diff options
| -rw-r--r-- | lib/Transforms/Scalar/LICM.cpp | 29 |
1 files changed, 10 insertions, 19 deletions
diff --git a/lib/Transforms/Scalar/LICM.cpp b/lib/Transforms/Scalar/LICM.cpp index 4358c0461a..f2cf68b4e9 100644 --- a/lib/Transforms/Scalar/LICM.cpp +++ b/lib/Transforms/Scalar/LICM.cpp @@ -67,7 +67,7 @@ namespace { BasicBlock *Preheader; // The preheader block of the current loop... Loop *CurLoop; // The current loop we are working on... AliasSetTracker *CurAST; // AliasSet information for the current loop... - DominatorTree *CurDT; // Dominator Tree for the current Loop... + DominatorTree *DT; // Dominator Tree for the current Loop... /// visitLoop - Hoist expressions out of the specified loop... /// @@ -173,6 +173,7 @@ bool LICM::runOnFunction(Function &) { // Get our Loop and Alias Analysis information... LI = &getAnalysis<LoopInfo>(); AA = &getAnalysis<AliasAnalysis>(); + DT = &getAnalysis<DominatorTree>(); // Hoist expressions out of all of the top-level loops. const std::vector<Loop*> &TopLevelLoops = LI->getTopLevelLoops(); @@ -223,9 +224,7 @@ void LICM::visitLoop(Loop *L, AliasSetTracker &AST) { // that we are guaranteed to see definitions before we see uses. This allows // us to perform the LICM transformation in one pass, without iteration. // - CurDT = &getAnalysis<DominatorTree>(); - - HoistRegion(CurDT->getNode(L->getHeader())); + HoistRegion(DT->getNode(L->getHeader())); // Now that all loop invariants have been removed from the loop, promote any // memory references to scalars that we can... @@ -290,36 +289,28 @@ bool LICM::SafeToHoist(Instruction &Inst) { BasicBlock *InstBB = Inst.getParent(); //Get the Dominator Tree Node for the instruction's basic block/ - DominatorTree::Node *InstDTNode = CurDT->getNode(InstBB); + DominatorTree::Node *InstDTNode = DT->getNode(InstBB); //Get the exit blocks for the current loop. - const std::vector<BasicBlock* > ExitBlocks = CurLoop->getExitBlocks(); + const std::vector<BasicBlock* > &ExitBlocks = CurLoop->getExitBlocks(); //For each exit block, get the DT node and walk up the DT until //the instruction's basic block is found or we exit the loop. for(unsigned i=0; i < ExitBlocks.size(); ++i) { - DominatorTree::Node *IDom = CurDT->getNode(ExitBlocks[i]); + DominatorTree::Node *IDom = DT->getNode(ExitBlocks[i]); - //Using boolean variable because exit nodes are not "contained" - //in the loop, so can not use that as the while test condition - //for first pass. - bool inLoop = true; - - while(inLoop) { + while(IDom != InstDTNode) { - //compare Instruction DT node to Current DT Node - if(IDom == InstDTNode) - return true; - //Get next Immediate Dominator. IDom = IDom->getIDom(); //See if we exited the loop. - inLoop = CurLoop->contains(IDom->getNode()); + if(!CurLoop->contains(IDom->getNode())) + return false; } - return false; } } + return true; } |