Take OptimizationLevel class out of Pass Builder

Pulled out the OptimizationLevel class from PassBuilder in order to be able to access it from within the PassManager and avoid include conflicts.

Reviewed By: mtrofin

Differential Revision: https://reviews.llvm.org/D107025

Author: tarinduj

clang/lib/CodeGen/BackendUtil.cpp

@@ -1069,42 +1069,42 @@ void EmitAssemblyHelper::EmitAssembly(BackendAction Action,
     DwoOS->keep();
 }
 
-static PassBuilder::OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
+static OptimizationLevel mapToLevel(const CodeGenOptions &Opts) {
   switch (Opts.OptimizationLevel) {
   default:
     llvm_unreachable("Invalid optimization level!");
 
   case 0:
-    return PassBuilder::OptimizationLevel::O0;
+    return OptimizationLevel::O0;
 
   case 1:
-    return PassBuilder::OptimizationLevel::O1;
+    return OptimizationLevel::O1;
 
   case 2:
     switch (Opts.OptimizeSize) {
     default:
       llvm_unreachable("Invalid optimization level for size!");
 
     case 0:
-      return PassBuilder::OptimizationLevel::O2;
+      return OptimizationLevel::O2;
 
     case 1:
-      return PassBuilder::OptimizationLevel::Os;
+      return OptimizationLevel::Os;
 
     case 2:
-      return PassBuilder::OptimizationLevel::Oz;
+      return OptimizationLevel::Oz;
     }
 
   case 3:
-    return PassBuilder::OptimizationLevel::O3;
+    return OptimizationLevel::O3;
   }
 }
 
 static void addSanitizers(const Triple &TargetTriple,
                           const CodeGenOptions &CodeGenOpts,
                           const LangOptions &LangOpts, PassBuilder &PB) {
   PB.registerOptimizerLastEPCallback([&](ModulePassManager &MPM,
-                                         PassBuilder::OptimizationLevel Level) {
+                                         OptimizationLevel Level) {
     if (CodeGenOpts.hasSanitizeCoverage()) {
       auto SancovOpts = getSancovOptsFromCGOpts(CodeGenOpts);
       MPM.addPass(ModuleSanitizerCoveragePass(
@@ -1122,7 +1122,7 @@ static void addSanitizers(const Triple &TargetTriple,
         FunctionPassManager FPM;
         FPM.addPass(
             MemorySanitizerPass({TrackOrigins, Recover, CompileKernel}));
-        if (Level != PassBuilder::OptimizationLevel::O0) {
+        if (Level != OptimizationLevel::O0) {
           // MemorySanitizer inserts complex instrumentation that mostly
           // follows the logic of the original code, but operates on
           // "shadow" values. It can benefit from re-running some
@@ -1325,26 +1325,26 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
   if (!CodeGenOpts.DisableLLVMPasses) {
     // Map our optimization levels into one of the distinct levels used to
     // configure the pipeline.
-    PassBuilder::OptimizationLevel Level = mapToLevel(CodeGenOpts);
+    OptimizationLevel Level = mapToLevel(CodeGenOpts);
 
     bool IsThinLTO = CodeGenOpts.PrepareForThinLTO;
     bool IsLTO = CodeGenOpts.PrepareForLTO;
 
     if (LangOpts.ObjCAutoRefCount) {
       PB.registerPipelineStartEPCallback(
-          [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
-            if (Level != PassBuilder::OptimizationLevel::O0)
+          [](ModulePassManager &MPM, OptimizationLevel Level) {
+            if (Level != OptimizationLevel::O0)
               MPM.addPass(
                   createModuleToFunctionPassAdaptor(ObjCARCExpandPass()));
           });
       PB.registerPipelineEarlySimplificationEPCallback(
-          [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
-            if (Level != PassBuilder::OptimizationLevel::O0)
+          [](ModulePassManager &MPM, OptimizationLevel Level) {
+            if (Level != OptimizationLevel::O0)
               MPM.addPass(ObjCARCAPElimPass());
           });
       PB.registerScalarOptimizerLateEPCallback(
-          [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
-            if (Level != PassBuilder::OptimizationLevel::O0)
+          [](FunctionPassManager &FPM, OptimizationLevel Level) {
+            if (Level != OptimizationLevel::O0)
               FPM.addPass(ObjCARCOptPass());
           });
     }
@@ -1357,7 +1357,7 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
     // vtables so that codegen doesn't complain.
     if (IsThinLTOPostLink)
       PB.registerPipelineStartEPCallback(
-          [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
+          [](ModulePassManager &MPM, OptimizationLevel Level) {
             MPM.addPass(LowerTypeTestsPass(/*ExportSummary=*/nullptr,
                                            /*ImportSummary=*/nullptr,
                                            /*DropTypeTests=*/true));
@@ -1368,12 +1368,12 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
         CodeGenOpts.InstrumentFunctionsAfterInlining ||
         CodeGenOpts.InstrumentForProfiling) {
       PB.registerPipelineStartEPCallback(
-          [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
+          [](ModulePassManager &MPM, OptimizationLevel Level) {
             MPM.addPass(createModuleToFunctionPassAdaptor(
                 EntryExitInstrumenterPass(/*PostInlining=*/false)));
           });
       PB.registerOptimizerLastEPCallback(
-          [](ModulePassManager &MPM, PassBuilder::OptimizationLevel Level) {
+          [](ModulePassManager &MPM, OptimizationLevel Level) {
             MPM.addPass(createModuleToFunctionPassAdaptor(
                 EntryExitInstrumenterPass(/*PostInlining=*/true)));
           });
@@ -1383,7 +1383,7 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
     // of the pipeline.
     if (LangOpts.Sanitize.has(SanitizerKind::LocalBounds))
       PB.registerScalarOptimizerLateEPCallback(
-          [](FunctionPassManager &FPM, PassBuilder::OptimizationLevel Level) {
+          [](FunctionPassManager &FPM, OptimizationLevel Level) {
             FPM.addPass(BoundsCheckingPass());
           });
 
@@ -1394,15 +1394,13 @@ void EmitAssemblyHelper::EmitAssemblyWithNewPassManager(
 
     if (Optional<GCOVOptions> Options = getGCOVOptions(CodeGenOpts, LangOpts))
       PB.registerPipelineStartEPCallback(
-          [Options](ModulePassManager &MPM,
-                    PassBuilder::OptimizationLevel Level) {
+          [Options](ModulePassManager &MPM, OptimizationLevel Level) {
             MPM.addPass(GCOVProfilerPass(*Options));
           });
     if (Optional<InstrProfOptions> Options =
             getInstrProfOptions(CodeGenOpts, LangOpts))
       PB.registerPipelineStartEPCallback(
-          [Options](ModulePassManager &MPM,
-                    PassBuilder::OptimizationLevel Level) {
+          [Options](ModulePassManager &MPM, OptimizationLevel Level) {
             MPM.addPass(InstrProfiling(*Options, false));
           });
 

llvm/examples/Bye/Bye.cpp

@@ -55,8 +55,7 @@ llvm::PassPluginLibraryInfo getByePluginInfo() {
   return {LLVM_PLUGIN_API_VERSION, "Bye", LLVM_VERSION_STRING,
           [](PassBuilder &PB) {
             PB.registerVectorizerStartEPCallback(
-                [](llvm::FunctionPassManager &PM,
-                   llvm::PassBuilder::OptimizationLevel Level) {
+                [](llvm::FunctionPassManager &PM, OptimizationLevel Level) {
                   PM.addPass(Bye());
                 });
             PB.registerPipelineParsingCallback(

llvm/include/llvm/Passes/OptimizationLevel.h

@@ -0,0 +1,127 @@
+//===-------- LLVM-provided High-Level Optimization levels -*- 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
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// This header enumerates the LLVM-provided high-level optimization levels.
+/// Each level has a specific goal and rationale.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_PASSES_OPTIMIZATIONLEVEL_H
+#define LLVM_PASSES_OPTIMIZATIONLEVEL_H
+
+#include <assert.h>
+
+namespace llvm {
+
+class OptimizationLevel final {
+  unsigned SpeedLevel = 2;
+  unsigned SizeLevel = 0;
+  OptimizationLevel(unsigned SpeedLevel, unsigned SizeLevel)
+      : SpeedLevel(SpeedLevel), SizeLevel(SizeLevel) {
+    // Check that only valid combinations are passed.
+    assert(SpeedLevel <= 3 &&
+           "Optimization level for speed should be 0, 1, 2, or 3");
+    assert(SizeLevel <= 2 &&
+           "Optimization level for size should be 0, 1, or 2");
+    assert((SizeLevel == 0 || SpeedLevel == 2) &&
+           "Optimize for size should be encoded with speedup level == 2");
+  }
+
+public:
+  OptimizationLevel() = default;
+  /// Disable as many optimizations as possible. This doesn't completely
+  /// disable the optimizer in all cases, for example always_inline functions
+  /// can be required to be inlined for correctness.
+  static const OptimizationLevel O0;
+
+  /// Optimize quickly without destroying debuggability.
+  ///
+  /// This level is tuned to produce a result from the optimizer as quickly
+  /// as possible and to avoid destroying debuggability. This tends to result
+  /// in a very good development mode where the compiled code will be
+  /// immediately executed as part of testing. As a consequence, where
+  /// possible, we would like to produce efficient-to-execute code, but not
+  /// if it significantly slows down compilation or would prevent even basic
+  /// debugging of the resulting binary.
+  ///
+  /// As an example, complex loop transformations such as versioning,
+  /// vectorization, or fusion don't make sense here due to the degree to
+  /// which the executed code differs from the source code, and the compile
+  /// time cost.
+  static const OptimizationLevel O1;
+  /// Optimize for fast execution as much as possible without triggering
+  /// significant incremental compile time or code size growth.
+  ///
+  /// The key idea is that optimizations at this level should "pay for
+  /// themselves". So if an optimization increases compile time by 5% or
+  /// increases code size by 5% for a particular benchmark, that benchmark
+  /// should also be one which sees a 5% runtime improvement. If the compile
+  /// time or code size penalties happen on average across a diverse range of
+  /// LLVM users' benchmarks, then the improvements should as well.
+  ///
+  /// And no matter what, the compile time needs to not grow superlinearly
+  /// with the size of input to LLVM so that users can control the runtime of
+  /// the optimizer in this mode.
+  ///
+  /// This is expected to be a good default optimization level for the vast
+  /// majority of users.
+  static const OptimizationLevel O2;
+  /// Optimize for fast execution as much as possible.
+  ///
+  /// This mode is significantly more aggressive in trading off compile time
+  /// and code size to get execution time improvements. The core idea is that
+  /// this mode should include any optimization that helps execution time on
+  /// balance across a diverse collection of benchmarks, even if it increases
+  /// code size or compile time for some benchmarks without corresponding
+  /// improvements to execution time.
+  ///
+  /// Despite being willing to trade more compile time off to get improved
+  /// execution time, this mode still tries to avoid superlinear growth in
+  /// order to make even significantly slower compile times at least scale
+  /// reasonably. This does not preclude very substantial constant factor
+  /// costs though.
+  static const OptimizationLevel O3;
+  /// Similar to \c O2 but tries to optimize for small code size instead of
+  /// fast execution without triggering significant incremental execution
+  /// time slowdowns.
+  ///
+  /// The logic here is exactly the same as \c O2, but with code size and
+  /// execution time metrics swapped.
+  ///
+  /// A consequence of the different core goal is that this should in general
+  /// produce substantially smaller executables that still run in
+  /// a reasonable amount of time.
+  static const OptimizationLevel Os;
+  /// A very specialized mode that will optimize for code size at any and all
+  /// costs.
+  ///
+  /// This is useful primarily when there are absolute size limitations and
+  /// any effort taken to reduce the size is worth it regardless of the
+  /// execution time impact. You should expect this level to produce rather
+  /// slow, but very small, code.
+  static const OptimizationLevel Oz;
+
+  bool isOptimizingForSpeed() const { return SizeLevel == 0 && SpeedLevel > 0; }
+
+  bool isOptimizingForSize() const { return SizeLevel > 0; }
+
+  bool operator==(const OptimizationLevel &Other) const {
+    return SizeLevel == Other.SizeLevel && SpeedLevel == Other.SpeedLevel;
+  }
+  bool operator!=(const OptimizationLevel &Other) const {
+    return SizeLevel != Other.SizeLevel || SpeedLevel != Other.SpeedLevel;
+  }
+
+  unsigned getSpeedupLevel() const { return SpeedLevel; }
+
+  unsigned getSizeLevel() const { return SizeLevel; }
+};
+} // namespace llvm
+
+#endif