R300 swizzle W/XYZ interaction strangeness

[Jerome G. <j.g...@gm...>]

Hi Ben,

I don't know if you remember but we got a discussion
on swizzle issue when we have to write W to a XYZ few
month ago. You solved the issue by syncing the XYZ & W
emit, right  (emitting W with the last XYZ emit) ?

It seems that if you emit something like :
srcmask(WZX) writemask(X) you have the wrong result but
srcmask(WZX) writemask(XY or XZ or XYZ) give right result
without syncing. I am update my swizzling table to do so.

So i wonder if you have anythought on that, or anybody
else. Doing so i am able to avoid syncing, this may
not be a big save anyway.

We may miss something here on r300...

best,
Jerome Glisse