Kyrylo Tkachov <[email protected]> writes:
> Hi Richard,
>
>> On 23 Apr 2025, at 13:47, Richard Sandiford <[email protected]>
>> 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,
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
