Ping: [PATCH] Prevent crash when expand movstr fail when movstr pattern is defined

Jakub Jelinek jakub@redhat.com
Sat Jan 18 10:44:00 GMT 2014


On Sat, Jan 18, 2014 at 10:37:18AM +0000, Richard Sandiford wrote:
> Review ping for this patch.  IMO it almost counts as obviously correct
> but just in case...
> 
> Kito Cheng <kito@0xlab.org> writes:
> > expand_movstr is work fine when we don't define movstr pattern or
> > always expand it successfully, however it's will crash when if movstr
> > expand fail since expand_insn expect always expand successfully (it's
> > place a gcc_unreachable() when expand fail).
> >
> > this patch use maybe_expand_insn instead of expand_insn, check it done
> > or not and just return NULL_RTX for generate a libcall if fail to
> > expand movstr.
> >
> > 2014-01-11  Kito Cheng  <kito@0xlab.org>
> >
> >         * gcc/builtins.c (expand_movstr): Check movstr expand done or fail.

Ok.

> > --- a/gcc/builtins.c
> > +++ b/gcc/builtins.c
> > @@ -3239,7 +3239,8 @@ expand_movstr (tree dest, tree src, rtx target, int endp)
> >    create_output_operand (&ops[0], endp ? target : NULL_RTX, Pmode);
> >    create_fixed_operand (&ops[1], dest_mem);
> >    create_fixed_operand (&ops[2], src_mem);
> > -  expand_insn (CODE_FOR_movstr, 3, ops);
> > +  if (!maybe_expand_insn (CODE_FOR_movstr, 3, ops))
> > +    return NULL_RTX;
> >
> >    if (endp && target != const0_rtx)
> >      {

	Jakub



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