On 4/9/07, Alexander Skwar <listen@alexander.skwar.name> wrote:

· maxim wexler <blissfix@yahoo.com>:

> One suggests using -O3 -pipe, the other, -O2 without
> the pipe.

The resulting binaries of a -O2 -pipe compile will be
the same as those of a -O2 (no pipe) compile.

See http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Overall-Options.html#index-pipe-81

> How much difference does this make? Is the extra level
> of optimization with pipe the equivalent of the lower
> level without?

There's no extra level of optimization.

So the question boils down to: Is -O3 better than -O2? Answer: Depends.
On a system with not that much cache, it might not be.

Alexander Skwar
--
BOFH Excuse #16:

somebody was calculating pi on the server

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