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Differential D50484

[libFuzzer] Increase the iteration limit in shrink.test
ClosedPublic

Authored by george.karpenkov on Aug 8 2018, 5:39 PM.

Details

Reviewers
kcc
morehouse
vitalybuka
Commits
rG8389196dd978: Merging r339303: --------------------------------------------------------------…
rG67d858d5e46b: [libFuzzer] Increase the iteration limit in shrink.test
rL339315: Merging r339303:
rCRT339303: [libFuzzer] Increase the iteration limit in shrink.test
rL339303: [libFuzzer] Increase the iteration limit in shrink.test
Summary

After https://reviews.llvm.org/D48800, shrink.test started failing on x86_64h architecture.
Looking into this, the optimization pass is too eager to unroll the loop on x86_64h, possibly leading to worse coverage data.

Alternative solutions include not unrolling the loop when fuzzing, or disabling this test on that architecture.

Diff Detail

Event Timeline

george.karpenkov created this revision.Aug 8 2018, 5:39 PM
Herald added a subscriber: dmgreen. · View Herald TranscriptAug 8 2018, 5:39 PM
morehouse accepted this revision.Aug 8 2018, 5:40 PM
This revision is now accepted and ready to land.Aug 8 2018, 5:40 PM
Closed by commit rL339303: [libFuzzer] Increase the iteration limit in shrink.test (authored by george.karpenkov). · Explain WhyAug 8 2018, 5:42 PM
This revision was automatically updated to reflect the committed changes.
Herald added subscribers: llvm-commits, delcypher. · View Herald TranscriptAug 8 2018, 5:42 PM

Revision Contents

PathSize
test/
fuzzer/
2 lines

Diff 159836

test/fuzzer/shrink.test

RUN: %cpp_compiler %S/ShrinkControlFlowTest.cpp -o %t-ShrinkControlFlowTest RUN: %cpp_compiler %S/ShrinkControlFlowTest.cpp -o %t-ShrinkControlFlowTest
RUN: %cpp_compiler %S/ShrinkValueProfileTest.cpp -o %t-ShrinkValueProfileTest RUN: %cpp_compiler %S/ShrinkValueProfileTest.cpp -o %t-ShrinkValueProfileTest
RUN: %run %t-ShrinkControlFlowTest -seed=1 -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60 -runs=1000000 -shrink=1 -reduce_inputs=0 2>&1 | FileCheck %s --check-prefix=SHRINK1 RUN: %run %t-ShrinkControlFlowTest -seed=1 -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60 -runs=2000000 -shrink=1 -reduce_inputs=0 2>&1 | FileCheck %s --check-prefix=SHRINK1
# Limit max_len to run this negative test faster. # Limit max_len to run this negative test faster.
RUN: %run %t-ShrinkControlFlowTest -seed=1 -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60 -runs=1000000 -shrink=0 -reduce_inputs=0 -max_len=64 2>&1 | FileCheck %s --check-prefix=SHRINK0 RUN: %run %t-ShrinkControlFlowTest -seed=1 -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60 -runs=1000000 -shrink=0 -reduce_inputs=0 -max_len=64 2>&1 | FileCheck %s --check-prefix=SHRINK0
RUN: %run %t-ShrinkValueProfileTest -seed=1 -exit_on_item=aea2e3923af219a8956f626558ef32f30a914ebc -runs=100000 -shrink=1 -reduce_inputs=0 -use_value_profile=1 2>&1 | FileCheck %s --check-prefix=SHRINK1_VP RUN: %run %t-ShrinkValueProfileTest -seed=1 -exit_on_item=aea2e3923af219a8956f626558ef32f30a914ebc -runs=100000 -shrink=1 -reduce_inputs=0 -use_value_profile=1 2>&1 | FileCheck %s --check-prefix=SHRINK1_VP
SHRINK0: Done 1000000 runs in SHRINK0: Done 1000000 runs in
SHRINK1: INFO: found item with checksum '0eb8e4ed029b774d80f2b66408203801cb982a60', exiting. SHRINK1: INFO: found item with checksum '0eb8e4ed029b774d80f2b66408203801cb982a60', exiting.
SHRINK1_VP: INFO: found item with checksum 'aea2e3923af219a8956f626558ef32f30a914ebc', exiting SHRINK1_VP: INFO: found item with checksum 'aea2e3923af219a8956f626558ef32f30a914ebc', exiting