Date: Mon, 10 Jan 94 11:23 GMT
From: mjo AT mrao DOT cam DOT ac DOT uk (Martin Oldfield)
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: fp in interrupt handlers


We've got a piece of code hanging off the clock interrupt. Under
certain circumstances it appears to crash. The causes are
correspondingly difficult to pin-down, but the following data have
been collected:
	
1)	If the interrupt routine does no fp, then the problem
	disappears.

2)	If we add a bit of asm code to save and restore the fp
	registers as we enter and leave the interrupt routine,	
	things get better - we've not seen this crash but hesitate 
	to say that this is definately the cause.

Is it possible that the fp status isn't being correctly saved or should
we look elsewhere for a bug ?

Thanks in advance,
M.