[PATCH] D20085: [libfuzzer] Refactoring coverage state-management code..

[Mike Aizatsky via llvm-commits]

aizatsky added a comment.

I don't see any performance difference. Tested on chromium's mp4_box_reader_fuzzer (166M binary).

Before:

$ ./out/fuzzer/mp4_box_reader_fuzzer -seed=1 -runs=1000000 ~/tmp/fuzzers/mp4_box_reader_fuzzer
INFO: Seed: 1
INFO: -max_len is not provided, using 500
#0      READ   units: 429 exec/s: 0
#429    INITED cov: 517 bits: 686 indir: 23 units: 120 exec/s: 0
#16384  pulse  cov: 547 bits: 686 indir: 25 units: 120 exec/s: 5461
#32768  pulse  cov: 547 bits: 686 indir: 25 units: 120 exec/s: 5461
#65536  pulse  cov: 547 bits: 686 indir: 25 units: 120 exec/s: 5041
#131072 pulse  cov: 547 bits: 686 indir: 25 units: 120 exec/s: 5041
#262144 pulse  cov: 547 bits: 686 indir: 25 units: 120 exec/s: 4681
^C==32409== libFuzzer: run interrupted; exiting
./out/fuzzer/mp4_box_reader_fuzzer -seed=1 -runs=1000000   63.74s user 2.01s system 99% cpu 1:05.82 total

After:

$ ./out/fuzzer/mp4_box_reader_fuzzer -seed=1 -runs=1000000 ~/tmp/fuzzers/mp4_box_reader_fuzzer
INFO: Seed: 1
INFO: -max_len is not provided, using 500
#0      READ   units: 425 exec/s: 0
#425    INITED cov: 381 bits: 686 indir: 23 units: 120 exec/s: 0
#426    NEW    cov: 411 bits: 686 indir: 25 units: 121 exec/s: 0 L: 157 MS: 1 InsertByte-
#4002   NEW    cov: 411 bits: 686 indir: 25 units: 122 exec/s: 4002 L: 453 MS: 2 EraseByte-ShuffleBytes-
#4003   NEW    cov: 412 bits: 686 indir: 25 units: 123 exec/s: 4003 L: 453 MS: 3 EraseByte-ShuffleBytes-ShuffleBytes-
#16384  pulse  cov: 412 bits: 686 indir: 25 units: 123 exec/s: 5461
#30789  NEW    cov: 412 bits: 688 indir: 25 units: 124 exec/s: 4398 L: 187 MS: 3 ChangeByte-ChangeBit-EraseByte-
#32768  pulse  cov: 412 bits: 688 indir: 25 units: 124 exec/s: 4681
#65536  pulse  cov: 412 bits: 688 indir: 25 units: 124 exec/s: 4681
#131072 pulse  cov: 412 bits: 688 indir: 25 units: 124 exec/s: 5041
#262144 pulse  cov: 412 bits: 688 indir: 25 units: 124 exec/s: 5041
^C==29836== libFuzzer: run interrupted; exiting
./out/fuzzer/mp4_box_reader_fuzzer -seed=1 -runs=1000000   99.80s user 0.61s system 99% cpu 1:40.48 total


http://reviews.llvm.org/D20085