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From: "glaubitz at physik dot fu-berlin.de" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug target/66930] [5 Regression]: gengtype.c is miscompiled during stage2
Date: Thu, 23 Jul 2015 09:08:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66930

--- Comment #9 from John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin.de> ---
(In reply to Kazumoto Kojima from comment #8)
> (In reply to John Paul Adrian Glaubitz from comment #7)
> > What do you mean? Using -O1 will trigger all kinds of bugs? Or is it rather
> > about PR target/66358?
> 
> Just my 2 cents.  Even on the primary targets, bootstrap with other
> than '-g -O2' are not so well tested.

Ah, I didn't know that. Really interesting fact!

> Most packages are built with -O2, aren't they?

They are, true.

> After all, -O1 should work but not safer than -O2,
> IMO.  O2 does many optimizations, and some of them might cause bug.
> OTOH, some of them simplify the intermediate code.  With -O1, we could
> see highly complex intermediate code in some cases and they might cause
> problem.  We have just seen an example in this PR.

I agree and, as I said, I already asked Matthias to revert to -O2.

Let's see how far we'll get this time. My board is still building.

Adrian