Commit Graph

134 Commits

Author SHA1 Message Date
Chandler Carruth 9ae926b973 [IR] Replace `isa<TerminatorInst>` with `isTerminator()`.
This is a bit awkward in a handful of places where we didn't even have
an instruction and now we have to see if we can build one. But on the
whole, this seems like a win and at worst a reasonable cost for removing
`TerminatorInst`.

All of this is part of the removal of `TerminatorInst` from the
`Instruction` type hierarchy.

llvm-svn: 340701
2018-08-26 09:51:22 +00:00
Tobias Grosser 80677bce11 [ScopBuilder] Slightly improve code structure [NFCI]
First build the surrounding loops and then build up the polyhedral
structures. Before r326664 we had to mix these updates, clean this
up to improve readability (slightly).

llvm-svn: 334412
2018-06-11 14:59:28 +00:00
Nicola Zaghen 349506a926 [polly] Update uses of DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM

Differential Revision: https://reviews.llvm.org/D44978

llvm-svn: 332352
2018-05-15 13:37:17 +00:00
Michael Kruse 5369ea5dd5 Allow arbitrary function calls for debugging purposes.
Add the switch -polly-debug-func to define the name of a debug
function. This function is ignored for any validity check.

Its purpose is to allow to observe a value after transformation by a
SCoP, and to follow which statements are executed in which order. For
instance, consider the following code:

    static void dbg_printf(int sum, int i) {
      fprintf(stderr, "The value of sum is %d, i=%d\n", sum, i);
      fflush(stderr);
    }

    void func(int n) {
      int sum = 0;
      for (int i = 0; i < 16; i+=1) {
        sum += i;
        dbg_printf(sum, i);
      }
    }

Executing this after Polly's codegen with -polly-debug-func=dbg_printf
reveals the new execution order and the assumed values at that point of
execution.

Differential Revision: https://reviews.llvm.org/D45728

llvm-svn: 330466
2018-04-20 18:55:44 +00:00
Tobias Grosser b94863001a [ScopInfo] Do not use the set dimension ids to carry loop information
isl does not guarantee that set dimension ids will be preserved, so using them
to carry information is not a good idea. Furthermore, the loop information can
be derived without problem from the statement itself. As this even requires
less code than propagating loop information on set dimension ids, starting from
this commit we just derive the loop information in collectSurroundingLoops
directly from the IR.

Interestingly this also results in a couple of isl sets to take a simpler
representation.

llvm-svn: 326664
2018-03-03 19:27:54 +00:00
Michael Kruse a6716d9d81 [ScopBuilder] scalar-indep: Fix mutually referencing PHIs.
Two or more PHIs mutually using each other directly or indirectly as
incoming value could cause that a PHI WRITE be added before the PHI READ
(i.e. it overwrites the current incoming value with the next incoming
value before it being read).

Fix by ensuring that the PHI WRITE and PHI READ are in the same statement.

This should fix the miscompile of SingleSource/Benchmark/Misc/whetstone
from the test-suite.

llvm-svn: 324934
2018-02-12 21:09:40 +00:00
Michael Kruse a43ba2d84f [ScopBuilder] Make -polly-stmt-granularity=scalar-indep the default.
Splitting basic blocks into multiple statements if there are now
additional scalar dependencies gives more freedom to the scheduler, but
more statements also means higher compile-time complexity. Switch to
finer statement granularity, the additional compile time should be
limited by the number of operations quota.

The regression tests are written for the -polly-stmt-granularity=bb
setting, therefore we add that flag to those tests that break with the
new default. Some of the tests only fail because the statements are
named differently due to a basic block resulting in multiple statements,
but which are removed during simplification of statements without
side-effects. Previous commits tried to reduce this effect, but it is
not completely avoidable.

Differential Revision: https://reviews.llvm.org/D42151

llvm-svn: 324169
2018-02-03 06:59:47 +00:00
Michael Kruse 217704f7a8 [ScopInfo] Allow epilogues to be the main statement of a BB.
Do not add a "_last" suffix to the statement name if there is no (other)
main statement for a basic block. In other words, it becomes the main
statement itself. This further reduces the statement naming difference
between -polly-stmt-granularity=bb and
-polly-stmt-granularity=scalar-indep.

llvm-svn: 324168
2018-02-03 05:43:00 +00:00
Michael Kruse a230f22f4b [ScopBuilder] Prefer PHI Write accesses in the statement the incoming value is defined.
Theoretically, a PHI write can be added to any statement that represents
the incoming basic block. We previously always chose the last because
the incoming value's definition is guaranteed to be defined.

With this patch the PHI write is added to the statement that defines the
incoming value. It avoids the requirement for a scalar dependency between
the defining statement and the statement containing the write. As such the
logic for -polly-stmt-granularity=scalar-indep that ensures that there is
such scalar dependencies can be removed.

Differential Revision: https://reviews.llvm.org/D42147

llvm-svn: 323284
2018-01-23 23:56:36 +00:00
Michael Kruse 9cfb0ac223 [ScopBuilder] Revise statement naming when there are multiple statements per BB.
The goal is to have -polly-stmt-granularity=bb and
-polly-stmt-granularity=scalar-indep to have the same names if there is
just one statement per basic block.

This fixes a fluke when Polybench's jacobi-2d is optimized differently
depending on the -polly-stmt-granularity option, although both options
create the same SCoP, just with different statement names.

The new naming scheme is:

With -polly-use-llvm-names=0:
Stmt<BBIdx as decimal><Idx within BB as letter>

With -polly-use-llvm-names=1:
Stmt_BBName_<Idx within BB as letter>

The <Idx within BB> suffix is omitted for the main statement of a BB. The
main statement is either the one containing the first store or call
(those cannot be removed by the simplifyer), or if there is no such
instruction, the first. If after simplification there is just a single
statement left, it should be the main statement and have the same names as
with -polly-stmt-granularity=bb.

Differential Revision: https://reviews.llvm.org/D42136

llvm-svn: 322852
2018-01-18 15:15:50 +00:00
Michael Kruse d6e2208671 [ScopInfo] Pass name to ScopStmt ctor. NFC.
This will give control of the statement's name to the caller.
Required to give -polly-stmt-granularity=scalar-indep more control
over the name of the generated statement in a follow-up commit.

llvm-svn: 322851
2018-01-18 15:15:38 +00:00
Michael Kruse 5f0e8a46cf [ScopBuilder] Split statements on encountering store instructions.
Introduce -polly-stmt-granularity=store option.

Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D37337

llvm-svn: 320360
2017-12-11 12:51:24 +00:00
Michael Kruse 188b437fcb [ScopBuilder] Fix typo. NFC.
Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D41047

llvm-svn: 320336
2017-12-10 22:56:32 +00:00
Sanjay Patel 1b5114fa52 [Analysis] update to use new fast-math API - isFast()
llvm-svn: 317491
2017-11-06 16:52:31 +00:00
Adam Nemet e0f1541f41 Rename OptimizationDiagnosticInfo.h to OptimizationRemarkEmitter.h
Polly version of r315249 on LLVM trunk.

llvm-svn: 315253
2017-10-09 23:49:08 +00:00
Michael Kruse cc345e6e94 [ScopBuilder] Introduce -polly-stmt-granularity=scalar-indep option.
The option splits BasicBlocks into minimal statements such that no
additional scalar dependencies are introduced.

The algorithm is based on a union-find structure, and unites sets if
putting them into separate statements would introduce a scalar
dependencies. As a consequence, instructions may be split into separate
statements such their relative order is different than the statements
they are in. This is accounted for instructions whose relative order
matters (e.g. memory accesses).

The algorithm is generic in that heuristic changes can be made
relatively easily. We might relax the order requirement for read-reads
or accesses to different base pointers. Forwardable instructions can be
made to not cause a join.

This implementation gives us a speed-up of 82% in SPEC 2006 456.hmmer
benchmark by allowing loop-distribution in a hot loop such that one of
the loops can be vectorized.

Differential Revision: https://reviews.llvm.org/D38403

llvm-svn: 314983
2017-10-05 13:43:00 +00:00
Michael Kruse 482d3f41e5 [ScopBuilder] Introduce -polly-stmt-granularity option. NFC.
The option is introduced with only one possible value
-polly-stmt-granularity=bb which represents the current behaviour, which
is outlined into the new function buildSequentialBlockStmts().

More options will be added in future commits.

llvm-svn: 314900
2017-10-04 12:18:57 +00:00
Michael Kruse 4ee19603e9 [ScopBuilder] Iterate over statement instructions. NFC.
Iterate over statement instructions instead over basic block
instructions when creating MemoryAccesses. It allows making the creation
of MemoryAccesses independent of how the basic blocks are split into
multiple ScopStmts.

llvm-svn: 314665
2017-10-02 11:41:33 +00:00
Michael Kruse f5745b4e7d [ScopBuilder] Build invariant loads separately.
Create the MemoryAccesses of invariant loads separately and before
all other MemoryAccesses.

Invariant loads are classified as synthesizable and therefore are not
contained in any statement. When iterating over all instructions of all
statements, the invariant loads are consequently not processed and
iterating over them separately becomes necessary.

This patch can change the order in which MemoryAccesses are created, but
otherwise has no functional change.

Some temporary code is introduced to ensure correctness, but will be
removed in the next commit.

llvm-svn: 314664
2017-10-02 11:41:27 +00:00
Michael Kruse 89a6f3db02 [ScopBuilder] Build escaping dependencies separately.
Instructions that compute escaping values might be synthesizable and
therefore not contained in any ScopStmt. When buildAccessFunctions is
changed to only iterate over the instruction list of statement,
"free" instructions still need to be written. We do this after the
main MemoryAccesses have been created.

This can change the order in which MemoryAccesses are created, but has
otherwise no functional change.

llvm-svn: 314663
2017-10-02 11:41:19 +00:00
Michael Kruse 0bedec0e65 [ScopBuilder] Specialize exit block handling. NFC.
Decouple handling of exit block PHIs and other MemoryAccesses. Exit PHIs
only need the PHI handling part of buildAccessFunctions but requires
code for skipping them in while creating other MemoryAcesses.

This change will make it easier to modify how statement MemoryAccesses
are created without considering the exit block special case.

llvm-svn: 314662
2017-10-02 11:41:12 +00:00
Michael Kruse 2dd5fa4dc7 [ScopBuilder] Fix typo. NFC.
Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D38322

llvm-svn: 314519
2017-09-29 15:13:05 +00:00
Tobias Grosser ee457594c2 [ScopDetect/Info] Look through PHIs that follow an error block
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
2017-09-24 09:25:30 +00:00
Michael Kruse 8ee179d3b4 Revert "[ScopDetect/Info] Look through PHIs that follow an error block"
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
2017-09-06 19:05:40 +00:00
Tobias Grosser 4baedc70d1 [ScopDetect/Info] Look through PHIs that follow an error block
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
2017-09-02 08:25:55 +00:00
Tobias Grosser bd15d13d4e [ScopInfo] Use statement lists for entry blocks of region statements
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
2017-08-31 03:15:56 +00:00
Tobias Grosser d3edc16416 Revert "[ScopInfo] Use statement lists for entry blocks of region statements"
This reverts commit r312128. It aused some memory issues.

llvm-svn: 312209
2017-08-31 02:43:49 +00:00
Tobias Grosser 6fbe4c8501 [ScopInfo] Use statement lists for entry blocks of region statements
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
2017-08-30 15:08:21 +00:00
Michael Kruse f3387836d0 [ScopBuilder/ScopInfo] Move reduction detection to ScopBuilder. NFC.
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
2017-08-30 13:05:08 +00:00
Michael Kruse 35aa9d862e [ScopBuilder/ScopInfo] Move ScopStmt::collectSurroundingLoops to ScopBuilder. NFC.
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
2017-08-30 13:05:01 +00:00
Michael Kruse eb83141f9e [ScopBuilder/ScopInfo] Move ScopStmt::buildDomain to ScopBuilder. NFC.
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
2017-08-30 13:04:54 +00:00
Michael Kruse a29f8c03d4 [ScopBuilder/ScopInfo] Move ScopStmt::buildAccessRelations to ScopBuilder. NFC.
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
2017-08-30 13:04:46 +00:00
Michael Kruse f6eb3a2ed2 [ScopBuilder/ScopInfo] Move and inline Scop::init into ScopBuilder::buildScop. NFC.
The method is only needed in the SCoP building phase, and doesn't need
to be part of the general API.

llvm-svn: 312114
2017-08-30 13:04:39 +00:00
Michael Kruse 860870b7b0 [ScopBuilder] Report to dbgs() on SCoP bailout. NFC.
This allows to use -debug to see that a SCoP was found in ScopDetect,
but dismissed by ScopBuilder.

llvm-svn: 312113
2017-08-30 11:52:03 +00:00
Michael Kruse 591255183b [ScopBuilder] Introduce metadata for splitting scop statement.
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
2017-08-30 10:11:06 +00:00
Michael Kruse a4f447c2a4 [PM] Properly require and preserve OptimizationRemarkEmitter. NFCI.
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
2017-08-28 14:07:33 +00:00
Eugene Zelenko 0c4c2ce0b0 [Polly] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 311489
2017-08-22 21:25:51 +00:00
Tobias Grosser 2332fa3604 [ScopInfo] Move InvalidDomain to isl++ [NFC]
llvm-svn: 310203
2017-08-06 15:36:48 +00:00
Michael Kruse a508a4e619 [ScopBuilder/Simplify] Refactor isEscaping. NFC.
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
2017-07-27 14:39:52 +00:00
Michael Kruse 8d89179e33 [ScopInfo] Rename ScopStmt::contains(BB) to represents(BB). NFC.
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
2017-07-25 16:25:37 +00:00
Michael Kruse 07e8c36dc7 [ForwardOpTree] Support read-only value uses.
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
2017-07-24 12:43:27 +00:00
Michael Kruse cd4c977b8b [ScopInfo] Print instructions in dump().
Print a statement's instruction on dump() regardless of
-polly-print-instructions. dump() is supposed to be used in the debugger
only and never in regression tests. While debugging, get all the
information we have and we are not bound to break anything. For non-dump
purposes of print, forward the setting of -polly-print-instructions as
parameters.

Some calls to print() had to be changed because the
PollyPrintInstructions setting is only available in ScopInfo.cpp.
In ScheduleOptimizer.cpp, dump() was used in regression tests.
That's not what dump() is for.

The print parameter "PrintInstructions" will also be useful for an
explicit print SCoP pass in a future patch.

llvm-svn: 308746
2017-07-21 15:35:53 +00:00
Michael Kruse 4642c3ce85 [ScopBuilder] Avoid use of getStmtFor(BB). NFC.
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 ScopBuilder by fetching
the statement in which the instruction lies.

Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D35610

llvm-svn: 308610
2017-07-20 12:47:09 +00:00
Eli Friedman e737fc120e [Polly] [OptDiag] Updating Polly Diagnostics Remarks
Utilizing newer LLVM diagnostic remark API in order to enable use of
opt-viewer tool. Polly Diagnostic Remarks also now appear in YAML
remark file.

In this patch, I've added the OptimizationRemarkEmitter into certain
classes where remarks are being emitted and update the remark emit calls
itself. I also provide each remark a BasicBlock or Instruction from where
it is being called, in order to compute the hotness of the remark.

Patch by Tarun Rajendran!

Differential Revision: https://reviews.llvm.org/D35399

llvm-svn: 308233
2017-07-17 23:58:33 +00:00
Tobias Grosser 21cbcf03d3 ScopInfo: Remove not-in-DomainMap statements in separate function
This separates ScopBuilder internal and ScopBuilder external functionality.

llvm-svn: 308152
2017-07-16 23:55:38 +00:00
Tobias Grosser 13acbb91ee [Polly] Use Isl c++ for InvalidDomainMap
Reviewers: grosser, Meinersbur, bollu

Subscribers: maxf, pollydev

Tags: #polly

Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D35308

llvm-svn: 308089
2017-07-15 09:01:31 +00:00
Michael Kruse 476f855ec8 [ScopInfo] Do not use ScopStmt in Domain derivation of ScopInfo. NFC
ScopStmts were being used in the computation of the Domain of the SCoPs
in ScopInfo. Once statements are split, there will not be a 1-to-1
correspondence between Stmts and Basic blocks. Thus this patch avoids
the use of getStmtFor() by creating a map of BB to InvalidDomain and
using it to compute the domain of the statements.

Contributed-by: Nanidini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D33942

llvm-svn: 306667
2017-06-29 12:47:41 +00:00
Michael Kruse 7604d9add5 [ScopBuilder] Pass ScopStmts around instead of BasicBlocks. NFC.
During the construction of MemoryAccesses in ScopBuilder, BasicBlocks
were used in function parameters, assuming that the ScopStmt an be
directly derived from it. This won't be true anymore once we split
BasicBlocks into multiple ScopStmt. As a preparation for such a change
in the future, we instead pass the ScopStmt and avoid the use of
getStmtFor().

There are two occasions where a kind of mapping from BasicBlock to
ScopStmt is still required.

1. Get the statement representing the incoming block of a `PHINode`
   using `getLastStmtOf`.

2. One statement is required to write a scalar to be readable by those
   which need it. This is most often the statement which contains its
   definition, which we get using `getStmtFor(Instruction*)`.

Differential Revision: https://reviews.llvm.org/D34369

llvm-svn: 306132
2017-06-23 17:55:36 +00:00
Michael Kruse a6d48f59a1 Fix a lot of typos. NFC.
llvm-svn: 304974
2017-06-08 12:06:15 +00:00
Michael Kruse 678aa336fa [ScopBuilder] Exclude ignored intrinsics from explicit instruction list.
Ignored intrinsics are ignored at code generation, therefore do not
need to be part of the instruction list.

Specifically, llvm.lifetime.* intrinisics are removed before code
generation, referencing them would cause a use-after-free error.

Contributed-by: Nandini Singhal <cs15mtech01004@iith.ac.in>

Differential Revision: https://reviews.llvm.org/D33768

llvm-svn: 304483
2017-06-01 21:46:27 +00:00
Michael Kruse ed0c2f7e90 [ScopInfo] Do not add terminator & synthesizable instructions to the output instructions.
Such instructions are generates on-demand by the CodeGenerator and thus
do not need representation in a statement.

Differential Revision: https://reviews.llvm.org/D33642

llvm-svn: 304151
2017-05-29 12:27:38 +00:00
Tobias Grosser 1e55db30d5 Delinearize memory accesses that reference parameters coming from function calls
Certain affine memory accesses which we model today might contain products of
parameters which we might combined into a new parameter to be able to create an
affine expression that represents these memory accesses. Especially in the
context of OpenCL, this approach looses information as memory accesses such as
A[get_global_id(0) * N + get_global_id(1)] are assumed to be linear. We
correctly recover their multi-dimensional structure by assuming that parameters
that are the result of a function call at IR level likely are not parameters,
but indeed induction variables. The resulting access is now
A[get_global_id(0)][get_global_id(1)] for an array A[][N].

llvm-svn: 304075
2017-05-27 15:18:53 +00:00
Tobias Grosser d5fcbef8ee [Polly] Added the list of Instructions to output in ScopInfo pass
Summary: This patch outputs all the list of instructions in BlockStmts.

Reviewers: Meinersbur, grosser, bollu

Subscribers: bollu, llvm-commits, pollydev

Differential Revision: https://reviews.llvm.org/D33163

llvm-svn: 304062
2017-05-27 04:40:18 +00:00
Philip Pfaffe 1a0128faaa [Polly] Add handling of Top Level Regions
Summary:
My goal is to make the newly added `AllowWholeFunctions` options more usable/powerful.

The changes to ScopBuilder.cpp are exclusively checks to prevent `Region.getExit()` from being dereferenced, since Top Level Regions (TLRs) don't have an exit block.

In ScopDetection's `isValidCFG`, I removed a check that disallowed ReturnInstructions to have return values. This might of course have been intentional, so I would welcome your feedback on this and maybe a small explanation why return values are forbidden. Maybe it can be done but needs more changes elsewhere?

The remaining changes in ScopDetection are simply to consider the AllowWholeFunctions option in more places, i.e. allow TLRs when it is set and once again avoid derefererncing `getExit()` if it doesn't exist.

Finally, in ScopHelper.cpp I extended `polly::isErrorBlock` to handle regions without exit blocks as well: The original check was if a given BasicBlock dominates all predecessors of the exit block. Therefore I do the same for TLRs by regarding all BasicBlocks terminating with a ReturnInst as predecessors of a "virtual" function exit block.

Patch by: Lukas Boehm

Reviewers: philip.pfaffe, grosser, Meinersbur

Reviewed By: grosser

Subscribers: pollydev, llvm-commits, bollu

Tags: #polly

Differential Revision: https://reviews.llvm.org/D33411

llvm-svn: 303790
2017-05-24 18:39:39 +00:00
Siddharth Bhat 06e3c74d83 [Fortran Support] Change "global" pattern match to work for params
Summary:
- Rename global / local naming convention that did not make much sense
to Visible / Invisible, where the visible refers to whether the ALLOCATE
call to the Fortran array is present in the current module or not.

- This match now works on both cross fortran module globals and on
parameters to functions since neither of them are necessarily allocated
at the point of their usage.

- Add testcase that matches against both a load and a store against
function parameters.

Differential Revision: https://reviews.llvm.org/D33190

llvm-svn: 303356
2017-05-18 16:47:13 +00:00
Siddharth Bhat 0fe7231a2f [Fortran Support] Add pattern match for Fortran Arrays that are parameters.
- This breaks the previous assumption that Fortran Arrays are `GlobalValue`.

- The names of functions were getting unwieldy. So, I renamed the
Fortran related functions.

Differential Revision: https://reviews.llvm.org/D33075

llvm-svn: 303040
2017-05-15 08:41:30 +00:00
Siddharth Bhat f2dbba8183 [Fortran Support] Detect Fortran arrays & metadata from dragonegg output
Add the ability to tag certain memory accesses as those belonging to
Fortran arrays. We do this by pattern matching against known patterns
of Dragonegg's LLVM IR output from Fortran code.

Fortran arrays have metadata stored with them in a struct. This struct
is called the "Fortran array descriptor", and a reference to this is
stored in each MemoryAccess.

Differential Revision: https://reviews.llvm.org/D32639

llvm-svn: 302653
2017-05-10 13:11:20 +00:00
Tobias Grosser f3adab4c20 [Polly] Canonicalize arrays according to base-ptr equivalence class
Summary:
    In case two arrays share base pointers in the same invariant load equivalence
    class, we canonicalize all memory accesses to the first of these arrays
    (according to their order in the equivalence class).

    This enables us to optimize kernels such as boost::ublas by ensuring that
    different references to the C array are interpreted as accesses to the same
    array. Before this change the runtime alias check for ublas would fail, as it
    would assume models of the C array with differing (but identically valued) base
    pointers would reference distinct regions of memory whereas the referenced
    memory regions were indeed identical.

    As part of this change we remove most of the MemoryAccess::get*BaseAddr
    interface. We removed already all references to get*BaseAddr in previous
    commits to ensure that no code relies on matching base pointers between
    memory accesses and scop arrays -- except for three remaining uses where we
    need the original base pointer. We document for these situations that
    MemoryAccess::getOriginalBaseAddr may return a base pointer that is distinct
    to the base pointer of the scop array referenced by this memory access.

Reviewers: sebpop, Meinersbur, zinob, gareevroman, pollydev, huihuiz, efriedma, jdoerfert

Reviewed By: Meinersbur

Subscribers: etherzhhb

Tags: #polly

Differential Revision: https://reviews.llvm.org/D28518

llvm-svn: 302636
2017-05-10 10:59:58 +00:00
Michael Kruse 391a2ac09b [ScopBuilder] Move Scop::init to ScopBuilder. NFC.
Scop::init is used only during SCoP construction. Therefore ScopBuilder
seems the more appropriate place for it. We integrate it onto its only
caller ScopBuilder::buildScop where some other construction steps
already took place.

Differential Revision: https://reviews.llvm.org/D32908

llvm-svn: 302276
2017-05-05 20:09:08 +00:00
Michael Kruse f1052ceb5e [ScopBuilder] Do not verify unfeasible SCoPs.
SCoPs with unfeasible runtime context are thrown away and therefore
do not need their uses verified.

The added test case requires a complexity limit to exceed.
Normally, error statements are removed from the SCoP and for that
reason are skipped during the verification. If there is a unfeasible
runtime context (here: because of the complexity limit being reached),
the removal of error statements and other SCoP construction steps are
skipped to not waste time. Error statements are not modeled in SCoPs
and therefore have no requirements on whether the scalars used in
them are available.

llvm-svn: 302234
2017-05-05 13:38:35 +00:00
Michael Kruse 704c03e03b [ScopBuilder] Add missing semicolon after LLVM_FALLTHROUGH.
It was forgotten in r302157.

llvm-svn: 302163
2017-05-04 15:55:54 +00:00
Michael Kruse eedae7630a Introduce VirtualUse. NFC.
If a ScopStmt references a (scalar) value, there are multiple
possibilities where this value can come. The decision about what kind of
use it is must be handled consistently at different places, which can be
error-prone. VirtualUse is meant to centralize the handling of the
different types of value uses.

This patch makes ScopBuilder and CodeGeneration use VirtualUse. This
already helps to show inconsistencies with the value handling. In order
to keep this patch NFC, exceptions to the general rules are added.
These might be fixed later if they turn to problems. Overall, this
should result in fewer post-codegen IR-verification errors, but instead
assertion failures in `getNewValue` that are closer to the actual error.

Differential Revision: https://reviews.llvm.org/D32667

llvm-svn: 302157
2017-05-04 15:22:57 +00:00
Tobias Grosser 72684bbaf5 [ScopInfo] Remove code not needed anymore after r302004
llvm-svn: 302005
2017-05-03 08:02:32 +00:00
Michael Kruse 89b1f94e64 Revert "Remove references to AssumptionCache. NFC."
The AssumptionCache removal of r289756 has been reverted in
r290086/r290087. A different solution has been implemented in r291671
which keeps the AssumptionCache. We can therefore use it again in Polly.

This reverts r289791.

llvm-svn: 298089
2017-03-17 13:56:53 +00:00
Michael Kruse 5545407fa4 [ScopInfo] Introduce ScopStmt::getSurroundingLoop(). NFC.
Introduce ScopStmt::getSurroundingLoop() to replace getFirstNonBoxedLoopFor.

getSurroundingLoop() returns the precomputed surrounding/first non-boxed
loop. Except in ScopDetection, the list of boxed loops is only used to
get the surrounding loop. getFirstNonBoxedLoopFor also requires LoopInfo
at every use which is not necessarily available everywhere where we may
want to use it.

Differential Revision: https://reviews.llvm.org/D30985

llvm-svn: 297899
2017-03-15 22:16:43 +00:00
Eli Friedman 71329901ea Tidy up getFirstNonBoxedLoopFor [NFC]
Move the function getFirstNonBoxedLoopFor which is used in ScopBuilder
and in ScopInfo to Support/ScopHelpers to make it reusable in other
locations. No functionality change.

Patch by Sameer Abu Asal.

Differential Revision: https://reviews.llvm.org/D28754

llvm-svn: 292168
2017-01-16 22:54:29 +00:00
Tobias Grosser 4d5a917287 Use typed enums to model MemoryKind and move MemoryKind out of ScopArrayInfo
To benefit of the type safety guarantees of C++11 typed enums, which would have
caught the type mismatch fixed in r291960, we make MemoryKind a typed enum.
This change also allows us to drop the 'MK_' prefix and to instead use the more
descriptive full name of the enum as prefix. To reduce the amount of typing
needed, we use this opportunity to move MemoryKind from ScopArrayInfo to a
global scope, which means the ScopArrayInfo:: prefix is not needed. This move
also makes historically sense. In the beginning of Polly we had different
MemoryKind enums in both MemoryAccess and ScopArrayInfo, which were later
canonicalized to one. During this canonicalization we just choose the enum in
ScopArrayInfo, but did not consider to move this shared enum to global scope.

Reviewed-by: Michael Kruse <llvm@meinersbur.de>
Differential Revision: https://reviews.llvm.org/D28090

llvm-svn: 292030
2017-01-14 20:25:44 +00:00
Tobias Grosser cdbe5c9d6c Fix some typos in comments
llvm-svn: 291247
2017-01-06 17:30:34 +00:00
Michael Kruse 7037fde427 Remove references to AssumptionCache. NFC.
The AssumptionCache was removed in r289756 after being replaced by the an
addtional operand list of affected values in r289755. The absence of that cache
means that we have now have to manually search for llvm.assume intrinsics as
now done by other passes (LazyValueInfo, CodeMetrics) do not take into
account an llvm::Instruction's user lists (ScalarEvolution).

llvm-svn: 289791
2016-12-15 09:25:14 +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
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
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 cfadb2293f [DBG] Collect statistics about statically infeasible SCoPs
llvm-svn: 287263
2016-11-17 21:44:47 +00:00
Tobias Grosser 26be8e99b6 [ScopBuilder] Drop unnecessary namespace identifiers [NFC]
llvm-svn: 286781
2016-11-13 21:28:13 +00:00
Tobias Grosser 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
Eli Friedman b9c6f01a81 [ScopInfo] Make memset etc. affine where possible.
We don't actually check whether a MemoryAccess is affine in very many
places, but one important one is in checks for aliasing.

Differential Revision: https://reviews.llvm.org/D25706

llvm-svn: 285746
2016-11-01 20:53:11 +00:00
Michael Kruse fa53c86dc1 [ScopInfo/CodeGen] ExitPHI reads are implicit.
Under some conditions MK_Value read accessed where converted to MK_ExitPHI read
accessed. This is unexpected because MK_ExitPHI read accesses are implicit after
the scop execution. This behaviour was introduced in r265261, which fixed a
failed assertion/crash in CodeGen.

Instead, we fix this failure in CodeGen itself. createExitPHINodeMerges(),
despite its name, also handles accesses of kind MK_Value, only to skip them
because they access values that are usually not PHI nodes in the SCoP region's
exit block. Except in the situation observed in r265261.

Do not convert value accessed to ExitPHI accesses and do not handle
value accesses like ExitPHI accessed in CodeGen anymore.

llvm-svn: 284023
2016-10-12 16:31:09 +00:00
Roman Gareev f5aff70405 Store the size of the outermost dimension in case of newly created arrays that require memory allocation.
We do not need the size of the outermost dimension in most cases, but if we
allocate memory for newly created arrays, that size is needed.

Reviewed-by: Michael Kruse <llvm@meinersbur.de>

Differential Revision: https://reviews.llvm.org/D23991

llvm-svn: 281234
2016-09-12 17:08:31 +00:00
Roman Gareev e2ee79afde Simplify AccFuncMap to vector<> AccessFunctions
getAccessFunctions() is dead code and the 'BB' argument
of getOrCreateAccessFunctions() is not used. This patch deletes
getAccessFunctions and transforms AccFuncMap into
a std::vector<std::unique_ptr<MemoryAccess>> AccessFunctions.

Reviewed-by: Tobias Grosser <tobias@grosser.es>

Differential Revision: https://reviews.llvm.org/D23759

llvm-svn: 279394
2016-08-21 11:09:19 +00:00
Tobias Grosser b143e31164 [ScopInfo] Make scalars used by PHIs in non-affine regions available
Normally this is ensured when adding PHI nodes, but as PHI node dependences
do not need to be added in case all incoming blocks are within the same
non-affine region, this was missed.

This corrects an issue visible in LNT's sqlite3, in case invariant load hoisting
was disabled.

llvm-svn: 278792
2016-08-16 11:44:48 +00:00
Weiming Zhao 7614e178cb Fix a build warning of unhandled enum in switch
Summary: LLVM adds a new value FMRB_DoesNotReadMemory in the enumeration.

Reviewers: andrew.w.kaylor, chrisj, zinob, grosser, jdoerfert

Subscribers: Meinersbur, pollydev

Differential Revision: http://reviews.llvm.org/D22109

llvm-svn: 275085
2016-07-11 18:27:52 +00:00
Michael Kruse 586e579fe8 Fix assertion due to buildMemoryAccess.
For llvm the memory accesses from nonaffine loops should be visible,
however for polly those nonaffine loops should be invisible/boxed.

This fixes llvm.org/PR28245

Cointributed-by: Huihui Zhang <huihuiz@codeaurora.org>

Differential Revision: http://reviews.llvm.org/D21591

llvm-svn: 274842
2016-07-08 12:38:28 +00:00
Michael Kruse 73fa33b102 Create a dedicated header file for ScopBuilder. NFC.
It is only used internally by the ScopInfo pass. By moving it into its
own header file we avoid it being processed that use only ScopInfo.

llvm-svn: 273983
2016-06-28 01:37:28 +00:00
Michael Kruse 2133cb9a24 Move ScopBuilder into its own file. NFC.
The methods in ScopBuilder are used for the construction of a Scop,
while the remaining classes of ScopInfo are required by all passes that
use Polly's polyhedral analysis.

llvm-svn: 273982
2016-06-28 01:37:20 +00:00