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(-Os versus -O2 relation) Was: case where gcc generates bigger binaries than MSVC
- To: egcs at egcs dot cygnus dot com, law at cygnus dot com, mat at lcs dot mit dot edu
- Subject: (-Os versus -O2 relation) Was: case where gcc generates bigger binaries than MSVC
- From: Jan Hubicka <jh at suse dot cz>
- Date: Thu, 11 May 2000 10:25:16 +0200
Hi
Disabling all code alignments for Os optimizations of for a while on my TODO
list. Only open question is whether it is better to do that in backend
on generally (there are probably backends requiring some instruction alignment,
so backend side seems to be better for me).
I am not sure about DATA_ALIGNMENT. The decision IMO that needs to be made
is whether we want -O2 and -Os code to be combined.
At XaoS I compile main engine with -O2 and user interface with -Os.
In case the static storage comming from -Os will be missaligned, we will
get penalty on -O2 code.
Of course it makes prefect sense -Os mean "optimize for size as much as possible",
but then it also may imply -mpreferred-stack-boundary=2.
Honya