Commit Graph

2787 Commits

Author SHA1 Message Date
Michael Kruse 209b463240 Add unittests for foreach(Elt|Piece). NFC.
llvm-svn: 288925
2016-12-07 17:48:02 +00:00
Michael Kruse b9a683d75d Add more ISL foreachElt functions. NFC.
Add and implement foreachElt for isl_map, isl_set and isl_union_set. These are
used by an out-of-tree patch which is in process of being upstreamed.

llvm-svn: 288924
2016-12-07 17:47:57 +00:00
Michael Kruse 2ead2bfc12 Add IslPtr type traits. NFC.
Add traits for isl_id and isl_multi_aff, required by out-of-tree patches
currently in progress of upstreaming.

isl_union_pw_aff_dump has been added to ISL during one of the last ISL
updates, such that we can also enable its dump() trait.

llvm-svn: 288915
2016-12-07 16:17:59 +00:00
Michael Kruse 1b8eb4104b Update to isl-0.17.1-314-g3106e8d
This version includes an update for imath (isl-0.17.1-49-g2f1c129). It fixes
the compilation under windows, which does not know ssize_t.

In addition, isl-0.17.1-288-g0500299 changed the way isl_test finds the source
directory. It now generates a file isl_srcdir.c at configure-time, containing
the source path, to not require setting the environment variable "srcdir" at
test-time. The cmake build system had to be modified to also generate that file.

llvm-svn: 288811
2016-12-06 14:37:39 +00:00
Johannes Doerfert bda814350a Allow to disable unsigned operations (zext, icmp ugt, ...)
Unsigned operations are often useful to support but the heuristics are
not yet tuned. This options allows to disable them if necessary.

llvm-svn: 288521
2016-12-02 17:55:41 +00:00
Johannes Doerfert a94ae1aede Do not allow multiple possibly aliasing ptrs in an expression
Relational comparisons should not involve multiple potentially
  aliasing pointers. Similarly this should hold for switch conditions
  and the two conditions involved in equality comparisons (separately!).
  This is a heuristic based on the C semantics that does only allow such
  operations when the base pointers do point into the same object.
  Since this makes aliasing likely we will bail out early instead of
  producing a probably failing runtime check.

llvm-svn: 288516
2016-12-02 17:49:52 +00:00
Johannes Doerfert 2df9963fe3 Rerun mem2reg after the inliner
It did happen that after the inliner finished we end up with promotable
allocas in a function. We now run mem2reg to make sure everything is
promoted if possible.

llvm-svn: 288514
2016-12-02 17:43:57 +00:00
Tobias Grosser bedef00e2c [ScopInfo] Fold constant coefficients in array dimensions to the right
This allows us to delinearize code such as the one below, where the array
sizes are A[][2 * n] as there are n times two elements in the innermost
dimension. Alternatively, we could try to generate another dimension for the
struct in the innermost dimension, but as the struct has constant size,
recovering this dimension is easy.

   struct com {
     double Real;
     double Img;
   };

   void foo(long n, struct com A[][n]) {
     for (long i = 0; i < 100; i++)
       for (long j = 0; j < 1000; j++)
         A[i][j].Real += A[i][j].Img;
   }

   int main() {
     struct com A[100][1000];
     foo(1000, A);

llvm-svn: 288489
2016-12-02 08:10:56 +00:00
Tobias Grosser 491b799a4d [ScopInfo] Separate construction and finalization of memory accesses [NFC]
After having built memory accesses we perform some additional transformations
on them to increase the chances that our delinearization guesses the right
shape. Only after these transformations, we take the assumptions that the
array shape we predict is such that no out-of-bounds memory accesses arise.

Before this change, the construction of the memory access, the access folding
that improves the represenation for certain parametric subscripts, and taking
the assumption was all done right after a memory access was created. In this
change we split this now into three separate iterations over all memory
accesses. This means only after all memory accesses have been built, we start
to canonicalize accesses, and to take assumptions. This split prepares for
future canonicalizations that must consider all memory accesses for deriving
additional beneficial transformations.

llvm-svn: 288479
2016-12-02 05:21:22 +00:00
Johannes Doerfert b1d6608430 [NFC] Check for feasibility prior to the profitability check
Feasibility is checked late on its own but early it is hidden behind
the "PollyProcessUnprofitable" guard. This change will make sure we opt
out early if the runtime context is infeasible anyway.

llvm-svn: 288329
2016-12-01 11:12:14 +00:00
Johannes Doerfert b6c5a5dd01 [FIX] Do not try to hoist obviously overwritten loads
llvm-svn: 288328
2016-12-01 11:10:45 +00:00
Tobias Grosser dc6b87c56e Add newline at end of debug print
In '[DBG] Allow to emit the RTC value at runtime' the diagnostics were printed
without a newline at the end of each diagnostic. We add such a newline to
improve readability.

llvm-svn: 288323
2016-12-01 08:08:47 +00:00
Eugene Zelenko b3ee0ba7a1 Fix some Clang-tidy modernize-use-default and Include What You Use warnings; other minor fixes (NFC).
This preparation to remove SetVector.h dependency on SmallSet.h.

llvm-svn: 288174
2016-11-29 18:14:12 +00:00
Michael Kruse 36e79ecaec [DeLICM] Add pass boilerplate code.
Add an empty DeLICM pass, without any functional parts.

Extracting the boilerplate from the the functional part reduces the size of the
code to review (https://reviews.llvm.org/D24716)

Suggested-by: Tobias Grosser <tobias@grosser.es>
llvm-svn: 288160
2016-11-29 16:41:21 +00:00
Michael Kruse 11c5e07925 canSynthesize: Remove unused argument LI. NFC.
The helper function polly::canSynthesize() does not directly use the LoopInfo
analysis, hence remove it from its argument list.

llvm-svn: 288144
2016-11-29 15:11:04 +00:00
Tobias Grosser df8f35b7b8 Update for clang-format change in r288119
llvm-svn: 288134
2016-11-29 12:52:08 +00:00
Tobias Grosser 278f9e7d27 [ScopInfo] Use SCEVRewriteVisitor to simplify SCEVSensitiveParameterRewriter [NFC]
llvm-svn: 287984
2016-11-26 17:58:40 +00:00
Tobias Grosser b45ae5601b [ScopDetect] Expand statistics of the detected scops
We now collect:

  Number of total loops
  Number of loops in scops
  Number of scops
  Number of scops with maximal loop depth 1
  Number of scops with maximal loop depth 2
  Number of scops with maximal loop depth 3
  Number of scops with maximal loop depth 4
  Number of scops with maximal loop depth 5
  Number of scops with maximal loop depth 6 and larger
  Number of loops in scops (profitable scops only)
  Number of scops (profitable scops only)
  Number of scops with maximal loop depth 1 (profitable scops only)
  Number of scops with maximal loop depth 2 (profitable scops only)
  Number of scops with maximal loop depth 3 (profitable scops only)
  Number of scops with maximal loop depth 4 (profitable scops only)
  Number of scops with maximal loop depth 5 (profitable scops only)
  Number of scops with maximal loop depth 6 and larger (profitable scops only)

These statistics are certainly completely accurate as we might drop scops
when building up their polyhedral representation, but they should give a good
indication of the number of scops we detect.

llvm-svn: 287973
2016-11-26 07:37:46 +00:00
Tobias Grosser 5c00b0dc74 [ScopDetectionDiagnostic] Collect statistics for each diagnostic type
Our original statistics were added before we introduced a more fine-grained
diagnostic system, but the granularity of our statistics has never been
increased accordingly. This change introduces now one statistic counter per
diagnostic to enable us to collect fine-grained statistics about who certain
scops are not detected. In case coarser grained statistics are needed, the
user is expected to combine counters manually.

llvm-svn: 287968
2016-11-26 05:53:09 +00:00
Tobias Grosser 0dcbcaa98b [ScopDetectionDiagnostic] IrreducibleRegion is a subclasses of CFG
Reflect this correctly in the RejectReasonKind enum. The definition of
RejectReasonKind::IrreducibleRegion was introduced in r258497, when we started
to refuse regions containing irreducible loops.

llvm-svn: 287965
2016-11-26 05:08:27 +00:00
Tobias Grosser 8c21b1a50f [ScopDetectionDiagnostic] Remove leftover RejectReasonKind for Conditions [NFC]
In r248118 some diagnostics for unstructured control flow have been removed,
but the corresponding RejectReasonKind was accidentally not removed. This
change removes it, as it is not needed any more.

llvm-svn: 287964
2016-11-26 05:08:24 +00:00
Tobias Grosser c64269ea1b [ScopDectionDiagnostic] Use scoped enums instead three letter prefix [NFC]
This improves readability of the code.

llvm-svn: 287963
2016-11-26 03:44:31 +00:00
Hongbin Zheng 4ff1c3983d Fix typo.
llvm-svn: 287819
2016-11-23 21:59:33 +00:00
Tobias Grosser eab0943ec0 Update to isl-0.17.1-284-gbb38638
Regular maintenance update with only minor changes.

llvm-svn: 287703
2016-11-22 21:31:59 +00:00
Tobias Grosser b3c3d149b9 [CodeGen] Add flag to code-generate most memory access expressions
Introduce the new flag -polly-codegen-generate-expressions which forces Polly
to code generate AST expressions instead of using our SCEV based access
expression generation even for cases where the original memory access relation
was not changed and the SCEV based access expression could be code generated
without any issue.

This is an experimental option for better testing the isl ast expression
generation. The default behavior of Polly remains unchanged. We also exclude
a couple of cases for which the AST expression is not yet working.

llvm-svn: 287694
2016-11-22 20:21:16 +00:00
Tobias Grosser d51a945f38 [test] Simplify test case by removing unreferenced instructions [NFC]
Drop instructions that do not influence the memory impact of a basic block.
They are not needed to reproduce the original bug (verified) and will cause
random test noise if we would decide to only model the instructions that
have visible side-effects.

llvm-svn: 287626
2016-11-22 07:18:57 +00:00
Tobias Grosser 88c025e82e [test] Ensure important basic blocks in test case have side effects
Add two store instructions at the end of basic blocks that are required to
reproduce the original bug to ensure we always process and model these basic
blocks. This makes this test case stable even in case we would decide to bail
out early of basic blocks which do not modify the global state. Also add
additional check lines to verify how we model the basic block.

llvm-svn: 287625
2016-11-22 07:06:59 +00:00
Tobias Grosser 07ce9a0bcc test: add more details to non-affine test case
We add CHECK lines to this test case to make it easier to see the difference
between affine and non-affine memory accesses. We also change the test case to
use a parameteric index expression as otherwise our range analysis will
understand that the non-affine memory access can only access input[1],
which makes it difficult to see that the memory access is in-fact modeled as
non-affine access.

llvm-svn: 287623
2016-11-22 06:28:08 +00:00
Hongbin Zheng d559da84af Update comment for r287566
llvm-svn: 287572
2016-11-21 20:27:55 +00:00
Hongbin Zheng dac3808873 Fix format
llvm-svn: 287568
2016-11-21 20:17:00 +00:00
Hongbin Zheng a8fb73fc0b Split ScopInfo::addScopStmt into two versions. NFC
One for adding statement for region, another one for BB

llvm-svn: 287566
2016-11-21 20:09:40 +00:00
Hongbin Zheng 3ffa6f40b0 Minor change
llvm-svn: 287562
2016-11-21 19:26:10 +00:00
Tobias Grosser 1f0236d8e5 [ScopDetect] Use mayReadOrWriteMemory to shorten condition
llvm-svn: 287525
2016-11-21 09:07:30 +00:00
Tobias Grosser b94e9b31d0 [ScopDetect] Remove unnecessary namespace qualifier
llvm-svn: 287524
2016-11-21 09:04:45 +00:00
Johannes Doerfert 81aa6e882f [NFC] Adjust naming scheme of statistic variables
Suggested-by: Tobias Grosser <tobias@grosser.es>
llvm-svn: 287347
2016-11-18 14:37:08 +00:00
Johannes Doerfert 6cd59e9076 Probably overwritten loads should not be considered hoistable
Do not assume a load to be hoistable/invariant if the pointer is used by
another instruction in the SCoP that might write to memory and that is
always executed.

llvm-svn: 287272
2016-11-17 22:25:17 +00:00
Johannes Doerfert 50dfbc572a [NFC] Add flag to disable error block assumptions
The declaration as an "error block" is currently aggressive and not very
smart. This patch allows to disable error blocks completely. This might
be useful to prevent SCoP expansion to a point where the assumed context
becomes infeasible, thus the SCoP has to be discarded.

llvm-svn: 287271
2016-11-17 22:16:35 +00:00
Johannes Doerfert c97654681e [FIX] Do not try to hoist memory intrinsic
Since we do not necessarily treat memory intrinsics as non-affine
anymore, we have to check for them explicitly before we try to hoist an
access.

llvm-svn: 287270
2016-11-17 22:11:56 +00:00
Johannes Doerfert b3265a3612 [NFC] Skip over trivial assumptions
Filter trivial assumptions, thus assume { : } or restrict { : 0 = 1 },
as they clutter the user output as well as the statistics.

llvm-svn: 287269
2016-11-17 22:08:40 +00:00
Johannes Doerfert dae2e9287d [DBG] Collect statistics about actually versioned SCoPs
llvm-svn: 287267
2016-11-17 21:55:43 +00:00
Johannes Doerfert 8c5464a715 [DBG] Allow to emit the RTC value at runtime
The new command line flag "polly-codegen-emit-rtc-print" can be used to
place a "printf" in the generated code that will print the RTC value and
the overflow state.

llvm-svn: 287265
2016-11-17 21:49:19 +00:00
Johannes Doerfert cfadb2293f [DBG] Collect statistics about statically infeasible SCoPs
llvm-svn: 287263
2016-11-17 21:44:47 +00:00
Johannes Doerfert cd195326bf [DBG] Collect statistics about taken assumptions
llvm-svn: 287261
2016-11-17 21:41:08 +00:00
Tobias Grosser 06e1592663 Update to isl-0.17.1-267-gbf9723d
This update corrects an incorrect generation of min/max expressions in the isl
AST generator and a problematic nullptr dereference.

llvm-svn: 287098
2016-11-16 11:06:47 +00:00
Tobias Grosser 26be8e99b6 [ScopBuilder] Drop unnecessary namespace identifiers [NFC]
llvm-svn: 286781
2016-11-13 21:28:13 +00:00
Tobias Grosser 5743e8de86 [SCEVAffinator] Do not scan redundantly for parameters
In r286430 "SCEVValidator: add new parameters resulting from constant
extraction" we added functionality to scan for parameters after constant
extraction has taken place to ensure newly created parameters are correctly
registered. This addition made the already existing registration of parameters
redundant. Hence, we remove the corresponding call in this commit.

An alternative solution would have been to also perform constant extraction when
validating SCEV expressions and to then scan for parameters when validating
a SCEV expression. However, as SCEV validation is used during SCoP detection
where we want to be especially fast, adding additional functionality on this
hot path should be avoided if good alternatives exist. In this case, we can
choose to continue to only transform SCEV expression when actually modeling
them. As all transformations we perform are expected to not change the validity
of the SCEV expressions, this solution seems preferable.

Suggested-by: Eli Friedman <efriedma@codeaurora.org>
llvm-svn: 286780
2016-11-13 21:28:07 +00:00
Tobias Grosser 70d2709b1a [ScopDetect] Conservatively handle inaccessible memory alias attributes
Commit r286294 introduced support for inaccessiblememonly and
inaccessiblemem_or_argmemonly attributes to BasicAA, which we need to
support to avoid undefined behavior. This change just refuses all calls
which are annotated with these attributes, which is conservatively correct.
In the future we may consider to model and support such function calls
in Polly.

llvm-svn: 286771
2016-11-13 19:27:24 +00:00
Tobias Grosser a9cac6a732 [tests] Adjust test output to recent changed SCEV canonocalization [NFC]
LLVM recently changed the SCEV canonicalization which changed the output of
one of our GPGPU test cases.

llvm-svn: 286770
2016-11-13 19:27:17 +00:00
Tobias Grosser a2f8fa33aa [ScopDetect] Evaluate and verify branches at branch condition, not icmp
The validity of a branch condition must be verified at the location of the
branch (the branch instruction), not the location of the icmp that is
used in the branch instruction. When verifying at the wrong location, we
may accept an icmp that is defined within a loop which itself dominates, but
does not contain the branch instruction. Such loops cannot be modeled as
we only introduce domain dimensions for surrounding loops. To address this
problem we change the scop detection to evaluate and verify SCEV expressions at
the right location.

This issue has been around since at least r179148 "scop detection: properly
instantiate SCEVs to the place where they are used", where we explicitly
set the scope to the wrong location. Before this commit the scope
was not explicitly set, which probably also resulted in the scope around the
ICmp to be choosen.

This resolves http://llvm.org/PR30989

Reported-by: Eli Friedman <efriedma@codeaurora.org>
llvm-svn: 286769
2016-11-13 19:27:04 +00:00
Tobias Grosser f67433abd9 SCEVAffinator: pass parameter-only set to addRestriction if BB=nullptr
Assumptions can either be added for a given basic block, in which case the set
describing the assumptions is expected to match the dimensions of its domain.
In case no basic block is provided a parameter-only set is expected to describe
the assumption.

The piecewise expressions that are generated by the SCEVAffinator sometimes
have a zero-dimensional domain (e.g., [p] -> { [] : p <= -129 or p >= 128 }),
which looks similar to a parameter-only domain, but is still a set domain.

This change adds an assert that checks that we always pass parameter domains to
addAssumptions if BB is empty to make mismatches here fail early.

We also change visitTruncExpr to always convert to parameter sets, if BB is
null. This change resolves http://llvm.org/PR30941

Another alternative to this change would have been to inspect all code to make
sure we directly generate in the SCEV affinator parameter sets in case of empty
domains. However, this would likely complicate the code which combines parameter
and non-parameter domains when constructing a statement domain. We might still
consider doing this at some point, but as this likely requires several non-local
changes this should probably be done as a separate refactoring.

Reported-by: Eli Friedman <efriedma@codeaurora.org>
llvm-svn: 286444
2016-11-10 11:44:10 +00:00