[PGO] Add PGO support at -O0 in the experimental new pass manager

Add PGO support at -O0 in the experimental new pass manager to sync the
behavior of the legacy pass manager.

Also change the test of gcc-flag-compatibility.c for more complete test:
(1) change the match string to "profc" and "profd" to ensure the
    instrumentation is happening.
(2) add IR format proftext so that PGO use compilation is tested.

Differential Revision: https://reviews.llvm.org/D64029

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367628 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Passes/PassBuilder.h b/include/llvm/Passes/PassBuilder.h
index 5e6660599f93416e34a15ba332ad76380467b325..f73e4b42dd4bf5aa3bab27a73dca3588ca601887 100644 (file)
--- a/include/llvm/Passes/PassBuilder.h
+++ b/include/llvm/Passes/PassBuilder.h
@@ -629,6 +629,12 @@ public:
     TopLevelPipelineParsingCallbacks.push_back(C);
   }
 
+  /// Add PGOInstrumenation passes for O0 only.
+  void addPGOInstrPassesForO0(ModulePassManager &MPM, bool DebugLogging,
+                              bool RunProfileGen, bool IsCS,
+                              std::string ProfileFile,
+                              std::string ProfileRemappingFile);
+
 private:
   static Optional<std::vector<PipelineElement>>
   parsePipelineText(StringRef Text);
@@ -660,7 +666,6 @@ private:
                          OptimizationLevel Level, bool RunProfileGen, bool IsCS,
                          std::string ProfileFile,
                          std::string ProfileRemappingFile);
-
   void invokePeepholeEPCallbacks(FunctionPassManager &, OptimizationLevel);
 
   // Extension Point callbacks

diff --git a/lib/Passes/PassBuilder.cpp b/lib/Passes/PassBuilder.cpp
index eef94bf9012a2e3dca13690a8c1b3c51de846bb5..6cb6afa00d83b5b35f77f0561b80d63d0c1b5d82 100644 (file)
--- a/lib/Passes/PassBuilder.cpp
+++ b/lib/Passes/PassBuilder.cpp
@@ -541,6 +541,7 @@ void PassBuilder::addPGOInstrPasses(ModulePassManager &MPM, bool DebugLogging,
                                     bool RunProfileGen, bool IsCS,
                                     std::string ProfileFile,
                                     std::string ProfileRemappingFile) {
+  assert(Level != O0 && "Not expecting O0 here!");
   // Generally running simplification passes and the inliner with an high
   // threshold results in smaller executables, but there may be cases where
   // the size grows, so let's be conservative here and skip this simplification
@@ -571,34 +572,62 @@ void PassBuilder::addPGOInstrPasses(ModulePassManager &MPM, bool DebugLogging,
     CGPipeline.addPass(createCGSCCToFunctionPassAdaptor(std::move(FPM)));
 
     MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPipeline)));
+
+    // Delete anything that is now dead to make sure that we don't instrument
+    // dead code. Instrumentation can end up keeping dead code around and
+    // dramatically increase code size.
+    MPM.addPass(GlobalDCEPass());
   }
 
-  // Delete anything that is now dead to make sure that we don't instrument
-  // dead code. Instrumentation can end up keeping dead code around and
-  // dramatically increase code size.
-  MPM.addPass(GlobalDCEPass());
+  if (!RunProfileGen) {
+    assert(!ProfileFile.empty() && "Profile use expecting a profile file!");
+    MPM.addPass(PGOInstrumentationUse(ProfileFile, ProfileRemappingFile, IsCS));
+    // Cache ProfileSummaryAnalysis once to avoid the potential need to insert
+    // RequireAnalysisPass for PSI before subsequent non-module passes.
+    MPM.addPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
+    return;
+  }
 
-  if (RunProfileGen) {
-    MPM.addPass(PGOInstrumentationGen(IsCS));
+  // Perform PGO instrumentation.
+  MPM.addPass(PGOInstrumentationGen(IsCS));
 
-    FunctionPassManager FPM;
-    FPM.addPass(
-        createFunctionToLoopPassAdaptor(LoopRotatePass(), DebugLogging));
-    MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
-
-    // Add the profile lowering pass.
-    InstrProfOptions Options;
-    if (!ProfileFile.empty())
-      Options.InstrProfileOutput = ProfileFile;
-    Options.DoCounterPromotion = true;
-    Options.UseBFIInPromotion = IsCS;
-    MPM.addPass(InstrProfiling(Options, IsCS));
-  } else if (!ProfileFile.empty()) {
+  FunctionPassManager FPM;
+  FPM.addPass(createFunctionToLoopPassAdaptor(LoopRotatePass(), DebugLogging));
+  MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
+
+  // Add the profile lowering pass.
+  InstrProfOptions Options;
+  if (!ProfileFile.empty())
+    Options.InstrProfileOutput = ProfileFile;
+  // Do counter promotion at Level greater than O0.
+  Options.DoCounterPromotion = true;
+  Options.UseBFIInPromotion = IsCS;
+  MPM.addPass(InstrProfiling(Options, IsCS));
+}
+
+void PassBuilder::addPGOInstrPassesForO0(ModulePassManager &MPM,
+                                         bool DebugLogging, bool RunProfileGen,
+                                         bool IsCS, std::string ProfileFile,
+                                         std::string ProfileRemappingFile) {
+  if (!RunProfileGen) {
+    assert(!ProfileFile.empty() && "Profile use expecting a profile file!");
     MPM.addPass(PGOInstrumentationUse(ProfileFile, ProfileRemappingFile, IsCS));
     // Cache ProfileSummaryAnalysis once to avoid the potential need to insert
     // RequireAnalysisPass for PSI before subsequent non-module passes.
     MPM.addPass(RequireAnalysisPass<ProfileSummaryAnalysis, Module>());
+    return;
   }
+
+  // Perform PGO instrumentation.
+  MPM.addPass(PGOInstrumentationGen(IsCS));
+  // Add the profile lowering pass.
+  InstrProfOptions Options;
+  if (!ProfileFile.empty())
+    Options.InstrProfileOutput = ProfileFile;
+  // Do not do counter promotion at O0.
+  Options.DoCounterPromotion = false;
+  Options.UseBFIInPromotion = IsCS;
+  MPM.addPass(InstrProfiling(Options, IsCS));
 }
 
 static InlineParams
@@ -1801,9 +1830,19 @@ Error PassBuilder::parseModulePass(ModulePassManager &MPM,
                               .Case("O3", O3)
                               .Case("Os", Os)
                               .Case("Oz", Oz);
-    if (L == O0)
-      // At O0 we do nothing at all!
+    if (L == O0) {
+      // Add instrumentation PGO passes -- at O0 we can still do PGO.
+      if (PGOOpt && Matches[1] != "thinlto" &&
+          (PGOOpt->Action == PGOOptions::IRInstr ||
+           PGOOpt->Action == PGOOptions::IRUse))
+        addPGOInstrPassesForO0(
+            MPM, DebugLogging,
+            /* RunProfileGen */ (PGOOpt->Action == PGOOptions::IRInstr),
+            /* IsCS */ false, PGOOpt->ProfileFile,
+            PGOOpt->ProfileRemappingFile);
+      // Do nothing else at all!
       return Error::success();
+    }
 
     if (Matches[1] == "default") {
       MPM.addPass(buildPerModuleDefaultPipeline(L, DebugLogging));

diff --git a/test/Other/new-pm-pgo-O0.ll b/test/Other/new-pm-pgo-O0.ll
new file mode 100644 (file)
index 0000000..6a6da67
--- /dev/null
+++ b/test/Other/new-pm-pgo-O0.ll
@@ -0,0 +1,21 @@
+; RUN: opt -debug-pass-manager -passes='default<O0>' -pgo-kind=pgo-instr-gen-pipeline -profile-file='temp' %s 2>&1 |FileCheck %s --check-prefixes=GEN
+; RUN: llvm-profdata merge %S/Inputs/new-pm-pgo.proftext -o %t.profdata
+; RUN: opt -debug-pass-manager -passes='default<O0>' -pgo-kind=pgo-instr-use-pipeline -profile-file='%t.profdata' %s 2>&1 |FileCheck %s --check-prefixes=USE_DEFAULT,USE
+; RUN: opt -debug-pass-manager -passes='thinlto-pre-link<O0>' -pgo-kind=pgo-instr-use-pipeline -profile-file='%t.profdata' %s 2>&1 \
+; RUN:     |FileCheck %s --check-prefixes=USE_PRE_LINK,USE
+; RUN: opt -debug-pass-manager -passes='lto-pre-link<O0>' -pgo-kind=pgo-instr-use-pipeline -profile-file='%t.profdata' %s 2>&1 \
+; RUN:     |FileCheck %s --check-prefixes=USE_PRE_LINK,USE
+; RUN: opt -debug-pass-manager -passes='thinlto<O0>' -pgo-kind=pgo-instr-use-pipeline -profile-file='%t.profdata' %s 2>&1 \
+; RUN:     |FileCheck %s --check-prefixes=USE_POST_LINK,USE
+
+;
+; GEN: Running pass: PGOInstrumentationGen
+; USE_DEFAULT: Running pass: PGOInstrumentationUse
+; USE_PRE_LINK: Running pass: PGOInstrumentationUse
+; USE_POST_LINK-NOT: Running pass: PGOInstrumentationUse
+; USE-NOT: Running pass: PGOIndirectCallPromotion
+; USE-NOT: Running pass: PGOMemOPSizeOpt
+
+define void @foo() {
+  ret void
+}