same code with r226900, before the copyrename patch:
>
> cmp r1, #0
> rev16ne r0, r0
> uxthne r0, r0
> .L2:
> sxth r0, r0
> b foos16
>
> Did you use any other configuration flags or compiler options or assembler
> version or something to get you the better-optimized code?
Hmmm, I double checked, and with r226900 before the patch I definitely get:
cmp r1, #0
revshne r0, r0
.L2:
b foos16
The options are just -O2 -S.
It is an arm-none-eabi toolchain (with newlib as the C-library) and the
relevant configure options I can think of are:
--disable-shared --disable-nls --disable-threads --disable-tls
--enable-checking=yes --enable-languages=c,c++,fortran --with-newlib
--with-fpu=neon-fp-armv8 --with-arch=armv8-a --without-isl
