


LLVM-BCANALYZER(1)      LLVM Command Guide     LLVM-BCANALYZER(1)


NAME
       llvm-bcanalyzer - LLVM bitcode analyzer

SYNOPSIS
       llvm-bcanalyzer [options] [filename]

DESCRIPTION
       The llvm-bcanalyzer command is a small utility for analyzing bitcode
       files.  The tool reads a bitcode file (such as generated with the 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 filename is omitted or is "-", then 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.

OPTIONS
       -nodetails
           Causes llvm-bcanalyzer to abbreviate its output by writing out only
           a module level summary. The details for individual functions are
           not displayed.

       -dump
           Causes 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.

       -verify
           Causes llvm-bcanalyzer to verify the module produced by reading the
           bitcode. This ensures that the statistics generated are based on a
           consistent module.

       -help
           Print a summary of command line options.

EXIT STATUS
       If llvm-bcanalyzer succeeds, it will exit with 0.  Otherwise, if an
       error occurs, it will exit with a non-zero value, usually 1.

SUMMARY OUTPUT DEFINITIONS
       The following items are always printed by llvm-bcanalyzer. They
       comprize the summary output.

       Bitcode Analysis Of Module
           This just provides the name of the module for which bitcode
           analysis is being generated.

       Bitcode Version Number
           The bitcode version (not LLVM version) of the file read by the
           analyzer.




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LLVM-BCANALYZER(1)      LLVM Command Guide     LLVM-BCANALYZER(1)


       File Size
           The size, in bytes, of the entire bitcode file.

       Module Bytes
           The size, in bytes, of the module block. Percentage is relative to
           File Size.

       Function Bytes
           The size, in bytes, of all the function blocks. Percentage is
           relative to File Size.

       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.

       Constant Pool Bytes
           The size, in bytes, of the Constant Pool Blocks Percentage is
           relative to File Size.

       Module Globals Bytes
           Ths size, in bytes, of the Global Variable Definitions and their
           initializers.  Percentage is relative to File Size.

       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.

       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.

       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.

       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.

       Number Of Bitcode Blocks
           The total number of blocks of any kind in the bitcode file.

       Number Of Functions
           The total number of function definitions in the bitcode file.

       Number Of Types
           The total number of types defined in the Global Types Pool.





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LLVM-BCANALYZER(1)      LLVM Command Guide     LLVM-BCANALYZER(1)


       Number Of Constants
           The total number of constants (of any type) defined in the Constant
           Pool.

       Number Of Basic Blocks
           The total number of basic blocks defined in all functions in the
           bitcode file.

       Number Of Instructions
           The total number of instructions defined in all functions in the
           bitcode file.

       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.

       Number Of Operands
           The total number of operands used in all instructions in the
           bitcode file.

       Number Of Compaction Tables
           The total number of compaction tables in all functions in the
           bitcode file.

       Number Of Symbol Tables
           The total number of symbol tables in all functions in the bitcode
           file.

       Number Of Dependent Libs
           The total number of dependent libraries found in the bitcode file.

       Total Instruction Size
           The total size of the instructions in all functions in the bitcode
           file.

       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.

       Maximum Type Slot Number
           The maximum value used for a type's slot number. Larger slot number
           values take more bytes to encode.

       Maximum Value Slot Number
           The maximum value used for a value's slot number. Larger slot
           number values take more bytes to encode.

       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



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LLVM-BCANALYZER(1)      LLVM Command Guide     LLVM-BCANALYZER(1)


           type.

       Bytes Per Global
           The average size of a global definition (constants and global
           variables).

       Bytes Per Function
           The average number of bytes per function definition. This is
           computed by dividing Function Bytes by Number Of Functions.

       # of VBR 32-bit Integers
           The total number of 32-bit integers encoded using the Variable Bit
           Rate encoding scheme.

       # of VBR 64-bit Integers
           The total number of 64-bit integers encoded using the Variable Bit
           Rate encoding scheme.

       # 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.

       # 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.

       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.

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.

       Type
           The type signature of the function.

       Byte Size
           The total number of bytes in the function's block.

       Basic Blocks
           The number of basic blocks defined by the function.

       Instructions
           The number of instructions defined by the function.

       Long Instructions
           The number of instructions using the long instruction format in the
           function.





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LLVM-BCANALYZER(1)      LLVM Command Guide     LLVM-BCANALYZER(1)


       Operands
           The number of operands used by all instructions in the function.

       Instruction Size
           The number of bytes consumed by instructions in the function.

       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.

       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.

       Number of VBR 32-bit Integers
           The total number of 32-bit integers found in this function (for any
           use).

       Number of VBR 64-bit Integers
           The total number of 64-bit integers found in this function (for any
           use).

       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.

       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.

       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.

SEE ALSO
       llvm-dis, <http://llvm.org/docs/BitCodeFormat.html>

AUTHORS
       Maintained by the LLVM Team (<http://llvm.org>).












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