gcc-16 bugs

April 23, 2026

Almost exactly a year passed since my previous pile report. gcc-16 was branched off from master and will receive only regression fixes. master is called gcc-17 now.

Instead of posting incremental updates at arbitrary tine I’ll try yearly ones. That should cover all the bugs I saw in a release cycle in a single post.

Summary

During gcc-16 cycle I found 31 bug:

Fun Bugs

All wrong code seen at runtime of compiled programs were fun to extract. Minimized examples are not very pretty to look sat. I’ll just leave the links here:

Histogram

This time I got most bugs from tree-optimization subsystem:

Almost as many bugs came up in target-specific areas.

Parting Words

gcc-master is still able to produce new interesting bugs.

31 bug per year is slightly more than one bug per week. It feels like a lot given how little time I spend to extract the samples.

Of 31 bugs I saw I reported 22. The rest were caught (and sometimes already fixed!) by others by the time I got to them.

Have fun!