From 9839514634da169e18798c53e4ab5f26a5dc96a8 Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Mon, 7 Nov 2011 11:42:00 -0500
Subject: [PATCH] Scheduler: be less eager about entering loops, more eager
about leaving them.
---
loopy/schedule.py | 43 +++++++++++++++++++++++++------------------
1 file changed, 25 insertions(+), 18 deletions(-)
diff --git a/loopy/schedule.py b/loopy/schedule.py
index 8c61405e0..bd5151da9 100644
--- a/loopy/schedule.py
+++ b/loopy/schedule.py
@@ -197,7 +197,6 @@ def generate_loop_schedules_internal(kernel, loop_priority, schedule=[]):
# {{{ decide about debug mode
debug_mode = False
- #if (set(["D", "u"]) <= scheduled_insn_ids and active_inames_set == set(["e"])):
if False:
debug_mode = True
@@ -206,6 +205,9 @@ def generate_loop_schedules_internal(kernel, loop_priority, schedule=[]):
print "--------------------------------------------"
dump_schedule(schedule)
+ #if len(schedule) == 3:
+ #from pudb import set_trace; set_trace()
+
if debug_mode:
print "active:", ",".join(active_inames)
print "entered:", ",".join(entered_inames)
@@ -289,6 +291,22 @@ def generate_loop_schedules_internal(kernel, loop_priority, schedule=[]):
# }}}
+ # {{{ see if we're ready to leave a loop
+
+ if last_entered_loop is not None:
+ can_leave = True
+ for insn_id in unscheduled_insn_ids:
+ insn = kernel.id_to_insn[insn_id]
+ if last_entered_loop in kernel.insn_inames(insn):
+ can_leave = False
+ break
+
+ if can_leave:
+ schedule = schedule + [LeaveLoop(iname=last_entered_loop)]
+ made_progress = True
+
+ # }}}
+
# {{{ see if any loop can be entered now
available_loops = (kernel.all_referenced_inames()
@@ -298,7 +316,11 @@ def generate_loop_schedules_internal(kernel, loop_priority, schedule=[]):
- parallel_inames
)
- if available_loops:
+ # Don't be eager about scheduling new loops--if progress has been made,
+ # revert to top of scheduler and see if more progress can be made another
+ # way. (hence 'and not made_progress')
+
+ if available_loops and not made_progress:
useful_loops = []
for iname in available_loops:
@@ -336,7 +358,7 @@ def generate_loop_schedules_internal(kernel, loop_priority, schedule=[]):
# {{{ tier building
# Build priority tiers. If a schedule is found in the first tier, then
- # loops in the second are not even tried.
+ # loops in the second are not even tried (and so on).
loop_priority_set = set(loop_priority)
useful_and_desired = set(useful_loops) & loop_priority_set
@@ -372,21 +394,6 @@ def generate_loop_schedules_internal(kernel, loop_priority, schedule=[]):
# }}}
- # {{{ see if we're ready to leave a loop
-
- if last_entered_loop is not None:
- can_leave = True
- for insn_id in unscheduled_insn_ids:
- insn = kernel.id_to_insn[insn_id]
- if last_entered_loop in kernel.insn_inames(insn):
- can_leave = False
- break
-
- if can_leave:
- schedule = schedule + [LeaveLoop(iname=last_entered_loop)]
- made_progress = True
-
- # }}}
if debug_mode:
raw_input("Enter:")
--
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