diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 45 |
1 files changed, 30 insertions, 15 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 8366cd6855..f635af3974 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -12676,16 +12676,19 @@ static bool TryToSinkInstruction(Instruction *I, BasicBlock *DestBlock) { /// many instructions are dead or constant). Additionally, if we find a branch /// whose condition is a known constant, we only visit the reachable successors. /// -static void AddReachableCodeToWorklist(BasicBlock *BB, +static bool AddReachableCodeToWorklist(BasicBlock *BB, SmallPtrSet<BasicBlock*, 64> &Visited, InstCombiner &IC, const TargetData *TD) { + bool MadeIRChange = false; SmallVector<BasicBlock*, 256> Worklist; Worklist.push_back(BB); std::vector<Instruction*> InstrsForInstCombineWorklist; InstrsForInstCombineWorklist.reserve(128); + SmallPtrSet<ConstantExpr*, 64> FoldedConstants; + while (!Worklist.empty()) { BB = Worklist.back(); Worklist.pop_back(); @@ -12714,6 +12717,29 @@ static void AddReachableCodeToWorklist(BasicBlock *BB, Inst->eraseFromParent(); continue; } + + + + if (TD) { + // See if we can constant fold its operands. + for (User::op_iterator i = Inst->op_begin(), e = Inst->op_end(); + i != e; ++i) { + ConstantExpr *CE = dyn_cast<ConstantExpr>(i); + if (CE == 0) continue; + + // If we already folded this constant, don't try again. + if (!FoldedConstants.insert(CE)) + continue; + + Constant *NewC = + ConstantFoldConstantExpression(CE, BB->getContext(), TD); + if (NewC && NewC != CE) { + *i = NewC; + MadeIRChange = true; + } + } + } + InstrsForInstCombineWorklist.push_back(Inst); } @@ -12755,6 +12781,8 @@ static void AddReachableCodeToWorklist(BasicBlock *BB, // some N^2 behavior in pathological cases. IC.Worklist.AddInitialGroup(&InstrsForInstCombineWorklist[0], InstrsForInstCombineWorklist.size()); + + return MadeIRChange; } bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { @@ -12768,7 +12796,7 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { // the reachable instructions. Ignore blocks that are not reachable. Keep // track of which blocks we visit. SmallPtrSet<BasicBlock*, 64> Visited; - AddReachableCodeToWorklist(F.begin(), Visited, *this, TD); + MadeIRChange |= AddReachableCodeToWorklist(F.begin(), Visited, *this, TD); // Do a quick scan over the function. If we find any blocks that are // unreachable, remove any instructions inside of them. This prevents @@ -12787,7 +12815,6 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { MadeIRChange = true; } - // If I is not void type then replaceAllUsesWith undef. // This allows ValueHandlers and custom metadata to adjust itself. if (!I->getType()->isVoidTy()) @@ -12823,18 +12850,6 @@ bool InstCombiner::DoOneIteration(Function &F, unsigned Iteration) { continue; } - if (TD) { - // See if we can constant fold its operands. - for (User::op_iterator i = I->op_begin(), e = I->op_end(); i != e; ++i) - if (ConstantExpr *CE = dyn_cast<ConstantExpr>(i)) - if (Constant *NewC = ConstantFoldConstantExpression(CE, - F.getContext(), TD)) - if (NewC != CE) { - *i = NewC; - MadeIRChange = true; - } - } - // See if we can trivially sink this instruction to a successor basic block. if (I->hasOneUse()) { BasicBlock *BB = I->getParent(); |