From: dmcintyr@nyx.cs.du.edu (Doug McIntyre) Subject: Re: what are -O6 and -N? Date: Fri, 9 Jul 1993 15:43:29 GMT
rxg3321@ultb.isc.rit.edu (R.X. Getter) writes:
>Just out of curiousity, what does -O6 do for the compiler. The highest
>optimization level in the documentation is -O2. Also, what is -N?
>I notice that it makes a lot of executables much smaller. (programs in
>textutil, fileutil et. al from prep) but I can't find any documentation
>for it. (or anything for ld for that matter) Any information will be
>appreciated.
-O6 does absolutely nothing more than -O2. There are some i386
machine descriptors that do handle an -O3, but linux's isn't one of them.
(Read the GCC source for total confirmation).
-N means the linker doesn't pad the text segment and data segments out to
page sizes (ie. 4096 bytes). It also means the kernel can't demand page
those apps, but you usually only use it where the code size is smaller than
1 page anyway..