Reapply r271728 after adding move cobstructor for ProfileSummaryInfo

llvm-svn: 271745

llvm/include/llvm/Analysis/ProfileSummaryInfo.h

@@ -0,0 +1,113 @@
+//===- llvm/Analysis/ProfileSummaryInfo.h - profile summary ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains a pass that provides access to profile summary
+// information.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_PROFILE_SUMMARY_INFO_H
+#define LLVM_ANALYSIS_PROFILE_SUMMARY_INFO_H
+
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/IR/ProfileSummary.h"
+#include "llvm/IR/ValueHandle.h"
+#include "llvm/Pass.h"
+#include <memory>
+
+namespace llvm {
+class ProfileSummary;
+/// \brief Analysis providing profile information.
+///
+/// This is an immutable analysis pass that provides ability to query global
+/// (program-level) profile information. The main APIs are isHotCount and
+/// isColdCount that tells whether a given profile count is considered hot/cold
+/// based on the profile summary. This also provides convenience methods to
+/// check whether a function is hot or cold.
+
+// FIXME: Provide convenience methods to determine hotness/coldness of other IR
+// units. This would require making this depend on BFI.
+class ProfileSummaryInfo {
+private:
+  Module &M;
+  std::unique_ptr<ProfileSummary> Summary;
+  void computeSummary();
+  void computeThresholds();
+  // Count thresholds to answer isHotCount and isColdCount queries.
+  Optional<uint64_t> HotCountThreshold, ColdCountThreshold;
+
+public:
+  ProfileSummaryInfo(Module &M) : M(M) {}
+  ProfileSummaryInfo(ProfileSummaryInfo &&Arg)
+      : M(Arg.M), Summary(std::move(Arg.Summary)) {}
+  /// \brief Returns true if \p F is a hot function.
+  bool isHotFunction(const Function *F);
+  /// \brief Returns true if \p F is a cold function.
+  bool isColdFunction(const Function *F);
+  /// \brief Returns true if count \p C is considered hot.
+  bool isHotCount(uint64_t C);
+  /// \brief Returns true if count \p C is considered cold.
+  bool isColdCount(uint64_t C);
+};
+
+/// An analysis pass based on legacy pass manager to deliver ProfileSummaryInfo.
+class ProfileSummaryInfoWrapperPass : public ImmutablePass {
+  std::unique_ptr<ProfileSummaryInfo> PSI;
+
+public:
+  static char ID;
+  ProfileSummaryInfoWrapperPass();
+
+  ProfileSummaryInfo *getPSI(Module &M);
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesAll();
+  }
+};
+
+/// An analysis pass based on the new PM to deliver ProfileSummaryInfo.
+class ProfileSummaryAnalysis
+    : public AnalysisInfoMixin<ProfileSummaryAnalysis> {
+public:
+  typedef ProfileSummaryInfo Result;
+
+  ProfileSummaryAnalysis() {}
+  ProfileSummaryAnalysis(const ProfileSummaryAnalysis &Arg) {}
+  ProfileSummaryAnalysis(ProfileSummaryAnalysis &&Arg) {}
+  ProfileSummaryAnalysis &operator=(const ProfileSummaryAnalysis &RHS) {
+    return *this;
+  }
+  ProfileSummaryAnalysis &operator=(ProfileSummaryAnalysis &&RHS) {
+    return *this;
+  }
+
+  Result run(Module &M);
+
+private:
+  friend AnalysisInfoMixin<ProfileSummaryAnalysis>;
+  static char PassID;
+};
+
+/// \brief Printer pass that uses \c ProfileSummaryAnalysis.
+class ProfileSummaryPrinterPass
+    : public PassInfoMixin<ProfileSummaryPrinterPass> {
+  raw_ostream &OS;
+
+public:
+  explicit ProfileSummaryPrinterPass(raw_ostream &OS) : OS(OS) {}
+  PreservedAnalyses run(Module &M, AnalysisManager<Module> &AM);
+};
+
+} // end namespace llvm
+
+#endif

llvm/include/llvm/InitializePasses.h

@@ -254,6 +254,7 @@ void initializePreISelIntrinsicLoweringPass(PassRegistry&);
 void initializePrintFunctionPassWrapperPass(PassRegistry&);
 void initializePrintModulePassWrapperPass(PassRegistry&);
 void initializePrintBasicBlockPassPass(PassRegistry&);
+void initializeProfileSummaryInfoWrapperPassPass(PassRegistry &);
 void initializeProcessImplicitDefsPass(PassRegistry&);
 void initializePromotePassPass(PassRegistry&);
 void initializePruneEHPass(PassRegistry&);

llvm/lib/Analysis/CMakeLists.txt

@@ -57,6 +57,7 @@ add_llvm_library(LLVMAnalysis
   OrderedBasicBlock.cpp
   PHITransAddr.cpp
   PostDominators.cpp
+  ProfileSummaryInfo.cpp
   PtrUseVisitor.cpp
   RegionInfo.cpp
   RegionPass.cpp

llvm/lib/Analysis/ProfileSummaryInfo.cpp

@@ -0,0 +1,161 @@
+//===- ProfileSummaryInfo.cpp - Global profile summary information --------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains a pass that provides access to the global profile summary
+// information.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/ProfileSummaryInfo.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/ProfileSummary.h"
+using namespace llvm;
+
+// The following two parameters determine the threshold for a count to be
+// considered hot/cold. These two parameters are percentile values (multiplied
+// by 10000). If the counts are sorted in descending order, the minimum count to
+// reach ProfileSummaryCutoffHot gives the threshold to determine a hot count.
+// Similarly, the minimum count to reach ProfileSummaryCutoffCold gives the
+// threshold for determining cold count (everything <= this threshold is
+// considered cold).
+
+static cl::opt<int> ProfileSummaryCutoffHot(
+    "profile-summary-cutoff-hot", cl::Hidden, cl::init(999000), cl::ZeroOrMore,
+    cl::desc("A count is hot if it exceeds the minimum count to"
+             " reach this percentile of total counts."));
+
+static cl::opt<int> ProfileSummaryCutoffCold(
+    "profile-summary-cutoff-cold", cl::Hidden, cl::init(999999), cl::ZeroOrMore,
+    cl::desc("A count is cold if it is below the minimum count"
+             " to reach this percentile of total counts."));
+
+// Find the minimum count to reach a desired percentile of counts.
+static uint64_t getMinCountForPercentile(SummaryEntryVector &DS,
+                                         uint64_t Percentile) {
+  auto Compare = [](const ProfileSummaryEntry &Entry, uint64_t Percentile) {
+    return Entry.Cutoff < Percentile;
+  };
+  auto It = std::lower_bound(DS.begin(), DS.end(), Percentile, Compare);
+  // The required percentile has to be <= one of the percentiles in the
+  // detailed summary.
+  if (It == DS.end())
+    report_fatal_error("Desired percentile exceeds the maximum cutoff");
+  return It->MinCount;
+}
+
+// The profile summary metadata may be attached either by the frontend or by
+// any backend passes (IR level instrumentation, for example). This method
+// checks if the Summary is null and if so checks if the summary metadata is now
+// available in the module and parses it to get the Summary object.
+void ProfileSummaryInfo::computeSummary() {
+  if (Summary)
+    return;
+  auto *SummaryMD = M.getProfileSummary();
+  if (!SummaryMD)
+    return;
+  Summary.reset(ProfileSummary::getFromMD(SummaryMD));
+}
+
+// Returns true if the function is a hot function. If it returns false, it
+// either means it is not hot or it is unknown whether F is hot or not (for
+// example, no profile data is available).
+bool ProfileSummaryInfo::isHotFunction(const Function *F) {
+  computeSummary();
+  if (!F || !Summary)
+    return false;
+  auto FunctionCount = F->getEntryCount();
+  // FIXME: The heuristic used below for determining hotness is based on
+  // preliminary SPEC tuning for inliner. This will eventually be a
+  // convenience method that calls isHotCount.
+  return (FunctionCount &&
+          FunctionCount.getValue() >=
+              (uint64_t)(0.3 * (double)Summary->getMaxFunctionCount()));
+}
+
+// Returns true if the function is a cold function. If it returns false, it
+// either means it is not cold or it is unknown whether F is cold or not (for
+// example, no profile data is available).
+bool ProfileSummaryInfo::isColdFunction(const Function *F) {
+  computeSummary();
+  if (F->hasFnAttribute(Attribute::Cold)) {
+    return true;
+  }
+  auto FunctionCount = F->getEntryCount();
+  // FIXME: The heuristic used below for determining coldness is based on
+  // preliminary SPEC tuning for inliner. This will eventually be a
+  // convenience method that calls isHotCount.
+  return (FunctionCount &&
+          FunctionCount.getValue() <=
+              (uint64_t)(0.01 * (double)Summary->getMaxFunctionCount()));
+}
+
+// Compute the hot and cold thresholds.
+void ProfileSummaryInfo::computeThresholds() {
+  if (!Summary)
+    computeSummary();
+  if (!Summary)
+    return;
+  auto &DetailedSummary = Summary->getDetailedSummary();
+  HotCountThreshold =
+      getMinCountForPercentile(DetailedSummary, ProfileSummaryCutoffHot);
+  ColdCountThreshold =
+      getMinCountForPercentile(DetailedSummary, ProfileSummaryCutoffCold);
+}
+
+bool ProfileSummaryInfo::isHotCount(uint64_t C) {
+  if (!HotCountThreshold)
+    computeThresholds();
+  return HotCountThreshold && C >= HotCountThreshold.getValue();
+}
+
+bool ProfileSummaryInfo::isColdCount(uint64_t C) {
+  if (!ColdCountThreshold)
+    computeThresholds();
+  return ColdCountThreshold && C <= ColdCountThreshold.getValue();
+}
+
+ProfileSummaryInfo *ProfileSummaryInfoWrapperPass::getPSI(Module &M) {
+  if (!PSI)
+    PSI.reset(new ProfileSummaryInfo(M));
+  return PSI.get();
+}
+
+INITIALIZE_PASS(ProfileSummaryInfoWrapperPass, "profile-summary-info",
+                "Profile summary info", false, true)
+
+ProfileSummaryInfoWrapperPass::ProfileSummaryInfoWrapperPass()
+    : ImmutablePass(ID) {
+  initializeProfileSummaryInfoWrapperPassPass(*PassRegistry::getPassRegistry());
+}
+
+char ProfileSummaryAnalysis::PassID;
+ProfileSummaryInfo ProfileSummaryAnalysis::run(Module &M) {
+  return ProfileSummaryInfo(M);
+}
+
+// FIXME: This only tests isHotFunction and isColdFunction and not the
+// isHotCount and isColdCount calls.
+PreservedAnalyses ProfileSummaryPrinterPass::run(Module &M,
+                                                 AnalysisManager<Module> &AM) {
+  ProfileSummaryInfo &PSI = AM.getResult<ProfileSummaryAnalysis>(M);
+
+  OS << "Functions in " << M.getName() << " with hot/cold annotations: \n";
+  for (auto &F : M) {
+    OS << F.getName();
+    if (PSI.isHotFunction(&F))
+      OS << " :hot ";
+    else if (PSI.isColdFunction(&F))
+      OS << " :cold ";
+    OS << "\n";
+  }
+  return PreservedAnalyses::all();
+}
+
+char ProfileSummaryInfoWrapperPass::ID = 0;

llvm/lib/IR/ProfileSummary.cpp

@@ -144,6 +144,8 @@ static bool getSummaryFromMD(MDTuple *MD, SummaryEntryVector &Summary) {
 }
 
 ProfileSummary *ProfileSummary::getFromMD(Metadata *MD) {
+  if (!MD)
+    return nullptr;
   if (!isa<MDTuple>(MD))
     return nullptr;
   MDTuple *Tuple = cast<MDTuple>(MD);

llvm/lib/Passes/PassBuilder.cpp

@@ -35,6 +35,7 @@
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
 #include "llvm/Analysis/PostDominators.h"
+#include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/Analysis/RegionInfo.h"
 #include "llvm/Analysis/ScalarEvolution.h"
 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
@@ -68,8 +69,8 @@
 #include "llvm/Transforms/Scalar/DCE.h"
 #include "llvm/Transforms/Scalar/DeadStoreElimination.h"
 #include "llvm/Transforms/Scalar/EarlyCSE.h"
-#include "llvm/Transforms/Scalar/GVN.h"
 #include "llvm/Transforms/Scalar/GuardWidening.h"
+#include "llvm/Transforms/Scalar/GVN.h"
 #include "llvm/Transforms/Scalar/LoopRotation.h"
 #include "llvm/Transforms/Scalar/LoopSimplifyCFG.h"
 #include "llvm/Transforms/Scalar/LowerAtomic.h"

llvm/lib/Passes/PassRegistry.def

@@ -22,6 +22,7 @@
 MODULE_ANALYSIS("callgraph", CallGraphAnalysis())
 MODULE_ANALYSIS("lcg", LazyCallGraphAnalysis())
 MODULE_ANALYSIS("no-op-module", NoOpModuleAnalysis())
+MODULE_ANALYSIS("profile-summary", ProfileSummaryAnalysis())
 MODULE_ANALYSIS("targetlibinfo", TargetLibraryAnalysis())
 MODULE_ANALYSIS("verify", VerifierAnalysis())
 
@@ -50,8 +51,9 @@ MODULE_PASS("no-op-module", NoOpModulePass())
 MODULE_PASS("pgo-icall-prom", PGOIndirectCallPromotion())
 MODULE_PASS("pgo-instr-gen", PGOInstrumentationGen())
 MODULE_PASS("pgo-instr-use", PGOInstrumentationUse())
-MODULE_PASS("print", PrintModulePass(dbgs()))
+MODULE_PASS("print-profile-summary", ProfileSummaryPrinterPass(dbgs()))
 MODULE_PASS("print-callgraph", CallGraphPrinterPass(dbgs()))
+MODULE_PASS("print", PrintModulePass(dbgs()))
 MODULE_PASS("print-lcg", LazyCallGraphPrinterPass(dbgs()))
 MODULE_PASS("sample-profile", SampleProfileLoaderPass())
 MODULE_PASS("strip-dead-prototypes", StripDeadPrototypesPass())

llvm/test/Analysis/ProfileSummary/basic.ll

@@ -0,0 +1,39 @@
+; RUN: opt < %s -disable-output -passes=print-profile-summary -S 2>&1 | FileCheck %s
+
+define void @f1() !prof !20 {
+; CHECK-LABEL: f1 :hot
+
+  ret void
+}
+
+define void @f2() !prof !21 {
+; CHECK-LABEL: f2 :cold
+
+  ret void
+}
+
+define void @f3() !prof !22 {
+; CHECK-LABEL: f3
+
+  ret void
+}
+
+!llvm.module.flags = !{!1}
+!20 = !{!"function_entry_count", i64 400}
+!21 = !{!"function_entry_count", i64 1}
+!22 = !{!"function_entry_count", i64 100}
+
+!1 = !{i32 1, !"ProfileSummary", !2}
+!2 = !{!3, !4, !5, !6, !7, !8, !9, !10}
+!3 = !{!"ProfileFormat", !"InstrProf"}
+!4 = !{!"TotalCount", i64 10000}
+!5 = !{!"MaxCount", i64 10}
+!6 = !{!"MaxInternalCount", i64 1}
+!7 = !{!"MaxFunctionCount", i64 1000}
+!8 = !{!"NumCounts", i64 3}
+!9 = !{!"NumFunctions", i64 3}
+!10 = !{!"DetailedSummary", !11}
+!11 = !{!12, !13, !14}
+!12 = !{i32 10000, i64 100, i32 1}
+!13 = !{i32 999000, i64 100, i32 1}
+!14 = !{i32 999999, i64 1, i32 2}