1 llvm-bcanalyzer - LLVM bitcode analyzer 2 ======================================= 3 4 SYNOPSIS 5 -------- 6 7 :program:`llvm-bcanalyzer` [*options*] [*filename*] 8 9 DESCRIPTION 10 ----------- 11 12 The :program:`llvm-bcanalyzer` command is a small utility for analyzing bitcode 13 files. The tool reads a bitcode file (such as generated with the 14 :program:`llvm-as` tool) and produces a statistical report on the contents of 15 the bitcode file. The tool can also dump a low level but human readable 16 version of the bitcode file. This tool is probably not of much interest or 17 utility except for those working directly with the bitcode file format. Most 18 LLVM users can just ignore this tool. 19 20 If *filename* is omitted or is ``-``, then :program:`llvm-bcanalyzer` reads its 21 input from standard input. This is useful for combining the tool into a 22 pipeline. Output is written to the standard output. 23 24 OPTIONS 25 ------- 26 27 .. program:: llvm-bcanalyzer 28 29 .. option:: -nodetails 30 31 Causes :program:`llvm-bcanalyzer` to abbreviate its output by writing out only 32 a module level summary. The details for individual functions are not 33 displayed. 34 35 .. option:: -dump 36 37 Causes :program:`llvm-bcanalyzer` to dump the bitcode in a human readable 38 format. This format is significantly different from LLVM assembly and 39 provides details about the encoding of the bitcode file. 40 41 .. option:: -verify 42 43 Causes :program:`llvm-bcanalyzer` to verify the module produced by reading the 44 bitcode. This ensures that the statistics generated are based on a consistent 45 module. 46 47 .. option:: -help 48 49 Print a summary of command line options. 50 51 EXIT STATUS 52 ----------- 53 54 If :program:`llvm-bcanalyzer` succeeds, it will exit with 0. Otherwise, if an 55 error occurs, it will exit with a non-zero value, usually 1. 56 57 SUMMARY OUTPUT DEFINITIONS 58 -------------------------- 59 60 The following items are always printed by llvm-bcanalyzer. They comprize the 61 summary output. 62 63 **Bitcode Analysis Of Module** 64 65 This just provides the name of the module for which bitcode analysis is being 66 generated. 67 68 **Bitcode Version Number** 69 70 The bitcode version (not LLVM version) of the file read by the analyzer. 71 72 **File Size** 73 74 The size, in bytes, of the entire bitcode file. 75 76 **Module Bytes** 77 78 The size, in bytes, of the module block. Percentage is relative to File Size. 79 80 **Function Bytes** 81 82 The size, in bytes, of all the function blocks. Percentage is relative to File 83 Size. 84 85 **Global Types Bytes** 86 87 The size, in bytes, of the Global Types Pool. Percentage is relative to File 88 Size. This is the size of the definitions of all types in the bitcode file. 89 90 **Constant Pool Bytes** 91 92 The size, in bytes, of the Constant Pool Blocks Percentage is relative to File 93 Size. 94 95 **Module Globals Bytes** 96 97 Ths size, in bytes, of the Global Variable Definitions and their initializers. 98 Percentage is relative to File Size. 99 100 **Instruction List Bytes** 101 102 The size, in bytes, of all the instruction lists in all the functions. 103 Percentage is relative to File Size. Note that this value is also included in 104 the Function Bytes. 105 106 **Compaction Table Bytes** 107 108 The size, in bytes, of all the compaction tables in all the functions. 109 Percentage is relative to File Size. Note that this value is also included in 110 the Function Bytes. 111 112 **Symbol Table Bytes** 113 114 The size, in bytes, of all the symbol tables in all the functions. Percentage is 115 relative to File Size. Note that this value is also included in the Function 116 Bytes. 117 118 **Dependent Libraries Bytes** 119 120 The size, in bytes, of the list of dependent libraries in the module. Percentage 121 is relative to File Size. Note that this value is also included in the Module 122 Global Bytes. 123 124 **Number Of Bitcode Blocks** 125 126 The total number of blocks of any kind in the bitcode file. 127 128 **Number Of Functions** 129 130 The total number of function definitions in the bitcode file. 131 132 **Number Of Types** 133 134 The total number of types defined in the Global Types Pool. 135 136 **Number Of Constants** 137 138 The total number of constants (of any type) defined in the Constant Pool. 139 140 **Number Of Basic Blocks** 141 142 The total number of basic blocks defined in all functions in the bitcode file. 143 144 **Number Of Instructions** 145 146 The total number of instructions defined in all functions in the bitcode file. 147 148 **Number Of Long Instructions** 149 150 The total number of long instructions defined in all functions in the bitcode 151 file. Long instructions are those taking greater than 4 bytes. Typically long 152 instructions are GetElementPtr with several indices, PHI nodes, and calls to 153 functions with large numbers of arguments. 154 155 **Number Of Operands** 156 157 The total number of operands used in all instructions in the bitcode file. 158 159 **Number Of Compaction Tables** 160 161 The total number of compaction tables in all functions in the bitcode file. 162 163 **Number Of Symbol Tables** 164 165 The total number of symbol tables in all functions in the bitcode file. 166 167 **Number Of Dependent Libs** 168 169 The total number of dependent libraries found in the bitcode file. 170 171 **Total Instruction Size** 172 173 The total size of the instructions in all functions in the bitcode file. 174 175 **Average Instruction Size** 176 177 The average number of bytes per instruction across all functions in the bitcode 178 file. This value is computed by dividing Total Instruction Size by Number Of 179 Instructions. 180 181 **Maximum Type Slot Number** 182 183 The maximum value used for a type's slot number. Larger slot number values take 184 more bytes to encode. 185 186 **Maximum Value Slot Number** 187 188 The maximum value used for a value's slot number. Larger slot number values take 189 more bytes to encode. 190 191 **Bytes Per Value** 192 193 The average size of a Value definition (of any type). This is computed by 194 dividing File Size by the total number of values of any type. 195 196 **Bytes Per Global** 197 198 The average size of a global definition (constants and global variables). 199 200 **Bytes Per Function** 201 202 The average number of bytes per function definition. This is computed by 203 dividing Function Bytes by Number Of Functions. 204 205 **# of VBR 32-bit Integers** 206 207 The total number of 32-bit integers encoded using the Variable Bit Rate 208 encoding scheme. 209 210 **# of VBR 64-bit Integers** 211 212 The total number of 64-bit integers encoded using the Variable Bit Rate encoding 213 scheme. 214 215 **# of VBR Compressed Bytes** 216 217 The total number of bytes consumed by the 32-bit and 64-bit integers that use 218 the Variable Bit Rate encoding scheme. 219 220 **# of VBR Expanded Bytes** 221 222 The total number of bytes that would have been consumed by the 32-bit and 64-bit 223 integers had they not been compressed with the Variable Bit Rage encoding 224 scheme. 225 226 **Bytes Saved With VBR** 227 228 The total number of bytes saved by using the Variable Bit Rate encoding scheme. 229 The percentage is relative to # of VBR Expanded Bytes. 230 231 DETAILED OUTPUT DEFINITIONS 232 --------------------------- 233 234 The following definitions occur only if the -nodetails option was not given. 235 The detailed output provides additional information on a per-function basis. 236 237 **Type** 238 239 The type signature of the function. 240 241 **Byte Size** 242 243 The total number of bytes in the function's block. 244 245 **Basic Blocks** 246 247 The number of basic blocks defined by the function. 248 249 **Instructions** 250 251 The number of instructions defined by the function. 252 253 **Long Instructions** 254 255 The number of instructions using the long instruction format in the function. 256 257 **Operands** 258 259 The number of operands used by all instructions in the function. 260 261 **Instruction Size** 262 263 The number of bytes consumed by instructions in the function. 264 265 **Average Instruction Size** 266 267 The average number of bytes consumed by the instructions in the function. 268 This value is computed by dividing Instruction Size by Instructions. 269 270 **Bytes Per Instruction** 271 272 The average number of bytes used by the function per instruction. This value 273 is computed by dividing Byte Size by Instructions. Note that this is not the 274 same as Average Instruction Size. It computes a number relative to the total 275 function size not just the size of the instruction list. 276 277 **Number of VBR 32-bit Integers** 278 279 The total number of 32-bit integers found in this function (for any use). 280 281 **Number of VBR 64-bit Integers** 282 283 The total number of 64-bit integers found in this function (for any use). 284 285 **Number of VBR Compressed Bytes** 286 287 The total number of bytes in this function consumed by the 32-bit and 64-bit 288 integers that use the Variable Bit Rate encoding scheme. 289 290 **Number of VBR Expanded Bytes** 291 292 The total number of bytes in this function that would have been consumed by 293 the 32-bit and 64-bit integers had they not been compressed with the Variable 294 Bit Rate encoding scheme. 295 296 **Bytes Saved With VBR** 297 298 The total number of bytes saved in this function by using the Variable Bit 299 Rate encoding scheme. The percentage is relative to # of VBR Expanded Bytes. 300 301 SEE ALSO 302 -------- 303 304 :doc:`/CommandGuide/llvm-dis`, :doc:`/BitCodeFormat` 305 306
