[Bug-gnubg] Some questions about build options and toolchain

[Philippe Michel]

When building gnubg, there is some automake magic to have some files in 
the lib directory compiled with different flags from the rest.

Is it really needed or is it a relic from early SSE days, trying to build 
a unique binary with both SSE and non-SSE evaluation routines and the 
right one selected at runtime ?

On my machine, I compile with -march=native -mtune=native, get SSE 
instructions everywhere, not just in libsimd_la-XXX objects and everything 
works fine.


Second question, for those who make binary packages for various 
distributions :

With gnubg, the -O3 compilation flag brings a significant speed 
improvement. -ffast-math helps as well.

What is your policy about such flags in upstream sources ? Do you follow 
them ? Override them ? Take them as a hint and decide on a case by case 
basis ? I suppose the issue alredy happens with numerical libraries, audio 
and video processing code, etc...


Finally, would it cause trouble to someone if gnubg was build as C99 code 
(-std=gnu99 really, since it would have to cater with embedded asm).