search for: optmised

On Feb 26, 2011, at 1:36 PM, Joerg Sonnenberger wrote: > On Sat, Feb 26, 2011 at 01:07:39PM -0800, Jakob Stoklund Olesen wrote: >> >> You may want to consider using xorl+decl instead. It is also three >> bytes, and there are no false dependencies. The xor idiom is recognized >> by processors as old as Pentium 4 as having no dependencies. > > Any examples of how

Hello Michael, On Tue, Jan 27, 2015 at 6:01 PM, Michael S. Tsirkin <mst at redhat.com> wrote: > Hi Nikolay, > I poked at src/lib/virtio/virtq.lua a bit - > I was surprised to find no explicit CPU memory > barriers in the virtq implementation. > These are typically required when using virtio > on smp machines - the spec actually mention where > barriers are necessary.

On Sat, Feb 26, 2011 at 01:07:39PM -0800, Jakob Stoklund Olesen wrote: > > On Feb 25, 2011, at 7:27 PM, Joerg Sonnenberger wrote: > > > I'm trying to add a X86 pattern to turn > > movl $-1, %eax > > into > > orl $-1, $eax > > Please make sure to measure the performance impact of doing this. You > are creating a false dependency on the last

On Sat, Feb 26, 2011 at 02:04:54PM -0800, Jakob Stoklund Olesen wrote: > > On Feb 26, 2011, at 1:36 PM, Joerg Sonnenberger wrote: > > > On Sat, Feb 26, 2011 at 01:07:39PM -0800, Jakob Stoklund Olesen wrote: > >> > >> You may want to consider using xorl+decl instead. It is also three > >> bytes, and there are no false dependencies. The xor idiom is

...libpt* libraries by hand. This worked for me: ... also this. Because if you do not deal well with update-alternatives, you loose the plug-and-play of installing and installing BLAS providing packages. For the gcbd package/vignette/paper I hacked together a plugin-package, locally built and hence optmised, but following the Atlas packaging: edd at max:~$ dpkg -f /var/spool/atlas39/libatlas39_3.9.25-1_amd64.deb dpkg -f /var/spool/atlas39/libatlas39_3.9.25-1_amd64.deb Package: libatlas39 Source: atlas39 Version: 3.9.25-1 Architecture: amd64 Maintainer: Dirk Eddelbuettel <edd at debian.org> In...

Hi Nikolay, I poked at src/lib/virtio/virtq.lua a bit - I was surprised to find no explicit CPU memory barriers in the virtq implementation. These are typically required when using virtio on smp machines - the spec actually mention where barriers are necessary. Are the barriers implicit somehow for lua? I'd be curious to learn. Thanks, -- MST

Hi Nikolay, I poked at src/lib/virtio/virtq.lua a bit - I was surprised to find no explicit CPU memory barriers in the virtq implementation. These are typically required when using virtio on smp machines - the spec actually mention where barriers are necessary. Are the barriers implicit somehow for lua? I'd be curious to learn. Thanks, -- MST