From: Jeff Law <law@redhat.com>
To: David Malcolm <dmalcolm@redhat.com>, Andi Kleen <andi@firstfloor.org>
Cc: gcc-patches@gcc.gnu.org, Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH] Add XINSN macro and use it within NEXT_INSN/PREV_INSN (was Re: [PATCH] Force rtl templates to be inlined)
Date: Fri, 05 Sep 2014 18:45:00 -0000 [thread overview]
Message-ID: <540A04B7.4020704@redhat.com> (raw)
In-Reply-To: <1409861057.19403.19.camel@surprise>
On 09/04/14 14:04, David Malcolm wrote:
> On Tue, 2014-09-02 at 19:50 +0200, Andi Kleen wrote:
>>> I suspect the bulk of them currently are coming from the safe_as_a
>>> <rtx_insn *> calls within NEXT_INSN and PREV_INSN; do you happen to have
>>> information handy on that?
>>
>> Yes that's right:
>>
>> - 1.03% lto1 [.] bool is_a_helper<rtx_insn*>::test<rtx_def>(rtx_def*) â–’
>> - bool is_a_helper<rtx_insn*>::test<rtx_def>(rtx_def*) â–’
>> - 92.20% bool is_a<rtx_insn*, rtx_def>(rtx_def*) â–’
>> - 98.53% rtx_insn* safe_as_a<rtx_insn*, rtx_def>(rtx_def*) â–’
>> - 73.28% NEXT_INSN(rtx_insn const*) â–’
>
> The is_a_helper for rtx_insn * is non-trivial, so it may be worth
> avoiding it, even when inlined.
>
> The attached patch rewrites the inline NEXT_INSN/PREV_INSN to avoid
> doing the safe_as_a, instead tightening up the interface so that one can
> only set them to an insn, and introducing a new XINSN access macro and
> corresponding rt_insn member of the union.
>
> Bootstrapped on x86_64-unknown-linux-gnu (Fedora 20), and has been
> rebuilt as part of a config-list.mk build for all working configurations
> (albeit with other patches for the latter case).
>
> OK for trunk?
So is this just to deal with the overhead in the safe_as_a helper until
we can strengthen more code? And is that overhead significant in an
optimized build?
Would an alternate approach be to make the checking in safe_as_a
conditionalized on ENABLE_CHECKING?
jeff
next prev parent reply other threads:[~2014-09-05 18:45 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-02 7:05 [PATCH] Force rtl templates to be inlined Andi Kleen
2014-09-02 7:09 ` Andrew Pinski
2014-09-02 7:20 ` Andi Kleen
2014-09-02 7:22 ` Andrew Pinski
2014-09-02 8:37 ` Steven Bosscher
2014-09-02 8:42 ` pinskia
2014-09-02 8:43 ` Richard Biener
2014-09-02 16:52 ` Andi Kleen
2014-09-03 9:50 ` Richard Biener
2014-09-04 3:58 ` Andi Kleen
2014-09-04 13:02 ` Richard Biener
2014-09-04 18:52 ` Jan Hubicka
2014-09-03 9:52 ` Richard Biener
2014-09-02 14:59 ` David Malcolm
2014-09-02 17:50 ` Andi Kleen
2014-09-04 20:07 ` [PATCH] Add XINSN macro and use it within NEXT_INSN/PREV_INSN (was Re: [PATCH] Force rtl templates to be inlined) David Malcolm
2014-09-04 20:46 ` Jakub Jelinek
2014-09-04 21:23 ` David Malcolm
2014-09-05 18:41 ` Jeff Law
2014-09-05 18:32 ` Jeff Law
2014-09-05 18:45 ` Jeff Law [this message]
2014-09-05 19:05 ` David Malcolm
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