[PowerPC 64]r12 is not updated to GEP when control transferred from virtual thunk function .

[Alan Modra]

On Mon, May 20, 2019 at 03:39:50AM -0500, Segher Boessenkool wrote:
> But it means it needs to make a stub for every global entry point that
> is used?

Mostly.  Calls via function pointer don't (*), nor do you need stubs
when generating inline PLT calls.  I'll note that use of the global
entry point for direct calls is closely associated with needing a PLT
entry, and the stubs we're talking about here are similar to the code
other architectures put in their .plt section.

*) The exception is when a non-PIC executable initialises a function
pointer in read-only memory to a function defined outside the
executable.  This case requires a special stub in the executable to
serve as the address of the function.

-- 
Alan Modra
Australia Development Lab, IBM