LLParser: Handle BlockAddresses on-the-fly
[oota-llvm.git] / lib / Transforms / Scalar / DCE.cpp
index dbb68f3e0bd1a1e4e207be0992132f70b2717aaf..99fac751df8e73162a74e8f08c40d106c48cdda1 100644 (file)
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "dce"
 #include "llvm/Transforms/Scalar.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Instruction.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/InstIterator.h"
 #include "llvm/ADT/Statistic.h"
-#include <set>
+#include "llvm/IR/InstIterator.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/Pass.h"
+#include "llvm/Target/TargetLibraryInfo.h"
+#include "llvm/Transforms/Utils/Local.h"
 using namespace llvm;
 
+#define DEBUG_TYPE "dce"
+
 STATISTIC(DIEEliminated, "Number of insts removed by DIE pass");
 STATISTIC(DCEEliminated, "Number of insts removed");
 
@@ -38,11 +39,14 @@ namespace {
     DeadInstElimination() : BasicBlockPass(ID) {
       initializeDeadInstEliminationPass(*PassRegistry::getPassRegistry());
     }
-    virtual bool runOnBasicBlock(BasicBlock &BB) {
+    bool runOnBasicBlock(BasicBlock &BB) override {
+      if (skipOptnoneFunction(BB))
+        return false;
+      TargetLibraryInfo *TLI = getAnalysisIfAvailable<TargetLibraryInfo>();
       bool Changed = false;
       for (BasicBlock::iterator DI = BB.begin(); DI != BB.end(); ) {
         Instruction *Inst = DI++;
-        if (isInstructionTriviallyDead(Inst)) {
+        if (isInstructionTriviallyDead(Inst, TLI)) {
           Inst->eraseFromParent();
           Changed = true;
           ++DIEEliminated;
@@ -51,7 +55,7 @@ namespace {
       return Changed;
     }
 
-    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
       AU.setPreservesCFG();
     }
   };
@@ -76,9 +80,9 @@ namespace {
       initializeDCEPass(*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();
     }
  };
@@ -88,6 +92,11 @@ char DCE::ID = 0;
 INITIALIZE_PASS(DCE, "dce", "Dead Code Elimination", false, false)
 
 bool DCE::runOnFunction(Function &F) {
+  if (skipOptnoneFunction(F))
+    return false;
+
+  TargetLibraryInfo *TLI = getAnalysisIfAvailable<TargetLibraryInfo>();
+
   // Start out with all of the instructions in the worklist...
   std::vector<Instruction*> WorkList;
   for (inst_iterator i = inst_begin(F), e = inst_end(F); i != e; ++i)
@@ -102,7 +111,7 @@ bool DCE::runOnFunction(Function &F) {
     Instruction *I = WorkList.back();
     WorkList.pop_back();
 
-    if (isInstructionTriviallyDead(I)) {       // If the instruction is dead.
+    if (isInstructionTriviallyDead(I, TLI)) { // If the instruction is dead.
       // Loop over all of the values that the instruction uses, if there are
       // instructions being used, add them to the worklist, because they might
       // go dead after this one is removed.
@@ -115,13 +124,8 @@ bool DCE::runOnFunction(Function &F) {
       I->eraseFromParent();
 
       // Remove the instruction from the worklist if it still exists in it.
-      for (std::vector<Instruction*>::iterator WI = WorkList.begin();
-           WI != WorkList.end(); ) {
-        if (*WI == I)
-          WI = WorkList.erase(WI);
-        else
-          ++WI;
-      }
+      WorkList.erase(std::remove(WorkList.begin(), WorkList.end(), I),
+                     WorkList.end());
 
       MadeChange = true;
       ++DCEEliminated;