From 6f16409112310404e167f84d7fdd52143161aae1 Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Sun, 23 Aug 2015 14:30:24 -0500
Subject: [PATCH] Fix nesting safety of loop_insn_dep_map
---
loopy/schedule.py | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)
diff --git a/loopy/schedule.py b/loopy/schedule.py
index 55a1c6aab..1d0dc1221 100644
--- a/loopy/schedule.py
+++ b/loopy/schedule.py
@@ -171,7 +171,7 @@ def find_used_inames_within(kernel, sched_index):
return result
-def loop_nest_map(kernel):
+def find_loop_nest_map(kernel):
"""Returns a dictionary mapping inames to other inames that are
always nested around them.
"""
@@ -212,7 +212,7 @@ def loop_nest_map(kernel):
return result
-def loop_insn_dep_map(kernel):
+def find_loop_insn_dep_map(kernel, loop_nest_map):
"""Returns a dictionary mapping inames to other instruction ids that need to
be scheduled before the iname should be eligible for scheduling.
"""
@@ -230,10 +230,27 @@ def loop_insn_dep_map(kernel):
dep_insn_inames = kernel.insn_inames(dep_insn)
if iname in dep_insn_inames:
- # Nothing to be learened, dependency is in loop over iname.
+ # Nothing to be learned, dependency is in loop over iname
+ # already.
continue
- result.setdefault(iname, set()).add(dep_insn_id)
+ # To make sure dep_insn belongs outside of iname, we must prove
+ # (via loop_nest_map) that all inames that dep_insn will be
+ # executed inside are nested *around* iname.
+ if not dep_insn_inames <= loop_nest_map[iname]:
+ continue
+
+ iname_dep = result.setdefault(iname, set())
+ if dep_insn_id not in iname_dep:
+ logger.debug("{knl}: loop dependency map: iname '{iname}' "
+ "depends on '{dep_insn}' via '{insn}'"
+ .format(
+ knl=kernel.name,
+ iname=iname,
+ dep_insn=dep_insn_id,
+ insn=insn.id))
+
+ iname_dep.add(dep_insn_id)
return result
@@ -1226,10 +1243,11 @@ def generate_loop_schedules(kernel, debug_args={}):
iname for iname in kernel.all_inames()
if isinstance(kernel.iname_to_tag.get(iname), ParallelTag))
+ loop_nest_map = find_loop_nest_map(kernel)
sched_state = SchedulerState(
kernel=kernel,
- loop_nest_map=loop_nest_map(kernel),
- loop_insn_dep_map=loop_insn_dep_map(kernel),
+ loop_nest_map=loop_nest_map,
+ loop_insn_dep_map=find_loop_insn_dep_map(kernel, loop_nest_map),
breakable_inames=ilp_inames,
ilp_inames=ilp_inames,
vec_inames=vec_inames,
--
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