LLVM API Documentation

Analyzer.h

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00001 //===-- llvm/Bytecode/Analyzer.h - Analyzer for Bytecode files --*- C++ -*-===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by Reid Spencer and is distributed under the
00006 // University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This functionality is implemented by the lib/Bytecode/Reader library.
00011 // It is used to read VM bytecode files from a file or memory buffer
00012 // and print out a diagnostic analysis of the contents of the file. It is
00013 // intended for three uses: (a) understanding the bytecode format, (b) ensuring
00014 // correctness of bytecode format, (c) statistical analysis of generated
00015 // bytecode files.
00016 //
00017 //===----------------------------------------------------------------------===//
00018 
00019 #ifndef LLVM_BYTECODE_ANALYZER_H
00020 #define LLVM_BYTECODE_ANALYZER_H
00021 
00022 #include "llvm/Bytecode/Format.h"
00023 #include <string>
00024 #include <map>
00025 #include <iostream>
00026 
00027 namespace llvm {
00028 
00029 // Forward declarations
00030 class Function;
00031 class Module;
00032 
00033 /// This structure is used to contain the output of the Bytecode Analysis
00034 /// library. It simply contains fields to hold each item of the analysis
00035 /// results.
00036 /// @brief Bytecode Analysis results structure
00037 struct BytecodeAnalysis {
00038   std::string ModuleId;     ///< Identification of the module
00039   unsigned version;         ///< The version number of the bytecode file
00040   unsigned byteSize;        ///< The size of the bytecode file in bytes
00041   unsigned numTypes;        ///< The number of types
00042   unsigned numValues;       ///< The number of values
00043   unsigned numBlocks;       ///< The number of *bytecode* blocks
00044   unsigned numFunctions;    ///< The number of functions defined
00045   unsigned numConstants;    ///< The number of constants
00046   unsigned numGlobalVars;   ///< The number of global variables
00047   unsigned numInstructions; ///< The number of instructions in all functions
00048   unsigned numBasicBlocks;  ///< The number of BBs in all functions
00049   unsigned numOperands;     ///< The number of BBs in all functions
00050   unsigned numCmpctnTables; ///< The number of compaction tables
00051   unsigned numSymTab;       ///< The number of symbol tables
00052   unsigned numAlignment;    ///< The number of alignment bytes
00053   unsigned numLibraries;    ///< The number of dependent libraries
00054   unsigned libSize;         ///< Number of bytes taken by dep libs.
00055   unsigned maxTypeSlot;     ///< The maximum slot number for types
00056   unsigned maxValueSlot;    ///< The maximum slot number for values
00057   double   fileDensity;     ///< Density of file (bytes/definition)
00058     ///< This is the density of the bytecode file. It is the ratio of
00059     ///< the number of bytes to the number of definitions in the file. Smaller
00060     ///< numbers mean the file is more compact (denser). Larger numbers mean
00061     ///< the file is more sparse.
00062   double   globalsDensity;  ///< density of global defs (bytes/definition)
00063   double   functionDensity; ///< Average density of functions (bytes/function)
00064   unsigned instructionSize; ///< Size of instructions in bytes
00065   unsigned longInstructions;///< Number of instructions > 4 bytes
00066   unsigned vbrCount32;      ///< Number of 32-bit vbr values
00067   unsigned vbrCount64;      ///< Number of 64-bit vbr values
00068   unsigned vbrCompBytes;    ///< Number of vbr bytes (compressed)
00069   unsigned vbrExpdBytes;    ///< Number of vbr bytes (expanded)
00070 
00071   typedef std::map<BytecodeFormat::CompressedBytecodeBlockIdentifiers,unsigned>
00072       BlockSizeMap;
00073   BlockSizeMap BlockSizes;
00074 
00075   /// A structure that contains various pieces of information related to
00076   /// an analysis of a single function.
00077   struct BytecodeFunctionInfo {
00078     std::string description;  ///< Function type description
00079     std::string name;         ///< Name of function if it has one
00080     unsigned byteSize;        ///< The size of the function in bytecode bytes
00081     unsigned numInstructions; ///< The number of instructions in the function
00082     unsigned numBasicBlocks;  ///< The number of basic blocks in the function
00083     unsigned numPhis;         ///< Number of Phi Nodes in Instructions
00084     unsigned numOperands;     ///< The number of operands in the function
00085     double   density;         ///< Density of function
00086     unsigned instructionSize; ///< Size of instructions in bytes
00087     unsigned longInstructions;///< Number of instructions > 4 bytes
00088     unsigned vbrCount32;      ///< Number of 32-bit vbr values
00089     unsigned vbrCount64;      ///< Number of 64-bit vbr values
00090     unsigned vbrCompBytes;    ///< Number of vbr bytes (compressed)
00091     unsigned vbrExpdBytes;    ///< Number of vbr bytes (expanded)
00092   };
00093 
00094   /// A mapping of function slot numbers to the collected information about
00095   /// the function.
00096   std::map<const Function*,BytecodeFunctionInfo> FunctionInfo;
00097 
00098   /// The content of the progressive verification
00099   std::string VerifyInfo;
00100 
00101   /// Flags for what should be done
00102   bool detailedResults;       ///< If true, FunctionInfo has contents
00103   bool progressiveVerify;     ///< If true, VerifyInfo has contents
00104 };
00105 
00106 /// This function is the main entry point into the bytecode analysis library. It
00107 /// allows you to simply provide a \p filename and storage for the \p Results
00108 /// that will be filled in with the analysis results.
00109 /// @brief Analyze contents of a bytecode File
00110 Module* AnalyzeBytecodeFile(
00111       const std::string& Filename, ///< The name of the bytecode file to read
00112       BytecodeAnalysis& Results,   ///< The results of the analysis
00113       std::string* ErrorStr = 0,   ///< Errors, if any.
00114       std::ostream* output = 0     ///< Stream for dump output, if wanted
00115     );
00116 
00117 /// This function is an alternate entry point into the bytecode analysis
00118 /// library. It allows you to provide an arbitrary memory buffer which is
00119 /// assumed to contain a complete bytecode file. The \p Buffer is analyzed and
00120 /// the \p Results are filled in.
00121 /// @brief Analyze contents of a bytecode buffer.
00122 Module* AnalyzeBytecodeBuffer(
00123        const unsigned char* Buffer, ///< Pointer to start of bytecode buffer
00124        unsigned BufferSize,         ///< Size of the bytecode buffer
00125        const std::string& ModuleID, ///< Identifier for the module
00126        BytecodeAnalysis& Results,   ///< The results of the analysis
00127        std::string* ErrorStr = 0,   ///< Errors, if any.
00128        std::ostream* output = 0     ///< Stream for dump output, if wanted
00129      );
00130 
00131 /// This function prints the contents of rhe BytecodeAnalysis structure in
00132 /// a human legible form.
00133 /// @brief Print BytecodeAnalysis structure to an ostream
00134 void PrintBytecodeAnalysis(BytecodeAnalysis& bca, std::ostream& Out );
00135 
00136 /// @brief std::ostream inserter for BytecodeAnalysis structure
00137 inline std::ostream& operator<<(std::ostream& Out, BytecodeAnalysis& bca ) {
00138     PrintBytecodeAnalysis(bca,Out);
00139     return Out;
00140 }
00141 
00142 } // End llvm namespace
00143 
00144 #endif