| %default {"preinstr":"", "result":"a0", "chkzero":"0"} | |
| /* | |
| * Generic 32-bit binary operation. Provide an "instr" line that | |
| * specifies an instruction that performs "result = a0 op a1". | |
| * This could be a 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 | |
| * vCC (a1). Useful for integer division and modulus. Note that we | |
| * *don't* check for (INT_MIN / -1) here, because the CPU handles it | |
| * correctly. | |
| * | |
| * For: add-int, sub-int, mul-int, div-int, rem-int, and-int, or-int, | |
| * xor-int, shl-int, shr-int, ushr-int | |
| */ | |
| /* binop vAA, vBB, vCC */ | |
| srl a4, rINST, 8 # a4 <- AA | |
| lbu a2, 2(rPC) # a2 <- BB | |
| lbu a3, 3(rPC) # a3 <- CC | |
| GET_VREG a0, a2 # a0 <- vBB | |
| GET_VREG a1, a3 # a1 <- vCC | |
| .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, a4 # vAA <- $result | |
| GOTO_OPCODE v0 # jump to next instruction |