[PATCH] Inline assembly division needs __volatile__

[Ximin Luo]

Torbjörn Granlund:
> Ximin Luo <infinity0 at pwned.gg> writes:
> 
>   Any chance my patch could be tested and merged?
> 
> I tried applying it, but it fails for the current head.  Manual merging
> is required.  (It applies flawlessly to GMP 6.1, though.)
> 
> If you could modify your patch to apply to the GMP head, then that would
> help.  The repo is here: https://gmplib.org/repo/gmp/
> 

I've rebased, tidied up the whitespace, and added a test case - see attached patches. However, I'm not sure the test case will be very useful since it is GCC-7.2 specific, is only for x86-64, and is sensitive to being changed in a way that might make GCC-7.2 not perform the target optimisation. You can decide whether to keep it...

(I assigned copyright to FSF to be consistent with the other files, I assume something this small doesn't need a specific CLA/waiver...)

>   I did not ask other projects' opinions on this yet, since they seemed
>   to have copied the code from GMP. Could you confirm that GMP is the
>   original source?
> 
> I originally wrote it for use in GCC, glibc, and GMP.  I only actively
> maintain the GMP version.
> 
> (The versions has diverged, unfortunately.  The GMP version now contains
> some GMPisms which might need cleaning up if we want to make the
> versions converge.)
> 

That would be good yes... would also be a good to put a warning at the top of that file along the lines of "the original version is from GMP at address <URL>, please submit all change requests there rather than this project, and update regularly".

Might also be a good idea to expose it as a public header file, then at least projects that already depend on GMP (e.g. flint and other scientific stuff) can just #include it instead of copying it.

X

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