| %default {"preinstr":"", "result":"a0", "chkzero":"0"} | |
| /* | |
| * Generic 32-bit "lit16" binary operation. Provide an "instr" line | |
| * that specifies an instruction that performs "result = a0 op a1". | |
| * This could be an MIPS instruction or a function call. (If the result | |
| * comes back in a register other than a0, you can override "result".) | |
| * | |
| * If "chkzero" is set to 1, we perform a divide-by-zero check on | |
| * CCCC (a1). Useful for integer division and modulus. | |
| * | |
| * For: add-int/lit16, rsub-int, mul-int/lit16, div-int/lit16, | |
| * rem-int/lit16, and-int/lit16, or-int/lit16, xor-int/lit16 | |
| */ | |
| /* binop/lit16 vA, vB, #+CCCC */ | |
| lh a1, 2(rPC) # a1 <- sign-extended CCCC | |
| ext a2, rINST, 8, 4 # a2 <- A | |
| ext a3, rINST, 12, 4 # a3 <- B | |
| GET_VREG a0, a3 # a0 <- vB | |
| .if $chkzero | |
| beqz a1, common_errDivideByZero # is second operand zero? | |
| .endif | |
| FETCH_ADVANCE_INST 2 # advance rPC, load rINST | |
| $preinstr # optional op | |
| $instr # $result <- op, a0-a3 changed | |
| GET_INST_OPCODE v0 # extract opcode from rINST | |
| SET_VREG $result, a2 # vA <- $result | |
| GOTO_OPCODE v0 # jump to next instruction | |