8929 Commits

Author SHA1 Message Date
Teresa Johnson
9c2eb220ed [ThinLTO] Summarize vcall_visibility metadata
Summary:
Second patch in series to support Safe Whole Program Devirtualization
Enablement, see RFC here:
http://lists.llvm.org/pipermail/llvm-dev/2019-December/137543.html

Summarize vcall_visibility metadata in ThinLTO global variable summary.

Depends on D71907.

Reviewers: pcc, evgeny777, steven_wu

Subscribers: mehdi_amini, Prazek, inglorion, hiraditya, dexonsmith, arphaman, ostannard, llvm-commits, cfe-commits, davidxl

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71911
2020-01-23 13:19:56 -08:00
Daniil Suchkov
6fc9e60149 NFC. Remove obsolete SimpleAnalysis infrastructure
Apparently cache of AliasSetTrackers held by LICM was the only user of
SimpleAnalysis infrastructure. Now, given that we no longer have that
cache, this infrastructure is obsolete and, taking into account its
nature, we don't want any new solutions to be based on it.

Reviewers: asbirlea, fhahn, efriedma, reames

Reviewed-By: asbirlea

Differential Revision: https://reviews.llvm.org/D73085
2020-01-23 13:58:30 +07:00
Nikita Popov
efba7ed05e [PatternMatch] Make m_c_ICmp swap the predicate (PR42801)
This addresses https://bugs.llvm.org/show_bug.cgi?id=42801.
The m_c_ICmp() matcher is changed to provide the swapped predicate
if the operands are swapped.

Existing uses of m_c_ICmp() fall in one of two categories: Working
on equality predicates only, where swapping is irrelevant.
Or performing a manual swap, in which case this patch removes it.

The only exception is the foldICmpWithLowBitMaskedVal() fold, which
does not swap the predicate, and instead reasons about whether
a swap occurred or not for each predicate. Getting the swapped
predicate allows us to merge the logic for pairs of predicates,
instead of duplicating it.

Differential Revision: https://reviews.llvm.org/D72976
2020-01-22 22:56:26 +01:00
Nico Weber
cd470717d1 Revert "[DA][TTI][AMDGPU] Add option to select GPUDA with TTI"
This reverts commit a90a6502ab35d3c15c7d56772e409c5632ce6cfb.
Broke tests on Windows: http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/13808
2020-01-22 12:56:19 -05:00
Sander de Smalen
4cf16efe49 [AArch64][SVE] Add patterns for unpredicated load/store to frame-indices.
This patch also fixes up a number of cases in DAGCombine and
SelectionDAGBuilder where the size of a scalable vector is used in a
fixed-width context (thus triggering an assertion failure).

Reviewers: efriedma, c-rhodes, rovka, cameron.mcinally

Reviewed By: efriedma

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71215
2020-01-22 14:32:27 +00:00
Sander de Smalen
67d4c9924c Add support for (expressing) vscale.
In LLVM IR, vscale can be represented with an intrinsic. For some targets,
this is equivalent to the constexpr:

  getelementptr <vscale x 1 x i8>, <vscale x 1 x i8>* null, i32 1

This can be used to propagate the value in CodeGenPrepare.

In ISel we add a node that can be legalized to one or more
instructions to materialize the runtime vector length.

This patch also adds SVE CodeGen support for VSCALE, which maps this
node to RDVL instructions (for scaled multiples of 16bytes) or CNT[HSD]
instructions (scaled multiples of 2, 4, or 8 bytes, respectively).

Reviewers: rengolin, cameron.mcinally, hfinkel, sebpop, SjoerdMeijer, efriedma, lattner

Reviewed by: efriedma

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68203
2020-01-22 10:09:27 +00:00
Austin Kerbow
a90a6502ab [DA][TTI][AMDGPU] Add option to select GPUDA with TTI
Summary: Enable the new diveregence analysis by default for AMDGPU.

Reviewers: rampitec, nhaehnle, arsenm

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73049
2020-01-21 21:13:20 -08:00
Mircea Trofin
2e42cc7a50 [NFC] small rename of private member in InlineCost.cpp
Summary:
Follow-up from https://reviews.llvm.org/D71733. Also moved an
initialization to the base class, where it belonged in the first place.

Reviewers: eraman, davidxl

Reviewed By: davidxl

Subscribers: hiraditya, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72949
2020-01-20 13:03:15 -08:00
Sanjay Patel
da9c93f330 [InstSimplify] fold select of vector constants that include undef elements
As mentioned in D72643, we'd like to be able to assert that any select
of equivalent constants has been removed before we're deep into InstCombine.

But there's a loophole in that assertion for vectors with undef elements
that don't match exactly.

This patch should close that gap. If we have undefs, we can't safely
propagate those unless both constants elements for that lane are undef.

Differential Revision: https://reviews.llvm.org/D72958
2020-01-20 08:48:32 -05:00
dfukalov
de34b54edc [SCEV] Swap guards estimation sequence. NFC
Summary:
Loop unroll spends a lot of time in SCEVs processing in case when a function
contains hundreds of simple 'for' loops with a quite complex arrays indexes like

  for (int i = 0; i < 8; ++i) {
    for (int j = 0; j < 32; ++j) {
      C[j*8+i] = B[j*32+i+128] + A[i*64+128];
    }
  }
  for (int i = 0; i < 8; ++i) {
    for (int j = 0; j < 8; ++j) {
      for (int k = 0; k < 32; ++k) {
        D[k*64+i*8+j] = D[k*64+i*8+j] + E[i+16] * C[k*8+j+256];
      }
    }
  }

The patch improves loop unroll speed since isLoopBackedgeGuardedByCond takes
much less time than isLoopEntryGuardedByCond in the edge case.

Reviewers: skatkov, sanjoy, mkazantsev

Reviewed By: sanjoy

Subscribers: fhahn, hiraditya, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72929
2020-01-20 16:41:16 +03:00
Alina Sbirlea
9f6c6ee6b9 [MemDepAnalysis/VNCoercion] Move static method to its only use. [NFCI]
Static method MemoryDependenceResults::getLoadLoadClobberFullWidthSize
does not have or use any info specific to MemoryDependenceResults.
Move it to its only user: VNCoercion.
2020-01-17 15:18:42 -08:00
Alina Sbirlea
78d4096d03 [LazyCallGraph] Add invalidate method.
Summary: Add invalidate method in LazyCallGraph.

Reviewers: chandlerc, silvas

Subscribers: hiraditya, sanjoy.google, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72817
2020-01-17 10:47:51 -08:00
Alina Sbirlea
630a8011e4 [CallGraph] Add invalidate method.
Summary: Add invalidate method in CallGraph.

Reviewers: Eugene.Zelenko, chandlerc

Subscribers: hiraditya, sanjoy.google, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72816
2020-01-17 10:47:51 -08:00
Alina Sbirlea
62a50a95fc [BrachProbablityInfo] Add invalidate method.
Summary: Add invalidate method for BrachProbablityInfo.

Reviewers: Eugene.Zelenko, chandlerc

Subscribers: hiraditya, sanjoy.google, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72815
2020-01-17 10:47:51 -08:00
Alina Sbirlea
5cc99d05f5 [GlobalsModRef] Add invalidate method
Summary: Add invalidate method to GlobalsAA.

Reviewers: tejohnson, chandlerc

Subscribers: hiraditya, sanjoy.google, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72818
2020-01-17 10:33:54 -08:00
David Blaikie
65eb74e94b PointerLikeTypeTraits: Standardize NumLowBitsAvailable on static constexpr rather than anonymous enum
This is (more?) usable by GDB pretty printers and seems nicer to write.

There's one tricky caveat that in C++14 (LLVM's codebase today) the
static constexpr member declaration is not a definition - so odr use of
this constant requires an out of line definition, which won't be
provided (that'd make all these trait classes more annoyidng/expensive
to maintain). But the use of this constant in the library implementation
is/should always be in a non-odr context - only two unit tests needed to
be touched to cope with this/avoid odr using these constants.

Based on/expanded from D72590 by Christian Sigg.
2020-01-16 15:30:50 -08:00
Eric Christopher
de022a8824 [NFC] Fold isHugeExpression into hasHugeExpression and update callers
accordingly.
2020-01-16 15:28:54 -08:00
Francesco Petrogalli
66c120f025 [VectorUtils] Rework the Vector Function Database (VFDatabase).
Summary:
This commits is a rework of the patch in
https://reviews.llvm.org/D67572.

The rework was requested to prevent out-of-tree performance regression
when vectorizing out-of-tree IR intrinsics. The vectorization of such
intrinsics is enquired via the static function `isTLIScalarize`. For
detail see the discussion in https://reviews.llvm.org/D67572.

Reviewers: uabelho, fhahn, sdesmalen

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72734
2020-01-16 15:08:26 +00:00
Mircea Trofin
5466597fee [NFC] Refactor InlineResult for readability
Summary:
InlineResult is used both in APIs assessing whether a call site is
inlinable (e.g. llvm::isInlineViable) as well as in the function
inlining utility (llvm::InlineFunction). It means slightly different
things (can/should inlining happen, vs did it happen), and the
implicit casting may introduce ambiguity (casting from 'false' in
InlineFunction will default a message about hight costs,
which is incorrect here).

The change renames the type to a more generic name, and disables
implicit constructors.

Reviewers: eraman, davidxl

Reviewed By: davidxl

Subscribers: kerbowa, arsenm, jvesely, nhaehnle, eraman, hiraditya, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72744
2020-01-15 13:34:20 -08:00
evgeny
10cadee5ce [ThinLTO] Always import constants
This patch imports constant variables even when they can't be internalized
(which results in promotion). This offers some extra constant folding
opportunities.

Differential revision: https://reviews.llvm.org/D70404
2020-01-15 19:29:01 +03:00
Sjoerd Meijer
07028b5a87 [SCEV] Follow up of D71563: addressing post commit comment. NFC. 2020-01-13 08:54:38 +00:00
Zheng Chen
a6342c247a [SCEV] accurate range for addrecexpr with nuw flag
If addrecexpr has nuw flag, the value should never be less than its
start value and start value does not required to be SCEVConstant.

Reviewed By: nikic, sanjoy

Differential Revision: https://reviews.llvm.org/D71690
2020-01-12 20:22:37 -05:00
Zheng Chen
569ccfc384 [SCEV] more accurate range for addrecexpr with nsw flag.
Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D72436
2020-01-11 23:26:35 -05:00
Mircea Trofin
064087581a [NFC][InlineCost] Factor cost modeling out of CallAnalyzer traversal.
Summary:
The goal is to simplify experimentation on the cost model. Today,
CallAnalyzer decides 2 things: legality, and benefit. The refactoring
keeps legality assessment in CallAnalyzer, and factors benefit
evaluation out, as an extension.

Reviewers: davidxl, eraman

Reviewed By: davidxl

Subscribers: kamleshbhalui, fedor.sergeev, hiraditya, baloghadamsoftware, haicheng, a.sidorin, Szelethus, donat.nagy, dkrupp, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71733
2020-01-10 15:30:24 -08:00
Sjoerd Meijer
67bf9a6154 [SVEV] Recognise hardware-loop intrinsic loop.decrement.reg
Teach SCEV about the @loop.decrement.reg intrinsic, which has exactly the same
semantics as a sub expression. This allows us to query hardware-loops, which
contain this @loop.decrement.reg intrinsic, so that we can calculate iteration
counts, exit values, etc. of hardwareloops.

This "int_loop_decrement_reg" intrinsic is defined as "IntrNoDuplicate". Thus,
while hardware-loops and tripcounts now become analysable by SCEV, this
prevents the usual loop transformations from applying transformations on
hardware-loops, which is what we want at this point, for which I have added
test cases for loopunrolling and IndVarSimplify and LFTR.

Differential Revision: https://reviews.llvm.org/D71563
2020-01-10 09:35:00 +00:00
Sanjay Patel
f53b38d12a [InstSimplify] select Cond, true, false --> Cond
This is step 1 of damage control assuming that we need to remove several
over-reaching folds for select-of-booleans because they can cause
miscompiles as shown in D72396.

The scalar case seems obviously safe:
https://rise4fun.com/Alive/jSj

And I don't think there's any danger for vectors either - if the
condition is poisoned, then the select must be poisoned too, so undef
elements don't make any difference.

Differential Revision: https://reviews.llvm.org/D72412
2020-01-09 09:04:20 -05:00
Mircea Trofin
338a601612 Revert "[NFC][InlineCost] Factor cost modeling out of CallAnalyzer traversal."
This reverts commit 76aab66d34446ccf764cf8127b73e1517df75fb4.

Failure:
http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/20562,
will investigate and resubmit.
2020-01-08 17:42:23 -08:00
Mircea Trofin
76aab66d34 [NFC][InlineCost] Factor cost modeling out of CallAnalyzer traversal.
Summary:
The goal is to simplify experimentation on the cost model. Today,
CallAnalyzer decides 2 things: legality, and benefit. The refactoring
keeps legality assessment in CallAnalyzer, and factors benefit
evaluation out, as an extension.

Reviewers: davidxl, eraman

Subscribers: kamleshbhalui, fedor.sergeev, hiraditya, baloghadamsoftware, haicheng, a.sidorin, Szelethus, donat.nagy, dkrupp, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71733
2020-01-08 17:12:36 -08:00
czhengsz
8b8ba44047 [SCEV] get more accurate range for AddExpr with wrap flag.
Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D64869
2020-01-07 20:58:04 -05:00
Jim Lin
ab1bcda851 [NFC] Use isX86() instead of getArch()
Summary: This is a clean up for https://reviews.llvm.org/D72247.

Reviewers: MaskRay, craig.topper, jhenderson

Reviewed By: MaskRay

Subscribers: hiraditya, rupprecht, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D72320
2020-01-07 17:35:44 +08:00
Neil Henning
103a58c8f2 Add ExternalAAWrapperPass to createLegacyPMAAResults.
Our out-of-tree custom aliasing solution for the HPC# Burst compiler
here at Unity makes use of the `ExternalAAwrapperPass` infrastructure to
insert our custom aliasing resolution into the core of LLVM. This is
great for all cases except for function inlining, where because
`createLegacyPMAAResults` does not make use of `ExternalAAWrapperPass`,
when we have a definite no-alias result within a function it won't be
propagated to the calling function during inlining.

This commit just rectifies this oversight by adding the missing
dependency.

Differential Revision: https://reviews.llvm.org/D71348
2020-01-06 08:50:18 +00:00
Anton Afanasyev
a792953330 [Metadata] Add TBAA struct metadata to AAMDNode
Summary:
Make `AAMDNodes`' `getAAMetadata()` and `setAAMetadata()` to take `!tbaa.struct`
into account as well as `!tbaa`. This impacts llvm.org/pr42022.
This is a temprorary fix needed to keep `!tbaa.struct` tag by SROA pass.
New field `TBAAStruct` should be deleted when `!tbaa` tag replaces `!tbaa.struct`.
Merging two `!tbaa.struct`'s to one is conservatively considered to be `nullptr`
(giving `MayAlias`) -- this could be enhanced, but relying on the said future
replacement.

Reviewers: RKSimon, spatel, vporpo

Subscribers: hiraditya, kosarev, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70924
2020-01-06 11:05:15 +03:00
Florian Hahn
b8a3c34eee Revert "[SCEV] Move ScalarEvolutionExpander.cpp to Transforms/Utils (NFC)."
This reverts commit 51ef53f3bd23559203fe9af82ff2facbfedc1db3, as it
breaks some bots.
2020-01-04 18:44:38 +00:00
Florian Hahn
51ef53f3bd [SCEV] Move ScalarEvolutionExpander.cpp to Transforms/Utils (NFC).
SCEVExpander modifies the underlying function so it is more suitable in
Transforms/Utils, rather than Analysis. This allows using other
transform utils in SCEVExpander.

Reviewers: sanjoy.google, efriedma, reames

Reviewed By: sanjoy.google

Differential Revision: https://reviews.llvm.org/D71537
2020-01-04 18:29:35 +00:00
Florian Hahn
99f74a64a2 [SCEV] Remove unused ScalarEvolutionExpander.h includes (NFC). 2020-01-04 18:29:35 +00:00
Mark de Wever
8dc7b982b4 [NFC] Fixes -Wrange-loop-analysis warnings
This avoids new warnings due to D68912 adds -Wrange-loop-analysis to -Wall.

Differential Revision: https://reviews.llvm.org/D71857
2020-01-01 20:01:37 +01:00
Danilo Carvalho Grael
2abda66848 [NFC][DA] Remove duplicate code in checkSrcSubscript and checkDstSubscript
Summary:
[DA] Move common code in checkSrcSubscript and checkDstSubscript to a
new function checkSubscript. This avoids duplicate code and possible
out of sync in the future.

Reviewers: sebpop, jmolloy, reames

Reviewed By: sebpop

Subscribers: bmahjour, hiraditya, llvm-commits, amehsan

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71087

Patch by zhongduo.
2019-12-27 10:06:19 -05:00
Jordan Rupprecht
02a6b0bc3b Temporarily revert "Reapply [LVI] Normalize pointer behavior" and "[LVI] Restructure caching"
This reverts commits 7e18aeba5062cd4324a9efb7bc25c9dbc4a34c2c (D70376) 21fbd5587cdfa11dabb3aeb0ead2d3d5fd0b490d (D69914) due to increased memory usage.
2019-12-20 10:25:57 -08:00
Mircea Trofin
93ac81cc9d [NFC][InlineCost] Simplify internal inlining cost interface
Summary:
All the use cases of CallAnalyzer use the same call site parameter to
both construct the CallAnalyzer, and then pass to the analysis member.
This change removes this duplication.

Reviewers: davidxl, eraman, Jim

Reviewed By: davidxl

Subscribers: Jim, hiraditya, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71645
2019-12-19 15:32:15 -08:00
Roman Lebedev
047186cc98
[ValueTracking] isKnownNonZero() should take non-null-ness assumptions into consideration (PR43267)
Summary:
It is pretty common to assume that something is not zero.
Even optimizer itself sometimes emits such assumptions
(e.g. `addAssumeNonNull()` in `PromoteMemoryToRegister.cpp`).

But we currently don't deal with such assumptions :)
The only way `isKnownNonZero()` handles assumptions is
by calling `computeKnownBits()` which calls `computeKnownBitsFromAssume()`.
But `x != 0` does not tell us anything about set bits,
it only says that there are *some* set bits.
So naturally, `KnownBits` does not get populated,
and we fail to make use of this assumption.

I propose to deal with this special case by special-casing it
via adding a `isKnownNonZeroFromAssume()` that returns boolean
when there is an applicable assumption.

While there, we also deal with other predicates,
mainly if the comparison is with constant.

Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=43267 | PR43267 ]].

Differential Revision: https://reviews.llvm.org/D71660
2019-12-20 01:47:57 +03:00
Roman Lebedev
92083a295a
[ValueTracking] isValidAssumeForContext(): CxtI itself also must transfer execution to successor
This is a pretty rare case, when CxtI and assume are
in the same basic block, with assume being located later.

We were already checking that assumption was guaranteed to be
executed, but we omitted CxtI itself from consideration,
and as the test (miscompile) shows, that is incorrect.

As noted in D71660 review by @nikic.
2019-12-20 01:47:57 +03:00
Bardia Mahjour
86acaa9457 [DDG] Data Dependence Graph - Ordinals
Summary:
This patch associates ordinal numbers to the DDG Nodes allowing
the builder to order nodes within a pi-block in program order. The
algorithm works by simply assuming the order in which the BBList
is fed into the builder. The builder already relies on the blocks being
in program order so that it can compute the dependencies correctly.
Similarly the order of instructions in their parent basic blocks
determine their program order.

Authored By: bmahjour

Reviewer: Meinersbur, fhahn, myhsu, xtian, dmgreen, kbarton, jdoerfert

Reviewed By: Meinersbur

Subscribers: ychen, arphaman, simoll, a.elovikov, mgorny, hiraditya, jfb, wuzish, llvm-commits, jsji, Whitney, etiotto, ppc-slack

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D70986
2019-12-19 10:57:33 -05:00
Mircea Trofin
5a956c85df [NFC][InlineCost] Run clang-format on InlineCost.cpp
Reviewers: davidxl

Reviewed By: davidxl

Subscribers: Jim, eraman, hiraditya, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D71646
2019-12-18 08:10:44 -08:00
evgeny
ad364956ed [ThinLTO] Show preserved symbols in DOT files
Differential revision: https://reviews.llvm.org/D71608
2019-12-18 18:33:15 +03:00
Anna Welker
7cd1cfdd6b [NFC][TTI] Add Alignment for isLegalMasked[Gather/Scatter]
Add an extra parameter so alignment can be taken under
consideration in gather/scatter legalization.

Differential Revision: https://reviews.llvm.org/D71610
2019-12-18 09:14:39 +00:00
Teresa Johnson
878ab6df03 [TLI] Support for per-Function TLI that overrides available libfuncs
Summary:

Follow-on to D66428 and D71193, to build the TLI per-function so
that -fno-builtin* handling can be migrated to use function attributes.
See discussion on D61634 for background. This is an enabler for fixing
handling of these options for LTO, for example.

With D71193, the -fno-builtin* flags are converted to function
attributes, so we can now set this information per-function on the TLI.

In this patch, the TLI constructor is changed to take a Function, which
can be used to override the available builtins. The TLI is augmented
with an array that can be used to specify which builtins are not
available for the corresponding function. The available function checks
are changed to consult this override before checking the underlying
module level baseline TLII. New code is added to set this override
array based on the attributes.

I also removed the code that sets availability in the TLII in clang from
the options, which is no longer needed.

I removed a per-Triple caching of TLII objects in the analysis object,
as it is based on the Module's Triple which is the same for all
functions in any case. Is there a case where we would be compiling
multiple Modules with different Triples in one compilation?

Finally, I have changed the legacy analysis wrapper to create and use
the new PM analysis class (TargetLibraryAnalysis) in getTLI. This is
consistent with the behavior of getTTI for the legacy
TargetTransformInfo analysis. This change means that getTLI now creates
a new TLI on each call (although that should be very cheap as we cache
the module level TLII, and computing the per-function
attribute based availability should also be reasonably efficient).
I measured the compile time for a large C++ file with tens of thousands
of functions and as expected there was no increase.

Reviewers: chandlerc, hfinkel, gchatelet

Subscribers: mehdi_amini, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D67923
2019-12-16 09:19:30 -08:00
Sanjay Patel
6080387f13 [InstSimplify] fold splat of inserted constant to vector constant
shuf (inselt ?, C, IndexC), undef, <IndexC, IndexC...> --> <C, C...>

This is another missing shuffle fold pattern uncovered by the
shuffle correctness fix from D70246.

The problem was visible in the post-commit thread example, but
we managed to overcome the limitation for that particular case
with D71220.

This is something like the inverse of the previous fix - there
we didn't demand the inserted scalar, and here we are only
demanding an inserted scalar.

Differential Revision: https://reviews.llvm.org/D71488
2019-12-15 09:32:03 -05:00
Francesco Petrogalli
19f73f0d1b Revert "[VectorUtils] Introduce the Vector Function Database (VFDatabase)."
This reverts commit 0be81968a283fd4161cb9ac9748d5ed200926292.

The VFDatabase needs some rework to be able to handle vectorization
and subsequent scalarization of intrinsics in out-of-tree versions of
the compiler. For more details, see the discussion in
https://reviews.llvm.org/D67572.
2019-12-13 19:42:04 +00:00
Nicola Zaghen
97572775d2 Reland [DataLayout] Fix occurrences that size and range of pointers are assumed to be the same.
GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in which getIndexSizeInBits was used interchangeably with getPointerSizeInBits. This notably caused issues
with Instcombine's visitPtrToInt; but the unit tests was incorrect, so this remained undiscovered.

This fixes the buildbot failures.

Differential Revision: https://reviews.llvm.org/D68328

Patch by Joseph Faulls!
2019-12-13 14:30:21 +00:00
Nikita Popov
21fbd5587c Reapply [LVI] Normalize pointer behavior
This is a rebase of the change over D70376, which fixes an LVI cache
invalidation issue that also affected this patch.

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Related to D69686. As noted there, LVI currently behaves differently
for integer and pointer values: For integers, the block value is always
valid inside the basic block, while for pointers it is only valid at
the end of the basic block. I believe the integer behavior is the
correct one, and CVP relies on it via its getConstantRange() uses.

The reason for the special pointer behavior is that LVI checks whether
a pointer is dereferenced in a given basic block and marks it as
non-null in that case. Of course, this information is valid only after
the dereferencing instruction, or in conservative approximation,
at the end of the block.

This patch changes the treatment of dereferencability: Instead of
including it inside the block value, we instead treat it as something
similar to an assume (it essentially is a non-nullness assume) and
incorporate this information in intersectAssumeOrGuardBlockValueConstantRange()
if the context instruction is the terminator of the basic block.
This happens either when determining an edge-value internally in LVI,
or when a terminator was explicitly passed to getValueAt(). The latter
case makes this change not fully NFC, because we can now fold
terminator icmps based on the dereferencability information in the
same block. This is the reason why I changed one JumpThreading test
(it would optimize the condition away without the change).

Of course, we do not want to recompute dereferencability on each
intersectAssume call, so we need a new cache for this. The
dereferencability analysis requires walking the entire basic block
and computing underlying objects of all memory operands. This was
previously done separately for each queried pointer value. In the
new implementation (both because this makes the caching simpler,
and because it is faster), I instead only walk the full BB once and
cache all the dereferenced pointers. So the traversal is now performed
only once per BB, instead of once per queried pointer value.

I think the overall model now makes more sense than before, and there
will be no more pitfalls due to differing integer/pointer behavior.

Differential Revision: https://reviews.llvm.org/D69914
2019-12-13 08:59:58 +01:00