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* [IR] redefine 'UnsafeAlgebra' / 'reassoc' fast-math-flags and add 'trans' ↵Sanjay Patel2017-11-061-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fast-math-flag As discussed on llvm-dev: http://lists.llvm.org/pipermail/llvm-dev/2016-November/107104.html and again more recently: http://lists.llvm.org/pipermail/llvm-dev/2017-October/118118.html ...this is a step in cleaning up our fast-math-flags implementation in IR to better match the capabilities of both clang's user-visible flags and the backend's flags for SDNode. As proposed in the above threads, we're replacing the 'UnsafeAlgebra' bit (which had the 'umbrella' meaning that all flags are set) with a new bit that only applies to algebraic reassociation - 'AllowReassoc'. We're also adding a bit to allow approximations for library functions called 'ApproxFunc' (this was initially proposed as 'libm' or similar). ...and we're out of bits. 7 bits ought to be enough for anyone, right? :) FWIW, I did look at getting this out of SubclassOptionalData via SubclassData (spacious 16-bits), but that's apparently already used for other purposes. Also, I don't think we can just add a field to FPMathOperator because Operator is not intended to be instantiated. We'll defer movement of FMF to another day. We keep the 'fast' keyword. I thought about removing that, but seeing IR like this: %f.fast = fadd reassoc nnan ninf nsz arcp contract afn float %op1, %op2 ...made me think we want to keep the shortcut synonym. Finally, this change is binary incompatible with existing IR as seen in the compatibility tests. This statement: "Newer releases can ignore features from older releases, but they cannot miscompile them. For example, if nsw is ever replaced with something else, dropping it would be a valid way to upgrade the IR." ( http://llvm.org/docs/DeveloperPolicy.html#ir-backwards-compatibility ) ...provides the flexibility we want to make this change without requiring a new IR version. Ie, we're not loosening the FP strictness of existing IR. At worst, we will fail to optimize some previously 'fast' code because it's no longer recognized as 'fast'. This should get fixed as we audit/squash all of the uses of 'isFast()'. Note: an inter-dependent clang commit to use the new API name should closely follow commit. Differential Revision: https://reviews.llvm.org/D39304 llvm-svn: 317488
* Fix a -Wparentheses warning. NFC.Hans Wennborg2017-10-041-1/+1
| | | | llvm-svn: 314936
* [LoopDeletion] Move deleteDeadLoop to to LoopUtils. NFCMarcello Maggioni2017-10-041-0/+122
| | | | llvm-svn: 314934
* Refactor collectChildrenInLoop to LoopUtils [NFC]Alina Sbirlea2017-09-151-0/+21
| | | | | | | | | | | | Summary: Move to LoopUtils method that collects all children of a node inside a loop. Reviewers: majnemer, sanjoy Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D37870 llvm-svn: 313322
* [LV] Minor savings to Sink casts to unravel first order recurrenceAyal Zaks2017-08-151-1/+2
| | | | | | | | | Two minor savings: avoid copying the SinkAfter map and avoid moving a cast if it is not needed. Differential Revision: https://reviews.llvm.org/D36408 llvm-svn: 310910
* [LoopUtils] Add an extra parameter OpValue to propagateIRFlags function,Dinar Temirbulatov2017-07-191-11/+16
| | | | | | | | | If OpValue is non-null, we only consider operations similar to OpValue when intersecting. Differential Revision: https://reviews.llvm.org/D35292 llvm-svn: 308428
* [LV] Sink casts to unravel first order recurrenceAyal Zaks2017-06-301-3/+16
| | | | | | | | | | | Check if a single cast is preventing handling a first-order-recurrence Phi, because the scheduling constraints it imposes on the first-order-recurrence shuffle are infeasible; but they can be made feasible by moving the cast downwards. Record such casts and move them when vectorizing the loop. Differential Revision: https://reviews.llvm.org/D33058 llvm-svn: 306884
* [LoopSimplify] Re-instate r306081 with a bug fix w.r.t. indirectbr.Chandler Carruth2017-06-251-0/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This was reverted in r306252, but I already had the bug fixed and was just trying to form a test case. The original commit factored the logic for forming dedicated exits inside of LoopSimplify into a helper that could be used elsewhere and with an approach that required fewer intermediate data structures. See that commit for full details including the change to the statistic, etc. The code looked fine to me and my reviewers, but in fact didn't handle indirectbr correctly -- it left the 'InLoopPredecessors' vector dirty. If you have code that looks *just* right, you can end up leaking these predecessors into a subsequent rewrite, and crash deep down when trying to update PHI nodes for predecessors that don't exist. I've added an assert that makes the bug much more obvious, and then changed the code to reliably clear the vector so we don't get this bug again in some other form as the code changes. I've also added a test case that *does* manage to catch this while also giving some nice positive coverage in the face of indirectbr. The real code that found this came out of what I think is CPython's interpreter loop, but any code with really "creative" interpreter loops mixing indirectbr and other exit paths could manage to tickle the bug. I was hard to reduce the original test case because in addition to having a particular pattern of IR, the whole thing depends on the order of the predecessors which is in turn depends on use list order. The test case added here was designed so that in multiple different predecessor orderings it should always end up going down the same path and tripping the same bug. I hope. At least, it tripped it for me without manipulating the use list order which is better than anything bugpoint could do... llvm-svn: 306257
* Revert "[LoopSimplify] Factor the logic to form dedicated exits into a utility."Daniel Jasper2017-06-251-62/+0
| | | | | | | This leads to a segfault. Chandler already has a test case and should be able to recommit with a fix soon. llvm-svn: 306252
* [Analysis][Transforms] Use commutable matchers instead of m_CombineOr in a ↵Craig Topper2017-06-241-2/+1
| | | | | | few places. NFC llvm-svn: 306204
* [LoopSimplify] Factor the logic to form dedicated exits into a utility.Chandler Carruth2017-06-231-0/+62
| | | | | | | | | | | | | | | | | | | | | | I want to use the same logic as LoopSimplify to form dedicated exits in another pass (SimpleLoopUnswitch) so I wanted to factor it out here. I also noticed that there is a pretty significantly more efficient way to implement this than the way the code in LoopSimplify worked. We don't need to actually retain the set of unique exit blocks, we can just rewrite them as we find them and use only a set to deduplicate. This did require changing one part of LoopSimplify to not re-use the unique set of exits, but it only used it to check that there was a single unique exit. That part of the code is about to walk the exiting blocks anyways, so it seemed better to rewrite it to use those exiting blocks to compute this property on-demand. I also had to ditch a statistic, but it doesn't seem terribly valuable. Differential Revision: https://reviews.llvm.org/D34049 llvm-svn: 306081
* Sort the remaining #include lines in include/... and lib/....Chandler Carruth2017-06-061-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | I did this a long time ago with a janky python script, but now clang-format has built-in support for this. I fed clang-format every line with a #include and let it re-sort things according to the precise LLVM rules for include ordering baked into clang-format these days. I've reverted a number of files where the results of sorting includes isn't healthy. Either places where we have legacy code relying on particular include ordering (where possible, I'll fix these separately) or where we have particular formatting around #include lines that I didn't want to disturb in this patch. This patch is *entirely* mechanical. If you get merge conflicts or anything, just ignore the changes in this patch and run clang-format over your #include lines in the files. Sorry for any noise here, but it is important to keep these things stable. I was seeing an increasing number of patches with irrelevant re-ordering of #include lines because clang-format was used. This patch at least isolates that churn, makes it easy to skip when resolving conflicts, and gets us to a clean baseline (again). llvm-svn: 304787
* Add a late IR expansion pass for the experimental reduction intrinsics.Amara Emerson2017-05-101-5/+4
| | | | | | | | | This pass uses a new target hook to decide whether or not to expand a particular intrinsic to the shuffevector sequence. Differential Revision: https://reviews.llvm.org/D32245 llvm-svn: 302631
* Introduce experimental generic intrinsics for horizontal vector reductions.Amara Emerson2017-05-091-0/+202
| | | | | | | | | | | | | | - This change allows targets to opt-in to using them instead of the log2 shufflevector algorithm. - The SLP and Loop vectorizers have the common code to do shuffle reductions factored out into LoopUtils, and now have a unified interface for generating reductions regardless of the preference of the target. LoopUtils now uses TTI to determine what kind of reductions the target wants to handle. - For CodeGen, basic legalization support is added. Differential Revision: https://reviews.llvm.org/D30086 llvm-svn: 302514
* Revert "Compute safety information in a much finer granularity."Evgeniy Stepanov2017-04-241-8/+16
| | | | | | Use-after-free in llvm::isGuaranteedToExecute. llvm-svn: 301214
* Compute safety information in a much finer granularity.Xin Tong2017-04-241-16/+8
| | | | | | | | | | | | | | | | | | | Summary: Instead of keeping a variable indicating whether there are early exits in the loop. We keep all the early exits. This improves LICM's ability to move instructions out of the loop based on is-guaranteed-to-execute. I am going to update compilation time as well soon. Reviewers: hfinkel, sanjoy, efriedma, mkuper Reviewed By: hfinkel Subscribers: llvm-commits, mzolotukhin Differential Revision: https://reviews.llvm.org/D32433 llvm-svn: 301196
* [LV] Fix the vector code generation for first order recurrenceAnna Thomas2017-04-131-12/+3
| | | | | | | | | | | | | | | | | | | Summary: In first order recurrences where phi's are used outside the loop, we should generate an additional vector.extract of the second last element from the vectorized phi update. This is because we require the phi itself (which is the value at the second last iteration of the vector loop) and not the phi's update within the loop. Also fix the code gen when we just unroll, but don't vectorize. Fixes PR32396. Reviewers: mssimpso, mkuper, anemet Subscribers: llvm-commits, mzolotukhin Differential Revision: https://reviews.llvm.org/D31979 llvm-svn: 300238
* [LV] Avoid vectorizing first order recurrence when phi uses are outside loopAnna Thomas2017-04-111-4/+14
| | | | | | | | | | | | | | | | | | In the vectorization of first order recurrence, we vectorize such that the last element in the vector will be the one extracted to pass into the scalar remainder loop. However, this is not true when there is a phi (other than the primary induction variable) is used outside the loop. In such a case, we need the value from the second last iteration (i.e. the phi value), not the last iteration (which would be the phi update). I've added a test case for this. Also see PR32396. A follow up patch would generate the correct code gen for such cases, and turn this vectorization on. Differential Revision: https://reviews.llvm.org/D31910 Reviewers: mssimpso llvm-svn: 299985
* Fix up a comment. NFC.Michael Kuperstein2017-01-181-1/+0
| | | | llvm-svn: 292425
* [LV] Allow reductions that have several uses outside the loopMichael Kuperstein2017-01-181-5/+12
| | | | | | | | | | | We currently check whether a reduction has a single outside user. We don't really need to require that - we just need to make sure a single value is used externally. The number of external users of that value shouldn't actually matter. Differential Revision: https://reviews.llvm.org/D28830 llvm-svn: 292424
* [LV] Don't panic when encountering the IV of an outer loop.Michael Kuperstein2017-01-101-2/+7
| | | | | | | | | | | | | | | | | | Bail out instead of asserting when we encounter this situation, which can actually happen. The reason the test uses the new PM is that the "bad" phi, incidentally, gets cleaned up by LoopSimplify. But LICM can create this kind of phi and preserve loop simplify form, so the cleanup has no chance to run. This fixes PR31190. We may want to solve this in a less conservative manner, since this phi is actually uniform within the inner loop (or we may want LICM to output a cleaner promotion to begin with). Differential Revision: https://reviews.llvm.org/D28490 llvm-svn: 291589
* Remove stale comment. NFC.Michael Kuperstein2016-12-031-3/+0
| | | | llvm-svn: 288572
* [LoopUnroll] Implement profile-based loop peelingMichael Kuperstein2016-11-301-7/+7
| | | | | | | | | | | | | | | | | | | This implements PGO-driven loop peeling. The basic idea is that when the average dynamic trip-count of a loop is known, based on PGO, to be low, we can expect a performance win by peeling off the first several iterations of that loop. Unlike unrolling based on a known trip count, or a trip count multiple, this doesn't save us the conditional check and branch on each iteration. However, it does allow us to simplify the straight-line code we get (constant-folding, etc.). This is important given that we know that we will usually only hit this code, and not the actual loop. This is currently disabled by default. Differential Revision: https://reviews.llvm.org/D25963 llvm-svn: 288274
* Use profile info to adjust loop unroll threshold.Dehao Chen2016-11-171-0/+36
| | | | | | | | | | | | | | Summary: For flat loop, even if it is hot, it is not a good idea to unroll in runtime, thus we set a lower partial unroll threshold. For hot loop, we set a higher unroll threshold and allows expensive tripcount computation to allow more aggressive unrolling. Reviewers: davidxl, mzolotukhin Subscribers: sanjoy, mehdi_amini, llvm-commits Differential Revision: https://reviews.llvm.org/D26527 llvm-svn: 287186
* [LCSSA] Perform LCSSA verification only for the current loop nest.Igor Laevsky2016-10-281-0/+5
| | | | | | | | | Now LPPassManager will run LCSSA verification only for the top-level loop which was processed on the current iteration. Differential Revision: https://reviews.llvm.org/D25873 llvm-svn: 285394
* [LoopUnroll] Use OptimizationRemarkEmitter directly not via the analysis passAdam Nemet2016-08-261-4/+0
| | | | | | | | | | | | | | | | We can't mark ORE (a function pass) preserved as required by the loop passes because that is how we ensure that the required passes like LazyBFI are all available any time ORE is used. See the new comments in the patch. Instead we use it directly just like the inliner does in D22694. As expected there is some additional overhead after removing the caching provided by analysis passes. The worst case, I measured was LNT/CINT2006_ref/401.bzip2 which regresses by 12%. As before, this only affects -Rpass-with-hotness and not default compilation. llvm-svn: 279829
* Use the range variant of find/find_if instead of unpacking begin/endDavid Majnemer2016-08-121-1/+1
| | | | | | | | | If the result of the find is only used to compare against end(), just use is_contained instead. No functionality change is intended. llvm-svn: 278469
* Use range algorithms instead of unpacking begin/endDavid Majnemer2016-08-111-1/+1
| | | | | | No functionality change is intended. llvm-svn: 278417
* [LoopUnroll] Include hotness of region in opt remarkAdam Nemet2016-07-291-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | LoopUnroll is a loop pass, so the analysis of OptimizationRemarkEmitter is added to the common function analysis passes that loop passes depend on. The BFI and indirectly BPI used in this pass is computed lazily so no overhead should be observed unless -pass-remarks-with-hotness is used. This is how the patch affects the O3 pipeline: Dominator Tree Construction Natural Loop Information Canonicalize natural loops Loop-Closed SSA Form Pass Basic Alias Analysis (stateless AA impl) Function Alias Analysis Results Scalar Evolution Analysis + Lazy Branch Probability Analysis + Lazy Block Frequency Analysis + Optimization Remark Emitter Loop Pass Manager Rotate Loops Loop Invariant Code Motion Unswitch loops Simplify the CFG Dominator Tree Construction Basic Alias Analysis (stateless AA impl) Function Alias Analysis Results Combine redundant instructions Natural Loop Information Canonicalize natural loops Loop-Closed SSA Form Pass Scalar Evolution Analysis + Lazy Branch Probability Analysis + Lazy Block Frequency Analysis + Optimization Remark Emitter Loop Pass Manager Induction Variable Simplification Recognize loop idioms Delete dead loops Unroll loops ... llvm-svn: 277203
* [LoopUtils] Sort headersAdam Nemet2016-07-261-3/+4
| | | | llvm-svn: 276776
* [Loop Vectorizer] Handling loops FP induction variables.Elena Demikhovsky2016-07-241-12/+106
| | | | | | | | | | | | | | | | Allowed loop vectorization with secondary FP IVs. Like this: float *A; float x = init; for (int i=0; i < N; ++i) { A[i] = x; x -= fp_inc; } The auto-vectorization is possible when the induction binary operator is "fast" or the function has "unsafe" attribute. Differential Revision: https://reviews.llvm.org/D21330 llvm-svn: 276554
* [LICM] Make isGuaranteedToExecute more accurate.Eli Friedman2016-06-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: Make isGuaranteedToExecute use the isGuaranteedToTransferExecutionToSuccessor helper, and make that helper a bit more accurate. There's a potential performance impact here from assuming that arbitrary calls might not return. This probably has little impact on loads and stores to a pointer because most things alias analysis can reason about are dereferenceable anyway. The other impacts, like less aggressive hoisting of sdiv by a variable and less aggressive hoisting around volatile memory operations, are unlikely to matter for real code. This also impacts SCEV, which uses the same helper. It's a minor improvement there because we can tell that, for example, memcpy always returns normally. Strictly speaking, it's also introducing a bug, but it's not any worse than everywhere else we assume readonly functions terminate. Fixes http://llvm.org/PR27857. Reviewers: hfinkel, reames, chandlerc, sanjoy Subscribers: broune, llvm-commits Differential Revision: http://reviews.llvm.org/D21167 llvm-svn: 272489
* Move isGuaranteedToExecute out of LICM.Evgeniy Stepanov2016-06-101-0/+39
| | | | | | | Also rename LICMSafetyInfo to LoopSafetyInfo. Both will be used in LoopUnswitch in a separate change. llvm-svn: 272420
* [PM] Port LCSSA to the new PM.Easwaran Raman2016-06-091-1/+1
| | | | | | Differential Revision: http://reviews.llvm.org/D21090 llvm-svn: 272294
* Vectorizer: track non-fast FP instructions through phis when finding reductions.Tim Northover2016-05-271-1/+1
| | | | | | | | When we traced through a phi node looking for floating-point reductions, we forgot whether we'd ever seen an instruction without fast-math flags (that would block vectorization). This propagates it through to the end. llvm-svn: 271015
* [LoopVectorize] Handling induction variable with non-constant step.Elena Demikhovsky2016-05-101-27/+65
| | | | | | | | | | | | | | | | | | | | | | | Allow vectorization when the step is a loop-invariant variable. This is the loop example that is getting vectorized after the patch: int int_inc; int bar(int init, int *restrict A, int N) { int x = init; for (int i=0;i<N;i++){ A[i] = x; x += int_inc; } return x; } "x" is an induction variable with *loop-invariant* step. But it is not a primary induction. Primary induction variable with non-constant step is not handled yet. Differential Revision: http://reviews.llvm.org/D19258 llvm-svn: 269023
* [LV] Identify more induction PHIs by coercing expressions to AddRecExprsSilviu Baranga2016-05-051-3/+30
| | | | | | | | | | | | | | | | | | Summary: Some PHIs can have expressions that are not AddRecExprs due to the presence of sext/zext instructions. In order to prevent the Loop Vectorizer from bailing out when encountering these PHIs, we now coerce the SCEV expressions to AddRecExprs using SCEV predicates (when possible). We only do this when the alternative would be to not vectorize. Reviewers: mzolotukhin, anemet Subscribers: mssimpso, sanjoy, mzolotukhin, llvm-commits Differential Revision: http://reviews.llvm.org/D17153 llvm-svn: 268633
* [LoopUtils] Extend findStringMetadataForLoop to return the value for metadataAdam Nemet2016-04-221-7/+18
| | | | | | | | | | | | | | | | E.g. for: !1 = {"llvm.distribute", i32 1} it now returns the MDOperand for 1. I will use this in LoopDistribution to check the value of the metadata. Note that the change is backward-compatible with its current use in LoopVersioningLICM. An Optional implicitly converts to a bool depending whether it contains a value or not. llvm-svn: 267190
* [LoopUtils] Fix typo in commentAdam Nemet2016-04-211-1/+1
| | | | llvm-svn: 267016
* [LoopUtils] Add asserts to findStringMetadataForLoop. NFCAdam Nemet2016-04-211-0/+5
| | | | | | | These ensure that operand array has at least one element and it is the self-reference. llvm-svn: 267015
* [LoopUtils] Move def of findStringMetadataForLoop to LoopUtils.cpp. NFCAdam Nemet2016-04-211-0/+22
| | | | | | | The decl is in LoopUtils.h. I think that this was added to LoopVersioningLICM.cpp by mistake. llvm-svn: 267014
* [LoopUtils, LV] Fix PR27246 (first-order recurrences)Matthew Simpson2016-04-111-1/+1
| | | | | | | | | | | | This patch ensures that when we detect first-order recurrences, we reject a phi node if its previous value is also a phi node. During vectorization the initial and previous values of the recurrence are shuffled together to create the value for the current iteration. However, phi nodes are not widened like other instructions. This fixes PR27246. Differential Revision: http://reviews.llvm.org/D18971 llvm-svn: 265983
* Remove HasFnAttribute guards to getFnAttribute callsNirav Dave2016-03-301-4/+2
| | | | | | | | | | | | These checks are redundant and can be removed Reviewers: hans Subscribers: llvm-commits, mzolotukhin Differential Revision: http://reviews.llvm.org/D18564 llvm-svn: 264872
* [LoopUtils, LV] Fix PR26734Matthew Simpson2016-03-031-1/+1
| | | | | | | | The vectorization of first-order recurrences (r261346) caused PR26734. When detecting these recurrences, we need to ensure that the previous value is actually defined inside the loop. This patch includes the fix and test case. llvm-svn: 262624
* [LV] Vectorize first-order recurrencesMatthew Simpson2016-02-191-0/+37
| | | | | | | | | | | | | | | | | | This patch enables the vectorization of first-order recurrences. A first-order recurrence is a non-reduction recurrence relation in which the value of the recurrence in the current loop iteration equals a value defined in the previous iteration. The load PRE of the GVN pass often creates these recurrences by hoisting loads from within loops. In this patch, we add a new recurrence kind for first-order phi nodes and attempt to vectorize them if possible. Vectorization is performed by shuffling the values for the current and previous iterations. The vectorization cost estimate is updated to account for the added shuffle instruction. Contributed-by: Matthew Simpson and Chad Rosier <mcrosier@codeaurora.org> Differential Revision: http://reviews.llvm.org/D16197 llvm-svn: 261346
* [LPM] Factor all of the loop analysis usage updates into a common helperChandler Carruth2016-02-191-0/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | routine. We were getting this wrong in small ways and generally being very inconsistent about it across loop passes. Instead, let's have a common place where we do this. One minor downside is that this will require some analyses like SCEV in more places than they are strictly needed. However, this seems benign as these analyses are complete no-ops, and without this consistency we can in many cases end up with the legacy pass manager scheduling deciding to split up a loop pass pipeline in order to run the function analysis half-way through. It is very, very annoying to fix these without just being very pedantic across the board. The only loop passes I've not updated here are ones that use AU.setPreservesAll() such as IVUsers (an analysis) and the pass printer. They seemed less relevant. With this patch, almost all of the problems in PR24804 around loop pass pipelines are fixed. The one remaining issue is that we run simplify-cfg and instcombine in the middle of the loop pass pipeline. We've recently added some loop variants of these passes that would seem substantially cleaner to use, but this at least gets us much closer to the previous state. Notably, the seven loop pass managers is down to three. I've not updated the loop passes using LoopAccessAnalysis because that analysis hasn't been fully wired into LoopSimplify/LCSSA, and it isn't clear that those transforms want to support those forms anyways. They all run late anyways, so this is harmless. Similarly, LSR is left alone because it already carefully manages its forms and doesn't need to get fused into a single loop pass manager with a bunch of other loop passes. LoopReroll didn't use loop simplified form previously, and I've updated the test case to match the trivially different output. Finally, I've also factored all the pass initialization for the passes that use this technique as well, so that should be done regularly and reliably. Thanks to James for the help reviewing and thinking about this stuff, and Ben for help thinking about it as well! Differential Revision: http://reviews.llvm.org/D17435 llvm-svn: 261316
* function names start with a lower case letter ; NFCSanjay Patel2016-01-121-1/+1
| | | | llvm-svn: 257496
* Revert r255115 until we figure out how to fix the bot failures.Silviu Baranga2015-12-091-43/+0
| | | | llvm-svn: 255117
* [LV][LAA] Add a layer over SCEV to apply run-time checked knowledge on SCEV ↵Silviu Baranga2015-12-091-0/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* [Utils] Put includes in correct order. NFC.Weiming Zhao2015-11-241-3/+3
| | | | | | | | | | | | | | | | | | | Summary: Followed the guidelines in: http://llvm.org/docs/CodingStandards.html#include-style However, I noticed that uppercase named headers come before lowercase ones throughout the codebase. So kept them as is. Patch by Mandeep Singh Grang <mgrang@codeaurora.org> Reviewers: majnemer, davide, jmolloy, atrick Subscribers: sanjoy Differential Revision: http://reviews.llvm.org/D14939 llvm-svn: 254005
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