diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index e9cfc56714e3..d3e04f830747 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -69,6 +69,7 @@ #include "llvm/Operator.h" #include "llvm/Analysis/ConstantFolding.h" #include "llvm/Analysis/Dominators.h" +#include "llvm/Analysis/InstructionSimplify.h" #include "llvm/Analysis/LoopInfo.h" #include "llvm/Analysis/ValueTracking.h" #include "llvm/Assembly/Writer.h" @@ -2874,7 +2875,10 @@ const SCEV *ScalarEvolution::createNodeForPHI(PHINode *PN) { // PHI's incoming blocks are in a different loop, in which case doing so // risks breaking LCSSA form. Instcombine would normally zap these, but // it doesn't have DominatorTree information, so it may miss cases. - if (Value *V = PN->hasConstantValue(DT)) { + if (Value *V = SimplifyInstruction(PN, TD, DT)) { + // TODO: The following check is suboptimal. For example, it is pointless + // if V is a constant. Since the problematic case is if V is defined inside + // a deeper loop, it would be better to check for that directly. bool AllSameLoop = true; Loop *PNLoop = LI->getLoopFor(PN->getParent()); for (size_t i = 0, e = PN->getNumIncomingValues(); i != e; ++i)