Commit Graph

66 Commits

Author SHA1 Message Date
Mogball
2b5134f1b7 [mlir] Fix bytecode reading of resource sections
This partially reverts #66380. The assertion that the underlying buffer
of an EncodingReader is aligned to any required alignments for resource
sections. Resources know their own alignment and pad their buffers
accordingly, but the bytecode reader doesn't know that ahead of time.
Consequently, it cannot give the resource EncodingReader a base buffer
aligned to the maximum required alignment.

A simple example from the test fails without this:

```mlir
module @TestDialectResources attributes {
  bytecode.test = dense_resource<resource> : tensor<4xi32>
} {}
{-#
  dialect_resources: {
    builtin: {
      resource: "0x2000000001000000020000000300000004000000",
      resource_2: "0x2000000001000000020000000300000004000000"
    }
  }
```
2023-09-29 18:39:56 -07:00
Christian Sigg
1c8c365de2 [mlir][bytecode] Check that bytecode source buffer is sufficiently aligned. (#66380)
Before this change, the `ByteCode` test failed on CentOS 7 with
devtoolset-9, because strings happen to be only 8 byte aligned. In
general though, strings have no alignment guarantee.

Increase resource alignment in test to 32 bytes. 
Adjust test to sufficiently align buffer.
Add test to check error when buffer is insufficiently aligned.
2023-09-17 13:46:01 +02:00
Adrian Kuegel
7d6fb14057 [mlir] Apply ClangTidy fix (NFC)
redundant get() call on smart pointer.
2023-08-07 15:45:36 +02:00
Mehdi Amini
2ef44aa443 [MLIR][Bytecode] Add missing field initializer in constructor initializer list
Leaving this field unitialized could led to crashes when it'll diverge from the
IRNumbering phase.

Differential Revision: https://reviews.llvm.org/D156965
2023-08-02 23:31:01 -07:00
Matteo Franciolini
bff6a4292f Expose callbacks for encoding of types/attributes
[mlir] Expose a mechanism to provide a callback for encoding types and attributes in MLIR bytecode.

Two callbacks are exposed, respectively, to the BytecodeWriterConfig and to the ParserConfig. At bytecode parsing/printing, clients have the ability to specify a callback to be used to optionally read/write the encoding. On failure, fallback path will execute the default parsers and printers for the dialect.

Testing shows how to leverage this functionality to support back-deployment and backward-compatibility usecases when roundtripping to bytecode a client dialect with type/attributes dependencies on upstream.

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D153383
2023-07-28 16:45:42 -07:00
Mehdi Amini
b86a13211f Revert "Expose callbacks for encoding of types/attributes"
This reverts commit b299ec1666.

The authorship informations were incorrect.
2023-07-28 16:45:42 -07:00
Mehdi Amini
b299ec1666 Expose callbacks for encoding of types/attributes
[mlir] Expose a mechanism to provide a callback for encoding types and attributes in MLIR bytecode.

Two callbacks are exposed, respectively, to the BytecodeWriterConfig and to the ParserConfig. At bytecode parsing/printing, clients have the ability to specify a callback to be used to optionally read/write the encoding. On failure, fallback path will execute the default parsers and printers for the dialect.

Testing shows how to leverage this functionality to support back-deployment and backward-compatibility usecases when roundtripping to bytecode a client dialect with type/attributes dependencies on upstream.

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D153383
2023-07-28 10:44:02 -07:00
River Riddle
0e6000f647 [mlir:bytecode] Only visit the all regions path if the op has regions
Zero region operations return true for both isBeforeAllRegions and
isAfterAllRegions when using WalkStage. The bytecode walk only
expects region holding operations in the after regions path, so
guard against that.
2023-07-25 16:06:33 -07:00
River Riddle
4af01bf956 [mlir:bytecode] Support lazy loading dynamically isolated regions
We currently only support lazy loading for regions that
statically implement the IsolatedFromAbove trait, but that
limits the amount of operations that can be lazily loaded. This review
lifts that restriction by computing which operations have isolated
regions when numbering, allowing any operation to be lazily loaded
as long as it doesn't use values defined above.

Differential Revision: https://reviews.llvm.org/D156199
2023-07-25 15:55:34 -07:00
River Riddle
5ab6589551 [mlir:bytecode] Fix bytecode lazy loading for ops with multiple regions
We currently encode each region as a separate section, but
the reader expects all of the regions to be in the same section.
This updates the writer to match the behavior that the reader
expects.

Differential Revision: https://reviews.llvm.org/D156198
2023-07-25 15:55:34 -07:00
Mehdi Amini
9ea6b30ac2 Update ODS variadic segments "magic" attributes to use native Properties
The operand_segment_sizes and result_segment_sizes Attributes are now inlined
in the operation as native propertie. We continue to support building an
Attribute on the fly for `getAttr("operand_segment_sizes")` and setting the
property from an attribute with `setAttr("operand_segment_sizes", attr)`.

A new bytecode version is introduced to support backward compatibility and
backdeployments.

Differential Revision: https://reviews.llvm.org/D155919
2023-07-24 18:16:58 -07:00
Mehdi Amini
a7cd64c9f1 Revert "Update ODS variadic segments "magic" attributes to use native Properties"
This reverts commit 20b93abca6.

One python test is broken, WIP.
2023-07-24 12:27:42 -07:00
Mehdi Amini
20b93abca6 Update ODS variadic segments "magic" attributes to use native Properties
The operand_segment_sizes and result_segment_sizes Attributes are now inlined
in the operation as native propertie. We continue to support building an
Attribute on the fly for `getAttr("operand_segment_sizes")` and setting the
property from an attribute with `setAttr("operand_segment_sizes", attr)`.

A new bytecode version is introduced to support backward compatibility and
backdeployments.

Differential Revision: https://reviews.llvm.org/D155919
2023-07-24 11:37:57 -07:00
Andrzej Warzynski
79c83e12c8 [mlir][VectorType] Allow arbitrary dimensions to be scalable
At the moment, only the trailing dimensions in the vector type can be
scalable, i.e. this is supported:

    vector<2x[4]xf32>

and this is not allowed:

    vector<[2]x4xf32>

This patch extends the vector type so that arbitrary dimensions can be
scalable. To this end, an array of bool values is added to every vector
type to denote whether the corresponding dimensions are scalable or not.
For example, for this vector:

  vector<[2]x[3]x4xf32>

the following array would be created:

  {true, true, false}.

Additionally, the current syntax:

  vector<[2x3]x4xf32>

is replaced with:

  vector<[2]x[3]x4xf32>

This is primarily to simplify parsing (this way, the parser can easily
process one dimension at a time rather than e.g. tracking whether
"scalable block" has been entered/left).

NOTE: The `isScalableDim` parameter of `VectorType` (introduced in this
patch) makes `numScalableDims` redundant. For the time being,
`numScalableDims` is preserved to facilitate the transition between the
two parameters. `numScalableDims` will be removed in one of the
subsequent patches.

This change is a part of a larger effort to enable scalable
vectorisation in Linalg. See this RFC for more context:
  * https://discourse.llvm.org/t/rfc-scalable-vectorisation-in-linalg/

Differential Revision: https://reviews.llvm.org/D153372
2023-06-27 19:21:59 +01:00
River Riddle
6ee1aba8ac [mlir][bytecode] Fix lazy loading of non-isolated regions
The bytecode reader currently assumes all regions can be lazy
loaded, which breaks reading any non-isolated region. This patch
fixes that by properly handling nested non-lazy regions, and only
considers isolated regions as lazy.

Differential Revision: https://reviews.llvm.org/D153795
2023-06-26 16:33:20 -07:00
Ulrich Weigand
bb0bbed610 Fix bytecode reader/writer on big-endian platforms
This makes the bytecode reader/writer work on big-endian platforms.
The only problem was related to encoding of multi-byte integers,
where both reader and writer code make implicit assumptions about
endianness of the host platform.

This fixes the current test failures on s390x, and in addition allows
to remove the UNSUPPORTED markers from all other bytecode-related
test cases - they now also all pass on s390x.

Also adding a GFAIL_SKIP to the MultiModuleWithResource unit test,
as this still fails due to an unrelated endian bug regarding
decoding of external resources.

Differential Revision: https://reviews.llvm.org/D153567

Reviewed By: mehdi_amini, jpienaar, rriddle
2023-06-23 09:22:55 +02:00
Mehdi Amini
9c1e55873e Use symbolic name for previous MLIR Bytecode versions
Reviewed By: jpienaar, burmako

Differential Revision: https://reviews.llvm.org/D151621
2023-06-06 01:19:56 -07:00
Kevin Gleason
0ee4875ddf [mlir][bytecode] Error if requested bytecode version is unsupported
Currently desired bytecode version is clamped to the maximum. This allows requesting bytecode versions that do not exist. We have added callsite validation for this in StableHLO to ensure we don't pass an invalid version number, probably better if this is managed upstream. If a user wants to use the current version, then omitting `setDesiredBytecodeVersion` is the best way to do that (as opposed to providing a large number).

Adding this check will also properly error on older version numbers as we increment the minimum supported version. Silently claming on minimum version would likely lead to unintentional forward incompatibilities.

Separately, due to bytecode version being `int64_t` and using methods to read/write uints, we can generate payloads with invalid version numbers:

```
mlir-opt file.mlir --emit-bytecode --emit-bytecode-version=-1 | mlir-opt
<stdin>:0:0: error: bytecode version 18446744073709551615 is newer than the current version 5
```

This is fixed with version bounds checking as well.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D151838
2023-05-31 19:20:42 -07:00
Haojian Wu
5217498dc8 [mlir][bazel] Port for 660f714e26 2023-05-27 08:05:19 +02:00
Jie Fu
5e8ed850d3 [mlir] Fix non-const lvalue reference to type 'uint64_t' cannot bind to type 'size_t' error (NFC)
/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:1007:39: error: non-const lvalue reference to type 'uint64_t' (aka 'unsigned long long') cannot bind to a value of unrelated type 'size_t' (aka 'unsigned long')
    if (failed(propReader.parseVarInt(count)))
                                      ^~~~~
/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:191:39: note: passing argument to parameter 'result' here
  LogicalResult parseVarInt(uint64_t &result) {
                                      ^
/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:1020:44: error: non-const lvalue reference to type 'uint64_t' (aka 'unsigned long long') cannot bind to a value of unrelated type 'size_t' (aka 'unsigned long')
      if (failed(offsetsReader.parseVarInt(dataSize)) ||
                                           ^~~~~~~~
/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:191:39: note: passing argument to parameter 'result' here
  LogicalResult parseVarInt(uint64_t &result) {
                                      ^
2 errors generated.
2023-05-27 09:53:10 +08:00
Mehdi Amini
660f714e26 [MLIR] Add native Bytecode support for properties
This is adding a new interface (`BytecodeOpInterface`) to allow operations to
opt-in skipping conversion to attribute and serializing properties to native
bytecode.

The scheme relies on a new section where properties are stored in sequence

  { size, serialize_properties }, ...

The operations are storing the index of a properties, a table of offset is
built when loading the properties section the first time.

This is a re-commit of 837d1ce0dc which conflicted with another patch upgrading
the bytecode and the collision wasn't properly resolved before.

Differential Revision: https://reviews.llvm.org/D151065
2023-05-26 17:45:01 -07:00
Mehdi Amini
bb9a0c736b Revert "[MLIR] Add native Bytecode support for properties"
This reverts commit ca5a12fd69
and follow-up fixes:

df34c288c4
07dc906883
ab80ad0095
837d1ce0dc

The first commit was incomplete and broken, I'll prepare a new version
later, in the meantime pull this work out of tree.
2023-05-25 21:02:31 -07:00
Mehdi Amini
df34c288c4 Fix MLIR Bytecode backward deployment
The condition for guarding the properties section was reversed.
2023-05-25 20:40:03 -07:00
Eugene Burmako
07dc906883 Fix MLIR back-deployment to version < 5 ; properties section should not be emitted.
This was an oversight in the development of bytecode version 5, which was
caught by downstream StableHLO compatibility tests.

Differential revision: https://reviews.llvm.org/D151531
2023-05-25 20:31:47 -07:00
Jie Fu
ab80ad0095 [mlir] Fix non-const lvalue reference to type 'uint64_t' cannot bind to type 'size_t' error (NFC)
/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:1007:39: error: non-const lvalue reference to type 'uint64_t' (aka 'unsigned long long') cannot bind to a value of unrelated type 'size_t' (aka 'unsigned long')
    if (failed(propReader.parseVarInt(count)))
                                      ^~~~~
/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:191:39: note: passing argument to parameter 'result' here
  LogicalResult parseVarInt(uint64_t &result) {
                                      ^
/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:1033:41: error: non-const lvalue reference to type 'uint64_t' (aka 'unsigned long long') cannot bind to a value of unrelated type 'size_t' (aka 'unsigned long')
    if (failed(dialectReader.readVarInt(propertiesIdx)))
                                        ^~~~~~~~~~~~~
/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:926:38: note: passing argument to parameter 'result' here
  LogicalResult readVarInt(uint64_t &result) override {
                                     ^
2 errors generated.

/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:1033:41: error: non-const lvalue reference to type 'uint64_t' (aka 'unsigned long long') cannot bind to a value of unrelated type 'size_t' (aka 'unsigned long')
    if (failed(dialectReader.readVarInt(propertiesIdx)))
                                        ^~~~~~~~~~~~~
/Users/jiefu/llvm-project/mlir/lib/Bytecode/Reader/BytecodeReader.cpp:926:38: note: passing argument to parameter 'result' here
  LogicalResult readVarInt(uint64_t &result) override {
                                     ^
1 error generated.
2023-05-26 10:02:21 +08:00
Mehdi Amini
837d1ce0dc [MLIR] Add native Bytecode support for properties
This is adding a new interface (`BytecodeOpInterface`) to allow operations to
opt-in skipping conversion to attribute and serializing properties to native
bytecode.

The scheme relies on a new section where properties are stored in sequence

  { size, serialize_properties }, ...

The operations are storing the index of a properties, a table of offset is
built when loading the properties section the first time.

Back-deployment to version prior to 4 are relying on getAttrDictionnary() which
we intend to deprecate and remove: that is putting a de-factor end-of-support
horizon for supporting deployments to version older than 4.

Differential Revision: https://reviews.llvm.org/D151065
2023-05-25 15:15:47 -07:00
Jacques Pienaar
1826fadb0d [mlir][bytecode] Avoid recording null arglocs & realloc opnames.
For block arg locs a common case is no/uknown location (where the producer
signifies they don't care about blockarg location). Also avoid needing to
dynamically resize opnames during parsing.

Assumed to be post lazy loading change, so chose version 3.

Differential Revision: https://reviews.llvm.org/D151038
2023-05-25 09:24:50 -07:00
Mehdi Amini
cfd90939f7 Fix MLIR bytecode loading of resources
The bytecode reader didn't handle properly the case where resource names
conflicted and were renamed, leading to orphan handles in the IR as well
as overwriting the exiting resources.

Differential Revision: https://reviews.llvm.org/D151408
2023-05-25 00:27:59 -07:00
Mehdi Amini
3b0106fe9d Fix MLIR bytecode reader for unregistered dialects
At the moment we accept (in tests) unregistered dialects and in particular:

  "new_processor_id_and_range"()

where there is no `.` separator. We probably will remove support for this
from the parser, but for now we're adding compatibility support in the
reader.

Differential Revision: https://reviews.llvm.org/D151386
2023-05-25 00:27:59 -07:00
Matteo Franciolini
612781918f Preserve use-list orders in mlir bytecode
This patch implements a mechanism to read/write use-list orders from/to the mlir bytecode format. When producing bytecode, use-list orders are appended to each value of the IR. When reading bytecode, use-lists orders are loaded in memory and used at the end of parsing to sort the existing use-list chains.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D149755
2023-05-21 16:48:12 -07:00
Mehdi Amini
3128b3105d Add support for Lazyloading to the MLIR bytecode
IsolatedRegions are emitted in sections in order for the reader to be
able to skip over them. A new class is exposed to manage the state and
allow the readers to load these IsolatedRegions on-demand.

Differential Revision: https://reviews.llvm.org/D149515
2023-05-20 15:24:33 -07:00
Tres Popp
5550c82189 [mlir] Move casting calls from methods to function calls
The MLIR classes Type/Attribute/Operation/Op/Value support
cast/dyn_cast/isa/dyn_cast_or_null functionality through llvm's doCast
functionality in addition to defining methods with the same name.
This change begins the migration of uses of the method to the
corresponding function call as has been decided as more consistent.

Note that there still exist classes that only define methods directly,
such as AffineExpr, and this does not include work currently to support
a functional cast/isa call.

Caveats include:
- This clang-tidy script probably has more problems.
- This only touches C++ code, so nothing that is being generated.

Context:
- https://mlir.llvm.org/deprecation/ at "Use the free function variants
  for dyn_cast/cast/isa/…"
- Original discussion at https://discourse.llvm.org/t/preferred-casting-style-going-forward/68443

Implementation:
This first patch was created with the following steps. The intention is
to only do automated changes at first, so I waste less time if it's
reverted, and so the first mass change is more clear as an example to
other teams that will need to follow similar steps.

Steps are described per line, as comments are removed by git:
0. Retrieve the change from the following to build clang-tidy with an
   additional check:
   https://github.com/llvm/llvm-project/compare/main...tpopp:llvm-project:tidy-cast-check
1. Build clang-tidy
2. Run clang-tidy over your entire codebase while disabling all checks
   and enabling the one relevant one. Run on all header files also.
3. Delete .inc files that were also modified, so the next build rebuilds
   them to a pure state.
4. Some changes have been deleted for the following reasons:
   - Some files had a variable also named cast
   - Some files had not included a header file that defines the cast
     functions
   - Some files are definitions of the classes that have the casting
     methods, so the code still refers to the method instead of the
     function without adding a prefix or removing the method declaration
     at the same time.

```
ninja -C $BUILD_DIR clang-tidy

run-clang-tidy -clang-tidy-binary=$BUILD_DIR/bin/clang-tidy -checks='-*,misc-cast-functions'\
               -header-filter=mlir/ mlir/* -fix

rm -rf $BUILD_DIR/tools/mlir/**/*.inc

git restore mlir/lib/IR mlir/lib/Dialect/DLTI/DLTI.cpp\
            mlir/lib/Dialect/Complex/IR/ComplexDialect.cpp\
            mlir/lib/**/IR/\
            mlir/lib/Dialect/SparseTensor/Transforms/SparseVectorization.cpp\
            mlir/lib/Dialect/Vector/Transforms/LowerVectorMultiReduction.cpp\
            mlir/test/lib/Dialect/Test/TestTypes.cpp\
            mlir/test/lib/Dialect/Transform/TestTransformDialectExtension.cpp\
            mlir/test/lib/Dialect/Test/TestAttributes.cpp\
            mlir/unittests/TableGen/EnumsGenTest.cpp\
            mlir/test/python/lib/PythonTestCAPI.cpp\
            mlir/include/mlir/IR/
```

Differential Revision: https://reviews.llvm.org/D150123
2023-05-12 11:21:25 +02:00
Jacques Pienaar
3449e7a832 [mlir][bytecode] Fix dialect version parsing.
We were querying the wrong EncReader along some paths that resulted in
failures depending on if one encountered an Attribute from an unloaded
dialect before encountering an operation from that dialect.

Also fix error where we were able to emit "custom" form for an attribute
without custom form in TestDialect.

Differential Revision: https://reviews.llvm.org/D150260
2023-05-11 05:19:06 -07:00
Jacques Pienaar
5c90e1ffb0 [mlir][bytecode] Return error instead of min version
Can't return a well-formed IR output while enabling version to be bumped
up during emission. Previously it would return min version but
potentially invalid IR which was confusing, instead make it return
error and abort immediately instead.

Differential Revision: https://reviews.llvm.org/D149569
2023-04-30 22:11:02 -07:00
Jacques Pienaar
0610e2f6a2 [mlir][bytecode] Allow client to specify a desired version.
Add method to set a desired bytecode file format to generate. Change
write method to be able to return status including the minimum bytecode
version needed by reader. This enables generating an older version of
the bytecode (not dialect ops, attributes or types). But this does not
guarantee that an older version can always be generated, e.g., if a
dialect uses a new encoding only available at later bytecode version.
This clamps setting to at most current version.

Differential Revision: https://reviews.llvm.org/D146555
2023-04-29 05:35:53 -07:00
Jakub Kuderski
8c258fda1f [ADT][mlir][NFCI] Do not use non-const lvalue-refs with enumerate
Replace references to enumerate results with either result_pairs
(reference wrapper type) or structured bindings. I did not use
structured bindings everywhere as it wasn't clear to me it would
improve readability.

This is in preparation to the switch to zip semantics which won't
support non-const lvalue reference to elements:
https://reviews.llvm.org/D144503.

I chose to use values instead of const lvalue-refs because MLIR is
biased towards avoiding `const` local variables. This won't degrade
performance because currently `result_pair` is cheap to copy (size_t
+ iterator), and in the future, the enumerator iterator dereference
will return temporaries anyway.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D146006
2023-03-15 10:43:56 -04:00
Matteo Franciolini
0e0b6070fd Implements MLIR Bytecode versioning capability
A dialect can opt-in to handle versioning through the
`BytecodeDialectInterface`. Few hooks are exposed to the dialect to allow
managing a version encoded into the bytecode file. The version is loaded
lazily and allows to retrieve the version information while parsing the input
IR, and gives an opportunity to each dialect for which a version is present
to perform IR upgrades post-parsing through the `upgradeFromVersion` method.
Custom Attribute and Type encodings can also be upgraded according to the
dialect version using readAttribute and readType methods.

There is no restriction on what kind of information a dialect is allowed to
encode to model its versioning. Currently, versioning is supported only for
bytecode formats.

Reviewed By: rriddle, mehdi_amini

Differential Revision: https://reviews.llvm.org/D143647
2023-03-10 23:28:56 +01:00
Rahul Kayaith
55cf53fd0f [mlir][Parser] Make parse{Attribute,Type} null-terminate input
`parseAttribute` and `parseType` require null-terminated strings as
input, but this isn't great considering the argument type is
`StringRef`. This changes them to copy to a null-terminated buffer by
default, with a `isKnownNullTerminated` flag added to disable the
copying.

closes #58964

Reviewed By: rriddle, kuhar, lattner

Differential Revision: https://reviews.llvm.org/D145182
2023-03-03 17:03:27 -05:00
Rahul Kayaith
f5f8a46bb0 [mlir][AsmParser] Improve parse{Attribute,Type} error handling
Currently these functions report errors directly to stderr, this updates
them to use diagnostics instead. This also makes partially-consumed
strings an error if the `numRead` parameter isn't provided (the
docstrings already claimed this happened, but it didn't.)

While here I also tried to reduce the number of overloads by switching
to using default parameters.

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D144804
2023-03-01 17:14:59 -05:00
River Riddle
1fbccfd693 [mlir][IRNumbering] Fix the dialect comparator to be strict
Check if rhs is the dialect to be ordered first, ensuring that
we don't inadvertantly order something before it by
falling back to pure number comparison.

This only shows up depending on the implementation of
stable_sort. This was hit in a build of MSVC that was
checking for strict ordering.
2023-02-07 18:06:34 -08:00
Kazu Hirata
55e2cd1609 Use llvm::count{lr}_{zero,one} (NFC) 2023-01-28 12:41:20 -08:00
Kazu Hirata
83d56fb17a Drop the ZeroBehavior parameter from countLeadingZeros and the like (NFC)
This patch drops the ZeroBehavior parameter from bit counting
functions like countLeadingZeros.  ZeroBehavior specifies the behavior
when the input to count{Leading,Trailing}Zeros is zero and when the
input to count{Leading,Trailing}Ones is all ones.

ZeroBehavior was first introduced on May 24, 2013 in commit
eb91eac9fb.  While that patch did not
state the intention, I would guess ZeroBehavior was for performance
reasons.  The x86 machines around that time required a conditional
branch to implement countLeadingZero<uint32_t> that returns the 32 on
zero:

        test    edi, edi
        je      .LBB0_2
        bsr     eax, edi
        xor     eax, 31
.LBB1_2:
        mov     eax, 32

That is, we can remove the conditional branch if we don't care about
the behavior on zero.

IIUC, Intel's Haswell architecture, launched on June 4, 2013,
introduced several bit manipulation instructions, including lzcnt and
tzcnt, which eliminated the need for the conditional branch.

I think it's time to retire ZeroBehavior as its utility is very
limited.  If you care about compilation speed, you should build LLVM
with an appropriate -march= to take advantage of lzcnt and tzcnt.
Even if not, modern host compilers should be able to optimize away
quite a few conditional branches because the input is often known to
be nonzero from dominating conditional branches.

Differential Revision: https://reviews.llvm.org/D141798
2023-01-18 19:58:44 -08:00
Joe Loser
a288d7f937 [llvm][ADT] Replace uses of makeMutableArrayRef with deduction guides
Similar to how `makeArrayRef` is deprecated in favor of deduction guides, do the
same for `makeMutableArrayRef`.

Once all of the places in-tree are using the deduction guides for
`MutableArrayRef`, we can mark `makeMutableArrayRef` as deprecated.

Differential Revision: https://reviews.llvm.org/D141814
2023-01-16 14:49:37 -07:00
Kazu Hirata
0a81ace004 [mlir] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to remove #include "llvm/ADT/Optional.h".

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 01:25:58 -08:00
serge-sans-paille
984b800a03 Move from llvm::makeArrayRef to ArrayRef deduction guides - last part
This is a follow-up to https://reviews.llvm.org/D140896, split into
several parts as it touches a lot of files.

Differential Revision: https://reviews.llvm.org/D141298
2023-01-10 11:47:43 +01:00
River Riddle
18546ff8dd [mlir:Bytecode] Add shared_ptr<SourceMgr> overloads to allow safe mmap of data
The bytecode reader currently has no mechanism that allows for directly referencing
data from the input buffer safely. This commit adds shared_ptr<SourceMgr> overloads
that provide an explicit and safe way of extending the lifetime of the input. The usage of
these new overloads is adopted in all of our tooling, and is implicitly used in the filename
only parser methods.

Differential Revision: https://reviews.llvm.org/D139366
2022-12-11 22:45:34 -08:00
Kazu Hirata
4f81805a3f [mlir] Use std::optional instead of None in comments (NFC)
This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-10 17:11:23 -08:00
Kazu Hirata
b2379415b9 [Reader] Use std::optional in BytecodeReader.cpp (NFC)
This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-10 10:31:26 -08:00
Kazu Hirata
192d9dd731 [mlir] Use std::nullopt instead of None in comments (NFC)
This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-04 19:58:32 -08:00
bzcheeseman
ae461d8b99 [MLIR][Bytecode] Ensure dataIt is aligned coming out of EncodingReader::alignTo.
This addresses the TODO in the code previously and checks that the address of `dataIt` is properly aligned to the requested alignment.

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D137855
2022-11-13 09:27:23 -08:00