This patch adds the `ConvertToLLVMAttrInterface` and
`ConvertToLLVMOpInterface` interfaces. It also modifies the
`convert-to-llvm` pass to use these interfaces when available.
The `ConvertToLLVMAttrInterface` interfaces allows attributes to
configure conversion to LLVM, including the conversion target, LLVM type
converter, and populating conversion patterns. See the `NVVMTargetAttr`
implementation of this interface for an example of how this interface
can be used to configure conversion to LLVM.
The `ConvertToLLVMOpInterface` interface collects all convert to LLVM
attributes stored in an operation.
Finally, the `convert-to-llvm` pass was modified to use these interfaces
when available. This allows applying `convert-to-llvm` to GPU modules
and letting the `NVVMTargetAttr` decide which patterns to populate.
Most `*-to-llvm` conversion patterns require a type converter. This
revision adds a type converter to the
`populateConvertToLLVMConversionPatterns` function and implements the
interface for the MemRef dialect.
Differential Revision: https://reviews.llvm.org/D157387
The multiple -convert-XXX-to-llvm passes are really nice testing tools for
individual dialects, but the expectation is that a proper conversion should
assemble the conversion patterns using `populateXXXToLLVMConversionPatterns()
APIs. However most customers just chain the conversion passes by convenience.
This pass makes it composable more transparently to assemble the required
patterns for conversion to LLVM dialect by using an interface.
The Pass will scan the input and collect all the dialect present, and for
those who implement the `ConvertToLLVMPatternInterface` it will use it to
populate the conversion pattern, and possible the conversion target.
Since these conversions can involve intermediate dialects, or target other
dialects than LLVM (for example AVX or NVVM), this pass can't statically
declare the required `getDependentDialects()` before the pass pipeline
begins. This is worked around by using an extension in the dialectRegistry
that will be invoked for every new loaded dialects in the context. This
allows to lookup the interface ahead of time and use it to query the
dependent dialects.
Differential Revision: https://reviews.llvm.org/D157183
