"Kewen.Lin" <li...@linux.ibm.com> writes:
> Hi Richard,
>
>>> Yeah, the comments were confusing, its intent is to check which targets
>>> support partial vectors and which usage to be used.
>>>
>>> How about to update them like:
>>>
>>> "Return true if loops using partial vectors are supported and usage kind is
>>> 1/2".
>>
>> I wasn't really commenting on the comment so much as the intent.
>> It should be possible to run the testsuite with:
>>
>> --target_board unix/--param=vect-partial-vector-usage=1
>>
>> and get the right results.
>>
>>>> E.g. maybe use check_compile to run gcc with “-Q --help=params” and an
>>>> arbitrary output type (probably assembly). Then use “regexp” on the
>>>> lines to parse the --param=vect-partial-vector-usage value. At that
>>>> point it would be worth caching the result.
>>>
>>> Now the default value of this parameter is 2, even for those targets which
>>> don't have the supports with partial vectors. Since we will get the value
>>> 2 on those unsupported targets, it looks like we have to set it manually?
>>
>> I think that just means we want:
>>
>> vect_len_load_store
>> the len_load_store equivalent of vect_fully_masked, i.e. whether
>> the target supports len load/store (regardless of whether the
>> --param enables it)
>>
>> vect_partial_vectors
>> (vect_fully_masked || vect_len_load_store) && param != 0
>>
>> vect_partial_vectors_usage_1
>> (vect_fully_masked || vect_len_load_store) && param == 1
>>
>> vect_partial_vectors_usage_2
>> (vect_fully_masked || vect_len_load_store) && param == 2
>>
>
> Thanks for the clarification!
>
> Sorry for the late update, this new version depends on the --help= patch,
> I held it for a while.
>
> Bootstrapped/regtested on powerpc64le-linux-gnu P9, with/without any
> explicit usage setting, it also works well with --target_board
> unix/--param=vect-partial-vector-usage=1.
>
> By the way, for the testing on usage 1, it needs the function
> check_effective_target_vect_len_load_store to return true for Power9,
> this part will be sent for review separately.
Gah, sorry for the slow reply. Thought I'd already reviewed this,
but just realised I hadn't.
> diff --git a/gcc/doc/sourcebuild.texi b/gcc/doc/sourcebuild.texi
> index 9f37ac26241..2290af5812d 100644
> --- a/gcc/doc/sourcebuild.texi
> +++ b/gcc/doc/sourcebuild.texi
> @@ -1689,6 +1689,19 @@ Target supports AND, IOR and XOR reduction on vectors.
>
> @item vect_fold_extract_last
> Target supports the @code{fold_extract_last} optab.
> +
> +@item vect_len_load_store
> +Target supports loops using length-based partial vectors.
Probably easiest to talk in terms of internals, so:
Target supports the @code{len_load} and @code{len_store} optabs.
> +@item vect_partial_vectors_usage_1
> +Target supports loops using partial vectors but only for those loops whose
> need
> +to iterate can be removed.
Here too I think it might be better to talk in terms of existing
features and flags, so:
Target supports loop vectorization with partial vectors and
@code{vect-partial-vector-usage} is set to 1.
> +@item vect_partial_vectors_usage_2
> +Target supports loops using partial vectors and for all loops.
Similarly here for 2.
> +
> +@item vect_partial_vectors
> +Target supports loops using partial vectors.
For this one, probably:
Target supports loop vectorization with partial vectors and
@code{vect-partial-vector-usage} is nonzero.
> diff --git a/gcc/testsuite/gcc.dg/vect/slp-multitypes-11.c
> b/gcc/testsuite/gcc.dg/vect/slp-multitypes-11.c
> index 5200ed1cd94..d6b0604db78 100644
> --- a/gcc/testsuite/gcc.dg/vect/slp-multitypes-11.c
> +++ b/gcc/testsuite/gcc.dg/vect/slp-multitypes-11.c
> @@ -49,5 +49,7 @@ int main (void)
> }
>
> /* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target
> vect_unpack } } } */
> -/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect"
> { target vect_unpack xfail { vect_variable_length && vect_load_lanes } } } }
> */
> +/* The epilogues are vectorized using partial vectors. */
> +/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect"
> { target { vect_unpack && {! vect_partial_vectors_usage_1 } } xfail {
> vect_variable_length && vect_load_lanes } } } } */
> +/* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 2 "vect"
> { target { vect_unpack && { vect_partial_vectors_usage_1 } } xfail {
> vect_variable_length && vect_load_lanes } } } } */
No need for the braces around vect_partial_vectors_usage_1 when it's
not negated. Same for later tests.
> +# Return true if loops using partial vectors are supported but only for loops
> +# whose need to iterate can be removed, that is, value of
> +# param_vect_partial_vector_usage is set to 1.
For these comments, I think it would be good to use the sourcebuild.texi
wording, but with:
Return true if the target supports …
instead of just “Target supports …”.
OK with those changes, thanks.
Richard
