[mlir][gpu][target] Use promises to verify TargetAttrs IR correctness. (#65787)

This patch employs the updated promise mechanism to enforce Target
Attribute IR constraints. Due to this patch, TargetAttributes
implementations no longer have to be registered before executing
translation to LLVM IR in cases where they are not needed, like when
translating `gpu.binary` operations.

Author: fabianmcg

mlir/include/mlir/Dialect/GPU/IR/CompilationAttrInterfaces.td

@@ -42,7 +42,15 @@ def GPUTargetAttrInterface : AttrInterface<"TargetAttrInterface"> {
   ];
 }
 
-def GPUTargetArrayAttr : TypedArrayAttrBase<GPUTargetAttrInterface,
+def GPUTargetAttr :
+    ConfinedAttr<AnyAttr, [PromisedAttrInterface<GPUTargetAttrInterface>]> {
+  let description = [{
+    Generic GPU target attribute. These attributes must implement or promise
+    the `GPUTargetAttrInterface` interface.
+  }];
+}
+
+def GPUTargetArrayAttr : TypedArrayAttrBase<GPUTargetAttr,
   "array of GPU target attributes">;
 
 def GPUNonEmptyTargetArrayAttr :
@@ -51,6 +59,7 @@ def GPUNonEmptyTargetArrayAttr :
 //===----------------------------------------------------------------------===//
 // GPU offloading translation attribute trait.
 //===----------------------------------------------------------------------===//
+
 def OffloadingTranslationAttrTrait :
    NativeTrait<"OffloadingTranslationAttrTrait", ""> {
   let cppNamespace = "::mlir::gpu";
@@ -65,7 +74,7 @@ def OffloadingTranslationAttr :
     ConfinedAttr<AnyAttr, [HasOffloadingTranslationAttrTrait]> {
   let description = [{
     Generic GPU offloading translation attribute. These attributes must
-    implement an interface for handling the translation of PU offloading
+    implement an interface for handling the translation of GPU offloading
     operations like `gpu.binary` & `gpu.launch_func`. An example of such
     interface is the `OffloadingLLVMTranslationAttrInterface` interface.
   }];

mlir/include/mlir/Dialect/GPU/IR/CompilationAttrs.td

@@ -32,8 +32,9 @@ def GPU_ObjectAttr : GPU_Attr<"Object", "object"> {
       #gpu.object<#nvvm.target, "...">
     ```
   }];
-  let parameters = (ins "TargetAttrInterface":$target, "StringAttr":$object);
+  let parameters = (ins "Attribute":$target, "StringAttr":$object);
   let assemblyFormat = [{`<` $target `,` $object `>`}];
+  let genVerifyDecl = 1;
 }
 
 def GPUObjectArrayAttr :

mlir/include/mlir/Target/LLVMIR/Dialect/All.h

@@ -14,8 +14,6 @@
 #ifndef MLIR_TARGET_LLVMIR_DIALECT_ALL_H
 #define MLIR_TARGET_LLVMIR_DIALECT_ALL_H
 
-#include "mlir/Target/LLVM/NVVM/Target.h"
-#include "mlir/Target/LLVM/ROCDL/Target.h"
 #include "mlir/Target/LLVMIR/Dialect/AMX/AMXToLLVMIRTranslation.h"
 #include "mlir/Target/LLVMIR/Dialect/ArmNeon/ArmNeonToLLVMIRTranslation.h"
 #include "mlir/Target/LLVMIR/Dialect/ArmSME/ArmSMEToLLVMIRTranslation.h"
@@ -51,13 +49,6 @@ static inline void registerAllToLLVMIRTranslations(DialectRegistry &registry) {
 
   // Extension required for translating GPU offloading Ops.
   gpu::registerOffloadingLLVMTranslationInterfaceExternalModels(registry);
-
-  // GPU target attribute interfaces are not used during translation, however
-  // the IR fails to verify if they are not registered due to the promise
-  // mechanism.
-  // TODO: remove these.
-  NVVM::registerNVVMTargetInterfaceExternalModels(registry);
-  ROCDL::registerROCDLTargetInterfaceExternalModels(registry);
 }
 
 /// Registers all the translations to LLVM IR required by GPU passes.
@@ -70,6 +61,9 @@ registerAllGPUToLLVMIRTranslations(DialectRegistry &registry) {
   registerLLVMDialectTranslation(registry);
   registerNVVMDialectTranslation(registry);
   registerROCDLDialectTranslation(registry);
+
+  // Extension required for translating GPU offloading Ops.
+  gpu::registerOffloadingLLVMTranslationInterfaceExternalModels(registry);
 }
 
 /// Registers all dialects that can be translated from LLVM IR and the

mlir/lib/Dialect/GPU/IR/GPUDialect.cpp

@@ -1954,6 +1954,20 @@ void AllocOp::getCanonicalizationPatterns(RewritePatternSet &results,
   results.add<SimplifyDimOfAllocOp>(context);
 }
 
+//===----------------------------------------------------------------------===//
+// GPU object attribute
+//===----------------------------------------------------------------------===//
+
+LogicalResult ObjectAttr::verify(function_ref<InFlightDiagnostic()> emitError,
+                                 Attribute target, StringAttr object) {
+  if (!target)
+    return emitError() << "the target attribute cannot be null";
+  if (target.hasPromiseOrImplementsInterface<TargetAttrInterface>())
+    return success();
+  return emitError() << "the target attribute must implement or promise the "
+                        "`gpu::TargetAttrInterface`";
+}
+
 //===----------------------------------------------------------------------===//
 // GPU select object attribute
 //===----------------------------------------------------------------------===//
@@ -1965,11 +1979,11 @@ gpu::SelectObjectAttr::verify(function_ref<InFlightDiagnostic()> emitError,
   if (target) {
     if (auto intAttr = mlir::dyn_cast<IntegerAttr>(target)) {
       if (intAttr.getInt() < 0) {
-        return emitError() << "The object index must be positive.";
+        return emitError() << "the object index must be positive";
       }
-    } else if (!(::mlir::isa<TargetAttrInterface>(target))) {
+    } else if (!target.hasPromiseOrImplementsInterface<TargetAttrInterface>()) {
       return emitError()
-             << "The target attribute must be a GPU Target attribute.";
+             << "the target attribute must be a GPU Target attribute";
     }
   }
   return success();

mlir/lib/Target/LLVMIR/CMakeLists.txt

@@ -57,8 +57,6 @@ add_mlir_translation_library(MLIRToLLVMIRTranslationRegistration
   MLIROpenACCToLLVMIRTranslation
   MLIROpenMPToLLVMIRTranslation
   MLIRROCDLToLLVMIRTranslation
-  MLIRNVVMTarget
-  MLIRROCDLTarget
   )
 
 add_mlir_translation_library(MLIRTargetLLVMIRImport