[PATCH] D17381: [Polly] [RFC] Memory reference level dependency analysis

[Tobias Grosser via llvm-commits]

grosser added a comment.

Comments inline.


================
Comment at: lib/Analysis/DependenceInfo.cpp:126
@@ +125,3 @@
+      if (OptAnalysisLevel == REFERENCE_LEVEL_ANALYSIS)
+        accdom = tag(accdom, MA->getArrayId());
+
----------------
etherzhhb wrote:
> we can tag it with MA->getId() as well
MA->getId() will allow you to distinguish two accesses in the same statement to the same array, but by a different instruction.

polly_array_ref is just a name. If polly_memory_access sounds better, we can easily change it.

================
Comment at: lib/Analysis/DependenceInfo.cpp:305-309
@@ -266,4 +304,7 @@
+
+  if (isl_union_map_is_empty(AccessSchedule) &&
+      OptAnalysisLevel == STATEMENT_LEVEL_ANALYSIS) {
     isl_union_map_free(AccessSchedule);
     Schedule = S.getScheduleTree();
   } else {
     auto *ScheduleMap =
----------------
etherzhhb wrote:
> Can we improve this if-else?
Yes, see https://llvm.org/bugs/show_bug.cgi?id=26320 for a first description why the second code path is there. Johannes, who wrote this code, might be able to tell you better what would be needed to move reduction dependences to schedule trees.




Repository:
  rL LLVM

http://reviews.llvm.org/D17381