Commit Graph

30 Commits

Author SHA1 Message Date
Owen Anderson
390b9f00eb Remove dead code, that I apparently wrote a while back. We seem to be doing well enough
without whatever this was trying to do.  When/if someone has the time to do some empirical
evaluations, it might be worth it to figure out what this code was trying to do and see if
it's worth resurrecting/fixing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123684 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-17 22:39:54 +00:00
Chris Lattner
b298db7253 random cleanups
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123221 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 08:00:40 +00:00
Chris Lattner
d9e079706e improve loop rotation to use CodeMetrics to analyze the
size of a loop header instead of its own code size estimator.
This allows it to handle bitcasts etc more precisely.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122681 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02 07:35:53 +00:00
Owen Anderson
205942a4a5 Passes do not need to recursively initialize passes that they preserve, if
they do not also require them.  This allows us to reduce inter-pass linkage
dependencies.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116854 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-19 20:08:44 +00:00
Owen Anderson
081c34b725 Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116820 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-19 17:21:58 +00:00
Owen Anderson
2ab36d3502 Begin adding static dependence information to passes, which will allow us to
perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116334 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-12 19:48:12 +00:00
Owen Anderson
ce665bd2e2 Now with fewer extraneous semicolons!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115996 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07 22:25:06 +00:00
Owen Anderson
69daca59ff Revert r114919, which caused some serious regressions on ARM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115053 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-29 18:05:19 +00:00
Owen Anderson
8d9e92ce2d Weight loop unrolling counts by nesting depth. Unrolling deeply nested loops tends to cause high
register pressure and thus excess spills, which we don't currently recover from well.  This should
be re-evaluated in the future if our ability to generate good spills/splits improves.

Partial fix for <rdar://problem/7635585>.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114919 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-27 22:58:54 +00:00
Owen Anderson
8ea298a4e3 Lower the unrolling theshold to 150. Empirical tests indicate that this is a sweet spot in the performance per
code size increase curve.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113595 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-10 17:57:00 +00:00
Owen Anderson
f9a26b89f8 What the loop unroller cares about, rather than just not unrolling loops with calls, is
not unrolling loops that contain calls that would be better off getting inlined.  This mostly
comes up when an interleaved devirtualization pass has devirtualized a call which the inliner
will inline on a future pass.  Thus, rather than blocking all loops containing calls, add
a metric for "inline candidate calls" and block loops containing those instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113535 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-09 20:32:23 +00:00
Owen Anderson
547462b98c Revert r113439, which relaxed the requirement that loops containing calls cannot be unrolled. After some discussion,
there seems to be a better way to achieve the same effect.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113528 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-09 20:02:23 +00:00
Owen Anderson
cc443c37ee r113526 introduced an unintended change to the loop unrolling threshold. Revert it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113527 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-09 19:11:57 +00:00
Owen Anderson
20672e48b3 Fix typo in code to cap the loop code size reduction calculation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113526 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-09 19:08:59 +00:00
Owen Anderson
6add2fbb69 Use code-size reduction metrics to estimate the amount of savings we'll get when we unroll a loop.
Next step is to recalculate the threshold values given this new heuristic.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113525 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-09 19:07:31 +00:00
Owen Anderson
4975447d94 Relax the "don't unroll loops containing calls" rule. Instead, when a loop contains a call, lower the
unrolling threshold to the optimize-for-size threshold.  Basically, for loops containing calls, unrolling
can still be profitable as long as the loop is REALLY small.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113439 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-08 23:10:07 +00:00
Owen Anderson
e9f1882406 Add a separate unrolling threshold when the current function is being optimized for size.
The threshold value of 50 is arbitrary, and I chose it simply by analogy to the inlining thresholds, where
the baseline unrolling threshold is slightly smaller than the baseline inlining threshold.  This could
undoubtedly use some tuning.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113306 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-07 23:15:30 +00:00
Chris Lattner
937790195e now that loop passes don't use DomFrontier, there is no reason
for the unroller to pretend it supports updating it.  It still
has a horrible hack for DomTree.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112444 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-29 17:21:35 +00:00
Owen Anderson
90c579de5a Reapply r110396, with fixes to appease the Linux buildbot gods.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110460 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06 18:33:48 +00:00
Owen Anderson
1f74590e9d Revert r110396 to fix buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110410 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06 00:23:35 +00:00
Owen Anderson
9ccaf53ada Don't use PassInfo* as a type identifier for passes. Instead, use the address of the static
ID member as the sole unique type identifier.  Clean up APIs related to this change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110396 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-05 23:42:04 +00:00
Owen Anderson
b57e6558c7 Experiments show that we can safely increase our unrolling threshold without unduly impacting code size, particularly
since unrolling is not enabled at -Os.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110233 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-04 18:32:46 +00:00
Dan Gohman
052f000158 Remove LCSSA's bogus dependence on LoopSimplify and LoopSimplify's bogus
dependence on DominanceFrontier. Instead, add an explicit DominanceFrontier
pass in StandardPasses.h to ensure that it gets scheduled at the right
time.

Declare that loop unrolling preserves ScalarEvolution, and shuffle some
getAnalysisUsages.

This eliminates one LoopSimplify and one LCCSA run in the standard
compile opts sequence.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109413 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-26 18:11:16 +00:00
Owen Anderson
d13db2c59c Fix batch of converting RegisterPass<> to INTIALIZE_PASS().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109045 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-21 22:09:45 +00:00
Dan Gohman
bbf81d8811 Add a DominatorTree argument to isLCSSA so that it doesn't have to
compute a set of reachable blocks for itself each time it is called, which
is fairly frequently.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98179 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-10 19:38:49 +00:00
Jakob Stoklund Olesen
d450e5b886 Don't unroll loops containing function calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95454 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 23:21:31 +00:00
David Greene
d241e38d26 Change errs() to dbgs().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92623 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 01:27:44 +00:00
Dan Gohman
a2aabe38ae Replace LoopUnrollPass.cpp's custom code-size estimation code using
the new common CodeMetrics code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85663 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-31 14:54:17 +00:00
Dan Gohman
3f9432ebca Remove an unnecessary #include.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85661 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-31 14:39:43 +00:00
Dan Gohman
928a75f057 Rename UnrollLoop.cpp to LoopUnroll.cpp, and LoopUnroll.cpp to
LoopUnrollPass.cpp, for consistency with other passes which are
similarly split.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85659 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-31 14:37:31 +00:00