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* [NewGVN] Simplify a DEBUG() statement. NFCI.Davide Italiano2017-05-091-2/+1
| | | | llvm-svn: 302579
* [NewGVN] Explain why sorting by pointer values doesn't introduce ↵Davide Italiano2017-05-091-0/+4
| | | | | | | | non-determinism. Thanks to Eli for pointing out in a post-commit review comment. llvm-svn: 302566
* [NewGVN] Fix a consistent order for phi nodes operands.Davide Italiano2017-05-091-7/+19
| | | | | | | | | | | | | | | | | | | | | | | | | The way we currently define congruency for two PHIExpression(s) is: 1) The operands to the phi functions are congruent 2) The PHIs are defined in the same BasicBlock. NewGVN works under the assumption that phi operands are in predecessor order, or at least in some consistent order. OTOH, is valid IR: patatino: %meh = phi i16 [ %0, %winky ], [ %conv1, %tinky ] %banana = phi i16 [ %0, %tinky ], [ %conv1, %winky ] br label %end and the in-memory representations of the two SSA registers have an inconsistent order. This violation of NewGVN assumptions results into two PHIs found congruent when they're not. While we think it's useful to have always a consistent order enforced, let's fix this in NewGVN sorting uses in predecessor order before creating a PHI expression. Differential Revision: https://reviews.llvm.org/D32990 llvm-svn: 302552
* NewGVN: Make all of symbolic evaluation logically const.Daniel Berlin2017-05-091-64/+74
| | | | llvm-svn: 302550
* [Float2Int] Replace a ConstantRange copy with a move. Remove an extra call ↵Craig Topper2017-05-051-3/+4
| | | | | | to MapVector::find. llvm-svn: 302256
* [LoopIdiom] check for safety while expandingAditya Kumar2017-05-051-0/+10
| | | | | | | | | Loop Idiom recognition was generating memset in a case that would result generating a division operation to an unsafe location. Differential Revision: https://reviews.llvm.org/D32674 llvm-svn: 302238
* [JumpThreading] When processing compares, explicitly check that the result ↵Craig Topper2017-05-041-1/+1
| | | | | | | | type is not a vector rather than check for it being an integer. Compares always return a scalar integer or vector of integers. isIntegerTy returns false for vectors, but that's not completely obvious. So using isVectorTy is less confusing. llvm-svn: 302198
* [JumpThreading] Change a dyn_cast that is already protected by an isa check ↵Craig Topper2017-05-041-16/+14
| | | | | | | | to a static cast. Combine the with another static cast. NFC Differential Revision: https://reviews.llvm.org/D32874 llvm-svn: 302197
* [Float2Int] Remove return of ConstantRange from seen method. Nothing uses it ↵Craig Topper2017-05-041-2/+1
| | | | | | so it just creates and discards a ConstantRange object for no reason. llvm-svn: 302193
* [NewGVN] Remove unneeded newline and format assertions. NFCI.Davide Italiano2017-05-041-5/+4
| | | | llvm-svn: 302173
* [TailCallElim] Remove an unused argument. NFCIXin Tong2017-05-031-9/+6
| | | | llvm-svn: 302080
* Fix typos in commentSanjoy Das2017-05-031-4/+4
| | | | llvm-svn: 302063
* [IR] Abstract away ArgNo+1 attribute indexing as much as possibleReid Kleckner2017-05-032-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Do three things to help with that: - Add AttributeList::FirstArgIndex, which is an enumerator currently set to 1. It allows us to change the indexing scheme with fewer changes. - Add addParamAttr/removeParamAttr. This just shortens addAttribute call sites that would otherwise need to spell out FirstArgIndex. - Remove some attribute-specific getters and setters from Function that take attribute list indices. Most of these were only used from BuildLibCalls, and doesNotAlias was only used to test or set if the return value is malloc-like. I'm happy to split the patch, but I think they are probably easier to review when taken together. This patch should be NFC, but it sets the stage to change the indexing scheme to this, which is more convenient when indexing into an array: 0: func attrs 1: retattrs 2...: arg attrs Reviewers: chandlerc, pete, javed.absar Subscribers: david2050, llvm-commits Differential Revision: https://reviews.llvm.org/D32811 llvm-svn: 302060
* [Loop Deletion] Delete loops that are never executedAnna Thomas2017-05-031-14/+90
| | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Currently, loop deletion deletes loop where the only values that are used outside the loop are loop-invariant. This patch adds logic to delete loops where the loop is proven to be never executed (i.e. the only predecessor of the loop preheader has a constant conditional branch as terminator, and the preheader is not the taken target). This will remove loops that become dead after loop-unswitching generates constant conditional branches. The next steps are: 1. moving the loop deletion implementation to LoopUtils. 2. Add logic in loop-simplifyCFG which will support changing conditional constant branches to unconditional branches. If loops become unreachable in this process, they can be removed using `deleteDeadLoop` function. Reviewers: chandlerc, efriedma, sanjoy, reames Reviewed by: sanjoy Subscribers: mzolotukhin, llvm-commits Differential Revision: https://reviews.llvm.org/D32494 llvm-svn: 302015
* Re-land r301697 "[IR] Make add/remove Attributes use AttrBuilder instead of ↵Reid Kleckner2017-05-021-2/+1
| | | | | | | | | | AttributeList" This time, I fixed, built, and tested clang. This reverts r301712. llvm-svn: 301981
* [NewGVN] Fix typo and format comment. NFCI.Davide Italiano2017-05-021-7/+4
| | | | llvm-svn: 301974
* SpeculativeExecution: Stop using whitelist for costsMatt Arsenault2017-05-021-42/+1
| | | | | | | Just let TTI's cost do this instead of arbitrarily restricting this. llvm-svn: 301950
* Empty Space. NFCXin Tong2017-05-011-1/+1
| | | | llvm-svn: 301878
* [NewGVN] Don't derive incorrect implications.Davide Italiano2017-05-011-4/+4
| | | | | | | | | | | | | | In the testcase attached, we believe %tmp1 implies %tmp4. where: br i1 %tmp1, label %bb2, label %bb7 br i1 %tmp4, label %bb5, label %bb7 because Wwhile looking at PredicateInfo stuffs we end up calling isImpliedTrueByMatchingCmp() with the arguments backwards. Differential Revision: https://reviews.llvm.org/D32718 llvm-svn: 301849
* Take indirect branch into account as well when folding.Xin Tong2017-05-011-6/+10
| | | | | | | | We may not be able to rewrite indirect branch target, but we also want to take it into account when folding, i.e. if it and all its successor's predecessors go to the same destination, we can fold, i.e. no need to thread. llvm-svn: 301816
* Rename WeakVH to WeakTrackingVH; NFCSanjoy Das2017-05-018-72/+57
| | | | | | This relands r301424. llvm-svn: 301812
* [JumpThread] Add some assertions for expected ConstantInt/BlockAddressXin Tong2017-05-011-2/+5
| | | | llvm-svn: 301808
* [JumpThread] Do RAUW in case Cond folds to a constant in the CFGXin Tong2017-05-011-8/+24
| | | | | | | | | | | | | | Summary: [JumpThread] Do RAUW in case Cond folds to a constant in the CFG Reviewers: sanjoy Reviewed By: sanjoy Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D32407 llvm-svn: 301804
* Rename isKnownNotFullPoison to programUndefinedIfPoison; NFCSanjoy Das2017-04-301-1/+1
| | | | | | | | | | | | | | | | | Summary: programUndefinedIfPoison makes more sense, given what the function does; and I'm about to add a function with a name similar to isKnownNotFullPoison (so do the rename to avoid confusion). Reviewers: broune, majnemer, bjarke.roune Reviewed By: broune Subscribers: mcrosier, llvm-commits, mzolotukhin Differential Revision: https://reviews.llvm.org/D30444 llvm-svn: 301776
* [LoopUnswitch] Make DEBUG output more readable (part 2).Davide Italiano2017-04-291-1/+1
| | | | | | | | | I fixed my miscompile in r301722 and I hope I don't have to take a look at this code again now that Chandler has a new LoopUnswitch pass, but maybe this could be of use for somebody else in the meanwhile. llvm-svn: 301723
* [LoopUnswitch] Don't remove instructions with side effects.Davide Italiano2017-04-291-1/+2
| | | | | | | | This fixes PR32818. Differential Revision: https://reviews.llvm.org/D32664 llvm-svn: 301722
* Revert r301697 "[IR] Make add/remove Attributes use AttrBuilder instead of ↵Hans Wennborg2017-04-281-1/+2
| | | | | | | | | | | | | | | | | | AttributeList" This broke the Clang build. (Clang-side patch missing?) Original commit message: > [IR] Make add/remove Attributes use AttrBuilder instead of > AttributeList > > This change cleans up call sites and avoids creating temporary > AttributeList objects. > > NFC llvm-svn: 301712
* InferAddressSpaces: Search constant expressions for addrspacecastsMatt Arsenault2017-04-281-12/+48
| | | | | | | These are pretty common when using local memory, and the 64-bit generic addressing is much more expensive to compute. llvm-svn: 301711
* InferAddressSpaces: Avoid looking up deleted valuesMatt Arsenault2017-04-281-3/+10
| | | | | | | | | | | While looking at pure addressing expressions, it's possible for the value to appear later in Postorder. I haven't been able to come up with a testcase where this exhibits an actual issue, but if you insert a dump before the value map lookup, a few testcases crash. llvm-svn: 301705
* InferAddressSpaces: Infer from just addrspacecastsMatt Arsenault2017-04-281-0/+12
| | | | | | | | Eliminates some more cases where some subset of the addressing computation remains flat. Some cases with addrspacecasts in nested constant expressions are still left behind however. llvm-svn: 301704
* LoopRotate: Fix use after scope bugDaniel Berlin2017-04-281-3/+4
| | | | llvm-svn: 301702
* [IR] Make add/remove Attributes use AttrBuilder instead of AttributeListReid Kleckner2017-04-281-2/+1
| | | | | | | | | This change cleans up call sites and avoids creating temporary AttributeList objects. NFC llvm-svn: 301697
* [LoopUnswitch] Make DEBUG output more readable.Davide Italiano2017-04-281-1/+1
| | | | | | | | | While debugging a miscompile I realized loopunswitch doesn't put newlines when printing the instruction being replacement. Ending up with a single line with many instruction replaced isn't the best for readability and/or mental sanity. llvm-svn: 301692
* Make getParamAlignment use argument numbersReid Kleckner2017-04-281-1/+1
| | | | | | | | | | | | | | | | | | The method is called "get *Param* Alignment", and is only used for return values exactly once, so it should take argument indices, not attribute indices. Avoids confusing code like: IsSwiftError = CS->paramHasAttr(ArgIdx, Attribute::SwiftError); Alignment = CS->getParamAlignment(ArgIdx + 1); Add getRetAlignment to handle the one case in Value.cpp that wants the return value alignment. This is a potentially breaking change for out-of-tree backends that do their own call lowering. llvm-svn: 301682
* Kill off the old SimplifyInstruction API by converting remaining users.Daniel Berlin2017-04-287-38/+25
| | | | llvm-svn: 301673
* [RS4GC] Simplify attribute handling code NFCReid Kleckner2017-04-281-47/+25
| | | | | | | Avoids use of AttributeList::getNumSlots, making it easier to change the underlying implementation. llvm-svn: 301671
* [EarlyCSE] Mark the condition of assume intrinsic as trueMax Kazantsev2017-04-281-3/+9
| | | | | | | | | | | | | | EarlyCSE should not just ignore assumes. It should use the fact that its condition is true for all dominated instructions. Reviewers: sanjoy, reames, apilipenko, anna, skatkov Reviewed By: reames, sanjoy Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D32482 llvm-svn: 301625
* [EarlyCSE] Remove guards with conditions known to be trueMax Kazantsev2017-04-281-3/+18
| | | | | | | | | | | | | | | | | If a condition is calculated only once, and there are multiple guards on this condition, we should be able to remove all guards dominated by the first of them. This patch allows EarlyCSE to try to find the condition of a guard among the known values, and if it is true, remove the guard. Otherwise we keep the guard and mark its condition as 'true' for future consideration. Reviewers: sanjoy, reames, apilipenko, skatkov, anna, dberlin Reviewed By: reames, sanjoy Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D32476 llvm-svn: 301623
* [SROA] Fix nondeterminism exposed by Simon's r299221.Davide Italiano2017-04-271-14/+12
| | | | | | | Use a SmallSetSetVector instead of a SmallPtrSet as iterating over the latter is not stable ('<' relies on addresses). llvm-svn: 301599
* [PM/LoopUnswitch] Introduce a new, simpler loop unswitch pass.Chandler Carruth2017-04-273-0/+629
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, this pass only focuses on *trivial* loop unswitching. At that reduced problem it remains significantly better than the current loop unswitch: - Old pass is worse than cubic complexity. New pass is (I think) linear. - New pass is much simpler in its design by focusing on full unswitching. (See below for details on this). - New pass doesn't carry state for thresholds between pass iterations. - New pass doesn't carry state for correctness (both miscompile and infloop) between pass iterations. - New pass produces substantially better code after unswitching. - New pass can handle more trivial unswitch cases. - New pass doesn't recompute the dominator tree for the entire function and instead incrementally updates it. I've ported all of the trivial unswitching test cases from the old pass to the new one to make sure that major functionality isn't lost in the process. For several of the test cases I've worked to improve the precision and rigor of the CHECKs, but for many I've just updated them to handle the new IR produced. My initial motivation was the fact that the old pass carried state in very unreliable ways between pass iterations, and these mechansims were incompatible with the new pass manager. However, I discovered many more improvements to make along the way. This pass makes two very significant assumptions that enable most of these improvements: 1) Focus on *full* unswitching -- that is, completely removing whatever control flow construct is being unswitched from the loop. In the case of trivial unswitching, this means removing the trivial (exiting) edge. In non-trivial unswitching, this means removing the branch or switch itself. This is in opposition to *partial* unswitching where some part of the unswitched control flow remains in the loop. Partial unswitching only really applies to switches and to folded branches. These are very similar to full unrolling and partial unrolling. The full form is an effective canonicalization, the partial form needs a complex cost model, cannot be iterated, isn't canonicalizing, and should be a separate pass that runs very late (much like unrolling). 2) Leverage LLVM's Loop machinery to the fullest. The original unswitch dates from a time when a great deal of LLVM's loop infrastructure was missing, ineffective, and/or unreliable. As a consequence, a lot of complexity was added which we no longer need. With these two overarching principles, I think we can build a fast and effective unswitcher that fits in well in the new PM and in the canonicalization pipeline. Some of the remaining functionality around partial unswitching may not be relevant today (not many test cases or benchmarks I can find) but if they are I'd like to add support for them as a separate layer that runs very late in the pipeline. Purely to make reviewing and introducing this code more manageable, I've split this into first a trivial-unswitch-only pass and in the next patch I'll add support for full non-trivial unswitching against a *fixed* threshold, exactly like full unrolling. I even plan to re-use the unrolling thresholds, as these are incredibly similar cost tradeoffs: we're cloning a loop body in order to end up with simplified control flow. We should only do that when the total growth is reasonably small. One of the biggest changes with this pass compared to the previous one is that previously, each individual trivial exiting edge from a switch was unswitched separately as a branch. Now, we unswitch the entire switch at once, with cases going to the various destinations. This lets us unswitch multiple exiting edges in a single operation and also avoids numerous extremely bad behaviors, where we would introduce 1000s of branches to test for thousands of possible values, all of which would take the exact same exit path bypassing the loop. Now we will use a switch with 1000s of cases that can be efficiently lowered into a jumptable. This avoids relying on somehow forming a switch out of the branches or getting horrible code if that fails for any reason. Another significant change is that this pass actively updates the CFG based on unswitching. For trivial unswitching, this is actually very easy because of the definition of loop simplified form. Doing this makes the code coming out of loop unswitch dramatically more friendly. We still should run loop-simplifycfg (at the least) after this to clean up, but it will have to do a lot less work. Finally, this pass makes much fewer attempts to simplify instructions based on the unswitch. Something like loop-instsimplify, instcombine, or GVN can be used to do increasingly powerful simplifications based on the now dominating predicate. The old simplifications are things that something like loop-instsimplify should get today or a very, very basic loop-instcombine could get. Keeping that logic separate is a big simplifying technique. Most of the code in this pass that isn't in the old one has to do with achieving specific goals: - Updating the dominator tree as we go - Unswitching all cases in a switch in a single step. I think it is still shorter than just the trivial unswitching code in the old pass despite having this functionality. Differential Revision: https://reviews.llvm.org/D32409 llvm-svn: 301576
* NewGVN: Use new SimplifyQuery based APIDaniel Berlin2017-04-261-11/+11
| | | | llvm-svn: 301466
* CorrelatedValuePropagation: Rename a variable for consistencyDaniel Berlin2017-04-261-2/+2
| | | | llvm-svn: 301435
* [ValueTracking] Introduce a KnownBits struct to wrap the two APInts for ↵Craig Topper2017-04-261-3/+4
| | | | | | | | | | | | | | | | computeKnownBits This patch introduces a new KnownBits struct that wraps the two APInt used by computeKnownBits. This allows us to treat them as more of a unit. Initially I've just altered the signatures of computeKnownBits and InstCombine's simplifyDemandedBits to pass a KnownBits reference instead of two separate APInt references. I'll do similar to the SelectionDAG version of computeKnownBits/simplifyDemandedBits as a separate patch. I've added a constructor that allows initializing both APInts to the same bit width with a starting value of 0. This reduces the repeated pattern of initializing both APInts. Once place default constructed the APInts so I added a default constructor for those cases. Going forward I would like to add more methods that will work on the pairs. For example trunc, zext, and sext occur on both APInts together in several places. We should probably add a clear method that can be used to clear both pieces. Maybe a method to check for conflicting information. A method to return (Zero|One) so we don't write it out everywhere. Maybe a method for (Zero|One).isAllOnesValue() to determine if all bits are known. I'm sure there are many other methods we can come up with. Differential Revision: https://reviews.llvm.org/D32376 llvm-svn: 301432
* Reverts commit r301424, r301425 and r301426Sanjoy Das2017-04-267-48/+66
| | | | | | | | | | | | Commits were: "Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts" "Add a new WeakVH value handle; NFC" "Rename WeakVH to WeakTrackingVH; NFC" The changes assumed pointers are 8 byte aligned on all architectures. llvm-svn: 301429
* Rename WeakVH to WeakTrackingVH; NFCSanjoy Das2017-04-267-66/+48
| | | | | | | | | | | | | | | | Summary: I plan to use WeakVH to mean "nulls itself out on deletion, but does not track RAUW" in a subsequent commit. Reviewers: dblaikie, davide Reviewed By: davide Subscribers: arsenm, mehdi_amini, mcrosier, mzolotukhin, jfb, llvm-commits, nhaehnle Differential Revision: https://reviews.llvm.org/D32266 llvm-svn: 301424
* Fix unused-variable warning caused by r301407.Haojian Wu2017-04-261-2/+0
| | | | llvm-svn: 301411
* Convert LoopRotation to use SimplifyQuery version of SimplifyInstruction. ↵Daniel Berlin2017-04-261-7/+13
| | | | | | Add AssumptionCache, DominatorTree, TLI if available. llvm-svn: 301407
* Convert CVP to use SimplifyQuery version of SimplifyInstruction. Add ↵Daniel Berlin2017-04-261-10/+20
| | | | | | AssumptionCache, DominatorTree, TLI if available. llvm-svn: 301405
* InferAddressSpaces: Use reference arguments instead of pointersMatt Arsenault2017-04-241-15/+15
| | | | llvm-svn: 301276
* InferAddressSpaces: Remove redundant assertMatt Arsenault2017-04-241-1/+0
| | | | | | | This is just asserting all the operations are handled in the switch, which the unreachable already handles. llvm-svn: 301270
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