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path: root/llvm/lib/Transforms/Scalar/LoopSink.cpp
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* [PM] Port LoopSink to the new pass manager.Chandler Carruth2017-01-201-0/+37
| | | | | | | | | | | | | | | | | | | | | | Like several other loop passes (the vectorizer, etc) this pass doesn't really fit the model of a loop pass. The critical distinction is that it isn't intended to be pipelined together with other loop passes. I plan to add some documentation to the loop pass manager to make this more clear on that side. LoopSink is also different because it doesn't really need a lot of the infrastructure of our loop passes. For example, if there aren't loop invariant instructions causing a preheader to exist, there is no need to form a preheader. It also doesn't need LCSSA because this pass is only involved in sinking invariant instructions from a preheader into the loop, not reasoning about live-outs. This allows some nice simplifications to the pass in the new PM where we can directly walk the loops once without restructuring them. Differential Revision: https://reviews.llvm.org/D28921 llvm-svn: 292589
* [LoopSink] Trivial comment cleanup.Chandler Carruth2017-01-201-1/+2
| | | | llvm-svn: 292588
* [PM] Separate the LoopAnalysisManager from the LoopPassManager and moveChandler Carruth2017-01-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | the latter to the Transforms library. While the loop PM uses an analysis to form the IR units, the current plan is to have the PM itself establish and enforce both loop simplified form and LCSSA. This would be a layering violation in the analysis library. Fundamentally, the idea behind the loop PM is to *transform* loops in addition to running passes over them, so it really seemed like the most natural place to sink this was into the transforms library. We can't just move *everything* because we also have loop analyses that rely on a subset of the invariants. So this patch splits the the loop infrastructure into the analysis management that has to be part of the analysis library, and the transform-aware pass manager. This also required splitting the loop analyses' printer passes out to the transforms library, which makes sense to me as running these will transform the code into LCSSA in theory. I haven't split the unittest though because testing one component without the other seems nearly intractable. Differential Revision: https://reviews.llvm.org/D28452 llvm-svn: 291662
* Add an assert for hasLoopInvariantOperandsXin Tong2017-01-101-0/+3
| | | | | | | | | | | | Summary: Add an assert for hasLoopInvariantOperands Reviewers: danielcdh, sanjoy Subscribers: mzolotukhin, llvm-commits Differential Revision: https://reviews.llvm.org/D28501 llvm-svn: 291516
* Remove a unnecessary hasLoopInvariantOperands check in loop sink.Xin Tong2017-01-051-2/+1
| | | | | | | | | | | | | | | | Summary: Preheader instruction's operands will always be invariant w.r.t. the loop which its the preheader for. Memory aliases are handled in canSinkOrHoistInst. Reviewers: danielcdh, davidxl Subscribers: mzolotukhin, llvm-commits Differential Revision: https://reviews.llvm.org/D28270 llvm-svn: 291132
* Enable Loop Sink pass for functions that has profile.Dehao Chen2016-11-091-0/+5
| | | | | | | | | | | | Summary: For functions with profile data, we are confident that loop sink will be optimal in sinking code. Reviewers: davidxl, hfinkel Subscribers: mehdi_amini, mzolotukhin, llvm-commits Differential Revision: https://reviews.llvm.org/D26155 llvm-svn: 286325
* Add Loop Sink pass to reverse the LICM based of basic block frequency.Dehao Chen2016-10-271-0/+328
Summary: LICM may hoist instructions to preheader speculatively. Before code generation, we need to sink down the hoisted instructions inside to loop if it's beneficial. This pass is a reverse of LICM: looking at instructions in preheader and sinks the instruction to basic blocks inside the loop body if basic block frequency is smaller than the preheader frequency. Reviewers: hfinkel, davidxl, chandlerc Subscribers: anna, modocache, mgorny, beanz, reames, dberlin, chandlerc, mcrosier, junbuml, sanjoy, mzolotukhin, llvm-commits Differential Revision: https://reviews.llvm.org/D22778 llvm-svn: 285308
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