Joined: 10 Apr 2002
Location: Porto Alegre, BR
|Posted: Fri Jun 28, 2002 3:39 am Post subject: Flags included by -O options in gcc 3.1
|From the gcc3 forum:
|slik wrote: |
|-mcpu and -march will differ per your cpu of course, this is from a newish duron with -march=athlon passed in.
I've seen people putting flags in thier setups that are already included with a given -O flag, so..
Also notice that -fomit-frame-pointer isn't included with this processor.
options are added to previous optimization level.
no -O option passed, same as -O0
options enabled: -fpeephole -ffunction-cse -fkeep-static-consts -fpcc-struct-return -fgcse-lm -fgcse-sm -fsched-interblock -fsched-spec -fbranch-count-reg -fcommon -fgnu-linker -fargument-alias -fident -fmath-errno -ftrapping-math -m80387 -mhard-float -mno-soft-float -mieee-fp -mfp-ret-in-387 -mcpu=athlon -march=athlon
-O1 same as -O adds best for debugging
-fdefer-pop -fthread-jumps -fcprop-registers -fmerge-constants -fguess-branch-probability
-foptimize-sibling-calls -fcse-follow-jumps -fcse-skip-blocks -fexpensive-optimizations -fstrength-reduce -fforce-mem -fcaller-saves -fgcse -frerun-cse-after-loop -frerun-loop-opt -fdelete-null-pointer-checks -fschedule-insns2 -freorder-blocks -fregmove -foptimize-register-move -fstrict-aliasing -fpeephole2
-Os is the same as for -O2 but also preforms further optimization to reduce size of executable.
| www.gentoo.org | www.tldp.org | www.google.com |