Add a first attempt at dominator information for MBB's. Use with caution: this has been tested to compile. It has not yet been confirmed to generate correct analysis.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43438 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 170 insertions, 0 deletions

diff --git a/include/llvm/CodeGen/MachineDominators.h b/include/llvm/CodeGen/MachineDominators.h
new file mode 100644
index 0000000..621ba2f
--- /dev/null
+++ b/include/llvm/CodeGen/MachineDominators.h
@@ -0,0 +1,170 @@
+//=- llvm/CodeGen/MachineDominators.h - Machine Dom Calculation --*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Owen Anderson and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines classes mirroring those in llvm/Analysis/Dominators.h,
+// but for target-specific code rather than target-independent IR.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_MACHINEDOMINATORS_H
+#define LLVM_CODEGEN_MACHINEDOMINATORS_H
+
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/Analysis/Dominators.h"
+#include "llvm/Analysis/DominatorInternals.h"
+
+namespace llvm {
+
+void WriteAsOperand(std::ostream &, const MachineBasicBlock*, bool t) {  }
+
+//===-------------------------------------
+/// DominatorTree Class - Concrete subclass of DominatorTreeBase that is used to
+/// compute a normal dominator tree.
+///
+class MachineDominatorTree : public MachineFunctionPass {
+public:
+  static char ID; // Pass ID, replacement for typeid
+  DominatorTreeBase<MachineBasicBlock>* DT;
+  
+  MachineDominatorTree() : MachineFunctionPass(intptr_t(&ID)) {
+    DT = new DominatorTreeBase<MachineBasicBlock>(false);
+  }
+  
+  ~MachineDominatorTree() {
+    DT->releaseMemory();
+    delete DT;
+  }
+  
+  /// getRoots -  Return the root blocks of the current CFG.  This may include
+  /// multiple blocks if we are computing post dominators.  For forward
+  /// dominators, this will always be a single block (the entry node).
+  ///
+  inline const std::vector<MachineBasicBlock*> &getRoots() const {
+    return DT->getRoots();
+  }
+  
+  inline MachineBasicBlock *getRoot() const {
+    return DT->getRoot();
+  }
+  
+  inline MachineDomTreeNode *getRootNode() const {
+    return DT->getRootNode();
+  }
+  
+  virtual bool runOnFunction(Function &F);
+  
+  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+    AU.setPreservesAll();
+  }
+  
+  inline bool dominates(MachineDomTreeNode* A, MachineDomTreeNode* B) const {
+    return DT->dominates(A, B);
+  }
+  
+  inline bool dominates(MachineBasicBlock* A, MachineBasicBlock* B) const {
+    return DT->dominates(A, B);
+  }
+  
+  // dominates - Return true if A dominates B. This performs the
+  // special checks necessary if A and B are in the same basic block.
+  bool dominates(MachineInstr *A, MachineInstr *B) const {
+    MachineBasicBlock *BBA = A->getParent(), *BBB = B->getParent();
+    if (BBA != BBB) return DT->dominates(BBA, BBB);
+
+    // Loop through the basic block until we find A or B.
+    MachineBasicBlock::iterator I = BBA->begin();
+    for (; &*I != A && &*I != B; ++I) /*empty*/;
+
+    //if(!DT.IsPostDominators) {
+      // A dominates B if it is found first in the basic block.
+      return &*I == A;
+    //} else {
+    //  // A post-dominates B if B is found first in the basic block.
+    //  return &*I == B;
+    //}
+  }
+  
+  inline bool properlyDominates(const MachineDomTreeNode* A,
+                                MachineDomTreeNode* B) const {
+    return DT->properlyDominates(A, B);
+  }
+  
+  inline bool properlyDominates(MachineBasicBlock* A,
+                                MachineBasicBlock* B) const {
+    return DT->properlyDominates(A, B);
+  }
+  
+  /// findNearestCommonDominator - Find nearest common dominator basic block
+  /// for basic block A and B. If there is no such block then return NULL.
+  inline MachineBasicBlock *findNearestCommonDominator(MachineBasicBlock *A,
+                                                       MachineBasicBlock *B) {
+    return DT->findNearestCommonDominator(A, B);
+  }
+  
+  inline MachineDomTreeNode *operator[](MachineBasicBlock *BB) const {
+    return DT->getNode(BB);
+  }
+  
+  /// getNode - return the (Post)DominatorTree node for the specified basic
+  /// block.  This is the same as using operator[] on this class.
+  ///
+  inline MachineDomTreeNode *getNode(MachineBasicBlock *BB) const {
+    return DT->getNode(BB);
+  }
+  
+  /// addNewBlock - Add a new node to the dominator tree information.  This
+  /// creates a new node as a child of DomBB dominator node,linking it into 
+  /// the children list of the immediate dominator.
+  inline MachineDomTreeNode *addNewBlock(MachineBasicBlock *BB,
+                                         MachineBasicBlock *DomBB) {
+    return DT->addNewBlock(BB, DomBB);
+  }
+  
+  /// changeImmediateDominator - This method is used to update the dominator
+  /// tree information when a node's immediate dominator changes.
+  ///
+  inline void changeImmediateDominator(MachineBasicBlock *N,
+                                       MachineBasicBlock* NewIDom) {
+    DT->changeImmediateDominator(N, NewIDom);
+  }
+  
+  inline void changeImmediateDominator(MachineDomTreeNode *N,
+                                       MachineDomTreeNode* NewIDom) {
+    DT->changeImmediateDominator(N, NewIDom);
+  }
+  
+  /// eraseNode - Removes a node from  the dominator tree. Block must not
+  /// domiante any other blocks. Removes node from its immediate dominator's
+  /// children list. Deletes dominator node associated with basic block BB.
+  inline void eraseNode(MachineBasicBlock *BB) {
+    DT->eraseNode(BB);
+  }
+  
+  /// splitBlock - BB is split and now it has one successor. Update dominator
+  /// tree to reflect this change.
+  inline void splitBlock(MachineBasicBlock* NewBB) {
+    DT->splitBlock(NewBB);
+  }
+  
+  
+  virtual void releaseMemory() { 
+    DT->releaseMemory();
+  }
+  
+  virtual void print(std::ostream &OS, const Module* M= 0) const {
+    DT->print(OS, M);
+  }
+};
+
+}
+
+#endif
\ No newline at end of file