//
// 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 "adce"
#include "llvm/Transforms/Scalar.h"
#include "llvm/Constants.h"
#include "llvm/Instructions.h"
#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
#include "llvm/Support/Debug.h"
#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Compiler.h"
#include <algorithm>
using namespace llvm;
-namespace {
- Statistic<> NumBlockRemoved("adce", "Number of basic blocks removed");
- Statistic<> NumInstRemoved ("adce", "Number of instructions removed");
- Statistic<> NumCallRemoved ("adce", "Number of calls and invokes removed");
+STATISTIC(NumBlockRemoved, "Number of basic blocks removed");
+STATISTIC(NumInstRemoved , "Number of instructions removed");
+STATISTIC(NumCallRemoved , "Number of calls removed");
+namespace {
//===----------------------------------------------------------------------===//
// ADCE Class
//
// This class does all of the work of Aggressive Dead Code Elimination.
// It's public interface consists of a constructor and a doADCE() method.
//
-class ADCE : public FunctionPass {
+class VISIBILITY_HIDDEN ADCE : public FunctionPass {
Function *Func; // The function that we are working on
std::vector<Instruction*> WorkList; // Instructions that just became live
std::set<Instruction*> LiveSet; // The set of live instructions
// The public interface for this class
//
public:
+ static char ID; // Pass identification, replacement for typeid
+ ADCE() : FunctionPass((intptr_t)&ID) {}
+
// Execute the Aggressive Dead Code Elimination Algorithm
//
virtual bool runOnFunction(Function &F) {
inline void markInstructionLive(Instruction *I) {
if (!LiveSet.insert(I).second) return;
- DEBUG(std::cerr << "Insn Live: " << *I);
+ DOUT << "Insn Live: " << *I;
WorkList.push_back(I);
}
inline void markTerminatorLive(const BasicBlock *BB) {
- DEBUG(std::cerr << "Terminator Live: " << *BB->getTerminator());
+ DOUT << "Terminator Live: " << *BB->getTerminator();
markInstructionLive(const_cast<TerminatorInst*>(BB->getTerminator()));
}
};
-
- RegisterOpt<ADCE> X("adce", "Aggressive Dead Code Elimination");
} // End of anonymous namespace
+char ADCE::ID = 0;
+static RegisterPass<ADCE> X("adce", "Aggressive Dead Code Elimination");
+
FunctionPass *llvm::createAggressiveDCEPass() { return new ADCE(); }
void ADCE::markBlockAlive(BasicBlock *BB) {
/// successors it goes to. This eliminate a use of the condition as well.
///
TerminatorInst *ADCE::convertToUnconditionalBranch(TerminatorInst *TI) {
- BranchInst *NB = new BranchInst(TI->getSuccessor(0), TI);
+ BranchInst *NB = BranchInst::Create(TI->getSuccessor(0), TI);
BasicBlock *BB = TI->getParent();
// Remove entries from PHI nodes to avoid confusing ourself later...
AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
-
- // Iterate over all invokes in the function, turning invokes into calls if
- // they cannot throw.
- for (Function::iterator BB = Func->begin(), E = Func->end(); BB != E; ++BB)
- if (InvokeInst *II = dyn_cast<InvokeInst>(BB->getTerminator()))
- if (Function *F = II->getCalledFunction())
- if (AA.onlyReadsMemory(F)) {
- // The function cannot unwind. Convert it to a call with a branch
- // after it to the normal destination.
- std::vector<Value*> Args(II->op_begin()+3, II->op_end());
- std::string Name = II->getName(); II->setName("");
- Instruction *NewCall = new CallInst(F, Args, Name, II);
- II->replaceAllUsesWith(NewCall);
- new BranchInst(II->getNormalDest(), II);
-
- // Update PHI nodes in the unwind destination
- II->getUnwindDest()->removePredecessor(BB);
- BB->getInstList().erase(II);
-
- if (NewCall->use_empty()) {
- BB->getInstList().erase(NewCall);
- ++NumCallRemoved;
- }
- }
-
// Iterate over all of the instructions in the function, eliminating trivially
// dead instructions, and marking instructions live that are known to be
// needed. Perform the walk in depth first order so that we avoid marking any
for (BasicBlock::iterator II = BB->begin(), EI = BB->end(); II != EI; ) {
Instruction *I = II++;
if (CallInst *CI = dyn_cast<CallInst>(I)) {
- Function *F = CI->getCalledFunction();
- if (F && AA.onlyReadsMemory(F)) {
+ if (AA.onlyReadsMemory(CI)) {
if (CI->use_empty()) {
BB->getInstList().erase(CI);
++NumCallRemoved;
isa<UnwindInst>(I) || isa<UnreachableInst>(I)) {
// FIXME: Unreachable instructions should not be marked intrinsically
// live here.
- markInstructionLive(I);
+ markInstructionLive(I);
} else if (isInstructionTriviallyDead(I)) {
// Remove the instruction from it's basic block...
BB->getInstList().erase(I);
for (pred_iterator PI = pred_begin(I), E = pred_end(I); PI != E; ++PI)
markInstructionLive((*PI)->getTerminator());
- DEBUG(std::cerr << "Processing work list\n");
+ DOUT << "Processing work list\n";
// AliveBlocks - Set of basic blocks that we know have instructions that are
// alive in them...
}
DEBUG(
- std::cerr << "Current Function: X = Live\n";
+ DOUT << "Current Function: X = Live\n";
for (Function::iterator I = Func->begin(), E = Func->end(); I != E; ++I){
- std::cerr << I->getName() << ":\t"
- << (AliveBlocks.count(I) ? "LIVE\n" : "DEAD\n");
+ DOUT << I->getName() << ":\t"
+ << (AliveBlocks.count(I) ? "LIVE\n" : "DEAD\n");
for (BasicBlock::iterator BI = I->begin(), BE = I->end(); BI != BE; ++BI){
- if (LiveSet.count(BI)) std::cerr << "X ";
- std::cerr << *BI;
+ if (LiveSet.count(BI)) DOUT << "X ";
+ DOUT << *BI;
}
});
// node as a special case.
//
if (!AliveBlocks.count(&Func->front())) {
- BasicBlock *NewEntry = new BasicBlock();
- new BranchInst(&Func->front(), NewEntry);
+ BasicBlock *NewEntry = BasicBlock::Create();
+ BranchInst::Create(&Func->front(), NewEntry);
Func->getBasicBlockList().push_front(NewEntry);
AliveBlocks.insert(NewEntry); // This block is always alive!
LiveSet.insert(NewEntry->getTerminator()); // The branch is live
// postdominator that is alive, and the last postdominator that is
// dead...
//
- PostDominatorTree::Node *LastNode = DT[TI->getSuccessor(i)];
- PostDominatorTree::Node *NextNode = 0;
+ DomTreeNode *LastNode = DT[TI->getSuccessor(i)];
+ DomTreeNode *NextNode = 0;
if (LastNode) {
NextNode = LastNode->getIDom();
projects / oota-llvm.git / blobdiff