Commit Graph

1604 Commits

Author SHA1 Message Date
Tobias Grosser 535afd808d ScopInfo: Check for possibly nested GEP in fixed-size delin
We currently only consider the first GEP when delinearizing access functions,
which makes us loose information about additional index expression offsets,
which results in our SCoP model to be incorrect. With this patch we now
compare the base pointers used to ensure we do not miss any additional offsets.
This fixes llvm.org/PR27195.

We may consider supporting nested GEP in our delinearization heuristics in
the future.

llvm-svn: 265379
2016-04-05 06:23:45 +00:00
Johannes Doerfert 1519491eaf Do not allow to complex branch conditions
Even before we build the domain the branch condition can become very
  complex, especially if we have to build the complement of a lot of
  equality constraints. With this patch we bail if the branch condition
  has a lot of basic sets and parameters.

  After this patch we now successfully compile
    External/SPEC/CINT2000/186_crafty/186_crafty
  with "-polly-process-unprofitable -polly-position=before-vectorizer".

llvm-svn: 265286
2016-04-04 07:59:41 +00:00
Johannes Doerfert 642594ae87 Exploit graph properties during domain generation
As a CFG is often structured we can simplify the steps performed during
  domain generation. When we push domain information we can utilize the
  information from a block A to build the domain of a block B, if A dominates B
  and there is no loop backede on a path from A to B. When we pull domain
  information we can use information from a block A to build the domain of a
  block B if B post-dominates A. This patch implements both ideas and thereby
  simplifies domains that were not simplified by isl. For the FINAL basic block
  in test/ScopInfo/complex-successor-structure-3.ll we used to build a universe
  set with 81 basic sets. Now it actually is represented as universe set.

  While the initial idea to utilize the graph structure depended on the
  dominator and post-dominator tree we can use the available region
  information as a coarse grained replacement. To this end we push the
  region entry domain to the region exit and pull it from the region
  entry for the region exit if applicable.

  With this patch we now successfully compile
    External/SPEC/CINT2006/400_perlbench/400_perlbench
  and
    SingleSource/Benchmarks/Adobe-C++/loop_unroll.

Differential Revision: http://reviews.llvm.org/D18450

llvm-svn: 265285
2016-04-04 07:57:39 +00:00
Johannes Doerfert a07f0ac73f Factor out "adjustDomainDimensions" function [NFC]
llvm-svn: 265284
2016-04-04 07:50:40 +00:00
Johannes Doerfert d5edbd61a1 [FIX] Do not create a SCoP in the presence of infinite loops
If a loop has no exiting blocks the region covering we use during
  schedule genertion might not cover that loop properly. For now we bail
  out as we would not optimize these loops anyway.

llvm-svn: 265280
2016-04-03 23:09:06 +00:00
Tobias Grosser 151ae32dba Revert "[FIX] Do not create a SCoP in the presence of infinite loops"
This reverts commit r265260, as it caused the following 'make check-polly'
failures:

    Polly :: ScopDetect/index_from_unpredictable_loop.ll
    Polly :: ScopInfo/multiple_exiting_blocks.ll
    Polly :: ScopInfo/multiple_exiting_blocks_two_loop.ll
    Polly :: ScopInfo/schedule-const-post-dominator-walk-2.ll
    Polly :: ScopInfo/schedule-const-post-dominator-walk.ll
    Polly :: ScopInfo/switch-5.ll

llvm-svn: 265272
2016-04-03 19:36:52 +00:00
Johannes Doerfert 2075b5d2a1 [FIX] Do not create two SAI objects for exit PHIs
If an exit PHI is written and also read in the SCoP we should not create two
  SAI objects but only one. As the read is only modeled to ensure OpenMP code
  generation knows about it we can simply use the EXIT_PHI MemoryKind for both
  accesses.

llvm-svn: 265261
2016-04-03 11:16:00 +00:00
Johannes Doerfert 7dcceb82e9 [FIX] Do not create a SCoP in the presence of infinite loops
If a loop has no exiting blocks the region covering we use during
  schedule genertion might not cover that loop properly. For now we bail
  out as we would not optimize these loops anyway.

llvm-svn: 265260
2016-04-03 11:12:39 +00:00
Johannes Doerfert 6ba927148d [FIX] Adjust the insert point for non-affine region PHIs
If a non-affine region PHI is generated we should not move the insert
  point prior to the synthezised value in the same block as we might
  split that block at the insert point later on. Only if the incoming
  value should be placed in a different block we should change the
  insertion point.

llvm-svn: 265132
2016-04-01 11:25:47 +00:00
Tobias Grosser db6db505c9 ScoPDetection: Obtain a known free diagnostic ID
... instead of hardcoding something that has been free at some point. This fixes
a crash triggered by r265084, where the diagnostic IDs have been shifted in a
way that resulted our hardcode ID to not be assigned any implementation.  Our ID
was likely already wrong earlier on, but this time we really crashed nicely.

llvm-svn: 265114
2016-04-01 07:15:19 +00:00
Tobias Grosser 6deba4ea03 Revert 264782 and 264789
These caused LNT failures due to new assertions when running with
-polly-position=before-vectorizer -polly-process-unprofitable for:

FAIL: clamscan.compile_time
FAIL: cjpeg.compile_time
FAIL: consumer-jpeg.compile_time
FAIL: shapes.compile_time
FAIL: clamscan.execution_time
FAIL: cjpeg.execution_time
FAIL: consumer-jpeg.execution_time
FAIL: shapes.execution_time

The failures have been introduced by r264782, but r264789 had to be reverted
as it depended on the earlier patch.

llvm-svn: 264885
2016-03-30 18:18:31 +00:00
Johannes Doerfert a144fb148b Exploit graph properties during domain generation
As a CFG is often structured we can simplify the steps performed
  during domain generation. When we push domain information we can
  utilize the information from a block A to build the domain of a
  block B, if A dominates B. When we pull domain information we can
  use information from a block A to build the domain of a block B
  if B post-dominates A. This patch implements both ideas and thereby
  simplifies domains that were not simplified by isl. For the FINAL
  basic block in
    test/ScopInfo/complex-successor-structure-3.ll .
  we used to build a universe set with 81 basic sets. Now it actually is
  represented as universe set.

  While the initial idea to utilize the graph structure depended on the
  dominator and post-dominator tree we can use the available region
  information as a coarse grained replacement. To this end we push the
  region entry domain to the region exit and pull it from the region
  entry for the region exit.

Differential Revision: http://reviews.llvm.org/D18450

llvm-svn: 264789
2016-03-29 21:31:05 +00:00
Johannes Doerfert e11e08bd1f Factor out "adjustDomainDimensions" function [NFC]
llvm-svn: 264782
2016-03-29 20:41:24 +00:00
Johannes Doerfert 29cb067000 Factor out "getFirstNonBoxedLoopFor" function [NFC]
llvm-svn: 264781
2016-03-29 20:32:43 +00:00
Johannes Doerfert 5fb9b21c24 Bail as early as possible
Instead of waiting for the domain construction to finish we will now
  bail as early as possible in case a complexity problem is encountered.
  This might save compile time but more importantly it makes the "abort"
  explicit. While we can always check if we invalidated the assumed
  context we can simply propagate the result of the construction back.
  This also removes the HasComplexCFG flag that was used for the very
  same reason.

Differential Revision: http://reviews.llvm.org/D18504

llvm-svn: 264775
2016-03-29 20:02:05 +00:00
Michael Kruse 88a2256a34 Revert "[ScopInfo] Fix domains after loops."
This reverts commit r264118. The approach is still under discussion.

llvm-svn: 264705
2016-03-29 07:50:52 +00:00
Hongbin Zheng 52ae58259d Add fine-grain dependences analysis to release notes.
Differential Revision: http://reviews.llvm.org/D17905

llvm-svn: 264575
2016-03-28 12:41:49 +00:00
Johannes Doerfert 6462d8c1d9 Generalize the domain complexity restrictions
This patch applies the restrictions on the number of domain conjuncts
  also to the domain parts of piecewise affine expressions we generate.
  To this end the wording is change slightly. It was needed to support
  complex additions featuring zext-instructions but it also fixes PR27045.

  lnt profitable runs reports only little changes that might be noise:
  Compile Time:
    Polybench/[...]/2mm                     +4.34%
    SingleSource/[...]/stepanov_container   -2.43%
  Execution Time:
    External/[...]/186_crafty               -2.32%
    External/[...]/188_ammp                 -1.89%
    External/[...]/473_astar                -1.87%

llvm-svn: 264514
2016-03-26 16:17:00 +00:00
Tobias Grosser 7dcae2e14a Add files forgotten in r264452
llvm-svn: 264460
2016-03-25 20:32:51 +00:00
Tobias Grosser 37034db826 Update to isl-0.16.1-145-g243bf7c
Just an import to keep track with the latest version of isl. We are not looking
for specific features.

llvm-svn: 264452
2016-03-25 19:38:18 +00:00
Tobias Grosser b339594f5d CodegenCleanup: Drop -load-combine pass
This pass is not enabled in the default tool chain and currently can run into an
infinite loop, due to other parts of LLVM generating incorrect IR
(http://llvm.org/PR27065) -- which is not executed and consequently does not
seem to disturb other passes.  As this pass is not really needed, we can just
drop it to get our build clean.

This fixes the timeout issues in MultiSource/Benchmarks/MiBench/consumer-jpeg
and MultiSource/Benchmarks/mediabench/jpeg/jpeg-6a/cjpeg for
-polly-position=before-vectorizer -polly-process-unprofitable.. Unfortunately,
we are still left with a miscompile in cjpeg.

llvm-svn: 264396
2016-03-25 12:11:06 +00:00
Johannes Doerfert 733ea34f38 [FIX] Handle accesses to "null" in MemIntrinsics
This fixes PR27035. While we now exclude MemIntrinsics from the
  polyhedral model if they would access "null" we could exploit this
  even more, e.g., remove all parameter combinations that would lead to
  the execution of this statement from the context.

llvm-svn: 264284
2016-03-24 13:50:04 +00:00
Johannes Doerfert 549768c01a [FIX] Verify the alias group before returning it
Similar to r262612 we need to check not only the pointer SCEV and the
type of an alias group but also the actual access instruction. The
reason is again the same: The pointer SCEV is not flow sensitive but the
access function is. In r262612 we avoided consolidating alias groups
even though the pointer SCEV and the type were the same but the access
function was not. Here it is simpler as we can simply check all members
of an alias group against the given access instruction.

llvm-svn: 264274
2016-03-24 13:22:16 +00:00
Johannes Doerfert 47197fe3f3 Add namespace for struct [NFC]
This will clean up the doxygen documentation.

llvm-svn: 264272
2016-03-24 13:20:52 +00:00
Johannes Doerfert 01b723ba43 Remove obsolete CMD option [NFC]
llvm-svn: 264270
2016-03-24 13:19:51 +00:00
Johannes Doerfert 2b470e8e61 Remove obsolete code
Since r261226 we should not see this situation any more, if so it is probably
  a bug that would only be hidden.

llvm-svn: 264269
2016-03-24 13:19:16 +00:00
Johannes Doerfert 13d5d5b184 Remove weird comment [NFC]
llvm-svn: 264268
2016-03-24 13:16:49 +00:00
Tobias Grosser bfb6a9683b Codegen:Do not invalidate dominator tree when bailing out during code generation
When codegenerating invariant loads in some rare cases we cannot generate code
and bail out. This change ensures that we maintain a valid dominator tree
in these situations. This fixes llvm.org/PR26736

Contributed-by: Matthias Reisinger <d412vv1n@gmail.com>
llvm-svn: 264142
2016-03-23 06:57:51 +00:00
Tobias Grosser 898a636210 Add option to disallow modref function calls in scops.
This might be useful to evaluate the benefit of us handling modref funciton
calls. Also, a new bug that was triggered by modref function calls was
recently reported http://llvm.org/PR27035. To ensure the same issue does not
cause troubles for other people, we temporarily disable this until the bug
is resolved.

llvm-svn: 264140
2016-03-23 06:40:15 +00:00
Michael Kruse 49a59ca093 [ScopInfo] Fix domains after loops.
ISL can conclude additional conditions on parameters from restrictions
on loop variables. Such conditions persist when leaving the loop and the
loop variable is projected out. This results in a narrower domain for
exiting the loop than entering it and is logically impossible for
non-infinite loops.

We fix this by not adding a lower bound i>=0 when constructing BB
domains, but defer it to when also the upper bound it computed, which
was done redundantly even before this patch.

This reduces the number of LNT fails with -polly-process-unprofitable
-polly-position=before-vectorizer from 8 to 6.

llvm-svn: 264118
2016-03-22 23:27:42 +00:00
Tobias Grosser 5a8c052baf Invalidate scop on encountering a complex control flow
We bail out if current scop has a complex control flow as this could lead to
building of large domain conditions. This is to reduce compile time.  This
addresses r26382.

Contributed-by: Chris Jenneisch <chrisj@codeaurora.org>

Differential Revision: http://reviews.llvm.org/D18362

llvm-svn: 264105
2016-03-22 22:05:32 +00:00
Tobias Grosser 0904c69110 ScopInfo: Do not generate dependences for i1 values used in affine branches
Affine branches are fully modeled and regenerated from the polyhedral domain and
consequently do not require any input conditions to be propagated.

llvm-svn: 263678
2016-03-16 23:33:54 +00:00
Tobias Grosser 6733ba826a docs: Add doxygen mainpage
(and test if doxygen is updated on-commit)

llvm-svn: 262855
2016-03-07 21:17:48 +00:00
Michael Kruse afd2db5351 [SCEVValidator] Fix loop exit values considered affine.
Index calculations can use the last value that come out of a loop.
Ideally, ScalarEvolution can compute that exit value directly without
depending on the loop induction variable, but not in all cases.

This changes isAffine to not consider such loop exit values as affine to
avoid that SCEVExpander adds uses of the original loop induction
variable.

This fix is analogous to r262404 that applies to general uses of loop
exit values instead of index expressions and loop bouds as in this
patch.

This reduces the number of LNT test-suite fails with
-polly-position=before-vectorizer -polly-unprofitable
from 10 to 8.

llvm-svn: 262665
2016-03-03 22:10:52 +00:00
Michael Kruse 09eb4451d2 Pass scope and LoopInfo to SCEVValidator. NFC.
The scope will be required in the following fix. This commit separates
the large changes that do not change behaviour from the small, but
functional change.

llvm-svn: 262664
2016-03-03 22:10:47 +00:00
Michael Kruse faedfcbf6d [BlockGenerator] Fix PHI merges for MK_Arrays.
Value merging is only necessary for scalars when they are used outside
of the scop. While an array's base pointer can be used after the scop,
it gets an extra ScopArrayInfo of type MK_Value. We used to generate
phi's for both of them, where one was assuming the reault of the other
phi would be the original value, because it has already been replaced by
the previous phi. This resulted in IR that the current IR verifier
allows, but is probably illegal.

This reduces the number of LNT test-suite fails with
-polly-position=before-vectorizer -polly-process-unprofitable
from 16 to 10.

Also see llvm.org/PR26718.

llvm-svn: 262629
2016-03-03 17:20:43 +00:00
Johannes Doerfert ac37c565b5 Fix typo [NFC]
llvm-svn: 262613
2016-03-03 12:30:19 +00:00
Johannes Doerfert df88023d2b [FIX] Consolidation of loads with same pointer but different access relation
This should fix PR19422.

  Thanks to Jeremy Huddleston Sequoia for reporting this.
  Thanks to Roman Gareev for his investigation and the reduced test case.

llvm-svn: 262612
2016-03-03 12:26:58 +00:00
Hongbin Zheng 2a798853f8 Allow the client of DependenceInfo to obtain dependences at different granularities.
llvm-svn: 262591
2016-03-03 08:15:33 +00:00
Michael Kruse 1bf6bafb2d Fix: Add pass manager barrier.
The LNT test suite with -polly-process-unprofitable
-polly-position=before-vectorizer currenty fails 59 tests. With this
barrier added, only 16 keep failing. This is probably because Polly's
code generation currently does not correctly preserve all analyses it
promised to preserve. Temporarily add this barrier until further
investigation.

llvm-svn: 262488
2016-03-02 14:59:16 +00:00
Michael Kruse c7e0d9c216 Fix non-synthesizable loop exit values.
Polly recognizes affine loops that ScalarEvolution does not, in
particular those with loop conditions that depend on hoisted invariant
loads. Check for SCEVAddRec dependencies on such loops and do not
consider their exit values as synthesizable because SCEVExpander would
generate them as expressions that depend on the original induction
variables. These are not available in generated code.

llvm-svn: 262404
2016-03-01 21:44:06 +00:00
Michael Kruse b3a7935d54 [SCEVValidator] Remove redundant visit.
SCEVAddRecExpr::getStart() is synonymous to SCEVAddRecExpr::getOperand(0)
which will be visited in the following loop anyway.

llvm-svn: 262375
2016-03-01 19:30:54 +00:00
Johannes Doerfert 066dbf3f8e Track assumptions and restrictions separatly
In order to speed up compile time and to avoid random timeouts we now
  separately track assumptions and restrictions. In this context
  assumptions describe parameter valuations we need and restrictions
  describe parameter valuations we do not allow. During AST generation
  we create a runtime check for both, whereas the one for the
  restrictions is negated before a conjunction is build.

  Except the In-Bounds assumptions we currently only track restrictions.

Differential Revision: http://reviews.llvm.org/D17247

llvm-svn: 262328
2016-03-01 13:06:28 +00:00
Johannes Doerfert abadd71da1 [FIX] Prevent compile time problems due to complex invariant loads
This cures the symptoms we see in h264 of SPEC2006 but not the cause.

llvm-svn: 262327
2016-03-01 13:05:14 +00:00
Michael Kruse 0b56681d21 [ScopDetection] Fix use-after-free.
removeCachedResults deletes the DetectionContext from
DetectionContextMap such that any it cannot be used anymore.
Unfortunately invalid<ReportUnprofitable> and RejectLogs.insert still do
use it. Because the memory is part of a map and not returned to to the
OS immediatly, such that the observable effect was only a memory leak
due to reference counters not decreased when the second call to
removeCachedResults does not remove the DetectionContext because because
it already has been removed.

Fix by not removing the DetectionContext prematurely. The second call to
removeCachedResults will handle it anyway.

llvm-svn: 262235
2016-02-29 16:54:18 +00:00
Tobias Grosser 0865e775bf ScopInfo: Remove indentation in hoistInvariantLoads
We move verifyInvariantLoads out of this function to allow for an early return
without the need for code duplication. A similar transformation was suggested
by Johannes Doerfert in post commit review of r262033.

llvm-svn: 262203
2016-02-29 07:29:42 +00:00
Tobias Grosser 4fb9e51664 ScopInfo: Drop some debug statements
This debug output distracts from the -debug-only=polly-scops output. As it is
rather verbose and only really needed for debugging the domain construction
I drop this output. The domain construction is meanwhile stable enough to
not require regular debugging.

llvm-svn: 262117
2016-02-27 06:59:30 +00:00
Hongbin Zheng 8efb22ef25 Enable llvm's isa/cast/dyn_cast on MemAccInst.
Differential Revision: http://reviews.llvm.org/D17250

llvm-svn: 262100
2016-02-27 01:49:58 +00:00
Hongbin Zheng 9691d71674 Introduce fine-grain dependence analysis by tagging access functions and schedules tree with either the id of memory access or memory references.
Differential Revision: http://reviews.llvm.org/D17381

llvm-svn: 262039
2016-02-26 17:05:24 +00:00
Tobias Grosser 8fa3e4c3fb ScopDetect/Info: Add option to disable invariant load hoisting
This is helpful for test case reduction and other experiments.

llvm-svn: 262033
2016-02-26 16:43:35 +00:00