CONFIG_ARC_FPU_SAVE_RESTORE is not available for thedefaultarchitecture x86.
Result is shown for architecture arc

Enable FPU state persistence across context switch

modulename: fpu.ko

configname: CONFIG_ARC_FPU_SAVE_RESTORE

Linux Kernel Configuration
└─>ARC Architecture Configuration
└─>ARC CPU Configuration
└─>Enable FPU state persistence across context switch
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Double Precision Floating Point unit had dedictaed regs which
need to be saved/restored across context-switch.
Note that ARC FPU is overly simplistic, unlike say x86, which has
hardware pieces to allow software to conditionally save/restore,
based on actual usage of FPU by a task. Thus our implemn does
this for all tasks in system.

source code: