Well -O3, personally is no recommended in my opinion as that optimises the build beyond the safety limit unless it''s set at -O2 for stability.
However I did experiment on compiling it with -O2 last week and set the -march=i686 compile flags but that build causes the server to crash all of a sudden; as I said from above. I didn't include the -msse2 compile flag and this is the Makefile opt flags I had used:
Code:
C_OPT_FLAGS = -O2 -march=i686 -DNDEBUG=1 -fno-exceptions -fno-rtti -funroll-loops -fomit-frame-pointer -pipe -mtune=native
Plus I don't know about the other compile flags like funroll-loops or fomit-frame-pointer on the build's stability... But I got a reference on why -O3 isn't safe from link below, in case you had no idea:
http://stackoverflow.com/questions/1...dangerous-in-g