- Teach LSR to avoid changing cmp iv stride if it will create an immediate that

  cannot be folded into target cmp instruction.
- Avoid a phase ordering issue where early cmp optimization would prevent the
  later count-to-zero optimization.
- Add missing checks which could cause LSR to reuse stride that does not have
  users.
- Fix a bug in count-to-zero optimization code which failed to find the pre-inc
  iv's phi node.
- Remove, tighten, loosen some incorrect checks disable valid transformations.
- Quite a bit of code clean up.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86969 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 0 deletions

diff --git a/include/llvm/Analysis/IVUsers.h b/include/llvm/Analysis/IVUsers.h
index 948c675..22fbb35 100644
--- a/include/llvm/Analysis/IVUsers.h
+++ b/include/llvm/Analysis/IVUsers.h
@@ -161,6 +161,10 @@ public:
   void addUser(const SCEV *Offset, Instruction *User, Value *Operand) {
     Users.push_back(new IVStrideUse(this, Offset, User, Operand));
   }
+
+  void removeUser(IVStrideUse *User) {
+    Users.erase(User);
+  }
 };
 
 class IVUsers : public LoopPass {
@@ -201,6 +205,9 @@ public:
   /// return true.  Otherwise, return false.
   bool AddUsersIfInteresting(Instruction *I);
 
+  void AddUser(const SCEV *Stride, const SCEV *Offset,
+               Instruction *User, Value *Operand);
+
   /// getReplacementExpr - Return a SCEV expression which computes the
   /// value of the OperandValToReplace of the given IVStrideUse.
   const SCEV *getReplacementExpr(const IVStrideUse &U) const;