On 11/22/2017 11:09 AM, Richard Sandiford wrote:
> Richard Sandiford <richard.sandif...@linaro.org> writes:
>> This patch makes vectorizable_reduction cope with variable-length vectors.
>> We can handle the simple case of an inner loop reduction for which
>> the target has native support for the epilogue operation. For now we
>> punt on other cases, but patches after the main SVE submission allow
>> SLP and double reductions too.
>
> Here's an updated version that applies on top of the recent removal
> of REDUC_*_EXPR.
>
> Thanks,
> Richard
>
>
> 2017-11-22 Richard Sandiford <richard.sandif...@linaro.org>
> Alan Hayward <alan.hayw...@arm.com>
> David Sherwood <david.sherw...@arm.com>
>
> gcc/
> * tree.h (build_index_vector): Declare.
> * tree.c (build_index_vector): New function.
> * tree-vect-loop.c (get_initial_def_for_reduction): Treat the number
> of units as polynomial, forcibly converting it to a constant if
> vectorizable_reduction has already enforced the condition.
> (get_initial_defs_for_reduction): Likewise.
> (vect_create_epilog_for_reduction): Likewise. Use build_index_vector
> to create a {1,2,3,...} vector.
> (vectorizable_reduction): Treat the number of units as polynomial.
> Choose vectype_in based on the largest scalar element size rather
> than the smallest number of units. Enforce the restrictions
> relied on above.
I assume you'll work with Richi to address any conflicts with his patch
to allow the target to specify a preferred mode for final reductions
using shifts or extractions.
OK.
jeff
