| =pod | |
| =head1 NAME | |
| llvm-bcanalyzer - LLVM bitcode analyzer | |
| =head1 SYNOPSIS | |
| B<llvm-bcanalyzer> [I<options>] [F<filename>] | |
| =head1 DESCRIPTION | |
| The B<llvm-bcanalyzer> command is a small utility for analyzing bitcode files. | |
| The tool reads a bitcode file (such as generated with the B<llvm-as> tool) and | |
| produces a statistical report on the contents of the bitcode file. The tool | |
| can also dump a low level but human readable version of the bitcode file. | |
| This tool is probably not of much interest or utility except for those working | |
| directly with the bitcode file format. Most LLVM users can just ignore | |
| this tool. | |
| If F<filename> is omitted or is C<->, then B<llvm-bcanalyzer> reads its input | |
| from standard input. This is useful for combining the tool into a pipeline. | |
| Output is written to the standard output. | |
| =head1 OPTIONS | |
| =over | |
| =item B<-nodetails> | |
| Causes B<llvm-bcanalyzer> to abbreviate its output by writing out only a module | |
| level summary. The details for individual functions are not displayed. | |
| =item B<-dump> | |
| Causes B<llvm-bcanalyzer> to dump the bitcode in a human readable format. This | |
| format is significantly different from LLVM assembly and provides details about | |
| the encoding of the bitcode file. | |
| =item B<-verify> | |
| Causes B<llvm-bcanalyzer> to verify the module produced by reading the | |
| bitcode. This ensures that the statistics generated are based on a consistent | |
| module. | |
| =item B<-help> | |
| Print a summary of command line options. | |
| =back | |
| =head1 EXIT STATUS | |
| If B<llvm-bcanalyzer> succeeds, it will exit with 0. Otherwise, if an error | |
| occurs, it will exit with a non-zero value, usually 1. | |
| =head1 SUMMARY OUTPUT DEFINITIONS | |
| The following items are always printed by llvm-bcanalyzer. They comprize the | |
| summary output. | |
| =over | |
| =item B<Bitcode Analysis Of Module> | |
| This just provides the name of the module for which bitcode analysis is being | |
| generated. | |
| =item B<Bitcode Version Number> | |
| The bitcode version (not LLVM version) of the file read by the analyzer. | |
| =item B<File Size> | |
| The size, in bytes, of the entire bitcode file. | |
| =item B<Module Bytes> | |
| The size, in bytes, of the module block. Percentage is relative to File Size. | |
| =item B<Function Bytes> | |
| The size, in bytes, of all the function blocks. Percentage is relative to File | |
| Size. | |
| =item B<Global Types Bytes> | |
| The size, in bytes, of the Global Types Pool. Percentage is relative to File | |
| Size. This is the size of the definitions of all types in the bitcode file. | |
| =item B<Constant Pool Bytes> | |
| The size, in bytes, of the Constant Pool Blocks Percentage is relative to File | |
| Size. | |
| =item B<Module Globals Bytes> | |
| Ths size, in bytes, of the Global Variable Definitions and their initializers. | |
| Percentage is relative to File Size. | |
| =item B<Instruction List Bytes> | |
| The size, in bytes, of all the instruction lists in all the functions. | |
| Percentage is relative to File Size. Note that this value is also included in | |
| the Function Bytes. | |
| =item B<Compaction Table Bytes> | |
| The size, in bytes, of all the compaction tables in all the functions. | |
| Percentage is relative to File Size. Note that this value is also included in | |
| the Function Bytes. | |
| =item B<Symbol Table Bytes> | |
| The size, in bytes, of all the symbol tables in all the functions. Percentage is | |
| relative to File Size. Note that this value is also included in the Function | |
| Bytes. | |
| =item B<Dependent Libraries Bytes> | |
| The size, in bytes, of the list of dependent libraries in the module. Percentage | |
| is relative to File Size. Note that this value is also included in the Module | |
| Global Bytes. | |
| =item B<Number Of Bitcode Blocks> | |
| The total number of blocks of any kind in the bitcode file. | |
| =item B<Number Of Functions> | |
| The total number of function definitions in the bitcode file. | |
| =item B<Number Of Types> | |
| The total number of types defined in the Global Types Pool. | |
| =item B<Number Of Constants> | |
| The total number of constants (of any type) defined in the Constant Pool. | |
| =item B<Number Of Basic Blocks> | |
| The total number of basic blocks defined in all functions in the bitcode file. | |
| =item B<Number Of Instructions> | |
| The total number of instructions defined in all functions in the bitcode file. | |
| =item B<Number Of Long Instructions> | |
| The total number of long instructions defined in all functions in the bitcode | |
| file. Long instructions are those taking greater than 4 bytes. Typically long | |
| instructions are GetElementPtr with several indices, PHI nodes, and calls to | |
| functions with large numbers of arguments. | |
| =item B<Number Of Operands> | |
| The total number of operands used in all instructions in the bitcode file. | |
| =item B<Number Of Compaction Tables> | |
| The total number of compaction tables in all functions in the bitcode file. | |
| =item B<Number Of Symbol Tables> | |
| The total number of symbol tables in all functions in the bitcode file. | |
| =item B<Number Of Dependent Libs> | |
| The total number of dependent libraries found in the bitcode file. | |
| =item B<Total Instruction Size> | |
| The total size of the instructions in all functions in the bitcode file. | |
| =item B<Average Instruction Size> | |
| The average number of bytes per instruction across all functions in the bitcode | |
| file. This value is computed by dividing Total Instruction Size by Number Of | |
| Instructions. | |
| =item B<Maximum Type Slot Number> | |
| The maximum value used for a type's slot number. Larger slot number values take | |
| more bytes to encode. | |
| =item B<Maximum Value Slot Number> | |
| The maximum value used for a value's slot number. Larger slot number values take | |
| more bytes to encode. | |
| =item B<Bytes Per Value> | |
| The average size of a Value definition (of any type). This is computed by | |
| dividing File Size by the total number of values of any type. | |
| =item B<Bytes Per Global> | |
| The average size of a global definition (constants and global variables). | |
| =item B<Bytes Per Function> | |
| The average number of bytes per function definition. This is computed by | |
| dividing Function Bytes by Number Of Functions. | |
| =item B<# of VBR 32-bit Integers> | |
| The total number of 32-bit integers encoded using the Variable Bit Rate | |
| encoding scheme. | |
| =item B<# of VBR 64-bit Integers> | |
| The total number of 64-bit integers encoded using the Variable Bit Rate encoding | |
| scheme. | |
| =item B<# of VBR Compressed Bytes> | |
| The total number of bytes consumed by the 32-bit and 64-bit integers that use | |
| the Variable Bit Rate encoding scheme. | |
| =item B<# of VBR Expanded Bytes> | |
| The total number of bytes that would have been consumed by the 32-bit and 64-bit | |
| integers had they not been compressed with the Variable Bit Rage encoding | |
| scheme. | |
| =item B<Bytes Saved With VBR> | |
| The total number of bytes saved by using the Variable Bit Rate encoding scheme. | |
| The percentage is relative to # of VBR Expanded Bytes. | |
| =back | |
| =head1 DETAILED OUTPUT DEFINITIONS | |
| The following definitions occur only if the -nodetails option was not given. | |
| The detailed output provides additional information on a per-function basis. | |
| =over | |
| =item B<Type> | |
| The type signature of the function. | |
| =item B<Byte Size> | |
| The total number of bytes in the function's block. | |
| =item B<Basic Blocks> | |
| The number of basic blocks defined by the function. | |
| =item B<Instructions> | |
| The number of instructions defined by the function. | |
| =item B<Long Instructions> | |
| The number of instructions using the long instruction format in the function. | |
| =item B<Operands> | |
| The number of operands used by all instructions in the function. | |
| =item B<Instruction Size> | |
| The number of bytes consumed by instructions in the function. | |
| =item B<Average Instruction Size> | |
| The average number of bytes consumed by the instructions in the function. This | |
| value is computed by dividing Instruction Size by Instructions. | |
| =item B<Bytes Per Instruction> | |
| The average number of bytes used by the function per instruction. This value is | |
| computed by dividing Byte Size by Instructions. Note that this is not the same | |
| as Average Instruction Size. It computes a number relative to the total function | |
| size not just the size of the instruction list. | |
| =item B<Number of VBR 32-bit Integers> | |
| The total number of 32-bit integers found in this function (for any use). | |
| =item B<Number of VBR 64-bit Integers> | |
| The total number of 64-bit integers found in this function (for any use). | |
| =item B<Number of VBR Compressed Bytes> | |
| The total number of bytes in this function consumed by the 32-bit and 64-bit | |
| integers that use the Variable Bit Rate encoding scheme. | |
| =item B<Number of VBR Expanded Bytes> | |
| The total number of bytes in this function that would have been consumed by | |
| the 32-bit and 64-bit integers had they not been compressed with the Variable | |
| Bit Rate encoding scheme. | |
| =item B<Bytes Saved With VBR> | |
| The total number of bytes saved in this function by using the Variable Bit | |
| Rate encoding scheme. The percentage is relative to # of VBR Expanded Bytes. | |
| =back | |
| =head1 SEE ALSO | |
| L<llvm-dis|llvm-dis>, L<http://llvm.org/docs/BitCodeFormat.html> | |
| =head1 AUTHORS | |
| Maintained by the LLVM Team (L<http://llvm.org/>). | |
| =cut |