Re: [PATCH GCC]Move simplification from fold-cond.c to match.pd and extend it

["Bin.Cheng" <amker dot cheng at gmail dot com>]

On Wed, Nov 23, 2016 at 10:29 AM, Richard Biener
<richard.guenther@gmail.com> wrote:
> On Fri, Nov 18, 2016 at 11:20 AM, Bin Cheng <Bin.Cheng@arm.com> wrote:
>> Hi,
>> This is a rework of https://gcc.gnu.org/ml/gcc-patches/2016-10/msg02005.html.  According to review comment, I extended the original patch and made it covering last kind simplification of fold_cond_expr_with_comparison (Well, this patch handles <, <=, > and >=.  == will be handled by a follow up).  This patch also adds several tests, some tests are for existing fold_cond_expr_with_comparison simplification but not covered yet; others are for new extension.
>> Bootstrap and test on x86_64 and AArch64 along with following patches, is it OK?
>
> I think you don't need the explicit types in the result
>
> +   (if (code == MAX_EXPR)
> +    (convert (max @1 (convert:from_type @2)))
> +    (if (code == MIN_EXPR)
> +     (convert (min @1 (convert:from_type @2))))))))
>
> A simple (convert (max @1 (convert @2))) should work.
Hi Richiard, could you explain about this more please?  If convert2
appears in the code, @2 would be of type after conversion?

Thanks,
bin
>
> Otherwise ok.
>
> Thanks,
> Richard.
>
>> Thanks,
>> bin
>>
>> 2016-11-16  Bin Cheng  <bin.cheng@arm.com>
>>
>>         * fold-const.c (fold_cond_expr_with_comparison): Move simplification
>>         for A cmp C1 ? A : C2 to below, also simplify remaining code.
>>         * match.pd: Move and extend simplification from above to here:
>>         (cond (cmp (convert1? x) c1) (convert2? x) c2) -> (minmax (x c)).
>>         * tree-if-conv.c (ifcvt_follow_ssa_use_edges): New func.
>>         (predicate_scalar_phi): Call fold_stmt using the new valueize func.
>>
>> gcc/testsuite/ChangeLog
>> 2016-11-16  Bin Cheng  <bin.cheng@arm.com>
>>
>>         * gcc.dg/fold-cond_expr-1.c: New test.
>>         * gcc.dg/fold-condcmpconv-1.c: New test.
>>         * gcc.dg/fold-condcmpconv-2.c: New test.
>>         * gcc.dg/tree-ssa/pr66726.c: Adjust test strings.