> On 25 Apr 2025, at 12:06, Richard Sandiford <richard.sandif...@arm.com> wrote:
>
> Kyrylo Tkachov <ktkac...@nvidia.com> writes:
>> Hi Richard,
>>
>>> On 23 Apr 2025, at 13:47, Richard Sandiford <richard.sandif...@arm.com>
>>> wrote:
>>>
>>> Thanks for all the feedback. I've tried to address it in the version
>>> below. I'll push later today if there are no further comments.
>>>
>>> Richard
>>>
>>>
>>> The list is structured as:
>>>
>>> - new configurations
>>> - command-line changes
>>> - ACLE changes
>>> - everything else
>>>
>>> As usual, the list of new architectures, CPUs, and features is from a
>>> purely mechanical trawl of the associated .def files. I've identified
>>> features by their architectural name to try to improve searchability.
>>> Similarly, the list of ACLE changes includes the associated ACLE
>>> feature macros, again to try to improve searchability.
>>>
>>> The list summarises some of the target-specific optimisations because
>>> it sounded like Tamar had received feedback that people found such
>>> information interesting.
>>>
>>> I've used the passive tense for most entries, to try to follow the
>>> style used elsewhere.
>>>
>>> We don't yet define __ARM_FEATURE_FAMINMAX, but I'll fix that
>>> separately.
>>
>> Thanks again for doing this…
>>
>>>
>>> + </li>
>>> + <li>Support has been added for the following features of the Arm C
>>> + Language Extensions
>>> + (<a href="https://github.com/ARM-software/acle";>ACLE</a>):
>>> + <ul>
>>> + <li>guarded control stacks</li>
>>> + <li>lookup table instructions with 2-bit and 4-bit indices
>>> + (predefined macro
>>> + <code>__ARM_FEATURE_LUT</code>, enabled by <code>+lut</code>)
>>> + </li>
>>> + <li>floating-point absolute minimum and maximum instructions
>>> + (predefined macro <code>__ARM_FEATURE_FAMINMAX</code>,
>>> + enabled by <code>+faminmax</code>)
>>> + </li>
>>> + <li>FP8 conversions (predefined macro
>>> + <code>__ARM_FEATURE_FP8</code>, enabled by <code>+fp8</code>)
>>> + </li>
>>> + <li>FP8 2-way dot product to half precision instructions
>>> + (predefined macro <code>__ARM_FEATURE_FP8DOT2</code>,
>>> + enabled by <code>+fp8dot2</code>)
>>> + </li>
>>> + <li>FP8 4-way dot product to single precision instructions
>>> + (predefined macro <code>__ARM_FEATURE_FP8DOT4</code>,
>>> + enabled by <code>+fp8dot4</code>)
>>> + </li>
>>> + <li>FP8 multiply-accumulate to half precision and single precision
>>> + instructions (predefined macro <code>__ARM_FEATURE_FP8FMA</code>,
>>> + enabled by <code>+fp8fma</code>)
>>> + </li>
>>> + <li>SVE FP8 2-way dot product to half precision instructions
>>> + (predefined macro <code>__ARM_FEATURE_SSVE_FP8DOT2</code>,
>>> + enabled by <code>+ssve-fp8dot2</code>)
>>> + </li>
>>> + <li>SVE FP8 4-way dot product to single precision instructions
>>> + (predefined macro <code>__ARM_FEATURE_SSVE_FP8DOT4</code>,
>>> + enabled by <code>+ssve-fp8dot4</code>)
>>> + </li>
>>> + <li>SVE FP8 multiply-accumulate to half precision and single
>>> precision
>>> + instructions (predefined macro
>>> <code>__ARM_FEATURE_SSVE_FP8FMA</code>,
>>> + enabled by <code>+ssve-fp8fma</code>)
>>
>>
>> … Should these FP8 entries say “SSVE FP8” rather than “SVE FP8”?
>
> The official description is "SVE(2) ... instructions in Streaming
> SVE mode". But yeah, I suppose dropping the "in Streaming SVE mode"
> was a mistake. I've pushed the following incremental patch.
Thanks, that looks clearer.
Kyrill
>
> Thanks,
> Richard
>
>
> diff --git a/htdocs/gcc-15/changes.html b/htdocs/gcc-15/changes.html
> index a71249ff..3cec4ff4 100644
> --- a/htdocs/gcc-15/changes.html
> +++ b/htdocs/gcc-15/changes.html
> @@ -847,17 +847,20 @@ asm (".text; %cc0: mov %cc2, %%r0; .previous;"
> instructions (predefined macro <code>__ARM_FEATURE_FP8FMA</code>,
> enabled by <code>+fp8fma</code>)
> </li>
> - <li>SVE FP8 2-way dot product to half precision instructions
> - (predefined macro <code>__ARM_FEATURE_SSVE_FP8DOT2</code>,
> - enabled by <code>+ssve-fp8dot2</code>)
> + <li>SVE FP8 2-way dot product to half precision instructions in
> + Streaming SVE mode (predefined macro
> + <code>__ARM_FEATURE_SSVE_FP8DOT2</code>, enabled by
> + <code>+ssve-fp8dot2</code>)
> </li>
> - <li>SVE FP8 4-way dot product to single precision instructions
> - (predefined macro <code>__ARM_FEATURE_SSVE_FP8DOT4</code>,
> - enabled by <code>+ssve-fp8dot4</code>)
> + <li>SVE FP8 4-way dot product to single precision instructions in
> + Streaming SVE mode (predefined macro
> + <code>__ARM_FEATURE_SSVE_FP8DOT4</code>, enabled by
> + <code>+ssve-fp8dot4</code>)
> </li>
> <li>SVE FP8 multiply-accumulate to half precision and single precision
> - instructions (predefined macro
> <code>__ARM_FEATURE_SSVE_FP8FMA</code>,
> - enabled by <code>+ssve-fp8fma</code>)
> + instructions in Streaming SVE mode (predefined macro
> + <code>__ARM_FEATURE_SSVE_FP8FMA</code>, enabled by
> + <code>+ssve-fp8fma</code>)
> </li>
> <li>SVE2.1 instructions (predefined macro
> <code>__ARM_FEATURE_SVE2p1</code>, enabled by <code>+sve2p1</code>)
> --
> 2.43.0
>
