Summary:
ScopDetection used to check if a loop withing a region was infinite and emitted a diagnostic in such cases. After r310940 there's no point checking against that situation, as infinite loops don't appear in regions anymore.
The test failure was observed on these two polly buildbots:
http://lab.llvm.org:8011/builders/polly-arm-linux/builds/8368http://lab.llvm.org:8011/builders/polly-amd64-linux/builds/10310
This patch XFAILs `ReportLoopHasNoExit.ll` and turns infinite loop detection into an assert.
Reviewers: grosser, sanjoy, bollu
Reviewed By: grosser
Subscribers: efriedma, aemerson, kristof.beyls, dberlin, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36776
llvm-svn: 311503
Utilizing newer LLVM diagnostic remark API in order to enable use of
opt-viewer tool. Polly Diagnostic Remarks also now appear in YAML
remark file.
In this patch, I've added the OptimizationRemarkEmitter into certain
classes where remarks are being emitted and update the remark emit calls
itself. I also provide each remark a BasicBlock or Instruction from where
it is being called, in order to compute the hotness of the remark.
Patch by Tarun Rajendran!
Differential Revision: https://reviews.llvm.org/D35399
llvm-svn: 308233
This patch makes sure that in case a loop is not fully contained within a region
that later forms a SCoP, none of the loop backedges are allowed to be part of
the region. We currently do not support the situation where only some of a loops
backedges are part of a scop. Today, this can break both scop modeling and code
generation. One such breaking test case is for example
test/ScopDetectionDiagnostics/loop_partially_in_scop-2.ll, where we totally
forgot to code generate some of the backedges. Fortunately, it is commonly not
necessary to support these partial loops, it is way more common that either
no backedge is included in a region or all loop backedge are included.
This fixes a recent miscompile in
MultiSource/Benchmarks/MiBench/consumer-typeset which was exposed after
r306477.
llvm-svn: 308113
Scops that exit with an unreachable are today still permitted, but make little
sense to optimize. We therefore can already skip them during scop detection.
This speeds up scop detection in certain cases and also ensures that bugpoint
does not introduce unreachables when reducing test cases.
In practice this change should have little impact, as the performance of
unreachable code is unlikely to matter.
This commit is part of a series that makes Polly more robust in the presence
of unreachables.
llvm-svn: 297151
Formatting unnamed array names is expensive in LLVM as the this requires
deriving the numbered virtual instruction name (e.g., %12) for an llvm::Value,
which is currently not implemented efficiently. As instruction numberes anyhow
do not really carry a lot of information for the user, we just print 'unknown'
instead.
This change reduces the scop detection time from 24 to 19 seconds, for one of
our large-scale inputs. This is a reduction by 21%.
llvm-svn: 294894
Before this change the user only saw "Unspecified Error", when a region
contained the entry block. Now we report:
"Scop contains function entry (not yet supported)."
llvm-svn: 293169
clang-format has been updated in r289531 to keep labels and values on
the same line. This change updates Polly to the new formatting style.
llvm-svn: 289533
Our original statistics were added before we introduced a more fine-grained
diagnostic system, but the granularity of our statistics has never been
increased accordingly. This change introduces now one statistic counter per
diagnostic to enable us to collect fine-grained statistics about who certain
scops are not detected. In case coarser grained statistics are needed, the
user is expected to combine counters manually.
llvm-svn: 287968
Summary:
Both `canUseISLTripCount()` and `addOverApproximatedRegion()` contained checks
to reject endless loops which are now removed and replaced by a single check
in `isValidLoop()`.
For reporting such loops the `ReportLoopOverlapWithNonAffineSubRegion` is
renamed to `ReportLoopHasNoExit`. The test case
`ReportLoopOverlapWithNonAffineSubRegion.ll` is adapted and renamed as well.
The schedule generation in `buildSchedule()` is based on the following
assumption:
Given some block B that is contained in a loop L and a SESE region R,
we assume that L is contained in R or the other way around.
However, this assumption is broken in the presence of endless loops that are
nested inside other loops. Therefore, in order to prevent erroneous behavior
in `buildSchedule()`, r265280 introduced a corresponding check in
`canUseISLTripCount()` to reject endless loops. Unfortunately, it was possible
to bypass this check with -polly-allow-nonaffine-loops which was fixed by adding
another check to reject endless loops in `allowOverApproximatedRegion()` in
r273905. Hence there existed two separate locations that handled this case.
Thank you Johannes Doerfert for helping to provide the above background
information.
Reviewers: Meinersbur, grosser
Subscribers: _jdoerfert, pollydev
Differential Revision: https://reviews.llvm.org/D24560
Contributed-by: Matthias Reisinger <d412vv1n@gmail.com>
llvm-svn: 281987
LLVM's coding guideline suggests to not use @brief for one-sentence doxygen
comments to improve readability. Switch this once and for all to ensure people
do not copy @brief comments from other parts of Polly, when writing new code.
llvm-svn: 280468
Reject and report regions that contains loops overlapping nonaffine region.
This situation typically happens in the presence of inifinite loops.
This addresses bug llvm.org/PR28071.
Differential Revision: http://reviews.llvm.org/D21312
Contributed-by: Huihui Zhang <huihuiz@codeaurora.org>
llvm-svn: 273905
llvm commonly adds a comment to the closing brace of a namespace to indicate
which namespace is closed. clang-tidy provides with llvm-namespace-comment
a handy tool to check for this habit. We use it to ensure we consitently use
namespace comments in Polly.
There are slightly different styles in how namespaces are closed in LLVM. As
there is no large difference between the different comment styles we go for the
style clang-tidy suggests by default.
To reproduce this fix run:
for i in `ls tools/polly/lib/*/*.cpp`; \
clang-tidy -checks='-*,llvm-namespace-comment' -p build $i -fix \
-header-filter=".*"; \
done
This cleanup was suggested by Eugene Zelenko <eugene.zelenko@gmail.com> in
http://reviews.llvm.org/D21488 and was split out to increase readability.
llvm-svn: 273621
This patch cleans up the rejection log handling during the
ScopDetection. It consists of two interconnected parts:
- We keep all detection contexts for a function in order to provide
more information to the user, e.g., about the rejection of
extended/intermediate regions.
- We remove the mutable "RejectLogs" member as the information is
available through the detection contexts.
llvm-svn: 269323
With this patch we will optimistically assume that the result of an unsigned
comparison is the same as the result of the same comparison interpreted as
signed.
llvm-svn: 267559
We also disable this feature by default, as there are still some issues in
combination with invariant load hoisting that slipped through my initial
testing.
llvm-svn: 260025
This allows code such as:
void multiple_types(char *Short, char *Float, char *Double) {
for (long i = 0; i < 100; i++) {
Short[i] = *(short *)&Short[2 * i];
Float[i] = *(float *)&Float[4 * i];
Double[i] = *(double *)&Double[8 * i];
}
}
To model such code we use as canonical element type of the modeled array the
smallest element type of all original array accesses, if type allocation sizes
are multiples of each other. Otherwise, we use a newly created iN type, where N
is the gcd of the allocation size of the types used in the accesses to this
array. Accesses with types larger as the canonical element type are modeled as
multiple accesses with the smaller type.
For example the second load access is modeled as:
{ Stmt_bb2[i0] -> MemRef_Float[o0] : 4i0 <= o0 <= 3 + 4i0 }
To support code-generating these memory accesses, we introduce a new method
getAccessAddressFunction that assigns each statement instance a single memory
location, the address we load from/store to. Currently we obtain this address by
taking the lexmin of the access function. We may consider keeping track of the
memory location more explicitly in the future.
We currently do _not_ handle multi-dimensional arrays and also keep the
restriction of not supporting accesses where the offset expression is not a
multiple of the access element type size. This patch adds tests that ensure
we correctly invalidate a scop in case these accesses are found. Both types of
accesses can be handled using the very same model, but are left to be added in
the future.
We also move the initialization of the scop-context into the constructor to
ensure it is already available when invalidating the scop.
Finally, we add this as a new item to the 2.9 release notes
Reviewers: jdoerfert, Meinersbur
Differential Revision: http://reviews.llvm.org/D16878
llvm-svn: 259784
We support now code such as:
void multiple_types(char *Short, char *Float, char *Double) {
for (long i = 0; i < 100; i++) {
Short[i] = *(short *)&Short[2 * i];
Float[i] = *(float *)&Float[4 * i];
Double[i] = *(double *)&Double[8 * i];
}
}
To support such code we use as element type of the modeled array the smallest
element type of all original array accesses. Accesses with larger types are
modeled as multiple accesses with the smaller type.
For example the second load access is modeled as:
{ Stmt_bb2[i0] -> MemRef_Float[o0] : 4i0 <= o0 <= 3 + 4i0 }
To support jscop-rewritable memory accesses we need each statement instance to
only be assigned a single memory location, which will be the address at which
we load the value. Currently we obtain this address by taking the lexmin of
the access function. We may consider keeping track of the memory location more
explicitly in the future.
llvm-svn: 259587
Polly currently does not support irreducible control and it is probably not
worth supporting. This patch adds code that checks for irreducible control
and refuses regions containing irreducible control.
Polly traditionally had rather restrictive checks on the control flow structure
which would have refused irregular control, but within the last couple of months
most of the control flow restrictions have been removed. As part of this
generalization we accidentally allowed irregular control flow.
Contributed-by: Karthik Senthil and Ajith Pandel
llvm-svn: 258497
At some point we enforced lcssa for the loop surrounding the entry block.
This is not only questionable as it does not check any other loop but also
not needed any more.
llvm-svn: 253789
Volatile or atomic memory accesses are currently not supported. Neither did
we think about any special handling needed nor do we support the unknown
instructions the alias set tracker turns them into sometimes. Before this
patch, us not supporting unkown instructions in an alias set caused the
following assertion failures:
Assertion `AG.size() > 1 && "Alias groups should contain at least two accesses"'
failed
llvm-svn: 251234
This patch allows switch instructions with affine conditions in the
SCoP. Also switch instructions in non-affine subregions are allowed.
Both did not require much changes to the code, though there was some
refactoring needed to integrate them without code duplication.
In the llvm-test suite the number of profitable SCoPs increased from
135 to 139 but more importantly we can handle more benchmarks and user
inputs without preprocessing.
Differential Revision: http://reviews.llvm.org/D13200
llvm-svn: 248701
This check was needed at some point but seems not useful anymore. Only
one adjustment in the domain generation was needed to cope with the
cases this check prevented from happening before.
llvm-svn: 248695
Upcoming revisions of isl require us to include header files explicitly, which
have previously been already transitively included. Before we add them, we sort
the existing includes.
Thanks to Chandler for sort_includes.py. A simple, but very convenient script.
llvm-svn: 236930
This change adds location information for the detected regions in Polly when the
required debug information is available.
The JSCOP output format is extended with a "location" field which contains the
information in the format "source.c:start-end"
The dot output is extended to contain the location information for each nested
region in the analyzed function.
As part of this change, the existing getDebugLocation function has been moved
into lib/Support/ScopLocation.cpp to avoid having to include
polly/ScopDetectionDiagnostics.h.
Differential Revision: http://reviews.llvm.org/D9431
Contributed-by: Roal Jordans <r.jordans@tue.nl>
llvm-svn: 236393
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
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
This commit drops a call to std::sort, which sorted the base pointers that
possibly alias according to the address at which their corresponding llvm::Value
was allocated. There does not seem to be any good reason, why those pointers
should be (re)sorted and this only makes the output indeterministic.
llvm-svn: 218052
At the moment we assume that only elements of identical size are stored/loaded
to a certain base pointer. This patch adds logic to the scop detection to verify
this.
Differential Revision: http://reviews.llvm.org/D5329
llvm-svn: 217727
This will spill out information about LLVM-internals. However, in cases
where the name of the Value matches the name of the array in the source,
we provide more useful information. In cases where we spill internals,
the information still might help the user to pin down the correct
arrays.
The problem we face here is: The error is pinned to the debug location
of one of the offending values out of the alias set instead of all of them.
The more information we give the user about the set of aliasing
pointers the better.
llvm-svn: 215830
Store the llvm::Value pointers of the AliasSet instead of the AliasSet
itself.
We have to be careful about changed IR when the message is generated,
because the Value pointers might not exist anymore. This would render
the Diagnostic invalid. For now we just assert there.
Simply do not retreive a diagnostic message after the IR has changed
it's not valid information anyway.
llvm-svn: 215625
Jakub Kuderski