Agent Software Testing

gzip

1.14
Terms
Run
One campaign of one tool on one program.
Cores
The parallel processes of one campaign.
Budget
The longest a campaign may run.
Fixed track
The command line is given and the tool supplies only the input. Method
Open track
The tool also chooses arguments, files and environment. Method
Median
The middle value over a tool's runs; the median of two runs is their mean.
standard
Conventional gcov replay of every retained test case, same counting code and denominators. Method
Unreached
A branch that none of the main-group tools that ran on the program reaches (4 to 12 tools).
Union of runs
The branches that at least one of a tool's runs reaches, each counted once.
Output tokens
Model output of a whole campaign, reasoning included, as self-reported in the release.
Sanitiser signature
The sanitiser, the error kind and the innermost frame in the program's own source; two can share a cause.
Language model
A system in which a language model does the central reasoning of a classical technique, such as concolic execution.
Symbolic
Runs the program on symbolic inputs and asks a constraint solver for concrete inputs that reach new paths.
Fuzzer
Coverage-guided fuzzing: mutates inputs and keeps those that reach new code.
Hybrid
A fuzzer paired with a concolic executor; each supplies the other with inputs.
Main
Shown by default: the tools a reader is most likely to compare.
Ablation
Variants of the agent that switch off or change one part, to show what that part adds.
Seeding
Runs of a tool that start from seeds produced by another system.
Control
Systems that run without the agent, as a reference for the main group.
Release
A dated snapshot of the data, named like 2026.1. It never changes; corrections go into the next release.
Superseded
An entry that a newer one replaces. It stays in the release and shows under all versions.
Withdrawn
An entry taken out of the comparison after it was published.

GNU gzip compresses files with the DEFLATE algorithm and gzip -d decompresses them.

Branches
3,08338.9% unreached (6 tools)
Language
C
Inputs
command-line arguments, files, standard input, environment
Fixed track
none agreed
Tools with runs
216 main
Runs
6969 with branch sets

Branch map

gzip.cinflate.cprintf-parse.cvasnprintf.ctrees.c
1 tool 1172 to 3 3064 tools 695 tools 231all 6 1,162Unreached 1,198

Coverage over time

Use the left and right arrow keys, Home and End to move along the time axis. The value of every line at that time is read out.

The chart needs JavaScript. The final values are in the Final coverage table below.

Showing 6 of 6
Curves: curves/ in the results repository

Final coverage

Final coverage of every tool on gzip
ToolMedianMin to maxShare (median)RunsMedian curveOutput tokens
Main group, 6 tools
Agolic KLEE, GPT-5.5agent, open track, six cores, version 1.0.1+2407fd07
1,5661,563–1,5713265,374
Agolic KLEE, DeepSeek V4.1 Flashagent, open track, six cores, version 1.0.1+8a86838e
1,6361,625–1,66231,417,262
Agolic Direct-Input, DeepSeek V4.1 Flashagent, open track, six cores, version 1.0.1+8a86838e
1,7901,718–1,83633,208,166
KLEE fixed options, 6 coressymbolic, open track, six cores, version efa1e052
1,0991,088–1,1023not applicable
KLEE uniform options, 6 coressymbolic, open track, six cores, version efa1e052
1,4301,419–1,4343not applicable
SymTuner, 6 coressymbolic, open track, six cores, version 71806b45
1,4511,433–1,4613not applicable
Ablation group, 10 tools
Seeding group, 2 tools
Control group, 3 tools
finals.csv in the results repository

Branches reached by one tool only

Branches reached by each main-group tool and by it only, on gzip
ToolRuns in unionBranches reachedShare (union)Reached by this tool only
Agolic KLEE, GPT-5.5
31,6580
Agolic KLEE, DeepSeek V4.1 Flash
31,6992
Agolic Direct-Input, DeepSeek V4.1 Flash
31,847115
KLEE fixed options, 6 cores
31,1720
KLEE uniform options, 6 cores
31,4640
SymTuner, 6 cores
31,4960

Sanitiser findings

Signatures in each tool’s final test cases.

Distinct sanitiser signatures of each tool on gzip
ToolRuns replayedAddressSanitizerkind, signaturesUndefinedBehaviorSanitizerkind, signatures
Agolic KLEE, GPT-5.5
3none found
  • shift-exponent-too-large1
Agolic KLEE, DeepSeek V4.1 Flash
3none found
  • shift-exponent-too-large1
Agolic Direct-Input, DeepSeek V4.1 Flash
3none found
  • shift-exponent-too-large1
KLEE fixed options, 6 cores
3none found
  • shift-exponent-too-large1
KLEE uniform options, 6 cores
3none found
  • shift-exponent-too-large1
SymTuner, 6 cores
3none found
  • shift-exponent-too-large1
KLEE fixed options, 1 core
5none foundnone found
KLEE uniform options, 1 core
5none found
  • shift-exponent-too-large1
SymTuner, 1 core
5none found
  • shift-exponent-too-large1
Agolic KLEE, GPT-5.4
3none found
  • shift-exponent-too-large1
Agolic KLEE, GPT-5.5, effort low
3none found
  • shift-exponent-too-large1
Agolic KLEE, GPT-5.5, effort extra high
3none found
  • shift-exponent-too-large1
Agolic KLEE, GPT-5.5, Harness-Entry Mode only
3none found
  • shift-exponent-too-large1
Agolic KLEE, GPT-5.5, Seeded-Prefix Mode only
3none found
  • shift-exponent-too-large1
Agolic KLEE, GPT-5.5, seed finder off
3none found
  • shift-exponent-too-large1
Agolic KLEE, GPT-5.5, proposal review off
3none found
  • shift-exponent-too-large1
Agolic KLEE, GPT-5.5, run history withheld
3none found
  • shift-exponent-too-large1
Agolic KLEE, DeepSeek V4.1 Flash, effort low
3none found
  • shift-exponent-too-large1
Agolic KLEE, DeepSeek V4.1 Flash, effort high
3none found
  • shift-exponent-too-large1
SymTuner rerun, 6 cores
3none found
  • shift-exponent-too-large1
SymTuner from the agent's seeds, 6 cores, its own tests
3none found
  • shift-exponent-too-large1

Counts are of untriaged signatures. † marks fewer than three runs.