[polly] r271705 - [FIX] Fix potential issue related to subtraction from an unsigned 0 in circularShiftOutputDims

[Roman Gareev via llvm-commits]

Author: romangareev
Date: Fri Jun  3 13:46:29 2016
New Revision: 271705

URL: http://llvm.org/viewvc/llvm-project?rev=271705&view=rev
Log:
[FIX] Fix potential issue related to subtraction from an unsigned 0 in circularShiftOutputDims

Reported-by: Mehdi Amini <mehdi.amini at apple.com>
Contributed-by: Michael Kruse <llvm at meinersbur.de>

Differential Revision: http://reviews.llvm.org/D20969

Modified:
    polly/trunk/lib/Transform/ScheduleOptimizer.cpp

Modified: polly/trunk/lib/Transform/ScheduleOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/Transform/ScheduleOptimizer.cpp?rev=271705&r1=271704&r2=271705&view=diff
==============================================================================
--- polly/trunk/lib/Transform/ScheduleOptimizer.cpp (original)
+++ polly/trunk/lib/Transform/ScheduleOptimizer.cpp Fri Jun  3 13:46:29 2016
@@ -463,8 +463,10 @@ static bool containsMatrMult(__isl_keep
 ///
 /// @param IslMap The isl map to be modified.
 static __isl_give isl_map *circularShiftOutputDims(__isl_take isl_map *IslMap) {
-  auto InputDimsId = isl_map_get_tuple_id(IslMap, isl_dim_in);
   auto DimNum = isl_map_dim(IslMap, isl_dim_out);
+  if (DimNum == 0)
+    return IslMap;
+  auto InputDimsId = isl_map_get_tuple_id(IslMap, isl_dim_in);
   IslMap = isl_map_move_dims(IslMap, isl_dim_in, 0, isl_dim_out, DimNum - 1, 1);
   IslMap = isl_map_move_dims(IslMap, isl_dim_out, 0, isl_dim_in, 0, 1);
   return isl_map_set_tuple_id(IslMap, isl_dim_in, InputDimsId);