qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Fam Zheng <fam@euphon.net>, Kevin Wolf <kwolf@redhat.com>,
	qemu-devel@nongnu.org, qemu-block@nongnu.org,
	Max Reitz <mreitz@redhat.com>
Subject: Re: [PATCH 1/3] block/nvme: Initialize constant values with const_le32()
Date: Thu, 17 Sep 2020 15:52:07 +0200	[thread overview]
Message-ID: <d4a7bb78-5f2f-70a2-44c6-7c4198bd0426@redhat.com> (raw)
In-Reply-To: <20200917095521.GC809514@stefanha-x1.localdomain>

On 9/17/20 11:55 AM, Stefan Hajnoczi wrote:
> On Wed, Sep 16, 2020 at 10:40:02PM +0200, Philippe Mathieu-Daudé wrote:
>> To avoid multiple endianess conversion, as we know the device
>> registers are in little-endian, directly use const_le32() with
>> constant values.
> 
> Can cpu_to_X() be extended to handle constant expressions? That way the
> programmer doesn't need to remember the const_X() API exists.
> 
> Maybe __builtin_constant_p() can be used:
> https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html#index-_005f_005fbuiltin_005fconstant_005fp

Yes it works! Good idea :)



  reply	other threads:[~2020-09-17 13:53 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-16 20:40 [PATCH 0/3] block/nvme: Fix NVMeRegs alignment/packing and use atomic operations Philippe Mathieu-Daudé
2020-09-16 20:40 ` [PATCH 1/3] block/nvme: Initialize constant values with const_le32() Philippe Mathieu-Daudé
2020-09-17  9:55   ` Stefan Hajnoczi
2020-09-17 13:52     ` Philippe Mathieu-Daudé [this message]
2020-09-16 20:40 ` [PATCH 2/3] block/nvme: Use atomic operations instead of 'volatile' keyword Philippe Mathieu-Daudé
2020-09-17 10:42   ` Stefan Hajnoczi
2020-09-16 20:40 ` [PATCH 3/3] block/nvme: Align NVMeRegs structure to 4KiB and mark it packed Philippe Mathieu-Daudé
2020-09-17 11:07   ` Stefan Hajnoczi

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=d4a7bb78-5f2f-70a2-44c6-7c4198bd0426@redhat.com \
    --to=philmd@redhat.com \
    --cc=fam@euphon.net \
    --cc=kwolf@redhat.com \
    --cc=mreitz@redhat.com \
    --cc=qemu-block@nongnu.org \
    --cc=qemu-devel@nongnu.org \
    --cc=stefanha@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).