Using -O2 -fno-guess-branch-probability -fno-tree-ch -fno-tree-dominator-opts -fno-tree-lrs -fno-tree-dce -fno-tree-vrp -funit-at-a-time -ftree-copy-prop -ftree-copyrename on the SPEC CPU2000 benchmark 176.gcc yields an infinite loop (using the train input which usually runs for 2s runs for hours).
This is confirmed on Fedora Core 4 / x86 (Intel Pentium 4), and also on an linux/amd64 for which I have no details. Removing any of the -fno-X flags seems to solve the issue, and adding -ffloat-store doesn't change a thing, which suggests this is not floating-point (convergence) related. -- Summary: -O2 -fno-guess-branch-probability -fno-tree-ch -fno- tree-dominator-opts -fno-tree-lrs -fno-tree-dce -fno- tree-vrp -funit-at-a-time -ftree-copy-prop -ftree- copyrename yields an infinite loop in SPEC benchmark 176.gcc Product: gcc Version: 4.1.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: kenneth dot hoste at elis dot ugent dot be GCC host triplet: i686-Linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31642