Profile: Add a library for the instrumentation based profiling format

This provides a library to work with the instrumentation based
profiling format that is used by clang's -fprofile-instr-* options and
by the llvm-profdata tool. This is a binary format, rather than the
textual one that's currently in use.

The tests are in the subsequent commits that use this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203703 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Profile/ProfileData.h

@@ -0,0 +1,55 @@
+//=-- ProfileData.h - Instrumented profiling format support -------*- 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 support for instrumentation based PGO and coverage.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_PROFILE_PROFILEDATA_H__
+#define LLVM_PROFILE_PROFILEDATA_H__
+
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/system_error.h"
+
+#include <vector>
+
+namespace llvm {
+
+const char PROFILEDATA_MAGIC[4] = {'L', 'P', 'R', 'F'};
+const uint32_t PROFILEDATA_VERSION = 1;
+
+const error_category &profiledata_category();
+
+struct profiledata_error {
+  enum ErrorType {
+    success = 0,
+    bad_magic,
+    unsupported_version,
+    too_large,
+    truncated,
+    malformed,
+    unknown_function
+  };
+  ErrorType V;
+
+  profiledata_error(ErrorType V) : V(V) {}
+  operator ErrorType() const { return V; }
+};
+
+inline error_code make_error_code(profiledata_error E) {
+  return error_code(static_cast<int>(E), profiledata_category());
+}
+
+template <> struct is_error_code_enum<profiledata_error> : std::true_type {};
+template <> struct is_error_code_enum<profiledata_error::ErrorType>
+  : std::true_type {};
+
+} // end namespace llvm
+
+#endif // LLVM_PROFILE_PROFILEDATA_H__

include/llvm/Profile/ProfileDataReader.h

@@ -0,0 +1,93 @@
+//=-- ProfileDataReader.h - Instrumented profiling reader ---------*- 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 support for reading profiling data for instrumentation
+// based PGO and coverage.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_PROFILE_PROFILEDATA_READER_H__
+#define LLVM_PROFILE_PROFILEDATA_READER_H__
+
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/ErrorOr.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <vector>
+
+namespace llvm {
+
+class ProfileDataCursor;
+
+/// Reader for the profile data that is used for instrumentation based PGO.
+class ProfileDataReader {
+private:
+  /// The profile data file contents.
+  std::unique_ptr<MemoryBuffer> DataBuffer;
+  /// Offsets into DataBuffer for each function's counters.
+  StringMap<uint32_t> DataOffsets;
+  /// The maximal execution count among all functions.
+  uint64_t MaxFunctionCount;
+
+  ProfileDataReader(const ProfileDataReader &) LLVM_DELETED_FUNCTION;
+  ProfileDataReader &operator=(const ProfileDataReader &) LLVM_DELETED_FUNCTION;
+protected:
+  ProfileDataReader(std::unique_ptr<MemoryBuffer> &DataBuffer)
+      : DataBuffer(DataBuffer.release()) {}
+
+  /// Populate internal state using the profile data's index
+  error_code readIndex();
+public:
+
+  class name_iterator {
+    typedef StringMap<unsigned>::const_iterator IterTy;
+    IterTy Ix;
+  public:
+    explicit name_iterator(const IterTy &Ix) : Ix(Ix) {}
+
+    StringRef operator*() const { return Ix->getKey(); }
+
+    bool operator==(const name_iterator &RHS) const { return Ix == RHS.Ix; }
+    bool operator!=(const name_iterator &RHS) const { return Ix != RHS.Ix; }
+
+    inline name_iterator& operator++() { ++Ix; return *this; }
+  };
+
+  /// Iterators over the names of indexed items
+  name_iterator begin() const {
+    return name_iterator(DataOffsets.begin());
+  }
+  name_iterator end() const {
+    return name_iterator(DataOffsets.end());
+  }
+
+private:
+  error_code findFunctionCounts(StringRef FuncName, uint64_t &FunctionHash,
+                                ProfileDataCursor &Cursor);
+public:
+  /// The number of profiled functions
+  size_t numProfiledFunctions() { return DataOffsets.size(); }
+  /// Fill Counts with the profile data for the given function name.
+  error_code getFunctionCounts(StringRef FuncName, uint64_t &FunctionHash,
+                               std::vector<uint64_t> &Counts);
+  /// Get the frequency with which a function is called relative to the function
+  /// that is called most often in the program.
+  error_code getCallFrequency(StringRef FuncName, uint64_t &FunctionHash,
+                              double &F);
+
+  static error_code create(std::string Path,
+                           std::unique_ptr<ProfileDataReader> &Result);
+};
+
+} // end namespace llvm
+
+#endif // LLVM_PROFILE_PROFILEDATA_READER_H__

include/llvm/Profile/ProfileDataWriter.h

@@ -0,0 +1,54 @@
+//=-- ProfileDataWriter.h - Instrumented profiling writer ---------*- 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 support for writing profiling data for instrumentation
+// based PGO and coverage.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_PROFILE_PROFILEDATA_WRITER_H__
+#define LLVM_PROFILE_PROFILEDATA_WRITER_H__
+
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/DataTypes.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <vector>
+
+namespace llvm {
+
+struct __attribute__((packed)) ProfileDataHeader {
+  char     Magic[4];
+  uint32_t Version;
+  uint32_t DataStart;
+  uint32_t Padding;
+  uint64_t MaxFunctionCount;
+};
+
+/// Writer for instrumentation based profile data
+class ProfileDataWriter {
+  StringMap<size_t> FunctionOffsets;
+  std::vector<uint64_t> FunctionData;
+  uint32_t DataStart;
+  uint64_t MaxFunctionCount;
+
+  void write32(raw_ostream &OS, uint32_t Value);
+  void write64(raw_ostream &OS, uint64_t Value);
+public:
+  ProfileDataWriter()
+      : DataStart(sizeof(ProfileDataHeader)), MaxFunctionCount(0) {}
+
+  void addFunctionCounts(StringRef FuncName, uint64_t FunctionHash,
+                         uint64_t NumCounters, const uint64_t *Counters);
+  void write(raw_ostream &OS);
+};
+
+} // end namespace llvm
+
+#endif // LLVM_PROFILE_PROFILEDATA_WRITER_H__

lib/CMakeLists.txt

@@ -16,3 +16,4 @@ add_subdirectory(ExecutionEngine)
 add_subdirectory(Target)
 add_subdirectory(AsmParser)
 add_subdirectory(LineEditor)
+add_subdirectory(Profile)

lib/LLVMBuild.txt

@@ -16,7 +16,7 @@
 ;===------------------------------------------------------------------------===;
 
 [common]
-subdirectories = Analysis AsmParser Bitcode CodeGen DebugInfo ExecutionEngine LineEditor Linker IR IRReader LTO MC Object Option Support TableGen Target Transforms
+subdirectories = Analysis AsmParser Bitcode CodeGen DebugInfo ExecutionEngine LineEditor Linker IR IRReader LTO MC Object Option Profile Support TableGen Target Transforms
 
 [component_0]
 type = Group

lib/Makefile

@@ -12,6 +12,6 @@ include $(LEVEL)/Makefile.config
 
 PARALLEL_DIRS := IR AsmParser Bitcode Analysis Transforms CodeGen Target \
                  ExecutionEngine Linker LTO MC Object Option DebugInfo   \
-                 IRReader LineEditor
+                 IRReader LineEditor Profile
 
 include $(LEVEL)/Makefile.common

lib/Profile/CMakeLists.txt

@@ -0,0 +1,5 @@
+add_llvm_library(LLVMProfile
+  ProfileData.cpp
+  ProfileDataReader.cpp
+  ProfileDataWriter.cpp
+  )

lib/Profile/LLVMBuild.txt

@@ -0,0 +1,21 @@
+;===- ./lib/Profile/LLVMBuild.txt ------------------------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = Profile
+parent = Libraries

lib/Profile/Makefile

@@ -0,0 +1,14 @@
+##===- lib/Profile/Makefile --------------------------------*- Makefile -*-===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+##===----------------------------------------------------------------------===##
+
+LEVEL = ../..
+LIBRARYNAME = LLVMProfile
+BUILD_ARCHIVE := 1
+
+include $(LEVEL)/Makefile.common

lib/Profile/ProfileData.cpp

@@ -0,0 +1,54 @@
+//=-- ProfileData.cpp - Instrumented profiling format support ---------------=//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for clang's instrumentation based PGO and
+// coverage.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Profile/ProfileData.h"
+#include "llvm/Support/ErrorHandling.h"
+
+using namespace llvm;
+
+namespace {
+class ProfileDataErrorCategoryType : public _do_message {
+  const char *name() const override { return "llvm.profiledata"; }
+  std::string message(int IE) const {
+    profiledata_error::ErrorType E =
+        static_cast<profiledata_error::ErrorType>(IE);
+    switch (E) {
+    case profiledata_error::success: return "Success";
+    case profiledata_error::bad_magic:
+      return "Invalid file format (bad magic)";
+    case profiledata_error::unsupported_version:
+      return "Unsupported format version";
+    case profiledata_error::too_large:
+      return "Too much profile data";
+    case profiledata_error::truncated:
+      return "Truncated profile data";
+    case profiledata_error::malformed:
+      return "Malformed profile data";
+    case profiledata_error::unknown_function:
+      return "No profile data available for function";
+    }
+    llvm_unreachable("A value of profiledata_error has no message.");
+  }
+  error_condition default_error_condition(int EV) const {
+    if (EV == profiledata_error::success)
+      return errc::success;
+    return errc::invalid_argument;
+  }
+};
+}
+
+const error_category &llvm::profiledata_category() {
+  static ProfileDataErrorCategoryType C;
+  return C;
+}