[PATCH, middle-end]: Fix g++.dg/other/vector-compare.C testsuite failure on alpha

[Uros Bizjak]

On Fri, Sep 21, 2012 at 5:26 PM, Eric Botcazou <ebotcazou@adacore.com> wrote:
>> Although the testcase doesn't trip on this part, the result_mode is
>> taken from the operand mode of cmp{mem,str,strn}_optab. As in the
>> second case, there is no guarantee that compare that compares the
>> result of cmp{mem,str,stn}_optab can handle output mode of this optab.
>
> It's up to you to write a correct pattern with an appropriate result mode.

OK, I can live with this; if some other unfortunate target trips here,
we will know how to fix it.

>> The testcase does not fail on release branches, but simply due to the
>> fact that BLKmode compares are not adequately tested. Otherwise,
>> BLKmode compares would always fail on alpha.
>
> What happens for the testcase on the release branches?  It doesn't use BKLmode
> compares?  If so, is it ever possible to use BLKmode compares on Alpha?

Vector compare testcases can't be compiled with 4.7- - vector compares
are not implemented for C++ there. As observed, BLKmode compare is not
triggered for alpha in the whole testsuite, as far as release branches
are concerned.

Uros.