Improve tgamma accuracy (bug 18613) [committed]

[Szabolcs Nagy]

On 01/07/15 22:50, Joseph Myers wrote:
> I saw some failures of new tgamma tests for ARM.  On investigation these 
> appear to be a GCC bug; 
> <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66731> filed.  So if you see 
> missing errno settings for tgamma_upward on ARM, or, I think but haven't 
> tested, AArch64, that GCC bug is the cause.
> 

hm i tried to verify this on aarch64 and also regenerate the libm ulps

but the new ulps file somehow become much smaller than expected

$ grep Function NewUlps
Function: Real part of "cexp_downward":
Function: Imaginary part of "cexp_downward":
Function: Real part of "cexp_towardzero":
Function: Imaginary part of "cexp_towardzero":
Function: Real part of "cexp_upward":
Function: Imaginary part of "cexp_upward":
Function: Real part of "csin_upward":
Function: Real part of "csinh_downward":
Function: "jn_downward":
Function: "jn_towardzero":
Function: "jn_upward":
Function: "tgamma_downward":
Function: "tgamma_towardzero":
Function: "tgamma_upward":

so most functions have no errors and 'make regen-ulps'
has no error output.

a bit earlier version at 31545c23277cd54a1edd41c85d8255fb589158e3
the ulps file looks as i'd expect, still investigating..