//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
+#define DEBUG_TYPE "dce"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Instruction.h"
#include <set>
using namespace llvm;
-namespace {
- Statistic<> DIEEliminated("die", "Number of insts removed");
- Statistic<> DCEEliminated("dce", "Number of insts removed");
+STATISTIC(DIEEliminated, "Number of insts removed by DIE pass");
+STATISTIC(DCEEliminated, "Number of insts removed");
+namespace {
//===--------------------------------------------------------------------===//
// DeadInstElimination pass implementation
//
-
struct DeadInstElimination : public BasicBlockPass {
+ static char ID; // Pass identification, replacement for typeid
+ DeadInstElimination() : BasicBlockPass(ID) {
+ initializeDeadInstEliminationPass(*PassRegistry::getPassRegistry());
+ }
virtual bool runOnBasicBlock(BasicBlock &BB) {
bool Changed = false;
- for (BasicBlock::iterator DI = BB.begin(); DI != BB.end(); )
- if (dceInstruction(DI)) {
+ for (BasicBlock::iterator DI = BB.begin(); DI != BB.end(); ) {
+ Instruction *Inst = DI++;
+ if (isInstructionTriviallyDead(Inst)) {
+ Inst->eraseFromParent();
Changed = true;
++DIEEliminated;
- } else
- ++DI;
+ }
+ }
return Changed;
}
AU.setPreservesCFG();
}
};
-
- RegisterPass<DeadInstElimination> X("die", "Dead Instruction Elimination");
}
-FunctionPass *llvm::createDeadInstEliminationPass() {
+char DeadInstElimination::ID = 0;
+INITIALIZE_PASS(DeadInstElimination, "die",
+ "Dead Instruction Elimination", false, false)
+
+Pass *llvm::createDeadInstEliminationPass() {
return new DeadInstElimination();
}
-//===----------------------------------------------------------------------===//
-// DeadCodeElimination pass implementation
-//
-
namespace {
+ //===--------------------------------------------------------------------===//
+ // DeadCodeElimination pass implementation
+ //
struct DCE : public FunctionPass {
+ static char ID; // Pass identification, replacement for typeid
+ DCE() : FunctionPass(ID) {
+ initializeDCEPass(*PassRegistry::getPassRegistry());
+ }
+
virtual bool runOnFunction(Function &F);
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesCFG();
}
};
-
- RegisterPass<DCE> Y("dce", "Dead Code Elimination");
}
+char DCE::ID = 0;
+INITIALIZE_PASS(DCE, "dce", "Dead Code Elimination", false, false)
+
bool DCE::runOnFunction(Function &F) {
// Start out with all of the instructions in the worklist...
std::vector<Instruction*> WorkList;
I->eraseFromParent();
// Remove the instruction from the worklist if it still exists in it.
- for (std::vector<Instruction*>::iterator WI = WorkList.begin(),
- E = WorkList.end(); WI != E; ++WI)
- if (*WI == I) {
- WorkList.erase(WI);
- --E;
- --WI;
- }
+ for (std::vector<Instruction*>::iterator WI = WorkList.begin();
+ WI != WorkList.end(); ) {
+ if (*WI == I)
+ WI = WorkList.erase(WI);
+ else
+ ++WI;
+ }
MadeChange = true;
++DCEEliminated;