Re: Follow-up to PR51471

[Jeff Law <law at redhat dot com>]

On 11/11/14 15:28, Eric Botcazou wrote:
> In https://gcc.gnu.org/ml/gcc-patches/2012-01/msg00363.html, Tom reported an
> ICE in the DWARF CFI pass because a frame-related insn was speculated by the
> reorg pass and, therefore, disabled the optimization.  It turns out that the
> same code (when condition == const_true_rtx) can also duplicate frame-related
> insns, leading to the same ICE in the DWARF CFI pass; we have run into that
> building newlib for a port we are about to contribute.
>
> Hence the attached patch, which disables the optimization in this case too and
> adds a comment for both.  Tested on SPARC/Solaris, applied on the mainline.
>
>
> 2014-11-11  Eric Botcazou  <ebotcazou@adacore.com>
>
> 	* reorg.c (fill_slots_from_thread): Do not copy frame-related insns.
I wonder how many other problems of this nature are lurking in reorg.c. 
 For example steal_delay_list_from_{target,fallthrough} or the code 
which searches for arithmetic at the branch target, and puts the 
opposite insn in a delay slot.

In fact, I really wonder if we should be allowing anything frame related 
outside fill_simple_delay_slots.

jeff