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* [LoopSimplifyCFG] Invalidate SCEV in LoopSimplifyCFGDavid Green2018-06-191-3/+7
| | | | | | | | | | LoopSimplifyCFG, being a loop pass, needs to preserve scalar evolution. This invalidates SE for the loops altered during block merging. Differential Revision: https://reviews.llvm.org/D48258 llvm-svn: 335036
* [LoopInterchange] Move PHI handling to adjustLoopBranches.Florian Hahn2018-06-191-30/+40
| | | | | | | | | | | | | | | | | | | | | This patch moves the logic to handle reduction PHI nodes to the end of adjustLoopBranches. Reduction PHI nodes in the outer loop header can be moved to the inner loop header and reduction PHI nodes from the inner loop header can be moved to the outer loop header. In the latter situation, we have to deal with 1 kind of PHI nodes: PHI nodes that are part of inner loop-only reductions. We can replace the PHI node with the value coming from outside the inner loop. Reviewers: mcrosier, efriedma, karthikthecool Reviewed By: efriedma Differential Revision: https://reviews.llvm.org/D46198 llvm-svn: 335027
* CorrelatedValuePropagation: Preserve DT.Michael Zolotukhin2018-06-161-5/+18
| | | | | | | | | | | | | | Summary: We only modify CFG in a couple of places, and we can preserve DT there with a little effort. Reviewers: davide, vsk Subscribers: hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D48059 llvm-svn: 334895
* [EarlyCSE] Fix MSVC build. NFCI.Simon Pilgrim2018-06-141-9/+5
| | | | | | MSVC doesn't let you assign different lambdas through a ternary operator. llvm-svn: 334715
* [EarlyCSE] Propagate conditions of AND and OR instructionsMax Kazantsev2018-06-141-14/+43
| | | | | | | | | | | This patches teaches EarlyCSE to figure out that if `and i1 %x, %y` is true then both `%x` and `%y` are true in the taken branch, and if `or i1 %x, %y` is false then both `%x` and `%y` are false in non-taken branch. Fix for PR37635. Differential Revision: https://reviews.llvm.org/D47574 Reviewed By: reames llvm-svn: 334707
* [NFC] fix trivial typos in commentsHiroshi Inoue2018-06-1414-31/+31
| | | | llvm-svn: 334687
* Use SmallPtrSet explicitly for SmallSets with pointer types (NFC).Florian Hahn2018-06-124-12/+12
| | | | | | | | | | | | | | Currently SmallSet<PointerTy> inherits from SmallPtrSet<PointerTy>. This patch replaces such types with SmallPtrSet, because IMO it is slightly clearer and allows us to get rid of unnecessarily including SmallSet.h Reviewers: dblaikie, craig.topper Reviewed By: dblaikie Differential Revision: https://reviews.llvm.org/D47836 llvm-svn: 334492
* Use SmallPtrSet instead of SmallSet in places where we iterate over the set.Craig Topper2018-06-091-1/+1
| | | | | | | | SmallSet forwards to SmallPtrSet for pointer types. SmallPtrSet supports iteration, but a normal SmallSet doesn't. So if it wasn't for the forwarding, this wouldn't work. These places were found by hiding the begin/end methods in the SmallSet forwarding llvm-svn: 334343
* reapply r334209 with fixes for harfbuzz in ChromiumDaniil Fukalov2018-06-081-16/+26
| | | | | | | | | | | r334209 description: [LSR] Check yet more intrinsic pointer operands the patch fixes another assertion in isLegalUse() Differential Revision: https://reviews.llvm.org/D47794 llvm-svn: 334300
* Revert r334209 "[LSR] Check yet more intrinsic pointer operands"Reid Kleckner2018-06-081-12/+4
| | | | | | | This causes cast failures when compiling harfbuzz in Chromium. Reproducer on the way. llvm-svn: 334254
* [LSR] Check yet more intrinsic pointer operandsDaniil Fukalov2018-06-071-4/+12
| | | | | | | | the patch fixes another assertion in isLegalUse() Differential Revision: https://reviews.llvm.org/D47794 llvm-svn: 334209
* SpeculativeExecution Pass: Set PreserveCFG to avoid unnecessary analyses ↵Michael Zolotukhin2018-06-071-0/+2
| | | | | | | | | invalidation. The pass doesn't touch CFG in any way, only moves instructions between blocks. llvm-svn: 334150
* Move Analysis/Utils/Local.h back to TransformsDavid Blaikie2018-06-0435-35/+35
| | | | | | | | | | Review feedback from r328165. Split out just the one function from the file that's used by Analysis. (As chandlerc pointed out, the original change only moved the header and not the implementation anyway - which was fine for the one function that was used (since it's a template/inlined in the header) but not in general) llvm-svn: 333954
* [PM/LoopUnswitch] Fix how the cloned loops are handled when updating analyses.Chandler Carruth2018-06-021-44/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: I noticed this issue because we didn't put the primary cloned loop into the `NonChildClonedLoops` vector and so never iterated on it. Once I fixed that, it made it clear why I had to do a really complicated and unnecesasry dance when updating the loops to remain in canonical form -- I was unwittingly working around the fact that the primary cloned loop wasn't in the expected list of cloned loops. Doh! Now that we include it in this vector, we don't need to return it and we can consolidate the update logic as we correctly have a single place where it can be handled. I've just added a test for the iteration order aspect as every time I changed the update logic partially or incorrectly here, an existing test failed and caught it so that seems well covered (which is also evidenced by the extensive working around of this missing update). Reviewers: asbirlea, sanjoy Subscribers: mcrosier, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D47647 llvm-svn: 333811
* Revert r333740: IPSCCP] Use PredicateInfo to propagate facts from cmp.Florian Hahn2018-06-011-112/+8
| | | | | | This is breaking the clang-with-thin-lto-ubuntu bot. llvm-svn: 333745
* Recommit r333268: [IPSCCP] Use PredicateInfo to propagate facts from cmp ↵Florian Hahn2018-06-011-8/+112
| | | | | | | | | | | | | | | | | | | instructions. This patch updates IPSCCP to use PredicateInfo to propagate facts to true branches predicated by EQ and to false branches predicated by NE. As a follow up, we should be able to extend it to also propagate additional facts about nonnull. Reviewers: davide, mssimpso, dberlin, efriedma Reviewed By: davide, dberlin Differential Revision: https://reviews.llvm.org/D45330 llvm-svn: 333740
* [LoopIdiomRecognize] Only convert loops to ctlz if we can prove that the ↵Craig Topper2018-05-311-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | input is non-negative. Summary: Loop idiom recognize tries to convert loops like ``` int foo(int x) { int cnt = 0; while (x) { x >>= 1; ++cnt; } return cnt; } ``` into calls to ctlz, but if x is initially negative this loop should be infinite. It happens that the cases that motivated this change have an absolute value of x before the loop. So this patch restricts the transform to cases where we know x is positive. Note: We are relying on the absolute value of INT_MIN to be undefined so we can assume that the result is always positive. Fixes PR37479 Reviewers: spatel, hfinkel, efriedma, javed.absar Reviewed By: efriedma Subscribers: dmgreen, llvm-commits Differential Revision: https://reviews.llvm.org/D47348 llvm-svn: 333702
* [JumpThreading] Fix some strange formatting of code inside LLVM_DEBUG. NFCCraig Topper2018-05-311-5/+5
| | | | | | I don't know if clang-format got confused here or what. llvm-svn: 333675
* [NFC] Factor out a method for further extensionMax Kazantsev2018-05-311-20/+32
| | | | llvm-svn: 333633
* [NewGVN] Fix set comparison; reflow commentGeorge Burgess IV2018-05-301-7/+8
| | | | | | | | | | | | | | | | Looks like we intended to compare this->Members with Other->Members here, but ended up comparing this->Members with this->Members. Oops. :) Since CongruenceClass::Members is a SmallPtrSet anyway, we can probably skip building std::sets if we're willing to write a bit more code. This appears to be no functional change (for sufficiently lax values of "no"): this equality check was only being called inside of an assert. So, worst case, we'll catch more bugs in the form of assertion failures. Thanks to d0k for noting this! llvm-svn: 333601
* [PM/LoopUnswitch] When using the new SimpleLoopUnswitch pass, scheduleChandler Carruth2018-05-301-25/+29
| | | | | | | | | | | | | | | | | | | | | | loop-cleanup passes at the beginning of the loop pass pipeline, and re-enqueue loops after even trivial unswitching. This will allow us to much more consistently avoid simplifying code while doing trivial unswitching. I've also added a test case that specifically shows effective iteration using this technique. I've unconditionally updated the new PM as that is always using the SimpleLoopUnswitch pass, and I've made the pipeline changes for the old PM conditional on using this new unswitch pass. I added a bunch of comments to the loop pass pipeline in the old PM to make it more clear what is going on when reviewing. Hopefully this will unblock doing *partial* unswitching instead of just full unswitching. Differential Revision: https://reviews.llvm.org/D47408 llvm-svn: 333493
* [LoopInstSimplify] Re-implement the core logic of loop-instsimplify toChandler Carruth2018-05-291-104/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | be both simpler and substantially more efficient. Rather than use a hand-rolled iteration technique that isn't quite the same as RPO, use the pre-built RPO loop body traversal utility. Once visiting the loop body in RPO, we can assert that we visit defs before uses reliably. When this is the case, the only need to iterate is when simplifying a def that is used by a PHI node along a back-edge. With this patch, the first pass over the loop body is just a complete simplification of every instruction across the loop body. When we encounter a use of a simplified instruction that stems from a PHI node in the loop body that has already been visited (due to some cyclic CFG, potentially the loop itself, or a nested loop, or unstructured control flow), we recall that specific PHI node for the second iteration. Nothing else needs to be preserved from iteration to iteration. On the second and later iterations, only instructions known to have simplified inputs are considered, each time starting from a set of PHIs that had simplified inputs along the backedges. Dead instructions are collected along the way, but deleted in a batch at the end of each iteration making the iterations themselves substantially simpler. This uses a new batch API for recursively deleting dead instructions. This alsa changes the routine to visit subloops. Because simplification is fundamentally transitive, we may need to visit the entire loop body, including subloops, to handle knock-on simplification. I've added a basic test file that helps demonstrate that all of these changes work. It includes both straight-forward loops with simplifications as well as interesting PHI-structures, CFG-structures, and a nested loop case. Differential Revision: https://reviews.llvm.org/D47407 llvm-svn: 333461
* Revert 333358 as it's failing on some builders.David Green2018-05-274-457/+9
| | | | | | I'm guessing the tests reply on the ARM backend being built. llvm-svn: 333359
* [UnrollAndJam] Add a new Unroll and Jam passDavid Green2018-05-274-9/+457
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a simple implementation of the unroll-and-jam classical loop optimisation. The basic idea is that we take an outer loop of the form: for i.. ForeBlocks(i) for j.. SubLoopBlocks(i, j) AftBlocks(i) Instead of doing normal inner or outer unrolling, we unroll as follows: for i... i+=2 ForeBlocks(i) ForeBlocks(i+1) for j.. SubLoopBlocks(i, j) SubLoopBlocks(i+1, j) AftBlocks(i) AftBlocks(i+1) Remainder So we have unrolled the outer loop, then jammed the two inner loops into one. This can lead to a simpler inner loop if memory accesses can be shared between the now-jammed loops. To do this we have to prove that this is all safe, both for the memory accesses (using dependence analysis) and that ForeBlocks(i+1) can move before AftBlocks(i) and SubLoopBlocks(i, j). Differential Revision: https://reviews.llvm.org/D41953 llvm-svn: 333358
* Revert r333268: [IPSCCP] Use PredicateInfo to propagate facts from...Florian Hahn2018-05-251-112/+8
| | | | | | | | | | | | | | | | | | | | | | Reverting this to see if this is causing the failures of the clang-with-thin-lto-ubuntu bot. [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions. This patch updates IPSCCP to use PredicateInfo to propagate facts to true branches predicated by EQ and to false branches predicated by NE. As a follow up, we should be able to extend it to also propagate additional facts about nonnull. Reviewers: davide, mssimpso, dberlin, efriedma Reviewed By: davide, dberlin Differential Revision: https://reviews.llvm.org/D45330 llvm-svn: 333323
* [IPSCCP] Use PredicateInfo to propagate facts from cmp instructions.Florian Hahn2018-05-251-8/+112
| | | | | | | | | | | | | | | | | This patch updates IPSCCP to use PredicateInfo to propagate facts to true branches predicated by EQ and to false branches predicated by NE. As a follow up, we should be able to extend it to also propagate additional facts about nonnull. Reviewers: davide, mssimpso, dberlin, efriedma Reviewed By: davide, dberlin Differential Revision: https://reviews.llvm.org/D45330 llvm-svn: 333268
* Restore the LoopInstSimplify pass, reverting r327329 that removed it.Chandler Carruth2018-05-253-0/+225
| | | | | | | | | | | | | | | The plan had always been to move towards using this rather than so much in-pass simplification within the loop pipeline, but we never got around to it.... until only a couple months after it was removed due to disuse. =/ This commit is just a pure revert of the removal. I will add tests and do some basic cleanup in follow-up commits. Then I'll wire it into the loop pass pipeline. Differential Revision: https://reviews.llvm.org/D47353 llvm-svn: 333250
* [LICM] Preserve DT and LoopInfo specificallyJun Bum Lim2018-05-241-2/+6
| | | | | | | | | | | | | | | | | | | Summary: In LICM, CFG could be changed in splitPredecessorsOfLoopExit(), which update only DT and LoopInfo. Therefore, we should preserve only DT and LoopInfo specifically, instead of all analyses that depend on the CFG (setPreservesCFG()). This change should fix PR37323. Reviewers: uabelho, davide, dberlin, Ka-Ka Reviewed By: dberlin Subscribers: mzolotukhin, bjope, mcrosier, llvm-commits Differential Revision: https://reviews.llvm.org/D46775 llvm-svn: 333198
* [NaryReassociate] Detect deleted instr with WeakVHKarl-Johan Karlsson2018-05-241-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | Summary: If NaryReassociate succeed it will, when replacing the old instruction with the new instruction, also recursively delete trivially dead instructions from the old instruction. However, if the input to the NaryReassociate pass contain dead code it is not save to recursively delete trivially deadinstructions as it might lead to deleting the newly created instruction. This patch will fix the problem by using WeakVH to detect this rare case, when the newly created instruction is dead, and it will then restart the basic block iteration from the beginning. This fixes pr37539 Reviewers: tra, meheff, grosser, sanjoy Reviewed By: sanjoy Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D47139 llvm-svn: 333155
* StructurizeCFG: Adjust the loop depth for a subregion to order the nodes ↵Changpeng Fang2018-05-231-7/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | correctly Summary: StructurizeCFG::orderNodes basically uses a reverse post-order (RPO) traversal of the region list to get the order. The only problem with it is that sometimes backedges for outer loops will be visited before backedges for inner loops. To solve this problem, a loop depth based approach has been used to make sure all blocks in this loop has been visited before moving on to outer loop. However, we found a problem for a SubRegion which is a loop itself: --> BB1 --> BB2 --> BB3 --> In this case, BB2 is a SubRegion (loop), and thus its loopdepth is different than that of BB1 and BB3. This fact will lead BB2 to be placed in the wrong order. In this work, we treat the SubRegion as a special case and use its exit block to determine the loop and its depth to guard the sorting. Reviewers: arsenm, jlebar Differential Revision: https://reviews.llvm.org/D46912 llvm-svn: 333111
* [LoopUnswitch] Fix SCEV invalidation in unswitchingMax Kazantsev2018-05-231-1/+7
| | | | | | | | | | | | Loop unswitching makes substantial changes to a loop that can also affect cached SCEV info in its outer loops as well, but it only cares to invalidate SCEV cache for the innermost loop in case of full unswitching and does not invalidate anything at all in case of trivial unswitching. As result, we may end up with incorrect data in cache. Differential Revision: https://reviews.llvm.org/D46045 Reviewed By: mzolotukhin llvm-svn: 333072
* [NewGVN] Fix handling of assumesFlorian Hahn2018-05-221-4/+4
| | | | | | | | | | | | | | | | This patch fixes two bugs: * test1: Previously assume(a >= 5) concluded that a == 5. That's only valid for assume(a == 5)... * test2: If operands were swapped, additional users were added to the wrong cmp operand. This resulted in an "unsettled iteration" assertion failure. Patch by Nikita Popov Differential Revision: https://reviews.llvm.org/D46974 llvm-svn: 333007
* [EarlyCSE] Improve EarlyCSE of some absolute value cases.Craig Topper2018-05-211-4/+12
| | | | | | | | | | Change matchSelectPattern to return X and -X for ABS/NABS in a well defined order. Adjust EarlyCSE to account for this. Ensure the SPF result is some kind of min/max and not abs/nabs in one place in InstCombine that made me nervous. Prevously we returned the two operands of the compare part of the abs pattern. The RHS is always going to be a 0i, 1 or -1 constant. This isn't a very meaningful thing to return for any one. There's also some freedom in the abs pattern as to what happens when the value is equal to 0. This freedom led to early cse failing to match when different constants were used in otherwise equivalent operations. By returning the input and its negation in a defined order we can ensure an exact match. This also makes sure both patterns use the exact same subtract instruction for the negation. I believe CSE should evebntually make this happen and properly merge the nsw/nuw flags. But I'm not familiar with CSE and what order it does things in so it seemed like it might be good to really enforce that they were the same. Differential Revision: https://reviews.llvm.org/D47037 llvm-svn: 332865
* [CVP] Require DomTree for new Pass ManagerDavid Green2018-05-211-9/+13
| | | | | | | | | We were previously using a DT in CVP through SimplifyQuery, but not requiring it in the new pass manager. Hence it would crash if DT was not already available. This now gets DT directly and plumbs it through to where it is used (instead of using it through SQ). llvm-svn: 332836
* Fix up a few grammar issues.Eric Christopher2018-05-211-1/+1
| | | | llvm-svn: 332835
* [IRCE] Fix miscompile with range checks against negative valuesMax Kazantsev2018-05-191-2/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the patch rL329547, we have lifted the over-restrictive limitation on collected range checks, allowing to work with range checks with the end of their range not being provably non-negative. However it appeared that the non-negativity of this value was assumed in the utility function `ClampedSubtract`. In particular, its reasoning is based on the fact that `0 <= SINT_MAX - X`, which is not true if `X` is negative. The function `ClampedSubtract` is only called twice, once with `X = 0` (which is OK) and the second time with `X = IRC.getEnd()`, where we may now see the problem if the end is actually a negative value. In this case, we may sometimes miscompile. This patch is the conservative fix of the miscompile problem. Rather than rejecting non-provably non-negative `getEnd()` values, we will check it for non-negativity in runtime. For this, we use function `smax(smin(X, 0), -1) + 1` that is equal to `1` if `X` is non-negative and is equal to 0 if `X` is negative. If we multiply `Begin, End` of safe iteration space by this function calculated for `X = IRC.getEnd()`, we will get the original `[Begin, End)` if `IRC.getEnd()` was non-negative (and, thus, `ClampedSubtract` worked correctly) and the empty range `[0, 0)` in case if ` IRC.getEnd()` was negative. So we in fact prohibit execution of the main loop if at least one of range checks was made against a negative value (and we figured it out in runtime). It is still better than what we have before (non-negativity had to be proved in compile time) and prevents us from miscompile, however it is sometiles too restrictive for unsigned range checks against a negative value (which in fact can be eliminated). Once we re-implement `ClampedSubtract` in a way that it handles negative `X` correctly, this limitation can be lifted, too. Differential Revision: https://reviews.llvm.org/D46860 Reviewed By: samparker llvm-svn: 332809
* [MergeICmps] Don't crash when memcmp is not availableBenjamin Kramer2018-05-191-0/+4
| | | | | | Fixes clang crashing with -fno-builtin, PR37527. llvm-svn: 332808
* [SROA] Handle PHI with multiple duplicate predecessorsBjorn Pettersson2018-05-171-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: The verifier accepts PHI nodes with multiple entries for the same basic block, as long as the value is the same. As seen in PR37203, SROA did not handle such PHI nodes properly when speculating loads over the PHI, since it inserted multiple loads in the predecessor block and changed the PHI into having multiple entries for the same basic block, but with different values. This patch teaches SROA to reuse the same speculated load for each PHI duplicate entry in such situations. Resolves: https://bugs.llvm.org/show_bug.cgi?id=37203 Reviewers: uabelho, chandlerc, hfinkel, bkramer, efriedma Reviewed By: efriedma Subscribers: dberlin, efriedma, llvm-commits Differential Revision: https://reviews.llvm.org/D46426 llvm-svn: 332577
* [SROA] pr37267: fix assertion failure in integer wideningHiroshi Inoue2018-05-171-0/+8
| | | | | | | | | | The current integer widening does not support rewriting partial split slices in rewriteIntegerStore (and rewriteIntegerLoad). This patch adds explicit checks for this case in isIntegerWideningViableForSlice. Before r322533, splitting is allowed only for the whole-alloca slice and hence the above case is implicitly rejected by another check `if (DL.getTypeStoreSize(ValueTy) > Size)` because whole-alloca slice is larger than the partition. Differential Revision: https://reviews.llvm.org/D46750 llvm-svn: 332575
* [STLExtras] Add size() for ranges, and remove distance()Vedant Kumar2018-05-162-2/+3
| | | | | | | | | | r332057 introduced distance() for ranges. Based on post-commit feedback, this renames distance() to size(). The new size() is also only enabled when the operation is O(1). Differential Revision: https://reviews.llvm.org/D46976 llvm-svn: 332551
* Fix LSR compile time hang.Evgeny Stupachenko2018-05-161-1/+6
| | | | | | | | | | | | | Summary: Limit number of reassociations in GenerateReassociationsImpl. Reviewers: qcolombet, mkazantsev Differential Revision: https://reviews.llvm.org/D46039 From: Evgeny Stupachenko <evstupac@gmail.com> <evgeny.v.stupachenko@intel.com> llvm-svn: 332426
* StructurizeCFG: fix inverting conditionsMarek Olsak2018-05-151-2/+3
| | | | | | | | | | | | | | | | Author: Samuel Pitoiset Without this patch, it appears to me that we are selecting the wrong operand when inverting conditions. In the attached test, it will select %tmp3 instead of %tmp4. To fix it, just use 'A' as everywhere. This fixes a regression introduced by "[PatternMatch] define m_Not using m_Xor and cst_pred_ty" https://reviews.llvm.org/D46351 llvm-svn: 332403
* [NFC] Add const to method signatureMax Kazantsev2018-05-151-1/+1
| | | | llvm-svn: 332317
* Rename DEBUG macro to LLVM_DEBUG.Nicola Zaghen2018-05-1446-1175/+1271
| | | | | | | | | | | | | | | | The DEBUG() macro is very generic so it might clash with other projects. The renaming was done as follows: - git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g' - git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM - Manual change to APInt - Manually chage DOCS as regex doesn't match it. In the transition period the DEBUG() macro is still present and aliased to the LLVM_DEBUG() one. Differential Revision: https://reviews.llvm.org/D43624 llvm-svn: 332240
* Reapply "[PR16756] Use SSAUpdaterBulk in JumpThreading."Michael Zolotukhin2018-05-121-26/+30
| | | | | | | | | Stage3/stage4 bootstrap miscompares should be fixed by a non-determinism fix in IDF (r332167). This reverts commit r330446. llvm-svn: 332168
* [Split GEP] handle trunc() in separate-const-offset-from-gep pass.Artem Belevich2018-05-111-2/+7
| | | | | | | | | | | Let separate-const-offset-from-gep pass handle trunc() when it calculates constant offset relative to base. The pass itself may insert trunc() instructions when it canonicalises array indices to pointer-size integers and needs to handle trunc() in order to evaluate the offset. Differential Revision: https://reviews.llvm.org/D46732 llvm-svn: 332142
* [Reassociate] Prevent infinite loops when processing PHIs.Davide Italiano2018-05-111-1/+8
| | | | | | | | | | | | | | | | | | | | | | Phi nodes can reside in live blocks but one of their incoming arguments can come from a dead block. Dead blocks and reassociate don't play nice together. In fact, reassociate performs an RPO as a first step to avoid processing dead blocks. The reason why Reassociate might not fixpoint when examining dead blocks is that the following: %xor0 = xor i16 %xor1, undef %xor1 = xor i16 %xor0, undef is perfectly valid LLVM IR (if it appears in a dead block), so the worklist algorithm keeps pushing the two instructions for reexamination. Note that this is not Reassociate fault, at least not entirely. It's llvm that has a weird definition of dominance. Fixes PR37390. llvm-svn: 332100
* [STLExtras] Add distance() for ranges, pred_size(), and succ_size()Vedant Kumar2018-05-104-9/+7
| | | | | | | | | | | This commit adds a wrapper for std::distance() which works with ranges. As it would be a common case to write `distance(predecessors(BB))`, this also introduces `pred_size()` and `succ_size()` helpers to make that easier to write. Differential Revision: https://reviews.llvm.org/D46668 llvm-svn: 332057
* [PM/LoopUnswitch] Avoid pointlessly creating an exit block set.Chandler Carruth2018-05-101-19/+4
| | | | | | | This code can just test whether blocks are *in* the loop, which we already have a dedicated set tracking in the loop itself. llvm-svn: 332004
* [DSE] Teach the pass about partial overwrite of atomic memory intrinsicsDaniel Neilson2018-05-101-9/+16
| | | | | | | | | | | | | | | | | | | Summary: This change teaches DSE that the atomic memory intrinsics can be overwriten partially in the same way as the non-atomic forms. Specifically, that the atomic memcpy & memset can be shortened at the end and that the atomic memset can be shortened at the beginning, if they partially overwritten by later stores. Reviewers: mkazantsev, skatkov, apilipenko, efriedma, rsmith, spatel, filcab, sanjoy Reviewed By: efriedma Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D45584 llvm-svn: 331991
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