12 Commits

Author SHA1 Message Date
Michael Kruse
b295c37a15 [DeLICM] Statistics for use in regression tests.
Print some measurements of the DeLICM transformation at -analyze to be
used in regression tests.

llvm-svn: 296347
2017-02-27 15:53:13 +00:00
Michael Kruse
e199f285b0 [DeLICM] Fortify against exceeding isl's max operations counter.
Control flow would flow-through after the check whether the operations
quota exceeded, with the intention that it would later be caught by
Knowledge::isUsable(). However, the Knowledge constructor has its own
assertions to check consistency which would fail if its fields have only
been initialized partially because some sets have been computed correctly
before the operations quota takes effect.

Fix by erroring-out early instead of falling-throught into the code that
might expect that everything has been computed correctly. For robustness,
also bail-out if any of the fields contain nullptr values instead of
relying on isl always setting exactly this error code if something went
wrong.

This should fix the
perf-x86_64-penryn-O3-polly-before-vectorizer-unprofitable
(-polly-process-unprofitable -polly-position=before-vectorizer
-polly-enable-delicm) buildbot.

llvm-svn: 296022
2017-02-23 21:58:20 +00:00
Michael Kruse
9f519714b3 [DeLICM] Add missing Doxygen comment. NFC.
llvm-svn: 295978
2017-02-23 14:51:50 +00:00
Michael Kruse
311ecb00dc [DeLICM] Capitalize parameter name. NFC.
llvm-svn: 295977
2017-02-23 14:51:45 +00:00
Michael Kruse
d8d32bb3d1 [DeLICM] Regression test for skipping map targets.
Add optimization-remarks-missed for when mapping targets have been
skipped and add regression tests for them.

llvm-svn: 295953
2017-02-23 10:25:20 +00:00
Michael Kruse
deb30e8278 [DeLICM] Add regression tests for DeLICM reject cases.
These tests were not included in the main DeLICM commit. These check the
cases where zone analysis cannot be successful because of assumption
violations.

We use the LLVM optimization remark infrastructure as it seems to be the
best fit for this kind of messages. I tried to make use if the
OptimizationRemarkEmitter. However, it would insert additional function
passes into the pass manager to get the hotness information. The pass
manager would insert them between the flatten pass and delicm, causing
the ScopInfo with the flattened schedule being thrown away.

Differential Revision: https://reviews.llvm.org/D30253

llvm-svn: 295846
2017-02-22 15:14:08 +00:00
Michael Kruse
8474470500 [DeLICM] Fix wrong comment. NFC.
Correct a comment that claimed that a store after load was detected
when the code checks a load after a store.

llvm-svn: 295835
2017-02-22 14:14:40 +00:00
Michael Kruse
43ed25f1d9 [DeLICM] Print message when zone analysis is not available on -analysis.
This is to distinguish the cases that analysis has failed from the case
where not transformation was performed.

llvm-svn: 295833
2017-02-22 13:48:35 +00:00
Michael Kruse
91cdafb86f [DeLICM] Use opt<int>.
There is no template specialization for cl::parser<unsigned long> such
that parsing an cl::opt<unsigned long> command line argument will fail.
Use opt<int> instead which has an associated parser.

llvm-svn: 295832
2017-02-22 13:48:18 +00:00
Michael Kruse
9e52c39f0a [DeLICM] Map values hoisted by LICM back to the array.
Implement the -polly-delicm pass. The pass intends to undo the
effects of LoopInvariantCodeMotion (LICM) which adds additional scalar
dependencies into SCoPs. DeLICM will try to map those scalars back to
the array elements they were promoted from, as long as the array
element is unused.

The is the main patch from the DeLICM/DePRE patch series. It does not
yet undo GVN PRE for which additional information about known values
is needed and does not handle PHI write accesses that have have no
target. As such its usefulness is limited. Patches for these issues
including regression tests for error situatons will follow.

Reviewers: grosser

Differential Revision: https://reviews.llvm.org/D24716

llvm-svn: 295713
2017-02-21 10:20:54 +00:00
Michael Kruse
e23e94a08d [DeLICM] Add Knowledge class. NFC.
The Knowledge class remembers the state of data at any timepoint of a SCoP's
execution. Currently, it tracks whether an array element is unused or is
occupied by some value, and the writes to it. A future addition will be to also
remember which value it contains.

Objects are used to determine whether two Knowledge contain conflicting
information, i.e. two states cannot be true a the same time.

This commit was extracted from the DeLICM algorithm at
https://reviews.llvm.org/D24716.

llvm-svn: 295197
2017-02-15 16:59:10 +00:00
Michael Kruse
36e79ecaec [DeLICM] Add pass boilerplate code.
Add an empty DeLICM pass, without any functional parts.

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

Suggested-by: Tobias Grosser <tobias@grosser.es>
llvm-svn: 288160
2016-11-29 16:41:21 +00:00