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MUFOS



Joined: 17 Apr 2016
Posts: 47
MUFOS
Hello there, I was wondering how I could declare a bit in FASM.
Post 18 Apr 2016, 22:00
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Tyler



Joined: 19 Nov 2009
Posts: 1216
Location: NC, USA
Tyler
You can't. But you can declare a byte with "db" or reserve a byte with "rb". See the manual for exact usage.
Post 18 Apr 2016, 22:47
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Trinitek



Joined: 06 Nov 2011
Posts: 257
Trinitek
Are you looking to declare a bitfield or just a single bit?
Post 19 Apr 2016, 01:05
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MUFOS



Joined: 17 Apr 2016
Posts: 47
MUFOS
Trinitek wrote:
Are you looking to declare a bitfield or just a single bit?

Just a single bit.
Post 19 Apr 2016, 05:18
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Tyler



Joined: 19 Nov 2009
Posts: 1216
Location: NC, USA
Tyler
Since memory is only byte addressable, a single bit would have to be stored in a byte somewhere. Ergo you have to declare at least a byte. If you have multiple bits, you can use the same byte for at most 8 of them, but you must have a byte.

Or just keep it in a register or flag, but that gets a bit more complicated. If you keep it in a flag, you have to avoid intrusions which change that flag (hard to do). If you keep it in a register, you have to essentially dedicate that register to only holding a bit (or be really careful moving things into and out of the register, assuming those things have a predictable bit pattern that allows this to work), which would probably be a net negative to performance.
Post 19 Apr 2016, 06:18
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