Re: [Qemu-devel] [PATCH 6/6] virtio: optimize virtio_access_is_big_endian() for little-endian targets

2016-01-08 Thread Greg Kurz
On Thu, 7 Jan 2016 21:25:19 +0100 Laurent Vivier wrote: > > > On 07/01/2016 12:32, Greg Kurz wrote: > > When adding cross-endian support, we introduced the TARGET_IS_BIENDIAN macro > > and the virtio_access_is_big_endian() helper to have a branchless fast path > > in the virtio memory accessors

Re: [Qemu-devel] [PATCH 6/6] virtio: optimize virtio_access_is_big_endian() for little-endian targets

2016-01-07 Thread Laurent Vivier
On 07/01/2016 12:32, Greg Kurz wrote: > When adding cross-endian support, we introduced the TARGET_IS_BIENDIAN macro > and the virtio_access_is_big_endian() helper to have a branchless fast path > in the virtio memory accessors for targets that don't switch endian. > > This was considered as a s

[Qemu-devel] [PATCH 6/6] virtio: optimize virtio_access_is_big_endian() for little-endian targets

2016-01-07 Thread Greg Kurz
When adding cross-endian support, we introduced the TARGET_IS_BIENDIAN macro and the virtio_access_is_big_endian() helper to have a branchless fast path in the virtio memory accessors for targets that don't switch endian. This was considered as a strong requirement at the time. Now we have added