Recommit of r361790 that was temporarily reverted in r361793 due to bot breakage.

Summary:
The following changes were required to fix these tests:

1) Change LLVM_ENABLE_PLUGINS to an option and move it to
   llvm/CMakeLists.txt with an appropriate default -- which matches
   the original default behavior.

2) Move the plugins directory from clang/test/Analysis
   clang/lib/Analysis.  It's not enough to add an exclude to the
   lit.local.cfg file because add_lit_testsuites recurses the tree and
   automatically adds the appropriate `check-` targets, which don't
   make sense for the plugins because they aren't tests and don't
   have `RUN` statements.

   Here's a list of the `clang-check-anlysis*` targets with this
   change:

```
  $ ninja -t targets all| sed -n "s/.*\/\(check[^:]*\):.*/\1/p" | sort -u | grep clang-analysis
  check-clang-analysis
  check-clang-analysis-checkers
  check-clang-analysis-copypaste
  check-clang-analysis-diagnostics
  check-clang-analysis-engine
  check-clang-analysis-exploration_order
  check-clang-analysis-html_diagnostics
  check-clang-analysis-html_diagnostics-relevant_lines
  check-clang-analysis-inlining
  check-clang-analysis-objc
  check-clang-analysis-unified-sources
  check-clang-analysis-z3
```

3) Simplify the logic and only include the subdirectories under
   clang/lib/Analysis/plugins if LLVM_ENABLE_PLUGINS is set.

Reviewed By: NoQ

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D62445

llvm-svn: 362328

Let's us match horizontal op patterns on fast-variable-shuffle targets (Haswell etc.)

llvm-svn: 362327

Haswell etc. will combine shuffles to a extract_subvector(permd(x)) before isHorizontalBinOp can match it.

llvm-svn: 362326

We are also free to interpret this as 'BZHI'/'BEXTR'.
https://rise4fun.com/Alive/dD6

llvm-svn: 362325

Move this combine from x86 into generic DAGCombine, which currently only manages cases where the bitcast is between types of the same scalarsize.

Differential Revision: https://reviews.llvm.org/D59188

llvm-svn: 362324

[DAG] isBitwiseNot / isConstOrConstSplat - add support for build vector undefs + truncation (PR41020)

Add (opt-in) support for implicit truncation to isConstOrConstSplat, which allows us to match truncated 'all ones' cases in isBitwiseNot.

PR41020 compares against using ISD::isBuildVectorAllOnes() instead, but that predicate silently accepts any UNDEF elements in the build vector which might not be what we want in isBitwiseNot - so I've added an opt-in 'AllowUndefs' flag that is set to false by default but will allow us to enable it on individual cases where its safe.

Differential Revision: https://reviews.llvm.org/D62783

llvm-svn: 362323

These might have been replaced in multiple use cases.

llvm-svn: 362322

Helps with debugging as we recurse between them.

llvm-svn: 362321

These saturating math ops can be replaced with simple math.

llvm-svn: 362320

If we look past truncations of X too eagerly (D62786), we may
end up with 64-bit 'BEXTR', even though 32-bit-one would suffice.

llvm-svn: 362319

The results of the dyn_casts were immediately dereferenced on the next line
so they had better not be null.

I don't think there's any way for these dyn_casts to fail, so use a cast
of adding null check.

llvm-svn: 362315

LLVM CMake build already uses libtool instead of ar when building
for Apple platform and we should be using the same when building
runtimes. To do so, this change extracts the logic for finding
libtool into a separate file and then uses it from both the LLVM
build as well as the LLVM runtimes build.

Differential Revision: https://reviews.llvm.org/D62769

llvm-svn: 362313

Over a year ago, MachineInstr gained a fourth boolean parameter that occurs
before the TII pointer. When this happened, several places started accidentally
passing TII into this boolean parameter instead of the TII parameter.

llvm-svn: 362312

Forgot to do the widen forms when I was doing the others.

llvm-svn: 362310

llvm-svn: 362309

The AVX512BW and AVX512VL checks were never used. And AVX512 is the same
as AVX on all tests that weren't already split for AVX1 and AVX2.

llvm-svn: 362308

llvm-svn: 362307

Extract a willNotOverflow() helper function that is shared between
eliminateOverflowIntrinsic() and strengthenOverflowingOperation().
Use WithOverflowInst for the former.

We'll be able to reuse the same code for saturating intrinsics as
well.

llvm-svn: 362305

Summary: Fneg can be implemented with an xor rather than a function call so we don't need to add the function call overhead. This was pointed out in D62699

Reviewers: efriedma, cameron.mcinally

Reviewed By: efriedma

Subscribers: javed.absar, eraman, hiraditya, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62747

llvm-svn: 362304

llvm-svn: 362303

llvm-svn: 362302

In reality APInt::getBitsNeeded(INT_MIN, base) cases require one less bit than is returned

llvm-svn: 362301

llvm-svn: 362300

The `cfcmsa` and `ctcmsa` instructions accept index of MSA control
register. The MIPS64 SIMD Architecture define eight MSA control
registers. But register index for `cfcmsa` and `ctcmsa` instructions
might be any number in 0..31 range. If the index is greater then 7,
`cfcmsa` writes zero to the destination registers and `ctcmsa` does
nothing [1].

[1] MIPS Architecture for Programmers Volume IV-j:
    The MIPS64 SIMD Architecture Module
https://www.mips.com/?do-download=the-mips64-simd-architecture-module

Differential Revision: https://reviews.llvm.org/D62597

llvm-svn: 362299

If we would allow register coalescing on PTRDISPREGS class then register
allocator can lock Z register to some virtual register. Larger instructions
requiring a memory acces then fail during the register allocation phase since
there is no available register to hold a pointer if Y register was already
taken for a stack frame. This patch prevents it by keeping Z register
spillable. It does it by not allowing coalescer to lock it.

Original discussion on https://github.com/avr-rust/rust/issues/128.

llvm-svn: 362298

llvm-svn: 362297

llvm-svn: 362296

I have initially added it in for test to display both
whether the binop w/ constant is sinked or hoisted.
But as it can be seen from the 'sub (sub C, %x), %y'
test, that actually conceals the issues it is supposed to test.

At least two more patterns are unhandled:
* 'add (sub C, %x), %y' - D62266
* 'sub (sub C, %x), %y'

llvm-svn: 362295

Fix for https://bugs.llvm.org/show_bug.cgi?id=31181 and partial fix
for LFTR poison handling issues in general.

When LFTR moves a condition from pre-inc to post-inc, it may now
depend on value that is poison due to nowrap flags. To avoid this,
we clear any nowrap flag that SCEV cannot prove for the post-inc
addrec.

Additionally, LFTR may switch to a different IV that is dynamically
dead and as such may be arbitrarily poison. This patch will correct
nowrap flags in some but not all cases where this happens. This is
related to the adoption of IR nowrap flags for the pre-inc addrec.
(See some of the switch_to_different_iv tests, where flags are not
dropped or insufficiently dropped.)

Finally, there are likely similar issues with the handling of GEP
inbounds, but we don't have a test case for this yet.

Differential Revision: https://reviews.llvm.org/D60935

llvm-svn: 362292

Two more tests with a switch to a dynamically dead IV, with poison
occuring on the first or second iteration.

llvm-svn: 362291

This allows the DWARFExpression class to handle addresses without
crashing on targets with 16-bit pointers like AVR.

This is required in order to generate assembly from clang via the '-S'
flag.

This fixes an error with the following message:

clang: llvm/include/llvm/DebugInfo/DWARF/DWARFExpression.h:132: llvm::DWARFExpression::DWARFExpression(llvm::DataExtractor, uint16_t, uint8_t):
       Assertion `AddressSize == 8 || AddressSize == 4' failed.
llvm-svn: 362290

llvm-svn: 362289

llvm-svn: 362288

[X86] Make the X86FoldTablesEmitter functional again. Fix the spacing in the output to make it easier to diff.

Fix a few other formatting issues in the manual table. And remove some
old FIXMEs.

llvm-svn: 362287

Summary:
This was flagged in https://www.viva64.com/en/b/0629/ under "Snippet No.
33".

It seems that this statement is doing the standard bitwise trick for
adjusting a value to have a specific alignment.

The issue is that getStubAlignment() returns an unsigned, while DataSize
is declared a uint64_t. The right hand side of the expression is not
extended to 64b before bitwise negation, resulting in the top half of
the mask being 0s, which is not correct for realignment.

Reviewers: lhames, MaskRay

Reviewed By: MaskRay

Subscribers: RKSimon, MaskRay, hiraditya, llvm-commits, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62227

llvm-svn: 362286

llvm-svn: 362285

llvm-svn: 362284

ARM64 CodeView test was incorrectly put under test/DebugInfo/COFF folder which
runs for all all architectures. This fix moves it to a subfolder AArch64 with
lit.local.cfg which specify it supports AArch64 only.

llvm-svn: 362283

At the moment, LoopPredication completely bails out if it sees a latch of the form:
%cmp = icmp ne %iv, %N
br i1 %cmp, label %loop, label %exit
OR
%cmp = icmp ne %iv.next, %NPlus1
br i1 %cmp, label %loop, label %exit

This is unfortunate since this is exactly the form that LFTR likes to produce. So, go ahead and recognize simple cases where we can.

For pre-increment loops, we leverage the fact that LFTR likes canonical counters (i.e. those starting at zero) and a (presumed) range fact on RHS to discharge the check trivially.

For post-increment forms, the key insight is in remembering that LFTR had to insert a (N+1) for the RHS. CVP can hopefully prove that add nsw/nuw (if there's appropriate range on N to start with). This leaves us both with the post-inc IV and the RHS involving an nsw/nuw add, and SCEV can discharge that with no problem.

This does still need to be extended to handle non-one steps, or other harder patterns of variable (but range restricted) starting values. That'll come later.

Differential Revision: https://reviews.llvm.org/D62748

llvm-svn: 362282

We were hashing the string pointer, not the string, so two instructions
could be identical (isIdenticalTo), but have different hash codes.

This showed up as a very rare, non-deterministic assertion failure
rehashing a DenseMap constructed by MachineOutliner.  So there's no
"real" testcase, just a unittest which checks that the hash function
behaves correctly.

I'm a little scared fixing this is going to cause a regression in
outlining or MachineCSE, but hopefully we won't run into any issues.

Differential Revision: https://reviews.llvm.org/D61975

llvm-svn: 362281