Avoid creating a redundant zero APInt.

[oota-llvm.git] / include / llvm / Analysis / SparsePropagation.h

diff --git a/include/llvm/Analysis/SparsePropagation.h b/include/llvm/Analysis/SparsePropagation.h
index cad18d79bf778d2bf4ad0aa03246a026b586a499..bc9ae6172b80e02b7a48e45152dfe2157be683b4 100644 (file)
--- a/include/llvm/Analysis/SparsePropagation.h
+++ b/include/llvm/Analysis/SparsePropagation.h
@@ -32,7 +32,7 @@ namespace llvm {
   class SparseSolver;
   
 /// AbstractLatticeFunction - This class is implemented by the dataflow instance
-/// to specify what the lattice values are and what how they handle merges etc.
+/// to specify what the lattice values are and how they handle merges etc.
 /// This gives the client the power to compute lattice values from instructions,
 /// constants, etc.  The requirement is that lattice values must all fit into
 /// a void*.  If a void* is not sufficient, the implementation should use this
@@ -119,7 +119,8 @@ class SparseSolver {
   SparseSolver(const SparseSolver&);    // DO NOT IMPLEMENT
   void operator=(const SparseSolver&);  // DO NOT IMPLEMENT
 public:
-  SparseSolver(AbstractLatticeFunction *Lattice) : LatticeFunc(Lattice) {}
+  explicit SparseSolver(AbstractLatticeFunction *Lattice)
+    : LatticeFunc(Lattice) {}
   ~SparseSolver() {
     delete LatticeFunc;
   }
@@ -146,6 +147,14 @@ public:
   ///
   LatticeVal getOrInitValueState(Value *V);
   
+  /// isEdgeFeasible - Return true if the control flow edge from the 'From'
+  /// basic block to the 'To' basic block is currently feasible.  If
+  /// AggressiveUndef is true, then this treats values with unknown lattice
+  /// values as undefined.  This is generally only useful when solving the
+  /// lattice, not when querying it.
+  bool isEdgeFeasible(BasicBlock *From, BasicBlock *To,
+                      bool AggressiveUndef = false);
+  
 private:
   /// UpdateState - When the state for some instruction is potentially updated,
   /// this function notices and adds I to the worklist if needed.
@@ -161,11 +170,8 @@ private:
   
   /// getFeasibleSuccessors - Return a vector of booleans to indicate which
   /// successors are reachable from a given terminator instruction.
-  void getFeasibleSuccessors(TerminatorInst &TI, SmallVectorImpl<bool> &Succs);
-  
-  /// isEdgeFeasible - Return true if the control flow edge from the 'From'
-  /// basic block to the 'To' basic block is currently feasible...
-  bool isEdgeFeasible(BasicBlock *From, BasicBlock *To);
+  void getFeasibleSuccessors(TerminatorInst &TI, SmallVectorImpl<bool> &Succs,
+                             bool AggressiveUndef);
   
   void visitInst(Instruction &I);
   void visitPHINode(PHINode &I);