diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index 84e02e47a0c..00a4475e28e 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -1158,6 +1158,19 @@ SCEVHandle ScalarEvolution::getAddRecExpr(std::vector &Operands, return getAddRecExpr(Operands, L); // { X,+,0 } --> X } + // Canonicalize nested AddRecs in by nesting them in order of loop depth. + if (SCEVAddRecExpr *NestedAR = dyn_cast(Operands[0])) { + const Loop* NestedLoop = NestedAR->getLoop(); + if (L->getLoopDepth() < NestedLoop->getLoopDepth()) { + std::vector NestedOperands(NestedAR->op_begin(), + NestedAR->op_end()); + SCEVHandle NestedARHandle(NestedAR); + Operands[0] = NestedAR->getStart(); + NestedOperands[0] = getAddRecExpr(Operands, L); + return getAddRecExpr(NestedOperands, NestedLoop); + } + } + SCEVAddRecExpr *&Result = (*SCEVAddRecExprs)[std::make_pair(L, std::vector(Operands.begin(), Operands.end()))];