:orphan:

.. title:: CONFIG_FPU_SHARING

.. kconfig:: CONFIG_FPU_SHARING

CONFIG_FPU_SHARING
##################

*FPU register sharing*

Type: ``bool``

Help
====

.. code-block:: none

    This option enables preservation of the hardware floating point registers
    across context switches to allow multiple threads to perform concurrent
    floating point operations.

    Note that some compiler configurations may activate a floating point
    context by generating FP instructions for any thread, and that
    context must be preserved when switching such threads in and out.
    The developers can still disable the FP sharing mode in their
    application projects, and switch to Unshared FP registers mode,
    if it is guaranteed that the image code does not generate FP
    instructions outside the single thread context that is allowed
    to do so.

Direct dependencies
===================

\ :kconfig:`FPU <CONFIG_FPU>` && \ :kconfig:`MULTITHREADING <CONFIG_MULTITHREADING>`

*(Includes any dependencies from ifs and menus.)*

Defaults
========

No defaults. Implicitly defaults to ``n``.

Symbols that imply this symbol
==============================

- \ :kconfig:`ARMV7_M_ARMV8_M_FP <CONFIG_ARMV7_M_ARMV8_M_FP>`
- \ :kconfig:`CPU_CORTEX_A <CONFIG_CPU_CORTEX_A>`

Kconfig definition
==================



At ``<Zephyr Architecture>/Kconfig:865``

Included via ``Kconfig:8`` → ``Kconfig.zephyr:39``

Menu path: (Top) → Floating Point Options → Enable floating point unit (FPU)

.. code-block:: kconfig

    config FPU_SHARING
    	bool "FPU register sharing"
    	depends on FPU && MULTITHREADING
    	help
    	  This option enables preservation of the hardware floating point registers
    	  across context switches to allow multiple threads to perform concurrent
    	  floating point operations.
	  
    	  Note that some compiler configurations may activate a floating point
    	  context by generating FP instructions for any thread, and that
    	  context must be preserved when switching such threads in and out.
    	  The developers can still disable the FP sharing mode in their
    	  application projects, and switch to Unshared FP registers mode,
    	  if it is guaranteed that the image code does not generate FP
    	  instructions outside the single thread context that is allowed
    	  to do so.

*(The 'depends on' condition includes propagated dependencies from ifs and menus.)*