Messages in this thread | | | Date | Wed, 20 Feb 2013 23:29:58 -0500 (EST) | From | Nicolas Pitre <> | Subject | Re: [RFC] arm: use built-in byte swap function |
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On Wed, 20 Feb 2013, Kim Phillips wrote:
> On Wed, 20 Feb 2013 10:43:18 -0500 > Nicolas Pitre <nico@fluxnic.net> wrote: > > > On Wed, 20 Feb 2013, Woodhouse, David wrote: > > > On Wed, 2013-02-20 at 09:06 -0500, Nicolas Pitre wrote: > > > > ... in which case there is no harm shipping a .c file and trivially > > > > enforcing -O2, the rest being equal. > > > > > > For today's compilers, unless the wind changes. > > > > We'll adapt if necessary. Going with -O2 should remain pretty safe anyway. > > Alas, not so for gcc 4.4 - I had forgotten I had tested > Ubuntu/Linaro 4.4.7-1ubuntu2 here: > > https://patchwork.kernel.org/patch/2101491/ > > add -O2 to that test script and gcc 4.4 *always* emits calls to > __bswap[sd]i2, even with -march=armv6k+.
Crap. OK, assembly code is the way to go then.
> I'll try working on an assembly version given it probably > makes more sense, future-gcc-immunity-wise.
Agreed.
Nicolas
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