Third-party library: Binary vs. recompilation

**Felix Clark** · 10-22-2009, 11:43 AM

Hi,

I do not exactly end the interest of a recompile Qt lib example rather than using the precompiled binaries?

Performance Issues? And if so why?

Thank you

**Fabian Nadal** · 10-22-2009, 11:45 AM

It also depends on the OS library if you got a multi-target and multi-arch eh. Secondly, yes the perfs may change if you take the time tuner options compilers.

**Cohen Cassius** · 10-22-2009, 11:46 AM

linux binary format is different from the Windows binary.

**Felix Clark** · 10-22-2009, 11:50 AM

ok but I suppose talking about windows binary, interest recomplier is only optimization that can be done via the compiler options?, developers who produce the binary have not already done?

**Daevon Vettori** · 10-22-2009, 11:51 AM

Rarely. ATLAS kind of stuff do x by generating binary versions of LAPACK / BLAS with different set of optimizations.

**Cayden Morakel** · 10-22-2009, 11:53 AM

You can adjust the processor you have (usually when you supplied binaries, you limit the instruction set to something relatively old - for gcc-march - and you optimized for something more recent but not the last out --mtune for gcc, you can amuse yourself not to provide versions for all 42 possible cases). For a library, you have more choices of dynamic / static or multi-threaded or not and some choices in what is configured (you can completely deactivate the support of things that you do not use).

**Felix Clark** · 10-22-2009, 11:54 AM

ok interesting. Another issue directly related, in visual, when compiled, the compiler detects the CPU of the machine and carry out optimizations? Or if you want to use the instruction sets of a given μ it is for us to mention it in the command line.