Re: PR33713: remove -fforce-addr

["Steven Bosscher" <stevenb.gcc@gmail.com>]

On Nov 30, 2007 1:02 AM, Michael Meissner <michael.meissner@amd.com> wrote:
> I'm coming in late to this.

You could say that yes, especially since bugs with -fforce-addr have
existed for years.


>  Given there were a few examples that were faster
> with -fforce-addr, do we want to remove it without trying to fix the code?

Why would you want to fix this?  This is just another flag that is not
enabled by default. It usually (almost always, actually) results in
worse code if enabled.

So there are a few exceptions, where enabling -fflag-addr sometimes
still gives slightly better code.  But that is no different from e.g.
merges from branches (tree-ssa, df), or the removal of -fforce-mem,
which also caused small slowdowns for some benchmarks, but with an
improvemed overall score.  Those changes affected the generated code
with the default flags.  I didn't hear you (or anyone else) question
those patches.

So your question looks like a bikeshed to me.

But maybe you are volunteering? ;-)


> I didn't see from the bug report that the slowdowns had been addressed.

Which slowdowns?  This flag is not enabled by default.  Almost all
SPEC benchmarks, at least, slow down with -fforce-addr.  Nothing slows
down with the default options.  In fact nothing even *changes* at all
with the default options.

Stop spreading FUD.


> I also would prefer a deprecated switch get a warning, rather than silently
> accepting it.

Silently accepting is what is done for other removed flags too.  See
http://gcc.gnu.org/ml/gcc-patches/2006-02/msg01949.html.  You're too
late for that discussion, too :-P

Gr.
Steven