From: Segher Boessenkool <segher@kernel.crashing.org>
To: stefan@franke.ms
Cc: "'gcc-help'" <gcc-help@gcc.gnu.org>
Subject: Re: How to recognize registers after reload ?.
Date: Fri, 23 Oct 2020 05:20:34 -0500 [thread overview]
Message-ID: <20201023102034.GA2672@gate.crashing.org> (raw)
In-Reply-To: <0cd001d6a90f$0fd96f80$2f8c4e80$@bebbosoft.de>
On Fri, Oct 23, 2020 at 09:35:20AM +0200, Stefan Franke wrote:
> it seems your define_expand for movsi is too narrow. It should accept all mandatory forms. The distinction - to register/memory - should be done in movsi itself. There is also no need for a database to distinguish.
The requirement is that reload (which should be LRA on all newer ports,
and is recommended for all ports) always has a path to reload whatever
is thrown at it. This does mean you need both r->m and m->r in one
pattern normally, yes (all r's can be spilled to stack, and there is no
m->m instruction). Of course you get by far the best code if you do
have all normal moves in one pattern (one per mode), as you say.
You disallow m->m in the insn condition, like
"gpc_reg_operand (operands[0], SImode)
|| gpc_reg_operand (operands[1], SImode)"
Segher
next prev parent reply other threads:[~2020-10-23 10:21 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 [this message]
2020-10-23 11:38 ` Henri Cloetens
2020-10-23 10:02 ` Segher Boessenkool
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