From: Nathan Sidwell <nathan@acm.org>
To: Richard Biener <richard.guenther@gmail.com>
Cc: Fis Trivial <ybbs.daans@hotmail.com>,
Jason Merrill <jason@redhat.com>,
"gcc@gcc.gnu.org" <gcc@gcc.gnu.org>
Subject: Re: Compiling c++ template is very slow.
Date: Fri, 09 Mar 2018 13:49:00 -0000 [thread overview]
Message-ID: <d049cbec-7447-b120-2ed9-f98cc1fb0aa7@acm.org> (raw)
In-Reply-To: <CAFiYyc32QZud5fQArzpqiO75Qe5d-8zchy21UqqcCsxE5qcbRQ@mail.gmail.com>
On 03/09/2018 08:42 AM, Richard Biener wrote:
>> No. (if it's a vbase, it shows the offset in the complete object, IIRC, and
>> there's other data to let code generation know some vtable inspection is
>> needed when the dynamic type is unknown).
>
> So there's no multiple inheritance of classes with VLA members then I guess.
> Or rather there's no such thing as VLA members ;)
I guess.
> If it's always constant I suggest to make it a non-tree ... I suspect while not
> addressing the complexity it would improve compile-time a lot...
Not disagreeing -- I think there's a bunch of stuff in BINFOs that
either don't need to be trees, or don't even need to be there.
> Oh, and in the testcase there's no virtual methods so nobody should look
> at BINFO_OFFSET anyway?
It's used for conversions to bases. (So it's not immediately clear to
me that making it not a tree would win -- you'd be pushing the
int->INTEGER_CST conversions into each base conversion generation.
Don't forget, small integer_csts are commonized)
nathan
--
Nathan Sidwell
prev parent reply other threads:[~2018-03-09 13:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-09 2:33 Fis Trivial
2018-03-09 10:32 ` Richard Biener
2018-03-09 11:51 ` Richard Biener
2018-03-09 13:08 ` Nathan Sidwell
2018-03-09 13:42 ` Richard Biener
2018-03-09 13:49 ` Nathan Sidwell [this message]
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