I seem to have lost this patch in my dev tree for some reason.
After introducing --param max-combine-insns it was the idea
to restrict combine to two-insn combines for -Og as combine
is a major RTL compile-time hog.
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied.
Richard.
2014-09-03 Richard Biener <rguent...@suse.de>
* opts.c (default_options_optimization): Adjust
max-combine-insns to 2 for -Og.
Index: gcc/opts.c
===================================================================
*** gcc/opts.c (revision 214810)
--- gcc/opts.c (working copy)
*************** default_options_optimization (struct gcc
*** 636,641 ****
--- 637,648 ----
default_param_value (PARAM_MIN_CROSSJUMP_INSNS),
opts->x_param_values, opts_set->x_param_values);
+ /* Restrict the amount of work combine does at -Og while retaining
+ most of its useful transforms. */
+ if (opts->x_optimize_debug)
+ maybe_set_param_value (PARAM_MAX_COMBINE_INSNS, 2,
+ opts->x_param_values, opts_set->x_param_values);
+
/* Allow default optimizations to be specified on a per-machine basis. */
maybe_default_options (opts, opts_set,
targetm_common.option_optimization_table,
