SSE2 test doing nothing?

jubatus / jubatus_core

Jubatus algorithm component

GNU Lesser General Public License v2.1

20 stars 29 forks source link

SSE2 test doing nothing? #374

Closed kmaehashi closed 7 years ago

kmaehashi commented 7 years ago

https://github.com/jubatus/jubatus_core/blob/1.0.3/wscript#L120-L122

  if not func_multiver_enabled:
    sse2_test_code = '#ifdef __SSE2__\nint main() {}\n#else\n#error\n#endif'
    conf.check_cxx(fragment=sse2_test_code, msg='Checking for sse2', mandatory=False)

It seems that it has not effect. @kazuki

kazuki commented 7 years ago

__SSE2__ is defined only sse2 supported architecture (like x86_64).

if configure on no sse2 architecture, __SSE2__ is not defined and goto #error route (like i386).

kmaehashi commented 7 years ago

Exactly, so maybe mandatory=False should be removed? I think currently it just slips.

kazuki commented 7 years ago

Main subject of this test is output a sse2 supporting status.

Implementation of lsh is three types.

AVX2 vectorized code (FMV enabled)
SSE2 vectorized code (FMV enabled or SSE2 enabled)
non vectorized code (fallback. FMV enabled or SSE2 disabled)

If mandatory=False removed, jubatus_core cannot build on non x86_64 archtecture (like i386, emscripten-javascript).

kmaehashi commented 7 years ago

Thank you, it made things clear. I didn't know that it was just for informational purpose.