https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66358
--- Comment #24 from Kazumoto Kojima <kkojima at gcc dot gnu.org> --- (In reply to David Binderman from comment #23) > Problem seems to have gone away with gcc version 6.1.1, dated 20160621 Thanks for your report. I've confirmed that the testcases don't fail with the head of 5/6/7 branches on sh4-unknown-linux-gnu. I think that now the issue is latent on those branches, though. Register allocation has the unstable nature and we could see the issue again when R0 is allocated with the old RA like in the way which #14 describes.