Giuliano Pochini wrote: Giuliano Pochini wrote: > > As the jmp_buf is a different size in Altivec and non-Altivec code > > Because with Altivec we need to save V registers, right ? Well, I suppose > intel developers had the same problem with P-III "vector" unit. How did they > solve the problem ?
As far as I can tell, by ignoring it, and making the assumption that only low-level libraries will use the vector registers. I plan to take a similar approach, and warn users not to mix Altivec and exceptions. > > To add to the problem, throwing exceptions on an error is just what a > > modern C++ library is supposed to do. Throwing or catching an exception > > in Altivec code will produce sequences that cannot execute on a G3 > > Why ?? (sorry for my ignorance...) I haven't studied GCC's implementation of exceptions in great detail. The compiler saves and restores all the non-transient registers as part of the exception sequence. When generating Altivec code this produces stvx and lvx instructions, which will cause an illegal instruction exception on G3 processors. - Adrian Cox
