Messages in this thread | | | Subject | Re: [PATCH v4 01/17] x86/common: Align cpu_caps_cleared and cpu_caps_set to unsigned long | From | Paolo Bonzini <> | Date | Mon, 4 Mar 2019 14:13:18 +0100 |
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On 04/03/19 13:44, Peter Zijlstra wrote: > On Mon, Mar 04, 2019 at 11:48:18AM +0100, Paolo Bonzini wrote: >> True that. On the other hand btsl/btrl is also one byte smaller if no >> operand is %r8-%r15. > > Because then we loose the REX prefix, right. Now _that_ might actually > be a reason to do that :-)
I knew that would be the right way to put it for you. :)
>> In any case, /me wonders if we should have a macro like >> >> #define DECLARE_LE_BITMAP(name,bits) \ >> u32 name[DIV_ROUND_UP(bits, 32)] __aligned(sizeof(unsigned long)) > > s/u32/__le32/ > > To go in bitops/le.h, sure, if there's enough users.
Hmm... actually that should be "BITS_TO_LONGS(bits) * sizeof(unsigned long) / 4" because bitmap functions may access (or even clear) the last word as 64 bits.
Paolo
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