[SCEV] Change the SCEV Predicates interfaces for conversion to AddRecExpr to return SCEVAddRecExpr* instead of SCEV*

Summary:
This changes the conversion functions from SCEV * to SCEVAddRecExpr from
ScalarEvolution and PredicatedScalarEvolution to return a SCEVAddRecExpr*
instead of a SCEV* (which removes the need of most clients to do a
dyn_cast right after calling these functions).

We also don't add new predicates if the transformation was not successful.

This is not entirely a NFC (as it can theoretically remove some predicates
from LAA when we have an unknown dependece), but I couldn't find an obvious
regression test for it.

Reviewers: sanjoy

Subscribers: sanjoy, mzolotukhin, llvm-commits

Differential Revision: http://reviews.llvm.org/D18368

llvm-svn: 264161

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Analysis/LoopAccessAnalysis.cpp b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
index 159d6ae64a0..04a4b1fa5a3 100644
--- a/llvm/lib/Analysis/LoopAccessAnalysis.cpp
+++ b/llvm/lib/Analysis/LoopAccessAnalysis.cpp
@@ -837,7 +837,7 @@ int llvm::isStridedPtr(PredicatedScalarEvolution &PSE, Value *Ptr,
 
   const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PtrScev);
   if (Assume && !AR)
-    AR = dyn_cast<SCEVAddRecExpr>(PSE.getAsAddRec(Ptr));
+    AR = PSE.getAsAddRec(Ptr);
 
   if (!AR) {
     DEBUG(dbgs() << "LAA: Bad stride - Not an AddRecExpr pointer " << *Ptr