1%default {"preinstr":"", "result":"a0", "chkzero":"0"}
2    /*
3     * Generic 32-bit "lit16" binary operation.  Provide an "instr" line
4     * that specifies an instruction that performs "result = a0 op a1".
5     * This could be an MIPS instruction or a function call.  (If the result
6     * comes back in a register other than a0, you can override "result".)
7     *
8     * If "chkzero" is set to 1, we perform a divide-by-zero check on
9     * vCC (a1).  Useful for integer division and modulus.
10     *
11     * For: add-int/lit16, rsub-int, mul-int/lit16, div-int/lit16,
12     *      rem-int/lit16, and-int/lit16, or-int/lit16, xor-int/lit16
13     */
14    # binop/lit16 vA, vB,                  /* +CCCC */
15    FETCH_S(a1, 1)                         #  a1 <- ssssCCCC (sign-extended)
16    GET_OPB(a2)                            #  a2 <- B
17    GET_OPA(rOBJ)                          #  rOBJ <- A+
18    GET_VREG(a0, a2)                       #  a0 <- vB
19    and       rOBJ, rOBJ, 15
20    .if $chkzero
21    # cmp a1, 0; is second operand zero?
22    beqz      a1, common_errDivideByZero
23    .endif
24    FETCH_ADVANCE_INST(2)                  #  advance rPC, load rINST
25
26    $preinstr                              #  optional op
27    $instr                                 #  $result <- op, a0-a3 changed
28    GET_INST_OPCODE(t0)                    #  extract opcode from rINST
29    SET_VREG_GOTO($result, rOBJ, t0)       #  vAA <- $result
30    /* 10-13 instructions */
31