1llvm-bcanalyzer - LLVM bitcode analyzer 2======================================= 3 4 5SYNOPSIS 6-------- 7 8 9**llvm-bcanalyzer** [*options*] [*filename*] 10 11 12DESCRIPTION 13----------- 14 15 16The **llvm-bcanalyzer** command is a small utility for analyzing bitcode files. 17The tool reads a bitcode file (such as generated with the **llvm-as** tool) and 18produces a statistical report on the contents of the bitcode file. The tool 19can also dump a low level but human readable version of the bitcode file. 20This tool is probably not of much interest or utility except for those working 21directly with the bitcode file format. Most LLVM users can just ignore 22this tool. 23 24If *filename* is omitted or is ``-``, then **llvm-bcanalyzer** reads its input 25from standard input. This is useful for combining the tool into a pipeline. 26Output is written to the standard output. 27 28 29OPTIONS 30------- 31 32 33 34**-nodetails** 35 36 Causes **llvm-bcanalyzer** to abbreviate its output by writing out only a module 37 level summary. The details for individual functions are not displayed. 38 39 40 41**-dump** 42 43 Causes **llvm-bcanalyzer** to dump the bitcode in a human readable format. This 44 format is significantly different from LLVM assembly and provides details about 45 the encoding of the bitcode file. 46 47 48 49**-verify** 50 51 Causes **llvm-bcanalyzer** to verify the module produced by reading the 52 bitcode. This ensures that the statistics generated are based on a consistent 53 module. 54 55 56 57**-help** 58 59 Print a summary of command line options. 60 61 62 63 64EXIT STATUS 65----------- 66 67 68If **llvm-bcanalyzer** succeeds, it will exit with 0. Otherwise, if an error 69occurs, it will exit with a non-zero value, usually 1. 70 71 72SUMMARY OUTPUT DEFINITIONS 73-------------------------- 74 75 76The following items are always printed by llvm-bcanalyzer. They comprize the 77summary output. 78 79 80**Bitcode Analysis Of Module** 81 82 This just provides the name of the module for which bitcode analysis is being 83 generated. 84 85 86 87**Bitcode Version Number** 88 89 The bitcode version (not LLVM version) of the file read by the analyzer. 90 91 92 93**File Size** 94 95 The size, in bytes, of the entire bitcode file. 96 97 98 99**Module Bytes** 100 101 The size, in bytes, of the module block. Percentage is relative to File Size. 102 103 104 105**Function Bytes** 106 107 The size, in bytes, of all the function blocks. Percentage is relative to File 108 Size. 109 110 111 112**Global Types Bytes** 113 114 The size, in bytes, of the Global Types Pool. Percentage is relative to File 115 Size. This is the size of the definitions of all types in the bitcode file. 116 117 118 119**Constant Pool Bytes** 120 121 The size, in bytes, of the Constant Pool Blocks Percentage is relative to File 122 Size. 123 124 125 126**Module Globals Bytes** 127 128 Ths size, in bytes, of the Global Variable Definitions and their initializers. 129 Percentage is relative to File Size. 130 131 132 133**Instruction List Bytes** 134 135 The size, in bytes, of all the instruction lists in all the functions. 136 Percentage is relative to File Size. Note that this value is also included in 137 the Function Bytes. 138 139 140 141**Compaction Table Bytes** 142 143 The size, in bytes, of all the compaction tables in all the functions. 144 Percentage is relative to File Size. Note that this value is also included in 145 the Function Bytes. 146 147 148 149**Symbol Table Bytes** 150 151 The size, in bytes, of all the symbol tables in all the functions. Percentage is 152 relative to File Size. Note that this value is also included in the Function 153 Bytes. 154 155 156 157**Dependent Libraries Bytes** 158 159 The size, in bytes, of the list of dependent libraries in the module. Percentage 160 is relative to File Size. Note that this value is also included in the Module 161 Global Bytes. 162 163 164 165**Number Of Bitcode Blocks** 166 167 The total number of blocks of any kind in the bitcode file. 168 169 170 171**Number Of Functions** 172 173 The total number of function definitions in the bitcode file. 174 175 176 177**Number Of Types** 178 179 The total number of types defined in the Global Types Pool. 180 181 182 183**Number Of Constants** 184 185 The total number of constants (of any type) defined in the Constant Pool. 186 187 188 189**Number Of Basic Blocks** 190 191 The total number of basic blocks defined in all functions in the bitcode file. 192 193 194 195**Number Of Instructions** 196 197 The total number of instructions defined in all functions in the bitcode file. 198 199 200 201**Number Of Long Instructions** 202 203 The total number of long instructions defined in all functions in the bitcode 204 file. Long instructions are those taking greater than 4 bytes. Typically long 205 instructions are GetElementPtr with several indices, PHI nodes, and calls to 206 functions with large numbers of arguments. 207 208 209 210**Number Of Operands** 211 212 The total number of operands used in all instructions in the bitcode file. 213 214 215 216**Number Of Compaction Tables** 217 218 The total number of compaction tables in all functions in the bitcode file. 219 220 221 222**Number Of Symbol Tables** 223 224 The total number of symbol tables in all functions in the bitcode file. 225 226 227 228**Number Of Dependent Libs** 229 230 The total number of dependent libraries found in the bitcode file. 231 232 233 234**Total Instruction Size** 235 236 The total size of the instructions in all functions in the bitcode file. 237 238 239 240**Average Instruction Size** 241 242 The average number of bytes per instruction across all functions in the bitcode 243 file. This value is computed by dividing Total Instruction Size by Number Of 244 Instructions. 245 246 247 248**Maximum Type Slot Number** 249 250 The maximum value used for a type's slot number. Larger slot number values take 251 more bytes to encode. 252 253 254 255**Maximum Value Slot Number** 256 257 The maximum value used for a value's slot number. Larger slot number values take 258 more bytes to encode. 259 260 261 262**Bytes Per Value** 263 264 The average size of a Value definition (of any type). This is computed by 265 dividing File Size by the total number of values of any type. 266 267 268 269**Bytes Per Global** 270 271 The average size of a global definition (constants and global variables). 272 273 274 275**Bytes Per Function** 276 277 The average number of bytes per function definition. This is computed by 278 dividing Function Bytes by Number Of Functions. 279 280 281 282**# of VBR 32-bit Integers** 283 284 The total number of 32-bit integers encoded using the Variable Bit Rate 285 encoding scheme. 286 287 288 289**# of VBR 64-bit Integers** 290 291 The total number of 64-bit integers encoded using the Variable Bit Rate encoding 292 scheme. 293 294 295 296**# of VBR Compressed Bytes** 297 298 The total number of bytes consumed by the 32-bit and 64-bit integers that use 299 the Variable Bit Rate encoding scheme. 300 301 302 303**# of VBR Expanded Bytes** 304 305 The total number of bytes that would have been consumed by the 32-bit and 64-bit 306 integers had they not been compressed with the Variable Bit Rage encoding 307 scheme. 308 309 310 311**Bytes Saved With VBR** 312 313 The total number of bytes saved by using the Variable Bit Rate encoding scheme. 314 The percentage is relative to # of VBR Expanded Bytes. 315 316 317 318 319DETAILED OUTPUT DEFINITIONS 320--------------------------- 321 322 323The following definitions occur only if the -nodetails option was not given. 324The detailed output provides additional information on a per-function basis. 325 326 327**Type** 328 329 The type signature of the function. 330 331 332 333**Byte Size** 334 335 The total number of bytes in the function's block. 336 337 338 339**Basic Blocks** 340 341 The number of basic blocks defined by the function. 342 343 344 345**Instructions** 346 347 The number of instructions defined by the function. 348 349 350 351**Long Instructions** 352 353 The number of instructions using the long instruction format in the function. 354 355 356 357**Operands** 358 359 The number of operands used by all instructions in the function. 360 361 362 363**Instruction Size** 364 365 The number of bytes consumed by instructions in the function. 366 367 368 369**Average Instruction Size** 370 371 The average number of bytes consumed by the instructions in the function. This 372 value is computed by dividing Instruction Size by Instructions. 373 374 375 376**Bytes Per Instruction** 377 378 The average number of bytes used by the function per instruction. This value is 379 computed by dividing Byte Size by Instructions. Note that this is not the same 380 as Average Instruction Size. It computes a number relative to the total function 381 size not just the size of the instruction list. 382 383 384 385**Number of VBR 32-bit Integers** 386 387 The total number of 32-bit integers found in this function (for any use). 388 389 390 391**Number of VBR 64-bit Integers** 392 393 The total number of 64-bit integers found in this function (for any use). 394 395 396 397**Number of VBR Compressed Bytes** 398 399 The total number of bytes in this function consumed by the 32-bit and 64-bit 400 integers that use the Variable Bit Rate encoding scheme. 401 402 403 404**Number of VBR Expanded Bytes** 405 406 The total number of bytes in this function that would have been consumed by 407 the 32-bit and 64-bit integers had they not been compressed with the Variable 408 Bit Rate encoding scheme. 409 410 411 412**Bytes Saved With VBR** 413 414 The total number of bytes saved in this function by using the Variable Bit 415 Rate encoding scheme. The percentage is relative to # of VBR Expanded Bytes. 416 417 418 419 420SEE ALSO 421-------- 422 423 424llvm-dis|llvm-dis, `http://llvm.org/docs/BitCodeFormat.html <http://llvm.org/docs/BitCodeFormat.html>`_ 425