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Re: Call for compiler help/advice: atomic builtins for v3
Richard Henderson wrote:
>On Mon, Nov 07, 2005 at 01:35:13AM +0100, Paolo Carlini wrote:
>
>
>>We have to add to the library
>>out-of-line versions of the builtins... (in order to do that, we may end
>>up restoring the old inline assembly implementations of CAS, for example)
>>
>>
>I don't think you need to restore inline assembly.
>
>
Would be a dirty short-cut... ;)
>>If I understand correctly, this is what we are already doing in the
>>*.so, for i386 vs i486+. I would not call that "optimization flag",
>>however. Can you clarify?
>>
>>
>I'm not sure how you were previously controling what went in here.
>By configuration name?
>
Yes, see configure.host
> That's certainly one way to do it, and
>probably the most reliable.
>
>
Ok, thanks.
>Another method is to use -march=i486 on the command line, and from
>there use the __i486__ defines already present to determine what
>to do. Note that, at least for x86, -mtune=cpu affects __tune_cpu__,
>but not __cpu__.
>
>My thinking would be along the lines of
>
>
[snip]
Ok, thanks. That is also by and large what I had in mind, modulo I would
exploit our current infrastructure that you can ascertain looking to
configure.host.
To be sure: can you confirm that there is no easy solution for the
x86_64 issue? I mean, it's annoying that we cannot inline the builtins
for i686, but even more so for x86_64...
Paolo.