> Altivec raises an interesting question of binary compatibility, in the > area of C++ exceptions and C setjmp/longjmp. > > 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 ? > it is not possible to jump or pass exceptions between the two. > This is a problem, because: > 1) Now would not be a good time to change the size of a jmp_buf. > 2) We do not need two incompatible 32-bit PowerPC ABIs under Linux. > 2a) Most libraries installed by a distribution will be non-Altivec code, > to avoid having both G[123] and G4 binary variants of the distribution. I agree. > 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...) Bye.
