[llvm-commits] [llvm] r109412 - /llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp

[Dan Gohman]

Author: djg
Date: Mon Jul 26 13:02:06 2010
New Revision: 109412

URL: http://llvm.org/viewvc/llvm-project?rev=109412&view=rev
Log:
Preserve ScalarEvolution in the loop unroller.

Modified:
    llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp

Modified: llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp?rev=109412&r1=109411&r2=109412&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp Mon Jul 26 13:02:06 2010
@@ -24,6 +24,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/ConstantFolding.h"
 #include "llvm/Analysis/LoopPass.h"
+#include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils/BasicBlockUtils.h"
@@ -127,6 +128,11 @@
     return false;
   }
 
+  // Notify ScalarEvolution that the loop will be substantially changed,
+  // if not outright eliminated.
+  if (ScalarEvolution *SE = LPM->getAnalysisIfAvailable<ScalarEvolution>())
+    SE->forgetLoop(L);
+
   // Find trip count
   unsigned TripCount = L->getSmallConstantTripCount();
   // Find trip multiple if count is not available