[PATCH] D29425: [SLP] Use SCEV to sort memory accesses

Eli Friedman via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Thu Feb 2 11:36:21 PST 2017

efriedma added inline comments.

Comment at: lib/Analysis/LoopAccessAnalysis.cpp:1071
+  // TODO: Do we really need the map, or can we just rely on the SCEV cache?
   for (auto *Val : VL) {
The SCEV cache is reasonably fast, but it's obviously faster not to do a hashtable lookup at all.

Comment at: lib/Analysis/LoopAccessAnalysis.cpp:1095
+                  SE.getMinusSCEV(Right.first, Left.first));
+              return (Diff && (Diff->getAPInt().isStrictlyPositive()));
std::sort requires your comparator to produce a strict weak ordering; otherwise, it has undefined behavior.


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