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Re: [PATCH] mudflap: remove usage of builtin_frame_address
Andreas Krebbel1 <KREBBEL1@de.ibm.com> writes:
> Unfortunately simply returning frame_pointer_rtx instead of
> hard_frame_pointer_rtx in builtin_frame_address does not appear
> to be the right way. [...] Most probably it would also break
> mips where the frame pointer is eliminated to stack pointer.
I'm just echoing what rth said here really, but in those circumstances,
__builtin_frame_address() should return the value of the stack pointer.
In other words, using frame_pointer_rtx should be exactly right for mips.
In theory (not tested ;) this should also help mips16, where the hard
frame pointer is offset from the soft frame pointer by the size of the
outgoing arguments. I think any mips users of __b_f_a() would expect it
to return a pointer to the first outgoing argument in all circumstances,
including when a mips16 function decides to use a hard frame pointer.
I think the current value of __builtin_frame_address() is just as
broken for mips as it is for s390.