[mlir][spirv] Add basic definitions for supporting availability

SPIR-V has a few mechanisms to control op availability: version,
extension, and capabilities. These mechanisms are considered as
different availability classes.

This commit introduces basic definitions for modelling SPIR-V
availability classes. Specifically, an `Availability` class is
added to SPIRVBase.td, along with two subclasses: MinVersion
and MaxVersion for versioning. SPV_Op is extended to take a
list of `Availability`. Each `Availability` instance carries
information for generating op interfaces for the corresponding
availability class and also the concrete availability
requirements.

With the availability spec on ops, we can now auto-generate the
op interfaces of all SPIR-V availability classes and also
synthesize the op's implementations of these interfaces. The
interface generation is done via new TableGen backends
-gen-avail-interface-{decls|defs}. The op's implementation is
done via -gen-spirv-avail-impls.

Differential Revision: https://reviews.llvm.org/D71930

2 files changed, 9 insertions, 0 deletions

diff --git a/mlir/lib/Dialect/SPIRV/CMakeLists.txt b/mlir/lib/Dialect/SPIRV/CMakeLists.txt
index 2c3b1b95a68..d3af53e3aaa 100644
--- a/mlir/lib/Dialect/SPIRV/CMakeLists.txt
+++ b/mlir/lib/Dialect/SPIRV/CMakeLists.txt
@@ -15,6 +15,7 @@ add_llvm_library(MLIRSPIRV
   )
 
 add_dependencies(MLIRSPIRV
+  MLIRSPIRVAvailabilityIncGen
   MLIRSPIRVCanonicalizationIncGen
   MLIRSPIRVEnumsIncGen
   MLIRSPIRVLoweringStructGen
diff --git a/mlir/lib/Dialect/SPIRV/SPIRVOps.cpp b/mlir/lib/Dialect/SPIRV/SPIRVOps.cpp
index f42c077f77e..1de7bceaf23 100644
--- a/mlir/lib/Dialect/SPIRV/SPIRVOps.cpp
+++ b/mlir/lib/Dialect/SPIRV/SPIRVOps.cpp
@@ -3063,8 +3063,16 @@ static LogicalResult verify(spirv::VariableOp varOp) {
 namespace mlir {
 namespace spirv {
 
+// TableGen'erated operation interfaces for querying versions, extensions, and
+// capabilities.
+#include "mlir/Dialect/SPIRV/SPIRVAvailability.cpp.inc"
+
+// TablenGen'erated operation definitions.
 #define GET_OP_CLASSES
 #include "mlir/Dialect/SPIRV/SPIRVOps.cpp.inc"
 
+// TableGen'erated operation availability interface implementations.
+#include "mlir/Dialect/SPIRV/SPIRVOpAvailabilityImpl.inc"
+
 } // namespace spirv
 } // namespace mlir