DOC: add a release note

1 files changed, 47 insertions, 0 deletions

diff --git a/doc/release/upcoming_changes/13516.improvement.rst b/doc/release/upcoming_changes/13516.improvement.rst
new file mode 100644
index 000000000..1b32b61d7
--- /dev/null
+++ b/doc/release/upcoming_changes/13516.improvement.rst
@@ -0,0 +1,47 @@
+Enable multi-platform SIMD compiler optimizations
+-------------------------------------------------
+
+A series of improvements for NumPy infrastructure to pave the way to
+**NEP-38**, that can be summarized as follow:
+
+-  **New Build Arguments** :
+
+   -  ``--cpu-baseline`` to specify the minimal set of required
+      optimizations, default value is ``min`` which provides the minimum
+      CPU features that can safely run on a wide range of users
+      platforms.
+
+   -  ``--cpu-dispatch`` to specify the dispatched set of additional
+      optimizations, default value is ``max -xop -fma4`` which enables
+      all CPU features, except for AMD legacy features.
+
+   -  ``--disable-optimization`` to explicitly disable the whole new
+      improvements, It also adds a new **C** compiler #definition
+      called ``NPY_DISABLE_OPTIMIZATION`` which it can be used as
+      guard for any SIMD code.
+
+-  **Advanced CPU dispatcher**: A flexible cross-architecture CPU dispatcher built
+   on the top of Python/Numpy distutils, support all common compilers with a wide range of CPU features.
+
+   The new dispatcher requires a special file extension ``*.dispatch.c`` to mark the dispatch-able
+   **C** sources. These sources have the ability to be compiled multiple times so that each compilation process
+   represents certain CPU features and provides different #definitions and flags that affect the code paths.
+
+-  **New auto-generated C header ``core/src/common/_cpu_dispatch.h``**
+   This header is generated by the distutils module 'ccompiler_opt', and contains all the #definitions
+   and headers of instruction sets, that had been configured through command arguments '--cpu-baseline' and '--cpu-dispatch'.
+
+-  **New C header ``core/src/common/npy_cpu_dispatch.h``**
+
+   This header contains all utilities that required for the whole CPU dispatching process,
+   it also can be considered as a bridge linking the new infrastructure work with NumPy CPU runtime detection.
+
+-  **Add new attributes to NumPy umath module(Python level)**
+
+   -  ``__cpu_baseline__`` a list contains the minimal set of required optimizations that supported
+      by the compiler and platform according to the specified values to command argument '--cpu-baseline'.
+
+   -  ``__cpu_dispatch__`` a list contains the dispatched set of additional optimizations that supported by the compiler
+      and platform according to the specified values to command argument '--cpu-dispatch'.
+
+-  **Print the supported CPU features during the run of PytestTester**