Altivec Linux support in GCC

[Kumar Gala]

I have a few questions that I'm trying to understand with AltiVec 
support in GCC for Linux.

1. What are there two options to enable the support? (-maltivec 
-mabi=altivec).  If I have a Linux PPC targeted GCC why do I need to 
tell it to use the abi to get altivec code generation?  This just seems 
confusing to the user (I dont have to specify the abi for any other 
option).

2. Why does STACK_BOUNDARY change for TARGET_ALTIVEC_ABI?  The stack 
alignment is the same with or without AltiVec according the SVR4 PPC 
ABI.

It seems that a single GCC targeted for PowerPC Linux should be able to 
support generation for int+fp+altivec, and if you dont use altivec in 
your code you dont get altivec generated by the compiler [ie you get 
the same .S out you would today, w/o enabling -maltivec -mabi=altivec].

- kumar