diff options
Diffstat (limited to 'llvm/lib/Transforms/Scalar/SCCP.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/SCCP.cpp | 62 |
1 files changed, 32 insertions, 30 deletions
diff --git a/llvm/lib/Transforms/Scalar/SCCP.cpp b/llvm/lib/Transforms/Scalar/SCCP.cpp index ed4f7d0da87..1c227be8d93 100644 --- a/llvm/lib/Transforms/Scalar/SCCP.cpp +++ b/llvm/lib/Transforms/Scalar/SCCP.cpp @@ -310,7 +310,7 @@ private: // getValueState - Return the LatticeVal object that corresponds to the value. // This function is necessary because not all values should start out in the - // underdefined state... Argument's should be overdefined, and + // underdefined state. Argument's should be overdefined, and // constants should be marked as constants. If a value is not known to be an // Instruction object, then use this accessor to get its value from the map. // @@ -327,12 +327,12 @@ private: return LV; } } - // All others are underdefined by default... + // All others are underdefined by default. return ValueState[V]; } // markEdgeExecutable - Mark a basic block as executable, adding it to the BB - // work list if it is not already executable... + // work list if it is not already executable. // void markEdgeExecutable(BasicBlock *Source, BasicBlock *Dest) { if (!KnownFeasibleEdges.insert(Edge(Source, Dest)).second) @@ -359,12 +359,12 @@ private: void getFeasibleSuccessors(TerminatorInst &TI, SmallVector<bool, 16> &Succs); // isEdgeFeasible - Return true if the control flow edge from the 'From' basic - // block to the 'To' basic block is currently feasible... + // block to the 'To' basic block is currently feasible. // bool isEdgeFeasible(BasicBlock *From, BasicBlock *To); // OperandChangedState - This method is invoked on all of the users of an - // instruction that was just changed state somehow.... Based on this + // instruction that was just changed state somehow. Based on this // information, we need to update the specified user of this instruction. // void OperandChangedState(User *U) { @@ -377,7 +377,7 @@ private: private: friend class InstVisitor<SCCPSolver>; - // visit implementations - Something changed in this instruction... Either an + // visit implementations - Something changed in this instruction. Either an // operand made a transition, or the instruction is newly executable. Change // the value type of I to reflect these changes if appropriate. // @@ -397,7 +397,7 @@ private: void visitExtractValueInst(ExtractValueInst &EVI); void visitInsertValueInst(InsertValueInst &IVI); - // Instructions that cannot be folded away... + // Instructions that cannot be folded away. void visitStoreInst (Instruction &I); void visitLoadInst (LoadInst &I); void visitGetElementPtrInst(GetElementPtrInst &I); @@ -418,7 +418,7 @@ private: void visitVAArgInst (Instruction &I) { markOverdefined(&I); } void visitInstruction(Instruction &I) { - // If a new instruction is added to LLVM that we don't handle... + // If a new instruction is added to LLVM that we don't handle. errs() << "SCCP: Don't know how to handle: " << I; markOverdefined(&I); // Just in case } @@ -485,7 +485,7 @@ void SCCPSolver::getFeasibleSuccessors(TerminatorInst &TI, // isEdgeFeasible - Return true if the control flow edge from the 'From' basic -// block to the 'To' basic block is currently feasible... +// block to the 'To' basic block is currently feasible. // bool SCCPSolver::isEdgeFeasible(BasicBlock *From, BasicBlock *To) { assert(BBExecutable.count(To) && "Dest should always be alive!"); @@ -493,7 +493,7 @@ bool SCCPSolver::isEdgeFeasible(BasicBlock *From, BasicBlock *To) { // Make sure the source basic block is executable!! if (!BBExecutable.count(From)) return false; - // Check to make sure this edge itself is actually feasible now... + // Check to make sure this edge itself is actually feasible now. TerminatorInst *TI = From->getTerminator(); if (BranchInst *BI = dyn_cast<BranchInst>(TI)) { if (BI->isUnconditional()) @@ -530,11 +530,11 @@ bool SCCPSolver::isEdgeFeasible(BasicBlock *From, BasicBlock *To) { // Make sure to skip the "default value" which isn't a value for (unsigned i = 1, E = SI->getNumSuccessors(); i != E; ++i) - if (SI->getSuccessorValue(i) == CPV) // Found the taken branch... + if (SI->getSuccessorValue(i) == CPV) // Found the taken branch. return SI->getSuccessor(i) == To; - // Constant value not equal to any of the branches... must execute - // default branch then... + // If the constant value is not equal to any of the branches, we must + // execute default branch. return SI->getDefaultDest() == To; } return false; @@ -551,7 +551,7 @@ bool SCCPSolver::isEdgeFeasible(BasicBlock *From, BasicBlock *To) { llvm_unreachable(0); } -// visit Implementations - Something changed in this instruction... Either an +// visit Implementations - Something changed in this instruction, either an // operand made a transition, or the instruction is newly executable. Change // the value type of I to reflect these changes if appropriate. This method // makes sure to do the following actions: @@ -612,14 +612,14 @@ void SCCPSolver::visitPHINode(PHINode &PN) { return; } - if (OperandVal == 0) { // Grab the first value... + if (OperandVal == 0) { // Grab the first value. OperandVal = IV.getConstant(); } else { // Another value is being merged in! // There is already a reachable operand. If we conflict with it, // then the PHI node becomes overdefined. If we agree with it, we // can continue on. - // Check to see if there are two different constants merging... + // Check to see if there are two different constants merging. if (IV.getConstant() != OperandVal) { // Yes there is. This means the PHI node is not constant. // You must be overdefined poor PHI. @@ -687,7 +687,7 @@ void SCCPSolver::visitTerminatorInst(TerminatorInst &TI) { BasicBlock *BB = TI.getParent(); - // Mark all feasible successors executable... + // Mark all feasible successors executable. for (unsigned i = 0, e = SuccFeasible.size(); i != e; ++i) if (SuccFeasible[i]) markEdgeExecutable(BB, TI.getSuccessor(i)); @@ -819,7 +819,7 @@ void SCCPSolver::visitSelectInst(SelectInst &I) { } } -// Handle BinaryOperators and Shift Instructions... +// Handle BinaryOperators and Shift Instructions. void SCCPSolver::visitBinaryOperator(Instruction &I) { LatticeVal &IV = ValueState[&I]; if (IV.isOverdefined()) return; @@ -946,7 +946,7 @@ void SCCPSolver::visitBinaryOperator(Instruction &I) { } } -// Handle ICmpInst instruction... +// Handle ICmpInst instruction. void SCCPSolver::visitCmpInst(CmpInst &I) { LatticeVal &IV = ValueState[&I]; if (IV.isOverdefined()) return; @@ -1104,7 +1104,7 @@ void SCCPSolver::visitShuffleVectorInst(ShuffleVectorInst &I) { #endif } -// Handle getelementptr instructions... if all operands are constants then we +// Handle getelementptr instructions. If all operands are constants then we // can turn this into a getelementptr ConstantExpr. // void SCCPSolver::visitGetElementPtrInst(GetElementPtrInst &I) { @@ -1117,8 +1117,9 @@ void SCCPSolver::visitGetElementPtrInst(GetElementPtrInst &I) { for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i) { LatticeVal &State = getValueState(I.getOperand(i)); if (State.isUndefined()) - return; // Operands are not resolved yet... - else if (State.isOverdefined()) { + return; // Operands are not resolved yet. + + if (State.isOverdefined()) { markOverdefined(IV, &I); return; } @@ -1127,7 +1128,7 @@ void SCCPSolver::visitGetElementPtrInst(GetElementPtrInst &I) { } Constant *Ptr = Operands[0]; - Operands.erase(Operands.begin()); // Erase the pointer from idx list... + Operands.erase(Operands.begin()); // Erase the pointer from idx list. markConstant(IV, &I, ConstantExpr::getGetElementPtr(Ptr, &Operands[0], Operands.size())); @@ -1306,7 +1307,7 @@ void SCCPSolver::Solve() { // Process the work lists until they are empty! while (!BBWorkList.empty() || !InstWorkList.empty() || !OverdefinedInstWorkList.empty()) { - // Process the instruction work list... + // Process the instruction work list. while (!OverdefinedInstWorkList.empty()) { Value *I = OverdefinedInstWorkList.back(); OverdefinedInstWorkList.pop_back(); @@ -1318,13 +1319,14 @@ void SCCPSolver::Solve() { // // Anything on this worklist that is overdefined need not be visited // since all of its users will have already been marked as overdefined - // Update all of the users of this instruction's value... + // Update all of the users of this instruction's value. // for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; ++UI) OperandChangedState(*UI); } - // Process the instruction work list... + + // Process the instruction work list. while (!InstWorkList.empty()) { Value *I = InstWorkList.back(); InstWorkList.pop_back(); @@ -1336,7 +1338,7 @@ void SCCPSolver::Solve() { // // Anything on this worklist that is overdefined need not be visited // since all of its users will have already been marked as overdefined. - // Update all of the users of this instruction's value... + // Update all of the users of this instruction's value. // if (!getValueState(I).isOverdefined()) for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); @@ -1344,7 +1346,7 @@ void SCCPSolver::Solve() { OperandChangedState(*UI); } - // Process the basic block work list... + // Process the basic block work list. while (!BBWorkList.empty()) { BasicBlock *BB = BBWorkList.back(); BBWorkList.pop_back(); @@ -1559,7 +1561,7 @@ char SCCP::ID = 0; static RegisterPass<SCCP> X("sccp", "Sparse Conditional Constant Propagation"); -// createSCCPPass - This is the public interface to this file... +// createSCCPPass - This is the public interface to this file. FunctionPass *llvm::createSCCPPass() { return new SCCP(); } @@ -1664,7 +1666,7 @@ char IPSCCP::ID = 0; static RegisterPass<IPSCCP> Y("ipsccp", "Interprocedural Sparse Conditional Constant Propagation"); -// createIPSCCPPass - This is the public interface to this file... +// createIPSCCPPass - This is the public interface to this file. ModulePass *llvm::createIPSCCPPass() { return new IPSCCP(); } |
