Author Topic: How are exceptions handled?  (Read 2014 times)

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Offline fb39ca4

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How are exceptions handled?
« on: July 03, 2011, 03:29:00 pm »
How does ndless handle exceptions? I specifically want to know about [explosion]divide by zero.[/explosion]

Offline z80man

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Re: How are exceptions handled?
« Reply #1 on: July 03, 2011, 03:49:47 pm »
If the ARM is anything like the SuperH (which it very much is) then no automatic exception is generated for divide by 0. Instead an undefined result is what happens. For an exception there must be a specific test for 0 before division begins. This would be done as a conditional statement and not as an internal exception processing. I would though confirm this with someone who actually does low-level nspire dev such as calc84

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Offline fb39ca4

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Re: How are exceptions handled?
« Reply #2 on: July 03, 2011, 04:01:29 pm »
So what would the value of undefined be? So I can check for it and abort the iteration of the loop it is in.

Offline z80man

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Re: How are exceptions handled?
« Reply #3 on: July 03, 2011, 04:07:39 pm »
mathematically speaking it should be infinity or negative infinity which floating points represent properly but for integers I believe it would just be 0 but once again I'm not sure.

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Offline AngelFish

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Re: How are exceptions handled?
« Reply #4 on: July 03, 2011, 04:30:02 pm »
Ndless might actually generate "exceptions" because of how compilers handle floating point arithmetic. These of course wouldn't be hardware exceptions without an FPU, but it might be possible to catch them.
∂²Ψ    -(2m(V(x)-E)Ψ
---  = -------------
∂x²        ℏ²Ψ