On Thu, 17 Feb 2011, Guy Martin wrote: > I've spotted this regression while testing gcc 4.5.2. > It hangs while doing one of the configure test of diffutils. > > I've attached a reduced test case. The program is supposed to > segfault because of a stack overflow. However, with 4.5, it just hangs. > It seems that 4.5 simply over-optimize the function and replaces it > with a single jump. > > Should I open a PR ? My sense is the test is wrong and the optimization is correct. Optimizations such as this are done at the tree and rtl level. For the most part, backends do not perform loop optimizations. So, if you think the generated code is incorrect based on the C standard, then a PR should be opened. There are quite a few '-f' options that affect optimization behavior. So, you may be able to disable loop optimizations and restore the previous behavior. There may be a newer autoconf test available. Dave -- J. David Anglin dave.anglin@xxxxxxxxxxxxxx National Research Council of Canada (613) 990-0752 (FAX: 952-6602) -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
