Re: [PATCH 3/9] dce: Don't dead-code delete separately wrapped restores

[Jeff Law]

On 07/31/2016 07:42 PM, Segher Boessenkool wrote:
Deleting restores (before a noreturn) that are dead confuses dwarf2cfi.
2016-06-07  Segher Boessenkool  <seg...@kernel.crashing.org>

        * dce.c (delete_unmarked_insns): Don't delete instructions with
        a REG_CFA_RESTORE note.
I don't really understand this one.  Why is the restore marked dead and 
why doesn't that happen for normal epilogues?  Something wonky seems to 
be going on here.

jeff