Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [1/4] powerpc: Discard ffs()/__ffs() function and use builtin functions instead | Date | Mon, 5 Jun 2017 20:21:49 +1000 (AEST) |
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On Fri, 2017-04-21 at 11:18:46 UTC, Christophe Leroy wrote: > With the ffs() function as defined in arch/powerpc/include/asm/bitops.h > GCC will not optimise the code in case of constant parameter, as shown > by the small exemple below. ... > > In addition, when reading the generated vmlinux, we can observe > that with the builtin functions, GCC sometimes efficiently spreads > the instructions within the generated functions while the inline > assembly force them to remain grouped together. > > __builtin_ffs() is already used in arch/powerpc/include/asm/page_32.h > > Those builtins have been in GCC since at least 3.4.6 (see > https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Other-Builtins.html ) > > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Series applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/f83647d642270f6b9d75736817fb5a
cheers
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