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Diffstat (limited to 'board-js2x/slof/helper.fs')
| -rw-r--r-- | board-js2x/slof/helper.fs | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/board-js2x/slof/helper.fs b/board-js2x/slof/helper.fs index 1e2b030..c522c90 100644 --- a/board-js2x/slof/helper.fs +++ b/board-js2x/slof/helper.fs @@ -37,3 +37,12 @@ ENDCASE drop ; + +\ count the number of bits equal 1 +\ the idea is to clear in each step the least significant bit +\ v&(v-1) does exactly this, so count the steps until v == 0 +: cnt-bits ( 64-bit-value -- #bits=1 ) + dup IF + 41 1 DO dup 1- and dup 0= IF drop i LEAVE THEN LOOP + THEN +; |