[llvm] r217437 - Re-factor sample profile reader into lib/ProfileData.
Diego Novillo
dnovillo at google.com
Tue Sep 9 05:40:52 PDT 2014
Author: dnovillo
Date: Tue Sep 9 07:40:50 2014
New Revision: 217437
URL: http://llvm.org/viewvc/llvm-project?rev=217437&view=rev
Log:
Re-factor sample profile reader into lib/ProfileData.
Summary:
This patch moves the profile reading logic out of the Sample Profile
transformation into a generic profile reader facility in
lib/ProfileData.
The intent is to use this new reader to implement a sample profile
reader/writer that can be used to convert sample profiles from external
sources into LLVM.
This first patch introduces no functional changes. It moves the profile
reading code from lib/Transforms/SampleProfile.cpp into
lib/ProfileData/SampleProfReader.cpp.
In subsequent patches I will:
- Add a bitcode format for sample profiles to allow for more efficient
encoding of the profile.
- Add a writer for both text and bitcode format profiles.
- Add a 'convert' command to llvm-profdata to be able to convert between
the two (and serve as entry point for other sample profile formats).
Reviewers: bogner, echristo
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5250
Added:
llvm/trunk/include/llvm/ProfileData/SampleProfReader.h
llvm/trunk/lib/ProfileData/SampleProfReader.cpp
Modified:
llvm/trunk/include/llvm/IR/DiagnosticInfo.h
llvm/trunk/lib/ProfileData/CMakeLists.txt
llvm/trunk/lib/Transforms/Scalar/LLVMBuild.txt
llvm/trunk/lib/Transforms/Scalar/SampleProfile.cpp
Modified: llvm/trunk/include/llvm/IR/DiagnosticInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/DiagnosticInfo.h?rev=217437&r1=217436&r2=217437&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/DiagnosticInfo.h (original)
+++ llvm/trunk/include/llvm/IR/DiagnosticInfo.h Tue Sep 9 07:40:50 2014
@@ -18,6 +18,7 @@
#include "llvm-c/Core.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/IR/DebugLoc.h"
+#include "llvm/IR/Module.h"
#include "llvm/Support/Casting.h"
namespace llvm {
Added: llvm/trunk/include/llvm/ProfileData/SampleProfReader.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ProfileData/SampleProfReader.h?rev=217437&view=auto
==============================================================================
--- llvm/trunk/include/llvm/ProfileData/SampleProfReader.h (added)
+++ llvm/trunk/include/llvm/ProfileData/SampleProfReader.h Tue Sep 9 07:40:50 2014
@@ -0,0 +1,194 @@
+//===- SampleProfReader.h - Read LLVM sample profile data -----------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains definitions needed for reading sample profiles.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_PROFILEDATA_SAMPLEPROFREADER_H
+#define LLVM_PROFILEDATA_SAMPLEPROFREADER_H
+
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/IR/DiagnosticInfo.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace llvm;
+
+namespace sampleprof {
+
+/// \brief Represents the relative location of an instruction.
+///
+/// Instruction locations are specified by the line offset from the
+/// beginning of the function (marked by the line where the function
+/// header is) and the discriminator value within that line.
+///
+/// The discriminator value is useful to distinguish instructions
+/// that are on the same line but belong to different basic blocks
+/// (e.g., the two post-increment instructions in "if (p) x++; else y++;").
+struct LineLocation {
+ LineLocation(int L, unsigned D) : LineOffset(L), Discriminator(D) {}
+ int LineOffset;
+ unsigned Discriminator;
+};
+} // End namespace sampleprof
+
+namespace llvm {
+template <> struct DenseMapInfo<sampleprof::LineLocation> {
+ typedef DenseMapInfo<int> OffsetInfo;
+ typedef DenseMapInfo<unsigned> DiscriminatorInfo;
+ static inline sampleprof::LineLocation getEmptyKey() {
+ return sampleprof::LineLocation(OffsetInfo::getEmptyKey(),
+ DiscriminatorInfo::getEmptyKey());
+ }
+ static inline sampleprof::LineLocation getTombstoneKey() {
+ return sampleprof::LineLocation(OffsetInfo::getTombstoneKey(),
+ DiscriminatorInfo::getTombstoneKey());
+ }
+ static inline unsigned getHashValue(sampleprof::LineLocation Val) {
+ return DenseMapInfo<std::pair<int, unsigned>>::getHashValue(
+ std::pair<int, unsigned>(Val.LineOffset, Val.Discriminator));
+ }
+ static inline bool isEqual(sampleprof::LineLocation LHS,
+ sampleprof::LineLocation RHS) {
+ return LHS.LineOffset == RHS.LineOffset &&
+ LHS.Discriminator == RHS.Discriminator;
+ }
+};
+}
+
+namespace sampleprof {
+
+typedef DenseMap<LineLocation, unsigned> BodySampleMap;
+
+/// \brief Representation of the samples collected for a function.
+///
+/// This data structure contains all the collected samples for the body
+/// of a function. Each sample corresponds to a LineLocation instance
+/// within the body of the function.
+class FunctionSamples {
+public:
+ FunctionSamples()
+ : TotalSamples(0), TotalHeadSamples(0) {}
+ void print(raw_ostream & OS);
+ void addTotalSamples(unsigned Num) { TotalSamples += Num; }
+ void addHeadSamples(unsigned Num) { TotalHeadSamples += Num; }
+ void addBodySamples(int LineOffset, unsigned Discriminator, unsigned Num) {
+ assert(LineOffset >= 0);
+ BodySamples[LineLocation(LineOffset, Discriminator)] += Num;
+ }
+
+ /// \brief Return the number of samples collected at the given location.
+ /// Each location is specified by \p LineOffset and \p Discriminator.
+ unsigned samplesAt(int LineOffset, unsigned Discriminator) {
+ return BodySamples.lookup(LineLocation(LineOffset, Discriminator));
+ }
+
+ bool empty() { return BodySamples.empty(); }
+
+private:
+ /// \brief Total number of samples collected inside this function.
+ ///
+ /// Samples are cumulative, they include all the samples collected
+ /// inside this function and all its inlined callees.
+ unsigned TotalSamples;
+
+ /// \brief Total number of samples collected at the head of the function.
+ unsigned TotalHeadSamples;
+
+ /// \brief Map instruction locations to collected samples.
+ ///
+ /// Each entry in this map contains the number of samples
+ /// collected at the corresponding line offset. All line locations
+ /// are an offset from the start of the function.
+ BodySampleMap BodySamples;
+};
+
+/// \brief Sample-based profile reader.
+///
+/// Each profile contains sample counts for all the functions
+/// executed. Inside each function, statements are annotated with the
+/// collected samples on all the instructions associated with that
+/// statement.
+///
+/// For this to produce meaningful data, the program needs to be
+/// compiled with some debug information (at minimum, line numbers:
+/// -gline-tables-only). Otherwise, it will be impossible to match IR
+/// instructions to the line numbers collected by the profiler.
+///
+/// From the profile file, we are interested in collecting the
+/// following information:
+///
+/// * A list of functions included in the profile (mangled names).
+///
+/// * For each function F:
+/// 1. The total number of samples collected in F.
+///
+/// 2. The samples collected at each line in F. To provide some
+/// protection against source code shuffling, line numbers should
+/// be relative to the start of the function.
+///
+/// The reader supports two file formats: text and bitcode. The text format
+/// is useful for debugging and testing, while the bitcode format is more
+/// compact. They can both be used interchangeably.
+class SampleProfileReader {
+public:
+ SampleProfileReader(const Module &M, StringRef F)
+ : Profiles(0), Filename(F), M(M) {}
+
+ /// \brief Print all the profiles to dbgs().
+ void dump();
+
+ /// \brief Load sample profiles from the associated file.
+ bool load();
+
+ /// \brief Print the profile for \p FName on stream \p OS.
+ void printFunctionProfile(raw_ostream &OS, StringRef FName);
+
+ /// \brief Print the profile for \p FName on dbgs().
+ void dumpFunctionProfile(StringRef FName);
+
+ /// \brief Return the samples collected for function \p F.
+ FunctionSamples *getSamplesFor(const Function &F) {
+ return &Profiles[F.getName()];
+ }
+
+ /// \brief Report a parse error message.
+ void reportParseError(int64_t LineNumber, Twine Msg) const {
+ DiagnosticInfoSampleProfile Diag(Filename.data(), LineNumber, Msg);
+ M.getContext().diagnose(Diag);
+ }
+
+protected:
+ bool loadText();
+ bool loadBitcode() { llvm_unreachable("not implemented"); }
+
+ /// \brief Map every function to its associated profile.
+ ///
+ /// The profile of every function executed at runtime is collected
+ /// in the structure FunctionSamples. This maps function objects
+ /// to their corresponding profiles.
+ StringMap<FunctionSamples> Profiles;
+
+ /// \brief Path name to the file holding the profile data.
+ StringRef Filename;
+
+ /// \brief Module being compiled. Used to access the current
+ /// LLVM context for diagnostics.
+ const Module &M;
+};
+
+} // End namespace sampleprof
+
+#endif // LLVM_PROFILEDATA_SAMPLEPROFREADER_H
Modified: llvm/trunk/lib/ProfileData/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ProfileData/CMakeLists.txt?rev=217437&r1=217436&r2=217437&view=diff
==============================================================================
--- llvm/trunk/lib/ProfileData/CMakeLists.txt (original)
+++ llvm/trunk/lib/ProfileData/CMakeLists.txt Tue Sep 9 07:40:50 2014
@@ -5,4 +5,5 @@ add_llvm_library(LLVMProfileData
CoverageMapping.cpp
CoverageMappingWriter.cpp
CoverageMappingReader.cpp
+ SampleProfReader.cpp
)
Added: llvm/trunk/lib/ProfileData/SampleProfReader.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ProfileData/SampleProfReader.cpp?rev=217437&view=auto
==============================================================================
--- llvm/trunk/lib/ProfileData/SampleProfReader.cpp (added)
+++ llvm/trunk/lib/ProfileData/SampleProfReader.cpp Tue Sep 9 07:40:50 2014
@@ -0,0 +1,238 @@
+//===- SampleProfReader.cpp - Read LLVM sample profile data ---------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the class that reads LLVM sample profiles. It
+// supports two file formats: text and bitcode. The textual representation
+// is useful for debugging and testing purposes. The bitcode representation
+// is more compact, resulting in smaller file sizes. However, they can
+// both be used interchangeably.
+//
+// NOTE: If you are making changes to the file format, please remember
+// to document them in the Clang documentation at
+// tools/clang/docs/UsersManual.rst.
+//
+// Text format
+// -----------
+//
+// Sample profiles are written as ASCII text. The file is divided into
+// sections, which correspond to each of the functions executed at runtime.
+// Each section has the following format
+//
+// function1:total_samples:total_head_samples
+// offset1[.discriminator]: number_of_samples [fn1:num fn2:num ... ]
+// offset2[.discriminator]: number_of_samples [fn3:num fn4:num ... ]
+// ...
+// offsetN[.discriminator]: number_of_samples [fn5:num fn6:num ... ]
+//
+// The file may contain blank lines between sections and within a
+// section. However, the spacing within a single line is fixed. Additional
+// spaces will result in an error while reading the file.
+//
+// Function names must be mangled in order for the profile loader to
+// match them in the current translation unit. The two numbers in the
+// function header specify how many total samples were accumulated in the
+// function (first number), and the total number of samples accumulated
+// in the prologue of the function (second number). This head sample
+// count provides an indicator of how frequently the function is invoked.
+//
+// Each sampled line may contain several items. Some are optional (marked
+// below):
+//
+// a. Source line offset. This number represents the line number
+// in the function where the sample was collected. The line number is
+// always relative to the line where symbol of the function is
+// defined. So, if the function has its header at line 280, the offset
+// 13 is at line 293 in the file.
+//
+// Note that this offset should never be a negative number. This could
+// happen in cases like macros. The debug machinery will register the
+// line number at the point of macro expansion. So, if the macro was
+// expanded in a line before the start of the function, the profile
+// converter should emit a 0 as the offset (this means that the optimizers
+// will not be able to associate a meaningful weight to the instructions
+// in the macro).
+//
+// b. [OPTIONAL] Discriminator. This is used if the sampled program
+// was compiled with DWARF discriminator support
+// (http://wiki.dwarfstd.org/index.php?title=Path_Discriminators).
+// DWARF discriminators are unsigned integer values that allow the
+// compiler to distinguish between multiple execution paths on the
+// same source line location.
+//
+// For example, consider the line of code ``if (cond) foo(); else bar();``.
+// If the predicate ``cond`` is true 80% of the time, then the edge
+// into function ``foo`` should be considered to be taken most of the
+// time. But both calls to ``foo`` and ``bar`` are at the same source
+// line, so a sample count at that line is not sufficient. The
+// compiler needs to know which part of that line is taken more
+// frequently.
+//
+// This is what discriminators provide. In this case, the calls to
+// ``foo`` and ``bar`` will be at the same line, but will have
+// different discriminator values. This allows the compiler to correctly
+// set edge weights into ``foo`` and ``bar``.
+//
+// c. Number of samples. This is an integer quantity representing the
+// number of samples collected by the profiler at this source
+// location.
+//
+// d. [OPTIONAL] Potential call targets and samples. If present, this
+// line contains a call instruction. This models both direct and
+// number of samples. For example,
+//
+// 130: 7 foo:3 bar:2 baz:7
+//
+// The above means that at relative line offset 130 there is a call
+// instruction that calls one of ``foo()``, ``bar()`` and ``baz()``,
+// with ``baz()`` being the relatively more frequently called target.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ProfileData/SampleProfReader.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorOr.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/LineIterator.h"
+#include "llvm/Support/Regex.h"
+
+using namespace sampleprof;
+using namespace llvm;
+
+/// \brief Print the samples collected for a function on stream \p OS.
+///
+/// \param OS Stream to emit the output to.
+void FunctionSamples::print(raw_ostream &OS) {
+ OS << TotalSamples << ", " << TotalHeadSamples << ", " << BodySamples.size()
+ << " sampled lines\n";
+ for (BodySampleMap::const_iterator SI = BodySamples.begin(),
+ SE = BodySamples.end();
+ SI != SE; ++SI)
+ OS << "\tline offset: " << SI->first.LineOffset
+ << ", discriminator: " << SI->first.Discriminator
+ << ", number of samples: " << SI->second << "\n";
+ OS << "\n";
+}
+
+/// \brief Print the function profile for \p FName on stream \p OS.
+///
+/// \param OS Stream to emit the output to.
+/// \param FName Name of the function to print.
+void SampleProfileReader::printFunctionProfile(raw_ostream &OS,
+ StringRef FName) {
+ OS << "Function: " << FName << ":\n";
+ Profiles[FName].print(OS);
+}
+
+/// \brief Dump the function profile for \p FName.
+///
+/// \param FName Name of the function to print.
+void SampleProfileReader::dumpFunctionProfile(StringRef FName) {
+ printFunctionProfile(dbgs(), FName);
+}
+
+/// \brief Dump all the function profiles found.
+void SampleProfileReader::dump() {
+ for (StringMap<FunctionSamples>::const_iterator I = Profiles.begin(),
+ E = Profiles.end();
+ I != E; ++I)
+ dumpFunctionProfile(I->getKey());
+}
+
+/// \brief Load samples from a text file.
+///
+/// See the documentation at the top of the file for an explanation of
+/// the expected format.
+///
+/// \returns true if the file was loaded successfully, false otherwise.
+bool SampleProfileReader::loadText() {
+ ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+ MemoryBuffer::getFile(Filename);
+ if (std::error_code EC = BufferOrErr.getError()) {
+ std::string Msg(EC.message());
+ M.getContext().diagnose(DiagnosticInfoSampleProfile(Filename.data(), Msg));
+ return false;
+ }
+ MemoryBuffer &Buffer = *BufferOrErr.get();
+ line_iterator LineIt(Buffer, '#');
+
+ // Read the profile of each function. Since each function may be
+ // mentioned more than once, and we are collecting flat profiles,
+ // accumulate samples as we parse them.
+ Regex HeadRE("^([^0-9].*):([0-9]+):([0-9]+)$");
+ Regex LineSample("^([0-9]+)\\.?([0-9]+)?: ([0-9]+)(.*)$");
+ while (!LineIt.is_at_eof()) {
+ // Read the header of each function.
+ //
+ // Note that for function identifiers we are actually expecting
+ // mangled names, but we may not always get them. This happens when
+ // the compiler decides not to emit the function (e.g., it was inlined
+ // and removed). In this case, the binary will not have the linkage
+ // name for the function, so the profiler will emit the function's
+ // unmangled name, which may contain characters like ':' and '>' in its
+ // name (member functions, templates, etc).
+ //
+ // The only requirement we place on the identifier, then, is that it
+ // should not begin with a number.
+ SmallVector<StringRef, 3> Matches;
+ if (!HeadRE.match(*LineIt, &Matches)) {
+ reportParseError(LineIt.line_number(),
+ "Expected 'mangled_name:NUM:NUM', found " + *LineIt);
+ return false;
+ }
+ assert(Matches.size() == 4);
+ StringRef FName = Matches[1];
+ unsigned NumSamples, NumHeadSamples;
+ Matches[2].getAsInteger(10, NumSamples);
+ Matches[3].getAsInteger(10, NumHeadSamples);
+ Profiles[FName] = FunctionSamples();
+ FunctionSamples &FProfile = Profiles[FName];
+ FProfile.addTotalSamples(NumSamples);
+ FProfile.addHeadSamples(NumHeadSamples);
+ ++LineIt;
+
+ // Now read the body. The body of the function ends when we reach
+ // EOF or when we see the start of the next function.
+ while (!LineIt.is_at_eof() && isdigit((*LineIt)[0])) {
+ if (!LineSample.match(*LineIt, &Matches)) {
+ reportParseError(
+ LineIt.line_number(),
+ "Expected 'NUM[.NUM]: NUM[ mangled_name:NUM]*', found " + *LineIt);
+ return false;
+ }
+ assert(Matches.size() == 5);
+ unsigned LineOffset, NumSamples, Discriminator = 0;
+ Matches[1].getAsInteger(10, LineOffset);
+ if (Matches[2] != "")
+ Matches[2].getAsInteger(10, Discriminator);
+ Matches[3].getAsInteger(10, NumSamples);
+
+ // FIXME: Handle called targets (in Matches[4]).
+
+ // When dealing with instruction weights, we use the value
+ // zero to indicate the absence of a sample. If we read an
+ // actual zero from the profile file, return it as 1 to
+ // avoid the confusion later on.
+ if (NumSamples == 0)
+ NumSamples = 1;
+ FProfile.addBodySamples(LineOffset, Discriminator, NumSamples);
+ ++LineIt;
+ }
+ }
+
+ return true;
+}
+
+/// \brief Load execution samples from a file.
+///
+/// This function examines the header of the given file to determine
+/// whether to use the text or the bitcode loader.
+bool SampleProfileReader::load() {
+ // TODO Actually detect the file format.
+ return loadText();
+}
Modified: llvm/trunk/lib/Transforms/Scalar/LLVMBuild.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LLVMBuild.txt?rev=217437&r1=217436&r2=217437&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LLVMBuild.txt (original)
+++ llvm/trunk/lib/Transforms/Scalar/LLVMBuild.txt Tue Sep 9 07:40:50 2014
@@ -20,4 +20,4 @@ type = Library
name = Scalar
parent = Transforms
library_name = ScalarOpts
-required_libraries = Analysis Core IPA InstCombine Support Target TransformUtils
+required_libraries = Analysis Core IPA InstCombine Support Target TransformUtils ProfileData
Modified: llvm/trunk/lib/Transforms/Scalar/SampleProfile.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SampleProfile.cpp?rev=217437&r1=217436&r2=217437&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SampleProfile.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SampleProfile.cpp Tue Sep 9 07:40:50 2014
@@ -26,7 +26,6 @@
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallSet.h"
-#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/PostDominators.h"
@@ -42,15 +41,14 @@
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/Pass.h"
+#include "llvm/ProfileData/SampleProfReader.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
-#include "llvm/Support/LineIterator.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include "llvm/Support/Regex.h"
#include "llvm/Support/raw_ostream.h"
#include <cctype>
using namespace llvm;
+using namespace sampleprof;
#define DEBUG_TYPE "sample-profile"
@@ -65,76 +63,48 @@ static cl::opt<unsigned> SampleProfileMa
"sample block/edge weights through the CFG."));
namespace {
-/// \brief Represents the relative location of an instruction.
-///
-/// Instruction locations are specified by the line offset from the
-/// beginning of the function (marked by the line where the function
-/// header is) and the discriminator value within that line.
-///
-/// The discriminator value is useful to distinguish instructions
-/// that are on the same line but belong to different basic blocks
-/// (e.g., the two post-increment instructions in "if (p) x++; else y++;").
-struct InstructionLocation {
- InstructionLocation(int L, unsigned D) : LineOffset(L), Discriminator(D) {}
- int LineOffset;
- unsigned Discriminator;
-};
-}
-
-namespace llvm {
-template <> struct DenseMapInfo<InstructionLocation> {
- typedef DenseMapInfo<int> OffsetInfo;
- typedef DenseMapInfo<unsigned> DiscriminatorInfo;
- static inline InstructionLocation getEmptyKey() {
- return InstructionLocation(OffsetInfo::getEmptyKey(),
- DiscriminatorInfo::getEmptyKey());
- }
- static inline InstructionLocation getTombstoneKey() {
- return InstructionLocation(OffsetInfo::getTombstoneKey(),
- DiscriminatorInfo::getTombstoneKey());
- }
- static inline unsigned getHashValue(InstructionLocation Val) {
- return DenseMapInfo<std::pair<int, unsigned>>::getHashValue(
- std::pair<int, unsigned>(Val.LineOffset, Val.Discriminator));
- }
- static inline bool isEqual(InstructionLocation LHS, InstructionLocation RHS) {
- return LHS.LineOffset == RHS.LineOffset &&
- LHS.Discriminator == RHS.Discriminator;
- }
-};
-}
-
-namespace {
-typedef DenseMap<InstructionLocation, unsigned> BodySampleMap;
typedef DenseMap<BasicBlock *, unsigned> BlockWeightMap;
typedef DenseMap<BasicBlock *, BasicBlock *> EquivalenceClassMap;
typedef std::pair<BasicBlock *, BasicBlock *> Edge;
typedef DenseMap<Edge, unsigned> EdgeWeightMap;
typedef DenseMap<BasicBlock *, SmallVector<BasicBlock *, 8>> BlockEdgeMap;
-/// \brief Representation of the runtime profile for a function.
+/// \brief Sample profile pass.
///
-/// This data structure contains the runtime profile for a given
-/// function. It contains the total number of samples collected
-/// in the function and a map of samples collected in every statement.
-class SampleFunctionProfile {
+/// This pass reads profile data from the file specified by
+/// -sample-profile-file and annotates every affected function with the
+/// profile information found in that file.
+class SampleProfileLoader : public FunctionPass {
public:
- SampleFunctionProfile()
- : TotalSamples(0), TotalHeadSamples(0), HeaderLineno(0), DT(nullptr),
- PDT(nullptr), LI(nullptr), Ctx(nullptr) {}
+ // Class identification, replacement for typeinfo
+ static char ID;
+
+ SampleProfileLoader(StringRef Name = SampleProfileFile)
+ : FunctionPass(ID), DT(nullptr), PDT(nullptr), LI(nullptr), Ctx(nullptr),
+ Reader(), Samples(nullptr), Filename(Name), ProfileIsValid(false) {
+ initializeSampleProfileLoaderPass(*PassRegistry::getPassRegistry());
+ }
+
+ bool doInitialization(Module &M) override;
+
+ void dump() { Reader->dump(); }
+
+ const char *getPassName() const override { return "Sample profile pass"; }
+
+ bool runOnFunction(Function &F) override;
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.setPreservesCFG();
+ AU.addRequired<LoopInfo>();
+ AU.addRequired<DominatorTreeWrapperPass>();
+ AU.addRequired<PostDominatorTree>();
+ }
+
+protected:
unsigned getFunctionLoc(Function &F);
- bool emitAnnotations(Function &F, DominatorTree *DomTree,
- PostDominatorTree *PostDomTree, LoopInfo *Loops);
+ bool emitAnnotations(Function &F);
unsigned getInstWeight(Instruction &I);
unsigned getBlockWeight(BasicBlock *B);
- void addTotalSamples(unsigned Num) { TotalSamples += Num; }
- void addHeadSamples(unsigned Num) { TotalHeadSamples += Num; }
- void addBodySamples(int LineOffset, unsigned Discriminator, unsigned Num) {
- assert(LineOffset >= 0);
- BodySamples[InstructionLocation(LineOffset, Discriminator)] += Num;
- }
- void print(raw_ostream &OS);
void printEdgeWeight(raw_ostream &OS, Edge E);
void printBlockWeight(raw_ostream &OS, BasicBlock *BB);
void printBlockEquivalence(raw_ostream &OS, BasicBlock *BB);
@@ -147,32 +117,11 @@ public:
unsigned visitEdge(Edge E, unsigned *NumUnknownEdges, Edge *UnknownEdge);
void buildEdges(Function &F);
bool propagateThroughEdges(Function &F);
- bool empty() { return BodySamples.empty(); }
-protected:
- /// \brief Total number of samples collected inside this function.
- ///
- /// Samples are cumulative, they include all the samples collected
- /// inside this function and all its inlined callees.
- unsigned TotalSamples;
-
- /// \brief Total number of samples collected at the head of the function.
- /// FIXME: Use head samples to estimate a cold/hot attribute for the function.
- unsigned TotalHeadSamples;
-
- /// \brief Line number for the function header. Used to compute relative
- /// line numbers from the absolute line LOCs found in instruction locations.
- /// The relative line numbers are needed to address the samples from the
- /// profile file.
+ /// \brief Line number for the function header. Used to compute absolute
+ /// line numbers from the relative line numbers found in the profile.
unsigned HeaderLineno;
- /// \brief Map line offsets to collected samples.
- ///
- /// Each entry in this map contains the number of samples
- /// collected at the corresponding line offset. All line locations
- /// are an offset from the start of the function.
- BodySampleMap BodySamples;
-
/// \brief Map basic blocks to their computed weights.
///
/// The weight of a basic block is defined to be the maximum
@@ -212,105 +161,12 @@ protected:
/// \brief LLVM context holding the debug data we need.
LLVMContext *Ctx;
-};
-
-/// \brief Sample-based profile reader.
-///
-/// Each profile contains sample counts for all the functions
-/// executed. Inside each function, statements are annotated with the
-/// collected samples on all the instructions associated with that
-/// statement.
-///
-/// For this to produce meaningful data, the program needs to be
-/// compiled with some debug information (at minimum, line numbers:
-/// -gline-tables-only). Otherwise, it will be impossible to match IR
-/// instructions to the line numbers collected by the profiler.
-///
-/// From the profile file, we are interested in collecting the
-/// following information:
-///
-/// * A list of functions included in the profile (mangled names).
-///
-/// * For each function F:
-/// 1. The total number of samples collected in F.
-///
-/// 2. The samples collected at each line in F. To provide some
-/// protection against source code shuffling, line numbers should
-/// be relative to the start of the function.
-class SampleModuleProfile {
-public:
- SampleModuleProfile(const Module &M, StringRef F)
- : Profiles(0), Filename(F), M(M) {}
-
- void dump();
- bool loadText();
- void loadNative() { llvm_unreachable("not implemented"); }
- void printFunctionProfile(raw_ostream &OS, StringRef FName);
- void dumpFunctionProfile(StringRef FName);
- SampleFunctionProfile &getProfile(const Function &F) {
- return Profiles[F.getName()];
- }
-
- /// \brief Report a parse error message.
- void reportParseError(int64_t LineNumber, Twine Msg) const {
- DiagnosticInfoSampleProfile Diag(Filename.data(), LineNumber, Msg);
- M.getContext().diagnose(Diag);
- }
-
-protected:
- /// \brief Map every function to its associated profile.
- ///
- /// The profile of every function executed at runtime is collected
- /// in the structure SampleFunctionProfile. This maps function objects
- /// to their corresponding profiles.
- StringMap<SampleFunctionProfile> Profiles;
-
- /// \brief Path name to the file holding the profile data.
- ///
- /// The format of this file is defined by each profiler
- /// independently. If possible, the profiler should have a text
- /// version of the profile format to be used in constructing test
- /// cases and debugging.
- StringRef Filename;
-
- /// \brief Module being compiled. Used mainly to access the current
- /// LLVM context for diagnostics.
- const Module &M;
-};
-/// \brief Sample profile pass.
-///
-/// This pass reads profile data from the file specified by
-/// -sample-profile-file and annotates every affected function with the
-/// profile information found in that file.
-class SampleProfileLoader : public FunctionPass {
-public:
- // Class identification, replacement for typeinfo
- static char ID;
-
- SampleProfileLoader(StringRef Name = SampleProfileFile)
- : FunctionPass(ID), Profiler(), Filename(Name), ProfileIsValid(false) {
- initializeSampleProfileLoaderPass(*PassRegistry::getPassRegistry());
- }
-
- bool doInitialization(Module &M) override;
-
- void dump() { Profiler->dump(); }
-
- const char *getPassName() const override { return "Sample profile pass"; }
-
- bool runOnFunction(Function &F) override;
-
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- AU.setPreservesCFG();
- AU.addRequired<LoopInfo>();
- AU.addRequired<DominatorTreeWrapperPass>();
- AU.addRequired<PostDominatorTree>();
- }
-
-protected:
/// \brief Profile reader object.
- std::unique_ptr<SampleModuleProfile> Profiler;
+ std::unique_ptr<SampleProfileReader> Reader;
+
+ /// \brief Samples collected for the body of this function.
+ FunctionSamples *Samples;
/// \brief Name of the profile file to load.
StringRef Filename;
@@ -320,26 +176,11 @@ protected:
};
}
-/// \brief Print this function profile on stream \p OS.
-///
-/// \param OS Stream to emit the output to.
-void SampleFunctionProfile::print(raw_ostream &OS) {
- OS << TotalSamples << ", " << TotalHeadSamples << ", " << BodySamples.size()
- << " sampled lines\n";
- for (BodySampleMap::const_iterator SI = BodySamples.begin(),
- SE = BodySamples.end();
- SI != SE; ++SI)
- OS << "\tline offset: " << SI->first.LineOffset
- << ", discriminator: " << SI->first.Discriminator
- << ", number of samples: " << SI->second << "\n";
- OS << "\n";
-}
-
/// \brief Print the weight of edge \p E on stream \p OS.
///
/// \param OS Stream to emit the output to.
/// \param E Edge to print.
-void SampleFunctionProfile::printEdgeWeight(raw_ostream &OS, Edge E) {
+void SampleProfileLoader::printEdgeWeight(raw_ostream &OS, Edge E) {
OS << "weight[" << E.first->getName() << "->" << E.second->getName()
<< "]: " << EdgeWeights[E] << "\n";
}
@@ -348,8 +189,8 @@ void SampleFunctionProfile::printEdgeWei
///
/// \param OS Stream to emit the output to.
/// \param BB Block to print.
-void SampleFunctionProfile::printBlockEquivalence(raw_ostream &OS,
- BasicBlock *BB) {
+void SampleProfileLoader::printBlockEquivalence(raw_ostream &OS,
+ BasicBlock *BB) {
BasicBlock *Equiv = EquivalenceClass[BB];
OS << "equivalence[" << BB->getName()
<< "]: " << ((Equiv) ? EquivalenceClass[BB]->getName() : "NONE") << "\n";
@@ -359,174 +200,10 @@ void SampleFunctionProfile::printBlockEq
///
/// \param OS Stream to emit the output to.
/// \param BB Block to print.
-void SampleFunctionProfile::printBlockWeight(raw_ostream &OS, BasicBlock *BB) {
+void SampleProfileLoader::printBlockWeight(raw_ostream &OS, BasicBlock *BB) {
OS << "weight[" << BB->getName() << "]: " << BlockWeights[BB] << "\n";
}
-/// \brief Print the function profile for \p FName on stream \p OS.
-///
-/// \param OS Stream to emit the output to.
-/// \param FName Name of the function to print.
-void SampleModuleProfile::printFunctionProfile(raw_ostream &OS,
- StringRef FName) {
- OS << "Function: " << FName << ":\n";
- Profiles[FName].print(OS);
-}
-
-/// \brief Dump the function profile for \p FName.
-///
-/// \param FName Name of the function to print.
-void SampleModuleProfile::dumpFunctionProfile(StringRef FName) {
- printFunctionProfile(dbgs(), FName);
-}
-
-/// \brief Dump all the function profiles found.
-void SampleModuleProfile::dump() {
- for (StringMap<SampleFunctionProfile>::const_iterator I = Profiles.begin(),
- E = Profiles.end();
- I != E; ++I)
- dumpFunctionProfile(I->getKey());
-}
-
-/// \brief Load samples from a text file.
-///
-/// The file contains a list of samples for every function executed at
-/// runtime. Each function profile has the following format:
-///
-/// function1:total_samples:total_head_samples
-/// offset1[.discriminator]: number_of_samples [fn1:num fn2:num ... ]
-/// offset2[.discriminator]: number_of_samples [fn3:num fn4:num ... ]
-/// ...
-/// offsetN[.discriminator]: number_of_samples [fn5:num fn6:num ... ]
-///
-/// Function names must be mangled in order for the profile loader to
-/// match them in the current translation unit. The two numbers in the
-/// function header specify how many total samples were accumulated in
-/// the function (first number), and the total number of samples accumulated
-/// at the prologue of the function (second number). This head sample
-/// count provides an indicator of how frequent is the function invoked.
-///
-/// Each sampled line may contain several items. Some are optional
-/// (marked below):
-///
-/// a- Source line offset. This number represents the line number
-/// in the function where the sample was collected. The line number
-/// is always relative to the line where symbol of the function
-/// is defined. So, if the function has its header at line 280,
-/// the offset 13 is at line 293 in the file.
-///
-/// b- [OPTIONAL] Discriminator. This is used if the sampled program
-/// was compiled with DWARF discriminator support
-/// (http://wiki.dwarfstd.org/index.php?title=Path_Discriminators)
-///
-/// c- Number of samples. This is the number of samples collected by
-/// the profiler at this source location.
-///
-/// d- [OPTIONAL] Potential call targets and samples. If present, this
-/// line contains a call instruction. This models both direct and
-/// indirect calls. Each called target is listed together with the
-/// number of samples. For example,
-///
-/// 130: 7 foo:3 bar:2 baz:7
-///
-/// The above means that at relative line offset 130 there is a
-/// call instruction that calls one of foo(), bar() and baz(). With
-/// baz() being the relatively more frequent call target.
-///
-/// FIXME: This is currently unhandled, but it has a lot of
-/// potential for aiding the inliner.
-///
-///
-/// Since this is a flat profile, a function that shows up more than
-/// once gets all its samples aggregated across all its instances.
-///
-/// FIXME: flat profiles are too imprecise to provide good optimization
-/// opportunities. Convert them to context-sensitive profile.
-///
-/// This textual representation is useful to generate unit tests and
-/// for debugging purposes, but it should not be used to generate
-/// profiles for large programs, as the representation is extremely
-/// inefficient.
-///
-/// \returns true if the file was loaded successfully, false otherwise.
-bool SampleModuleProfile::loadText() {
- ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
- MemoryBuffer::getFile(Filename);
- if (std::error_code EC = BufferOrErr.getError()) {
- std::string Msg(EC.message());
- M.getContext().diagnose(DiagnosticInfoSampleProfile(Filename.data(), Msg));
- return false;
- }
- MemoryBuffer &Buffer = *BufferOrErr.get();
- line_iterator LineIt(Buffer, '#');
-
- // Read the profile of each function. Since each function may be
- // mentioned more than once, and we are collecting flat profiles,
- // accumulate samples as we parse them.
- Regex HeadRE("^([^0-9].*):([0-9]+):([0-9]+)$");
- Regex LineSample("^([0-9]+)\\.?([0-9]+)?: ([0-9]+)(.*)$");
- while (!LineIt.is_at_eof()) {
- // Read the header of each function.
- //
- // Note that for function identifiers we are actually expecting
- // mangled names, but we may not always get them. This happens when
- // the compiler decides not to emit the function (e.g., it was inlined
- // and removed). In this case, the binary will not have the linkage
- // name for the function, so the profiler will emit the function's
- // unmangled name, which may contain characters like ':' and '>' in its
- // name (member functions, templates, etc).
- //
- // The only requirement we place on the identifier, then, is that it
- // should not begin with a number.
- SmallVector<StringRef, 3> Matches;
- if (!HeadRE.match(*LineIt, &Matches)) {
- reportParseError(LineIt.line_number(),
- "Expected 'mangled_name:NUM:NUM', found " + *LineIt);
- return false;
- }
- assert(Matches.size() == 4);
- StringRef FName = Matches[1];
- unsigned NumSamples, NumHeadSamples;
- Matches[2].getAsInteger(10, NumSamples);
- Matches[3].getAsInteger(10, NumHeadSamples);
- Profiles[FName] = SampleFunctionProfile();
- SampleFunctionProfile &FProfile = Profiles[FName];
- FProfile.addTotalSamples(NumSamples);
- FProfile.addHeadSamples(NumHeadSamples);
- ++LineIt;
-
- // Now read the body. The body of the function ends when we reach
- // EOF or when we see the start of the next function.
- while (!LineIt.is_at_eof() && isdigit((*LineIt)[0])) {
- if (!LineSample.match(*LineIt, &Matches)) {
- reportParseError(
- LineIt.line_number(),
- "Expected 'NUM[.NUM]: NUM[ mangled_name:NUM]*', found " + *LineIt);
- return false;
- }
- assert(Matches.size() == 5);
- unsigned LineOffset, NumSamples, Discriminator = 0;
- Matches[1].getAsInteger(10, LineOffset);
- if (Matches[2] != "")
- Matches[2].getAsInteger(10, Discriminator);
- Matches[3].getAsInteger(10, NumSamples);
-
- // FIXME: Handle called targets (in Matches[4]).
-
- // When dealing with instruction weights, we use the value
- // zero to indicate the absence of a sample. If we read an
- // actual zero from the profile file, return it as 1 to
- // avoid the confusion later on.
- if (NumSamples == 0)
- NumSamples = 1;
- FProfile.addBodySamples(LineOffset, Discriminator, NumSamples);
- ++LineIt;
- }
- }
-
- return true;
-}
-
/// \brief Get the weight for an instruction.
///
/// The "weight" of an instruction \p Inst is the number of samples
@@ -538,7 +215,7 @@ bool SampleModuleProfile::loadText() {
/// \param Inst Instruction to query.
///
/// \returns The profiled weight of I.
-unsigned SampleFunctionProfile::getInstWeight(Instruction &Inst) {
+unsigned SampleProfileLoader::getInstWeight(Instruction &Inst) {
DebugLoc DLoc = Inst.getDebugLoc();
unsigned Lineno = DLoc.getLine();
if (Lineno < HeaderLineno)
@@ -547,8 +224,7 @@ unsigned SampleFunctionProfile::getInstW
DILocation DIL(DLoc.getAsMDNode(*Ctx));
int LOffset = Lineno - HeaderLineno;
unsigned Discriminator = DIL.getDiscriminator();
- unsigned Weight =
- BodySamples.lookup(InstructionLocation(LOffset, Discriminator));
+ unsigned Weight = Samples->samplesAt(LOffset, Discriminator);
DEBUG(dbgs() << " " << Lineno << "." << Discriminator << ":" << Inst
<< " (line offset: " << LOffset << "." << Discriminator
<< " - weight: " << Weight << ")\n");
@@ -564,7 +240,7 @@ unsigned SampleFunctionProfile::getInstW
/// \param B The basic block to query.
///
/// \returns The computed weight of B.
-unsigned SampleFunctionProfile::getBlockWeight(BasicBlock *B) {
+unsigned SampleProfileLoader::getBlockWeight(BasicBlock *B) {
// If we've computed B's weight before, return it.
std::pair<BlockWeightMap::iterator, bool> Entry =
BlockWeights.insert(std::make_pair(B, 0));
@@ -588,7 +264,7 @@ unsigned SampleFunctionProfile::getBlock
/// the weights of every basic block in the CFG.
///
/// \param F The function to query.
-bool SampleFunctionProfile::computeBlockWeights(Function &F) {
+bool SampleProfileLoader::computeBlockWeights(Function &F) {
bool Changed = false;
DEBUG(dbgs() << "Block weights\n");
for (Function::iterator B = F.begin(), E = F.end(); B != E; ++B) {
@@ -623,7 +299,7 @@ bool SampleFunctionProfile::computeBlock
/// \param DomTree Opposite dominator tree. If \p Descendants is filled
/// with blocks from \p BB1's dominator tree, then
/// this is the post-dominator tree, and vice versa.
-void SampleFunctionProfile::findEquivalencesFor(
+void SampleProfileLoader::findEquivalencesFor(
BasicBlock *BB1, SmallVector<BasicBlock *, 8> Descendants,
DominatorTreeBase<BasicBlock> *DomTree) {
for (SmallVectorImpl<BasicBlock *>::iterator I = Descendants.begin(),
@@ -660,7 +336,7 @@ void SampleFunctionProfile::findEquivale
/// dominates B2, B2 post-dominates B1 and both are in the same loop.
///
/// \param F The function to query.
-void SampleFunctionProfile::findEquivalenceClasses(Function &F) {
+void SampleProfileLoader::findEquivalenceClasses(Function &F) {
SmallVector<BasicBlock *, 8> DominatedBBs;
DEBUG(dbgs() << "\nBlock equivalence classes\n");
// Find equivalence sets based on dominance and post-dominance information.
@@ -731,8 +407,8 @@ void SampleFunctionProfile::findEquivale
/// \param UnknownEdge Set if E has not been visited before.
///
/// \returns E's weight, if known. Otherwise, return 0.
-unsigned SampleFunctionProfile::visitEdge(Edge E, unsigned *NumUnknownEdges,
- Edge *UnknownEdge) {
+unsigned SampleProfileLoader::visitEdge(Edge E, unsigned *NumUnknownEdges,
+ Edge *UnknownEdge) {
if (!VisitedEdges.count(E)) {
(*NumUnknownEdges)++;
*UnknownEdge = E;
@@ -753,7 +429,7 @@ unsigned SampleFunctionProfile::visitEdg
/// \param F Function to process.
///
/// \returns True if new weights were assigned to edges or blocks.
-bool SampleFunctionProfile::propagateThroughEdges(Function &F) {
+bool SampleProfileLoader::propagateThroughEdges(Function &F) {
bool Changed = false;
DEBUG(dbgs() << "\nPropagation through edges\n");
for (Function::iterator BI = F.begin(), EI = F.end(); BI != EI; ++BI) {
@@ -857,7 +533,7 @@ bool SampleFunctionProfile::propagateThr
///
/// We are interested in unique edges. If a block B1 has multiple
/// edges to another block B2, we only add a single B1->B2 edge.
-void SampleFunctionProfile::buildEdges(Function &F) {
+void SampleProfileLoader::buildEdges(Function &F) {
for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) {
BasicBlock *B1 = I;
@@ -900,7 +576,7 @@ void SampleFunctionProfile::buildEdges(F
/// known, the weight for that edge is set to the weight of the block
/// minus the weight of the other incoming edges to that block (if
/// known).
-void SampleFunctionProfile::propagateWeights(Function &F) {
+void SampleProfileLoader::propagateWeights(Function &F) {
bool Changed = true;
unsigned i = 0;
@@ -965,7 +641,7 @@ void SampleFunctionProfile::propagateWei
///
/// \returns the line number where \p F is defined. If it returns 0,
/// it means that there is no debug information available for \p F.
-unsigned SampleFunctionProfile::getFunctionLoc(Function &F) {
+unsigned SampleProfileLoader::getFunctionLoc(Function &F) {
NamedMDNode *CUNodes = F.getParent()->getNamedMetadata("llvm.dbg.cu");
if (CUNodes) {
for (unsigned I = 0, E1 = CUNodes->getNumOperands(); I != E1; ++I) {
@@ -1031,11 +707,10 @@ unsigned SampleFunctionProfile::getFunct
/// metadata on B using the computed values for each of its branches.
///
/// \param F The function to query.
+/// \param S The set of samples collected during \p F's execution.
///
/// \returns true if \p F was modified. Returns false, otherwise.
-bool SampleFunctionProfile::emitAnnotations(Function &F, DominatorTree *DomTree,
- PostDominatorTree *PostDomTree,
- LoopInfo *Loops) {
+bool SampleProfileLoader::emitAnnotations(Function &F) {
bool Changed = false;
// Initialize invariants used during computation and propagation.
@@ -1045,10 +720,6 @@ bool SampleFunctionProfile::emitAnnotati
DEBUG(dbgs() << "Line number for the first instruction in " << F.getName()
<< ": " << HeaderLineno << "\n");
- DT = DomTree;
- PDT = PostDomTree;
- LI = Loops;
- Ctx = &F.getParent()->getContext();
// Compute basic block weights.
Changed |= computeBlockWeights(F);
@@ -1075,8 +746,8 @@ INITIALIZE_PASS_END(SampleProfileLoader,
"Sample Profile loader", false, false)
bool SampleProfileLoader::doInitialization(Module &M) {
- Profiler.reset(new SampleModuleProfile(M, Filename));
- ProfileIsValid = Profiler->loadText();
+ Reader.reset(new SampleProfileReader(M, Filename));
+ ProfileIsValid = Reader->load();
return true;
}
@@ -1091,11 +762,13 @@ FunctionPass *llvm::createSampleProfileL
bool SampleProfileLoader::runOnFunction(Function &F) {
if (!ProfileIsValid)
return false;
- DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
- PostDominatorTree *PDT = &getAnalysis<PostDominatorTree>();
- LoopInfo *LI = &getAnalysis<LoopInfo>();
- SampleFunctionProfile &FunctionProfile = Profiler->getProfile(F);
- if (!FunctionProfile.empty())
- return FunctionProfile.emitAnnotations(F, DT, PDT, LI);
+
+ DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree();
+ PDT = &getAnalysis<PostDominatorTree>();
+ LI = &getAnalysis<LoopInfo>();
+ Ctx = &F.getParent()->getContext();
+ Samples = Reader->getSamplesFor(F);
+ if (!Samples->empty())
+ return emitAnnotations(F);
return false;
}
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