From: Peter Bergner <bergner@linux.ibm.com>
To: Jeff Law <jeffreyalaw@gmail.com>,
Ajit Agarwal <aagarwa1@linux.ibm.com>,
gcc-patches <gcc-patches@gcc.gnu.org>
Cc: Segher Boessenkool <segher@kernel.crashing.org>,
Richard Biener <richard.guenther@gmail.com>,
Raphael Zinsly <rzinsly@ventanamicro.com>
Subject: Re: [PATCH] rtl-optimization: ppc backend generates unnecessary signed extension.
Date: Fri, 24 Mar 2023 16:34:49 -0500 [thread overview]
Message-ID: <0caf5e53-76e2-afc6-8b8c-363e56cd8212@linux.ibm.com> (raw)
In-Reply-To: <ccee126d-44e9-690e-fac3-00e91fde8c51@gmail.com>
On 3/23/23 6:12 PM, Jeff Law via Gcc-patches wrote:
>>>> Is there a reason why REE cannot see that our (reg:QI 4) is a param register
>>>> and thus due to our ABI, already correctly sign/zero extended?
>>>
>>> I don't think REE has ever considered exploiting ABI constraints. Handling
>>> that might be a notable improvement on various targets. It'd be a great
>>> place to do some experimentation.
>>
>> Ok, so sounds like a good follow-on project after this patch is reviewed
>> and committed (stage1). Thanks for your input!
>
> Agreed. I suspect that risc-v will benefit from such work as well.
> With that in mind, if y'all start poking at this, please loop in Raphael
> (on cc) who's expressed an interest in this space.
Will do. I suspect that it'll be best to come up with some generic interface
using target hooks like "param regs are sign/zero extended" or "call return
values are sign/zero extended", etc. that targets can conditionally opt into
depending on their ABI that is in effect.
Peter
next prev parent reply other threads:[~2023-03-24 21:34 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-23 10:38 Ajit Agarwal
2023-03-23 12:38 ` Peter Bergner
2023-03-23 15:32 ` Ajit Agarwal
2023-03-23 15:32 ` Ajit Agarwal
2023-03-23 16:29 ` Peter Bergner
2023-03-23 16:32 ` Jeff Law
2023-03-23 16:53 ` Peter Bergner
2023-03-23 23:12 ` Jeff Law
2023-03-24 21:34 ` Peter Bergner [this message]
2023-03-25 18:09 ` Jeff Law
2023-03-31 0:01 ` Hans-Peter Nilsson
2023-03-31 14:01 ` Jeff Law
2023-03-23 13:47 ` Jeff Law
2023-03-23 15:36 ` Ajit Agarwal
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