| Message ID | CABu31nOYxjg5yhLSNdAzZ8X+wdicGRXa_2hsFE7GfO5Ud_YdBA@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On 04/17/2013 02:12 PM, Steven Bosscher wrote: >> On Fri, Mar 29, 2013 at 1:05 PM, Steven Bosscher wrote: >>> It looks like there are places in the middle end that use remove_insn >>> on insns that are not actually emitted. This breaks the assert I added >>> in df_insn_delete. The patch disables the assert for now. The comment >>> before the assert is now even messier than before but I think it's >>> better to explain why the assert cannot work than to remove the >>> comment and the assert altogether. > > This is no longer necessary, now that remove_insn doesn't use > df_insn_delete. Only a small patch to lower-subreg.c is needed to > restore the check. > > Bootstrapped&tested (unix{,-m32}) on powerpc64-unknown-linux-gnu. > OK for trunk? > > Ciao! > Steven > > > * lower-subreg.c (resolve_simple_move): If called self-recursive, > do not delete_insn insns that have not yet been emitted, only > unlink them with remove_insn. > * df-scan.c (df_insn_delete): Revert r197492. OK. Jeff
Index: lower-subreg.c =================================================================== --- lower-subreg.c (revision 198002) +++ lower-subreg.c (working copy) @@ -1069,7 +1069,13 @@ resolve_simple_move (rtx set, rtx insn) emit_insn_before (insns, insn); - delete_insn (insn); + /* If we get here via self-recursion, then INSN is not yet in the insns + chain and delete_insn will fail. We only want to remove INSN from the + current sequence. See PR56738. */ + if (in_sequence_p ()) + remove_insn (insn); + else + delete_insn (insn); return insns; } Index: df-scan.c =================================================================== --- df-scan.c (revision 198002) +++ df-scan.c (working copy) @@ -1158,17 +1158,7 @@ df_insn_delete (rtx insn) In any case, we expect BB to be non-NULL at least up to register allocation, so disallow a non-NULL BB up to there. Not perfect but better than nothing... */ - /* ??? bb can also be NULL if lower-subreg.c:resolve_simple_mov emits - an insn into a sequence and then does delete_insn on it. Not sure - if that makes sense, but for now it means this assert cannot work. - See PR56738. - Disable for now but revisit before the end of GCC 4.9 stage1. */ -#if 0 gcc_checking_assert (bb != NULL || reload_completed); -#else - if (bb == NULL) - return; -#endif df_grow_bb_info (df_scan); df_grow_reg_info ();