//
//===----------------------------------------------------------------------===//
-#define DEBUG_TYPE "adce"
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/CFG.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/Pass.h"
-#include "llvm/Support/CFG.h"
using namespace llvm;
+#define DEBUG_TYPE "adce"
+
STATISTIC(NumRemoved, "Number of instructions removed");
namespace {
initializeADCEPass(*PassRegistry::getPassRegistry());
}
- virtual bool runOnFunction(Function& F);
+ bool runOnFunction(Function& F) override;
- virtual void getAnalysisUsage(AnalysisUsage& AU) const {
+ void getAnalysisUsage(AnalysisUsage& AU) const override {
AU.setPreservesCFG();
}
if (skipOptnoneFunction(F))
return false;
- SmallPtrSet<Instruction*, 128> alive;
- SmallVector<Instruction*, 128> worklist;
+ SmallPtrSet<Instruction*, 128> Alive;
+ SmallVector<Instruction*, 128> Worklist;
// Collect the set of "root" instructions that are known live.
for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I)
isa<DbgInfoIntrinsic>(I.getInstructionIterator()) ||
isa<LandingPadInst>(I.getInstructionIterator()) ||
I->mayHaveSideEffects()) {
- alive.insert(I.getInstructionIterator());
- worklist.push_back(I.getInstructionIterator());
+ Alive.insert(I.getInstructionIterator());
+ Worklist.push_back(I.getInstructionIterator());
}
// Propagate liveness backwards to operands.
- while (!worklist.empty()) {
- Instruction* curr = worklist.pop_back_val();
- for (Instruction::op_iterator OI = curr->op_begin(), OE = curr->op_end();
+ while (!Worklist.empty()) {
+ Instruction* Curr = Worklist.pop_back_val();
+ for (Instruction::op_iterator OI = Curr->op_begin(), OE = Curr->op_end();
OI != OE; ++OI)
if (Instruction* Inst = dyn_cast<Instruction>(OI))
- if (alive.insert(Inst))
- worklist.push_back(Inst);
+ if (Alive.insert(Inst).second)
+ Worklist.push_back(Inst);
}
// The inverse of the live set is the dead set. These are those instructions
// 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.
+ // NOTE: We reuse the Worklist vector here for memory efficiency.
for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I)
- if (!alive.count(I.getInstructionIterator())) {
- worklist.push_back(I.getInstructionIterator());
+ if (!Alive.count(I.getInstructionIterator())) {
+ Worklist.push_back(I.getInstructionIterator());
I->dropAllReferences();
}
- for (SmallVectorImpl<Instruction *>::iterator I = worklist.begin(),
- E = worklist.end(); I != E; ++I) {
+ for (SmallVectorImpl<Instruction *>::iterator I = Worklist.begin(),
+ E = Worklist.end(); I != E; ++I) {
++NumRemoved;
(*I)->eraseFromParent();
}
- return !worklist.empty();
+ return !Worklist.empty();
}
FunctionPass *llvm::createAggressiveDCEPass() {