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Re: [MiNT] Firebee Coldfire MiNT Kernel and NFS

On 05/09/2014 10:29, Andreas Schwab wrote:
Vincent Rivière <vincent.riviere@freesbee.fr> writes:

In our case, the next instruction is BEQ, which means that only the Z flag
is important. And fortunately, that one is set identically by both

No, it isn't.

Could you please elaborate?

From the documentation posted by Thomas:

Z - Set if the operand was zero; cleared otherwise.

Z - Set if the bit tested is zero; cleared otherwise.

Humm... it seems you are right.
Both TAS and BSET #7 sets the bit 7.

But the Z flag is different:
- with TAS, it reflects the previous status of the whole byte
- with BSET, it reflects only the previous status of the bit 7

So care must be taken when choosing the right bit for BSET, and check the whole logic of the routine.

Thanks for the hint.

Vincent Rivière