This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH 06/25] Remove constant vec_select restriction.
On 9/5/18 5:49 AM, ams@codesourcery.com wrote:
>
> The vec_select operator is documented to require a const_int for the lane
> selector operand, but GCN has an instruction that can select the lane at
> runtime, so it seems reasonable to remove this restriction.
>
> This patch simply replaces assertions that the operand is constant with early
> exits from the optimizers. I think it's reasonable that vec_select with a
> non-constant operand cannot be optimized, yet.
>
> Also included is the necessary documentation tweak.
>
> 2018-09-05 Andrew Stubbs <ams@codesourcery.com>
>
> gcc/
> * doc/rtl.texi: Adjust vec_select description.
> * simplify-rtx.c (simplify_binary_operation_1): Allow VEC_SELECT to use
> non-constant selectors.
OK. Seems like it could go in now since you're just early returning
rather than asserting -- it should affect any in-tree port.
jeff