[slime-devel] Re: weird CMUCL behavior of ext:set-floating-point-modes

[Helmut Eller]

Luke Gorrie <luke at bluetail.com> writes:

>> I am experiencing odd behavior using SLIME with CMUCL.  It seems that
>> a call to ext:set-floating-point-modes is failing to set the modes
>> correctly.  From within SLIME, I have the following interaction:
>
> I don't understand this stuff, but it does appear to be caused by our
> using SIGIO.

It seems that CMUCL saves and restores the FPU modes in the signal
handler.  Apparently it's even possible to cheat: 

CL-USER> (progn (ext:set-floating-point-modes :traps nil)
		(throw 'lisp::top-level-catcher nil))
; Evaluation aborted
CL-USER> (ext:get-floating-point-modes)
(:traps nil :rounding-mode :nearest :current-exceptions nil :accrued-exceptions
 nil :fast-mode nil ...)
CL-USER> 


Helmut.