Polly was accidently modifying a debug info metadata node when
attempting to generate a new unique metadata node for the loop id.
The problem was that we had dwarf metadata that referred to a
metadata node with a null value, like this:
!6 = ... some dwarf metadata referring to !7 ...
!7 = {null}
When we attempt to generate a new metadata node, we reserve the
first space for self-referential node by setting the first argument
to null and then mutating the node later to refer to itself.
However, because the nodes are uniqued based on pointer values, when
we get the new metadata node it actually referred to an existing
node (!7 in the example). When we went to modify the metadata to
point to itself, we were accidently mutating the dwarf metatdata. We
ended up in this situation:
!6 = ... some dwarf metadata referring to !7 ...
!7 = {!7}
and this causes an assert when generating the debug info. The fix is
simple, we just need to use a unique value when getting a new
metadata node. The MDNode::getTemporary() provides exactly the API
we need (and it is used in clang to generate the unique nodes).
Differential Revision: http://reviews.llvm.org/D6174
llvm-svn: 221550
We introduces a new flag -polly-parallel and use it to annotate the for-nodes in
the isl ast that we want to execute thread parallel (e.g., using OpenMP). We
previously already emmitted openmp annotations, but we did this for various
kinds of parallel loops, including some which we can not run in parallel.
With this patch we now have three annotations:
1) #pragma known-parallel [reduction]
2) #pragma omp for
3) #pragma simd
meaning:
1) loop has no loop carried dependences
2) loop will be executed thread-parallel
3) loop can possibly be vectorized
This patch introduces 1) and reduces the use of 2) to only the cases where we
will actually generate thread parallel code.
It is in preparation of openmp code generation in our isl backend.
Legacy:
- We also have a command line option -enable-polly-openmp. This option controls
the OpenMP code generation in CLooG. It will become an alias of
-polly-parallel after the CLooG code generation has been dropped.
http://reviews.llvm.org/D6142
llvm-svn: 221479
This patch moves the SCEV based (re)generation of values before the checking for
scop-constant terms. It enables us to provide SCEV based replacements, which
are necessary to correctly generate OpenMP subfunctions when using the SCEV
based code generation.
When recomputing a new value for a value used in the code of the original scop,
we previously directly returned the same original value for all scop-constant
expressions without even trying to regenerate these values using our SCEV
expression. This is correct when the newly generated code remains fully in the
same function, however in case we want to outline parts of the newly generated
scop into subfunctions, this approach means we do not have any opportunity to
update these values in the SCEV based code generation. (In the non-SCEV based
code generation, we can provide such updates through the GlobalMap). To ensure
we have this opportunity, we first try to regenerate scalar terms with our SCEV
builder and will only return scop-constant expressions if SCEV based code
generation was not possible.
This change should not affect the results of the existing code generation
passes. It only impacts the upcoming OpenMP based code generation.
This commit also adds a test case. This test case passes before and after this
commit. It was added to ensure test coverage for the changed code.
llvm-svn: 221393
There was no good reason why this code was split accross two functions.
In subsequent changes we will change the order in which values are looked up.
Doing so would make the split into two functions even more arbitrary.
We also slightly improve the documentation.
llvm-svn: 221388
When our RuntimeDebugBuilder calles fflush(NULL) to flush all output streams, it
is important that the types we use in the call match the ones used in a
declaration of fflush possible already available in the translation unit.
As we just pass on a NULL pointer, the type of the pointer value does not really
matter. However, as LLVM complains in case of mismatched types, we make sure
to create a NULL pointer of identical type.
No test case, as RuntimeDebugBuilder is not permanently used in Polly. Calls to
it are until now only used to add informative output during debugging sessions.
llvm-svn: 221251
Originally we have needed this code to map the isl_id of an array to its base
pointer. However, as now the isl_id contains a reference to the array itself we
obtain the base pointer from this isl_id and we do not need to add this
information to the IDToValue map.
llvm-svn: 220876
The description of the parameter value passed to -enable-polly-aligned did
not make any sense at all, but was just a leftover coming from when this option
was copied form -enable-polly-openmp. We just drop it as the option description
gives sufficient information already.
llvm-svn: 220445
This makes sure we consistently use dbgs() when printing debug output.
Previously, the code just mixed calls to isl_*_dump() with printing to dbgs()
and was relying for both methods to interact in predictable ways (same output
stream, no unexpected reordering of outputs).
llvm-svn: 220443
By adding braces into the DEBUG statement we can make clang-format format code
such as:
DEBUG(stmt1(); stmt2())
as multi-line code:
DEBUG({
stmt1();
stmt2();
});
This makes control-flow in debug statements easier to read.
llvm-svn: 220441
This patch does not change the semantic on it's own. However, the
dependence analysis as well as dce will now use the newest available
access relation for each memory access, thus if at some point the json
importer or any other pass will run before those two and set a new
access relation the behaviour will be different. In general it is
unclear if the dependence analysis and dce should be run on the old or
new access functions anyway. If we need to access the original access
function from the outside later, we can expose the getter again.
Differential Revision: http://reviews.llvm.org/D5707
llvm-svn: 219612
In case the pieceweise affine function used to create an isl_ast_expr
had empty cases (e.g., with contradicting constraints on the
parameters), it was possible that the condition of the isl_ast_expr
select was not a comparison but a constant (thus of type i64).
This patch does two thing:
1) Handle the case the condition of a select is not a i1 type like C.
2) Try to simplify the pieceweise affine functions for the min/max
access when we generate runtime alias checks. That step can often
remove empty or redundant cases as well as redundant constrains.
This fixes bug: http://llvm.org/PR21167
Differential Revision: http://reviews.llvm.org/D5627
llvm-svn: 219208
This resolved the issues with delinearized accesses that might alias,
thus delinearization doesn't deactivate runtime alias checks anymore.
Differential Revision: http://reviews.llvm.org/D5614
llvm-svn: 219078
This class allows to store information about the arrays in the SCoP.
For each base pointer in the SCoP one object is created storing the
type and dimension sizes of the array. The objects can be obtained via
the SCoP, a MemoryAccess or the isl_id associated with the output
dimension of a MemoryAccess (the description of what is accessed).
So far we use the information in the IslExprBuilder to create the
right base type before indexing into the base array. This fixes the
bug http://llvm.org/bugs/show_bug.cgi?id=21113 (both test cases are
included). On top of that we can now build runtime alias checks for
delinearized arrays as the dimension sizes are also part of the
ScopArrayInfo objects.
Differential Revision: http://reviews.llvm.org/D5613
llvm-svn: 219077
+ Generalized function names and comments
+ Removed OpenMP (omp) from the names and comments
+ Use common names (non OpenMP specific) for runtime library call creation
methodes
+ Commented the parallel code generator and all its member functions
+ Refactored some values and methodes
Differential Revision: http://reviews.llvm.org/D4990
llvm-svn: 219003
This also forbids the json importer to access other memory locations
than the original instruction as we to reuse the alignment of the
original load/store.
Differential Revision: http://reviews.llvm.org/D5560
llvm-svn: 218883
The LoopAnnotator doesn't annotate only loops any more, thus it is
called ScopAnnotator from now on.
This also removes unnecessary polly:: namespace tags.
llvm-svn: 218878
The command line flag -polly-annotate-alias-scopes controls whether or not
Polly annotates alias scopes in the new SCoP (default ON). This can improve
later optimizations as the new SCoP is basically an alias free environment for
them.
llvm-svn: 218877
This change allows to annotate all parallel loops with loop id metadata.
Furthermore, it will annotate memory instructions with
llvm.mem.parallel_loop_access metadata for all surrounding parallel loops.
This is especially usefull if an external paralleliser is used.
This also removes the PollyLoopInfo class and comments the
LoopAnnotator.
A test case for multiple parallel loops is attached.
llvm-svn: 218793
This fixes two problems which are usualy caused together:
1) The elements of an isl AST access expression could be pointers
not only integers, floats and vectores thereof.
2) The runtime alias checks need to compare pointers but if they
are of a different type we need to cast them into a "max" type
similar to the non pointer case.
llvm-svn: 218113
This change will build all alias groups (minimal/maximal accesses
to possible aliasing base pointers) we have to check before
we can assume an alias free environment. It will also use these
to create Runtime Alias Checks (RTC) in the ISL code generation
backend, thus allow us to optimize SCoPs despite possibly aliasing
pointers when this backend is used.
This feature will be enabled for the isl code generator, e.g.,
--polly-code-generator=isl, but disabled for:
- The cloog code generator (still the default).
- The case delinearization is enabled.
- The case non-affine accesses are allowed.
llvm-svn: 218046
During the IslAst parallelism check also compute the minimal dependency
distance and store it in the IstAst for node.
Reviewer: sebpop
Differential Revision: http://reviews.llvm.org/D4987
llvm-svn: 217729
This allows us to omit the GuardBB in front of created loops
if we can show the loop trip count is at least one. It also
simplifies the dominance relation inside the new created region.
A GuardBB (even with a constant branch condition) might trigger
false dominance errors during function verification.
Differential Revision: http://reviews.llvm.org/D5297
llvm-svn: 217525
Summary:
+ Refactor the runtime check (RTC) build function
+ Added helper function to create an PollyIRBuilder
+ Change the simplify region function to create not
only unique entry and exit edges but also enfore that
the entry edge is unconditional
+ Cleaned the IslCodeGeneration runOnScop function:
- less post-creation changes of the created IR
+ Adjusted and added test cases
Reviewers: grosser, sebpop, simbuerg, dpeixott
Subscribers: llvm-commits, #polly
Differential Revision: http://reviews.llvm.org/D5076
llvm-svn: 217508
This previous code added in r216842 most likely created unnecessary copies.
Reported-by: Duncan P. N. Exon Smith <dexonsmith@apple.com>
llvm-svn: 217507
There was a bug in the IslAst which caused that no more outermost
parallel loops were detected/checked after a parallel outermost loop
of depth 1.
+ Test case attached
llvm-svn: 217452
This reverts commit 215466 (and 215528, a trivial formatting fix).
The intention of these commits is a good one, but unfortunately they broke
our LNT buildbot:
http://lab.llvm.org:8011/builders/perf-x86_64-penryn-O3-polly-codegen-isl
Several of the cleanup changes that have been combined in this 'fixup' are
trivial and could probably be committed as obvious changes without risking to
break the build. The remaining changes are little and it should be easy to
figure out what went wrong.
llvm-svn: 215817
Use the explicit analysis if possible, only for splitBlock we will continue
to use the Pass * argument. This change allows us to remove the getAnalysis
calls from the code generation.
llvm-svn: 215121
+ Remove the class IslGenerator which duplicates the functionality of
IslExprBuilder.
+ Use the IslExprBuilder to create code for memory access relations.
+ Also handle array types during access creation.
+ Enable scev codegen for one of the transformed memory access tests,
thus access creation without canonical induction variables available.
+ Update one test case to the new output.
llvm-svn: 214659
+ Split all reduction dependences and map them to the causing memory accesses.
+ Print the types & base addresses of broken reductions for each "reduction
parallel" marked loop (OpenMP style).
+ 3 test cases to show how reductions are now represented in the isl ast.
The mapping "(ast) loops -> broken reductions" is also needed to find the
memory accesses we need to privatize in a loop.
llvm-svn: 214489
The functions isParallel, isInnermostParallel and IsOutermostParallel in
IslAstInfo will now return true even in the presence of broken reductions.
To compensate for this change the negated result of isReductionParallel can
be used.
llvm-svn: 214488
+ Perform the parallelism check on the innermost loop only once.
+ Inline the markOpenmpParallel function.
+ Rename all IslAstUserPayload * into Payload to make it consistent.
llvm-svn: 214448
David Peixotto