SPARC, register renaming, __builtin_return_address

[David Edelsohn]

>>>>> Franz Sirl writes:

Franz> But I think that's not worth it, it's easy for the targets to either return 
Franz> 0 if they don't support b_r_a(1) or force a valid stackframe otherwise. The 
Franz> whole purpose of the testcase is to test for uniform behaviour for b_r_a(1).

	I think this is the key point: either return 0 for b_r_a(1) or
force a stack-frame when b_r_a() is detected.

David