SIGFPE on 8245
Andy G.
adgospod at gmail.com
Sat Aug 20 05:40:42 EST 2005
I'm working with a rather large multi-threaded application that after
a several hour run will often produce a floating point exception
(specifically a divide by zero exception). I've manged to catch the
signal and use some home grown code to examine the current state of
the running thread as well as all of the others, but sadly this debug
information never provides any valuable information. It appears as
though the crash is happening in the pthread library when trying to
execute a floating point store instruction (0x8114 listed below).
00008108 <__pthread_timedsuspend_new>:
8108: 7d 80 00 26 mfcr r12
810c: 94 21 fc 90 stwu r1,-880(r1)
8110: 7c 08 02 a6 mflr r0
8114: d9 c1 02 e0 stfd f14,736(r1) <--- SIGFPE happens here
After looking over the 32-bit PPC Programming Env Manual it seems to
me that the floating point operations that result in +/- infinity will
disable the FPU and write the FPECR with the cause. Next time a
floating point instruction is attempted we will get an exception since
the FPU is disabled and then we will throw the exception.
This information unfortunately tells me that I have to start digging
through the source code to find the programming error, but I'm hoping
I'm wrong about this. Any advice or tips?
Thanks in advance,
-andy
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