From: Segher Boessenkool <segher@kernel.crashing.org>
To: Henri Cloetens <henri.cloetens@blueice.be>
Cc: Jeff Law <law@redhat.com>, gcc-help <gcc-help@gcc.gnu.org>
Subject: Re: How to recognize registers after reload ?.
Date: Fri, 23 Oct 2020 05:02:50 -0500 [thread overview]
Message-ID: <20201023100250.GZ2672@gate.crashing.org> (raw)
In-Reply-To: <734be852-33ed-ee19-88a9-99a5905db5cf@blueice.be>
Hi,
On Fri, Oct 23, 2020 at 09:28:49AM +0200, Henri Cloetens wrote:
> R30 = 1 // move immediate to register
> [R20] = R30 // move to *a
> return
>
> Now, to get this, there is not one movsi - pattern, because if there is
> only one,
> combine will combine both moves into something like
> [R20] = 1
> and this does not exist, and combine crashes.
You keep saying this. The combine pass should *not* crash, and you
haven't shown any evidence it did. It will attempt to do this
combination, and your backend will either or not say that is an existing
insn; in neither case will combine crash.
Some later pass might well not like what you said is a valid insn. Just
say *that* if that is what you mean!
Segher
prev parent reply other threads:[~2020-10-23 10:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-22 8:02 Henri Cloetens
2020-10-22 21:30 ` Jeff Law
2020-10-22 22:24 ` Segher Boessenkool
2020-10-22 23:47 ` Jeff Law
2020-10-23 7:28 ` Henri Cloetens
2020-10-23 7:35 ` AW: " Stefan Franke
2020-10-23 7:56 ` Henri Cloetens
2020-10-23 10:20 ` Segher Boessenkool
2020-10-23 11:38 ` Henri Cloetens
2020-10-23 10:02 ` Segher Boessenkool [this message]
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