Strengthen the "non-constant stride must dominate loop preheader" check.

llvm-svn: 64703

2 files changed, 26 insertions, 0 deletions

diff --git a/llvm/include/llvm/Analysis/ScalarEvolution.h b/llvm/include/llvm/Analysis/ScalarEvolution.h
index 0786b51f535..d94329d265b 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolution.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolution.h
@@ -89,6 +89,10 @@ namespace llvm {
                                       const SCEVHandle &Conc,
                                       ScalarEvolution &SE) const = 0;
 
+    /// dominates - Return true if elements that makes up this SCEV dominates
+    /// the specified basic block.
+    virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const = 0;
+
     /// print - Print out the internal representation of this scalar to the
     /// specified stream.  This should really only be used for debugging
     /// purposes.
@@ -124,6 +128,10 @@ namespace llvm {
                                       const SCEVHandle &Conc,
                                       ScalarEvolution &SE) const;
 
+    virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const {
+      return true;
+    }
+
     /// Methods for support type inquiry through isa, cast, and dyn_cast:
     static inline bool classof(const SCEVCouldNotCompute *S) { return true; }
     static bool classof(const SCEV *S);
diff --git a/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h b/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
index 652a99d0fca..61bb25a03b9 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -20,6 +20,7 @@ namespace llvm {
   class ConstantInt;
   class ConstantRange;
   class APInt;
+  class DominatorTree;
 
   enum SCEVTypes {
     // These should be ordered in terms of increasing complexity to make the
@@ -58,6 +59,10 @@ namespace llvm {
       return this;
     }
 
+    bool dominates(BasicBlock *BB, DominatorTree *DT) const {
+      return true;
+    }
+
     virtual void print(std::ostream &OS) const;
     void print(std::ostream *OS) const { if (OS) print(*OS); }
 
@@ -100,6 +105,8 @@ namespace llvm {
       return SE.getTruncateExpr(H, Ty);
     }
 
+    virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const;
+
     virtual void print(std::ostream &OS) const;
     void print(std::ostream *OS) const { if (OS) print(*OS); }
 
@@ -142,6 +149,8 @@ namespace llvm {
       return SE.getZeroExtendExpr(H, Ty);
     }
 
+    bool dominates(BasicBlock *BB, DominatorTree *DT) const;
+
     virtual void print(std::ostream &OS) const;
     void print(std::ostream *OS) const { if (OS) print(*OS); }
 
@@ -184,6 +193,8 @@ namespace llvm {
       return SE.getSignExtendExpr(H, Ty);
     }
 
+    bool dominates(BasicBlock *BB, DominatorTree *DT) const;
+
     virtual void print(std::ostream &OS) const;
     void print(std::ostream *OS) const { if (OS) print(*OS); }
 
@@ -250,6 +261,8 @@ namespace llvm {
                                                  const SCEVHandle &Conc,
                                                  ScalarEvolution &SE) const;
 
+    bool dominates(BasicBlock *BB, DominatorTree *DT) const;
+
     virtual const char *getOperationStr() const = 0;
 
     virtual const Type *getType() const { return getOperand(0)->getType(); }
@@ -343,6 +356,7 @@ namespace llvm {
         return SE.getUDivExpr(L, R);
     }
 
+    bool dominates(BasicBlock *BB, DominatorTree *DT) const;
 
     virtual const Type *getType() const;
 
@@ -437,6 +451,8 @@ namespace llvm {
                                                  const SCEVHandle &Conc,
                                                  ScalarEvolution &SE) const;
 
+    bool dominates(BasicBlock *BB, DominatorTree *DT) const;
+
     virtual void print(std::ostream &OS) const;
     void print(std::ostream *OS) const { if (OS) print(*OS); }
 
@@ -518,6 +534,8 @@ namespace llvm {
       return this;
     }
 
+    bool dominates(BasicBlock *BB, DominatorTree *DT) const;
+
     virtual const Type *getType() const;
 
     virtual void print(std::ostream &OS) const;