optimization options

bhauji bhauji ravi.srinivasan@poseidon-systems.com
Thu Dec 18 09:29:00 GMT 2003


hi all.

i was looking at the optimization options that gcc
provides and am confused by a couple (for now!)

-ffast-math
a> -fno-math-errno
tried some programs using sqrt function. should it not
be using the FSQRT instruction in the pentium? it does
not seem to be doing so. so no difference on x86.
should this be a glibc query instead?

b>-funsafe-math-optimizations
turned this option on with some functions like pow but
there was no difference

c>fno-trapping-math
no idea what this does!

anyone here with ideas on how to test this option?

cheerio,
ravi
P.S: also if anyone has info about
-fexpensive-optimizations, do let me know.



More information about the Gcc-help mailing list