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