https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82271
Bug ID: 82271 Summary: loop gets miscompiled on powerpc at -O2 Product: gcc Version: 7.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: sirl at gcc dot gnu.org Target Milestone: --- Created attachment 42211 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42211&action=edit testcase The attached testcase removes conditions in the loop when compiled for powerpc-eabi with -O2. On the trunk the bug got fixed (went latent?) with r247886. Applying this revision to current 7.2.1@r252980 also fixes it there. When comparing trunk compilers r247885 and r247886 the differences start in the ivopts dump. Further on in the vrp2 dump, the difference is easy to see, r247886 does have "if (nAccessSize_67 == 4096)", r247885 doesn't have it. A quick check suggests this bug is there since at least 4.7. If I read the dumps correctly, I couldn't reproduce it with x86, either -m32 or -m64.