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Schedule by INSN_COST in case of tie

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2018-09-13  Vlad Lazar  <vlad.lazar@arm.com>

	* haifa-sched.c (rank_for_schedule): Schedule by INSN_COST.
	(rfs_decision): New scheduling decision.

From-SVN: r264270
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Vlad Lazar 2018-09-13 13:43:48 +00:00 • committed by Vlad Lazar
parent 2aa4cc744f
commit d8d9514c87
2 changed files with 15 additions and 2 deletions
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gcc/ChangeLog
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@ -1,3 +1,8 @@
2018-09-13 Vlad Lazar <vlad.lazar@arm.com>
* haifa-sched.c (rank_for_schedule): Schedule by INSN_COST.
(rfs_decision): New scheduling decision.
2018-09-13 Richard Biener <rguenther@suse.de>
PR bootstrap/87134

12
gcc/haifa-sched.c
View file

@ -2542,7 +2542,7 @@ enum rfs_decision {
RFS_SCHED_GROUP, RFS_PRESSURE_DELAY, RFS_PRESSURE_TICK,
RFS_FEEDS_BACKTRACK_INSN, RFS_PRIORITY, RFS_SPECULATION,
RFS_SCHED_RANK, RFS_LAST_INSN, RFS_PRESSURE_INDEX,
RFS_DEP_COUNT, RFS_TIE, RFS_FUSION, RFS_N };
RFS_DEP_COUNT, RFS_TIE, RFS_FUSION, RFS_COST, RFS_N };
/* Corresponding strings for print outs. */
static const char *rfs_str[RFS_N] = {
@ -2550,7 +2550,7 @@ static const char *rfs_str[RFS_N] = {
"RFS_SCHED_GROUP", "RFS_PRESSURE_DELAY", "RFS_PRESSURE_TICK",
"RFS_FEEDS_BACKTRACK_INSN", "RFS_PRIORITY", "RFS_SPECULATION",
"RFS_SCHED_RANK", "RFS_LAST_INSN", "RFS_PRESSURE_INDEX",
"RFS_DEP_COUNT", "RFS_TIE", "RFS_FUSION" };
"RFS_DEP_COUNT", "RFS_TIE", "RFS_FUSION", "RFS_COST" };
/* Statistical breakdown of rank_for_schedule decisions. */
struct rank_for_schedule_stats_t { unsigned stats[RFS_N]; };
@ -2803,6 +2803,14 @@ rank_for_schedule (const void *x, const void *y)
if (flag_sched_dep_count_heuristic && val != 0)
return rfs_result (RFS_DEP_COUNT, val, tmp, tmp2);
/* Sort by INSN_COST rather than INSN_LUID. This means that instructions
which take longer to execute are prioritised and it leads to more
dual-issue opportunities on in-order cores which have this feature. */
if (INSN_COST (tmp) != INSN_COST (tmp2))
return rfs_result (RFS_COST, INSN_COST (tmp2) - INSN_COST (tmp),
tmp, tmp2);
/* If insns are equally good, sort by INSN_LUID (original insn order),
so that we make the sort stable. This minimizes instruction movement,
thus minimizing sched's effect on debugging and cross-jumping. */