Messages in this thread | | | Date | Thu, 7 Apr 2016 11:43:33 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 10/30] Add x86-specific parity functions |
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On Thu, Apr 07, 2016 at 08:31:09AM +0200, Dmitry Vyukov wrote: > Hweight custom calling convention caused crashes with KCOV coverage. > We had to disable instrumentation of the file.
I guess we can do something like this:
if (likely(static_cpu_has(X86_FEATURE_POPCNT))) asm volatile(POPCNT32 : "="REG_OUT (res) : REG_IN (w)); else res = __sw_hweight32(w);
and get rid of the custom calling convention.
Along with some numbers showing that the change doesn't cause any noticeable slowdown...
-- Regards/Gruss, Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --
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