Messages in this thread | | | From | Linus Torvalds <> | Date | Tue, 12 Feb 2013 15:49:07 -0800 | Subject | Re: [tip:x86/mm] x86, mm: Redesign get_user with a __builtin_choose_expr hack |
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On Tue, Feb 12, 2013 at 3:19 PM, H. Peter Anvin <hpa@zytor.com> wrote: > > Yes, but there doesn't seem to be any other way to do this. gcc won't > even allow "=cd" even if we know the variable is 64 bits, even though > "=A" is documented to be equivalent to "=da".
No, "=da" means value "in edx _or_ %eax". Not the same as "A".
But you're right, there's nothing similar for %ebx:%ecx. I thought there was. I was really sure we did something special for 64-bit adc etc.
> Let me know what you think.
I guess we don't have any choice. And the other cleanups certainly look good.
Linus
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