Summary:
Add a document which describes:
- GEMM performance comparison.
- An experiment that measures the compile time impact
of enabling Polly when compiling LLVM+Clang+Polly.
Contributed-by: Theodoros Theodoridis<theodoros.theodoridis@inf.ethz.ch>
Differential Revision: https://reviews.llvm.org/D38330
llvm-svn: 314419
In order for debuggers to be able to call an inline method, it must have
been instantiated somewhere. The dump() methods are usually not used, so
add an instantiation in debug builds.
This allows to call .dump() on any isl++ object from the gcc/gdb and
Visual Studio debugger in debug builds with assertions enabled.
In optimized builds, even with assertions enabled, the dump() methods
are also inlined in GICHelper.cpp, so no externally visible symbols
will be available either.
Differential Revision: https://reviews.llvm.org/D38198
llvm-svn: 314395
In case a PHI node follows an error block we can assume that the incoming value
can only come from the node that is not an error block. As a result, conditions
that seemed non-affine before are now in fact affine.
This is a recommit of r312663 after fixing
test/Isl/CodeGen/phi_after_error_block_outside_of_scop.ll
llvm-svn: 314075
Such RTCs may introduce integer wrapping intrinsics with more than 64 bit,
which are translated to library calls on AOSP that are not part of the
runtime and will consequently cause linker errors.
Thanks to Eli Friedman for reporting this issue and reducing the test case.
llvm-svn: 314065
Remove an assertion that tests the injectivity of the
PHIRead -> PHIWrite relation. That is, allow a single PHI write to be
used by multiple PHI reads. This may happen due to some statements
containing the PHI write not having the statement instances that would
overwrite the previous incoming value due to (assumed/invalid) contexts.
This result in that PHI write is mapped to multiple targets which is not
supported. Codegen will select one one of the targets using
getAddressFunction(). However, the runtime check should protect us from
this case ever being executed.
We therefore allow injective PHI relations. Additional calculations to
detect/santitize this case would probably not be worth the compuational
effort.
This fixes llvm.org/PR34485
llvm-svn: 313902
Before this patch, ScopInfo::getValueDef(SAI) used
getStmtFor(Instruction*) to find the MemoryAccess that writes a
MemoryKind::Value. In cases where the value is synthesizable within the
statement that defines, the instruction is not added to the statement's
instruction list, which means getStmtFor() won't return anything.
If the synthesiable instruction is not synthesiable in a different
statement (due to being defined in a loop that and ScalarEvolution
cannot derive its escape value), we still need a MemoryKind::Value
and a write to it that makes it available in the other statements.
Introduce a separate map for this purpose.
This fixes MultiSource/Benchmarks/MallocBench/cfrac where
-polly-simplify could not find the writing MemoryAccess for a use. The
write was not marked as required and consequently was removed.
Because this could in principle happen as well for PHI scalars,
add such a map for PHI reads as well.
llvm-svn: 313881
Since -polly-codegen reports itself to preserve DependenceInfo and IslAstInfo,
we might get those analysis that were computed by a different ScopInfo for a
different Scop structure. This would be unfortunate because DependenceInfo and
IslAstInfo hold references to resources allocated by
ScopInfo/ScopBuilder/Scop (e.g. isl_id). If -polly-codegen and
DependenceInfo/IslAstInfo do not agree on which Scop to use, unpredictable
things can happen.
When the ScopInfo/Scop object is freed, there is a high probability that the
new ScopInfo/Scop object will be created at the same heap position with the
same address. Comparing whether the Scop or ScopInfo address is the expected
therefore is unreliable.
Instead, we compare the address of the isl_ctx object. Both, DependenceInfo
and IslAstInfo must hold a reference to the isl_ctx object to ensure it is
not freed before the destruction of those analyses which might happen after
the destruction of the Scop/ScopInfo they refer to. Hence, the isl_ctx
will not be freed and its address not reused as long there is a
DependenceInfo or IslAstInfo around.
This fixes llvm.org/PR34441
llvm-svn: 313842
Fix walking over the schedule tree to collect its properties
(Number of permutable bands etc.).
Also add regression tests for these statistics.
llvm-svn: 313750
Computing the reaching definition in forwardTree() can take a long time
if the coefficients are large. When the forwarding is
carried-out (doIt==true), forwardTree() must execute entirely or not at
all to get a consistent output, which means we cannot just allow
out-of-quota errors to happen in the middle of the processing.
We introduce the class IslQuotaScope which allows to opt-in code that is
conformant and has been tested with out-of-quota events. In case of
ForwardOpTree, out-of-quota is allowed during the operand tree
examination, but not during the transformation. The same forwardTree()
recursion is used for examination and execution, meaning that the
reaching definition has already been computed in the examination tree
walk and cached for reuse in the transformation tree walk.
This should fix the time-out of grtestutils.ll of the asop buildbot. If
the compilation still takes too long, we can reduce the max-operations
allows for -polly-optree.
Differential Revision: https://reviews.llvm.org/D37984
llvm-svn: 313690
cl::opt<unsigned long> is not specialized and hence the option
-polly-optree-max-ops impossible to use.
Replace by supported option cl::opt<unsigned>.
Also check for an error state when computing the written value, which
happens when the quota runs out.
llvm-svn: 313546
In r301670 IR verification was disabled. Since then, CodeGen writing
malformed IR would only be noticed by unpredictable behavior in
follow-up passes (e.g. segfaults, infinite loops) or IR verification in
the backend assert builds.
Re-enable -polly-codegen-verify at for the regression tests to ensure
that malformed IR is detected where Polly generated malformed IR in the
past and changes in CodeGen are at least partially covered by
check-polly
(otherwise malformed IR may only get noticed when the buildbots run the
test-suite).
Differential Revision: https://reviews.llvm.org/D37969
llvm-svn: 313527
This is a resubmission of r313270. It broke standalone builds of
compiler-rt because we were not correctly generating the llvm-lit
script in the standalone build directory.
The fixes incorporated here attempt to find llvm/utils/llvm-lit
from the source tree returned by llvm-config. If present, it
will generate llvm-lit into the output directory. Regardless,
the user can specify -DLLVM_EXTERNAL_LIT to point to a specific
lit.py on their file system. This supports the use case of
someone installing lit via a package manager. If it cannot find
a source tree, and -DLLVM_EXTERNAL_LIT is either unspecified or
invalid, then we print a warning that tests will not be able
to run.
Differential Revision: https://reviews.llvm.org/D37756
llvm-svn: 313407
This patch is still breaking several multi-stage compiler-rt bots.
I already know what the fix is, but I want to get the bots green
for now and then try re-applying in the morning.
llvm-svn: 313335
This patch simplifies LLVM's lit infrastructure by enforcing an ordering
that a site config is always run before a source-tree config.
A significant amount of the complexity from lit config files arises from
the fact that inside of a source-tree config file, we don't yet know if
the site config has been run. However it is *always* required to run
a site config first, because it passes various variables down through
CMake that the main config depends on. As a result, every config
file has to do a bunch of magic to try to reverse-engineer the location
of the site config file if they detect (heuristically) that the site
config file has not yet been run.
This patch solves the problem by emitting a mapping from source tree
config file to binary tree site config file in llvm-lit.py. Then, during
discovery when we find a config file, we check to see if we have a
target mapping for it, and if so we use that instead.
This mechanism is generic enough that it does not affect external users
of lit. They will just not have a config mapping defined, and everything
will work as normal.
On the other hand, for us it allows us to make many simplifications:
* We are guaranteed that a site config will be executed first
* Inside of a main config, we no longer have to assume that attributes
might not be present and use getattr everywhere.
* We no longer have to pass parameters such as --param llvm_site_config=<path>
on the command line.
* It is future-proof, meaning you don't have to edit llvm-lit.in to add
support for new projects.
* All of the duplicated logic of trying various fallback mechanisms of
finding a site config from the main config are now gone.
One potentially noteworthy thing that was required to implement this
change is that whereas the ninja check targets previously used the first
method to spawn lit, they now use the second. In particular, you can no
longer run lit.py against the source tree while specifying the various
`foo_site_config=<path>` parameters. Instead, you need to run
llvm-lit.py.
Differential Revision: https://reviews.llvm.org/D37756
llvm-svn: 313270
The remaining parts produced by the full partial tile isolation can contain
hot spots that are worth to be optimized. Currently, we rely on the simple
loop unrolling pass, LiCM and the SLP vectorizer to optimize such parts.
However, the approach can suffer from the lack of the information about
aliasing that Polly provides using additional alias metadata or/and the lack
of the information required by simple loop unrolling pass.
This patch is the first step to optimize the remaining parts. To do it, we
unroll and separate them. In case of, for instance, Intel Kaby Lake, it helps
to increase the performance of the generated code from 39.87 GFlop/s to
49.23 GFlop/s.
The next possible step is to avoid unrolling performed by Polly in case of
isolated and remaining parts and rely only on simple loop unrolling pass and
the Loop vectorizer.
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: https://reviews.llvm.org/D37692
llvm-svn: 312929
Update CodegenCleanup using the function-level passes added by
populatePassManager that run between EP_EarlyAsPossible and
EP_VectorizerStart in -O3.
The changes in particular are:
- Added pass create arguments, e.g. ExpensiveCombines for InstCombine.
- Remove reroll pass. The option -reroll-loops is disabled by default.
- Add passes run with UnitAtATime, which is the default.
- Add instances of LibCallsShrinkWrap, TailCallElimination, SCCP
(sparse conditional constant propagation), Float2Int
that did not run before.
- Add instances of GVN as in the default pipeline.
Notes:
- GVNHoist, GVNSink, NewGVN are still disabled in the -O3 pipeline.
- The optimization level and other optimization parameters are not
accessible outside of PassManagerBuilder, hence we cannot add passes
depending on these.
Differential Revision: https://reviews.llvm.org/D37571
llvm-svn: 312875
The type of NewValue might change due to ScalarEvolution
looking though bitcasts. The synthesized NewValue therefore
becomes the type before the bitcast.
llvm-svn: 312718
This reverts commit
r312410 - [ScopDetect/Info] Look through PHIs that follow an error block
The commit caused generation of invalid IR due to accessing a parameter
that does not dominate the SCoP.
llvm-svn: 312663
Up to now ZoneAlgo considered array elements access by something else
than a LoadInst or StoreInst as not analyzable. This patch removes that
restriction by using the unknown ValInst to describe the written
content, repectively the element type's null value in case of memset.
Differential Revision: https://reviews.llvm.org/D37362
llvm-svn: 312630
Since r312249 instructions of a entry block of region statements are
not marked as root anymore and hence can theoretically be removed
if unused. Theoretically, because the instruction list was not changed.
Still, MemoryAccesses for unused instructions were removed. This lead
to a failed assertion in the code generator when the MemoryAccess for
the still listed instruction was not found.
This hould fix the
Assertion failed: ArrayAccess && "No array access found for instruction!",
file ScopInfo.h, line 1494
compiler crashes.
llvm-svn: 312566
Before this patch, OpTree did not consider forwarding an operand tree consisting
of only single LoadInst as useful. The motivation was that, like an access to a
read-only variable, it would just replace one MemoryAccess by another. However,
in contrast to read-only accesses, this would replace a scalar access by an
array access, which is something worth doing.
In addition, leaving scalar MemoryAccess is problematic in that VirtualUse
prioritizes inter-Stmt use over intra-Stmt. It was possible that the same LLVM
value has a MemoryAccess for accessing the remote Stmt's LoadInst as well as
having the same LoadInst in its own instruction list (due to being forwarded
from another operand tree).
With this patch we ensure that if a LoadInst is forwarded is any operand tree,
also the operand tree containing just the LoadInst is forwarded as well, which
effectively removes the scalar MemoryAccess such that only the array access
remains, not both.
Thanks Michael for the detailed explanation.
Reviewers: Meinersbur, bellu, singam-sanjay, gareevroman
Subscribers: hfinkel, pollydev, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D37424
llvm-svn: 312456
In certain situations, the context in the isl_ast_build could result for the
min/max locations of our alias sets to become empty, which would cause an
internal error in isl, which is then unable to derive a value for these
expressions. Check these conditions before code generating expressions and
instead assume that alias check succeeded. This is valid, as the corresponding
memory accesses will not be executed under any valid context.
This fixed llvm.org/PR34432. Thanks to Qirun Zhang for reporting.
llvm-svn: 312455
In case a PHI node follows an error block we can assume that the incoming value
can only come from the node that is not an error block. As a result, conditions
that seemed non-affine before are now in fact affine.
llvm-svn: 312410
In Polly, we specifically add a paramter to represent the outermost dimension
size of fortran arrays. We do this because this information is statically
available from the fortran metadata generated by dragonegg.
However, we were only materializing these parameters (meaning, creating an
llvm::Value to back the isl_id) from *memory accesses*. This is wrong,
we should materialize parameters from *scop array info*.
It is wrong because if there is a case where we detect 2 fortran arrays,
but only one of them is accessed, we may not materialize the other array's
dimensions at all.
This is incorrect. We fix this by looping over all
`polly::ScopArrayInfo` in a scop, rather that just all `polly::MemoryAccess`.
Differential Revision: https://reviews.llvm.org/D37379
llvm-svn: 312350
Mark scalar dependences for different statements belonging to same BB
as 'Inter'.
Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>
Differential Revision: https://reviews.llvm.org/D37147
llvm-svn: 312324
Currently, GVN can be necessary to eliminate redundant instructions in case
of, for instance, GEMM and float type. This patch makes GVN be run during
the cleanup.
Reviewed-by: Tobias Grosser <tobias@grosser.es>,
Michael Kruse <llvm@meinersbur.de>
Differential Revision: https://reviews.llvm.org/D37340
llvm-svn: 312307
Summary:
After region statements now also have instruction lists, this is a
straightforward extension.
Reviewers: Meinersbur, bollu, singam-sanjay, gareevroman
Reviewed By: Meinersbur
Subscribers: hfinkel, pollydev, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D37298
llvm-svn: 312249
This is useful when we face certain intrinsics such as `llvm.exp.*`
which cannot be lowered by the NVPTX backend while other intrinsics can.
So, we would need to keep blacklists of intrinsics that cannot be
handled by the NVPTX backend. It is much simpler to try and promote
all intrinsics to libdevice versions.
This patch makes function/intrinsic very uniform, and will always try to use
a libdevice version if it exists.
Differential Revision: https://reviews.llvm.org/D37056
llvm-svn: 312239
The adds code generation support for the previous commit.
This patch has been re-applied, after the memory issue in the previous patch
has been fixed.
llvm-svn: 312211
By using statement lists in the entry blocks of region statements, instruction
level analyses also work on region statements.
We currently only model the entry block of a region statements, as this is
sufficient for most transformations the known-passes currently execute. Modeling
instructions in the presence of control flow (e.g. infinite loops) is left
out to not increase code complexity too much. It can be added when good use
cases are found.
This change set is reapplied, after a memory corruption issue had been fixed.
llvm-svn: 312210
By using statement lists in the entry blocks of region statements, instruction
level analyses also work on region statements.
We currently only model the entry block of a region statements, as this is
sufficient for most transformations the known-passes currently execute. Modeling
instructions in the presence of control flow (e.g. infinite loops) is left
out to not increase code complexity too much. It can be added when good use
cases are found.
llvm-svn: 312128
Reduction detection is only executed in the SCoP building phase.
Hence it fits better into ScopBuilder to separate
SCoP-construction from SCoP modeling.
llvm-svn: 312118
This method is only called in the SCoP building phase.
Therefore it fits better into ScopBuilder to separate
SCoP-construction from SCoP modeling.
llvm-svn: 312117
This method is only called in the SCoP building phase.
Therefore it fits better into ScopBuilder to separate
SCoP-construction from SCoP modeling.
llvm-svn: 312116
This method is only called in the SCoP building phase.
Therefore it fits better into ScopBuilder to separate
SCoP-construction from SCoP modeling.
This mostly mechanical change makes ScopBuilder directly access some of
ScopStmt/MemoryAccess private fields. We add ScopBuilder as a friend
class and will add proper accessor functions sometime later.
llvm-svn: 312115
This patch allows annotating of metadata in ir instruction
(with "polly_split_after"), which specifies where to split a particular
scop statement.
Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>
Differential Revision: https://reviews.llvm.org/D36402
llvm-svn: 312107
The intrinsics memset, memcopy and memmove do have their memory accesses
modeled by ScopBuilder. Do not consider them error-case behavior.
Test case will come with a future patch that requires memory intrinsics
outside of error blocks.
llvm-svn: 312021
Commit r252725 introduced a "return false" if an ignored intrinsics was
found. The consequence of this was that the mere existence of an ignored
intrinsic (such as llvm.dbg.value) before a call that would have
qualified the block to be an error block, to not be an error block.
The obvious goal was to just skip ignored intrinsics, not changing the
meaning of what an error block is.
llvm-svn: 312020
ZoneAlgo used to bail out for the complete SCoP if it encountered
something violating its assumption. This meant the neither OpTree can
forward any load nor DeLICM do anything in such cases, even if their
transformations are unrelated to the violations.
This patch adds a list of compatible elements (currently with the
granularity of entire arrays) that can be used for analysis. OpTree
and DeLICM can then check whether their transformations only concern
compatible elements, and skip non-compatible ones.
This will be useful for e.g. Polybench's benchmarks covariance,
correlation, bicg, doitgen, durbin, gramschmidt, adi that have
assumption violation, but which are not necessarily relevant
for all transformations.
Differential Revision: https://reviews.llvm.org/D37219
llvm-svn: 311929
Properly require and preserve the OptimizationRemarkEmitter for use in
ScopPass. Previously one had to get the ORE from ScopDetection because
CodeGeneration did not mark it as preserved. It would need to be
recomputed which results in the legacy PM to throw away all previous
SCoP analysis.
This also changes the implementation of ScopPass::getAnalysisUsage to
not unconditionally preserve all passes, but only those needed to be
preserved by any SCoP pass (at least when using the legacy PM). This
allows invalidating DependenceInfo (and IslAstInfo) in case the pass
would cause them to change (e.g. OpTree, DeLICM, MaximalArrayExpansion)
JSONImporter should also invalidate the DependenceInfo. In this patch
it marks DependenceInfo as preserved anyway because some regression
tests depend on it.
Differential Revision: https://reviews.llvm.org/D37010
llvm-svn: 311888
In cases where the entry block of a scop was not contained in a loop that was
part of the scop region and at the same time there was a loop surrounding the
scop, we missed to count the loops in the scop and consequently did not consider
the scop profitable. We correct this by only moving to the loop parent, in case
the current loop is loop contained in the scop.
This increases the number of loops in COSMO which we assume to be profitable
from 3974 to 4981.
llvm-svn: 311863
Whether a partial write is tautological/unsatisfiable not only
depends on the access domain, but also on the domain covered
by its node in the AST.
In the example below, there are two instances of Stmt_cond_false. It may have a partial write access that is not executed in instance Stmt_cond_false(0).
for (int c0 = 0; c0 < tmp5; c0 += 1) {
Stmt_for_body344(c0);
if (tmp5 >= c0 + 2)
Stmt_cond_false(c0);
Stmt_cond_end(c0);
}
if (tmp5 <= 0) {
Stmt_for_body344(0);
Stmt_cond_false(0);
Stmt_cond_end(0);
}
Isl cannot derive a subscript for an array element that is never accessed.
This caused an error in that no subscript expression has been generated
in IslNodeBuilder::createNewAccesses, but BlockGenerator expected one
to exist because there is an execution of that write, just not in that
ast node.
Fixed by instead of determining whether the access domain is empty,
inspect whether isl generated a constant "false" ast expression in
the current ast node.
This should fix a compiler crash of the aosp buildbot.
llvm-svn: 311663
This is a stylistic change to make the function a little more readable.
Also add a debug print to show what instruction contains a use of a
function we don't understand in the kernel.
Differential Revision: https://reviews.llvm.org/D37058
llvm-svn: 311648
Summary:
This patch comes directly after https://reviews.llvm.org/D34982 which allows fully indexed expansion of MemoryKind::Array. This patch allows expansion for MemoryKind::Value and MemoryKind::PHI.
MemoryKind::Value seems to be working with no majors modifications of D34982. A test case has been added. Unfortunatly, no "run time" checks can be done for now because as @Meinersbur explains in a comment on D34982, DependenceInfo need to be cleared and reset to take expansion into account in the remaining part of the Polly pipeline. There is no way to do that in Polly for now.
MemoryKind::PHI is not working. Test case is in place, but not working. To expand MemoryKind::Array, we expand first the write and then after the reads. For MemoryKind::PHI, the idea of the current implementation is to exchange the "roles" of the read and write and expand first the read according to its domain and after the writes.
But with this strategy, I still encounter the problem of union_map in new access map.
For example with the following source code (source code of the test case) :
```
void mse(double A[Ni], double B[Nj]) {
int i,j;
double tmp = 6;
for (i = 0; i < Ni; i++) {
for (int j = 0; j<Nj; j++) {
tmp = tmp + 2;
}
B[i] = tmp;
}
}
```
Polly gives us the following statements and memory accesses :
```
Statements {
Stmt_for_body
Domain :=
{ Stmt_for_body[i0] : 0 <= i0 <= 9999 };
Schedule :=
{ Stmt_for_body[i0] -> [i0, 0, 0] };
ReadAccess := [Reduction Type: NONE] [Scalar: 1]
{ Stmt_for_body[i0] -> MemRef_tmp_04__phi[] };
MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
{ Stmt_for_body[i0] -> MemRef_tmp_11__phi[] };
Instructions {
%tmp.04 = phi double [ 6.000000e+00, %entry.split ], [ %add.lcssa, %for.end ]
}
Stmt_for_inc
Domain :=
{ Stmt_for_inc[i0, i1] : 0 <= i0 <= 9999 and 0 <= i1 <= 9999 };
Schedule :=
{ Stmt_for_inc[i0, i1] -> [i0, 1, i1] };
MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
{ Stmt_for_inc[i0, i1] -> MemRef_tmp_11__phi[] };
ReadAccess := [Reduction Type: NONE] [Scalar: 1]
{ Stmt_for_inc[i0, i1] -> MemRef_tmp_11__phi[] };
MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
{ Stmt_for_inc[i0, i1] -> MemRef_add_lcssa__phi[] };
Instructions {
%tmp.11 = phi double [ %tmp.04, %for.body ], [ %add, %for.inc ]
%add = fadd double %tmp.11, 2.000000e+00
%exitcond = icmp ne i32 %inc, 10000
}
Stmt_for_end
Domain :=
{ Stmt_for_end[i0] : 0 <= i0 <= 9999 };
Schedule :=
{ Stmt_for_end[i0] -> [i0, 2, 0] };
MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
{ Stmt_for_end[i0] -> MemRef_tmp_04__phi[] };
ReadAccess := [Reduction Type: NONE] [Scalar: 1]
{ Stmt_for_end[i0] -> MemRef_add_lcssa__phi[] };
MustWriteAccess := [Reduction Type: NONE] [Scalar: 0]
{ Stmt_for_end[i0] -> MemRef_B[i0] };
Instructions {
%add.lcssa = phi double [ %add, %for.inc ]
store double %add.lcssa, double* %arrayidx, align 8
%exitcond5 = icmp ne i64 %indvars.iv.next, 10000
}
}
```
and the following dependences :
```
{ Stmt_for_inc[i0, 9999] -> Stmt_for_end[i0] : 0 <= i0 <= 9999;
Stmt_for_inc[i0, i1] -> Stmt_for_inc[i0, 1 + i1] : 0 <= i0 <= 9999 and 0 <= i1 <= 9998;
Stmt_for_body[i0] -> Stmt_for_inc[i0, 0] : 0 <= i0 <= 9999;
Stmt_for_end[i0] -> Stmt_for_body[1 + i0] : 0 <= i0 <= 9998 }
```
When trying to expand this memory access :
```
{ Stmt_for_inc[i0, i1] -> MemRef_tmp_11__phi[] };
```
The new access map would look like this :
```
{ Stmt_for_inc[i0, 9999] -> MemRef_tmp_11__phi_exp[i0] : 0 <= i0 <= 9999; Stmt_for_inc[i0, i1] ->MemRef_tmp_11__phi_exp[i0, 1 + i1] : 0 <= i0 <= 9999 and 0 <= i1 <= 9998 }
```
The idea to implement the expansion for PHI access is an idea from @Meinersbur and I don't understand why my implementation does not work. I should have miss something in the understanding of the idea.
Contributed by: Nicolas Bonfante <nicolas.bonfante@gmail.com>
Reviewers: Meinersbur, simbuerg, bollu
Reviewed By: Meinersbur
Subscribers: llvm-commits, pollydev, Meinersbur
Differential Revision: https://reviews.llvm.org/D36647
llvm-svn: 311619
Add statistics about
- Which optimizations are applied
- Number of loops in Scops at various stages
- Number of scalar/singleton writes at various stages representative
for scalar false dependencies
- Number of parallel loops
These will be useful to find regressions due to moving Polly further
down of LLVM's pass pipeline.
Differential Revision: https://reviews.llvm.org/D37049
llvm-svn: 311553
Loop with zero iteration are, syntactically, loops. They have been
excluded from the loop counter even for the non-profitable counters.
This seems to be unintentially as the sentinel value of '0' minimal
iterations does exclude such loops.
Fix by never considering the iteration count when the sentinel
value of 0 is found.
This makes the recently added NumTotalLoops couter redundant
with NumLoopsOverall, which now is equivalent. Hence, NumTotalLoops
is removed as well.
Note: The test case 'ScopDetect/statistics.ll' effectively does not
check profitability, because -polly-process-unprofitable is passed
to all test cases.
llvm-svn: 311551
MSVC warns about comparison between a signed and unsigned integer.
The rules of C(++) define that an unsigned comparison has to be
carried-out in this case. This is unlikely to be intended.
Fix by assigning the loop's upper bound to a signed integer first.
This also avoids repeated evaluation of the invariant upper bound.
llvm-svn: 311548
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
Summary:
There is no need to emit alias metadata for scalars, as basicaa will easily
distinguish them from arrays. This reduces the size of the metadata we generate.
This is especially useful after we moved to -polly-position=before-vectorizer,
where a lot more scalar dependences are introduced, which increased the size of
the alias analysis metadata and made us commonly reach the limits after which
we do not emit alias metadata that have been introduced to prevent quadratic
growth of this alias metadata.
This improves 2mm performance from 1.5 seconds to 0.17 seconds.
Reviewers: Meinersbur, bollu, singam-sanjay
Reviewed By: Meinersbur
Subscribers: pollydev, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D37028
llvm-svn: 311498
Currently, in case of GEMM and the pattern matching based optimizations, we
use only the SLP Vectorizer out of two LLVM vectorizers. Since the Loop
Vectorizer can get in the way of optimal code generation, we disable the Loop
Vectorizer for the innermost loop using mark nodes and emitting the
corresponding metadata.
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: https://reviews.llvm.org/D36928
llvm-svn: 311473
This was originally a `#define`. It is much easier to play around with
this as an environment variable when we run on large programs.
Differential Revision: https://reviews.llvm.org/D37012
llvm-svn: 311471
The implementation of computeArrayUnused did not consider writes without
reads before, except for the first write in the SCoP. This caused it to
'forget' writes directly following another write.
This patch re-adds the entire reaching defintion of a write that has not
been covered before by a read.
This fixes Polybench 4.2 2mm where only one of the matrix-multiplication
was detected.
llvm-svn: 311403
Dragonegg generates most function parameters as pointers to the actual
parameters. However, it does not mark these parameters with the
dereferencable attribute.
Polly is conservative when it comes to invariant load
hoisting, thus we add runtime checks to invariant load hoisted pointers
when we do not know that pointers are dereferencable. This is correct behaviour,
but is a performance penalty.
Add a flag that allows all pointer parameters to be dereferencable. That
way, polly can speculatively load-hoist paramters to functions without
runtime checks.
Differential Revision: https://reviews.llvm.org/D36461
llvm-svn: 311329
This feature was not enabled for `PPCGCodeGeneration`. Now that this is
enabled, we can benchmark Scops that have been optimised with
`-polly-codegen-ppcg` with the `-polly-codegen-perf-monitoring` option.
Differential Revision: https://reviews.llvm.org/D36934
llvm-svn: 311328
The pattern recognition for MatMul is restrictive.
The number of "disjuncts" in the isl_map containing constraint
information was previously required to be 1
(as per isl_*_coalesce - which should ideally produce a domain map with
a single disjunct, but does not under some circumstances).
This was changed and made more flexible.
Contributed-by: Annanay Agarwal <cs14btech11001@iith.ac.in>
Differential Revision: https://reviews.llvm.org/D36460
llvm-svn: 311302
We now load the function pointer for `cuMemAllocManaged` dynamically, so
it should be possible to compile `GPUJIT` on non-CUDA systems again.
It should now be possible to link on non-cuda systems again.
Thanks to Philipp Schaad for noticing this inconsitency.
Differential Revision: https://reviews.llvm.org/D36921
llvm-svn: 311289
We still see some issues with parameter space mismatches. Revert this to get
a clean baseline. We will recommit after these issues have been resolved.
This reverts commit 0e360a14194f722ded7aa2bc9d4be2ed2efeeb49.
llvm-svn: 311268
Instead of using Twines and temporary expressions, we do string manipulation
through a std::string. This resolves a memory corruption issue, which likely
was caused by twines loosing their underlying string too soon.
llvm-svn: 311264
- We should iterate over `I`, which is `Cur` expanded out to an
instruction, and not `Cur` itself.
- This is a bugfix.
Differential Revision: https://reviews.llvm.org/D36923
llvm-svn: 311261
Summary:
This information is necessary for PPCG to perform correct life range reordering.
With these changes applied we can live-range reorder some of the important
kernels in COSMO.
We also update and rename one test case, which previously could not be optimized
and now is optimized thanks to live-range reordering. To preserve test coverage
we add a new test case scalar-writes-in-scop-requires-abort.ll, which exercises
our automatic abort in case of scalar writes in the kernel.
Reviewers: Meinersbur, bollu, singam-sanjay
Subscribers: nemanjai, pollydev, llvm-commits, kbarton
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36929
llvm-svn: 311259
Kernel argument sizes now only get appended to the kernel launch parameter list if the OpenCL runtime is selected, not if CUDA runtime is chosen.
Differential revision: D36925
llvm-svn: 311248
When using -polly-ignore-integer-wrapping and -polly-acc-codegen-managed-memory
we add parameter dimensions lazily to the domains, which results in PPCG not
including parameter dimensions that are only used in memory accesses in the
kernel space. To make sure these parameters are still passed to the kernel, we
collect these parameter dimensions and align the kernel's parameter space
before code-generating it.
llvm-svn: 311239
Summary:
When trying to expand memory accesses, the current version of Polly uses statement Level dependences. The actual implementation is not working in case of multiple dependences per statement. For example in the following source code :
```
void mse(double A[Ni], double B[Nj], double C[Nj], double D[Nj]) {
int i,j;
for (j = 0; j < Ni; j++) {
for (int i = 0; i<Nj; i++)
S: B[i] = i;
for (int i = 0; i<Nj; i++)
T: D[i] = i;
U: A[j] = B[j];
C[j] = D[j];
}
}
```
The statement U has two dependences with S and T. The current version of polly fails during expansion.
This patch aims to fix this bug. For that, we use Reference Level dependences to be able to filter dependences according to statement and memory ref. The principle of expansion remains the same as before.
We also noticed that we need to bail out if load come after store (at the same position) in same statement. So a check was added to isExpandable.
Contributed by: Nicholas Bonfante <nicolas.bonfante@insa-lyon.fr>
Reviewers: Meinersbur, simbuerg, bollu
Reviewed By: Meinersbur, simbuerg
Subscribers: pollydev, llvm-commits
Differential Revision: https://reviews.llvm.org/D36791
llvm-svn: 311165
Summary:
Drop unused parameter dimensions to reduce the size of the sets we are working
with. Especially the computed dependences tend to accumulate a lot of parameters
that are present in the input memory accesses, but often not necessary to
express the actual dependences. As isl represents maps and sets with dense
matrices, reducing the dimensionality of isl sets commonly reduces code
generation performance.
This reduces compile time from 17 to 11 seconds for our test case. While this is
not impressive, this patch helped me to identify the previous two performance
improvements and additionally also increases readability of the isl data
structures we use.
Reviewers: Meinersbur, bollu, singam-sanjay
Reviewed By: bollu
Subscribers: nemanjai, pollydev, llvm-commits, kbarton
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36869
llvm-svn: 311161
Summary:
They are not used and consequently do not even need to be computed. This reduces
the overall compile time for our kernel from 1m33s to 17s.
Reviewers: Meinersbur, bollu, singam-sanjay
Reviewed By: bollu
Subscribers: nemanjai, pollydev, llvm-commits, kbarton
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36868
llvm-svn: 311157
Summary:
This change reduces the overall number of synchronize calls for kernels with
a lot of output data at the cost of additional synchronize calls for kernels
launched in sequence without any device to host transfers in between. As the
latter pattern is a lot less frequent, this seems a better tradeoff.
Even though the above motivation would be motivation enough, this is just
a step towards enabling ppcg to not compute to and from device copy calls
at all, which would be incorrect in case we still relied on these calls to
place our synchronization statements.
Reviewers: Meinersbur, bollu, singam-sanjay
Reviewed By: bollu
Subscribers: nemanjai, kbarton, pollydev, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36867
llvm-svn: 311155
This avoid the construction of very large sets and in many cases also keeps the
number of parameters low. As a result, we see a compile time reduction from 5
minutes to only slightly above 1 minute for one of our larger test cases.
llvm-svn: 311127
We add a ScopInliner pass which inlines functions based on a simple heuristic:
Let `g` call `f`.
If we can model all of `f` as a Scop, we inline `f` into `g`.
This requires `-polly-detect-full-function` to be enabled. So, the pass
asserts that `-polly-detect-full-function` is enabled.
Differential Revision: https://reviews.llvm.org/D36832
llvm-svn: 311126
Reuse the machinery built for replacing global arrays to replace malloc/free as
well. Example replacement that was missed earlier:
```
call void \
bitcast (void (i8*)* @free to void (%custom_type*)*) (%custom_type* %13)
```
- Since the `bitcast` is a `ConstantExpr`, `replaceAllUsesWith` would miss
this. We don't miss this anymore.
Differential Revision: https://reviews.llvm.org/D36825
llvm-svn: 311121
In release builds LLVM may not pass along LLVM names consistently. We make the
test cases independent of the LLVM-IR names to avoid spurious test case
failures.
llvm-svn: 311118
- If we have global arrays, we would like to rewrite them to global
pointers which are allocated using `cudaMallocManaged`.
- If we have allocas in a function, we would like to rewrite them to
heap-allocations with `cudaMallocManaged` and `cudaFree`.
- With these rewrite mechanisms, we can offload _any_ function to the
GPU with no code rewrite whatsover.
Differential Revision: https://reviews.llvm.org/D36516
llvm-svn: 311080
Summary:
This pass detangles induction variables from functions, which take variables by
reference. Most fortran functions compiled with gfortran pass variables by
reference. Unfortunately a common pattern, printf calls of induction variables,
prevent in this situation the promotion of the induction variable to a register,
which again inhibits any kind of loop analysis. To work around this issue
we developed a specialized pass which introduces separate alloca slots for
known-read-only references, which indicate the mem2reg pass that the induction
variables can be promoted to registers and consquently enable SCEV to work.
We currently hardcode the information that a function
_gfortran_transfer_integer_write does not read its second parameter, as
dragonegg does not add the right annotations and we cannot change old dragonegg
releases. Hopefully flang will produce the right annotations.
Reviewers: Meinersbur, bollu, singam-sanjay
Reviewed By: bollu
Subscribers: mgorny, pollydev, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36800
llvm-svn: 311066
ReportLoopHasNoExit started failing after r310940 that added
infinite loops to postdominators. The change made regions not
contain infinite loops anymore.
This patch unbreaks the polly tree by XFAILING the
ReportLoopHasNoExit test. Full fix is under review in D36776.
llvm-svn: 310980
Requesting size 0 allocations from `cuMalloc` / `cuMallocManaged` fails.
If there is a size 0 allocation that can be statically proved, the we
fail at PPCGCodeGeneration. This is because if size 0 allocation could
take place, we should not generate code that tries to use this array.
However, there are cases where we cannot statically prove this, and at
runtime we get a request for 0 bytes of memory. We choose to allocate
size 1 to allow the program to continue running.
Differential Revision: https://reviews.llvm.org/D36751
llvm-svn: 310941
Summary:
Before, if we fail to parse a jscop file, this will be reported as an
error and importing is aborted. However, this isn't actually strong
enough, since although the import is aborted, the scop has already been
modified and is very likely broken. Instead, make this a hard failure
and throw an LLVM error. This new behaviour requires small changes to
the tests for the legacy pass, namely using `not` to verify the error.
Further, fixed the jscop file for the
base_pointer_load_is_inst_inside_invariant_1 testcase.
Reviewed By: Meinersbur
Split out of D36578.
llvm-svn: 310599
Summary:
I pulled out all functionality into static functions, and use those both
in the legacy passes and in the new ones.
Reviewers: grosser, Meinersbur, bollu
Reviewed By: Meinersbur
Subscribers: llvm-commits, pollydev
Differential Revision: https://reviews.llvm.org/D36578
llvm-svn: 310597
Summary:
During code generation for a Scop we modify the IR of a function.
While this shouldn't affect a Scop in the formal sense, the implementation
caches various information about the IR such as SCEV expressions for bounds or
parameters. This cached information needs to be updated or invalidated. To this
end, SPMUpdater allows passes to report when they've invalidated a Scop to the
PassManager, which will then flush and recompute all Scops. This in turn
invalidates all iterators, so references to Scops shouldn't be held.
Reviewers: grosser, Meinersbur, bollu
Reviewed By: grosser
Subscribers: llvm-commits, pollydev
Differential Revision: https://reviews.llvm.org/D36524
llvm-svn: 310551
We are working towards removing uses of Scop::getStmtFor(BB). In this
patch, we remove dependency of Scop::getStmtFor(Inst) on getStmtFor(BB).
To do so, we introduce a map of instructions to their corresponding scop
statements and use it to get the instructions' statement.
Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>
Differential Revision: https://reviews.llvm.org/D35663
llvm-svn: 310494
This pass is useful to automatically convert a codebase that uses malloc/free
to use their managed memory counterparts.
Currently, rewrite malloc and free to the `polly_{malloc,free}Managed` variants.
A future patch will teach ManagedMemoryRewrite to rewrite global arrays
as pointers to globally allocated managed memory.
Differential Revision: https://reviews.llvm.org/D36513
llvm-svn: 310471
Codegen with -polly-parallel queried the unmapped MemoryAccess, but only
the MemoryKind after mapping is relevant for codegen.
This should fix various fails of the
perf-x86_64-penryn-O3-polly-parallel-fast buildbot.
llvm-svn: 310466
The previous value of "polly-delicm" was forgotten to to be changed when
ForwardOpTree was split from DeLICM.
Thanks to Tobias for noticing!
llvm-svn: 310465
distributeDomain() and filterKnownValInst() are used in a scop
of ForwardOpTree that limits the number of isl operations.
Therefore some isl functions may return null after any operation.
Remove assertion that assume non-null results and handle
isl_*_foreach returning isl::stat::error.
I hope this fixes the crash of the asop buildbot at ihevc_recon.c.
llvm-svn: 310461
Previously, we used to compute this with `elementSizeInBits / 8`. This
would yield an element size of 0 when the array had element size < 8 in
bits.
To fix this, ask data layout what the size in bytes should be.
Differential Revision: https://reviews.llvm.org/D36459
llvm-svn: 310448
We introduce another level of alias metadata to distinguish the individual
non-aliasing accesses that have inter iteration alias-free base pointers
marked with "Inter iteration alias-free" mark nodes. To distinguish two
accesses, the comparison of raw pointers representing base pointers is used.
In case of, for example, ublas's prod function that implements GEMM, and
DeLiCM we can get accesses to same location represented by different raw
pointers. Consequently, we create different alias sets that can prevent
accesses from, for example, being sinked or hoisted.
To avoid the issue, we compare the corresponding SCEV information instead
of the corresponding raw pointers.
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: https://reviews.llvm.org/D35761
llvm-svn: 310380
Currently, only convex isolation sets can be efficiently processed by isl.
Consequently, as a temporary solution, we use a different algorithm for partial
tile isolation that helps to build convex isolation sets in some cases.
Reviewed-by: Tobias Grosser <tobias@grosser.es>
Differential Revision: https://reviews.llvm.org/D36278
llvm-svn: 310374
This allows us to get rid of stores that are overwritten within the very same
basic block, without ever being read beforehand. This simplification is
necessary for delicm to run on pb4's correlation.
llvm-svn: 310369
To do this, we replicate what `CodeGeneration` does. We expose
`markNodeUnreachable` from `CodeGeneration` to `PPCGCodeGeneration`.
Differential Revision: https://reviews.llvm.org/D36457
llvm-svn: 310350
It is possible that partial writes are empty (write is never executed).
In this case, when in PHINode's incoming edge is never taken such that
the incoming write becomes an empty partial write, if enabled. The
issue is that when converting the union_map to an map, it's space
cannot be derived from the union_map itself. Rather, we need to
determine its space independently.
This fixes test-suite's MultiSource/Benchmarks/ASC_Sequoia/CrystalMk.
llvm-svn: 310348
- It's useful to know the amount of memory asked for since, for example,
asking for `0` bytes of memory is illegal.
- Line number is helpful since we print the same message in the function
at different points.
llvm-svn: 310340
In certain cases delicm might decide to not leave the original array write in
the loop body, but to remove it and instead leave a transformed phi node as
write access. This commit teached the matmul pattern detection to order the
memory accesses according to when the access actually happens and use this
information to detect the new pattern. This makes pattern based matmul
optimization work for 2mm and 3mm in polybench 4 after
polly-position=before-vectorizer has been enabled.
llvm-svn: 310338
Polly has traditionally always been executed at the beginning of the pass
pipeline as LLVM's inliner and DeLICM passes introduced plenty of scalar
dependences which prevented any kind of useful high-level loop optimizations
later in the pass pipeline. With DeLICM now being available, Polly can also
run optimizations when folded into the pass pipeline. This has the benefit
that Polly should now be more effective on C++ code and as an additional bonus,
no additional early canonicalization phase must be run. As a result, Polly
touches the code only if it applies a transformation. Code that does not
benefit from Polly is not touched and consequently will have the very same
execution time as without Polly enabled. Random performance changes, as could
sometimes be observed with polly-position=early are consequently not possible
any more. If performance is changed, this is due to Polly is choosing to
perform a transformation. If this choice is wrong, it can be fixed directly
in Polly.
http://polly.llvm.org/docs/Architecture.html#polly-in-the-llvm-pass-pipeline
llvm-svn: 310319
This allows us to remove more scalar dependences. While this feature is still
rather experimental, we want to give it sufficient test coverage.
llvm-svn: 310314
Two write statements which write into the very same array slot generally are
conflicting. However, in case the value that is written is identical, this
does not cause any problem. Hence, allow such write pairs in this specific
situation.
llvm-svn: 310311
This commit implements the initial version of fully-indexed static
expansion.
```
for(int i = 0; i<Ni; i++)
for(int j = 0; j<Ni; j++)
S: B[j] = j;
T: A[i] = B[i]
```
After the pass, we want this :
```
for(int i = 0; i<Ni; i++)
for(int j = 0; j<Ni; j++)
S: B[i][j] = j;
T: A[i] = B[i][i]
```
For now we bail (fail) in the following cases:
- Scalar access
- Multiple writes per SAI
- MayWrite Access
- Expansion that leads to an access to the original array
Furthermore: We still miss checks for escaping references to the array
base pointers. A future commit will add the missing escape-checks to
stay correct in those cases. The expansion is still locked behind a
CLI-Option and should not yet be used.
Patch contributed by: Nicholas Bonfante <bonfante.nicolas@gmail.com>
Reviewers: simbuerg, Meinersbur, bollu
Reviewed By: Meinersbur
Subscribers: mgorny, llvm-commits, pollydev
Differential Revision: https://reviews.llvm.org/D34982
llvm-svn: 310304
This is an addition to the -polly-optree pass that reuses the array
content analysis from DeLICM to find array elements that contain the
same value as the value loaded when the target statement instance
is executed.
The analysis is now enabled by default.
The known content analysis could also be used to rematerialize any
llvm::Value that was written to some array element, but currently
only loads are forwarded.
Differential Revision: https://reviews.llvm.org/D36380
llvm-svn: 310279
This update is mostly a maintenance update, but also exposes a couple of new
functions that will be needed for the next version of the isl++ bindings.
llvm-svn: 310205
Summary:
Small patch to fix the JSON exporter.
Currently, using "opt -polly-export-jscop" does not generate jscop files, but gives an error:
*** Error in `opt': corrupted double-linked list: 0x0000000000bc4bb0 ***
Updated the function getAccessRelationStr() to work with the current version of getAccessRelation(), fixing the JSON exporter
Reviewers: bollu, grosser
Reviewed By: grosser
Subscribers: grosser, llvm-commits, pollydev
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36370
llvm-svn: 310199
Summary:
This resolves some "instruction does not dominate use" errors, as we used to
prepare the arrays at the location of the first kernel, which not necessarily
dominated all other kernel calls.
Reviewers: Meinersbur, bollu, singam-sanjay
Subscribers: nemanjai, pollydev, llvm-commits, kbarton
Differential Revision: https://reviews.llvm.org/D36372
llvm-svn: 310196
A Scop with a loop outside it is not handled currently by
PPCGCodeGeneration. The test case is such that the Scop has only one inner loop
that is detected. This currently breaks codegen.
The fix is to reuse the existing mechanism in `IslNodeBuilder` within
`GPUNodeBuilder.
Differential Revision: https://reviews.llvm.org/D36290
llvm-svn: 310193
This logic is duplicated, so we refactor it into a separate function.
This will be used in a later patch to teach PPCGCodeGen code generation
for loops that are outside the scop.
Differential Revision: https://reviews.llvm.org/D36310
llvm-svn: 310192
In https://reviews.llvm.org/D36278 it was pointed out that the behavior of
getPartialTilePrefixes is not very well understood. To allow for a better
understanding, we first provide some basic unittests.
llvm-svn: 310175
The method forwardSpeculatable forwards speculatively executable
instructions and is currently the only way to forward an
instruction.
In the future we intend to add more methods.
llvm-svn: 310056
Summary:
Testing the new-pm passes becomes much easier once they behave more like the
old passes in terms of the order in which Scops are processed and printed. This
requires three changes:
- ScopInfo: Use an ordered map to store scops
- ScopInfo: Iterate and print Scops in reverse order to match legacy PM behaviour
- ScopDetection: print function name in ScopAnalysisPrinter
Reviewers: grosser, Meinersbur, bollu
Reviewed By: grosser
Subscribers: pollydev, llvm-commits
Differential Revision: https://reviews.llvm.org/D36303
llvm-svn: 310052
The complication of bspatch.cc of the AOSP buildbot currently fails
presumably because the occurance of a MetadataAsValue in an operand.
This kind of value can occur as operands of intrinsics, the typical
example being the debug intrinsics.
Polly currently ignores the debug intrinsics and it is not yet clear
which other intrinic might occur. For such cases, and to unbreak the
AOSP buildbot, treat a MetadataAsValue as a constant because it can be
referenced without modification in generated code.
llvm-svn: 309992
With this patch, we get rid of the last use of getStmtFor(BB). Here
this is done by getting the last statement of the incoming block in
case the user is a phi node; otherwise just fetching the statement
comprising the instruction for which the virtual use is being created.
Differential Revision: https://reviews.llvm.org/D36268
llvm-svn: 309947
Summary:
In case the option -polly-ignore-parameter-bounds is set, not all parameters
will be added to context and domains. This is useful to keep the size of the
sets and maps we work with small. Unfortunately, for AST generation it is
necessary to ensure all parameters are part of the schedule tree. Hence,
we modify the GPGPU code generation to make sure this is the case.
To obtain the necessary information we expose a new function
Scop::getFullParamSpace(). We also make a couple of functions const to be
able to make SCoP::getFullParamSpace() const.
Reviewers: Meinersbur, bollu, gareevroman, efriedma, huihuiz, sebpop, simbuerg
Subscribers: nemanjai, kbarton, pollydev, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36243
llvm-svn: 309939
When we have `-polly-ignore-parameter-bounds`, `Scop::Context` does not contain
all the paramters present in the program.
The construction of the `isl_multi_pw_aff` requires all the indivisual `pw_aff`
to have the same parameter dimensions. To achieve this, we used to realign
every `pw_aff` with `Scop::Context`. However, in conjunction with
`-polly-ignore-parameter-bounds`, this is now incorrect, since `Scop::Context`
does not contain all parameters.
We set this up correctly by creating a space that has all the parameters
used by all the `isl_pw_aff`. Then, we realign all `isl_pw_aff` to this space.
llvm-svn: 309934
These passes have been tested over the last month and should generally help
to remove scalar data dependences in Polly. We enable them to give them even
wider test coverage. Large performance regressions and any kind of correctness
regressions are not expected.
llvm-svn: 309878
When compiling with clang, explicit instantiation of the
OwningScopAnalysisManagerFunctionProxy needs to happen within the polly
namespace. Same goes with the specialization of its run method.
llvm-svn: 309835
Summary:
This patch is a first attempt at registering Polly passes with the LLVM tools. Tool plugins are still unsupported, but this registration is usable from the tools if Polly is linked into them (albeit requiring minimal patches to those tools). Registration requires a small amount of machinery (the owning analysis proxies), necessary for injecting ScopAnalysisManager objects into the calling tools.
This patch is marked WIP because the registration is incomplete. Parsing manual pipelines is fully supported, but default pass injection into the O3 pipeline is lacking, mostly because there is opportunity for some redesign here, I believe. The first point of order would be insertion points. I think it makes sense to run before the vectorizers. Running Polly Early, however, is weird. Mostly because it actually is the default (which to me is unexpected), and because Polly runs it's own O1 pipeline. Why not instead insert it at an appropriate place somewhere after simplification happend? Running after the loop optimizers seems intuitive, but it also seems wasteful, since multiple consecutive loops might well be a single scop, and we don't need to run for all of them.
My second request for comments would be regarding all those smallish helper passes we have, like PollyViewer, PollyPrinter, PollyImportJScop. Right now these are controlled by command line options, deciding whether they should be part of the Polly pipeline. What is your opinion on treating them like real passes, and have the user write an appropriate pipeline if they want to use any of them?
Reviewers: grosser, Meinersbur, bollu
Reviewed By: grosser
Subscribers: llvm-commits, pollydev
Tags: #polly
Differential Revision: https://reviews.llvm.org/D35458
llvm-svn: 309826
Summary:
**Remove debug metadata from instruction to be copied to prevent the source file's debug metadata being copied into GPUModule and eventually failing Module verification and ASM string codegeneration.**
When copying the instruction onto the Module meant for the GPU, debug metadata attached to an instruction causes all related metadata to be pulled into the Module, including the DICompileUnit, which is not listed in llvm.dbg.cu of the Module. This fails the verification of the Module and generation of the ASM string.
The only debug metadata of the instruction, the DebugLoc, is unset by this patch.
This patch reattempts https://reviews.llvm.org/D35630 by targeting only those instructions that are to end up in a Module meant for the GPU.
Reviewers: grosser, bollu
Reviewed By: grosser
Subscribers: pollydev
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36161
llvm-svn: 309822
Summary: I made a mistake in handling transitive invalidation of analysis results. I've updated the list of preserved analyses as well as the correct result dependences.
The Invalidator passed through the invalidate() path can be used to
transitively invalidate analyses. It frequently happens that analysis
results depend on other analyses, and thus store references to their
results. When the dependee now gets invalidated, the depender needs to
be invalidated as well. This is the purpose of the Invalidator object,
which can be used to check whether some dependee analysis is in the
process of being invalidated. I originally was checking the wrong
dependee analyses, which is an actual error, you can only check analysis
results that are in the cache (which they are if you've captured their
reference). The invalidation I'm handling inside the proxy deals with
the standard analyses the proxy passes into the Scop pipeline, since I'm
capturing their reference.
This checking allows us to actually preserve a couple of results outside
of the proxy, since the Scop pipeline shouldn't break those, or
otherwise should update them accordingly.
Reviewers: grosser, Meinersbur, bollu
Reviewed By: grosser
Subscribers: pollydev, llvm-commits
Differential Revision: https://reviews.llvm.org/D36216
llvm-svn: 309811
We introduce `polly_mallocManaged` and `polly_freeManaged` as
proxies for `cudaMallocManaged` / `cudaFree`. This is currently not
used by Polly. It is auxiliary code that is used in `COSMO`.
This is useful because `polly_mallocManaged` matches the signature of `malloc`,
while `cudaMallocManaged` does not. We introduce `polly_freeManaged` for
symmetry.
We use this in COSMO to use the unified memory feature of the newer
CUDA APIs (>= 6).
Differential Revision: https://reviews.llvm.org/D35991
llvm-svn: 309808
On mixing the driver and runtime APIs, it is quite possible that a
context already exists due to runtime API usage. In this case, Polly should
try to use the same context.
This patch teaches GPUJIT to detect that a context exists and how to
pick up this context.
Without this, calling `cudaMallocManaged`, for example, before a
polly-generated kernel launch causes P100 to *hang*.
This is a part of (https://reviews.llvm.org/D35991) that was extracted
out.
Differential Revision: https://reviews.llvm.org/D36162
llvm-svn: 309802
Commit r309730 moved the call to canForwardTree into an assert(), even
though this function has side-effects if its DoIt parameter is true. To
avoid a warning in release builds, do an (void)Execution of its result
instead.
To avoid such confusion in the future, rename
canForwardTree() to forwardTree().
llvm-svn: 309753
The previous algorithm was to search a writes and the sours of its value
operand, and see whether the write just stores the same read value back,
which includes a search whether there is another write access between
them. This is O(n^2) in the max number of accesses in a statement
(+ the complexity of isl comparing the access functions).
The new algorithm is more similar to the one used for searching for
overwrites and coalescable writes. It scans over all accesses in order
of execution while tracking which array elements still have the same
value since it was read. This is O(n), not counting the complexity
within isl. It should be more reliable than trying to catch all
non-conforming cases in the previous approach. It is also less code.
We now also support if the write is a partial write of the read's
domain, and to some extent non-affine subregions.
Differential Revision: https://reviews.llvm.org/D36137
llvm-svn: 309734
With a lot of reads and writes to the same array in a statement,
some isl sets that capture the state between access can become
complex such that isl takes more considerable time and memory
for operations on them.
The problems identified were:
- is_subset() takes considerable time with many disjoints in the
arguments. We limit the number of disjoints to 4, any additional
information is thrown away.
- subtract() can lead to many disjoints. We instead assume that any
array element is possibly accessed, which removes all disjoints.
- subtract_domain() may lead to considerable processing, even if all
elements are are to be removed. Instead, we remove determine and
remove the affected spaces manually. No behaviour is changed.
llvm-svn: 309728
This is necessary to get accurate traces from `nvprof` / `nvcc`.
Otherwise, we lose some profiling information.
Differential Revision: https://reviews.llvm.org/D35940
llvm-svn: 309682
It is possible that the `HostPtr` that coresponds to an array could be
invariant load hoisted. Make sure we use the invariant load hoisted
value by using `IslNodeBuilder::getLatestValue`.
Differential Revision: https://reviews.llvm.org/D36001
llvm-svn: 309681
We populate `IslNodeBuilder::ValueMap` which contains replacements for
`llvm::Value`s. There was no simple method to pick up a replacement if
it exists, otherwise fall back to the original.
Create a method `IslNodeBuilder::getLatestValue` which provides this
functionality.
This will be used in a later patch to fix bugs in `PPCGCodeGeneration`
where the latest value is not being used.
Differential Revision: https://reviews.llvm.org/D36000
llvm-svn: 309674
This allows -polly-optree to move instructions that depend on
synthesizable values.
The difficulty for synthesizable values is that their value depends on
the location. When it is moved over a loop header, and the SCEV
expression depends on the loop induction variable (SCEVAddRecExpr), it
would use the current induction variable instead of the last one.
At the moment we cannot forward PHI nodes such that crossing the header
of loops referenced by SCEVAddRecExpr is not possible (assuming the loop
header has at least two incoming blocks: for entering the loop and the
backedge, such any instruction to be forwarded must have a phi between
use and definition).
A remaining issue is when the forwarded value is used after the loop,
but is only synthesizable inside the loop. This happens e.g. if
ScalarEvolution is unable to determine the number of loop iterations or
the initial loop value. We do not forward in this situation.
Differential Revision: https://reviews.llvm.org/D36102
llvm-svn: 309609
In addition to array and PHI writes, also allow scalar value writes.
The only kind of write not allowed are writes by functions
(including memcpy/memmove/memset).
llvm-svn: 309582
Summary:
This allows us to map functions such as exp, expf, expl, for which no
LLVM intrinsics exist. Instead, we link to NVIDIA's libdevice which provides
high-performance implementations of a wide range of (math) functions. We
currently link only a small subset, the exp, cos and copysign functions. Other
functions will be enabled as needed.
Reviewers: bollu, singam-sanjay
Reviewed By: bollu
Subscribers: tstellar, tra, nemanjai, pollydev, mgorny, llvm-commits, kbarton
Tags: #polly
Differential Revision: https://reviews.llvm.org/D35703
llvm-svn: 309560
This reverts commit r309490 as it triggers on our AOSP buildbut error messages
of the form:
inlinable function call in a function with debug info must have a !dbg location
llvm-svn: 309556
Summary:
**Remove debug metadata from instruction to be copied to prevent the source file's debug metadata being copied into GPUModule and eventually failing Module verification and ASM string codegeneration.**
When copying the instruction onto the Module meant for the GPU, debug metadata attached to an instruction causes all related metadata to be pulled into the Module, including the DICompileUnit, which is not listed in llvm.dbg.cu of the Module. This fails the verification of the Module and generation of the ASM string.
The only debug metadata of the instruction, the DebugLoc, is unset by this patch.
Reviewers: grosser, bollu, Meinersbur
Reviewed By: grosser, bollu
Subscribers: pollydev
Tags: #polly
Differential Revision: https://reviews.llvm.org/D35630
llvm-svn: 309490
Write coalescing combines write accesses that
- Write the same llvm::Value.
- Write to the same array.
- Unless they do not write anything in a statement instance (partial
writes), write to the same element.
- There is no other access between them that accesses the same element.
This is particularly useful after DeLICM, which leaves partial writes to
disjoint domains.
Differential Revision: https://reviews.llvm.org/D36010
llvm-svn: 309489
ScopStmt::contains is currently implemented on the basis of BasicBlock
and does not take the instruction list into account. Therefore any
instruction copied by -polly-optree into another statement currently
triggers that assertion.
Remove that assertion for now. We might re-enable it when the
implementation of ScopStmt::contains changes.
llvm-svn: 309421
This fixes a bug in isl_flow where triggering the compute out could result in
undefined or unexpected behavior. This fixes some recent regressions we saw
in the android buildbots. Thanks Eli Friedman for reducing the corresponding
test cases.
llvm-svn: 309274
ScopBuilder and Simplify (through VirtualInstruction.cpp) previously
used this functionality in their own implementation. Refactor them
both into a common one into the Scop class.
BlockGenerator also makes use of a similiar functionality, but also
records outside users and takes place after region simplification.
Merging it as well would be more complicated.
llvm-svn: 309273
After region exit simplification, the incoming block of a phi node in
the SCoP region's exit block lands outside of the region. Since we
treat SCoPs as if this already happened, we need to account for that
when looking for outside uses of scalars (i.e. escaping scalars).
llvm-svn: 309271
A region statement's instruction list is always empty and ignored by the code
generator. Don't give the impression that it means anything.
llvm-svn: 309197
A PHI node's incoming block is the user of its operand, not the PHI's parent.
Assuming the PHINode's parent being the user lead to the removal of a
MemoryAccesses because its use was assumed to be inside of the SCoP.
llvm-svn: 309164
Translate the ScheduleOptimizer to use the new isl C++ bindings.
Reviewed-by: Michael Kruse <llvm@meinersbur.de>
Differential Revision: https://reviews.llvm.org/D35845
llvm-svn: 309119
Since there will be no more a 1:1 correspondence between statements and
basic blocks, we would like to get rid of the method getStmtFor(BB)
and its uses. Here we remove one of its uses in ScopInfo by fetching
the statement in which the call instruction lies.
Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>
Differential Revision: https://reviews.llvm.org/D35691
llvm-svn: 309110
In the following loop:
int i;
for (i = 0; i < func(); i+=1)
;
SCoP:
for (int j = 0; j<n; j+=1)
S(i, j)
The value i is synthesizable in the SCoP that includes only the j-loop.
This is because i is fixed within the SCoP, it is irrelevant whether
it originates from another loop.
This fixes a strange case where a PHI was synthesiable in a SCoP,
but not its incoming value, triggering an assertion.
This should fix MultiSource/Applications/sgefa/sgefa of the
perf-x86_64-penryn-O3-polly-before-vectorizer-unprofitable buildbot.
llvm-svn: 309109
It seems I still had some incomplete changes in the tree when committing.
In general, we only import changes from isl upstream. In this case, the
changes were especially unfortunate, as they broke the error management
in isl_flow.c and consequently caused regressions.
Thanks to Michael Kruse for spotting this mistake.
llvm-svn: 309039
In future, there will be no more a 1:1 correspondence between statements
and basic blocks, the name `contains` does not correctly capture their
relationship. A BB may infact comprise of multiple statements; hence we
describe a statement 'representing' a basic block.
Differential Revision: https://reviews.llvm.org/D35838
llvm-svn: 308982
Summary:
This consists instances of two changes:
- Accept any order of checks for a specific loop form, that appear in different order in the new vs legacy-PM.
- Remove checks for specific regions.
Reviewers: grosser
Reviewed By: grosser
Subscribers: pollydev, llvm-commits
Tags: #polly
Differential Revision: https://reviews.llvm.org/D35837
llvm-svn: 308976
Invariant load hoisted scalars, and arrays whose size we can statically compute
to be 0 do not need to be allocated as arrays.
Invariant load hoisted scalars are sent to the kernel directly as parameters.
Earlier, we used to allocate `0` bytes of memory for these because our
computation of size from `PPCGCodeGeneration::getArraySize` would result in `0`.
Now, since we don't invariant loads as arrays in PPCGCodeGeneration, this
problem does not occur anymore.
Differential Revision: https://reviews.llvm.org/D35795
llvm-svn: 308971
Read-only values (values defined before the SCoP) require special
handing with -polly-analyze-read-only-scalars=true (which is the
default). If active, each use of a value requires a read access.
When a copied value uses a read-only value, we must also ensure that
such a MemoryAccess is available or is created.
Differential Revision: https://reviews.llvm.org/D35764
llvm-svn: 308876
Summary:
- We were using `.count` in `StringRef`, which matches substrings.
- We may want to use this for equality as well.
- Generalise this, so allow regexes as a parameter to `polly-only-func`.
Differential Revision: https://reviews.llvm.org/D35728
llvm-svn: 308875
Siddharth Bhat