Index: llvm/trunk/lib/Transforms/Scalar/LICM.cpp =================================================================== --- llvm/trunk/lib/Transforms/Scalar/LICM.cpp +++ llvm/trunk/lib/Transforms/Scalar/LICM.cpp @@ -460,14 +460,10 @@ if (inSubLoop(BB, CurLoop, LI)) continue; - // Keep track of whether the prefix of instructions visited so far are such - // that the next instruction visited is guaranteed to execute if the loop - // is entered. - bool IsMustExecute = CurLoop->getHeader() == BB; // Keep track of whether the prefix instructions could have written memory. - // TODO: This and IsMustExecute may be done smarter if we keep track of all - // throwing and mem-writing operations in every block, e.g. using something - // similar to isGuaranteedToExecute. + // TODO: This may be done smarter if we keep track of all throwing and + // mem-writing operations in every block, e.g. using something similar to + // isGuaranteedToExecute. bool IsMemoryNotModified = CurLoop->getHeader() == BB; for (BasicBlock::iterator II = BB->begin(), E = BB->end(); II != E;) { @@ -493,10 +489,9 @@ // if (CurLoop->hasLoopInvariantOperands(&I) && canSinkOrHoistInst(I, AA, DT, CurLoop, CurAST, true, ORE) && - (IsMustExecute || - isSafeToExecuteUnconditionally( - I, DT, CurLoop, SafetyInfo, ORE, - CurLoop->getLoopPreheader()->getTerminator()))) { + isSafeToExecuteUnconditionally( + I, DT, CurLoop, SafetyInfo, ORE, + CurLoop->getLoopPreheader()->getTerminator())) { hoist(I, DT, CurLoop, SafetyInfo, ORE); Changed = true; continue; @@ -531,15 +526,13 @@ if (((I.use_empty() && match(&I, m_Intrinsic())) || isGuard(&I)) && - IsMustExecute && IsMemoryNotModified && - CurLoop->hasLoopInvariantOperands(&I)) { + IsMemoryNotModified && CurLoop->hasLoopInvariantOperands(&I) && + SafetyInfo->isGuaranteedToExecute(I, DT, CurLoop)) { hoist(I, DT, CurLoop, SafetyInfo, ORE); Changed = true; continue; } - if (IsMustExecute) - IsMustExecute = isGuaranteedToTransferExecutionToSuccessor(&I); if (IsMemoryNotModified) IsMemoryNotModified = !I.mayWriteToMemory(); }