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playground:reversing_bits_in_a_byte

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playground:reversing_bits_in_a_byte [2020-02-22 18:40]
verz
playground:reversing_bits_in_a_byte [2020-03-12 13:05] (current)
tlr
Line 53: Line 53:
         ror         ror
         rts         rts
 +</​code>​
 +
 +--
 +Optimized version, at 84cycl +rts (enter with the value in .A, result in .A)
 +<​code>​
 + sta $02 ; 3
 + lda #1 ; 2
 +lp:
 + ror $02 ; 5
 + rol ; 2
 + bcc lp ; 3(2)
 + ; =84
 + rts
 +</​code>​
 +
 +or slightly unrolled:
 +<​code>​
 + sta $02 ; 3
 + lda #1 ; 2
 +lp:
 + ror $02 ; 5
 + rol ; 2
 + ror $02 ; 5
 + rol ; 2
 + bcc lp ; 3(2)
 + ; =72
 + rts
 </​code>​ </​code>​
  
playground/reversing_bits_in_a_byte.txt ยท Last modified: 2020-03-12 13:05 by tlr