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Re: Call GNU ld with -O*


On Fri, Jul 12, 2013 at 12:25:16PM -0700, Ian Lance Taylor wrote:
> For gold I think it has two effects.  If you use compressed debug
> sections, it will compress them with zlib level 9 rather than 1.  If

Marc's patch enabled it only for -O3/-Ofast (which are already compile time
expensive options, thus it perhaps it doesn't hurt that much to spend extra
time in the linker too) and -Os (then you are really looking for small,
and if ld -O2 provides that, then perhaps it is desirable too).

> you use -O2 or greater it will optimize string tables (e.g., the table
> holding the names of symbols) such that if the table stores two
> strings S1 and S2, and S2 is a suffix of S1, it will store only S1,
> and change pointers to S2 to point to the suffix of S1.  So you are
> correct that the result will be smaller, but not faster to link.

Oh, gold doesn't do this by default?  ld.bfd does (unless it changed since
I've implemented many years ago).

	Jakub


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