[Bug c++/94957] Compilation slowww for simple code with -O1/2/3 and -g in GCC 8 and 9

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94957

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Some of it changed recently, e.g. when the FEs use ARRAY_RANGE_REFs in the
initializer the gimplifier's gimplify_init_ctor_eval emits a loop.
But in this case I think we need the FE to emit the loop itself.
Marek, would you like to have a look?
I'd use serial code if the array doesn't have too many elts (perhaps compare to
a param, or hardcode something small like 16).