[PING] [PATCH] S/390: Do not turn maybe-uninitialized warnings into errors

Andreas Krebbel krebbel@linux.ibm.com
Fri Nov 6 12:14:59 GMT 2020


On 06.11.20 04:52, Jeff Law via Gcc-patches wrote:
> 
> On 10/30/20 7:01 AM, Richard Biener wrote:
>>
>> It's not that more / different inlining inherently exposes _more_
>> false positives in the middle-end warnings.  They simply expose
>> others and the GCC codebase is cleansed (by those who change
>> inliner heuristics / tunings) from those by either fixing the analysis
>> or modifying the code (like putting in initializers).
> 
> Right.  The change in heuristics inherently perturb the middle end
> warnings.  It has been and continues to be a source of significant
> headaches in Fedora.

Stefan did some measurements and in fact we see only a few benchmarks improving with our aggressive
settings. However, in these cases the performance benefits are significant. We will continue looking
into these cases. Perhaps more selective ways can be found to achieve the same.

I've just committed a patch to switch back to the default values. With that patch bootstrapping on Z
works fine again even without --disable-werror.

Andreas

gcc/ChangeLog:

	* config/s390/s390.c (s390_option_override_internal): Remove
	override of inline params.
---
 gcc/config/s390/s390.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index b8961a315aa..847cedde674 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -15469,13 +15469,6 @@ s390_option_override_internal (struct gcc_options *opts,
   SET_OPTION_IF_UNSET (opts, opts_set, param_sched_pressure_algorithm, 2);
   SET_OPTION_IF_UNSET (opts, opts_set, param_min_vect_loop_bound, 2);

-  /* Use aggressive inlining parameters.  */
-  if (opts->x_s390_tune >= PROCESSOR_2964_Z13)
-    {
-      SET_OPTION_IF_UNSET (opts, opts_set, param_inline_min_speedup, 2);
-      SET_OPTION_IF_UNSET (opts, opts_set, param_max_inline_insns_auto, 80);
-    }
-
   /* Set the default alignment.  */
   s390_default_align (opts);


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