Problems Building 7.0-Beta3 with -Os

[Alexander Leidinger]

Quoting Ruslan Ermilov <ru at freebsd.org> (from Thu, 6 Dec 2007 10:22:39 +0300):

> On Wed, Dec 05, 2007 at 03:16:28PM -0800, David O'Brien wrote:
>> [...]  -Os is a collection of
>> optimizations that is between -O1 and -O2.  That is -Os includes
>> everything that -O1 does, and -O2 includes everything that -Os does.
>> In otherwords:  -O1 < -Os < -O2   (properly)
>>
> I read it differently.  From the manpage:
>
> : -Os Optimize for size.  -Os enables all -O2 optimizations that do not
> :     typically increase code size.  It also performs further optimiza-
> :     tions designed to reduce code size.
>
> It says that -Os is a subset of -O2 optimizations plus some
> extra optimizations.  Reading further in a manpage, there's
> only one, -mspace.

And after the import of the new gcc in 7, a lot of people noticed,  
that the resulting binaries are larger with -Os than with -O2. This  
doesn't help for the original problem (not being able to compile  
FreeBSD), but gives a hint to prefer -O2 over -Os when the problem is  
found.

Bye,
Alexander.

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