If the shift amount is known, we can determine the known bits of the
output based on the known bits of two inputs.
This is essentially the same functionality as implemented in D54869,
but for ValueTracking rather than InstCombine SimplifyDemandedBits.
Differential Revision: https://reviews.llvm.org/D55140
llvm-svn: 348091
Generalize the existing MatchSelectPatternTest class to also work
with other types of tests. This reduces the amount of boilerplate
necessary to write ValueTracking tests in general, and computeKnownBits
tests in particular.
The inherited convention is that the function must be @test and the
tested instruction %A.
Differential Revision: https://reviews.llvm.org/D55141
llvm-svn: 348043
Every Analysis pass has a get method that returns a reference of the Result of
the Analysis, for example, BlockFrequencyInfo
&BlockFrequencyInfoWrapperPass::getBFI(). I believe that
ProfileSummaryInfo::getPSI() is the only exception to that, as it was returning
a pointer.
Another change is renaming isHotBB and isColdBB to isHotBlock and isColdBlock,
respectively. Most methods use BB as the argument of variable names while
methods usually refer to Basic Blocks as Blocks, instead of BB. For example,
Function::getEntryBlock, Loop:getExitBlock, etc.
I also fixed one of the comments.
Patch by Rodrigo Caetano Rocha!
Differential Revision: https://reviews.llvm.org/D54669
llvm-svn: 347182
We have a lot of various bugs that are caused by misuse of SCEV (in particular in LV),
all of them can simply be described as "we ask SCEV to prove some fact on invalid IR".
Some of examples of those are PR36311, PR37221, PR39160.
The problem is that these failues manifest differently (what we saw was failure of various
asserts across SCEV, but there can also be miscompiles). This patch adds an assert into two
SCEV methods that strongly rely on correctness of the IR and are involved in known failues.
This will at least allow us to have a clear indication of what was wrong in this case.
This patch also fixes a unit test with incorrect IR that fails this verification.
Differential Revision: https://reviews.llvm.org/D52930
Reviewed By: fhahn
llvm-svn: 346389
In PR39475:
https://bugs.llvm.org/show_bug.cgi?id=39475
..we may fail to recognize/simplify fabs() in some cases because we do not
canonicalize fcmp with a -0.0 operand.
Adding that canonicalization can cause regressions on min/max FP tests, so
that's this patch: for the purpose of determining whether something is min/max,
let the value returned by the select determine how we treat a 0.0 operand in the fcmp.
This patch doesn't actually change the -0.0 to +0.0. It just changes the analysis, so
we don't fail to recognize equivalent min/max patterns that only differ in the
signbit of 0.0.
Differential Revision: https://reviews.llvm.org/D54001
llvm-svn: 346097
This patch gives the IR ComputeNumSignBits the same functionality as the
DAG version (the code is derived from the existing code).
This an extension of the single input shuffle analysis added with D53659.
Differential Revision: https://reviews.llvm.org/D53987
llvm-svn: 346071
Summary:
Changes all uses of minnan/maxnan to minimum/maximum
globally. These names emphasize that the semantic difference between
these operations is more than just NaN-propagation.
Reviewers: arsenm, aheejin, dschuff, javed.absar
Subscribers: jholewinski, sdardis, wdng, sbc100, jgravelle-google, jrtc27, atanasyan, llvm-commits
Differential Revision: https://reviews.llvm.org/D53112
llvm-svn: 345218
Summary:
This is patch 2 of the new DivergenceAnalysis (https://reviews.llvm.org/D50433).
This patch contains a generic divergence analysis implementation for
unstructured, reducible Control-Flow Graphs. It contains two new classes.
The `SyncDependenceAnalysis` class lazily computes sync dependences, which
relate divergent branches to points of joining divergent control. The
`DivergenceAnalysis` class contains the generic divergence analysis
implementation.
Reviewers: nhaehnle
Reviewed By: nhaehnle
Subscribers: sameerds, kristina, nhaehnle, xbolva00, tschuett, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D51491
llvm-svn: 344734
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
There are places where we need to merge multiple LocationSizes of
different sizes into one, and get a sensible result.
There are other places where we want to optimize aggressively based on
the value of a LocationSizes (e.g. how can a store of four bytes be to
an area of storage that's only two bytes large?)
This patch makes LocationSize hold an 'imprecise' bit to note whether
the LocationSize can be treated as an upper-bound and lower-bound for
the size of a location, or just an upper-bound.
This concludes the series of patches leading up to this. The most recent
of which is r344108.
Fixes PR36228.
Differential Revision: https://reviews.llvm.org/D44748
llvm-svn: 344114
Summary:
This CL allows constant vectors of floats to be recognized as non-NaN
and non-zero in select patterns. This change makes
`matchSelectPattern` more powerful generally, but was motivated
specifically because I wanted fminnan and fmaxnan to be created for
vector versions of the scalar patterns they are created for.
Tested with check-all on all targets. A testcase in the WebAssembly
backend that tests the non-nan codepath is in an upcoming CL.
Reviewers: aheejin, dschuff
Subscribers: sunfish, llvm-commits
Differential Revision: https://reviews.llvm.org/D52324
llvm-svn: 343364
Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@
The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.
Here we get a basic implementation consisting of:
* PassInstrumentationCallbacks class that handles registration of callbacks
and access to them.
* PassInstrumentation class that handles instrumentation-point interfaces
that call into PassInstrumentationCallbacks.
* Callbacks accept StringRef which is just a name of the Pass right now.
There were some ideas to pass an opaque wrapper for the pointer to pass instance,
however it appears that pointer does not actually identify the instance
(adaptors and managers might have the same address with the pass they govern).
Hence it was decided to go simple for now and then later decide on what the proper
mental model of identifying a "pass in a phase of pipeline" is.
* Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies
on different IRUnits (e.g. Analyses).
* PassInstrumentationAnalysis analysis is explicitly requested from PassManager through
usual AnalysisManager::getResult. All pass managers were updated to run that
to get PassInstrumentation object for instrumentation calls.
* Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra
args out of a generic PassManager's extra args. This is the only way I was able to explicitly
run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or
RepeatedPass::run.
TODO: Upon lengthy discussions we agreed to accept this as an initial implementation
and then get rid of getAnalysisResult by improving RepeatedPass implementation.
* PassBuilder takes PassInstrumentationCallbacks object to pass it further into
PassInstrumentationAnalysis. Callbacks registration should be performed directly
through PassInstrumentationCallbacks.
* new-pm tests updated to account for PassInstrumentationAnalysis being run
* Added PassInstrumentation tests to PassBuilderCallbacks unit tests.
Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.
Made getName helper to return std::string (instead of StringRef initially) to fix
asan builtbot failures on CGSCC tests.
Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D47858
llvm-svn: 342664
Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@
The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.
Here we get a basic implementation consisting of:
* PassInstrumentationCallbacks class that handles registration of callbacks
and access to them.
* PassInstrumentation class that handles instrumentation-point interfaces
that call into PassInstrumentationCallbacks.
* Callbacks accept StringRef which is just a name of the Pass right now.
There were some ideas to pass an opaque wrapper for the pointer to pass instance,
however it appears that pointer does not actually identify the instance
(adaptors and managers might have the same address with the pass they govern).
Hence it was decided to go simple for now and then later decide on what the proper
mental model of identifying a "pass in a phase of pipeline" is.
* Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies
on different IRUnits (e.g. Analyses).
* PassInstrumentationAnalysis analysis is explicitly requested from PassManager through
usual AnalysisManager::getResult. All pass managers were updated to run that
to get PassInstrumentation object for instrumentation calls.
* Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra
args out of a generic PassManager's extra args. This is the only way I was able to explicitly
run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or
RepeatedPass::run.
TODO: Upon lengthy discussions we agreed to accept this as an initial implementation
and then get rid of getAnalysisResult by improving RepeatedPass implementation.
* PassBuilder takes PassInstrumentationCallbacks object to pass it further into
PassInstrumentationAnalysis. Callbacks registration should be performed directly
through PassInstrumentationCallbacks.
* new-pm tests updated to account for PassInstrumentationAnalysis being run
* Added PassInstrumentation tests to PassBuilderCallbacks unit tests.
Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.
Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D47858
llvm-svn: 342597
Summary:
Pass Execution Instrumentation interface enables customizable instrumentation
of pass execution, as per "RFC: Pass Execution Instrumentation interface"
posted 06/07/2018 on llvm-dev@
The intent is to provide a common machinery to implement all
the pass-execution-debugging features like print-before/after,
opt-bisect, time-passes etc.
Here we get a basic implementation consisting of:
* PassInstrumentationCallbacks class that handles registration of callbacks
and access to them.
* PassInstrumentation class that handles instrumentation-point interfaces
that call into PassInstrumentationCallbacks.
* Callbacks accept StringRef which is just a name of the Pass right now.
There were some ideas to pass an opaque wrapper for the pointer to pass instance,
however it appears that pointer does not actually identify the instance
(adaptors and managers might have the same address with the pass they govern).
Hence it was decided to go simple for now and then later decide on what the proper
mental model of identifying a "pass in a phase of pipeline" is.
* Callbacks accept llvm::Any serving as a wrapper for const IRUnit*, to remove direct dependencies
on different IRUnits (e.g. Analyses).
* PassInstrumentationAnalysis analysis is explicitly requested from PassManager through
usual AnalysisManager::getResult. All pass managers were updated to run that
to get PassInstrumentation object for instrumentation calls.
* Using tuples/index_sequence getAnalysisResult helper to extract generic AnalysisManager's extra
args out of a generic PassManager's extra args. This is the only way I was able to explicitly
run getResult for PassInstrumentationAnalysis out of a generic code like PassManager::run or
RepeatedPass::run.
TODO: Upon lengthy discussions we agreed to accept this as an initial implementation
and then get rid of getAnalysisResult by improving RepeatedPass implementation.
* PassBuilder takes PassInstrumentationCallbacks object to pass it further into
PassInstrumentationAnalysis. Callbacks registration should be performed directly
through PassInstrumentationCallbacks.
* new-pm tests updated to account for PassInstrumentationAnalysis being run
* Added PassInstrumentation tests to PassBuilderCallbacks unit tests.
Other unit tests updated with registration of the now-required PassInstrumentationAnalysis.
Reviewers: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D47858
llvm-svn: 342544
The previous implementation traversed all loop blocks and bailed if one
was not a latch block. Since we are only interested in latch blocks, we
should only traverse those.
llvm-svn: 341926
Summary:
End goal is to update MemorySSA in all loop passes. LoopUnswitch clones all blocks in a loop. SimpleLoopUnswitch clones some blocks. LoopRotate clones some instructions.
Some of these loop passes also make CFG changes.
This is an API based on what I found needed in LoopUnswitch, SimpleLoopUnswitch, LoopRotate, LoopInstSimplify, LoopSimplifyCFG.
Adding dependent patches using this API for context.
Reviewers: george.burgess.iv, dberlin
Subscribers: sanjoy, jlebar, Prazek, llvm-commits
Differential Revision: https://reviews.llvm.org/D45299
llvm-svn: 341855
These classes don't make any changes to IR and have no reason to be in
Transform/Utils. This patch moves them to Analysis folder. This will allow
us reusing these classes in some analyzes, like MustExecute.
llvm-svn: 341015
In order for more complex updates of MSSA to happen (e.g. those in
D45299), MemoryDefs need to be actual `Use`s of what they're optimized
to. This patch makes that happen.
In addition, this patch changes our optimization behavior for Defs
slightly: we'll now consider a Def optimization invalid if the
MemoryAccess it's optimized to changes. That we weren't doing this
before was a bug, but given that we were tracking these with a WeakVH
before, it was sort of difficult for that to matter.
We're already have both of these behaviors for MemoryUses. The
difference is that a MemoryUse's defining access is always its optimized
access, and defining accesses are always `Use`s (in the LLVM sense).
Nothing exploded when testing a stage3 clang+llvm locally, so...
This also includes the test-case promised in r340461.
llvm-svn: 340577
Summary:
Profile count of a block is computed by multiplying its block frequency
by entry count and dividing the result by entry block frequency. Do
rounded division in the last step and update test cases appropriately.
Reviewers: davidxl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D50822
llvm-svn: 339835
MemorySSA currently creates MemoryAccesses for lifetime intrinsics, and
sometimes treats them as clobbers. This may/may not be the best way
forward, but while we're doing it, we should consider
MayAlias/PartialAlias to be clobbers.
The ideal fix here is probably to remove all of this reasoning about
lifetimes from MemorySSA + put it into the passes that need to care. But
that's a wayyy broader fix that needs some consensus, and we have
miscompiles + a release branch today, and this should solve the
miscompiles just as well.
differential revision is D43269. Landing without an explicit LGTM (and
without using the special please-autoclose-this syntax) so we can still
use that revision as a place to decide what the right fix here is.
llvm-svn: 339411
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
This pass is being added in order to make the information available to BasicAA,
which can't do caching of this information itself, but possibly this information
may be useful for other passes.
Incorporates code based on Daniel Berlin's implementation of Tarjan's algorithm.
Differential Revision: https://reviews.llvm.org/D47893
llvm-svn: 335857
Summary: If file stream arg is not captured and source is fopen, we could replace IO calls by unlocked IO ("_unlocked" function variants) to gain better speed,
Reviewers: efriedma, RKSimon, spatel, sanjoy, hfinkel, majnemer, lebedev.ri, rja
Reviewed By: rja
Subscribers: rja, srhines, efriedma, lebedev.ri, llvm-commits
Differential Revision: https://reviews.llvm.org/D45736
llvm-svn: 332452
r327219 added wrappers to std::sort which randomly shuffle the container before
sorting. This will help in uncovering non-determinism caused due to undefined
sorting order of objects having the same key.
To make use of that infrastructure we need to invoke llvm::sort instead of
std::sort.
Note: This patch is one of a series of patches to replace *all* std::sort to
llvm::sort. Refer the comments section in D44363 for a list of all the
required patches.
llvm-svn: 329475
Summary:
Clang's __builtin_operator_new/delete was recently taught about the aligned allocation overloads (r328134). This patch makes LLVM aware of them as well.
This allows the compiler to perform certain optimizations including eliding new/delete calls.
Reviewers: rsmith, majnemer, dblaikie, vsk, bkramer
Reviewed By: bkramer
Subscribers: ckennelly, llvm-commits
Differential Revision: https://reviews.llvm.org/D44769
llvm-svn: 329218
Summary:
Building MemorySSA gathers alias information for Defs/Uses.
Store and expose this information when optimizing uses (when building MemorySSA),
and when optimizing defs or updating uses (getClobberingMemoryAccess).
Current patch does not propagate alias information through MemoryPhis.
Reviewers: gbiv, dberlin
Subscribers: Prazek, sanjoy, llvm-commits
Differential Revision: https://reviews.llvm.org/D38569
llvm-svn: 327035
getCompare returns true, false or undef constants if the comparison can
be evaluated, or nullptr if it cannot. This is in line with what
ConstantExpr::getCompare returns. It also allows us to use
ConstantExpr::getCompare for comparing constants.
Reviewers: davide, mssimpso, dberlin, anna
Reviewed By: davide
Differential Revision: https://reviews.llvm.org/D43761
llvm-svn: 326720
The only cases I can come up with where this invalidation needs to
happen is when there's a deletion somewhere. If we find more creative
test-cases, we can probably go with another approach mentioned on
PR36529.
Fixes PR36529.
llvm-svn: 326177
SCEV tracks the correspondence of created SCEV to original instruction.
However during creation of SCEV it is possible that nuw/nsw/exact flags are
lost.
As a result during expansion of the SCEV the instruction with nuw/nsw/exact
will be used where it was expected and we produce poison incorreclty.
Reviewers: sanjoy, mkazantsev, sebpop, jbhateja
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41578
llvm-svn: 322058
InsertBinop tries to find an appropriate instruction instead of
creating a new instruction. When it checks whether instruction is
the same as we need to create it ignores nuw/nsw/exact flags.
It leads to invalid behavior when poison instruction can be used
when it was not expected. Specifically, for example Expander
expands the SCEV built for instruction
%a = add i32 %v, 1
It is possible that InsertBinop can find an instruction
% b = add nuw nsw i32 %v, 1
and will use it instead of version w/o nuw nsw.
It is incorrect.
The patch conservatively ignores all instructions with any of
poison flags installed.
Reviewers: sanjoy, mkazantsev, sebpop, jbhateja
Reviewed By: sanjoy
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D41576
llvm-svn: 321475
When unsafe algerbra is allowed calls to cabs(r) can be replaced by:
sqrt(creal(r)*creal(r) + cimag(r)*cimag(r))
Patch by Paul Walker, thanks!
Differential Revision: https://reviews.llvm.org/D40069
llvm-svn: 320901
When the lowest bits of the operands to an integer multiply are known, the low bits of the result are deducible.
Code to deduce known-zero bottom bits already existed, but this change improves on that by deducing known-ones.
Patch by: Pedro Ferreira
Reviewers: craig.topper, sanjoy, efriedma
Differential Revision: https://reviews.llvm.org/D34029
llvm-svn: 320269
Summary:
Make enum ModRefInfo an enum class. Changes to ModRefInfo values should
be done using inline wrappers.
This should prevent future bit-wise opearations from being added, which can be more error-prone.
Reviewers: sanjoy, dberlin, hfinkel, george.burgess.iv
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D40933
llvm-svn: 320107
This function checks that:
1) It is safe to expand a SCEV;
2) It is OK to materialize it at the specified location.
For example, attempt to expand a loop's AddRec to the same loop's preheader should fail.
Differential Revision: https://reviews.llvm.org/D39236
llvm-svn: 318377
This reverts commit r315713. It causes PR34968.
I think I know what the problem is, but I don't think I'll have time to fix it
this week.
llvm-svn: 315962
Nikita Popov