Commit Graph

551 Commits

Author SHA1 Message Date
Tobias Grosser 95e59aaa54 OpenMP: Name addresses in subfunction structure
While debugging, this makes it easier to understand due to which memory
reference these stores have been introduced.

llvm-svn: 248717
2015-09-28 16:46:38 +00:00
Tobias Grosser 28b9a14b07 BlockGenerator: Generate synthesisable instructions only on-demand
Instructions which we can synthesis from a SCEV expression are not generated
directly, but only when they are used as an operand of another instruction. This
avoids generating unnecessary instruction and works more reliably than first
inserting them and then deleting them later on.

Suggested-by: Johannes Doerfert <doerfert@cs.uni-saarland.de>

Differential Revision: http://reviews.llvm.org/D13208

llvm-svn: 248712
2015-09-28 13:47:50 +00:00
Johannes Doerfert 9a132f36c3 Allow switch instructions in SCoPs
This patch allows switch instructions with affine conditions in the
  SCoP. Also switch instructions in non-affine subregions are allowed.
  Both did not require much changes to the code, though there was some
  refactoring needed to integrate them without code duplication.

  In the llvm-test suite the number of profitable SCoPs increased from
  135 to 139 but more importantly we can handle more benchmarks and user
  inputs without preprocessing.

Differential Revision: http://reviews.llvm.org/D13200

llvm-svn: 248701
2015-09-28 09:33:22 +00:00
Tobias Grosser f223cdf17e [tests] Add memory writes to make this scop not trivially empty
llvm-svn: 248697
2015-09-28 07:37:06 +00:00
Johannes Doerfert f32f5f2305 Remove obsolete check
This check was needed at some point but seems not useful anymore. Only
  one adjustment in the domain generation was needed to cope with the
  cases this check prevented from happening before.

llvm-svn: 248695
2015-09-28 01:30:37 +00:00
Tobias Grosser 0722a1e5d5 BlockGenerator: Be less agressive with deleting dead instructions
We now only delete trivially dead instructions in the BB we copy (copyBB), but
not in any other BB.  Only for copyBB we know that there will _never_ be any
future uses of instructions that have no use after copyBB has been generated.
Other instructions in the AST that have been generated by IslNodeBuilder may
look dead at the moment, but may possibly still be referenced by GlobalMaps. If
we delete them now, later uses would break surprisingly.

We do not have a test case that breaks due to us deleting too many instructions.
This issue was found by inspection.

llvm-svn: 248688
2015-09-27 19:50:16 +00:00
Tobias Grosser 0ff79e586d BlockGenerator: Simplify code generated for region statements
After having generated a new user statement a couple of inefficient or
trivially dead instructions may remain. This commit runs instruction
simplification over the newly generated blocks to ensure unneeded
instructions are removed right away.

This commit does adds simplification for non-affine subregions which was not
yet part of 248681.

llvm-svn: 248683
2015-09-27 11:35:00 +00:00
Tobias Grosser 412f9774f8 [CodeGen test] Replace undef values with some defined constants
Otherwise, part of the computation will be just simplified away when we add
instruction simplification support to the RegionGenerator.

llvm-svn: 248682
2015-09-27 11:34:53 +00:00
Tobias Grosser 1b9d25a42d BlockGenerator: Simplify code generated for scop statements
After having generated a new user statement a couple of inefficient or trivially
dead instructions may remain. This commit runs instruction simplification over
the newly generated blocks to ensure unneeded instructions are removed right
away.

This commit does not yet add simplification for non-affine subregions.

llvm-svn: 248681
2015-09-27 11:17:22 +00:00
Johannes Doerfert fb19dd694c Create parallel code in a separate block
This commit basically reverts r246427 but still solves the issue
  tackled by that commit. Instead of emitting initialization code in the
  beginning of the start block we now generate parallel code in its own
  block and thereby guarantee separation. This is necessary as we cannot
  generate code for hoisted loads prior to the start block but it still
  needs to be placed prior to everything else.

llvm-svn: 248674
2015-09-26 20:57:59 +00:00
Tobias Grosser 06c495c2b0 Add test case from llvm.org/PR17187
The new domain construction algorithm now correctly models this test case (and
derives an empty run-time condition). Add this test case to ensure we do not
regress.

llvm-svn: 248669
2015-09-26 14:27:54 +00:00
Johannes Doerfert 12155a9ef4 Add test case from open bug
The bug (15771) was fixed already with the new domain generation
  but the test case was not added till now.

llvm-svn: 248668
2015-09-26 14:03:29 +00:00
Johannes Doerfert c6987c18de [FIX] Use the surrounding loop for non-affine SCoP regions
When the whole SCoP is a non-affine region we need to use the
  surrounding loop in the construction of the schedule as that is
  the one that will be looked up after the schedule generation.

  This fixes bug 24947

llvm-svn: 248667
2015-09-26 13:41:43 +00:00
Tobias Grosser bbda083c75 Add test case for delinearization through bitcasts
This was forgotten in r247928

llvm-svn: 248663
2015-09-26 08:55:59 +00:00
Tobias Grosser 99c70dd8d1 Ensure memory accesses to the same array have identical dimensionality
When recovering multi-dimensional memory accesses, it may happen that different
accesses to the same base array are recovered with different dimensionality.
This patch ensures that the dimensionalities are unified by adding zero valued
dimensions to acesses with lower dimensionality. When starting to model
fixed-size arrays as multi-dimensional in 247906, this has not been taken
care of.

llvm-svn: 248662
2015-09-26 08:55:54 +00:00
Tobias Grosser 8016f3a4f5 Add missing PHI to test case
llvm-svn: 248563
2015-09-25 05:41:30 +00:00
Tobias Grosser da95a4a7c7 Handle read-only scalars used in PHI-nodes correctly
This change addresses three issues:

  - Read only scalars that enter a PHI node through an edge that comes from
    outside the scop are not modeled any more, as such PHI nodes will always
    be initialized to this initial value right before the SCoP is entered.
  - For PHI nodes that depend on a scalar value that is defined outside the
    scop, but where the scalar values is passed through an edge that itself
    comes from a BB that is part of the region, we introduce in this basic
    block a read of the out-of-scop value to ensure it's value is available
    to write it into the PHI alloc location.
  - Read only uses of scalars by PHI nodes are ignored in the general read only
    handling code, as they are taken care of by the general PHI node modeling
    code.

llvm-svn: 248535
2015-09-24 20:59:59 +00:00
Michael Kruse 2d0ece960f Remove Analysis Output of TempScopInfo
After the merge of TempScopInfo into ScopInfo the analysis output 
remained because of the existing unit tests. These remains are removed 
and the units tests converted to match the equivalent output of 
ScopInfo's analysis output. The unit tests are also moved into the
directory of ScopInfo tests.

Differential Revision: http://reviews.llvm.org/D13116

llvm-svn: 248485
2015-09-24 11:41:21 +00:00
Tobias Grosser b1c39429d9 Do not model delinearized and linearized access relation for a single access
A missing return statement that previously did not have a visibly negative
effect caused after some data-structure changes in r248024 multi-dimensional
accesses to be modeled both multi-dimensional as well as linearized. This
commit adds the missing return to avoid the incorrect double modeling as
well as the compile time increases it caused.

llvm-svn: 248171
2015-09-21 16:19:25 +00:00
Johannes Doerfert 6a72a2af13 Use <nsw> AddRecs in the affinator to avoid bounded assumptions
If we encounter a <nsw> tagged AddRec for a loop we know the trip count of
  that loop has to be bounded or the semantics is undefined anyway. Hence, we
  only need to add unbounded assumptions if no such AddRec is known.

llvm-svn: 248128
2015-09-20 16:59:23 +00:00
Johannes Doerfert 707a406078 Add bounded loop assumption
So far we ignored the unbounded parts of the iteration domain, however
  we need to assume they do not occure at all to remain sound if they do.

llvm-svn: 248126
2015-09-20 16:38:19 +00:00
Johannes Doerfert f2cc86edae Simplify domain generation
We now add loop carried information during the second traversal of the
  region instead of in a intermediate step in-between. This makes the
  generation simpler, removes code and should even be faster.

llvm-svn: 248125
2015-09-20 16:15:32 +00:00
Johannes Doerfert 0c1123a831 [FIX] Repair test case that was unprofitable
llvm-svn: 248124
2015-09-20 16:14:41 +00:00
Johannes Doerfert 06c57b594c Allow loops with multiple back edges
In order to allow multiple back edges we:
    - compute the conditions under which each back edge is taken
    - build the union over all these conditions, thus the condition that
      any back edge is taken
    - apply the same logic to the union we applied to a single back edge

llvm-svn: 248120
2015-09-20 15:00:20 +00:00
Johannes Doerfert 7175bdfbe4 Add loop trip count based heuristic for SCoP detection
As we currently do not perform any optimizations that targets (or is
  even aware) small trip counts we will skip them when we count the
  loops in a region.

llvm-svn: 248119
2015-09-20 14:56:54 +00:00
Michael Kruse e2bccbbfb2 Merge IRAccess into MemoryAccess
All MemoryAccess objects will be owned by ScopInfo::AccFuncMap which 
previously stored the IRAccess objects. Instead of creating new 
MemoryAccess objects, the already created ones are reused, but their 
order might be different now. Some fields of IRAccess and MemoryAccess 
had the same meaning and are merged.

This is the last step of fusioning TempScopInfo.{h|cpp} and 
ScopInfo.{h.cpp}. Some refactoring might still make sense.

Differential Revision: http://reviews.llvm.org/D12843

llvm-svn: 248024
2015-09-18 19:59:43 +00:00
Tobias Grosser 5fd8c0961e Model fixed-size multi-dimensional arrays if possible multi-dimensional
If the GEP instructions give us enough insights, model scalar accesses as
multi-dimensional (and generate the relevant run-time checks to ensure
correctness). This will allow us to simplify the dependence computation in
a subsequent commit.

llvm-svn: 247906
2015-09-17 17:28:15 +00:00
Johannes Doerfert 883f8c1d2f Use modulo semantic to generate non-integer-overflow assumptions
This will allow to generate non-wrap assumptions for integer expressions
  that are part of the SCoP. We compare the common isl representation of
  the expression with one computed with modulo semantic. For all parameter
  combinations they are not equal we can have integer overflows.

  The nsw flags are respected when the modulo representation is computed,
  nuw and nw flags are ignored for now.

  In order to not increase compile time to much, the non-wrap assumptions
  are collected in a separate boundary context instead of the assumed
  context. This helps compile time as the boundary context can become
  complex and it is therefor not advised to use it in other operations
  except runtime check generation. However, the assumed context is e.g.,
  used to tighten dependences. While the boundary context might help to
  tighten the assumed context it is doubtful that it will help in practice
  (it does not effect lnt much) as the boundary (or no-wrap assumptions)
  only restrict the very end of the possible value range of parameters.

  PET uses a different approach to compute the no-wrap context, though lnt runs
  have shown that this version performs slightly better for us.

llvm-svn: 247732
2015-09-15 22:52:53 +00:00
Michael Kruse da8d6203f4 Fix after renamed CMake cache entry
LLVM_EXTERNAL_CLANG_BUILD was changed to LLVM_TOOL_CLANG_BUILD in
r242059.

llvm-svn: 247675
2015-09-15 10:51:15 +00:00
Michael Kruse fa62b1763c Run polly-check-format with unit tests
Add polly-check-format as dependency of check-polly if clang-format is 
available in the same build.

Differential Revision: http://reviews.llvm.org/D12850

llvm-svn: 247600
2015-09-14 19:11:48 +00:00
Tobias Grosser aaadc5302c [test] Load Polly before using the polly flags
llvm-svn: 247551
2015-09-14 11:49:05 +00:00
Johannes Doerfert 334f9e87c6 [FIX] XFAIL test that depends on pending LLVM commit
llvm-svn: 247550
2015-09-14 11:45:34 +00:00
Johannes Doerfert e114dc024e [FIX] Handle error blocks in non-affine regions correctly
llvm-svn: 247545
2015-09-14 11:15:58 +00:00
Johannes Doerfert 40fa56f59f [FIX] Allow the whole SCoP to be a non-affine subregion
llvm-svn: 247544
2015-09-14 11:15:07 +00:00
Johannes Doerfert 36255eecd8 Revert r247278 "Disable support for modulo expressions"
This reverts commit 00c5b6ca8832439193036aadaaaee92a43236219.

  We can handle modulo expressions in the domain again.

llvm-svn: 247542
2015-09-14 11:14:23 +00:00
Johannes Doerfert ca1e38fa43 Propagate exit conditions as described in the PET paper
At some point we build loop trip counts using this method. It was replaced by
  a simpler trick that works only for affine (e.g., not modulo) constraints and
  relies on the removal of unbounded parts. In order to allow modulo constrains
  again we go back to the former, more accurate method.

llvm-svn: 247540
2015-09-14 11:12:52 +00:00
Michael Kruse 07d5df4db8 Fix out-of-range access in test case
The function use_after_scop would iterate from 0 to 1024 and accessing element A[1024] where A has only valid indexes from 0 to 1023. Polly detects the situation of unconditionally undefined behavior and bail out in ScopInfo as non-feasible for optimization.

Other tests add impossible context assumptions as well, hance might show the same problem.

llvm-svn: 247412
2015-09-11 13:45:05 +00:00
David Blaikie 0afc1e4ecc Update polly for explicit type parameter to global alias change
llvm-svn: 247382
2015-09-11 03:42:32 +00:00
Tobias Grosser 34b11fc197 XFAIL tests that require an additional LLVM patch to work
llvm-svn: 247338
2015-09-10 21:32:29 +00:00
Johannes Doerfert 90db75ed24 Runtime error check elimination
Hoist runtime checks in the loop nest if they guard an "error" like event.
  Such events are recognized as blocks with an unreachable terminator or a call
  to the ubsan function that deals with out of bound accesses. Other "error"
  events can be added easily.

  We will ignore these blocks when we detect/model/optmize and code generate SCoPs
  but we will make sure that they would not have been executed using the assumption
  framework.

llvm-svn: 247310
2015-09-10 17:51:27 +00:00
Johannes Doerfert f4fa9879fb [FIX] Do not assume only one loop can be left at a time
llvm-svn: 247291
2015-09-10 15:53:59 +00:00
Johannes Doerfert b68cffb5df Allow general loops with one latch
As we do not rely on ScalarEvolution any more we do not need to get
  the backedge taken count. Additionally, our domain generation handles
  everything that is affine and has one latch and our ScopDetection will
  over-approximate everything else.

  This change will therefor allow loops with:
    - one latch
    - exiting conditions that are affine

  Additionally, it will not check for structured control flow anymore.
  Hence, loops and conditionals are not necessarily single entry single
  exit regions any more.

Differential Version: http://reviews.llvm.org/D12758

llvm-svn: 247289
2015-09-10 15:27:46 +00:00
Michael Kruse d868b5d509 Merge TempScopInfo into ScopInfo
The TempScopInfo (-polly-analyze-ir) pass is removed and its work taken
over by ScopInfo (-polly-scops). Several tests depend on
-polly-analyze-ir and use -polly-scops instead which for the moment
prints the output of both passes. This again is not expected by some
other tests, especially those with negative searches, which have been
adapted.

Differential Version: http://reviews.llvm.org/D12694

llvm-svn: 247288
2015-09-10 15:25:24 +00:00
Michael Kruse 9cc1b9d31e Clean-up unit tests
Remove redundant flags and duplicate invocations of the same test.

llvm-svn: 247285
2015-09-10 14:42:09 +00:00
Johannes Doerfert 5b9ff8b667 Replace ScalarEvolution based domain generation
This patch replaces the last legacy part of the domain generation, namely the
ScalarEvolution part that was used to obtain loop bounds. We now iterate over
the loops in the region and propagate the back edge condition to the header
blocks. Afterwards we propagate the new information once through the whole
region. In this process we simply ignore unbounded parts of the domain and
thereby assume the absence of infinite loops.

  + This patch already identified a couple of broken unit tests we had for
    years.
  + We allow more loops already and the step to multiple exit and multiple back
    edges is minimal.
  + It allows to model the overflow checks properly as we actually visit
    every block in the SCoP and know where which condition is evaluated.
  - It is currently not compatible with modulo constraints in the
    domain.

Differential Revision: http://reviews.llvm.org/D12499

llvm-svn: 247279
2015-09-10 13:00:06 +00:00
Johannes Doerfert 171f07ed71 Disable support for modulo expressions
The support for modulo expressions is not comlete and makes the new
  domain generation harder. As the currently broken domain generation
  needs to be replaced, we will first swap in the new, fixed domain
  generation and make it compatible with the modulo expressions later.

llvm-svn: 247278
2015-09-10 12:56:46 +00:00
Chandler Carruth 66ef16b289 [PM] Update Polly for the new AA infrastructure landed in r247167.
llvm-svn: 247198
2015-09-09 22:13:56 +00:00
Johannes Doerfert 7ca8dc2d2d Disable support for pointer expressions
The support for pointer expressions is broken as it can only handle
  some patterns in the IslExprBuilder. We should to treat pointers in
  expressions the same as integers at some point and revert this patch.

llvm-svn: 247147
2015-09-09 14:19:04 +00:00
Johannes Doerfert 717b866798 Allow PHI nodes in the region exit block
While we do not need to model PHI nodes in the region exit (as it is not part
  of the SCoP), we need to prepare for the case that the exit block is split in
  code generation to create a single exiting block. If this will happen, hence
  if the region did not have a single exiting block before, we will model the
  operands of the PHI nodes as escaping scalars in the SCoP.

Differential Revision: http://reviews.llvm.org/D12051

llvm-svn: 247078
2015-09-08 21:44:27 +00:00
Tobias Grosser 02e6589bda Move more compile-time bailouts into -polly-detect-unprofitable
Instead of having two separate options
-polly-detect-scops-in-functions-without-loops and
-polly-detect-scops-in-regions-without-loops we now just use
-polly-detect-unprofitable to force the detection of scops ignoring any compile
time saving bailout heuristics.

llvm-svn: 247057
2015-09-08 19:46:41 +00:00