AlignVectors treats all loaded/stored values as vectors of bytes,
and masks as corresponding vectors of booleans, so make getMask
produce a 1-element vector for scalars from the start.

This makes it possible to use update_llc_test_checks to manage tests
that check for incorrect x86 stack offsets. It does not yet modify any
test to make use of this new option.

The ABI demands a data16 prefix for lea in 64-bit LP64 mode, but not in
64-bit ILP32 mode. In both modes this prefix would ordinarily be
ignored, but the instructions may be changed by the linker to
instructions that are affected by the prefix.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D93157

This adds some basic MVE masked load/store costs, notably changing the
cost of legal loads/stores to the MVECostFactor and the cost of
scalarized instructions to 8*NumElts.

Differential Revision: https://reviews.llvm.org/D86538

When it comes to the scalar cost of any predicated block, the loop
vectorizer by default regards this predication as a sign that it is
looking at an if-conversion and divides the scalar cost of the block by
2, assuming it would only be executed half the time. This however makes
no sense if the predication has been introduced to tail predicate the
loop.

Original patch by Anna Welker

Differential Revision: https://reviews.llvm.org/D86452

Support all the spellings of boolean datatypes according to https://yaml.org/type/bool.html

Reviewed By: silvas

Differential Revision: https://reviews.llvm.org/D92755

This introduces more flexible multiclass for declaring two flags controlling the same boolean keypath.

Compared to existing Opt{In,Out}FFlag multiclasses, the new syntax makes it easier to read option declarations and reason about the keypath.

This also makes specifying common properties of both flags possible.

I'm open to suggestions on the class names. Not 100% sure the benefits are worth the added complexity.

Depends on D92774.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D92775

We don't need to always generate `-f[no-]experimental-new-pass-manager`.

This patch does not change the behavior of any other command line flag. (For example `-triple` is still being always generated.)

Reviewed By: dexonsmith, Bigcheese

Differential Revision: https://reviews.llvm.org/D92857

gcov computes the line execution count as the sum of (a) counts from
predecessors on other lines and (b) the sum of loop execution counts of blocks
on the same line (think of loops on one line).

For (b), we use Donald B. Johnson's cycle enumeration algorithm and perform
cycle cancelling for each cycle. This number of candidate cycles were
exponential and D93036 made it polynomial by skipping zero count cycles.  The
time complexity is high (O(V*E^2) (it could be O(E^2) but the linear `Blocks`
check made it higher) and the implementation is complex.

We could just identify loops and sum all back edges. However, this requires a
dominator tree construction which is more complex. The time complexity can be
decreased to almost linear, though.

This patch just performs cycle cancelling iteratively. Add two members
`traversable` and `incoming` to GCOVArc. There are 3 states:

* `!traversable`: blocks not on this line or explored blocks
* `traversable && incoming == nullptr`: unexplored blocks
* `traversable && incoming != nullptr`: blocks which are being explored (on the stack)

If an arc points to a block being explored, a cycle has been found.

Let E be the number of arcs. Every time a cycle is found, at least one arc is
saturated (`edgeCount` reduced to 0), so there are at most E cycles. Finding one
cycle takes O(E) time, so the overall time complexity is O(E^2). Note that we
always augment through a back edge and never need to augment its reverse edge so
reverse edges in traditional flow networks are not needed.

Reviewed By: xinhaoyuan

Differential Revision: https://reviews.llvm.org/D93073

Fixed to properly compute the live-in lists of new blocks.

Review: Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D92803

The performance improvement on LBM previously achieved with improved software
prefetching (36d4421f) have gone lost recently with e00f189d. There now is one
memory access in the loop that LoopDataPrefetch cannot handle (while before
there was none) which the heuristic rejects.

This patch adds a small margin by allowing 1 non-prefetched memory access for
every 32 prefetched ones, so that the heuristic doesn't bail in this type of
case.

Review: Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D92985

Summary:

 "Speculative fix for link failure on bots" with a mention of "the clang-ppc64le-rhel bot fails on link: http://lab.llvm.org:8011/#/builders/57/builds/2307/steps/6/logs/stdio".

PPCAsmPrinter.cpp:(.text._ZN12_GLOBAL__N_116PPCAIXAsmPrinter19emitFunctionBodyEndEv+0x2f8): undefined reference to `llvm::XCOFF::getNameForTracebackTableLanguageId(llvm::XCOFF::TracebackTable::LanguageID)'
PPCAsmPrinter.cpp:(.text._ZN12_GLOBAL__N_116PPCAIXAsmPrinter19emitFunctionBodyEndEv+0x2170): undefined reference to `llvm::XCOFF::parseParmsType(unsigned int, unsigned int)'

Preparation for D92745 which will add more tests to these files.

SUMMARY:
 1. added a new option -xcoff-traceback-table to control whether generate traceback table for function.
 2. implement the functionality of emit traceback table of a function.

Reviewers: hubert.reinterpretcast, Jason Liu
Differential Revision: https://reviews.llvm.org/D92398

This transform was added at:
c63799fc

From what I see, it's the first demanded elements transform that adds
a new instruction using the IRBuilder. There are similar folds in
the generic demanded bits chunk of instcombine that also use the
InsertPointGuard code pattern.

The tests here would assert/crash because the new instruction was
being added at the start of the demanded elements analysis rather
than at the instruction that is being replaced.

This migrates all LLVM (except Kaleidoscope and
CodeGen/StackProtector.cpp) DebugLoc::get to DILocation::get.

The CodeGen/StackProtector.cpp usage may have a nullptr Scope
and can trigger an assertion failure, so I don't migrate it.

Reviewed By: #debug-info, dblaikie

Differential Revision: https://reviews.llvm.org/D93087

The (scevgep, scevgep5) relation regressed with a patch I was
trying, but wasn't tested.

This reverts commit a87fccb3.

A test appears to fail with expensive checks. Reverting while I
investigate.

This patch adds support for lowering function calls with the
rv_marker attribute. The goal is to expand such calls to the
following sequence of instructions:

    BL @fn
    mov x29, x29

This sequence of instructions triggers Objective-C runtime optimizations,
hence we want to ensure no instructions get moved in between them.
This patch achieves that by adding a new CALL_RVMARKER ISD node,
which gets turned into the BLR_RVMARKER pseudo, which eventually gets
expanded into the sequence mentioned above. The sequence is then marked
as instruction bundle, to avoid anything being moved in between.

@ahatanak is working on using this attribute in the front- & middle-end.

Together with the front- & middle-end changes, this should address
PR31925 for AArch64.

Reviewed By: t.p.northover

Differential Revision: https://reviews.llvm.org/D92569

Add a "see also" link from the condensed doxygen description of
`SmallVector` to the more complete description in the ProgrammersManual.

ExceptionHandling:: is a bit misleading - we actually use the term for both
exceptions and non-exception .eh_frame usage.

Add simple pass for removing redundant vsetvli instructions within a basic block. This handles the case where the AVL register and VTYPE immediate are the same and no other instructions that change VTYPE or VL are between them.

There are going to be more opportunities for improvement in this space as we development more complex tests.

Differential Revision: https://reviews.llvm.org/D92679

Test execution can continue even if previous cases failed.

If we have two unknown sizes and one GEP operand and one non-GEP
operand, then we currently simply return MayAlias. The comment says
we can't do anything useful ... but we can! We can still check that
the underlying objects are different (and do so for the GEP-GEP case).

To reduce the compile-time impact, this a) checks this early, before
doing the relatively expensive GEP decomposition that will not be
used and b) doesn't do the check if the other operand is a phi or
select. In that case, the phi/select will already recurse, so this
would just do two slightly different recursive walks that arrive at
the same roots.

Compile-time is still a bit of a mixed bag: https://llvm-compile-time-tracker.com/compare.php?from=624af932a808b363a888139beca49f57313d9a3b&to=845356e14adbe651a553ed11318ddb5e79a24bcd&stat=instructions
On average this is a small improvement, but sqlite with ThinLTO has
a 0.5% regression (lencod has a 1% improvement).

The BasicAA test case checks this by using two memsets with unknown
size. However, the more interesting case where this is useful is
the LoopVectorize test case, as analysis of accesses in loops tends
to always us unknown sizes.

Differential Revision: https://reviews.llvm.org/D92401

Addressing clang bootstrap under the dynamic linking mode running out of static
allocation of value profile nodes, reported in D81682.

Differential Revision: https://reviews.llvm.org/D92669

Extract some changes not directly related to tileLoops out of D92974:
 * Refactor `createLoopSkeleton` out of `createCanonicalLoop`.
 * Introduce `ComputeIP` parameter to the `createCanonicalLoop` overload inserts instructions to compute the trip count. Specifying the location is necessary to make these instructions appear before the outermost loop of a loop nest that is tiled.
 * Introduce `Name` parameter to `createCanonicalLoop`. This can help better understanding the origin of values of basic blocks with many loops. The default value is "loop" instead of "for" which could be confused with the "for directive" (aka worksharing-loop) and does not apply to Fortran.
 * Remove `CanonicalLoopInfo::eraseFromParent` which is currently unused and untested and was added in anticipation to be used by `tileLoops`. `eraseFromParent` has shown to be insufficient when more than a single loop is involved and is replaced by `removeUnusedBlocksFromParent` in D92974.

Reviewed By: SouraVX

Differential Revision: https://reviews.llvm.org/D93088

D73999 / commit 75af9da7
added for LLVM 11 a check that sh_flags and sh_entsize (and sh_type)
changes are an error, in line with GNU assembler.

However, GNU assembler accepts and GCC generates an abbreviated form:
while the first .section contains the flags and entsize, subsequent
sections simply contain the name without repeating entsize or flags.

Do likewise for better compatibility.

See https://bugs.llvm.org/show_bug.cgi?id=48201

Reviewed By: jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D92052

Currently unknown keys when inputting mapping traits have the location set to the Value.
Example:
```
YAML:1:14: error: unknown key 'UnknownKey'
{UnknownKey: SomeValue}
             ^~~~~~~~~
```
This is unhelpful for a user as it draws them to fix the wrong item.

Reviewed By: silvas

Differential Revision: https://reviews.llvm.org/D93037

Change-Id: I482bbf528255f2eacd3878ddfe7edb9a8f63d5c2