[SCEV] Use move semantics in ScalarEvolution::setRange

Summary: This makes setRange take ConstantRange by rvalue reference since most callers were passing an unnamed temporary ConstantRange. We can then move that ConstantRange into the DenseMap caches. For the callers that weren't passing a temporary, I've added std::move to to the local variable being passed.

Reviewers: sanjoy, mzolotukhin, efriedma

Reviewed By: sanjoy

Subscribers: takuto.ikuta, llvm-commits

Differential Revision: https://reviews.llvm.org/D32943

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302371 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Analysis/ScalarEvolution.h b/include/llvm/Analysis/ScalarEvolution.h
index 7e48e4917b87ad2dc8674c8615f3443ff3a28715..85350fa159d6cc3ffbb86fa35d08e782d75adf17 100644 (file)
--- a/include/llvm/Analysis/ScalarEvolution.h
+++ b/include/llvm/Analysis/ScalarEvolution.h
@@ -782,13 +782,13 @@ private:
 
   /// Set the memoized range for the given SCEV.
   const ConstantRange &setRange(const SCEV *S, RangeSignHint Hint,
-                                const ConstantRange &CR) {
+                                ConstantRange &&CR) {
     DenseMap<const SCEV *, ConstantRange> &Cache =
         Hint == HINT_RANGE_UNSIGNED ? UnsignedRanges : SignedRanges;
 
-    auto Pair = Cache.insert({S, CR});
+    auto Pair = Cache.try_emplace(S, std::move(CR));
     if (!Pair.second)
-      Pair.first->second = CR;
+      Pair.first->second = std::move(CR);
     return Pair.first->second;
   }
 

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index d2a3010c77e457425ba6565733628f42a05b299c..7facf36f52dcb8352ddc368c52c2f3f28b1253af 100644 (file)
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -4800,7 +4800,7 @@ ScalarEvolution::getRange(const SCEV *S,
       }
     }
 
-    return setRange(AddRec, SignHint, ConservativeResult);
+    return setRange(AddRec, SignHint, std::move(ConservativeResult));
   }
 
   if (const SCEVUnknown *U = dyn_cast<SCEVUnknown>(S)) {
@@ -4831,10 +4831,10 @@ ScalarEvolution::getRange(const SCEV *S,
                           APInt::getSignedMaxValue(BitWidth).ashr(NS - 1) + 1));
     }
 
-    return setRange(U, SignHint, ConservativeResult);
+    return setRange(U, SignHint, std::move(ConservativeResult));
   }
 
-  return setRange(S, SignHint, ConservativeResult);
+  return setRange(S, SignHint, std::move(ConservativeResult));
 }
 
 // Given a StartRange, Step and MaxBECount for an expression compute a range of