[Bug debug/68860] [6/7 regression] FAIL: gcc.dg/guality/pr36728-1.c -flto -O3 -g line 16/7 arg1 == 1

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68860

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Bill Seurer from comment #9)
> The pr36728 and pr68860 test cases that check the arguments (where the
> arguments are unused) all currently (and for a long time) fail on power. 
> They show up as "optimized out" in gdb as in the initial report here.
> 
> Is there some point to testing the value of the unused arguments in these
> test cases?

Of course there is a point, in lots of real-world code many variables are
optimized away, either in whole functions or just part of it, yet users very
often still want to be able to query those values.
DWARF (starting with DWARF 4) has ways to express even that in the debug info,
using DW_OP_stack_value etc., if there is a way to compute their values from
some other registers, memory content, constants etc.
The various DWARF extensions we've added (many of them are going to be in DWARF
5) enhance that even further (e.g. the DW_OP_GNU_entry_value,
DW_OP_GNU_parameter_ref, DW_OP_GNU_implicit_pointer, etc.).