Commit Graph

17 Commits

Author SHA1 Message Date
Tobias Grosser f4ee371e60 tests: Drop -polly-detect-unprofitable and -polly-no-early-exit
These flags are now always passed to all tests and need to be disabled if
not needed. Disabling these flags, rather than passing them to almost all
tests, significantly simplfies our RUN: lines.

llvm-svn: 249422
2015-10-06 15:36:44 +00:00
Tobias Grosser 808cd69a92 Use schedule trees to represent execution order of statements
Instead of flat schedules, we now use so-called schedule trees to represent the
execution order of the statements in a SCoP. Schedule trees make it a lot easier
to analyze, understand and modify properties of a schedule, as specific nodes
in the tree can be choosen and possibly replaced.

This patch does not yet fully move our DependenceInfo pass to schedule trees,
as some additional performance analysis is needed here. (In general schedule
trees should be faster in compile-time, as the more structured representation
is generally easier to analyze and work with). We also can not yet perform the
reduction analysis on schedule trees.

For more information regarding schedule trees, please see Section 6 of
https://lirias.kuleuven.be/handle/123456789/497238

llvm-svn: 242130
2015-07-14 09:33:13 +00:00
Tobias Grosser a608569856 Replace srem by function call in nonaffine test cases
This makes the test cases nonaffine even if Polly some days gains support for
the srem instruction, an instruction which is currently not modeled but which
can clearly be modeled statically. A call to a function without definition
will always remain non-affine, as there is just insufficient static information
for it to be modeled more precisely.

llvm-svn: 240458
2015-06-23 20:55:05 +00:00
Tobias Grosser 173ecab705 Remove target triples from test cases
I just learned that target triples prevent test cases to be run on other
architectures. Polly test cases are until now sufficiently target independent
to not require any target triples. Hence, we drop them.

llvm-svn: 235384
2015-04-21 14:28:02 +00:00
David Blaikie c94eca0546 Update Polly tests to handle explicitly typed load changes in LLVM.
llvm-svn: 230796
2015-02-27 21:22:50 +00:00
David Blaikie bad3ff207f Update Polly tests to handle explicitly typed gep changes in LLVM
llvm-svn: 230784
2015-02-27 19:20:19 +00:00
Tobias Grosser d1e33e7061 ScopDetection: Only detect scops that have at least one read and one write
Scops that only read seem generally uninteresting and scops that only write are
most likely initializations where there is also little to optimize.  To not
waste compile time we bail early.

Differential Revision: http://reviews.llvm.org/D7735

llvm-svn: 229820
2015-02-19 05:31:07 +00:00
Johannes Doerfert 7ceb040213 Add early exits for SCoPs we did not optimize
This allows us to skip ast and code generation if we did not optimize
  a SCoP and will not generate parallel or alias annotations. The
  initial heuristic to exit is simple but allows improvements later on.

  All failing test cases have been modified to disable early exit, thus
  to keep their coverage.

  Differential Revision: http://reviews.llvm.org/D7254

llvm-svn: 228851
2015-02-11 17:25:09 +00:00
Tobias Grosser 3f29619614 Drop all constant scheduling dimensions
Schedule dimensions that have the same constant value accross all statements do
not carry any information, but due to the increased dimensionality of the
schedule cost compile time. To not pay this cost, we remove constant dimensions
if possible.

llvm-svn: 225067
2015-01-01 23:01:11 +00:00
Tobias Grosser f4daf34496 Revert "Added support for modulo expressions"
This reverts commit 215684. The intention of the commit is great, but
unfortunately it seems to be the cause of 14 LNT test suite failures:

http://lab.llvm.org:8011/builders/perf-x86_64-penryn-O3-polly/builds/116

To make our buildbots and performance testers green until this issue is solved,
we temporarily revert this commit.

llvm-svn: 215816
2014-08-16 09:08:55 +00:00
Johannes Doerfert 5130c849aa Added support for modulo expressions
The support is limited to signed modulo access and condition
  expressions with a constant right hand side, e.g., A[i % 2] or
  A[i % 9]. Test cases are modified according to this new feature and
  new test cases are added.

Differential Revision: http://reviews.llvm.org/D4843

llvm-svn: 215684
2014-08-15 01:14:11 +00:00
Tobias Grosser c2920ff747 DeadCodeElimination: Fix liveout computation
We move back to a simple approach where the liveout is the last must-write
statement for a data-location plus all may-write statements. The previous
approach did not work out. We would have to consider per-data-access
dependences, instead of per-statement dependences to correct it. As this adds
complexity and it seems we would not gain anything over the simpler approach
that we implement in this commit, I moved us back to the old approach of
computing the liveout, but enhanced it to also add may-write accesses.

We also fix the test case and explain why we can not perform dead code
elimination in this case.

llvm-svn: 212925
2014-07-14 08:32:01 +00:00
Tobias Grosser 780ce0f8e3 DeadCodeElim: Compute correct liveout for non-affine accesses
Thanks to Johannes Doerfert for narrowing down the bug.

Reported-by: Chris Jenneisch <chrisj@codeaurora.org>
llvm-svn: 212796
2014-07-11 07:12:10 +00:00
Tobias Grosser 356faa8f09 Dead code elimination: Schedule another approximative step before actual DCE
In 'obsequi' we have a scop in which the current dead code elimination works,
but the generated code is way too complex. To avoid this trouble (and to not
disable the DCE entirely) we add an additional approximative step before
the actual dead code elimination. This should fix one of the two current
nightly-test issues.

Polly could be improved to handle 'obsequi' by teaching it to introduce only a
single parameter for (%1 and zext %1) which halves the number of parameters and
allows polly to derive a simpler representation for the set of live iterations.
However, this needs some time to investigate.

I will commit a test case as soon as we have a reduced one.

llvm-svn: 202010
2014-02-24 08:52:20 +00:00
Tobias Grosser 38c36ea18e Do not fail in case we do not have valid dependences
In case we do not have valid dependences, we do not run dead code elimination or
the schedule optimizer. This fixes an infinite loop in the dead code
elimination (PR12110).

llvm-svn: 201982
2014-02-23 15:15:44 +00:00
Tobias Grosser 817d51dd1b DCE: Switch to hybrid precise-unprecise analysis
Instead of giving a choice between a precise (but possibly very complex)
analysis and an approximative analysis we now use a hybrid approach which uses N
precise steps followed by one approximating step. The precision of the analysis
can be changed by increasing N. With a default of 'N' = 2, we get fully precise
results for our current test cases and should not run into performance problems
for more complex test cases. We can adjust this value when we got more
experience with this dead code elimination.

llvm-svn: 201888
2014-02-21 20:51:46 +00:00
Tobias Grosser 37eb422f69 Add polyhedral dead code elimination.
This pass eliminates loop iterations that compute results that are not used
later on. This can help e.g. in D, where the default zero-initialization is
often unnecessary if right after new values are assigned to an array.

Contributed-by: Peter Conn <conn.peter@gmail.com>
llvm-svn: 201817
2014-02-20 21:43:54 +00:00