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path: root/lib/Transforms/Scalar/LoopUnrollPass.cpp
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2011-09-02Enable SCEV-based unrolling by default.Andrew Trick
This changes loop unrolling to use the same mechanism for trip count computation as indvars. This is a stronger check that tends to unroll more loops. A very common side-effect is that many single iteration loops will be removed sooner. The real goal was simply to remove dependence on canonical IVs. x86 is break even. ARM performance changes to expect (+ is good): External/SPEC/CFP2000/183.equake/183.equake +13% SingleSource/Benchmarks/Dhrystone/fldry +21% MultiSource/Applications/spiff/spiff +3% SingleSource/Benchmarks/Stanford/Puzzle -14% The Puzzle regression is actually an improvement in loop optimization that defeats GVN: rdar://problem/10065079. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139009 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-11Allow loop unrolling to get known trip counts from ScalarEvolution.Andrew Trick
SCEV unrolling can unroll loops with arbitrary induction variables. It is a prerequisite for -disable-iv-rewrite performance. It is also easily handles loops of arbitrary structure including multiple exits and is generally more robust. This is under a temporary option to avoid affecting default behavior for the next couple of weeks. It is needed so that I can checkin unit tests for updateUnloop. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137384 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-10Invoke SimplifyIndVar when we partially unroll a loop. Fixes PR10534.Andrew Trick
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137203 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-23Move trip count discovery outside of the generic LoopUnroll helper. ThisAndrew Trick
removes its dependence on canonical induction variables. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135829 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-23whitespaceAndrew Trick
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135828 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-14fix a couple -Wsign-compare warnings.Chris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129501 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-13Fixed the revision 129449.Junjie Gu
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129450 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-13Passing unroll parameters (unroll-count, threshold, and partial unroll) via ↵Junjie Gu
LoopUnroll class's ctor. Doing so will allow multiple context with different loop unroll parameters to run. This is a minor change and no effect on existing application. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129449 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-17Remove dead code, that I apparently wrote a while back. We seem to be doing ↵Owen Anderson
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
2011-01-11random cleanupsChris Lattner
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123221 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-02improve loop rotation to use CodeMetrics to analyze theChris Lattner
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
2010-10-19Passes do not need to recursively initialize passes that they preserve, ifOwen Anderson
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
2010-10-19Get rid of static constructors for pass registration. Instead, every pass ↵Owen Anderson
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
2010-10-12Begin adding static dependence information to passes, which will allow us toOwen Anderson
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
2010-10-07Now with fewer extraneous semicolons!Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115996 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-29Revert r114919, which caused some serious regressions on ARM.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115053 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-27Weight loop unrolling counts by nesting depth. Unrolling deeply nested loops ↵Owen Anderson
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
2010-09-10Lower the unrolling theshold to 150. Empirical tests indicate that this is ↵Owen Anderson
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
2010-09-09What the loop unroller cares about, rather than just not unrolling loops ↵Owen Anderson
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
2010-09-09Revert r113439, which relaxed the requirement that loops containing calls ↵Owen Anderson
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
2010-09-09r113526 introduced an unintended change to the loop unrolling threshold. ↵Owen Anderson
Revert it. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113527 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-09Fix typo in code to cap the loop code size reduction calculation.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113526 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-09Use code-size reduction metrics to estimate the amount of savings we'll get ↵Owen Anderson
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
2010-09-08Relax the "don't unroll loops containing calls" rule. Instead, when a loop ↵Owen Anderson
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
2010-09-07Add a separate unrolling threshold when the current function is being ↵Owen Anderson
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
2010-08-29now that loop passes don't use DomFrontier, there is no reasonChris Lattner
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
2010-08-06Reapply r110396, with fixes to appease the Linux buildbot gods.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110460 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-06Revert r110396 to fix buildbots.Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110410 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-05Don't use PassInfo* as a type identifier for passes. Instead, use the ↵Owen Anderson
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
2010-08-04Experiments show that we can safely increase our unrolling threshold without ↵Owen Anderson
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
2010-07-26Remove LCSSA's bogus dependence on LoopSimplify and LoopSimplify's bogusDan Gohman
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
2010-07-21Fix batch of converting RegisterPass<> to INTIALIZE_PASS().Owen Anderson
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109045 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-10Add a DominatorTree argument to isLCSSA so that it doesn't have toDan Gohman
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
2010-02-05Don't unroll loops containing function calls.Jakob Stoklund Olesen
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95454 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05Change errs() to dbgs().David Greene
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92623 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-31Replace LoopUnrollPass.cpp's custom code-size estimation code usingDan Gohman
the new common CodeMetrics code. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85663 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-31Remove an unnecessary #include.Dan Gohman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85661 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-31Rename UnrollLoop.cpp to LoopUnroll.cpp, and LoopUnroll.cpp toDan Gohman
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
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