Patchwork PR56729

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Submitter Steven Bosscher
Date March 29, 2013, 12:05 p.m.
Message ID <CABu31nNLS7m1ZAx5tDSWvA4S5-zMQyBaaQ-Yt2tqZXebtdv3jg@mail.gmail.com>
Download mbox | patch
Permalink /patch/232387/
State New
Headers show

Comments

Steven Bosscher - March 29, 2013, 12:05 p.m.
Hello,

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.

Bootstrapped&tested on powerpc64-unknown-linux-gnu (also tested 32bits ppc).
OK for trunk?

Ciao!
Steven


        PR middle-end/56729
        * df-scan.c (df_insn_delete): Disable failing assert.
Richard Guenther - April 2, 2013, 9:22 a.m.
On Fri, Mar 29, 2013 at 1:05 PM, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
> Hello,
>
> 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.
>
> Bootstrapped&tested on powerpc64-unknown-linux-gnu (also tested 32bits ppc).
> OK for trunk?

Ok.

Thanks,
Richard.

> Ciao!
> Steven
>
>
>         PR middle-end/56729
>         * df-scan.c (df_insn_delete): Disable failing assert.
>
> Index: df-scan.c
> ===================================================================
> --- df-scan.c   (revision 197180)
> +++ df-scan.c   (working copy)
> @@ -1158,8 +1158,17 @@ 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 ();

Patch

Index: df-scan.c
===================================================================
--- df-scan.c   (revision 197180)
+++ df-scan.c   (working copy)
@@ -1158,8 +1158,17 @@  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 ();