//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "sccp"
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/InstVisitor.h"
#include "llvm/IR/Instructions.h"
-#include "llvm/InstVisitor.h"
#include "llvm/Pass.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include <algorithm>
using namespace llvm;
+#define DEBUG_TYPE "sccp"
+
STATISTIC(NumInstRemoved, "Number of instructions removed");
STATISTIC(NumDeadBlocks , "Number of basic blocks unreachable");
}
public:
- LatticeVal() : Val(0, undefined) {}
+ LatticeVal() : Val(nullptr, undefined) {}
bool isUndefined() const { return getLatticeValue() == undefined; }
bool isConstant() const {
ConstantInt *getConstantInt() const {
if (isConstant())
return dyn_cast<ConstantInt>(getConstant());
- return 0;
+ return nullptr;
}
void markForcedConstant(Constant *V) {
if (Constant *C = dyn_cast<Constant>(V)) {
Constant *Elt = C->getAggregateElement(i);
- if (Elt == 0)
+ if (!Elt)
LV.markOverdefined(); // Unknown sort of constant.
else if (isa<UndefValue>(Elt))
; // Undef values remain undefined.
}
void visitCallSite (CallSite CS);
void visitResumeInst (TerminatorInst &I) { /*returns void*/ }
- void visitUnwindInst (TerminatorInst &I) { /*returns void*/ }
void visitUnreachableInst(TerminatorInst &I) { /*returns void*/ }
void visitFenceInst (FenceInst &I) { /*returns void*/ }
void visitAtomicCmpXchgInst (AtomicCmpXchgInst &I) { markOverdefined(&I); }
LatticeVal BCValue = getValueState(BI->getCondition());
ConstantInt *CI = BCValue.getConstantInt();
- if (CI == 0) {
+ if (!CI) {
// Overdefined condition variables, and branches on unfoldable constant
// conditions, mean the branch could go either way.
if (!BCValue.isUndefined())
LatticeVal SCValue = getValueState(SI->getCondition());
ConstantInt *CI = SCValue.getConstantInt();
- if (CI == 0) { // Overdefined or undefined condition?
+ if (!CI) { // Overdefined or undefined condition?
// All destinations are executable!
if (!SCValue.isUndefined())
Succs.assign(TI.getNumSuccessors(), true);
// Overdefined condition variables mean the branch could go either way,
// undef conditions mean that neither edge is feasible yet.
ConstantInt *CI = BCValue.getConstantInt();
- if (CI == 0)
+ if (!CI)
return !BCValue.isUndefined();
// Constant condition variables mean the branch can only go a single way.
LatticeVal SCValue = getValueState(SI->getCondition());
ConstantInt *CI = SCValue.getConstantInt();
- if (CI == 0)
+ if (!CI)
return !SCValue.isUndefined();
return SI->findCaseValue(CI).getCaseSuccessor() == To;
#ifndef NDEBUG
dbgs() << "Unknown terminator instruction: " << *TI << '\n';
#endif
- llvm_unreachable(0);
+ llvm_unreachable(nullptr);
}
// visit Implementations - Something changed in this instruction, either an
// constant. If they are constant and don't agree, the PHI is overdefined.
// If there are no executable operands, the PHI remains undefined.
//
- Constant *OperandVal = 0;
+ Constant *OperandVal = nullptr;
for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
LatticeVal IV = getValueState(PN.getIncomingValue(i));
if (IV.isUndefined()) continue; // Doesn't influence PHI node.
if (IV.isOverdefined()) // PHI node becomes overdefined!
return markOverdefined(&PN);
- if (OperandVal == 0) { // Grab the first value.
+ if (!OperandVal) { // Grab the first value.
OperandVal = IV.getConstant();
continue;
}
void SCCPSolver::visitInsertValueInst(InsertValueInst &IVI) {
StructType *STy = dyn_cast<StructType>(IVI.getType());
- if (STy == 0)
+ if (!STy)
return markOverdefined(&IVI);
// If this has more than one index, we can't handle it, drive all results to
// If this is an AND or OR with 0 or -1, it doesn't matter that the other
// operand is overdefined.
if (I.getOpcode() == Instruction::And || I.getOpcode() == Instruction::Or) {
- LatticeVal *NonOverdefVal = 0;
+ LatticeVal *NonOverdefVal = nullptr;
if (!V1State.isOverdefined())
NonOverdefVal = &V1State;
else if (!V2State.isOverdefined())
// The common case is that we aren't tracking the callee, either because we
// are not doing interprocedural analysis or the callee is indirect, or is
// external. Handle these cases first.
- if (F == 0 || F->isDeclaration()) {
+ if (!F || F->isDeclaration()) {
CallOverdefined:
// Void return and not tracking callee, just bail.
if (I->getType()->isVoidTy()) return;
// since all of its users will have already been marked as overdefined
// 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)
- if (Instruction *I = dyn_cast<Instruction>(*UI))
- OperandChangedState(I);
+ for (User *U : I->users())
+ if (Instruction *UI = dyn_cast<Instruction>(U))
+ OperandChangedState(UI);
}
// Process the instruction work list.
// Update all of the users of this instruction's value.
//
if (I->getType()->isStructTy() || !getValueState(I).isOverdefined())
- for (Value::use_iterator UI = I->use_begin(), E = I->use_end();
- UI != E; ++UI)
- if (Instruction *I = dyn_cast<Instruction>(*UI))
- OperandChangedState(I);
+ for (User *U : I->users())
+ if (Instruction *UI = dyn_cast<Instruction>(U))
+ OperandChangedState(UI);
}
// Process the basic block work list.
/// Sparse Conditional Constant Propagator.
///
struct SCCP : public FunctionPass {
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequired<TargetLibraryInfo>();
}
static char ID; // Pass identification, replacement for typeid
// runOnFunction - Run the Sparse Conditional Constant Propagation
// algorithm, and return true if the function was modified.
//
- bool runOnFunction(Function &F);
+ bool runOnFunction(Function &F) override;
};
} // end anonymous namespace
DEBUG(dbgs() << "SCCP on function '" << F.getName() << "'\n");
const DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
- const DataLayout *DL = DLP ? &DLP->getDataLayout() : 0;
+ const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
const TargetLibraryInfo *TLI = &getAnalysis<TargetLibraryInfo>();
SCCPSolver Solver(DL, TLI);
/// Constant Propagation.
///
struct IPSCCP : public ModulePass {
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequired<TargetLibraryInfo>();
}
static char ID;
IPSCCP() : ModulePass(ID) {
initializeIPSCCPPass(*PassRegistry::getPassRegistry());
}
- bool runOnModule(Module &M);
+ bool runOnModule(Module &M) override;
};
} // end anonymous namespace
// Delete any dead constantexpr klingons.
GV->removeDeadConstantUsers();
- for (Value::const_use_iterator UI = GV->use_begin(), E = GV->use_end();
- UI != E; ++UI) {
- const User *U = *UI;
- if (const StoreInst *SI = dyn_cast<StoreInst>(U)) {
+ for (const Use &U : GV->uses()) {
+ const User *UR = U.getUser();
+ if (const StoreInst *SI = dyn_cast<StoreInst>(UR)) {
if (SI->getOperand(0) == GV || SI->isVolatile())
return true; // Storing addr of GV.
- } else if (isa<InvokeInst>(U) || isa<CallInst>(U)) {
+ } else if (isa<InvokeInst>(UR) || isa<CallInst>(UR)) {
// Make sure we are calling the function, not passing the address.
- ImmutableCallSite CS(cast<Instruction>(U));
- if (!CS.isCallee(UI))
+ ImmutableCallSite CS(cast<Instruction>(UR));
+ if (!CS.isCallee(&U))
return true;
- } else if (const LoadInst *LI = dyn_cast<LoadInst>(U)) {
+ } else if (const LoadInst *LI = dyn_cast<LoadInst>(UR)) {
if (LI->isVolatile())
return true;
- } else if (isa<BlockAddress>(U)) {
+ } else if (isa<BlockAddress>(UR)) {
// blockaddress doesn't take the address of the function, it takes addr
// of label.
} else {
bool IPSCCP::runOnModule(Module &M) {
DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
- const DataLayout *DL = DLP ? &DLP->getDataLayout() : 0;
+ const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
const TargetLibraryInfo *TLI = &getAnalysis<TargetLibraryInfo>();
SCCPSolver Solver(DL, TLI);
for (unsigned i = 0, e = BlocksToErase.size(); i != e; ++i) {
// If there are any PHI nodes in this successor, drop entries for BB now.
BasicBlock *DeadBB = BlocksToErase[i];
- for (Value::use_iterator UI = DeadBB->use_begin(), UE = DeadBB->use_end();
- UI != UE; ) {
+ for (Value::user_iterator UI = DeadBB->user_begin(),
+ UE = DeadBB->user_end();
+ UI != UE;) {
// Grab the user and then increment the iterator early, as the user
// will be deleted. Step past all adjacent uses from the same user.
Instruction *I = dyn_cast<Instruction>(*UI);
"Overdefined values should have been taken out of the map!");
DEBUG(dbgs() << "Found that GV '" << GV->getName() << "' is constant!\n");
while (!GV->use_empty()) {
- StoreInst *SI = cast<StoreInst>(GV->use_back());
+ StoreInst *SI = cast<StoreInst>(GV->user_back());
SI->eraseFromParent();
}
M.getGlobalList().erase(GV);