8000 GH-113464: Add the JIT to What's New (GH-133486) · python/cpython@57c9810 · GitHub
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GH-113464: Add the JIT to What's New (GH-133486)
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‎Doc/using/configure.rst

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@@ -302,14 +302,21 @@ General Options
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.. option:: --enable-experimental-jit=[no|yes|yes-off|interpreter]
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Indicate how to integrate the :ref:`JIT compiler <whatsnew313-jit-compiler>`.
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* ``no`` - build the interpreter without the JIT.
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* ``yes`` - build the interpreter with the JIT.
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* ``yes-off`` - build the interpreter with the JIT but disable it by default.
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* ``interpreter`` - build the interpreter without the JIT, but with the tier 2 enabled interpreter.
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By convention, ``--enable-experimental-jit`` is a shorthand for ``--enable-experimental-jit=yes``.
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Indicate how to integrate the :ref:`experimental just-in-time compiler <whatsnew314-jit-compiler>`.
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* ``no``: Don't build the JIT.
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* ``yes``: Enable the JIT. To disable it at runtime, set the environment
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variable :envvar:`PYTHON_JIT=0 <PYTHON_JIT>`.
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* ``yes-off``: Build the JIT, but disable it by default. To enable it at
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runtime, set the environment variable :envvar:`PYTHON_JIT=1 <PYTHON_JIT>`.
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* ``interpreter``: Enable the "JIT interpreter" (only useful for those
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debugging the JIT itself). To disable it at runtime, set the environment
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variable :envvar:`PYTHON_JIT=0 <PYTHON_JIT>`.
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``--enable-experimental-jit=no`` is the default behavior if the option is not
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provided, and ``--enable-experimental-jit`` is shorthand for
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``--enable-experimental-jit=yes``. See :file:`Tools/jit/README.md` for more
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information, including how to install the necessary build-time dependencies.
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.. note::
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‎Doc/whatsnew/3.14.rst

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:ref:`argparse <whatsnew314-color-argparse>`,
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:ref:`json <whatsnew314-color-json>` and
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:ref:`calendar <whatsnew314-color-calendar>` CLIs
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* :ref:`Binary releases for the experimental just-in-time compiler <whatsnew314-jit-compiler>`
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(Contributed by Łukasz Langa in :gh:`131507`.)
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.. _whatsnew314-jit-compiler:
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Binary releases for the experimental just-in-time compiler
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----------------------------------------------------------
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The official macOS and Windows release binaries now include an *experimental*
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just-in-time (JIT) compiler. Although it is **not** recommended for production
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use, it can be tested by setting :envvar:`PYTHON_JIT=1 <PYTHON_JIT>` as an
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environment variable. Downstream source builds and redistributors can use the
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:option:`--enable-experimental-jit=yes-off` configuration option for similar
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behavior.
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The JIT is at an early stage and still in active development. As such, the
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typical performance impact of enabling it can range from 10% slower to 20%
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faster, depending on workload. To aid in testing and evaluation, a set of
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introspection functions has been provided in the :data:`sys._jit` namespace.
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:func:`sys._jit.is_available` can be used to determine if the current executable
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supports JIT compilation, while :func:`sys._jit.is_enabled` can be used to tell
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if JIT compilation has been enabled for the current process.
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Currently, the most significant missing functionality is that native debuggers
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and profilers like ``gdb`` and ``perf`` are unable to unwind through JIT frames
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(Python debuggers and profilers, like :mod:`pdb` or :mod:`profile`, continue to
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work without modification). Free-threaded builds do not support JIT compilation.
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Please report any bugs or major performance regressions that you encounter!
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.. seealso:: :pep:`744`
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Other language changes
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======================
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‎Tools/jit/README.md

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## Building
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For `PCbuild`-based builds, pass the new `--experimental-jit` option to `build.bat`.
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For `PCbuild`-based builds, pass the `--experimental-jit` option to `build.bat`.
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For all other builds, pass the new `--enable-experimental-jit` option to `configure`.
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For all other builds, pass the `--enable-experimental-jit` option to `configure`.
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Otherwise, just configure and build as you normally would. Cross-compiling "just works", since the JIT is built for the host platform.
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The JIT can also be enabled or disabled using the `PYTHON_JIT` environment variable, even on builds where it is enabled or disabled by default. More details about configuring CPython with the JIT and optional values for `--enable-experimental-jit` can be found [here](https://docs.python.org/dev/whatsnew/3.13.html#experimental-jit-compiler).
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The JIT can also be enabled or disabled using the `PYTHON_JIT` environment variable, even on builds where it is enabled or disabled by default. More details about configuring CPython with the JIT and optional values for `--enable-experimental-jit` can be found [here](https://docs.python.org/dev/using/configure.html#cmdoption-enable-experimental-jit).
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[^pep-744]: [PEP 744](https://peps.python.org/pep-0744/)
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