The following works around the DSE part of PR89115, consuming huge
amounts of memory and compile-time. To make "bad" testcases behave
more reasonably the following cuts down --param
max-dse-active-local-stores from 5000 to 500, reducing compile-time
by a factor of 2.5 and memory use by a factor of 5.3.
I'm making both existing scalings relative to the default
(but keep the actual scaled down value).
Bootstrap & regtest running on x86_64-unknown-linux-gnu.
Richard.
2019-01-30 Richard Biener <rguent...@suse.de>
PR rtl-optimization/89115
* opts.c (default_options_optimization): Reduce
PARAM_MAX_DSE_ACTIVE_LOCAL_STORES by a factor of 10 at -O1.
Make PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP reduction relative
to the default.
Index: gcc/opts.c
===================================================================
--- gcc/opts.c (revision 268383)
+++ gcc/opts.c (working copy)
@@ -670,7 +670,16 @@ default_options_optimization (struct gcc
/* For -O1 only do loop invariant motion for very small loops. */
maybe_set_param_value
(PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP,
- opt2 ? default_param_value (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP) : 1000,
+ opt2 ? default_param_value (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP)
+ : default_param_value (PARAM_LOOP_INVARIANT_MAX_BBS_IN_LOOP) / 10,
+ opts->x_param_values, opts_set->x_param_values);
+
+ /* For -O1 reduce the maximum number of active local stores for RTL DSE
+ since this can consume huge amounts of memory (PR89115). */
+ maybe_set_param_value
+ (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES,
+ opt2 ? default_param_value (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES)
+ : default_param_value (PARAM_MAX_DSE_ACTIVE_LOCAL_STORES) / 10,
opts->x_param_values, opts_set->x_param_values);
/* At -Ofast, allow store motion to introduce potential race conditions. */
