#define DEBUG_TYPE "adce"
#include "llvm/Transforms/Scalar.h"
+#include "llvm/BasicBlock.h"
#include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
#include "llvm/Pass.h"
-#include "llvm/Support/Compiler.h"
+#include "llvm/Support/CFG.h"
#include "llvm/Support/InstIterator.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
-
+#include "llvm/ADT/Statistic.h"
using namespace llvm;
STATISTIC(NumRemoved, "Number of instructions removed");
namespace {
- struct VISIBILITY_HIDDEN ADCE : public FunctionPass {
+ struct ADCE : public FunctionPass {
static char ID; // Pass identification, replacement for typeid
- ADCE() : FunctionPass((intptr_t)&ID) {}
-
- DenseSet<Instruction*> alive;
- SmallVector<Instruction*, 1024> worklist;
+ ADCE() : FunctionPass(&ID) {}
virtual bool runOnFunction(Function& F);
static RegisterPass<ADCE> X("adce", "Aggressive Dead Code Elimination");
bool ADCE::runOnFunction(Function& F) {
- alive.clear();
- worklist.clear();
+ 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)
if (isa<TerminatorInst>(I.getInstructionIterator()) ||
- I->mayWriteToMemory()) {
+ isa<DbgInfoIntrinsic>(I.getInstructionIterator()) ||
+ I->mayHaveSideEffects()) {
alive.insert(I.getInstructionIterator());
worklist.push_back(I.getInstructionIterator());
}
NumRemoved++;
(*I)->eraseFromParent();
}
-
+
return !worklist.empty();
}