AltiVec stack boundary

[Daniel Jacobowitz]

I'm sure this has come up before, but I don't understand how the
-maltivec definition of STACK_BOUNDARY can be right.  We tell the
compiler that STACK_BOUNDARY == 128 if -maltivec, without telling it
that other people may ignore that, because -maltivec is not supposed
to be an ABI changing option but IIUC STACK_BOUNDARY is.

Why isn't it 64 in the !TARGET_ALTIVEC case with
PREFERRED_STACK_BOUNDARY == 128?

-- 
Daniel Jacobowitz
CodeSourcery