GCC problems with Altivec / PowerPC

[David Edelsohn]

 As a workaround I tried to use inline assembly for loads and stores:

#define asm_lvx( vec, idx, ptr )       \
	asm ( "lvx %0,%1,%2"	       \
	    : "=v" (vec)		\
	      : "r" (idx), "r" (ptr)
	      )

 But there's a problem, in lvx/stvx '0' in second term acts as
literal 0, not as register number. Shouldn't gcc be able to
understand those instructions and not use r0 ?

Constraint letter "r" means any GPR.  If you are going to create the
address manually, you explicitly need to tell GCC only to use a base
register by using constraint letter "b".

	The extra stack manipulation is a known problem.

	For the memcpy look, open a Bugzilla.

David