Commit Graph

8339 Commits

Author SHA1 Message Date
Max Kazantsev bf00f03f56 [NFC] Sanitizing asserts for OrderedBasicBlock
llvm-svn: 341917
2018-09-11 08:46:19 +00:00
Max Kazantsev 90edc98c58 [NFC] Rename variable
llvm-svn: 341901
2018-09-11 05:10:01 +00:00
Peter Collingbourne c7d281905b Prevent Constant Folding From Optimizing inrange GEP
This patch does the following things:

1. update SymbolicallyEvaluateGEP so that it bails out if it cannot preserve inrange arribute;
2. update llvm/test/Analysis/ConstantFolding/gep.ll to remove UB in it;
3. remove inaccurate comment above ConstantFoldInstOperandsImpl in llvm/lib/Analysis/ConstantFolding.cpp;
4. add a new regression test that makes sure that no optimizations change an inrange GEP in an unexpected way.

Patch by Zhaomo Yang!

Differential Revision: https://reviews.llvm.org/D51698

llvm-svn: 341888
2018-09-11 01:53:36 +00:00
Alina Sbirlea 7980099adb API to update MemorySSA for cloned blocks and added CFG edges.
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
2018-09-10 20:13:01 +00:00
Philip Reames 5660bd460b [AST] Visit memtransfer arguments in order
The only point to this change is the test diffs.  When I remove this code entirely (in favor of the recently added generic handling), I don't want there to be any confusion due to spurious test diffs.

As an aside, the fact out tests are AST construction order dependent is not great.  I thought about fixing that, but the reasonable schemes I might want (e.g. sort by name) need the test diffs anyways.

Philip

llvm-svn: 341841
2018-09-10 16:00:27 +00:00
Alina Sbirlea 65f385da63 [MemorySSA] Relax verification of clobbering accesses.
llvm-svn: 341733
2018-09-07 23:51:41 +00:00
Philip Reames cb8b3278e5 [AST] Generalize argument specific aliasing
AliasSetTracker has special case handling for memset, memcpy and memmove which pre-existed argmemonly on functions and readonly and writeonly on arguments. This patch generalizes it using the AA infrastructure to any call correctly annotated.

The motivation here is to cut down on confusion, not performance per se. For most instructions, there is a direct mapping to alias set. However, this is not guaranteed by the interface and was not in fact true for these three intrinsics *and only these three intrinsics*. I kept getting myself confused about this invariant, so I figured it would be good to clearly distinguish between a instructions and alias sets. Calls happened to be an easy target.

The nice side effect is that custom implementations of memset/memcpy/memmove - including wrappers discovered by IPO - can now be optimized the same as builts by LICM.

Note: The actual removal of the memset/memtransfer specific handling will happen in a follow on NFC patch.  It was originally part of this one, but separate for ease of review and rebase.

Differential Revision: https://reviews.llvm.org/D50730

llvm-svn: 341713
2018-09-07 21:36:11 +00:00
Alina Sbirlea f98c2c5e6d [MemorySSA] Update MemoryPhi wiring for block splitting to consider if identical edges were merged.
Summary:
Block splitting is done with either identical edges being merged, or not.
Only critical edges can be split without merging identical edges based on an option.
Teach the memoryssa updater to take this into account: for the same edge between two blocks only move one entry from the Phi in Old to the new Phi in New.

Reviewers: george.burgess.iv

Subscribers: sanjoy, jlebar, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D51563

llvm-svn: 341709
2018-09-07 21:14:48 +00:00
Jessica Paquette a0aa5b35e7 Output per-function size-info remarks
This patch adds per-function size information remarks. Previously, passing
-Rpass-analysis=size-info would only give you per-module changes. By adding
the ability to do this per-function, it's easier to see which functions
contributed the most to size changes.

https://reviews.llvm.org/D51467

llvm-svn: 341588
2018-09-06 21:19:54 +00:00
Alina Sbirlea b23648cfdb [LoopPassManager] MemorySSA should be preserved when enabled.
llvm-svn: 341587
2018-09-06 20:54:24 +00:00
Max Kazantsev 6afebe1d30 [NFC] Simplify inner structure of InstructionPrecedenceTracking
Currently it has a set KnownBlocks that marks blocks as having cached
answers and a map FirstSpecialInsts that maps these blocks to first
special instructions in them. The value in the map is always non-null,
and for blocks that are known to have no special instructions the map
does not have an instance.

This patch removes KnownBlocks as obsolete. Instead, for blocks that
are known to have no special instructions, we just put a nullptr value.
This makes the code much easier to read.

llvm-svn: 341531
2018-09-06 09:29:42 +00:00
Max Kazantsev 8a9e059e5c Return "[NFC] Add severe validation of InstructionPrecedenceTracking"
This validation patch has been reverted as rL341147 because of conserns raised by
@reames. This revision returns it as is to raise a discussion and address the concerns.

Differential Revision: https://reviews.llvm.org/D51523
Reviewed By: reames

llvm-svn: 341526
2018-09-06 08:33:02 +00:00
Jessica Paquette 71e9778006 [NFC] Optionally pass a function to emitInstrCountChangedRemark
In basic block, loop, and function passes, we already have a function that
we can use to emit optimization remarks. We can use that instead of searching
the module for the first suitable function (that is, one that contains at
least one basic block.)

llvm-svn: 341253
2018-08-31 20:54:37 +00:00
Jessica Paquette 9a23c55920 [NFC] Pass the instruction delta to emitInstrCountChangedRemark
Instead of counting the size of the entire module every time we run a pass,
pass along a delta instead and use that to emit the remark.

This means we only have to use (on average) smaller IR units to calculate
instruction counts. E.g, in a BB pass, we only need to look at the delta of
the BB instead of the delta of the entire module.

6/6

(This improved compile time for size remarks on sqlite3 + O2 significantly)

llvm-svn: 341250
2018-08-31 20:20:57 +00:00
Jessica Paquette 1fc443b887 [NFC] Pre-calculate SCC IR counts in size remarks.
Same vein as the previous commits. Pre-calculate the size of
the module and use that to decide if we're going to emit a
remark.

This one comes with a FIXME and TODO. First off, CallGraphSCC
and CallGraphNode don't have a getInstructionCount function. So,
for now, we do the same thing as in a module pass.

Second off, we're not really saving anything here yet, because
as before, I need to change emitInstrCountChangedRemark to take
in a delta. Keeping the patches small though, so that's coming up
next.

5/6

llvm-svn: 341249
2018-08-31 20:20:56 +00:00
Jessica Paquette 872a4c92b2 [NFC] Pre-calculate loop IR counts in size remarks.
Another commit reducing compile time in size remarks.

Cache the size of the module and loop, and update values based
off of deltas instead. Avoid recalculating the size of the
whole module whenever possible.

3/6

llvm-svn: 341247
2018-08-31 20:20:54 +00:00
Max Kazantsev c683d643c9 Revert "[NFC] Add severe validation of InstructionPrecedenceTracking" for discussion
llvm-svn: 341147
2018-08-31 00:01:54 +00:00
Andrew Kaylor d9b6b81d08 Reverting r340807.
This patch restores the old behavior of getAllocationDataForFunction in MemoryBuiltins.cpp.

llvm-svn: 341091
2018-08-30 18:37:18 +00:00
Nicolai Haehnle 35617ed4cb [NFC] Rename the DivergenceAnalysis to LegacyDivergenceAnalysis
Summary:
This is patch 1 of the new DivergenceAnalysis (https://reviews.llvm.org/D50433).

The purpose of this patch is to free up the name DivergenceAnalysis for the new generic
implementation. The generic implementation class will be shared by specialized
divergence analysis classes.

Patch by: Simon Moll

Reviewed By: nhaehnle

Subscribers: jvesely, jholewinski, arsenm, nhaehnle, mgorny, jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D50434

Change-Id: Ie8146b11be2c50d5312f30e11c7a3036a15b48cb
llvm-svn: 341071
2018-08-30 14:21:36 +00:00
Max Kazantsev ec9b386820 [NFC] Add severe validation of InstructionPrecedenceTracking
llvm-svn: 341051
2018-08-30 10:26:06 +00:00
Max Kazantsev d3487bdb61 [NFC] Rename map to make the naming consistent
llvm-svn: 341043
2018-08-30 09:24:33 +00:00
Max Kazantsev d3a4cbe153 [NFC] Move OrderedInstructions and InstructionPrecedenceTracking to Analysis
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
2018-08-30 04:49:03 +00:00
Max Kazantsev 3c284bde3f Re-enable "[NFC] Unify guards detection"
rL340921 has been reverted by rL340923 due to linkage dependency
from Transform/Utils to Analysis which is not allowed. In this patch
this has been fixed, a new utility function moved to Analysis.

Differential Revision: https://reviews.llvm.org/D51152

llvm-svn: 341014
2018-08-30 03:39:16 +00:00
Alina Sbirlea 6edcc9ee86 [MemorySSA] Silence warning.
llvm-svn: 340995
2018-08-29 23:20:29 +00:00
Alina Sbirlea 5bce4d5a85 [MemorySSA] Fix checkClobberSanity to skip Start only for Defs and Uses.
llvm-svn: 340981
2018-08-29 22:38:51 +00:00
Philip Reames f562fc8dbf [LICM] Hoist stores of invariant values to invariant addresses out of loops
Teach LICM to hoist stores out of loops when the store writes to a location otherwise unused in the loop, writes a value which is invariant, and is guaranteed to execute if the loop is entered.

Worth noting is that this transformation is partially overlapping with the existing promotion transformation. Reasons this is worthwhile anyway include:
 * For multi-exit loops, this doesn't require duplication of the store.
 * It kicks in for case where we can't prove we exit through a normal exit (i.e. we may throw), but can prove the store executes before that possible side exit.

Differential Revision: https://reviews.llvm.org/D50925

llvm-svn: 340974
2018-08-29 21:49:30 +00:00
Alina Sbirlea f5403d83e7 [MemorySSA] Add expesive check for validating clobber accesses.
Summary: Add validation of clobber accesses as expensive check.

Reviewers: george.burgess.iv

Subscribers: sanjoy, jlebar, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D51327

llvm-svn: 340951
2018-08-29 18:26:04 +00:00
Hans Wennborg 2c390c54f6 Revert r340921 "[NFC] Unify guards detection"
This broke the build, see e.g.

http://lab.llvm.org:8011/builders/clang-cmake-armv8-lnt/builds/4626/
http://lab.llvm.org:8011/builders/clang-ppc64be-linux-lnt/builds/18647/
http://lab.llvm.org:8011/builders/clang-cmake-x86_64-avx2-linux/builds/5856/
http://lab.llvm.org:8011/builders/lld-x86_64-freebsd/builds/22800/

> We have multiple places in code where we try to identify whether or not
> some instruction is a guard. This patch factors out this logic into a separate
> utility function which works uniformly in all places.
>
> Differential Revision: https://reviews.llvm.org/D51152
> Reviewed By: fedor.sergeev

llvm-svn: 340923
2018-08-29 12:21:32 +00:00
Max Kazantsev 1dafaa87d9 [NFC] Unify guards detection
We have multiple places in code where we try to identify whether or not
some instruction is a guard. This patch factors out this logic into a separate
utility function which works uniformly in all places.

Differential Revision: https://reviews.llvm.org/D51152
Reviewed By: fedor.sergeev

llvm-svn: 340921
2018-08-29 11:37:34 +00:00
Fedor Sergeev 43083111a2 [NFC][PassTiming] factor out generic PassTimingInfo
Moving PassTimingInfo from legacy pass manager code into a separate header.
Making it suitable for both legacy and new pass manager.
Adding a test on -time-passes main functionality.

llvm-svn: 340872
2018-08-28 21:06:51 +00:00
David Chisnall 5e52cadf89 Fix in getAllocationDataForFunction
Summary:
Correct to use set like behaviour of AllocType.  Should check for
subset, not precise value.

Reviewers: theraven

Reviewed By: theraven

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D50959

llvm-svn: 340807
2018-08-28 08:59:06 +00:00
George Burgess IV 6a9aa02ff3 [MemorySSA] Add NDEBUG checks to verifiers; NFC
verify*() methods are intended to have no side-effects (unless we detect
broken MSSA, in which case they assert()), and all of the other verify
methods are wrapped by `#ifndef NDEBUG`.

llvm-svn: 340793
2018-08-28 00:32:32 +00:00
Roman Tereshin 02320eee6b Revert "[SCEV][NFC] Check NoWrap flags before lexicographical comparison of SCEVs"
This reverts r319889.

Unfortunately, wrapping flags are not a part of SCEV's identity (they
do not participate in computing a hash value or in equality
comparisons) and in fact they could be assigned after the fact w/o
rebuilding a SCEV.

Grep for const_cast's to see quite a few of examples, apparently all
for AddRec's at the moment.

So, if 2 expressions get built in 2 slightly different ways: one with
flags set in the beginning, the other with the flags attached later
on, we may end up with 2 expressions which are exactly the same but
have their operands swapped in one of the commutative N-ary
expressions, and at least one of them will have "sorted by complexity"
invariant broken.

2 identical SCEV's won't compare equal by pointer comparison as they
are supposed to.

A real-world reproducer is added as a regression test: the issue
described causes 2 identical SCEV expressions to have different order
of operands and therefore compare not equal, which in its turn
prevents LoadStoreVectorizer from vectorizing a pair of consecutive
loads.

On a larger example (the source of the test attached, which is a
bugpoint) I have seen even weirder behavior: adding a constant to an
existing SCEV changes the order of the existing terms, for instance,
getAddExpr(1, ((A * B) + (C * D))) returns (1 + (C * D) + (A * B)).

Differential Revision: https://reviews.llvm.org/D40645

llvm-svn: 340777
2018-08-27 21:41:37 +00:00
Chandler Carruth 9ae926b973 [IR] Replace `isa<TerminatorInst>` with `isTerminator()`.
This is a bit awkward in a handful of places where we didn't even have
an instruction and now we have to see if we can build one. But on the
whole, this seems like a win and at worst a reasonable cost for removing
`TerminatorInst`.

All of this is part of the removal of `TerminatorInst` from the
`Instruction` type hierarchy.

llvm-svn: 340701
2018-08-26 09:51:22 +00:00
Chandler Carruth 96fc1de77d [IR] Begin removal of TerminatorInst by removing successor manipulation.
The core get and set routines move to the `Instruction` class. These
routines are only valid to call on instructions which are terminators.

The iterator and *generic* range based access move to `CFG.h` where all
the other generic successor and predecessor access lives. While moving
the iterator here, simplify it using the iterator utilities LLVM
provides and updates coding style as much as reasonable. The APIs remain
pointer-heavy when they could better use references, and retain the odd
behavior of `operator*` and `operator->` that is common in LLVM
iterators. Adjusting this API, if desired, should be a follow-up step.

Non-generic range iteration is added for the two instructions where
there is an especially easy mechanism and where there was code
attempting to use the range accessor from a specific subclass:
`indirectbr` and `br`. In both cases, the successors are contiguous
operands and can be easily iterated via the operand list.

This is the first major patch in removing the `TerminatorInst` type from
the IR's instruction type hierarchy. This change was discussed in an RFC
here and was pretty clearly positive:
http://lists.llvm.org/pipermail/llvm-dev/2018-May/123407.html

There will be a series of much more mechanical changes following this
one to complete this move.

Differential Revision: https://reviews.llvm.org/D47467

llvm-svn: 340698
2018-08-26 08:41:15 +00:00
John Brawn 980da83f84 [PhiValues] Use callback value handles to invalidate deleted values
The way that PhiValues is integrated with BasicAA it is possible for a pass
which uses BasicAA to pick up an instance of BasicAA that uses PhiValues without
intending to, and then delete values from a function in a way that causes
PhiValues to return dangling pointers to these deleted values. Fix this by
having a set of callback value handles to invalidate values when they're
deleted.

llvm-svn: 340613
2018-08-24 15:48:30 +00:00
Craig Topper dfa176e813 [ValueTracking] Fix assert message and add test case for r340546 and PR38677.
The bug was already fixed. This just adds a test case for it.

llvm-svn: 340556
2018-08-23 17:45:53 +00:00
Craig Topper 15f8692381 [ValueTracking] Fix an assert from r340480.
We need to allow ConstantExpr Selects in addition to SelectInst.

I'll try to put together a test case, but I wanted to fix the issues being reported.

Fixes PR38677

llvm-svn: 340546
2018-08-23 17:15:02 +00:00
Craig Topper bec15b6516 [ValueTracking] Teach computeNumSignBits to understand min/max clamp patterns with constant/splat values
If we have a min/max pair we can do a better job of counting sign bits if we look at them together. This is similar to what is done in the SelectionDAG version of computeNumSignBits for ISD::SMAX/SMIN.

Differential Revision: https://reviews.llvm.org/D51112

llvm-svn: 340480
2018-08-22 23:27:50 +00:00
George Burgess IV 5676a5d48c [MemorySSA] Invalidate optimized Defs upon moving them; NFC
We're currently getting this behavior implicitly, since we determine if
a Def's optimization is valid based on the ID of its defining access.
This is incorrect, though I wouldn't be surprised if this was masked in
part by that we're using a WeakVH to track what Defs are optimized to.
(Not to mention that we don't move Defs super often, AFAICT). I'll
submit a patch to fix this shortly.

This also includes a minor refactor to reduce duplication a bit.

No test is included, since like said, this already happens to be our
behavior. I'll add a test for this with my fix to the other bug
mentioned above.

llvm-svn: 340461
2018-08-22 22:34:38 +00:00
Philip Reames 8abf4484fe [AA] Remove a needless variable [NFC]
There's no need to track a seperate variable for argmemonly aliasing.  This falls out naturally of the modinfo union.  Note that we may return earlier than we would have earlier if all arguments are explicitly readnone.  The overall result doesn't change, just how we get there.

llvm-svn: 340443
2018-08-22 19:50:45 +00:00
Philip Reames f8681cea87 [AST] Minor whitespace cleanup [NFC]
llvm-svn: 340440
2018-08-22 19:30:46 +00:00
George Burgess IV d61e7071cd [MemorySSA] Move two simple getters; NFC
We're calling these functions quite a bit from outside of MemorySSA.cpp
now. Given that they're relatively simple one-liners, I think the style
preference is to have them inline.

llvm-svn: 340430
2018-08-22 18:02:46 +00:00
Philip Reames fdd73b5037 [AST] Fix a whitespace typo [NFC]
llvm-svn: 340384
2018-08-22 03:36:42 +00:00
Philip Reames 5d90c14b76 [AST] Reorder code to reduce a future patch diff [NFC]
llvm-svn: 340383
2018-08-22 03:33:55 +00:00
Philip Reames 825c74c241 [AST] Move a function definition into the cpp [NFC]
llvm-svn: 340382
2018-08-22 03:32:52 +00:00
Philip Reames c3c23e8cf2 [AST] Remove notion of volatile from alias sets [NFCI]
Volatility is not an aliasing property. We used to model volatile as if it had extremely conservative aliasing implications, but that hasn't been true for several years now. So, it doesn't make sense to be in AliasSet.

It also turns out the code is entirely a noop. Outside of the AST code to update it, there was only one user: load store promotion in LICM. L/S promotion doesn't need the check since it walks all the users of the address anyway. It already checks each load or store via !isUnordered which causes us to bail for volatile accesses. (Look at the lines immediately following the two remove asserts.)

There is the possibility of some small compile time impact here, but the only case which will get noticeably slower is a loop with a large number of loads and stores to the same address where only the last one we inspect is volatile. This is sufficiently rare it's not worth optimizing for..

llvm-svn: 340312
2018-08-21 17:59:11 +00:00
Sanjay Patel f3ae9cc33e [InstSimplify] use isKnownNeverNaN to fold more fcmp ord/uno
Remove duplicate tests from InstCombine that were added with
D50582. I left negative tests there to verify that nothing
in InstCombine tries to go overboard. If isKnownNeverNaN is
improved to handle the FP binops or other cases, we should
have coverage under InstSimplify, so we could remove more
duplicate tests from InstCombine at that time.

llvm-svn: 340279
2018-08-21 14:45:13 +00:00
Max Kazantsev bfbd4d1fb6 [NFC] Factor out predecessors collection into a separate method
It may be reused in a different piece of logic.

Differential Revision: https://reviews.llvm.org/D50890
Reviewed By: reames

llvm-svn: 340250
2018-08-21 07:15:06 +00:00
Philip Reames a5a8546ac6 [AST] Mark invariant.starts as being readonly
These intrinsics are modelled as writing for control flow purposes, but they don't actually write to any location. Marking these - as we did for guards - allows LICM to hoist loads out of loops containing invariant.starts.

Differential Revision: https://reviews.llvm.org/D50861

llvm-svn: 340245
2018-08-21 00:55:35 +00:00
Matt Arsenault 450fcc77a7 ValueTracking: Handle more instructions in isKnownNeverNaN
llvm-svn: 340187
2018-08-20 16:51:00 +00:00
Philip Reames 96bc076c3a [AST] Clarify printing of unknown size locations [NFC]
Printing "unknown" is much more clear than an arbitrary large integer

llvm-svn: 340108
2018-08-17 23:17:31 +00:00
Alina Sbirlea 0dfe830318 [IDF] Teach Iterated Dominance Frontier to use a snapshot CFG based on a GraphDiff.
Summary:
Create the ability to compute IDF using a CFG View.
For this, we'll need a new DT created using a list of Updates (to be refactored later to a GraphDiff), and the GraphTraits based on the same GraphDiff.

Reviewers: kuhar, george.burgess.iv, mzolotukhin

Subscribers: sanjoy, jlebar, llvm-commits

Differential Revision: https://reviews.llvm.org/D50675

llvm-svn: 340052
2018-08-17 17:39:15 +00:00
Florian Hahn 19f9e32f07 [InstrSimplify,NewGVN] Add option to ignore additional instr info when simplifying.
NewGVN uses InstructionSimplify for simplifications of leaders of
congruence classes. It is not guaranteed that the metadata or other
flags/keywords (like nsw or exact) of the leader is available for all members
in a congruence class, so we cannot use it for simplification.

This patch adds a InstrInfoQuery struct with a boolean field
UseInstrInfo (which defaults to true to keep the current behavior as
default) and a set of helper methods to get metadata/keywords for a
given instruction, if UseInstrInfo is true. The whole thing might need a
better name, to avoid confusion with TargetInstrInfo but I am not sure
what a better name would be.

The current patch threads through InstrInfoQuery to the required
places, which is messier then it would need to be, if
InstructionSimplify and ValueTracking would share the same Query struct.

The reason I added it as a separate struct is that it can be shared
between InstructionSimplify and ValueTracking's query objects. Also,
some places do not need a full query object, just the InstrInfoQuery.

It also updates some interfaces that do not take a Query object, but a
set of optional parameters to take an additional boolean UseInstrInfo.

See https://bugs.llvm.org/show_bug.cgi?id=37540.

Reviewers: dberlin, davide, efriedma, sebpop, hiraditya

Reviewed By: hiraditya

Differential Revision: https://reviews.llvm.org/D47143

llvm-svn: 340031
2018-08-17 14:39:04 +00:00
Sanjay Patel 411b86081e [ConstantFolding] add simplifications for funnel shift intrinsics
This is another step towards being able to canonicalize to the funnel shift 
intrinsics in IR (see D49242 for the initial patch). 
We should not have any loss of simplification power in IR between these and 
the equivalent IR constructs.

Differential Revision: https://reviews.llvm.org/D50848

llvm-svn: 340022
2018-08-17 13:23:44 +00:00
Max Kazantsev 7b78d3920c [MustExecute] Fix algorithmic bug in isGuaranteedToExecute. PR38514
The description of `isGuaranteedToExecute` does not correspond to its implementation.
According to description, it should return `true` if an instruction is executed under the
assumption that its loop is *entered*. However there is a sophisticated alrogithm inside
that tries to prove that the instruction is executed if the loop is *exited*, which is not the
same thing for infinite loops. There is an attempt to protect from dealing with infinite loops
by prohibiting loops without exit blocks, however an infinite loop can have exit blocks.

As result of that, MustExecute can falsely consider some blocks that are never entered as
mustexec, and LICM can hoist dangerous instructions out of them basing on this fact.
This may introduce UB to programs which did not contain it initially.

This patch removes the problematic algorithm and replaced it with a one which tries to
prove what is required in description.

Differential Revision: https://reviews.llvm.org/D50558
Reviewed By: reames

llvm-svn: 339984
2018-08-17 06:19:17 +00:00
Philip Reames 684fa57ef7 [MemLoc] Fix a bug causing any use of invariant.end to crash in LICM
The fix is fairly simple, but is says something unpleasant about the usage and testing of invariant.start/end scopes that this went undetected.  To put this in perspective, *any* invariant.end in a loop flowing through LICM crashed.  I haven't bothered to figure out just how far back this goes, but it's not caused by any of the recent changes.  We're probably talking months if not years.  

llvm-svn: 339936
2018-08-16 20:48:55 +00:00
Philip Reames 0e2f9b9e30 [LICM][NFC] Restructure pointer invalidation API in terms of MemoryLocation
Main value is just simplifying code.  I'll further simply the argument handling case in a bit, but that involved a slightly orthogonal change so I went with the mildy ugly intermediate for this patch.

Note that the isSized check in the old LICM code was not carried across.  It turns out that check was dead.  a) no test exercised it, and b) langref and verifier had been updated to disallow unsized types used in loads.

llvm-svn: 339930
2018-08-16 20:11:15 +00:00
Max Kazantsev a7415874c9 [NFC] Add missing const modifier
llvm-svn: 339844
2018-08-16 06:28:04 +00:00
Easwaran Raman aca738b742 [BFI] Use rounding while computing profile counts.
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
2018-08-16 00:26:59 +00:00
Alina Sbirlea cc2e8ccc6f [MemorySSA] Expose the verify as a debug option.
Summary: Expose VerifyMemorySSA as a debug option. If set, passes will call the MSSA->verifyMemorySSA() after calling into the updater's APIs when MemorySSA should be valid.

Reviewers: george.burgess.iv

Subscribers: sanjoy, jlebar, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D50749

llvm-svn: 339795
2018-08-15 17:34:55 +00:00
Max Kazantsev 5a10d127b9 [AliasSetTracker] Do not treat experimental_guard intrinsic as memory writing instruction
The `experimental_guard` intrinsic has memory write semantics to model the thread-exiting
logic, but does not do any actual writes to memory. Currently, `AliasSetTracker` treats it as a
normal memory write. As result, a loop-invariant load cannot be hoisted out of loop because
the guard may possibly alias with it.

This patch makes `AliasSetTracker` so that it doesn't treat guards as memory writes.

Differential Revision: https://reviews.llvm.org/D50497
Reviewed By: reames

llvm-svn: 339753
2018-08-15 06:21:02 +00:00
Max Kazantsev 530b8d1c3d [NFC] Refactoring of LoopSafetyInfo, step 1
Turn structure into class, encapsulate methods, add clarifying comments.

Differential Revision: https://reviews.llvm.org/D50693
Reviewed By: reames

llvm-svn: 339752
2018-08-15 05:55:43 +00:00
Reid Kleckner 40e7663b1f [BasicAA] Don't assume tail calls with byval don't alias allocas
Summary:
Calls marked 'tail' cannot read or write allocas from the current frame
because the current frame might be destroyed by the time they run.
However, a tail call may use an alloca with byval. Calling with byval
copies the contents of the alloca into argument registers or stack
slots, so there is no lifetime issue. Tail calls never modify allocas,
so we can return just ModRefInfo::Ref.

Fixes PR38466, a longstanding bug.

Reviewers: hfinkel, nlewycky, gbiv, george.burgess.iv

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D50679

llvm-svn: 339636
2018-08-14 01:24:35 +00:00
Philip Reames 90bffb3eb9 [AST] Minor formatting cleanup [NFC]
llvm-svn: 339627
2018-08-13 22:34:14 +00:00
Philip Reames 0f396696d1 [AST] Cleanup code by using MemoryLocation utility [NFC]
Differential Revision: https://reviews.llvm.org/D50588

llvm-svn: 339625
2018-08-13 22:25:16 +00:00
Craig Topper 484b342c68 [X86] Add constant folding for AVX512 versions of scalar floating point to integer conversion intrinsics.
Summary:
We've supported constant folding for sse versions for many years. This patch adds support for the avx512 versions including unsigned with the default rounding mode. We could probably do more with other roundings modes and SAE in the future.

The test cases are largely based on the sse.ll test cases. But I did add some test cases to ensure the unsigned versions don't accept negative values. Also checked the bounds of f64->i32 conversions to make sure unsigned has a larger positive range than signed.

Reviewers: RKSimon, spatel, chandlerc

Reviewed By: RKSimon

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D50553

llvm-svn: 339529
2018-08-12 22:09:54 +00:00
Benjamin Kramer bae6aab6fb [InstSimplify] Guard against large shift amounts.
These are always UB, but can happen for large integer inputs. Testing it
is very fragile as -simplifycfg will nuke the UB top-down.

llvm-svn: 339515
2018-08-12 11:43:03 +00:00
George Burgess IV ff08c80efc [MemorySSA] "Fix" lifetime intrinsic handling
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
2018-08-10 05:14:43 +00:00
Matt Arsenault d54b7f0592 ValueTracking: Start enhancing isKnownNeverNaN
llvm-svn: 339399
2018-08-09 22:40:08 +00:00
Sanjay Patel c6944f795d [InstSimplify] move minnum/maxnum with Inf folds from instcombine
llvm-svn: 339396
2018-08-09 22:20:44 +00:00
Sanjay Patel 9b07347033 [InstSimplify] fold fsub+fadd with common operand
llvm-svn: 339176
2018-08-07 20:32:55 +00:00
Sanjay Patel 4364d604c2 [InstSimplify] fold fadd+fsub with common operand
llvm-svn: 339174
2018-08-07 20:23:49 +00:00
Sanjay Patel f7a8fb2dee [InstSimplify] fold fsub+fsub with common operand
llvm-svn: 339171
2018-08-07 20:14:27 +00:00
Wei Mi b1ef2cc53d [SampleFDO] Fix a bug in getOrCompHotCountThreshold/getOrCompColdCountThreshold
getOrCompHotCountThreshold/getOrCompColdCountThreshold introduced in
https://reviews.llvm.org/D45377 contain a bad mistake and will only return 1 or 0
instead of the true hot/cold cutoff value. The patch fixes the mistake. But the
mistake seems not causing big performance difference according to internal server
benchmarks testing.

Differential Revision: https://reviews.llvm.org/D50370

llvm-svn: 339162
2018-08-07 18:13:10 +00:00
Sanjay Patel 948ff87d7d [InstSimplify] move minnum/maxnum with common op fold from instcombine
llvm-svn: 339144
2018-08-07 14:36:27 +00:00
Matt Arsenault 56b31d8d75 ValueTracking: Handle canonicalize in CannotBeNegativeZero
Also fix apparently missing test coverage for any of the
handling here.

llvm-svn: 339023
2018-08-06 15:16:26 +00:00
Max Kazantsev 2dbbd64cb7 Re-enable "[ValueTracking] Teach isKnownNonNullFromDominatingCondition about AND"
The patch was reverted because of bug detected by sanitizer. The bug is fixed,
respective tests added.

Differential Revision: https://reviews.llvm.org/D50172

llvm-svn: 339005
2018-08-06 11:14:18 +00:00
Max Kazantsev 3271f379a9 Revert rL338990 to see if it causes sanitizer failures
Multiple failues reported by sanitizer-x86_64-linux, seem to be caused by this
patch. Reverting to see if they sustain without it.

Differential Revision: https://reviews.llvm.org/D50172

llvm-svn: 338994
2018-08-06 08:10:28 +00:00
Max Kazantsev 34b0666be9 [ValueTracking] Teach isKnownNonNullFromDominatingCondition about AND
`isKnownNonNullFromDominatingCondition` is able to prove non-null basing on `br` or `guard`
by `%p != null` condition, but is unable to do so basing on `(%p != null) && %other_cond`.
This patch allows it to do so.

Differential Revision: https://reviews.llvm.org/D50172
Reviewed By: reames

llvm-svn: 338990
2018-08-06 06:11:36 +00:00
David Bolvansky c0aa4b75a4 Enrich inline messages
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

llvm-svn: 338969
2018-08-05 14:53:08 +00:00
Hiroshi Inoue 73f8b255b6 [InstSimplify] fold extracting from std::pair (2/2)
This is the second patch of the series which intends to enable jump threading for an inlined method whose return type is std::pair<int, bool> or std::pair<bool, int>. 
The first patch is https://reviews.llvm.org/rL338485.

This patch handles code sequences that merges two values using `shl` and `or`, then extracts one value using `and`.

Differential Revision: https://reviews.llvm.org/D49981

llvm-svn: 338817
2018-08-03 05:39:48 +00:00
Krzysztof Parzyszek 90f3249ce2 [SCEV] Properly solve quadratic equations
Differential Revision: https://reviews.llvm.org/D48283

llvm-svn: 338758
2018-08-02 19:13:35 +00:00
Sanjay Patel 3f6e9a71f7 [InstSimplify] move minnum/maxnum with undef fold from instcombine
llvm-svn: 338719
2018-08-02 14:33:40 +00:00
Sanjay Patel f9a0d593e9 [ValueTracking] fix maxnum miscompile for cannotBeOrderedLessThanZero (PR37776)
This adds the NAN checks suggested in PR37776:
https://bugs.llvm.org/show_bug.cgi?id=37776

If both operands to maxnum are NAN, that should get constant folded, so we don't 
have to handle that case. This is the same assumption as other FP ops in this
function. Returning 'false' is always conservatively correct.

Copying from the bug report:

Currently, we have this for "when is cannotBeOrderedLessThanZero 
(mustBePositiveOrNaN) true for maxnum":
               L
        -------------------
        | Pos | Neg | NaN |
   ------------------------
   |Pos |  x  |  x  |  x  |
   ------------------------
 R |Neg |  x  |     |  x  |
   ------------------------
   |NaN |  x  |  x  |  x  |
   ------------------------


The cases with (Neg & NaN) are wrong. We should have:

                L
        -------------------
        | Pos | Neg | NaN |
   ------------------------
   |Pos |  x  |  x  |  x  |
   ------------------------
 R |Neg |  x  |     |     |
   ------------------------
   |NaN |  x  |     |  x  |
   ------------------------

Differential Revision: https://reviews.llvm.org/D50081

llvm-svn: 338716
2018-08-02 13:46:20 +00:00
Sanjay Patel 28c7e41c09 [InstSimplify] move minnum/maxnum with same arg fold from instcombine
llvm-svn: 338652
2018-08-01 23:05:55 +00:00
David Bolvansky fbbb83c782 Revert "Enrich inline messages", tests fail
llvm-svn: 338496
2018-08-01 08:02:40 +00:00
David Bolvansky 7f36cd9d96 Enrich inline messages
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

llvm-svn: 338494
2018-08-01 07:37:16 +00:00
Hiroshi Inoue 02f79eae06 [InstSimplify] fold extracting from std::pair (1/2)
This patch intends to enable jump threading when a method whose return type is std::pair<int, bool> or std::pair<bool, int> is inlined.
For example, jump threading does not happen for the if statement in func.

std::pair<int, bool> callee(int v) {
  int a = dummy(v);
  if (a) return std::make_pair(dummy(v), true);
  else return std::make_pair(v, v < 0);
}

int func(int v) {
  std::pair<int, bool> rc = callee(v);
  if (rc.second) {
    // do something
  }

SROA executed before the method inlining replaces std::pair by i64 without splitting in both callee and func since at this point no access to the individual fields is seen to SROA.
After inlining, jump threading fails to identify that the incoming value is a constant due to additional instructions (like or, and, trunc).

This series of patch add patterns in InstructionSimplify to fold extraction of members of std::pair. To help jump threading, actually we need to optimize the code sequence spanning multiple BBs.
These patches does not handle phi by itself, but these additional patterns help NewGVN pass, which calls instsimplify to check opportunities for simplifying instructions over phi, apply phi-of-ops optimization to result in successful jump threading. 
SimplifyDemandedBits in InstCombine, can do more general optimization but this patch aims to provide opportunities for other optimizers by supporting a simple but common case in InstSimplify.

This first patch in the series handles code sequences that merges two values using shl and or and then extracts one value using lshr.

Differential Revision: https://reviews.llvm.org/D48828

llvm-svn: 338485
2018-08-01 04:40:32 +00:00
David Bolvansky ab79414f7b Revert Enrich inline messages
llvm-svn: 338389
2018-07-31 14:47:22 +00:00
David Bolvansky b562dbabda Enrich inline messages
Summary:
This patch improves Inliner to provide causes/reasons for negative inline decisions.
1. It adds one new message field to InlineCost to report causes for Always and Never instances. All Never and Always instantiations must provide a simple message.
2. Several functions that used to return the inlining results as boolean are changed to return InlineResult which carries the cause for negative decision.
3. Changed remark priniting and debug output messages to provide the additional messages and related inline cost.
4. Adjusted tests for changed printing.

Patch by: yrouban (Yevgeny Rouban)


Reviewers: craig.topper, sammccall, sgraenitz, NutshellySima, shchenz, chandlerc, apilipenko, javed.absar, tejohnson, dblaikie, sanjoy, eraman, xbolva00

Reviewed By: tejohnson, xbolva00

Subscribers: xbolva00, llvm-commits, arsenm, mehdi_amini, eraman, haicheng, steven_wu, dexonsmith

Differential Revision: https://reviews.llvm.org/D49412

llvm-svn: 338387
2018-07-31 14:25:24 +00:00
John Brawn cd5f37f3f1 [MemDep] Use PhiValuesAnalysis to improve alias analysis results
This is being done in order to make GVN able to better optimize certain inputs.
MemDep doesn't use PhiValues directly, but does need to notifiy it when things
get invalidated.

Differential Revision: https://reviews.llvm.org/D48489

llvm-svn: 338384
2018-07-31 14:19:29 +00:00
David Bolvansky 16d8a69b90 [InstSimplify] Fold another Select with And/Or pattern
Summary: Proof: https://rise4fun.com/Alive/L5J

Reviewers: lebedev.ri, spatel

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49975

llvm-svn: 338383
2018-07-31 14:17:15 +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
John Brawn cd73fe8989 [BasicAA] Use PhiValuesAnalysis if available when handling phi alias
By using PhiValuesAnalysis we can get all the values reachable from a phi, so
we can be more precise instead of giving up when a phi has phi operands. We
can't make BaseicAA directly use PhiValuesAnalysis though, as the user of
BasicAA may modify the function in ways that PhiValuesAnalysis can't cope with.

For this optional usage to work correctly BasicAAWrapperPass now needs to be not
marked as CFG-only (i.e. it is now invalidated even when CFG is preserved) due
to how the legacy pass manager handles dependent passes being invalidated,
namely the depending pass still has a pointer to the now-dead dependent pass.

Differential Revision: https://reviews.llvm.org/D44564

llvm-svn: 338242
2018-07-30 11:52:08 +00:00
Sanjay Patel 54421ce918 [InstSimplify] fold funnel shifts with 0-shift amount
llvm-svn: 338218
2018-07-29 16:36:38 +00:00
Sanjay Patel f52eeb1123 [InstSimplify] refactor intrinsic simplifications; NFCI
llvm-svn: 338215
2018-07-29 14:42:08 +00:00
David Bolvansky f947608ddf [InstCombine] Fold Select with AND/OR condition
Summary:
Fold
```
%A = icmp ne i8 %X, %V1
%B = icmp ne i8 %X, %V2
%C = or i1 %A, %B
%D = select i1 %C, i8 %X, i8 %V1
ret i8 %D
  =>
ret i8 %X

Fixes https://bugs.llvm.org/show_bug.cgi?id=38334
Proof: https://rise4fun.com/Alive/plI8

Reviewers: spatel, lebedev.ri

Reviewed By: lebedev.ri

Subscribers: craig.topper, llvm-commits

Differential Revision: https://reviews.llvm.org/D49919

llvm-svn: 338191
2018-07-28 06:55:51 +00:00
Fangrui Song a8301fce51 Replace LLVM_ALIGNAS with alignas as a follow-up of r337330
The minimum required GCC version was raised to 4.8 (which started to support alignas) in r284497.

llvm-svn: 338099
2018-07-27 05:38:14 +00:00
Keno Fischer 864fbd8e9a [SCEV] Don't expand Wrap predicate using inttoptr in ni addrspaces
Summary:
In non-integral address spaces, we're not allowed to introduce inttoptr/ptrtoint
intrinsics. Instead, we need to expand any pointer arithmetic as geps on the
base pointer. Luckily this is a common task for SCEV, so all we have to do here
is hook up the corresponding helper function and add test case.

Fixes PR38290

Reviewers: sanjoy
Differential Revision: https://reviews.llvm.org/D49832

llvm-svn: 338073
2018-07-26 21:55:06 +00:00
Keno Fischer 259ea987f5 [SCEV] Add an expandAddToGEP overload for a single operand. NFC.
Only wanting to pass a single SCEV operand to use as the offset of
the GEP is a common operation. Right now this requires creating a
temporary stack array at every call site. Add an overload
that encapsulates that pattern and simplify the call sites.

Suggested-By: sanjoy (in https://reviews.llvm.org/D49832)
llvm-svn: 338072
2018-07-26 21:55:03 +00:00
Roman Tereshin ed047b0184 [SCEV] Add [zs]ext{C,+,x} -> (D + [zs]ext{C-D,+,x})<nuw><nsw> transform
as well as sext(C + x + ...) -> (D + sext(C-D + x + ...))<nuw><nsw>
similar to the equivalent transformation for zext's

if the top level addition in (D + (C-D + x * n)) could be proven to
not wrap, where the choice of D also maximizes the number of trailing
zeroes of (C-D + x * n), ensuring homogeneous behaviour of the
transformation and better canonicalization of such AddRec's

(indeed, there are 2^(2w) different expressions in `B1 + ext(B2 + Y)` form for
the same Y, but only 2^(2w - k) different expressions in the resulting `B3 +
ext((B4 * 2^k) + Y)` form, where w is the bit width of the integral type)

This patch generalizes sext(C1 + C2*X) --> sext(C1) + sext(C2*X) and
sext{C1,+,C2} --> sext(C1) + sext{0,+,C2} transformations added in
r209568 relaxing the requirements the following way:

1. C2 doesn't have to be a power of 2, it's enough if it's divisible by 2
 a sufficient number of times;
2. C1 doesn't have to be less than C2, instead of extracting the entire
  C1 we can split it into 2 terms: (00...0XXX + YY...Y000), keep the
  second one that may cause wrapping within the extension operator, and
  move the first one that doesn't affect wrapping out of the extension
  operator, enabling further simplifications;
3. C1 and C2 don't have to be positive, splitting C1 like shown above
 produces a sum that is guaranteed to not wrap, signed or unsigned;
4. in AddExpr case there could be more than 2 terms, and in case of
  AddExpr the 2nd and following terms and in case of AddRecExpr the
  Step component don't have to be in the C2*X form or constant
  (respectively), they just need to have enough trailing zeros,
  which in turn could be guaranteed by means other than arithmetics,
  e.g. by a pointer alignment;
5. the extension operator doesn't have to be a sext, the same
  transformation works and profitable for zext's as well.

Apparently, optimizations like SLPVectorizer currently fail to
vectorize even rather trivial cases like the following:

 double bar(double *a, unsigned n) {
   double x = 0.0;
   double y = 0.0;
   for (unsigned i = 0; i < n; i += 2) {
     x += a[i];
     y += a[i + 1];
   }
   return x * y;
 }

If compiled with `clang -std=c11 -Wpedantic -Wall -O3 main.c -S -o - -emit-llvm`
(!{!"clang version 7.0.0 (trunk 337339) (llvm/trunk 337344)"})

it produces scalar code with the loop not unrolled with the unsigned `n` and
`i` (like shown above), but vectorized and unrolled loop with signed `n` and
`i`. With the changes made in this commit the unsigned version will be
vectorized (though not unrolled for unclear reasons).

How it all works:

Let say we have an AddExpr that looks like (C + x + y + ...), where C
is a constant and x, y, ... are arbitrary SCEVs. Let's compute the
minimum number of trailing zeroes guaranteed of that sum w/o the
constant term: (x + y + ...). If, for example, those terms look like
follows:

        i
XXXX...X000
YYYY...YY00
   ...
ZZZZ...0000

then the rightmost non-guaranteed-zero bit (a potential one at i-th
position above) can change the bits of the sum to the left (and at
i-th position itself), but it can not possibly change the bits to the
right. So we can compute the number of trailing zeroes by taking a
minimum between the numbers of trailing zeroes of the terms.

Now let's say that our original sum with the constant is effectively
just C + X, where X = x + y + .... Let's also say that we've got 2
guaranteed trailing zeros for X:

         j
CCCC...CCCC
XXXX...XX00  // this is X = (x + y + ...)

Any bit of C to the left of j may in the end cause the C + X sum to
wrap, but the rightmost 2 bits of C (at positions j and j - 1) do not
affect wrapping in any way. If the upper bits cause a wrap, it will be
a wrap regardless of the values of the 2 least significant bits of C.
If the upper bits do not cause a wrap, it won't be a wrap regardless
of the values of the 2 bits on the right (again).

So let's split C to 2 constants like follows:

0000...00CC  = D
CCCC...CC00  = (C - D)

and represent the whole sum as D + (C - D + X). The second term of
this new sum looks like this:

CCCC...CC00
XXXX...XX00
-----------  // let's add them up
YYYY...YY00

The sum above (let's call it Y)) may or may not wrap, we don't know,
so we need to keep it under a sext/zext. Adding D to that sum though
will never wrap, signed or unsigned, if performed on the original bit
width or the extended one, because all that that final add does is
setting the 2 least significant bits of Y to the bits of D:

YYYY...YY00 = Y
0000...00CC = D
-----------  <nuw><nsw>
YYYY...YYCC

Which means we can safely move that D out of the sext or zext and
claim that the top-level sum neither sign wraps nor unsigned wraps.

Let's run an example, let's say we're working in i8's and the original
expression (zext's or sext's operand) is 21 + 12x + 8y. So it goes
like this:

0001 0101  // 21
XXXX XX00  // 12x
YYYY Y000  // 8y

0001 0101  // 21
ZZZZ ZZ00  // 12x + 8y

0000 0001  // D
0001 0100  // 21 - D = 20
ZZZZ ZZ00  // 12x + 8y

0000 0001  // D
WWWW WW00  // 21 - D + 12x + 8y = 20 + 12x + 8y

therefore zext(21 + 12x + 8y) = (1 + zext(20 + 12x + 8y))<nuw><nsw>

This approach could be improved if we move away from using trailing
zeroes and use KnownBits instead. For instance, with KnownBits we could
have the following picture:

    i
10 1110...0011  // this is C
XX X1XX...XX00  // this is X = (x + y + ...)

Notice that some of the bits of X are known ones, also notice that
known bits of X are interspersed with unknown bits and not grouped on
the rigth or left.

We can see at the position i that C(i) and X(i) are both known ones,
therefore the (i + 1)th carry bit is guaranteed to be 1 regardless of
the bits of C to the right of i. For instance, the C(i - 1) bit only
affects the bits of the sum at positions i - 1 and i, and does not
influence if the sum is going to wrap or not. Therefore we could split
the constant C the following way:

    i
00 0010...0011  = D
10 1100...0000  = (C - D)

Let's compute the KnownBits of (C - D) + X:

XX1 1            = carry bit, blanks stand for known zeroes
 10 1100...0000  = (C - D)
 XX X1XX...XX00  = X
--- -----------
 XX X0XX...XX00

Will this add wrap or not essentially depends on bits of X. Adding D
to this sum, however, is guaranteed to not to wrap:

0    X
 00 0010...0011  = D
 sX X0XX...XX00  = (C - D) + X
--- -----------
 sX XXXX   XX11

As could be seen above, adding D preserves the sign bit of (C - D) +
X, if any, and has a guaranteed 0 carry out, as expected.

The more bits of (C - D) we constrain, the better the transformations
introduced here canonicalize expressions as it leaves less freedom to
what values the constant part of ((C - D) + x + y + ...) can take.

Reviewed By: mzolotukhin, efriedma

Differential Revision: https://reviews.llvm.org/D48853

llvm-svn: 337943
2018-07-25 18:01:41 +00:00
Xinliang David Li 45a607e563 Add an option to specify the name of
an function whose CFG is to be viewed/printed.

Differential Revision: https://reviews.llvm.org/D49447

llvm-svn: 337940
2018-07-25 17:22:12 +00:00
Stanislav Mekhanoshin b8269a9589 Fix llvm::ComputeNumSignBits with some operations and llvm.assume
Currently ComputeNumSignBits does early exit while processing some
of the operations (add, sub, mul, and select). This prevents the
function from using AssumptionCacheTracker if passed.

Differential Revision: https://reviews.llvm.org/D49759

llvm-svn: 337936
2018-07-25 16:39:24 +00:00
Roman Tereshin 1ba1f9310c [SCEV] Add zext(C + x + ...) -> D + zext(C-D + x + ...)<nuw><nsw> transform
if the top level addition in (D + (C-D + x + ...)) could be proven to
not wrap, where the choice of D also maximizes the number of trailing
zeroes of (C-D + x + ...), ensuring homogeneous behaviour of the
transformation and better canonicalization of such expressions.

This enables better canonicalization of expressions like

  1 + zext(5 + 20 * %x + 24 * %y)  and
      zext(6 + 20 * %x + 24 * %y)

which get both transformed to

  2 + zext(4 + 20 * %x + 24 * %y)

This pattern is common in address arithmetics and the transformation
makes it easier for passes like LoadStoreVectorizer to prove that 2 or
more memory accesses are consecutive and optimize (vectorize) them.

Reviewed By: mzolotukhin

Differential Revision: https://reviews.llvm.org/D48853

llvm-svn: 337859
2018-07-24 21:48:56 +00:00
Manoj Gupta f9f50f634d ConstantFolding: Avoid a crash.
Summary:
Check if the parent basic block and caller exists
before calling CS.getCaller when constant folding
strip.invariant.group instrinsic.

This avoids a crash when the function containing the intrinsic
is being inlined. The instruction is checked for any simplifiction
but has not yet been added to a basic block.

Reviewers: Prazek, rsmith, efriedma

Reviewed By: efriedma

Subscribers: eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D49690

llvm-svn: 337742
2018-07-23 21:20:00 +00:00
Alexandros Lamprineas bf6009c234 [MemorySSAUpdater] Update Phi operands after trivial Phi elimination
Bug fix for PR37445. The underlying problem and its fix are similar to PR37808.
The bug lies in MemorySSAUpdater::getPreviousDefRecursive(), where PhiOps is
computed before the call to tryRemoveTrivialPhi() and it ends up being out of
date, pointing to stale data. We have now turned each of the PhiOps into a
TrackingVH<MemoryAccess>.

Differential Revision: https://reviews.llvm.org/D49425

llvm-svn: 337680
2018-07-23 10:56:30 +00:00
Jiading Gai a269437258 Test commit, fix a minor typo.
llvm-svn: 337657
2018-07-22 20:04:42 +00:00
Xin Tong 023e25ad14 [ORE] Move loop invariant ORE checks outside the PM loop.
Summary:
This takes 22ms out of ~20s compiling sqlite3.c because we call it
for every unit of compilation and every pass.

Reviewers: paquette, anemet

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D49586

llvm-svn: 337654
2018-07-22 05:27:41 +00:00
Chen Zheng 69bb064539 [InstrSimplify] fold sdiv if two operands are negated and non-overflow
Differential Revision: https://reviews.llvm.org/D49382

llvm-svn: 337642
2018-07-21 12:27:54 +00:00
Alina Sbirlea 20c2962585 [MemorySSA] Add API to update MemoryPhis, following CFG changes.
Summary:
When splitting predecessors in BasicBlockUtils, we create a new block as an immediate predecessor of the original BB, then we connect a given set of predecessors to the new block.
The API in this patch will be used to update MemoryPhis for this CFG change.
If all predecessors are being moved, we move the MemoryPhi directly. Otherwise we create a new MemoryPhi in the NewBB and populate its incoming values, while deleting them from BB's Phi.
[Split from D45299 for easier review]

Reviewers: george.burgess.iv

Subscribers: sanjoy, jlebar, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D49156

llvm-svn: 337581
2018-07-20 17:13:05 +00:00
Chen Zheng f801d0fea9 [InstSimplify] fold srem instruction if its two operands are negated.
Differential Revision: https://reviews.llvm.org/D49423

llvm-svn: 337545
2018-07-20 13:00:47 +00:00
Shoaib Meenai a57d7139b3 [Analysis] Fix typo in assert. NFC
Test commit to see if my mailing list woes have been resolved.

llvm-svn: 337485
2018-07-19 19:11:29 +00:00
Max Kazantsev d41faecc49 [SCEV] Fix buggy behavior in getAddExpr with truncs
SCEV tries to constant-fold arguments of trunc operands in SCEVAddExpr, and when it does
that, it passes wrong flags into the recursion. It is only valid to pass flags that are proved for
narrow type into a computation in wider type if we can prove that trunc instruction doesn't
actually change the value. If it did lose some meaningful bits, we may end up proving wrong
no-wrap flags for sum of arguments of trunc.

In the provided test we end up with `nuw` where it shouldn't be because of this bug.

The solution is to conservatively pass `SCEV::FlagAnyWrap` which is always a valid thing to do.

Reviewed By: sanjoy
Differential Revision: https://reviews.llvm.org/D49471

llvm-svn: 337435
2018-07-19 01:46:21 +00:00
Alexandros Lamprineas f854ce84c4 [MemorySSAUpdater] Remove deleted trivial Phis from active workset
Bug fix for PR37808. The regression test is a reduced version of the
original reproducer attached to the bug report. As stated in the report,
the problem was that InsertedPHIs was keeping dangling pointers to
deleted Memory-Phis. MemoryPhis are created eagerly and sometimes get
zapped shortly afterwards. I've used WeakVH instead of an expensive
removal operation from the active workset.

Differential Revision: https://reviews.llvm.org/D48372

llvm-svn: 337149
2018-07-16 07:51:27 +00:00
Chen Zheng ccc8422464 [InstCombine] add more SPFofSPF folding
Differential Revision: https://reviews.llvm.org/D49238

llvm-svn: 337143
2018-07-16 02:23:00 +00:00
Sanjay Patel 92d0c1c129 [InstSimplify] fold minnum/maxnum with NaN arg
This fold is repeated/misplaced in instcombine, but I'm
not sure if it's safe to remove that yet because some
other folds appear to be asserting that the transform
has occurred within instcombine itself.

This isn't the best fix for PR37776, but it probably
hides the bug with the given code example:
https://bugs.llvm.org/show_bug.cgi?id=37776

We have another test to demonstrate the more general bug.

llvm-svn: 337127
2018-07-15 14:52:16 +00:00
Tim Shen a064622bd3 Re-apply "[SCEV] Strengthen StrengthenNoWrapFlags (reapply r334428)."
llvm-svn: 337075
2018-07-13 23:58:46 +00:00
Evgeniy Stepanov ca8c2f7638 Revert "CallGraphSCCPass: iterate over all functions."
This reverts commit r336419: use-after-free on CallGraph::FunctionMap elements
due to the use of a stale iterator in CGPassManager::runOnModule.

The iterator may be invalidated if a pass removes a function, ex.:
  llvm::LegacyInlinerBase::inlineCalls
  inlineCallsImpl
  llvm::CallGraph::removeFunctionFromModule

llvm-svn: 337018
2018-07-13 16:32:31 +00:00
Tim Renouf f3d8295105 DivergenceAnalysis: added debug output
Summary:
This commit does two things:

1. modified the existing DivergenceAnalysis::dump() so it dumps the
   whole function with added DIVERGENT: annotations;

2. added code to do that dump if the appropriate -debug-only option is
   on.

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47700

Change-Id: Id97b605aab1fc6f5a11a20c58a99bbe8c565bf83
llvm-svn: 336998
2018-07-13 13:13:30 +00:00
Fangrui Song 9bb6c392e3 [InstCombine] Simplify isKnownNegation
llvm-svn: 336957
2018-07-12 22:56:23 +00:00
George Burgess IV e7cdb7edf7 Remove redundant *_or_null checks; NFC
For the first one, we dereference `NewDef` right before the `if` anyway.
For the second, we shouldn't have NULL users().

llvm-svn: 336952
2018-07-12 21:56:31 +00:00
Chen Zheng fdf13ef342 [InstSimplify] simplify add instruction if two operands are negative
Differential Revision: https://reviews.llvm.org/D49216

llvm-svn: 336881
2018-07-12 03:06:04 +00:00
Alina Sbirlea 0f53355e83 [MemorySSA] Add APIs to move memory accesses between blocks, following CFG changes.
Summary:
The move APIs added in this patch will be used to update MemorySSA when CFG changes merge or split blocks, by moving memory accesses accordingly in MemorySSA's internal data structures.
[Split from D45299 for easier review]

Reviewers: george.burgess.iv

Subscribers: sanjoy, jlebar, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D48897

llvm-svn: 336860
2018-07-11 22:11:46 +00:00
Simon Pilgrim 667a5b541f [TargetTransformInfo] Add pow2 analysis for scalar constants
Add ConstantInt analysis to getOperandInfo so we get more realistic div/rem expansion costs comparable to the vector costs.

llvm-svn: 336827
2018-07-11 17:51:27 +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
George Burgess IV 3fbfa9c403 Make llvm.objectsize more conservative with null
In non-zero address spaces, we were reporting that an object at `null`
always occupies zero bytes. This is incorrect in many cases, so just
return `unknown` in those cases for now.

Differential Revision: https://reviews.llvm.org/D48860

llvm-svn: 336611
2018-07-09 22:21:16 +00:00
Diego Caballero 29a07b37bf [LoopInfo] Port loop exit interfaces from Loop to LoopBase
This patch ports hasDedicatedExits, getUniqueExitBlocks and
getUniqueExitBlock in Loop to LoopBase so that they can be used
from other LoopBase sub-classes.

Reviewers: chandlerc, sanjoy, hfinkel, fhahn

Reviewed By: chandlerc

Differential Revision: https://reviews.llvm.org/D48817

llvm-svn: 336572
2018-07-09 17:52:49 +00:00
Tim Shen 2ed501d656 Revert "[SCEV] Strengthen StrengthenNoWrapFlags (reapply r334428)."
This reverts commit r336140. Our tests shows that LSR assert fails with it.

llvm-svn: 336473
2018-07-06 23:20:35 +00:00
Vedant Kumar b3091da3af Use Type::isIntOrPtrTy where possible, NFC
It's a bit neater to write T.isIntOrPtrTy() over `T.isIntegerTy() ||
T.isPointerTy()`.

I used Python's re.sub with this regex to update users:

  r'([\w.\->()]+)isIntegerTy\(\)\s*\|\|\s*\1isPointerTy\(\)'

llvm-svn: 336462
2018-07-06 20:17:42 +00:00
Tim Northover 7ee46ed992 CallGraphSCCPass: iterate over all functions.
Previously we only iterated over functions reachable from the set of
external functions in the module. But since some of the passes under
this (notably the always-inliner and coroutine lowerer) are required for
correctness, they need to run over everything.

This just adds an extra layer of iteration over the CallGraph to keep
track of which functions we've already visited and get the next batch of
SCCs.

Should fix PR38029.

llvm-svn: 336419
2018-07-06 08:04:47 +00:00
Tim Shen c7cef4bcc4 [SCEV] Strengthen StrengthenNoWrapFlags (reapply r334428).
Summary:
Comment on Transforms/LoopVersioning/incorrect-phi.ll: With the change
SCEV is able to prove that the loop doesn't wrap-self (due to zext i16
to i64), disabling the entire loop versioning pass. Removed the zext and
just use i64.

Reviewers: sanjoy

Subscribers: jlebar, hiraditya, javed.absar, bixia, llvm-commits

Differential Revision: https://reviews.llvm.org/D48409

llvm-svn: 336140
2018-07-02 20:01:54 +00:00
Sanjay Patel 284ba0c18f [ValueTracking] allow undef elements when matching vector abs
llvm-svn: 336111
2018-07-02 14:43:40 +00:00
Piotr Padlewski 5b3db45e8f Implement strip.invariant.group
Summary:
This patch introduce new intrinsic -
strip.invariant.group that was described in the
RFC: Devirtualization v2

Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar

Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits

Differential Revision: https://reviews.llvm.org/D47103

Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>
llvm-svn: 336073
2018-07-02 04:49:30 +00:00
Alina Sbirlea da1e80feb7 [MemorySSA] Add APIs to MemoryPhis to delete incoming blocks/values, and an updater API to remove blocks.
Summary:
MemoryPhis now have APIs analogous to BB Phis to remove an incoming value/block.
The MemorySSAUpdater uses the above APIs when updating MemorySSA given a set of dead blocks about to be deleted.

Reviewers: george.burgess.iv

Subscribers: sanjoy, jlebar, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D48396

llvm-svn: 336015
2018-06-29 20:46:16 +00:00
Sean Fertile cd0d7634f6 Revert "Extend CFGPrinter and CallPrinter with Heat Colors"
This reverts r335996 which broke graph printing in Polly.

llvm-svn: 336000
2018-06-29 17:48:58 +00:00
Sean Fertile 3b0535b424 Extend CFGPrinter and CallPrinter with Heat Colors
Extends the CFGPrinter and CallPrinter with heat colors based on heuristics or
profiling information. The colors are enabled by default and can be toggled
on/off for CFGPrinter by using the option -cfg-heat-colors for both
-dot-cfg[-only] and -view-cfg[-only].  Similarly, the colors can be toggled
on/off for CallPrinter by using the option -callgraph-heat-colors for both
-dot-callgraph and -view-callgraph.

Patch by Rodrigo Caetano Rocha!

Differential Revision: https://reviews.llvm.org/D40425

llvm-svn: 335996
2018-06-29 17:13:58 +00:00
Roman Shirokiy 272eac85c7 Fix overconfident assert in ScalarEvolution::isImpliedViaMerge
We can have AddRec with loops having many predecessors.
This changes an assert to an early return.

Differential Revision: https://reviews.llvm.org/D48766

llvm-svn: 335965
2018-06-29 11:46:30 +00:00
Roman Lebedev 8d081b78e4 SCEVExpander::expandAddRecExprLiterally(): check before casting as Instruction
Summary:
An alternative to D48597.
Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=37936 | PR37936 ]].

The problem is as follows:
1. `indvars` marks `%dec` as `NUW`.
2. `loop-instsimplify` runs `instsimplify`, which constant-folds `%dec` to -1 (D47908)
3. `loop-reduce` tries to do some further modification, but crashes
    with an type assertion in cast, because `%dec` is no longer an `Instruction`,

If the runline is split into two, i.e. you first run `-indvars -loop-instsimplify`,
store that into a file, and then run `-loop-reduce`, there is no crash.

So it looks like the problem is due to `-loop-instsimplify` not discarding SCEV.
But in this case we can just not crash if it's not an `Instruction`.
This is just a local fix, unlike D48597, so there may very well be other problems.

Reviewers: mkazantsev, uabelho, sanjoy, silviu.baranga, wmi

Reviewed By: mkazantsev

Subscribers: evstupac, javed.absar, spatel, llvm-commits

Differential Revision: https://reviews.llvm.org/D48599

llvm-svn: 335950
2018-06-29 07:44:20 +00:00
John Brawn bdbbd8381f Add a PhiValuesAnalysis pass to calculate the underlying values of phis
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
2018-06-28 14:13:06 +00:00
Jakub Kuderski 555e41bbf2 [AliasSet] Fix UnknownInstructions printing
Summary:
AliasSet::print uses `I->printAsOperand` to print UnknownInstructions. The problem is that not all UnknownInstructions have names (e.g. call instructions). When such instructions are printed, they appear as `<badref>` in AliasSets, which is very confusing, as the values are perfectly valid.

This patch fixes that by printing UnknownInstructions without a name using `print` instead of `printAsOperand`.

Reviewers: asbirlea, chandlerc, sanjoy, grosser

Reviewed By: asbirlea

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D48609

llvm-svn: 335751
2018-06-27 16:34:30 +00:00
Sanjay Patel ad0bfb844d [InstSimplify] fold shifts by sext bool
https://rise4fun.com/Alive/c3Y

llvm-svn: 335633
2018-06-26 17:31:38 +00:00
Sanjay Patel 2b7e31095d [InstSimplify] fold srem with sext bool divisor
llvm-svn: 335616
2018-06-26 15:32:54 +00:00
Teresa Johnson 519055336d [ThinLTO] Add string saver onto index for value names
Summary:
Adds a string saver to the ModuleSummaryIndex so it can store value
names in the case of adding a ValueInfo for a GUID when we don't
have the name stored in a Module string table. This is motivated
by the upcoming summary parser patch, where we will read value names
from the summary entry and want to store them, even when a Module
is not available.

Currently this allows us to store the name in the legacy bitcode case,
and I have added a test to show that.

Reviewers: pcc, dexonsmith

Subscribers: mehdi_amini, inglorion, eraman, steven_wu, llvm-commits

Differential Revision: https://reviews.llvm.org/D47842

llvm-svn: 335570
2018-06-26 02:29:08 +00:00
Teresa Johnson 7bea1aad6a [ThinLTO] Compute GUID directly from GV when building per-module index
Summary:
I discovered when writing the summary parsing support that the
per-module index builder and writer are computing the GUID from the
value name alone (ignoring the linkage type). This was ok since those
GUID were not emitted in the bitcode, and there are never multiple
conflicting names in a single module.

However, I don't see a reason for making the GUID computation different
for the per-module case. It also makes things simpler on the parsing
side to have the GUID computation consistent. So this patch changes the
summary analysis phase and the per-module summary writer to compute the
GUID using the facility on the GlobalValue.

Reviewers: pcc, dexonsmith

Subscribers: llvm-commits, inglorion

Differential Revision: https://reviews.llvm.org/D47844

llvm-svn: 335560
2018-06-26 00:20:49 +00:00
Florian Hahn b10b141a79 Revert r335513: [SCEVExp] Advance found insertion point
llvm-svn: 335522
2018-06-25 20:55:26 +00:00
Florian Hahn 5947c17fd4 [SCEVExp] Advance found insertion point until we find a non-dbg instruction.
This avoids creating unnecessary casts if the IP used to be a dbg info
intrinsic. Fixes PR37727.

Reviewers: vsk, aprantl, sanjoy, efriedma

Reviewed By: vsk, efriedma

Differential Revision: https://reviews.llvm.org/D47874

llvm-svn: 335513
2018-06-25 19:17:29 +00:00
Sanjay Patel 1e911fa746 [InstSimplify] fold div/rem of zexted bool
I was looking at an unrelated fold and noticed that
we don't have this simplification (because the other
fold would break existing tests).

Name: zext udiv
  %z = zext i1 %x to i32
  %r = udiv i32 %y, %z
=>
  %r = %y

Name: zext urem
  %z = zext i1 %x to i32
  %r = urem i32 %y, %z
=>
  %r = 0

Name: zext sdiv
  %z = zext i1 %x to i32
  %r = sdiv i32 %y, %z
=>
  %r = %y

Name: zext srem
  %z = zext i1 %x to i32
  %r = srem i32 %y, %z
=>
  %r = 0

https://rise4fun.com/Alive/LZ9

llvm-svn: 335512
2018-06-25 18:51:21 +00:00
Alexander Richardson 85e200e934 Add Triple::isMIPS()/isMIPS32()/isMIPS64(). NFC
There are quite a few if statements that enumerate all these cases. It gets
even worse in our fork of LLVM where we also have a Triple::cheri (which
is mips64 + CHERI instructions) and we had to update all if statements that
check for Triple::mips64 to also handle Triple::cheri. This patch helps to
reduce our diff to upstream and should also make some checks more readable.

Reviewed By: atanasyan

Differential Revision: https://reviews.llvm.org/D48548

llvm-svn: 335493
2018-06-25 16:49:20 +00:00
David Green 8699492304 [DA] Delinearise AddRecs if we can prove they don't wrap
We can prove that some delinearized subscripts do not wrap around to become
negative by the fact that they are from inbound geps of load/store locations.
This helps improve the delinearisation in cases where we can't prove that they
are non-negative from SCEV alone.

Differential Revision: https://reviews.llvm.org/D48481

llvm-svn: 335481
2018-06-25 15:13:26 +00:00
George Burgess IV 97ec62455d [MSSA] Add domination number verifier; NFC
It's easy for domination numbers to get out-of-date, and this is no more
costly than any of the other verifiers we already have, so it seems nice
to have.

A stage3 build with this Works On My Machine, so this hasn't caught any
bugs... yet. :)

llvm-svn: 335444
2018-06-25 05:30:36 +00:00
George Burgess IV 2cbf9730b0 [MSSA] Remove incorrect comment + `auto`ify dyn_cast results; NFC
llvm-svn: 335399
2018-06-22 22:34:07 +00:00
Chandler Carruth fe70b29cf7 [LegacyPM] Fix PR37888 by teaching the legacy loop pass manager how to
clear out deleted loops from the current queue beyond just the current
loop.

This is important because SimpleLoopUnswitch will now enqueue the same
loop to be re-processed. When it does this with the legacy PM, we don't
have a way of canceling the rest of the pipeline and so we can end up
deleting the loop before we reprocess it. =/

This change also makes it easy to support deleting other loops in the
queue to process, although I don't have any use cases for that.

Differential Revision: https://reviews.llvm.org/D48470

llvm-svn: 335317
2018-06-22 02:43:41 +00:00
Tim Shen 63f244c4f4 [SCEV] Re-apply r335197 (with Polly fixes).
Summary:
This initiates a discussion on changing Polly accordingly while re-applying r335197 (D48338).

I have never worked on Polly. The proposed change to param_div_div_div_2.ll is not educated, but just patterns that match the output.

All LLVM files are already reviewed in D48338.

Reviewers: jdoerfert, bollu, efriedma

Subscribers: jlebar, sanjoy, hiraditya, llvm-commits, bixia

Differential Revision: https://reviews.llvm.org/D48453

llvm-svn: 335292
2018-06-21 21:29:54 +00:00
David Green d143c65de3 [DA] Enable -da-delinearize by default
This enables da-delinearize in Dependence Analysis for delinearizing array
accesses into multiple dimensions. This can help to increase the power of
Dependence analysis on multi-dimensional arrays and prevent having to fall
back to the slower and less accurate MIV tests. It adds static checks on the
bounds of the arrays to ensure that one dimension doesn't overflow into
another, and brings our code in line with our tests.

Differential Revision: https://reviews.llvm.org/D45872

llvm-svn: 335217
2018-06-21 11:53:16 +00:00
Tim Shen 433b9761ce Revert "[SCEV] Improve zext(A /u B) and zext(A % B)"
This reverts commit r335197, as some bots are not happy.

llvm-svn: 335198
2018-06-21 02:15:32 +00:00
Tim Shen 5af61e0a28 [SCEV] Improve zext(A /u B) and zext(A % B)
Summary:
Try to match udiv and urem patterns, and sink zext down to the leaves.

I'm not entirely sure why some unrelated tests change, but the added <nsw>s seem right.

Reviewers: sanjoy

Subscribers: jlebar, hiraditya, bixia, llvm-commits

Differential Revision: https://reviews.llvm.org/D48338

llvm-svn: 335197
2018-06-21 01:49:07 +00:00
Alina Sbirlea 201d02c75c [MemorySSA] Verify Phi incoming blocks are block predecessors.
Summary: Make the MemorySSA verify also check that all Phi incoming blocks are block predecessors.

Reviewers: george.burgess.iv

Subscribers: sanjoy, jlebar, Prazek, llvm-commits

Differential Revision: https://reviews.llvm.org/D48333

llvm-svn: 335174
2018-06-20 21:06:13 +00:00
Sanjay Patel 0c57de4c21 [InstSimplify] Fix missed optimization in simplifyUnsignedRangeCheck()
For both operands are unsigned, the following optimizations are valid, and missing:

   1. X > Y && X != 0 --> X > Y
   2. X > Y || X != 0 --> X != 0
   3. X <= Y || X != 0 --> true
   4. X <= Y || X == 0 --> X <= Y
   5. X > Y && X == 0 --> false

unsigned foo(unsigned x, unsigned y) { return x > y && x != 0; }
should fold to x > y, but I found we haven't done it right now.
besides, unsigned foo(unsigned x, unsigned y) { return x < y && y != 0; }
Has been folded to x < y, so there may be a bug.

Patch by: Li Jia He!

Differential Revision: https://reviews.llvm.org/D47922

llvm-svn: 335129
2018-06-20 14:22:49 +00:00
Sanjay Patel 2ca3360b11 [IR] move shuffle mask queries from TTI to ShuffleVectorInst
The optimizer is getting smarter (eg, D47986) about differentiating shuffles 
based on its mask values, so we should make queries on the mask constant 
operand generally available to avoid code duplication.

We'll probably use this soon in the vectorizers and instcombine (D48023 and 
https://bugs.llvm.org/show_bug.cgi?id=37806).

We might clean up TTI a bit more once all of its current 'SK_*' options are 
covered.

Differential Revision: https://reviews.llvm.org/D48236

llvm-svn: 335067
2018-06-19 18:44:00 +00:00
Sanjoy Das 6e9b355cc9 Revert "[SCEV] Add nuw/nsw to mul ops in StrengthenNoWrapFlags"
This reverts r334428.  It incorrectly marks some multiplications as nuw.  Tim
Shen is working on a proper fix.

Original commit message:

[SCEV] Add nuw/nsw to mul ops in StrengthenNoWrapFlags where safe.

Summary:
Previously we would add them for adds, but not multiplies.

llvm-svn: 335016
2018-06-19 04:09:44 +00:00
Benjamin Kramer 1193bbf6b7 Fix namespaces. No functionality change.
llvm-svn: 334890
2018-06-16 13:37:52 +00:00
Justin Lebar 3f5490af21 Revert "[SCEV] Use LLVM_MARK_AS_BITMASK_ENUM in SCEV." -- breaks MSVC builds.
This reverts D48237.

llvm-svn: 334878
2018-06-16 00:14:10 +00:00
Justin Lebar 018c3790f9 Revert "[SCEV] Simplify some flags expressions." -- dependent revision breaks MSVC builds.
This reverts D48238.

llvm-svn: 334877
2018-06-16 00:13:57 +00:00
Justin Lebar af30bb1c90 [SCEV] Simplify some flags expressions.
Summary:
Sending for presubmit review out of an abundance of caution; it would be
bad to mess this up.

Reviewers: sanjoy

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D48238

llvm-svn: 334875
2018-06-15 23:52:11 +00:00
Justin Lebar 6cb702d00d [SCEV] Use LLVM_MARK_AS_BITMASK_ENUM in SCEV.
Summary:
Obviates the need for mask/clear/setFlags helpers.

There are some expressions here which can be simplified, but to keep
this easy to review, I have not simplified them in this patch.

No functional change.

Reviewers: sanjoy

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D48237

llvm-svn: 334874
2018-06-15 23:51:57 +00:00
Benjamin Kramer 7f68a309ac [BPI] Remove unnecessary std::list
vector is sufficient here. No functionality change intended.

llvm-svn: 334865
2018-06-15 21:06:43 +00:00
George Burgess IV aa283d80fe [MSSA] Print more optimization information
In particular, when asked to print a MemoryAccess, we'll now print where
defs are optimized to, and we'll print optimized access types.

This patch also introduces an operator<< to make printing AliasResults
easier.

Patch by Juneyoung Lee!

Differential Revision: https://reviews.llvm.org/D47860

llvm-svn: 334760
2018-06-14 19:55:53 +00:00
Justin Lebar bdb0a58c91 [SCEV] Fix a variable name, NFC.
llvm-svn: 334738
2018-06-14 17:14:01 +00:00
Justin Lebar fe455464eb [SCEV] Simplify zext/trunc idiom that appears when handling bitmasks.
Summary:
Specifically, we transform

  zext(2^K * (trunc X to iN)) to iM ->
  2^K * (zext(trunc X to i{N-K}) to iM)<nuw>

This is helpful because pulling the 2^K out of the zext allows further
optimizations.

Reviewers: sanjoy

Subscribers: hiraditya, llvm-commits, timshen

Differential Revision: https://reviews.llvm.org/D48158

llvm-svn: 334737
2018-06-14 17:13:48 +00:00
Justin Lebar b326904dba [SCEV] Simplify trunc-of-add/mul to add/mul-of-trunc under more circumstances.
Summary:
Previously we would do this simplification only if it did not introduce
any new truncs (excepting new truncs which replace other cast ops).

This change weakens this condition: If the number of truncs stays the
same, but we're able to transform trunc(X + Y) to X + trunc(Y), that's
still simpler, and it may open up additional transformations.

While we're here, also clean up some duplicated code.

Reviewers: sanjoy

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D48160

llvm-svn: 334736
2018-06-14 17:13:35 +00:00
Justin Lebar 62a0747926 [SCEV] Fix indentation and combine two if statements in getMulExpr, NFC.
llvm-svn: 334735
2018-06-14 17:13:22 +00:00
Simon Pilgrim c0d53aba7b [CostModel] Cleanup isSingleSourceVectorMask to match other shuffle matchers. NFCI.
llvm-svn: 334699
2018-06-14 09:48:19 +00:00
Simon Pilgrim 32702cc86a [CostModel] Recognise REVERSE shuffle mask if the elements come from the second src
llvm-svn: 334698
2018-06-14 09:35:00 +00:00
Simon Pilgrim 54a138a0c5 [CostModel] Recognise BROADCAST shuffle mask if the elements come from the second src
llvm-svn: 334620
2018-06-13 16:52:02 +00:00
Simon Pilgrim e39fa6cbbb [CostModel] Replace ShuffleKind::SK_Alternate with ShuffleKind::SK_Select (PR33744)
As discussed on PR33744, this patch relaxes ShuffleKind::SK_Alternate which requires shuffle masks to only match an alternating pattern from its 2 sources:

e.g. v4f32: <0,5,2,7> or <4,1,6,3>

This seems far too restrictive as most SIMD hardware which will implement it using a general blend/bit-select instruction, so replaces it with SK_Select, permitting elements from either source as long as they are inline:

e.g. v4f32: <0,5,2,7>, <4,1,6,3>, <0,1,6,7>, <4,1,2,3> etc.

This initial patch just updates the name and cost model shuffle mask analysis, later patch reviews will update SLP to better utilise this - it still limits itself to SK_Alternate style patterns.

Differential Revision: https://reviews.llvm.org/D47985

llvm-svn: 334513
2018-06-12 16:12:29 +00:00
Simon Pilgrim 51ef8dabcd Fix signed/unsigned warning. NFCI.
llvm-svn: 334509
2018-06-12 15:14:34 +00:00
Simon Pilgrim 0783921987 [CostModel] Treat Identity shuffle masks as zero cost
As discussed on D47985, identity shuffle masks should probably be free.

I've limited this to the case where the input and output types all match - but we could probably accept all cases.

Differential Revision: https://reviews.llvm.org/D47986

llvm-svn: 334506
2018-06-12 14:47:13 +00:00
Justin Lebar 4da41c13a5 [SCEV] Add transform zext((A * B * ...)<nuw>) --> (zext(A) * zext(B) * ...)<nuw>.
Reviewers: sanjoy

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D48041

llvm-svn: 334429
2018-06-11 18:57:58 +00:00
Justin Lebar aa4fec94d8 [SCEV] Add nuw/nsw to mul ops in StrengthenNoWrapFlags where safe.
Summary:
Previously we would add them for adds, but not multiplies.

Reviewers: sanjoy

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D48038

llvm-svn: 334428
2018-06-11 18:57:42 +00:00
Justin Lebar 7b4656c1d3 Fix indentation in ScalarEvolution.cpp.
Whitespace-only change.  (clang-formatted the whole block.)

llvm-svn: 334427
2018-06-11 18:57:27 +00:00
Tim Shen cc63761720 [SCEV] Canonicalize "A /u C1 /u C2" to "A /u (C1*C2)".
Summary: FWIW InstCombine already folds this. Also avoid the case where C1*C2 overflows.

Reviewers: sunfish, sanjoy

Subscribers: hiraditya, bixia, llvm-commits

Differential Revision: https://reviews.llvm.org/D47965

llvm-svn: 334425
2018-06-11 18:44:58 +00:00
Krzysztof Parzyszek b10ea39270 [SCEV] Look through zero-extends in howFarToZero
An expression like
  (zext i2 {(trunc i32 (1 + %B) to i2),+,1}<%while.body> to i32)
will become zero exactly when the nested value becomes zero in its type.
Strip injective operations from the input value in howFarToZero to make
the value simpler.

Differential Revision: https://reviews.llvm.org/D47951

llvm-svn: 334318
2018-06-08 20:43:07 +00:00
Roman Lebedev f87321a2dc [NFC][InstSimplify] SimplifyAddInst(): coding style: variable names.
llvm-svn: 334299
2018-06-08 15:44:53 +00:00
Roman Lebedev b060ce45ca [InstSimplify] add nuw %x, -1 -> -1 fold.
Summary:
`%ret = add nuw i8 %x, C`
From [[ https://llvm.org/docs/LangRef.html#add-instruction | langref ]]:
    nuw and nsw stand for “No Unsigned Wrap” and “No Signed Wrap”,
    respectively. If the nuw and/or nsw keywords are present,
    the result value of the add is a poison value if unsigned
    and/or signed overflow, respectively, occurs.

So if `C` is `-1`, `%x` can only be `0`, and the result is always `-1`.

I'm not sure we want to use `KnownBits`/`LVI` here, because there is
exactly one possible value (all bits set, `-1`), so some other pass
should take care of replacing the known-all-ones with constant `-1`.

The `test/Transforms/InstCombine/set-lowbits-mask-canonicalize.ll` change *is* confusing.
What happening is, before this: (omitting `nuw` for simplicity)
1. First, InstCombine D47428/rL334127 folds `shl i32 1, %NBits`) to `shl nuw i32 -1, %NBits`
2. Then, InstSimplify D47883/rL334222 folds `shl nuw i32 -1, %NBits` to `-1`,
3. `-1` is inverted to `0`.
But now:
1. *This* InstSimplify fold `%ret = add nuw i32 %setbit, -1` -> `-1` happens first,
   before InstCombine D47428/rL334127 fold could happen.
Thus we now end up with the opposite constant,
and it is all good: https://rise4fun.com/Alive/OA9

https://rise4fun.com/Alive/sldC
Was mentioned in D47428 review.
Follow-up for D47883.

Reviewers: spatel, craig.topper

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47908

llvm-svn: 334298
2018-06-08 15:44:47 +00:00
Artur Pilipenko 4d063e7bb1 [BPI] Apply invoke heuristic before loop branch heuristic
Currently the loop branch heuristic is applied before the invoke heuristic which makes us overestimate the probability of the unwind destination of invokes inside loops. This in turn makes us grossly underestimate the frequencies of loops with invokes.

Reviewed By: skatkov, vsk

Differential Revision: https://reviews.llvm.org/D47371

llvm-svn: 334285
2018-06-08 13:03:21 +00:00
Roman Lebedev 2683802ba0 [InstSimplify] shl nuw C, %x -> C iff signbit is set on C.
Summary:
`%r = shl nuw i8 C, %x`

As per langref:
```
If the nuw keyword is present, then the shift produces
a poison value if it shifts out any non-zero bits.
```
Thus, if the sign bit is set on `C`, then `%x` can only be `0`,
which means that `%r` can only be `C`.
Or in other words, set sign bit means that the signed value
is negative, so the constant is `<= 0`.

https://rise4fun.com/Alive/WMk
https://rise4fun.com/Alive/udv

Was mentioned in D47428 review.

We already handle the `0` constant, https://godbolt.org/g/UZq1sJ, so this only handles negative constants.

Could use computeKnownBits() / LazyValueInfo,
but the cost-benefit analysis (https://reviews.llvm.org/D47891)
suggests it isn't worth it.

Reviewers: spatel, craig.topper

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47883

llvm-svn: 334222
2018-06-07 20:03:45 +00:00
Sanjay Patel 4b1205b40f [TargetLibraryInfo] add mappings from LLVM sin/cos intrinsics to SVML calls
These weren't included in D19544 - probably just an oversight.
D40044 made it more likely that we'll have LLVM math intrinsics rather 
than libcalls, so this bug was more easily exposed.
As the tests/code show, we already have the complete mappings for pow/exp/log.

I don't have any experience with SVML, so I don't know if anything else is 
missing. It's also not clear to me that we should be doing this transform in 
IR rather than DAG/isel, but that's a separate issue.

Differential Revision: https://reviews.llvm.org/D47610

llvm-svn: 334211
2018-06-07 18:21:24 +00:00
Teresa Johnson 4ffc3e7834 [ThinLTO] Rename index IsAnalysis flag to HaveGVs (NFC)
With the upcoming patch to add summary parsing support, IsAnalysis would
be true in contexts where we are not performing module summary analysis.
Rename to the more specific and approprate HaveGVs, which is essentially
what this flag is indicating.

llvm-svn: 334140
2018-06-06 22:22:01 +00:00
John Brawn c5a6392be3 [ValueTracking] Match select abs pattern when there's an sext involved
When checking a select to see if it matches an abs, allow the true/false values
to be a sign-extension of the comparison value instead of requiring that they're
directly the comparison value, as all the comparison cares about is the sign of
the value.

This fixes a regression due to r333702, where we were no longer generating ctlz
due to isKnownNonNegative failing to match such a pattern.

Differential Revision: https://reviews.llvm.org/D47631

llvm-svn: 333927
2018-06-04 16:53:57 +00:00
David Green 2911b3a07a [DA] Fix direction vectors for weakZeroSrcSIV
Both weakZeroSrcSIV and weakZeroDstSIV are currently giving the same
direction vectors. Fix weakZeroSrcSIVtest by flipping the directions
it gives.

Differential Revision: https://reviews.llvm.org/D46678

llvm-svn: 333658
2018-05-31 14:55:29 +00:00
Karl-Johan Karlsson ebaaa2ddae [ValueTracking] Fix endless recursion in isKnownNonZero()
Summary:
The isKnownNonZero() function have checks that abort the recursion when
it reaches the specified max depth. However one of the recursive calls
was placed before the max depth check was done, resulting in a endless
recursion that eventually triggered a segmentation fault.

Fixed the problem by moving the max depth check above the first
recursive call.

Reviewers: Prazek, nlopes, spatel, craig.topper, hfinkel

Reviewed By: hfinkel

Subscribers: hfinkel, bjope, llvm-commits

Differential Revision: https://reviews.llvm.org/D47531

llvm-svn: 333557
2018-05-30 15:56:46 +00:00
Daniel Neilson 6b23fb764e [AliasSet] Teach the alias set how to handle atomic memcpy/memmove/memset
Summary:
The atomic variants of the memcpy/memmove/memset intrinsics can be treated
the same was as the regular forms, with respect to aliasing. Update the
AliasSetTracker to treat the atomic forms the same was as the regular forms.

llvm-svn: 333551
2018-05-30 14:43:39 +00:00
Daniel Neilson 3a6c50f4e0 [BasicAA] Teach the analysis about atomic memcpy
Summary:
A simple change to derive mod/ref info from the atomic memcpy
intrinsic in the same way as from the regular memcpy intrinsic.

llvm-svn: 333454
2018-05-29 19:23:50 +00:00
George Burgess IV 45f263dd90 [MemorySSA] Reflow comments + clean up control flow; NFC
Style guide says `else`s after returns are iffy, and I agree. I also
don't know what broke the comments here and in CFLAA, but *shrug*.

llvm-svn: 333332
2018-05-26 02:28:55 +00:00
George Burgess IV e81681805c [CFLAA] Reflow comments; NFC
llvm-svn: 333330
2018-05-26 02:17:43 +00:00
George Burgess IV 319be3a4e6 Replace AA's uses of uint64_t with LocationSize; NFC.
The uint64_ts that we pass around AA to represent MemoryLocation sizes
are logically an Optional<uint64_t>. In D44748, we want to add an extra
'imprecise' bit to this Optional<uint64_t> to represent whether a given
MemoryLocation size is an upper-bound or an exact size. For more context
on why, please see D44748.

That patch is quite large, but reviewers seem to be OK with the
approach. In D45581 (my first attempt to split 'noise' out of D44748),
reames asked that I land a precursor that is solely replacing uint64_t
with LocationSize, which starts out as `using LocationSize = uint64_t;`.
He also gave me the OK to submit this rename without further review.

llvm-svn: 333314
2018-05-25 21:16:58 +00:00
Craig Topper 8f77dcadff Recommit r333226 "[ValueTracking] Teach computeKnownBits that the result of an absolute value pattern that uses nsw flag is always positive."
Libfuzzer tests have been fixed to prevent being optimized.

Original commit message:

If the nsw flag is used in the absolute value then it is undefined for INT_MIN. For all other value it will produce a positive number. So we can assume the result is positive.

This breaks some InstCombine abs/nabs combining tests because we simplify the second compare from known bits rather than as the whole pattern. Looks like we can probably fix it by adding a neg+abs/nabs combine to just swap the select operands. N

Differential Revision: https://reviews.llvm.org/D47041

llvm-svn: 333300
2018-05-25 19:18:09 +00:00
David Stenberg 05b6a53340 [MustExecute] Fix a debug invariant issue in isGuaranteedToExecute()
Summary:
Look past debug intrinsics when querying whether an instruction is the
first instruction in the header block. The commit includes a reproducer
for a case where LICM would not hoist an instruction, due to the presence
of the intrinsic.

A caveat with this commit is that the check will not work properly if
the instruction at hand is a debug intrinsic. I assume that no one
depends on isGuaranteedToExecute() to return true for debug intrinsics
for these cases (and that this might be an indication of another debug
invariant issue), so I thought that it was not worth adding that extra
bit of complexity.

Reviewers: reames, anna

Reviewed By: anna

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47197

llvm-svn: 333274
2018-05-25 13:02:59 +00:00
Craig Topper 8174281b93 Revert r333226 "[ValueTracking] Teach computeKnownBits that the result of an absolute value pattern that uses nsw flag is always positive."
This breaks some libFuzzer tests. http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fuzzer/builds/15589/steps/check-fuzzer/logs/stdio

Reverting to investigate

llvm-svn: 333253
2018-05-25 04:01:56 +00:00
Craig Topper 49f23fe349 [ValueTracking] Teach computeKnownBits that the result of an absolute value pattern that uses nsw flag is always positive.
If the nsw flag is used in the absolute value then it is undefined for INT_MIN. For all other value it will produce a positive number. So we can assume the result is positive.

This breaks some InstCombine abs/nabs combining tests because we simplify the second compare from known bits rather than as the whole pattern. Looks like we can probably fix it by adding a neg+abs/nabs combine to just swap the select operands. Need to check alive to make sure there are no corner cases.

Differential Revision: https://reviews.llvm.org/D47041

llvm-svn: 333226
2018-05-24 21:22:51 +00:00
Jakub Kuderski ef33edd9b5 [Dominators] Add PDT constructor from Function
Summary: This patch adds a PDT constructor from Function and lets codes previously using a local class to do this use PostDominatorTree class directly.

Reviewers: davide, kuhar, grosser, dberlin

Reviewed By: kuhar

Author: NutshellySima

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46709

llvm-svn: 333102
2018-05-23 17:29:21 +00:00
Piotr Padlewski d6f7346a4b Fix aliasing of launder.invariant.group
Summary:
Patch for capture tracking broke
bootstrap of clang with -fstict-vtable-pointers
which resulted in debbugging nightmare. It was fixed
https://reviews.llvm.org/D46900 but as it turned
out, there were other parts like inliner (computing of
noalias metadata) that I found after bootstraping with enabled
assertions.

Reviewers: hfinkel, rsmith, chandlerc, amharc, kuhar

Subscribers: JDevlieghere, eraman, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D47088

llvm-svn: 333070
2018-05-23 09:16:44 +00:00
David Bolvansky 1f343fa0e0 [InstCombine] Remove calloc transformations
Summary: Previous patch does not care if a value is changed between calloc and strlen. This needs to be removed from InstCombine and maybe moved to DSE later after some rework.

Reviewers: efriedma

Reviewed By: efriedma

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47218

llvm-svn: 333022
2018-05-22 20:27:36 +00:00
David Bolvansky 41f4b64ee1 [InstCombine] Calloc-ed strings optimizations
Summary:
Example cases:
strlen(calloc(...)) -> 0

Reviewers: efriedma, bkramer

Reviewed By: bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47059

llvm-svn: 332990
2018-05-22 15:41:23 +00:00
Simon Pilgrim 4162d77744 [TTI] Add uniform/non-uniform constant Pow2 detection to TargetTransformInfo::getInstructionThroughput
This enables us to detect more fast path sdiv cases under cost analysis.

This patch also enables us to handle non-uniform-constant pow2 cases for X86 SDIV costs.

Found while working on D46276

Future patches can then extend the vectorizers to more fully support non-uniform pow2 cases.

Differential Revision: https://reviews.llvm.org/D46637

llvm-svn: 332969
2018-05-22 10:40:09 +00:00
Craig Topper f14e62c9a5 [EarlyCSE] Improve EarlyCSE of some absolute value cases.
Change matchSelectPattern to return X and -X for ABS/NABS in a well defined order. Adjust EarlyCSE to account for this. Ensure the SPF result is some kind of min/max and not abs/nabs in one place in InstCombine that made me nervous.

Prevously we returned the two operands of the compare part of the abs pattern. The RHS is always going to be a 0i, 1 or -1 constant. This isn't a very meaningful thing to return for any one. There's also some freedom in the abs pattern as to what happens when the value is equal to 0. This freedom led to early cse failing to match when different constants were used in otherwise equivalent operations. By returning the input and its negation in a defined order we can ensure an exact match. This also makes sure both patterns use the exact same subtract instruction for the negation. I believe CSE should evebntually make this happen and properly merge the nsw/nuw flags. But I'm not familiar with CSE and what order it does things in so it seemed like it might be good to really enforce that they were the same.

Differential Revision: https://reviews.llvm.org/D47037

llvm-svn: 332865
2018-05-21 18:42:42 +00:00
Piotr Padlewski 5642a42442 Propagate nonnull and dereferenceable throught launder
Summary:
invariant.group.launder should not stop propagation
of nonnull and dereferenceable, because e.g. we would not be
able to hoist loads speculatively.

Reviewers: rsmith, amharc, kuhar, xbolva00, hfinkel

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D46972

llvm-svn: 332788
2018-05-18 23:54:33 +00:00
Piotr Padlewski ce358262eb Dissallow non-empty metadata for invariant.group
Summary:
This feature is not needed, but it might be usefull in the future
to use metadata to mark what which function should support it
(and strip it when not).

Reviewers: rsmith, sanjoy, amharc, kuhar

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45419

llvm-svn: 332787
2018-05-18 23:53:46 +00:00
Piotr Padlewski a26a08cb52 Constant fold launder of null and undef
Summary:
This might be useful because clang will add
some barriers for pointer comparisons.

Reviewers: majnemer, dberlin, hfinkel, nlewycky, davide, rsmith, amharc,
kuhar

Subscribers: davide, amharc, llvm-commits

Differential Revision: https://reviews.llvm.org/D32423

llvm-svn: 332786
2018-05-18 23:52:57 +00:00
Piotr Padlewski 153fe60079 [MemDep] Fixed handling of invariant.group
Summary:
Memdep had funny bug related to invariant.groups - because it did not
invalidated cache, in some very rare cases it was possible to show memory
dependence of the instruction that was deleted, but because other
instruction took it's place it resulted in call to vtable!
Thanks @amharc for repro!.

Reviewers: dberlin, kuhar, amharc

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D45320

Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com>
llvm-svn: 332781
2018-05-18 22:40:34 +00:00
Jessica Paquette e49374d009 Add remarks describing when a pass changes the IR instruction count of a module
This patch adds a remark which tells the user when a pass changes the number of
IR instructions in a module.

It can be enabled by using -Rpass-analysis=size-info.

The point of this is to make it easier to collect statistics on how passes
modify programs in terms of code size. This is similar in concept to timing
reports, but using a remark-based interface makes it easy to diff changes over
multiple compilations of the same program.

By adding functionality like this, we can see
  * Which passes impact code size the most
  * How passes impact code size at different optimization levels
  * Which pass might have contributed the most to an overall code size
    regression

The patch lives in the legacy pass manager, but since it's simply emitting
remarks, it shouldn't be too difficult to adapt the functionality to the new
pass manager as well. This can also be adapted to handle MachineInstr counts in
code gen passes.

https://reviews.llvm.org/D38768

llvm-svn: 332739
2018-05-18 17:26:39 +00:00
Serguei Katkov 5095883fe9 [LICM] Extend the MustExecute scope
CanProveNotTakenFirstIteration utility does not handle the case when
condition of the branch is a constant. Add its handling.

Reviewers: reames, anna, mkazantsev
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D46996

llvm-svn: 332695
2018-05-18 04:56:28 +00:00
George Burgess IV c6526176cf Revert r332657: "[AA] cfl-anders-aa with field sensitivity"
I don't believe the person who LGTMed this review has appropriate
context on this code. I apologize if I'm wrong.

llvm-svn: 332674
2018-05-17 21:56:39 +00:00
Heejin Ahn b4be38fcdd [WebAssembly] Add Wasm personality and isScopedEHPersonality()
Summary:
- Add wasm personality function
- Re-categorize the existing `isFuncletEHPersonality()` function into
two different functions: `isFuncletEHPersonality()` and
`isScopedEHPersonality(). This becomes necessary as wasm EH uses scoped
EH instructions (catchswitch, catchpad/ret, and cleanuppad/ret) but not
outlined funclets.
- Changed some callsites of `isFuncletEHPersonality()` to
`isScopedEHPersonality()` if they are related to scoped EH IR-level
stuff.

Reviewers: majnemer, dschuff, rnk

Subscribers: jfb, sbc100, jgravelle-google, eraman, JDevlieghere, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D45559

llvm-svn: 332667
2018-05-17 20:52:03 +00:00
David Bolvansky b1c59e3f30 [AA] cfl-anders-aa with field sensitivity
Summary:
There was some unfinished work started for offset tracking in CFLGraph by the author of implementation of Andersen algorithm. This work was completed and support for field sensitivity was added to the core of Andersen algorithm.

The performance results seem promising.

SPEC2006 int_base score was increased by 1.1 % (I  compared clang 6.0 with clang 6.0 with this patch). The avergae compile time was increased by +- 1 % according my measures with small and medium C/C++ projects (I did not tested it on the large projects with milions of lines of code)

Reviewers: chandlerc, george.burgess.iv, rja

Reviewed By: rja

Subscribers: rja, llvm-commits

Differential Revision: https://reviews.llvm.org/D46282

llvm-svn: 332657
2018-05-17 20:23:33 +00:00
Mikael Holmen 2ca16899ec Require DominatorTree when requiring/preserving LoopInfo in the old pass manager
Summary:
Require DominatorTree when requiring/preserving LoopInfo in the old pass manager

BreakCriticalEdges tries to keep LoopInfo and DominatorTree updated if they
exist. However, since commit r321653 and r321805, to update LoopInfo we
must have a DominatorTree, or we will hit an assert.

To fix this we now make a couple of passes that only required/preserved
LoopInfo also require DominatorTree.

This solves PR37334.

Reviewers: eli.friedman, efriedma

Reviewed By: efriedma

Subscribers: efriedma, llvm-commits

Differential Revision: https://reviews.llvm.org/D46829

llvm-svn: 332583
2018-05-17 09:05:40 +00:00
Martin Storsjo c10788728b [Analysis] Only use _unlocked stdio functions on linux
The existing comment said that the functions were available only
on GNU/Linux (and on certain Android versions), but only checked
T.isGNUEnvironment() which also is true on MinGW (for arch-windows-gnu
triplets), which doesn't have such functions.

Existing checks in the initialize function in TargetLibraryInfo.cpp
also use only T.isOSLinux() to check for glibc features.

This fixes use of stdio on MinGW.

Differential Revision: https://reviews.llvm.org/D47002

llvm-svn: 332581
2018-05-17 08:16:08 +00:00
Vedant Kumar 5a0872c2b7 [STLExtras] Add size() for ranges, and remove distance()
r332057 introduced distance() for ranges. Based on post-commit feedback,
this renames distance() to size(). The new size() is also only enabled
when the operation is O(1).

Differential Revision: https://reviews.llvm.org/D46976

llvm-svn: 332551
2018-05-16 23:20:42 +00:00
Krzysztof Pszeniczny 2ba8fd4914 [BasicAA] Fix handling of invariant group launders
Summary:
A recent patch ([[ https://reviews.llvm.org/rL331587 | rL331587 ]]) to Capture Tracking taught it that the `launder_invariant_group` intrinsic captures its argument only by returning it. Unfortunately, BasicAA still considered every call instruction as a possible escape source and hence concluded that the result of a `launder_invariant_group` call cannot alias any local non-escaping value. This led to [[ https://bugs.llvm.org/show_bug.cgi?id=37458 | bug 37458 ]].

This patch updates the relevant check for escape sources in BasicAA.

Reviewers: Prazek, kuhar, rsmith, hfinkel, sanjoy, xbolva00

Reviewed By: hfinkel, xbolva00

Subscribers: JDevlieghere, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D46900

llvm-svn: 332466
2018-05-16 13:16:54 +00:00
David Bolvansky ca22d427b9 [SimplifyLibcalls] Replace locked IO with unlocked IO
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
2018-05-16 11:39:52 +00:00
Michael Zolotukhin 67cfbaac89 [MemorySSA] Don't sort IDF blocks.
Summary:
After r332167 we started to sort the IDF blocks inside IDF calculation, so
there is no need to re-sort them on the user site. The test changes are due to
a slightly different order we're using now (originally we used DFSInNumber and
now the blocks are sorted by a pair (LevelFromRoot, DFSInNumber)).

Reviewers: dberlin, mgrang

Subscribers: Prazek, hiraditya, george.burgess.iv, llvm-commits

Differential Revision: https://reviews.llvm.org/D46899

llvm-svn: 332385
2018-05-15 18:40:29 +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
Michael Zolotukhin 046da97806 [IDF] Enforce the returned blocks to be sorted.
Summary:
Currently the order of blocks returned by `IDF::calculate` can be
non-deterministic. This was discovered in several attempts to enable
SSAUpdaterBulk for JumpThreading (which led to miscompare in bootstrap between
stage 3 and stage4). Originally, the blocks were put into a priority queue with
a depth level as their key, and this patch adds a DFSIn number as a second key
to specify a deterministic order across blocks from one level.

The solution was suggested by Daniel Berlin.

Reviewers: dberlin, davide

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D46646

llvm-svn: 332167
2018-05-12 01:44:32 +00:00
Martin Storsjo 0d7c37756b [Analysis] Validate the return type of s(n)printf like libcalls
If the sprintf function is static (as on mingw-w64, where many stdio
functions are static inline wrappers), earlier optimization passes
could optimize out the return value altogether, and make it void,
which could break optimizations of this libcall that touch the
return value.

This fixes the issue discussed in PR37408 for the sprintf function.

Differential Revision: https://reviews.llvm.org/D46752

llvm-svn: 332106
2018-05-11 16:53:56 +00:00
Wei Mi 0c2f6be662 [SampleFDO] Don't treat warm callsite with inline instance in the profile as cold
We found current sampleFDO had a performance issue when triaging a regression.
For a callsite with inline instance in the profile, even if hot callsite inliner
cannot inline it, it may still execute enough times and should not be treated as
cold in regular inliner later. However, currently if such callsite is not inlined
by hot callsite inliner, and the BB where the callsite locates doesn't get
samples from other instructions inside of it, the callsite will have no profile
metadata annotated. In regular inliner cost analysis, if the callsite has no
profile annotated and its caller has profile information, it will be treated as
cold.

The fix changes the isCallsiteHot check and chooses to compare
CallsiteTotalSamples with hot cutoff value computed by ProfileSummaryInfo.

Differential Revision: https://reviews.llvm.org/D45377

llvm-svn: 332058
2018-05-10 23:02:27 +00:00
Vedant Kumar e0b5f86b30 [STLExtras] Add distance() for ranges, pred_size(), and succ_size()
This commit adds a wrapper for std::distance() which works with ranges.
As it would be a common case to write `distance(predecessors(BB))`, this
also introduces `pred_size()` and `succ_size()` helpers to make that
easier to write.

Differential Revision: https://reviews.llvm.org/D46668

llvm-svn: 332057
2018-05-10 23:01:54 +00:00
Omer Paparo Bivas fbb83deef7 [InstCombine] Moving overflow computation logic from InstCombine to ValueTracking; NFC
Differential Revision: https://reviews.llvm.org/D46704

Change-Id: Ifabcbe431a2169743b3cc310f2a34fd706f13f02
llvm-svn: 332026
2018-05-10 19:46:19 +00:00
David Bolvansky 10c218d4af [CFLGraph] Fixed Select instruction handling
Summary:
Operand 0 is the condition, not the true value.

Use op 1 and op 2 as the correct values.

Reviewers: george.burgess.iv, nlopes, efriedma

Reviewed By: george.burgess.iv

Subscribers: craig.topper, rjmccall, lebedev.ri, llvm-commits

Differential Revision: https://reviews.llvm.org/D46343

llvm-svn: 331976
2018-05-10 11:47:36 +00:00
Serguei Katkov 7d02f059e7 SCEV] Do not use induction in isKnownPredicate for simplification umax.
During simplification umax we trigger isKnownPredicate twice. As a first attempt it
tries the induction. To do that it tries to get post increment of SCEV.
Re-writing the SCEV may result in simplification of umax. If the SCEV contains a lot
of umax operations this recursion becomes very slow.

The added test demonstrates the slow behavior.

To resolve this we use only simple ways to check whether the predicate is known.

Reviewers: sanjoy, mkazantsev
Reviewed By: sanjoy
Subscribers: lebedev.ri, javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D46046

llvm-svn: 331949
2018-05-10 01:40:43 +00:00
Shiva Chen 2c864551df [DebugInfo] Add DILabel metadata and intrinsic llvm.dbg.label.
In order to set breakpoints on labels and list source code around
labels, we need collect debug information for labels, i.e., label
name, the function label belong, line number in the file, and the
address label located. In order to keep these information in LLVM
IR and to allow backend to generate debug information correctly.
We create a new kind of metadata for labels, DILabel. The format
of DILabel is

!DILabel(scope: !1, name: "foo", file: !2, line: 3)

We hope to keep debug information as much as possible even the
code is optimized. So, we create a new kind of intrinsic for label
metadata to avoid the metadata is eliminated with basic block.
The intrinsic will keep existing if we keep it from optimized out.
The format of the intrinsic is

llvm.dbg.label(metadata !1)

It has only one argument, that is the DILabel metadata. The
intrinsic will follow the label immediately. Backend could get the
label metadata through the intrinsic's parameter.

We also create DIBuilder API for labels to be used by Frontend.
Frontend could use createLabel() to allocate DILabel objects, and use
insertLabel() to insert llvm.dbg.label intrinsic in LLVM IR.

Differential Revision: https://reviews.llvm.org/D45024

Patch by Hsiangkai Wang.

llvm-svn: 331841
2018-05-09 02:40:45 +00:00
Piotr Padlewski e9832dfdf3 [CaptureTracking] Handle capturing of launder.invariant.group
Summary:
launder.invariant.group has the same rules of capturing as
bitcast, gep, etc - the original value is not captured
if the returned pointer is not captured.

With this patch, we mark 40% more functions as noalias when compiling with -fstrict-vtable-pointers;
1078 vs 1778  (39.37%)

Reviewers: sanjoy, davide, nlewycky, majnemer, mehdi_amini

Subscribers: JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D32673

llvm-svn: 331587
2018-05-05 10:23:27 +00:00
Piotr Padlewski 5dde809404 Rename invariant.group.barrier to launder.invariant.group
Summary:
This is one of the initial commit of "RFC: Devirtualization v2" proposal:
https://docs.google.com/document/d/16GVtCpzK8sIHNc2qZz6RN8amICNBtvjWUod2SujZVEo/edit?usp=sharing

Reviewers: rsmith, amharc, kuhar, sanjoy

Subscribers: arsenm, nhaehnle, javed.absar, hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D45111

llvm-svn: 331448
2018-05-03 11:03:01 +00:00
Max Kazantsev 58fce7e54b Re-enable "[SCEV] Make computeExitLimit more simple and more powerful"
This patch was temporarily reverted because it has exposed bug 37229 on
PowerPC platform. The bug is unrelated to the patch and was just a general
bug in the optimization done for PowerPC platform only. The bug was fixed
by the patch rL331410.

This patch returns the disabled commit since the bug was fixed.

llvm-svn: 331427
2018-05-03 02:37:55 +00:00
David Bolvansky 8d693602a1 [CFLGraph][NFC] Simplify/reorder switch in visitConstantExpr
Reviewers: hfinkel, efriedma, spatel, dsanders, Danil, rjmccall

Reviewed By: rjmccall

Subscribers: dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D46259

llvm-svn: 331312
2018-05-01 21:35:32 +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
Alina Sbirlea 020363edcc [ModRefInfo] Rename local variable IsMustAlias to avoid shadowing MustAlias enum entry.
llvm-svn: 331222
2018-04-30 20:11:13 +00:00
Nico Weber 432a38838d IWYU for llvm-config.h in llvm, additions.
See r331124 for how I made a list of files missing the include.
I then ran this Python script:

    for f in open('filelist.txt'):
        f = f.strip()
        fl = open(f).readlines()

        found = False
        for i in xrange(len(fl)):
            p = '#include "llvm/'
            if not fl[i].startswith(p):
                continue
            if fl[i][len(p):] > 'Config':
                fl.insert(i, '#include "llvm/Config/llvm-config.h"\n')
                found = True
                break
        if not found:
            print 'not found', f
        else:
            open(f, 'w').write(''.join(fl))

and then looked through everything with `svn diff | diffstat -l | xargs -n 1000 gvim -p`
and tried to fix include ordering and whatnot.

No intended behavior change.

llvm-svn: 331184
2018-04-30 14:59:11 +00:00
Serguei Katkov f4c681eb65 [SCEV] Touch the unsused stats variables for product build.
This is a fix by elimination compiler warnings considered as errors.

llvm-svn: 331103
2018-04-28 06:41:35 +00:00
Serguei Katkov 6c6b40b330 [SCEV] Reduce the number of invocation to non trivial getExact function
The invocation of getExact in ScalarEvolution::getBackedgeTakenInfo is used
only for getting statistic and for assert. 
Even if statistics is disabled, the code related to it will be eliminated
the invocation to getExact itself will not be eliminated
because it may have side-effects like creation of new SCEVs.

So do invocation only when we collect statistics or executes asserts.

Reviewers: mkazantsev, sanjoy, javed.absar
Reviewed By: javed.absar
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D46178

llvm-svn: 331099
2018-04-28 03:53:36 +00:00
Roman Lebedev 6959b8e76f [PatternMatch] Stabilize the matching order of commutative matchers
Summary:
Currently, we
1. match `LHS` matcher to the `first` operand of binary operator,
2. and then match `RHS` matcher to the `second` operand of binary operator.
If that does not match, we swap the `LHS` and `RHS` matchers:
1. match `RHS` matcher to the `first` operand of binary operator,
2. and then match `LHS` matcher to the `second` operand of binary operator.

This works ok.
But it complicates writing of commutative matchers, where one would like to match
(`m_Value()`) the value on one side, and use (`m_Specific()`) it on the other side.

This is additionally complicated by the fact that `m_Specific()` stores the `Value *`,
not `Value **`, so it won't work at all out of the box.

The last problem is trivially solved by adding a new `m_c_Specific()` that stores the
`Value **`, not `Value *`. I'm choosing to add a new matcher, not change the existing
one because i guess all the current users are ok with existing behavior,
and this additional pointer indirection may have performance drawbacks.
Also, i'm storing pointer, not reference, because for some mysterious-to-me reason
it did not work with the reference.

The first one appears trivial, too.
Currently, we
1. match `LHS` matcher to the `first` operand of binary operator,
2. and then match `RHS` matcher to the `second` operand of binary operator.
If that does not match, we swap the ~~`LHS` and `RHS` matchers~~ **operands**:
1. match ~~`RHS`~~ **`LHS`** matcher to the ~~`first`~~ **`second`** operand of binary operator,
2. and then match ~~`LHS`~~ **`RHS`** matcher to the ~~`second`~ **`first`** operand of binary operator.

Surprisingly, `$ ninja check-llvm` still passes with this.
But i expect the bots will disagree..

The motivational unittest is included.
I'd like to use this in D45664.

Reviewers: spatel, craig.topper, arsenm, RKSimon

Reviewed By: craig.topper

Subscribers: xbolva00, wdng, llvm-commits

Differential Revision: https://reviews.llvm.org/D45828

llvm-svn: 331085
2018-04-27 21:23:20 +00:00
Philip Reames e4ec473b3f [MustExecute/LICM] Special case first instruction in throwing header
We currently have a hard to solve analysis problem around the order of instructions within a potentially throwing block.  We can't cheaply determine whether a given instruction is before the first potential throw in the block.  While we're working on that in the background, special case the first instruction within the header.

why this particular special case?  Well, headers are guaranteed to execute if the loop does, and it turns out we tend to produce this form in practice.

In a follow on patch, I tend to extend LICM with an alternate approach which works for any instruction in the header before the first throw, but this is the best I can come up with other users of the analysis (such as store promotion.)

Note: I can't show the difference in the analysis result since we're ORing in the expensive instruction walk used by SCEV.  Using the full walk is not suitable for a general solution.
llvm-svn: 331079
2018-04-27 20:44:01 +00:00
Serguei Katkov 1956a48d27 [SCEV] Add trivial case handling for umin utilities. NFC.
Reviewers: sanjoy, mkazantsev
Reviewed By: mkazantsev
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D46175

llvm-svn: 331022
2018-04-27 08:02:50 +00:00
Serguei Katkov fa7fd13cf8 [SCEV] Introduce bulk umin creation utilities
Add new umin creation method which accepts a list of operands.

SCEV does not represents umin which is required in getExact, so
it transforms umin to umax with not. As a result the transformation of
tree of max to max with several operands does not work.
We just use the new introduced method for creation umin from several operands.

Reviewers: sanjoy, mkazantsev
Reviewed By: sanjoy
Subscribers: javed.absar, llvm-commits
Differential Revision: https://reviews.llvm.org/D46047

llvm-svn: 331015
2018-04-27 03:56:53 +00:00
Matt Morehouse 1ae1febfde Revert "[SimplifyLibcalls] Replace locked IO with unlocked IO"
This reverts r331002 due to sanitizer bot breakage.

llvm-svn: 331011
2018-04-27 01:48:09 +00:00
David Bolvansky 2c9cc9c731 [SimplifyLibcalls] Replace locked IO with unlocked IO
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

Subscribers: lebedev.ri, llvm-commits

Differential Revision: https://reviews.llvm.org/D45736

llvm-svn: 331002
2018-04-26 22:31:43 +00:00
Matthew Simpson b4096ebe26 [TTI, AArch64] Add transpose shuffle kind
This patch adds a new shuffle kind useful for transposing a 2xn matrix. These
transpose shuffle masks read corresponding even- or odd-numbered vector
elements from two n-dimensional source vectors and write each result into
consecutive elements of an n-dimensional destination vector. The transpose
shuffle kind is meant to model the TRN1 and TRN2 AArch64 instructions. As such,
this patch also considers transpose shuffles in the AArch64 implementation of
getShuffleCost.

Differential Revision: https://reviews.llvm.org/D45982

llvm-svn: 330941
2018-04-26 13:48:33 +00:00
Max Kazantsev 2c287ec9c5 Revert "[SCEV] Make computeExitLimit more simple and more powerful"
This reverts commit 023c8be90980e0180766196cba86f81608b35d38.

This patch triggers miscompile of zlib on PowerPC platform. Most likely it is
caused by some pre-backend PPC-specific pass, but we don't clearly know the
reason yet. So we temporally revert this patch with intention to return it
once the problem is resolved. See bug 37229 for details.

llvm-svn: 330893
2018-04-26 02:07:40 +00:00
Daniel Neilson 3c148720fa [CaptureTracking] Fixup const correctness of DomTree arg (NFC)
Summary:
The PointerMayBeCapturedBefore function's DomTree arg should be
const instead of non-const. There are no non-const uses of it
in the function.

llvm-svn: 330769
2018-04-24 21:12:45 +00:00
Xin Tong adb5bfe75b [LVI] Fix typo. NFC
llvm-svn: 330688
2018-04-24 07:38:07 +00:00