[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

4 files changed, 119 insertions, 0 deletions

diff --git a/mlir/test/Dialect/CMakeLists.txt b/mlir/test/Dialect/CMakeLists.txt
new file mode 100644
index 00000000000..cc1766c6127
--- /dev/null
+++ b/mlir/test/Dialect/CMakeLists.txt
@@ -0,0 +1 @@
+add_subdirectory(SPIRV)
diff --git a/mlir/test/Dialect/SPIRV/CMakeLists.txt b/mlir/test/Dialect/SPIRV/CMakeLists.txt
new file mode 100644
index 00000000000..25ea9625ae8
--- /dev/null
+++ b/mlir/test/Dialect/SPIRV/CMakeLists.txt
@@ -0,0 +1,14 @@
+add_llvm_library(MLIRSPIRVTestPasses
+  TestAvailability.cpp
+
+  ADDITIONAL_HEADER_DIRS
+  ${MLIR_MAIN_INCLUDE_DIR}/mlir/Dialect/SPIRV
+  ${MLIR_MAIN_INCLUDE_DIR}/mlir/IR
+  )
+
+target_link_libraries(MLIRSPIRVTestPasses
+  MLIRIR
+  MLIRPass
+  MLIRSPIRV
+  MLIRSupport
+  )
diff --git a/mlir/test/Dialect/SPIRV/TestAvailability.cpp b/mlir/test/Dialect/SPIRV/TestAvailability.cpp
new file mode 100644
index 00000000000..bb164215995
--- /dev/null
+++ b/mlir/test/Dialect/SPIRV/TestAvailability.cpp
@@ -0,0 +1,73 @@
+//===- TestAvailability.cpp - Pass to test SPIR-V op availability ---------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/SPIRV/SPIRVOps.h"
+#include "mlir/Dialect/SPIRV/SPIRVTypes.h"
+#include "mlir/IR/Function.h"
+#include "mlir/Pass/Pass.h"
+
+using namespace mlir;
+
+namespace {
+/// A pass for testing SPIR-V op availability.
+struct TestAvailability : public FunctionPass<TestAvailability> {
+  void runOnFunction() override;
+};
+} // end anonymous namespace
+
+void TestAvailability::runOnFunction() {
+  auto f = getFunction();
+  llvm::outs() << f.getName() << "\n";
+
+  Dialect *spvDialect = getContext().getRegisteredDialect("spv");
+
+  f.getOperation()->walk([&](Operation *op) {
+    if (op->getDialect() != spvDialect)
+      return WalkResult::advance();
+
+    auto &os = llvm::outs();
+
+    if (auto minVersion = dyn_cast<spirv::QueryMinVersionInterface>(op))
+      os << " min version: "
+         << spirv::stringifyVersion(minVersion.getMinVersion()) << "\n";
+
+    if (auto maxVersion = dyn_cast<spirv::QueryMaxVersionInterface>(op))
+      os << " max version: "
+         << spirv::stringifyVersion(maxVersion.getMaxVersion()) << "\n";
+
+    if (auto extension = dyn_cast<spirv::QueryExtensionInterface>(op)) {
+      os << " extensions: [";
+      for (const auto &exts : extension.getExtensions()) {
+        os << " [";
+        interleaveComma(exts, os, [&](spirv::Extension ext) {
+          os << spirv::stringifyExtension(ext);
+        });
+        os << "]";
+      }
+      os << " ]\n";
+    }
+
+    if (auto capability = dyn_cast<spirv::QueryCapabilityInterface>(op)) {
+      os << " capabilities: [";
+      for (const auto &caps : capability.getCapabilities()) {
+        os << " [";
+        interleaveComma(caps, os, [&](spirv::Capability cap) {
+          os << spirv::stringifyCapability(cap);
+        });
+        os << "]";
+      }
+      os << " ]\n";
+    }
+    os.flush();
+
+    return WalkResult::advance();
+  });
+}
+
+static PassRegistration<TestAvailability> pass("test-spirv-op-availability",
+                                               "Test SPIR-V op availability");
diff --git a/mlir/test/Dialect/SPIRV/availability.mlir b/mlir/test/Dialect/SPIRV/availability.mlir
new file mode 100644
index 00000000000..ed4d29cc51d
--- /dev/null
+++ b/mlir/test/Dialect/SPIRV/availability.mlir
@@ -0,0 +1,31 @@
+// RUN: mlir-opt -disable-pass-threading -test-spirv-op-availability %s | FileCheck %s
+
+// CHECK-LABEL: iadd
+func @iadd(%arg: i32) -> i32 {
+  // CHECK: min version: V_1_0
+  // CHECK: max version: V_1_5
+  // CHECK: extensions: [ ]
+  // CHECK: capabilities: [ ]
+  %0 = spv.IAdd %arg, %arg: i32
+  return %0: i32
+}
+
+// CHECK: atomic_compare_exchange_weak
+func @atomic_compare_exchange_weak(%ptr: !spv.ptr<i32, Workgroup>, %value: i32, %comparator: i32) -> i32 {
+  // CHECK: min version: V_1_0
+  // CHECK: max version: V_1_3
+  // CHECK: extensions: [ ]
+  // CHECK: capabilities: [ [Kernel] ]
+  %0 = spv.AtomicCompareExchangeWeak "Workgroup" "Release" "Acquire" %ptr, %value, %comparator: !spv.ptr<i32, Workgroup>
+  return %0: i32
+}
+
+// CHECK-LABEL: subgroup_ballot
+func @subgroup_ballot(%predicate: i1) -> vector<4xi32> {
+  // CHECK: min version: V_1_3
+  // CHECK: max version: V_1_5
+  // CHECK: extensions: [ ]
+  // CHECK: capabilities: [ [GroupNonUniformBallot] ]
+  %0 = spv.GroupNonUniformBallot "Workgroup" %predicate : vector<4xi32>
+  return %0: vector<4xi32>
+}