[Qemu-devel] PPC LFDU instruction emulation problem?

[Ely Soto]

I seem to hit a weird emulation issue.
I'm still new so take what I say with a grain of salt.

In my tests the LFDU instruction is
not updating the Condition Register ($CR) when the condition becomes ZERO.

The following assembly will loop forever.

falconScrubFloop:
        lfdu
       0,8(r17) /* load floating point value
and increment register ( f0 <- ($r17) and $r17 += 8 */
        bc
       16,0,falconScrubFloop    
   /* branch till counter == 0, This is equivalent to
bdnz or branch if not zero */

The MSR is set to allow floating point
$MSR = 0x2000.

Not sure what's going on yet.

Ely Soto, Flight Software Engineer
Orbital Sciences Corp. Dulles, VA.
address@hidden
Office No. 703-406-5341
Mobile No. 703-403-7077

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