From: Segher Boessenkool <segher@kernel.crashing.org>
To: Vladimir Makarov <vmakarov@redhat.com>
Cc: Richard Biener <richard.guenther@gmail.com>,
gcc@gcc.gnu.org,
John Darrington <john@darrington.wattle.id.au>,
Jeff Law <law@redhat.com>,
Paul Koning <paulkoning@comcast.net>
Subject: Re: Indirect memory addresses vs. lra
Date: Thu, 15 Aug 2019 21:22:00 -0000 [thread overview]
Message-ID: <20190815212245.GR31406@gate.crashing.org> (raw)
In-Reply-To: <61d0afa8-2253-1a52-9081-42983f48ada7@redhat.com>
On Thu, Aug 15, 2019 at 02:30:19PM -0400, Vladimir Makarov wrote:
> >Couldn't we spill the frame pointer? Basically we should be able to
> >compute the first address into a reg, spill that, do the second (both
> >could require the frame pointer), spill the frame pointer, reload the
> >first computed address from the stack, execute the insn and then reload
> >the frame pointer.
> >
> >Maybe the frame pointer can also be implemented 'virually' in an index
> >register that you keep updated so that sp + reg
> >Is the FP. Or frame accesses can use a
> >Stack slot as FP and the indirect memory
> >Addressing... (is there an indirect lea?)
> >
> Yes, it could be a solution. It just needs some target maintainer
> creativity. There are a lot of things (tricks) can be done in
> machine-dependent code which would not require RA changes.
You can even go as far as not having the hard frame pointer be a machine
register at all. In RTL it will still be a reg, but that doesn't mean
the machine code you emit should be like that; you can use a special
fixed memory location for it, for example.
Segher
next prev parent reply other threads:[~2019-08-15 21:22 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-04 19:18 John Darrington
2019-08-08 16:25 ` Vladimir Makarov
2019-08-08 16:44 ` Paul Koning
2019-08-08 17:21 ` Segher Boessenkool
2019-08-08 17:25 ` Paul Koning
2019-08-08 19:09 ` Segher Boessenkool
2019-08-08 17:30 ` Paul Koning
2019-08-08 19:19 ` Segher Boessenkool
2019-08-08 19:57 ` Jeff Law
2019-08-09 8:14 ` John Darrington
2019-08-09 14:17 ` Segher Boessenkool
2019-08-09 14:23 ` Paul Koning
2019-08-10 6:10 ` John Darrington
2019-08-10 16:15 ` Segher Boessenkool
2019-08-09 16:07 ` Jeff Law
2019-08-09 17:34 ` Vladimir Makarov
2019-08-10 6:06 ` John Darrington
2019-08-10 16:12 ` Segher Boessenkool
2019-08-12 6:47 ` John Darrington
2019-08-12 8:40 ` Segher Boessenkool
2019-08-12 13:35 ` Vladimir Makarov
2019-08-15 16:29 ` Vladimir Makarov
2019-08-15 16:38 ` Richard Biener
2019-08-15 17:41 ` John Darrington
2019-08-15 18:30 ` Vladimir Makarov
2019-08-15 21:22 ` Segher Boessenkool [this message]
2019-08-15 17:36 ` John Darrington
2019-08-15 18:23 ` Vladimir Makarov
2019-08-16 11:24 ` Special Memory Constraint [was Re: Indirect memory addresses vs. lra] John Darrington
2019-08-16 14:50 ` Vladimir Makarov
2019-08-19 7:36 ` John Darrington
2019-08-19 13:14 ` Vladimir Makarov
2019-08-19 15:07 ` Segher Boessenkool
2019-08-19 18:06 ` John Darrington
2019-08-20 6:56 ` Richard Biener
2019-08-20 7:07 ` John Darrington
2019-08-20 7:30 ` Richard Biener
2019-08-08 18:46 ` Indirect memory addresses vs. lra Vladimir Makarov
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