fenv support vs. SMP systems

[Joseph Myers]

On Mon, 13 Jul 2020, Joel Sherrill wrote:

> It does use the term "system variable" but that doesn't scope it to 
> process or thread.

C11 (the first version of ISO C to introduce threads) says "The 
floating-point environment has thread storage duration. The initial state 
for a thread’s floating-point environment is the current state of the 
floating-point environment of the thread that creates it at the time of 
creation.".

-- 
Joseph S. Myers
joseph@codesourcery.com