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| author | Remy Oukaour <remy.oukaour@gmail.com> | 2018-01-10 11:57:28 -0500 |
|---|---|---|
| committer | Remy Oukaour <remy.oukaour@gmail.com> | 2018-01-10 11:57:28 -0500 |
| commit | cc95d1208d4a6b8291a5430a8d652a9337074788 (patch) | |
| tree | 106d9efeef959c9fc5e1321afad24f102ab6dea9 /macros/code.asm | |
| parent | 22b607b664b1b350ad96340b39440c8e4296006c (diff) | |
Use maskbits more, and clarify its usage
Diffstat (limited to 'macros/code.asm')
| -rw-r--r-- | macros/code.asm | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/macros/code.asm b/macros/code.asm index 5ec214d50..5a0b82a24 100644 --- a/macros/code.asm +++ b/macros/code.asm @@ -39,15 +39,17 @@ ENDM mobile EQUS "ret" maskbits: MACRO +; masks just enough bits to cover the argument +; e.g. "maskbits %00010100" becomes "and %00011111" ; example usage in rejection sampling: ; .loop ; call Random -; maskbits 30 +; maskbits 30 +- 1 ; cp 30 ; jr nc, .loop x = 1 rept 8 -if \1 > x +if x < (\1) x = (x + 1) * 2 +- 1 endc endr |