[Mageia-dev] Clanlib2 and SSE2 on i586

Tue Dec 4 20:57:15 CET 2012

On Tue, Dec 4, 2012 at 6:08 PM, Pascal Terjan <pterjan at gmail.com> wrote:
+> On Tue, Dec 4, 2012 at 6:00 PM, Jose Jorge <lists.jjorge at free.fr> wrote:
+>> Le 04/12/2012 13:21, Pascal Terjan a écrit :
+>>>
+>>> On Tue, Dec 4, 2012 at 12:10 PM, AL13N<alien at rmail.be>  wrote:
+>>>>>
+>>>>> The code should really be complied but only enabled at runtime if it's
+>>>>>
+>>>>> available. PulseAudio does this. It's more of a pain to code for but
+>>>>> does make like easier for distributions.
+>>>>>
+>>>>> But yeah, short term fix, nuke the test, and as a meme says, keep calm
+>>>>> and carry on.
+>>
+>>
+>> It is not only a test, it is a crash.
+>
+> It is a crash because the code says to crash if there is no sse2.
+>
+>>>>
+>>>> but, do ALL recent i586 CPU's have SSE2? what about the embedded and VIA
+>>>> cpu's and the likes?
+>>
+>>
+>> http://en.wikipedia.org/wiki/SSE2#CPUs_supporting_SSE2
+>>
+>>
+>>>
+>>> The test is that it refuses to run if the lib is not using sse2 while
+>>> it could (slowly).
+>>>
+>>> The clanSWRender lib needs to be fixed to have sse2 support on sse2
+>>> system and not on non sse2 systems so that we can enable it but that's
+>>> something unrelated to dropping this test.
+>>
+>>
+>> No, the clanSWRender has only a SSE2 implementation because no one wants to
+>> write a SW render which is too slow.
+>> http://lists.debian.org/debian-devel-games/2012/03/msg00076.html
+>
+> The message complains that your CPU has SSE2 but it can not use it as
+> clanSWRender was built without support from it.
+> How can it be built without support for SSE2 if it is not optional ?
+>
+>> I wonder if we could enable for now SSE2, till upstream/somebody has a
+>> better fix : for now, all SSE2 cpus crash. Enabling SSE2 it will only crash
+>> on non-SSE2 cpus (older than 10 years)
+>
+> The crash is in the app, are there other apps using clanSWRender which
+> are working fine without SSE2 but would crash if clanSWRender had SSE2
+> support?
+
+So, reading more about it, clanSWRender is a software renderer instead
+of using one of the opengl ones
+Why would an application need it? Is it faster than using for example
+mesa's software rendering?
+