http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60822
--- Comment #3 from Mikael Pettersson <mikpelinux at gmail dot com> --- Started with r140275: 2008-09-11 Andreas Schwab <sch...@suse.de> * config/m68k/m68k.h (IRA_COVER_CLASSES): Define. which seems to enable IRA for M68K. The code generation difference for the C test case at this revision is: --- pr60822-r140274.s 2014-04-12 20:50:32.324607341 +0200 +++ pr60822-r140275.s 2014-04-12 20:46:21.835089754 +0200 @@ -9,10 +9,10 @@ link.w %fp,#0 move.l %d2,-(%sp) move.l 8(%fp),%a0 - move.l #800000,%d1 - move.l #1700004,%d0 - move.l (%a0,%d1.l),%d1 - add.l (%a0,%d0.l),%d1 + move.l #800000,%d0 + move.l #1700004,%d1 + move.l (%a0,%d0.l),%d1 + add.l (%a0,%d1.l),%d1 smi %d0 ext.w %d0 ext.l %d0 I assume this revision merely exposed a pre-existing latent problem.