hex.tables.clean_table_entry__table (arity 3)

Generic n-entry XOR-dispatch table: when jumped to at entry d, XORs d into dst and jumps to ret. n must be a power of two and the table must be (1<<n)-padded. The 1-arity form specialises this to n=256, ret=hex.tables.ret.

Signature

def clean_table_entry__table n, dst, ret @ clean { ... }

Defined in hex/tables_init.fj — lines 46–51 (view on GitHub).

Complexity

  • Time: log(n) / 2     (an overage over all entries, of jumping to an entry in this table)

  • Space: n

See the complexity glossary for what @, w, dw, dbit, n mean.

Source

Click to view the macro body

def clean_table_entry__table n, dst, ret @ clean {
  clean:
    rep(n, d) stl.fj \
        d==0?0: (dst+dbit+(#d)-1), \
        (d==((1<<(#d))>>1)) ? ret : clean+(d^((1<<(#d))>>1))*dw
}

Used by

Example uses

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