Commit Graph

15 Commits

Author SHA1 Message Date
Johannes Doerfert eca9e890b9 Remove read-only statements from the SCoP
We do not need to model read-only statements in the SCoP as they will
  not cause any side effects that are visible to the outside anyway.
  Removing them should safe us time and might even simplify the ASTs we
  generate.

Differential Revision: http://reviews.llvm.org/D14272

llvm-svn: 251948
2015-11-03 16:54:49 +00:00
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 b1c39429d9 Do not model delinearized and linearized access relation for a single access
A missing return statement that previously did not have a visibly negative
effect caused after some data-structure changes in r248024 multi-dimensional
accesses to be modeled both multi-dimensional as well as linearized. This
commit adds the missing return to avoid the incorrect double modeling as
well as the compile time increases it caused.

llvm-svn: 248171
2015-09-21 16:19:25 +00:00
Michael Kruse e2bccbbfb2 Merge IRAccess into MemoryAccess
All MemoryAccess objects will be owned by ScopInfo::AccFuncMap which 
previously stored the IRAccess objects. Instead of creating new 
MemoryAccess objects, the already created ones are reused, but their 
order might be different now. Some fields of IRAccess and MemoryAccess 
had the same meaning and are merged.

This is the last step of fusioning TempScopInfo.{h|cpp} and 
ScopInfo.{h.cpp}. Some refactoring might still make sense.

Differential Revision: http://reviews.llvm.org/D12843

llvm-svn: 248024
2015-09-18 19:59:43 +00:00
Tobias Grosser 5fd8c0961e Model fixed-size multi-dimensional arrays if possible multi-dimensional
If the GEP instructions give us enough insights, model scalar accesses as
multi-dimensional (and generate the relevant run-time checks to ensure
correctness). This will allow us to simplify the dependence computation in
a subsequent commit.

llvm-svn: 247906
2015-09-17 17:28:15 +00:00
Johannes Doerfert 883f8c1d2f Use modulo semantic to generate non-integer-overflow assumptions
This will allow to generate non-wrap assumptions for integer expressions
  that are part of the SCoP. We compare the common isl representation of
  the expression with one computed with modulo semantic. For all parameter
  combinations they are not equal we can have integer overflows.

  The nsw flags are respected when the modulo representation is computed,
  nuw and nw flags are ignored for now.

  In order to not increase compile time to much, the non-wrap assumptions
  are collected in a separate boundary context instead of the assumed
  context. This helps compile time as the boundary context can become
  complex and it is therefor not advised to use it in other operations
  except runtime check generation. However, the assumed context is e.g.,
  used to tighten dependences. While the boundary context might help to
  tighten the assumed context it is doubtful that it will help in practice
  (it does not effect lnt much) as the boundary (or no-wrap assumptions)
  only restrict the very end of the possible value range of parameters.

  PET uses a different approach to compute the no-wrap context, though lnt runs
  have shown that this version performs slightly better for us.

llvm-svn: 247732
2015-09-15 22:52:53 +00:00
Johannes Doerfert 96425c2574 Traverse the SCoP to compute non-loop-carried domain conditions
In order to compute domain conditions for conditionals we will now
  traverse the region in the ScopInfo once and build the domains for
  each block in the region. The SCoP statements can then use these
  constraints when they build their domain.

  The reason behind this change is twofold:
    1) This removes a big chunk of preprocessing logic from the
       TempScopInfo, namely the Conditionals we used to build there.
       Additionally to moving this logic it is also simplified. Instead
       of walking the dominance tree up for each basic block in the
       region (as we did before), we now traverse the region only
       once in order to collect the domain conditions.
    2) This is the first step towards the isl based domain creation.
       The second step will traverse the region similar to this step,
       however it will propagate back edge conditions. Once both are in
       place this conditional handling will allow multiple exit loops
       additional logic.

Reviewers: grosser

Differential Revision: http://reviews.llvm.org/D12428

llvm-svn: 246398
2015-08-30 21:13:53 +00:00
Tobias Grosser ed21a1fc7e Do not detect Scops with only one loop.
If a region does not have more than one loop, we do not identify it as
a Scop in ScopDetection. The main optimizations Polly is currently performing
(tiling, preparation for outer-loop vectorization and loop fusion) are unlikely
to have a positive impact on individual loops. In some cases, Polly's run-time
alias checks or conditional hoisting may still have a positive impact, but those
are mostly enabling transformations which LLVM already performs for individual
loops. As we do not focus on individual loops, we leave them untouched to not
introduce compile time regressions and execution time noise. This results in
good compile time reduction (oourafft: -73.99%, smg2000: -56.25%).

Contributed-by: Pratik Bhatu <cs12b1010@iith.ac.in>

Reviewers: grosser

Differential Revision: http://reviews.llvm.org/D12268

llvm-svn: 246161
2015-08-27 16:55:18 +00:00
Tobias Grosser c0f8452592 Fix test cases which fail due to changes in isl's set representation
llvm-svn: 245301
2015-08-18 15:28:02 +00:00
Tobias Grosser d2d15a8c65 Dependences: Zero pad the schedule map
The schedule map we derive from a schedule tree map may map statements into
schedule spaces of different dimensionality. This change adds zero padding
to ensure just a single schedule space is used and the translation from
a union_map to an isl_multi_union_pw_aff does not fail.

llvm-svn: 243849
2015-08-02 13:30:33 +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 3e6070ef03 Update isl to c3892bebc0
Various smaller improvements and bugfixes.

llvm-svn: 236932
2015-05-09 09:37:30 +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
Tobias Grosser 094999bb55 Drop unneccessary -basicaa passes in DependenceInfo test cases
llvm-svn: 235374
2015-04-21 09:17:52 +00:00
Johannes Doerfert f6557f98a2 Rename the Dependences pass to DependenceInfo [NFC]
We rename the Dependences pass to DependenceInfo as a first step to a
  caching pass policy. The new DependenceInfo pass will later provide
  "Dependences" for a SCoP.

  To keep consistency the test folder is renamed too.

llvm-svn: 231308
2015-03-04 22:43:40 +00:00