update tuning.md and test file

Signed-off-by: Bangtian Liu <liubangtian@gmail.com>

Author: bangtianliu

compiler/src/iree/compiler/Codegen/Common/test/verify_tuning_specs.mlir

@@ -54,6 +54,15 @@ module @foo_module attributes { transform.with_named_sequence } {
 
 // -----
 
-// expected-error @+1{{The default tuning specification must include an operation with the symbol name '__kernel_config'}}
+// expected-error @+1{{The tuning specification must include a named sequence with the symbol name '__kernel_config'}}
 module @iree_default_tuning_spec attributes { iree_codegen.tuning_spec_with_default_entrypoint } {
 }
+
+// -----
+
+// expected-error @+1{{The tuning specification must include a named sequence with the symbol name '__kernel_config'}}
+module @iree_default_tuning_spec attributes { iree_codegen.tuning_spec_with_default_entrypoint } {
+  func.func @__kernel_config(%arg0: i32) -> () {
+    return
+  }
+}

compiler/src/iree/compiler/Codegen/Dialect/Codegen/IR/IREECodegenAttrs.h

@@ -45,7 +45,7 @@ namespace mlir::iree_compiler {
 // Constant names.
 //===----------------------------------------------------------------------===//
 constexpr StringLiteral kConfigAttrName = "lowering_config";
-constexpr StringLiteral kTuningDefaultSpecAttrName =
+constexpr StringLiteral kTuningSpecDefaultEntrypointAttrName =
     "iree_codegen.tuning_spec_with_default_entrypoint";
 constexpr StringLiteral kTuningSpecEntrypointAttrName =
     "iree_codegen.tuning_spec_entrypoint";

compiler/src/iree/compiler/Codegen/Dialect/Codegen/IR/IREECodegenDialect.cpp

@@ -64,7 +64,7 @@ IREECodegenDialect::verifyOperationAttribute(Operation *op,
   //         b. It must have exactly one argument type, and the argument must be
   //         of type `transform::AnyOpType`.
 
-  if (symbol == kTuningDefaultSpecAttrName) {
+  if (symbol == kTuningSpecDefaultEntrypointAttrName) {
     if (auto moduleOp = dyn_cast<ModuleOp>(op)) {
       if (!llvm::any_of(moduleOp.getOps(), [](auto &op) {
             if (auto namedSeqOp = dyn_cast<transform::NamedSequenceOp>(&op)) {
@@ -75,8 +75,8 @@ IREECodegenDialect::verifyOperationAttribute(Operation *op,
             return false;
           })) {
         return moduleOp.emitError()
-               << "The default tuning specification must include an "
-                  "operation with the symbol name '"
+               << "The tuning specification must include a named "
+                  "sequence with the symbol name '"
                << kKernelConfigSpecName << "'.";
       }
     }

docs/website/docs/reference/tuning.md

@@ -123,6 +123,8 @@ that conform to the following format:
   `!transform.any_op`.
 * All entry points in the final tuning specs must either read
   (`transform.readonly`) or consume (`transform.consumed`) the argument.
+* The `iree_codegen.tuning_spec_with_default_entrypoint` attribute ensures that
+  the tuning spec includes a named sequence op marked with `__kernel_config`.
 
 The tuning spec above attempts to match `linalg.generic` ops that correspond to the
 matmul operation with the RHS operand transposed (a.k.a. mmt) of shape