As our delinearization works optimistically, we need in some cases run-time
checks that verify our optimistic assumptions. A simple example is the
following code:
void foo(long n, long m, long o, double A[n][m][o]) {
for (long i = 0; i < 100; i++)
for (long j = 0; j < 150; j++)
for (long k = 0; k < 200; k++)
A[i][j][k] = 1.0;
}
After clang linearized the access to A and we delinearized it again to
A[i][j][k] we need to ensure that we do not access the delinearized array
out of bounds (this information is not available in LLVM-IR). Hence, we
need to verify the following constraints at run-time:
CHECK: Assumed Context:
CHECK: [o, m] -> { : m >= 150 and o >= 200 }
llvm-svn: 212198
To translate the old induction variables as they exist before Polly to new
new induction variables introduced during AST code generation we need to
generate code that computes the new values from the old ones. We can do this
by just looking at the arguments isl generates in each scheduled statement.
Example:
// Old
for i
S(i)
// New
for c0
for c1
S(c0 + c1)
To get the value of i, we need to compute 'c0 + c1'. This expression is readily
available in the user statements generated by isl and just needs to be
translated to LLVM-IR.
This replaces an old confusing construct that constructed during ast generation
an isl multi affine expression that described this relation and which was then
again ast generated for each statement and argument when translating the isl ast
to LLVM-IR. This approach was difficult to understand and the additional ast
generation calls where entirely redundant as isl provides the relevant
expressions as arguments of the generated user statements.
llvm-svn: 212186
This change is particularly useful in the code generation as we need
to know which binary operator/identity element we need to combine/initialize
the privatization locations.
+ Print the reduction type for each memory access
+ Adjusted the test cases to comply with the new output format and
to test for the right reduction type
llvm-svn: 212126
Iterate over all store memory accesses and check for valid binary reduction
candidate loads by following the operands of the stored value. For each
candidate pair we check if they have the same base address and there are no
other accesses which may overlap with them. This ensures that no intermediate
value can escape into other memory locations or is overwritten at some point.
+ 17 test cases for reduction detection and reduction dependency modeling
llvm-svn: 211957
Enabling -keep-going in ScopDetection causes expansion to an invalid
Scop candidate.
Region A <- Valid candidate
|
Region B <- Invalid candidate
If -keep-going is enabled, ScopDetection would expand A to A+B because
the RejectLog is never checked for errors during expansion.
With this patch only A becomes a valid Scop.
llvm-svn: 211875
This change will ease the transision to multiple reductions per statement as
we can now distinguish the effects of multiple reductions in the same
statement.
+ Wrapped reduction dependences are used to compute privatization dependences
+ Modified test cases to account for the change
llvm-svn: 211795
This dependency analysis will keep track of memory accesses if they might be
part of a reduction. If not, the dependences are tracked on a statement level.
The main reason to do this is to reduce the compile time while beeing able to
distinguish the effects of reduction and non-reduction accesses.
+ Adjusted two test cases
llvm-svn: 211794
Use a container class to store the reject logs. Delegating most calls to
the internal std::map and add a few convenient shortcuts (e.g.,
hasErrors()).
llvm-svn: 211780
Add support for generating optimization remarks after completing the
detection of Scops.
The goal is to provide end-users with useful hints about opportunities that
help to increase the size of the detected Scops in their code.
By default the remark is unspecified and the debug location is empty. Future
patches have to expand on the messages generated.
This patch brings a simple test case for ReportFuncCall to demonstrate the
feature.
Reports all missed opportunities to increase the size/number of valid
Scops:
clang <...> -Rpass-missed="polly-detect" <...>
opt <...> -pass-remarks-missed="polly-detect" <...>
Reports beginning and end of all valid Scops:
clang <...> -Rpass="polly-detect" <...>
opt <...> -pass-remarks="polly-detect" <...>
Differential Revision: http://reviews.llvm.org/D4171
llvm-svn: 211769
Due to bad habit we sometimes used a variable %defaultOpts that listed
a set of passes commonly run to prepare for Polly. None of these test cases
actually needs special preparation and only two of them need the 'basicaa' to
be scheduled. Scheduling the required alias analysis explicitly makes the test
cases clearer.
llvm-svn: 211671
We had a set of test cases that have been incomplete and XFAILED. This patch
completes a couple of the interesting ones and removes the ones which seem
redundant or not sufficiently reduced to be useful.
llvm-svn: 211670
Insert a header into the new testcase containing a sample RUN line a FIXME and
an XFAIL. Then insert the formated C code and finally the LLVM-IR without
attributes, the module ID or the target triple.
llvm-svn: 211612
We use llvm.codegen intrinsic to generate code for embedded LLVM-IR
strings. The reason we introduce such a intrinsic is that previous
clang/opt tools was NOT linked with various LLVM targets and their
AsmParsers and AsmPrinters. Since clang/opt been linked with all the
needed libraries, we no longer need the llvm.codegen intrinsic.
llvm-svn: 211573
+ Collect reduction dependences
+ Introduced TYPE_RED in Dependences.h which can be used to obtain the
reduction dependences
+ Used TYPE_RED to prevent parallelization while we do not have a privatizing
code generation
+ Relax the dependences for non-parallel code generation
+ Add privatization dependences to ensure correctness
+ 12 Test cases to check for reduction and privatization dependences
llvm-svn: 211369
+ Flag to indicate reduction like statements
+ Command line option to (dis)allow multiplicative reduction opcodes
+ Two simple positive test cases, one fp test case w and w/o fast math
+ One "negative" test case (only reduction like but no reduction)
llvm-svn: 211114
+ Added const iterator version
+ Changed name to begin/end to allow range loops
+ Changed call sites to range loops
+ Changed typename to (const_)iterator
llvm-svn: 210927
In general this fixes ambiguity that can arise from using
a different namespace that declares the same symbols as
we do.
One example inside llvm would be:
createIndVarSimplifyPass(..);
Which can be found in:
llvm/Transforms/Scalar.h
and
polly/LinkAllPasses.h
llvm-svn: 210755
Fixes#19976.
The error log does not contain an error, in case we reject a candidate
without generating a diagnostic message by using invalid<>(...). This is
the case for the top-level region of a function.
The patch comes without a test-case because adding a useful one requires
additional code just for triggering it. Before the patch it would only trigger,
if we try to print the CFG with Scop error annotations.
llvm-svn: 210753
We do this currently only for test cases where we have integer offsets that
clearly access array dimensions out-of-bound.
-; for (long i = 0; i < n; i++)
-; for (long j = 0; j < m; j++)
-; for (long k = 0; k < o; k++)
+; for (long i = 0; i < n - 3; i++)
+; for (long j = 4; j < m; j++)
+; for (long k = 0; k < o - 7; k++)
; A[i+3][j-4][k+7] = 1.0;
This will be helpful if we later want to simplify the access functions under the
assumption that they do not access memory out of bounds.
llvm-svn: 210179
Without this patch, the testcase would fail on the delinearization of the second
array:
; void foo(long n, long m, long o, double A[n][m][o]) {
; for (long i = 0; i < n; i++)
; for (long j = 0; j < m; j++)
; for (long k = 0; k < o; k++) {
; A[i+3][j-4][k+7] = 1.0;
; A[i][0][k] = 2.0;
; }
; }
; CHECK: [n, m, o] -> { Stmt_for_body6[i0, i1, i2] -> MemRef_A[3 + i0, -4 + i1, 7 + i2] };
; CHECK: [n, m, o] -> { Stmt_for_body6[i0, i1, i2] -> MemRef_A[i0, 0, i2] };
Here is the output of FileCheck on the testcase without this patch:
; CHECK: [n, m, o] -> { Stmt_for_body6[i0, i1, i2] -> MemRef_A[i0, 0, i2] };
^
<stdin>:26:2: note: possible intended match here
[n, m, o] -> { Stmt_for_body6[i0, i1, i2] -> MemRef_A[o0] };
^
It is possible to find a good delinearization for A[i][0][k] only in the context
of the delinearization of both array accesses.
There are two ways to delinearize together all array subscripts touching the
same base address: either duplicate the code from scop detection to first gather
all array references and then run the delinearization; or as implemented in this
patch, use the same delinearization info that we computed during scop detection.
llvm-svn: 210117
+ CL-option --polly-tile-sizes=<int,...,int>
The i'th value is used as a tile size for dimension i, if
there is no i'th value, the value of --polly-default-tile-size is
used
+ CL-option --polly-default-tile-size=int
Used if no tile size is given for a dimension i
+ 3 Simple testcases
llvm-svn: 209753
Instead of relying on the delinearization to infer the size of an element,
compute the element size from the base address type. This is a much more precise
way of computing the element size than before, as we would have mixed together
the size of an element with the strides of the innermost dimension.
llvm-svn: 209695
Support a 'keep-going' mode for the ScopDetection. In this mode, we just keep
on detecting, even if we encounter an error.
This is useful for diagnosing SCoP candidates. Sometimes you want all the
errors. Invalid SCoPs will still be refused in the end, we just refuse to
abort on the first error.
llvm-svn: 209574
This stores all RejectReasons created for one region
in a RejectLog inside the DetectionContext. For now
this only keeps track of the last error.
A separate patch will enable the tracking of all errors.
This patch itself does no harm (yet).
llvm-svn: 209572
SVN r209103 removed the OwningPtr variant of the MemoryBuffer APIs. Switch to
the equivalent std::unique_ptr versions. This should clear up the build bots.
llvm-svn: 209104
Tag the GPGPU codegen test cases as unsupported if the nvptx target is not
included in the current llvm build.
Contributed-by: Yabin Hu <yabin.hwu@gmail.com>
llvm-svn: 208779
definition below all of the header #include lines, Polly edition.
If you want to know more details about this, you can see the recent
commits to Debug.h in LLVM. This is just the Polly segment of a cleanup
I'm doing globally for this macro.
llvm-svn: 206852
Commit r206510 falsely advertised to fix the load cases, even though it only
fixed the store case. This commit adds the same fix for the load case including
the missing test coverage.
llvm-svn: 206577
Even tough we may want to generate a vector load, the address from which to load
still is a scalar. Make sure even if previous address computations may have been
vectorized, that the addresses are also available as scalars.
This fixes http://llvm.org/PR19469
Reported-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
llvm-svn: 206510
The following example shows a non-parallel loop
void f(int a[]) {
int i;
for (i = 0; i < 10; ++i)
A[i] = A[i+5];
}
which, in case we import a schedule that limits the iteration domain
to 0 <= i < 5, becomes parallel. Previously we crashed in such cases, now we
just recognize it as parallel.
This fixes http://llvm.org/PR19435
Reported-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
llvm-svn: 206318
We update to a newer version of isl, which includes changes to the compute
out facility that make it a lot more predicable. With our new value, we can
reliably bail out for all reported bugs, while still being able to compute
dependences for all but two test cases in the LLVM test suite. For the remaining
two test cases, the dependence problem we construct is unnecessarily complex,
so there is hope we can improve on this. However, to avoid any future issues,
having a reliable compute out facility in place is important.
llvm-svn: 206106
We only supported a very old version of OpenScop that was entirely different
to what OpenScop is today. To not confuse people, we remove this old and
unusable support. If anyone is interested to add OpenScop support back in,
the relevant patches are available in version control.
llvm-svn: 206026
Reversed the order in which LD_LIBRARY_PATH is defined in order to make sure the
${CLOOG_INSTALL} prefix is found first.
Contributed-by: Christian Bielert <cib123@googlemail.com>
llvm-svn: 205556
This replaces the ancient INVALID/INVALID_NOVERIFY macros with a real
function.
The new invalid(..) function uses small diagnostic objects that are
generated on demand. We can store arbitrary additional information per
error type and generate useful debug/error messages on the fly.
Use it as follows:
if (/* Some error condition (ReportFoo) */)
invalid<ReportFoo>(Context, /*Assert=*/true/false,
(/* List of helpful diagnostic objects */));
Where ReportFoo is a subclass of RejectReason that is able to take the
list of helpful diagnostic objects in its constructor.
The implementation of invalid will create the report and fire
an assertion, if necessary.
llvm-svn: 205414
During code preperation trivial PHI nodes (mainly introduced by lcssa) are
deleted to decrease the number of introduced allocas (==> dependences). However
simply replacing them by their only incoming value would cause the independent
block pass to introduce new allocas. To prevent this we try to share stack slots
during code preperarion, hence to reuse a already created alloca 'to demote' the
trivial PHI node. This works if we know that the value stored in this alloca
will be the incoming value of the trivial PHI at the end of the predecessor
block of this trivial PHI.
Contributed-by: Johannes Doerfert <doerfert@cs.uni-saarland.de>
llvm-svn: 205320
We explicitly specifying all filenames instead of assuming some naming
convention used by clang and opt.
Contributed-by: Johannes Doerfert <doerfert@cs.uni-saarland.de>
llvm-svn: 204726
For complex examples it may happen that we do not compute dependences. In this
case we do not want to crash, but just not detect parallel loops.
llvm-svn: 204470
It does not seem to add a lot of value, as it leaves unclear which parts are
mature and whichs not. Adding this informatin also does not make sense, as it
changes rapidly.
llvm-svn: 204447
This patch enables vectorization of loops containing backward array
traversal (array stride is -1).
Contributed-by: Chris Jenneisch <chrisj@codeaurora.org>
llvm-svn: 204257
This ensures that the polly passes get properly registered both, when using
polly as a loadable module and when directly linking it into clang/opt/bugpoint.
llvm-svn: 204255
llvm.org/PR19081 reports that the polly dependence analysis causes some h264
compilation to hang. We adjust the compute out, to ensure we do not block on
expensive dependence calculations.
llvm-svn: 204168
This reverts the broken modularized build.
This builds the classic loadable module. The separation
of library and plugin is yet to be done in a future patch.
llvm-svn: 203952
to avoid build errors like this:
In file included from ../include/llvm/IR/IntrinsicInst.h:30:0,
from ../tools/polly/lib/CodeGen/BlockGenerators.cpp:28:
../include/llvm/IR/Intrinsics.h:41:34: fatal error: llvm/IR/Intrinsics.gen: No such file or directory
The earlier change in commit b1d2e6d5c3ce151ef6b7213c00019715e63d7cfb has been
accidentally reverted in:
commit 6b1963814877f5b1b161d3a73a3c8246c4ad4787
Author: simbuerg <simbuerg@91177308-0d34-0410-b5e6-96231b3b80d8>
Date: Tue Mar 11 21:26:06 2014 +0000
Refactor Polly's Pass creation and initialization.
Rename some files and adjust cmake accordingly
llvm-svn: 203843
In case we are at the innermost band, we try to prepare for vectorization. This
means, we look for the innermost parallel loop and strip mine this loop to the
innermost level using a strip-mine factor corresponding to the number of vector
iterations.
For whatever reason, the code that implemented this feature was broken. We now
added a comment, a test case and obviously also the right code.
llvm-svn: 203544
1) The isl_int -> isl_val changes are the ones Tobias suggested.
One additional isl_val_free is added (and needed)
2) Three scoplib_vector_free are added, maybe we would need even
more (and matrix_free) but it's hard to place them right.
3) Cleaned the includes (and removed 'extern C')
This fixes the broken compilation for the scoplib import and export.
Contributed-by: Johannes Doerfert <doerfert@cs.uni-saarland.de>
llvm-svn: 203500
to avoid build errors like this:
In file included from ../include/llvm/IR/IntrinsicInst.h:30:0,
from ../tools/polly/lib/CodeGen/BlockGenerators.cpp:28:
../include/llvm/IR/Intrinsics.h:41:34: fatal error: llvm/IR/Intrinsics.gen: No such file or directory
llvm-svn: 203495
This is necessary to avoid test failures in the CLooG test suite due to the
recent isl update.
We also need to update two polly test cases which rely on a certain order in the
textual description that isl chooses for its sets and maps. Changes here are not
often, but we should probably switch to a check that verifies such maps are
semantically equivalent instead of represented identically.
llvm-svn: 203476
Older isl versions did not properly guard all function declarations for the
use in C++. Specifically, the isl/val_gmp.h header was not properly guarded.
This patch ensures we have the proper guards in place and do not accidentally
link to name-mangled C++ versions of those functions that are not available in
libisl.so.
llvm-svn: 203462
Value::user_iterator changes in LLVM r203364. Converts several of these
loops to nice range based loops in the process.
Built and tested cleanly for me, yay for being able to fully build and
test Polly changes!
llvm-svn: 203381
We currently need to always name instructions, as the polly test suite currently
matches for certain names. We should improve the test suite at some point.
This fixes 'make check-polly' in NDEBUG builds.
llvm-svn: 202855
For now we only mark innermost loops for the loop vectorizer. We could later
also mark not-innermost loops to enable the introduction of openmp parallelism.
llvm-svn: 202854
PollyIRBuilder is currently just a typedef to IRBuilder<>. Consequently, this
change should not affect behavior. In subsequent patches we will extend its
functionality to emit loop.parallel metadata.
llvm-svn: 202853
This fixes the buildbots who failed, because the linker eliminated most of the
Polly functionality when building without BUILD_SHARED_LIBS=ON.
Besides fixing the build, this change also brings additional functionality. With
the new separation between the general polly libraries and the functionality for
the polly module, it is now possible to link polly directly into a tool instead
of using requiring users to load a shared library.
llvm-svn: 202762
The module LLVMPolly.so links to that. There is really no reason to build a
large number of mini-libraries here, especially as we do have dependences
between the libraries that are not properly handled and that make linking fail
on darwin.
Submitted-by: David Fang <fang@csl.cornell.edu>
llvm-svn: 202743
We mostly iterate over read-only values. Following a suggestion by Duncan P.N
Exons Smith, we use the construct 'const auto &' for this.
llvm-svn: 202651
clang-formats behaviour has changed for a couple of C++11 formattings. We adapt
Polly to ensure our formatting checks are clean again.
llvm-svn: 202650
clang-format requires a space before the ":" in the foreach loop. Even though
this is surprising to me, we follow this style to make our formatting
consistent with clang-format. I found that this clang-format style is used in a
couple of C++11 examples, hence I believe the fact that clang-format adds a
colon is not a bug but just something I was not used to yet.
llvm-svn: 202648
In 'obsequi' we have a scop in which the current dead code elimination works,
but the generated code is way too complex. To avoid this trouble (and to not
disable the DCE entirely) we add an additional approximative step before
the actual dead code elimination. This should fix one of the two current
nightly-test issues.
Polly could be improved to handle 'obsequi' by teaching it to introduce only a
single parameter for (%1 and zext %1) which halves the number of parameters and
allows polly to derive a simpler representation for the set of live iterations.
However, this needs some time to investigate.
I will commit a test case as soon as we have a reduced one.
llvm-svn: 202010
Sven suggested to use this simpler code generation strategy as the convex_hull
computation is apparently rather inefficient. We do not have a test case that
shows a difference, but, in case we find a test case where this makes a
difference, we can reconsider our decission.
llvm-svn: 201997
In case we do not have valid dependences, we do not run dead code elimination or
the schedule optimizer. This fixes an infinite loop in the dead code
elimination (PR12110).
llvm-svn: 201982
Instead of giving a choice between a precise (but possibly very complex)
analysis and an approximative analysis we now use a hybrid approach which uses N
precise steps followed by one approximating step. The precision of the analysis
can be changed by increasing N. With a default of 'N' = 2, we get fully precise
results for our current test cases and should not run into performance problems
for more complex test cases. We can adjust this value when we got more
experience with this dead code elimination.
llvm-svn: 201888
In case the domain of a statement is empty, the schedule optimizer set by
accident the schedule to a NULL pointer. This is incorrect. Instead, we set
it to an empty isl_map with zero schedule dimensions. We already checked for
this in our test cases, but unfortunately the test cases did not fail as
expected. The assert we add in this commit now ensures that the test cases
fail properly in case we regress on this again.
llvm-svn: 201886
We now skip the debug intrinsics which is a lot better than crashing due to
uncopied metadata references. We should step by step investigate which debug
intrinsics we can copy without trouble.
We still keep the debug location metadata.
llvm-svn: 201860
This pass eliminates loop iterations that compute results that are not used
later on. This can help e.g. in D, where the default zero-initialization is
often unnecessary if right after new values are assigned to an array.
Contributed-by: Peter Conn <conn.peter@gmail.com>
llvm-svn: 201817
We do not have a use for this information at the moment. If we need this at some
point, the "instruction -> access" mapping needs to be enhanced as a single
instruction could then possibly perform multiple accesses.
This patch allows us to build the polyhedral information for scops with scalar
dependences.
llvm-svn: 201815
In rare cases the modification of one scop can effect the validity of other
scops, as code generation of an earlier scop may make the scalar evolution
functions derived for later scops less precise. The example that triggered this
patch was a scop that contained an 'or' expression as follows:
%add13710 = or i32 %j.19, 1
--> {(1 + (4 * %l)),+,2}<nsw><%for.body81>
Scev could only analyze the 'or' as it knew %j.19 is a multiple of 2. This
information was not available after the first scop was code generated (or
independent-blocks was run on it) and SCEV could not derive a precise SCEV
expression any more. This means we could not any more code generate this SCoP.
My current understanding is that there is always the risk that an earlier code
generation change invalidates later scops. As the example we have seen here is
difficult to avoid, we use this occasion to guard us against all such
invalidations.
This patch "solves" this issue by verifying right before we start working on
a detected scop, if this scop is in fact still valid. This adds a certain
overhead. However the verification we run is anyways very fast and secondly
it is only run on detected scops. So the overhead should not be very large. As
a later optimization we could detect scops only on demand, such that we need
to run scop-detections always only a single time.
This should fix the single last failure in the LLVM test-suite for the new
scev-based code generation.
llvm-svn: 201593
Tobias Grosser