Commit Graph

102 Commits

Author SHA1 Message Date
Michael Kruse
6fa65f8a98 [Polly][MatMul] Abandon dependence analysis.
The copy statements inserted by the matrix-multiplication optimization
introduce new dependencies between the copy statements and other
statements. As a result, the DependenceInfo must be recomputed.

Not recomputing them caused IslAstInfo to deduce that some loops are
parallel but cause race conditions when accessing the packed arrays.
As a result, matrix-matrix multiplication currently cannot be
parallelized.

Also see discussion at https://reviews.llvm.org/D125202
2022-06-29 17:20:05 -05:00
Fangrui Song
95a134254a Remove unneeded cl::ZeroOrMore for cl::opt/cl::list options 2022-06-05 01:07:51 -07:00
Fangrui Song
36c7d79dc4 Remove unneeded cl::ZeroOrMore for cl::opt options
Similar to 557efc9a8b.
This commit handles options where cl::ZeroOrMore is more than one line below
cl::opt.
2022-06-04 00:10:42 -07:00
Michael Kruse
bd93df937a [Polly] Mark classes as final by default. NFC.
This make is obivious that a class was not intended to be derived from.

NPM analysis pass can unfortunately not marked as final because they are
derived from a llvm::Checker<T> template internally by the NPM.

Also normalize the use of classes/structs
 * NPM passes are structs
 * Legacy passes are classes
 * structs that have methods and are not a visitor pattern are classes
 * structs have public inheritance by default, remove "public" keyword
 * Use typedef'ed type instead of inline forward declaration
2022-05-17 12:05:39 -05:00
Michael Kruse
5c02808131 [polly] Introduce -polly-print-* passes to replace -analyze.
The `opt -analyze` option only works with the legacy pass manager and might be removed in the future, as explained in llvm.org/PR53733. This patch introduced -polly-print-* passes that print what the pass would print with the `-analyze` option and replaces all uses of `-analyze` in the regression tests.

There are two exceptions: `CodeGen\single_loop_param_less_equal.ll` and `CodeGen\loop_with_condition_nested.ll` use `-analyze on the `-loops` pass which is not part of Polly.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D120782
2022-03-14 10:27:15 -05:00
Michael Kruse
ad84c6f657 [polly] Match function definitions and header declarations. NFC.
Ensure that function definitions match their declrations in header
files, even if they have no effect on linking. This includes

 1. Both have the same __isl_* annotations

 2. Both use the same type alias

 3. Remove unused declarations that have no definition

 4. Use explicit polly namespace qualifier for definitions; generally,
    the .cpp file should use at most an anon namespace region since
    only symbols declared in the header file can be accessed from other
    translation units anyway. For defintions that have been declared in
    the header file, the explicit namespace qualifier ensures that both
    match.
2022-02-16 12:52:17 -06:00
Riccardo Mori
44596fe6a9 [Polly][Isl] Use the function unsignedFromIslSize to manage a isl::size object. NFCI
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in lib/External/isl/include/isl/isl-noxceptions.h and the official isl C++ interface.
In the official interface the type `isl::size` cannot be casted to an unsigned without previously having checked if it contains a valid value with the function `isl::size::is_error()`.
For this reason two helping functions have been added:
 - `IslAssert`: assert that no errors are present in debug builds and just disables the mandatory error check in non-debug builds
 - `unisgnedFromIslSIze`: cast the `isl::size` object to `unsigned`

Changes made:
 - Add the functions `IslAssert` and `unsignedFromIslSize`
 - Add the utility function `rangeIslSize()`
 - Retype `MaxDisjunctsInDomain` from `int` to `unsigned`
 - Retype `RunTimeChecksMaxAccessDisjuncts` from `int` to `unsigned`
 - Retype `MaxDimensionsInAccessRange` from `int` to `unsigned`
 - Replaced some usages of `isl_size` to `unsigned` since we aim not to use `isl_size` anymore
 - `isl-noexceptions.h` has been generated by e704f73c88

No functional change intended.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D113101
2021-11-05 11:15:22 +01:00
Michael Kruse
e470f9268a [Polly] Implement user-directed loop distribution/fission.
This is a simple version without the possibility to define distribute
points or followup-transformations. However, it is the first
transformation that has to check whether the transformation is correct.

It interprets the same metadata as the LoopDistribute pass.

Re-apply after revert in c7bcd72a38 with
fix: Take isBand out of #ifndef NDEBUG since it now is used
unconditionally.
2021-09-23 21:11:01 -05:00
Petr Hosek
c7bcd72a38 Revert "[Polly] Implement user-directed loop distribution/fission."
This reverts commit 52c30adc7d which
breaks the build when NDEBUG is defined.
2021-09-23 14:04:25 -07:00
Michael Kruse
52c30adc7d [Polly] Implement user-directed loop distribution/fission.
This is a simple version without the possibility to define distribute
points or followup-transformations. However, it is the first
transformation that has to check whether the transformation is correct.

It interprets the same metadata as the LoopDistribute pass.
2021-09-22 17:28:25 -05:00
Riccardo Mori
d3fdbda6b0 [Polly][Isl] Move to the new-polly-generator branch version of isl-noexceptions.h. NFCI
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

With this commit we are moving from the `polly-generator` branch to the `new-polly-generator` branch that is more mantainable and is based on the official C++ interface `cpp-checked.h`.

Changes made:
 - There are now many sublcasses for `isl::ast_node` representing different isl types. Use `isl::ast_node_for`, `isl::ast_node_user`, `isl::ast_node_block` and `isl::ast_node_mark` where needed.
 - There are now many sublcasses for `isl::schedule_node` representing different isl types. Use `isl::schedule_node_mark`, `isl::schedule_node_extension`, `isl::schedule_node_band` and `isl::schedule_node_filter` where needed.
 - Replace the `isl::*::dump` with `dumpIslObj` since the isl dump method is not exposed in the C++ interface.
 - `isl::schedule_node::get_child` has been renamed to `isl::schedule_node::child`
 - `isl::pw_multi_aff::get_pw_aff` has been renamed to `isl::pw_multi_aff::at`
 - The constructor `isl::union_map(isl::union_pw_multi_aff)` has been replaced with the static method `isl::union_map::from()`
 - Replace usages of `isl::val::add_ui` with `isl::val::add`
 - `isl::union_set_list::alloc` is now a constructor
 - All the `isl_size` values are now wrapped inside the class `isl::size` use `isl::size::release` to get the internal `isl_size` value where needed.
 - `isl-noexceptions.h` has been generated by 73f5ed1f4d

No functional change intended.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D107225
2021-08-16 15:53:26 +02:00
Riccardo Mori
84dfbf5a77 [Polly][Isl] Stop using isl::set::lex_le_set. NFC
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Changes made:
 - Stop using `isl::set::lex_le_set`. The official way to do this is to use `isl::map::lex_le_at`
 - Removed `isl::set::lex_le_set` from `isl-noexceptions.h`
 - `isl-noexceptions.h` has been generated by this 266fea1d3d

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D106269
2021-07-19 17:23:56 +02:00
Riccardo Mori
159e072f81 [Polly] Use isl::set::tuple_dim instead of isl::set::dim. NFC
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Note that not all the usages of `isl::set::dim` were replaced
2021-07-19 12:43:23 +02:00
Riccardo Mori
d5ee355f89 [Polly][Isl] Use isl::union_map::unite() instead of isl::union_map::add_map(). NFC
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Changes made:
 - Use `isl::union_map::unite()` instead of `isl::union_map::add_map()`
 - `isl-noexceptions.h` has been generated by this 3f43ae29fa

Depends on D106059

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D106061
2021-07-19 12:11:00 +02:00
Riccardo Mori
bad3ebbaae [Polly][Isl] Stop generating isl::union_{set,map} from isl::space. NFC
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Changes made:
 - Stop generating `isl::union_set` and isl::union_map` from `isl::space` and instead generate them from `isl::ctx`
 - Disable clang-format on `isl-noexceptions.h`
 - Removed `isl::union_{set,map}` generator from `isl::space` from `isl-noexceptions.h`
 - `isl-noexceptions.h` has been generated by this 87c3413b6f

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D106059
2021-07-19 11:24:53 +02:00
patacca
b55aedd0b8 [Polly][Isl] Use isl::union_set::unite() instead of isl::union_set::add_set(). NFC
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Changes made:
 - Use `isl::union_set::unite()` instead of `isl::union_set::add_set()`
 - `isl-noexceptions.h` has been generated by this 390c44982b

Depends on D104994

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D105444
2021-07-07 16:26:55 +02:00
patacca
f482497c38 [Polly][Isl] Use isl::set::tuple_dim, isl::map::domain_tuple_dim and isl::map::range_tuple_dim. NFC
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Changes made:
 - Use `isl::set::tuple_dim` instead of `isl::set::dim` and `isl::set::n_dim`
 - Use `isl::map::domain_tuple_dim` instead of `isl::map::dim`
 - Use `isl::map::range_tuple_dim` instead of `isl::map::dim`
 - isl-noexceptions.h has been generated by this 45576e1b42

Note that not all the usage of `isl::{set,map}::dim` where replaced

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D104994
2021-07-06 11:20:45 +02:00
patacca
7c7978a122 [Polly][Isl] Removing explicit operator bool() from isl C++ bindings. NFC.
This is part of an effort to reduce the differences between the custom C++ bindings used right now by polly in `lib/External/isl/include/isl/isl-noxceptions.h` and the official isl C++ interface.

Changes made:
 - Removing explicit operator bool() from all the classes in the isl C++ bindings.
 - Replace each call to operator bool() to method `is_null()`.
 - isl-noexceptions.h has been generated by this 27396daac5

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D103976
2021-06-11 14:44:24 +02:00
Michael Kruse
ab0556bb20 [Polly] Regenerate isl-noexceptions.h.
Regenerate the C++ wrapper header from the current isl version's
headers.

The most notable change is that some dimension sizes are represented by
an isl_size (instead of unsigned), which is a signed int. Additionally,
some function may return -1 in case of an error which already had been
fixed in the past. The C++ may no return -1 instead of UINT_MAX which
caused the problems.

Some types in Polly had been changed from unsigned to isl_size
(that were not already auto) and some loops/comparision had to be
changed to avoid unsigned/signed comparison warnings.
2021-02-14 19:17:54 -06:00
Michael Kruse
acbdd07de6 [DependenceInfo] Compute WAR dependence info using ISL kills. NFC.
When reading code of Dependences::calculateDependences, I noticed that
WAR is computed specifically by buildWAR.  Given ISL now
supports "kills" in approximate dataflow analysis, this patch takes
advantage of it.

This patch also cleans up a couple lines redundant codes.

Patch by bin.narwal <bin.narwal@gmail.com>

Differential Revision: https://reviews.llvm.org/D66741

llvm-svn: 370396
2019-08-29 18:55:55 +00:00
Michael Kruse
ac5c8318d7 [DependenceInfo] Remove dead initialization. NFC.
Fix scan-analyzer issue:
Value stored to 'WARMemAccesses' during its initialization is never read

Patch by Dominik Adamski <adamski.dominik@gmail.com>

Signed-off-by: Dominik Adamski <adamski.dominik@gmail.com>
llvm-svn: 361196
2019-05-20 20:54:17 +00:00
Michael Kruse
031bb16556 Apply include-what-you-use #include removal suggestions. NFC.
This removes unused includes (and forward declarations) as
suggested by include-what-you-use. If a transitive include of a removed
include is required to compile a file, I added the required header (or
forward declaration if suggested by include-what-you-use).

This should reduce compilation time and reduce the number of iterative
recompilations when a header was changed.

llvm-svn: 357209
2019-03-28 20:19:49 +00:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Michael Kruse
0e4e6e5e87 [DepInfo] Use isl++ in Dependences::isValidSchedule. NFC.
Also change StatementToIslMapTy to hold isl::map, because it is used as a
parameter.

llvm-svn: 339484
2018-08-10 22:33:27 +00:00
Tobias Grosser
6d69f92864 [DependenceInfo] Use isl++ to replace foreach_set with for loop
llvm-svn: 337248
2018-07-17 07:08:06 +00:00
Tobias Grosser
6a6d9df78e getDependences to new C++ interface
Reviewers: Meinersbur, grosser, bollu, cs15btech11044, jdoerfert

Reviewed By: grosser

Subscribers: pollydev, llvm-commits

Tags: #polly

Differential Revision: https://reviews.llvm.org/D47786

llvm-svn: 334092
2018-06-06 13:10:32 +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
Huihui Zhang
71e54ccd06 [Polly][IslAst] Fix minimal dependence distance.
Summary:
When checking the parallelism of a scheduling dimension, we first check if excluding reduction dependences the loop is parallel or not.
If the loop is not parallel, then we need to return the minimal dependence distance of all data dependences, including the previously subtracted reduction dependences.


Reviewers: grosser, Meinersbur, efriedma, eli.friedman, jdoerfert, bollu

Reviewed By: Meinersbur

Subscribers: llvm-commits, pollydev

Tags: #polly

Differential Revision: https://reviews.llvm.org/D45236

llvm-svn: 329214
2018-04-04 18:08:13 +00:00
Tobias Grosser
61bd3a4840 [ScopInfo] Move Scop::getPwAffOnly to isl++ [NFC]
llvm-svn: 310231
2017-08-06 21:42:38 +00:00
Tobias Grosser
e127033f98 [ScopInfo] Move Scop::getAssumedContext to isl++ [NFC]
llvm-svn: 310228
2017-08-06 21:42:09 +00:00
Tobias Grosser
b65ccc4302 [ScopInfo] Translate Scop::getParamSpace to isl++ [NFC]
llvm-svn: 310224
2017-08-06 20:11:59 +00:00
Tobias Grosser
6ad1640a1d [ScopInfo] Move ScopStmt::getSchedule to isl++
llvm-svn: 310215
2017-08-06 17:45:28 +00:00
Tobias Grosser
dcf8d696ff Move ScopInfo::getDomain(), getDomainSpace(), getDomainId() to isl++
llvm-svn: 310209
2017-08-06 16:39:52 +00:00
Tobias Grosser
1959dbda75 Move MemoryAccess::get*ArrayId to isl++
llvm-svn: 308843
2017-07-23 04:08:59 +00:00
Tobias Grosser
1515f6b937 Move MemoryAccess::NewAccessRelation to isl++
We also move related accessor functions

llvm-svn: 308840
2017-07-23 04:08:38 +00:00
Tobias Grosser
fe46c3ff3a Move MemoryAccess::id to isl++
llvm-svn: 308836
2017-07-23 04:08:11 +00:00
Michael Kruse
a6d48f59a1 Fix a lot of typos. NFC.
llvm-svn: 304974
2017-06-08 12:06:15 +00:00
Philip Pfaffe
24a1bb2cf9 Post-commit fix of a comment
llvm-svn: 303628
2017-05-23 11:25:05 +00:00
Philip Pfaffe
3ef36fa222 [Polly][NewPM] Port DependenceInfo to the new ScopPassManager.
Summary: This patch ports DependenceInfo to the new ScopPassManager. Printing is implemented as a seperate printer pass.

Reviewers: grosser, Meinersbur

Reviewed By: grosser

Subscribers: llvm-commits, pollydev

Tags: #polly

Differential Revision: https://reviews.llvm.org/D33421

llvm-svn: 303621
2017-05-23 10:09:06 +00:00
Philip Pfaffe
838e0884ef [Polly][NewPM] Port ScopInfo to the new PassManager
llvm-svn: 303056
2017-05-15 12:55:14 +00:00
Siddharth Bhat
729377f063 [Polly] [DependenceInfo] change WAR generation, Read will not block Read
Earlier, the call to buildFlow was:
    WAR = buildFlow(Write, Read, MustWrite, Schedule).

This meant that Read could block another Read, since must-sources can
block each other.

Fixed the call to buildFlow to correctly compute Read. The resulting
code needs to do some ISL juggling to get the output we want.

Bug report: https://bugs.llvm.org/show_bug.cgi?id=32623

Reviewers: Meinersbur

Tags: #polly

Differential Revision: https://reviews.llvm.org/D32011

llvm-svn: 301266
2017-04-24 22:23:12 +00:00
Siddharth Bhat
bcbfdade41 [Polly] [DependenceInfo] change WAR, WAW generation to correct semantics
= Change of WAR, WAW generation: =

- `buildFlow(Sink, MustSource, MaySource, Sink)` treates any flow of the form
    `sink <- may source <- must source` as a *may* dependence.

- we used to call:
```lang=cpp, name=old-flow-call.cpp
Flow = buildFlow(MustWrite, MustWrite, Read, Schedule);
WAW = isl_union_flow_get_must_dependence(Flow);
WAR = isl_union_flow_get_may_dependence(Flow);
```

- This caused some WAW dependences to be treated as WAR dependences.
- Incorrect semantics.

- Now, we call WAR and WAW correctly.

== Correct WAW: ==
```lang=cpp, name=new-waw-call.cpp
   Flow = buildFlow(Write, MustWrite, MayWrite, Schedule);
   WAW = isl_union_flow_get_may_dependence(Flow);
   isl_union_flow_free(Flow);
```

== Correct WAR: ==
```lang=cpp, name=new-war-call.cpp
    Flow = buildFlow(Write, Read, MustaWrite, Schedule);
    WAR = isl_union_flow_get_must_dependence(Flow);
    isl_union_flow_free(Flow);
```

- We want the "shortest" WAR possible (exact dependences).
- We mark all the *must-writes* as may-source, reads as must-souce.
- Then, we ask for *must* dependence.
- This removes all the reads that flow through a *must-write*
  before reaching a sink.
- Note that we only block ealier writes with *must-writes*. This is
  intuitively correct, as we do not want may-writes to block
  must-writes.
- Leaves us with direct (R -> W).

- This affects reduction generation since RED is built using WAW and WAR.

= New StrictWAW for Reductions: =

- We used to call:
```lang=cpp,name=old-waw-war-call.cpp
      Flow = buildFlow(MustWrite, MustWrite, Read, Schedule);
      WAW = isl_union_flow_get_must_dependence(Flow);
      WAR = isl_union_flow_get_may_dependence(Flow);
```

- This *is* the right model of WAW we need for reductions, just not in general.
- Reductions need to track only *strict* WAW, without any interfering reductions.

= Explanation: Why the new WAR dependences in tests are correct: =

- We no longer set WAR = WAR - WAW
- Hence, we will have WAR dependences that were originally removed.
- These may look incorrect, but in fact make sense.

== Code: ==
```lang=llvm, name=new-war-dependence.ll
  ;    void manyreductions(long *A) {
  ;      for (long i = 0; i < 1024; i++)
  ;        for (long j = 0; j < 1024; j++)
  ; S0:          *A += 42;
  ;
  ;      for (long i = 0; i < 1024; i++)
  ;        for (long j = 0; j < 1024; j++)
  ; S1:          *A += 42;
  ;
```
=== WAR dependence: ===
  {  S0[1023, 1023] -> S1[0, 0] }

- Between `S0[1023, 1023]` and `S1[0, 0]`, we will have the dependences:

```lang=cpp, name=dependence-incorrect, counterexample
        S0[1023, 1023]:
    *-- tmp = *A (load0)--*
WAR 2   add = tmp + 42    |
    *-> *A = add (store0) |
                         WAR 1
        S1[0, 0]:         |
        tmp = *A (load1)  |
        add = tmp + 42    |
        A = add (store1)<-*
```

- One may assume that WAR2 *hides* WAR1 (since store0 happens before
  store1). However, within a statement, Polly has no idea about the
  ordering of loads and stores.

- Hence, according to Polly, the code may have looked like this:
```lang=cpp, name=dependence-correct
    S0[1023, 1023]:
    A = add (store0)
    tmp = A (load0) ---*
    add = A + 42       |
                     WAR 1
    S1[0, 0]:          |
    tmp = A (load1)    |
    add = A + 42       |
    A = add (store1) <-*
```

- So, Polly  generates (correct) WAR dependences. It does not make sense
  to remove these dependences, since they are correct with respect to
  Polly's model.

    Reviewers: grosser, Meinersbur

    tags: #polly

    Differential revision: https://reviews.llvm.org/D31386

llvm-svn: 299429
2017-04-04 13:08:23 +00:00
Huihui Zhang
d6d6a3f2ee revert test commit r299024
llvm-svn: 299026
2017-03-29 20:23:56 +00:00
Huihui Zhang
9d19e9d232 test commit, add blank line
llvm-svn: 299024
2017-03-29 20:10:45 +00:00
Siddharth Bhat
44b6cb4e63 [DependenceInfo] change name Write to MustWrite to remove ambiguity [NFC]
"Write" is an overloaded term. In collectInfo() till buildFlow(), it is
used to mean "must writes". However, within the memory based analysis,
it is used to mean "both may and must writes". Renaming the Write
variable helps clarify this difference.

Reviewers: grosser

Tags: #polly

Differential Revision: https://reviews.llvm.org/D31181

llvm-svn: 298361
2017-03-21 11:54:08 +00:00
Siddharth Bhat
4fe11cf95f [DependenceInfo] Remove idempotent union: must-writes with may-writes [NFC]
Since may-writes are always a superset of the must-writes, there is no
point in taking a union of one with the other.

llvm-svn: 298085
2017-03-17 13:26:10 +00:00
Siddharth Bhat
db5dd14cbb [DependenceInfo] Replace use of deprecated isl_dim_n_out [NFC]
Change isl_dim_n_out to isl_map_dim(*, isl_dim_out)

llvm-svn: 298075
2017-03-17 12:59:01 +00:00
Siddharth Bhat
65f3d5201e [DependenceInfo] Track may-writes and build flow information in
Dependences::calculateDependences.

This ensures that we handle may-writes correctly when building
dependence information. Also add a test case checking correctness of
may-write information. Not handling it before was an oversight.

Differential Revision: https://reviews.llvm.org/D31075

llvm-svn: 298074
2017-03-17 12:31:28 +00:00
Siddharth Bhat
65c4026992 Set Dependences::RED to be non-null once Dependences::calculateDependences()
occurs, even if there is no actual reduction. This ensures correctness
with isl operations.

llvm-svn: 297981
2017-03-16 20:06:49 +00:00
Michael Kruse
2c7169d00c [DependenceInfo] Remove unused variable. NFC.
llvm-svn: 295987
2017-02-23 15:41:01 +00:00