[PATCH] fix powerpc64le bootstrap failure caused by r243661 (PR 78817)

[Jakub Jelinek]

On Fri, Dec 16, 2016 at 09:36:25AM -0700, Martin Sebor wrote:
> > It does for me with an allmodconf. At -O2 I get three warnings, and at
> > -O3 I get two additional warnings. Now these additional ones happen way
> > too deep into the pipeline to be reliable. (For a reduced testcase see:
> > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78817#c8)
> 
> The warning looks quite justified in this case.  The first call
> to sm_read_sector exits with the pointer being null and so the
> second call is diagnosed.  That seems like a great example of
> when the warning is useful.

No.  The first call to sm_read_sector just doesn't exit.  So it is warning
about dead code.

> I don't claim it can't be improved but it seems pretty good as
> it is already.  Among the 6 instances it's found in GCC three
> look like real bugs.

None look like real bugs to me.

	Jakub