"Asm.fif" include

PROGRAM{

NEWPROC add
NEWPROC sub
NEWPROC mul

sub <{ s3 s3 XCHG2 SUB s2 XCHG0 SUB }>s PROC

// compute (5+i)^4 * (239-i)
main PROC:<{
  5 INT 1 INT  // 5+i
  2DUP
  mul CALL
  2DUP
  mul CALL
  239 INT -1 INT
  mul JMP
}>

add PROC:<{
  s1 s2 XCHG
  ADD -ROT ADD SWAP
}>

// a b c d -- ac-bd ad+bc : complex number multiplication
mul PROC:<{
  s3 s1 PUSH2  // a b c d a c
  MUL          // a b c d ac
  s3 s1 PUSH2  // a b c d ac b d
  MUL          // a b c d ac bd
  SUB          // a b c d ac-bd
  s4 s4 XCHG2  // ac-bd b c a d
  MUL          // ac-bd b c ad
  -ROT MUL ADD
}>

}END>s
dup csr. runvmdict .s