hex.sub_shifted

dst[:dst_n] -= src[:src_n] << (4*hex_shift)

Signature

def sub_shifted dst_n, src_n, dst, src, hex_shift @ do_dec, end { ... }

Defined in hex/math.fj — lines 175–182 (view on GitHub).

Complexity

• Time: src_n(4@+12)   + 5@+10        // It's on average, see the note in hex.inc.

• Space: src_n(2.5@+39) + (dst_n - hex_shift)(1.5@+13) + 4@+40

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

Requires init

The following must be initialised before this macro is invoked:

• hex.sub.init (or hex.init)

Source

Click to view the macro body

def sub_shifted dst_n, src_n, dst, src, hex_shift @ do_dec, end {
    .sub.clear_carry
    rep(src_n, i) .sub dst+(hex_shift + i)*dw, src+i*dw
    .sub.clear_carry end, do_dec
  do_dec:
    rep(dst_n - (src_n + hex_shift), i) .dec.step dst+(src_n + hex_shift + i)*dw, end
  end:
}

Depends on

• hex.sub.clear_carry/0

• hex.sub.clear_carry/2

Used by

• hex.sub.sub_hex_shifted_constant/5

Example uses

• hex.sub.sub_hex_shifted_constant in hex/math.fj

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