Richard Sandiford <rdsandif...@googlemail.com> writes:
> Jeff Law <l...@redhat.com> writes:
>> On 08/05/2015 08:18 AM, Richard Sandiford wrote:
>>> Building some targets results in a warning about orig_dup[i] potentially
>>> being used uninitialised. I think the warning is fair, since it isn't
>>> obvious that the reog_data-based loop bound remains unchanged between:
>>>
>>> for (i = 0; i < recog_data.n_dups; i++)
>>> orig_dup[i] = *recog_data.dup_loc[i];
>>>
>>> and:
>>>
>>> for (i = 0; i < recog_data.n_dups; i++)
>>> *recog_data.dup_loc[i] = orig_dup[i];
>>>
>>> Tested on x86_64-linux-gnu. OK to install?
>>>
>>> Thanks,
>>> Richard
>>>
>>> gcc/
>>> * reload1.c (elimination_costs_in_insn): Make it obvious to the
>>> compiler that the n_dups and n_operands loop bounds are invariant.
>> So thinking more about this, I think the best way forward is to:
>>
>> 1. Create a new BZ with the false positive extracted from c#4.
>>
>> 2. Install your patch and close 55035.
>>
>> I'll take care of #1, you can handle #2.
>
> Thanks, I've now done #2.
Unfortunately the patch broke sparcv9-sun-solaris2* (only,
sparc-sun-solaris2* is fine) bootstrap:
/vol/gcc/src/hg/trunk/local/gcc/reload1.c: In function 'void
elimination_costs_in_insn(rtx_insn*)':
/vol/gcc/src/hg/trunk/local/gcc/reload1.c:3772:41: error: 'orig_dup[1]' may be
used uninitialized in this function [-Werror=maybe-uninitialized]
*recog_data.dup_loc[i] = orig_dup[i];
^
/vol/gcc/src/hg/trunk/local/gcc/reload1.c:3772:41: error: 'orig_dup[0]' may be
used uninitialized in this function [-Werror=maybe-uninitialized]
Rainer
--
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Rainer Orth, Center for Biotechnology, Bielefeld University
