[Bug rtl-optimization/57676] [4.9/5/6 Regression] ICE: Maximum number of LRA constraint passes is achieved (30)

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57676

--- Comment #9 from Jeffrey A. Law <law at redhat dot com> ---
Vlad, would it make sense to record what insns needed a reload & what insns
were generated for reloads.  Then on the next iteration, if the insns needing a
reload are different than the ones needing reloads in previous iterations +
insns generated for reloads in previous iterations, allow iteration to
continue.

ie, detect the case when we've got this kind of cascading effect and we're
still making progress and as long as we're still making progress allow
iteration to continue.