On 9/2/16, Segher Boessenkool <seg...@kernel.crashing.org> wrote:
> On Fri, Sep 02, 2016 at 02:21:07PM -0400, Eric Gallager wrote:
>> ../../gcc/combine.c: In function ‘int combine_instructions(rtx_insn*,
>> unsigned int)’:
>> ../../gcc/combine.c:1310:8: warning: ‘prev’ may be used uninitialized
>> in this function [-Wmaybe-uninitialized]
>> if ((next = try_combine (insn, prev, NULL, NULL,
>> ^~
>
> That is:
>
> if (HAVE_cc0
> && JUMP_P (insn)
> && (prev = prev_nonnote_insn (insn)) != 0
> && NONJUMP_INSN_P (prev)
> && sets_cc0_p (PATTERN (prev)))
> {
> if ((next = try_combine (insn, prev, NULL, NULL,
> &new_direct_jump_p,
> last_combined_insn)) != 0)
>
> so prev is always initialised here. Could you try to find out why GCC
> warns anyway? Or open a PR?
>
> HAVE_cc0 probably expands to 0 (I'm not sure what your target is), that
> might have something to do with it.
>
>
> Segher
>
My target is i386-apple-darwin9.8.0. If HAVE_cc0 expands to 0, then
the code inside the brackets wouldn't even be reached anyways, would
it? Where would HAVE_cc0 be defined?
