Hello,
I am working on a custom gcc.9.2.0 back end, and have an issue with
frame pointer elimination.
- the result is OK till step '276 : ira (register allocation)
- the result is NG from step '277 onward (reload)
What it did: It used R19 for the frame pointer. This register is
call-clobbered, but is not used for
argument passing. Some way, it assumed to be free, but it is not.
So, the frame pointer is put in it, it is call-clobbered, and the result
is incorrect.
If the compile flag -fomit-frame-pointer is used, the issue goes away.
Has anybody any idea where to look ?.
Best Regards,
Henri.
