Commit Graph

376209 Commits

Author SHA1 Message Date
Craig Topper 7b5a0e2f88 [RISCV] Move shift ComplexPatterns and custom isel to PatFrags with predicates
ComplexPatterns are kind of weird, they don't call any of the predicates on their operands. And their "complexity" used for tablegen ordering purposes in the matcher table is hand specified.

This started as an attempt to just use sext_inreg + SLOIPat to implement SLOIW just to have one less Select function. The matching for the or+shl is the same as long as you know the immediate is less than 32 for SLOIW. But that didn't work out because using uimm5 with SLOIPat didn't do anything if it was a ComplexPattern.

I realized I could just use a PatFrag with the opcodes I wanted to match and an immediate predicate would then evaluate correctly. This also computes the complexity just like any other pattern does. Then I just needed to check the constraints on the immediates in the predicate. Conveniently the predicate is evaluated after the fragment has been matched. So the structure has already been checked, we just need to find the constants.

I'll note that this is unusual, I didn't find any other targets looking through operands in PatFrag predicate. There is a PredicateCodeUsesOperands feature that can be used to collect the operands into an array that is used by AMDGPU/VOP3Instructions.td. I believe that feature exists to handle commuted matching, but since the nodes here use constants, they aren't ever commuted

Differential Revision: https://reviews.llvm.org/D91901
2021-01-05 11:37:48 -08:00
Alan Phipps 16f3401eae [Coverage] Fix test failures from commit rG9f2967bcfe2f
Fix test failures with Branch Coverage tests from commit rG9f2967bcfe2f
that failed build on builder clang-x64-windows-msvc while building llvm:
    http://lab.llvm.org:8011/#builders/123/builds/2155
2021-01-05 13:35:52 -06:00
Thomas Lively 497026c902 [WebAssembly] Prototype prefetch instructions
As proposed in https://github.com/WebAssembly/simd/pull/352 and using the
opcodes used in the V8 prototype:
https://chromium-review.googlesource.com/c/v8/v8/+/2543167. These instructions
are only usable via intrinsics and clang builtins to make them opt-in while they
are being benchmarked.

Differential Revision: https://reviews.llvm.org/D93883
2021-01-05 11:32:03 -08:00
Jan Svoboda f111cf992d [clang][cli] Specify correct integer width for -fbuild-session-timestamp
This fixes an issue where large integer values were rejected as invalid.

Reviewed By: arphaman

Differential Revision: https://reviews.llvm.org/D94101
2021-01-05 20:10:07 +01:00
Arthur Eubanks 28a326eba0 [NFC] Rename registerAliasAnalyses -> registerDefaultAliasAnalyses
To clarify that this only affects the "default" AA.

Reviewed By: ychen

Differential Revision: https://reviews.llvm.org/D93980
2021-01-05 11:07:58 -08:00
Craig Topper 210bc3dc0e [RISCV] Don't parse 'vmsltu.vi v0, v1, 0' as 'vmsleu.vi v0, v1, -1'
vmsltu.vi v0, v1, 0 is always false there is no unsigned number
less than 0. vmsleu.vi v0, v1, -1 on the other hand is always true
since -1 will be considered unsigned max and all numbers are <=
unsigned max.

A similar problem exists for vmsgeu.vi v0, v1, 0 which is always true,
but becomes vmsgtu.vi v0, v1, -1 which is always false.

To match the GNU assembler we'll emit vmsne.vv and vmseq.vv with
the same register for these cases instead.

I'm using AsmParserOnly pseudo instructions here because we can't
match an explicit immediate in an InstAlias. And we can't use a
AsmOperand for the zero because the output we want doesn't use an
immediate so there's nowhere to name the AsmOperand we want to use.

To keep the implementations similar I'm also handling signed with
pseudo instructions even though they don't have this issue. This
way we can avoid the special renderMethod that decremented by 1 so
the immediate we see for the pseudo instruction in processInstruction
is 0 and not -1. Another option might have been to have a different
simm5_plus1 operand for the unsigned case or just live with the
immediate being pre-decremented. I felt this way was clearer, but I'm
open to other opinions.

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D94035
2021-01-05 10:59:30 -08:00
Felipe de Azevedo Piovezan 86d68e2885 [mlir] Gen removeAttr methods with tablegen
If an operation defines an optional attribute (OptionalAttr or
UnitAttr), transformations may wish to remove these attributes while
maintaining invariants established by the operation. Currently, the only
way to do this is by calling `Operation::removeAttr("attrName")`, which
requires developers to know the exact name of the attribute used by
table-gen. Furthermore, if the attribute name changes, this won't be
detected at compile time. Instead, `removeAttr` would return an empty
attribute and no errors would be raised, unless the caller checks for
the returned value.

This patch adds table gen support for generating `remove<AttrName>Attr`
methods for OptionalAttributes defined by operations.

Implementation choice: to preserve camelCase for the method's name, the
first character of an attribute called `myAttr` is changed to upper case
in order to preserve the coding style, so the final method would be
called `removeMyAttr`.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D93903
2021-01-05 18:48:09 +00:00
Whitney Tsang 601636de98 [LoopNest] Allow empty basic blocks without loops
Addressed Florian's post commit review comments:
1. included STLExtras.h
2. changed std::all_of to llvm::all_of

Differential Revision: https://reviews.llvm.org/D93665
2021-01-05 18:44:43 +00:00
Dan Zheng 7afd5cfbc7 [NFC] Fix -Wrange-loop-analysis warnings.
Remove unnecessary `&` from loop variables.

Fix warnings: "loop variable is always a copy because the range does not
return a reference".

```
[240/2862] Building CXX object tools/mlir/tools/mlir-tblgen/CMakeFiles/mlir-tblgen.dir/TypeDefGen.cpp.o
llvm-project/mlir/tools/mlir-tblgen/TypeDefGen.cpp:50:25: warning: loop variable 'typeDef' is always a copy because the range of type 'llvm::iterator_range<llvm::mapped_iterator<std::__1::__wrap_iter<llvm::Record **>, (lambda at llvm-project/mlir/tools/mlir-tblgen/TypeDefGen.cpp:40:16), mlir::tblgen::TypeDef> >' does not return a reference [-Wrange-loop-analysis]
    for (const TypeDef &typeDef : defs)
                        ^
llvm-project/mlir/tools/mlir-tblgen/TypeDefGen.cpp:50:10: note: use non-reference type 'mlir::tblgen::TypeDef'
    for (const TypeDef &typeDef : defs)
         ^~~~~~~~~~~~~~~~~~~~~~~~
llvm-project/mlir/tools/mlir-tblgen/TypeDefGen.cpp:64:23: warning: loop variable 'typeDef' is always a copy because the range of type 'llvm::iterator_range<llvm::mapped_iterator<std::__1::__wrap_iter<llvm::Record **>, (lambda at llvm-project/mlir/tools/mlir-tblgen/TypeDefGen.cpp:40:16), mlir::tblgen::TypeDef> >' does not return a reference [-Wrange-loop-analysis]
  for (const TypeDef &typeDef : defs)
                      ^
llvm-project/mlir/tools/mlir-tblgen/TypeDefGen.cpp:64:8: note: use non-reference type 'mlir::tblgen::TypeDef'
  for (const TypeDef &typeDef : defs)
       ^~~~~~~~~~~~~~~~~~~~~~~~
2 warnings generated.

[1934/2862] Building CXX object tools...Files/toyc-ch4.dir/mlir/MLIRGen.cpp.o
llvm-project/mlir/examples/toy/Ch4/mlir/MLIRGen.cpp:139:22: warning: loop variable 'name_value' is always a copy because the range of type 'detail::zippy<detail::zip_shortest, ArrayRef<unique_ptr<VariableExprAST, default_delete<VariableExprAST> > > &, MutableArrayRef<BlockArgument> >' does not return a reference [-Wrange-loop-analysis]
    for (const auto &name_value :
                     ^
llvm-project/mlir/examples/toy/Ch4/mlir/MLIRGen.cpp:139:10: note: use non-reference type 'std::__1::tuple<const std::__1::unique_ptr<toy::VariableExprAST, std::__1::default_delete<toy::VariableExprAST> > &, mlir::BlockArgument &>'
    for (const auto &name_value :
         ^~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.

[1940/2862] Building CXX object tools...Files/toyc-ch5.dir/mlir/MLIRGen.cpp.o
llvm-project/mlir/examples/toy/Ch5/mlir/MLIRGen.cpp:139:22: warning: loop variable 'name_value' is always a copy because the range of type 'detail::zippy<detail::zip_shortest, ArrayRef<unique_ptr<VariableExprAST, default_delete<VariableExprAST> > > &, MutableArrayRef<BlockArgument> >' does not return a reference [-Wrange-loop-analysis]
    for (const auto &name_value :
                     ^
llvm-project/mlir/examples/toy/Ch5/mlir/MLIRGen.cpp:139:10: note: use non-reference type 'std::__1::tuple<const std::__1::unique_ptr<toy::VariableExprAST, std::__1::default_delete<toy::VariableExprAST> > &, mlir::BlockArgument &>'
    for (const auto &name_value :
         ^~~~~~~~~~~~~~~~~~~~~~~~
1 warning generated.
```

Reviewed By: jpienaar

Differential Revision: https://reviews.llvm.org/D94003
2021-01-05 18:44:17 +00:00
Craig Topper 249d7de119 [RISCV] Don't print zext.b alias.
This alias for andi x, 255 was recently added to the spec. If we
print it, code we output can't be compiled with -fno-integrated-as
unless the GNU assembler is also a version that supports alias.

Reviewed By: lenary

Differential Revision: https://reviews.llvm.org/D93826
2021-01-05 10:41:08 -08:00
Sanjay Patel 3b8b2c7da2 [SLP] delete unused pairwise reduction option
SLP tries to model 2 forms of vector reductions: pairwise and splitting.
From the cost model code comments, those are defined using an example as:

  /// Pairwise:
  ///  (v0, v1, v2, v3)
  ///  ((v0+v1), (v2+v3), undef, undef)
  /// Split:
  ///  (v0, v1, v2, v3)
  ///  ((v0+v2), (v1+v3), undef, undef)

I don't know the full history of this functionality, but it was partly
added back in D29402. There are apparently no users at this point (no
regression tests change). X86 might have managed to work-around the need
for this through cost model and codegen improvements.

Removing this code makes it easier to continue the work that was started
in D87416 / D88193. The alternative -- if there is some target that is
silently using this option -- is to move this logic into LoopUtils. We
have related/duplicate functionality there via llvm::createTargetReduction().

Differential Revision: https://reviews.llvm.org/D93860
2021-01-05 13:23:07 -05:00
Craig Topper c707716c04 [RISCV] Match vmslt(u).vx intrinsics with a small immediate to vmsle(u).vx.
There are vmsle(u).vx and vmsle(u).vi instructions, but there is
only vmslt(u).vx and no vmslt(u).vi. vmslt(u).vi can be emulated
for some immediates by decrementing the immediate and using vmsle(u).vi.

To avoid the user needing to know about this, this patch does this
conversion.

The assembler does the same thing for vmslt(u).vi and vmsge(u).vi
pseudoinstructions. There is no vmsge(u).vx intrinsic or
instruction so this patch is limited to vmslt(u).

Reviewed By: frasercrmck

Differential Revision: https://reviews.llvm.org/D94070
2021-01-05 10:20:21 -08:00
Sergey Dmitriev 761aca1e2e [llvm-link] fix linker behavior when linking archives with --only-needed option
This patch fixes linker behavior when archive is linked with other inputs
as a library (i.e. when --only-needed option is specified). In this case library
is expected to be normally linked first into a separate module and only after
that linker should import required symbols from the linked library module.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D92535
2021-01-05 10:02:51 -08:00
Matt Arsenault a427f15d60 GlobalISel: Add isKnownToBeAPowerOfTwo helper function 2021-01-05 12:59:08 -05:00
Yitzhak Mandelbaum 675a2973ee [libTooling] Add support for smart pointers to relevant Transformer `Stencil`s.
Stencils `maybeDeref` and `maybeAddressOf` are designed to handle nodes that may
be pointers. Currently, they only handle native pointers. This patch extends the
support to recognize smart pointers and handle them as well.

Differential Revision: https://reviews.llvm.org/D93637
2021-01-05 17:57:41 +00:00
Jonas Devlieghere c82beaba31 [lldb] Add timers to Reproducer::Keep and Reproducer::Discard 2021-01-05 09:54:31 -08:00
Hanhan Wang 30dcbb2a83 [mlir][Linalg] Add a test case that consumer has "reduction" loops.
In the past, this was a missing test case and the fusion was not supported. It's
supported after the revisit of init_tensor in Linalg.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D94093
2021-01-05 09:47:07 -08:00
Stephen Kelly f22c0f40b5 [ASTMatchers] Omit methods from explicit template instantations
Differential Revision: https://reviews.llvm.org/D94032
2021-01-05 17:42:33 +00:00
David Green 0c59a4da59 [ARM][AArch64] Some extra test to show anyextend lowering. NFC 2021-01-05 17:34:23 +00:00
Simon Pilgrim 55488bd3cd CGExpr - EmitMatrixSubscriptExpr - fix getAs<> null-dereference static analyzer warning. NFCI.
getAs<> can return null if the cast is invalid, which can lead to null pointer deferences. Use castAs<> instead which will assert that the cast is valid.
2021-01-05 17:08:11 +00:00
Joe Nash 60466fad2d [AMDGPU] Remove deprecated V_MUL_LO_I32 from GFX10
It was removed in GFX10 GPUs, but LLVM could
generate it.

Reviewed By: rampitec, arsenm

Differential Revision: https://reviews.llvm.org/D94020

Change-Id: Id1c716d71313edcfb768b2b175a6789ef9b01f3c
2021-01-05 11:59:57 -05:00
Yitzhak Mandelbaum 9eb2284f60 [clang-tidy] Update uses of deprecated Transformer APIs in StringFindStrContainsCheck.
Migrates `change` to `changeTo`; changes to new constructor API (2-arg construct
+ `setRule`); refactors use of `addInclude` to newer version.

Differential Revision: https://reviews.llvm.org/D93695
2021-01-05 16:49:29 +00:00
Alex Zinenko c69c9e0f0f [mlir] Remove LLVMType, LLVM dialect types now derive Type directly
BEGIN_PUBLIC
[mlir] Remove LLVMType, LLVM dialect types now derive Type directly

This class has become a simple `isa` hook with no proper functionality.
Removing will allow us to eventually make the LLVM dialect type infrastructure
open, i.e., support non-LLVM types inside container types, which itself will
make the type conversion more progressive.

Introduce a call `LLVM::isCompatibleType` to be used instead of
`isa<LLVMType>`. For now, this is strictly equivalent.
END_PUBLIC

Depends On D93681

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D93713
2021-01-05 17:36:54 +01:00
Jinsong Ji f26bc0ddd5 [RegisterClassInfo] Return non-zero for RC without allocatable reg
In some case, the RC may have 0 allocatable reg.
eg: VRSAVERC in PowerPC, which has only 1 reg, but it is also reserved.

The curreent implementation will keep calling the computePSetLimit because
getRegPressureSetLimit assume computePSetLimit will return a non-zero value.

The fix simply early return the value from TableGen for such special case.

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D92907
2021-01-05 16:18:34 +00:00
Florian Hahn 51d5991f04
[Clang] Add AArch64 VCMLA LANE variants.
This patch adds the LANE variants for VCMLA on AArch64 as defined in
"Arm Neon Intrinsics Reference for ACLE Q3 2020" [1]

This patch also updates `dup_typed` to accept constant type strings directly.

Based on a patch by Tim Northover.

[1] https://developer.arm.com/documentation/ihi0073/latest

Reviewed By: SjoerdMeijer

Differential Revision: https://reviews.llvm.org/D93014
2021-01-05 16:14:00 +00:00
Alan Phipps 9f2967bcfe [Coverage] Add support for Branch Coverage in LLVM Source-Based Code Coverage
This is an enhancement to LLVM Source-Based Code Coverage in clang to track how
many times individual branch-generating conditions are taken (evaluate to TRUE)
and not taken (evaluate to FALSE).  Individual conditions may comprise larger
boolean expressions using boolean logical operators.  This functionality is
very similar to what is supported by GCOV except that it is very closely
anchored to the ASTs.

Differential Revision: https://reviews.llvm.org/D84467
2021-01-05 09:51:51 -06:00
Stephen Kelly 53c3acb89f [clang-tidy] Add extra tests
By default, check_clang_tidy runs tests in c++11-or-later mode.

Differential Revision: https://reviews.llvm.org/D94029
2021-01-05 15:43:56 +00:00
LLVM GN Syncbot bf09e25e1e [gn build] Port fec1a442e3 2021-01-05 15:34:25 +00:00
Bradley Smith c73ae747cb [AArch64][SVE] Add optimization to remove redundant ptest instructions
Co-Authored-by: Graham Hunter <graham.hunter@arm.com>
Co-Authored-by: Paul Walker <paul.walker@arm.com>

Differential Revision: https://reviews.llvm.org/D93292
2021-01-05 15:28:36 +00:00
Valeriy Savchenko fec1a442e3 [-Wcalled-once-parameter] Introduce 'called_once' attribute
This commit introduces a new attribute `called_once`.
It can be applied to function-like parameters to signify that
this parameter should be called exactly once.  This concept
is particularly widespread in asynchronous programs.

Additionally, this commit introduce a new group of dataflow
analysis-based warnings to check this property.  It identifies
and reports the following situations:
  * parameter is called twice
  * parameter is never called
  * parameter is not called on one of the paths

Current implementation can also automatically infer `called_once`
attribute for completion handler paramaters that should follow the
same principle by convention.  This behavior is OFF by default and
can be turned on by using `-Wcompletion-handler`.

Differential Revision: https://reviews.llvm.org/D92039

rdar://72812043
2021-01-05 18:26:44 +03:00
Stephen Kelly 7e4f53f748 [ASTMatchers] Fix traversal matchers with explicit and defaulted methods
Differential Revision: https://reviews.llvm.org/D94030
2021-01-05 15:22:21 +00:00
Joe Ellis 3d5b18a3fd [clang][AArch64][SVE] Avoid going through memory for coerced VLST arguments
VLST arguments are coerced to VLATs at the function boundary for
consistency with the VLAT ABI. They are then bitcast back to VLSTs in
the function prolog. Previously, this conversion is done through memory.
With the introduction of the llvm.vector.{insert,extract} intrinsic, we
can avoid going through memory here.

Depends on D92761

Differential Revision: https://reviews.llvm.org/D92762
2021-01-05 15:18:21 +00:00
Whitney Tsang c005518936 [LoopNest] Allow empty basic blocks without loops
Allow loop nests with empty basic blocks without loops in different
levels as perfect.

Reviewers: Meinersbur

Differential Revision: https://reviews.llvm.org/D93665
2021-01-05 15:09:38 +00:00
Florian Hahn 8a47e6252a
[VPlan] Re-add interleave group members to plan.
Creating in-loop reductions relies on IR references to map
IR values to VPValues after interleave group creation.

Make sure we re-add the updated member to the plan, so the look-ups
still work as expected

This fixes a crash reported after D90562.
2021-01-05 15:06:47 +00:00
Simon Pilgrim 73a44f437b [X86][AVX] combineVectorSignBitsTruncation - use PACKSS/PACKUS in more AVX cases
AVX512 has fast truncation ops, but if the truncation source is a concatenation of subvectors then its likely that we can use PACK more efficiently.

This is only guaranteed to work for truncations to 128/256-bit vectors as the PACK works across 128-bit sub-lanes, for now I've just disabled 512-bit truncation cases but we need to get them working eventually for D61129.
2021-01-05 15:01:45 +00:00
Stephen Kelly c3403dc63d [ASTMatchers] Fix build when no targets are enabled
This makes sense to do when building only tools like clang-tidy for
example.

Differential Revision: https://reviews.llvm.org/D93987
2021-01-05 14:40:35 +00:00
Stephen Kelly c3a21e5de3 [ASTMatchers] Ensure that we can match inside lambdas
Because we don't know in ASTMatchFinder whether we're matching in AsIs
or IgnoreUnlessSpelledInSource mode, we need to traverse the lambda
twice, but store whether we're matching in nodes spelled in source or
not.

Differential Revision: https://reviews.llvm.org/D93688
2021-01-05 14:39:46 +00:00
Alexander Belyaev 89ae5b5b6a [mlir] Add canonicalization pattern out_tensor->linalg->dim to out_tensor->dim.
Differential Revision: https://reviews.llvm.org/D94079
2021-01-05 15:15:21 +01:00
Anastasia Stulova 6f770292a0 [OpenCL] Restrict pointer to member functions.
Pointers to member functions are a special case
of function pointers and therefore have to be
disallowed.

Tags: #clang

Differential Revision: https://reviews.llvm.org/D93958
2021-01-05 13:32:18 +00:00
Simon Pilgrim dc74d7ed1f [X86] getMemoryOpCost - use dyn_cast_or_null<StoreInst>. NFCI.
Use instead of the isa_and_nonnull<StoreInst> and use the StoreInst::getPointerOperand wrapper instead of a hardcoded Instruction::getOperand.

Looks cleaner and avoids a spurious clang static analyzer null dereference warning.
2021-01-05 13:23:09 +00:00
Kazushi (Jam) Marukawa 489000d851 [VE] Change clang to support SjLj Lowering
We supports SjLj exception handling in the backend, so changing
clang to allow lowering using SjLj exceptions.  Update a regression
test also.

Reviewed By: simoll

Differential Revision: https://reviews.llvm.org/D94076
2021-01-05 22:19:02 +09:00
Fraser Cormack 9a1ac97d3a [CodeGen] Format SelectionDAG::getConstant methods (NFC) 2021-01-05 12:59:46 +00:00
Jay Foad 3914bebe91 [AMDGPU] Handle v_fmac_legacy_f32 in SIFoldOperands
Convert it to v_fma_legacy_f32 if it is profitable to do so, just like
other mac instructions that are converted to their mad equivalents.

Differential Revision: https://reviews.llvm.org/D94010
2021-01-05 11:55:33 +00:00
Jay Foad 639a50e2f1 [AMDGPU] Precommit test case for D94010 2021-01-05 11:55:14 +00:00
Jay Foad 4e6054a86c [AMDGPU] Split out new helper function macToMad in SIFoldOperands. NFC.
Differential Revision: https://reviews.llvm.org/D94009
2021-01-05 11:54:48 +00:00
Giulio Girardi 2f8d1e9eb2 [clangd] When querying drivers by binary, look in PATH too
Sometimes compile_commands.json databases are created without an
absolute path for the driver in the command field. By default the driver
name is appended to the current directory, however if no driver is found
in that location assume it was in the default PATH and try finding it
there

Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D93600
2021-01-05 12:54:07 +01:00
Sven van Haastregt 0e4d2361b8 [OpenCL] Warn about side effects for unevaluated vec_step arg
The argument to the `vec_step` builtin is not evaluated.  Hoist the
diagnostic for this in `Sema::CheckUnaryExprOrTypeTraitOperand` such
that it comes before `Sema::CheckVecStepTraitOperandType`.

A minor side-effect of this change is that it also produces the
warning for `co_await` and `co_yield` as `sizeof` arguments now, which
seems to be reasonable given that the warning is emitted for `typeid`
already.

Differential Revision: https://reviews.llvm.org/D91348
2021-01-05 11:51:10 +00:00
Kazushi (Jam) Marukawa f784be0777 [VE] Support SJLJ exception related instructions
Support EH_SJLJ_LONGJMP, EH_SJLJ_SETJMP, and EH_SJLJ_SETUP_DISPATCH
for SjLj exception handling.  NC++ uses SjLj exception handling, so
implement it first.  Add regression tests also.

Reviewed By: simoll

Differential Revision: https://reviews.llvm.org/D94071
2021-01-05 20:19:15 +09:00
Simon Pilgrim 313d982df6 [IR] Add ConstantInt::getBool helpers to wrap getTrue/getFalse. 2021-01-05 11:01:10 +00:00
Paul Walker eba6deab22 [SVE] Lower vector CTLZ, CTPOP and CTTZ operations.
CTLZ and CTPOP are lowered to CLZ and CNT instructions respectively.

CTTZ is not a native SVE operation but is instead lowered to:
  CTTZ(V) => CTLZ(BITREVERSE(V))

In the case of fixed-length support using SVE we also lower CTTZ
operating on NEON sized vectors because of its reliance on
BITREVERSE which is also lowered to SVE intructions at these lengths.

Differential Revision: https://reviews.llvm.org/D93607
2021-01-05 10:42:35 +00:00