epiphany chip emulator

[Gravis]

[EggBaconAndSpam]

Same problem, that's not how sign extension works.
You would have to repeat the MSB of the immediate to fill an entire 32bit int.
All you are doing is repeating said MSB _once_, so 1111b would become 10001111b (bit widths not important).
This way -1 (1111b) would be converted to -113...

You could try the following: (the immediate is a signed 8 bit)

int SIMM = (int)(char)get_num(op, 7, 8); // cast to char, sign extend to int

for example (int)(char)(0xFF) == -1

[Gravis]

[EggBaconAndSpam]

Yeah, the problem is, you can't simply set the sign flag...
We are dealing with a two's complement here.
Maybe ysapir can cast some light onto the problem.

Also, the immediate field starts at bit 7, not 8. (might just be the all-encompassing off-by-one...) // nevermind, was just me being off-by-one

Also, casting will be just as fast, and its behaviour is guaranteed by the standard.

[Gravis]

[Gravis]

[Gravis]

[Gravis]

[mangibu]

Hi Gravis!
Could you please tell me a little bit about your development environment (OS, Tools…)?
Thank you.
Michael

[Gravis]