Update isl to isl-0.17.1-57-g1879898

With this update the isl AST generation extracts disjunctive constraints early
on. As a result, code that previously resulted in two branches with (close-to)
identical code within them:

  if (P <= -1) {
    for (int c0 = 0; c0 < N; c0 += 1)
      Stmt_store(c0);
  } else if (P >= 1)
    for (int c0 = 0; c0 < N; c0 += 1)
       Stmt_store(c0);

results now in only a single branch body:

  if (P <= -1 || P >= 1)
    for (int c0 = 0; c0 < N; c0 += 1)
       Stmt_store(c0);

This resolves http://llvm.org/PR27559

Besides the above change, this isl update brings better simplification of
sets/maps containing existentially quantified dimensions and fixes a bug in
isl's coalescing.

llvm-svn: 272500

1 files changed, 2 insertions, 1 deletions

diff --git a/polly/lib/External/isl/test_inputs/codegen/cloog/walters.c b/polly/lib/External/isl/test_inputs/codegen/cloog/walters.c
index 2c1bd93858b..f65491528c6 100644
--- a/polly/lib/External/isl/test_inputs/codegen/cloog/walters.c
+++ b/polly/lib/External/isl/test_inputs/codegen/cloog/walters.c
@@ -8,8 +8,9 @@
       S1(c0, c0 / 3, c0 / 3, c0 / 3);
     } else if ((c0 - 1) % 3 == 0) {
       S2(c0, (c0 - 1) / 3, (c0 + 2) / 3, (c0 - 1) / 3);
-    } else
+    } else {
       S3(c0, (c0 - 2) / 3, (c0 + 1) / 3, (c0 + 1) / 3);
+    }
     S4(c0, c0 / 3, (c0 - 1) / 3 + 1, c0 - (c0 - 1) / 3 - c0 / 3 - 1);
   }
 }