Eliminate a redundant FoldingSet lookup.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106872 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2010-06-25 18:47:08 +00:00
parent 57bb394803
commit 420ab9102c

View File

@ -845,9 +845,9 @@ const SCEV *ScalarEvolution::getTruncateExpr(const SCEV *Op,
return getAddRecExpr(Operands, AddRec->getLoop());
}
// The cast wasn't folded; create an explicit cast node.
// Recompute the insert position, as it may have been invalidated.
if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
// The cast wasn't folded; create an explicit cast node. We can reuse
// the existing insert position since if we get here, we won't have
// made any changes which would invalidate it.
SCEV *S = new (SCEVAllocator) SCEVTruncateExpr(ID.Intern(SCEVAllocator),
Op, Ty);
UniqueSCEVs.InsertNode(S, IP);