http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55934
--- Comment #2 from Steven Bosscher <steven at gcc dot gnu.org> 2013-01-11 12:49:16 UTC --- This is trivially fixed with the following patch: Index: lra-assigns.c =================================================================== --- lra-assigns.c (revision 195104) +++ lra-assigns.c (working copy) @@ -1240,6 +1240,9 @@ assign_by_spills (void) asm_p = true; error_for_asm (insn, "%<asm%> operand has impossible constraints"); + /* Avoid further trouble with this insn. */ + PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx); + lra_set_insn_deleted (insn); } } lra_assert (asm_p);