http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51271
--- Comment #14 from vries at gcc dot gnu.org 2011-12-17 12:49:21 UTC --- Created attachment 26119 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26119 res_hconf.c.221r.mach, using Andrew's patch (In reply to comment #13) > I think my patch for PR 51471 will also fix this bug. I now know why I could > not reproduce it, I was using slightly different scheduling (-march=octeon > rather than the default). I tried out the patch, and the compiler does not assert any more. However, I'm not convinced that it fixes the problem. The patch inhibits scheduling of frame-related instructions in delay slots. AFAIU, the instruction causing problems in this PR is insn 141, and it is not marked as frame-related, so the patch has no direct effect on that instruction. The patch seems to have the following effect: the frame-related insn 129 (from the prologue) is inhibited from being scheduled into the delay slot of jump_insn 60. So instead, insn 141 is now scheduled into the delay slot of jump_insn 60. As a consequence insn 141 is now executed on both paths leading up to block 8, and the assert is not triggered anymore. rtl.h: ... /* 1 in an INSN or a SET if this rtx is related to the call frame, either changing how we compute the frame address or saving and restoring registers in the prologue and epilogue. <SNIP>. */ unsigned frame_related : 1; ... given this definition, maybe insn 141 should be marked as frame-related, since it restores a reg in the epilogue.
