A few API functions were (accidentally?) removed in 3.6

[musicinmybrain]

Although sleef 3.6 is supposed to be an ABI-compatible update for 3.5.1 (the SONAME version is still 3), comparing the main shared library using fedabipkgdiff from libabigail shows that a handful of symbols were removed. Of these, Sleef_sincospil_u05 and Sleef_sincospil_u35 were documented API functions.

Comparing the ABI of binaries between sleef-3.5.1-33.fc41.x86_64.rpm and sleef-3.6-1.fc41.x86_64.rpm:

================ changes of 'libsleef.so.3.5.1'===============
  Functions changes summary: 4 Removed, 67 Changed (1796 filtered out), 148 Added functions
  Variables changes summary: 0 Removed, 0 Changed, 0 Added variable

  4 Removed functions:

    [D] 'function const Sleef_longdouble2 Sleef_sincospil_u05(long double)'    {Sleef_sincospil_u05}
    [D] 'function const Sleef_longdouble2 Sleef_sincospil_u35(long double)'    {Sleef_sincospil_u35}
    [D] 'function const Sleef_quad2 Sleef_sincospiq_u05(Sleef_quad)'    {Sleef_sincospiq_u05}
    [D] 'function const Sleef_quad2 Sleef_sincospiq_u35(Sleef_quad)'    {Sleef_sincospiq_u35}

This is on x86_64; I haven’t checked other architectures.

In a quick glance at the source code, it wasn’t immediately obvious to me why these symbols disappeared. I do notice that they are all at the end of rename.h, after a comment line:

sleef/src/libm/rename.h

Lines 175 to 181 in a99491a

	//
	#define xsincospil_u05 Sleef_sincospil_u05
	#define xsincospil_u35 Sleef_sincospil_u35
	#define xsincospiq_u05 Sleef_sincospiq_u05
	#define xsincospiq_u35 Sleef_sincospiq_u35

While nothing in rename.h has changed between 3.5.1 and 3.6, maybe this was affected by changes in mkrename.c?

[musicinmybrain]

I bisected this to 1d66bbd.

The changes in sleeflibm_header.h.org.in look suspicious:

1d66bbd#diff-6a6c4d54f858f55978b29ae41b00d4a8b484ddf7908a136abd4f9a003458d2c3L312

[blapie]

Good point. It seems that scalar long double/quad sincospi implementation was removed along with the long double DFT (where it was used).
I agree that this should have triggered a new major version. I would be keen to re-integrate the function as it can still be useful to users.

Maybe a bit of background from @shibatch could help?

What would be the process to fix 3.6? Would we simply have to create a new patch release?

I will be officially AFK until April 22 (sabbatical), but @joanaxcruz, @joeramsay and @shibatch might be able to follow up on this one.

[musicinmybrain]

I’m going to hold off on updating the Fedora package past 3.5.1 for up to another month or two, in the hope that it will still be possible to avoid an ABI break (and update Sleef in existing stable releases).

[blapie]

Hi! Sorry about the delay in responding to that. We are planning a patch release including a fix for that in the next month. Will post more in discussions.

[musicinmybrain]

Thanks for the update!