From: Segher Boessenkool <segher@kernel.crashing.org>
To: Andrea Corallo <andrea.corallo@arm.com>
Cc: Andrew Pinski <pinskia@gmail.com>,
Richard Earnshaw <richard.earnshaw@arm.com>, nd <nd@arm.com>,
GCC Patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH 2/2] Aarch64: Add branch diluter pass
Date: Wed, 22 Jul 2020 11:43:22 -0500 [thread overview]
Message-ID: <20200722164322.GA32057@gate.crashing.org> (raw)
In-Reply-To: <gkrpn8ny7tt.fsf@arm.com>
Hi!
On Wed, Jul 22, 2020 at 03:53:34PM +0200, Andrea Corallo wrote:
> Andrew Pinski <pinskia@gmail.com> writes:
> > Can you give a simple example of what this patch does?
>
> Sure, this pass simply moves a sliding window over the insns trying to
> make sure that we never have more then 'max_branch' branches for every
> 'granule_size' insns.
>
> If too many branches are detected nops are added where considered less
> armful to correct that.
Should that actually be a sliding window, or should there actually just
not be more than N branches per aligned block of machine code? Like,
per fetch group.
Can you not use ASM_OUTPUT_ALIGN_WITH_NOP (or ASM_OUTPUT_MAX_SKIP_ALIGN
even) then? GCC has infrastructure for that, already.
Segher
next prev parent reply other threads:[~2020-07-22 16:43 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-22 10:02 [PATCH 1/2] Add new RTX instruction class FILLER_INSN Andrea Corallo
2020-07-22 10:09 ` [PATCH 2/2] Aarch64: Add branch diluter pass Andrea Corallo
2020-07-22 10:39 ` Andrew Pinski
2020-07-22 13:53 ` Andrea Corallo
2020-07-22 16:43 ` Segher Boessenkool [this message]
2020-07-22 19:45 ` Andrea Corallo
2020-07-23 22:47 ` Segher Boessenkool
2020-07-24 7:01 ` Andrea Corallo
2020-07-24 11:53 ` Segher Boessenkool
2020-07-24 13:21 ` Andrea Corallo
2020-07-24 22:09 ` Segher Boessenkool
2020-07-28 18:55 ` Andrea Corallo
2020-07-28 22:07 ` Segher Boessenkool
2020-07-22 12:24 ` [PATCH 1/2] Add new RTX instruction class FILLER_INSN Richard Biener
2020-07-22 13:16 ` Richard Earnshaw (lists)
2020-07-22 14:51 ` Andrea Corallo
2020-07-22 18:41 ` Joseph Myers
2020-07-24 21:18 ` Segher Boessenkool
2020-07-26 18:19 ` Eric Botcazou
2020-07-28 19:29 ` Andrea Corallo
2020-08-19 9:13 ` Andrea Corallo
2020-08-19 10:52 ` Richard Sandiford
2020-08-19 17:28 ` Segher Boessenkool
2020-08-19 16:51 ` Segher Boessenkool
2020-08-19 17:47 ` Andrea Corallo
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