[Mlir-commits] [mlir] [MLIR] Implement remark emitting policies in MLIR (PR #160526)

Guray Ozen llvmlistbot at llvm.org
Wed Sep 24 07:10:05 PDT 2025


https://github.com/grypp updated https://github.com/llvm/llvm-project/pull/160526

>From fe1e62902ddea0034f53458d85f36ae336fc3e7f Mon Sep 17 00:00:00 2001
From: Guray Ozen <gozen at nvidia.com>
Date: Wed, 24 Sep 2025 15:53:29 +0200
Subject: [PATCH 1/3] [MLIR] Implement remark emitting policies in MLIR

This update introduces two new remark emitting policies:
1. `RemarkEmittingPolicyAll`, which emits all remarks,
2. `RemarkEmittingPolicyFinal`, which only emits final remarks after processing.

The `RemarkEngine` is modified to support these policies, allowing for more flexible remark handling based on user configuration.

PR also adds flag to `mlir-opt`
```
  --remark-policy=<value>                                    - Specify the policy for remark output.
    =all                                                     -   Print all remarks
    =final                                                   -   Print final remarks
```
---
 mlir/include/mlir/IR/Remarks.h                | 128 +++++++++++++++++-
 mlir/include/mlir/Remark/RemarkStreamer.h     |   1 +
 .../include/mlir/Tools/mlir-opt/MlirOptMain.h |   9 ++
 mlir/lib/IR/MLIRContext.cpp                   |   2 +
 mlir/lib/IR/Remarks.cpp                       |  59 +++++---
 mlir/lib/Remark/RemarkStreamer.cpp            |   4 +-
 mlir/lib/Tools/mlir-opt/MlirOptMain.cpp       |  32 ++++-
 mlir/test/Pass/remark-final.mlir              |  15 ++
 mlir/test/lib/Pass/TestRemarksPass.cpp        |   7 +-
 mlir/unittests/IR/RemarkTest.cpp              |  87 +++++++++++-
 10 files changed, 311 insertions(+), 33 deletions(-)
 create mode 100644 mlir/test/Pass/remark-final.mlir

diff --git a/mlir/include/mlir/IR/Remarks.h b/mlir/include/mlir/IR/Remarks.h
index 20e84ec83cd01..03c83c3e78a00 100644
--- a/mlir/include/mlir/IR/Remarks.h
+++ b/mlir/include/mlir/IR/Remarks.h
@@ -24,6 +24,8 @@
 #include "mlir/IR/MLIRContext.h"
 #include "mlir/IR/Value.h"
 
+#include <functional>
+
 namespace mlir::remark {
 
 /// Define an the set of categories to accept. By default none are, the provided
@@ -144,7 +146,7 @@ class Remark {
 
   llvm::StringRef getCategoryName() const { return categoryName; }
 
-  llvm::StringRef getFullCategoryName() const {
+  llvm::StringRef getCombinedCategoryName() const {
     if (categoryName.empty() && subCategoryName.empty())
       return {};
     if (subCategoryName.empty())
@@ -318,7 +320,7 @@ class InFlightRemark {
 };
 
 //===----------------------------------------------------------------------===//
-// MLIR Remark Streamer
+// Pluggable Remark Utilities
 //===----------------------------------------------------------------------===//
 
 /// Base class for MLIR remark streamers that is used to stream
@@ -338,6 +340,26 @@ class MLIRRemarkStreamerBase {
   virtual void finalize() {} // optional
 };
 
+/// Base class for MLIR remark emitting policies that is used to emit
+/// optimization remarks to the underlying remark streamer. The derived classes
+/// should implement the `reportRemark` method to provide the actual emitting
+/// implementation.
+using ReportFn = llvm::unique_function<void(const Remark &)>;
+
+class RemarkEmittingPolicyBase {
+protected:
+  ReportFn reportImpl;
+
+public:
+  RemarkEmittingPolicyBase() = default;
+  virtual ~RemarkEmittingPolicyBase() = default;
+
+  void initialize(ReportFn fn) { reportImpl = std::move(fn); }
+
+  virtual void reportRemark(const Remark &remark) = 0;
+  virtual void finalize() = 0;
+};
+
 //===----------------------------------------------------------------------===//
 // Remark Engine (MLIR Context will own this class)
 //===----------------------------------------------------------------------===//
@@ -355,6 +377,8 @@ class RemarkEngine {
   std::optional<llvm::Regex> failedFilter;
   /// The MLIR remark streamer that will be used to emit the remarks.
   std::unique_ptr<MLIRRemarkStreamerBase> remarkStreamer;
+  /// The MLIR remark policy that will be used to emit the remarks.
+  std::unique_ptr<RemarkEmittingPolicyBase> remarkEmittingPolicy;
   /// When is enabled, engine also prints remarks as mlir::emitRemarks.
   bool printAsEmitRemarks = false;
 
@@ -392,6 +416,8 @@ class RemarkEngine {
   InFlightRemark emitIfEnabled(Location loc, RemarkOpts opts,
                                bool (RemarkEngine::*isEnabled)(StringRef)
                                    const);
+  /// Report a remark.
+  void reportImpl(const Remark &remark);
 
 public:
   /// Default constructor is deleted, use the other constructor.
@@ -407,8 +433,10 @@ class RemarkEngine {
   ~RemarkEngine();
 
   /// Setup the remark engine with the given output path and format.
-  LogicalResult initialize(std::unique_ptr<MLIRRemarkStreamerBase> streamer,
-                           std::string *errMsg);
+  LogicalResult
+  initialize(std::unique_ptr<MLIRRemarkStreamerBase> streamer,
+             std::unique_ptr<RemarkEmittingPolicyBase> remarkEmittingPolicy,
+             std::string *errMsg);
 
   /// Report a remark.
   void report(const Remark &&remark);
@@ -446,6 +474,43 @@ inline InFlightRemark withEngine(Fn fn, Location loc, Args &&...args) {
 
 namespace mlir::remark {
 
+//===----------------------------------------------------------------------===//
+// Remark Emitting Policies
+//===----------------------------------------------------------------------===//
+
+/// Policy that emits all remarks.
+class RemarkEmittingPolicyAll : public detail::RemarkEmittingPolicyBase {
+public:
+  RemarkEmittingPolicyAll();
+
+  void reportRemark(const detail::Remark &remark) override {
+    reportImpl(remark);
+  }
+  void finalize() override {}
+};
+
+/// Policy that emits final remarks.
+class RemarkEmittingPolicyFinal : public detail::RemarkEmittingPolicyBase {
+private:
+  /// Postponed remarks. They are deferred to the end of the pipeline, where the
+  /// user can intercept them for custom processing, otherwise they will be
+  /// reported on engine destruction.
+  llvm::DenseSet<detail::Remark> postponedRemarks;
+
+public:
+  RemarkEmittingPolicyFinal();
+
+  void reportRemark(const detail::Remark &remark) override {
+    postponedRemarks.erase(remark);
+    postponedRemarks.insert(remark);
+  }
+  void finalize() override {
+    for (auto &remark : postponedRemarks)
+      reportImpl(remark);
+    postponedRemarks.clear();
+  }
+};
+
 /// Create a Reason with llvm::formatv formatting.
 template <class... Ts>
 inline detail::LazyTextBuild reason(const char *fmt, Ts &&...ts) {
@@ -513,8 +578,63 @@ inline detail::InFlightRemark analysis(Location loc, RemarkOpts opts) {
 LogicalResult enableOptimizationRemarks(
     MLIRContext &ctx,
     std::unique_ptr<remark::detail::MLIRRemarkStreamerBase> streamer,
+    std::unique_ptr<remark::detail::RemarkEmittingPolicyBase>
+        remarkEmittingPolicy,
     const remark::RemarkCategories &cats, bool printAsEmitRemarks = false);
 
 } // namespace mlir::remark
 
+// DenseMapInfo specialization for Remark
+namespace llvm {
+template <>
+struct DenseMapInfo<mlir::remark::detail::Remark> {
+  static constexpr StringRef kEmptyKey = "<EMPTY_KEY>";
+  static constexpr StringRef kTombstoneKey = "<TOMBSTONE_KEY>";
+
+  /// Helper to provide a static dummy context for sentinel keys.
+  static mlir::MLIRContext *getStaticDummyContext() {
+    static mlir::MLIRContext dummyContext;
+    return &dummyContext;
+  }
+
+  /// Create an empty remark
+  static inline mlir::remark::detail::Remark getEmptyKey() {
+    return mlir::remark::detail::Remark(
+        mlir::remark::RemarkKind::RemarkUnknown, mlir::DiagnosticSeverity::Note,
+        mlir::UnknownLoc::get(getStaticDummyContext()),
+        mlir::remark::RemarkOpts::name(kEmptyKey));
+  }
+
+  /// Create a dead remark
+  static inline mlir::remark::detail::Remark getTombstoneKey() {
+    return mlir::remark::detail::Remark(
+        mlir::remark::RemarkKind::RemarkUnknown, mlir::DiagnosticSeverity::Note,
+        mlir::UnknownLoc::get(getStaticDummyContext()),
+        mlir::remark::RemarkOpts::name(kTombstoneKey));
+  }
+
+  /// Compute the hash value of the remark
+  static unsigned getHashValue(const mlir::remark::detail::Remark &remark) {
+    return llvm::hash_combine(remark.getLocation().getAsOpaquePointer(),
+                              llvm::hash_value(remark.getRemarkName()),
+                              llvm::hash_value(remark.getCategoryName()));
+  }
+
+  static bool isEqual(const mlir::remark::detail::Remark &lhs,
+                      const mlir::remark::detail::Remark &rhs) {
+    // Check for empty/tombstone keys first
+    if (lhs.getRemarkName() == kEmptyKey ||
+        lhs.getRemarkName() == kTombstoneKey ||
+        rhs.getRemarkName() == kEmptyKey ||
+        rhs.getRemarkName() == kTombstoneKey) {
+      return lhs.getRemarkName() == rhs.getRemarkName();
+    }
+
+    // For regular remarks, compare key identifying fields
+    return lhs.getLocation() == rhs.getLocation() &&
+           lhs.getRemarkName() == rhs.getRemarkName() &&
+           lhs.getCategoryName() == rhs.getCategoryName();
+  }
+};
+} // namespace llvm
 #endif // MLIR_IR_REMARKS_H
diff --git a/mlir/include/mlir/Remark/RemarkStreamer.h b/mlir/include/mlir/Remark/RemarkStreamer.h
index 170d6b439a442..19a70fa4c4daa 100644
--- a/mlir/include/mlir/Remark/RemarkStreamer.h
+++ b/mlir/include/mlir/Remark/RemarkStreamer.h
@@ -45,6 +45,7 @@ namespace mlir::remark {
 /// mlir::emitRemarks.
 LogicalResult enableOptimizationRemarksWithLLVMStreamer(
     MLIRContext &ctx, StringRef filePath, llvm::remarks::Format fmt,
+    std::unique_ptr<detail::RemarkEmittingPolicyBase> remarkEmittingPolicy,
     const RemarkCategories &cat, bool printAsEmitRemarks = false);
 
 } // namespace mlir::remark
diff --git a/mlir/include/mlir/Tools/mlir-opt/MlirOptMain.h b/mlir/include/mlir/Tools/mlir-opt/MlirOptMain.h
index 0fbe15fa2e0db..b7394387b0f9a 100644
--- a/mlir/include/mlir/Tools/mlir-opt/MlirOptMain.h
+++ b/mlir/include/mlir/Tools/mlir-opt/MlirOptMain.h
@@ -44,6 +44,11 @@ enum class RemarkFormat {
   REMARK_FORMAT_BITSTREAM,
 };
 
+enum class RemarkPolicy {
+  REMARK_POLICY_ALL,
+  REMARK_POLICY_FINAL,
+};
+
 /// Configuration options for the mlir-opt tool.
 /// This is intended to help building tools like mlir-opt by collecting the
 /// supported options.
@@ -242,6 +247,8 @@ class MlirOptMainConfig {
 
   /// Set the reproducer output filename
   RemarkFormat getRemarkFormat() const { return remarkFormatFlag; }
+  /// Set the remark policy to use.
+  RemarkPolicy getRemarkPolicy() const { return remarkPolicyFlag; }
   /// Set the remark format to use.
   std::string getRemarksAllFilter() const { return remarksAllFilterFlag; }
   /// Set the remark output file.
@@ -265,6 +272,8 @@ class MlirOptMainConfig {
 
   /// Remark format
   RemarkFormat remarkFormatFlag = RemarkFormat::REMARK_FORMAT_STDOUT;
+  /// Remark policy
+  RemarkPolicy remarkPolicyFlag = RemarkPolicy::REMARK_POLICY_ALL;
   /// Remark file to output to
   std::string remarksOutputFileFlag = "";
   /// Remark filters
diff --git a/mlir/lib/IR/MLIRContext.cpp b/mlir/lib/IR/MLIRContext.cpp
index 1fa04ed8e738f..358f0fc39b19d 100644
--- a/mlir/lib/IR/MLIRContext.cpp
+++ b/mlir/lib/IR/MLIRContext.cpp
@@ -278,6 +278,8 @@ class MLIRContextImpl {
     }
   }
   ~MLIRContextImpl() {
+    // finalize remark engine before destroying anything else.
+    remarkEngine.reset();
     for (auto typeMapping : registeredTypes)
       typeMapping.second->~AbstractType();
     for (auto attrMapping : registeredAttributes)
diff --git a/mlir/lib/IR/Remarks.cpp b/mlir/lib/IR/Remarks.cpp
index a55f61aff77bb..dca2da67d8a98 100644
--- a/mlir/lib/IR/Remarks.cpp
+++ b/mlir/lib/IR/Remarks.cpp
@@ -16,7 +16,7 @@
 #include "llvm/ADT/StringRef.h"
 
 using namespace mlir::remark::detail;
-
+using namespace mlir::remark;
 //------------------------------------------------------------------------------
 // Remark
 //------------------------------------------------------------------------------
@@ -70,7 +70,7 @@ static void printArgs(llvm::raw_ostream &os, llvm::ArrayRef<Remark::Arg> args) {
 void Remark::print(llvm::raw_ostream &os, bool printLocation) const {
   // Header: [Type] pass:remarkName
   StringRef type = getRemarkTypeString();
-  StringRef categoryName = getFullCategoryName();
+  StringRef categoryName = getCombinedCategoryName();
   StringRef name = remarkName;
 
   os << '[' << type << "] ";
@@ -140,7 +140,7 @@ llvm::remarks::Remark Remark::generateRemark() const {
   r.RemarkType = getRemarkType();
   r.RemarkName = getRemarkName();
   // MLIR does not use passes; instead, it has categories and sub-categories.
-  r.PassName = getFullCategoryName();
+  r.PassName = getCombinedCategoryName();
   r.FunctionName = getFunction();
   r.Loc = locLambda();
   for (const Remark::Arg &arg : getArgs()) {
@@ -225,7 +225,7 @@ InFlightRemark RemarkEngine::emitOptimizationRemarkAnalysis(Location loc,
 // RemarkEngine
 //===----------------------------------------------------------------------===//
 
-void RemarkEngine::report(const Remark &&remark) {
+void RemarkEngine::reportImpl(const Remark &remark) {
   // Stream the remark
   if (remarkStreamer)
     remarkStreamer->streamOptimizationRemark(remark);
@@ -235,19 +235,19 @@ void RemarkEngine::report(const Remark &&remark) {
     emitRemark(remark.getLocation(), remark.getMsg());
 }
 
+void RemarkEngine::report(const Remark &&remark) {
+  if (remarkEmittingPolicy)
+    remarkEmittingPolicy->reportRemark(remark);
+}
+
 RemarkEngine::~RemarkEngine() {
+  if (remarkEmittingPolicy)
+    remarkEmittingPolicy->finalize();
+
   if (remarkStreamer)
     remarkStreamer->finalize();
 }
 
-llvm::LogicalResult
-RemarkEngine::initialize(std::unique_ptr<MLIRRemarkStreamerBase> streamer,
-                         std::string *errMsg) {
-  // If you need to validate categories/filters, do so here and set errMsg.
-  remarkStreamer = std::move(streamer);
-  return success();
-}
-
 /// Returns true if filter is already anchored like ^...$
 static bool isAnchored(llvm::StringRef s) {
   s = s.trim();
@@ -300,15 +300,31 @@ RemarkEngine::RemarkEngine(bool printAsEmitRemarks,
     failedFilter = buildFilter(cats, cats.failed);
 }
 
+llvm::LogicalResult RemarkEngine::initialize(
+    std::unique_ptr<MLIRRemarkStreamerBase> streamer,
+    std::unique_ptr<RemarkEmittingPolicyBase> remarkEmittingPolicy,
+    std::string *errMsg) {
+
+  remarkStreamer = std::move(streamer);
+
+  // Capture `this`. Ensure RemarkEngine is not moved after this.
+  auto reportFunc = [this](const Remark &r) { this->reportImpl(r); };
+  remarkEmittingPolicy->initialize(ReportFn(std::move(reportFunc)));
+
+  this->remarkEmittingPolicy = std::move(remarkEmittingPolicy);
+  return success();
+}
+
 llvm::LogicalResult mlir::remark::enableOptimizationRemarks(
-    MLIRContext &ctx,
-    std::unique_ptr<remark::detail::MLIRRemarkStreamerBase> streamer,
-    const remark::RemarkCategories &cats, bool printAsEmitRemarks) {
+    MLIRContext &ctx, std::unique_ptr<detail::MLIRRemarkStreamerBase> streamer,
+    std::unique_ptr<detail::RemarkEmittingPolicyBase> remarkEmittingPolicy,
+    const RemarkCategories &cats, bool printAsEmitRemarks) {
   auto engine =
-      std::make_unique<remark::detail::RemarkEngine>(printAsEmitRemarks, cats);
+      std::make_unique<detail::RemarkEngine>(printAsEmitRemarks, cats);
 
   std::string errMsg;
-  if (failed(engine->initialize(std::move(streamer), &errMsg))) {
+  if (failed(engine->initialize(std::move(streamer),
+                                std::move(remarkEmittingPolicy), &errMsg))) {
     llvm::report_fatal_error(
         llvm::Twine("Failed to initialize remark engine. Error: ") + errMsg);
   }
@@ -316,3 +332,12 @@ llvm::LogicalResult mlir::remark::enableOptimizationRemarks(
 
   return success();
 }
+
+//===----------------------------------------------------------------------===//
+// Remark emitting policies
+//===----------------------------------------------------------------------===//
+
+namespace mlir::remark {
+RemarkEmittingPolicyAll::RemarkEmittingPolicyAll() = default;
+RemarkEmittingPolicyFinal::RemarkEmittingPolicyFinal() = default;
+} // namespace mlir::remark
diff --git a/mlir/lib/Remark/RemarkStreamer.cpp b/mlir/lib/Remark/RemarkStreamer.cpp
index d213a1a2068d6..bf362862d24f6 100644
--- a/mlir/lib/Remark/RemarkStreamer.cpp
+++ b/mlir/lib/Remark/RemarkStreamer.cpp
@@ -60,6 +60,7 @@ void LLVMRemarkStreamer::finalize() {
 namespace mlir::remark {
 LogicalResult enableOptimizationRemarksWithLLVMStreamer(
     MLIRContext &ctx, StringRef path, llvm::remarks::Format fmt,
+    std::unique_ptr<detail::RemarkEmittingPolicyBase> remarkEmittingPolicy,
     const RemarkCategories &cat, bool printAsEmitRemarks) {
 
   FailureOr<std::unique_ptr<detail::MLIRRemarkStreamerBase>> sOr =
@@ -67,7 +68,8 @@ LogicalResult enableOptimizationRemarksWithLLVMStreamer(
   if (failed(sOr))
     return failure();
 
-  return remark::enableOptimizationRemarks(ctx, std::move(*sOr), cat,
+  return remark::enableOptimizationRemarks(ctx, std::move(*sOr),
+                                           std::move(remarkEmittingPolicy), cat,
                                            printAsEmitRemarks);
 }
 
diff --git a/mlir/lib/Tools/mlir-opt/MlirOptMain.cpp b/mlir/lib/Tools/mlir-opt/MlirOptMain.cpp
index 30fd384f3977c..212793c22d152 100644
--- a/mlir/lib/Tools/mlir-opt/MlirOptMain.cpp
+++ b/mlir/lib/Tools/mlir-opt/MlirOptMain.cpp
@@ -37,6 +37,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Remarks/RemarkFormat.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/InitLLVM.h"
 #include "llvm/Support/LogicalResult.h"
 #include "llvm/Support/ManagedStatic.h"
@@ -45,6 +46,7 @@
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/ThreadPool.h"
 #include "llvm/Support/ToolOutputFile.h"
+#include <memory>
 
 using namespace mlir;
 using namespace llvm;
@@ -226,6 +228,18 @@ struct MlirOptMainConfigCLOptions : public MlirOptMainConfig {
                                     "bitstream", "Print bitstream file")),
         llvm::cl::cat(remarkCategory)};
 
+    static llvm::cl::opt<RemarkPolicy, /*ExternalStorage=*/true> remarkPolicy{
+        "remark-policy",
+        llvm::cl::desc("Specify the policy for remark output."),
+        cl::location(remarkPolicyFlag),
+        llvm::cl::value_desc("format"),
+        llvm::cl::init(RemarkPolicy::REMARK_POLICY_ALL),
+        llvm::cl::values(clEnumValN(RemarkPolicy::REMARK_POLICY_ALL, "all",
+                                    "Print all remarks"),
+                         clEnumValN(RemarkPolicy::REMARK_POLICY_FINAL, "final",
+                                    "Print final remarks")),
+        llvm::cl::cat(remarkCategory)};
+
     static cl::opt<std::string, /*ExternalStorage=*/true> remarksAll(
         "remarks-filter",
         cl::desc("Show all remarks: passed, missed, failed, analysis"),
@@ -517,18 +531,28 @@ performActions(raw_ostream &os,
     return failure();
 
   context->enableMultithreading(wasThreadingEnabled);
-
+  // Set the remark categories and policy.
   remark::RemarkCategories cats{
       config.getRemarksAllFilter(), config.getRemarksPassedFilter(),
       config.getRemarksMissedFilter(), config.getRemarksAnalyseFilter(),
       config.getRemarksFailedFilter()};
 
   mlir::MLIRContext &ctx = *context;
+  // Helper to create the appropriate policy based on configuration
+  auto createPolicy = [&config]()
+      -> std::unique_ptr<mlir::remark::detail::RemarkEmittingPolicyBase> {
+    if (config.getRemarkPolicy() == RemarkPolicy::REMARK_POLICY_ALL)
+      return std::make_unique<mlir::remark::RemarkEmittingPolicyAll>();
+    if (config.getRemarkPolicy() == RemarkPolicy::REMARK_POLICY_FINAL)
+      return std::make_unique<mlir::remark::RemarkEmittingPolicyFinal>();
+
+    llvm_unreachable("Invalid remark policy");
+  };
 
   switch (config.getRemarkFormat()) {
   case RemarkFormat::REMARK_FORMAT_STDOUT:
     if (failed(mlir::remark::enableOptimizationRemarks(
-            ctx, nullptr, cats, true /*printAsEmitRemarks*/)))
+            ctx, nullptr, createPolicy(), cats, true /*printAsEmitRemarks*/)))
       return failure();
     break;
 
@@ -537,7 +561,7 @@ performActions(raw_ostream &os,
                            ? "mlir-remarks.yaml"
                            : config.getRemarksOutputFile();
     if (failed(mlir::remark::enableOptimizationRemarksWithLLVMStreamer(
-            ctx, file, llvm::remarks::Format::YAML, cats)))
+            ctx, file, llvm::remarks::Format::YAML, createPolicy(), cats)))
       return failure();
     break;
   }
@@ -547,7 +571,7 @@ performActions(raw_ostream &os,
                            ? "mlir-remarks.bitstream"
                            : config.getRemarksOutputFile();
     if (failed(mlir::remark::enableOptimizationRemarksWithLLVMStreamer(
-            ctx, file, llvm::remarks::Format::Bitstream, cats)))
+            ctx, file, llvm::remarks::Format::Bitstream, createPolicy(), cats)))
       return failure();
     break;
   }
diff --git a/mlir/test/Pass/remark-final.mlir b/mlir/test/Pass/remark-final.mlir
new file mode 100644
index 0000000000000..cb4790b1a11e4
--- /dev/null
+++ b/mlir/test/Pass/remark-final.mlir
@@ -0,0 +1,15 @@
+// RUN: mlir-opt %s --test-remark --remarks-filter="category.*" --remark-policy=final --remark-format=yaml --remarks-output-file=%t.yaml
+// RUN: FileCheck %s < %t.yaml
+module @foo {
+  "test.op"() : () -> ()
+  
+}
+
+// CHECK-NOT: This is a test passed remark (should be dropped)
+
+// CHECK: !Passed
+// CHECK: Remark:          This is a test passed remark
+// CHECK: !Analysis
+// CHECK: Remark:          This is a test analysis remark
+// CHECK: !Failure
+// CHECK: Remark:          This is a test failed remark
diff --git a/mlir/test/lib/Pass/TestRemarksPass.cpp b/mlir/test/lib/Pass/TestRemarksPass.cpp
index 3b25686b3dc14..5ca2d1a8550aa 100644
--- a/mlir/test/lib/Pass/TestRemarksPass.cpp
+++ b/mlir/test/lib/Pass/TestRemarksPass.cpp
@@ -43,7 +43,12 @@ class TestRemarkPass : public PassWrapper<TestRemarkPass, OperationPass<>> {
           << remark::add("This is a test missed remark")
           << remark::reason("because we are testing the remark pipeline")
           << remark::suggest("try using the remark pipeline feature");
-
+      mlir::remark::passed(
+          loc,
+          remark::RemarkOpts::name("test-remark").category("category-1-passed"))
+          << remark::add("This is a test passed remark (should be dropped)")
+          << remark::reason("because we are testing the remark pipeline")
+          << remark::suggest("try using the remark pipeline feature");
       mlir::remark::passed(
           loc,
           remark::RemarkOpts::name("test-remark").category("category-1-passed"))
diff --git a/mlir/unittests/IR/RemarkTest.cpp b/mlir/unittests/IR/RemarkTest.cpp
index 5bfca255c22ca..77840c6094118 100644
--- a/mlir/unittests/IR/RemarkTest.cpp
+++ b/mlir/unittests/IR/RemarkTest.cpp
@@ -53,10 +53,12 @@ TEST(Remark, TestOutputOptimizationRemark) {
                                         /*missed=*/categoryUnroll,
                                         /*analysis=*/categoryRegister,
                                         /*failed=*/categoryInliner};
-
+    std::unique_ptr<remark::RemarkEmittingPolicyAll> policy =
+        std::make_unique<remark::RemarkEmittingPolicyAll>();
     LogicalResult isEnabled =
         mlir::remark::enableOptimizationRemarksWithLLVMStreamer(
-            context, yamlFile, llvm::remarks::Format::YAML, cats);
+            context, yamlFile, llvm::remarks::Format::YAML, std::move(policy),
+            cats);
     ASSERT_TRUE(succeeded(isEnabled)) << "Failed to enable remark engine";
 
     // PASS: something succeeded
@@ -203,9 +205,10 @@ TEST(Remark, TestOutputOptimizationRemarkDiagnostic) {
                                         /*missed=*/categoryUnroll,
                                         /*analysis=*/categoryRegister,
                                         /*failed=*/categoryUnroll};
-
-    LogicalResult isEnabled =
-        remark::enableOptimizationRemarks(context, nullptr, cats, true);
+    std::unique_ptr<remark::RemarkEmittingPolicyAll> policy =
+        std::make_unique<remark::RemarkEmittingPolicyAll>();
+    LogicalResult isEnabled = remark::enableOptimizationRemarks(
+        context, nullptr, std::move(policy), cats, true);
 
     ASSERT_TRUE(succeeded(isEnabled)) << "Failed to enable remark engine";
 
@@ -286,8 +289,11 @@ TEST(Remark, TestCustomOptimizationRemarkDiagnostic) {
                                         /*analysis=*/std::nullopt,
                                         /*failed=*/categoryLoopunroll};
 
+    std::unique_ptr<remark::RemarkEmittingPolicyAll> policy =
+        std::make_unique<remark::RemarkEmittingPolicyAll>();
     LogicalResult isEnabled = remark::enableOptimizationRemarks(
-        context, std::make_unique<MyCustomStreamer>(), cats, true);
+        context, std::make_unique<MyCustomStreamer>(), std::move(policy), cats,
+        true);
     ASSERT_TRUE(succeeded(isEnabled)) << "Failed to enable remark engine";
 
     // Remark 1: pass, category LoopUnroll
@@ -315,4 +321,73 @@ TEST(Remark, TestCustomOptimizationRemarkDiagnostic) {
   EXPECT_NE(errOut.find(pass2Msg), std::string::npos); // printed
   EXPECT_EQ(errOut.find(pass3Msg), std::string::npos); // filtered out
 }
+
+TEST(Remark, TestRemarkFinal) {
+  testing::internal::CaptureStderr();
+  const auto *pass1Msg = "I failed";
+  const auto *pass2Msg = "I failed too";
+  const auto *pass3Msg = "I succeeded";
+  const auto *pass4Msg = "I succeeded too";
+
+  std::string categoryLoopunroll("LoopUnroll");
+  std::string myPassname1("myPass1");
+  std::string myPassname2("myPass2");
+  std::string myPassname3("myPass3");
+  std::string funcName("myFunc");
+
+  std::string seenMsg = "";
+
+  {
+    MLIRContext context;
+    Location loc = FileLineColLoc::get(&context, "test.cpp", 1, 5);
+    Location locOther = FileLineColLoc::get(&context, "test.cpp", 55, 5);
+
+    // Setup the remark engine
+    mlir::remark::RemarkCategories cats{/*all=*/"",
+                                        /*passed=*/categoryLoopunroll,
+                                        /*missed=*/categoryLoopunroll,
+                                        /*analysis=*/categoryLoopunroll,
+                                        /*failed=*/categoryLoopunroll};
+
+    std::unique_ptr<remark::RemarkEmittingPolicyFinal> policy =
+        std::make_unique<remark::RemarkEmittingPolicyFinal>();
+    LogicalResult isEnabled = remark::enableOptimizationRemarks(
+        context, std::make_unique<MyCustomStreamer>(), std::move(policy), cats,
+        true);
+    ASSERT_TRUE(succeeded(isEnabled)) << "Failed to enable remark engine";
+
+    // Remark 1: failure
+    remark::failed(loc, remark::RemarkOpts::name("Unroller")
+                            .category(categoryLoopunroll)
+                            .subCategory(myPassname1))
+        << pass1Msg;
+
+    // Remark 2: failure
+    remark::missed(loc, remark::RemarkOpts::name("Unroller")
+                            .category(categoryLoopunroll)
+                            .subCategory(myPassname2))
+        << remark::reason(pass2Msg);
+
+    // Remark 3: pass
+    remark::passed(loc, remark::RemarkOpts::name("Unroller")
+                            .category(categoryLoopunroll)
+                            .subCategory(myPassname3))
+        << pass3Msg;
+
+    // Remark 4: pass
+    remark::passed(locOther, remark::RemarkOpts::name("Unroller")
+                                 .category(categoryLoopunroll)
+                                 .subCategory(myPassname3))
+        << pass4Msg;
+  }
+
+  llvm::errs().flush();
+  std::string errOut = ::testing::internal::GetCapturedStderr();
+
+  // Containment checks for messages.
+  EXPECT_EQ(errOut.find(pass1Msg), std::string::npos); // dropped
+  EXPECT_EQ(errOut.find(pass2Msg), std::string::npos); // dropped
+  EXPECT_NE(errOut.find(pass3Msg), std::string::npos); // shown
+  EXPECT_NE(errOut.find(pass4Msg), std::string::npos); // shown
+}
 } // namespace

>From 63cbc946cef2b19dc16c3b428b550e13653b68e0 Mon Sep 17 00:00:00 2001
From: Guray Ozen <gozen at nvidia.com>
Date: Wed, 24 Sep 2025 16:00:26 +0200
Subject: [PATCH 2/3] fx

---
 mlir/include/mlir/IR/Remarks.h | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/mlir/include/mlir/IR/Remarks.h b/mlir/include/mlir/IR/Remarks.h
index 03c83c3e78a00..a0909373df5cf 100644
--- a/mlir/include/mlir/IR/Remarks.h
+++ b/mlir/include/mlir/IR/Remarks.h
@@ -340,12 +340,12 @@ class MLIRRemarkStreamerBase {
   virtual void finalize() {} // optional
 };
 
+using ReportFn = llvm::unique_function<void(const Remark &)>;
+
 /// Base class for MLIR remark emitting policies that is used to emit
 /// optimization remarks to the underlying remark streamer. The derived classes
 /// should implement the `reportRemark` method to provide the actual emitting
 /// implementation.
-using ReportFn = llvm::unique_function<void(const Remark &)>;
-
 class RemarkEmittingPolicyBase {
 protected:
   ReportFn reportImpl;
@@ -492,22 +492,33 @@ class RemarkEmittingPolicyAll : public detail::RemarkEmittingPolicyBase {
 /// Policy that emits final remarks.
 class RemarkEmittingPolicyFinal : public detail::RemarkEmittingPolicyBase {
 private:
-  /// Postponed remarks. They are deferred to the end of the pipeline, where the
-  /// user can intercept them for custom processing, otherwise they will be
-  /// reported on engine destruction.
+  /// user can intercept them for custom processing via a registered callback,
+  /// otherwise they will be reported on engine destruction.
   llvm::DenseSet<detail::Remark> postponedRemarks;
+  /// Optional user callback for intercepting postponed remarks.
+  std::function<void(const detail::Remark &)> postponedRemarkCallback;
 
 public:
   RemarkEmittingPolicyFinal();
 
+  /// Register a callback to intercept postponed remarks before they are
+  /// reported. The callback will be invoked for each postponed remark in
+  /// finalize().
+  void
+  setPostponedRemarkCallback(std::function<void(const detail::Remark &)> cb) {
+    postponedRemarkCallback = std::move(cb);
+  }
+
   void reportRemark(const detail::Remark &remark) override {
     postponedRemarks.erase(remark);
     postponedRemarks.insert(remark);
   }
   void finalize() override {
-    for (auto &remark : postponedRemarks)
+    for (auto &remark : postponedRemarks) {
+      if (postponedRemarkCallback)
+        postponedRemarkCallback(remark);
       reportImpl(remark);
-    postponedRemarks.clear();
+    }
   }
 };
 
@@ -570,8 +581,8 @@ inline detail::InFlightRemark analysis(Location loc, RemarkOpts opts) {
 
 /// Setup remarks for the context. This function will enable the remark engine
 /// and set the streamer to be used for optimization remarks. The remark
-/// categories are used to filter the remarks that will be emitted by the remark
-/// engine. If a category is not specified, it will not be emitted. If
+/// categories are used to filter the remarks that will be emitted by the
+/// remark engine. If a category is not specified, it will not be emitted. If
 /// `printAsEmitRemarks` is true, the remarks will be printed as
 /// mlir::emitRemarks. 'streamer' must inherit from MLIRRemarkStreamerBase and
 /// will be used to stream the remarks.

>From f303b91bd9e7bf85396c9e9796bb50e3227bf3ed Mon Sep 17 00:00:00 2001
From: Guray Ozen <gozen at nvidia.com>
Date: Wed, 24 Sep 2025 16:09:43 +0200
Subject: [PATCH 3/3] gx

---
 mlir/test/Pass/remark-final.mlir | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/mlir/test/Pass/remark-final.mlir b/mlir/test/Pass/remark-final.mlir
index cb4790b1a11e4..38af8a4bc245d 100644
--- a/mlir/test/Pass/remark-final.mlir
+++ b/mlir/test/Pass/remark-final.mlir
@@ -7,9 +7,6 @@ module @foo {
 
 // CHECK-NOT: This is a test passed remark (should be dropped)
 
-// CHECK: !Passed
-// CHECK: Remark:          This is a test passed remark
-// CHECK: !Analysis
-// CHECK: Remark:          This is a test analysis remark
-// CHECK: !Failure
-// CHECK: Remark:          This is a test failed remark
+// CHECK-DAG: !Analysis
+// CHECK-DAG: !Failure
+// CHECK-DAG: !Passed



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