[Bug tree-optimization/78319] [7 Regression] PASS->FAIL: gcc.dg/uninit-pred-8_a.c bogus warning (test for bogus messages, line 20)

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78319

--- Comment #18 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Richard Earnshaw from comment #17)
> (In reply to Jakub Jelinek from comment #15)
> 
> > Unless people commonly use
> > RUNTESTFLAGS='--target_board=unix\{-mtune=cortex-a15,-mtune=cortex-m7\}' or
> > something similar, that might work well.  The amount of tests that use
> > -mtune= in dg-options or dg-additional-options across all arches is big, so
> > most likely such RUNTESTFLAGS wouldn't be a very good idea.
> 
> 
> I think you're confusing ARM's use of -mtune with x86's.  The x86 equivalent
> of -mtune on ARM is -mcpu: it is rare to see -mtune in testsuite runs.
> 
> (On ARM there are two main options here -- -march and -mtune: -march selects
> the permitted instructions; -mtune controls how to pick from within the
> permitted set.  -mcpu is a convenience option that controls both options at
> the same time).

>From your description x86 -mtune is exactly what arm -mtune is, select CPU to
tune for within the ISA chosen by other options (so something that affects
scheduling choices, costs etc.).  My comment has been mainly about the flags
comming from --target_board being appended after dg-options, i.e. that if
-mtune= would be commonly used in --target_board, then it wouldn't work well.
If it is not used and people use -march= or -mcpu= there instead, then using
/* { dg-additional-options "-mtune=..." { target ... } } */
is fine.