Add dump() routines to help debug debug info :)

[oota-llvm.git] / lib / VMCore / BasicBlock.cpp

diff --git a/lib/VMCore/BasicBlock.cpp b/lib/VMCore/BasicBlock.cpp
index 431bb5090a764870d1f8179ef97667c2b3f75747..a76f659233d4270f4ed29e1db56a292f1fa8c56c 100644 (file)
--- 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.
 //
 //===----------------------------------------------------------------------===//
 //
@@ -15,6 +15,7 @@
 #include "llvm/Constants.h"
 #include "llvm/Instructions.h"
 #include "llvm/Type.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/CFG.h"
 #include "llvm/Support/LeakDetector.h"
 #include "llvm/Support/Compiler.h"
@@ -35,16 +36,20 @@ namespace {
   /// DummyInst - An instance of this class is used to mark the end of the
   /// instruction list.  This is not a real 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; }
@@ -134,20 +139,19 @@ TerminatorInst *BasicBlock::getTerminator() {
   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;
+Instruction* BasicBlock::getFirstNonPHI() {
+  BasicBlock::iterator i = begin();
+  // All valid basic blocks should have a terminator,
+  // which is not a PHINode. If we have an invalid basic
+  // block we'll get an assertion failure when dereferencing
+  // a past-the-end iterator.
+  while (isa<PHINode>(i)) ++i;
+  return &*i;
 }
 
 void BasicBlock::dropAllReferences() {
@@ -165,6 +169,25 @@ BasicBlock *BasicBlock::getSinglePredecessor() {
   return (PI == E) ? ThePred : 0 /*multiple preds*/;
 }
 
+/// getUniquePredecessor - If this basic block has a unique predecessor block,
+/// return the block, otherwise return a null pointer.
+/// Note that unique predecessor doesn't mean single edge, there can be 
+/// multiple edges from the unique predecessor to this block (for example 
+/// a switch statement with multiple cases having the same destination).
+BasicBlock *BasicBlock::getUniquePredecessor() {
+  pred_iterator PI = pred_begin(this), E = pred_end(this);
+  if (PI == E) return 0; // No preds.
+  BasicBlock *PredBB = *PI;
+  ++PI;
+  for (;PI != E; ++PI) {
+    if (*PI != PredBB)
+      return 0;
+    // The same predecessor appears multiple times in the predecessor list.
+    // This is OK.
+  }
+  return PredBB;
+}
+
 /// removePredecessor - This method is used to notify a BasicBlock that the
 /// specified Predecessor of the block is no longer able to reach it.  This is
 /// actually not used to update the Predecessor list, but is actually used to
@@ -257,14 +280,16 @@ 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 *InsertBefore = next(Function::iterator(this))
+                               .getNodePtrUnchecked();
+  BasicBlock *New = BasicBlock::Create(BBName, getParent(), InsertBefore);
 
   // 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