X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FVMCore%2FBasicBlock.cpp;h=17469d6bdb2f9b1d61f03977eddd909249568ad9;hb=280a6e607d8eb7401749a92db624a82de47da777;hp=98d12d8f1381368a497887dec4fe6037a4942545;hpb=9d80930e950214d026afd3a3d18cda32629efdb9;p=oota-llvm.git

diff --git a/lib/VMCore/BasicBlock.cpp b/lib/VMCore/BasicBlock.cpp
index 98d12d8f138..17469d6bdb2 100644
--- a/lib/VMCore/BasicBlock.cpp
+++ b/lib/VMCore/BasicBlock.cpp
@@ -2,8 +2,8 @@
 //
 //                     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.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -17,24 +17,38 @@
 #include "llvm/Type.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/LeakDetector.h"
+#include "llvm/Support/Compiler.h"
 #include "SymbolTableListTraitsImpl.h"
 #include <algorithm>
 using namespace llvm;
 
+inline ValueSymbolTable *
+ilist_traits<Instruction>::getSymTab(BasicBlock *BB) {
+  if (BB)
+    if (Function *F = BB->getParent())
+      return &F->getValueSymbolTable();
+  return 0;
+}
+
+
 namespace {
   /// DummyInst - An instance of this class is used to mark the end of the
   /// instruction list.  This is not a real instruction.
-  struct DummyInst : public Instruction {
+  struct VISIBILITY_HIDDEN DummyInst : public Instruction {
+    // allocate space for exactly zero operands
+    void *operator new(size_t s) {
+      return User::operator new(s, 0);
+    }
     DummyInst() : Instruction(Type::VoidTy, OtherOpsEnd, 0, 0) {
       // This should not be garbage monitored.
       LeakDetector::removeGarbageObject(this);
     }
 
-    virtual Instruction *clone() const {
+    Instruction *clone() const {
       assert(0 && "Cannot clone EOL");abort();
       return 0;
     }
-    virtual const char *getOpcodeName() const { return "*end-of-list-inst*"; }
+    const char *getOpcodeName() const { return "*end-of-list-inst*"; }
 
     // Methods for support type inquiry through isa, cast, and dyn_cast...
     static inline bool classof(const DummyInst *) { return true; }
@@ -56,25 +70,25 @@ iplist<Instruction> &ilist_traits<Instruction>::getList(BasicBlock *BB) {
 
 // Explicit instantiation of SymbolTableListTraits since some of the methods
 // are not in the public header file...
-template class SymbolTableListTraits<Instruction, BasicBlock, Function>;
+template class SymbolTableListTraits<Instruction, BasicBlock>;
 
 
-BasicBlock::BasicBlock(const std::string &Name, Function *Parent,
+BasicBlock::BasicBlock(const std::string &Name, Function *NewParent,
                        BasicBlock *InsertBefore)
-  : Value(Type::LabelTy, Value::BasicBlockVal, Name) {
-  // Initialize the instlist...
-  InstList.setItemParent(this);
+  : Value(Type::LabelTy, Value::BasicBlockVal), Parent(0) {
 
   // Make sure that we get added to a function
   LeakDetector::addGarbageObject(this);
 
   if (InsertBefore) {
-    assert(Parent &&
+    assert(NewParent &&
            "Cannot insert block before another block with no function!");
-    Parent->getBasicBlockList().insert(InsertBefore, this);
-  } else if (Parent) {
-    Parent->getBasicBlockList().push_back(this);
+    NewParent->getBasicBlockList().insert(InsertBefore, this);
+  } else if (NewParent) {
+    NewParent->getBasicBlockList().push_back(this);
   }
+  
+  setName(Name);
 }
 
 
@@ -88,7 +102,8 @@ void BasicBlock::setParent(Function *parent) {
   if (getParent())
     LeakDetector::addGarbageObject(this);
 
-  InstList.setParent(parent);
+  // Set Parent=parent, updating instruction symtab entries as appropriate.
+  InstList.setSymTabObject(&Parent, parent);
 
   if (getParent())
     LeakDetector::removeGarbageObject(this);
@@ -102,17 +117,43 @@ void BasicBlock::eraseFromParent() {
   getParent()->getBasicBlockList().erase(this);
 }
 
+/// moveBefore - Unlink this basic block from its current function and
+/// insert it into the function that MovePos lives in, right before MovePos.
+void BasicBlock::moveBefore(BasicBlock *MovePos) {
+  MovePos->getParent()->getBasicBlockList().splice(MovePos,
+                       getParent()->getBasicBlockList(), this);
+}
+
+/// moveAfter - Unlink this basic block from its current function and
+/// insert it into the function that MovePos lives in, right after MovePos.
+void BasicBlock::moveAfter(BasicBlock *MovePos) {
+  Function::iterator I = MovePos;
+  MovePos->getParent()->getBasicBlockList().splice(++I,
+                                       getParent()->getBasicBlockList(), this);
+}
+
 
 TerminatorInst *BasicBlock::getTerminator() {
   if (InstList.empty()) return 0;
   return dyn_cast<TerminatorInst>(&InstList.back());
 }
 
-const TerminatorInst *const BasicBlock::getTerminator() const {
+const TerminatorInst *BasicBlock::getTerminator() const {
   if (InstList.empty()) return 0;
   return dyn_cast<TerminatorInst>(&InstList.back());
 }
 
+Instruction* BasicBlock::getFirstNonPHI()
+{
+    BasicBlock::iterator i = begin();
+    // All valid basic blocks should have a terminator,
+    // which is not a PHINode. If we have invalid basic
+    // block we'll get assert when dereferencing past-the-end
+    // iterator.
+    while (isa<PHINode>(i)) ++i;
+    return &*i;
+}
+
 void BasicBlock::dropAllReferences() {
   for(iterator I = begin(), E = end(); I != E; ++I)
     I->dropAllReferences();
@@ -189,8 +230,17 @@ void BasicBlock::removePredecessor(BasicBlock *Pred,
     // Okay, now we know that we need to remove predecessor #pred_idx from all
     // PHI nodes.  Iterate over each PHI node fixing them up
     PHINode *PN;
-    for (iterator II = begin(); (PN = dyn_cast<PHINode>(II)); ++II)
+    for (iterator II = begin(); (PN = dyn_cast<PHINode>(II)); ) {
+      ++II;
       PN->removeIncomingValue(Pred, false);
+      // If all incoming values to the Phi are the same, we can replace the Phi
+      // with that value.
+      Value* PNV = 0;
+      if (!DontDeleteUselessPHIs && (PNV = PN->hasConstantValue())) {
+        PN->replaceAllUsesWith(PNV);
+        PN->eraseFromParent();
+      }
+    }
   }
 }
 
@@ -211,14 +261,14 @@ BasicBlock *BasicBlock::splitBasicBlock(iterator I, const std::string &BBName) {
   assert(I != InstList.end() &&
          "Trying to get me to create degenerate basic block!");
 
-  BasicBlock *New = new BasicBlock(BBName, getParent(), getNext());
+  BasicBlock *New = BasicBlock::Create(BBName, getParent(), getNext());
 
   // Move all of the specified instructions from the original basic block into
   // the new basic block.
   New->getInstList().splice(New->end(), this->getInstList(), I, end());
 
   // Add a branch instruction to the newly formed basic block.
-  new BranchInst(New, this);
+  BranchInst::Create(New, this);
 
   // Now we must loop through all of the successors of the New block (which
   // _were_ the successors of the 'this' block), and update any PHI nodes in