X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FScalar%2FConstantProp.cpp;h=664c3f6a222f7df19f6ddd74bb03da8780059abf;hb=827454e6e28cfed93db990b03b720ef7c23e6917;hp=7085ef98006e21a54625886c02415c6e6a355d1e;hpb=2ed01d8f0bdb8aa73d893a8beb23b1838422fa32;p=oota-llvm.git

diff --git a/lib/Transforms/Scalar/ConstantProp.cpp b/lib/Transforms/Scalar/ConstantProp.cpp
index 7085ef98006..664c3f6a222 100644
--- a/lib/Transforms/Scalar/ConstantProp.cpp
+++ b/lib/Transforms/Scalar/ConstantProp.cpp
@@ -1,44 +1,66 @@
-//===- ConstantProp.cpp - Code to perform Simple Constant Propogation -----===//
+//===- ConstantProp.cpp - Code to perform Simple Constant Propagation -----===//
 //
-// This file implements constant propogation and merging:
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements constant propagation and merging:
 //
 // Specifically, this:
 //   * Converts instructions like "add int 1, 2" into 3
 //
 // Notice that:
 //   * This pass has a habit of making definitions be dead.  It is a good idea
-//     to to run a DIE pass sometime after running this pass.
+//     to run a DIE pass sometime after running this pass.
 //
 //===----------------------------------------------------------------------===//
 
-#include "llvm/Transforms/Scalar/ConstantProp.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/ConstantHandling.h"
+#define DEBUG_TYPE "constprop"
+#include "llvm/Transforms/Scalar.h"
+#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Constant.h"
 #include "llvm/Instruction.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/InstIterator.h"
+#include "llvm/ADT/Statistic.h"
 #include <set>
+using namespace llvm;
+
+STATISTIC(NumInstKilled, "Number of instructions killed");
 
 namespace {
-  struct ConstantPropogation : public FunctionPass {
-    const char *getPassName() const { return "Simple Constant Propogation"; }
+  struct ConstantPropagation : public FunctionPass {
+    static char ID; // Pass identification, replacement for typeid
+    ConstantPropagation() : FunctionPass(ID) {
+      initializeConstantPropagationPass(*PassRegistry::getPassRegistry());
+    }
 
-    inline bool runOnFunction(Function *F);
+    bool runOnFunction(Function &F);
 
     virtual void getAnalysisUsage(AnalysisUsage &AU) const {
-      AU.preservesCFG();
+      AU.setPreservesCFG();
     }
   };
 }
 
-Pass *createConstantPropogationPass() {
-  return new ConstantPropogation();
+char ConstantPropagation::ID = 0;
+INITIALIZE_PASS(ConstantPropagation, "constprop",
+                "Simple constant propagation", false, false)
+
+FunctionPass *llvm::createConstantPropagationPass() {
+  return new ConstantPropagation();
 }
 
 
-bool ConstantPropogation::runOnFunction(Function *F) {
+bool ConstantPropagation::runOnFunction(Function &F) {
   // Initialize the worklist to all of the instructions ready to process...
-  std::set<Instruction*> WorkList(inst_begin(F), inst_end(F));
+  std::set<Instruction*> WorkList;
+  for(inst_iterator i = inst_begin(F), e = inst_end(F); i != e; ++i) {
+      WorkList.insert(&*i);
+  }
   bool Changed = false;
 
   while (!WorkList.empty()) {
@@ -48,16 +70,21 @@ bool ConstantPropogation::runOnFunction(Function *F) {
     if (!I->use_empty())                 // Don't muck with dead instructions...
       if (Constant *C = ConstantFoldInstruction(I)) {
         // Add all of the users of this instruction to the worklist, they might
-        // be constant propogatable now...
+        // be constant propagatable now...
         for (Value::use_iterator UI = I->use_begin(), UE = I->use_end();
              UI != UE; ++UI)
           WorkList.insert(cast<Instruction>(*UI));
-        
+
         // Replace all of the uses of a variable with uses of the constant.
         I->replaceAllUsesWith(C);
-        
+
+        // Remove the dead instruction.
+        WorkList.erase(I);
+        I->eraseFromParent();
+
         // We made a change to the function...
         Changed = true;
+        ++NumInstKilled;
       }
   }
   return Changed;