This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH GCC8][28/33]Don't count non-interger PHIs for register pressure
- From: "Bin.Cheng" <amker dot cheng at gmail dot com>
- To: Richard Biener <richard dot guenther at gmail dot com>
- Cc: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Date: Wed, 26 Apr 2017 14:37:09 +0100
- Subject: Re: [PATCH GCC8][28/33]Don't count non-interger PHIs for register pressure
- Authentication-results: sourceware.org; auth=none
- References: <VI1PR0802MB21768BD089A0E74CD6143825E7190@VI1PR0802MB2176.eurprd08.prod.outlook.com> <CAFiYyc2aoLsDigoU7VwXER=XZ9kBj5VN8reNjongHq+GajnKYw@mail.gmail.com>
On Wed, Apr 26, 2017 at 2:32 PM, Richard Biener
<richard.guenther@gmail.com> wrote:
> On Tue, Apr 18, 2017 at 12:52 PM, Bin Cheng <Bin.Cheng@arm.com> wrote:
>> Hi,
>> Given only integer variables are meaningful for register pressure estimation in IVOPTs,
>> this patch skips non-integer type PHIs when counting register pressure.
>> Is it OK?
>
> Huh. I suppose it only makes a difference because you are ignoring
> POINTER_TYPE_P
> IVs? At least I would be surprised if get_iv returns true for float
> or vector PHIs (yeah, see
> early out in get_iv)? So why exclude POINTER_TYPE_P IVs?
Hmm, but if get_iv returns non-NULL, the phi won't be counted because
loop is continued? Actually, all IV and invariants are skipped by
checking get_iv, so this is only to skip floating point phis.
Thanks,
bin
>
> Richard.
>
>> Thanks,
>> bin
>>
>> 2017-04-11 Bin Cheng <bin.cheng@arm.com>
>>
>> * tree-ssa-loop-ivopts.c (determine_set_costs): Skip non-interger
>> when counting register pressure.
>>