Bug 2336715

Summary: flac failed to build with GCC 15 on aarch64 (CRC wrong code issue?)
Product: [Fedora] Fedora Reporter: Dave Malcolm <dmalcolm>
Component: gccAssignee: Jakub Jelinek <jakub>
Status: CLOSED RAWHIDE QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: unspecified    
Version: rawhideCC: ajax, dmalcolm, fweimer, gnome-sig, jakub, jlaw, josmyers, jwakely, mcermak, mclasen, mlichvar, mpolacek, msebor, nickc, nixuser, rstrode, sipoyare
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OS: Linux   
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Last Closed: 2025-01-16 14:23:53 UTC Type: ---
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Bug Blocks: 2333037    

Description Dave Malcolm 2025-01-09 19:55:37 UTC 
I'm experimentally rebuilding rawhide with the not-yet-released GCC 15 to see if anything breaks, and to help write the porting guide.  See https://fedoraproject.org/wiki/User:Dmalcolm/gcc-15

My test build with GCC 15 failed, but just on aarch64:
https://copr.fedorainfracloud.org/coprs/dmalcolm/gcc-15-smoketest-3.failed/build/8476332/

whereas my test build with GCC 14 succeeded:
https://copr.fedorainfracloud.org/coprs/dmalcolm/gcc-15-smoketest-3.failed.checker/build/8478555/

Looking at the failure logs:
https://download.copr.fedorainfracloud.org/results/dmalcolm/gcc-15-smoketest-3.failed/fedora-rawhide-aarch64/08476332-flac/builder-live.log.gz

I see:
testing FLAC__crc16 ... FAILED, FLAC__crc16 result did not match reference CRC for 1 bytes of test data

I believe GCC 15 gained an optimization pass for CRC logic, so I'm worried this might be a GCC wrong-code issue.


Reproducible: Didn't try
Comment 1 Dave Malcolm 2025-01-09 23:15:07 UTC 
Possibly a dup of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117997
Comment 2 Dave Malcolm 2025-01-13 03:17:56 UTC 
Might be fixed by https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117997#c14 (I'm not sure)
Comment 3 Jakub Jelinek 2025-01-13 12:32:20 UTC 
Yeah, this should be fixed in the upcoming gcc-15.0.1-0.1.fc42 (plan to start building in the evening).
Comment 4 Siddhesh Poyarekar 2025-01-16 14:23:53 UTC 
Confirmed with another scratch rebuild that this is fixed with gcc-15.0.1-0.3.fc42.