[llvm] [IR] Move RepeatedPass into separate header (NFC) (PR #96211)

[Nikita Popov via llvm-commits]

https://github.com/nikic created https://github.com/llvm/llvm-project/pull/96211

I don't think there is a good reason for this pass to be part of the core PassManager.h header (which is included ~everywhere), so move it into a separate one. This should enable us to also drop the PassInstrumentation.h include in PassManager.h in a followup.

>From 671ba6d476c1e4e395d75ea9989d234c1e6ad26f Mon Sep 17 00:00:00 2001
From: Nikita Popov <npopov at redhat.com>
Date: Thu, 20 Jun 2024 17:51:13 +0200
Subject: [PATCH] [IR] Move RepeatedPass into separate header (NFC)

I don't think there is a good reason for this pass to be part of
the core PassManager.h header, so move it into a separate one.
This should enable us to also drop the PassInstrumentation.h
include in PassManager.h in a followup.
---
 llvm/include/llvm/IR/PassManager.h            | 52 --------------
 llvm/include/llvm/IR/RepeatedPass.h           | 70 +++++++++++++++++++
 .../llvm/Transforms/Scalar/LoopPassManager.h  |  1 +
 3 files changed, 71 insertions(+), 52 deletions(-)
 create mode 100644 llvm/include/llvm/IR/RepeatedPass.h

diff --git a/llvm/include/llvm/IR/PassManager.h b/llvm/include/llvm/IR/PassManager.h
index 5661a1d58c8ec..65ba524bf49c4 100644
--- a/llvm/include/llvm/IR/PassManager.h
+++ b/llvm/include/llvm/IR/PassManager.h
@@ -950,58 +950,6 @@ struct InvalidateAllAnalysesPass : PassInfoMixin<InvalidateAllAnalysesPass> {
   }
 };
 
-/// A utility pass template that simply runs another pass multiple times.
-///
-/// This can be useful when debugging or testing passes. It also serves as an
-/// example of how to extend the pass manager in ways beyond composition.
-template <typename PassT>
-class RepeatedPass : public PassInfoMixin<RepeatedPass<PassT>> {
-public:
-  RepeatedPass(int Count, PassT &&P)
-      : Count(Count), P(std::forward<PassT>(P)) {}
-
-  template <typename IRUnitT, typename AnalysisManagerT, typename... Ts>
-  PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM, Ts &&... Args) {
-
-    // Request PassInstrumentation from analysis manager, will use it to run
-    // instrumenting callbacks for the passes later.
-    // Here we use std::tuple wrapper over getResult which helps to extract
-    // AnalysisManager's arguments out of the whole Args set.
-    PassInstrumentation PI =
-        detail::getAnalysisResult<PassInstrumentationAnalysis>(
-            AM, IR, std::tuple<Ts...>(Args...));
-
-    auto PA = PreservedAnalyses::all();
-    for (int i = 0; i < Count; ++i) {
-      // Check the PassInstrumentation's BeforePass callbacks before running the
-      // pass, skip its execution completely if asked to (callback returns
-      // false).
-      if (!PI.runBeforePass<IRUnitT>(P, IR))
-        continue;
-      PreservedAnalyses IterPA = P.run(IR, AM, std::forward<Ts>(Args)...);
-      PA.intersect(IterPA);
-      PI.runAfterPass(P, IR, IterPA);
-    }
-    return PA;
-  }
-
-  void printPipeline(raw_ostream &OS,
-                     function_ref<StringRef(StringRef)> MapClassName2PassName) {
-    OS << "repeat<" << Count << ">(";
-    P.printPipeline(OS, MapClassName2PassName);
-    OS << ')';
-  }
-
-private:
-  int Count;
-  PassT P;
-};
-
-template <typename PassT>
-RepeatedPass<PassT> createRepeatedPass(int Count, PassT &&P) {
-  return RepeatedPass<PassT>(Count, std::forward<PassT>(P));
-}
-
 } // end namespace llvm
 
 #endif // LLVM_IR_PASSMANAGER_H
diff --git a/llvm/include/llvm/IR/RepeatedPass.h b/llvm/include/llvm/IR/RepeatedPass.h
new file mode 100644
index 0000000000000..902324bc28a60
--- /dev/null
+++ b/llvm/include/llvm/IR/RepeatedPass.h
@@ -0,0 +1,70 @@
+//===- RepeatedPass.h - Runs another pass multiple times --------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_IR_REPEATEDPASS_H
+#define LLVM_IR_REPEATEDPASS_H
+
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+/// A utility pass template that simply runs another pass multiple times.
+///
+/// This can be useful when debugging or testing passes. It also serves as an
+/// example of how to extend the pass manager in ways beyond composition.
+template <typename PassT>
+class RepeatedPass : public PassInfoMixin<RepeatedPass<PassT>> {
+public:
+  RepeatedPass(int Count, PassT &&P)
+      : Count(Count), P(std::forward<PassT>(P)) {}
+
+  template <typename IRUnitT, typename AnalysisManagerT, typename... Ts>
+  PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM, Ts &&... Args) {
+
+    // Request PassInstrumentation from analysis manager, will use it to run
+    // instrumenting callbacks for the passes later.
+    // Here we use std::tuple wrapper over getResult which helps to extract
+    // AnalysisManager's arguments out of the whole Args set.
+    PassInstrumentation PI =
+        detail::getAnalysisResult<PassInstrumentationAnalysis>(
+            AM, IR, std::tuple<Ts...>(Args...));
+
+    auto PA = PreservedAnalyses::all();
+    for (int i = 0; i < Count; ++i) {
+      // Check the PassInstrumentation's BeforePass callbacks before running the
+      // pass, skip its execution completely if asked to (callback returns
+      // false).
+      if (!PI.runBeforePass<IRUnitT>(P, IR))
+        continue;
+      PreservedAnalyses IterPA = P.run(IR, AM, std::forward<Ts>(Args)...);
+      PA.intersect(IterPA);
+      PI.runAfterPass(P, IR, IterPA);
+    }
+    return PA;
+  }
+
+  void printPipeline(raw_ostream &OS,
+                     function_ref<StringRef(StringRef)> MapClassName2PassName) {
+    OS << "repeat<" << Count << ">(";
+    P.printPipeline(OS, MapClassName2PassName);
+    OS << ')';
+  }
+
+private:
+  int Count;
+  PassT P;
+};
+
+template <typename PassT>
+RepeatedPass<PassT> createRepeatedPass(int Count, PassT &&P) {
+  return RepeatedPass<PassT>(Count, std::forward<PassT>(P));
+}
+
+} // end namespace llvm
+
+#endif // LLVM_IR_REPEATEDPASS_H
diff --git a/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h b/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
index 6aab1f98e6781..5807892230abb 100644
--- a/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
+++ b/llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
@@ -41,6 +41,7 @@
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/LoopNestAnalysis.h"
 #include "llvm/IR/PassManager.h"
+#include "llvm/IR/RepeatedPass.h"
 #include "llvm/Transforms/Utils/LCSSA.h"
 #include "llvm/Transforms/Utils/LoopSimplify.h"
 #include "llvm/Transforms/Utils/LoopUtils.h"