Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Promote the SME(2) ABI status from Alpha to Beta #243

Merged
merged 1 commit into from
Feb 5, 2024
Merged

Promote the SME(2) ABI status from Alpha to Beta #243

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
50 changes: 26 additions & 24 deletions aapcs64/aapcs64.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -178,7 +178,7 @@ The following support level definitions are used by the Arm ABI specifications:
The content of this specification is a draft, and Arm considers the
likelihood of future incompatible changes to be significant.

Parts related to SME are at **Alpha** release quality.
Parts related to SME are at **Beta** release quality.

The ILP32 variant is at **Beta** release quality.

Expand Down Expand Up @@ -252,6 +252,8 @@ changes to the content of the document for that release.
| 2023Q3 | 6\ :sup:`th` | In `Data Types`_ include _BitInt(N) in language mapping. |
| | October 2023 | |
+------------+--------------------+------------------------------------------------------------------+
| | | - Change the status of the SME support from Alpha to Beta. |
+------------+--------------------+------------------------------------------------------------------+

References
^^^^^^^^^^
Expand Down Expand Up @@ -924,7 +926,7 @@ it need not preserve any scalable predicate register contents.
SME state
---------

**(Alpha)**
**(Beta)**

`SME`_ defines the following pieces of processor state:

Expand Down Expand Up @@ -987,7 +989,7 @@ of address translation. See also `Pointers`_, above.
Properties of a thread
^^^^^^^^^^^^^^^^^^^^^^

**(Alpha)**
**(Beta)**

The AAPCS64 classifies `threads`_ as follows, with the classification being
invariant for the lifetime of a given thread:
Expand Down Expand Up @@ -1019,7 +1021,7 @@ the current thread has access to SME or TPIDR2_EL0.
TPIDR2_EL0
^^^^^^^^^^

**(Alpha)**
**(Beta)**

This section only applies to threads that have `access to TPIDR2_EL0`_.

Expand Down Expand Up @@ -1216,7 +1218,7 @@ Normal returns
.. _`returns normally`:
.. _`returned normally`:

**(Alpha)**
**(Beta)**

The AAPCS64 uses “\ _`normal return`\ ” to refer to the act of causing
execution to resume at a caller-supplied address after a subroutine call,
Expand Down Expand Up @@ -1249,7 +1251,7 @@ The ZA lazy saving scheme
Overview
^^^^^^^^

**(Alpha)**
**(Beta)**

SME provides a piece of storage called “ZA” that can be enabled and
disabled using a processor state bit called “\ `PSTATE.ZA`_\ ”. This storage
Expand Down Expand Up @@ -1307,7 +1309,7 @@ and restore ZA after the call.
ZA save buffers
^^^^^^^^^^^^^^^

**(Alpha)**
**(Beta)**

A “\ _`ZA save buffer`\ “ is an area of memory of size W×16×\ `SVL.B`_
bytes for some cardinal W. The value of W is a property of the save
Expand All @@ -1322,7 +1324,7 @@ slice is laid out in the same order as for the ZA STR instruction.
ZA states
^^^^^^^^^

**(Alpha)**
**(Beta)**

The AAPCS64 uses the term “\ _`ZA_LIVE`\ ” to refer the number of leading
horizontal slices of ZA that might have useful contents. That is,
Expand Down Expand Up @@ -1476,7 +1478,7 @@ Setting up a lazy save buffer
.. _`set up a lazy save buffer`:
.. _`sets up a lazy save buffer`:

**(Alpha)**
**(Beta)**

If ZA is active, a thread can “set up a lazy save buffer” for the current
ZA contents by using the following procedure:
Expand All @@ -1500,7 +1502,7 @@ Abandoning a lazy save
.. _`abandon the lazy save`:
.. _`abandons the lazy save`:

**(Alpha)**
**(Beta)**

If ZA is dormant and the current contents of ZA are no longer needed,
the thread can “abandon the lazy save” and free up ZA for other operations
Expand All @@ -1514,7 +1516,7 @@ Committing a lazy save
.. _`commit the lazy save`:
.. _`commits the lazy save`:

**(Alpha)**
**(Beta)**

If ZA is dormant, a thread can “commit the lazy save” and free up ZA for
other operations by using the following procedure:
Expand Down Expand Up @@ -1559,7 +1561,7 @@ Preserving ZA
.. _`preserved ZA`:
.. _`preserves ZA`:

**(Alpha)**
**(Beta)**

If a call to a subroutine S `returns normally`_, the call is said to
“preserve ZA” *for that particular return* if one of the following
Expand Down Expand Up @@ -1601,7 +1603,7 @@ Complying with the lazy saving scheme

.. _`complies with the lazy saving scheme`:

**(Alpha)**
**(Beta)**

A call to a subroutine S is said to “\ _`comply with the lazy saving scheme`\ ”
if one of the following conditions is true:
Expand Down Expand Up @@ -1659,7 +1661,7 @@ become SME-aware. Counterexamples include the C library subroutine
Changes to the TPIDR2 block
^^^^^^^^^^^^^^^^^^^^^^^^^^^

**(Alpha)**
**(Beta)**

If, for a particular call C to a subroutine S:

Expand Down Expand Up @@ -1698,7 +1700,7 @@ Types of subroutine interface
PSTATE.SM interfaces
^^^^^^^^^^^^^^^^^^^^

**(Alpha)**
**(Beta)**

A subroutine's “PSTATE.SM interface” specifies the possible states of
`PSTATE.SM`_ on entry to a subroutine and the possible states of `PSTATE.SM`_
Expand Down Expand Up @@ -1740,7 +1742,7 @@ If a subroutine has a streaming-compatible interface, it can call
ZA interfaces
^^^^^^^^^^^^^

**(Alpha)**
**(Beta)**

As noted in `ZA states`_, there are three possible ZA states: off,
dormant, and active. A subroutine's “ZA interface” specifies the possible
Expand Down Expand Up @@ -2036,7 +2038,7 @@ Support routines
SME support routines
--------------------

**(Alpha)**
**(Beta)**

Every platform that supports SME must provide the following runtime
support routines:
Expand Down Expand Up @@ -2064,7 +2066,7 @@ support routines:

.. |__arm_sme_state| replace:: ``__arm_sme_state``

**(Alpha)**
**(Beta)**

Platforms that support SME must provide a function with the
following properties:
Expand Down Expand Up @@ -2114,7 +2116,7 @@ following properties:
``__arm_tpidr2_save``
^^^^^^^^^^^^^^^^^^^^^

**(Alpha)**
**(Beta)**

Platforms that support SME must provide a subroutine to `commit a lazy save`_,
with the subroutine having the following properties:
Expand Down Expand Up @@ -2172,7 +2174,7 @@ If ZA was dormant on entry then it remains dormant on return.

.. _`turn ZA off`:

**(Alpha)**
**(Beta)**

Platforms that support SME must provide a subroutine to set PSTATE.ZA to 0,
with the subroutine having the following properties:
Expand Down Expand Up @@ -2206,7 +2208,7 @@ with the subroutine having the following properties:
``__arm_tpidr2_restore``
^^^^^^^^^^^^^^^^^^^^^^^^

**(Alpha)**
**(Beta)**

Platforms that support SME must provide a subroutine to restore data after
a lazy save, with the subroutine having the following properties:
Expand Down Expand Up @@ -2257,7 +2259,7 @@ Pseudo-code examples
SME pseudo-code examples
------------------------

**(Alpha)**
**(Beta)**

This section gives examples of various sequences that conform
to the SME PCS rules. In each case, comments in the code give
Expand Down Expand Up @@ -2790,7 +2792,7 @@ The argument list is then processed according to the standard rules for procedur
setjmp and longjmp
------------------

**(Alpha)**
**(Beta)**

The C subroutines ``setjmp`` and ``longjmp`` have a `private-ZA`_
`non-streaming interface`_. In addition to the standard requirements
Expand Down Expand Up @@ -2825,7 +2827,7 @@ because not all calls to ``setjmp`` have a partnering call to
Exceptions
----------

**(Alpha)**
**(Beta)**

If:

Expand Down
Loading