Messages in this thread | | | Subject | Re: cmpxchg and x86 flags output | From | "H. Peter Anvin" <> | Date | Tue, 21 Jun 2016 17:09:03 -0700 |
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On 06/21/16 10:24, H. Peter Anvin wrote: > On 06/21/16 02:06, David Howells wrote: >> >> However, there's probably not a great deal of difference to be had if the >> inline asm codes the appropriate instruction in each case for something like >> x86*. The emitted code ought to look the same. The second biggest win for >> the intriniscs, I think, is the ability to ask the CMPXCHG instruction whether >> it actually did anything rather than comparing the result. I added two >> variants, one that only returned the yes/no and one that passed back the value >> as well as the yes/no. >> > > Right, and we want that either way. The API change that you are > proposing is definitely what we want; the specifics of the x86 > implementation is sort of orthogonal. >
So how do we make this move forward?
-hpa
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