Commit Graph

147 Commits

Author SHA1 Message Date
Thomas Raoux
7efdc117b1 [mlir][nvvm] Add lowering of gpu.printf to nvvm
When converting to nvvm lowering gpu.printf to vprintf allows us to
support printing when running on cuda.

Differential Revision: https://reviews.llvm.org/D141049
2023-01-06 17:29:30 +00:00
Krzysztof Drewniak
f6076bd81f [mlir][ROCDL] Translate known block size attributes to ROCDL
1. When converting from the GPU dialect to the ROCDL dialect, if the
function that contains a gpu.thread_id or gpu.block_id op is annotated
with gpu.known_{block,grid}_size, use that size to set a "range"
attribute on the corresponding rocdl intrinsic so that the LLVM
frontend can optimize based on that range information.
1b. When translating from the rocdl dialect to LLVM IR, use the
"range" attribute, if present, to set !range metadata on the relevant
function call.
2. Deprecate the old rocdl.max_flat_work_group_size attribute, which
was used in a tensorflow backend. Instead, use
rocdl.flat_work_group_size going forward to allow kernel generators to
specify the minimum and maximum work group sizes a kernel may be
launched with in one attribute, thus more closely matching the backend.
3. When translating from gpu.func to llvm.func within gpu-to-rocdl,
copy the known_block_size attribute as rocdl.reqd_work_group_size to
enable further translations to set the corresponding metadata on the
LLVM IR function. Also, set the rocdl.flat_work_group_size attribute
to ensure that the reqd_work_group_size metadata and the
amdgpu-flat-work-group-size metadata are consistent.
3b. Extend the ROCDL to LLVM IR translation to set the
!reqd_work_group_size metadata on LLVM functions

Also update tests and add functions to the ROCDL dialect to ensure
attribute names are used consistently.

Depends on D139865

Reviewed By: antiagainst

Differential Revision: https://reviews.llvm.org/D139866
2023-01-02 21:04:13 +00:00
Jeff Niu
53406427cd [mlir] FunctionOpInterface: turn required attributes into interface methods (Reland)
Reland D139447, D139471 With flang actually working

- FunctionOpInterface: make get/setFunctionType interface methods

This patch removes the concept of a `function_type`-named type attribute
as a requirement for implementors of FunctionOpInterface. Instead, this
type should be provided through two interface methods, `getFunctionType`
and `setFunctionTypeAttr` (*Attr because functions may use different
concrete function types), which should be automatically implemented by
ODS for ops that define a `$function_type` attribute.

This also allows FunctionOpInterface to materialize function types if
they don't carry them in an attribute, for example.

Importantly, all the function "helper" still accept an attribute name to
use in parsing and printing functions, for example.

- FunctionOpInterface: arg and result attrs dispatch to interface

This patch removes the `arg_attrs` and `res_attrs` named attributes as a
requirement for FunctionOpInterface and replaces them with interface
methods for the getters, setters, and removers of the relevent
attributes. This allows operations to use their own storage for the
argument and result attributes.

Reviewed By: jpienaar

Differential Revision: https://reviews.llvm.org/D139736
2022-12-10 15:17:09 -08:00
David Spickett
cf98e8273c Revert "[mlir] FunctionOpInterface: make get/setFunctionType interface methods"
and "[mlir] Fix examples build"

This reverts commit fbc253fe81 and
96cf183bcc.

Which I missed in the first revert in f3379feabe.
2022-12-09 15:36:48 +00:00
Jeff Niu
fbc253fe81 [mlir] FunctionOpInterface: make get/setFunctionType interface methods
This patch removes the concept of a `function_type`-named type attribute
as a requirement for implementors of FunctionOpInterface. Instead, this
type should be provided through two interface methods, `getFunctionType`
and `setFunctionTypeAttr` (*Attr because functions may use different
concrete function types), which should be automatically implemented by
ODS for ops that define a `$function_type` attribute.

This also allows FunctionOpInterface to materialize function types if
they don't carry them in an attribute, for example.

Importantly, all the function "helper" still accept an attribute name to
use in parsing and printing functions, for example.

Reviewed By: rriddle, lattner

Differential Revision: https://reviews.llvm.org/D139447
2022-12-08 11:32:27 -08:00
Uday Bondhugula
5ceaeed659 Improve type conversion error propagation/failure during LLVM lowering
Improve type conversion error propagation/failure during LLVM lowering.

BEFORE

```
llvm-mlir/mlir/lib/Conversion/LLVMCommon/TypeConverter.cpp:304: SmallVector<mlir::Type, 5> mlir::LLVMTypeConverter::getMemRefDescriptorFields(mlir::MemRefType, bool): Assertion `isStrided(type) && "Non-strided layout maps must have been normalized away"' failed.
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
...
```

AFTER
```
<unknown>:0: error: integer overflow during size computation
<unknown>:0: error: Conversion to strided form failed either due to non-strided layout maps (which should have been normalized away) or other reasons
<unknown>:0: error: failed to legalize operation 'gpu.func' that was explicitly marked illegal
<unknown>:0: note: see current operation:
"gpu.func"() ( {
...
```

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D139072
2022-12-03 16:30:44 +05:30
River Riddle
b74192b7ae [mlir] Remove support for non-prefixed accessors
This finishes off a year long pursuit to LLVMify the generated
operation accessors, prefixing them with get/set. Support for
any other accessor naming is fully removed after this commit.

https://discourse.llvm.org/t/psa-raw-accessors-are-being-removed/65629

Differential Revision: https://reviews.llvm.org/D136727
2022-12-02 13:32:36 -08:00
Christian Sigg
b251b608b5 [mlir][gpu] Unroll ops on vectors which map to intrinsic calls
Unroll ops that map to intrinsics when lowering to LLVM, because intrinsics don't support vector operands/results.

Reviewed By: herhut

Differential Revision: https://reviews.llvm.org/D136345
2022-10-28 10:33:38 +02:00
Ivan Butygin
a93ec06ae6 [mlir][gpu] Introduce host_shared flag to gpu.alloc
Motivation: we have lowering pipeline based on upstream gpu and spirv dialects and and we are using host shared gpu memory to transfer data between host and device.
Add `host_shared` flag to `gpu.alloc` to distinguish between shared and device-only gpu memory allocations.

Differential Revision: https://reviews.llvm.org/D133533
2022-10-05 22:01:30 +02:00
River Riddle
10c04f4641 [mlir:GPU][NFC] Update GPU API to use prefixed accessors
This doesn't flip the switch for prefix generation yet, that'll be
done in a followup.
2022-09-30 15:27:10 -07:00
Jakub Kuderski
abc362a107 [mlir][arith] Change dialect name from Arithmetic to Arith
Suggested by @lattner in https://discourse.llvm.org/t/rfc-define-precise-arith-semantics/65507/22.

Tested with:
`ninja check-mlir check-mlir-integration check-mlir-mlir-spirv-cpu-runner check-mlir-mlir-vulkan-runner check-mlir-examples`

and `bazel build --config=generic_clang @llvm-project//mlir:all`.

Reviewed By: lattner, Mogball, rriddle, jpienaar, mehdi_amini

Differential Revision: https://reviews.llvm.org/D134762
2022-09-29 11:23:28 -04:00
Kazu Hirata
0820c6ef60 [mlir] Don't include StringSwitch.h (NFC)
These files don't seem to use StringSwitch.
2022-09-18 23:09:40 -07:00
Michele Scuttari
67d0d7ac0a [MLIR] Update pass declarations to new autogenerated files
The patch introduces the required changes to update the pass declarations and definitions to use the new autogenerated files and allow dropping the old infrastructure.

Reviewed By: mehdi_amini, rriddle

Differential Review: https://reviews.llvm.org/D132838
2022-08-31 12:28:45 +02:00
Michele Scuttari
039b969b32 Revert "[MLIR] Update pass declarations to new autogenerated files"
This reverts commit 2be8af8f0e.
2022-08-30 22:21:55 +02:00
Michele Scuttari
2be8af8f0e [MLIR] Update pass declarations to new autogenerated files
The patch introduces the required changes to update the pass declarations and definitions to use the new autogenerated files and allow dropping the old infrastructure.

Reviewed By: mehdi_amini, rriddle

Differential Review: https://reviews.llvm.org/D132838
2022-08-30 21:56:31 +02:00
Tyker
688c51a5ac [MLIR] Add mlir::TypedValue
mlir::TypedValue is a wrapper class for mlir::Values with a known type
getType will return the known type and all assignements will be checked

Also the tablegen Operation generator was adapted to use mlir::TypedValue
when appropriate
2022-08-28 20:26:37 -07:00
Jeff Niu
5e0c3b4309 [mlir][LLVMIR] Clean up the definitions of ReturnOp/CallOp 2022-08-11 00:35:02 -04:00
Jeff Niu
0af643f3ce [mlir][LLVMIR] (NFC) Add convenience builders for ConstantOp
And clean up some of the user code
2022-08-09 15:34:36 -04:00
Krzysztof Drewniak
c2fc8d9b95 [mlir][GPU] Allow bare pointer memrefs when calling GPU kernels
In the ROCm runtime (and probably CUDA as well), all kernel arguments
are aligned. Therefore, enable using bare pointers for memref
arguments to kernels when these memrefs have static shape and a
trivial layout.

This is a substantial optimization to launching kernels that use
memrefs with known, static sizes, since it causes the kernel launch
packet to no longer include information already known to the kernel,
which can enable packing the kernel launch arguments into launch
packets instead of having to allocate an entire separate structure to
hold unneeded memref information.

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D130716
2022-08-02 20:58:34 +00:00
Markus Böck
bd7eff1f2a [mlir][flang] Make use of the new GEPArg builder of GEP Op to simplify code
This is the follow up on https://reviews.llvm.org/D130730 which goes through upstream code and removes creating constant values in favour of using the constant indices in GEP directly. This leads to less and more readable code and more compact IR as well.

Differential Revision: https://reviews.llvm.org/D130731
2022-08-01 17:22:55 +02:00
Jeff Niu
b7f93c2809 [mlir] (NFC) run clang-format on all files 2022-07-14 13:32:13 -07:00
Mogball
e16d13322b [mlir] (NFC) Clean up bazel and CMake target names
All dialect targets in bazel have been named *Dialect and all dialect
targets in CMake have been named MLIR*Dialect.
2022-06-13 16:24:15 +00:00
Mogball
d7ef488bb6 [mlir][gpu] Move GPU headers into IR/ and Transforms/
Depends on D127350

Reviewed By: rriddle

Differential Revision: https://reviews.llvm.org/D127352
2022-06-09 22:49:03 +00:00
Alexander Batashev
0252357b3e [mlir][LLVM] Add support for Calling Convention in LLVMFuncOp
This patch adds support for Calling Convention attribute in LLVM
dialect, including enums, custom syntax and import from LLVM IR.
Additionally fix import of dso_local attribute.

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D126161
2022-05-27 09:43:31 +03:00
River Riddle
4a3460a791 [mlir:FunctionOpInterface] Rename the "type" attribute to "function_type"
This removes any potential confusion with the `getType` accessors
which correspond to SSA results of an operation, and makes it
clear what the intent is (i.e. to represent the type of the function).

Differential Revision: https://reviews.llvm.org/D121762
2022-03-16 17:07:04 -07:00
River Riddle
5a7b919409 [mlir][NFC] Rename StandardToLLVM to FuncToLLVM
The current StandardToLLVM conversion patterns only really handle
the Func dialect. The pass itself adds patterns for Arithmetic/CFToLLVM, but
those should be/will be split out in a followup. This commit focuses solely
on being an NFC rename.

Aside from the directory change, the pattern and pass creation API have been renamed:
 * populateStdToLLVMFuncOpConversionPattern -> populateFuncToLLVMFuncOpConversionPattern
 * populateStdToLLVMConversionPatterns -> populateFuncToLLVMConversionPatterns
 * createLowerToLLVMPass -> createConvertFuncToLLVMPass

Differential Revision: https://reviews.llvm.org/D120778
2022-03-07 11:25:23 -08:00
River Riddle
1f971e23f0 [mlir] Trim a huge number of unnecessary dependencies on the Func dialect
The Func has a large number of legacy dependencies carried over from the old
Standard dialect, which was pervasive and contained a large number of varied
operations. With the split of the standard dialect and its demise, a lot of lingering
dead dependencies have survived to the Func dialect. This commit removes a
large majority of then, greatly reducing the dependence surface area of the
Func dialect.
2022-03-01 12:10:04 -08:00
River Riddle
23aa5a7446 [mlir] Rename the Standard dialect to the Func dialect
The last remaining operations in the standard dialect all revolve around
FuncOp/function related constructs. This patch simply handles the initial
renaming (which by itself is already huge), but there are a large number
of cleanups unlocked/necessary afterwards:

* Removing a bunch of unnecessary dependencies on Func
* Cleaning up the From/ToStandard conversion passes
* Preparing for the move of FuncOp to the Func dialect

See the discussion at https://discourse.llvm.org/t/standard-dialect-the-final-chapter/6061

Differential Revision: https://reviews.llvm.org/D120624
2022-03-01 12:10:04 -08:00
Krzysztof Drewniak
84718d37db [MLIR][GPU] Add gpu.set_default_device op
This op is added to allow MLIR code running on multi-GPU systems to
select the GPU they want to execute operations on when no GPU is
otherwise specified.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D119883
2022-02-17 21:30:09 +00:00
River Riddle
330838eb90 [mlir] Fix GpuToLLVM conversion pass after ControlFlow operations were split from Standard 2022-02-06 15:10:03 -08:00
River Riddle
9f85c198db [mlir] Finish replacing OwningRewritePatternList with RewritePatternSet
OwningRewritePatternList has been deprecated for ~10 months now, we can remove
the leftover using directives at this point.

Differential Revision: https://reviews.llvm.org/D118287
2022-01-26 23:11:02 -08:00
River Riddle
7ceffae18c [mlir] Convert OpTrait::FunctionLike to FunctionOpInterface
This commit refactors the FunctionLike trait into an interface (FunctionOpInterface).
FunctionLike as it is today is already a pseudo-interface, with many users checking the
presence of the trait and then manually into functionality implemented in the
function_like_impl namespace. By transitioning to an interface, these accesses are much
cleaner (ideally with no direct calls to the impl namespace outside of the implementation
of the derived function operations, e.g. for parsing/printing utilities).

I've tried to maintain as much compatability with the current state as possible, while
also trying to clean up as much of the cruft as possible. The general migration plan for
current users of FunctionLike is as follows:

* function_like_impl -> function_interface_impl
Realistically most user calls should remove references to functions within this namespace
outside of a vary narrow set (e.g. parsing/printing utilities). Calls to the attribute name
accessors should be migrated to the `FunctionOpInterface::` equivalent, most everything
else should be updated to be driven through an instance of the interface.

* OpTrait::FunctionLike -> FunctionOpInterface
`hasTrait` checks will need to be moved to isa, along with the other various Trait vs
Interface API differences.

* populateFunctionLikeTypeConversionPattern -> populateFunctionOpInterfaceTypeConversionPattern

Fixes #52917

Differential Revision: https://reviews.llvm.org/D117272
2022-01-18 20:56:53 -08:00
Mogball
aae5125550 [mlir] Replace StrEnumAttr -> EnumAttr in core dialects
Removes uses of `StrEnumAttr` in core dialects

Reviewed By: mehdi_amini, rriddle

Differential Revision: https://reviews.llvm.org/D117514
2022-01-18 17:15:00 +00:00
Mehdi Amini
cac7aabbd8 Apply clang-tidy fixes for readability-identifier-naming to MLIR (NFC) 2022-01-14 02:26:28 +00:00
Alex Zinenko
cafaa35036 [mlir] Make it possible to directly supply constant values to LLVM GEPOp
In LLVM IR, the GEP indices that correspond to structures are required to be
i32 constants. MLIR models constants as just values defined by special
operations, and there is no verification that it is the case for structure
indices in GEP. Furthermore, some common transformations such as control flow
simplification may lead to the operands becoming non-constant. Make it possible
to directly supply constant values to LLVM GEPOp to guarantee they remain
constant until the translation to LLVM IR. This is not yet a requirement and
the verifier is not modified, this will be introduced separately.

Reviewed By: wsmoses

Differential Revision: https://reviews.llvm.org/D116757
2022-01-07 09:56:01 +01:00
Mehdi Amini
564bcf9d02 Align adaptor's generator accessors for attribute on the Op class
Each attribute has two accessor: one suffixed with `Attr` which returns the attribute itself
and one without the suffix which unwrap the attribute.
For example for a StringAttr attribute with a field named `kind`, we'll generate:

StringAttr getKindAttr();
StringRef getKind();

Differential Revision: https://reviews.llvm.org/D116466
2022-01-05 05:42:15 +00:00
Mehdi Amini
e4853be2f1 Apply clang-tidy fixes for performance-for-range-copy to MLIR (NFC) 2022-01-02 22:19:56 +00:00
Mehdi Amini
79a0330a52 Fix crash from use of a temporary after its scope exit
Introduced in D110448 and broke some bots (reported by ASAN).

Differential Revision: https://reviews.llvm.org/D110448
2021-12-10 05:04:23 +00:00
Krzysztof Drewniak
e1da62910e [MLIR][GPU] Define gpu.printf op and its lowerings
- Define a gpu.printf op, which can be lowered to any GPU printf() support (which is present in CUDA, HIP, and OpenCL). This op only supports constant format strings and scalar arguments
- Define the lowering of gpu.pirntf to a call to printf() (which is what is required for AMD GPUs when using OpenCL) as well as to the hostcall interface present in the AMD Open Compute device library, which is the interface present when kernels are running under HIP.
- Add a "runtime" enum that allows specifying which of the possible runtimes a ROCDL kernel will be executed under or that the runtime is unknown. This enum controls how gpu.printf is lowered

This change does not enable lowering for Nvidia GPUs, but such a lowering should be possible in principle.

And:
[MLIR][AMDGPU] Always set amdgpu-implicitarg-num-bytes=56 on kernels

This is something that Clang always sets on both OpenCL and HIP kernels, and failing to include it causes mysterious crashes with printf() support.

In addition, revert the max-flat-work-group-size to (1, 256) to avoid triggering bugs in the AMDGPU backend.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D110448
2021-12-09 15:54:31 +00:00
River Riddle
0c7890c844 [mlir] Convert NamedAttribute to be a class
NamedAttribute is currently represented as an std::pair, but this
creates an extremely clunky .first/.second API. This commit
converts it to a class, with better accessors (getName/getValue)
and also opens the door for more convenient API in the future.

Differential Revision: https://reviews.llvm.org/D113956
2021-11-18 05:39:29 +00:00
River Riddle
195730a650 [mlir][NFC] Replace references to Identifier with StringAttr
This is part of the replacement of Identifier with StringAttr.

Differential Revision: https://reviews.llvm.org/D113953
2021-11-16 17:36:26 +00:00
Jacques Pienaar
cfb72fd3a0 [mlir] Switch arith, llvm, std & shape dialects to accessors prefixed both form.
Following
https://llvm.discourse.group/t/psa-ods-generated-accessors-will-change-to-have-a-get-prefix-update-you-apis/4476,
this follows flipping these dialects to _Both prefixed form. This
changes the accessors to have a prefix. This was possibly mostly without
breaking breaking changes if the existing convenience methods were used.

(https://github.com/jpienaar/llvm-project/blob/main/clang-tools-extra/clang-tidy/misc/AddGetterCheck.cpp
was used to migrate the callers post flipping, using the output from
Operator.cpp)

Differential Revision: https://reviews.llvm.org/D112383
2021-10-24 18:36:33 -07:00
Mogball
a54f4eae0e [MLIR] Replace std ops with arith dialect ops
Precursor: https://reviews.llvm.org/D110200

Removed redundant ops from the standard dialect that were moved to the
`arith` or `math` dialects.

Renamed all instances of operations in the codebase and in tests.

Reviewed By: rriddle, jpienaar

Differential Revision: https://reviews.llvm.org/D110797
2021-10-13 03:07:03 +00:00
Uday Bondhugula
08b63db8bb [MLIR][GPU] Add GPU launch op support for dynamic shared memory
Add support for dynamic shared memory for GPU launch ops: add an
optional operand to gpu.launch and gpu.launch_func ops to specify the
amount of "dynamic" shared memory to use. Update lowerings to connect
this operand to the GPU runtime.

Differential Revision: https://reviews.llvm.org/D110800
2021-10-01 16:46:07 +05:30
River Riddle
ef976337f5 [mlir:OpConversion] Remove the remaing usages of the deprecated matchAndRewrite methods
This commits updates the remaining usages of the ArrayRef<Value> based
matchAndRewrite/rewrite methods in favor of the new OpAdaptor
overload.

Differential Revision: https://reviews.llvm.org/D110360
2021-09-24 17:51:41 +00:00
Alex Zinenko
8b58ab8ccd [mlir] Factor type reconciliation out of Standard-to-LLVM conversion
Conversion to the LLVM dialect is being refactored to be more progressive and
is now performed as a series of independent passes converting different
dialects. These passes may produce `unrealized_conversion_cast` operations that
represent pending conversions between built-in and LLVM dialect types.
Historically, a more monolithic Standard-to-LLVM conversion pass did not need
these casts as all operations were converted in one shot. Previous refactorings
have led to the requirement of running the Standard-to-LLVM conversion pass to
clean up `unrealized_conversion_cast`s even though the IR had no standard
operations in it. The pass must have been also run the last among all to-LLVM
passes, in contradiction with the partial conversion logic. Additionally, the
way it was set up could produce invalid operations by removing casts between
LLVM and built-in types even when the consumer did not accept the uncasted
type, or could lead to cryptic conversion errors (recursive application of the
rewrite pattern on `unrealized_conversion_cast` as a means to indicate failure
to eliminate casts).

In fact, the need to eliminate A->B->A `unrealized_conversion_cast`s is not
specific to to-LLVM conversions and can be factored out into a separate type
reconciliation pass, which is achieved in this commit. While the cast operation
itself has a folder pattern, it is insufficient in most conversion passes as
the folder only applies to the second cast. Without complex legality setup in
the conversion target, the conversion infra will either consider the cast
operations valid and not fold them (a separate canonicalization would be
necessary to trigger the folding), or consider the first cast invalid upon
generation and stop with error. The pattern provided by the reconciliation pass
applies to the first cast operation instead. Furthermore, having a separate
pass makes it clear when `unrealized_conversion_cast`s could not have been
eliminated since it is the only reason why this pass can fail.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D109507
2021-09-09 16:51:24 +02:00
Alex Zinenko
821262eef2 [mlir] Fix GPU LaunchFunc conversion to the LLVM dialect
The conversion has been incorrectly using the operands of the original
operation instead of the converted operands provided to the matchAndRewrite
call. This may lead to spurious materializations and generally invalid IR if
the producer of the original operands is deleted in the process of conversion.

Reviewed By: csigg

Differential Revision: https://reviews.llvm.org/D109356
2021-09-07 16:50:11 +02:00
Loren Maggiore
361458b1ce [mlir] create gpu memset op
Create a gpu memset op and corresponding CUDA and ROCm wrappers.

Reviewed By: herhut, lorenrose1013

Differential Revision: https://reviews.llvm.org/D107548
2021-09-04 08:13:04 +02:00
Chris Lattner
faf1c22408 [Builder] Eliminate the StringRef/StringAttr forms of getSymbolRefAttr.
The StringAttr version doesn't need a context, so we can just use the
existing `SymbolRefAttr::get` form.  The StringRef version isn't preferred
so we want to encourage people to use StringAttr.

There is an additional form of getSymbolRefAttr that takes a (SymbolTrait
implementing) operation.  This should also be moved, but I'll do that as
a separate patch.

Differential Revision: https://reviews.llvm.org/D108922
2021-08-30 16:05:36 -07:00
Chris Lattner
41d4aa7de6 [SymbolRefAttr] Revise SymbolRefAttr to hold a StringAttr.
SymbolRefAttr is fundamentally a base string plus a sequence
of nested references.  Instead of storing the string data as
a copies StringRef, store it as an already-uniqued StringAttr.

This makes a lot of things simpler and more efficient because:
1) references to the symbol are already stored as StringAttr's:
   there is no need to copy the string data into MLIRContext
   multiple times.
2) This allows pointer comparisons instead of string
   comparisons (or redundant uniquing) within SymbolTable.cpp.
3) This allows SymbolTable to hold a DenseMap instead of a
   StringMap (which again copies the string data and slows
   lookup).

This is a moderately invasive patch, so I kept a lot of
compatibility APIs around.  It would be nice to explore changing
getName() to return a StringAttr for example (right now you have
to use getNameAttr()), and eliminate things like the StringRef
version of getSymbol.

Differential Revision: https://reviews.llvm.org/D108899
2021-08-29 21:54:47 -07:00