Ping
Richard Sandiford <richard.sandif...@linaro.org> writes:
> James Greenhalgh <james.greenha...@arm.com> writes:
>> On Thu, Jan 04, 2018 at 11:27:56AM +0000, Richard Sandiford wrote:
>>> Ping**2
>>
>> This is OK.
>
> Thanks.
>
>> It took me a while to get the hang of the interface - a worked example
>> in the comment in vec-perm-indices.c would probably have been helpful.
>> It took until your code for REV for this to really make sense to me; so
>> perhaps that make for a good example.
>
> Yeah, good idea.
>
> Is the following OK? Tested on aarch64-linux-gnu.
>
> Thanks,
> Richard
>
>
> 2018-01-09 Richard Sandiford <richard.sandif...@linaro.org>
>
> gcc/
> * vec-perm-indices.c (vec_perm_indices::series_p): Give examples
> of usage.
>
> Index: gcc/vec-perm-indices.c
> ===================================================================
> --- gcc/vec-perm-indices.c 2018-01-03 11:12:55.709763763 +0000
> +++ gcc/vec-perm-indices.c 2018-01-09 15:46:40.004232873 +0000
> @@ -114,7 +114,18 @@ vec_perm_indices::rotate_inputs (int del
> }
>
> /* Return true if index OUT_BASE + I * OUT_STEP selects input
> - element IN_BASE + I * IN_STEP. */
> + element IN_BASE + I * IN_STEP. For example, the call to test
> + whether a permute reverses a vector of N elements would be:
> +
> + series_p (0, 1, N - 1, -1)
> +
> + which would return true for { N - 1, N - 2, N - 3, ... }.
> + The calls to test for an interleaving of elements starting
> + at N1 and N2 would be:
> +
> + series_p (0, 2, N1, 1) && series_p (1, 2, N2, 1).
> +
> + which would return true for { N1, N2, N1 + 1, N2 + 1, ... }. */
>
> bool
> vec_perm_indices::series_p (unsigned int out_base, unsigned int out_step,
