[llvm-commits] [polly] r144281 - /polly/trunk/lib/RegisterPasses.cpp

[Tobias Grosser]

Author: grosser
Date: Thu Nov 10 06:45:07 2011
New Revision: 144281

URL: http://llvm.org/viewvc/llvm-project?rev=144281&view=rev
Log:
Add a workaround to fix SCoPs rejected because of 'region not simple'

Modified:
    polly/trunk/lib/RegisterPasses.cpp

Modified: polly/trunk/lib/RegisterPasses.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/RegisterPasses.cpp?rev=144281&r1=144280&r2=144281&view=diff
==============================================================================
--- polly/trunk/lib/RegisterPasses.cpp (original)
+++ polly/trunk/lib/RegisterPasses.cpp Thu Nov 10 06:45:07 2011
@@ -114,10 +114,19 @@
 
   PM.add(polly::createCodePreparationPass());
   PM.add(polly::createRegionSimplifyPass());
-  // FIXME: Needed as RegionSimplifyPass destroys the canonical form of
-  //        induction variables (It changes the order of the operands in the
-  //        PHI nodes).
+  // FIXME: The next two passes should not be necessary here. They are currently
+  //        because of two problems:
+  //
+  //        1. The RegionSimplifyPass destroys the canonical form of induction
+  //           variables,as it produces PHI nodes with incorrectly ordered
+  //           operands. To fix this we run IndVarSimplify.
+  //
+  //        2. IndVarSimplify does not preserve the region information and
+  //           the regioninfo pass does currently not recover simple regions.
+  //           As a result we need to run the RegionSimplify pass again to
+  //           recover them
   PM.add(llvm::createIndVarSimplifyPass());
+  PM.add(polly::createRegionSimplifyPass());
 
   if (PollyViewer)
     PM.add(polly::createDOTViewerPass());