From cd045c08cad9bc3e1e3e234453f5f4464b705e02 Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Fri, 12 Feb 2010 19:20:37 +0000 Subject: [PATCH] Fix this code to avoid dereferencing an end() iterator in offset distributions it doesn't expect. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96002 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopStrengthReduce.cpp | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp index 73d3f9db896..a218af94c7e 100644 --- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp +++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp @@ -2271,6 +2271,10 @@ void LSRInstance::GenerateCrossUseConstantOffsets() { const SCEV *Reg = *I; const ImmMapTy &Imms = Map.find(Reg)->second; + // It's not worthwhile looking for reuse if there's only one offset. + if (Imms.size() == 1) + continue; + DEBUG(dbgs() << "Generating cross-use offsets for " << *Reg << ':'; for (ImmMapTy::const_iterator J = Imms.begin(), JE = Imms.end(); J != JE; ++J) @@ -2299,7 +2303,7 @@ void LSRInstance::GenerateCrossUseConstantOffsets() { }; for (size_t i = 0, e = array_lengthof(OtherImms); i != e; ++i) { ImmMapTy::const_iterator M = OtherImms[i]; - if (M == J) continue; + if (M == J || M == JE) continue; // Compute the difference between the two. int64_t Imm = (uint64_t)JImm - M->first; -- 2.34.1