Commit Graph

29 Commits

Author SHA1 Message Date
Christian Sigg bafe418d12 [mlir] Change test-gpu-to-cubin to derive from SerializeToBlobPass
Clean-up after D98279, remove one call to createConvertGPUKernelToBlobPass().

Depends On D98203

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D98360
2021-03-11 10:42:20 +01:00
Alex Zinenko dd5165a920 [mlir] replace LLVM dialect float types with built-ins
Continue the convergence between LLVM dialect and built-in types by replacing
the bfloat, half, float and double LLVM dialect types with their built-in
counterparts. At the API level, this is a direct replacement. At the syntax
level, we change the keywords to `bf16`, `f16`, `f32` and `f64`, respectively,
to be compatible with the built-in type syntax. The old keywords can still be
parsed but produce a deprecation warning and will be eventually removed.

Depends On D94178

Reviewed By: mehdi_amini, silvas, antiagainst

Differential Revision: https://reviews.llvm.org/D94179
2021-01-08 17:38:12 +01:00
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
Wen-Heng (Jack) Chung 2cbbc266ec [mlir][gpu] Refactor ConvertGpuLaunchFuncToCudaCalls pass.
Due to similar APIs between CUDA and ROCm (HIP),
ConvertGpuLaunchFuncToCudaCalls pass could be used on both platforms with some
refactoring.

In this commit:

- Migrate ConvertLaunchFuncToCudaCalls from GPUToCUDA to GPUCommon, and rename.
- Rename runtime wrapper APIs be platform-neutral.
- Let GPU binary annotation attribute be specifiable as a PassOption.
- Naming changes within the implementation and tests.

Subsequent patches would introduce ROCm-specific tests and runtime wrapper
APIs.

Differential Revision: https://reviews.llvm.org/D80167
2020-05-21 08:53:47 -05:00
Mehdi Amini 5c3ebd7725 Revert "[mlir][gpu] Refactor ConvertGpuLaunchFuncToCudaCalls pass."
This reverts commit cdb6f05e2d.

The build is broken with:

  You have called ADD_LIBRARY for library obj.MLIRGPUtoCUDATransforms without any source files. This typically indicates a problem with your CMakeLists.txt file
2020-05-21 03:44:35 +00:00
Wen-Heng (Jack) Chung cdb6f05e2d [mlir][gpu] Refactor ConvertGpuLaunchFuncToCudaCalls pass.
Due to similar APIs between CUDA and ROCm (HIP),
ConvertGpuLaunchFuncToCudaCalls pass could be used on both platforms with some
refactoring.

In this commit:

- Migrate ConvertLaunchFuncToCudaCalls from GPUToCUDA to GPUCommon, and rename.
- Rename runtime wrapper APIs be platform-neutral.
- Let GPU binary annotation attribute be specifiable as a PassOption.
- Naming changes within the implementation and tests.

Subsequent patches would introduce ROCm-specific tests and runtime wrapper
APIs.

Differential Revision: https://reviews.llvm.org/D80167
2020-05-20 16:11:48 -05:00
Frederik Gossen 0372db05bb [MLIR] Use nested symbol to identify kernel in `LaunchFuncOp`.
Summary:
Use a nested symbol to identify the kernel to be invoked by a `LaunchFuncOp` in the GPU dialect.
This replaces the two attributes that were used to identify the kernel module and the kernel within seperately.

Differential Revision: https://reviews.llvm.org/D78551
2020-04-22 07:44:29 +00:00
Mehdi Amini bab5bcf8fd Add a flag on the context to protect against creation of operations in unregistered dialects
Differential Revision: https://reviews.llvm.org/D76903
2020-03-30 19:37:31 +00:00
Alex Zinenko 5a1778057f [mlir] use unpacked memref descriptors at function boundaries
The existing (default) calling convention for memrefs in standard-to-LLVM
conversion was motivated by interfacing with LLVM IR produced from C sources.
In particular, it passes a pointer to the memref descriptor structure when
calling the function. Therefore, the descriptor is allocated on stack before
the call. This convention leads to several problems. PR44644 indicates a
problem with stack exhaustion when calling functions with memref-typed
arguments in a loop. Allocating outside of the loop may lead to concurrent
access problems in case the loop is parallel. When targeting GPUs, the contents
of the stack-allocated memory for the descriptor (passed by pointer) needs to
be explicitly copied to the device. Using an aggregate type makes it impossible
to attach pointer-specific argument attributes pertaining to alignment and
aliasing in the LLVM dialect.

Change the default calling convention for memrefs in standard-to-LLVM
conversion to transform a memref into a list of arguments, each of primitive
type, that are comprised in the memref descriptor. This avoids stack allocation
for ranked memrefs (and thus stack exhaustion and potential concurrent access
problems) and simplifies the device function invocation on GPUs.

Provide an option in the standard-to-LLVM conversion to generate auxiliary
wrapper function with the same interface as the previous calling convention,
compatible with LLVM IR porduced from C sources. These auxiliary functions
pack the individual values into a descriptor structure or unpack it. They also
handle descriptor stack allocation if necessary, serving as an allocation
scope: the memory reserved by `alloca` will be freed on exiting the auxiliary
function.

The effect of this change on MLIR-generated only LLVM IR is minimal. When
interfacing MLIR-generated LLVM IR with C-generated LLVM IR, the integration
only needs to require auxiliary functions and change the function name to call
the wrapper function instead of the original function.

This also opens the door to forwarding aliasing and alignment information from
memrefs to LLVM IR pointers in the standrd-to-LLVM conversion.
2020-02-10 15:03:43 +01:00
Tres Popp 9a52ea5cf9 Create a gpu.module operation for the GPU Dialect.
Summary:
This is based on the use of code constantly checking for an attribute on
a model and instead represents the distinct operaion with a different
op. Instead, this op can be used to provide better filtering.

Reverts "Revert "[mlir] Create a gpu.module operation for the GPU Dialect.""

This reverts commit ac446302ca4145cdc89f377c0c364c29ee303be5 after
fixing internal Google issues.

This additionally updates ROCDL lowering to use the new gpu.module.

Reviewers: herhut, mravishankar, antiagainst, nicolasvasilache

Subscribers: jholewinski, mgorny, mehdi_amini, jpienaar, burmako, shauheen, csigg, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, llvm-commits, mravishankar, rriddle, antiagainst, bkramer

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72921
2020-01-21 14:05:03 +01:00
Benjamin Kramer 0133cc60e4 Revert "[mlir] Create a gpu.module operation for the GPU Dialect."
This reverts commit 4624a1e8ac. Causing
problems downstream.
2020-01-15 17:52:17 +01:00
Tres Popp 4624a1e8ac [mlir] Create a gpu.module operation for the GPU Dialect.
Summary:
This is based on the use of code constantly checking for an attribute on
a model and instead represents the distinct operaion with a different
op. Instead, this op can be used to provide better filtering.

Reviewers: herhut, mravishankar, antiagainst, rriddle

Reviewed By: herhut, antiagainst, rriddle

Subscribers: liufengdb, aartbik, jholewinski, mgorny, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, csigg, arpith-jacob, mgester, lucyrfox, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72336
2020-01-14 12:05:47 +01:00
Alex Zinenko 6273fa0c6a Plug gpu.func into the GPU lowering pipelines
This updates the lowering pipelines from the GPU dialect to lower-level
dialects (NVVM, SPIRV) to use the recently introduced gpu.func operation
instead of a standard function annotated with an attribute. In particular, the
kernel outlining is updated to produce gpu.func instead of std.func and the
individual conversions are updated to consume gpu.funcs and disallow standard
funcs after legalization, if necessary. The attribute "gpu.kernel" is preserved
in the generic syntax, but can also be used with the custom syntax on
gpu.funcs. The special kind of function for GPU allows one to use additional
features such as memory attribution.

PiperOrigin-RevId: 285822272
2019-12-16 12:12:48 -08:00
Alex Zinenko d5e627f84b Introduce Linkage attribute to the LLVM dialect
LLVM IR supports linkage on global objects such as global variables and
functions. Introduce the Linkage attribute into the LLVM dialect, backed by an
integer storage. Use this attribute on LLVM::GlobalOp and make it mandatory.
Implement parsing/printing of the attribute and conversion to LLVM IR.

See tensorflow/mlir#277.

PiperOrigin-RevId: 283309328
2019-12-02 03:28:10 -08:00
Alex Zinenko 5f867d26b4 Use LLVM_Type instead of AnyType in the definition of LLVM_CallOp
The type constraint had to be relaxed due to the order of lowering passes in
the examples, that since has been fixed. The relaxed version was still used by
the CUDA lowering for launch sizes of `index` type. This is not necessary since
the GPU dialect does not restrict the type of the launch size operands. Use an
LLVM type instead and restore the check in the LLVM_CallOp definition.

PiperOrigin-RevId: 275920109
2019-10-21 14:12:19 -07:00
Alex Zinenko 5e7959a353 Use llvm.func to define functions with wrapped LLVM IR function type
This function-like operation allows one to define functions that have wrapped
LLVM IR function type, in particular variadic functions. The operation was
added in parallel to the existing lowering flow, this commit only switches the
flow to use it.

Using a custom function type makes the LLVM IR dialect type system more
consistent and avoids complex conversion rules for functions that previously
had to use the built-in function type instead of a wrapped LLVM IR dialect type
and perform conversions during the analysis.

PiperOrigin-RevId: 273910855
2019-10-10 01:34:06 -07:00
Alex Zinenko 11d12670da GPUToCUDA: attach CUBIN to the nested module rather than to the function
Originally, we were attaching attributes containing CUBIN blobs to the kernel
function called by `gpu.launch_func`. This kernel is now contained in a nested
module that is used as a compilation unit. Attach compiled CUBIN blobs to the
module rather than to the function since we were compiling the module. This
also avoids duplication of the attribute on multiple kernels within the same
module.

PiperOrigin-RevId: 273497303
2019-10-08 05:11:26 -07:00
Alex Zinenko 52e082b6ed GPUToCUDA: emit addressof directly instead of wrapping it into a getter function
Originally, the CUBIN getter function was introduced as a mechanism to
circumvent the absence of globals in the LLVM dialect. It would allocate memory
and populate it with the CUBIN data. LLVM dialect now supports globals and they
are already used to store CUBIN data, making the getter function a trivial
address computation of a global. Emit the address computation directly at the
place of `gpu.launch_func` instead of putting it in a function and calling it.
This simplifies the conversion flow and prepares it for using the
DialectConversion infrastructure.

PiperOrigin-RevId: 273496221
2019-10-08 05:03:42 -07:00
Alex Zinenko 16af5924cb Fuse GenerateCubinAccessors pass into LaunchFunctToCuda
Now that the accessor function is a trivial getter of the global variable, it
makes less sense to have the getter generation as a separate pass. Move the
getter generation into the lowering of `gpu.launch_func` to CUDA calls. This
change is mostly code motion, but the process can be simplified further by
generating the addressof inplace instead of using a call. This is will be done
in a follow-up.

PiperOrigin-RevId: 273492517
2019-10-08 04:35:33 -07:00
Alex Zinenko 90d65d32d6 Use named modules for gpu.launch_func
The kernel function called by gpu.launch_func is now placed into an isolated
nested module during the outlining stage to simplify separate compilation.
Until recently, modules did not have names and could not be referenced. This
limitation was circumvented by introducing a stub kernel at the same name at
the same nesting level as the module containing the actual kernel. This
relation is only effective in one direction: from actual kernel function to its
launch_func "caller".

Leverage the recently introduced symbol name attributes on modules to refer to
a specific nested module from `gpu.launch_func`. This removes the implicit
connection between the identically named stub and kernel functions. It also
enables support for `gpu.launch_func`s to call different kernels located in the
same module.

PiperOrigin-RevId: 273491891
2019-10-08 04:30:32 -07:00
Christian Sigg b8676da1fc Outline GPU kernel function into a nested module.
Roll forward of commit 5684a12.

When outlining GPU kernels, put the kernel function inside a nested module. Then use a nested pipeline to generate the cubins, independently per kernel. In a final pass, move the cubins back to the parent module.

PiperOrigin-RevId: 270639748
2019-09-23 03:17:01 -07:00
George Karpenkov 2df646bef6 Automated rollback of commit 5684a12434
PiperOrigin-RevId: 270126672
2019-09-19 14:34:30 -07:00
MLIR Team 5684a12434 Outline GPU kernel function into a nested module.
When outlining GPU kernels, put the kernel function inside a nested module. Then use a nested pipeline to generate the cubins, independently per kernel. In a final pass, move the cubins back to the parent module.

PiperOrigin-RevId: 269987720
2019-09-19 01:51:28 -07:00
Alex Zinenko c335d9d313 LLVM dialect: prefix auxiliary operations with "mlir."
Some of the operations in the LLVM dialect are required to model the LLVM IR in
MLIR, for example "constant" operations are needed to declare a constant value
since MLIR, unlike LLVM, does not support immediate values as operands.  To
avoid confusion with actual LLVM operations, we prefix such axuiliary
operations with "mlir.".

PiperOrigin-RevId: 266942838
2019-09-03 09:10:56 -07:00
Alex Zinenko 006fcce44a ConvertLaunchFuncToCudaCalls: use LLVM dialect globals
This conversion has been using a stack-allocated array of i8 to store the
null-terminated kernel name in order to pass it to the CUDA wrappers expecting
a C string because the LLVM dialect was missing support for globals.  Now that
the suport is introduced, use a global instead.

Refactor global string construction from GenerateCubinAccessors into a common
utility function living in the LLVM namespace.

PiperOrigin-RevId: 264382489
2019-08-20 07:52:01 -07:00
Alex Zinenko 88de8b2a2b GenerateCubinAccessors: use LLVM dialect constants
The GenerateCubinAccessors was generating functions that fill
dynamically-allocated memory with the binary constant of a CUBIN attached as a
stirng attribute to the GPU kernel.  This approach was taken to circumvent the
missing support for global constants in the LLVM dialect (and MLIR in general).
Global constants were recently added to the LLVM dialect.  Change the
GenerateCubinAccessors pass to emit a global constant array of characters and a
function that returns a pointer to the first character in the array.

PiperOrigin-RevId: 263092052
2019-08-13 01:39:21 -07:00
Stephan Herhut e8b21a75f8 Add an mlir-cuda-runner tool.
This tool allows to execute MLIR IR snippets written in the GPU dialect
on a CUDA capable GPU. For this to work, a working CUDA install is required
and the build has to be configured with MLIR_CUDA_RUNNER_ENABLED set to 1.

PiperOrigin-RevId: 256551415
2019-07-04 07:53:54 -07:00
Stephan Herhut 630119f84f Add a pass that inserts getters for all cubins found via nvvm.cubin
annotations.

Getters are required as there are currently no global constants in MLIR and this
is an easy way to unblock CUDA execution while waiting for those.

PiperOrigin-RevId: 255169002
2019-06-26 05:33:11 -07:00
Stephan Herhut c72c6c3907 Make GPU to CUDA transformations independent of CUDA runtime.
The actual transformation from PTX source to a CUDA binary is now factored out,
enabling compiling and testing the transformations independently of a CUDA
runtime.

MLIR has still to be built with NVPTX target support for the conversions to be
built and tested.

PiperOrigin-RevId: 255167139
2019-06-26 05:16:37 -07:00