The simple test which I'll attach shortly, loops infinitely when compiled with -O1 -fstrength-reduce and executes fine with plain -O1. Doing a little debugging, it seems the loop index variable "i" is not incremented within the loop causing us to loop forever.
I have tested this using the latest FSF 4.1, 4.2 and mainline compiler sources and it only fails using the 4.1 compiler. Using an older 3.4.6 distro compiler, it executes fine, so this _looks_ like a regression. -- Summary: Simple test case loops infinitely with -O1 -fstrength- reduce. Product: gcc Version: 4.1.3 Status: UNCONFIRMED Severity: normal Priority: P3 Component: rtl-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: bergner at gcc dot gnu dot org GCC build triplet: i686-linux GCC host triplet: i686-linux GCC target triplet: i686-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30931