Re: [Qemu-devel] fpu problems with qemu-system-sparc

[Blue Swirl]

> I've checked and changed a lot of code inside the kernel and in qemu and 
> added
> debbugging output. The crash is more or less reproducible and the program
> crashes after 2-3 FPU disabled traps somewhere inside the libc init 
> routines.
> The FPU instructions cannot be the problem, because I disabled the trap in
> qemu and nothing crashed. Bit the trap is implemented like any other trap 
> and
> all other traps seem to work. Since the crash is only reproducible in, lets
> say 95% of all tests, it looks like a timing problem. Unfortunately, I have
> no idea about qemu's timer simulation. What else can I check?

I'd still check the ld/stfsr implementation. The V8 spec says that stfsr 
_may_ zero the ftt field in fsr and what you describe sounds like the 
trapping happens too often. Just add env->fsr &= ~FSR_FTT_MASK into 
op_stfsr.

The timer frequency can be changed by modifying CNT_FREQ in slavio_timer.c 
if you want to try that.

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