[PATCH] riscv: eliminate unreliable __builtin_frame_address(1)

[Andreas Schwab]

On Jan 19 2022, Jessica Clarke wrote:

> My point is that the only thing that can possibly read the incoming
> frame pointer of a leaf function is the leaf function itself, and since
> it knows where it’s putting it then there is no ABI issue, it just
> remembers where it put it and loads it from there.

llvm sidesteps that issue by always saving ra when creating a frame,
even in a leaf function, so it can use a constant offset.

-- 
Andreas Schwab, schwab at linux-m68k.org
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