| =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 funtion. 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 |
