https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91491
Bug ID: 91491 Summary: [9 Regression] glib2.0 build not working when built with -O2 on x86_64-linux-gnu Product: gcc Version: 9.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: doko at debian dot org Target Milestone: --- Created attachment 46731 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46731&action=edit preprocessed source [forwarded from https://bugs.debian.org/931921] Seen with 9.2.0 on x86_64-linux-gnu, works with GCC 8, or with GCC 9 -O1. Further tracked down to: On Fri, 02 Aug 2019 at 19:49:20 +0100, Simon McVittie wrote: > If you compile test_run_seed() with -O1, and the rest of gtestutils.c > with -O2, the clutter test hangs. Binary-searching through the extra optimizations enabled by -O2 [1] led me to the minimal change being: if you modify test_run_seed() to add __attribute__((optimize("no-tree-pre"))) then the clutter test passes. Without that attribute it fails. Attaching the preprocessed gtestutils source.