Commit Graph

329 Commits

Author SHA1 Message Date
Bjorn Pettersson 3655f0757f Make dependency between certain analysis passes transitive
LazyBlockFrequenceInfoPass, LazyBranchProbabilityInfoPass and
LoopAccessLegacyAnalysis all cache pointers to their nestled required
analysis passes. One need to use addRequiredTransitive to describe
that the nestled passes can't be freed until those analysis passes
no longer are used themselves.

There is still a bit of a mess considering the getLazyBPIAnalysisUsage
and getLazyBFIAnalysisUsage functions. Those functions are used from
both Transform, CodeGen and Analysis passes. I figure it is OK to
use addRequiredTransitive also when being used from Transform and
CodeGen passes. On the other hand, I figure we must do it when
used from other Analysis passes. So using addRequiredTransitive should
be more correct here. An alternative solution would be to add a
bool option in those functions to let the user tell if it is a
analysis pass or not. Since those lazy passes will be obsolete when
new PM has conquered the world I figure we can leave it like this
right now.

Intention with the patch is to fix PR49950. It at least solves the
problem for the reproducer in PR49950. However, that reproducer
need five passes in a specific order, so there are lots of various
"solutions" that could avoid the crash without actually fixing the
root cause.

Differential Revision: https://reviews.llvm.org/D100958
2021-05-04 11:50:08 +02:00
Florian Hahn 1ed7f8ede5
[LAA] Support pointer phis in loop by analyzing each incoming pointer.
SCEV does not look through non-header PHIs inside the loop. Such phis
can be analyzed by adding separate accesses for each incoming pointer
value.

This results in 2 more loops vectorized in SPEC2000/186.crafty and
avoids regressions when sinking instructions before vectorizing.

Reviewed By: Meinersbur

Differential Revision: https://reviews.llvm.org/D101286
2021-04-28 20:19:40 +01:00
Richard Smith 040c60d9b6 Fix a miscompile introduced by 99203f2.
getPointersDiff would previously round down the difference between two
pointers to a multiple of the element size of the pointee, which could
result in a pointer value being decreased a little.

Alexey Bataev has graciously agreed to add a testcase for this;
submitting the bugfix now to unblock.
2021-03-25 16:53:58 -07:00
Alexey Bataev 2f1b439089 [LoopAnalysis][NFC]Remove redundant code.
Removed redundant code for IsConsecutive variable.
2021-03-24 05:37:19 -07:00
Alexey Bataev 99203f2004 [Analysis]Add getPointersDiff function to improve compile time.
Added getPointersDiff function to LoopAccessAnalysis and used it instead
direct calculatoin of the distance between pointers and/or
isConsecutiveAccess function in SLP vectorizer to improve compile time
and detection of stores consecutive chains.

Part of D57059

Differential Revision: https://reviews.llvm.org/D98967
2021-03-23 14:25:36 -07:00
Alexey Bataev f1b47ad278 Revert "[Analysis]Add getPointersDiff function to improve compile time."
This reverts commit 065a14a12d to
investigate and fix crash in SLP vectorizer.
2021-03-23 13:17:54 -07:00
Alexey Bataev 065a14a12d [Analysis]Add getPointersDiff function to improve compile time.
Added getPointersDiff function to LoopAccessAnalysis and used it instead
direct calculatoin of the distance between pointers and/or
isConsecutiveAccess function in SLP vectorizer to improve compile time
and detection of stores consecutive chains.

Part of D57059

Differential Revision: https://reviews.llvm.org/D98967
2021-03-23 12:58:42 -07:00
Kazu Hirata 6a6e382161 [llvm] Drop unnecessary make_range (NFC) 2021-01-09 09:25:00 -08:00
Simon Pilgrim fa6d897799 [Analysis] MemoryDepChecker::couldPreventStoreLoadForward - remove dead store. NFCI.
As we're breaking from the loop when clamping MaxVF, clang static analyzer was warning that the VF iterator was being updated and never used.
2021-01-07 14:21:54 +00:00
Philip Reames f5fe8493e5 [LAA] Relax restrictions on early exits in loop structure
his is a preparation patch for supporting multiple exits in the loop vectorizer, by itself it should be mostly NFC. This patch moves the loop structure checks from LAA to their respective consumers (where duplicates don't already exist).  Moving the checks does end up changing some of the optimization warnings and debug output slightly, but nothing that appears to be a regression.

Why do this? Well, after auditing the code, I can't actually find anything in LAA itself which relies on having all instructions within a loop execute an equal number of times. This patch simply makes this explicit so that if one consumer - say LV in the near future (hopefully) - wants to handle a broader class of loops, it can do so.

Differential Revision: https://reviews.llvm.org/D92066
2020-12-14 12:44:01 -08:00
Nikita Popov 4df8efce80 [AA] Split up LocationSize::unknown()
Currently, we have some confusion in the codebase regarding the
meaning of LocationSize::unknown(): Some parts (including most of
BasicAA) assume that LocationSize::unknown() only allows accesses
after the base pointer. Some parts (various callers of AA) assume
that LocationSize::unknown() allows accesses both before and after
the base pointer (but within the underlying object).

This patch splits up LocationSize::unknown() into
LocationSize::afterPointer() and LocationSize::beforeOrAfterPointer()
to make this completely unambiguous. I tried my best to determine
which one is appropriate for all the existing uses.

The test changes in cs-cs.ll in particular illustrate a previously
clearly incorrect AA result: We were effectively assuming that
argmemonly functions were only allowed to access their arguments
after the passed pointer, but not before it. I'm pretty sure that
this was not intentional, and it's certainly not specified by
LangRef that way.

Differential Revision: https://reviews.llvm.org/D91649
2020-11-26 18:39:55 +01:00
Joe Ellis 06654a5348 [SVE] Fix TypeSize warning in RuntimePointerChecking::insert
The TypeSize warning would occur because RuntimePointerChecking::insert
was not scalable vector aware. The fix is to use
ScalarEvolution::getSizeOfExpr to grab the size of types.

Differential Revision: https://reviews.llvm.org/D90171
2020-11-25 16:59:03 +00:00
Cullen Rhodes 1ba4b82f67 [LAA] NFC: Rename [get]MaxSafeRegisterWidth -> [get]MaxSafeVectorWidthInBits
MaxSafeRegisterWidth is a misnomer since it actually returns the maximum
safe vector width. Register suggests it relates directly to a physical
register where it could be a vector spanning one or more physical
registers.

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D91727
2020-11-25 13:06:26 +00:00
Philip Reames 10ddb927c1 [SCEV] Use isa<> pattern for testing for CouldNotCompute [NFC]
Some older code - and code copied from older code - still directly tested against the singelton result of SE::getCouldNotCompute.  Using the isa<SCEVCouldNotCompute> form is both shorter, and more readable.
2020-11-24 18:47:49 -08:00
Philip Reames b3a8a15343 [LAA] Minor code style tweaks [NFC] 2020-11-24 15:49:27 -08:00
Florian Hahn a73166a452 [LAA] Use DL to get element size for bound computation.
Currently LAA uses getScalarSizeInBits to compute the size of an element
when computing the end bound of an access.

This does not work as expected for pointers to pointers, because
getScalarSizeInBits will return 0 for pointer types.

By using DataLayout to get the size of the element we can also correctly
handle pointer element types.

Note the changes to the existing test, which seems to also use the wrong
offset for the end.

Fixes PR47751.

Reviewed By: anemet

Differential Revision: https://reviews.llvm.org/D88953
2020-10-07 18:57:07 +01:00
Simon Pilgrim 71b89b1493 LoopAccessAnalysis.cpp - use const reference in for-range loops. NFCI. 2020-10-02 13:56:30 +01:00
Stefanos Baziotis 89c1e35f3c [LoopInfo] empty() -> isInnermost(), add isOutermost()
Differential Revision: https://reviews.llvm.org/D82895
2020-09-22 23:28:51 +03:00
Vitaly Buka b0eb40ca39 [NFC] Remove unused GetUnderlyingObject paramenter
Depends on D84617.

Differential Revision: https://reviews.llvm.org/D84621
2020-07-31 02:10:03 -07:00
Vitaly Buka 89051ebace [NFC] GetUnderlyingObject -> getUnderlyingObject
I am going to touch them in the next patch anyway
2020-07-30 21:08:24 -07:00
Florian Hahn 2062b3707c [LAA] Avoid adding pointers to the checks if they are not needed.
Currently we skip alias sets with only reads or a single write and no
reads, but still add the pointers to the list of pointers in RtCheck.

This can lead to cases where we try to access a pointer that does not
exist when grouping checks.  In most cases, the way we access
PositionMap masked that, as the value would default to index 0.

But in the example in PR46854 it causes a crash.

This patch updates the logic to avoid adding pointers for alias sets
that do not need any checks. It makes things slightly more verbose, by
first checking the numbers of reads/writes and bailing out early if we don't
need checks for the alias set.

I think this makes the logic a bit simpler to follow.

Reviewed By: anemet

Differential Revision: https://reviews.llvm.org/D84608
2020-07-30 19:21:14 +01:00
Ayal Zaks 7bf299c8d8 [LV] Vectorize without versioning-for-unit-stride under -Os/-Oz
If a loop is in a function marked OptSize, Loop Access Analysis should refrain
from generating runtime checks for unit strides that will version the loop.

If a loop is in a function marked OptSize and its vectorization is enabled, it
should be vectorized w/o any versioning.

Fixes PR46228.

Differential Revision: https://reviews.llvm.org/D81345
2020-07-07 15:04:21 +03:00
Simon Pilgrim db69b17409 LoopAccessAnalysis.h - reduce AliasAnalysis.h include to forward declaration. NFC.
Fix implicit include dependencies in source files and replace legacy AliasAnalysis typedef with AAResults where necessary.
2020-06-25 16:00:42 +01:00
Florian Hahn 6176f04436 [LAA] Do not set CanDoRT to false for AS that do not need RT checks.
Alternative approach to D80570.

canCheckPtrAtRT already contains checks the figure out for which alias
sets runtime checks are needed. But it currently sets CanDoRT to false
for alias sets for which we cannot do RT checks but also do not need
any.

If we know that we do not need RT checks based on the number of
reads/writes in the alias set, we can skip processing the AS.

This patch also adds an assertion to ensure that DepCands does not
contain more than one write from the alias set.

Reviewers: Ayal, anemet, hfinkel, dmgreen

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D80622
2020-06-14 20:55:59 +01:00
Florian Hahn 9b507b2127 [LAA] We only need pointer checks if there are non-zero checks (NFC).
If it turns out that we can do runtime checks, but there are no
runtime-checks to generate, set RtCheck.Need to false.

This can happen if we can prove statically that the pointers passed in
to canCheckPtrAtRT do not alias. This should not change any results, but
allows us to skip some work and assert that runtime checks are
generated, if LAA indicates that runtime checks are required.

Reviewers: anemet, Ayal

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D79969

Note: This is a recommit of 259abfc7cb,
with some suggested renaming.
2020-05-27 12:47:36 +01:00
Florian Hahn 2d0389821e Revert "[LAA] We only need pointer checks if there are non-zero checks (NFC)."
This reverts commit 259abfc7cb.

Reverting this, as I missed a case where we return without setting
RtCheck.Need.
2020-05-27 12:39:45 +01:00
Florian Hahn 259abfc7cb [LAA] We only need pointer checks if there are non-zero checks (NFC).
If it turns out that we can do runtime checks, but there are no
runtime-checks to generate, set RtCheck.Need to false.

This can happen if we can prove statically that the pointers passed in
to canCheckPtrAtRT do not alias. This should not change any results, but
allows us to skip some work and assert that runtime checks are
generated, if LAA indicates that runtime checks are required.

Reviewers: anemet, Ayal

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D79969
2020-05-27 12:37:20 +01:00
Florian Hahn bcbd26bfe6 [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.

This patch was originally committed as b8a3c34eee, but broke the
modules build, as LoopAccessAnalysis was using the Expander.

The code-gen part of LAA was moved to lib/Transforms recently, so this
patch can be landed again.

Reviewers: sanjoy.google, efriedma, reames

Reviewed By: sanjoy.google

Differential Revision: https://reviews.llvm.org/D71537
2020-05-20 10:53:40 +01:00
Florian Hahn 8528186b9b [LAA] Move runtime-check generation to Transforms/Utils/loopUtils (NFC)
Currently LAA's uses of ScalarEvolutionExpander blocks moving the
expander from Analysis to Transforms. Conceptually the expander does not
fit into Analysis (it is only used for code generation) and
runtime-check generation also seems to be better suited as a
transformation utility.

Reviewers: Ayal, anemet

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D78460
2020-05-10 17:39:26 +01:00
Florian Hahn 96c63f544f Recommit "[LAA] Remove one addRuntimeChecks function (NFC)."
The failing assertion has been fixed and the problematic test case has
been added.

This reverts the revert commit fc44617f28.
2020-05-10 15:19:57 +01:00
Florian Hahn fc44617f28 Revert "[LAA] Remove one addRuntimeChecks function (NFC)."
This reverts commit c28114c8ff.

This causes some bots to fail:

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-android/builds/30596/steps/build%20android%2Faarch64/logs/stdio
2020-05-10 13:28:00 +01:00
Florian Hahn c28114c8ff [LAA] Remove one addRuntimeChecks function (NFC).
In order to reduce the API surface area (preparation for D78460), remove
a addRuntimeChecks() function and do the additional check in the single
caller.

Reviewers: Ayal, anemet

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D79679
2020-05-10 12:48:55 +01:00
Florian Hahn 57fb56b30e [LAA] Remove unneeded PtrRtChecking argument (NFC).
The argument is not required and simplifies D78460 a bit.
2020-05-09 22:26:54 +01:00
Florian Hahn 616657b39c [LAA] Move CheckingPtrGroup/PointerCheck outside class (NFC).
This allows forward declarations of PointerCheck, which in turn reduce
the number of times LoopAccessAnalysis needs to be included.

Ultimately this helps with moving runtime check generation to
Transforms/Utils/LoopUtils.h, without having to include it there.

Reviewers: anemet, Ayal

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D78458
2020-04-28 21:47:31 +01:00
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
Florian Hahn b8a3c34eee Revert "[SCEV] Move ScalarEvolutionExpander.cpp to Transforms/Utils (NFC)."
This reverts commit 51ef53f3bd, 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
Francesco Petrogalli 19f73f0d1b Revert "[VectorUtils] Introduce the Vector Function Database (VFDatabase)."
This reverts commit 0be81968a2.

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
Francesco Petrogalli 0be81968a2 [VectorUtils] Introduce the Vector Function Database (VFDatabase).
This patch introduced the VFDatabase, the framework proposed in
http://lists.llvm.org/pipermail/llvm-dev/2019-June/133484.html. [*]

In this patch the VFDatabase is used to bridge the TargetLibraryInfo
(TLI) calls that were previously used to query for the availability of
vector counterparts of scalar functions.

The VFISAKind field `ISA` of VFShape have been moved into into VFInfo,
under the assumption that different vector ISAs may provide the same
vector signature. At the moment, the vectorizer accepts any of the
available ISAs as long as the signature provided by the VFDatabase
matches the one expected in the vectorization process. For example,
when targeting AVX or AVX2, which both have 256-bit registers, the IR
signature of the two vector functions associated to the two ISAs is
the same. The `getVectorizedFunction` method at the moment returns the
first available match. We will need to add more heuristics to the
search system to decide which of the available version (TLI, AVX,
AVX2, ...)  the system should prefer, when multiple versions with the
same VFShape are present.

Some of the code in this patch is based on the work done by Sumedh
Arani in https://reviews.llvm.org/D66025.

[*] Notice that in the proposal the VFDatabase was called SVFS. The
name VFDatabase is more in line with LLVM recommendations for
naming classes and variables.

Differential Revision: https://reviews.llvm.org/D67572
2019-12-10 16:36:44 +00:00
Reid Kleckner 05da2fe521 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00
Simon Pilgrim e2ded3d131 LoopAccessAnalysis isConsecutiveAccess() - silence static analyzer dyn_cast<SCEVConstant> null dereference warning. NFCI.
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use cast<SCEVConstant> directly and if not assert will fire for us.

llvm-svn: 373465
2019-10-02 13:08:56 +00:00
Teresa Johnson 9c27b59cec Change TargetLibraryInfo analysis passes to always require Function
Summary:
This is the first change to enable the TLI to be built 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.

This change should not affect behavior, as the provided function is not
yet used to build a specifically per-function TLI, but rather enables
that migration.

Most of the changes were very mechanical, e.g. passing a Function to the
legacy analysis pass's getTLI interface, or in Module level cases,
adding a callback. This is similar to the way the per-function TTI
analysis works.

There was one place where we were looking for builtins but not in the
context of a specific function. See FindCXAAtExit in
lib/Transforms/IPO/GlobalOpt.cpp. I'm somewhat concerned my workaround
could provide the wrong behavior in some corner cases. Suggestions
welcome.

Reviewers: chandlerc, hfinkel

Subscribers: arsenm, dschuff, jvesely, nhaehnle, mehdi_amini, javed.absar, sbc100, jgravelle-google, eraman, aheejin, steven_wu, george.burgess.iv, dexonsmith, jfb, asbirlea, gchatelet, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66428

llvm-svn: 371284
2019-09-07 03:09:36 +00:00
Jonas Devlieghere 0eaee545ee [llvm] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

llvm-svn: 369013
2019-08-15 15:54:37 +00:00
Hideki Saito 09fac2450b [LV] Avoid building interleaved group in presence of WAW dependency
Reviewers: hsaito, Ayal, fhahn, anna, mkazantsev

Reviewed By: hsaito

Patch by evrevnov, thanks!

Differential Revision: https://reviews.llvm.org/D63981

llvm-svn: 367654
2019-08-02 06:31:50 +00:00
Michael Liao 17a8a9277c [LAA] Re-check bit-width of pointers after stripping.
Summary:
- As the pointer stripping now tracks through `addrspacecast`, prepare
  to handle the bit-width difference from the result pointer.

Reviewers: jdoerfert

Subscribers: jvesely, nhaehnle, hiraditya, arphaman, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64928

llvm-svn: 366470
2019-07-18 17:30:27 +00:00
Matt Arsenault 2466ba97bc LoopDistribute/LAA: Respect convergent
This case is slightly tricky, because loop distribution should be
allowed in some cases, and not others. As long as runtime dependency
checks don't need to be introduced, this should be OK. This is further
complicated by the fact that LoopDistribute partially ignores if LAA
says that vectorization is safe, and then does its own runtime pointer
legality checks.

Note this pass still does not handle noduplicate correctly, as this
should always be forbidden with it. I'm not going to bother trying to
fix it, as it would require more effort and I think noduplicate should
be removed.

https://reviews.llvm.org/D62607

llvm-svn: 363160
2019-06-12 13:34:19 +00:00
Bjorn Pettersson 71e8c6f20f Add "const" in GetUnderlyingObjects. NFC
Summary:
Both the input Value pointer and the returned Value
pointers in GetUnderlyingObjects are now declared as
const.

It turned out that all current (in-tree) uses of
GetUnderlyingObjects were trivial to update, being
satisfied with have those Value pointers declared
as const. Actually, in the past several of the users
had to use const_cast, just because of ValueTracking
not providing a version of GetUnderlyingObjects with
"const" Value pointers. With this patch we get rid
of those const casts.

Reviewers: hfinkel, materi, jkorous

Reviewed By: jkorous

Subscribers: dexonsmith, jkorous, jholewinski, sdardis, eraman, hiraditya, jrtc27, atanasyan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61038

llvm-svn: 359072
2019-04-24 06:55:50 +00:00
Fangrui Song efd94c56ba Use llvm::stable_sort
While touching the code, simplify if feasible.

llvm-svn: 358996
2019-04-23 14:51:27 +00:00
Hiroshi Inoue 02a2bb2f54 [NFC] fix trivial typos in comments
llvm-svn: 353147
2019-02-05 08:30:48 +00:00
Hiroshi Inoue c437f310a5 [NFC] fix trivial typos in comments
llvm-svn: 352602
2019-01-30 05:26:31 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Florian Hahn ef307b8c26 [LAA] Avoid generating RT checks for known deps preventing vectorization.
If we found unsafe dependences other than 'unknown', we already know at
compile time that they are unsafe and the runtime checks should always
fail. So we can avoid generating them in those cases.

This should have no negative impact on performance as the runtime checks
that would be created previously should always fail. As a sanity check,
I measured the test-suite, spec2k and spec2k6 and there were no regressions.

Reviewers: Ayal, anemet, hsaito

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D55798

llvm-svn: 349794
2018-12-20 18:49:09 +00:00
Florian Hahn 485f2826ba [LAA] Introduce enum for vectorization safety status (NFC).
This patch adds a VectorizationSafetyStatus enum, which will be extended
in a follow up patch to distinguish between 'safe with runtime checks'
and 'known unsafe' dependences.

Reviewers: anemet, anna, Ayal, hsaito

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D54892

llvm-svn: 349556
2018-12-18 22:25:11 +00:00
Anna Thomas 5e9215f02b [LV] Avoid vectorizing unsafe dependencies in uniform address
Summary:
Currently, when vectorizing stores to uniform addresses, the only
instance we prevent vectorization is if there are multiple stores to the
same uniform address causing an unsafe dependency.
This patch teaches LAA to avoid vectorizing loops that have an unsafe
cross-iteration dependency between a load and a store to the same uniform address.

Fixes PR39653.

Reviewers: Ayal, efriedma

Subscribers: rkruppe, llvm-commits

Differential Revision: https://reviews.llvm.org/D54538

llvm-svn: 347220
2018-11-19 15:39:59 +00:00
Fangrui Song 7570932977 Use llvm::copy. NFC
llvm-svn: 347126
2018-11-17 01:44:25 +00:00
Anna Thomas 6f732bfb79 [LV] Teach vectorizer about variant value store into uniform address
Summary:
Teach vectorizer about vectorizing variant value stores to uniform
address. Similar to rL343028, we do not allow vectorization if we have
multiple stores to the same uniform address.

Cost model already has the change for considering the extract
instruction cost for a variant value store. See added test cases for how
vectorization is done.
The patch also contains changes to the ORE messages.

Reviewers: Ayal, mkuper, anemet, hsaito

Subscribers: rkruppe, llvm-commits

Differential Revision: https://reviews.llvm.org/D52656

llvm-svn: 344613
2018-10-16 15:46:26 +00:00
George Burgess IV 6ef8002c2c Replace most users of UnknownSize with LocationSize::unknown(); NFC
Moving away from UnknownSize is part of the effort to migrate us to
LocationSizes (e.g. the cleanup promised in D44748).

This doesn't entirely remove all of the uses of UnknownSize; some uses
require tweaks to assume that UnknownSize isn't just some kind of int.
This patch is intended to just be a trivial replacement for all places
where LocationSize::unknown() will Just Work.

llvm-svn: 344186
2018-10-10 21:28:44 +00:00
Anna Thomas b1e3d45318 [LV][LAA] Vectorize loop invariant values stored into loop invariant address
Summary:
We are overly conservative in loop vectorizer with respect to stores to loop
invariant addresses.
More details in https://bugs.llvm.org/show_bug.cgi?id=38546
This is the first part of the fix where we start with vectorizing loop invariant
values to loop invariant addresses.

This also includes changes to ORE for stores to invariant address.

Reviewers: anemet, Ayal, mkuper, mssimpso

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D50665

llvm-svn: 343028
2018-09-25 20:57:20 +00:00
Fangrui Song f78650a8de Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338293
2018-07-30 19:41:25 +00:00
Manoj Gupta 77eeac3d9e llvm: Add support for "-fno-delete-null-pointer-checks"
Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.

More details : https://lkml.org/lkml/2018/4/4/601

GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.

-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.

This feature is implemented in LLVM IR in this CL as the function attribute
"null-pointer-is-valid"="true" in IR (Under review at D47894).
The CL updates several passes that assumed null pointer dereferencing is
undefined to not optimize when the "null-pointer-is-valid"="true"
attribute is present.

Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv

Reviewed By: efriedma, george.burgess.iv

Subscribers: eraman, haicheng, george.burgess.iv, drinkcat, theraven, reames, sanjoy, xbolva00, llvm-commits

Differential Revision: https://reviews.llvm.org/D47895

llvm-svn: 336613
2018-07-09 22:27:23 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
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
2018-05-14 12:53:11 +00:00
Adrian Prantl 5f8f34e459 Remove \brief commands from doxygen comments.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.

Patch produced by

  for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done

Differential Revision: https://reviews.llvm.org/D46290

llvm-svn: 331272
2018-05-01 15:54:18 +00:00
Alexey Bataev 428e9d9d87 [SLP] Fix PR36481: vectorize reassociated instructions.
Summary:
If the load/extractelement/extractvalue instructions are not originally
consecutive, the SLP vectorizer is unable to vectorize them. Patch
allows reordering of such instructions.

Patch does not support reordering of the repeated instruction, this must
be handled in the separate patch.

Reviewers: RKSimon, spatel, hfinkel, mkuper, Ayal, ashahid

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43776

llvm-svn: 329085
2018-04-03 17:14:47 +00:00
Benjamin Kramer 2fc3b18922 Revert "[SLP] Fix PR36481: vectorize reassociated instructions."
This reverts commit r328980 and r329046. Makes the vectorizer crash.

llvm-svn: 329071
2018-04-03 14:40:33 +00:00
Alexey Bataev 3decaf4275 [SLP] Fix PR36481: vectorize reassociated instructions.
Summary:
If the load/extractelement/extractvalue instructions are not originally
consecutive, the SLP vectorizer is unable to vectorize them. Patch
allows reordering of such instructions.

Reviewers: RKSimon, spatel, hfinkel, mkuper, Ayal, ashahid

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D43776

llvm-svn: 328980
2018-04-02 14:51:37 +00:00
Renato Golin 038ede2a16 [NFC] Consolidate six getPointerOperand() utility functions into one place
There are six separate instances of getPointerOperand() utility.
LoopVectorize.cpp has one of them,
and I don't want to create a 7th one while I'm trying to move
LoopVectorizationLegality into a separate file
(eventual objective is to move it to Analysis tree).

See http://lists.llvm.org/pipermail/llvm-dev/2018-February/120999.html
for llvm-dev discussions

Closes D43323.

Patch by Hideki Saito <hideki.saito@intel.com>.

llvm-svn: 327173
2018-03-09 21:05:58 +00:00
Elena Demikhovsky 945b7e5aa6 Adding a width of the GEP index to the Data Layout.
Making a width of GEP Index, which is used for address calculation, to be one of the pointer properties in the Data Layout.
p[address space]:size:memory_size:alignment:pref_alignment:index_size_in_bits.
The index size parameter is optional, if not specified, it is equal to the pointer size.

Till now, the InstCombiner normalized GEPs and extended the Index operand to the pointer width.
It works fine if you can convert pointer to integer for address calculation and all registered targets do this.
But some ISAs have very restricted instruction set for the pointer calculation. During discussions were desided to retrieve information for GEP index from the Data Layout.
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120416.html

I added an interface to the Data Layout and I changed the InstCombiner and some other passes to take the Index width into account.
This change does not affect any in-tree target. I added tests to cover data layouts with explicitly specified index size.

Differential Revision: https://reviews.llvm.org/D42123

llvm-svn: 325102
2018-02-14 06:58:08 +00:00
Mohammad Shahid 3a934d6ab9 Revert r320548:[SLP] Vectorize jumbled memory loads
llvm-svn: 321181
2017-12-20 15:26:59 +00:00
Mohammad Shahid dbd30edb7f [SLP] Vectorize jumbled memory loads.
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask' of
jumbled accesses.

This patch fixes the mask representation by recording the 'use mask' in the usertree entry.

Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df

Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh

Reviewed By: Ayal

Subscribers: mgrang, dcaballe, hans, mzolotukhin

Differential Revision: https://reviews.llvm.org/D36130

llvm-svn: 320548
2017-12-13 03:08:29 +00:00
Dorit Nuzman eb13dd3eac [LV/LAA] Avoid specializing a loop for stride=1 when this predicate implies a
single-iteration loop

This fixes PR34681. Avoid adding the "Stride == 1" predicate when we know that
Stride >= Trip-Count. Such a predicate will effectively optimize a single
or zero iteration loop, as Trip-Count <= Stride == 1.

Differential Revision: https://reviews.llvm.org/D38785

llvm-svn: 317438
2017-11-05 16:53:15 +00:00
Adam Nemet 0965da2055 Rename OptimizationDiagnosticInfo.* to OptimizationRemarkEmitter.*
Sync it up with the name of the class actually defined here.  This has been
bothering me for a while...

llvm-svn: 315249
2017-10-09 23:19:02 +00:00
Hans Wennborg 9a9048e19f Revert r314806 "[SLP] Vectorize jumbled memory loads."
All the buildbots are red, e.g.
http://lab.llvm.org:8011/builders/clang-cmake-aarch64-lld/builds/2436/

> Summary:
> This patch tries to vectorize loads of consecutive memory accesses, accessed
> in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
> which was reverted back due to some basic issue with representing the 'use mask' of
> jumbled accesses.
>
> This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
>
> Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
>
> Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh
>
> Reviewed By: Ayal
>
> Subscribers: hans, mzolotukhin
>
> Differential Revision: https://reviews.llvm.org/D36130

llvm-svn: 314824
2017-10-03 18:32:29 +00:00
Mohammad Shahid 1d5422f27f [SLP] Vectorize jumbled memory loads.
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask' of
jumbled accesses.

This patch fixes the mask representation by recording the 'use mask' in the usertree entry.

Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df

Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh

Reviewed By: Ayal

Subscribers: hans, mzolotukhin

Differential Revision: https://reviews.llvm.org/D36130

llvm-svn: 314806
2017-10-03 15:28:48 +00:00
Hans Wennborg 57c3341ada Revert r313771 "[SLP] Vectorize jumbled memory loads."
This broke the buildbots, e.g.
http://bb.pgr.jp/builders/test-llvm-i686-linux-RA/builds/391

> Summary:
> This patch tries to vectorize loads of consecutive memory accesses, accessed
> in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
> which was reverted back due to some basic issue with representing the 'use mask'
> jumbled accesses.
>
> This patch fixes the mask representation by recording the 'use mask' in the usertree entry.
>
> Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df
>
> Subscribers: mzolotukhin
>
> Reviewed By: ayal
>
> Differential Revision: https://reviews.llvm.org/D36130
>
> Review comments updated accordingly
>
> Change-Id: I22ab0a8a9bac9d49d74baa81a08e1e486f5e75f0
>
> Added a TODO for sortLoadAccesses API
>
> Change-Id: I3c679bf1865422d1b45e17ea28f1992bca660b58
>
> Modified the TODO for sortLoadAccesses API
>
> Change-Id: Ie64a66cb5f9e2a7610438abb0e750c6e090f9565
>
> Review comment update for using OpdNum to insert the mask in respective location
>
> Change-Id: I016d0c1b29874e979efc0205bbf078991f92edce
>
> Fixes '-Wsign-compare warning' in LoopAccessAnalysis.cpp and code rebase
>
> Change-Id: I64b2ea5e68c1d7b6a028f5ef8251c5a97333f89b

llvm-svn: 313781
2017-09-20 18:00:03 +00:00
Mohammad Shahid 2b281de576 [SLP] Vectorize jumbled memory loads.
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask'
jumbled accesses.

This patch fixes the mask representation by recording the 'use mask' in the usertree entry.

Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df

Subscribers: mzolotukhin

Reviewed By: ayal

Differential Revision: https://reviews.llvm.org/D36130

Review comments updated accordingly

Change-Id: I22ab0a8a9bac9d49d74baa81a08e1e486f5e75f0

Added a TODO for sortLoadAccesses API

Change-Id: I3c679bf1865422d1b45e17ea28f1992bca660b58

Modified the TODO for sortLoadAccesses API

Change-Id: Ie64a66cb5f9e2a7610438abb0e750c6e090f9565

Review comment update for using OpdNum to insert the mask in respective location

Change-Id: I016d0c1b29874e979efc0205bbf078991f92edce

Fixes '-Wsign-compare warning' in LoopAccessAnalysis.cpp and code rebase

Change-Id: I64b2ea5e68c1d7b6a028f5ef8251c5a97333f89b
llvm-svn: 313771
2017-09-20 17:19:57 +00:00
Alexander Kornienko 6a140234ed Revert r313736: "[SLP] Vectorize jumbled memory loads."
The revision breaks buildbots:
http://lab.llvm.org:8011/builders/clang-x86_64-debian-fast/builds/6694/steps/test/logs/stdio

llvm-svn: 313758
2017-09-20 14:53:07 +00:00
Alexander Kornienko 7302344bdf Revert r313753: "Fix a -Wsign-compare warning in LoopAccessAnalysis.cpp"
llvm-svn: 313757
2017-09-20 14:52:56 +00:00
Alexander Kornienko 6c629b5728 Fix a -Wsign-compare warning in LoopAccessAnalysis.cpp
llvm-svn: 313753
2017-09-20 12:18:22 +00:00
Mohammad Shahid f8db9bd857 [SLP] Vectorize jumbled memory loads.
Summary:
This patch tries to vectorize loads of consecutive memory accesses, accessed
in non-consecutive or jumbled way. An earlier attempt was made with patch D26905
which was reverted back due to some basic issue with representing the 'use mask' of
jumbled accesses.

This patch fixes the mask representation by recording the 'use mask' in the usertree entry.

Change-Id: I9fe7f5045f065d84c126fa307ef6ebe0787296df

Reviewers: mkuper, loladiro, Ayal, zvi, danielcdh

Reviewed By: Ayal

Subscribers: mzolotukhin

Differential Revision: https://reviews.llvm.org/D36130

Commit after rebase for patch D36130

Change-Id: I8add1c265455669ef288d880f870a9522c8c08ab
llvm-svn: 313736
2017-09-20 08:18:28 +00:00
Alon Kom 682cfc1d4c [LV] Fix maximum legal VF calculation
This patch fixes pr34283, which exposed that the computation of
maximum legal width for vectorization was wrong, because it relied
on MaxInterleaveFactor to obtain the maximum stride used in the loop,
however not all strided accesses in the loop have an interleave-group
associated with them.
Instead of recording the maximum stride in the loop, which can be over
conservative (e.g. if the access with the maximum stride is not involved
in the dependence limitation), this patch tracks the actual maximum legal
width imposed by accesses that are involved in dependencies.

Differential Revision: https://reviews.llvm.org/D37507

llvm-svn: 313237
2017-09-14 07:40:02 +00:00
Silviu Baranga ac920f7716 [LAA] Allow more run-time alias checks by coercing pointer expressions to AddRecExprs
Summary:
LAA can only emit run-time alias checks for pointers with affine AddRec
SCEV expressions. However, non-AddRecExprs can be now be converted to
affine AddRecExprs using SCEV predicates.

This change tries to add the minimal set of SCEV predicates in order
to enable run-time alias checking.

Reviewers: anemet, mzolotukhin, mkuper, sanjoy, hfinkel

Reviewed By: hfinkel

Subscribers: mssimpso, Ayal, dorit, roman.shirokiy, mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D17080

llvm-svn: 313012
2017-09-12 07:48:22 +00:00
James Molloy 37dd4d7aaa [LAA] Correctly return a half-open range in expandBounds
This is a latent bug that's been hanging around for a while. For a loop-invariant
pointer, expandBounds would return the range {Ptr, Ptr}, but this was interpreted
as a half-open range, not a closed range. So we ended up planting incorrect
bounds checks. Even worse, they were tautological, so we ended up incorrectly
executing the optimized loop.

llvm-svn: 299526
2017-04-05 09:24:26 +00:00
Michael Kuperstein 5fb39a7966 [SLP] Revert everything that has to do with memory access sorting.
This reverts r293386, r294027, r294029 and r296411.

Turns out the SLP tree isn't actually a "tree" and we don't handle
accessing the same packet of loads in several different orders well,
causing miscompiles.

Revert until we can fix this properly.

llvm-svn: 297493
2017-03-10 18:59:07 +00:00
Amjad Aboud 5448e989a5 [SLP] Fixed non-deterministic behavior in Loop Vectorizer.
Differential Revision: https://reviews.llvm.org/D30638

llvm-svn: 297257
2017-03-08 05:09:10 +00:00
Michael Kuperstein 768d013a03 [SLP] Revert r296863 due to miscompiles.
Details and reproducer are on the email thread for r296863.

llvm-svn: 297103
2017-03-06 23:54:51 +00:00
Mohammad Shahid bdac9f30c0 [SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.It also needs to recompute the proper Lane for
external use of vectorizable scalars based on shuffle mask.

Reviewers: mkuper

Differential Revision: https://reviews.llvm.org/D30159

Change-Id: Ide8773ce0ad3562f3cf4d1a0ad0f487e2f60ce5d
llvm-svn: 296863
2017-03-03 10:02:47 +00:00
Hans Wennborg cc4ff78c9d Revert r296575 "[SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available"
It caused miscompiles, e.g. in Chromium (PR32109).

llvm-svn: 296654
2017-03-01 18:57:16 +00:00
Mohammad Shahid 175ffa8c35 [SLP] Fixes the bug due to absence of in order uses of scalars which needs to be available
for VectorizeTree() API.This API uses it for proper mask computation to be used in shufflevector IR.
The fix is to compute the mask for out of order memory accesses while building the vectorizable tree
instead of actual vectorization of vectorizable tree.

Reviewers: mkuper

Differential Revision: https://reviews.llvm.org/D30159

Change-Id: Id1e287f073fa4959713ba545fa4254db5da8b40d
llvm-svn: 296575
2017-03-01 03:51:54 +00:00
Michael Kuperstein c07cca85fb [SLP] Load sorting should not try to sort things that aren't loads.
We may get a VL where the first element is a load, but the others
aren't. Trying to sort such VLs can only lead to sorrow.

llvm-svn: 296411
2017-02-27 23:18:11 +00:00
Adam Nemet 41b019a39c [LAA] Remove unused LoopAccessReport
The need for this removed when I converted everything to use the opt-remark
classes directly with the streaming interface.

llvm-svn: 296017
2017-02-23 21:17:36 +00:00
Matthew Simpson a899f86054 [LAA] Remove unused code (NFC)
llvm-svn: 295493
2017-02-17 20:46:52 +00:00
Dorit Nuzman eac89d736c [LV/LoopAccess] Check statically if an unknown dependence distance can be
proven larger than the loop-count

This fixes PR31098: Try to resolve statically data-dependences whose
compile-time-unknown distance can be proven larger than the loop-count, 
instead of resorting to runtime dependence checking (which are not always 
possible).

For vectorization it is sufficient to prove that the dependence distance 
is >= VF; But in some cases we can prune unknown dependence distances early,
and even before selecting the VF, and without a runtime test, by comparing 
the distance against the loop iteration count. Since the vectorized code 
will be executed only if LoopCount >= VF, proving distance >= LoopCount 
also guarantees that distance >= VF. This check is also equivalent to the 
Strong SIV Test.

Reviewers: mkuper, anemet, sanjoy

Differential Revision: https://reviews.llvm.org/D28044

llvm-svn: 294892
2017-02-12 09:32:53 +00:00
Michael Kuperstein 2a735b71b6 [SLP] Make sortMemAccesses explicitly return an error. NFC.
llvm-svn: 294029
2017-02-03 19:32:50 +00:00
Michael Kuperstein 723999d4aa [SLP] Use SCEV to sort memory accesses.
This generalizes memory access sorting to use differences between SCEVs,
instead of relying on constant offsets. That allows us to properly do
SLP vectorization of non-sequentially ordered loads within loops bodies.

Differential Revision: https://reviews.llvm.org/D29425

llvm-svn: 294027
2017-02-03 19:09:45 +00:00
Mohammad Shahid 3121334d32 [SLP] Vectorize loads of consecutive memory accesses, accessed in non-consecutive (jumbled) way.
The jumbled scalar loads will be sorted while building the tree and these accesses will be marked to generate shufflevector after the vectorized load with proper mask.

Reviewers: hfinkel, mssimpso, mkuper

Differential Revision: https://reviews.llvm.org/D26905

Change-Id: I9c0c8e6f91a00076a7ee1465440a3f6ae092f7ad
llvm-svn: 293386
2017-01-28 17:59:44 +00:00
Chandler Carruth 3bab7e1a79 [PM] Separate the LoopAnalysisManager from the LoopPassManager and move
the latter to the Transforms library.

While the loop PM uses an analysis to form the IR units, the current
plan is to have the PM itself establish and enforce both loop simplified
form and LCSSA. This would be a layering violation in the analysis
library.

Fundamentally, the idea behind the loop PM is to *transform* loops in
addition to running passes over them, so it really seemed like the most
natural place to sink this was into the transforms library.

We can't just move *everything* because we also have loop analyses that
rely on a subset of the invariants. So this patch splits the the loop
infrastructure into the analysis management that has to be part of the
analysis library, and the transform-aware pass manager.

This also required splitting the loop analyses' printer passes out to
the transforms library, which makes sense to me as running these will
transform the code into LCSSA in theory.

I haven't split the unittest though because testing one component
without the other seems nearly intractable.

Differential Revision: https://reviews.llvm.org/D28452

llvm-svn: 291662
2017-01-11 09:43:56 +00:00
Chandler Carruth 410eaeb064 [PM] Rewrite the loop pass manager to use a worklist and augmented run
arguments much like the CGSCC pass manager.

This is a major redesign following the pattern establish for the CGSCC layer to
support updates to the set of loops during the traversal of the loop nest and
to support invalidation of analyses.

An additional significant burden in the loop PM is that so many passes require
access to a large number of function analyses. Manually ensuring these are
cached, available, and preserved has been a long-standing burden in LLVM even
with the help of the automatic scheduling in the old pass manager. And it made
the new pass manager extremely unweildy. With this design, we can package the
common analyses up while in a function pass and make them immediately available
to all the loop passes. While in some cases this is unnecessary, I think the
simplicity afforded is worth it.

This does not (yet) address loop simplified form or LCSSA form, but those are
the next things on my radar and I have a clear plan for them.

While the patch is very large, most of it is either mechanically updating loop
passes to the new API or the new testing for the loop PM. The code for it is
reasonably compact.

I have not yet updated all of the loop passes to correctly leverage the update
mechanisms demonstrated in the unittests. I'll do that in follow-up patches
along with improved FileCheck tests for those passes that ensure things work in
more realistic scenarios. In many cases, there isn't much we can do with these
until the loop simplified form and LCSSA form are in place.

Differential Revision: https://reviews.llvm.org/D28292

llvm-svn: 291651
2017-01-11 06:23:21 +00:00
Keno Fischer 92f377bd74 [LAA] Prevent invalid IR for loop-invariant bound in loop body
Summary:
If LAA expands a bound that is loop invariant, but not hoisted out
of the loop body, it used to use that value anyway, causing a
non-domination error, because the memcheck block is of course not
dominated by the scalar loop body. Detect this situation and expand
the SCEV expression instead.

Fixes PR31251

Reviewers: anemet
Subscribers: mzolotukhin, llvm-commits

Differential Revision: https://reviews.llvm.org/D27397

llvm-svn: 288705
2016-12-05 21:25:03 +00:00
Eugene Zelenko a3fe70d233 Fix some Clang-tidy and Include What You Use warnings; other minor fixes (NFC).
This preparation to remove SetVector.h dependency on SmallSet.h.

llvm-svn: 288256
2016-11-30 17:48:10 +00:00
Chandler Carruth dab4eae274 [PM] Change the static object whose address is used to uniquely identify
analyses to have a common type which is enforced rather than using
a char object and a `void *` type when used as an identifier.

This has a number of advantages. First, it at least helps some of the
confusion raised in Justin Lebar's code review of why `void *` was being
used everywhere by having a stronger type that connects to documentation
about this.

However, perhaps more importantly, it addresses a serious issue where
the alignment of these pointer-like identifiers was unknown. This made
it hard to use them in pointer-like data structures. We were already
dodging this in dangerous ways to create the "all analyses" entry. In
a subsequent patch I attempted to use these with TinyPtrVector and
things fell apart in a very bad way.

And it isn't just a compile time or type system issue. Worse than that,
the actual alignment of these pointer-like opaque identifiers wasn't
guaranteed to be a useful alignment as they were just characters.

This change introduces a type to use as the "key" object whose address
forms the opaque identifier. This both forces the objects to have proper
alignment, and provides type checking that we get it right everywhere.
It also makes the types somewhat less mysterious than `void *`.

We could go one step further and introduce a truly opaque pointer-like
type to return from the `ID()` static function rather than returning
`AnalysisKey *`, but that didn't seem to be a clear win so this is just
the initial change to get to a reliably typed and aligned object serving
is a key for all the analyses.

Thanks to Richard Smith and Justin Lebar for helping pick plausible
names and avoid making this refactoring many times. =] And thanks to
Sean for the super fast review!

While here, I've tried to move away from the "PassID" nomenclature
entirely as it wasn't really helping and is overloaded with old pass
manager constructs. Now we have IDs for analyses, and key objects whose
address can be used as IDs. Where possible and clear I've shortened this
to just "ID". In a few places I kept "AnalysisID" to make it clear what
was being identified.

Differential Revision: https://reviews.llvm.org/D27031

llvm-svn: 287783
2016-11-23 17:53:26 +00:00