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About -On optimization flag
- From: José Luis García Pallero <jgpallero at gmail dot com>
- To: gcc-help at gcc dot gnu dot org
- Date: Thu, 21 Oct 2010 16:37:41 +0200
- Subject: About -On optimization flag
Hello,
Using the -On optimization flag, what is the greatest "n" value that
can I use? In the gcc manual (4.5.1, 4.4.5, 3.4.6) the greatest level
documented is -O3
(http://gcc.gnu.org/onlinedocs/gcc-4.5.1/gcc/Optimize-Options.html#Optimize-Options),
but if you tray for example with -O4, -O5, -O9, etc. no warning nor
error is emitted. I've asket some people and all says that -O4 and -O5
are valid and higher level optimizators than the documented -O3.
What is the correct answer? Is -O3 the higher optimization level as is
documented in the manual or -O4, -O5 performs additional
optimizations? If -O3 is the higher why the use of -O4, -O5 not emits
a warning or error?
Thanks
--
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José Luis García Pallero
jgpallero@gmail.com
(o<
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Use Debian GNU/Linux and enjoy!
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