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path: root/llvm/lib/Transforms/Scalar/LoopDistribute.cpp
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* LPM: Stop threading `Pass *` through all of the loop utility APIs. NFCJustin Bogner2015-12-151-2/+2
| | | | | | | | | | | | | | | | | | | | | | A large number of loop utility functions take a `Pass *` and reach into it to find out which analyses to preserve. There are a number of problems with this: - The APIs have access to pretty well any Pass state they want, so it's hard to tell what they may or may not do. - Other APIs have copied these and pass around a `Pass *` even though they don't even use it. Some of these just hand a nullptr to the API since the callers don't even have a pass available. - Passes in the new pass manager don't work like the current ones, so the APIs can't be used as is there. Instead, we should explicitly thread the analysis results that we actually care about through these APIs. This is both simpler and more reusable. llvm-svn: 255669
* Re-commit r255115, with the PredicatedScalarEvolution class moved toSilviu Baranga2015-12-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ScalarEvolution.h, in order to avoid cyclic dependencies between the Transform and Analysis modules: [LV][LAA] Add a layer over SCEV to apply run-time checked knowledge on SCEV expressions Summary: This change creates a layer over ScalarEvolution for LAA and LV, and centralizes the usage of SCEV predicates. The SCEVPredicatedLayer takes the statically deduced knowledge by ScalarEvolution and applies the knowledge from the SCEV predicates. The end goal is that both LAA and LV should use this interface everywhere. This also solves a problem involving the result of SCEV expression rewritting when the predicate changes. Suppose we have the expression (sext {a,+,b}) and two predicates P1: {a,+,b} has nsw P2: b = 1. Applying P1 and then P2 gives us {a,+,1}, while applying P2 and the P1 gives us sext({a,+,1}) (the AddRec expression was changed by P2 so P1 no longer applies). The SCEVPredicatedLayer maintains the order of transformations by feeding back the results of previous transformations into new transformations, and therefore avoiding this issue. The SCEVPredicatedLayer maintains a cache to remember the results of previous SCEV rewritting results. This also has the benefit of reducing the overall number of expression rewrites. Reviewers: mzolotukhin, anemet Subscribers: jmolloy, sanjoy, llvm-commits Differential Revision: http://reviews.llvm.org/D14296 llvm-svn: 255122
* Revert r255115 until we figure out how to fix the bot failures.Silviu Baranga2015-12-091-2/+2
| | | | llvm-svn: 255117
* [LV][LAA] Add a layer over SCEV to apply run-time checked knowledge on SCEV ↵Silviu Baranga2015-12-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | expressions Summary: This change creates a layer over ScalarEvolution for LAA and LV, and centralizes the usage of SCEV predicates. The SCEVPredicatedLayer takes the statically deduced knowledge by ScalarEvolution and applies the knowledge from the SCEV predicates. The end goal is that both LAA and LV should use this interface everywhere. This also solves a problem involving the result of SCEV expression rewritting when the predicate changes. Suppose we have the expression (sext {a,+,b}) and two predicates P1: {a,+,b} has nsw P2: b = 1. Applying P1 and then P2 gives us {a,+,1}, while applying P2 and the P1 gives us sext({a,+,1}) (the AddRec expression was changed by P2 so P1 no longer applies). The SCEVPredicatedLayer maintains the order of transformations by feeding back the results of previous transformations into new transformations, and therefore avoiding this issue. The SCEVPredicatedLayer maintains a cache to remember the results of previous SCEV rewritting results. This also has the benefit of reducing the overall number of expression rewrites. Reviewers: mzolotukhin, anemet Subscribers: jmolloy, sanjoy, llvm-commits Differential Revision: http://reviews.llvm.org/D14296 llvm-svn: 255115
* Allow LLE/LD and the loop versioning infrastructure to use SCEV predicatesSilviu Baranga2015-11-091-4/+22
| | | | | | | | | | | | | | | | | | | Summary: LAA currently generates a set of SCEV predicates that must be checked by users. In the case of Loop Distribute/Loop Load Elimination, no such predicates could have been emitted, since we don't allow stride versioning. However, in the future there could be SCEV predicates that will need to be checked. This change adds support for SCEV predicate versioning in the Loop Distribute, Loop Load Eliminate and the loop versioning infrastructure. Reviewers: anemet Subscribers: mssimpso, sanjoy, llvm-commits Differential Revision: http://reviews.llvm.org/D14240 llvm-svn: 252467
* [LAA] LLE 3/6: Rename InterestingDependence to Dependences, NFCAdam Nemet2015-11-031-6/+5
| | | | | | | | | | | | | | Summary: We now collect all types of dependences including lexically forward deps not just "interesting" ones. Reviewers: hfinkel Subscribers: rengolin, llvm-commits Differential Revision: http://reviews.llvm.org/D13256 llvm-svn: 251985
* [LVer] Fix FIXME: hide addPHINodes, NFCAdam Nemet2015-08-201-2/+1
| | | | | | | | | | | | | | Since Ashutosh made findDefsUsedOutsideOfLoop public, we can clean this up. Now clients that don't compute DefsUsedOutsideOfLoop can just call versionLoop() and computing DefsUsedOutsideOfLoop will happen implicitly. With that there is no reason to expose addPHINodes anymore. Ashutosh, you can now drop the calls to findDefsUsedOutsideOfLoop and addPHINodes in LVerLICM and things should just work. llvm-svn: 245579
* Exposed findDefsUsedOutsideOfLoop as a loop utility functionAshutosh Nema2015-08-191-19/+1
| | | | | | | | | Exposed findDefsUsedOutsideOfLoop as a loop utility function by moving it from LoopDistribute to LoopUtils. Reviewed By: anemet llvm-svn: 245416
* [LVer] Remove unused Pass parameter from versionLoop, NFCAdam Nemet2015-08-141-1/+1
| | | | llvm-svn: 245032
* [LAA] Make the set of runtime checks part of the state of LAA, NFCAdam Nemet2015-08-071-1/+1
| | | | | | | | | | | | | | | | | | | | This is the full set of checks that clients can further filter. IOW, it's client-agnostic. This makes LAA complete in the sense that it now provides the two main results of its analysis precomputed: 1. memory dependences via getDepChecker().getInsterestingDependences() 2. run-time checks via getRuntimePointerCheck().getChecks() However, as a consequence we now compute this information pro-actively. Thus if the client decides to skip the loop based on the dependences we've computed the checks unnecessarily. In order to see whether this was a significant overhead I checked compile time on SPEC2k6 LTO bitcode files. The change was in the noise. The checks are generated in canCheckPtrAtRT, at the same place where we used to call groupChecks to merge checks. llvm-svn: 244368
* [LDist] Filter the checks locally rather than in LAA, NFCAdam Nemet2015-07-301-2/+43
| | | | | | | | | | | | | | | Before, we were passing the pointer partitions to LAA. Now, we get all the checks from LAA and filter out the checks within partitions in LoopDistribution. This effectively concludes the steps to move filtering memchecks from LAA into its clients. There is still some cleanup left to remove the unused interfaces in LAA that still take PtrPartition. (Moving this functionality to LoopDistribution also requires needsChecking on pointers to be made public.) llvm-svn: 243613
* [LDist][LVer] Explicitly pass the set of memchecks to LoopVersioning, NFCAdam Nemet2015-07-281-3/+5
| | | | | | | | | | | | | | | | | | Before the patch, the checks were generated internally in addRuntimeCheck. Now, we use the new overloaded version of addRuntimeCheck that takes the ready-made set of checks as a parameter. The checks are now generated by the client (LoopDistribution) with the new RuntimePointerChecking::generateChecks API. Also the new printChecks API is used to print out the checks for debugging. This is to continue the transition over to the new model whereby clients will get the full set of checks from LAA, filter it and then pass it to LoopVersioning and in turn to addRuntimeCheck. llvm-svn: 243382
* Use make_range(rbegin(), rend()) to allow foreach loops. NFC.Pete Cooper2015-07-241-3/+1
| | | | | | | | | | | Instead of the pattern for (auto I = x.rbegin(), E = x.end(); I != E; ++I) we can use make_range to construct the reverse range and iterate using that instead. llvm-svn: 243163
* [LAA] Introduce RuntimePointerChecking::PointerInfo, NFCAdam Nemet2015-07-141-2/+2
| | | | | | | Turn this structure-of-arrays (i.e. the various pointer attributes) into array-of-structures. llvm-svn: 242219
* [LAA] Lift RuntimePointerCheck out of LoopAccessInfo, NFCAdam Nemet2015-07-141-3/+2
| | | | | | | | | I am planning to add more nested classes inside RuntimePointerCheck so all these triple-nesting would be hard to follow. Also rename it to RuntimePointerChecking (i.e. append 'ing'). llvm-svn: 242218
* [LoopDist/LoopVer] Move LoopVersioning to a new module, NFCAdam Nemet2015-07-101-115/+1
| | | | | | | | | | | | | | | | | | | Summary: The class will obviously need improvement down the road. For one, there is no reason that addPHINodes would have to be exposed like that. I will make this and other improvements in follow-up patches. The main goal is to be able to share this functionality. The LoopLoadElimination pass I am working on needs it too. Later we can move other clients as well (LV and Ashutosh's LICMVer). Reviewers: hfinkel, ashutosh.nema Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D10577 llvm-svn: 241932
* [LoopDist] Move loop-versioning helper functions to Cloning, NFCAdam Nemet2015-07-101-66/+4
| | | | | | | | | | | | | | Summary: This makes them available to the LoopVersioning class as that is moved to its own module in the next patch. Reviewers: ashutosh.nema, hfinkel Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D10576 llvm-svn: 241931
* [LoopDist] Improve variable names and comments in LoopVersioning class, NFCAdam Nemet2015-06-221-25/+29
| | | | | | | | As with the previous patch, the goal is to turn the class into a general loop-versioning class. This patch removes any references to loop distribution. llvm-svn: 240352
* [LoopDist] Rename RuntimeCheckEmitter to LoopVersioning, NFCAdam Nemet2015-06-191-8/+8
| | | | llvm-svn: 240165
* [LoopDist] Move pointer-to-partition computation out of RuntimeCheckEmitter, NFCAdam Nemet2015-06-191-18/+12
| | | | | | | This starts preparing the class to become a (more) general LoopVersioning utility class. llvm-svn: 240164
* [LoopDistribute] Remove a layer of pointer indirection.Benjamin Kramer2015-05-211-41/+32
| | | | | | | Just store InstPartitions directly into the std::list. No functional change intended. llvm-svn: 237930
* Attempt to fix MSVC botsAdam Nemet2015-05-141-3/+3
| | | | llvm-svn: 237359
* New Loop Distribution passAdam Nemet2015-05-141-0/+985
Summary: This implements the initial version as was proposed earlier this year (http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-January/080462.html). Since then Loop Access Analysis was split out from the Loop Vectorizer and was made into a separate analysis pass. Loop Distribution becomes the second user of this analysis. The pass is off by default and can be enabled with -enable-loop-distribution. There is currently no notion of profitability; if there is a loop with dependence cycles, the pass will try to split them off from other memory operations into a separate loop. I decided to remove the control-dependence calculation from this first version. This and the issues with the PDT are actively discussed so it probably makes sense to treat it separately. Right now I just mark all terminator instruction required which keeps identical CFGs for each distributed loop. This seems to be working pretty well for 456.hmmer where even though there is an empty if-then block in the distributed loop initially, it gets completely removed. The pass keeps DominatorTree and LoopInfo updated. I've tested this with -loop-distribute-verify with the testsuite where we distribute ~90 loops. SimplifyLoop is violated in some cases and I have a FIXME covering this. Reviewers: hfinkel, nadav, aschwaighofer Reviewed By: aschwaighofer Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D8831 llvm-svn: 237358
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