Commit Graph

71 Commits

Author SHA1 Message Date
aartbik e8dcf5f87d [mlir] [VectorOps] Add expand/compress operations to Vector dialect
Introduces the expand and compress operations to the Vector dialect
(important memory operations for sparse computations), together
with a first reference implementation that lowers to the LLVM IR
dialect to enable running on CPU (and other targets that support
the corresponding LLVM IR intrinsics).

Reviewed By: reidtatge

Differential Revision: https://reviews.llvm.org/D84888
2020-08-04 12:00:42 -07:00
Alex Zinenko ec1f4e7c3b [mlir] switch the modeling of LLVM types to use the new mechanism
A new first-party modeling for LLVM IR types in the LLVM dialect has been
developed in parallel to the existing modeling based on wrapping LLVM `Type *`
instances. It resolves the long-standing problem of modeling identified
structure types, including recursive structures, and enables future removal of
LLVMContext and related locking mechanisms from LLVMDialect.

This commit only switches the modeling by (a) renaming LLVMTypeNew to LLVMType,
(b) removing the old implementaiton of LLVMType, and (c) updating the tests. It
is intentionally minimal. Separate commits will remove the infrastructure built
for the transition and update API uses where appropriate.

Depends On D85020

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D85021
2020-08-04 14:29:25 +02:00
Alex Zinenko aec38c619d [mlir] LLVMType: make getUnderlyingType private
The current modeling of LLVM IR types in MLIR is based on the LLVMType class
that wraps a raw `llvm::Type *` and delegates uniquing, printing and parsing to
LLVM itself. This is model makes thread-safe type manipulation hard and is
being progressively replaced with a cleaner MLIR model that replicates the type
system. In the new model, LLVMType will no longer have an underlying LLVM IR
type. Restrict access to this type in the current model in preparation for the
change.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D84389
2020-07-29 13:43:38 +02:00
aartbik 1485fd295b [mlir] [VectorOps] Improve scatter/gather CPU performance
Replaced the linearized address with the proper LLVM way of
defining vector of base + indices in SIMD style. This yields
much better code. Some prototype results with microbencmarking
sparse matrix x vector with 50% sparsity (about 2-3x faster):

         LINEARIZED     IMPROVED
GFLOPS  sdot  saxpy     sdot saxpy
16x16    1.6   1.4       4.4  2.1
32x32    1.7   1.6       5.8  5.9
64x64    1.7   1.7       6.4  6.4
128x128  1.7   1.7       5.9  5.9
256x256  1.6   1.6       6.1  6.0
512x512  1.4   1.4       4.9  4.7

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D84368
2020-07-22 23:47:36 -07:00
aartbik 19dbb230a2 [mlir] [VectorOps] Add scatter/gather operations to Vector dialect
Introduces the scatter/gather operations to the Vector dialect
(important memory operations for sparse computations), together
with a first reference implementation that lowers to the LLVM IR
dialect to enable running on CPU (and other targets that support
the corresponding LLVM IR intrinsics).

The operations can be used directly where applicable, or can be used
during progressively lowering to bring other memory operations closer to
hardware ISA support for a gather/scatter. The semantics of the operation
closely correspond to those of the corresponding llvm intrinsics.

Note that the operation allows for a dynamic index vector (which is
important for sparse computations). However, this first reference
lowering implementation "serializes" the address computation when
base + index_vector is converted to a vector of pointers. Exploring
how to use SIMD properly during these step is TBD. More general
memrefs and idiomatic versions of striding are also TBD.

Reviewed By: arpith-jacob

Differential Revision: https://reviews.llvm.org/D84039
2020-07-21 10:57:40 -07:00
Nicolas Vasilache affbc0cd1c [mlir] Add alignment attribute to LLVM memory ops and use in vector.transfer
Summary: The native alignment may generally not be used when lowering a vector.transfer to the underlying load/store operation. This revision fixes the unmasked load/store alignment to match that of the masked path.

Differential Revision: https://reviews.llvm.org/D83684
2020-07-13 17:35:20 -04:00
Benjamin Kramer 3bffe6022c [mlir][VectorOps] Lower vector.fma to llvm.fmuladd instead of llvm.fma
Summary:
These are semantically equivalent, but fmuladd allows decaying the op
into fmul+fadd if there is no fma instruction available. llvm.fma lowers
to scalar calls to libm fmaf, which is a lot slower.

Reviewers: nicolasvasilache, aartbik, ftynse

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, liufengdb, stephenneuendorffer, Joonsoo, grosul1, Kayjukh, jurahul, msifontes

Tags: #mlir

Differential Revision: https://reviews.llvm.org/D83666
2020-07-13 12:26:03 +02:00
aartbik 1bfdf7c7e3 [mlir] [VectorOps] Expose lowering pass options programmatically
The ConvertVectorToLLVM pass defines options that can be passed
on the command line (currently only reassociation of FP reductions
through -convert-vector-to-llvm='reassociate-fp-reductions). This
CL enables setting these options programmatically (forward looking
to more options than just reassociation, as well as setting the
values from code rather than command line).

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D83420
2020-07-08 14:58:07 -07:00
River Riddle 9db53a1827 [mlir][NFC] Remove usernames and google bug numbers from TODO comments.
These were largely leftover from when MLIR was a google project, and don't really follow LLVM guidelines.
2020-07-07 01:40:52 -07:00
aartbik ceb1b327b5 [mlir] [VectorOps] Add the ability to mark FP reductions with "reassociate" attribute
Rationale:
In general, passing "fastmath" from MLIR to LLVM backend is not supported, and even just providing such a feature for experimentation is under debate. However, passing fine-grained fastmath related attributes on individual operations is generally accepted. This CL introduces an option to instruct the vector-to-llvm lowering phase to annotate floating-point reductions with the "reassociate" fastmath attribute, which allows the LLVM backend to use SIMD implementations for such constructs. Oher lowering passes can start using this mechanism right away in cases where reassociation is allowed.

Benefit:
For some microbenchmarks on x86-avx2, speedups over 20 were observed for longer vector (due to cleaner, spill-free and SIMD exploiting code).

Usage:
mlir-opt --convert-vector-to-llvm="reassociate-fp-reductions"

Reviewed By: ftynse, mehdi_amini

Differential Revision: https://reviews.llvm.org/D82624
2020-06-26 11:03:14 -07:00
River Riddle 8d67d187ba [mlir][DialectConversion] Refactor how block argument types get converted
This revision removes the TypeConverter parameter passed to the apply* methods, and instead moves the responsibility of region type conversion to patterns. The types of a region can be converted using the 'convertRegionTypes' method, which acts similarly to the existing 'applySignatureConversion'. This method ensures that all blocks within, and including those moved into, a region will have the block argument types converted using the provided converter.

This has the benefit of making more of the legalization logic controlled by patterns, instead of being handled explicitly by the driver. It also opens up the possibility to support multiple type conversions at some point in the future.

This revision also adds a new utility class `FailureOr<T>` that provides a LogicalResult friendly facility for returning a failure or a valid result value.

Differential Revision: https://reviews.llvm.org/D81681
2020-06-18 15:59:22 -07:00
aartbik c9eeeb3871 [mlir] [VectorOps] remove print_i1 from runtime support library
Summary:
The "i1" (viz. bool) type does not have a proper equivalent on the "C"
size. So, to avoid any ABIs issues, we simply use print_i32 on an i32
value of one or zero for true and false. This has the added advantage
that one less function needs to be implemented when porting the runtime
support library.

Reviewers: ftynse, bkramer, nicolasvasilache

Reviewed By: ftynse

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, stephenneuendorffer, Joonsoo, grosul1, frgossen, Kayjukh, jurahul, msifontes

Tags: #mlir

Differential Revision: https://reviews.llvm.org/D82048
2020-06-18 11:07:43 -07:00
Jacques Pienaar 2d2c73c5cf [mlir] Remove OperandAdaptor
Use ::Adaptor alias instead uniformly. Makes the naming more consistent as
adaptor can refer to attributes now too.

Differential Revision: https://reviews.llvm.org/D81789
2020-06-15 06:01:31 -07:00
Nicolas Vasilache 5f9e0466f2 [mlir][Vector] Fix vector.transfer alignment calculation
https://reviews.llvm.org/D79246 introduces alignment propagation for vector transfer operations. Unfortunately, the alignment calculation is incorrect and can result in crashes.

This revision fixes the calculation by using the natural alignment of the memref elemental type, instead of the resulting vector type.

If more alignment is desired, it can be done in 2 ways:
1. use a proper vector.type_cast to transform a memref<axbxcxdxf32> into a memref<axbxvector<cxdxf32>> giving a natural alignment of vector<cxdxf32>
2. add an alignment attribute to vector transfer operations and propagate it.

With this change the alignment in the relevant tests goes down from 128 to 4.

Lastly, a few minor cleanups are performed and the custom `isMinorIdentityMap` is deprecated.

Differential Revision: https://reviews.llvm.org/D80734
2020-05-28 17:58:51 -04:00
aartbik c295a65da4 [mlir] [VectorOps] Add 'vector.flat_transpose' operation
Summary:
Provides a representation of the linearized LLVM instrinsic.
With tests and lowering implementation to LLVM IR dialect.
Prepares better lowering for 2-D vector.transpose.

Reviewers: nicolasvasilache, ftynse, reidtatge, bkramer, dcaballe

Reviewed By: ftynse, dcaballe

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, stephenneuendorffer, Joonsoo, grosul1, frgossen, Kayjukh, jurahul, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D80419
2020-05-27 11:09:48 -07:00
Nicolas Vasilache 1870e787af [mlir][Vector] Add an optional "masked" boolean array attribute to vector transfer operations
Summary:
Vector transfer ops semantic is extended to allow specifying a per-dimension `masked`
attribute. When the attribute is false on a particular dimension, lowering to LLVM emits
unmasked load and store operations.

Differential Revision: https://reviews.llvm.org/D80098
2020-05-18 11:52:08 -04:00
aartbik b1c688dbae [mlir] [VectorOps] Implement vector.create_mask lowering to LLVM IR
Summary:
First, compact implementation of lowering to LLVM IR. A bit more
challenging than the constant mask due to the dynamic indices, of course.
I like to hear if there are more efficient ways of doing this in LLVM,
but this for now at least gives us a functional reference implementation.

Reviewers: nicolasvasilache, ftynse, bkramer, reidtatge, andydavis1, mehdi_amini

Reviewed By: nicolasvasilache

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, stephenneuendorffer, Joonsoo, grosul1, frgossen, Kayjukh, jurahul, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79954
2020-05-15 11:02:30 -07:00
Reid Tatge 334a4159ec [mlir][Vector] NFC - Rename vector.strided_slice into vector.extract_strided_slice
Differential Revision: https://reviews.llvm.org/D79734
2020-05-11 14:21:10 -07:00
Alex Zinenko a99f62c40a [mlir] VectorToLLVM: propagate up from replaceTransferOp
In the Vector to LLVM conversion, the `replaceTransferOp` function calls
into a type converter that may fail and suppresses the status. Change
the function to return the failure status instead, Since it is called
from a pattern, the failure can be readily propagated to the rest of
infrastructure.
2020-05-07 11:53:48 +02:00
Wen-Heng (Jack) Chung a23f190213 [mlir][vector] set alignment when lowering transfer_read and transfer_write.
When emitting masked load / store, set alignment from data layout.

Differential Revision: https://reviews.llvm.org/D79246
2020-05-07 11:44:25 +02:00
aartbik 6937251f01 [mlir] [VectorOps] Included i1 support for vector.print
Summary:
Added boolean support to vector.print.
Useful for upcoming "mask" tests.

Reviewers: ftynse, nicolasvasilache, andydavis1

Reviewed By: andydavis1

Subscribers: mehdi_amini, rriddle, jpienaar, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, grosul1, frgossen, Kayjukh, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D79198
2020-04-30 14:56:26 -07:00
Wen-Heng (Jack) Chung be16075bfc [mlir][vector] let transfer_read and transfer_write take non-zero addrspace.
Enhance lowering logic and tests so vector.transfer_read and
vector.transfer_write take memrefs on non-zero addrspaces.

Differential Revision: https://reviews.llvm.org/D79023
2020-04-29 17:11:48 +02:00
Nicolas Vasilache b2c79c50ed [mlir][VectorOps] Extend VectorTransfer lowering to n-D memref with minor identity map
Summary: This revision extends the lowering of vector transfers to work with n-D memref and 1-D vector where the permutation map is an identity on the most minor dimensions (1 for now).

Differential Revision: https://reviews.llvm.org/D78925
2020-04-27 11:20:55 -04:00
aartbik 186709c6e0 [mlir] [VectorOps] Progressive lowering of vector.broadcast
Summary:
Rather than having a full, recursive, lowering of vector.broadcast
to LLVM IR, it is much more elegant to have a progressive lowering
of each vector.broadcast into a lower dimensional vector.broadcast,
until only elementary vector operations remain. This results
in more elegant, step-wise code, that is easier to understand.
Also makes some optimizations in the generated code.

Reviewers: nicolasvasilache, mehdi_amini, andydavis1, grosul1

Reviewed By: nicolasvasilache

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, grosul1, frgossen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78071
2020-04-16 21:02:27 -07:00
Uday Bondhugula a5b9316b24 [MLIR][NFC] applyPatternsGreedily -> applyPatternsAndFoldGreedily
Rename mlir::applyPatternsGreedily -> applyPatternsAndFoldGreedily. The
new name is a more accurate description of the method - it performs
both, application of the specified patterns and folding of all ops in
the op's region irrespective of whether any patterns have been supplied.

Differential Revision: https://reviews.llvm.org/D77478
2020-04-10 12:55:21 +05:30
Nicolas Vasilache 8345b86d9a [mlir][Vector] Add lowering of 1-D vector transfer_read/write to masked load/store
Summary:
This revision adds support to lower 1-D vector transfers to LLVM.
A mask of the vector length is created that compares the base offset + linear index to the dim of the vector.
In each position where this does not overflow (i.e. offset + vector index < dim), the mask is set to 1.

A notable fact is that the lowering uses llvm.dialect_cast to allow writing code in the simplest form by targeting the simplest mix of vector and LLVM dialects and
letting other conversions kick in.

Differential Revision: https://reviews.llvm.org/D77703
2020-04-09 16:17:05 -04:00
River Riddle bd1ccfe6df [mlir] Add a new RewritePattern::hasBoundedRewriteRecursion hook.
Summary: Some pattern rewriters, like dialect conversion, prohibit the unbounded recursion(or reapplication) of patterns on generated IR. Most patterns are not written with recursive application in mind, so will generally explode the stack if uncaught. This revision adds a hook to RewritePattern, `hasBoundedRewriteRecursion`, to signal that the pattern can safely be applied to the generated IR of a previous application of the same pattern. This allows for establishing a contract between the pattern and rewriter that the pattern knows and can handle the potential recursive application.

Differential Revision: https://reviews.llvm.org/D77782
2020-04-09 12:42:28 -07:00
River Riddle 1834ad4a69 [mlir][Pass] Update the PassGen to generate base classes instead of utilities
Summary:
This is much cleaner, and fits the same structure as many other tablegen backends. This was not done originally as the CRTP in the pass classes made it overly verbose/complex.

Differential Revision: https://reviews.llvm.org/D77367
2020-04-07 14:08:52 -07:00
River Riddle 80aca1eaf7 [mlir][Pass] Remove the use of CRTP from the Pass classes
This revision removes all of the CRTP from the pass hierarchy in preparation for using the tablegen backend instead. This creates a much cleaner interface in the C++ code, and naturally fits with the rest of the infrastructure. A new utility class, PassWrapper, is added to replicate the existing behavior for passes not suitable for using the tablegen backend.

Differential Revision: https://reviews.llvm.org/D77350
2020-04-07 14:08:52 -07:00
River Riddle 722f909f7a [mlir][Pass][NFC] Replace usages of ModulePass with OperationPass<ModuleOp>
ModulePass doesn't provide any special utilities and thus doesn't give enough benefit to warrant a special pass class. This revision replaces all usages with the more general OperationPass.

Differential Revision: https://reviews.llvm.org/D77339
2020-04-07 14:08:52 -07:00
River Riddle 9a277af2d4 [mlir][Pass] Add support for generating pass utilities via tablegen
This revision adds support for generating utilities for passes such as options/statistics/etc. that can be inferred from the tablegen definition. This removes additional boilerplate from the pass, and also makes it easier to remove the reliance on the pass registry to provide certain things(e.g. the pass argument).

Differential Revision: https://reviews.llvm.org/D76659
2020-04-01 02:10:46 -07:00
River Riddle 3dddd8969f [mlir][Pass] Move the registration of conversion passes to tablegen
This removes the need to statically register conversion passes, and also puts all of the conversions within one centralized file.

Differential Revision: https://reviews.llvm.org/D76658
2020-04-01 02:10:46 -07:00
River Riddle 3145427dd7 [mlir][NFC] Replace all usages of PatternMatchResult with LogicalResult
This also replaces usages of matchSuccess/matchFailure with success/failure respectively.

Differential Revision: https://reviews.llvm.org/D76313
2020-03-17 20:21:32 -07:00
Nicolas Vasilache 2fae7878d5 [mlir][Vector] Mostly-NFC - Restructure options for lowering to LLVM Matrix Intrinsics
Summary:
This revision restructures the calling of vector transforms to make it more flexible to ask for lowering through LLVM matrix intrinsics.
This also makes sure we bail out in degenerate cases (i.e. 1) in which LLVM complains about not being able to scalarize.

Differential Revision: https://reviews.llvm.org/D76266
2020-03-17 22:58:02 -04:00
Rob Suderman 4d60f47b08 [mlir][NFC] Renamed VectorOps to Vector
Summary: Renamed VectorOps to Vector to avoid the redundant Ops suffix.

Differential Revision: https://reviews.llvm.org/D76317
2020-03-17 15:28:08 -07:00
River Riddle bd5941b9ce [mlir] Remove the PatternState class and simplify PatternMatchResult.
Summary: PatternState was a mechanism to pass state between the match and rewrite calls of a RewritePattern. With the rise of matchAndRewrite, this class is unused and unnecessary. This revision removes PatternState and simplifies PatternMatchResult to just be a LogicalResult. A future revision will replace all usages of PatternMatchResult/matchSuccess/matchFailure with LogicalResult equivalents.

Differential Revision: https://reviews.llvm.org/D76202
2020-03-16 17:55:54 -07:00
Nicolas Vasilache bbf3ef8541 [mlir][Vector]Lower vector.contract to llvm.intr.matrix_multiply
Summary:
This revision adds lowering of vector.contract to llvm.intr.matrix_multiply.
Note that there is currently a mismatch between the MLIR vector dialect which
expects row-major layout and the LLVM matrix intrinsics which expect column
major layout.

As a consequence, we currently only match a vector.contract with indexing maps
that express column-major matrix multiplication.
Other cases would require additional transposes and it is better to wait for
LLVM intrinsics to provide a per-operation attribute that would specify which
layout is expected.

A separate integration test, not submitted to MLIR core, has independently
verified that correct execution occurs on a 2x2x2 matrix multiplication.

Differential Revision: https://reviews.llvm.org/D76014
2020-03-13 16:33:23 -04:00
aartbik a213ece30b [mlir] [VectorOps,LinAlg] Remove direct LLVM lowering for vector.broadcast
Summary:
The direct lowering of vector.broadcast into LLVM has been replaced by
progressive lowering into elementary vector ops. This also required a
small refactoring of a llvm.mlir test that used a direct vector.broadcast
operator (just to define a matmul).

Reviewers: nicolasvasilache, andydavis1, rriddle

Reviewed By: nicolasvasilache

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76143
2020-03-13 11:42:51 -07:00
aartbik 078776a679 [mlir] [VectorOps] Progressively lower vector.outerproduct to LLVM
Summary:
This replaces the direct lowering of vector.outerproduct to LLVM with progressive lowering into elementary vectors ops to avoid having the similar lowering logic at several places.

NOTE1: with the new progressive rule, the lowered llvm is slightly more elaborate than with the direct lowering, but the generated assembly is just as optimized; still if we want to stay closer to the original, we should add a "broadcast on extract" to shuffle rewrite (rather than special cases all the lowering steps)

NOTE2: the original outerproduct lowering code should now be removed but some linalg test work directly on vector and contain some dead code, so this requires another CL

Reviewers: nicolasvasilache, andydavis1

Reviewed By: nicolasvasilache, andydavis1

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75956
2020-03-12 13:45:42 -07:00
Nicolas Vasilache 63b683a816 [mlir][Vector] Add a vector.matrix_multiply op on 1-D vectors
Summary: This op mirrors the llvm.intr counterpart and allows lowering + type conversions in a progressive fashion.

Differential Revision: https://reviews.llvm.org/D75775
2020-03-09 13:34:03 -04:00
aartbik 0d924700a6 [mlir] [VectorOps] Merge VectorReduction/VectorReductionV2 into one Op
Summary:
Paying off some technical debt in VectorOps, where I introduced a special
op for a fused accumulator into reduction to avoid some issues around
printing and parsing an optional accumulator. This CL merges the two
into one op again and does things the right way (still would be nice
to have "assemblyFormat" for optional operands though....).

Reviewers: nicolasvasilache, andydavis1, ftynse, rriddle

Reviewed By: nicolasvasilache

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75699
2020-03-05 13:07:31 -08:00
Tim Shen 2a00ae3984 [MLIR] Add LLVMConversionTarget as a customization point. NFC.
This is in preparation for the next patch D75141. The purpose is to
provide a single place where LLVM dialect registers its ops as
legal/illegal.

Reviewers: ftynse, mravishankar, herhut

Subscribers: jholewinski, bixia, sanjoy.google, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, csigg, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, Joonsoo, llvm-commits

Differential Revision: https://reviews.llvm.org/D75140
2020-02-28 12:20:23 -08:00
Rob Suderman 69d757c0e8 Move StandardOps/Ops.h to StandardOps/IR/Ops.h
Summary:
NFC - Moved StandardOps/Ops.h to a StandardOps/IR dir to better match surrounding
directories. This is to match other dialects, and prepare for moving StandardOps
related transforms in out for Transforms and into StandardOps/Transforms.

Differential Revision: https://reviews.llvm.org/D74940
2020-02-21 11:58:47 -08:00
Lei Zhang 35b685270b [mlir] Add a signedness semantics bit to IntegerType
Thus far IntegerType has been signless: a value of IntegerType does
not have a sign intrinsically and it's up to the specific operation
to decide how to interpret those bits. For example, std.addi does
two's complement arithmetic, and std.divis/std.diviu treats the first
bit as a sign.

This design choice was made some time ago when we did't have lots
of dialects and dialects were more rigid. Today we have much more
extensible infrastructure and different dialect may want different
modelling over integer signedness. So while we can say we want
signless integers in the standard dialect, we cannot dictate for
others. Requiring each dialect to model the signedness semantics
with another set of custom types is duplicating the functionality
everywhere, considering the fundamental role integer types play.

This CL extends the IntegerType with a signedness semantics bit.
This gives each dialect an option to opt in signedness semantics
if that's what they want and helps code sharing. The parser is
modified to recognize `si[1-9][0-9]*` and `ui[1-9][0-9]*` as
signed and unsigned integer types, respectively, leaving the
original `i[1-9][0-9]*` to continue to mean no indication over
signedness semantics. All existing dialects are not affected (yet)
as this is a feature to opt in.

More discussions can be found at:

https://groups.google.com/a/tensorflow.org/d/msg/mlir/XmkV8HOPWpo/7O4X0Nb_AQAJ

Differential Revision: https://reviews.llvm.org/D72533
2020-02-21 09:16:54 -05:00
Alex Zinenko 870c1fd4c8 [mlir] NFC: rename LLVMOpLowering to ConvertToLLVMPattern
This better reflects the nature of the class and matches the current
naming scheme.

Differential Revision: https://reviews.llvm.org/D74774
2020-02-18 22:19:58 +01:00
Alex Zinenko 0f04384daf [mlir] NFC: Rename LLVMOpLowering::lowering to LLVMOpLowering::typeConverter
The existing name is an artifact dating back to the times when we did not have
a dedicated TypeConverter infrastructure. It is also confusing with with the
name of classes using it.

Differential revision: https://reviews.llvm.org/D74707
2020-02-18 15:57:10 +01:00
aartbik b21c799952 [mlir] [VectorOps] Initial framework for progressively lowering vector.contract
Summary:
This sets the basic framework for lowering vector.contract progressively
into simpler vector.contract operations until a direct vector.reduction
operation is reached. More details will be filled out progressively as well.

Reviewers: nicolasvasilache

Reviewed By: nicolasvasilache

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74520
2020-02-13 15:07:57 -08:00
aartbik e83b7b99da [mlir] [VectorOps] Implement vector.reduce operation
Summary:
This new operation operates on 1-D vectors and
forms the bridge between vector.contract and
llvm intrinsics for vector reductions.

Reviewers: nicolasvasilache, andydavis1, ftynse

Reviewed By: nicolasvasilache

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74370
2020-02-11 11:31:59 -08:00
Nicolas Vasilache 681f929f59 [mlir][VectorOps] Introduce a `vector.fma` op that works on n-D vectors and lowers to `llvm.intrin.fmuladd`
Summary:
The `vector.fma` operation is portable enough across targets that we do not want
to keep it wrapped under `vector.outerproduct` and `llvm.intrin.fmuladd`.
This revision lifts the op into the vector dialect and implements the lowering to LLVM by using two patterns:
1. a pattern that lowers from n-D to (n-1)-D by unrolling when n > 2
2. a pattern that converts from 1-D to the proper LLVM representation

Reviewers: ftynse, stellaraccident, aartbik, dcaballe, jsetoain, tetuante

Reviewed By: aartbik

Subscribers: fhahn, dcaballe, merge_guards_bot, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74075
2020-02-07 15:44:53 -05:00
Nicolas Vasilache 499ad45877 [mlir][VectorOps] Expose and use llvm.intrin.fma*
Summary:
This revision exposes the portable `llvm.fma` intrinsic in LLVMOps and uses it
in lieu of `llvm.fmuladd` when lowering the `vector.outerproduct` op to LLVM.
This guarantees proper `fma` instructions will be emitted if the target ISA
supports it.

`llvm.fmuladd` does not have this guarantee in its semantics, despite evidence
that the proper x86 instructions are emitted.

For more details, see https://llvm.org/docs/LangRef.html#llvm-fmuladd-intrinsic.

Reviewers: ftynse, aartbik, dcaballe, fhahn

Reviewed By: aartbik

Subscribers: mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74219
2020-02-07 15:38:40 -05:00