Add -polly-flatten-schedule pass.

The -polly-flatten-schedule pass reduces the number of scattering
dimensions in its isl_union_map form to make them easier to understand.
It is not meant to be used in production, only for debugging and
regression tests.

To illustrate, how it can make sets simpler, here is a lifetime set
used computed by the porposed DeLICM pass without flattening:

    { Stmt_reduction_for[0, 4] -> [0, 2, o2, o3] : o2 < 0;
      Stmt_reduction_for[0, 4] -> [0, 1, o2, o3] : o2 >= 5;
      Stmt_reduction_for[0, 4] -> [0, 1, 4, o3] : o3 > 0;
      Stmt_reduction_for[0, i1] -> [0, 1, i1, 1] : 0 <= i1 <= 3;
      Stmt_reduction_for[0, 4] -> [0, 2, 0, o3] : o3 <= 0 }

And here the same lifetime for a semantically identical one-dimensional
schedule:

    { Stmt_reduction_for[0, i1] -> [2 + 3i1] : 0 <= i1 <= 4 }

Differential Revision: https://reviews.llvm.org/D24310

llvm-svn: 280948

1 files changed, 12 insertions, 0 deletions

diff --git a/polly/test/update_check.py b/polly/test/update_check.py
index 69aa06c0df9..318fcfe53c9 100644
--- a/polly/test/update_check.py
+++ b/polly/test/update_check.py
@@ -170,6 +170,18 @@ def classyfier1(lines):
             continue
         elif line.startswith("New access function '"):
             yield {'NewAccessFunction'}
+        elif line == 'Schedule before flattening {':
+            while True:
+                yield  {'ScheduleBeforeFlattening'}
+                if line == '}':
+                    break
+                line = i.__next__()
+        elif line == 'Schedule after flattening {':
+            while True:
+                yield  {'ScheduleAfterFlattening'}
+                if line == '}':
+                    break
+                line = i.__next__()
         else:
             yield set()
         line = i.__next__()