Summary:
If any vector divisor element is undef, we can arbitrarily choose it be
zero which would make the div/rem an undef value by definition.

Reviewers: spatel, reames

Reviewed By: spatel

Subscribers: magabari, llvm-commits

Differential Revision: https://reviews.llvm.org/D42485

llvm-svn: 323343

Summary:
`getAction(const InstrAspect &) const` breaks encapsulation by exposing
the smaller components that are used to decide how to legalize an
instruction.

This is a problem because we need to change the implementation of
LegalizerInfo so that it's able to describe particular type combinations
rather than just cartesian products of types.

For example, declaring the following
  setAction({..., 0, s32}, Legal)
  setAction({..., 0, s64}, Legal)
  setAction({..., 1, s32}, Legal)
  setAction({..., 1, s64}, Legal)
currently declares these type combinations as legal:
  {s32, s32}
  {s64, s32}
  {s32, s64}
  {s64, s64}
but we currently have no means to say that, for example, {s64, s32} is
not legal. Some operations such as G_INSERT/G_EXTRACT/G_MERGE_VALUES/
G_UNMERGE_VALUES has relationships between the types that are currently
described incorrectly.

Additionally, G_LOAD/G_STORE currently have no means to legalize non-atomics
differently to atomics. The necessary information is in the MMO but we have no
way to use this in the legalizer. Similarly, there is currently no way for the
register type and the memory type to differ so there is no way to cleanly
represent extending-load/truncating-store in a way that can't be broken by
optimizers (resulting in illegal MIR).

This patch introduces LegalityQuery which provides all the information
needed by the legalizer to make a decision on whether something is legal
and how to legalize it.

Reviewers: ab, t.p.northover, qcolombet, rovka, aditya_nandakumar, volkan, reames, bogner

Reviewed By: bogner

Subscribers: bogner, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D42244

llvm-svn: 323342

This allows us to specify the magic number for the DJB hash function.
This feature is needed by dsymutil to emit Apple types accelerator
table.

llvm-svn: 323341

llvm-svn: 323340

This is needed in order to use our StringPool entries in the Apple
accelerator tables.

As this is NFC we rely on the existing tests for correctness.

llvm-svn: 323339

We're getting bug reports:
https://bugs.llvm.org/show_bug.cgi?id=35807
https://bugs.llvm.org/show_bug.cgi?id=35840
https://bugs.llvm.org/show_bug.cgi?id=36045
...where we blow up the stack in value tracking because other passes are sending 
in selects that have an operand that is itself the select.

We don't currently have a reliable way to avoid analyzing dead code that may take 
non-standard forms, so bail out when things go too far.

This mimics the recursion depth limitations in other parts of value tracking.

Unfortunately, this pushes the underlying problems for other passes (jump-threading,
simplifycfg, correlated-propagation) into hiding. If someone wants to uncover those
again, the first draft of this patch on Phab would do that (it would assert rather
than bail out).

Differential Revision: https://reviews.llvm.org/D42442

llvm-svn: 323331

llvm-svn: 323330

Add cases with vector non-splat pow2 contant divider.

llvm-svn: 323329

llvm-svn: 323328

llvm-svn: 323326

Summary:
Loads/stores of some NEON vector types are promoted to other vector
types with different lane sizes but same vector size. This is not a
problem in little-endian but, when in big-endian, it requires
additional byte reversals required to preserve the lane ordering
while keeping the right endianness of the data inside each lane.
For example:

%1 = load <4 x half>, <4 x half>* %p

results in the following assembly:

ld1 { v0.2s }, [x1]
rev32 v0.4h, v0.4h

This patch changes the promotion of these loads/stores so that the
actual vector load/store (LD1/ST1) takes care of the endianness
correctly and there is no need for further byte reversals. The
previous code now results in the following assembly:

ld1 { v0.4h }, [x1]

Reviewers: olista01, SjoerdMeijer, efriedma

Reviewed By: efriedma

Subscribers: aemerson, rengolin, javed.absar, llvm-commits, kristof.beyls

Differential Revision: https://reviews.llvm.org/D42235

llvm-svn: 323325

llvm-svn: 323324

Summary:
This patch implements the codegen of DWARF debug info for non-constant
'count' fields for DISubrange.

This is patch [2/3] in a series to extend LLVM's DISubrange Metadata
node to support debugging of C99 variable length arrays and vectors with
runtime length like the Scalable Vector Extension for AArch64. It is
also a first step towards representing more complex cases like arrays
in Fortran.

Reviewers: echristo, pcc, aprantl, dexonsmith, clayborg, kristof.beyls, dblaikie

Reviewed By: aprantl

Subscribers: fhahn, aemerson, rengolin, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D41696

llvm-svn: 323323

Summary:
Currently when a regular expression contains an invalid character
class name std::regex constructors throw an std::regex_error with
std::regex_constants::error_brack code.

This patch changes the code to std::regex_constants::error_ctype and
adds a test.

Reviewers: EricWF, mclow.lists

Reviewed By: mclow.lists

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D42291

llvm-svn: 323322

Combine expression patterns to form expressions with fewer, simple instructions.
This pass does not modify the CFG.

For example, this pass reduce width of expressions post-dominated by TruncInst
into smaller width when applicable.

It differs from instcombine pass in that it contains pattern optimization that
requires higher complexity than the O(1), thus, it should run fewer times than
instcombine pass.

Differential Revision: https://reviews.llvm.org/D38313

llvm-svn: 323321

[X86][SSE] Avoid calls to combineX86ShufflesRecursively that can't combine to target shuffles (PR32037)

Don't bother making recursive calls to combineX86ShufflesRecursively if we have more shuffle source operands than will be combined together with the remaining recursive depth.

See https://bugs.llvm.org/show_bug.cgi?id=32037#c26 and https://bugs.llvm.org/show_bug.cgi?id=32037#c27 for the reduction in compile times from this patch.

Differential Revision: https://reviews.llvm.org/D42378

llvm-svn: 323320

Summary:
Commonly string literals in protos are already multiline, so breaking them
further is undesirable.

Reviewers: djasper

Reviewed By: djasper

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D42373

llvm-svn: 323319

llvm-svn: 323318

(and also slightly reformatted the related lines to look better in
the rendered HTML)

llvm-svn: 323317

llvm-svn: 323316

This makes sure that the last cache line gets invalidated properly.

This matches the example code at
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0024a/BABJDBHI.html,
and also matches what libgcc does.

Differential Revision: https://reviews.llvm.org/D42196

llvm-svn: 323315

Differential Revision: https://reviews.llvm.org/D42410

llvm-svn: 323314

Summary:
This patch extends the DISubrange 'count' field to take either a
(signed) constant integer value or a reference to a DILocalVariable
or DIGlobalVariable.

This is patch [1/3] in a series to extend LLVM's DISubrange Metadata
node to support debugging of C99 variable length arrays and vectors with
runtime length like the Scalable Vector Extension for AArch64. It is
also a first step towards representing more complex cases like arrays
in Fortran.

Reviewers: echristo, pcc, aprantl, dexonsmith, clayborg, kristof.beyls, dblaikie

Reviewed By: aprantl

Subscribers: rnk, probinson, fhahn, aemerson, rengolin, JDevlieghere, llvm-commits

Differential Revision: https://reviews.llvm.org/D41695

llvm-svn: 323313

For the included test case, the DAG transformation
  concat_vectors(scalar, undef) -> scalar_to_vector(sclr)
would attempt to create a v2i32 vector for a v9i8
concat_vector.  Bail out to avoid creating a bitcast with
mismatching sizes later on.

Differential Revision: https://reviews.llvm.org/D42379

llvm-svn: 323312

Summary:
This is the first attempt to write down a guideline on adding exception handling support for a target. The content basically bases on the discussion on [1]. If you guys know who is exception handling expert, please add him as the reviewer. Thanks.

[1] http://lists.llvm.org/pipermail/llvm-dev/2018-January/120405.html

Reviewers: t.p.northover, theraven, nemanjai

Reviewed By: theraven

Subscribers: sdardis, llvm-commits

Differential Revision: https://reviews.llvm.org/D42178

llvm-svn: 323311

Summary:
The new test is now in the right directory with the other ASTVisitor tests and uses
now the provided TestVisitor framework.

Subscribers: hintonda, v.g.vassilev, klimek, cfe-commits, mgorny

Differential Revision: https://reviews.llvm.org/D37557

llvm-svn: 323310

This patch removes assert that SCEV is able to prove that a value is
non-negative. In fact, SCEV can sometimes be unable to do this because
its cache does not update properly. This assert will be returned once this
problem is resolved.

llvm-svn: 323309

This matches what MSVC does for alloca() function calls on ARM.
Even if MSVC doesn't support VLAs at the language level, it does
support the alloca function.

On the clang level, both the _alloca() (when emulating MSVC, which is
what the alloca() function expands to) and __builtin_alloca() builtin
functions, and VLAs, map to the same LLVM IR "alloca" function - so
within LLVM they're not distinguishable from each other.

Differential Revision: https://reviews.llvm.org/D42292

llvm-svn: 323308

Merging such globals loses the dllexport attribute. Add a test
to check that normal globals still are merged.

Differential Revision: https://reviews.llvm.org/D42127

llvm-svn: 323307

llvm-svn: 323306

I think these instructions used to be named differently and the regular expression reflected that. I guess we must have correct itinerary information that made this not matter for the scheduler test?

llvm-svn: 323305

[X86] Rename 256-bit VFRCZ instructions to have the Y before the rr/rm to match other instructions. NFC

llvm-svn: 323304

llvm-svn: 323303

"the the" -> "the"

llvm-svn: 323302

There are a couple tricky things with this patch.

I had to add an override of isVectorLoadExtDesirable to stop DAG combine from combining sign_extend with loads after legalization since we legalize sextload using a load+sign_extend. Overriding this hook actually prevents a lot sextloads from being created in the first place.

I also had to add isel patterns because DAG combine blindly combines sign_extend+truncate to a smaller sign_extend which defeats what legalization was trying to do.

Differential Revision: https://reviews.llvm.org/D42407

llvm-svn: 323301

Some users may have a custom build system which gives a different
name to the libc++ archive (or does not create an archive at all,
instead passing the object files directly to the linker). Give those
users a way to disable auto-linking.

Differential Revision: https://reviews.llvm.org/D42436

llvm-svn: 323300

This is somewhat preferable since (in many cases) it allows llc
to be run directly on the .ll files without having to pass the
`-mtriple` argument.

Differential Revision: https://reviews.llvm.org/D42438

llvm-svn: 323299

Summary:
Currently, there are 2 ways to verify a DomTree:
* `DT.verify()` -- runs full tree verification and checks all the properties and gives a reason why the tree is incorrect. This is run by when EXPENSIVE_CHECKS are enabled or when `-verify-dom-info` flag is set.
* `DT.verifyDominatorTree()` -- constructs a fresh tree and compares it against the old one. This does not check any other tree properties (DFS number, levels), nor ensures that the construction algorithm is correct. Used by some passes inside assertions.

This patch introduces DomTree verification levels, that try to close the gape between the two ways of checking trees by introducing 3 verification levels:
- Full -- checks all properties, but can be slow (O(N^3)). Used when manually requested (e.g. `assert(DT.verify())`) or when  `-verify-dom-info` is set.
- Basic -- checks all properties except the sibling property, and compares the current tree with a freshly constructed one instead. This should catch almost all errors, but does not guarantee that the construction algorithm is correct. Used when EXPENSIVE checks are enabled.
- Fast -- checks only basic properties (reachablility, dfs numbers, levels, roots), and compares with a fresh tree. This is meant to replace the legacy `DT.verifyDominatorTree()` and in my tests doesn't cause any noticeable performance impact even in the most pessimistic examples.

When used to verify dom tree wrapper pass analysis on sqlite3, the 3 new levels make `opt -O3` take the following amount of time on my machine:
- no verification: 8.3s
- `DT.verify(VerificationLevel::Fast)`: 10.1s
- `DT.verify(VerificationLevel::Basic)`: 44.8s
- `DT.verify(VerificationLevel::Full)`: 1m 46.2s
(and the previous `DT.verifyDominatorTree()` is within the noise of the Fast level)

This patch makes `DT.verifyDominatorTree()` pick between the 3 verification levels depending on EXPENSIVE_CHECKS and `-verify-dom-info`.

Reviewers: dberlin, brzycki, davide, grosser, dmgreen

Reviewed By: dberlin, brzycki

Subscribers: MatzeB, llvm-commits

Differential Revision: https://reviews.llvm.org/D42337

llvm-svn: 323298

This is already a simplification, and should help with avoiding a plt
reference when calling an intrinsic with -fno-plt.

With this change we return false for null GVs, so the caller only
needs to check the new metadata to decide if it should use foo@plt or
*foo@got.

llvm-svn: 323297

llvm-svn: 323296