[Bug tree-optimization/115049] [14/15 Regression] Silent severe miscompilation around inline functions

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115049

--- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> ---
-fipa-ra sounds like a likely culprit:

     Use caller save registers for allocation if those registers are not
     used by any called function.  In that case it is not necessary to
     save and restore them around calls.  This is only possible if
     called functions are part of same compilation unit as current
     function and they are compiled before it.