1.5.13 The floating-point status word in a multithreaded environment

Applicable to variants of the software floating-point libraries that require a status word (--fpmode=ieee_fixed or --fpmode=ieee_full), the floating-point status word is safe to use in a multithreaded environment, even with software floating-point.

A status word for each thread is stored in its own __user_perthread_libspace block.


In a hardware floating-point environment, the floating-point status word is stored in a Vector Floating-Point (VFP) register. In this case, your thread-switching mechanism must keep a separate copy of this register for each thread.
Non-ConfidentialPDF file icon PDF versionARM DUI0475M
Copyright © 2010-2016 ARM Limited or its affiliates. All rights reserved.