-//===- DCE.cpp - Code to perform dead code elimination --------------------===//
+//===- ADCE.cpp - Code to perform dead code elimination -------------------===//
//
// The LLVM Compiler Infrastructure
//
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/InstIterator.h"
STATISTIC(NumRemoved, "Number of instructions removed");
namespace {
- struct ADCE : public FunctionPass {
- static char ID; // Pass identification, replacement for typeid
- ADCE() : FunctionPass(ID) {
- initializeADCEPass(*PassRegistry::getPassRegistry());
- }
+struct ADCE : public FunctionPass {
+ static char ID; // Pass identification, replacement for typeid
+ ADCE() : FunctionPass(ID) {
+ initializeADCEPass(*PassRegistry::getPassRegistry());
+ }
- bool runOnFunction(Function& F) override;
+ bool runOnFunction(Function& F) override;
- void getAnalysisUsage(AnalysisUsage& AU) const override {
- AU.setPreservesCFG();
- }
-
- };
+ void getAnalysisUsage(AnalysisUsage& AU) const override {
+ AU.setPreservesCFG();
+ AU.addPreserved<GlobalsAAWrapperPass>();
+ }
+};
}
char ADCE::ID = 0;
SmallVector<Instruction*, 128> Worklist;
// Collect the set of "root" instructions that are known live.
- for (Instruction &I : inst_range(F)) {
- if (isa<TerminatorInst>(I) || isa<DbgInfoIntrinsic>(I) ||
- isa<LandingPadInst>(I) || I.mayHaveSideEffects()) {
+ for (Instruction &I : instructions(F)) {
+ if (isa<TerminatorInst>(I) || isa<DbgInfoIntrinsic>(I) || I.isEHPad() ||
+ I.mayHaveSideEffects()) {
Alive.insert(&I);
Worklist.push_back(&I);
}
// which have no side effects and do not influence the control flow or return
// value of the function, and may therefore be deleted safely.
// NOTE: We reuse the Worklist vector here for memory efficiency.
- for (Instruction &I : inst_range(F)) {
+ for (Instruction &I : instructions(F)) {
if (!Alive.count(&I)) {
Worklist.push_back(&I);
I.dropAllReferences();