Index: lib/Analysis/ScalarEvolutionExpander.cpp =================================================================== --- lib/Analysis/ScalarEvolutionExpander.cpp +++ lib/Analysis/ScalarEvolutionExpander.cpp @@ -1816,11 +1816,11 @@ const Instruction *At, Loop *L) { using namespace llvm::PatternMatch; - SmallVector Latches; - L->getLoopLatches(Latches); + SmallVector ExitingBlocks; + L->getExitingBlocks(ExitingBlocks); - // Look for suitable value in simple conditions at the loop latches. - for (BasicBlock *BB : Latches) { + // Look for suitable value in simple conditions at the loop exits. + for (BasicBlock *BB : ExitingBlocks) { ICmpInst::Predicate Pred; Instruction *LHS, *RHS; BasicBlock *TrueBB, *FalseBB; @@ -1887,28 +1887,20 @@ // UDivExpr is very likely a UDiv that ScalarEvolution's HowFarToZero or // HowManyLessThans produced to compute a precise expression, rather than a // UDiv from the user's code. If we can't find a UDiv in the code with some - // simple searching, assume the former consider UDivExpr expensive to + // simple searaching, assume the former consider UDivExpr expensive to // compute. BasicBlock *ExitingBB = L->getExitingBlock(); if (!ExitingBB) return true; - BranchInst *ExitingBI = dyn_cast(ExitingBB->getTerminator()); - if (!ExitingBI || !ExitingBI->isConditional()) + // We already tried to find existing value for plain 'S' at the beginning of + // this function. Now try to lookup 'S + 1' as it is common pattern + // involving division. This is just simple search heuristic. + if (!At) + At = &ExitingBB->back(); + if (!findExistingExpansion( + SE.getAddExpr(S, SE.getConstant(S->getType(), 1)), At, L)) return true; - - ICmpInst *OrigCond = dyn_cast(ExitingBI->getCondition()); - if (!OrigCond) - return true; - - const SCEV *RHS = SE.getSCEV(OrigCond->getOperand(1)); - RHS = SE.getMinusSCEV(RHS, SE.getConstant(RHS->getType(), 1)); - if (RHS != S) { - const SCEV *LHS = SE.getSCEV(OrigCond->getOperand(0)); - LHS = SE.getMinusSCEV(LHS, SE.getConstant(LHS->getType(), 1)); - if (LHS != S) - return true; - } } // HowManyLessThans uses a Max expression whenever the loop is not guarded by