Commit Graph

13 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
Johannes Doerfert ca1e38fa43 Propagate exit conditions as described in the PET paper
At some point we build loop trip counts using this method. It was replaced by
  a simpler trick that works only for affine (e.g., not modulo) constraints and
  relies on the removal of unbounded parts. In order to allow modulo constrains
  again we go back to the former, more accurate method.

llvm-svn: 247540
2015-09-14 11:12:52 +00:00
Johannes Doerfert 5b9ff8b667 Replace ScalarEvolution based domain generation
This patch replaces the last legacy part of the domain generation, namely the
ScalarEvolution part that was used to obtain loop bounds. We now iterate over
the loops in the region and propagate the back edge condition to the header
blocks. Afterwards we propagate the new information once through the whole
region. In this process we simply ignore unbounded parts of the domain and
thereby assume the absence of infinite loops.

  + This patch already identified a couple of broken unit tests we had for
    years.
  + We allow more loops already and the step to multiple exit and multiple back
    edges is minimal.
  + It allows to model the overflow checks properly as we actually visit
    every block in the SCoP and know where which condition is evaluated.
  - It is currently not compatible with modulo constraints in the
    domain.

Differential Revision: http://reviews.llvm.org/D12499

llvm-svn: 247279
2015-09-10 13:00:06 +00:00
Tobias Grosser a89dc57b41 Do not use '.' in subfunction names
Certain backends, e.g. NVPTX, do not support '.' in function names. Hence,
we ensure all '.' are replaced by '_' when generating function names for
subfunctions. For the current OpenMP code generation, this is not strictly
necessary, but future uses cases (e.g. GPU offloading) need this issue to be
fixed.

llvm-svn: 246980
2015-09-08 06:22:17 +00:00
Sunil Srivastava 19be68f088 Changed renaming of local symbols by inserting a dot before the numeric suffix.
Modified two test cases to adjust to the above change in renaming.
These two files were causing the buildbot failure in Polly, #30204 for example.
Details in http://reviews.llvm.org/D9483
This checkin goes with r237150 and r237151

llvm-svn: 237203
2015-05-12 22:44:24 +00:00
Tobias Grosser 09d3069740 Rename IslCodeGeneration to CodeGeneration
Besides class, function and file names, we also change the command line option
from -polly-codegen-isl to just -polly-codegen. The isl postfix is a leftover
from the times when we still had the CLooG based -polly-codegen. Today it is
just redundant and we drop it.

llvm-svn: 237099
2015-05-12 07:45:52 +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 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
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 683b8e4462 Remove -polly-codegen-scev option and related code
SCEV based code generation has been the default for two weeks after having
been tested for a long time. We now drop the support the non-scev-based code
generation.

llvm-svn: 222978
2014-11-30 14:33:31 +00:00
Tobias Grosser bf34f1d2b2 Introduce minimalistic cost model for auto parallelization
Instead of parallelizing every parallel outermost loop, we now use a very
minimalistic cost model. Specifically, we assume innermost loops are not
worth parallelising and all non-innermost loops are.

When parallelizing all loops in LNT we got several slowdowns/timeouts due to
us parallelizing innermost loops that are executed only a couple of times
(number of iterations not known statically). With this basic heuristic enabled
LNT does not show any more timeouts, while several interesting loops are still
parallelized.

There are many ways to obtain an improved heuristic. Constructing such an
improvide heuristic from a position of minimal slow-down and zero code size
increase seems to be the best, as it allows us to track progress on LNT.

llvm-svn: 222096
2014-11-16 14:24:53 +00:00
Tobias Grosser e3c0558e35 Add OpenMP code generation to isl backend
This backend supports besides the classical code generation the upcoming SCEV
based code generation (which the existing CLooG backend does not support
robustly).

OpenMP code generation in the isl backend benefits from our run-time alias
checks such that the set of loops that can possibly be parallelized is a lot
larger.

The code was tested on LNT. We do not regress on builds without -polly-parallel.
When using -polly-parallel most tests work flawlessly, but a few issues still
remain and will be addressed in follow up commits.

SCEV/non-SCEV codegen:
  - Compile time failure in ldecod and TimberWolfMC due a problem in our
    run-time alias check generation triggered by pointers that escape through
    the OpenMP subfunction (OpenMP specific).

  - Several execution time failures. Due to the larger set of loops that we now
    parallelize (compared to the classical code generation),  we currently run
    into some timeouts in tests with a lot loops that have a low trip count and
    are slowed down by parallelizing them.

SCEV only:

  - One existing failure in lencod due to llvm.org/PR21204 (not OpenMP specific)

OpenMP code generation is the last feature that was only available in the CLooG
backend. With the isl backend being the only one supporting features such as
run-time alias checks and delinearization, we will soon switch to use the isl
ast generator by the default and subsequently remove our dependency on CLooG.

http://reviews.llvm.org/D5517

llvm-svn: 222088
2014-11-15 21:32:53 +00:00