[mlir][spirv] Add a pass to deduce version/extension/capability

[antiagainst]

Summary

Creates an operation pass that deduces and attaches the minimal version/
capabilities/extensions requirements for spv.module ops.

For each spv.module op, this pass requires a spv.target_env attribute on
it or an enclosing module-like op to drive the deduction. The reason is
that an op can be enabled by multiple extensions/capabilities. So we need
to know which one to pick. spv.target_env gives the hard limit as for
what the target environment can support; this pass deduces what are
actually needed for a specific spv.module op.

Depends On D75869

[mravishankar]

mlir/include/mlir/Dialect/SPIRV/Passes.h

37

This seems to assume that there is a "linear" order of capabilities and extensions. Is that the case?
Also, is there a way to have a "Base" limit you can start with? It can be the most lenient or the least lenient set

mlir/lib/Dialect/SPIRV/TargetAndABI.cpp

298

Nit: To me reading this as a while loop is easier, but I dont know what the convention is

[antiagainst]

Address comments

[antiagainst]

mlir/include/mlir/Dialect/SPIRV/Passes.h

37

For an op, there can exists multiple capabilities to enable it. E.g., OpGroupNonUniformIAdd can be enabled by any of [GroupNonUniformArithmetic, GroupNonUniformClustered, GroupNonUniformPartitionedNV]. It's a set (although under the hood we indeed search linearly but that's implementation detail). Any one of them allowed by the target it should be fine and we'll pick that one.

It's hard to find a more "general" or well supported one that's also a moving target given new hardware coming up and existing ones updated.

[rriddle]

mlir/lib/Dialect/SPIRV/Transforms/UpdateVCEPass.cpp

76

nit: You can return the error directly. LogicalResult converts to WalkResult, (failure -> interrupt, success -> advance).

122

nit: Move the comment before the variable.

[antiagainst]

mlir/lib/Dialect/SPIRV/Transforms/UpdateVCEPass.cpp

122

I think this way it reads more naturally.

mlir/include/mlir/Dialect/SPIRV/Passes.h

 class ModuleOp;
 /// Creates a module pass that converts composite types used by objects in the
 /// StorageBuffer, PhysicalStorageBuffer, Uniform, and PushConstant storage
 /// classes with layout information.
 /// Right now this pass only supports Vulkan layout rules.
 std::unique_ptr<OpPassBase<mlir::ModuleOp>>
 createDecorateSPIRVCompositeTypeLayoutPass();
 
-/// Creates a module pass that lowers the ABI attributes specified during SPIR-V
-/// Lowering. Specifically,
-/// 1) Creates the global variables for arguments of entry point function using
-/// the specification in the ABI attributes for each argument.
-/// 2) Inserts the EntryPointOp and the ExecutionModeOp for entry point
-/// functions using the specification in the EntryPointAttr.
+/// Creates an operation pass that deduces and attaches the minimal version/
+/// capabilities/extensions requirements for spv.module ops.
+/// For each spv.module op, this pass requires a `spv.target_env` attribute on
+/// it or an enclosing module-like op to drive the deduction. The reason is
+/// that an op can be enabled by multiple extensions/capabilities. So we need
+/// to know which one to pick. `spv.target_env` gives the hard limit as for
+/// what the target environment can support; this pass deduces what are
+/// actually needed for a specific spv.module op.
+std::unique_ptr<OpPassBase<spirv::ModuleOp>>
+createUpdateVersionCapabilityExtensionPass();
+
+/// Creates an operation pass that lowers the ABI attributes specified during
+/// SPIR-V Lowering. Specifically,
+/// 1. Creates the global variables for arguments of entry point function using
+///    the specification in the `spv.interface_var_abi` attribute for each
+///    argument.
+/// 2. Inserts the EntryPointOp and the ExecutionModeOp for entry point
+///    functions using the specification in the `spv.entry_point_abi` attribute.
 std::unique_ptr<OpPassBase<spirv::ModuleOp>> createLowerABIAttributesPass();
 
 } // namespace spirv
 } // namespace mlir
 
 #endif // MLIR_DIALECT_SPIRV_PASSES_H_

mlir/include/mlir/Dialect/SPIRV/TargetAndABI.h

 /// Returns the attribute name for specifying SPIR-V target environment.
 StringRef getTargetEnvAttrName();
 
 /// Returns the default target environment: SPIR-V 1.0 with Shader capability
 /// and no extra extensions.
 TargetEnvAttr getDefaultTargetEnv(MLIRContext *context);
 
 /// Queries the target environment recursively from enclosing symbol table ops
+/// containing the given `op`.
+TargetEnvAttr lookupTargetEnv(Operation *op);
+
+/// Queries the target environment recursively from enclosing symbol table ops
 /// containing the given `op` or returns the default target environment as
 /// returned by getDefaultTargetEnv() if not provided.
 TargetEnvAttr lookupTargetEnvOrDefault(Operation *op);
 
 } // namespace spirv
 } // namespace mlir
 
 #endif // MLIR_DIALECT_SPIRV_TARGETANDABI_H

mlir/include/mlir/InitAllPasses.h

#endif
   quant::createConvertConstPass();
   quantizer::createAddDefaultStatsPass();
   quantizer::createRemoveInstrumentationPass();
   quantizer::registerInferQuantizedTypesPass();
 
   // SPIR-V
   spirv::createDecorateSPIRVCompositeTypeLayoutPass();
   spirv::createLowerABIAttributesPass();
+  spirv::createUpdateVersionCapabilityExtensionPass();
   createConvertGPUToSPIRVPass();
   createConvertStandardToSPIRVPass();
   createLegalizeStdOpsForSPIRVLoweringPass();
   createLinalgToSPIRVPass();
 
   // Vulkan
   createConvertGpuLaunchFuncToVulkanLaunchFuncPass();
   createConvertVulkanLaunchFuncToVulkanCallsPass();
 }
 
 } // namespace mlir
 
 #endif // MLIR_INITALLPASSES_H_

mlir/lib/Dialect/SPIRV/TargetAndABI.cpp

 spirv::TargetEnvAttr spirv::getDefaultTargetEnv(MLIRContext *context) {
   auto triple = spirv::VerCapExtAttr::get(spirv::Version::V_1_0,
                                           {spirv::Capability::Shader},
                                           ArrayRef<Extension>(), context);
   return spirv::TargetEnvAttr::get(triple,
                                    spirv::getDefaultResourceLimits(context));
 }
 
-spirv::TargetEnvAttr spirv::lookupTargetEnvOrDefault(Operation *op) {
-  Operation *symTable = op;
-  while (symTable) {
-    symTable = SymbolTable::getNearestSymbolTable(symTable);
-    if (!symTable)
+spirv::TargetEnvAttr spirv::lookupTargetEnv(Operation *op) {
+  while (op) {
+    op = SymbolTable::getNearestSymbolTable(op);
+    if (!op)
       break;
 
-    if (auto attr = symTable->getAttrOfType<spirv::TargetEnvAttr>(
+    if (auto attr = op->getAttrOfType<spirv::TargetEnvAttr>(
             spirv::getTargetEnvAttrName()))
       return attr;
 
-    symTable = symTable->getParentOp();
+    op = op->getParentOp();
   }
 
+  return {};
+}
+
+spirv::TargetEnvAttr spirv::lookupTargetEnvOrDefault(Operation *op) {
+  if (spirv::TargetEnvAttr attr = spirv::lookupTargetEnv(op))
+    return attr;
+
   return getDefaultTargetEnv(op->getContext());
 }

mlir/lib/Dialect/SPIRV/Transforms/CMakeLists.txt

 add_mlir_dialect_library(MLIRSPIRVTransforms
   DecorateSPIRVCompositeTypeLayoutPass.cpp
   LowerABIAttributesPass.cpp
+  UpdateVCEPass.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${MLIR_MAIN_INCLUDE_DIR}/mlir/Dialect/SPIRV
   )
 
 target_link_libraries(MLIRSPIRVTransforms
   PUBLIC
   MLIRPass
   MLIRSPIRV
   )

mlir/lib/Dialect/SPIRV/Transforms/UpdateVCEPass.cpp

+//===- DeduceVersionExtensionCapabilityPass.cpp ---------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements a pass to deduce minimal version/extension/capability
+// requirements for a spirv::ModuleOp.
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/SPIRV/Passes.h"
+#include "mlir/Dialect/SPIRV/SPIRVDialect.h"
+#include "mlir/Dialect/SPIRV/SPIRVOps.h"
+#include "mlir/Dialect/SPIRV/SPIRVTypes.h"
+#include "mlir/Dialect/SPIRV/TargetAndABI.h"
+#include "mlir/IR/Builders.h"
+#include "mlir/IR/Visitors.h"
+#include "llvm/ADT/SetVector.h"
+#include "llvm/ADT/SmallSet.h"
+
+using namespace mlir;
+
+namespace {
+/// Pass to deduce minimal version/extension/capability requirements for a
+/// spirv::ModuleOp.
+class UpdateVCEPass final
+    : public OperationPass<UpdateVCEPass, spirv::ModuleOp> {
+private:
+  void runOnOperation() override;
+};
+} // namespace
+
+void UpdateVCEPass::runOnOperation() {
+  spirv::ModuleOp module = getOperation();
+
+  spirv::TargetEnvAttr targetEnv = spirv::lookupTargetEnv(module);
+  if (!targetEnv) {
+    module.emitError("missing 'spv.target_env' attribute");
+    return signalPassFailure();
+  }
+
+  spirv::Version allowedVersion = targetEnv.getVersion();
+
+  // Build a set for available extensions in the target environment.
+  llvm::SmallSet<spirv::Extension, 4> allowedExtensions;
+  for (spirv::Extension ext : targetEnv.getExtensions())
+    allowedExtensions.insert(ext);
+
+  // Add extensions implied by the current version.
+  for (spirv::Extension ext : spirv::getImpliedExtensions(allowedVersion))
+    allowedExtensions.insert(ext);
+
+  // Build a set for available capabilities in the target environment.
+  llvm::SmallSet<spirv::Capability, 8> allowedCapabilities;
+  for (spirv::Capability cap : targetEnv.getCapabilities()) {
+    allowedCapabilities.insert(cap);
+
+    // Add capabilities implied by the current capability.
+    for (spirv::Capability c : spirv::getRecursiveImpliedCapabilities(cap))
+      allowedCapabilities.insert(c);
+  }
+
+  spirv::Version deducedVersion = spirv::Version::V_1_0;
+  llvm::SetVector<spirv::Extension> deducedExtensions;
+  llvm::SetVector<spirv::Capability> deducedCapabilities;
+
+  // Walk each SPIR-V op to deduce the minimal version/extension/capability
+  // requirements.
+  WalkResult walkResult = module.walk([&](Operation *op) -> WalkResult {
+    if (auto minVersion = dyn_cast<spirv::QueryMinVersionInterface>(op)) {
+      deducedVersion = std::max(deducedVersion, minVersion.getMinVersion());
+      if (deducedVersion > allowedVersion) {
+        return op->emitError("'") << op->getName() << "' requires min version "
+                                  << spirv::stringifyVersion(deducedVersion)
+                                  << " but target environment allows up to "
+                                  << spirv::stringifyVersion(allowedVersion);
+      }
+    }
+
+    // Deduce this op's extension requirement. For each op, the query interfacce
+    // returns a vector of vector for its extension requirements following
+    // ((Extension::A OR Extension::B) AND (Extension::C OR Extension::D))
+    // convention. Ops not implementing QueryExtensionInterface do not require
+    // extensions to be available.
+    if (auto extensions = dyn_cast<spirv::QueryExtensionInterface>(op)) {
+      for (const auto &ors : extensions.getExtensions()) {
+        bool satisfied = false; // True when at least one extension can be used
+        for (spirv::Extension ext : ors) {
+          if (allowedExtensions.count(ext)) {
+            deducedExtensions.insert(ext);
+            satisfied = true;
+            break;
+          }
+        }
+
+        if (!satisfied) {
+          SmallVector<StringRef, 4> extStrings;
+          for (spirv::Extension ext : ors)
+            extStrings.push_back(spirv::stringifyExtension(ext));
+
+          return op->emitError("'")
+                 << op->getName() << "' requires at least one extension in ["
+                 << llvm::join(extStrings, ", ")
+                 << "] but none allowed in target environment";
+        }
+      }
+    }
+
+    // Deduce this op's capability requirement. For each op, the queryinterface
+    // returns a vector of vector for its capability requirements following
+    // ((Capability::A OR Extension::B) AND (Capability::C OR Capability::D))
+    // convention. Ops not implementing QueryExtensionInterface do not require
+    // extensions to be available.
+    if (auto capabilities = dyn_cast<spirv::QueryCapabilityInterface>(op)) {
+      for (const auto &ors : capabilities.getCapabilities()) {
+        bool satisfied = false; // True when at least one capability can be used
+        for (spirv::Capability cap : ors) {
+          if (allowedCapabilities.count(cap)) {
+            deducedCapabilities.insert(cap);
+            satisfied = true;
+            break;
+          }
+        }
+
+        if (!satisfied) {
+          SmallVector<StringRef, 4> capStrings;
+          for (spirv::Capability cap : ors)
+            capStrings.push_back(spirv::stringifyCapability(cap));
+
+          return op->emitError("'")
+                 << op->getName() << "' requires at least one capability in ["
+                 << llvm::join(capStrings, ", ")
+                 << "] but none allowed in target environment";
+        }
+      }
+    }
+
+    return WalkResult::advance();
+  });
+
+  if (walkResult.wasInterrupted())
+    return signalPassFailure();
+
+  // TODO(antiagainst): verify that the deduced version is consistent with
+  // SPIR-V ops' maximal version requirements.
+
+  auto triple = spirv::VerCapExtAttr::get(
+      deducedVersion, deducedCapabilities.getArrayRef(),
+      deducedExtensions.getArrayRef(), &getContext());
+  module.setAttr("vce_triple", triple);
+}
+
+std::unique_ptr<OpPassBase<spirv::ModuleOp>>
+mlir::spirv::createUpdateVersionCapabilityExtensionPass() {
+  return std::make_unique<UpdateVCEPass>();
+}
+
+static PassRegistration<UpdateVCEPass>
+    pass("spirv-update-vce",
+         "Deduce and attach minimal (version, capabilities, extensions) "
+         "requirements to spv.module ops");

mlir/test/Dialect/SPIRV/Transforms/vce-deduction.mlir

+// RUN: mlir-opt -spirv-update-vce %s | FileCheck %s
+
+//===----------------------------------------------------------------------===//
+// Version
+//===----------------------------------------------------------------------===//
+
+// Test deducing minimal version.
+// spv.IAdd is available from v1.0.
+
+// CHECK: vce_triple = #spv.vce<v1.0, [Shader], []>
+spv.module "Logical" "GLSL450" {
+  spv.func @iadd(%val : i32) -> i32 "None" {
+    %0 = spv.IAdd %val, %val: i32
+    spv.ReturnValue %0: i32
+  }
+} attributes {
+  spv.target_env = #spv.target_env<
+    #spv.vce<v1.5, [Shader], []>,
+    {max_compute_workgroup_invocations = 128 : i32,
+     max_compute_workgroup_size = dense<[128, 128, 64]> : vector<3xi32>}>
+}
+
+// Test deducing minimal version.
+// spv.GroupNonUniformBallot is available since v1.3.
+
+// CHECK: vce_triple = #spv.vce<v1.3, [GroupNonUniformBallot, Shader], []>
+spv.module "Logical" "GLSL450" {
+  spv.func @group_non_uniform_ballot(%predicate : i1) -> vector<4xi32> "None" {
+    %0 = spv.GroupNonUniformBallot "Workgroup" %predicate : vector<4xi32>
+    spv.ReturnValue %0: vector<4xi32>
+  }
+} attributes {
+  spv.target_env = #spv.target_env<
+    #spv.vce<v1.5, [Shader, GroupNonUniformBallot], []>,
+    {max_compute_workgroup_invocations = 128 : i32,
+     max_compute_workgroup_size = dense<[128, 128, 64]> : vector<3xi32>}>
+}
+
+//===----------------------------------------------------------------------===//
+// Capability
+//===----------------------------------------------------------------------===//
+
+// Test minimal capabilities.
+
+// CHECK: vce_triple = #spv.vce<v1.0, [Shader], []>
+spv.module "Logical" "GLSL450" {
+  spv.func @iadd(%val : i32) -> i32 "None" {
+    %0 = spv.IAdd %val, %val: i32
+    spv.ReturnValue %0: i32
+  }
+} attributes {
+  spv.target_env = #spv.target_env<
+    #spv.vce<v1.0, [Shader, Float16, Float64, Int16, Int64, VariablePointers], []>,
+    {max_compute_workgroup_invocations = 128 : i32,
+     max_compute_workgroup_size = dense<[128, 128, 64]> : vector<3xi32>}>
+}
+
+// Test deducing implied capability.
+// AtomicStorage implies Shader.
+
+// CHECK: vce_triple = #spv.vce<v1.0, [Shader], []>
+spv.module "Logical" "GLSL450" {
+  spv.func @iadd(%val : i32) -> i32 "None" {
+    %0 = spv.IAdd %val, %val: i32
+    spv.ReturnValue %0: i32
+  }
+} attributes {
+  spv.target_env = #spv.target_env<
+    #spv.vce<v1.0, [AtomicStorage], []>,
+    {max_compute_workgroup_invocations = 128 : i32,
+     max_compute_workgroup_size = dense<[128, 128, 64]> : vector<3xi32>}>
+}
+
+// Test selecting the capability available in the target environment.
+// spv.GroupNonUniform op itself can be enabled via any of
+// * GroupNonUniformArithmetic
+// * GroupNonUniformClustered
+// * GroupNonUniformPartitionedNV
+// Its 'Reduce' group operation can be enabled via any of
+// * Kernel
+// * GroupNonUniformArithmetic
+// * GroupNonUniformBallot
+
+// CHECK: vce_triple = #spv.vce<v1.3, [GroupNonUniformArithmetic, Shader], []>
+spv.module "Logical" "GLSL450" {
+  spv.func @group_non_uniform_iadd(%val : i32) -> i32 "None" {
+    %0 = spv.GroupNonUniformIAdd "Subgroup" "Reduce" %val : i32
+    spv.ReturnValue %0: i32
+  }
+} attributes {
+  spv.target_env = #spv.target_env<
+    #spv.vce<v1.3, [Shader, GroupNonUniformArithmetic], []>,
+    {max_compute_workgroup_invocations = 128 : i32,
+     max_compute_workgroup_size = dense<[128, 128, 64]> : vector<3xi32>}>
+}
+
+// CHECK: vce_triple = #spv.vce<v1.3, [GroupNonUniformClustered, GroupNonUniformBallot, Shader], []>
+spv.module "Logical" "GLSL450" {
+  spv.func @group_non_uniform_iadd(%val : i32) -> i32 "None" {
+    %0 = spv.GroupNonUniformIAdd "Subgroup" "Reduce" %val : i32
+    spv.ReturnValue %0: i32
+  }
+} attributes {
+  spv.target_env = #spv.target_env<
+    #spv.vce<v1.3, [Shader, GroupNonUniformClustered, GroupNonUniformBallot], []>,
+    {max_compute_workgroup_invocations = 128 : i32,
+     max_compute_workgroup_size = dense<[128, 128, 64]> : vector<3xi32>}>
+}
+
+//===----------------------------------------------------------------------===//
+// Extension
+//===----------------------------------------------------------------------===//
+
+// Test deducing minimal extensions.
+// spv.SubgroupBallotKHR requires the SPV_KHR_shader_ballot extension.
+
+// CHECK: vce_triple = #spv.vce<v1.0, [SubgroupBallotKHR, Shader], [SPV_KHR_shader_ballot]>
+spv.module "Logical" "GLSL450" {
+  spv.func @subgroup_ballot(%predicate : i1) -> vector<4xi32> "None" {
+    %0 = spv.SubgroupBallotKHR %predicate: vector<4xi32>
+    spv.ReturnValue %0: vector<4xi32>
+  }
+} attributes {
+  spv.target_env = #spv.target_env<
+    #spv.vce<v1.0, [Shader, SubgroupBallotKHR],
+             [SPV_KHR_shader_ballot, SPV_KHR_shader_clock, SPV_KHR_variable_pointers]>,
+    {max_compute_workgroup_invocations = 128 : i32,
+     max_compute_workgroup_size = dense<[128, 128, 64]> : vector<3xi32>}>
+}
+
+// Test deducing implied extension.
+// Vulkan memory model requires SPV_KHR_vulkan_memory_model, which is enabled
+// implicitly by v1.5.
+
+// CHECK: vce_triple = #spv.vce<v1.0, [VulkanMemoryModel], [SPV_KHR_vulkan_memory_model]>
+spv.module "Logical" "Vulkan" {
+  spv.func @iadd(%val : i32) -> i32 "None" {
+    %0 = spv.IAdd %val, %val: i32
+    spv.ReturnValue %0: i32
+  }
+} attributes {
+  spv.target_env = #spv.target_env<
+    #spv.vce<v1.5, [Shader, VulkanMemoryModel], []>,
+    {max_compute_workgroup_invocations = 128 : i32,
+     max_compute_workgroup_size = dense<[128, 128, 64]> : vector<3xi32>}>
+}