In Polly we used both the term 'scattering' and the term 'schedule' to describe
the execution order of a statement without actually distinguishing between them.
We now uniformly use the term 'schedule' for the execution order. This
corresponds to the terminology of isl.
History: CLooG introduced the term scattering as the generated code can be used
as a sequential execution order (schedule) or as a parallel dimension
enumerating different threads of execution (placement). In Polly and/or isl the
term placement was never used, but we uniformly refer to an execution order as a
schedule and only later introduce parallelism. When doing so we do not talk
about about specific placement dimensions.
llvm-svn: 235380
This change is a step towards using a single isl_schedule object throughout
Polly. At the moment the schedule is just constructed from the flat
isl_union_map that defines the schedule. Later we will obtain it directly
from the scop and potentially obtain a schedule with a non-trivial internal
structure that will allow faster dependence analysis.
llvm-svn: 235378
isl_union_map_compute_flow() has been replaced by
isl_union_access_info_compute_flow(). This change does not intend to
change funcitonality, yet. However, it will allow us to pass in subsequent
changes schedule trees to the dependence analysis instead of flat schedules.
This should speed up dependence analysis for important cases significantly.
llvm-svn: 235373
Otherwise, instructions in different functions that share the same pointer (due
to earlier modifications), might get assigned incorrect memory access
information (belonging to instructions in previous functions), which can result
in arbitrary memory corruption and assertion failures.
This fixes llvm.org/PR23160 and possibly also llvm.org/PR23167.
Note: InsnToMemAcc is a global variable that should never have existed in the
first place. We will clean this up in a subsequent patch.
Reported-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
Debugged-by: Johannes Doerfert <doerfert@cs.uni-saarland.de>
llvm-svn: 235254
This will allow the ScopInfo to build the polyhedral representation for
non-affine regions that contain loops. Such loops are basically not visible
in the SCoP representation. Accesses that are variant in such loops are
therefor represented as non-affine accesses.
Differential Revision: http://reviews.llvm.org/D8153
llvm-svn: 234713
This will allow the ScopDetection to detect non-affine regions that
contain loops. All loops contained will be collected and are
accessible to later passes in order to adjust the access functions.
As the loops are non-affine and will not be part of the polyhedral
representation later, all accesses that are variant in these loops
have to be over approximated as non-affine accesses. They are
therefore handled the same way as other non-affine accesses.
Additionally, we do not count non-affine loops for the profitability
heuristic, thus a region with only a non-affine loop will only be
detected if the general detection of loop free regions is enabled.
Differential Revision: http://reviews.llvm.org/D8152
llvm-svn: 234711
This change ensures that we sign-extend integer types in case non-matching
operands are encountered when generating a multi-dimensional access offset.
This fixes http://llvm.org/PR23124
Reported-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
llvm-svn: 234122
As soon as one operand of the product is invalid, the entire product is invalid.
This happens for example if one of the operands is not loop-invariant.
This fixes http://llvm.org/PR23125
Reported-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com
llvm-svn: 234119
We do not have buildbots or anything that tests this functionality, hence it
most likely bitrots. People interested to use this functionality can always
recover it from svn history.
llvm-svn: 233570
This allows us to delinerize code such as:
A[][n]
for (i
for (j
A[i][n-j-1] = ...
which would previously have been delinearize to an access A[i+1][-j-1].
To recover the correct access we apply the piecewise expression:
{ A[i][j] -> A[i-1][i+N]: i < 0; A[i][j] -> A[i][i]: i >= 0}
This approach generalizes to higher dimensions.
llvm-svn: 233566
This will strip the constant factor of a parameter befor we add it to
the SCoP. As a result the access functions are simplified, e.g., for
the attached test case.
llvm-svn: 233501
When creating parameters the SCEVexpander may introduce new induction variables,
that possibly create scalar dependences in the original scop, before we code
generate the scop. The resulting scalar dependences may then inhibit correct
code generation of the scop. To prevent this, we first version the code without
a run-time check and only then introduce new parameters and the run-time
condition. The if-condition that guards the original scop from being modified by
the SCEVexpander.
This change causes some test case changes as the run-time conditions are now
introduced in the split basic block rather than in the entry basic block.
This fixes http://llvm.org/PR22069
Test case reduced by: Karthik Senthil
llvm-svn: 233477
This options was earlier used for experiments with the vectorizer, but to my
knowledge is not really used anymore. If anybody needs this, we can always
reintroduce this feature.
llvm-svn: 232934
Replacing the old band_tree based code with code that is based on the new
schedule tree [1] interface makes applying complex schedule transformations a lot
more straightforward. We now do not need to reason about the meaning of flat
schedules, but can use a more straightforward tree structure. We do not yet
exploit this a lot in the current code, but hopefully we will be able to do so
soon.
This change also allows us to drop some code, as isl now provides some higher
level interfaces to apply loop transformations such as tiling.
This change causes some small test case changes as isl uses a slightly different
way to perform loop tiling, but no significant functional changes are intended.
[1] http://impact.gforge.inria.fr/impact2014/papers/impact2014-verdoolaege.pdf
llvm-svn: 232911
These test cases did not verify the CHECK lines at all. We add the FileCheck
and also fix some broken CHECK lines. Being here, we extend the checks to
cover the whole loop structure.
llvm-svn: 232710
The BB vectorizer is deprecated and there is no point in generating code for it
any more. This option was introduced when there was not yet any loop vectorizer
in sight. Now being matured, Polly should target the loop vectorizer.
llvm-svn: 232099
This test case was supposed to test the range analysis but it became just
another delinearization test case after enabling delinearization.
Suggested-by: Johannes Doerfert
llvm-svn: 231599
When code generating array index expressions the types of the different
components of the index expressions may not always match. We extend the type of
the index expression (if possible) and assert otherwise.
llvm-svn: 231592
The performance test case just committed was the last open issue I was aware of.
We enable this by default to increase test coverage and to possibly trigger
reports of issues yet unknown.
llvm-svn: 231590
The new Dependences struct in the DependenceInfo holds all information
that was formerly part of the DependenceInfo. It also provides the
same interface for the user to access this information.
This is another step to a more general ScopPass interface that does
allow multiple SCoPs to be "in flight".
llvm-svn: 231327
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
No test cases unfortunately as we do not yet generate isl_ast_op_and_then or
isl_ast_op_or_else. Those will be added in a later commit.
llvm-svn: 231268
If a scalar was defined and used only in a non-affine subregion we do
not need to model the accesses. However, if the scalar was defined
inside the region and escapes the region we have to model the access.
The same is true if the scalar was defined outside and used inside the
region.
llvm-svn: 230960
When we generate code for a whole region we have to respect dominance
and update it too.
The first is achieved with multiple "BBMap"s. Each copied block in the
region gets its own map. It is initialized only with values mapped in
the immediate dominator block, if this block is in the region and was
therefor already copied. This way no values defined in a block that
doesn't dominate the current one will be used.
To update dominance information we check if the immediate dominator of
the original block we want to copy is in the region. If so we set the
immediate dominator of the current block to the copy of the immediate
dominator of the original block.
llvm-svn: 230774
After a function was created we will verify it for Debug builds. If
errors are found and debug-type equals "polly-codegen-isl" the SCoP,
the isl AST, the function as well as the errors will be printed.
llvm-svn: 230767
isl recently introduced a new interface to create run-time checks from
constraint sets. Use this interface to simplify our run-time check generation.
llvm-svn: 230640
For Polly the two interesting changes are short_circuit && and || AST
expressions as well as the introduction of isl_ast_build_expr_from_set,
a well defined interface to compute ast expressions from constraint sets.
llvm-svn: 230636
With the patches r230325, r230329 and r230340 we can handle non-affine
control flow in (loop-free) subregions. As all LLVM test-suite tests pass and
we get ~20% more non-trivial SCoPs, we activate it now by default.
llvm-svn: 230624
This update contains:
- Fixes of minor issues detected by clang's scan_build
- More schedule tree infrastructure additions
This update slightly changes the output of our dependence analysis, but these
changes are purely syntactially.
llvm-svn: 230528
This is the code generation for region statements that are created
when non-affine control flow was present in the input. A new
generator, similar to the block or vector generator, for regions is
used to traverse and copy the region statement and to adjust the
control flow inside the new region in the end.
llvm-svn: 230340
This allows us to model non-affine regions in the SCoP representation.
SCoP statements can now describe either basic blocks or non-affine
regions. In the latter case all accesses in the region are accumulated
for the statement and write accesses, except in the entry, have to be
marked as may-write.
Differential Revision: http://reviews.llvm.org/D7846
llvm-svn: 230329
With this patch we allow the SCoP detection to detect regions as SCoPs
which have non-affine control flow inside. All non-affine regions are
tracked and later accessible to the ScopInfo.
As there is no real difference, non-affine branches as well as
floating point branches are covered (and both called non-affine
control flow). However, the detection is restricted to
overapproximate only loop free regions.
llvm-svn: 230325
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
This is just a single commit that includes a performance optimization that
should improve dependence analysis time. Our performance bots should measure
this difference.
llvm-svn: 229476
This commit imports the latest isl version into lib/External/isl. The changes
relavant for Polly are:
1) Schedule trees [1] have been introduced as a more structured way to
describe schedules. Polly does not yet use them, but we may switch to them
in the near future.
2) Another set of coalescing changes [2] simplifies some data dependences and
removes a couple of code generation artifacts.
We now understand that the following sets can be merged:
{ Stmt_S1[i0, i1] -> Stmt_S2[i0 + i1] :
i0 >= 0 and i1 <= 1023 - i0 and i1 >= 1
Stmt_S1[i0, 0] -> Stmt_S2[i0] : i0 <= 1023 and i0 >= 1}
into:
{ Stmt_S1[i0, i1] -> Stmt_S2[i0 + i1] : i1 <= 1023 - i0 and i1 >= 0 and
i1 >= 1 - i0 and i0 >= 0 }
Changes of this kind reduce unnecessary specialization during code
generation.
- for (int c3 = 0; c3 <= 1023; c3 += 1) {
- if (c3 % 2 == 0) {
- Stmt_for_body3(c1, c3);
- } else
- Stmt_for_body3(c1, c3);
- }
+ for (int c3 = 0; c3 <= 1023; c3 += 1)
+ Stmt_for_body3(c1, c3);
[1] http://impact.gforge.inria.fr/impact2014/papers/impact2014-verdoolaege.pdf
[2] http://impact.gforge.inria.fr/impact2015/papers/impact2015-verdoolaege.pdf
llvm-svn: 229423
Alias checks might become costly if there are divisions that complicate the
description of the accessed locations. By overaproximating them we get fairly
accurate results without the huge compile time cost.
llvm-svn: 229252
namespace and header rather than the top-level header and using
declarations. These helpers impede modular builds and are going away.
Migrating away from them will also be necessary to start mixing in any
usage of the new pass manager.
llvm-svn: 229091
Without this change we get linker errors such as:
undefined reference to `llvm::dbgs()'
We only conditionally link in these libraries, as in BUILD_SHARED_LIBS=OFF mode,
linking in these libraries causes such functions (and especially global options)
to be defined twice. The "solution" I choose is most likely not ideal, but seems
to work. If any cmake specialist can suggest a better approach, this would be
appreciated.
We also drop a .c file that is not needed as it caused linker errors as well.
llvm-svn: 228914
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
These write are important as they will force the scheduling and code
generation of an otherwise trivial statement and also impose an order of
execution needed to guarantee the correct final value for a scalar in a loop.
Added test case modeled after ClamAV/clamscan.
llvm-svn: 228847
This change has two main purposes:
1) We do not use a static interface to hide an object we create and
destroy for every basic block we copy.
2) We allow the BlockGenerator to store information between calls to
the copyBB method. This will ease scalar/phi code generation
later on.
While a lot of method signatures were changed this should not cause
any real behaviour change.
Differential Revision: http://reviews.llvm.org/D7467
llvm-svn: 228443
This allows us to model PHI nodes in the polyhedral description
without demoting them. The modeling however will result in the
same accesses as the demotion would have introduced.
Differential Revision: http://reviews.llvm.org/D7415
llvm-svn: 228433
With this patch Polly is always GPL-free (no dependency on GMP any more). As a
result, building and distributing Polly will be easier. Furthermore, there is no
need to tightly coordinate isl and Polly releases anymore.
We import isl b3e0fa7a05d as well as imath 4d707e5ef2. These are the git
versions Polly currently was tested with when using utils/checkout_isl.sh. The
imported libraries are both MIT-style licensed.
We build isl and imath with -fvisibility=hidden to avoid clashes in case other
projects (such as gcc) use conflicting versions of isl. The use of imath can
temporarily reduce compile-time performance of Polly. We will work on
performance tuning in tree.
Patches to isl should be contributed first to the main isl repository and can
then later be reimported to Polly.
This patch is also a prerequisite for the upcoming isl C++ interface.
llvm-svn: 228193
The support is currently limited as we only allow them in the input but do
not emit them in the transformed SCoP due to the possible semantic changes.
Differential Revision: http://reviews.llvm.org/D5225
llvm-svn: 227054
lets 'ninja check-polly' pass for me with a lib64 build of LLVM.
I've not updated the standalone side as I don't use it and don't have an
easy way to test any changes I've made there. I mostly wanted to be able
to actually run Polly's tests when I update its use of LLVM's APIs
during my refactorings on the (very unlikely) off chance that I make
a change which compiles but does the wrong thing.
llvm-svn: 226420
This change ensures that the values that represent the array size of a
multi-dimensional access are correctly sign-extended when used to compute a
memory address used in the run-time alias check.
To make the test case more readable, we name the instructions that we generate.
llvm-svn: 225818
The max loop depth was incorrectly computed for scops that contain a
block from a loop but do not contain the entire loop. We need to
check that the full loop is contained in the region when computing
the max loop depth.
These scops occur when a region containing an inner loop is expanded
to include some blocks from the outer loop, but it cannot be fully
expanded to contain the outer loop because the region containing the
outer loop is invalid.
Differential Revision: http://reviews.llvm.org/D6913
llvm-svn: 225812
This support is still incomplete and consequently hidden behind a switch that
needs to be enabled. One problem is ATM that we incorrectly interpret very large
unsigned values as negative values even if used in an unsigned comparision.
llvm-svn: 225480
AF = dyn_cast<SCEVAddRecExpr>(Pair.second) may be NULL for some SCEVs that we do
not support. When reporting the error we still want to pass a pointer that is
known to always be non-NULL.
I do not yet have a test case for this, unfortunately.
llvm-svn: 225461
This would add another library dependency to Polly. In many cases the
JSCoP interface we have should be enough and an external JSCoP <> OpenSCoP
converter could be written. We can reconsider this if new use cases show up.
llvm-svn: 225390
We previously used a Twine here, but as pointed out by David Blaikie
and Mehdi Amini storing a temporary StringRef in a Twine is not a good
idea, as the StringRef will be freed before the Twine is used leaving
a Twine that points to uninitialized memory. We now make it explicit that
we use a StringRef here.
llvm-svn: 225342
Tobias Grosser