[Mlir-commits] [mlir] [MLIR] emitc: Add emitc translation unit op (PR #123298)

llvmlistbot at llvm.org llvmlistbot at llvm.org
Thu Jan 16 23:58:02 PST 2025


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-mlir-emitc

Author: Matthias Gehre (mgehre-amd)

<details>
<summary>Changes</summary>

A `emitc.tu` represents a translation unit that can be emitted into a single C++ file.

This allows to manage multiple translation units within the same MLIR module, but emit them into separate files.
This feature is opt-in; by default,
`mlir-translate` will continue to emit the whole module.

When specifying the `-translation-unit-id=id` flag, `mlir-translate` emits only the translation unit with that id.

Example:

```mlir
emitc.tu "main" {
  func @<!-- -->func_one() {
    return
  }
}
emitc.tu "test" {
  func @<!-- -->func_two() {
   return
  }
}
```

`mlir-translate -translation-unit-id=main` will emit `func_one` and `mlir-translate -translation-unit-id=test` will emit `func_two`.

---
Full diff: https://github.com/llvm/llvm-project/pull/123298.diff


6 Files Affected:

- (modified) mlir/include/mlir/Dialect/EmitC/IR/EmitC.td (+49) 
- (modified) mlir/include/mlir/Target/Cpp/CppEmitter.h (+3-1) 
- (modified) mlir/lib/Dialect/EmitC/IR/EmitC.cpp (+10) 
- (modified) mlir/lib/Target/Cpp/TranslateRegistration.cpp (+7-1) 
- (modified) mlir/lib/Target/Cpp/TranslateToCpp.cpp (+31-7) 
- (added) mlir/test/Target/Cpp/tu.mlir (+29) 


``````````diff
diff --git a/mlir/include/mlir/Dialect/EmitC/IR/EmitC.td b/mlir/include/mlir/Dialect/EmitC/IR/EmitC.td
index b16f5a8619fe7b..1fe4e34b3fa5ab 100644
--- a/mlir/include/mlir/Dialect/EmitC/IR/EmitC.td
+++ b/mlir/include/mlir/Dialect/EmitC/IR/EmitC.td
@@ -23,6 +23,7 @@ include "mlir/Interfaces/FunctionInterfaces.td"
 include "mlir/Interfaces/SideEffectInterfaces.td"
 include "mlir/IR/OpAsmInterface.td"
 include "mlir/IR/RegionKindInterface.td"
+include "mlir/IR/BuiltinAttributes.td"
 
 //===----------------------------------------------------------------------===//
 // EmitC op definitions
@@ -56,6 +57,54 @@ def IntegerIndexOrOpaqueType : Type<CPred<"emitc::isIntegerIndexOrOpaqueType($_s
 "integer, index or opaque type supported by EmitC">;
 def FloatIntegerIndexOrOpaqueType : AnyTypeOf<[EmitCFloatType, IntegerIndexOrOpaqueType]>;
 
+def EmitC_TranslationUnitOp
+    : EmitC_Op<"tu", [IsolatedFromAbove, NoRegionArguments, SymbolTable,
+                      OpAsmOpInterface]#GraphRegionNoTerminator.traits> {
+  let summary = "A translation unit container operation";
+  let description = [{
+    A `tu` represents a translation unit that can be emitted
+    into a single C++ file.
+
+    `mlir-translate` emits only the translation unit selected via
+    the `-translation-unit-id=id` flag. By default, no translation units are
+    emitted.
+
+    Example:
+
+    ```mlir
+    emitc.tu "main" {
+      emitc.func @func_one() {
+        emitc.return
+      }
+    }
+    ```
+  }];
+
+  let arguments = (ins Builtin_StringAttr:$id);
+  let regions = (region SizedRegion<1>:$bodyRegion);
+
+  let assemblyFormat = "$id attr-dict-with-keyword $bodyRegion";
+  let builders = [OpBuilder<(ins CArg<"StringRef">:$id)>];
+  let extraClassDeclaration = [{
+    /// Construct a module from the given location with an optional name.
+    static TranslationUnitOp create(Location loc, StringRef name);
+
+    //===------------------------------------------------------------------===//
+    // OpAsmOpInterface Methods
+    //===------------------------------------------------------------------===//
+
+    /// EmitC ops in the body of the translation_unit can omit their 'emitc.'
+    /// prefix in the assembly.
+    static ::llvm::StringRef getDefaultDialect() {
+      return "emitc";
+    }
+  }];
+
+  // We need to ensure that the body region has a block;
+  // the auto-generated builders do not guarantee that.
+  let skipDefaultBuilders = 1;
+}
+
 def EmitC_AddOp : EmitC_BinaryOp<"add", [CExpression]> {
   let summary = "Addition operation";
   let description = [{
diff --git a/mlir/include/mlir/Target/Cpp/CppEmitter.h b/mlir/include/mlir/Target/Cpp/CppEmitter.h
index 99d8696cc8e077..d76cfc9107332e 100644
--- a/mlir/include/mlir/Target/Cpp/CppEmitter.h
+++ b/mlir/include/mlir/Target/Cpp/CppEmitter.h
@@ -14,6 +14,7 @@
 #define MLIR_TARGET_CPP_CPPEMITTER_H
 
 #include "mlir/Support/LLVM.h"
+#include "llvm/ADT/StringRef.h"
 
 namespace mlir {
 class Operation;
@@ -24,7 +25,8 @@ namespace emitc {
 /// 'declareVariablesAtTop' enforces that all variables for op results and block
 /// arguments are declared at the beginning of the function.
 LogicalResult translateToCpp(Operation *op, raw_ostream &os,
-                             bool declareVariablesAtTop = false);
+                             bool declareVariablesAtTop = false,
+                             StringRef onlyTu = "");
 } // namespace emitc
 } // namespace mlir
 
diff --git a/mlir/lib/Dialect/EmitC/IR/EmitC.cpp b/mlir/lib/Dialect/EmitC/IR/EmitC.cpp
index fdc21d6c6e24b9..b51221b721dde3 100644
--- a/mlir/lib/Dialect/EmitC/IR/EmitC.cpp
+++ b/mlir/lib/Dialect/EmitC/IR/EmitC.cpp
@@ -1289,6 +1289,16 @@ void SwitchOp::getRegionInvocationBounds(
     bounds.emplace_back(/*lb=*/0, /*ub=*/regIndex == liveIndex);
 }
 
+//===----------------------------------------------------------------------===//
+// TranslationUnitOp
+//===----------------------------------------------------------------------===//
+void TranslationUnitOp::build(OpBuilder &builder, OperationState &state,
+                              StringRef id) {
+  state.addRegion()->emplaceBlock();
+  state.attributes.push_back(
+      builder.getNamedAttr("id", builder.getStringAttr(id)));
+}
+
 //===----------------------------------------------------------------------===//
 // TableGen'd op method definitions
 //===----------------------------------------------------------------------===//
diff --git a/mlir/lib/Target/Cpp/TranslateRegistration.cpp b/mlir/lib/Target/Cpp/TranslateRegistration.cpp
index 1aa98834a73f49..7e2bc9ad012b38 100644
--- a/mlir/lib/Target/Cpp/TranslateRegistration.cpp
+++ b/mlir/lib/Target/Cpp/TranslateRegistration.cpp
@@ -29,12 +29,18 @@ void registerToCppTranslation() {
       llvm::cl::desc("Declare variables at top when emitting C/C++"),
       llvm::cl::init(false));
 
+  static llvm::cl::opt<std::string> onlyTu(
+      "translation-unit-id",
+      llvm::cl::desc("Only emit the translation unit with the matching id"),
+      llvm::cl::init(""));
+
   TranslateFromMLIRRegistration reg(
       "mlir-to-cpp", "translate from mlir to cpp",
       [](Operation *op, raw_ostream &output) {
         return emitc::translateToCpp(
             op, output,
-            /*declareVariablesAtTop=*/declareVariablesAtTop);
+            /*declareVariablesAtTop=*/declareVariablesAtTop,
+            /*onlyTu=*/onlyTu);
       },
       [](DialectRegistry &registry) {
         // clang-format off
diff --git a/mlir/lib/Target/Cpp/TranslateToCpp.cpp b/mlir/lib/Target/Cpp/TranslateToCpp.cpp
index a91f5ab9311401..c9d66ad349db52 100644
--- a/mlir/lib/Target/Cpp/TranslateToCpp.cpp
+++ b/mlir/lib/Target/Cpp/TranslateToCpp.cpp
@@ -114,7 +114,8 @@ static FailureOr<int> getOperatorPrecedence(Operation *operation) {
 namespace {
 /// Emitter that uses dialect specific emitters to emit C++ code.
 struct CppEmitter {
-  explicit CppEmitter(raw_ostream &os, bool declareVariablesAtTop);
+  explicit CppEmitter(raw_ostream &os, bool declareVariablesAtTop,
+                      StringRef onlyTu);
 
   /// Emits attribute or returns failure.
   LogicalResult emitAttribute(Location loc, Attribute attr);
@@ -231,6 +232,9 @@ struct CppEmitter {
   /// be declared at the beginning of a function.
   bool shouldDeclareVariablesAtTop() { return declareVariablesAtTop; };
 
+  /// Returns whether this translation unit should be emitted
+  bool shouldEmitTu(TranslationUnitOp tu) { return tu.getId() == onlyTu; }
+
   /// Get expression currently being emitted.
   ExpressionOp getEmittedExpression() { return emittedExpression; }
 
@@ -258,6 +262,9 @@ struct CppEmitter {
   /// includes results from ops located in nested regions.
   bool declareVariablesAtTop;
 
+  /// Only emit translation units whos id matches this value.
+  std::string onlyTu;
+
   /// Map from value to name of C++ variable that contain the name.
   ValueMapper valueMapper;
 
@@ -960,6 +967,19 @@ static LogicalResult printOperation(CppEmitter &emitter, ModuleOp moduleOp) {
   return success();
 }
 
+static LogicalResult printOperation(CppEmitter &emitter, TranslationUnitOp tu) {
+  if (!emitter.shouldEmitTu(tu))
+    return success();
+
+  CppEmitter::Scope scope(emitter);
+
+  for (Operation &op : tu) {
+    if (failed(emitter.emitOperation(op, /*trailingSemicolon=*/false)))
+      return failure();
+  }
+  return success();
+}
+
 static LogicalResult printFunctionArgs(CppEmitter &emitter,
                                        Operation *functionOp,
                                        ArrayRef<Type> arguments) {
@@ -1159,8 +1179,10 @@ static LogicalResult printOperation(CppEmitter &emitter,
   return success();
 }
 
-CppEmitter::CppEmitter(raw_ostream &os, bool declareVariablesAtTop)
-    : os(os), declareVariablesAtTop(declareVariablesAtTop) {
+CppEmitter::CppEmitter(raw_ostream &os, bool declareVariablesAtTop,
+                       StringRef onlyTu)
+    : os(os), declareVariablesAtTop(declareVariablesAtTop),
+      onlyTu(onlyTu.str()) {
   valueInScopeCount.push(0);
   labelInScopeCount.push(0);
 }
@@ -1561,8 +1583,9 @@ LogicalResult CppEmitter::emitOperation(Operation &op, bool trailingSemicolon) {
                 emitc::GlobalOp, emitc::IfOp, emitc::IncludeOp, emitc::LoadOp,
                 emitc::LogicalAndOp, emitc::LogicalNotOp, emitc::LogicalOrOp,
                 emitc::MulOp, emitc::RemOp, emitc::ReturnOp, emitc::SubOp,
-                emitc::SwitchOp, emitc::UnaryMinusOp, emitc::UnaryPlusOp,
-                emitc::VariableOp, emitc::VerbatimOp>(
+                emitc::SwitchOp, emitc::TranslationUnitOp, emitc::UnaryMinusOp,
+                emitc::UnaryPlusOp, emitc::VariableOp, emitc::VerbatimOp>(
+
               [&](auto op) { return printOperation(*this, op); })
           // Func ops.
           .Case<func::CallOp, func::FuncOp, func::ReturnOp>(
@@ -1742,7 +1765,8 @@ LogicalResult CppEmitter::emitTupleType(Location loc, ArrayRef<Type> types) {
 }
 
 LogicalResult emitc::translateToCpp(Operation *op, raw_ostream &os,
-                                    bool declareVariablesAtTop) {
-  CppEmitter emitter(os, declareVariablesAtTop);
+                                    bool declareVariablesAtTop,
+                                    StringRef onlyTu) {
+  CppEmitter emitter(os, declareVariablesAtTop, onlyTu);
   return emitter.emitOperation(*op, /*trailingSemicolon=*/false);
 }
diff --git a/mlir/test/Target/Cpp/tu.mlir b/mlir/test/Target/Cpp/tu.mlir
new file mode 100644
index 00000000000000..ca10e0263a64fc
--- /dev/null
+++ b/mlir/test/Target/Cpp/tu.mlir
@@ -0,0 +1,29 @@
+// RUN: mlir-translate -mlir-to-cpp %s | FileCheck %s --check-prefix NO-FILTER
+// RUN: mlir-translate -mlir-to-cpp -translation-unit-id=non-existing %s | FileCheck %s --check-prefix NON-EXISTING
+// RUN: mlir-translate -mlir-to-cpp -translation-unit-id=tu_one %s | FileCheck %s --check-prefix TU-ONE
+// RUN: mlir-translate -mlir-to-cpp -translation-unit-id=tu_two %s | FileCheck %s --check-prefix TU-TWO
+
+
+// NO-FILTER-NOT: func_one
+// NO-FILTER-NOT: func_two
+
+// NON-EXISTING-NOT: func_one
+// NON-EXISTING-NOT: func_two
+
+// TU-ONE: func_one
+// TU-ONE-NOT: func_two
+
+// TU-TWO-NOT: func_one
+// TU-TWO: func_two
+
+emitc.tu "tu_one" {
+  emitc.func @func_one(%arg: f32) {
+    emitc.return
+  }
+}
+
+emitc.tu "tu_two" {
+  emitc.func @func_two(%arg: f32) {
+    emitc.return
+  }
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/123298


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