Guru
Joined: 11/02/2018
Location: AustraliaPosts: 2247
| Posted: 11:44am 24 Mar 2024 |
Some other bit reversal options in this thread.
This one is very clever.
> b%=73 : ? bin$(b%,8)
01001001
> Rb% = (b% * &H0202020202 and &H010884422010) mod 1023
> ? bin$(Rb%,8)
10010010
>
01001001
> Rb% = (b% * &H0202020202 and &H010884422010) mod 1023
> ? bin$(Rb%,8)
10010010
>
Footnote added 2024-03-25 07:16 by phil99
Using the above on a 16 bit device code.
> b% = 54321 : ? bin$(b%,16)
1101010000110001
> Rb% = (((b% and 255) * &H0202020202 and &H010884422010) mod 1023) << 8
> Rb% = Rb% + ((b% >> 8) * &H0202020202 and &H010884422010) mod 1023
> ? bin$(Rb%,16)
1000110000101011
>
1101010000110001
> Rb% = (((b% and 255) * &H0202020202 and &H010884422010) mod 1023) << 8
> Rb% = Rb% + ((b% >> 8) * &H0202020202 and &H010884422010) mod 1023
> ? bin$(Rb%,16)
1000110000101011
>
Footnote added 2024-03-25 07:22 by phil99
Or this.
> b% = 54321 : ? bin$(b%,16)
1101010000110001
> Rb% = (((b% and 255) * &H0202020202 and &H010884422010) mod 1023) << 8
> inc Rb%, ((b% >> 8) * &H0202020202 and &H010884422010) mod 1023
> ? bin$(Rb%,16)
1000110000101011
>
1101010000110001
> Rb% = (((b% and 255) * &H0202020202 and &H010884422010) mod 1023) << 8
> inc Rb%, ((b% >> 8) * &H0202020202 and &H010884422010) mod 1023
> ? bin$(Rb%,16)
1000110000101011
>